WO2025157739A1

WO2025157739A1 - Processing a glass sheet assembly for a vacuum insulated glass unit

Info

Publication number: WO2025157739A1
Application number: PCT/EP2025/051296
Authority: WO
Inventors: Søren Vejling ANDERSEN; Simon Johnsen; Thibault DE RYCKE; Karsten Hansgaard NIELSEN
Original assignee: VKR Holding AS
Current assignee: VKR Holding AS
Priority date: 2024-01-22
Filing date: 2025-01-20
Publication date: 2025-07-31
Anticipated expiration: 2026-07-22
Also published as: WO2025157720A1; WO2025157731A1; WO2025157734A1; WO2025157728A1; WO2025157735A1; WO2025157726A1

Abstract

Herein is disclosed a method of processing a glass sheet assembly for a vacuum insulated glass unit at a production line. A glass sheet assembly (1) comprising a first glass sheet (3) and a second glass sheet (4) is provided. The glass sheet assembly (1) comprises a solder material (7) for providing an edge sealing for enclosing and sealing the gap (5) between the 5 glass sheets (3, 4). The production line (10) comprises at least a preheating station (100) and an edge sealing station (200). The glass sheet assembly (1) is positioned at the preheating station (100, 101). The positioned glass sheet assembly (1) is heated in the preheating station (100, 101) to a preheating target temperature (T1). The preheated glass sheet assembly (1) is moved from the preheating station (100) and positioned at the edge sealing station (200).10 The solder material (7) of the preheated glass sheet assembly (1) is softened (t3-t5) at the edge sealing station (200) by locally heating the solder material (7) by means of one or more heating beams (9, 9_1, 9_2, 9_3, 9_4). (Fig. 3)15

Description

Processing a glass sheet assembly for a vacuum insulated glass unit

The present disclosure relates to a method of processing a glass sheet assembly for the manufacturing of a vacuum insulated glass (VIG) unit, and to a building window.

Background

Vacuum insulated glass (VIG) units have been developed for providing window glazing with improved thermal insulating properties. In the manufacturing of vacuum insulated glass (VIG) units it is well known that the two glass sheets should be clamped together while a solder material situated between the glass sheets, typically near the edges of the glass sheets, is heated to a temperature where the solder material is in a softened state for providing hermetic airtight seal of the gap between the glass sheets. The clamping may be conducted by means of a plurality of clamps provided to the opposing outer side surfaces of the two glass sheets and heating of the solder material may be made by general heating of the glass sheet assembly in an oven or by local heating by means of e.g. laser light. From EP 2 900 891 is known to locally heat the solder material by means of laser light and evacuate the gap via a pump-out tube provided through an opening in one of the glass sheets, while the solder material is sufficiently softened to clamp the two glass sheets together, thereby forming the hermetic sealing of the gap. When the gap is sufficiently evacuated, such as to or below 10'² Torr, the pump-out tube is sealed off to preserve the vacuum established in the gap of the VIG unit.

It is an object of the present disclosure to improve the manufacturing process of vacuum insulated glass (VIG) units to make the process more efficient and lower the production costs of such unit.

Brief description of the disclosure

The present disclosure, in a first aspect, relates to a method of processing a glass sheet assembly for a vacuum insulated glass unit at a production line. The method comprises the step of providing a glass sheet assembly comprising a first glass sheet and a second glass sheet, wherein a plurality of support structures for maintaining a gap between said first glass sheet and said second glass sheet of the vacuum insulated glass unit are arranged between major surfaces of the glass sheets. The glass sheet assembly comprises an edge seal for providing an edge sealing for enclosing and sealing the gap (between the glass sheets. The edge seal comprises a solder material. The production line comprises at least a preheating station and an edge sealing station. The method further comprises the step of positioning the glass sheet assembly at a preheating station of the production line. The positioned glass sheet assembly is heated in the preheating station to a preheating target temperature. The preheated glass sheet assembly may be moved from the preheating station and the preheated glass sheet assembly may be positioned at the edge sealing station. The solder material of the preheated glass sheet assembly is softened at the edge sealing station by locally heating the solder material by means of one or more laser light beams.

It is generally understood that in one or more embodiments of the present disclosure, one or both glass sheets may be reinforced glass sheets, such as tempered glass sheets, such as thermally tempered glass sheets. Such glass sheets may e.g. be stronger when compared to the amount of glass material used. Such glass sheets are stronger and may thus enable providing a larger support structure distance without the need of increasing the glass sheet thickness. Additionally or alternatively, such glass sheets may provide a VIG unit that can handle larger stress in the VIG units due to outer forces and/or when the VIG unit is subjected to larger temperature differences.

The preheating may e.g. provide that an improved connection between the solder material and the glass sheets may be obtained when the local heating is provided. It may also reduce stress situations in the glass sheets. Additionally or alternatively, preheating the glass sheet assembly at a first station and moving the preheated glass sheet assembly to another station where the solder material of the preheated glass sheet assembly is softened may allow speeding up the manufacturing and/or increase utilization options of equipment, such as equipment at the edge sealing station.

Additionally or alternatively, in embodiments of the present disclosure where the glass sheets may be thermally tempered glass sheet, the preheating may enable a fast manufacturing and/or help to provide a strong connection between the solder material and the glass sheets while at the same time reducing a de-tempering of the thermally tempered glass sheets if these are of the thermally tempered type. The preheating of the glass sheets may hence be provided to a temperature below a temperature where de-tempering of the glass sheets may start and/or become critical. Thermally tempered glass sheets may de-temper if heated to a hight temperature. In some embodiments, the preheating target temperature may be below or at 350 °C such as below or at 340 °C or below or at 330 °C. The local heating of the solder material to soften it may however be provided to a temperature above such a preheating target temperature in order to sufficiently soften the solder material and enable providing a strong bond between the glass sheets and the solder material. The local heating may however happen for a shorter period of time than the time it takes to preheat the entire glass sheet assembly to the target temperature at the preheating station.

In one or more embodiments of the present disclosure, said method may comprise the step of stopping said local heating of the solder material by means of one or more laser light beams. This may cause a cooling and thus a hardening the locally heated and softened solder material of the preheated glass sheet assembly. After this cooling and hardening of the seal material, an edge sealed glass sheet assembly is obtained.

It is understood that in embodiments of the present disclosure, the glass sheets of the glass sheet assembly may maintain the temperature from the preheating step in the edge sealing chamber. Additionally or alternatively, the temperature of the glass sheets may be allowed to gradually reduce during the local heating of the solder material in the edge sealing chamber.

In some embodiments of the present disclosure, active heating, such as convection heating, of the edge sealing chamber is provided.

In some embodiments of the present disclosure, the glass sheet assembly may be preheated, such as by means of convection heating, at the preheating station and subsequently moved into the edge sealing station while remained preheated, so as to be subjected to said locally heating of the solder material by means of said one or more laser light beams.

In some embodiments of the present disclosure, the solder material is a glass solder material comprising a low melting point glass solder frit material.

Glass solder material has e.g. the advantage of having mechanical and thermal properties close to those of the glass sheets, which provides for a durable and strong connection between the two. However, some glass solder compositions may include components that have less advantageous environmental properties that can be challenging when deposing of or recycling of scrapped VIG units. Low melting point glass solder frit material e.g. also provides the advantages that the temperature to which the solder material should be heated to provide a sufficient edge sealing may be lower when compared to other glass solder material types. This may e.g. be an advantage with regard to manufacturing speed and/or in order to reduce or avoid de-tempering of the glass sheets of the glass sheets assembly if these glass sheets are thermally tempered glass sheets. Alternatively, a metal solder material may be used, comprising a suitable alloy for the purpose.

In some embodiments of the present disclosure, the glass sheet assembly may be heated in the preheating station to a temperature above the glass transition temperature of the glass solder material, such as in the range of 5 to 20 °C, preferably in the range of 8 to 16 °C, above the glass transition temperature of the glass solder material.

This may be provided before the glass sheet assembly is transferred to the edge sealing station or to an intermediate station before being transferred to the edge sealing station.

Preheating the solder material to a temperature above the glass transition temperature of the glass solder material may e.g. help to reduce or avoid issues relating to stress buildup, such as stress buildup caused directly or indirectly by thermal expansion and/or shrinking.

When/if the solder material temperature is near, such as above, the glass transition temperature, e.g. during preheating, stress buildup may be removed or avoided.

Additionally or alternatively, the preheating may help to provide that the glass sheets have an elevated temperature resulting in an improved bonding between the glass sheets and the solder material. The local heating by heating beams may transfer further heat energy locally to the glass sheets from the solder material, thereby heating relevant areas of the glass sheets.

It is generally understood that the glass transition temperature Tg may be a rated glass transition temperature which is defined by the manufacturer and/or supplier of the glass solder material. It is generally understood that a rated melting temperature Tm of the glass solder material may be a temperature that is e.g. defined by the manufacturer and/or supplier of the glass solder material, and may be a “sealing temperature” of the solder material.

In one or more embodiments of the present disclosure, a plurality of glass sheet assemblies may be arranged in a preheating chamber of the preheating station. The glass sheet assemblies may in further embodiments of the present disclosure be provided into the preheating station by means of a transport system.

This may e.g. enable a faster manufacturing of VIG units and/or help to optimize the manufacturing of edge sealed glass sheets assemblies. The preheating may in general take more time that the softening by means of the one or more laser light beams. Thus, preheating a plurality of glass sheet assemblies may enable faster manufacturing and more optimized use of the laser sealing equipment.

The preheating chamber may in embodiments of the present disclosure comprise a plurality of glass sheet assembly storage locations, such as more than two, such as more than five or more than ten glass sheet assembly storage locations. This may e.g. be an advantage with respect to efficiency, manufacturing speed and/or the like.

In some embodiments of the present disclosure, each glass sheet assembly storage location may comprise one or more glass sheet assembly supports. Such glass sheet assembly may e.g. comprise one or more shelves, rails, conveyers such as rollers and/or belts, arranged above each other.

In some embodiments of the present disclosure, the preheating chamber may be an elongated chamber, wherein the glass sheet assemblies are arranged consecutively, in line, while one or more heaters heat the glass sheet assemblies while they gradually are moved forward towards the edge sealing station.

It may e.g. enable a space saving preheating solution if one or more supports are arranged above each other. If arranging the glass sheets consecutively in line, this may e.g. enable a more space saving and/or simple preheating solution In some embodiments of the present disclosure, the time period between the time at which said preheating is initiated, and the time at which said locally heating of the solder material is initiated, may be in the range of 10 minutes to 90 minutes, such as in in the range of 15 minutes to 70 minutes or in the range of 20 minutes to 50 minutes.

This may e.g. enable sufficient heating while also providing manufacturing advantages such as optimization of equipment use.

It is understood that in some embodiments of the present disclosure, a gate or door is arranged between the preheating station and the edge sealing station.

The preheating station and the edge sealing station may in embodiments of the present disclosure be consecutive stations of the production line.

In one or more embodiments of the present disclosure, the glass sheet assembly may be heated in the preheating station to a preheating target temperature in the range of 280 to 350 °C, such as in the range of 300 to 330 °C.

In one or more embodiments of the present disclosure, the glass sheet assembly may be heated in the preheating station to a preheating target temperature that is below or at 340 °C, such as below or at 330 °C, such as below or at 320 °C or below or at 300 °C. This may e.g. be an advantage if the glass sheets of the glass sheet assembly are thermally tempered glass sheets, as this preheating target temperature may be acceptable in order to reduce detempering of the glass sheets while still providing advantages with regard to e.g. providing a strong VIG unit.

It is understood that in some embodiments of the present disclosure, the preheating target temperature may be above 260 °C, such as above 280 °C, such as above 300 °C. In some embodiments, the preheating target temperature may be above 315 °C, such as above 330

In some embodiments of the present disclosure, the pre-heating may provide binder bum out from said solder material. This may e.g. be the case if the solder material is a glass solder material. This may provide an improved edge seal. In some embodiments of the present disclosure, the solder material of the glass sheet assembly may be substantially free from solvent prior to processing of the glass sheet assembly at the preheating station. This may e.g. enable providing an improved edge seal, as outgassing of solvent from the edge seal during the preheating is reduced or avoided. For example, a more dense and/or structurally uniform edge seal may be obtained.

In one or more embodiments of the present disclosure, a chamber of the edge sealing station in which the glass sheet assembly is arranged during said locally heating of the solder material may be heated, such as convection heated, by means of a heater, so as to maintain an elevated temperature of the glass sheet assembly during said local heating. Radiation heating may additionally or alternatively also be used for maintaining the glass sheet assembly elevated at the edge sealing station.

In one or more embodiments of the present disclosure, the average temperature of the glass sheets, in a chamber of at the edge sealing station, may be maintained within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C or within ± 5 °C of the preheating target temperature, such as by means of a heater. Hereby a strong VIG unit may be obtained which is resistant to thermal deflection.

In one or more embodiments of the present disclosure, the softening of the solder material by locally heating the solder material may be provided for a time period that is within 10 to 130 seconds, such as within 30 to 100 seconds, for example within 40 seconds to 90 seconds. Hereby fast manufacturing is obtained.

In some embodiments of the present disclosure, the softening of the solder material by locally heating the solder material may be provided for a time period that is within 10 to 130 seconds, such as within 10 to 100 seconds for example within 10 seconds to 90 seconds. Hereby fast manufacturing is obtained.

In one or more embodiments of the present disclosure, the softening of the solder material by said locally heating the solder material may be provided for a time period that is less than 5 minutes, such as less than 2 minutes, such as less than 100 seconds, before the local heating is stopped (t5). Hereby fast manufacturing is obtained. In one or more embodiments of the present disclosure, the softening of the solder material by locally heating the solder material may be provided for a time period that is larger than 10 seconds, such as larger than 30 seconds, for example larger than 60 seconds.

In one or more embodiments of the present disclosure, the softening of the solder material by locally heating the solder material may be provided for a time period that is between 10 seconds and 5 minutes, such as between 30 seconds and 5 minutes, such as between 30 seconds and 2 minutes.

In one or more embodiments of the present disclosure, said local heating may be provided by means of one or more laser light beams that are swept along the longitudinal direction the solder material. This may in some embodiments be provided in order so as to provide a suitably uniform heating of the solder material along the full longitudinal extent of the solder material.

A non-uniform heating of the solder material along the edge of the gap may cause variations in the features of the edge sealing along the length direction thereof, which may be the source of stress concentrations when the VIG unit is exposed to stresses, such as thermal stress. A non-uniform heating of the edge sealing where the solder material will have different degrees of softness when the pressure clamping is initiated may potentially cause the formation of voids and channels in parts of the solder material that is less softened and vetting less to the inner surfaces of the glass sheets. Also, in some further embodiments, a force clamping so as to force the first glass sheet and the second glass sheet towards each may be provided, such as initiated, during said local heating of the solder material at the edge sealing station. If the force clamping is provided by means of a pressure difference between the pressure in the gap of the glass sheet assembly and the pressure surrounding the glass sheet assembly , it has been found by the present inventors that a uniform heating of the solder material in the step of softening the solder material for providing an edge sealing may be relevant for obtaining an optimal sealing of the gap, e.g. since the features of the sealing with respect to durability and resistance to thermal stresses. the heating by means of said one or more laser light beams may comprise a plurality of consecutive, such as continuous, heating iterations along the longitudinal direction of the solder material so as to heat the total longitudinal extent of the solder material. This may e.g. help to provide a more even heating and hence even softening along the full/total longitudinal extent of the solder material. This may e.g. be advantageous if force clamping is obtained by means of a pressure difference between the gap and the exterior of the glass sheet assembly. It may also e.g. help to reduce stress concentrations and/or enable reducing or avoiding de-tempering of the glass sheets of the glass sheet assembly, if the glass sheets are thermally tempered glass sheets.

One laser light beam may be controlled to heat the total longitudinal extent of the solder material. Alternatively, the heating of the total longitudinal extent of the solder material may be provided by means of a plurality of laser light beams which each heat a sub-part/heating area of the solder material. One laser light beam may visit a first heating area more times than another laser light beam visits another second heating area of the solder material to heat that. It is understood that when the full length of all solder material stripes of the solder material of the edge seal has been subjected at least one time to a laser light beam so as to heat it, this may be considered a full heating iteration.

In some embodiments, each time a laser light beam spot visits or revisit the same local part of the solder material to heat it, this is a start of a new heating iteration.

In one or more embodiments of the present disclosure, the local heating of each meter of the solder material may be/provide at least 400 joule per each two seconds, such as at least 600 joule per each two seconds, for a period of at least 15 seconds, such as at least 30 seconds, such as at least 60 seconds during the step of softening the solder material. For example, in some embodiments of the present disclosure, a combined heating by means of one or more laser light beams, of each meter of the solder material may be at least 400 joule per each two seconds, such as at least 600 joule per each two seconds, for a period of at least 15 seconds, such as at least 30 seconds, such as at least 60 seconds during the step of softening the solder material. This may e.g. enable providing a fast and sufficiently uniform heating of the total solder material length.

In some embodiments, the full longitudinal extent of the solder material of the glass sheet assembly is exposed to a laser light beam at least 1 time per each two seconds, such as at least 1 times per second, such as at least 2 times per second during the step of softening the solder material at the edge sealing station. This may help to provide a uniform heating of the full solder material length.

In some embodiments, the full longitudinal extent of the solder material of the glass sheet assembly may be exposed to a laser light beam at least 100 times, such as at least 200 times, such as at least 400 times during the step of softening the solder material so as to provide a uniform heating of the solder material.

In one or more embodiments of the present disclosure, the heating of each meter of the solder material during the softening step by means of the one or more laser light beams is at least 30 joule per each one-tenth of a second for a period of at least 30 seconds such as at least 60 seconds during the step of softening the solder material at the edge sealing station..

In one or more embodiments of the present disclosure, the heating of each meter of the solder material during the softening step by means of the one or more laser light beams may be at least 30 joule per each one-tenth of a second for a period of at least 30 seconds such as at least 60 seconds. This may provide an even more uniform heating and softening of the full solder material length.

In one or more embodiments of the present disclosure, the heating of each meter of the solder material by means of the one or more laser light beams may be at least 40 joule, such as at least 50 joule per each one-tenth of a second for a period of at least 30 seconds such as at least 60 seconds or at least 80 seconds during the step of softening the solder material at the edge sealing station.

In one or more embodiments of the present disclosure, the combined heating by means of the one or more laser light beams of each meter of the solder material may be at least 50 joule, such as at least 60 joule per each one-tenth of a second for a period of at least 10 seconds such as at least 20 seconds during the step of softening the solder material at the edge sealing station.

In one or more embodiments of the present disclosure, the solder material, during the step of locally heating the solder material, may be heated by said one or more laser light beams, so that the temperature difference, such as the average temperature difference, between any two positions of the solder material along the full longitudinal extent of the solder material of the glass sheet assembly may not exceed 2°C, such as during at least 30% of the total heating time by means of the one or more heating beams. In some embodiments of the present disclosure, the solder material, during the step of locally heating the solder material, may be heated by one or more laser light beams so that the temperature difference between any two positions of the solder material along the full longitudinal extent of the solder material of the glass sheet assembly does not exceed 2°C during at least 40%, such as during at least 70%, such as during at least 95%, of the total heating time by means of the one or more heating beams.

In some embodiments of the present disclosure, said local heating may be provided by means of one or more laser light beams which is/are moved in the lengthwise direction of the solder material at a combined speed of at least 20 m/s such as at least 40 m/s during the softening step. This high moving speed of the one or more laser light beams may enable a sufficient degree of uniformity of the softening of the solder material. Also, a fast edge sealing process may be obtained.

In some embodiments of the present disclosure, the local heating may be provided by means of one or more laser light beams, wherein one or more of the one or more laser light beams each is moved in the lengthwise direction of the solder material at a speed of at least 20 m/s such as at least 40 m/s during the softening step. With such high moving speed of the laser light beams, a high degree of uniformity of the softening of the solder material may be achieved. Also, a fast edge sealing process may be obtained.

In some embodiments of the present disclosure, the full extent of the solder material of the glass sheet assembly may be exposed to a laser light beam at least 10 times per second, such as at least 20 times per second, such as at least 30 times per second, during the step of softening the solder material by means of one or more laser light beams. This may provide a more uniform heating of the total longitudinal extent of the solder material.

In some embodiments of the present disclosure, the power of one or more of the one or more laser light beams, such as each of the one or more laser light beams, may be at least 500 W, such as at least 750 W, such as at least 1000 W. This may e.g. enable a faster VIG unit manufacturing and/or help to provide a uniform heating of the total solder material length. In one or more embodiments of the present disclosure, the full extent of the solder material of the glass sheet assembly may be exposed to a laser light beam at least 500 times, such as at least 1000 times, such as at least 1500 times during the step of softening the solder material. This may e.g. enable a more gradual, stepwise heating of the full/total extent of the solder material, with smaller steps in temperature increase per heating iteration. Hence an even more uniform heating of the total length / total longitudinal extent of the solder material may be obtained.

In one or more embodiments of the present disclosure, the temperature of the solder material, may be increased by means of the one or more laser light beams by at least 30 °C, such as at least 50 °C, in less than 180 seconds, such as less than 120 seconds such as less than 100 seconds. This e.g. enables a fast VIG unit manufacturing.

In one or more embodiments of the present disclosure, the temperature of the full longitudinal extent of the solder material may be increased by means of the one or more laser light beams by at least 30 °C, such as at least 50 °C, in less than 180 seconds, such as less than 120 seconds such as less than 100 seconds. This e.g. enables a fast VIG unit manufacturing.

In one or more embodiments of the present disclosure, a mirror controller may control a mirror so as to move a redirected laser beam along the longitudinal direction of one or more solder material strips of the solder material so as to provide said local heating of the solder material. Several tests have shown that this works well and may enable fast and/or uniform heating of the solder material, also at higher laser beam power.

The mirror may in some embodiments be a beam steering mirror such as a galvanometer mirror. It is however understood that other types of suitable mirrors or mirror systems may also may be used in other embodiments of the present disclosure.

In one or more embodiments of the present disclosure, said mirror may be located outside a chamber of the edge sealing station in which the glass sheet assembly is arranged during said local heating. This may e.g. reduce risk of dust and dirt or other components, such as outgassed components form the solder material, attaching to the mirror. Additionally or alternatively, if the chamber in which the glass sheet assembly is arranged during the local heating by means of the one or more laser light beams is heated to an elevated temperature by a heater during the laser sealing process, arranging the mirror outside the chamber may also protect the mirror from high heat

In one or more embodiments of the present disclosure, a force clamping so as to force the first glass sheet and the second glass sheet towards each other may be provided during said local heating of the solder material at the edge sealing station. The force clamping may e.g. provide improved bonding between the glass sheets and/or provide an advantageous distribution of the solder material in the width direction of the solder material when it is softened.

In further embodiments of the present disclosure, said force clamping may comprise providing a pressure difference between the pressure in the gap and the pressure surrounding the glass sheet assembly so as to force the first glass sheet and the second glass sheet towards each other. This may e.g. provide manufacturing advantages. For example, it may e.g. enable a more simple force clamping solution and may e.g. enable omitting or reducing the need of mechanically applied clamping by means of e.g. clips or a mechanical press.

The providing of the pressure difference may in some embodiments of the present disclosure include a step of evacuating the gap, such as by means of an evacuation cup. Tests have shown that this is may be an advantageous way of providing the force clamping.

The force clamping, such as the pressure difference, may in some embodiments of the present disclosure be initiated during the softening the solder material by means of the one or more laser light beams. It may be preferred that the provision of the pressure difference is provided during the softening the solder material when the solder material is sufficiently soft to form a seal right after the pressure difference is established. For example, in some embodiments of the present disclosure, said providing of the force clamping, such as the pressure difference, may be initiated at a time after the local heating of the solder material has been initiated.

Hereby, the forming of voids and channels in the solder material between the gap and the surroundings may be prevented. The local heating and softening of the solder material may thus be provided for some time before the pressure difference is initiated, thereby e.g. reducing the risk of channels being formed in the edge seal material. It may additionally or alternatively help to enable providing a stronger VIG unit. In some embodiments, the providing of the pressure difference may be initiated at a time between said softening of the solder material by means of the local heating is started and ended.

In one or more embodiments of the present disclosure, said providing of the force clamping, such as the pressure difference, is initiated (t4) at least 5 seconds after, such as at least 10 seconds after, for example at least 30 seconds after the local heating (t3) of the solder material (7) has been initiated.

In one or more embodiments of the present disclosure, the pressure difference between the pressure in the gap and the pressure surrounding the glass sheet assembly may be eliminated. This may e.g. provide a cost efficient solution and/or a solution that is advantageous from a manufacturing point of view. For example, it may be achieved that the production equipment of the edge sealing station, in particular the device for providing the local heating of the solder material, can be in use almost continuously and thus be utilized very efficiently.

In one or more embodiments of the present disclosure, said elimination of the pressure difference between the pressure in the gap and the pressure surrounding the glass sheet assembly may be provided at a time after said locally heating of the solder material is stopped. This may e.g. provide that the solder material at least partly hardens due to cooling before the pressure difference is eliminated. The glass sheets may act as heat sinks that help to cool the solder glass relatively fast to a hardened state while the pressure difference is maintained. This may help to cause that a shape and/or size of the solder material obtained during providing the pressure difference may be at least partly or substantially fully maintained after the pressure difference is eliminated. Additionally or alternatively, a “pretensioning” of the solder material and/or glass sheets at and/or near the solder material, which may be obtained while the pressure difference is provided, may be at least partly, or substantially fully maintained after the pressure difference is released/eliminated.

For example, the elimination of the pressure difference between the pressure in the gap and the pressure surrounding the glass sheet assembly may be provided at least 2 seconds after, such as at least 5 seconds after, such as at least 10 seconds after, after said locally heating of the solder material is stopped.

In one or more embodiments of the present disclosure, the method may comprise the further steps of removing the edge sealed glass sheet assembly from the edge sealing station of the production line, and positioning the edge sealed glass sheet assembly at an evacuation station of the production line. The gap of the edge sealed glass sheet assembly is evacuated to a substantially vacuum, and the evacuated gap is then sealed off from the surroundings.

This may e.g. enable providing a more efficient and/or cost efficient manufacturing, e.g. since the final evacuation and sealing of the evacuated gap, which may take a longer time, may be provided at another location, hence freeing the edge sealing equipment such as laser, evacuation station and the like so they can be used for softening solder material of a new glass sheet assembly that should be edge sealed.

The glass sheet assembly may be moved directly form the edge sealing station to the evacuation station or an intermediate storage may be provided between the two.

In one or more embodiments of the present disclosure, a gate or door may be opened so as to allow moving the edge sealed glass sheet assembly into a chamber of the evacuation station and is thereafter closed again. This may e.g. enable improved control such as temperature control.

In one or more embodiments of the present disclosure, the gap may be evacuated at the evacuation station to a pressure below 0.05 mbar, such as below 0.005 mbar, such as 0.003 or 0.001 mbar or below by means of an evacuation pump.

In one or more embodiments of the present disclosure, the maximum pressure difference between the pressure in the gap and the pressure surrounding the glass sheet assembly at the edge sealing station may be less, such as at least ten times less, such as at least 100 times less, than the pressure difference between the pressure in the gap and the pressure surrounding the edge sealed glass sheet assembly at the evacuation station after sealing off the gap from the surroundings. This may e.g. provide advantageous manufacturing. The inventors have realized that the pressure difference in the edge sealing station may be used primarily for force clamping, and that it may therefore be beneficial to provide the final evacuation and sealing of the evacuated gap at another subsequent station, since the final evacuation of the gap may take a longer time. Thereby, the sealing station may be ready for processing a new glass sheet assembly to be edge sealed.

In one or more embodiments of the present disclosure, the evacuation of the gap at the evacuation station may be provided for at least 10 minutes, for example at least 20 minutes or for at least 25 minutes.

In some embodiments of the present disclosure, the evacuation of the gap at the evacuation station may be provided for less than 60 minutes, such as less than 40 minutes, for example less than 30 minutes.

In some embodiments, the edge sealing station and the evacuation station may be consecutive stations of the production line. In some embodiments, the preheating station, the edge sealing station and the evacuation station may be consecutive stations of the production line.

A gate or door may in embodiments of the present disclosure be arranged between the preheating station and the edge sealing station. Additionally or alternatively, a gate or door may be arranged between the edge sealing station and the evacuation station. This may provide improved control such as temperature control at the respective station.

In one or more embodiments of the present disclosure, the solder material is a low melting point glass solder frit material, and the temperature in the evacuation station chamber may be maintained, such as by convection heating and/or another suitable heating solution, larger than 100 °C, such as larger than 200 °C or larger than 250 °C, but lower than the glass transition temperature of the solder material, while the gap evacuation and sealing off is provided.

In one or more embodiments of the present disclosure, the temperature in the evacuation station chamber may be maintained, such as by convection heating, at a temperature above 200 °C, such as above 250 °C, while the gap evacuation and sealing off is provided. In one or more embodiments of the present disclosure, the distance between neighboring support structures in the gap is between 20 mm and 70 mm, such as between 25 mm and 65 mm, such as between 35 mm and 45 mm.

This may e.g. enable providing a VIG unit with improved heat insulation performance and/or a VIG unit where the support structures are less visible when a user looks through the VIG unit.

In some embodiments, more than 500 support structures, such as more than 1000 support structures, such as more than 3000 or more than 5000 support structures may be present in the gap. This may e.g. provide an improved force distribution.

In one or more embodiments of the present disclosure, one or both glass sheets of the glass sheet assembly has/have a thickness between 2 mm and 6 mm, such as between 2.5 mm and 6 mm, for example between 2.5 mm and 3.5 mm including both end points. This may be advantageous e.g. in order to reduce carbon foot print and/or VIG unit weight while also providing a stronger VIG unit.

In one or more embodiments of the present disclosure, one or both glass sheets of the glass sheet assembly has/have a thickness between 1 mm and 6 mm, such as between 2 mm and 4 mm, for example between 2.5 mm and 3.5 mm including both end points.

In one or more embodiments of the present disclosure, the glass sheet assembly is configured so that the distance between the major glass sheet surfaces facing the gap of the final vacuum insulated glass unit after the gap has been evacuated and sealed, is 0.5 mm or below, such as 0.3 mm or below, for example 0.2 mm or below. In some embodiments of the present disclosure, the distance between the major glass sheet surfaces facing the gap of the final vacuum insulated glass unit may be configured to be between 0.05 mm and 0.6 mm, such as between 0. 1 mm and 0.4 mm, such as between 0.15 and 0.25 mm.

In one or more embodiments of the present disclosure, the solder material height extending between the major surfaces of the glass sheets that faces the gap may be decreased by at least 10%, such as at least 20% or at least 40% when compared to the initial solder material height before the local heating of the solder material, this decrease may occur due to the local heating and the force clamping. In one or more embodiments of the present disclosure, the solder material strip width may be between 2 mm and 8 mm, such as between 3 mm and 6 mm, for example between 4 mm and 5 mm (both end points included) at initiation of said softening of the solder material by locally heating the solder material.

In one or more embodiments of the present disclosure, the solder material width, due to the processing by means of the local heating at the edge sealing station (200), may be deformed so as to have a final solder material width of between 4 mm and 16 mm, such as between 5 mm and 11 mm, for example between 7 mm and 9 mm.

In one or more embodiments of the present disclosure, the solder material width may be, during the processing at the edge sealing station, increased by at least 10%, such as at least 20% or at least 40% when compared to the initial solder material width before the local heating and temporary evacuation of the gap at the edge sealing station. This may e.g. provide a strong unit as a larger surface area of the solder material provides a bonding between the glass sheets.

In one or more embodiments of the present disclosure, the power of each of the one or more laser light beams may be, such as may be adjusted to, at least 1300 W such as at least 1500 W. This may enable a fast softening of the solder material and hence provide a faster manufacturing.

In one or more embodiments of the present disclosure, the preheating target temperature is within the range of Tg to Tg x 1.1, such as within the range of Tg to Tg x 1.05, such as within the range of Tg to Tg x 1.02, where Tg is the rated glass transition temperature of the solder material. This may e.g. help to provide an improved VIG unit and/or edge seal.

In one or more embodiments of the present disclosure, one or more of said one or more laser light beams maybe moved in the lengthwise direction of the solder material at a speed of at least 2 m/s such as at least 5 m/s, such as at least 9 m/s, for example at least 15 m/s during said softening of the solder material. The inventors have found that this may provide a sufficiently uniform heating of the full length of the solder material. In one or more embodiments of the present disclosure, said one or more laser light beams may each be moved in the lengthwise direction of the solder material at a speed of at least 2 m/s such as at least 5 m/s, such as at least 9 m/s, for example at least 15 m/s during said softening of the solder material.

In one or more embodiments of the present disclosure, the full longitudinal extent of the solder material is at least 1.5 meter, such as at least 2 meters, such as at least 3 meters. In some embodiments, the full longitudinal extent of the solder material may be between 1.5 meter and 10 meters, such as between 2 meter and 8 meters, such as between 3 meter and 6 meter. Such lengths are e.g. relevant when the VIG unit is for e.g. use in a building window or a cooler door or lid.

In one or more embodiments of the present disclosure, the full longitudinal extent of the solder material of the glass sheet assembly may be exposed to a laser light beam at least one time every fourth second, such as at least 1 time per second, such as at least 2 times per second during said softening of the solder material. Dependent on e.g. laser beam power, movement speed and/or the like, this may be sufficient in order to e.g. obtain a sufficiently uniform heating of the entire solder material length during the local heating, e.g. to reduce stress issues later on in the vinal VIG unit and/or to enable force clamping by means of a pressure difference as e.g. previously described according to various embodiments of the present disclosure.

In one or more embodiments of the present disclosure, the full longitudinal extent of the solder material of the glass sheet assembly may be exposed to a laser light beam at least 5 times per second, such as at least 9 times per second, such as at least 14 times per second during said softening of the solder material. Experiments have indicated that this may provide a sufficiently uniform heating of the entire solder material length during the local heating. It may e.g. enable reducing reduce stress issues later on in the VIG unit. Experiments indicates that it also enables using force clamping by means of a pressure difference as e.g. previously described according to various embodiments of the present disclosure.

In one or more embodiments of the present disclosure, the full longitudinal extent of the solder material may be exposed to a laser light beam the amount of times per second described above according to various embodiments of the present disclosure, during at least 30%, such as at least 60%, such as at least 90% or at least 95% of the heating time where the local heating is provided by means of one or more laser light beams so as to heat and soften the solder material.

In one or more embodiments of the present disclosure, the full longitudinal extent of the solder material of the glass sheet assembly may be exposed to a laser light beam at least 20 times, such as at least 100 times, such as at least 250 times, during said softening of the solder material. This may e.g. provide a sufficient heating and softening of the solder material. Additionally or alternatively, it may provide one or more of a gentle, stepwise heating of the full length of the solder material that may e.g. provide an improved edge seal, enable a fast manufacturing, and/or provide a sufficiently uniform heating of the entire solder material length during the local heating.

In some embodiments of the present disclosure, the sum of the power of the one or more laser light beams may be at least 200 W, such as at least 400 W. This may e.g. be acceptable dependent on e.g. the desired/accepted heating time where the local heating is provided, and the amount of solvent to be heated and softened. In some embodiments, the sum of the power of the one or more laser light beams may be at least 1000W or at least 2000 W. This may e.g. enable a fast manufacturing, also of bigger sealed glass sheet assemblies.

In some embodiments of the present disclosure, the sum of the power of the one or more laser light beams may be at least 250W per meter of solder material, such as at least 500W per meter of solder material, such as at least 750W per meter of solder material. This enables providing a fast and efficient edge seal, e.g. dependent on the size of the VIG unit to be produced. Also, it may enable e.g. more uniform solder material softening of the entire solder material length, and/or enable force clamping by means of a pressure difference.

In one or more embodiments of the present disclosure, the power of the one or more laser light beam(s) and/or the movement speed of the one or more laser light beams may be regulated, such as increased and/or decreased, during the softening the solder material at the edge sealing station. This may e.g. enable adapting the heating profile of the solder material so as to provide improved temperature control. For example, the temperature gradient of the solder material may be controlled, such as adjusted, during the heating of the solder material by means of the one or more heating beams. It may e.g. enable temperature control so as to reduce or avoiding de-tempering of the glass sheets and/or so as to adapt the heating to obtained advantageous edge seal characteristic, also in a fast manner. For example, various factors such as heat dissipation and/or temperature overshot when the solder material temperature gets near the target temperature may be compensated for by means of said regulation. Additionally or alternatively, soaking time and/or heating times and/or local temperature peaks may be adjusted in order to obtain a desired edge seal with advantageous properties. The regulation may e.g. enable providing an optimized temperature profde for the solder material and/or a fast edge sealing process.

In some embodiments, said regulation may be provided according to one or more predefined heating profiles. This may e.g. provide improved control of the heating of the solder material and/or enable easy adjustment/regulation.

In one or more embodiments of the present disclosure, the solder material may be heated by the one or more laser light beams according to different heating profiles, such as predefined heating profiles, during the softening of the solder material at the edge sealing station. This may e.g. enable providing one or more of the advantages above, for example enabling providing an optimized temperature profile for the solder material during the local heating and/or a fast edge sealing process.

In one or more embodiments of the present disclosure, the power of one or more of the one or more laser light beams, such as each of the one or more laser light beams, is at least 250W, such as at least 500 W. this may e.g. enable providing a fast and efficient heating of the solder material while also e.g. enabling providing a fast and uniform heating of the entire solder material length.

In one or more embodiments of the present disclosure, the heating of a local area of the solder material by means of the one or more laser light beams during a heating iteration may comprise, such as provide, a heating time followed by a soaking time for said local area before a laser light beam revisit said area. Tests have indicated that using a plurality of consecutive heating iterations for heating a local area of the solder material so that a solder material area is heated and reheated a plurality of consecutive times by means of one or more laser light beams, and where intermediate soaking time is provided between two consecutive heating times, may provide several promising features. For example, it may enable a more controlled heating, it may enable a faster manufacturing of VIG unit in a more gentle way, and/or it may give the solder material time and glass sheets time to “adapt” to the increased temperature.

In one or more embodiments of the present disclosure, the soaking time from a local peak temperature is reached, and to a new consecutive heating is started at the local area is larger, such as at least two times larger, such as at least four times larger or at least six times larger than the time it takes for the laser light beam to heat the solder material to a local peak temperature. This may e.g. enable a fast heating of the solder material while the intermediate soaking time allows the heating energy transferred to/induced in the solder material to distribute locally.

In one or more embodiments of the present disclosure, the soaking time from a local peak temperature is reached and to a new consecutive heating is started at the local area may be at least ten times larger, such as at least 15 times larger or at least 20 times larger than the time it takes for a laser light beam to heat the solder material at the area to a local peak temperature obtained during a heating iteration. This may e.g. provide longer intermediate soaking time which allows the heating energy transferred to/induced in the solder material to distribute in an advantageous way. It may also allow using a higher movement speed and laser beam power.

In one or more embodiments of the present disclosure, the heating time it takes for a laser light beam to increase the solder material temperature to a local peak temperature during a heating iteration may be less than 1 second, such as less than 0.5 second, such as less than 0.05 second. This may provide a more gentle heating of the solder material.

In further embodiments, the heating time it takes for a laser light beam to increase the solder material temperature to a local peak temperature during a heating iteration may be less than 0.2 second, such as less than 0. 1 second, such as less than 0.05 second. This may enable a fast heating of the solder material which may be accepted if e.g. larger movement speeds of the laser light beam(s) is/are used, such as movement speeds above 2 m/s, such as above 5 m/s or more. In one or more embodiments of the present disclosure, the heating time it takes for the laser light beam to heat the solder material to the local peak temperature during the heating iteration may be between 0.001 second and 1 second, such as between 0.005 or 0.01 second and 0.50 second, such as between 0.02 second and 0.1 second.

In one or more embodiments of the present disclosure, said one or more laser light beams may each be moved in the lengthwise direction of the solder material at the speed mentioned above according to various embodiments of the present disclosure at least 30%, such as at least 60%, such as at least 90% or at least 95% of the heating time where the one or more laser light beams provide said local heating so as to heat and soften the solder material.

In one or more embodiments of the present disclosure, the vacuum insulated glass unit may be for, such as for use in, a building window, such as a roof window, or for use in a cooling storage, such as a door or lid of a cooling storage

The present disclosure moreover relates to a vacuum insulated glass unit, wherein the vacuum insulated glass unit is manufactured by means of a method according to any of the items and/or claims, and/or according to any of the embodiments described above.

The present disclosure moreover relates to a building window, such as a roof window, comprising a vacuum insulated glass unit, wherein the vacuum insulated glass unit is manufactured by means of a method according to any of the items and/or claims, and/or according to any of the embodiments described above.

The present disclosure moreover relates to a cooling storage, such as a refrigerator, comprising a vacuum insulated glass unit, wherein the vacuum insulated glass unit is manufactured by means of a method according to any of the items and/or claims, and/or according to any of the embodiments described above.

Building windows used for covering apertures in an exterior wall or roof structure of a building, so as to allow sunlight to enter the building interior through the VIG unit provides several advantages. For example, a VIG unit provides improved heat insulation performance when compared to material usage for the VIG unit. However, building windows are subjected to temperature differences, and it may shift whether it is the exterior of the building or the interior of the building that is the hotter, after window installation at the building. Such temperature difference causes thermal stress in the VIG unit and may provide an edge deflection caused by temperature differences between the glass sheets of the VIG unit. The VIG unit hence need to be resistant to such thermal stress caused by temperature differences over the life span of the building window, such as a life span above 10 years, such as above 15 years, such as 20 years or more. Also, the building window may be suitable for installation in buildings where a temperature difference above 40° C or above 60° C may occur. A VIG unit manufactured according to a method according to one or more embodiments of the present disclosure may be suitable for such use.

A VIG unit installed in a lid or door of a cooling storage may also be subjected to thermal stress that may moreover vary over the life time of the cooling storage. For example when opening and closing the lid or door.

The local heating may in any of the embodiments of the present disclosure be provided by means of one or more infrared heating sources or ultrasonic heating sources in an alternative to the disclosed laser light heating source.

Figures

The present disclosure will in the following be described in greater detail with reference to the accompanying drawings:

Fig. 1 : illustrates a cross section of a vacuum insulated glass unit, according to embodiments of the present disclosure,

Fig. 2 : illustrates a glass sheet assembly, according to embodiments of the present disclosure,

Fig. 3 and fig. 4 : illustrate schematically a production line, according to various embodiments of the present disclosure,

Fig. 3a : illustrates schematically evacuation pumps for evacuating a gap, according to embodiments of the present disclosure,

Fig. 5 : illustrates a glass sheet assembly prior to providing a force clamping at e.g. an edge sealing station, according to embodiments of the present disclosure, Fig. 6 : illustrates solder material which is locally heated, such as at an edge sealing station, according to embodiments of the present disclosure,

Fig. 7 : illustrates a temperature graph relating to a processing of a glass sheet assembly, according to embodiments of the present disclosure,

Fig. 8 : illustrates a temperature graph of a solder material subjected to preheating, according to embodiments of the present disclosure,

Fig. 9 : illustrates a flowchart relating to a method of processing a glass sheet assembly for a vacuum insulated glass VIG unit, according to embodiments of the present disclosure,

Figs. 10-14 : illustrates softening of solder material of a glass sheet assembly by means of local heating by one or more heaters, such as one or more emitters, such as e.g. one or more mirrors, according to various embodiments of the present disclosure,

Fig. 15 : illustrates evacuation of a gap of a glass sheet assembly by means of an evacuation cup, according to embodiments of the present disclosure,

Fig. 16 : illustrates a mechanical clamping arrangement providing force clamping, according to embodiments of the present disclosure,

Figs. 17a-17b and 18a- 18b : illustrates control, such as adjustment, of heating power over the solder material strip width, according to embodiments of the present disclosure,

Fig. 19 : illustrates heating power adjustment, according to embodiments of the present disclosure,

Fig. 20 : illustrates heating power at a first distance, according to embodiments of the present disclosure,

Fig. 21 : illustrates a redirected/reflected heating beam that is transmitted through a chamber wall to a heat solder material strip of a glass sheet assembly, according to embodiments of the present disclosure,

Fig. 22 : illustrates two laser light beams heating solder material according to embodiments of the present disclosure,

Fig. 23 : illustrates a flow chart according to embodiments of the present disclosure,

Fig. 24 : illustrates a solution relating to processing of different glass sheet assembly types, according to embodiments of the present disclosure, Fig. 25 : illustrates a flow chart according to further embodiments of the present disclosure,

Fig. 26a : illustrates a time-temperature profile, according to embodiments of the present disclosure,

Fig. 26b : illustrates a local area/portion of a seal material comprising solder material,

Figs. 27a-27b : illustrate time-temperature profiles according to further embodiments of the present disclosure,

Figs. 28-31 : illustrate time-temperature profiles where adjustments are provided during a heating time, according to various embodiments of the present disclosure,

Figs. 32-33 : illustrate schematically time-temperature profiles of the progress of a heating iteration at a local area of a solder material, according to various embodiments of the present disclosure,

Figs. 34a-34b : illustrate schematically a multi-layer edge seal according to further, various embodiments of the present disclosure,

Figs. 35a-35c : illustrate schematically thermal edge deflections caused by temperature differences, according to embodiments of the present disclosure, and

Fig. 36 : illustrates schematically a building comprising building windows, which building windows comprises a VIG unit, according to embodiments of the present disclosure.

Detailed description

Fig. 1 illustrates schematically a cross section of a vacuum insulated glass (VIG) unit 30 according to embodiments of the present disclosure. The VIG unit 1 comprises a first glass sheet 3 comprising a first major surface 3a, and a second glass sheet 4 comprising a second major surface 4. These major glass sheet surfaces 3a, 4a faces each other and an evacuated gap 5 between the major surfaces 3a, 4a. The glass sheet surfaces 3a, 4a are substantially parallel.

A plurality of support structures 2 are arranged on the surface 3a with a mutual distance DIS1 to the neighbouring support structures. These support structures 2 are distributed inside the gap 5 according to a predetermined pattern, e.g. in rows and columns. The support structures 2 maintains the gap 5 between the major glass sheet surfaces 3a, 4a of the vacuum insulated glass (VIG) when the gap 5 has been evacuated and sealed.

The glass sheets 3, 4 are sealed together at the periphery of the glass sheets 3, 4 with the plurality of support structures 2 arranged between the major surfaces 3a, 4a in the gap 5. The sealing together of the first and second glass sheets 3, 4 comprises use of an edge seal material 7 such as a solder glass edge seal material or a solder metal edge seal material. In some embodiments, the edge seal material 7 may comprise solder material such as a glass solder material, for example a glass solder frit material, such as a low melting point glass solder frit material.

In some embodiments of the present disclosure, the low melting point glass solder frit material may have a rated melting temperature Tm below 500 °C, such as below 450 °C, such as below 410 °C.

In some embodiments of the present disclosure, the low melting point glass solder frit material may have a rated melting temperature Tm above 300 °C, such as above 340 °C, such as above 450 °C or above 370 °C.

In some embodiments of the present disclosure, the melting point glass solder frit material may have a rated glass transition temperature Tm below 360 °C, such as below 330 °C, such as below 315 °C. An example of a solder material 7 glass transition temperature may be between 290 °C and 320 °C, such as between 300 °C and 310 °C.

The sealing together of the glass sheet 3, 4 edges may provide a fused, rigid edge seal.

The glass sheets 3, 4 may be annealed glass sheets or tempered glass sheets, such as thermally tempered glass sheets.

One or both glass sheets 3, 4 may have a thickness TH1, TH2 between 1 mm and 6 mm, such as between 2 mm and 4 mm, for example between 2.5 mm and 3.5 mm including both end points. The glass sheets 3, 4 may be of the same or different thickness. Thermally tempered glass sheets 3, 4 may e.g. allow providing a VIG unit with larger mutual distance DIS 1 between the support structures 2 and/or may allow thinner glass sheets than annealed glass sheets.

The distance DIS1 between neighbouring support structures 2 may in embodiments of the present disclosure be between 20 mm and 70 mm, such as between 25 mm and 65 mm, such as between 35 mm and 45 mm.

The surface of the major surfaces 4a, 4b, 3a, 3b of thermally tempered glass sheets may be uneven due to e.g. a plurality of so-called roller waves, bending and/or due to global edge kink. These characteristics may originate from the manufacturing process of the thermally tempered glass sheets. The uneven surface is illustrated in fig. 1 by exaggerated glass sheet 3, 4 unevenness. In practice, the glass sheet unevenness may be less visible.

The gap 5 has been evacuated to a reduced pressure (e.g. provided at an evacuation and sealing station, see e.g. ref. 300 and description related thereto further below). In embodiments of the present disclosure, the pressure in the gap 5 may be below 0.05 mbar, such as below 0.005 mbar, such as 0.003 or 0.001 mbar or below. This may be obtained by means of an evacuation pump (not illustrated in fig. 1).

For this evacuation of the gap 5, the pump may have been connected directly or indirectly to an evacuation outlet 6, and after the evacuation, the evacuation outlet 6 is sealed by a gap sealing 6a, such as at least partly by means of a solder material and/or another sealing solution, such as a permanent sealing solution. In some embodiments, the evacuation hole 6 sealing solution 6a may comprise a solder material and/or a glass pipe to be sealed by heating when the gap 5 has been finally evacuated to provide a VIG unit. In fig. 1, the evacuation outlet 6 is provided by means of a through hole in the upper glass sheet 4. In other embodiments, the evacuation outlet 6 may be provided in the edge seal material 7 and/or between the edge seal material 7 and one of the glass sheets 3, 4.

In some embodiments, the evacuation of the gap 5 may be provided by means of a suction cup (not illustrated in fig. 1) arranged to cover an evacuation opening 6. In other embodiments, the evacuation may be provided inside an evacuation chamber, for example where the entire VIG unit assembly is placed inside the evacuation chamber of an evacuation and sealing station. The support structures 2, placed by means of a dispenser or the like, maintains a distance H2 between the glass sheet surfaces 3a, 4a across the evacuated gap when the gap 5 has been evacuated and sealed to provide the final VIG unit.

The distance H2 between the major glass sheet surfaces 3a, 4a facing the gap may in embodiments of the present disclosure be 0.5 mm or below, such as 0.3 mm or below, for example 0.2 mm or below.

The distance H2 between the major glass sheet surfaces 3a, 4a facing the gap 5 may in embodiments of the present disclosure be between 0.05 mm and 0.6 mm, such as between 0.1 mm and 0.4 mm, such as between 0.15 and 0.25 mm. It is understood that the support structures may have a height matching such a gap height / distance between the glass sheet surfaces 3a, 4a.

It is generally to be understood that the final VIG unit 30 may e.g. be transparent to at least visible light, i.e. light in the spectrum that is visible to the human eye.

Fig. 2 illustrates schematically a glass sheet assembly 1 seen from above and towards a major exterior glass sheet surface 4b, prior to gap 5 evacuation and prior to permanent gap 5 sealing, according to embodiments of the present disclosure. See also fig. 1.

The glass sheet assembly 1 comprises the first glass sheet 3 and the second glass sheet 4. A plurality of the support structures 2 for maintaining a gap 5 between the surfaces 3a, 4a of the first glass sheet 3 and second glass sheet 4 are arranged between the major surfaces 3a, 4a of the glass sheets 3, 4. The support structures/spacers 2 are distributed in the gap 2 at different locations at the major surfaces of the glass sheets, as e.g. illustrated in fig. 2, and are visible through the glass sheet 4.

It is understood that dependent on the mutual distance DIS1 between adjacent support structures 2 and the size (area) of the major surfaces of the glass sheets 4, 3, the assembly 1 (and VIG unit) may comprise more than 500 support structures 2, such as more than 1000 support structures 2, such as more than 3000 or more than 5000 support structures 2 in the gap 5. In some embodiments of the present disclosure, the support structures 2 may comprise or consist of metal, such as steel, titanium, iron or the like. In some embodiments, the structural integrity of the support structures 2 may be provided by means of a metal such as steel, titanium, iron or the like. In other embodiments, the support structures may comprise or consist of a ceramic material or a polymer material.

The glass sheet assembly 1 comprises the solder material 7 for providing an edge sealing for enclosing and sealing the gap 5 between the glass sheets 3,4. As can be seen, the solder material 7 is provided as elongated strips of solder material extending between comer portions A, B, C, D of the edge seal material 7.

The solder material 7 strips A-B, B-C, C-D and D-A together encloses the gap 5 and enables providing a hermetic seal of the gap 5 after the solder material 7 has been processed as e.g. described in more details below. The solder material 7 strips A-B, B-C, C-D and D-A each have a longitudinal direction LDS that is substantially parallel to an edge of the glass sheets 3, 4. See e.g. also description further below, such as in relation to fig. 10. In fig. 2, the gap 5 of the glass sheet assembly 1 is not evacuated and the evacuation hole 6 is not sealed. Hence the gap 5 is in fluid communication with the exterior of the glass sheet assembly 1.

Figs. 3 and 4 illustrates schematically a production line 10 according to various embodiments of the present disclosure. The production line 10 comprises different consecutive processing stations 100, 200, 300. These comprises a preheating station 100, an edge sealing station 200 and an evacuation station 300.

A plurality of glass sheet assemblies 1 as e.g. described above are arranged in a preheating chamber 101 of the preheating station 100. The glass sheet assemblies 1 are provided into the preheating station by means of a transport system 90.

In figs. 3 and 4, a preheating chamber 101 of the preheating station 100 comprises a plurality of glass sheet assembly storage locations 103. Each of the glass sheet assembly storage locations 103 may comprise one or more glass sheet assembly supports 112 such as one or more shelves, rails, conveyers such as rollers and/or belts, and/or the like arranged above each other, e.g. in a rack arrangement. An example of a glass sheet assembly supports 112 comprising a conveyer comprising rollers is schematically illustrated in fig. 3a, however relating to a glass sheet assembly support 313 of the evacuation and sealing station 300.

In some embodiments of the present disclosure, more than one, such as more than two, such as more than five or more than ten glass sheet assembly storage locations 103 may be provided in the preheating chamber 101.

In some embodiments, between one and fifty, such as between two and forty, for example between five and twenty glass sheet assembly storage locations 103 (Both end points included) may be provided in the preheating chamber 101. In fig. 4 and 3, the chamber 101 comprises seven glass sheet assembly storage locations 103 that are vertically displaced above each other and which are each configured to receive and store one or more glass sheet assembly 1, such as at least one glass sheet assembly 1, for example at least two glass sheet assemblies 1, during preheating in the chamber 101.

The preheating may hence in embodiments of the present disclosure comprise convection heating a plurality of glass sheet assemblies 1 at the preheating station.

Since the glass sheet assembly storage locations 103 in fig. 3 and 4 are vertically displaced, the transport system 90 in figs. 3-4 comprises a lift which displaces the respective glass sheet assembly 1 vertically and moves the glass assembly 1 into an unoccupied glass sheet assembly storage location 103 in the preheating chamber 101 at the desired vertical level. This may be provided by moving the glass sheet assembly 1 vertically to a predefined position, e.g. opposite to a selected, unoccupied glass sheet assembly storage location 103. Then a gate, door or the like 95 may be opened whereafter the respective glass sheet assembly 1 is moved into the preheating chamber 101 by means of the transport system 90 and/or other conveyer means such as rollers, belts or the like at the respective glass sheet assembly storage location 103. The gate/door 95 is then closed again.

The transport system 90 may comprise one or more motors 91, such as one or more electric or pneumatic motors, configured to move the support 92 on which the glass sheet assembly supports vertically, e.g. along a rail and/or support frame (not illustrated). The transport system 90 may comprise one or more motors 93, such as one or more electric motors and/or one or more pneumatic motors configured to move the glass sheet assembly 1 at least partly horizontally, into the preheating chamber 101.

In some embodiments, lifting parts, such as support 92 (e.g. a lift) and/or other parts, such as one or more motors 91, 93 and/or other parts of the transport system 90, such as chains, rails and/or the like, of the transport system 90 may be placed inside a transport chamber (not illustrated) to transport the glass sheet assembly 1 inside this transport chamber vertically and/or horizontally. This transport chamber may be a lifting chamber comprising a lift 92, 91. In some embodiments, such a transport chamber may be considered a part of the production line 10. In other embodiments it may not be considered part of the production line 10.

A hardware controller 96 comprising control circuitry may control the one or more motors 91, 93, the gate(s)/doors(s) 95 and/or the like based on timer input and/or sensor input in order to move a glass sheet assembly 1 into an unoccupied glass sheet assembly storage location 103 for preheating at station 100 , chamber 101. It is hence understood that control circuitry of the controller 86 and/or a combination of controllers 96, 106, 206 may receive input from a monitoring arrangement (not illustrated), and thereby administrate the glass sheet assembly storage locations 103. The monitoring arrangement may comprise e.g. one or more sensors (not illustrated) such as one or more optical sensors, one or more proximity sensors, one or more cameras, and/or the like. Sensor data and/or other data is provided to one or more of the controller(s) 96, 106 and/or 206 and/or may be exchanged between the controllers 96, 106 and/or 206 so as to control the transport system 90, gate/door(s) 95, transport arrangements of the respective glass sheet assembly storage locations 103 (of present) and/or the like in order to assure a continuous supply of glass sheet assemblies 1 to be preheated in the chamber 101.

The hardware controller 106 may control the heater(s) 102 of the pre-heating station and/or control transport arrangements of the respective glass sheet assembly storage locations 103 and/or the like. This control of the heater(s) 102 may be based on input from one or more temperature sensors (not illustrated) and based on one or more predefined temperature thresholds in order to preheat the glass sheet assemblies 1 as desired. In other embodiments of the present disclosure (not illustrated), the pre-heating station 100 may comprise a transport system 90 such as comprising a continuous belt, rollers and or the like for transporting the glass sheet assemblies 1. This/these assemblies 1 may be arranged inside a preheating chamber, e.g. an elongated chamber, and be arranged consecutively “in line” instead of being arranged in a stacked/rack preheating solution as illustrated in figs. 3 and 4. One or more heaters 102 may in this embodiment heat the glass sheet assemblies 1 as they gradually are moved forward towards the station 200. When a sufficiently pre-heated glass sheet assembly is moved into station 200, a new “cold” glass sheet assembly is moved into the pre-heating chamber while on or more further glass sheet assemblies 1 that is/are already present in the pre-heating chamber 10 is/are moved closer to the station 200.

In still further embodiments (not illustrated) the preheating chamber 101 itself may comprise a lift arrangement, e.g. by providing that the glass sheet assemblies may be moved inside the preheating chamber, e.g. moved vertically. This may be provided when loading a glass sheet assembly 1 into the preheating station and/or be provided in relation to loading the glass sheet assembly into the edge sealing station 200 chamber 201. In this embodiment, the glass sheet assembly storage locations 103 may be vertically movable in the chamber by means of a lifting system (not illustrated)

It is generally understood that in some embodiments of the present disclosure, the transport system 90, such as a transport system 90 described above according to different embodiments, may be operated as a buffer so that the glass sheet assembly 1 that has been in the pre-heating station for the longest time is moved into station 200 when this station is unoccupied. This may e.g. be referred to as a FIFO (First In, First Out) buffer. In other embodiments of the present disclosure, a sensor system may monitor the temperature of the individual glass sheet assembly and a controller 106 and/or 206 may pick a glass sheet assembly 1 for the station 200 from chamber 201 that complies with predetermined temperature criteria.

When a glass sheet assembly 1 has been sufficiently preheated (see e.g. temperature T1 in fig. 8) and the edge sealing station 200 is unoccupied /ready to receive a glass sheet assembly 1 to be processed in the edge sealing station 200, the preheated glass sheet assembly 1 is moved into the edge sealing chamber 201 of the edge sealing station 200. This may be provided by opening a second gate 105. A lift 210 in the edge sealing station may move a support 212 to the correct vertical level and received or picks the glass sheet assembly 1.

In some embodiments of the present disclosure, the lift 210 may then move vertically upwards or downwards to a predefined processing location, such as a predefined processing height, to obtain a desired distance to a heating arrangement 15 such as a laser arrangement 15. This may be advantageous in case the local heating is provided by means of e.g. one or more laser light beams. Providing the same distance to e.g. a mirror and/or lens arrangement of the heater may reduce need of calibration. The heating arrangement 15 may also be referred to as heater and may comprise or consist of an emitter.

In some embodiments, a sensor system, such as an optical sensor, may be used for determining the position of the solder material of the glass sheet in order to assure proper local heating.

The lift 210 may comprise a lifting system comprising a motor 211, such as an electric or pneumatic motor, for moving a support 212 which supports the glass sheet assembly to be processed.

It is generally understood that the support 212 may or may not comprise a transport arrangement (not illustrated). Such a transport arrangement may e.g. comprise one or more rollers, conveyer belt(s) and/or the like that may be used for movement of the glass sheet assembly 1 when moving the glass sheet assembly 1 from the station 100 and into station 200 and/or when moving the edge sealed glass sheet assembly 20 from the station 200 and into station 300. This transport arrangement may or may not support the glass sheet assembly 1 during the glass sheet assembly processing in the edge sealing station 200.

It is understood that in other embodiments of the present disclosure, the lift 210 of the edge sealing station may be omitted. For example in case the preheating station 100 is not a rack solution comprising vertically spaced apart glass sheet assembly storage locations 103 as illustrated in figs 3 and 4. E.g. as previously described where the glass sheet arrangements are arranged consecutively “in line” instead of being arranged in a stack/rack during preheating. In that case, the support 212 may be substantially fixed at e.g. a predefine distance to the heating arrangement 15. In this embodiment, the glass sheet assemblies may be loaded into the edge sealing chamber 201 of the edge sealing station 200 at the same vertical level each time from the pre-heating station 100 when the door/gate 105 is open.

In some embodiments, the lift 210 may be omitted and the glass sheet assemblies may be delivered to and/or moved from the support 212 at the same vertical level every time. This may e.g. be facilitated by providing a horizontal or vertical carousel solution at one or both stations 100, 300 or providing a horizontal or vertical carousel solution or another lift solution between the station 100 and station 200 and/or between the station 200 and station 300.

It is understood that in other embodiments of the present disclosure, if the preheating station 100 instead comprises a lift (not illustrated - see e.g. description above), the relevant glass sheet assembly may be moved vertically to a desired location (vertical level) inside the chamber 101, such as opposite to the support 212 in the edge sealing chamber 201, and then moved into that chamber 201 to rest on support 212.

At the edge sealing station 200, a heater 15 provides local heating of the solder material 7 of the glass sheet assembly 1. The local heating may in embodiments of the present disclosure comprise local heating by means of one or more heating beams 9, such as one or more laser light beams, as e.g. described in more details further below. In additional or alternative embodiments of the present disclosure, the local heating of the solder material may comprise local heating of the solder material 7 to soften it 7 by means of ultrasound and/or infrared radiation.

It is to be understood that the local heating of the solder material 7 is provided by the heater 15 so that the solder material 7 is heated and softened by the beam 9 from the heater 15, but that the majority of the area of the glass sheets 3, 4 arranged opposite to the gap 5 are not heated by the heater 15.

Hence, the heating beam(s) 9 is/are configured to provide heating directly at the area of the solder material 7 location, whereas heating by beam(s) 9 at other locations of the glass sheet assembly not arranged at or near the solder material 7 may be substantially omitted. In some embodiments, the heating beam 9 may be selected so that the solder material 7 is heated by the heater 15 by absorbing the energy provided by the beam 9. The glass sheets 3, 4 may be substantially transparent to the heater 15 beam 9 energy. This may e.g. be provided/obtained by selecting a suitable wavelength of the beam 15, such as a laser wavelength and/or by selecting a suitable solder material 7 type able to absorb the energy, such as the majority of the energy, provided by the beam 9. Hence, the beam 9 may heat the solder material 7 through the glass sheet 3 or 4.

In some embodiments, the heating beam(s) 9 may be near-infrared or infrared heating beam(s).

In some embodiments of the present disclosure, a laser light source, see e.g. also fig. 21, may provide the heating beam(s) 9. For example, a continuous wave laser or a pulsed laser. In some embodiments, the continuous wave laser or a pulsed laser may emit light in the nearinfrared (NIR) or infrared (IR) wavelength range.

In some embodiments of the present disclosure, the heating beam(s) 9 may be a laser light beam in the wavelength range of between 750 nm-1.400 nm (0.75-1.4 pm). For example, the laser light source may provide laser light with a wavelength of about 1000-1100 nm, such as about 1040-1060 nm, for example substantially 1050 nm.

In some embodiments of the present disclosure, the heating beam(s) 9 may be a laser light beam in the wavelength range of between 750 nm-15.000 nm (0.75-15 pm).

In the following, the local heating of the solder material 7 is described as being provided by means of a laser light beam 9. However, it is understood that other suitable heating solutions for local heating and softening of the solder material 7 to soften it 7 may additionally or alternatively be provided. It is understood that the laser light beam may be controllable/ steerable by a mirror arrangement (not illustrated) so as to move the laser light beam 9 along the longitudinal direction of one or more solder material 7 strip(s), e.g. at a speed providing an even heating and softening of the entire edge seal solder material 7 of the glass sheet assembly. The mirror arrangement may in some embodiments comprise one or more laser beam steering mirrors (see e.g. also fig. 22), for example comprising Piezo Tip/Tilt Platforms and /or Controllers. The mirror arrangement may be selected according to one or more of laser beam adjustment speed performance, precision, laser type compatibility and/or tilting angle performance. In some embodiments, the heater may comprise one or more lenses. In some embodiments, the heater may comprise one or more lenses for adjusting the laser light spot size subjected to the solder material 7.

In some embodiments of the present disclosure, the mirror / mirror arrangement (see also fig. 21) may be considered an emitter acting as a heater or a part of a heater. In this case the mirror directs/emits the laser light beam from a laser light source towards the solder material.

The local heating of the solder material 7 may e.g. be provided by moving one or more laser light beams 9 fast along the solder material 7 for a plurality of consecutive heating iterations as e.g. described in more details below.

When the solder material 7 has been heated locally to a desired/predetermined temperature (see e.g. T2 of figs. 7 and/or 8), and thereby a suitable softness, a pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 in the edge sealing chamber 201 is provided. The pressure difference provides that the first glass sheet 3 and the second glass sheet 4 are forced towards each other and thereby squeezes/clamps and deforms the softened solder material 7. This may also be referred to as force clamping. This may help to provide an enhanced edge sealing of the glass sheet assembly 20 and final VIG unit 30.

The pressure difference is maintained for a time period (See time t4-t5 of figs. 7 and/or 8) while continuous local heating is provided by moving the laser beam(s) 9 along the length of the solder material 7 to heat it 7, preferably in a plurality of heating iterations.

The local solder material 7 heating prior to providing the pressure difference may help to provide that the solder material is softened more than it was when the glass sheet assembly had been subjected to merely the preheating.

The pressure difference provides a force clamping of the solder material 7. It is understood that in other embodiments, the force clamping may be provided by means of other clamping solutions, e.g. comprising one or more actuators and/or clips. If there is a desire of omitting clips distributed around the glass sheet assembly for providing the force clamping, the pressure difference as described above and/or below, and/or an actuator solution, may be used, see e.g. fig. 16.

The glass sheets 3, 4 may generally e.g. maintain the temperature from the preheating step in the edge sealing chamber 201 (e.g. by means of one or more heaters such as convection heater(s) - not illustrated) or may be allowed to gradually reduce glass sheet temperature 3, 4 during the local heating of the solder material 7 in the sealing chamber 201. Generally, it is understood that in some embodiments, active heating, such as convection heating, of the edge sealing chamber 201 may be provided. In other embodiments, active heating, such as convection heating, of the edge sealing chamber 201 may be omitted.

The heating of the solder material 7 by means of the one or more laser beams 9 by moving the one or more laser beams 9 in a plurality of heating iterations along the solder material 7 provides that a substantially even, gradual heating and softening of the entire solder material 7 of solder material 8 stripes A-B, B-C, C-D and D-A of the glass sheet assembly 1 is obtained. Hence this may in embodiments of the present disclosure enable providing a pressure difference in order to obtain that the glass sheets 3, 4 clamps the softened solder material 7. This may also be referred to as force clamping in the present document. Thus, in some embodiments of the present disclosure, no external, mechanical clamping means, such as e.g. clips, may be needed to provide a desired clamping force on the heated and softened solder material 7.

The force clamping, such as the pressure difference, may be temporary and may be stopped, such as eliminated, again after sufficient heating of the solder material 7 has been obtained by the one or more heating beams at the edge sealing station 200.

In fig. 3, the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure P 1 surrounding the glass sheet assembly 1 in the edge sealing chamber 201 is provided by means of an evacuation cup 40 arranged to cover an evacuation hole (see ref. 6 of figs. 1 and 2). An evacuation pump 8 is in fluid communication with an intemal/inner cavity of the evacuation cup 40. The evacuation pump 8 thereby provides a reduced pressure in the gap 5 in order to obtain the pressure difference. This negative pressure may not be as great/large as the final negative pressure to be provided in the gap 5 of the final VIG unit 30. The pressure difference provided at edge sealing station 200 may merely be temporary and be provided in order to obtain a desired clamping force acting on the softened solder material 7.

The pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly unit at the edge sealing station 200 chamber 201 may in some embodiments of the present disclosure be at least 0.2 bar, such as at least 0.5 bar, such as at least 0.7 bar, such as at least 0.8 bar.

The pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 chamber 201 may in some embodiments of the present disclosure be at least 0.9 bar, such as at least 0.99 bar, such as at least 0.999 bar.

The pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 chamber 201 may in some embodiments of the present disclosure be between 0.2 bar and 0.99999 bar, such as between 0.5 bar and 0.9999 bar, such as between such as between 0.99 bar and 0.9999 bar.

The pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 chamber 201 may in some embodiments of the present disclosure be at least 0.5 bar.

The pressure in the gap 5, during the providing of the pressure difference between the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 chamber 201, may in some embodiments of the present disclosure be below 0.5 bar, such as below 0. 1 bar such as below 0.01 or below 0.001 bar. This may e.g. be obtained by gap 5 evacuation.

The pressure in the gap 5, during the providing of the pressure difference between the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 chamber 201, may in some embodiments of the present disclosure be above 0.005 mbar such as above 0.05 mbar, such as above 0.05 bar. The pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly unit may be obtained within 10 seconds, such as within 5 seconds, such as within 3 seconds or within 2 seconds.

The pressure in the gap 5, during the providing of the pressure difference between the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 chamber 201, may in some embodiments of the present disclosure be between 0.005 mbar and 0.5 bar, such as between 0.5 mbar, and 0.1 bar.

The pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 chamber 201 may in some embodiments of the present disclosure be less than 0.8 bar such as less than 0.5 bar. The pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly at the edge sealing station 200 chamber 201 may however in other embodiments of the present disclosure be at least 0.8 bar such as at least 0.9 bar or at least 0.99 bar.

It is generally understood that in some embodiments of the present disclosure, the pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 may be obtained by evacuating the gap 5, e.g. by means of an evacuation cup /suction cup 40. In other embodiments of the present disclosure, it may be obtained by temporarily sealing off the gap 5 and providing a higher pressure/overpressure in the edge sealing chamber 201. The pressure difference provides a clamping of the solder material 7 which may help to provide an improved edge sealing connection and/or help to compress and deform the solder material 7.

It is understood that the pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly unit at the edge sealing station 200 chamber 201 may in some embodiments of the present disclosure gradually continue to increase during substantially the entire process of locally heating the solder material 7 by means of e.g. one or more laser beams. In other embodiments, the pressure difference is set to a predetermined value and may be controlled to not increase further when this value, such as a predetermined pressure value, is reached. In some embodiments of the present disclosure, regulation circuitry and/or one or more hardware controllers may control the pressure in the gap 5 and/or the pressure in the edge sealing station 200 chamber 201 during the local heating of the solder material by means of e.g. one or more heating beams 9 such as one or more laser beams. The regulation circuitry and/or one or more hardware controllers may be configured to adjust the pressure in the gap 5 and/or the pressure in the edge sealing station 200 chamber 201 during the local heating of the solder material according to a predefined control scheme. This may e.g. be controlled based on one or more feedback loops such as e.g. relating to the pressure in the gap and/or the pressure in the edge sealing chamber 201, for example based on sensor input.

In fig. 3, the pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 is provided by evacuating the gap 5. e.g. by means of an evacuation cup 40. In the embodiment of fig. 4, a pump 8 instead provides the pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 by providing an overpressure P 1 in the chamber 201 relative to the pressure in the gap 5 so as to obtain a pressure difference in order to clamp the solder material 7 by means of the glass sheets 3, 4. In the embodiment of fig. 4, an evacuation hole 6 at the glass sheet assembly 1 may hence be temporarily sealed to allow creating an over pressure in the chamber 201 relative to the pressure in the gap 5.

When, or after, the solder material 7 has been finally heated to a desired temperature (See e.g. T3 of figs. 7 and/or 8), the temporary pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 is eliminated. E.g. by shutting off the evacuation pump 8 or opening or closing a valve. This release of the pressure difference may in some embodiments be provided at a time after the heating by means of the one or more heating beams is stopped.

Then the glass sheet assembly 20 is moved to the evacuation station 300 for final evacuation and sealing of the gap 5. It is understood that reference “20” represents the glass sheet assembly after it has been processed in the edge sealing station 200 and prior to that the gap 5 has been finally evacuated and sealed to obtain a VIG unit 30 at the evacuation station 300.

The edge sealed glass sheet assembly 20 is moved from the edge sealing compartment/chamber 201 and into the evacuation station 300 chamber 301. This movement of the assembly 30 may be provided by vertically lifting or lowering the glass sheet assembly 20 by means of the lift 210 and horizontally displacing/moving it into the chamber 301 to a storage location 303, e.g. by means of a transport arrangement (not illustrated) of the support 212 as e.g. previously described.

An alternative solution may comprise that storage location(s) 303 may be arranged in/as part of a carousel conveyer such as a vertical carousel conveyer or a horizontal carousel conveyer of the station 100 and/or 300. This may e.g. enable omitting the lift 210.

A gate or door 205 may be opened to allow moving the edge sealed glass sheet assembly 20 into the compartment/chamber 301 and may thereafter be closed again.

The evacuation station 300 may comprise a plurality of storage locations 303 for storing edge sealed glass sheet assemblies 20 during evacuation of the gap 5. This may e.g. be provided in substantially the same way as loading glass sheet assemblies 1 into the preheating compartment 101 and/or unloading glass sheet assemblies from the preheating compartment/chamber 101 and into the edge sealing station. Hence, The glass sheet assembly storage locations 303, such as a support 312 thereof, of the station 300 may (e.g. each) may comprise a shelve, rail, one or more conveyers such as rollers 313 (see fig. 3a) and/or belts, and/or the like. Each storage location may be arranged above each other, e.g. in a rack arrangement, and/or besides each other.

In some embodiments of the present disclosure, more than one, such as more than two, such as more than five or more than ten glass sheet assembly storage locations 303 may be provided in the evacuation station. In some embodiments, between one and fifty, such as between two and forty, for example between five and twenty glass sheet assembly storage locations 303 (Both end points included) may be provided in the evacuation chamber 301. In figs. 4 and 3, the evacuation chamber/compartment 301 comprises seven glass sheet assembly storage locations 103 that are vertically displaced above each other and which each is configured to receive and store one or more edge sealed glass sheet assembly 20, such as at least one edge sealed glass sheet assembly 20, for example at least two glass sheet assemblies 20, during evacuation and sealing of the gap 5 of the respective edge sealed assembly 20. An evacuation pump 308 (e.g. separate to the pump 8 used in station 200) evacuates the gap 5. This may as illustrated, in some embodiments, be provided by means of an evacuation cup 41 assigned each storage location 303 (only one cup 41 is referred to in fig. 3 and 4 for figure simplicity), and a relative movement between evacuation cup and the assembly 20 may in some embodiments be provided in order to obtain contact, such as substantially hermetic contact, between the cup 41 and the respective assembly 20 before gap evacuation 5. The cup(s) 41 is/are in fluid communication with the evacuation pump 308.

In some embodiments, a valve system (not illustrated) may be controlled to shut on and off a fluid communication between the respective cup 41 and a pump 308 in order to e.g. enable one pump 308 to evacuate a plurality of assemblies 20.

In still further embodiments, several pumps 308 may be provided, where one or more of these pumps 308 each evacuates one or more assembly 20 gaps 5.

In another or additional embodiments of the present disclosure (not illustrated), the entire chamber 301 may be an evacuation chamber, and a plurality of gaps of different assemblies 20 may be evacuated by evacuating the evacuation station 300 chamber 301.

In the embodiments of fig. 3 and 4, the cup(s) 41 may comprise a heater (not illustrated) to be activated for heating an evacuation hole 6 sealing 6a solution in order to seal the gap 5 when the gap 5 has been sufficiently evacuated by the pump 308.

In some embodiments of the present disclosure, the pump 308 may evacuate the gap 5 to a pressure below 0.05 mbar, such as below 0.005 mbar, such as below 0.003 mbar or below 0.001 mbar, before sealing to maintain that obtained gap 5 pressure. This may be considered a substantially vacuum.

In some embodiments of the present disclosure the maximum pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 (if the force clamping is provided by means of the pressure difference as e.g. previously explained, for example by temporary gap 5 evacuation) may be smaller than the pressure difference between the pressure in the gap 5 and the pressure surrounding the edge sealed glass sheet assembly 20, i.e. the VIG unit 30, at the evacuation station 300 after said (permanent) sealing off 6a the gap 5 from the surroundings.

In some embodiments of the present disclosure, the maximum pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1 at the edge sealing station 200 may be at least ten times less, such as at least 100 times less, than the pressure difference between the pressure in the gap 5 and the pressure surrounding the edge sealed glass sheet assembly 20 at the evacuation station 300 after said (permanent) sealing off 6a of the gap 5 from the surroundings.

A sufficient pressure difference provided by a pump 8 for force clamping purpose at the edge sealing station 200 may e.g. be obtained faster when compared to the time it takes to provide the final, low gap 5 pressure obtained at the evacuation station 300 by pump(s) 308 prior to final (permanent) sealing by a gap sealing 6a to obtain the VIG unit 30.

The evacuation and sealing of the gap 5 in the station 300 may take a longer time than the local heating and edge sealing of station 200. For example, the evacuation and sealing of the gap 5 in the station 300 may take at least twice as long, e.g. at least five times as long, for example at least ten or at least twenty times as long as the time it takes (see time t3 to t5 of figs 7 and 8) from the start (see time t3 of fig. 7 and/or 8) of locally softening the solder material 7, providing the force clamping, e.g. by pressure difference (see time t4 of figs 7 and/or 8) and eliminating the pressure difference again (see t5 of figs. 7 and/or 8) in the edge sealing station 200 as e.g. described above and/or in more details below.

In some embodiments of the present disclosure, a heating arrangement 302, such as a convection heating arrangement, may heat the assemblies 20 in the evacuation chamber 301 during the evacuation of the gap 5. This may e.g. be provided to a temperature above 150 °C, such as above 200 °C, e.g. above 300 °C. In some embodiments, the heating arrangement 302 may heat the assemblies 20 in the chamber 301 to a temperature below the glass transition temperature Tg of the edge sealing material 7. In some embodiments, the heating arrangement 302 may heat the assemblies 20 in the chamber 301 to a temperature below 305°C. Embodiments of the temperature in the chamber 301 are moreover described below in relation to fig. 9. In some embodiments of the present disclosure, the evacuation of the gap 5 at the evacuation station 300 may be provided for at least 5 minutes, such as at least 10 minutes, for example at least 20 minutes or at least 25 minutes.

In some embodiments of the present disclosure, the evacuation of the gap 5 at the evacuation station 300 may be provided for less than 60 minutes, such as less than 40 minutes, for example less than 30 minutes.

In some embodiments of the present disclosure, the evacuation of the gap 5 at the evacuation station 300 may be provided for between 5 minutes and 60 minutes, such as between 10 minutes and 40 minutes, for example between 15 minutes and 30 minutes. In certain embodiments of the present disclosure, the evacuation of the gap 5 may be provided for between 10 minutes and 30 minutes.

After the gap 5 has been evacuated and sealed, such as permanently sealed, at station 300, e.g. by means of melting a solder material and/or a glass component such as a glass tube so as to seal the gap 5, the assembly 20 has been turned into a VIG unit 30.

The VIG unit 30 is transported from the evacuation station 300 (e.g. through a gate or door 305) and to a cooling location or cooling arrangement (not illustrated), e.g. by means of a transportation system 400. This transportation system 400 may or may not comprise a lift for collecting the VIG units 30 from the evacuation station 300 when finished. E.g. as previously explained in relation to e.g. the transportation system 90.

In some embodiments (not illustrated) a buffer station may be placed between edge sealing station 200 and the evacuation station. This buffer station may receive assemblies 20 and the assemblies 20 may be moved into the evacuation chamber 301 when desired. In some embodiments hereof, said buffer station may comprise a lift or the like (e.g. as the lift 210 described above). This may e.g. be relevant if the preheating station 200 neither comprises a plurality of vertically displaced assembly storage locations 103, since the support 212 may then neither be vertically displaceable by a lift 210.

Hence, in some embodiments, the station 300 may comprise a plurality of vertically displaced assembly 20 storage locations 303, whereas the preheating station may not comprise a plurality of vertically displaced assembly 20 storage locations 303 (as e.g. previously described if an “in line” preheating solution is used).

It is generally understood that one, more or all of the doors/gates 95, 105, 205, 305 may comprise one or more gates/doors e.g. assigned each individual vertical level of the preheating station, or it may be a common gate. The gate/door may be openable and closeable by controlling one or more actuators such as one or more motors and/or one or more linear actuators.

It is understood that one or more of the stations 100, 200, 300 compartments 101, 201 and/or 301 may be surrounded/enclosed by heat insulating outer walls. In some embodiments the doors/gates 95, 105, 205, 305 may or may not be heat insulated. These walls may be separate to walls of a building in which the production line 10 is arranged.

It is generally understood that the production line 10 may be embodied as, or in a single device or apparatus comprising different consecutive stations 100, 200 300, or may be embodied as, or in separate devices, such as separate stations.

For example, in some embodiments of the present disclosure, the storage location(s) 303 and/or 103 may be arranged in/as part of, a carousel conveyer such as a vertical carousel conveyer or a horizontal carousel conveyer of the station 100 and/or 300.

Fig. 3a illustrates schematically an embodiment of the present disclosure, where more than one (in this case two) evacuation pumps 308 are dedicated one evacuation cup and are in direct or indirect fluid communication with an inner cavity of the cup 41 at station 300. Hence, a first and a second pump 308 may be provided for each storage location 303. This may provide that the number of evacuation pumps 308 assigned station 300 equals the double of the number of storage locations 303 at station 300. For example so that e.g. twenty storage locations 303 at station 300 results in forty evacuation pumps. Hence, when an assembly 20 gap 5 is evacuated at station 300 by a pump 308, a first pump may provide an initial gap 5 evacuation, and a further pump may then at the same time or at a later stage be started in order obtain the final, desired gap 5 evacuation before gap 5 sealing to obtain the VIG unit. In fig. 3a, the pumps are connected in series. In other embodiments, they may be connected in parallel.

Fig. 3a moreover schematically illustrates an embodiment of the present disclosure where the glass sheet assembly 20 support 312 of the storage location 303 comprises a conveyer such as a roller solution. Here, a plurality of rollers 313, such as passive rollers or active rollers driven directly or indirectly by one or more motors, are configured to transport the edge sealed glass sheet assembly to and from the station 300 chamber 301. Additionally, the conveyer 313 may support the glass sheet assembly during the gap evacuation 5 and sealing. In other embodiments, the glass sheet assembly 20 may support on another support during the gap 5 evacuation and sealing.

It is understood that the support 112, 312 of the stations 100, 300, in some embodiments of the present disclosure, may be substantially of the same type.

It is generally understood that each station 100, 200 and 300 of the production line 10, and possibly also transport systems and the like, in various embodiments of the present disclosure, may comprise one or more hardware controllers 96, CTR comprising one or more microprocessors which execute appropriate software stored in a data storage in order to handle/control one, more than one, or all of the station 100, 200, 300 related features of that respective station 100, 200, 300 such as controlling:

• Preheating at station 100,

• Temperature maintenance at station 100 and/or 200,

• local solder material 7 heating by one or more heating beams at station 200,

• transport to, between and/or from the respective station 100, 200, 300,

• providing pressure force clamping such as pressure difference, e.g. by gap 5 evacuation at station 200,

• gap 5 evacuation and gap sealing at station 300

• and/or the like.

In other or further embodiments, a central hardware controller CTR may be configured to control one, more than one, or all of the above mentioned of two or more stations 100, 200, 300. In some embodiments, a transport controller may be dedicated for controlling the transport to, from and/or between the stations 100, 200, 300. In some embodiments of the present disclosure, the controller or controllers, for example a controller subsystem and/or a processor subsystem, may be embodied by a single Central Processing Unit (CPU), but also by a combination or system of such CPUs and /or other types of processing units may be provided. The software to be executed may have been downloaded and/or stored in a memory, e.g. a volatile memory such as RAM or a nonvolatile memory such as Flash. Additionally or alternatively, the processor or processors may be implemented in a device or apparatus, such as in a controller, in the form of programmable logic, e.g., as a Field Programmable Gate Array (FPGA), a programmable Uogic Controller (PLC) and/or the like. In general, each functional unit of the control system may be implemented in the form of a circuit. In some embodiments, the control system for controlling the production line 10 may hence comprise a central controller and/or a plurality of distributed sub-system controllers assigned one or more of the respective station(s) 100, 200, 300.

Fig. 5 illustrates schematically a cross section of a glass sheet assembly 1 according to embodiments of the present disclosure, prior to providing the assembly 1 processing at edge sealing station 200. The cross section is seen in a plane that is perpendicular to the glass longitudinal direction of the solder material strip 7. In fig 5, the solder material 7 has a height Hl (before the processing in the edge sealing station 200) that is larger than the height of the support structures 2. A plurality of the support structures 2 may hence not be in contact with the upper glass sheet 3 before the final gap 5 evacuation to provide the VIG unit 30.

In fig. 5, the pressure P2 in the gap 5 and the ambient pressure Pl surrounding the assembly 1 are substantially equal.

The solder material 7 strip width W 1 before the processing in the edge sealing station 200 may be between 2 mm and 8 mm, such as between 3 mm and 6 mm, for example between 4 mm and 5 mm (both end points included). This is the case before introducing the assembly 1 to the preheating station and this width W 1 may substantially be maintained also after assembly 1 preheating at station 100, but before evacuation at the edge sealing station 200.

Fig. 6 illustrates schematically and in cross section an embodiment of the present disclosure when the solder material 7 is locally heated at the edge sealing station 200. Uocal heating by beam 9 has been provided substantially uniformly around the entire edge seal solder material of the assembly, e.g. during a plurality of heating iterations, and this has softened the solder material 7 further when compared to the softness of the solder material 7 after/at the end of the preheating and prior to the local heating at station 200.

When the solder material 7 has been sufficiently heated (see temperature T2 of figs 7-8), the pressure difference between the pressure P2 in the gap 5 of the glass sheet assembly 1 and the pressure Pl surrounding the glass sheet assembly 1 in the edge sealing chamber 201 is provided. This pressure difference provides that the glass sheets 3, 4 clamps and deforms the solder material 7 thereby reducing the height Hl of the solder material 7 and increasing the width W1 of the solder material 7. The height Hl of the solder material may in some embodiments be reduced to substantially height H2 as e.g. previously described. In some embodiments, the support structures 2 may at least partly help to limit the solder material height Hl reduction.

The solder material 7 width W 1 may, during the processing at the edge sealing station 200, in embodiments of the present disclosure, be increased with at least 10%, such as at least 20% or at least 40% when compared to the initial solder material width W 1 before the local heating and temporary evacuation of the gap 5 at the edge sealing station 200. This width may substantially be maintained after releasing/eliminating the pressure difference.

The solder material 7 width W 1 may, due to the processing at the edge sealing station 200, in embodiments of the present disclosure, be deformed to have a final solder material width W 1 of between 4 mm and 16 mm, such as between 5 mm and 11 mm, for example between 7 mm and 9 mm.

The solder material 7 width W 1 may in embodiments of the present disclosure be increased with at least 10%, such as at least 20% or at least 40% when compared to the initial solder material width W 1 before the local heating and temporary evacuation of the gap 5 at the edge sealing station 200.

The solder material 7 height W 1 may in embodiments of the present disclosure be decreased with at least 10%, such as at least 20% or at least 40% when compared to the initial solder material height Hl before the local heating and temporary evacuation of the gap 5 at the edge sealing station 200.

When the pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly has been eliminated, the increased width W 1 and decreased height Hl is substantially maintained, and more support structures 2 may possibly touch both the glass sheet surfaces 3a, 4a.

The beam 9 providing the local heating of the edge sealing material/solder material 7 may in embodiments of the present disclosure have a spot size W2 (e.g. spot width or spot diameter) that is at least 10%, such as at least 20%, such as at least 30% larger than the width W1 of the solder material 7 strip. In some embodiments of the present disclosure, the beam 9 providing the local heating of the edge sealing material/solder material 7 may have a spot size W2 (e.g. spot width or spot diameter) that is at least 50%, such as at least 90% larger than the width W1 of the solder material 7 strip.

The light intensity of a laser light beam has a gaussian distribution and the spot diameter W2 of the laser light beam can be defined in at least three different manners. Herein, the definition named l/e2 is employed, where the edge of the spot is defined as the position, where the irradiance is 13.5% of its maximal value in the cross-section of the beam.

For example, in some embodiments of the present disclosure, the beam 9 providing the local heating of the edge sealing material/solder material 7 may in embodiments of the present disclosure have a spot size W2 (e.g. spot width or spot diameter) that is between 10% and 150% larger, such as between 30% and 100% larger, for example between 40% and 80% larger, than the width W1 of the solder material 7 strip. The above-mentioned spot size W2 embodiments may be the spot size W2 relative to the solder material 7 strip width W 1 when the glass sheet assembly 1 has been positioned at the edge sealing station 200 and the heating of the solder material by means of the one or more beams 9 is initiated (e.g. substantially at time t3 - see figs. 7 or 8). Additionally or alternatively, the above mentioned spot size W2 embodiments may be the spot size W2 relative to the solder material 7 strip width W 1 strip(s) before or substantially at initiation (see e.g. time t4 mentioned above in relation to figs 7 or 8) of the temporary force clamping of the solder material 7 by means of the glass sheets 3, 4, e.g. by means of the pressure difference as previously described, for example by the previously mentioned temporary evacuation of the gap 5 at the edge sealing station 200 by an evacuation pump 8. Other solutions for providing a force clamping is/are explained below, e.g. in relation to fig. 16. Other embodiments of the spot size width W2 and/or control of the heating of the solder material by one or more heating beams 9 are described in relation to one or more of e.g. figs. 10-14 and/or figs. 17a-20 below.

Fig. 7 illustrates schematically a temperature graph relating to the processing of a glass sheet assembly 1 at an edge sealing station 200, such as e.g. the station 200 of fig. 3-4, according to embodiments of the present disclosure, from a time t3 to t5. The temperature graph Te illustrates the temperature of the solder material 7 during the processing at the/an edge sealing station 200.

At time t3, the local heating by e.g. means of laser of a heating arrangement 15 is started to heat the solder material. This comprises a plurality of consecutive and preferably continuous heating iterations along the solder material 7 so as to heat the solder material 7. This is provided with a heating energy and a movement speed that assures substantially equal heating of the entire edge seal material. For example in order to assure substantially the same temperature, and thereby substantially the same viscosity, of all of the solder material 7 of the assembly when the pressure difference is initiated at station 200 at time t4.

From time t3-t4 an initial, local heating of the edge seal materials provided by the one or more heaters at station 200, thereby softening the solder material 7 further when compared to the hardness of the solder material prior to the local heating of the solder material.

Prior to providing the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 in the edge sealing chamber 201 at time t4, the solder material 7 may, in embodiments of the present disclosure, be locally heated by one or more heaters 15 at the edge sealing station to a solder material temperature Te in the range of 20 to 100 °C, preferably in the range of 40 to 90 °C, such as in the range of 40 to 90 °C above the temperature T1 of the solder material 7 at the time t3 when the local heating by one or more heaters is initiated at the station 200. Hence, T2 - T1 (T2 minus Tl) may correspond to a temperature difference in the above-mentioned range. This may be provided in the time period t3-t4. In some embodiments of the present disclosure, prior to providing the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 in the edge sealing chamber 201 at time t4, the solder material 7 may be locally heated (see t3-t4) by one or more heaters 15 at the edge sealing station to a solder material temperature Te in the range of 20 to 120 °C, preferably in the range of 40 to 110 °C, such as in the range of 60 to 90 °C above the glass transition temperature Tg of the solder material 7.

The heating provided from time t3 to time t4 may be considered an initial local heating (and thereby softening) of the solder material 7. This may e.g. help to provide that an improved contact and/or a more airtight connection between the glass sheets 4, 5 and the solder material is obtained prior to providing the pressure difference.

The local heating of the solder material 7 provides that the temperature Te of the solder material 7 is elevated when compared to the general temperature, such as average temperature, of the glass sheets 3, 4 when the glass sheet assembly entered the edge sealing station.

At time t4, the providing of the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 is initiated. This causes an improved contact between the solder material 7 and the glass sheets as the glass sheets 3, 4 hereby clamps the solder material 7. As can be seen from fig. 7, the temperature Te of the solder material 7 drops to a reduced temperature T4 (when compared to T2) when initially providing the pressure difference, as the glass sheets 3, 4 acts as heat sinks. The local heating is however continued while the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 is maintained. This causes the solder material 7 temperature to increase again until an elevated solder material 7 target temperature T3 is reached at time t5.

At time t5, the local heating of the solder material 7 is stopped. Stopping the local heating of the solder material 7 causes the temperature of the solder material 7 to drop, as the glass sheets 3, 4 are colder than the solder material 7 and hence acts as heat sinks to cool the solder material 7. In some embodiments, the pressure difference may be maintained after stopping the local heating, and the pressure difference may hence first be eliminated at a later point t6 after the local heating was stopped t5.

The average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may in in embodiments of the present disclosure be lower than the maximum target heating temperature T3 of the solder material 7 while the local heating of the solder material 7 is provided at the station 200. This may help to provide a cooling and hardening of the solder material 7 after the local heating is stopped (see t5) as the glass sheets 3, 4 may act as heat sinks.

A glass sheet assembly heater 220, such as a convection heater, may assure that the chamber 201 is heated to a desired temperature during the local heating of the solder material 7.

The temperature in the chamber 201 may in some embodiments be determined/set based on e.g. the preheating target temperature Tl.

In some embodiments, the same heater may provide the heating of both chambers 101, 201. In other embodiments an individual heater 102, 220 may be provided for each chamber 101, 201 as indicated in figs 3 and 4.

The average temperature of the glass sheets 3, 4 may, during the locally heating at time t3-t5, in embodiments of the present disclosure, at the edge sealing station 200 chamber 201, be maintained within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C or within ± 5 °C of the temperature that they 3, 4 had when entering the edge sealing station chamber 201. This may be provided by means of the glass sheet assembly heater 220.

In some embodiments, the average temperature of the glass sheets 3, 4 may, at the edge sealing station chamber 201, be maintained within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C or within ± 5 °C of a preheating target temperature Tl (see fig. 8). This may be provided by means of the glass sheet assembly heater 220.

In some embodiments of the present disclosure, the average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may be at least 20 °C lower, such as at least 50 °C lower, for example at least 60 °C lower or at least 70 °C lower, than the maximum heating temperature T3 of the solder material 7 while the local heating of the solder material 7 is provided at the station 200.

In some embodiments of the present disclosure, the average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may be between 20 °C and 150 °C lower, such as between 30 °C and 100 °C lower, for example between 40 °C and 80 °C lower, than the maximum heating temperature T3 of the solder material 7 while the local heating of the solder material 7 is provided at the station 200.

In some embodiments of the present disclosure, the average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may be at least 5% lower, such as at least 10% lower, for example at least 15% lower, than the maximum heating temperature T3 of the solder material while the local heating of the solder material 7 is provided at the station 200.

The average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may be determined by providing plurality, such as at least 50, at least 200 or at least 400 temperature measurements of the glass sheet temperature and based thereon determine an average temperature of the glass sheet temperature. The temperature measurement points may be substantially evenly distributed over the area of the major surface of the glass sheet.

In some embodiments of the present disclosure, the average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may be between 5% and 40% lower, such as between 10% and 30% lower, for example between 15% and 25% lower, than the maximum heating temperature T3 of the solder material while the local heating of the solder material 7 is provided at the station 200.

In certain embodiments of the present disclosure, the average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may be between 16% and 23% lower than the maximum heating temperature T3 of the solder material while the local heating of the solder material 7 is provided at the station 200.

The average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may in in embodiments of the present disclosure be at a temperature that is above the glass transition temperature Tg of the solder material if the solder material comprises a glass solder material 7.

If the solder material comprises a glass solder material, a preheating of the solder material 7 to a temperature above the glass transition temperature Tg of the glass solder material may e.g. help to reduce or avoid issues relating to stress buildup, such as stress buildup caused directly or indirectly by thermal expansion and/or shrinking.

The average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may in in embodiments of the present disclosure be at a temperature that is such as in the range of 5 to 20 °C, such as in the range of 8 to 16 °C, above the glass transition temperature Tg of the glass solder material 7 while the local heating of the solder material 7 is provided at the station 200.

The average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 may in in embodiments of the present disclosure be a temperature that is within ± 40 °C of the glass transition temperature Tg of the solder material 7, such as within ± 30°C of the glass transition temperature Tg of the solder material, such as within ±20 °C of the glass transition temperature of the solder material while the local heating of the solder material 7 is provided at the station 200.

It is generally understood that in embodiments of the present disclosure, the solder material 7, if comprising or being a solder glass material, may, during the local heating at the edge sealing station 200, be heated to a maximum temperature T3 in the range of 40 to 120 °C, preferably in the range of 60 to 100 °C, above the glass transition temperature Tg of the glass solder material , during the softening (at time period t3-t5) of the glass solder material at edge sealing station 200.

It is generally understood that in embodiments of the present disclosure, the solder material 7, such as a glass solder material, may be heated to a maximum target temperature T3 in the range of 350 to 420 °C, such as in the range of 370 to 410 °C, during the step of softening the solder material 7 (at time period t3-t5). When this temperature is reached, the local heating may be stopped, see t5. It is generally understood that in embodiments of the present disclosure, the solder material 7, such as a glass solder material, may be heated to a maximum target temperature T3 that is above 350 °C, such as above 360 °C, such as above 380 °C during the step of softening the solder material 7 (at time period t3-t5).

It is generally understood that in embodiments of the present disclosure, the solder material 7, such as a glass solder material, may be heated to a maximum target temperature T3 that is below 430 °C, such as below 410 °C, such as below 395 °C during the step of softening the solder material 7 (at time period t3-t5).

In some embodiments, the local heating may be stopped t5 when the solder material 7 has reached a max target temperature T3 that is within the range of Tm to Tm x 1.1, such as within Tm to Tm x 1.05 such as within the range of Tm to Tm x 1.02. Tm is the rated solder material melting tempereature. For example, at a Tm = 380 °C, the range Tm to Tm x 1.1 will be 380 to 380 x 1.1 = 380 to 418 °C.

In some embodiments, the local heating may be stopped t5 when the solder material 7 has reached a max target temperature T3 that is within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C of the melting temperature Tm of the solder material 7.

In some embodiments, the local heating may be stopped t5 when the solder material 7 has reached a max target temperature T3 that is within the range of the solder material 7 melting temperature Tm to Tm + 30 °C, such as within the range of Tm to Tm + 20 °C, such as within the range of Tm to Tm + 10 °C. For example, a range of Tm to Tm + 20 °C where Tm is 380 °C, will be a range within 380 °C to 400 °C.

It is generally understood that in some embodiments of the present disclosure, said locally heating may heat the glass solder material 7 to a temperature T2 and/or T3 that is above a melting temperature Tm of the solder material 7.

In some embodiments, the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 is initiated at time t4 after the solder material 7 has reached a temperature above the melting temperature Tm of the solder material. In some embodiments, the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 may be initiated at time t4 when the solder material 7 has reached (by means of the local heating) a temperature that is within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C of the melting temperature Tm of the solder material 7.

In some embodiments, the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 may be initiated at time t4 when the solder material 7 has reached a temperature that is at least 10 °C, such as at least 20 °C, such as at least 30 °C above the melting temperature Tm of the solder material 7.

In some embodiments, the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 may be initiated at time t4 when the solder material 7 has reached a temperature that is within the range of the solder material 7 melting temperature Tm to Tm + 30 °C, such as within the range of Tm to Tm + 20 °C, such as within the range of Tm to Tm + 10 °C.

It is generally understood that the melting temperature Tm of the solder material 7 may be a rated melting temperature or a rated melting temperature range of the solder material 7 which is defined by the manufacturer and/or supplier of the solder material 7.

In some embodiments, the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 may be initiated at time t4 when the solder material 7 has reached a temperature that is within the range of Tm to Tm x 1.1, such as within Tm to Tm x 1.05 such as within the range of

Tm to Tm x 1.02, where Tm is the rated solder material melting temperature. For example, at a Tm = 380 °C, the range Tm to Tm x 1.1 will be 380 to 380 x 1.1 = 380 to 418 °C

If the melting temperature Tm is a rated range, the pressure surrounding the glass sheet assembly 1 may be initiated at time t4 when the solder material 7 has reached a temperature that is within ± 30 °C of that melting temperature Tm range, such as within ± 20 °C of that melting temperature Tm range, such as within ± 10 °C of that melting temperature Tm range. If the melting temperature Tm is a rated range, the pressure surrounding the glass sheet assembly 1 may be initiated at time t4 when the solder material 7 has reached a temperature that is within the melting temperature Tm range.

The melting temperature Tm may preferably be below 450 °C, such as below 410 °C, such as below 400 °C or below 390 °C. This may e.g. be relevant in the case that the glass sheets 3, 4 are thermally tempered glass sheets.

The melting temperature Tm of the solder material and/or temperature T2 and/or temperature T3 may be above 350 °C, such as above 370 °C, such as above 380 °C. The local heating may provide that this temperature may be acceptable also in case that the glass sheets 3, 4 are thermally tempered glass sheets.

In some embodiments of the present disclosure, where the solder material 7 is a glass solder material, the providing of the pressure difference may be initiated t4 when the solder material 7 has reached a temperature Te, T2 in the range of 30 to 100 °C, preferably in the range of 40 to 80 °C, such as in the range of 40 to 70 °C above the glass transition temperature Tg of the glass solder material.

In some embodiments of the present disclosure, the providing of the pressure difference may be initiated t4 when the glass solder material 7 has reached a temperature Te, T2 in the range of 350 to 400 °C, such as in the range of 365 to 385 °C.

As can be seen from fig. 7, the providing of the pressure difference may in embodiments of the present disclosure be initiated when the solder material 7 has reached a temperature T2 that is above the temperature that the solder material had at the start t3 of the local heating, and which is below the maximum temperature T3 reached by the solder material 7 during the softening of the solder material 7 at the station 200. For example, in some embodiments of the present disclosure, the providing of the pressure difference at time t4 may be initiated when the solder material 7 has reached a temperature T2 in the range of 5 to 50 °C below, such as in the range of 10 to 30 °C below, for example in the range of 5 to 20 °C below, the maximum temperature T3 reached by the solder material 7 during the softening of the solder material at the edge sealing station 200. However, in other embodiments of the present disclosure (not illustrated) the providing of the pressure difference may in embodiments of the present disclosure be initiated when (t4) the solder material 7 has reached a temperature T2 that substantially corresponds to, or even is above, the final, maximum solder material target temperature T3.

The local heating provided at time period t3-t4 may be considered a first softening provided in order to soften the solder material 7 by bringing it to an elevated (predefined) temperature T2 prior to providing the pressure difference. The local heating provided at time period t4-t5 may be considered a further softening provided in order to heat and soften the solder material 7 in order to bring the solder material 7 to the final, desired maximum sealing temperature T3 while the pressure difference is provided. It is understood that the local heating of the solder material 7 may be continued uninterrupted when initiating the providing of pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 at time t4. Hence the first and further local heating at time periods t3-t4 and t4-t5 (i.e. t3-t5) may be considered a continuous heating and softening step of the solder material 7 with an intermediate solder material temperature Te drop at/near time t4 when the providing of the pressure difference is initiated, where the temperature drop is caused by a lower average temperature of the glass sheets 3, 4 when compared to the temperature of the locally heated solder material 7.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 may be provided for a time period (see time period t3- t5) that is less than 10 minutes, such as less than five minutes, before the local heating is stopped t5.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 is provided for a time period t3-t5 that is less than 5 minutes, such as less than 2 minutes, such as less than 100 seconds, before the local heating is stopped t5.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 and providing the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly may be provided for a time period (see t4-t5) that is less than 5 minutes, such as less than two minutes, such as less than 70 seconds before the local heating is stopped and/or before the pressure difference between the pressure in the gap and the pressure surrounding the glass sheet assembly is eliminated.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 and providing the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly may be provided for a time period (see t4-t5) that is larger than 5 seconds, such as larger than 10 seconds, such as larger than 30 seconds, before the local heating is stopped.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 while also providing the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly may be provided for a time period (see t4-t5) that is between 5 seconds and 5 minutes, such as between 10 seconds and 2 minutes, for example between 30 seconds and 120 seconds or between 30 seconds and 70 seconds, before the local heating is stopped at t5.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 and providing the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly may be provided for a time period (see t4-t5) that is less than 150 seconds, such as less than 100 seconds, such as less than 80 seconds, before the local heating is stopped.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material may be provided for a time period (see time period t3-t5) that is less than 5 minutes, such as less than 3 minutes, such as less than 2 minutes, for example less than 100 seconds, before the local heating is stopped (t5).

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material may be provided for a time period (see time period t3-t5) that is less than 6 minutes, such as less than 3 minutes, such as less than 2 minutes, for example less than 100 seconds, before the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly 1 is eliminated.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material may be provided for a time period (see time period t3-t5) that is larger than 10 seconds, such as larger than 30 seconds, for example larger than 60 seconds.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material (t3-t5) may be provided for a time period (see time period t3-t5) that is within 10 to 130 seconds, such as within 30 to 100 seconds for example within 40 seconds to 90 seconds.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 prior to providing the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly may be provided for a time period (see t3-t4) of at least 5 seconds such as at least 10 seconds, for example at least 30 seconds before the providing of the pressure difference is initiated.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 prior to providing the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly may be provided for a time period (see t3-t4) of less than 3 minutes such as less than 100 seconds, such as less than 80 seconds before the providing of the pressure difference is initiated.

In some embodiments of the present disclosure, the softening of the solder material 7 by locally heating the solder material 7 prior to providing the pressure difference between the pressure in the gap 5 and the pressure surrounding the glass sheet assembly may be provided for a time period (see t3-t4) of between 5 seconds and 2 minutes, such as between 10 seconds and one minute, such as between 20 seconds and 40 seconds before the providing of the pressure difference is initiated. The local heating provided during t3-t5 provides that the solder material 7 may heat a small area of the glass sheets 3, 4 by conduction heating to a temperature at or close to T2 and T3. If the glass sheets 3, 4 are thermally tempered glass sheets, a de-tempering of the glass sheets due to elevated temperature T2, T3 may however be limited or even avoided since the heating is provided only locally at a desired area at one glass sheet side opposite to and/or in touch with the solder material 7.

In some embodiments of the present disclosure, it is understood that the heating power over substantially the entire solder material width W 1 provided by the heating beam(s) 9 may be changed, such as increased or decreased, during the heating of the solder material strip(s) 7. This may for example be provided before or after, or substantially when, a force clamping is initiated (see t4 of figs 7-8).

In further embodiments of the present disclosure, it is understood that the heating power over substantially the entire solder material width W 1 provided by the heating beam(s) 9 may be reduced towards the end of the heating of the solder material, e.g. at the last 20% of the time span between t4 and t5 during the heating of the solder material strip 7 by the one or more heating beams 9.

In some embodiments of the present disclosure, it is understood that the heating power over substantially the entire solder material width W 1 provided by the heating beam(s) 9 may be maintained substantially constant during the entire heating (see e.g. t3-4 and/or t4-t5 illustrated in figs. 7-8) of the solder material 7 by one or more laser light beams. In other embodiments, the heating power may be adjusted in the width W 1 direction of the solder material during the local heating by the one or more heating beams. Embodiments hereof are described in more details below, e.g. in relation to one or more of figs. 17a-20.

Fig. 7 illustrates a further embodiment of the present disclosure, where the elimination of the pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly 20 is provided at a time t6 after the locally heating of the solder material 7 is stopped t5. In the time between t5 and t6, the solder material 7 is cooled. This cooling may partly, primarily or substantially fully be obtained by means of the glass sheets 3, 4 by conduction cooling, as these have a lower average temperature (such as about a preheating temperature Tl, see fig. 8) than the locally heated solder material 7. This cooling may happen relatively fast, see the temperature drop of the solder material 7 temperature Te at the first third, or first half, of the time period between t5-t6. The cooling of the solder material 7 may provide that the solder material 7 at least partly hardens/gets less fluid due to cooling before the pressure difference is eliminated at t6. The cooling in the time interval t5- t6 may help to provide that a shape and/or size of the solder material 7 that is obtained during providing the pressure difference and locally heating the solder material 7 in time period t3-t5 may be at least partly or substantially fully maintained after the pressure difference is eliminated at t6. Additionally or alternatively, a “pre-tensioning” of the solder material 7 and/or glass sheets at and/or near the solder material 7, which may be obtained pr facilitated while the pressure difference and local heating is provided in time period t3-t5, may be at least partly, or substantially fully maintained after the pressure difference is released/eliminated.

In some embodiments of the present disclosure, the elimination of the pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly 20 is provided (t6) at least 2 seconds, such as at least five seconds, such as at least 10 seconds after the locally heating of the solder material 7 is stopped at time t5.

In some embodiments of the present disclosure, the elimination of the pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly 20 is provided (t6) at least 30 seconds, such as at least one minute after the locally heating of the solder material 7 is stopped at time t5.

In some embodiments of the present disclosure, the elimination of the pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly 20 may be provided (t6) at the latest five minutes after, such as at the latest three minutes after, such as at the latest one minute after, said locally heating of the solder material 7 is stopped (t5).

For example, in some embodiments of the present disclosure, the time period t5-t6 between the time t5 of stopping the locally heating of the solder material 7, and the time t6 of eliminating the pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly 20, may be between 2 seconds and 10 minutes, such as between 5 seconds to 5 minutes, for example within 10 seconds to 100 seconds. However, in other embodiments of the present disclosure, the elimination of the pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly 20 may be provided substantially at the same time as the locally heating of the solder material 7 is stopped t5.

Fig. 8 illustrates schematically an embodiment of the present disclosure wherein a preheating of a glass sheet assembly 1 is provided. It is understood that the process illustrated at time t2- t5 may substantially correspond to what is described above in relation to various embodiments of fig. 7. Fig. 8 illustrates the temperature Te of the solder material 7 during processing of the glass sheet assembly 1, including preheating.

At time tl, a preheating of the entire glass sheet assembly 1 is started in a preheating station 100 as e.g. described previously. At time tO the glass sheet assembly may have a temperature TO between 0 and 100 °C, for example between 10 and 50 °C, such as between 15 and 35 °C. The preheating may be provided by means of convection heating and/or conduction heating in the chamber 101. The gap 5 may be sealed or unsealed during the preheating. The preheating causes the temperature of the entire glass unit assembly 1, and hence also the solder material 7 temperature Te, to increase in the time period 11 -t2. At time t2, the glass sheet assembly 1 has reached a preheating target temperature Tl.

Also, it can be seen that during preheating (time tl -t2 in fig. 8) of the glass sheet assembly 1 at station 100, the increase in solder material temperature Te per time unit may reduce as the solder material temperature Te gets closer to the target preheating temperature Tl at time t2. This may e.g. be caused by that the temperature difference between the preheating target temperature (e.g. a temperature setting) Tl and the solder material temperature Te gradually reduces due to the preheating of the solder material 7 over time period 11 -t2.

In the embodiment illustrated in fig. 8, the solder material 7 is a glass solder material, and the preheating target temperature Tl is a temperature, such as a predefined temperature, set to a temperature above the glass transition temperature Tg of the solder material 7. This may e.g. help to reduce or avoid issues relating to stress buildup, such as stress buildup caused directly or indirectly by thermal expansion and/or shrinking. In other embodiments of the present disclosure, the preheating target temperature T1 may be a temperature, such as a predefined temperature, set to a temperature below a glass transition temperature Tg of the solder material 7.

The average temperature of the glass sheets 3, 4 of the glass sheet assembly 1 at T1 may in in embodiments of the present disclosure be a temperature that is in the range of 5 to 20 °C, such as in the range of 8 to 16 °C, above the glass transition temperature Tg of glass solder material 7.

It is generally understood that the glass transition temperature Tg may be a rated glass transition temperature of the glass solder material 7 which may be defined by the manufacturer and/or supplier of the glass solder material.

In some embodiments of the present disclosure, the glass sheet assembly 1 may be heated in the preheating station 100 in the time period 11 -t2 to a temperature in the range of 5-40 °C, such as in the range of 5 to 20 °C, preferably in the range of 8 to 16 °C above the glass transition temperature Tg of the glass solder material 7. This may be determined depending on the softening properties of the solder material 7.

In some embodiments of the present disclosure, the glass sheet assembly 1 may be heated in the preheating station 100 to a temperature T1 above 260 °C, such as above 280 °C, such as above 300 °C. This may be determined depending on e.g. the softening properties of the solder material 7.

In some embodiments of the present disclosure, the glass sheet assembly 1 may be heated in the preheating station 100 to a temperature T1 above 315 °C, such as above 330 °C.

In some embodiments of the present disclosure, the glass sheet assembly 1 may be heated in the preheating station 100 to a temperature T1 in the range of 260 to 350 °C, such as in the range of 280 to 330 °C, such as in the range of 300 to 330 °C. This may be determined depending on e.g. the softening properties of the solder material 7. In some embodiments of the present disclosure, the glass sheet assembly 1 may be heated in the preheating station 100 to a temperature T1 in the range of 260 to 330 °C, such as in the range of 270 to 300 °C.

In some embodiments of the present disclosure, if the glass sheets 3, 4 of the assembly 1 are thermally tempered glass sheets, the preheating target temperature T1 may be set to a temperature that reduces or substantially avoids de-tempering of the glass sheets 3, 4 due to the preheating.

In some embodiments, the preheating target temperature T1 may be within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C or within ± 5 °C of the glass transition temperature Tg of the solder material 7.

In some embodiments of the present disclosure, the preheating target temperature T1 may be within the range of Tg to Tg X 1.2, such as within Tg to Tg X 1.15, such as within the range of Tg to Tg x 1.1, where Tg is a rated solder material 7 glass transition tempereature Tg. For example, at a Tg = 308 °C, the range Tg to Tg x 1.1 will be 308 to 308 x 1.1 = 308 to 339 °C.

In certain embodiments of the present disclosure, the preheating target temperature T1 may be within the range of Tg to Tg x 1.1, such as within Tg to Tg x l.05 such as within the range of Tg to Tg x 1.02.

In some embodiments of the present disclosure, if the glass sheets 3, 4 of the assembly 1 are thermally tempered glass sheets, the preheating target temperature T1 (and also e.g. temperature at the edge sealing station chamber 201 controlled by means of a heater 220, see e.g. figs. 3-4) may be set to a temperature that provides that a de-tempering of the glass sheets 3, 4 of the assembly 20, after the edge sealing at the edge sealing station 200, is less than 20%, such less than 10%, or less than 3% when compared to the initial tempering strength of the glass sheets before preheating of the glass sheet assembly 1 and the local heating at the edge sealing station 200.

At time t2, the desired preheating target temperature T1 is reached, and in the time period t2- t3, the preheated glass sheet assembly 1 may await being moved into the edge sealing station 200 and/or may be moved into the edge sealing station 200. Glass sheet assembly 1 temperature, and hence the solder material temperature, is maintained substantially constant in time period t2-t3 at the preheating station. In some embodiments, the time period t2-t3 may be low, but this may depend om various factors such as the type of moving system, whether a “buffer” of preheated glass sheet assemblies 1 ready to be subjected to the processing in the edge sealing station may be desired, whether a “temperature soaking” at the preheating station is desired to obtain some advantages by assuring that the glass sheet assembly has been kept at a desired preheating temperature for some time and/or the like. In some embodiments, the time period t2-t3 may be optional and thus omitted.

The processing of the glass sheet assembly is then continued at the edge sealing station at time t3 as e.g. described according to various embodiments of the present disclosure in relation to fig. 7.

It is generally understood that in one or more embodiments of the present disclosure, if the solder material 7 of the glass sheet assembly 1 is or comprises a glass solder frit material, it may comprise glass powder, a binder material such as an organic binder material, and a filler material such as one or more inorganic fillers. In some embodiments, a solvent material may have been removed, e.g. by means of heating, during manufacturing of the glass sheet assembly 1 in order to obtain the solder material of the glass sheet assembly 1. Hence, the solder material 7 of the assembly 1 may be substantially free from solvent prior to processing at e.g. the preheating station 100.

It is generally understood that in one or more embodiments of the present disclosure, if the solder material 7 comprises a glass solder material 7, binder material may be present in the solder material 7 strips of the glass sheet assembly 1. In some embodiments, at the time period 11 -t3 , such as t2-t3, the preheating at the preheating target temperature T1 may provide binder bum out / binder removal from the solder material 7. Hence, already when the glass sheet assembly is placed at the edge sealing station 200 and/or when the local heating of the solder material 7 of the glass sheet assembly 1 by means of one or more heating beams is initiated (time t3 - see fig. 7 or 8) at the edge sealing station 200, only a low amount of binder material, or substantially no binder material, may be present in the solder material 7. In some embodiments, the binder material may comprise or consist of a polymer. One example of a binder material may be propylene carbonate (C4H6O3). For example, some binder material types may start to degenerate or in other ways be removed from the solder material 7 when heated to a temperature above 150 °C, such as above 200 °C. Hence, the preheating target temperature Tl, or even a lower heating temperature, may be sufficient to provide sufficient and efficient binder burnout if binder is present in the solder material.

In some embodiments, the time period 11 -t3 may be in the range of 10 minutes to 90 minutes, such as in in the range of 15 minutes to 70 minutes or in the range of 20 minutes to 50 minutes.

In some embodiments, the time period t2-t3 may be in the range of 5 minutes to 40 minutes, such as in in the range of 10 minutes to 35 minutes or in the range of 15 minutes to 30 minutes. At time T2 to t3, the preheating target temperature Tl is maintained, and the glass sheet assembly/ies is/are maintained at the elevated temperature Tl at the preheating station.

It is generally to be understood that the actions that are initiated at one or more of times tl, t2, t3, t4 and t5 may be controlled based on sensor input and/or based on timer input.

For example, the preheating time from 11 -t2 may be a predefined time interval that is based on experiential data of how long time the preheating takes. Alternatively or additionally, a monitoring system comprising one or more sensors such as temperature sensors may monitor the preheating temperature of the glass sheet assemblies and based thereon determine when an assembly 1 is sufficiently preheated.

The local heating time from t3-t4 may be a predefined time interval that is based on experiential data of how long time the initial local heating of the solder material, by means of one or more beams, takes before the solder material is soft enough to allow providing the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 in the edge sealing chamber 201.

Alternatively or additionally, a monitoring system comprising one or more sensors such as temperature sensors may monitor the temperature of the solder material at one or lore locations of the solder material around glass sheet assembly and based thereon a controller may determine when to provide the pressure difference at time t4. The local heating time from t4-t5 may be a predefined time interval that is based on experiential data of how long time the local heating of the solder material takes after the pressure difference is provided before the solder material has reached the desired maximum temperature T3. Alternatively or additionally, a monitoring system comprising one or more sensors such as temperature sensors may monitor the temperature of the solder material at one or lore locations of the solder material around glass sheet assembly and based thereon a controller may determine when to stop the local heating provided by heater(s) 15.

The time period from t5-t6 may be a predefined time interval that is based on experiential data of how long time a sufficient solder material cooling takes. Alternatively or additionally, a monitoring system comprising one or more sensors such as temperature sensors may monitor the temperature of the solder material at one or lore locations of the solder material around glass sheet assembly and based thereon a controller may determine when to eliminate the pressure difference.

Fig. 9 illustrates a flowchart relating to a method of processing a glass sheet assembly 1, 20 for a vacuum insulated glass VIG unit, according to embodiments of the present disclosure.

At step S91 (Preheat ass. to Tl), the glass sheet assembly 1 is preheated at a preheating station, see e.g. station 100 in figs. 3 and 4 and/or time range tl-t3 of fig. 8.

When the glass sheet assembly 1 has been preheated to a uniform preheating target temperature Tl at the preheating station, the glass sheet assembly 1 is removed at step S92 (Pos. ass. At ESS) from the preheating station and positioned in an edge sealing station 200 chamber 201. See e.g. fig. 3 and 4. Also, binder, such as a polymer, (if present in the solder material) may be partly or fully removed/bumed out during the preheating step SI as e.g. previously described. In other embodiments, binder material, such as a polymer, if present in the solder material 7, may have been partly or fully removed, such as burned out, from the solder material 7 prior to the preheating step.

Then, at step S93 (Heat ES by laser), the local heating of the solder material 7 is started (see time t3 of figs. 7-8). This may be provided by means of e.g. one or more laser beams 9 and may comprise a plurality of heating iterations by one or more laser beams as e.g. described in more details below. When a desired, local, substantially uniform, solder material 7 temperature is reached, e.g. a temperature T2 (or T3 if T2=T3) as described above, the temporary pressure difference is provided - Step S94 (Prov. Press, diff.) - at the edge sealing station, see time t4 in figs. 7 and 8. This may be provided by means of an over pressure in the edge sealing chamber 201 or by means of evacuating the glass assembly 1 gap 5. The local heating solder material 7 heating started at step S93 is continued until a desired solder material target temperature T3, such as a maximum temperature, is reached.

When the desired solder material target temperature T3, such as a maximum solder material temperature, has been reached, the local heating is stopped at step S95 (Stop heating at target, temp. (T3)). This causes the solder material to cool, e.g. by conduction cooling by means of the glass sheets. After this, when the solder material is sufficiently cooled, the pressure difference is eliminated at Step S96 (Elim. Press, diff), and in step S97 (Pos. ass. at evac. stat.), the edge sealed glass sheet assembly 20 is positioned at the evacuation station.

At the evacuation station, the gap 5 of the edge sealed assembly 20 is evacuated (Step S98 - Evac. ass.) to a pressure below 0.05 mbar, such as below 0.005 mbar, such as below 0.003 mbar or below 0.001 mbar, and then the gap is sealed at Step S99 (Seal gap of ass.), hereby a VIG unit 30 is obtained. The VIG unit 30 is then removed from the evacuation station 300 and cooled at step S910 (Cool VIG), e.g. by means of convection cooling. Some VIG unit cooling may also be allowed at the evacuation station 300 before moving the VIG unit from the evacuation station 300.

In some embodiments, the temperature in the evacuation station 300 chamber may be maintained, e.g. by convection heating, at a temperature above 200 °C, such as above 250 °C while the gap evacuation and sealing is provided at Step S98-S99.

In some embodiments, the temperature in the evacuation station 300 chamber 301 may be maintained, e.g. by convection heating, at a temperature between 100 °C, and 300 °C, such as at a temperature between 150 °C, and 250 °C, such as at a temperature between 190°C, and 240°C while the gap evacuation and sealing is provided at step S98-S99. In some embodiments, the temperature in the evacuation station 300 chamber may in in embodiments of the present disclosure be a temperature that is below the glass transition temperature Tg of the solder material 7 while the gap evacuation and sealing is provided at Step S98-S99.

In some embodiments, the temperature in the evacuation station 300 chamber may in in embodiments of the present disclosure be a temperature that is at or above the glass transition temperature Tg of the solder material 7 while the gap evacuation and sealing is provided at Step S98-S99.

In some embodiments where the solder material 7 is a glass solder material, the temperature in the evacuation station 300 chamber 301 may be a temperature that is larger than 100 °C, such as larger than 150 °C, for example larger than 200 °C or larger than 250 °C, but lower than the glass transition temperature Tg of the solder material, while the gap 5 evacuation and sealing is provided at Step S98-S99.

Figs. 10-14 illustrates schematically and in perspective, the softening of the solder material 7 in the edge sealing station, by means of local heating by one or more heaters 15- 15_4, according to various embodiments of the present disclosure. In the figures 10-13 the local heating is provided by one or more heating beams 9, 9 1, 9_2, 9_3, 9_4, such as laser light beams, according to various embodiments of the present disclosure.

The glass sheet assembly 1 is designed and arranged so that the heating beam 9, 9 1, 9_2, 9_3, 9_4 is transmitted through the major glass sheet 4 surface 4b of the glass sheet 4 of the assembly 1 that is arranged between the heater providing the heating beam and the solder material 7, so as to heat the solder material 7. See also fig. 6.

The solder material 7 is provided in four elongated solder material stripes/strips each having a longitudinal direction LDS that may be substantially parallel to the longitudinal extend of a proximate edge of the glass sheets 3, 4.

The glass sheet assembly 1 solder material 7 comprises:

• a first solder material strip A-B with length L_AB extending between the first solder material comer region A and the second solder material comer region B, • a second solder material strip B-C with length L_BC extending between the second solder material comer region B and a third solder material comer region C,

• a third solder material strip C-D with length L CD extending between the third solder material comer region C and a fourth solder material comer region D, and

• a fourth solder material strip D-A with length L_DA extending between the fourth solder material comer region D and the first solder material comer region A.

The solder material strips A-B and C-D are parallel. The solder material strips B-C and D-A are parallel. The solder material strips A-B and C-D extend in a longitudinal direction LDS that is substantially perpendicular to the longitudinal direction LDS of the solder material strips B-C and D-A.

Length L_BC and L_DA of the solder material strips B-C and D-A may be substantially the same. Additionally, the length L AB and L CD of the solder material strips A-B and C-D may be substantially the same. The length L AB and L CD of the solder material strips A-B and C-D may be smaller or larger than the length L_BC and L_DA of the solder material strips B-C and D-A. In some embodiments, all strips A-B, B-C, C-D, D-A may have substantially the same length. This may e.g. depend on the shape of the glass sheets.

Each of the solder material comer regions A, B, C, D may be arranged substantially at, near and/or opposite to a comer of one or both glass sheets 3, 4 proximate the respective solder material comer regions A, B, C, D.

The heater 15, 15 1, 15_2, 15_3, 15 4 illustrated in the figures 10-13 may comprise one or more movable mirrors that is/are controlled by a mirror controller according to a predefined control scheme (e.g. stored as software in a data storage) to be moved so as to direct a heating beam 9, 9 1, 9_2, 9_3, 9_4, such as a laser beam, towards the solder material strips A-B, B-C, C-D and D-E.

In fig. 10, a single laser beam 9 is moved consecutively along the solder material strips between the solder material comers from comers A-B, B-C, C-D and D to A in a plurality of heating iterations in order to locally and uniformly heat and soften the solder material 7. E.g. in order to obtain the temperature T2 and/or T3 as previously described in relation to one or more of figs. 6-9. In fig. 11, two laser beams 9 1, 9_2 may be moved consecutively along the solder material strips from comers A-B, B-C, C-D and D to A in a plurality of heating iterations in order to locally and uniformly heat and soften the solder material 7. E.g. in order to obtain the temperature T2 and/or T3 as previously described in relation to one or more of figs. 6-9. In this embodiment of fig. 11, the laser beam spots of beams 9 1, 9_2 that heat the solder material 7 may be spaced apart. In some embodiments, the laser beam 9 1, 9_2 spots that heats the solder material 7 may e.g. as illustrated in the embodiment of fig. 10, be spaced apart with a distance corresponding to half of the full, summarized length/extent

^solder = L_AB + L_BC + L_CD + L_DA of the solder material strips A-B, B-C, C-D, D-E.

In other embodiments, the local heating of the solder material by each beam 9 1, 9 2 may be divided between the beams (see also e.g. ARI and AR2) so that one of the beams heat a first longitudinal extent of the solder material 7 whereas the other beam heat another longitudinal extent of the solder material 7. The two beams 9 1, 9_2 may here hence together heat the total extent 2 L_soider of the solder material 7 with no or only partly overlap in heating areas of the solder material. For example, one heater 15 1 beam 9 1 may heat solder material strip A-B and B-C whereas the other heater 15 2 beam 9 2 heat solder material strip C-D and C-A. The transition between the heating areas may naturally be adapted as desired according to what may e.g. be considered beneficial in relation to e.g. the properties of the heaters, mirror(s) and/or different conditions at the edge sealing station 200. Moreover, the lengthwise coverage of the beams 9 1, 9_2, respectively along the solder material length S L_Soider may be adjusted to be equally long or so that one may be longer than the other.

If for example two laser light beams heat the solder material 7 (e.g. as in fig. 11), and each heat the full extent of the solder material, i.e. so that each of the laser light beams are moved to heat the full extent of the solder material stripes/strips A-B, B-C, C-D and D-A, then the same area of the solder material has been subjected to two heating iterations when both laser light beam spots have travelled around/swept the full extent L_AB + L_ BC + L_CD + L_DA of the solder material 7. On the other hand, if one of the beams 9 1, 9 2 heat a first part of the extent of the solder material, whereas the other beam heat the remaining part of the extent of the solder material 7, then it may be considered as one heating iteration when the total extent of the solder material has been heated by a laser beam spot. In fig. 12, four heaters 15 1, 15_2, 15_3, 15 4 are provided so that four heating beams 9 1, 9_2, 9_3, 9_4 together heat the solder material 7. In some embodiments these may be moved along the solder material in the same direction so that each heat the total length L_soider of the solder material, as indicated by arrows in the figure.

In other embodiments, the beams may be controlled so that each of the beams 9 1, 9_2, 9_3, 9 4 is moved along one solder material stripe A-B, B-C, C-D, D-A and only heat that stripe. Again, this heating may naturally be divided so that e.g. one, more than one, or all, of the beams provide heating also at the solder material comers where the transition between the solder material strips is provided and may heat both stripes/strips terminating at the respective solder material comer. In this case, when the full length of all solder material stripes have been subjected one time to a laser light spot, this may be considered a heating iteration.

Figs. 13 and 14 illustrates schematically and in perspective an embodiment of the present disclosure wherein two laser light beams 9 1, 9_2 are used in order to heat the full extent of the solder material. In this embodiment, the temporary pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 in the edge sealing chamber 201, is provided by evacuating the gap 5 of the glass sheet assembly.

A suction cup 40 is used for this and is in fluid communication with one or more evacuation pumps 8 by means of a piping connection 40a. See also figs. 3 and 4.

The evacuation outlet 6 for evacuating the gap 5 in the glass sheet assembly 1 may thus be provided by means of a through hole in a glass sheet, such as an upper glass sheet 4 of the glass sheet assembly 1. The evacuation cup 40 support directly or indirectly on the surface 4a of this glass sheet 4 to provide an airtight seal, and a gasket may hence be placed between the glass sheet assembly 1 and the cup 41 body.

The evacuation cup 40, the suction connection 40a, such as a piping, and the evacuation pump 8 together provides a clamping arrangement 40, 8, 40a which is configured to provide a force clamping of the glass sheet assembly 1 to provide that the glass sheets 3, 4 clamp the heated and softened solder material 7. E.g. at time t4 as described above in relation to e.g. fig. 7 and/or 8.

The evacuation cup 40 is arranged on an upper, outer, major side surface 4b of the glass sheet assembly. An inner cavity of the evacuation cup 40 is in fluid communication with the gap 5 by means of an evacuation opening 6 (see figs 1 and 2) through the second glass sheet 4. The inner cavity 42 of the evacuation cup is in fluid communication with the suction connection 40a.

In some embodiments of the present disclosure, at least the suction connection 40a, such as a piping, and possibly also the suction cup 40 dependent on cup size and/or evacuation opening 6 location, may act as an obstacle that prevents at least one of the laser light beams from heating the full extent L AB + L_BC + L CD + L_DA of the solder material 7.

Hence, the piping system 40a, cup 40 and/or other parts in the chamber 201 may provide an obstacle providing a shadow effect/area SA covering the solder material where one of the laser light beams, in this case beam 9 1, cannot locally heat the solder material 7. This is the case in fig. 13 and 14 where the piping 40a provides that the heater / means for providing a laser beam 15 1 cannot direct a beam 9 1 towards the shadow area SA of the solder material 7. Therefore the heating of the full extent of the solder material 7 may be divided between two heaters 15 1 , 15 2 as e.g. illustrated in figs. 13 and 14. Here, a first heater 15 1 provides a first beam 9 1 which heats a first area ARI of the solder material 7, whereas a further/other heater 1 2 provides a second beam 9_2 which heats a second area SA, AR2 of the solder material 7. The second area may hence comprise the part of the solder material 7 that is prevented from being heated by a first beam 9 1 from the heater 15 1.

The heaters 15 1 , 15 2 may be displaced in order to emit heating beams 9 1, 9_2 from different locations and/or angles at the station and towards the solder material of the glass sheet assembly 1.

It is generally understood that in some embodiments, laser light generated by a laser light source may be split by a beam splitter to:

• a first laser beam steering mirror which provides a first heating beam 9 1, and

• to a further laser beam steering mirror which provides a second heating beam 9_2. In that case, the laser beam steering mirrors may be considered (part of) different heaters even though the laser light source from which the laser light energy originates is the same.

It is generally understood that in other embodiments, a first laser light source may be dedicated for generating laser light to a first laser beam steering mirror which provides/directs a first beam 9 1, and a second laser light source may be dedicated for generating laser light to a second laser beam steering mirror which provides/directs a second beam 9_2. Hence different laser sources may be considered part of different heaters.

It is generally understood that in some embodiments of the present disclosure, each time a laser light beam spot visits or revisit the same part of the solder material 7 to heat it, this may be considered a new heating iteration.

Common to the various embodiments illustrated in figs. 10-14 may, in some embodiments of the present disclosure , be that the solder material 7 is softened by moving one or more laser light beams 9, 9 1, 9 2, 9 3, 9 4 along the longitudinal extent L AB, L_ BC, L CD, L_DA of the solder material 7 in a lengthwise direction of the solder material 7 at a speed sufficient to provide a uniform heating and thereby softening of the solder material 7 along the full extent L_AB + L_ BC, + L_CD + L_DA of the solder material 7 of the glass sheet assembly 1. This may be provided prior to and/or during providing the clamping/force clamping of the solder material 7 by means of the glass sheets 3, 4.

In some embodiments, the force clamping may be provided by providing a pressure difference between a pressure P2 in the glass assembly 1 gap 5 and the pressure Pl surrounding the glass sheet assembly 1 so as to force the first glass sheet 3 and the second glass sheet 4 towards each other. E.g. as explained above according to various embodiments of the present disclosure. In other embodiments of the present disclosure, the force clamping may be obtained by means of a mechanical clamping (see e.g. fig. 16). For example, in some embodiments, the mechanical clamping may comprise using one or more actuators for forcing a pressing member towards a major surface 4b of the glass sheet assembly in order to provide the force clamping. Hence, the force from the one or more actuators is transmitted through the glass sheet(s) and provides a clamping, and e.g. also deformation, of the heated and softened solder material 7. Fig. 14 moreover illustrates an embodiment of the present disclosure where the solder material 7 is divided into two different heating areas ARI, AR2. The first heating area ARI may be heated by a beam 9 1 from the first heater 15 1 , such as comprising first laser beam steering mirror, and the second heating area AR2 may be heated by a beam 9_2 from the second heater 15_2, such as comprising a second laser beam steering mirror. In fig. 14, the areas ARI, AR2 does substantially not overlap. In other embodiments, the areas ARI, AR2 may partly overlap.

The first area ARI covers a minor portion of the solder material strip length L AB (See fig. 10), over comer area B, extends along the entire solder material strip length L_BC, over comer area C and covers a major part of the length of the strip length L CD. The second area AR2 covers a minor portion of the solder material strip length L_CD, extends over comer area D, extends along the entire solder material strip length L_DA, extends over comer A and covers a major part of the length of the solder material strip length L A-B. Naturally, in other embodiments, the solder material 7 may be divided in other ways and even between even more heaters, see e.g. fig. 12.

In some embodiments, the solder material 7 at the heating areas ARI, AR2 may be heated simultaneously by different beams 9 1, 9_2.

In other embodiments, the solder material at the heating areas ARI, AR2 may be heated consecutively by different beams 9 1, 9_2 during a heating iteration. In this case, only one beam 9 1, 9_2 may be present (heat) at the time, and the other beam may be off or the like. For example, the beam 9_2 may heat the solder material 7 at the strip C-D, over the comer area D and towards the comer area A, over the comer area A and to the termination where the first area ARI starts (unless an overlap is provided). Then beam 9_2 is turned off and the solder material 7 at the area ARI may then be started to be heated by the beam 9 1 at the solder material 7 at heating area ARI at strip A-B, over comer area B and towards the comer area C, over the comer area C and to the termination where the second heating area AR2 starts again. Then the beam 9 1 may be turned off, and the second beam 9 2 may be turned on again and so on.

In some embodiments, the shift between beams 9 1, 9 2 may be provided by turning on and off different respective laser light sources dedicated for heating the solder material 7 at the respective area ARI, AR2. In other embodiments, a shifter may shift, such as direct, laser light from the same laser light source between the different heaters 15 1, 15_2, such as between different emitters, such as between different mirrors, for example by means of an optical arrangement comprising one or more lenses, mirrors and/or the like. Hence, in this case, the laser light source may be maintained on/active, possibly, in some embodiments, with a short “off time” or “idle time” during a shift between heaters 15 1, 15_2. However, in this embodiment, it may be the same laser light source for both heaters 15 1, 15_2 that is be used for generating laser light for heating the solder material 7 at both areas ARI, AR2.

It is generally understood that the solder material 7, during the step of locally heating and softening the solder material, may in embodiments of the present disclosure be heated by the one or more beams 9, 9_1, 9_2, 9_3, 9_4 so that the temperature difference between any two positions of the solder material along the full extent L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly does not exceed 2°C, such as does not exceed 0.5 °C such as does not exceed 0.2 °C. This may e.g. in some embodiments of the present disclosure be provided during the time period t3-t5, during the time period t3-t4 and/or during the time period t4-t5 as illustrated, and/or described above, e.g. in relation to one or more of figs. 7, 8 and/or 9.

It is generally understood that the solder material 7, during the step of locally heating and softening the solder material, may in embodiments of the present disclosure be heated by the one or more heating beams 9, 9_1, 9_2, 9_3, 9_4 so that the temperature difference between any two positions of the solder material 7 along the full extent L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly does not exceed 2°C, such as does not exceed 0.5 °C such as does not exceed 0.2 °C during at least 40%, such as during at least at least 70%, such as during at least 95%, of the total heating time (t3-t5) by means of the one or more heating beams 9, 9_1, 9_2, 9_3, 9_4.

The temperature difference between any two positions of the solder material along the full extent L_AB + L_ BC, + L_CD + L_DA of the solder material 7 of the glass sheet assembly 1 may be determined by the movement speed of the laser light beam(s). If the laser light beams are moved slowly, the temperature difference will be larger as the temperature difference to a large extend is determined by the heating of the solder material 7 by each heating iteration of the laser beam(s), i.e. each passage of each position of the solder material 7.

During the step of softening the solder material 7 at the edge sealing station, the solder material 7 may be heated by the one or more beams 9, 9 1, 9_2, 9_3, 9_4 so that the temperature difference between any two positions of the solder material along the full extent L_AB + L_ BC, + L_CD + L_DA of the solder material 7 of the glass sheet assembly does not exceed 2°C, such as does not exceed 0.5 °C such as does not exceed 0.2 °C. during at least 30%, such as at least 60%, such as at least 90% of the heating by means of the one or more laser light beams.

This relatively low temperature difference may e.g. be obtained by a fast movement speed of the laser light beams and/or by using a plurality of laser light beams.

In some embodiments of the present disclosure, the temperature of the solder material (7) during the step of softening the solder material 7 may be increased by the one or more laser light beams by at least 30 °C such as at least 50 °C in less than 180 seconds, such as less than 120 seconds such as less than 100 seconds. In some embodiments, the heating by means of the one or more beams 9, 9 1, 9_2, 9_3, 9_4 according to the various embodiments of figs. 10-13 may provide a local solder material 7 heating according to one or more embodiments described above in relation to one or more of figs. 7-9, such as a local heating as described in relation to the time period(s) t3-t5, t3-t4 and/or t4-t5 described above according to various embodiments of the present disclosure.

It is generally understood that if one 9 laser light beam (see fig. 10) or more than one 9 1, 9_2, 9_3 laser light beam laser light beam (see e.g. figs. 11, 12 and/or 13) is used for locally heating the solder material 7 so as to heat the solder material, one or more of:

• the power of the respective laser light beam 9 1 and/or 9_2,

• movement speed of the respective laser light beam 9 1 and/or 9_2

• on/off times of the respective laser light beam 9 1 and/or 9_2 may be adapted in order to assure substantially uniform heating of the total/full extent . ^solder = L_AB + L_BC + L_CD + L_DA of the solder material 7 enclosing the gap 5. This may be provided while locally heating the solder material to e.g. temperature T2 and/or T3 as e.g. described above in relation to fig. 7 and/or 8 in the time span t3-t5. In one or more embodiments of the present disclosure, the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be moved in the lengthwise direction LDS of the solder material (7) at a combined movement speed of at least 20 m/s such as at least 40 m/s during the step of softening the solder material 7. If only one laser light beam is used (fig. 10), the laser light beam 9 may be moved in the lengthwise direction LDS of the solder material (7) strips A-B, B-C. C-D, D-A at a speed of at least 20 m/s such as at least 40 m/s during the step of softening the solder material.

Hence, in some embodiments, each 9, 9_1, 9_2, 9_3, 9_4 laser light beam may be moved in the lengthwise direction LDS of the solder material 7 at a speed of at least 20 m/s such as at least 40 m/s during the step of softening the solder material.

If for example two beams 9 1 and 9 2 is provided (fig. 11), and each beam is moved with e.g. 30 meters per second, the combined speed will be 60 meters per second. In some embodiments of the present disclosure, one or more of the one or more beams 9_1, 9_2, 9_3, 9_4 may be moved with a speed lower than 20 m/s such as lower than 15 m/s, but the total/combined speed of the laser light beams may be above 20 m/s.

The combined speed may e.g. be determined by summarising the individual beam spot speed. For example, if three laser light beams are used for the local heating and softening, each moving with a speed of 14 m/s, the combined speed will be 14+14+14=42 m/s. It is naturally also understood that each of the one or more laser light beams 9, 9_1, 9_2, 9_3, 9_4 may be moved by means of one or more mirrors with a speed of at least 20 m/s such as at least 40 m/s along the solder material length during the step of softening the solder material 7.

The speed of the laser light beam(s) may, or may not, be adjusted and/or varied during the solder material heating 7 by the beam(s). In some embodiments of the present disclosure, the movement speed of the laser light beam(S) may be maintained constant during at least 30%, such as at least 60%, such as at least 90% or at least 95% of the heating time (see t3-t5 described in more details above) where the one or more laser light beams 9, 9_1, 9_2, 9_3, 9_4 heat and soften the solder material 7. In some embodiments of the present disclosure, the full extent L AB + L_ BC + L CD + L_DA of the solder material 7 may be at least 1.5 meter, such as at least 2 meters, such as at least 3 meters.

In some embodiments of the present disclosure, the full extent L AB + L_ BC + L CD + L_DA of the solder material 7 may be between 1.5 meter and 10 meters, such as between 2 meter and 8 meters, such as between 3 meter and 6 meter.

In some embodiments of the present disclosure, the full extent L AB + L_ BC + L CD + L_DA of the solder material 7 of the glass sheet assembly 1 may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 at least 10 times per second, such as at least 20 times per second, such as at least 30 times per second during the step of softening the solder material.

In some embodiments of the present disclosure, the full extent L AB + L_ BC + L CD + L_DA of the solder material 7 of the glass sheet assembly 1 may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 at least 500 times, such as at least 1000 times, such as at least 1500 times during the step of softening the solder material 7. It is understood that in some embodiments, e.g. the 500 times, such as at least 1000 times, such as at least 1500 times may also be referred to as 500, such as at least 1000, such as at least 1500 iterations or “heating iterations”.

For example, if the solder material 7 of the glass sheet assembly 1 is be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 spot least 500 times in order to locally heat and soften the solder material, this may correspond to 500 heating iterations. If one laser light beam is used, the laser light beam spot may be moved around the full extent L AB + L_ BC + L CD + L_DA of the solder material 7 of the glass sheet assembly 1, and each time the laser light beam spot revisit the same area of the solder material after having heated the remaining solder material, a new heating iteration is started.

In some embodiments of the present disclosure, the power of each of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be, such ass be adjusted to, at least 500 W, such as at least 750 W, such as at least 1000W or at least 1200W. In some embodiments of the present disclosure, the power of each of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be, such as be adjusted to, at least 1300 W such as at least 1500 W.

In some embodiments of the present disclosure, the combined heating by means of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 of each meter of the solder material may be at least 30 joule per each one-tenth of a second for a period of at least 30 seconds, such as at least 60 seconds, such as at least 80 seconds, during the step of softening the solder material 7 at the edge sealing station. Hence, if just one laser beam 9 is used, this may in embodiments of the present disclosure provide at least 30 joule per each one-tenth of a second for a period of at least 30 seconds such as at least 60, such as at least 80 seconds during the step of softening the solder material 7 at the edge sealing station. If instead more than one, for example two, laser light beams are used, the power of at least 30 joule per each one-tenth of a second for a period of at least 30 seconds such as at least 60, such as at least 80 seconds during the step of softening the solder material 7 at the edge sealing station may be divided between the two beams, e.g. according to a 50/50 ratio, a 60/40 ratio the like.

In some embodiments of the present disclosure, the combined heating by means of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 of each meter of the solder material may be at least 40 joule, such as at least 50 joule per each one-tenth of a second for a period of at least 30 seconds such as at least 60 seconds or at least 80 seconds during the step of softening the solder material 7 at the edge sealing station.

In some embodiments of the present disclosure, the combined heating by means of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 of each meter of the solder material may be at least 50 joule, such as at least 60 joule per each one-tenth of a second for a period of at least 10 seconds such as at least 20 seconds during the step of softening the solder material 7 at the edge sealing station.

In some embodiments of the present disclosure, the combined heating by means of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 of each meter of the solder material may be less than 150 joule per each one-tenth of a second, such as less than 100 joule per each one- tenth of a second, such as less than 60 joule per each one-tenth of a second, for a period of at least 30 seconds such as at least 60 seconds, such as at least 80 seconds during the step of softening the solder material 7 at the edge sealing station.

In some embodiments of the present disclosure, the combined heating by means of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 of each meter of the solder material may be between 30 joule and 150 joule, such as between such as between 50 joule and 100 joule, per each one-tenth of a second for a period of at least 30 seconds such as at least 60 seconds during the step of softening the solder material 7 at the edge sealing station.

It is generally understood that the power of one or more of the one or more laser light beam(s) may, in embodiments of the present disclosure, be maintained constant or may be regulated, such as increased and/or decreased, during the step of softening (t3-t5) the solder material 7 at the edge sealing station 200.

It is understood that if more than one beam 9, 9 1, 9_2, 9_3, 9_4, such as a laser light beam, is used for the heating and softening of the solder material 7 (see e.g. figs 11, 12 or 13), the beams may be provided by/generated by the same laser light source (e.g. by means of a laser light beam splitter), or may be provided by/generated by different laser light sources. One or more individually adjustable and/or movable mirrors may be considered part of each heater 15, 15 1, 15_2, 15_3, 15_4. The one or mirrors may be controlled, such as moved, in order to obtain the movement speeds and/or movement patters/directions described above according to various embodiments of the present disclosure.

Fig. 15 illustrates schematically a cross section of the glass sheet assembly 1 during evacuation of the gap 2. In this embodiment, an evacuation cup 40 is arranged on an upper, outer side surface 4b of the second glass sheet 4. Thereby, an inner cavity 42 of the evacuation cup 40, which is enclosed by an evacuation cup wall 43, such as an annular wall, is in fluid communication with the gap 5 by means of the evacuation opening 6 that extends through the glass sheet 4.

The inner cavity 42 of the evacuation cup 40 is in fluid communication with a suction connection 40a, such as a piping. A force clamping is thereby provided so that the glass sheets 3, 4 clamps the solder material 7 that has been heated and softened locally, e.g. by means of one or more laser beams, as e.g. described above. The force clamping is provided by applying a suction to the inner cavity 42 of the evacuation cup 40 by means of the suction connection 40a, e.g. by means of an evacuation pump. This provides a pressure difference between the pressure P2 in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1. The suction connection 40a may be connected to an evacuation pump (see e.g. ref. 8 in figs. 3 and 4).

The evacuation pump 8 may in some embodiments be arranged outside the chamber of an edge sealing station 200. This may e.g. be the case if the chamber of the edge sealing station is heated such as convection heated as e.g. described above. The suction connection 40a may hence connect the evacuation cup inside the chamber (see 201 of figs. 3-4) to an evacuation pump arranged outside the chamber.

The evacuation cup 40, the suction connection and an evacuation pump connected thereto may hence act as a clamping arrangement that may be used for clamping the solder material. In other embodiments, other types of clamping arrangements may be used, and hence, the suction cup may e.g. be omitted during the edge sealing.

In some embodiments, at least the suction connection 40a may act as an obstacle that prevents an emitter / heater (see e.g. refs 15, 15 1, 15_2, 15 3 and/or 15 4) described above, from heating the full length of the solder material 7, see also figs. 13 and/or 14.

A suction cup of substantially similar type as described above in relation to various embodiments of the present disclosure, such as in relation to fig. 15, may also be used at an evacuation and sealing station 300 as e.g. described above in relation to various embodiments, see references 41 in figs. 3-4.

Fig. 16 illustrates schematically an embodiment of the present disclosure, where a mechanical clamping arrangement 70 provides the force clamping in order to obtain that the solder material 7 is clamped when heated by one or more lasers at the edge sealing station. This may e.g. be an alternative to providing the pressure difference by means of an evacuation pump 8 as e.g. previously described. In fig. 16, the clamping arrangement 70 comprises actuators 71 (two are illustrated but it is understood that more or less than two actuators may be provided). The actuators are connected to a pressing body 72, e.g. a pressing plate. In fig. 16, they 71 are connected to the same pressing body 72, but in other embodiments, several pressing bodies 72 (not illustrated) may be displaced (individually or together) by means of one or more actuators 71.

In some embodiments, when (see e.g. t4 described previously) the solder material has been sufficiently heated by the laser(s) 9 1, 9_2, the pressing body is pressed towards the glass sheet assembly 1, thereby deforming the heated and softened solder material 7. However, when providing mechanical force clamping, it may be so that the force clamping is provided even before the local heating by means of one or more laser light beams is started (e.g. at or before the time t3 the local heating of the solder material is started).

The pressing plate(s) 72 may have a size providing that it does not overlap the solder material, thereby allowing the laser light beam(s) to heat the solder material 7 through the glass sheet surface 4b. However, the pressing body 72 may also in some embodiments, be at least partly transparent (e.g. by comprising a glass pressing body) to the laser light and in that case extend to a position opposite the solder material.

The pressing body 42 may be a rigid pressing body such as a metal pressing body, a glass pressing body, a polymer pressing body and/or the like.

In some embodiments, a softer layer 73, such as a resilient layer, such as a resilient mat, for example a silicone mat, a rubber mat or the like, may be placed between the glass sheet assembly 1 surface 4b and the pressing body, e.g. to obtain force distribution and/or glass sheet surface 4b protection.

In some embodiments, e.g. the one or more actuators 71 and/or the pressing body/ies may act as an obstacle preventing any one of two or more laser light beams 9 1, 9_2, from heating the full extent L AB + L_BC + L CD + L_DA of the solder material. However, in that case the emitters 15 1 , 15 2 may be arranged so that the laser light beams 9 1, 9_2 together heat and soften the full extent L AB + L_BC + L CD + L_DA of the solder material.

It is generally understood that if more than one emitter is provided, and hence that a plurality of emitters, such as two or more emitters (see e.g.l5_l, 15_2, 15_3, 1 4 described above) these may all heat the solder material through the same glass sheet 4 surface. This may e.g. be provided through the upper glass sheet 4 as e.g. illustrated in various figures (in fig. 16 illustrated by a dotted line), such as in one or more of figs. 11-16 described above.

However, in other embodiments (not illustrated), a first laser light beam may heat the solder material through a first of the glass sheets 4, and a further laser light beam may emit the solder material through the other of the glass sheets 3, e.g. from below of the glass sheet assembly 1. In that case, the support 212 may be adapted and/or the glass sheet assembly 1 may be arranged, so that an emitter may emit the laser light beam towards the lower glass sheet 3 to heat the solder material 7.

Fig. 17a-17b as well as figs. 18a-18b and figs. 19-20, illustrates schematically adjustment of heating power over the solder material 7 width Wl, according to various embodiments of the present disclosure. This may e.g. be provided in order to adapt the power supplied by the one or more heating beams 9 to different regions of the solder material 7 over the solder material width Wl. For example because the solder material 7 strip width Wl may change when the solder material 7 is heated by the local heating such as one or more heating beams 9, such as one or more laser light beams, and is clamped by the glass sheets 3, 4. Figs 17a.17b and figs. 18a- 18b illustrates a schematic cross section of a part of the glass sheet assembly 1 during heating by a heating beam(s) such as a laser light beam, according to various embodiments of the present disclosure. Figs. 19-20 schematically illustrates adjustment of heating power subjected to the solder material 7 by the one or more laser light beams, across the solder material width Wl, according to various embodiments of the present disclosure.

The glass sheets 3, 4 may (as described above according to various embodiments of the present disclosure) generally be colder than the solder material 7 when the solder material is heated by the laser light beam(s) at an edge sealing station, such as station 200 described above. In some embodiments, the glass sheets 3, 4 of the assembly 1 may have an elevated temperature that is obtained by means of a preheating step, such as at a preheating station 100 as described above (see e.g. one or more of figs. 3, 4, 7, 8), and the average temperature of the glass sheets 3, 4 may still be maintained below, and thus be colder, than the temperature of the solder material that is obtained by means of the one or more laser light beams 9 (see e.g. T2 and/or T3 as explained in more details in relation to e.g. figs. 7 and/or 8). The local heating beam 9, such as a laser light beam having a width/spot size W2, heats the solder material 7 through the upper glass sheet 4, and the solder material 7 thereby locally heats the glass sheets 3, 4 by conduction heating of the surfaces 4a, 3a abutting the solder material 7. Thus, the heating beam 9 may have the property of substantially not heating the glass sheets 3, 4 directly. Instead, the solder material 7 transfers the heating energy from the heating beam 9 to the glass sheets 3, 4.

The solder material 7 strips extends in a longitudinal direction LDS (see e.g. fig. 2) parallel to adjacent outer edges 3LE, 4LE of the first glass sheet 3 and second glass sheet respectively. The heating by the heating beam(s) 9, such as a laser light beam, causes the solder material 7 to soften, and the solder material 7 is then deformed, e.g. by a force clamping as e.g. described above. Thus, over time (see e.g. t3-t5 of fig. 7 and 8), when the solder material 7 is deformed and the solder material width W 1 increases, the solder material will 7 come into contact with a glass sheet surface 3a, 4a that has not yet been heated by the solder material 7 and is thus colder than the solder material. Tests have shown that a temperature drop of the solder material may occur when the force clamping is initiated, see e.g. time t4 at figs 7-8.

In fig. 17b it can be seen that the laser light beam 9 width w2 may be increased on a second softening step when compared to the laser light beam width W2 earlier in the heating of the solder material at a first softening step (fig. 17a). This may provide an adjustment of the heating power perpendicular to the longitudinal extend LDS of the solder material 7 during the heating time t3-t5 and may help to provide that increased heating power is provided/obtained at the second softening step at another region LADIS2 along across the width W1 of the solder material. In this second softening step, the power may be increased at least at the distance LADIS2 further from the edge 3LE than the centre SC of the beam. In the embodiment of fig. 17b, the spot centre SC of the laser light beam 9 however remains substantially at the same position when the laser light beam spot width W2 is increased.

Generally, in some embodiments, the beam spot width W2 may be increased by at least 1 mm such as at least 2 mm, such as at least 3 mm at the second softening step ST2 when compared to the beam spot width W2 at the first softening step STI . In some embodiments, the beam spot width W2 may be increased by 1 to 10 millimetres such as by 1 to 6 millimetres, such as by 2 to 4 millimetres at the second softening step ST2 when compared to the beam spot width W2 at the first softening step STI .

For example, the heating beam, such as a laser light beam, may, in various embodiments of the present disclosure, be adjusted so that the heating power is increased at the second softening step ST2 (see fig 19) during the heating time t3-t5 (see figs 7-8) at a region/ location where the solder material 7 was not initially present at the start of the heating and softening of the solder material 7 by means of the one or more laser light beams, when compared to the heating power subjected to that area region/ location at the start of the heating in the first softening step.

The solder material deformation causes the solder material height Hl (see also fig. 5) to reduce, and causes the solder material width W1 to increase, when compared to the height Hl and width W1 before the deformation of the solder material 7. In fig. 17a, the laser light beam 9 has a width W2 that covers the entire solder material width W 1. However, the laser light beam width W2 is here smaller than the final solder material width W 1 when the edge sealing at the edge sealing station 200 has ended. Hence, when the solder material width W1 increases due to the deformation of the solder material by means of e.g. a force clamping, the width W2 of the laser light beam may be adjusted, such as increased, to obtain that the entire, enlarged solder material width W1 is subjected to heating by the laser light beam 9.

In some embodiments, at the initiation of the heating of the solder material 7 by means of the laser light beam 9, the solder material 7 is heated in a first softening step STI (see fig. 19) to soften the solder material 7 by moving the laser light beam 9 or beams along the lengthwise extent LDS of the solder material 7 at a first distance LADIS1 between the centre of the spot CS of the one or more laser light beams at the solder material 7 and the adjacent outer edge 3LE of the first glass sheet 3. See fig. 17a. This may be provided at a plurality of times/ heating iterations. Thereafter, the centre of the beam spot CS may be maintained at the same distance LADIS 1 to the edge 3LE, but the beam 9 width W2 may be increased/enlarged as illustrated in fig. 17b.

This enlarged laser beam width W2 )(fig. 17b) may e.g. provide that a subsequent heating of the solder material 7 in a second softening step (see ST2 of fig. 19) with the enlarged laser light beam width W2 so as to soften the solder material 7 by moving the laser light beam(s) 9 along the lengthwise extent LDS of the solder material 7 a plurality of times/iterations result in that the heating power from the laser light beam(s) 9 at a second distance LADIS2 to the adjacent outer edge 3LE of the first glass sheet 3 becomes larger/increases (see HP1 in fig. 19) when compared to the heating power (See HP2 of fig. 19) at that second distance LADIS2 when the solder material 7 heating was provided by means of a laser light beam 9 with the initial, smaller laser light width W2. See fig. 17a and HP2 between STI and ST2 of fig. 19. The second distance LADIS2 from the edge 3LE is larger than the first distance LADIS1 from the edge 3LE.

Figs. 18a-18b illustrates an embodiment of the present disclosure where the adjustment of the heating power provided by the heating beam(s) 9 perpendicular to the longitudinal extend LDS of the solder material 7 during the heating time t3-t5, so as to provide increased heating power at another region LADIS2 across the width W1 of the solder material 7, is obtained by changing/moving the spot centre SC of the one or more laser light beams 9 from being arranged at the first distance LADIS1 at the first softening step STI (see fig. 19) to the adjacent outer edge 3LE (see fig. 18a) to be arranged at the second distance LADIS2 to the adjacent outer edge 3LE (see fig. 18b) at the second softening step ST2. Thereby the spot centre SC is moved further away from the edge 3LE at softening step ST2 compared to the distance LADIS1 at softening step STI. This may help to increase the heating power introduced into the solder material 7 at the second distance LADIS2 to the outer edge 3LE during the second softening step ST2 (See heating power HP1 in fig. 19).

In further embodiments of the present disclosure, both the spot width W2 and the distance from the spot centre SC to the adjacent outer edge 3LE may be adjusted in order to adjust the heating power across the solder material width Wl, during the heating (t3-t5) of the solder material by the heating beam(s) such as laser light beam(s).

It is generally understood that the heating power PLADIS2 at the area of the solder material 7 at the second distance LADIS2 may be lower (HP2) during the first softening step STI than during (HP1) the second heating step ST2. See also fig 19.

In some embodiments of the present disclosure the adjustment of the heating power at the second distance LADIS2 may be obtained by adjusting/varying the amount of laser light beams used for heating the solder material 7 during the heating time t3-t5 in order to adjust the heating power across the solder material width Wl, during the heating (t3-t5) at the different softening steps STI, ST2. For example, a first heating beam may heat a first part of the solder material across the width Wl at softening step STI, and a second beam may additionally heat the remaining part of the solder material across the width Wl at softening step ST2. The heating power may or may not be adjusted individually for each laser beam to control the heating power at step STI and ST2 respectively.

Generally, in further embodiments of the present disclosure, a raster solution may be used for heating the solder material 7 by means of the one or more heating beams 9 such as laser light beams. In this embodiment, the laser light beam(s) 9 may be moved in the longitudinal direction of the solder material (in a plurality of heating iterations as explained in more details above), while also a laser beam raster motion is used so as to ensure heating of the solder material across the solder material width Wl . In this case, when the solder material width increases, a controller may in further embodiments of the present disclosure control the heating beam 9 so that it during the raster motion “spend more time”, and hence provides more heating energy, at the solder material 7 area further from the adjacent edge 3LE at softening step ST2. The movement speed of the laser light beam in the direction transverse to the longitudinal solder material 7 strip direction LDS may thus be varied over the width Wl of the solder material and in some embodiments be controlled to be different in the different softening steps STI, ST2. If using a raster solution, the laser beam spot size, such as diameter, may in some further embodiments be smaller than the (initial) solder material width Wl, such as less than the half of the solder material width Wl, such as less than one quarter of the solder material width W 1.

Fig. 19 illustrates schematically the heating power HP1 HP2 adjustment, such as heating beam power HP1 HP2 adjustment, according to embodiments of the present disclosure. Here, the heating power PLADIS2 at the area of the solder material 7 at the second distance LADIS2 may become/be lower HP2 during the first softening step STI than the heating power HP1 at the same area during the second softening step ST2. This may in some embodiments be provided by one or more of:

• beam width W2 adjustment (figs. 17a — 17b),

• beam spot centre SC movement (figs 18a- 18b) in the width Wl direction of the solder material 7 strip, adjusting number of laser beams used, beam raster control and/or the like.

Generally, in embodiments of the present disclosure, the second distance LADIS2 to the adjacent edge 3LE, 4LE may be at least 1 mm, such as at least 2 mm larger than the first distance LADIS1. In embodiments of the present disclosure, the second distance LADIS2 may be at least 3 mm larger than the first distance LADIS 1.

Generally, in embodiments of the present disclosure, the second distance LADIS2 may be in the range of 0.5 to 5 millimetres larger than the first distance LADIS 1, such as in the range of 1 to 4 millimetres larger than the first distance LADIS 1, for example in the range of 1 to 3 millimetres larger than the first distance LADIS 1.

Generally, in embodiments of the present disclosure, the heating power PLADIS2 from the one or more laser light beams at the second distance LADIS2 to the adjacent outer edge 3LE may be at least 10%, such as at least 25% higher (See HP1) in the second softening step (ST2) than (see HP1) in the first softening step (STI), such as at least 35% higher.

In some embodiments of the present disclosure, the heating beam 9 width W2 may be at least 10%, such as at least 20%, such as at least 30% larger or at least 50% larger than the solder material width W 1.

Pig. 20 illustrates schematically a graph of the heating power PLADISI at the first distance LADIS1 during the softening steps STI, ST2, according to embodiments of the present disclosure. Here the heating power PLADISI from the one or more laser light beams 9 at the solder material 7 at the first distance LADIS 1 to the adjacent outer edge 3LE of the first glass sheet 3 is lower HP2 than the heating power HP1 at the solder material 7 at the second (larger) distance LADIS2 during the second softening step ST2. In this case, in some embodiments, the largest laser beam power may so to say be moved to be focused/positioned at the at the solder material 7 at the second distance LADIS2 (See figs 17a- 18b), in the second softening step ST2. Additionally or alternatively another heating power adjustment may be provided such as by adjusting number of laser light beams used and/or by raster control. Additionally or alternatively, spot width W2 may be adjusted between the first STI and second ST2 softening step.

It is understood that in some embodiments of the present disclosure, the adjustment of the heating power HP1, HP2 provided by one or more laser light beams (emitted by one or more emitters) over the width W1 of the solder material 7 strip as described above in relation to various embodiments of the present disclosure, e.g. in relation to one or more of figs 17a-20, may be provided at an edge sealing station 200 as e.g. described further above. For example as described in relation to one or more of figs. 3-16.

It is understood that in some embodiments of the present disclosure, the adjustment of the heating power provided by one or more laser light beams 9 (emitted by one or more emitters) over the width W 1 of the solder material 7 strip as described above in relation to various embodiments of the present disclosure, e.g. in relation to one or more of figs 17a-20, may be provided during one or more of the time period(s) t3-t4, t4-t5 and/or t3-t5 as e.g. described in more details in relation to e.g. fig. 7 and/or 8.

It is understood that in some embodiments, a force clamping arrangement as e.g. previously described may provide that the glass sheets 3, 4 clamp and deform the solder material 7 while being heated by the one or more heating beams 9, as e.g. described in more details above according to various embodiments of the present disclosure. In some embodiments, the force clamping is provided by a pressure difference between the pressure in the gap 5 and the pressure Pl surrounding the glass sheet assembly 1. In some embodiments hereof, this may be obtained by evacuating the gap 5, e.g. by means of an evacuation cup, during the heating of the solder material by means of the heating beam(s). This may in some embodiments provide that the solder material 7 width W 1 is changed “unevenly” so that it moves more in the direction of the gap 5 than in the direction away from the gap. If providing an adjustment of the heating power over the width W1 of the solder material 7 strip as e.g. described above in relation to e.g. one or more of figs 17a-20, an improved edge seal may e.g. be obtained.

In some embodiments, the force clamping may be initiated during the first softening step STI or the second softening step ST2. It is understood that the first and second softening steps STI, ST2 may be consecutive softening steps as e.g. illustrated in figs. 19 and 20. It is understood that in some embodiments, the maximum heating temperature of the solder material (See T3 in figs 7-8) may be obtained during the second softening step STI.

It is understood that in some embodiments, the entire width W1 of the solder material 7 may be heated by the one or more heating beams 9 during both the first and second heating steps STI, ST2.

It is generally understood that in some embodiments of the present disclosure, the solder material 7 may be heated by the one or more heating beams, (see e.g. 9, 9 1, 9_2, 9_3, 9_4 described above according to various embodiments of the present disclosure), so that the temperature difference between any two positions of the solder material 7 along the full extent L A-B + L_ B-C, + L C-D + L D-A of the solder material 7, and with the same distance ( such as e.g. LADIS1, LADIS2) to the adjacent edge (3LE), does not exceed 1 °C , such as does not exceed 0.5 °C, such as does not exceed 0.2 °C.

Figs. 17a-17b moreover illustrates a further embodiment of the present disclosure, where a coating 14 is present on a glass sheet surface(s) 3a facing the gap 5.

In the figs. 17a-17b, one coating 14 is illustrated at surface 3a, but it is understood that one or more coatings 14 may be present on one or both surfaces 3a, 4a in further embodiments of the present disclosure.

In embodiments of the present disclosure, the coating 14 may comprise one or more low-e coating(s) (also known as low-emissivity coatings). The low-e coating may e.g. comprise a low-e coating designed to maximize solar heat gain through the VIG unit. For example so as to maximize solar heat gain into a building to create the effect of “passive” heating and reducing reliance on artificial heating.

In one or more embodiments of the present disclosure, the coating 14 may comprise a low-e coating configured to limit the amount of solar heat that passes through the VIG unit. For example so as to enable limiting the amount of solar heat that passes into a building, e.g. for the purpose of keeping the building cooler and thus reducing energy consumption related to heat management at the room(s) of a building. This may e.g. be preferred in building windows.

Generally, the low-e coating(s) 14 may in embodiments of the present disclosure be configured to reduce the emission of radiant, infrared energy by increasing the amount of radiant heat that is maintained/kept on the side of the VIG unit where it originated, while letting visible light in the visible spectrum pass through the VIG unit.

For example a low-e coating may be configured reflect infrared radiation such as long-wave and/or short-wave infrared radiation entering through the glass sheet(s) 3, 4.

The low-e coating(s) 14 may e.g. be relevant if the VIG unit 30 is for use:

• In a building window allowing sunlight to enter through the VIG unit from a building exterior to a building interior,

• In a cooling storage (such as a refrigerator) door/lid, with view through the VIG unit to the interior storage,

• In an oven door,

• and/or the like.

The low e-coating(s) 14 may e.g., in embodiments of the present disclosure, comprise one or more silver coatings and/or pyrolytic coatings.

In some embodiments of the present disclosure, the one or more coatings 14, such as a low-e coating, may be placed between the solder material 7 and the glass sheet surface(s) 3a and/or 4a.

However, in one or more embodiments of the present disclosure, the coating(s) 14 may be terminated, such as removed, at the area where the solder material 7 interface with the glass sheet surface(s) 3a, 4a. This is illustrated in figs. 17a-17b.

Hence, as illustrated in figs. 17a-17b, said one or more coatings 14 may be terminated with a distance to the outer glass sheet edge 3LE, 4LE so that the glass material of the glass sheet 3, 4 comprising the one or more coatings 14 is direct contact with the solder material 7. In further embodiments, the one or more coatings 14 may be terminated with a distance to the outer glass sheet edge 3LE, 4LE so as to provide that the solder material 7 is substantially not in contact with the one or more coatings after the heating and softening of the solder material 7 by the one or more laser light beams (9. 9 1, 9_2, 9_3, 9_4) is terminated (see e.g. t5 as previously described). Hence, in this embodiment, the distance between the coating 14 and the outer glass sheet edge 3LE, 4LE may be larger than the final width W1 of the solder material so that the solder material will never get in contact with the coating 14. In other embodiments (not illustrated), the distance between the coating 14 and the outer glass sheet edge 3LE, 4LE may so that the solder material 7 first may get in contact with the coating when it is softened by the laser light beam(s) 9 and deformed to increase the solder material width W 1. In this latter embodiment, a part of the solder material 7 may come into contact with the coating 14 while another part of the solder material may not be in contact with the coating 14.

In other embodiments of the present disclosure, the low-e coating(s) 15 may be completely omitted from the VIG unit 30.

Hence, the glass sheet assembly 1 may be provided for the preheating station 100 and/or the edge sealing station 200 with the glass sheets 3,4, the support structures 2 in the gap 5, and the solder material 7 surrounding/enclosing the gap 5 as e.g. illustrated in several of the figures described above, such as in figs. 1 and 10.

Fig. 21 illustrates schematically a heating beam 9’, such as a laser light beam, from a heating beam source 17.

In fig. 21, a heating beam source 17, such as a laser light source, provides a “source” heating beam 9’ that is emitted from the laser light source 17. The source heating beam 9’ is directed 9, such as redirected, such as reflected, towards 9 the glass sheet assembly 1 by a heater 15, such by an emitter, such as by means of a mirror. The mirror 15 may be comprised in or by the heater or emitter.

The heating beam 9’ energy from the source 17 is redirected, such as reflected, by the heater and emitted in the redirected heating beam 9 towards the solder material 7 of the glass sheet assembly so as to heat it 7. The heating beam is in fig. 22 transmitted through a chamber 201 wall 230, such as a top wall, which is transparent to the laser light beam 9, for example a glass wall.

The mirror 15 may be or comprise a beam steering mirror. A mirror controller 16 may control/steer the mirror 15 so as to move the redirected beam 9 along the longitudinal direction LDS of one or more of the solder material strips of the glass sheet assembly 1 to heat the solder material 7, e.g. as previously described above according to various embodiments of the present disclosure. The mirror controller 16 may comprise one or more hardware processors, circuitries and/or the like adapted to control the mirror based on control software stored in a data storage. The mirror 15 may comprise a Tip/Tilt Platform, such as a Piezo Tip/Tilt Platform, which is controlled by the controller to Tip/Tilt the mirror 15 to move the laser beam 9. Hence, one or more of the mirror(s) 15, heating beam source(s) 17, controller(s) 16 and/or the like may be located outside the chamber 201 in which the glass sheet assembly 1 is arranged. This may e.g. be an advantage in case the chamber 201 is heated by a heater 220, such as a convection heater, to a temperature above 150 °C, such as above 250 °C or above 300 °C, such as above a (if the solder material if the solder material is a glass solder material) glass transition temperature Tg of the solder material.

Fig. 22 illustrates an embodiment of the present disclosure where two laser light beams heat the solder material 7 of the VIG unit assembly.

As also previously described, the glass sheet assembly 1 comprises an edge seal, and the edge seal comprises a solder material 7 for providing an edge sealing for enclosing and sealing the gap 5 between the glass sheets 3, 4. The solder material 7 comprises elongated strips A-B, B-C, C-D and D-A of solder material 7. These strips extends between comer portions A, B, C, D of the edge seal material 7. The strips each have a length, i.e. the strip AB (i.e. extending between comers A-B) has the length L_AB, the strip BC (i.e. extending between comers B-C) has the length L_BC, the strip CD (i.e. extending between comers C- D) has the length L CD and the strip DA (i.e. extending between comers D-A) has the length L_DA.

The two laser beams 9 1, 9_2 are be moved along the solder material strips from comers A- B, B-C, C-D and D to A in a plurality of heating iterations in order to locally and uniformly heat and soften the full/total longitudinal extent of the solder material 7. E.g. in order to obtain the temperature T2 and/or T3 as previously described in relation to one or more of figs. 6-9.

However, the local heating of the fill l/total Icngth/cxtcnt X f_so(der = L_AB + L_BC + L_CD + L_DA of the solder material 7 is divided between the laser light beams, in this case due to the shadow area SA as e.g. previously explained. However, the dividing of the heating may e.g. also be caused by wanting to use two or more lasers to e.g. speed up the local heating, in order to be able to use lasers of lower power and/or the like, for example also in embodiments where clips or other mechanical clamping is used for providing a force clamping, e.g. as an alternative to or in addition to the force clamping by means of a pump. In the embodiment of fig. 22, the laser beam spots of beams 9 1, 9_2 that heat the solder material 7 are spaced apart and heat different heating areas ARI, AR2 of the solder material. The areas ARI, AR2 together covers the full/total length/extent 2 L_soider ⁼ L_AB + L_BC + L_CD + L_DA of the solder material strips A-B, B-C, C-D, D-E. Hence, the local heating of the solder material by each beam 9 1, 9_2 is divided between the beams (see also e.g. ARI and AR2) as e.g. explained above, so that one of the beams heat a first longitudinal extent of the solder material 7 whereas the other beam heat another longitudinal extent of the solder material 7. In the embodiment of the fig. 22, the two beams 9 1, 9_2 together heat the total extent 2 L_soider of the solder material 7 with substantially no overlap in heating areas of the solder material.

For example, one heater 15 1 beam 9 1 may heat

• the full length L AB of the solder material strip A-B,

• the full length L_BC of the solder material strip B-C,

• the comer areas A, B, C

• the majority of the length L_DA of the solder material strip DA, and

• the majority of the length L CD of the solder material strip DA.

These solder material lengths are as illustrated in fig. 2 part of the heating area ARI that is heated by the laser beam 9 1 of the emitter 15 1

Another heater 15 2 beam 9_2 may heat.

• a minor part of the length L CD of the solder material strip DA,

• a minor part of the length L_DA of the solder material strip DA, and the comer area D

The area AR2 may cover at least the shadow area SA as previously described. The shadow area may be an area that the laser beam 9 1 may not reach for one or more reasons, such as due to one or more physical obstructions at the edge sealing station, due to restrictions in the operational area of the heater (such as defined by the characteristics of a mirror arrangement 15 1) and/or the like.

The total length of the respective heating area ARI, AR2 may be adjusted. In fig. 22, The area ARI may cover for example at least 80% or more of the total solder material length S ^solder so an AR1/AR2 ratio relating to the solder material length coverage is at least 80/20. In some embodiments of the present disclosure, the solder material length coverage AR1/AR2 may be between 55/45 and 98/2, such as between 65/35 and 90/10. Here, e.g. a ratio of 98/2 means that one heating area covers 98% of the total solder material length S ^solder whereas the remaining 2% is covered by another heating area. If more than two lasers are used, more heating areas may be present and be heated by each their laser beam.

In some embodiments, the solder material 7 at the heating areas ARI, AR2 may be heated simultaneously by the different beams 9 1, 9_2. In other embodiments, one laser light beam may be turned off while the other heat another area ARI, AR2

The laser light beams (9 1, 9 2) provides heating at the comer portions A, B, C, D of the solder material. The solder material comer portions provides the transition between the elongated, straight solder material strips A-B, B-C, C-D, D-E. For example, in fig. 22, the laser light beam 9 1 heat both solder material strips A-B, B-C and the corer region B. This is provided by that the laser light beam 9, 9 1 heat the solder material 7 at the solder material strip A-B along the longitudinal extent LDS of the strip A-B in a movement direction indicated by the arrow Al towards the comer area B, is continued to move over the comer area B to heat the comer area, and is moved along the strip B-C towards the further comer area C in the direction of the arrow A2. The same situation is the case for the same laser light beam at comers A and C, but it is understood that this may depend on how the heating of the solder material is obtained. In fig. 22, the comer D and parts of the strips C-D and D-A is heated by the laser 9_2 by heating in the direction of the arrows A3, A4 It is understood that if the movement of the beams is controlled by means of a mirror, the beam 9 1 may be moved from the starting point STP to the end point EP of the heating area ARI, and may be turned off, redirected or the like while the mirror moves to start heating the same area ARI again by means of the beam 9 1 from the starting point STP in a new, consecutive heating iteration. Meanwhile and/or during the heating of the area ARI, the other laser 9_2 may heat the area AR2.

It is generally understood that in some embodiments of the present disclosure, the mirror may be a beam steering mirror such as a galvanometer mirror, also called a galvanometric mirror system or a galvanometer scanner.

In some embodiments of the present disclosure, the distance between the emitter, such as a mirror, and the edge seal when the glass sheet assembly is heated by means of the one or more heating beams such as laser light beams, may be at least 0.5 meter, such as at least 1 meter, such as at least 1.5 or at least 2 meter. This may e.g. provide that the magnitude of the movement, such as angular movement, of the mirror needed to move the redirected laser light beam so as to heat a larger part of the solder material 7 length, such as a hole solder material strip or even more, may be reduced.

It is generally understood that a laser light beam may be turned off temporarily one or more times during the local heating of the solder material 7, e.g. when repositioning a mirror after an end point EP has been reached, so that a new heating iteration can be started from the starting points STP again. However, it is considered the same laser light beam that heats the area ARI, and it is directed from the same mirror. Different emitters, such as comprising mirrors, may redirect different heating beams. Also, in some embodiments, different mirrors may be used for heating the same area ARI, AR2 of the solder material. In other embodiments, just one mirror is assigned for use for heating one area ARI, AR2.

When the full length of all solder material strips (A-B, B-C, C-D and D-A) have been subjected one time to a laser light spot, this may be considered as one of said heating iterations.

In some embodiments, if one (e.g. lower power) laser light beam heat a first, shorter heating area, see e.g. AR2 in figs 22 or fig. 14, with a speed compared to the length of the heating area that provides more heating iterations per time unit when compared to the number of heating iterations per time unit of another area ARI, it may be considered one heating iteration when the full length of the longest heating area has been subjected to a heating iteration, since the remaining part of the solder material at area AR2 may have been heated by more than one heating iteration in the same time span.

As an example, according to embodiments of the present disclosure, see e.g. fig. 22, a laser beam 9 1, e.g. the one that is to cover the longest heating area ARI, may be set as follows:

• A movement speed along the longitudinal direction LDS of the edge seal speed of 10 m/s

• A beam power of 2100 W

• Controlled to provide between 450 and 500 heating iterations of the area ARI during the heating time t3-t5 whereas the one laser beam 9_2 may be set as follows:

• A beam power of 700 W

• Controlled to provide between 1500 and 1600 heating iterations of the area ARI .

As can be seen in the above example, the movement speed of both laser beams is the same, but the 700 W laser light beam may provide more heating iterations within the same time span since it is configured to cover a shorter solder material length - e.g. covered by AR2. However, since the power of the 700 W laser light beam is about 1/3 of the power of the laser light beam that heats the longer heating area ARI, the effective heating power per time unit induced into the solder material at the second shorter area AR2 may be within ±20%, such as within ±10%, such as within ±5%, of the power induced into first longer area ARI in the same time span, since the power of the laser beam 9 1 heating the first longer area ARI is larger.

Hence, it is generally understood that the power of the laser light beams, in some embodiments, may be different, but may be adapted in movement speed and/or power dependent on e.g. the length of the solder material that they are configured to heat, so as to provide substantially identical heating /heat increase of the total length L_soider ⁼ L_AB + L_BC + L_CD + L_DA of the solder material 7. Hence, the softness of the solder material along the total length may be substantially the same, for example to a degree so that force clamping by an (optional) pressure difference as described above and/or below may be obtained when desired.

In the above example, the heating by the 700 W laser provides that the solder material at the second area AR2 is revisited more times per time unit than the first area ARI, but each visit by a laser light spot causes a lower heat increase in the solder material at the area AR2 when compared to the heat increase in the solder material of the first area ARI when a laser light spot from the higher power laser light beam 9 1 visit a part of the solder material of the first area ARI .

In some embodiments, the laser light beams 9 1, 9_2 may be selected to have the same power, e.g. 500 W or more each. In some embodiments, the laser light beams 9 1, 9_2 may have different power. For example one laser beam 9 1 may have a power that is at least 10% higher, such as at least 25% higher, e.g. at least 40% higher than the power of the other beam 9_2. This may in some embodiments be compensated for by that the lower power beam 9_2 heats the solder material 7 by means of more heating iterations than the higher power beam 9 1. In still further embodiments, one laser beam 9 1 may have a power that is at least 100% higher, such as at least 150% higher, e.g. at least 200% higher than the power of the other beam 9_2.

If the shadow area SA can be omitted, e.g. by force clamping by other means than evacuating the gap 5 or by omitting other clamping means that may provide a shadow area, for example by using clamping clips, one laser beam may heat the total solder material length X L_soider, see e.g. fig. 10 in a plurality of consecutive heating iterations to provide a gradual, stepwise heat increase of the solder material.

It is generally understood that the different heating areas may be subjected to different heating profiles. The different heating profiles may e.g. be caused by one or more of

• different laser movement speeds of the laser light beams 9 1, 9_2,

• different number of heating iterations and/or

• different power of the laser light beams 9 1, 9_2. In some embodiments, the power of the first laser light beam 9 1 may be larger, such as at least 1.5 times larger, such as at least two times larger than the power of the second laser light beam.

As mentioned above, the second laser light beam may revisit the second heating area AR2 more times than the first laser light beam revisit the first heating area ARI during the total heating time t3-t5 by means of the laser light beams.

As mentioned above, in some embodiments, the second laser light beam 9_2 may move in the longitudinal direction of the solder material of the second heating area AR2 with a movement speed that is larger, such as at least 1.3 times larger, such as at least 2 times larger or at least 2.5 times larger than the movement speed of the first laser beam 9 1.

In some embodiments, the power of the first laser light beam 9 1 may be larger, such as at least 1.5 times larger, such as at least two times larger, than the power of the second laser light beam 9_2, and moreover, the second laser light beam 9_2may move in the longitudinal direction of the solder material of the second heating area AR2 with a movement speed that is larger, such as at least 1.3 times larger, such as at least 2 times larger or at least 2.5 times larger than the movement speed of the first laser beam 9 1.

It is understood that the total length of the solder material at the first heating area ARI may be larger, such as at least 30% larger, than the length of the seal material of the second heating area AR2. In some embodiments, the total length of the solder material at the first heating area ARI may be at least 100% larger, such as at least 200% or at least 300% larger, than the length of the seal material of the second heating area AR2.

In some embodiments of the present disclosure, the amount of heating energy induced into the first and second heating areas during the total heating time of the entire solder material length may be substantially the same.

Fig. 23 illustrates a part of a flow chart relating to a method of processing a glass sheet assembly 1, 20 for a vacuum insulated glass VIG unit, according to embodiments of the present disclosure. Some of the steps may be substantially identical to the steps described in fig. 9. At step S231 (Preheat ass. to Tl), the glass sheet assembly 1 is preheated at a preheating station, see e.g. station 100 in figs. 3 and 4 and/or time range tl-t3 of fig. 8. When the glass sheet assembly 1 has been preheated to a uniform preheating target temperature Tl at the preheating station, the preheated glass sheet assembly 1 is removed at step S232 (Pos. ph. ass. at ESS) from the preheating station and positioned in the chamber 201 of the edge sealing station 200. During this moving of the preheated glass sheet assembly 1 from the preheating station to the edge sealing station, the preheated glass sheet assembly is remained preheated. For example, during this moving of the preheated glass sheet assembly 1 from the preheating station 100 to the edge sealing station 200, the preheated glass sheet assembly 1 may have a temperature within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C or within ± 5 °C of the preheating target temperature Tl .

At step S233, the softening t3-t5 of the solder material 7 by locally heating the solder material by means of one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 is started. This comprises moving the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 in the lengthwise direction LDS of the solder material so as to heat the full longitudinal (LDS) extent . ^solder = L_AB + L_BC + L_CD + L_DA of the solder material 7 in a plurality of consecutive, such as continuous, heating iterations. For example, in some embodiments, just one laser beam may provide the heating of the full longitudinal (LDS) extent . L'soider = L_AB + L_BC + L_CD + L_DA of the solder material. In other embodiments, the heating of the full longitudinal (LDS) extent 2 L_soider = L_AB + L_BC + L_CD + L_DA of the solder material may be divided between two or more laser beams, e.g. by having these laser beams heat different heating areas ARI, AR2 / sub parts of the solder material. These areas ARI, AR2 may or may not overlap. In still other embodiments, the heating of the full longitudinal (LDS) extent 2 L_soider = L_AB + L_BC + L_CD + L_DA of the solder material 7 may be provided by two or more laser beams which each heat the full longitudinal (LDS) extent 2 L_sotder = L_AB + L_BC + L_CD + L_DA of the solder material 7. Embodiments of such heating are described in more details above and/or below.

When the full length of all solder material strips (A-B, B-C, C-D and D-A) have been subjected one time to a laser light spot, this may be considered as one of said heating iterations. Hence, as an example, for example 400 heating iterations implies revisiting the full longitudinal (LDS) extent 2 L_sotder = L_AB + L_BC + L_CD + L_DA of the solder material 400 times by a laser light spot (maybe more for some parts of the solder material if more than one laser is used and if different laser beam power is used) so as to heat it.

It is generally understood that the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4, as e.g. described according to various embodiments of the present disclosure above in relation to one or more of figs. 3-22 and/or below, may be moved in the lengthwise direction LDS of the solder material 7 at a combined speed of at least 2 m/s such as at least 5 m/s, such as at least 9 m/s, for example at least 15 m/s during said softening t3-t5 of the solder material 7.

It is generally understood that the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4, in some embodiments, may each is moved in the lengthwise direction LDS of the solder material 7 at a speed of at least 2 m/s, such as at least 5 m/s, such as at least 9 m/s, for example at least 15 m/s during said softening t3-t5 of the solder material 7.

In some embodiments of the present disclosure, the movement speed of one or more of one or more of the laser light beams 9, 9 1, 9_2, 9_3, 9_4, along the longitudinal direction of the solder material may be between 2 m/s and 100 m/s, such as between 2 m/s and 50 m/s, such as between 5 m/s and 40 m/s. For example, in some embodiments of the present disclosure, the movement speed of one or more of one or more of the laser light beams 9, 9 1, 9_2, 9_3, 9_4, along the longitudinal direction of the solder material may be between 9 m/s and 100 m/s, such as between 9 m/s and 50 m/s, such as between 10 m/s and 30 m/s.

It is generally understood that the movement speed of the one or more heating beams, such as laser light beams, disclosed according to various embodiments of the present disclosure above and/or below, May or may not be an average speed used during the heating of the solder material during the heating time t3-t5 from the heating by means of the one or more laser beams is started t3, and until it is ended t5.

In some embodiments of the present disclosure, one or more of the one or more heating beams, such as laser light beams, 9, 9 1, 9_2, 9_3, 9_4, may each be moved in the lengthwise direction LDS of the solder material 7 at the speed mentioned above according to various embodiments of the present disclosure during at least 30%, such as at least 60%, such as at least 90% or at least 95% of the heating time t3-t5 where the one or more heating beams 9, 9 1, 9_2, 9_3, 9_4 heat and soften the solder material 7. In some embodiments it may be at least 99% or substantially 100% of the heating time t3-t5.

In some embodiments of the present disclosure, one or more of the one or more heating beams, such as laser light beams, 9, 9 1, 9_2, 9_3, 9_4, may each be moved in the lengthwise direction LDS of the solder material 7 at the speed mentioned above according to various embodiments of the present disclosure during at least 10% of the heating time t3-t5 where the one or more heating beams 9, 9 1, 9_2, 9_3, 9_4 heat and soften the solder material 7.

If force clamping is provided by means of a pressure difference, one or more of the one or more heating beams, such as laser light beams, 9, 9 1, 9_2, 9_3, 9_4, may each be moved in the lengthwise direction LDS of the solder material 7 at a speed as mentioned above according to various embodiments of the present disclosure before and/or after the pressure difference so as to force clamp is initiated (see t4 of e.g. fig 8, fig. 26a or fig 27a).

In some embodiments of the present disclosure, the full longitudinal LDS extent 2 L_soider = L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly 1 may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 at least 1 time per second, such as at least 2 times per second during said softening t3-t5 of the solder material 7. It is understood that e.g. 2 times per second may correspond to two heating iterations.

In some embodiments of the present disclosure, the full longitudinal LDS extent 2 L_soider = L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly 1 may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 at least one time every second second, or at least one time every fourth second, during the local heating and thereby softening of the solder material 7 by means of one or more heating beams, such as laser light beams, during the heating time t3-t5.

In some embodiments of the present disclosure, the full longitudinal LDS extent 2 L_soider = L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly 1 may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 at least 5 times per second, such as at least 9 times per second, such as at least 14 times per second during said softening t3-t5 of the solder material 7.

In some embodiments of the present disclosure, the full longitudinal LDS extent 2 Voider- L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly 1 may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 between 2 and 50 times per second, such as between 4 and 40 times per second, such as between 8 and 30 times per second during the softening t3-t5 of the solder material 7.

It is understood that in some embodiments, the above mentioned frequency with which the full longitudinal LDS extent X L_soider, L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 may be provided during at least 30%, such as at least 60%, such as at least 90% or at least 95% of the heating time (see t3-t5 described in more details above) where the one or more heating beams such as laser light beams 9, 9 1, 9_2, 9_3, 9_4 heat and soften the solder material 7. In some embodiments it may be at least 99% or substantially 100% of the heating time t3-t5.

In some embodiments of the present disclosure, the full longitudinal LDS extent 2 Voider- L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 at least 20 times, such as least 100 times, such as at least 250 times, such as at least 400 times during said softening t3-t5 of the solder material 7.

In some embodiments of the present disclosure, the full longitudinal LDS extent 2 Voider- L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 between 20 times and 10000 times, such as between 100 times and 5000 times, such as at between 200 times and 2000 times during said softening t3-t5 of the solder material 7.

As an example, if the full longitudinal LDS extent 2 L_solder. L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly is exposed to a laser light beam 9 100 times during the softening t3-t5 of the solder material 7 before the heating by means of the laser light(t) beam(s) is ended t5, each local area (see ref. 18 of fig. 26b) is exposed to a laser light beam 100 times during the heating time t3-t5.

In some embodiments of the present disclosure, the full longitudinal LDS extent 2 Voider- L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly may be exposed to a laser light beam 9, 9 1, 9_2, 9_3, 9_4 between 100 times and 5000 times, such as between 300 times and 2000 times, during said softening t3-t5 of the solder material 7.

It is generally understood that in some embodiments, the solder material 7 may be exposed to the one or more heating beams, such as laser light beams, by that the heating beam heating a primer layer (described in more details further below) which then heats the solder material. In other embodiments, the solder material may be exposed directly to the heating beam(s). A combination thereof may also be provided dependent how transparent the primer layer may be to the heating beam.

In embodiments of the present disclosure, the power of each of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be at least 500 W, such as at least 750 W, such as at least 1000W. In some embodiments, the power of one or more of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be at least 1300 W such as at least 1500 W. In certain embodiments, the power of one or more of the one or more laser light beams may even be at least 2000 W, such as at least 2800 W.

However, in other embodiments of the present disclosure the power of one or more of the one or more laser light beams may be at least 100 W, such as at least 250W. In some embodiments of the present disclosure, the power of one or more of the one or more laser light beams may be below 20 kW, such as below 15 kW, such as below 11 kW, for example below 8000 W.

In some embodiments of the present disclosure, the power of one or more of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be between 100W and 20 kW, such as between 250 W and 15 kW, such as between 500 W and 11 kW.

In some embodiments of the present disclosure, the power of one or more of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be between 500 W and 15 kW, such as between 700 W and 8000 W.

In some embodiments of the present disclosure, the power of one or more of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be between 500 W and 5000 W, such as between 700 W and 3500 W.

In some embodiments of the present disclosure, the sum of the power of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be is at least 200 W, such as at least 400 W, such as at least 800 W, such as at least 1200 W, such as at least 2000 W.

In some embodiments, the sum of the power of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be between 200 W and 15 kW, such as between at least 400 W and 11 kW, such as between 800 W and 5000 W. For example, if two laser light beams are used for heating the solder material, and if one of these laser light beams has a power of 700W, and the other has a power of 2100W, the sum of the power of the laser light beams is 2800W.

In some embodiments of the present disclosure, the sum of the power of the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 may be at least 150W per meter of solder material, such as at least 250W per meter of solder material, such as at least 500W per meter of solder material, for example at least 750W per meter of solder material. For example, if a 2.5 meter edge seal (total edge seal length) of a glass sheet assembly is to be heated and softened by one or more laser light beams, and the sum of the power of the one or more laser light beams is at least 500W per meter of solder material, the sum of the power of the one or more laser light beams is 2.5 x 500W = at least 1250 W. Hence, if one laser light beam is used, it may have a power that is at least 1250 W. If more than one laser light beam is used for softening the solder material, the sum the laser light beam power of these beams will be at least 1250W. This power may be shared equally between the laser light beams, or the power of one laser light beam may be controlled/set to be higher than the power of the other laser light beam.

In some embodiments of the present disclosure, during the step of softening the solder material 7 at the edge sealing station 22, the solder material 7 may be heated by the one or more beams 9, 9 1, 9_2, 9_3, 9_4 so that the temperature difference between any two positions of the solder material along the total longitudinal extent L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly does not exceed 30 °C, such as does not exceed 20 °C such as does not exceed 10 °C during at least 30%, such as at least 60% or at least 90% of the heating by means of the one or more laser light beams t3-t5.

In certain embodiments of the present disclosure, during the step of softening the solder material 7 at the edge sealing station 22, the solder material 7 may be heated by the one or more beams 9, 9 1, 9_2, 9_3, 9_4 so that the temperature difference between any two positions of the solder material along the total longitudinal extent L AB + L_ BC, + L CD + L_DA of the solder material 7 of the glass sheet assembly does not exceed 8 °C, such as does not exceed 6 °C during at least 30%, such as at least 60% of the heating by means of the one or more laser light beams.

It is generally understood that one or more of the:

• laser light beam 9, 9 1, 9_2, 9_3, 9_4 power values,

• laser light beam 9, 9 1, 9_2, 9_3, 9_4 movement speed values,

• number of heating iterations, and/or

• temperature difference at the solder material along the longitudinal direction of the solder material described above in relation to fig. 23 may also, in some embodiments, be used in relation to other embodiments described in the present disclosure, for example one or more of the embodiments described above in relation to one or more of figs. 3-22. In other embodiments, one or more of the:

• laser light beam 9, 9 1, 9_2, 9_3, 9_4 power values,

• laser light beam 9, 9 1, 9_2, 9_3, 9_4 movement speed values,

• number of heating iterations, and/or

• amount of joule provided per each one-tenth of a second for a period of e.g. at least 30 seconds or at least 60 seconds,

• temperature difference at the solder material along the longitudinal direction of the solder material may be set as described in more details above and/or below, for example as described in relation to one or more of figs. 10-14.

The softening of the solder material by locally heating the solder material 7 by means of moving the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 in the lengthwise direction LDS of the solder material so as to heat the full/total longitudinal extent 2 L_soider = L_AB + L_ BC, + L CD + L_DA of the solder material 7 in a plurality of consecutive, such as continuous, heating iterations provides that a more even/uniform, gradual heating and softening of the total length L_soider of the solder material 7 is obtained during the heating time (t3-t5) where the solder material is heated by the one or more laser light beams. Hence the entire/total solder material length L_soider gradually increase in temperature Te during the heating time t3-t5 until the desired target temperature (see e.g. T3 in figs. 7-8) of the total solder material 7 length is reached.

Thus, the total longitudinal extent 2 L_soider = L AB + L_ BC, + L CD + L_DA of the solder material may be heated to have a uniform temperature at the same point in time during the heating time t3-t5 by means of the one or more laser light beams. For example, the full total longitudinal extent 2 L_soider = L AB + L_ BC, + L CD + L_DA of the solder material may be heated to have a uniform temperature at the same point in time so that e.g. force clamping by means of a pressure difference may be provided during the heating t3-t5. Local variations in temperature of the solder material may occur due to local temperature peaks Pt caused by heating by means of a heating beam at a local area of the solder material when the heating bema is swept along the solder material, but generally. However, a more uniform temperature of the total longitudinal extent 2 L_soider = L AB + L_ BC, + L CD + L_DA of the solder material at the same points in time is obtained during the heating t3-t5. I l l

The step S233 (St. las. & mir. (t3)) of softening t3-t5 of the solder material 7 by locally heating the solder material by means of one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 is started by turning on the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 and starting one or more mirrors so as to provide the plurality of consecutive heating iterations along the full longitudinal LDS extent 2 L_sotder = L_AB + L_BC + L_CD + L_DA of the solder material.

An iteration tracker, such as an iteration counter, may be started, see Step S234 (St. It. Count). This iteration tracker, such as a counter, may be used for keeping track on when the desired amount of heating iterations have been provided. A software program code may, when executed, keep track on when one iteration has been provided. Instead of a counter, a timer, movement detector, distance measurer and/or the like may be used. The iteration tracking, such as counting, may be a direct, indirect or derived counting. Instead of counting iterations, e.g. a timer may be used. It can be determined how many iterations that may be done per time unit by knowing the laser light beam movement speed and the total solder material length. For example, by determining the time for providing one heating iteration, the time for providing a desired number of consecutive heating iterations may be determined.

In optional step S235 (St. tim 1.), an optional, first timer is started. It is understood that the flow chart in fig. 23 also illustrates an optional embodiment of providing a force clamping as e.g. described above and/or below by means of providing a pressure difference. The timer may be set to a predefined time setting defining how long time after the heating by means of the one or more laser light beams is started , the pressure difference should be initiated. The steps and tests related thereto are illustrated in dashed boxes, to indicate that e.g. these tests and steps may be optional.

The iteration tracker (S234) may additionally or alternatively, in some embodiments, be used as means for determining when a delayed (i.e. an intentional delay to a time after laser heating is started) force clamping should be initiated.

In other embodiments, instead of or in addition to force clamping by means of a pressure difference, mechanical clamping by means of e.g. one or more actuators (see e.g. fig. 16) and/or a plurality of clips may be used for providing the force clamping. If using clips distributed around the edge of the assembly 1 for providing the force clamping, these may be applied at the glass assembly 1 already before arranging the assembly 1 in the edge sealing station 200, or even before arranging the assembly 1 in a preheating station 100. The clips may then be removed e.g. after the final evacuation and sealing of the VIG unit assembly has been provided. It is understood that exterior mechanical clamping parts for force clamping in other embodiments may be omitted and that alone active force clamping by means of evacuating the gap may be used.

In optional test TE231 (Tim 1. done?), it is tested if the pressure difference initiation timer set in step S235 is done. If it is done, this may mean that the pressure difference is to be initiated. Hence, in test TE232 (Press. Diff?), it is tested whether the pressure difference has already been initiated. If it has not, the pressure difference is initiated in step S236 (Prov. Press. Diff. (t4)) e.g. by turning on a pump. If the test TE232 on the other hand is positive, the pressure difference has already been initiated and step S236 is omitted, and it is continued to test TE233. This test may TE232 e.g. also be provided in other ways or e.g. omitted.

At test TE233 (Full It. Done?) it is tested by an iteration tester whether one full heating iteration has been done. That may e.g. be determined by means of one or more sensors such as optical sensors, by means of one or more outputs from a beam steering mirror controller and/or the like. When one heating iteration is done, the counter set in step S234 is reduced by 1 in step S237 (Count -1), alternatively it may be increased.

When all heating iterations set by the counter at step S234 have been provided (tested in test TE234 (It. Count fin.?)), the laser heating is stopped, see Step S238 (Stop heating (T3) (t5)) . If all iterations set by the counter at step S234 have not yet been provided (test TE234), the heating is continued and it is again tested if the heating should be stopped (TE234) when a new, full heating iteration has been provided (TE233).

It is noted that instead of using iteration counting or the like, a temperature measurement circuitry may measure, e.g. wirelessly by e.g. infrared measurement, e.g. at one or more locations of the edge seal, whether the solder material has been heated to the desired temperature T3. In that case, the temperature measurement may trigger stopping the local heating S238 (Stop heating (T3) (t5) when a temperature test turns out positive and the total solder material 7 length has hence been heated to the desired temperature.

It is also noted that instead of using iteration counting or the like, a timer may be used to determining whether the solder material has been heated to the desired temperature T3. In that case, a preset time may be set, and when the timer has ended/run out, the heating is stopped. This may e.g. be based on one or more of the following:

• experiential data

• data on seal material length,

• laser movement speed,

• laser power

• and/or the like.

Stopping the local heating reduces the temperature of the solder material. For example, in some embodiments, the temperature of the solder material caused by the heating by locally heating the solder material, may be above the melting point temperature Tm for less than 15 seconds, such as less than 10 seconds, such as less than 5 seconds.

In additional or alternative embodiments other embodiments, the temperature of the solder material caused by the heating by locally heating the solder material, may be above the melting point temperature Tm for more than 2 seconds, such as more than 5 seconds, such as more than 9 seconds.

In optional step S239 (St. Tim2.) a timer is started to give the solder material 7 time to cool before stopping the vacuum clamping. The time setting for the timer may e.g. be as described according to various embodiments above in relation to fig 7, and/or as described below.

When the timer set in step S239 is done (tested in test TE235 (Tim2. Done?) the optional pressure difference is eliminated, see step S2310 (Sto. press, diff (t6)).

After step S2310 (or after step S238, dependent on if the force clamping is provided by temporarily evacuating the gap 5), the edge sealed glass sheet assembly 20 may be moved to an evacuation and sealing station 300 as e.g. described according to various embodiments above and/or below for final evacuation and sealing. This enables using the edge sealing station for edge sealing a new glass sheet assembly 1.

It is understood that in some embodiments, instead of releasing the pressure difference at the edge sealing station, the pressure difference may be maintained while and/or after it is moved into the evacuation and sealing station 300. E.g. if the same evacuation cup is used at both stations and if the evacuation cup may be temporarily sealed.

It is understood that in still further embodiments, the edge sealing station may also be used for the final evacuation and sealing of the glass sheet assembly so as to obtain the final VIG unit 30. In that case, the consecutive station 300 of figs. 3-4 may be omitted. However, as the final gap 5 evacuation takes longer time than the time it takes to obtain the edge sealed glass sheet assembly 20 by means of the locally heating by means of e.g. one or more laser light beams, the manufacturing capacity may hereby be reduced. In other embodiments (not illustrated) the laser light emitters and e.g. other parts may be moved between different edge sealing stations, e.g. by being displaceable on e.g. a rail system, such as by means of one or more displacement motors, so as to locally heat the solder material of different glass sheet assemblies at one or more other edge sealing stations while an already edge sealed glass sheet assembly is evacuated and finally sealed off in another edge sealing station.

It is generally understood that in some embodiments of the present disclosure, the edge sealing station 200 may be used for edge sealing various types of glass sheet assemblies 1. The various types may differ in e.g. size and/or edge seal type. For example, a first glass sheet assembly type may comprise a solder material 7 with a full/total longitudinal extent S Lsoider ⁼ L_AB + L_ BC, + L_CD + L_DA that is e.g. 2.5 meter long, whereas another glass sheet assembly type may have a full/total longitudinal extent 2 L_soider ⁼ L_AB + L_ BC, + L_CD + L_DA of the solder material 7 of e.g. 4.5 meters. This may be caused by that the glass sheets of the second type has a larger surface area than the first type. Some edge seals may comprise primers whereas others may not. Also, some edge seals may comprise different primer characteristics that may call for different settings. In order to provide a desired edge sealing by means of the one or more laser light beams across different glass sheet assembly types, a controller may be configured to control the one or more laser light means dependent on the glass sheet assembly type.

Fig. 24 illustrates embodiments of the present disclosure, wherein a controller comprises a data storage DS with preset information Typ_l-Typ_n. Each type comprises a number of settings (Type Typ l e.g. comprises Titl, Pol and Spl) to be selected dependent on the glass sheet assembly type to be edge sealed at the edge sealing station.

For example Typ l may be preset as follows

• Titl = 480 heating iterations

• Po = 800 Watt

• Sp = 5 meter/second (m/s)

For example Typ_2 may be preset as follows

• Tit2 = 900 heating iterations

• Po = 1500 Watt

• Sp = 10 meter/second (m/s)

As can be seen, if the first assembly 1 type Typ_l is selected, 480 heating iterations may be provided with a laser beam power of 800 Watt and a movement speed along the longitudinal direction LDS of the solder material of 5 meter per second. If on the other hand the second assembly 1 type Typ_2 is selected, 900 heating iterations may be provided with a laser beam power of 1500 Watts and a movement speed along the longitudinal direction LDS of the solder material of 10 meter per second. Accordingly, if a glass sheet assembly of the first type is selected to be processed at the station 200, the first setting type type_l may be selected. If on the other hand a glass sheet assembly of the second type (e.g. having a longer edge seal than the first type) is selected to be processed at the station 200, the second setting type_2 may be selected.

It is understood that at least two different types, such as at least four different types, such as at least 8 different types Typ l, Typ_2, Typ_3, Typ n may be present in the data storage DS and relate to different settings to be used at different glass unit assembly types. The heating iterations Titl-Titn may in some embodiments be the total number of heating iterations to be provided at a sub-part of the total solder material length (e.g. if the total solder material length is divided into more than one heating area), or it may be the total number of heating iterations for the total length of the solder material. In some embodiments, different heating beams such as laser light beams, may be used for providing different numbers of heating iterations.

In other embodiments, different heating beams such as laser light beams, may be used for providing the same numbers of heating iterations.

The detection of the glass sheet assembly 1 to be processed at the edge sealing station may be provided by a human control person that by means of a user interface on e.g. a screen (not illustrated) selects between the correct type settings Typ_l . . . Typ_n dependent on the assembly 1 type to be processed. Thereby a controller CTR adjusts the relevant settings accordingly.

In other embodiments, the detection of the glass sheet assembly 1 to be processed at the edge sealing station may be automatized. For example, a scanner system 240 comprising one or more sensors, such as optical sensors, and/or the like may detect which type of glass sheet assembly that is to be processed at the edge sealing station 200. In some embodiments, the glass sheet assembly 1 may comprise a type ID label TID, such as a code, such as a bar code, a QR code, An ID number or the like. The type identification/type ID label TID comprises identification information enabling identification of the glass sheet assembly 1 type. The type identification label TID may be temporarily or permanently applied at the assembly 1, e.g. prior to the processing at the preheating station and/or prior to processing at the edge sealing station. In some embodiments, the type identification label TID may e.g. be engraved into a glass sheet 3, 4 of the glass sheet assembly, e.g. by laser, or it may be printed or the like onto the assembly 1. In other embodiments, no specific identification label may be present at the assembly 1, and the scanner 240, such as a camera, may e.g. be used for deriving dimensions or the like, e.g. by means of image recognition, in order to enable selecting a proper type Typ_l-Typ_4 from the storage DS.

Hence, by automatically detecting 240 the type of glass sheet assembly to be processed at the edge sealing station, a hardware controller CTR may receive such information 241 and based thereon access the data storage DS so as to automatically select the proper/intended type setting in the data storage DS. This identification may be done prior to the preheating step, it may be done when the assembly 1 enters the preheating station (if such a station is present), it may be done upon, such as during transfer from the preheating station to the edge sealing station, and/or it may be done and/or confirmed when the assembly has been positioned at the edge sealing station (e.g. as is the case in fig. 24). Hence, if detecting e.g. a “Type 2” assembly 1 by means of the scanner 240, the controller CTR, such as a micro controller or the like, may select the Typ_2 settings and provide the proper acts in order to assure that these are used when controlling the mirror controller 16 and the laser 17 beam 9', 9 power in order to provide the heating of the solder material.

Naturally, if more lasers than one are used for the local heating of the solder material 7 as e.g. described above and/or below according to various embodiments of the present disclosure, the type information in the data storage may enable selecting the proper settings for this too.

E.g. based on the above, a plurality of glass sheet assemblies of different types may be processed at the edge sealing station 200. The controller CTR may thus adjust one or more of

• the laser beam power,

• the movement speed of the laser light beam along the longitudinal direction LDS of the solder material 7,

• the number of heating iterations dependent on the type of glass sheet assembly 1 to be processed at the edge sealing station 200. The adjustment may e.g. be based on the preset values assigned each type Typ l, Typ_2, Typ_3, Typ n, which are stored in the data storage DS. In some embodiments, the controller CTR provides the adjustment based on input from the scanner system 240, such as a scanner system which reads a type identification label TID at the respective glass sheet assembly to be processed.

Fig. 25 illustrates a part of a flow chart relating to a method of softening the solder material by means of one or more laser light beams, according to embodiments of the present disclosure. In the example of fig. 25, it is assumed that a heating area, such as the area ARI or AR2, SA of fig. 13, 14 or 22 is to be heated by a laser light beam. Another laser light beam may e.g. heat another heating area.

In fig. 25, softening of the solder material 7 is provided in a plurality of consecutive heating iterations. Each heating iteration may comprise locally heating the solder material by means of moving one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 in the lengthwise direction LDS of the solder material. If the solder material 7 length L_soider is divided so that more than one heating area ARI, AR2 is present, these heating areas may be heated by a combination of laser light beams so as to heat the full longitudinal LDS extent

^solder ⁼ L_AB + L_BC + L_CD + L_DA , ARI + AR2 of the solder material 7, e.g. as described above according to different embodiments.

In step S251 (STP) a mirror, such as a beam steering mirror, is adjusted to be ready to provide heating of the solder material from a heating area starting point STP. For understanding, in the present non-limiting example, it is imagined that it is the heating area ARI of fig. 22 that is to be heated. The mirror is adjusted properly top start heating from the starting point STP when the laser light beam is turned on. In step S252 (Laser on), the laser light beam is turned on, and in step S253 (LB alo. ES (t3)), the laser light beam is moved along the lengthwise direction LDS of the solder material 7 strip D-A from the starting point STP, over the comer area A, along the lengthwise direction LDS of the solder material strip A-B, over the comer area B, along the lengthwise direction LDS of the solder material strip B-C, over the comer area C, and along the lengthwise direction LDS of the solder material strip C-D, to the end point EP of the heating area ARI .

As can be seen in test TE251 (EP rea?), when the end point EP of the heating area ARI is reached, the laser light beam may be turned off, redirected or the like, see step S254 (Laser off).

If not all desired/planned heating iterations are done, see test TE252 (All It. done?) - e.g. tested by means of counter, by means of a timer, by means of an optical sensor and/or the like -, the mirror is repositioned again (Step S251) to heat the same heating area ARI from the starting point STP again. This may be continued until all heating iterations have been performed so that the full length of the solder material at the area ARI is gradually increased (e.g. stepwise) in temperature until the desired target temperature has been obtained. The remaining area AR2 may be heated by means of another laser in substantially the same way. However, in some embodiments, the laser light beam power, number of heating iterations and/or movement speed of the laser light beam used for heating the second area AR2 may be different for the laser beam power, number of heating iterations and/or movement speed of the laser light beam used for heating the first area ARI .

Hence, each heating iteration may comprise locally heating the solder material by means of moving the two laser light beams in the lengthwise direction LDS of the solder material along different heating areas ARI, AR2 of the solder material, so as to heat the full longitudinal LDS extent X f_so(der = L_AB + L_BC + L_CD + L_DA , ARI + AR2 of the solder material 7. Here, one heating iteration is thus obtained by means of a combined heating where two laser light beams together heat the full longitudinal LDS extent

^solder ⁼ L_AB + L_BC + L_CD + L_DA , ARI + AR2.

It is understood that in other embodiments as e.g. previously described, the same laser light beam may heat the full longitudinal extent of the solder material.

One, more than one, or all, steps and tests illustrated in fig. 25 may in some embodiments be comprised in step S93 of fig. 9.

The heating of the heating areas ARI, AR2 may or may not be timed with respect to each other. The heating of the heating areas ARI, AR2, respectively may e.g. be heating operations that are controlled by the same hardware controller or may distributed to different sub-hardware controllers. The heating of the areas ARI, AR2 may in some embodiments be timed so as to start t3 and stop t5 at substantially the same time.

It is generally understood that the heating areas ARI, AR2 are arranged in continuation of each other along the solder material length (in the longitudinal direction LDS of the solder material 7), and may or may not overlap.

It is generally noted that any of the methods described in the present disclosure, for example in any of the claims and/or in relation to one or more of the figures described above and/or below, may be implemented by means of one or more computers. The term 'computer' may include any electronic device which is suitable to process information and perform steps as e.g. described in the present disclosure. The one or more computers may include general purpose computers such as laptop and desktop PCs, one or more programmable, logic controllers (PLC) , embedded computers and/or the like. It is understood that one or more data input interfaces and/or data output interfaces may be used for communication between the computer(s) and components/equipment such as comprising sensors, actuators, motors, heating equipment, one or more ventilators one or more pumps, one or more radiation heaters such as lasers, external to the computer(s).

It is generally understood that, as also previously described, the solder material 7 may be a glass solder material, for example a glass solder frit material, such as a low melting point solder frit material, such as a low melting point glass solder frit material (also called a low melting solder glass). The low melting point solder frit material, such as low melting point glass solder frit material may preferably be substantially lead free. The low melting point glass solder frit material may e.g. be vanadium based, bismuth based and/or tellurium based, but other solder material types and/or compositions may also be used.

Figures 26a and 26b illustrate a schematic time-temperature profde and its corresponding spatial context during the local heating of solder material 7, according to embodiments of the present disclosure. The temperature plotted in Fig. 26a is the temperature of a small section 18 of the solder material 7, as indicated in Fig. 26b. Fig 26a is based on measurements from a test where the solder material of a small, local area 18, such as a section, of the solder was measured during the heating by means of a laser light beam in a plurality of consecutive heating iterations. However, the stepwise heating of the solder is a reinterpretation of the stepwise heating, since it would not be possible to clearly represent all heating iterations in a single graph. See however fig. 27b which confirms the stepwise heating.

The local area 18 is a sub-part of the length of the solder material 7, and may or may not comprise the solder material extending along the entire width of the solder material 7 strip at said area 18.

The local area 18 may in some embodiments be a sub-part of the solder material 7 along the solder material length, where the length of the sub-part in the direction of the longitudinal extent of the solder material is 10 mm or less, such as 5 mm or less, such as e.g. 1 mm or less. In Fig. 26a, the time-temperature profile shows the temperatures Tl, T2, and T3, which correspond to specific points in the sealing process of the glass sheet assembly. The plot includes specific points in time, represented by tl, t2, t3, t4, t5, and t6, see also fig. 8.

A selection of the plurality of consecutive heating iterations is represented by il, i2, i3, iN, and iN+M, with il being the first iteration in the heating sequence. iN corresponds to the Nth local heating iteration, which is the first local heating iteration after the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly 1 is initiated. iN+M is the last local heating iteration of the plurality of consecutive heating iterations.

It is generally understood that these iterations may help control the amount of energy delivered over time to the solder material by means of the one or more radiation heating beams, such as laser light beams, ensuring the optimal softening and sealing of the solder material.

In this profile, Tl represents the pre-heating target temperature of the glass sheets, achieved through initial heating before one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 are used to locally heat and soften the solder material. T2 corresponds to the temperature of the solder material 7 when the pressure difference P2 is established between the gap 5 of the glass sheet assembly 1 and the pressure P 1 surrounding the glass sheet assembly 1 in the edge sealing chamber 201. T3 is the target temperature of the solder material 7, at which point the local heating by the one or more laser light beams 9, 9 1, 9_2, 9_3, 9_4 is discontinued.

The jumps in the temperature of the solder material between t3 and t5, as shown in Fig. 26a, correspond to the instances when a laser passes over the small section of solder material and it heats up stepwise due to the power input from the laser and the plurality of heating iterations. This provides a sawtooth like temperature profile. This may also be referred to as a stepwise heating or consecutive heating iterations in the present document. After the laser beam passes over this section, the solder material cools slightly, as heat is dissipated into e.g. the surrounding glass and the environment. When the laser beam passes over the section again in the next iteration, the temperature of the solder material jumps again, repeating this pattern with each passage of the laser during the plurality of consecutive heating iterations. If there are N+M local heating iterations between t3 and t5 or t6, then the time interval between each passage of the same laser light beam is (t6 - 13) / (N+M) or (t5 - 13) / (N+M) assuming that the same laser light beam sweeps the full extent of the solder material L_AB + L_ BC + L CD + L_DA and the local heating of the solder material comprises consecutive, continuous heating iterations. This may naturally be varied as e.g. explained above, dependent on the number of lasers used for heating, and the jumps in temperature may be caused by the same laser beam or more than one laser beam visiting the same area for reheating.

The gradient of the temperature profde of the solder material may decrease with time. This is due to the larger temperature difference that builds up between the solder material and its surroundings, including the glass sheets and the atmosphere. As the temperature difference increases, the rate of heat dissipation also increases during the time between two consecutive iterations. This greater heat dissipation results in a more pronounced cooling effect during the intervals between laser passes, contributing to the flattening of the temperature profde as time progresses.

Fig. 26a illustrates a further embodiment wherein, after t4, when the pressure difference is initiated, the jump in the temperature of the solder material 7 is caused by the effect of the vacuum clamping process. As the vacuum pressure is applied, the width of the solder material increases slightly due to the clamping force exerted by the glass sheets 3 and 4. This increase in width results in a reduction in the thickness of the solder material. The radiative flux of the laser light beam may remain constant for the same cross-sectional area of the solder material, and the reduced thickness of the solder material may provide that less material is being heated for the same amount of energy input from the laser light beam. As a result, the solder material absorbs more radiative flux per unit volume, which may lead to a more rapid increase in its temperature. This explains the observed jump in temperature in Fig. 26a after t4. In this stage, the clamping not only improves the contact between the solder material and the glass sheets, but the thinner solder material may also heat up more efficiently due to this change in geometry, allowing it to reach higher temperatures more quickly.

It is understood that various settings of the laser, such as the laser beam size and/or type, may influent on the heating profile, and also, measurement solutions may influent on how the transition at time t4 looks. Some tests indicates that only a low or substantially no temperature drop may occur when the force clamping is provided at t4, at least when using a significantly wider laser beam spot.

It is naturally to be understood that this effect may depend on e.g. one or more of

• the amount of solder material used, such as the thickness of the solder material used,

• the type of laser used,

• the type of solder material used

• if a primer between solder material and glass sheet is used or not

The cooling of the solder material during the period between each passage of a laser light beam is influenced by several factors. A thicker solder material may cool more slowly for a fixed cross-sectional area than a thinner material, which has less volume to dissipate heat. The thermal conductivity of the solder material also plays a role, with higher thermal conductivity materials cooling more quickly. A greater temperature difference between the solder material and its surroundings may also increase the rate of heat loss. A heater, such as e.g. a heater 220 as described above) may e.g. reduce such heat loss. The surface area exposed to the surrounding glass and air may affect cooling, as a larger surface area results in a higher rate of heat loss. The thermal conductivity of the glass sheets is also a factor, as higher conductivity glass acts as a better heat sink. Additionally, the ambient temperature in the sealing chamber influences the rate of cooling, with cooler surroundings promoting faster heat dissipation. Also, if a primer is used between the solder material and one of the glass sheets, this may affect the cooling of the solder material. Finally, the pressure in the sealing chamber may alter the heat transfer rate, with lower pressures reducing the rate of heat loss.

To better control the cooling rate of the solder material, at least one primer layer with a lower thermal conductivity than the solder material may be arranged between the solder material and one or both of the glass sheets.

The heating provided between t3 and t4 may be considered an initial local heating (and thereby softening) of the solder material 7. This time interval may help to improve contact and/or provide a more airtight connection between the glass sheets 4, 5, and the solder material before the pressure difference is applied.

At t4, the pressure difference between the pressure in the gap 5 of the glass sheet assembly 1 and the pressure surrounding the glass sheet assembly is initiated. This pressure difference causes the glass sheets 3, 4 to clamp the solder material 7, improving the contact between the solder material 7 and the glass sheets 3, 4, ensuring a more effective seal. The lower pressure in the gap 5 of the glass sheet assembly 1 may also, as explained above, at least to some extent slow the cooling rate of the solder material 7 between each passage of the laser light beam.

At t5, the local heating of the solder material 7 is stopped. Once the local heating is discontinued, the temperature of the solder material 7 begins to drop, as the glass sheets 3, 4 and the atmosphere surrounding the glass sheets 3, 4 are cooler than the solder material 7, acting as heat sinks to facilitate its cooling.

In some embodiments, as e.g. previously described, the pressure difference may be maintained after stopping the local heating, and the pressure difference may only be eliminated at a later point in time, t6, after the local heating has been stopped at t5. This approach can further improve the sealing by ensuring that the solder material has sufficiently cooled before the pressure is equalised.

It is generally understood that the laser light beam power may be obtained by means of adjusting the laser power.

Figs. 27a and 27b are time-temperature profiles of a local area / local portion 18 (see fig. 26b) that are based on a conducted temperature measurement Te test of the solder material temperature during heating by means of a laser light beam providing a plurality of consecutive heating iterations at the area 18. The test was conducted on a VIG unit assembly. No primer between glass sheet and solder material was used in this test. The stepwise heating between t3 and t5 as illustrated schematically in fig. 26a is not shown in fig. 27a, since that provides a more unclear view of the heating during the heating time t3-t5. If the stepwise heating with heating spikes was presented in fig. 27, it would merely indicate a very bold, uneven un-even temperature profile Te due to the plurality of heating iterations that may have a thickness corresponding in temperature to the height of the heating spikes/peaks Ptl illustrated in fig. 27b. However, a small cutout CO of the graph in fig. 27a is illustrated in fig. 27b where the stepwise heating can be seen. Due to the relatively high laser movement speed and the relatively large amount of heating iterations provided in the test, the steps would not be readable in fig. 27a. The cutout CO of fig. 27 that is illustrated in fig. 27b is taken from a location between t3 and t5 of the temperature graph Te in fig. 27a, in this case from 24 to 26 seconds into the heating time between t3 and t5.

The settings was as follows in the test illustrated in figs. 27a-27b:

• Laser movement speed along the longitudinal direction of the solder: 10 m/s

• Laser light beam power 1500 W

• Laser spot width ~015mm Gaussian beam

• Force clamping by evacuating the gap: at t4=2 minutes from the heating is started at t3.

• The glass sheet assembly was preheated to 310°C, and was approximately at this temperature when the heating was started at t3,

• Glass unit assembly size: 398 mm x 635 mm with tempered glass sheets.

• Total heating time from t3 to t5: 3 minutes and 7 seconds.

The temperature measurement in figs. 27a-27b was conducted by means of camera (a Infratec® ImageIR® 8300 hp camera was used and one or more measurement “pixels” were selected/defined). The camera was configured to provide temperature measurement at the centre of the edge seal (substantially midways between side edges of the edge seal). The measurement area size at the local area 18 may be e.g. 1 mm² or below 1 mm².

It is understood that Figs. 27a and 27b each are the result of approximation based on two test graphs in order to provide an improved understanding. In fig. 27a, the graph has been drafted as an approximation of the plots available from the test. It is noted that the test of figs 27a and 27b was two separate tests on substantially identical glass sheet assembly samples, where the test in fig. 27a was conducted in order to get a full (but lower resolution) temperature profile of the solder material during the entire heating time t3-t5, whereas the test in fig. 27b was conducted in order to get a higher resolution temperature profile of a local area of the solder material.

The sampling speed of the camera was in fig. 27b 100 fps (100 frames per second) and thus some of the plots that form basis for the graph may still vary a bit due to the relatively high number of heating iterations per second. However, it is clear from fig. 27b that each time the laser beam passes the solder material area (see 18 in fig. 26b) a rapid increase in temperature occurs, followed by a gradual cooling of the solder material until a new heating iteration is started at the same solder material area. As can be seen in fig. 27b, the solder material was subjected to approximately five heating iterations per second in the test. For example, a new heating iteration of the same area is started at time t_a. This causes the solder material temperature Te to rapidly increase to a local spike temperature Ptl (also called peak temperature in the present document), and when the laser light beam spot leaves the solder material area 18, the solder material temperature gradually reduces until time t_b where a new heating iteration is started.

It is understood that the higher the laser movement speed along the longitudinal direction of the solder material strip is, the shorter time (t_a to t_b) will there be between two adjacent spikes Ptl . In the same way, the lower the laser movement speed is, the longer time (t_a to t_b) will there be between two adjacent spikes Ptl.

In e.g. fig. 27a, The laser power and laser movement speed was maintained substantially constant over the heating time t3-t5. It is understood that in other embodiments of the present disclosure, the heat dissipation from the solder material that may cause a reduction of the speed with which the solder material reaches the target temperature T3 may be compensated for by control and/or regulation, e.g. by regulating one or more of the laser beam power, the number of laser beams used and/or the laser movement speed during the heating time t3-t5. It is generally understood that the laser beam power and laser beam movement speed may be adapted so that the heating iterations causes an overall gradual temperature increase in the seal material during the heating time t3-t5 until the desired target temperature T3 is reached.

The temperature values are not illustrated in neither fig. 27a nor fig. 27b, but as can be seen, the scale is set in fig. 27b so that each mark at the y-axis of fig. 27b (relating to temperature of the solder material) indicates a 5 °C jump in temperature. It can thus be derived from fig. 27b, that in the test, each heating iteration causes local temperature spikes/peaks Ptl of approximately 6-10°C (see fig. 27b), and that a stepwise heating of the solder material is obtained. As can be seen in the graph, the solder temperature may gradually reduce between time t_a and time t_b, prior to the start of the following heating iteration. The temperature spikes Ptl are as mentioned not illustrated in fig. 27a to improve understanding of the figure.

The maximum temperature increase Til of the solder material at a point/area (see e.g. ref 18 described above) of the solder material is obtained from the laser light beam starts heating the solder material area at a start time HIS and to the time the local peak temperature Ptl is obtained at the end of the heating of the area at time HIE, during a heating iteration. The remaining time where the solder material reduces in temperature from the heating end time HIE and to a new consecutive heating iteration is started at the same solder material area at time HIS2, the laser light beam may heat another part of the solder material og the glass assembly.

It is generally understood that by e.g. increasing or decreasing one or more of:

• the number of heating iterations

• the power of the laser light beam(s),

• the total heating time (t3-t5) by means of the one or more lasers

• the number of laser light beams used, the total heating time t3-t5 may be adjusted, e.g. to be in a time ranges as previously described according to various embodiments of the present disclosure.

It is generally to be understood, that in some embodiments of the present disclosure, the maximum temperature spike Ptl caused by a heating iteration, may be lower than 50°C, such as lower than 30°C, such as lower than 15°C. This may in some embodiments be the case for at least 5%, such as at least 20%, such as at least 50%, such as at least 90% of the total amount of heating iterations performed during the heating time t3-t5. This may e.g. be adjusted by adapting the laser movement speed along the longitudinal direction of the solder material and/or by adapting the laser power prior to and/or during the heating time t3-t5.

It is generally to be understood, that in some embodiments of the present disclosure, the maximum temperature spike Ptl caused by a heating iteration may in embodiments of the present disclosure be lower than 12°C, such as lower than I0°C, such as lower than 8°C per heating iteration. This may in some embodiments be the case for at least 20%, such as at least 50%, such as at least 90% or substantially all of the total amount of heating iterations performed during the heating time t3-t5. This may e.g. be adjusted by adapting the laser movement speed along the longitudinal direction of the solder material and/or by adapting the laser power prior to and/or during the heating time t3-t5. It is generally to be understood, that in some embodiments of the present disclosure, the maximum temperature spike Ptl caused by a heating iteration at a solder material point/area (see. e.g. 18 in fig. 26b), may in embodiments of the present disclosure be between 2°C and 50°C, such as between 4°C and 20 °C such as between 4 °C and 15°C per iteration. This may in some embodiments be the case for at least 20%, such as at least 50%, such as at least 90% of the total amount of heating iterations performed during the heating time t3-t5. This may e.g. be adjusted by adapting the laser movement speed along the longitudinal direction of the solder material and/or by adapting the laser power prior to and/or during the heating time t3- t5.

If the total number of heating iterations performed during the heating time t3-t5 is decreased, larger local, maximum temperature spikes/peaks Ptl may be accepted due to higher laser beam power in order to reduce the overall heating time t3-t5. The size of the temperature spikes may, in some embodiments, be adjusted during the heating, e.g. so as to be lower towards the end of the heating in order to reduce or avoid temperature overshot when the solder material temperature Te gets close to the target temperature T3.

The faster the movement speed of the one or more heating beams, such as laser light beams, the lower the local, maximum temperature spikes/peaks Ptl may become, as the amount of power induced into the local area of the solder material per time unit during a heating iteration is reduced.

In some embodiments of the present disclosure, the laser power and/or the laser movement speed may be kept substantially constant during the heating time t3-t5 where the solder material of the VIG unit assembly is locally heated by means of one or more lasers.

It is understood that in other embodiments of the present disclosure, one or more of the laser power, the laser movement speed and/or the like may be adjusted during the heating time t3- t5 where the solder material of the VIG unit assembly is locally heated by means of one or more heating beams 9, 9 1, 9_2, 9_3, 9_4 which is/are moved in the longitudinal direction of the solder material. It is generally understood that in embodiments where the laser beam power may be adjusted, before and/or during the heating time t3-t5, this power adjustment may involve e.g. one or more of the following:

• Using input power control which may involve adjusting the electrical power supplied to the laser which, in turn, affects the energy available.

• Pulse Width Modulation (PWM) so as to control the average power delivered by a pulsed laser. The laser may here in some embodiments be turned on and off (at high speeds) with variable predefined on and off times, and this changes the average power output of the laser light beam.

• Physical Optical Elements may be placed in a laser beam path of the laser so as to attenuate the beam and reduce its power,

• another way of laser beam power adjustment, e.g. implemented by the laser manufacturer.

It is though understood that other suitable ways of adjusting the laser power may also be used. The laser type, such as a continuous wave laser, may comprise a control system configured to be controlled so as to adjust the laser beam power. Hence, a user or a computer program may determine or set a power value for the laser light beam by means of said control system, e.g. by means of a user interface.

Figs. 28-31 illustrate schematic time-temperature profiles of the solder material temperature Te according to various embodiments of the present disclosure, where the power provided by the heating beam(s) and/or the laser movement speed is adjusted during the heating time t3- t5 (see e.g. figs 7-8, s6a and/or s7a). It is understood that the temperature profile Te of the solder material is schematically illustrated and represents a heating of a local area of the solder material, such as a sub-portion of the longitudinal extent of the solder material. It is also understood that more iterations than those illustrated within each heating profile HP1- HP4 may naturally be provided during the heating time t3-t5. Different predefined heating profiles HP1-HP4 are used in the various embodiments illustrated in figs. 28-31. It is understood that the figures are also schematic in the sense that e.g. heat dissipation, change in optical properties and/or other properties of the solder material during the heating, may not be accounted for in these figures. In figs. 28-33, laser light beams are used as examples of the heating beam(s), but other heating beam types may also be used in further embodiments of the present disclosure.

In fig. 28, the power of the laser light beam is maintained substantially constant during the local heating of the solder material. However, the heating iteration time It 1, It2, It3 is adjusted. Hence, during heating according to the heating profile HP1, a first power setting for the laser is used and a first laser movement speed is used to obtain the heating iteration time Itl . The time it takes for a or the laser light beam to revisit the same solder material area is Itl . At time t_EPl, The heating according to the first heating profile HP1 ends and a heating according to the second heating profile HP2 starts. Thus, between time t_EPl and t_EP2, the solder material is heated according to the second heating profile HP2. Here, the same laser power is used, but the iteration time It2 is increased by e.g. slowing down the movement speed of the laser, by shutting off a laser (if more than one is used) and/or the like. It can be seen that the solder material is thereby allowed to cool down more between each heating iteration, thereby reducing the temperature increase/time unit of the solder material. At time t_EP2, the heating according to the second heating profile HP2 is ended, and the heating according to the third heating profile HP3 is stared. Here, the laser movement speed is decreased further, again causing the iteration time It3 to increase which allows the solder material to cool more between each iteration. Heating profile HP3 is used until the heating is finished at t5. In fig. 28, The use of the heating profiles HP1, HP2, HP3 causes the heat increase of the solder material per time unit to decrease towards the end of the heating by means of the one or more laser light beams, when the solder material temperature gets closer to the target temperature T3. It is understood that if reducing the laser movement speed while maintaining the laser power, the peak Pt I temperature of the seal material may change, since the laser will provide more power to the seal material at each heating iteration, and the maximum heating spike Pt I may thus increase. This is schematically indicated in fig. 28. In other embodiments, both laser light movement speed and laser light beam power may be reduced in the same heating profile when compared to a heating profile used previously during the heating t3-t5.

In fig. 29, the power of the laser light beam is adjusted during the local heating of the solder material. However, the heating iteration time Itl is maintained constant. The heating iteration time Itl, It2, It3 of the respective heating profile HP1, HP2, HP3 in fig. 29 is substantially identical. In fig. 29 when heating according to the first heating profile HP1, the laser power is higher than when heating according to the second heating profile HP2. This causes a spike temperature Ptl in the solder material per heating iteration by using the first heating profile HP1 when compared to using the second heating profile HP2. Also, when heating according to the second heating profile HP2, the laser power is higher than when heating according to the third heating profile HP3. This causes the local spike temperature Ptl to reduce as time goes, and also the increase in solder material temperature per iteration period HIP (see fig. 33) decreases.

Fig. 30 illustrates an embodiment of the present disclosure, wherein the iteration time It2, It3 is changed during the heating by means of the one or more laser light beams during the local heating (t3-t5).

The laser beam power may be larger when the first heating profile HP 1 is used, when compared to when the second heating profile HP2 is used. This can be seen by that the temperature spikes Ptl are larger during HP1 than during HP2.

As also indicated in fig. 30, the heating iteration time Itl is larger when the first heating profile HP1 is used, when compared to the heating iteration time It2 used when the second heating profile HP2 is used. Hence, more lasers may be used when the second heating profile HP2 is used, and/or or the movement speed of the laser light beam(s) when heating according to the second heating profile HP2 may be adjusted to be faster than when heating according to the first heating profile HP 1. This can be seen by that the heating iteration time It2 is shorter than the heating iteration time Itl.

In fig. 30, the laser beam power may be larger when the second heating profile HP2 is used, when compared to when the third heating profile HP3 is used. This can be seen by that the temperature spikes Ptl are larger during HP2 than during the consecutive HP3. As also indicated in fig. 30, the heating iteration time It2 is larger when the second heating profile HP2 is used, when compared to the heating iteration time It3 when the consecutive third heating profile HP3 is used. Hence, e.g. more lasers may be used when the third heating profile HP3 is used, and/or or the movement speed of the laser light beam(s) along the longitudinal direction of the solder material when heating according to the third heating profile HP3 may be faster than when heating according to the second heating profile HP. This can be seen by that the heating iteration time It3 is shorter than the heating iteration time It2.

In some embodiments, a part of the reason for the larger temperature spike Ptl when using heating profile HP1 when compared to using heating profile HP2 in fig. 30, and also when using heating profile HP2 when compared to using the third profile HP3, may be that the heating iteration time Itl is increased when compared to It2, and that the heating iteration time It2 is increased when compared to It3. Longer heating iteration time may cause more energy to enter a local solder material area per heating iteration. However, additionally or alternatively, the laser beam power may also be adjusted to be different at one or more of the different heating profiles.

Fig. 31 also illustrates an embodiment of the present disclosure, wherein more heating energy is provided to the solder material earlier in the heating process than later in the heating process when getting closer to time t5.

In fig. 31, during the heating by means of the one or more laser light beams between time t3 and t5, the following applies:

• during the heating according to the first heating profile HP1 (from time t3), the heating iteration time Itl is lower/faster, and the laser beam power is higher, than the heating iteration time It2 and laser beam power used during the heating according to the second heating profile HP2,

• during the heating according to the second heating profile HP2, the heating iteration time It2 is lower/faster, and the laser beam power is higher, than the heating iteration time It3 and laser beam power used during the heating according to the third heating profile HP3,

• during the heating according to the third heating profile HP3, the heating iteration time It3 is lower/faster, and the laser beam power is higher, than the heating iteration time It4 and laser beam power used during the heating according to the fourth heating profile HP4.

Heating according to the first heating profile HP1 occurs during time t_EPl (or t3) to t_EP2, heating according to the second heating profile HP2 occurs during time t_EP2 to t_EP3, heating according to the third heating profile HP3 occurs during time t_EP3 to t_EP4, and heating according to the fourth heating profile HP4 occurs during time t_EP4 to t_EP5 (or t5).

It is generally understood that the two or more heating profiles HP1-HP4 may be used consecutively, e.g. as illustrated, during the local solder material heating t3-t5.

As can be seen in the various figures 28-31, The solder material temperature may briefly get above (see Ptl) the target temperature one or more, such as a plurality, of times during the heating between the times t3-t5. This may or may not be the case when more than one heating profile. However, since the solder material is heated by means of the one or more laser beams in a plurality of consecutive heating iterations along the longitudinal direction of the solder material, each local temperature peak/spike Ptl at the heating iterations may be controlled to not get too much over the target temperature T3, and also the time span that the solder temperature Te is above the target temperature T3 may be reduced.

In some embodiments, as e.g. illustrated in fig. 31, a plurality of consecutive, local temperature spikes/peaks Ptl (see the spike of the last two heating iterations during HP3, and all spiked during use of the last heating profile HP4) may get above the target temperature T3 as the solder material temperature Te approaches the target temperature T3.

In other embodiments, the target temperature and the control of the solder material heating may be set so that the first time the target temperature T3 is reached, the heating by means of the one or more laser light beams is stopped (t5).

In fig. 31, an initiation (time t4 as mentioned above) of the force clamping, as e.g. previously described between time t3 and time t5, is not indicated. This may be because that initiation of a force clamping during the heating by means of the one or more laser light beams is either omitted (e.g. because mechanical clamps are used for providing the force clamping) or that temperature fluctuations caused by the force clamping is at least partly compensated for by changing laser beam power and/or heating iteration time, e.g. by means of switching between heating profiles HP1-HP4. For example, if e.g. the force clamping is provided by means of evacuation of the gap between the glass sheets of the VIG unit assembly, as e.g. described above and/or below, a switch to a new heating profile may be done - e.g. at time t_EP2 or t_EP3. It is however understood that the force clamping may alternatively be initiated during heating according to a heating profile without switching to another heating profile at that time.

It is generally understood that the adjustment of the laser beam power and/or the heating iteration time may be adjusted during the local heating of the solder material by means of the one or more laser light beams, e.g. by means of a plurality of heating profiles HP1-HP5) so as to account for/adapt to e.g. one or more of:

• heat dissipation during the heating which may increase during the heating,

• changes in the properties of the solder material, such as the optical properties and/or other properties of the solder material, during the heating,

• changes in the heat conduction properties of the solder material

• initiation of a force clamping as e.g. previously described.

The adjustment of the laser beam power, the number of laser beams used and/or the heating iteration time may be adjusted during the local heating of the solder material by means of the one or more laser light beams so as to reduce the total heating time (t3-t5) used for the local heating, and/or so as to provide a more controlled heating of the solder material by optimizing the heating profile Te, for example so as to e.g. reduce or avoid de-tempering of the glass sheets of the VIG unit assembly and/or to reduce stress in the glass sheets of the VIG unit assembly, and/or to optimize one or more properties of the final edge seal.

In one or more of the embodiments illustrated in figs. 28-31, the temperature gradients GR1, Gr2, GR3, GR4 (The gradients are however only schematically illustrated in fig. 31) of the temperature profile Te of the solder material may be controlled, e.g. to decrease, during the heating between time t3 and t5: this may e.g. be done so that a first earlier gradient (e.g. GR1) may be /steeper larger at a first part of the heating of the solder material by means of the one or more laser light beams, when compared to a temperature gradient (E.g. GR3 or GR4) a later stage in the heating of the solder material by means of the one or more laser light beams, before the heating is ended at t5. See e.g. fig. 31.

It is understood that the temperature gradients GR1, GR2, GR3, GR4 of the obtained temperature profile Te at one or more local areas 18 of the solder material may represents a line which interconnects local minimum temperatures (Mtl, Mt2) on the temperature profile (Te), See e.g. fig. 31 and 33. The temperature gradient GR1-GR4 may also e.g. reduce over the time t3-t5 if a constant laser beam power and laser beam movement speed is used. This may e.g. be caused by increased heat dissipation as the solder material temperature increases, This is e.g. indicated in fig. 27a. However, this may be compensated for and/or controlled, so as to obtain a desired temperature profile, especially when the solder material temperature gets closer to, the target temperature.

The temperature profile, such as the temperature gradient GR1-GR4 of the temperature profile may e.g. be changed, such as increased or decreased, by controlling the sum of the power of the one or more heating beams, such as laser light beams, e.g. by adjusting the laser light beam power of one or more laser slight beams and/or the number of laser light beams used during the heating t3-t5.

Generally, the adjustment of the laser beam power and/or the heating iteration time Itl-It4 (see e.g. figs. 28-31) during the heating t3-t5 by means of the one or more laser light beams may be adjusted so that more energy is induced into the solder material 7 during the heating between time t3 and t5 at a first, earlier part of the heating of the solder material by means of the one or more laser light beams, when compared to the amount of heating energy induced into the solder material at a second, later stage in the heating of the solder material by means of the one or more laser light beams.

It is generally understood that in some embodiments, at least two, such as at least three, such as at least four different heating profiles HP1-HP4 may be used according to embodiments of the present disclosure when locally heating the solder material of a VIG unit assembly by means of one or more laser light beams as e.g. described above and/or below.

It is common to figs. 29-31 described above that the local heating of the solder material by means of the one or more laser light beams according to a first heating profile HP1 at the local area of the solder material ends at time t_EPl, and that local heating of the solder material by means of one or more laser light beams according to a second heating profile HP2 starts at time t_EPl. Hence a switch between the two heating profiles HP1, HP2 is done at time t_EP 1. In the same way, locally heating the solder material by means of the one or more laser light beams according to the second heating profile HP2 ends at time t_EP2, and local heating of the solder material by means of one or more laser light beams according to a third heating profde HP3 starts at time t_EP2. Hence a switch between the second and third heating profdes HP2, HP3 is done at time t_EP3. The same applies in Fig. 31.

It is generally understood that in some embodiments of the present disclosure, the heating of the solder material of the VIG unit assembly / glass unit assembly may be provided according to a single predetermined heating profde, where that heating profde provides that the power of the one or more laser light beam(s) and/or the movement speed of the one or more laser light beams is adjusted, such as increased and/or decreased, during the softening (t3-t5) the solder material 7. This heating profde may be based on an computer software and/or an algorithm or the like that calculates and adjusts the laser light beam power and/or the movement speed of the laser light beam and periodically or continuously regulate one or both of these parameters during the heating of the seal material during the heating time t3-t5.

It is generally understood that different heating profdes HP1-HP4 and/or different combination of heating profdes may be used for different VIG unit assembly sizes/types. In some embodiments, the heating profde(s) may be part of / used in an information type (see fig 24, Typ_l-Typ_n - see fig. 24), where each information type comprises a number of presettings to be selected dependent on the glass sheet assembly type, such as glass sheet assembly size, to be edge sealed at the edge sealing station 200. Hence, the solder material of different types of VIG unit assemblies may be heated according to different heating profde settings so that the heating profdes used are different for the different VIG unit assembly type. For example, larger glass sheet assemblies having a longer total edge seal length may possibly call for higher laser beam power and/or higher laser movement speed than smaller glass sheet assemblies having a shorter total edge seal length.

It is generally understood that in one or more embodiments of the present disclosure, one or both glass sheets 3, 4 may be reinforced glass sheets, such as tempered glass sheets, such as thermally tempered glass sheets.

As can be seen in figs. 28-31, the temperature Te of the solder material may exceed the target temperature T3 at least one time before the heating by means of the one or more laser light beams is stopped t5. In some embodiments the temperature Te, Ptl of the solder material may exceed the target temperature T3 a plurality of times, such as at least two times, such as at least five times, before the heating by means of the one or more laser light beams is stopped t5. This may be accepted, e.g. as long as each time the temperature Te, Ptl of the solder material exceeds the target temperature, the target temperature T3 is exceeded for less than 5 seconds, such as less than 2 seconds, such as less than 0.5 seconds. This may e.g. be relevant in order to reduce de-tempering (a de-hardening) of the glass sheets, if they are tempered glass sheets, and/or in order to obtain a solder material with more advantageous sealing properties when cooled. As can be seen, the local peak temperatures Ptl of the solder material may be the one that are accepted to exceed the target temperature T3, and the temperature of the solder material rapidly decreases from the peak temperature. The minimum solder material temperature obtained during a heating period may or may not be allowed to reach the target temperature. In other embodiments, the solder material temperature may be controlled so as to not Exceed the target temperature.

It is generally understood that the target temperature T3 mentioned in relation to various figures described above and/or below may be set to be at or be within e.g. ± 10 °C, such as within ± 5 °C of the rated melting temperature Tm or a rated melting temperature range of the solder material 7 which is defined by the manufacturer and/or supplier of the solder material 7.

It is generally understood that the rated melting temperature Tm may be a rated sealing temperature that should be reached for the solder material 7 in order to obtain the desired sealing properties of the solder material used. The manufacturer and/or provider of the solder material may inform the rated melting temperature Tm.

It is generally understood that the one or more heating profiles mentioned above may be based on a computer program code stored in a data storage, and that said code is executed by means of a controller comprising a hardware computer processor so as to control the movement speed of the heating beam(s), control the power of the heating beam(s), control the number of heating beams used and/or the like during the heating time t3-t5, e.g. according to the one or more heating profiles.

It is generally understood that the adjustment of the various parameters such as heating beam movement speed, heating beam power, number of heating beams used and/or the like may be controlled by the controller by means of an open loop control or a closed loop control. If a closed loop control is used, e.g. a PI, PD or PID (P= Proportional, I = integral D = derivative) control solution may be used based on feedback information, or another type of closed loop regulation may be used. Alternatively, a predefined control scheme may be used which is based on experiential test data, and hence, a predefined regulation scheme may be used, e.g. where switching so that heating according to different heating profiles as e.g. previously described, is used. Different heating profiles may or may not be used for different glass sheet assembly sizes, e.g. according to a control as described in relation to fig. 24.

Fig. 32. schematically illustrates a time-temperature profile Te of a heating iteration of a local area 18 at the solder material, according to further embodiments of the present disclosure. The graph is based on fig. 27b, but it is understood that various parameters, such as one or more of

• laser light beam power,

• laser beam movement speed along the longitudinal direction of the solder material,

• solder material type,

• solder material amount,

• if a primer is used or not between the solder material and one or both glass sheets, may be varied, which may affect the resulting temperature profile of the solder material.

A heating iteration of a local solder material aera/portion 18 (see e.g. ref 18 of fig. 26b) is started at the heating iteration start time HIS 1. The heating by means of the laser light beam occurs during the time interval from time HIS to time HIE, in the heating time HETI. When the laser has moved away from the solder material area again, the soaking time SOTI occurs from time HIE and until the new consecutive heating iteration is started at time HIS2. From the start HIS of the heating to the end HIE of the heating, the local maximum peak/spike temperature Ptl for that heating iteration is obtained.

As can be seen in the local temperature peak Ptl may be obtained at the solder material area fast during the heating time HETI, and the solder material temperature then reduces when the applied heating energy soaks into the solder material, into the glass sheets and/or the like during the soaking time SOTI before a new heating iteration is started. The soaking time SOTI from the heating of the solder material area/point 18 is ended at time HIE where the peak temperature Ptl is reached, and to a new consecutive heating in a new heating iteration is started at time HIS2 may as illustrated, in embodiments of the present disclosure, be larger, such as at least two times larger, such as at least four times larger or at least 6 times larger than the time HETI it takes (from Time HIS to HIE) for the laser light beam to heat the solder material to the peak temperature Ptl . The soaking time SOTI from the heating of the solder material area/point is ended (when the local peak temperature Ptl is reached) and to a new consecutive heating is started at time HIS2 may, in embodiments of the present disclosure be at least ten times larger, such as at least 15 times larger or at least 20 times larger than the time HETI it takes (from Time HIS to HIE) for the laser light beam to heat the solder material to the local peak temperature. The soaking time SOTI from the heating of the solder material area/point is ended at time HIE where the peak temperature Ptl is reached, and to a new consecutive heating is started HIS2, is in the example of fig. 32 approximately 12 times larger than the time HETI it takes (from Time HIS to HIE) for the laser light beam to heat the solder material to the peak temperature.

The heating time HETI it takes (from Time HIS to HIE) for the laser light beam to heat the solder material to the local peak temperature Ptl may in embodiments of the present disclosure be less than 1 second, such as less than 0.5 second, such as less than 0.05 second. This may in further embodiments of the present disclosure be the case for at least 10%, such as at least 50%, such as at least 90% of the total amount of heating iterations provided between the start of the local heating of the solder material (see t3 of fig. 27a) and to the end of the local heating of the solder material at time (se t5 fig. 27a). In some embodiments, the heating time HETI may apply for substantially all heating iterations provided by means of the one or more laser light beams.

The heating time HETI it takes (from Time HIS to HIE) for the laser light beam to heat the solder material to the local peak temperature Ptl may in embodiments of the present disclosure be less than 0.2 second, such as less than 0.1 second, such as less than 0.05 second or even less than 0.02 second. This may in further embodiments of the present disclosure be the case for at least 10%, such as at least 50%, such as at least 90% of the total amount of heating iterations provided between the start of the local heating of the solder material (see t3 of fig. 27a) and to the end of the local heating of the solder material at time (se t5 fig. 27a). In some embodiments, the heating time HETI may apply for substantially all heating iterations provided by means of the one or more laser light beams.

The heating time HETI it takes (from Time HIS to HIE) for the laser light beam to heat the solder material to the local peak temperature Ptl during the heating iteration may in embodiments of the present disclosure be between 0.001 second and 1 second, such as between 0.005 or 0.01 second and 0.50 second, such as between 0.02 second and 0.1 second. This may in further embodiments of the present disclosure be the case for at least 10%, such as at least 50%, such as at least 90% of the total amount of heating iterations provided between the start of the local heating of the solder material (see t3 of fig. 27a) and to the end of the local heating of the solder material at time (se t5 fig. 27a). In some embodiments, the heating time HETI may apply for substantially all heating iterations provided by means of the one or more laser light beams.

It is generally understood that in some embodiments of the present disclosure, a maximum temperature increase TI 1 of the solder material from the laser light beam starts heating the solder material area at a start time HIS and to the local peak temperature Ptl is obtained at the end of the heating of the area at time HIE, during a heating iteration, may be below 50°C, such as below 35 °C, such as below 20 °C, such as below 10 °C. This may in further embodiments of the present disclosure be the case for least 5%, at least 10% or at least 50%, such as at least 90% of all local peak temperatures Ptl reached during the total heating time t3-t5 where the one or more laser light beams is/are used for locally heating the solder material.

It is generally understood that in some embodiments of the present disclosure, a maximum temperature increase TI 1 of the solder material from the laser starts heating the solder material area at a start time HIS and to the local peak temperature Ptl is obtained at the end of the heating of the area at time HIE, during a heating iteration period, may be between 2 °C to 50 °C, such as between 3 °C to 35 °C, such as between 3 °C to 20 °C, such as between 5 °C to 10 °C. This may in further embodiments of the present disclosure be the case for at least 5%, at least 10% or at least 50%, such as at least 90% of all local peak temperatures Ptl reached during the total heating time t3-t5 where the one or more laser light beams is/are used for locally heating the solder material. The ambient temperature at the sealing station 200 may be controlled by means of a heater 220 as e.g. previously described to obtain an elevated temperature at the edge sealing station, e.g. a temperature above a glass transition temperature of the solder material. As can be seen, the heating iteration when heating the area 18 extends over a heating iteration period HIP, comprising the heating time HETI and the soaking time SOTI. From the peak temperature Ptl, the solder material temperature gradually decreases, and it is to be understood that when the temperature of the solder material increases when compared to the ambient temperature, the temperature profde during the heating time and/or soaking time may change. This may be caused by heat loss, and e.g. result in that the average temperature increase per heating iteration decreases, it may cause a faster cooling during the soaking time and/or the like. The laser light beam power and/or the laser light beam movement speed along the solder material length may be adapted at the start t3 of the heating of the solder material in order to take such factors such as heat loss into consideration. In some embodiments, laser light beam power and/or movement speed may be adjusted during the heating time between start t3 and end t5 of the heating by means of the one or more laser light beams. Additionally or alternatively, the number of laser light beams used before and/or during the heating time t3- t5 may be adjusted/changed in order to obtain a desired heating profde Te for the solder material.

Fig. 33 illustrates schematically a temperature-time profde of a local area 18 of the solder material over a local heating iteration, according to embodiments of the present disclosure. The local heating iteration starts at time HIS1, and extends over the heating iteration period HIP until a new consecutive heating iteration provides that the same solder material area/portion 18 is heated again (from starting at time HIS2) by a laser light beam. During the heating iteration period HIP, the solder material temperature is increased from a first minimum solder material temperature Mtl (obtained during a previous heating iteration which heated the area 18) and to a second minimum solder material temperature Mt2. The second minimum solder material temperature Mt2 is higher than the first minimum temperature Mtl. The difference in temperature between Mtl and Mt2 is ATI, which is the difference in the local solder material temperature measured at time HIS 1 and HIS2 respectively, i.e. ATI = Mt2-Mtl.

In fig. 33, The solder material temperature at the local area 18 is heated to the local peak temperature Ptl from the first minimum temperature Mtl, as e.g. previously described. During the following soaking time from the peak temperature Ptl is reached, the solder material temperature decreases to the local minimum temperature Mt2. If a lower temperature difference ATI is desired, for example the laser beam power may be decreased. If a higher temperature difference ATI is desired, for example the laser beam power may be increased.

It is understood that the temperature difference ATI may e.g. be an average temperature of the solder material at the local area.

It is generally understood that the local area 18 may have a length in the longitudinal direction of the solder material that is less than 10 mm, such as less than 1 mm.

It is generally understood that the local area 18 in some embodiments may be a surface area of the edge seal, such as a surface area of the solder material. That surface area may in some embodiments be e.g. 2 mm² or less, such as 1 mm² or less, such as 0.5 mm² and/or may correspond to the surface area where measurement equipment such as a camera measure the solder material temperature. The area 18 may comprise a middle surface area portion arranged midways (in a direction perpendicular to the longitudinal direction of the edge seal) between side edges of the edge seal, such as side edges of the solder material.

It is generally understood that the temperature(s) of the solder material may be determined directly or indirectly by temperature measurement, such as e.g. measured/determined directly or indirectly by means of infrared temperature measuring, e.g. by means of a camera or the like.

In some embodiments, the local increase ATI in the temperature, such as average temperature, of the solder material at the local solder material area/portion 18 per heating iteration period HIP may in some embodiments be below I0°C, such as below 5 °C, such as below 2 °C or below 1 °C. This may e.g. in further embodiments be the case if many iterations are used, such as if e.g. more than 20 or more than 50, such as more than 250 or more than 400, such as more than 1000, heating iterations are applied at the local area 18. Additionally or alternatively, it may be the case for at least 10%, such as at least 50%, or at least 80% of all heating iterations provided at the local area. In some embodiments, said heating during a heating iteration may provide that the temperature Mt2, such as the average temperature, of the solder material at said local area 18 is increased/larger at the end HIS2 of a heating iteration period HIP at the time when the area 18 is revisited by a heating beam, such as a laser light beam, when compared to the temperature Mtl, such as the average temperature, of the solder material at the local area 18 at the start HIS 1 of the heating iteration period, wherein the local increase ATI of the temperature of the solder material per heating iteration is below 15 °C, such as below 10 °C.

In some embodiments, a heating iteration may provide that the temperature Mt2, such as the average temperature, of the solder material at said local area 18 is increased/larger at the end HIS2 of a heating iteration period HIP at the time when the area 18 is revisited by a heating beam, such as a laser light beam, when compared to the temperature Mtl, such as the average temperature, of the solder material at the local area 18 at the start HIS 1 of the heating iteration, wherein the local increase ATI of the solder material temperature per heating iteration period is above 0.05 °C, such as above 0.1 °C, such as above 0.5 °C. For example, in some embodiments, it ATI may be above 1 °C, such as above 2 °C. In some embodiments, it ATI may be above 5 °C such as above 10 °C

In some embodiments, a heating iteration may provide that the temperature Mt2, such as the average temperature, of the solder material at said local area 18 is increased/larger at the end HIS2 of a heating iteration period HIP at the time when the area 18 is revisited by a heating beam, such as a laser light beam, when compared to the temperature Mtl, such as the average temperature, of the solder material at the local area 18 at the start HIS 1 of the heating iteration, wherein the local increase ATI of the solder material temperature per heating iteration period is between 0.05 °C and 15 °C, such as between 0.1 °C and 10 °C, for example between 1 °C and 5°C.

In other embodiments, a heating iteration may provide that the temperature Mt2, such as the average temperature, of the solder material at said local area 18 is increased/larger at the end HIS2 of a heating iteration period HIP at the time when the area 18 is revisited by a heating beam, such as a laser light beam, when compared to the temperature Mtl, such as the average temperature, of the solder material at the local area 18 at the start HIS 1 of the heating iteration, wherein the local increase ATI of the solder material temperature per heating iteration is above 3 °C, such as above 5 °C, such as above 8 °C per heating iteration. Said local increase ATI in the temperature, such as average temperature, at the local area 18 of the solder material may in embodiments of the present disclosure apply during at least 30%, such as during at least 50%, such as during at least 80%, or at least 90% of the total heating time (t3-t5) where the solder material is heated by means of the one or more heating beams such as laser light beams. It may also in some further embodiments apply during substantially the entire heating time t3-t5.

In some embodiments of the present disclosure, the total longitudinal LDS extent . ^solder = L_AB + L_BC + L_CD + L_DA of the seal material, such as said solder material of the seal material, may have a maximum temperature difference of less than 20 °C, such as less than 15 °C, such as less than 10 °C, such as less than 5 °C when the seal temperature or solder material temperature is averaged over portions of 10 mm length, such as 30 mm length, of the solder material 7, in the longitudinal direction of the solder material during t3-t5 said heating of the solder material by means of the one or more heating beams. This may in some further embodiments be obtained/provided during at least 30%, such as at least 50%, or at least 90%, of the heating time t3-t5. This may e.g. be calculated based on at least 5, such as at least 10, such as at least 100, measured temperature plots per 1 centimetre solder material.

In some embodiments of the present disclosure, the total longitudinal LDS extent . ^solder = L_AB + L_BC + L_CD + L_DA of the seal material, such as said solder material, may have a maximum temperature difference of less than 2 °C, such as less than 1 °C, when the solder material temperature is averaged over solder material portions of 10 mm length, such as 30 mm length, of the solder material 7 in the longitudinal direction of the solder material, during the heating t3-t5 of the solder material by means of the one or more heating beams, such as one or more laser light beams. This may e.g. be calculated based on at least 5, such as at least 10, such as at least 100, measured temperature plots per 1 centimetre solder material. This may in some further embodiments be obtained/provided during at least 30%, such as at least 50%, or at least 90%, of the heating time y3-t5.

As mentioned previously, local temperature peaks Pt may occur temporarily at each heating iteration heating an area 18, and that local temperature may be higher for a brief period after a laser has visited an area than the above mentioned maximum temperature difference(s). However, if averaging the solder material temperature over any a sub part length of the solder material, such as the 10 or 30 centimetres mentioned above, the solder material temperature over the total longitudinal LDS extent 2 L_soider = L_AB + L_BC + L_CD + L_DA of the solder material may be considered substantially uniform and within the above mentioned range(s) for the temperature difference.

As an example, the total longitudinal LDS extent 2 L_soider = L_AB + L_BC + L_CD + L_DA of the seal material may be divided into substantially equally large sub portions, such as e.g. 50, 100 or 200 substantially equally large sub portions. The average temperature of each sub portion may be calculated by e.g. obtaining e.g. 4, 10, 30 or more measured temperature plots per sub portion distributed along the longitudinal direction of each sub portion, e.g. at substantially the middle of the edge seal. The average temperature for each sub portion may then be calculated for each sub portion based on the obtained temperature plots from the respective sub portion. The maximum difference between the calculated average temperatures may thereby be determined, and may e.g. be less than 20 °C, such as less than 10 °C, such as less than 5, or less than 2 °C, such as less than 1 °C, as e.g. described above. This may in some further embodiments be obtained/provided during at least 30%, such as at least 50%, or at least 90%, of the heating time t3-t5.

As an example, the total longitudinal LDS extent 2 L_soider = L_AB + L_BC + L_CD + L_DA of the seal material may be divided into substantially equally large sub portions. For example, a seal material having a total length of 3 meters may be divided into consecutive portions of 30 mm, providing a total of 3000/30= 100 sub portion. The average temperature of each sub portion may be calculated by e.g. obtaining e.g. 30 measured temperature plots per sub portion, and the average temperature for each sub portion may be calculated. The maximum difference between the calculated average temperatures may thereby be determined, and may be of less than 20 °C, such as less than 10 °C, such as less than 2 °C as e.g. described above.

Generally, in one or more embodiments of the present disclosure, the full longitudinal extent of the solder material of the glass sheet assembly 1 may be exposed to a laser light beam between 10 times and 10000 times, such as between 50 times, and 5000 times, such as between 100 times and 1500 times, during the softening t3-t5 of the solder material 7. Generally, in one or more embodiments of the present disclosure, the full/total longitudinal extent of the solder material of the glass sheet assembly may be exposed to a laser light beam less than 20000 times, such as less than and 10000 times, such as less than 5000 times, during said softening of the solder material.

It is generally understood that the heating iterations illustrated in e.g. figs. 27-33 (having a heating iteration period HIP comprising a heating time HETI and a soaking time SOTI) may illustrate the local 18 result of the heating iterations provided to heat the solder material. Hence, the effect of the heating of the full longitudinal LDS extent 2 L_soider ⁼ L_AB + L_BC + L_CD + L_DA of the solder material 7 may be that the average temperature of the full longitudinal LDS extent of the solder material is relatively uniform, whereas local temporary temperature peaks Ptl may occur local areas 18 of the solder material when a laser light beam visits or revisit the solder material area 18 so as to heat it.

Figs 34a-34b illustrates schematically embodiments of the present disclosure, where the edge seal comprising the solder material 7 is a multi-layer edge seal. The edge seal comprises one or more primer layers 11 and the solder material 7. In the example of fig. 34a, a primer layer 11 is arranged at each side of the solder material 7, between the solder material and the respective glass sheet 3, 4, such as a reinforced glass sheet 3,4 , such as a tempered glass sheet 3,4, such as a thermally tempered glass sheet 3,4, and the solder material 7.

Edge seals comprising multiple layers are well known in the art, particularly in applications requiring enhanced thermal or mechanical performance. These multi-layered edge seals often incorporate different materials designed to serve specific functions, such as improving the hermiticity of the edge seal, enhancing adhesion to the glass substrates/sheets, and/or managing the thermal stress induced in the glass during the sealing process. By using combinations of glass-based materials, metals, or ceramics, manufacturers may achieve more reliable and durable seals for vacuum insulated glass (VIG) units.

WO 2014/052178 Al discloses forming an edge seal for VIG units, with the objective of forming the seal at lower temperatures without relying on toxic substances such as lead, which are increasingly restricted by regulations. The disclosed edge seal consists of a eutectic seal material placed between two absorber layers. These absorber layers, which may also be considered as primer layers, are applied to the surfaces of first and second glass substrates, rather than having the eutectic material directly contact the glass. US 6701749 B2 describes a method of forming a multiple-layered edge seal. The process involves applying a first portion of glass frit in solution to one or both of the glass substrates. The thickness of the first application ranges from 0.01 to 0.1 mm. After the frit is applied, the substrates with the first portion of frit on their surface are dried in an oven. Following the drying process, the glass substrates/sheets with the first frit portion(s) are thermally tempered, during which the frit fuses to the substrates, creating a strong bond between said frit and the glass substrate on which it is applied. A further portion of edge seal material is deposited over at least part of the first portion of edge seal material, and microwave energy is then used to heat the edge seal area, including both the first and second applications of frit. This process softens the second application of frit, causing it to bond and/or fuse into the pre-fired first application of frit. US 6641689 Bl discloses an edge seal structure for vacuum insulated glass (VIG) units, formed in multiple stages with multiple applications of solder material. The process starts with the application of initial portions of edge seal material, such as solder glass in slurry form, to the glass substrates before tempering. During the tempering process, the high temperatures cause the solder glass to diffuse into or bond with the glass substrates, forming a pre-tempered connection. The method allows the glass to retain more of its temper strength, as the higher temperatures needed to bond the solder glass are applied during tempering. This reduces the need for high temperatures later in the process for edge sealing. By applying an initial portion before tempering, the subsequent application of solder material can be done at lower post-tempering temperatures, which may help maintain temper strength of the glass.

Figs. 34a and 34b illustrate a cross-sectional view of a glass sheet assembly 1 for a vacuum insulated glass unit 30 according to embodiments of the present disclosure. The assembly includes a first glass sheet 3 and a second glass sheet 4, separated by a gap 5 that is maintained by a plurality of support structures 2. An edge seal comprising solder material 7 and primer layers 11 is provided in fig. 34a. It is understood that in other embodiments, one of the primer layers 11 may be omitted, see fig. 34b. The primer layer(s) 11 is/are positioned between the solder material 7 and the glass sheet 3,4. The primer layer 11 may, for example, be positioned so as to abut the solder material 7 and the respective glass sheet 3, 4.

In Fig. 34b, as the solder material 7 heats up when it is heated by the a heating beam 9 such as a laser light beam 9, it softens and begins to spread out laterally. In some examples, the primer layer 11, may absorb more readily the radiative flux of the heating beam 9, and provide a consistently heated surface for the solder material to spread out upon, which may e.g. ensure controlled expansion and adhesion during the sealing process.

As non-limiting examples, the solder material 7 may heat up in several ways, including but not limited to directly absorbing the radiative flux of the heating beam 9, conduction of heat from the heated primer layer 11 (which may be heated by the heating beam 9), and/or absorbing lower-energy radiation retransmitted from the primer layer 11 to the solder material. The solder material 7 may also heat up by a combination of these heating processes.

The primer layer(s) 11 may also comprise light-absorbing material, such as pigments, to enhance their ability to absorb the radiative flux from the laser light beam(s). These lightabsorbing materials may be selected to ensure that the primer layer(s) absorb the radiative flux more effectively than the glass substrates, providing a heated surface for the solder material 7.

The primer layer(s) 11 may be applied to the glass sheets during the thermal tempering process, which strengthens the glass while at the same time ensuring a strong bond between the primer layer and the glass surface. The primer layer(s) 11 may be designed or selected to have a higher softening and/or melting point than the temperatures used during the laser sealing for softening the solder material 7 to seal the gap of the glass sheet assembly, but the same or lower than the temperatures used during the glass tempering process used for thermally tempering the glass sheets 3, 4. This may help to ensure that the primer layer(s) remain(s) stable and intact during the laser sealing process, allowing the solder material to heat and soften without softening or melting the primer layer(s). Once the primer layer(s) 11 is/are in place and the glass sheets 3, 4 are fully tempered, the solder material 7 can be added to one or both primer layer(s), the glass sheet assembly can be finished and transported to proceed to start the edge sealing process and complete the formation of the edge seal, e.g. after a preheating of the glass sheet assembly at a preheating station is provided, in some embodiments as e.g. previously described. By applying the primer layers during tempering, the glass sheets may be better prepared for a sealing process at an edge sealing station 200, as the primer layers improve adhesion and thermal compatibility with the solder material, promoting a strong and durable seal. It may in some embodiments be so that the primer layer(s) are more integrated into the glass structure before the solder material is applied. It may also provide that lower melting point solder material 7, such as glass solder material, may provide a strong bond to the primer layer(s).

It is understood that in some embodiments, primer layers between one or both glass sheets and the solder material may be omitted.

It is understood that in embodiments of the present disclosure, the obtained VIG unit 30 may be for use in e.g.:

• a building window allowing sunlight to enter through the VIG unit from a building exterior to a building interior,

• In a cooling storage (such as a refrigerator) door or lid, with view through the VIG unit to the interior storage,

• In an oven door,

• and/or the like.

As previously mentioned, use of thermally tempered glass sheets 3, 4 for VIG units may be advantageous. Such thermally tempered glass sheets are stronger, and e.g. provides that a thinner glass sheet can be used. Also, larger distance between neighbouring support structures 2 may in embodiments of the present disclosure be obtained, and e.g. a distance DIS1 above 30 mm such as above 35 mm, such as 40 mm or larger may be used while still obtaining a VIG unit that is resistant to e.g. thermal stress caused by the glass sheets 3, 4 having different temperatures. Such thermal stress may e.g. occur if the VIG unit is to be used in a window such as building windows, such as e.g. a facade window or a roof window.

However, when using thermally tempered glass sheets, the temperatures and time duration at an elevated temperature of the tempered glass sheets become relevant to consider.

Experience and test indicate that for example if the tempered glass sheet is heated to a temperature of 400°, 5% of the pre-stress/ tempering strength in the glass sheet obtained during the tempering process may be lost in 6 minutes or less, while 20-25% of the pre-stress may be lost in 60 min. If heating the tempered glass sheet to e.g. around 450 °C the tempering may be lost or reduced even faster, and there are indications that 10-20% of the tempering strength may here be lost in 6 minutes or less. For example, fig. 4 of patent document US2017232712 suggests how thermally tempered glass may de-temper / loose it's tempering strength overtime dependent on temperature. Therefore, the properties of the solder material, but also the speed with which the edge seal is treated to get heated and softened to reach the melting temperature / sealing temperature Tm , as well as the way this is achieved, is relevant to consider in order to maintain the tempering strength of the glass sheets 3, 4, also at the edge of the final VIG unit 30 proximate the edge seal 7, 11. By using one or more higher power heating beams as e.g. previously described according to various embodiments of the present disclosure, and heating and softening the total longitudinal extent of the solder material in a plurality of consecutive heating iterations with e.g. a movement speed as e.g. described according to various embodiments of the present disclosure, the de-tempering / loss in tempering strength of the thermally tempered glass sheets 3, 4 may be reduced or even avoided. Also, larger and/or longer temperature peaks at the solder material and the surround parts of the glass sheet assembly may be reduced. Additionally or alternatively, a more uniform heating of the full extent of the solder material may be achieved which may provide advantages in relation to for example force clamping (such as by means of a pressure difference) and/or reduced local stress in the VIG unit.

VIG units 30 where the glass sheets 3, 4 are hardened glass sheets, such as thermally tempered glass sheets, may be advantageous in use scenarios where the VIG unit may be subjected to various types of forces over the time span where the VIG unit is used in the use scenario. This may e.g. be the case when the manufactured VIG units 3 are used in a building window such as a as vertically arranged building windows or roof windows. In roof windows, the major surfaces of the glass sheets 3, 4 are arranged with an angle relative to horizontal, which may dependent on the roof window type. In roof windows of the flat roof type, the major surfaces of the glass sheets of the VIG unit 30 may be arranged with an angle below 15° relative to horizontal, but may in some further embodiments be arranged with an angle larger than 0° relative to horizontal in order to e.g. assure that snow and/or water will be guided of the VIG unit by gravity. In other roof window types, the major surface of the glass sheets of the VIG unit 30 may be arranged with an angle above e.g. 17°, such as above 25°, such as above 35° relative to horizontal (when the VIG unit is in a closed position if the roof window is of the openable type). This may depend on the roof pitch of the building, and some roof window types, such as the top hung and/or center gung type, may be configured to be arranged in a roof structure where the final roof pitch is between e.g. 17°-70°.

The VIG unit of roof windows may also be laminated by means of a lamination interlayer arranged between the VIG unit and a further lamination glass. This may e.g. improve safety. The lamination interlayer may e.g. be a PVB (Polyvinyl butyral ) layer or an EVA (ethylenevinyl acetate) layer. The lamination interlayer may or may not be of the sound dampening type. The lamination interlayer of the sound dampening type may comprise a plurality of polymer layers abutting each other, where an intermediate polymer layer of the lamination interlayer has a different, such as lower, glass transition temperature than the neighboring layers of the lamination interlayer. The VIG unit 3 may be laminated only at one side or at both sides of the VIG unit. The further lamination glass may or may not be tempered.

VIG units 30 comprising solder material 7 edge seals have some characteristics that are different from more conventional insulating glass units. For example, even though the VIG unit in general have superior heat insulating properties compared to the conventional gas (such as Argon) filled insulating glass units, the edge seal of a VIG unit act as a cold bridge providing a large heat transfer between the glass sheets at the edge area of the VIG unit. Moreover, the edge seal of a VIG unit comprising solder material is very rigid and so to say fuses the glass sheets together. Due to the heat insulating properties of a VIG unit, combined with the characteristics of the edge seal, edge deflections and stress forces occur in the VIG unit when it is subjected to temperature differences between the VIG unit glass sheets, i.e. when one glass sheet is hotter than the other. This is e.g. the case when the VIG unit 30 is used as the insulating glass unit of a building window such as a roof window. Such edge deflections are e.g. described in patent document WO 2020/147900 Al. For example, figs. 28-30 of WO 2020/147900 Al and the description relating thereto relates to test of VIG unit edge deflection caused by temperature differences.

Figs. 35a-35c illustrates schematically thermal edge deflections of a VIG unit 30 caused by different temperatures Tempi, Temp2. The edge seal comprises a solder material edge seal such as a solder glass material, such as glass frit, e.g. as previously described, and the gap between the glass sheets is evacuated. The VIG unit 30 is laminated at one side in fig. 35a, e.g. as described above, and comprises a lamination glass LG attached to a glass sheet 3 of the VIG unit 30 by means of a lamination interlayer (not illustrated). The VIG unit 30 is subjected to a temperature difference where the temperature Tempi at the side of the second glass sheet 4 which faces away from the evacuated gap of the VIG unit 30 is larger than the temperature Temp2 at the side of the of the first glass sheet 3 which faces away from the evacuated gap of the VIG unit 30. This causes the temperature of the second glass sheet 4 to be larger than the temperature of the first glass sheet. Only very low heat transfer occurs between the glass sheets 3,4 of the VIG unit at the main area of the evacuated gap (e.g. proximate the center of the VIG unit). The support structures in the gap for maintaining the distance between the glass sheets may in some embodiments be the primary source for such heat transfer at this area. At the area of the edges and proximate the edges of the of the VIG unit, the heat transfer is larger due to the edge seal acting as a cold bridge. The edge seal is very stiff, and since the second glass sheet 4 is hotter than the first glass sheet 3 (due to temperature Tempi being higher than Temp2 in fig. 35a), the second glass sheet expands more, causing the VIG unit 30 edges to describe an edge deflection curve between comers CO of the VIG unit. The magnitude of the edge deflection when compared to a situation where the glass sheets 3, 4 have similar temperatures will increase with increased VIG unit size, and also when the temperature difference increases. Such edge deflections causes stress conditions of the VIG unit which may be damaging to the VIG unit.

Fig. 35b illustrates a situation (cross sectionally) where the thermal edge deflections of a VIG unit 30 (which is not laminated in this example) caused by different temperatures Tempi, Temp2 changes over time due to a change in the temperature difference between the glass sheets and a switch in edge deflection direction is also schematically illustrated. Such switch may occur when the there is a switch between which glass sheet 3, 4 is the hotter one. In scenario 1 SCI of the example of fig. 35b, the second glass sheet 4 (the upper glass sheet in the figure) is the hotter one since temperature Tempi is larger than temperature Temp2. The dashed, second scenario SC2 for the VIG unit 30 occur when the first glass sheet 3 (the lower glass sheet in the figure) is the hotter one due to temperature Temp2 being larger than temperature Temp 1.

The edge deflections at the VIG unit 30 causes a deflection of the VIG unit Defl that, if not restricted by e.g. mechanical restriction (such as by a frame or another restricting arrangement), may be approximately 1 mm per 10°C temperature difference between the glass sheets, where that temperature difference is present at center of the VIG unit. This is when compared to a situation where the glass sheets have the same temperature. Hence, for a VIG unit having a length of an edge of e.g. 2 meters, and subjected to a temperature difference of e.g. 50 °C between the glass sheets 3,4 at the centre of the VIG unit, the edge deflection may be approximately 5 x 2 mm = 10 mm. The deflection Defl is in fig. 35b defined between a first plane PLVIG1 that touches the center of the glass sheet and is parallel to a major surface of the VIG unit when the difference in temperature between the glass sheets 3,4 is substantially 0° C, and a second plane PLVIG2 which touches the comers of the VIG unit proximate the same major surface of the glass sheet and is parallel to a major surface of the VIG unit when the difference in temperature between the glass sheets 3,4 is substantially 0° C (Templ=Temp2).

The thermal edge deflections may even be more complex, as illustrated schematically in fig. 35c, since the edge deflection magnitude DEFI, DEF2 may depend on the length of the VIG unit edges. Hence, a rectangular VIG unit having two parallel edges which are longer than two other shorter, parallel edges of the VIG unit (which have a longitudinal direction that extends perpendicular to the longitudinal direction of the longer edges) may experience that the edge deflections of the longer edges may have a larger magnitude DEFI than the magnitude of the edge deflections DEF2 at the shorter edges.

The VIG unit 30, when using it at a building window (see e.g. 551 and 552 of fig. 36), , a refrigerator unit or the like, should be able to withstand and cope such thermal edge deflections as illustrated in figs. 35a-35c, and may even be required to cope the stress conditions caused by mechanically restricting the edge deflections, e.g. with the purpose of one or more of:

• moving and/or distributing the stress conditions in the VIG unit

• reducing optical distortion

• water tightening

• enabling a more space saving building window frame solution.

Fig. 36 illustrates schematically a building 550 comprising a roof structure 550a. The building comprises vertical facade windows 551 arranged in outer building walls of the building, and a roof window 552 arranged in the roof structure 550a. The VIG unit manufactured according to a method according to various embodiments of the present disclosure may be configured for or suitable for being installed in a building window 551 and/or 552 and to cope (with or without mechanical restriction) stress forces that are caused by temperature differences as e.g. described in relation to one or more of figs. 35a-35c. It is understood that the VIG unit 30 may be attached to a frame of the window. That frame may be movable relative to a fixation frame or the window to enable opening or closing the window, or the frame may be configured to be fixed relative to the building so that the VIG unit cannot move when the window is installed. The frame may comprise elongated profiles providing a rectangular frame opening, and light, such as sunlight, entering through the VIG unit enters through the frame opening. In some embodiments, the VIG unit may also be used in a building door (not illustrated).

The surface area of the major surfaces of the glass sheets 3, 4 of the VIG unit 30 for the building window or door, or for a cooling storage door or lid may in embodiments of the present disclosure, be at least 1 m², such as at least 1.5 m², such as at least 2 m².

Various embodiments of the present disclosure are described in the following items.

Items

1. A method of processing a glass sheet assembly ( 1) for a vacuum insulated glass (VIG) unit (30) at a production line (10), wherein the method comprises the step of

- providing a glass sheet assembly (1) comprising a first glass sheet (3) and a second glass sheet (4), wherein a plurality of support structures (2) for maintaining a gap (5) between said first glass sheet and said second glass sheet of the vacuum insulated glass unit are arranged between major surfaces (3a, 4a) of the glass sheets (3, 4), and wherein the glass sheet assembly (1) comprises an edge seal (7, 11) for providing an edge sealing for enclosing and sealing the gap (5) between the glass sheets (3, 4), wherein the edge seal comprises a solder material (7), wherein the production line (10) comprises at least a preheating station (100) and an edge sealing station (200), wherein the first glass sheet (3) as well as the second glass sheet (4) optionally are tempered glass sheets such as thermally tempered glass sheets, the method further comprising the steps of i) positioning the glass sheet assembly (1) at a preheating station (100, 101) of the production line (10), ii) heating the positioned glass sheet assembly (1) in the preheating station (100, 101) to a preheating target temperature (Tl), iii) optionally moving the preheated glass sheet assembly (1) from the preheating station (100) and positioning the preheated glass sheet assembly (1) at the edge sealing station (200), iv) softening (t3-t5) the solder material (7) of the preheated glass sheet assembly (1) at the edge sealing station (200) by locally heating the solder material (7) by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4).

2. The method according to item 1, wherein said method comprises the step of stopping (t5) said local heating of the solder material (7) by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4), thereby cooling and hardening the solder material (7) of the preheated glass sheet assembly (1), such as so as to obtain an edge sealed glass sheet assembly (20).

3. The method according to item 1 or 2, wherein the glass sheets (3, 4) maintain the temperature from the preheating step in the edge sealing chamber (201) or wherein the temperature of the glass sheets (3, 4) gradually reduce during the local heating of the solder material (7) in the edge sealing chamber (201).

4. The method according to any of the preceding items, wherein the solder material (7) is a glass solder material comprising a low melting point glass solder frit material.

5. The method according to item 4, wherein the glass sheet assembly (1) is heated in the preheating station (100, 101) to a temperature (Tl) above the glass transition temperature (Tg) of the glass solder material (7), such as in the range of 5 to 20 °C, preferably in the range of 8 to 16 °C, above the glass transition temperature (Tg) of the glass solder material (7).

6. The method according to any of the preceding items, wherein a plurality of glass sheet assemblies (1), are arranged in a preheating chamber (101) of the preheating station (100), such as wherein the glass sheet assemblies (1) are provided into the preheating station by means of a transport system (90).

7. The method according to any of the preceding items, wherein the preheating chamber (101) comprises a plurality of glass sheet assembly storage locations (103), such as more than two, such as more than five or more than ten glass sheet assembly storage locations (103).

8. The method according to item 7, wherein each glass sheet assembly storage location comprises one or more glass sheet assembly supports (112), such as one or more shelves, rails, conveyers such as rollers and/or belts, arranged above each other, or wherein said preheating chamber is an elongated chamber and wherein the glass sheet assemblies are arranged consecutively in line while one or more heaters (102) heat the glass sheet assemblies (1) while they gradually are moved forward towards the edge sealing station (200).

9. The method according to any of the preceding items, wherein the time period (t 1 -t3) between the time (tl) at which said preheating is initiated (tl), and the time (t3) at which said locally heating (9, 9 1, 9_2, 9_3, 9_4) of the solder material is initiated is in the range of 10 minutes to 90 minutes, such as in in the range of 15 minutes to 70 minutes or in the range of 20 minutes to 50 minutes.

10. The method according to any of the preceding items, wherein a gate or door (105) is arranged between the preheating station (100) and the edge sealing station (200).

11. The method according to any of the preceding items, wherein the preheating station (100) and the edge sealing station (200) are consecutive stations.

12. The method according to any of the preceding items, wherein the glass sheet assembly (1) is heated in the preheating station (100) to a preheating target temperature (Tl) in the range of 280 to 350 °C, such as in the range of 300 to 330 °C, and/or wherein the preheating target temperature (Tl) is below or at 340 °C, such as below or at 330 °C, such as below or at 320 °C or below or at 300 °C.

13. The method according to any of the preceding items, wherein the preheating target temperature (Tl) is above 260 °C, such as above 280 °C, such as above 300 °C, or wherein the preheating target temperature (Tl) is above 315 °C, such as above 330 °C.

14. The method according to any of the preceding items, wherein said pre-heating provides binder bum out from said solder material.

15. The method according to any of items 4, 5 or 14, wherein the solder material (7) of the glass sheet assembly (1) is substantially free from solvent prior to processing of the glass sheet assembly (1) at the preheating station (100).

16. The method according to any of the preceding items, wherein a chamber (201) in which the glass sheet assembly (1) is arranged during said locally heating (9, 9 1, 9_2, 9_3, 9_4) of the solder material (7), is heated, such as convection heated, by means of a heater (220) so as to maintain an elevated temperature of the glass sheet assembly during said local heating (9, 9_1, 9_2, 9_3, 9 4).

17. The method according to any of the preceding items, wherein the average temperature of the glass sheets (3, 4), in a chamber (201) of at the edge sealing station (200), is maintained within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C or within ± 5 °C of the preheating target temperature (Tl), such as by means of a heater (220).

18. The method according to any of the preceding items, wherein the softening of the solder material (7) by locally heating the solder material (t3-t5) is be provided for a time period (t3- t5) that is within 10 to 130 seconds, such as within 30 to 100 seconds.

19. The method according to any of the preceding items, wherein the softening of the solder material (7) by locally heating the solder material (t3-t5) is provided for a time period (t3-t5) that is within 10 to 130 seconds, such as within 10 to 100 seconds for example within 10 seconds to 90 seconds.

20. The method according to any of the preceding items, wherein said softening of the solder material (7) by locally heating the solder material is provided for a time period (t3-t5) that is less than 5 minutes, such as less than 2 minutes, such as less than 100 seconds, before the local heating is stopped (t5). 21. The method according to item 20, wherein the softening of the solder material (7) by locally heating the solder material is provided for a time period (t3-t5) that is larger than 10 seconds, such as larger than 30 seconds, for example larger than 60 seconds.

22. The method according to any of the preceding items, wherein said softening of the solder material (7) by locally heating the solder material is provided for a time period (t3-t5) that is between 10 seconds and 5 minutes, such as between 30 seconds and 5 minutes, such as between 30 seconds and 2 minutes.

23. The method according to any of the preceding items, wherein the local heating is provided by means of one or more laser light beams that are swept along the longitudinal direction (LDS) of the solder material in order to provide a suitably uniform heating of the solder material.

24. The method according to any of the preceding items, wherein the heating by means of said one or more laser light beams comprises a plurality of consecutive, such as continuous, heating iterations along the longitudinal direction (LDS) of the solder material (7) so as to heat the total longitudinal extent (2 hsoider = L_AB + L_BC + L_CD + L_DA ) ofthe solder material (7).

25. The method according to item 24, wherein when the full length (£ L_soider = L_AB + L_BC + L_CD + L_DA ) of all solder material stripes (A-B, B-C, C-D, D-A) of the solder material (7) of the edge seal have been subjected at least one time to a laser light spot so as to be heated, this is considered a heating iteration.

26. The method according to any of the preceding items, wherein the heating of each meter of the solder material during the softening step by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4) is at least 30 joule per each one-tenth of a second for a period of at least 30 seconds such as at least 60 seconds.

27. The method according to any of the preceding items, wherein the local heating, such as by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4), of each meter of the solder material is at least 400 joule per each two seconds, such as at least 600 joule per each two seconds, for a period of at least 15 seconds, such as at least 30 seconds, such as at least 60 seconds during the step of softening the solder material.

28. The method according to any of the preceding items, such as according to item 27, wherein the full longitudinal extent of the solder material of the glass sheet assembly is exposed to a laser light beam at least 1 time per each two seconds, such as at least 1 times per second, such as at least 2 times per second, during the step of softening the solder material so as to provide a uniform heating of the full solder material, and/or wherein the full longitudinal extent of the solder material of the glass sheet assembly is exposed to a laser light beam at least 100 times, such as at least 200 times, such as at least 400 times during the step of softening the solder material so as to provide a uniform heating of the solder material.

29. The method according to any of the preceding items, wherein the combined heating by means of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) of each meter of the solder material (7) is at least 50 joule, such as at least 60 joule per each one-tenth of a second for a period of at least 10 seconds such as at least 20 seconds during the step of softening the solder material (7) at the edge sealing station.

30. The method according to any of the preceding items, wherein the solder material (7), during the step of locally heating the solder material, is heated by said one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4), so that the temperature difference between any two positions of the solder material 7 along the full longitudinal extent (LDS, L AB + L_ BC, + L CD + L_DA) of the solder material (7) of the glass sheet assembly does not exceed 2°C, such as during at least 30% of the total heating time (t3-t5) by means of the one or more heating beams (9, 9_1, 9_2, 9_3, 9_4).

31. The method according to any of the preceding items, wherein said local heating is provided by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4) which are moved in the lengthwise direction (LDS) of the solder material (7) at a combined speed of at least 20 m/s such as at least 40 m/s during the softening step (7). 32. The method according to any of the preceding items, wherein said local heating is provided by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) which each is moved in the lengthwise direction (LDS) of the solder material (7) at a speed of at least 20 m/s such as at least 40 m/s during the softening step (7).

33. The method according to any of the preceding items, wherein the full extent (L_AB + L_ BC+ L CD + L_DA) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 10 times per second, such as at least 20 times per second, such as at least 30 times per second during the step of softening the solder material by means of one or more laser light beams.

34. The method according to any of the preceding items, wherein the power of each of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4,) is at least 500 W, such as at least 750 W, such as at least 1000W.

35. The method according to any of the preceding items, wherein the full extent (L_AB + L_ BC, + L_CD + L_DA) of the solder material (7) of the glass sheet assembly is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 500 times, such as at least 1000 times, such as at least 1500 times during the step of softening the solder material.

36. The method according to any of the preceding items, wherein the temperature of the solder material (7) is increased by means of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) by at least 30 °C, such as at least 50 °C, in less than 180 seconds, such as less than 120 seconds such as less than 100 seconds.

37. The method according to any of the preceding items, wherein the temperature of the full longitudinal extent (LDS, L AB + L_ BC, + L CD + L_DA) of the solder material (7) is increased by means of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) by at least 30 °C, such as at least 50 °C, in less than 180 seconds, such as less than 120 seconds such as less than 100 seconds.

38. The method according to any of the preceding items, wherein a mirror controller (16) controls a mirror (15) so as to move a redirected laser beam (9, 9 1, 9_2, 9_3, 9_4) along the longitudinal direction (LDS) of one or more solder material strips (A-B, B-C, C-D, D-E) of the solder material (7) so as to provide said local heating of the solder material (7).

39. The method according to item 38, wherein said mirror (15) is located outside a chamber (201) of the edge sealing station (200) in which the glass sheet assembly (1) is arranged during said local heating.

40. The method according to any of the preceding items, wherein the full extent (L_AB + L_ BC + L_CD + L_DA) of the solder material (7) is at least 1.5 meter, such as at least 2 meters, such as at least 3 meters, or wherein the full extent (L AB + L_ BC + L CD + L_DA) of the solder material (7) is between 1.5 meter and 10 meters, such as between 2 meter and 8 meters, such as between 3 meter and 6 meter.

41. The method according to any of the preceding items, wherein a force clamping so as to force the first glass sheet (3) and the second glass sheet (4) towards each other is provided, such as initiated, during said local heating of the solder material at the edge sealing station (200).

42. The method according to item 41, wherein said force clamping comprises providing (t4) a pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (1) so as to force the first glass sheet (3) and the second glass sheet (4) towards each other.

43. The method according to item 42, wherein the providing of the pressure difference includes a step of evacuating (8) the gap (5), such as by means of an evacuation cup.

44. The method according to any of items 41-43, wherein the force clamping, such as the pressure difference, is initiated (t4) during (t3-t5) the softening the solder material (7) by means of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4). 45. The method according to item 41, 42, 43 or 44, wherein said providing of the force clamping, such as the pressure difference, is initiated at a time (t4) after the local heating of the solder material (7) has been initiated (t3).

46. The method according to any of items 41-45, wherein said providing of the force clamping, such as the pressure difference, is initiated (t4) at least 5 seconds after, such as at least 10 seconds after, for example at least 30 seconds after the local heating (t3) of the solder material (7) has been initiated.

47. The method according to any of items 42-46, comprising the step of eliminating (t6) the pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly.

48. The method according to item 47, wherein said elimination of the pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (20) is provided at a time (t6) after said locally heating of the solder material (7) is stopped (t5), such as wherein the elimination of the pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (20) is provided at least 2 seconds after, such as at least 5 seconds after, such as at least 10 seconds after, after said locally heating of the solder material (7) is stopped (t5).

49. The method according to any of the preceding items, further comprising the subsequent, consecutive steps of a) removing the edge sealed glass sheet assembly (20) from the edge sealing station (200) of the production line (10), b) positioning the edge sealed glass sheet assembly (1) at an evacuation station (300) of the production line (10), c) evacuating the gap (5) to a substantially vacuum, and d) sealing off (6a) the gap (5) from the surroundings.

50. The method according to item 49, wherein a gate or door (205) is opened so as to allow moving the edge sealed glass sheet assembly (20) into a chamber (301) of the evacuation station (300), and is (205) thereafter closed again. 51. The method of any of items 49-50, wherein the gap (5) is evacuated at the evacuation station (300) to a pressure below 0.05 mbar, such as below 0.005 mbar, such as 0.003 or 0.001 mbar or below by means of an evacuation pump.

52. The method according to any according to any of items 42-48 and according to any of items 49-51 and, wherein the maximum pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (1) at the edge sealing station (200) is less, such as at least ten times less, such as at least 100 times less, than the pressure difference between the pressure in the gap (5) and the pressure surrounding the edge sealed glass sheet assembly (20) at the evacuation station (300) after sealing off (6a) the gap (5) from the surroundings.

53. The method according to any of items 49-52, wherein the preheating station (100), the edge sealing station (200) and the evacuation station (300) are consecutive stations of the production line (10).

54. The method according to any of items 49-53, wherein a gate or door (105) is arranged between the preheating station (100) and the edge sealing station (200), and/or wherein a gate or door (205) is arranged between the edge sealing station (200) and the evacuation station (300).

55. The method according to any of items 49-54, wherein the evacuation of the gap (5) at the evacuation station (300) is provided for at least 10 minutes, for example at least 20 minutes or for at least 25 minutes.

56. The method according to any of items 49-55, wherein the evacuation of the gap (5) at the evacuation station (300) is provided for less than 60 minutes, such as less than 40 minutes, for example less than 30 minutes.

57. The method according to any of items 49-56, wherein the solder material (7) is a low melting point glass solder frit material, and wherein the temperature in the evacuation station (300) chamber (301) is, such as is maintained, for example by convection heating, larger than 100 °C, such as larger than 200 °C or larger than 250 °C, but is lower than the glass transition temperature (Tg) of the solder material (7), while the gap (5) evacuation and sealing off is provided (S98-S99).

58. The method according to any of items 4-5 and according to any of items 49-57, wherein the temperature in the evacuation station (300) chamber (301) is maintained, such as by convection heating, at a temperature above 200 °C, such as above 250 °C, while the gap (5) evacuation and sealing off (6a) is provided.

59. The method according to any of the preceding items, wherein the distance (DIS1) between neighboring support structures (2) in the gap (5) is between 20 mm and 70 mm, such as between 25 mm and 65 mm, such as between 35 mm and 45 mm and/or wherein more than 500 support structures, such as more than 1000 support structures are arranged in the gap (5).

60. The method of any of the preceding items, wherein one or both glass sheets (3, 4) has/have a thickness (TH1, TH2) between 2 mm and 6 mm, such as between 2.5 mm and 6 mm, for example between 2.5 mm and 3.5 mm including both end points.

61. The method of any of the preceding items, wherein one or both glass sheets (3, 4) has/have a thickness (TH1, TH2) between 1 mm and 6 mm, such as between 2 mm and 4 mm, for example between 2.5 mm and 3.5 mm including both end points.

62. The method of any of the preceding items, wherein the glass sheet assembly (1) is configured so that the distance (H2) between the major glass sheet surfaces (3a, 4a) facing the gap of the final vacuum insulated glass unit (30) is 0.5 mm or below, such as 0.3 mm or below, for example 0.2 mm or below.

63. The method of any of the preceding items, wherein the distance (H2) between the major glass sheet surfaces (3a, 4a) facing the gap (5) of the final vacuum insulated glass unit (30) is configured to be between 0.05 mm and 0.6 mm, such as between 0.1 mm and 0.4 mm, such as between 0.15 and 0.25 mm. 64. The method of any of the preceding items, wherein the solder material (7) height (Hl) is decreased by at least 10%, such as at least 20% or at least 40% when compared to the initial solder material height (Hl) before the local heating (9, 9 1, 9_2, 9_3, 9_4) of the solder material.

65. The method according to any of the preceding items, wherein the solder material (7) strip width (Wl) is between 2 mm and 8 mm, such as between 3 mm and 6 mm, for example between 4 mm and 5 mm (both end points included) at initiation of said softening (t3-t5) of the solder material (7) by locally heating (9, 9 1, 9_2, 9_3, 9_4) the solder material.

66. The method of any of the preceding items, wherein the solder material (7) width (Wl), due to the processing by means of the local heating (9, 9 1, 9_2, 9_3, 9_4) at the edge sealing station (200), is deformed to have a final solder material width (Wl) of between 4 mm and 16 mm, such as between 5 mm and 11 mm, for example between 7 mm and 9 mm.

67. The method of any of the preceding items, wherein the solder material (7) width (Wl) is, during the processing at the edge sealing station (200), increased by at least 10%, such as at least 20% or at least 40% when compared to the initial solder material width (Wl) before the local heating and temporary evacuation of the gap (5) at the edge sealing station (200).

68. The method of any of the preceding items, wherein the power of each of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) is, such as is adjusted to, at least 1300 W such as at least 1500 W.

69. The method according to any of items 4-5, wherein the preheating target temperature (Tl) is within the range of Tg to Tg x 1.1, such as within the range of Tg to Tg x 1.05, such as within the range of Tg to Tg x 1.02, where Tg is the rated glass transition temperature of the solder material (7).

70. The method according to any of the preceding items, wherein one or more of said one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4) is/are moved in the lengthwise direction (LDS) of the solder material (7) at a speed of at least 2 m/s such as at least 5 m/s, such as at least 9 m/s, for example at least 15 m/s during said softening (t3-t5) of the solder material (7). 71. The method according to any of the preceding items, wherein the full longitudinal (LDS) extent (2 L_soider= L_AB + L_ BC, + L_CD + L_DA, , AR1+AR2) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least once every fourth second, such as at least 1 time per second, such as at least 2 times per second during said softening (t3-t5) of the solder material (7).

72. The method according to any of the preceding items, wherein the full longitudinal (LDS) extent (2 L_Soider L_AB + L_ BC, + L_CD + L_DA, , AR1+AR2) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 5 times per second, such as at least 9 times per second, such as at least 14 times per second during said softening (t3-t5) of the solder material (7).

73. The method according to any of items 33, 71 or 72, wherein the full longitudinal LDS extent (2 L_soider ■> L_AB + L_ BC, + L_CD + L_DA) of the solder material 7 is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) said amount of times per second during at least 30%, such as at least 60%, such as at least 90% or at least 95% of the heating time (t3-t5) where the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) heat and soften the solder material (7).

74. The method according to any of the preceding items, wherein the full longitudinal (LDS) extent (2 L_Soider L_AB + L_ BC, + L_CD + L_DA, , AR1+AR2) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 20 times, such as at least 100 times, such as at least 250 times, during said softening (t3-t5) of the solder material (7).

75. The method according to any of the preceding items, wherein the sum of the power of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4,) is at least 200 W, such as at least 400 W, such as at least 1000 W or at least 2000 W.

76. The method according to any of the preceding items, wherein the sum of the power of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) is at least 250W per meter of solder material, such as at least 500W per meter of solder material, such as at least 750W per meter of solder material. 77. The method according to any of the preceding items, wherein the power of the one or more laser light beam(s) and/or the movement speed of the one or more laser light beams is regulated (HP1, HP2, HP3, HP4, Itl, It2, It3, It4), such as increased and/or decreased, during the softening (t3-t5) the solder material (7) at the edge sealing station (200).

78. The method according to item 77, wherein said regulation is provided according to one or more predefined heating profiles (HP1-HP4).

79. The method according to any of the preceding items, such as item 78, wherein the solder material is heated by the one or more laser light beams according to different heating profiles (HP1, HP2, HP3, HP4), such as predefined heating profiles (HP1, HP2, HP3, HP4), during the softening (t3-t5) the solder material (7) at the edge sealing station (200).

80. The method according to any of the preceding items, wherein the power of one or more of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4,), such as each of the one or more laser light beams, is at least 250W, such as at least 500 W.

81. The method according to any of the preceding items, wherein the heating of a local area (18) of the solder material (7) by means of one or more laser light beams during a heating iteration comprises a heating time (HETI) followed by a soaking time (SOTI) for said area (18) before a laser light beam revisit said area (18).

82. The method according to item 81, wherein the soaking time (SOTI) from a local peak temperature (Pt) is reached and to a new consecutive heating at the local area (18) is started (HIS2) is larger, such as at least two times larger, such as at least four times larger, or at least six times larger, than the time (HETI) it takes for the laser light beam to heat the solder material to the local peak temperature (Ptl).

83. The method according to item 81, wherein the soaking time (SOTI) from a local peak temperature (Pt) is reached and to a new consecutive heating at the local area ( 18) is started (HIS2), is at least ten times larger, such as at least 15 times larger or at least 20 times larger than the time (HETI) it takes for a laser light beam to heat the solder material at the area (18) to the local peak temperature (Ptl) obtained during a heating iteration. 84. The method according to any of the preceding items, such as according to any of items 81-83, wherein the heating time (HETI) it takes for a laser light beam to increase (Til) the solder material temperature to a local (18) peak temperature (Ptl) during a heating iteration is less than 1 second, such as less than 0.5 second, such as less than 0.05 second, or wherein the heating time (HETI) it takes for a laser light beam to increase (Til) the solder material temperature to a local peak temperature (Ptl) during a heating iteration is less than 0.2 second, such as less than 0.1 second, such as less than 0.05 second-

85. The method according to any of items 31, 32 or 70, wherein said one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) each is/are moved in the lengthwise direction (LDS) of the solder material (7) at said speed during at least 30%, such as at least 60%, such as at least 90% of the heating time (t3-t5) where the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) heat and soften the solder material (7).

86. The method according to any of the preceding items, wherein the vacuum insulated glass (VIG) unit (30) is for, such as for use in, a building window, such as a roof window.

87. A building window, such as a roof window, comprising a vacuum insulated glass (VIG) unit (30), wherein the vacuum insulated glass (VIG) unit (30) is manufactured by means of a method according to any of the preceding items.

88. A cooling storage, such as a refrigerator, comprising a vacuum insulated glass (VIG) unit (30), such as wherein the vacuum insulated glass unit (30) is installed in a lid or door of the cooling storage, wherein the vacuum insulated glass unit (30) is manufactured by means of a method according to any of the items.

Claims

1. A method of processing a glass sheet assembly (1) for a vacuum insulated glass (VIG) unit (30) at a production line (10), wherein the method comprises the step of

- providing a glass sheet assembly (1) comprising a first glass sheet (3) and a second glass sheet (4), wherein a plurality of support structures (2) for maintaining a gap (5) between said first glass sheet and said second glass sheet of the vacuum insulated glass unit (30) are arranged between major surfaces (3a, 4a) of the glass sheets (3, 4), wherein the glass sheet assembly (1) comprises an edge seal (7, 11) for providing an edge sealing for enclosing and sealing the gap (5) between the glass sheets (3, 4), wherein the edge seal comprises a solder material (7), wherein the production line (10) comprises at least a preheating station (100) and an edge sealing station (200), the method further comprising the steps of: i) positioning the glass sheet assembly (1) at a preheating station (100, 101) of the production line (10), ii) heating the positioned glass sheet assembly (1) in the preheating station (100, 101) to a preheating target temperature (Tl), iii) moving the preheated glass sheet assembly (1) from the preheating station (100) and positioning the preheated glass sheet assembly (1) at the edge sealing station (200), iv) softening (t3-t5) the solder material (7) of the preheated glass sheet assembly (1) at the edge sealing station (200) by locally heating the solder material (7) by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4).

2. The method according to claim 1, wherein said method comprises the step of stopping (t5) said local heating of the solder material (7) by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4), thereby cooling and hardening the solder material (7) of the preheated glass sheet assembly (1), such as so as to obtain an edge sealed glass sheet assembly (20).

3. The method according to any of the preceding claims, wherein the power of one or more of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4,), such as each of the one or more laser light beams, is at least 250W, such as at least 500 W.

4. The method according to any of the preceding claims, wherein the solder material (7) is a glass solder material comprising a low melting point glass solder frit material.

5. The method according to claim 4, wherein the glass sheet assembly (1) is heated in the preheating station (100, 101) to a temperature (Tl) above the glass transition temperature (Tg) of the glass solder material (7).

6. The method according to any of the preceding claims, wherein a plurality of glass sheet assemblies (1) are arranged in a preheating chamber (101) of the preheating station (100), such as wherein the glass sheet assemblies (1) are provided into the preheating station by means of a transport system (90).

7. The method according to any of the preceding claims, wherein the preheating chamber (101) comprises a plurality of glass sheet assembly storage locations (103), such as more than two, such as more than five or more than ten glass sheet assembly storage locations (103).

8. The method according to any of the preceding claims, wherein the time period (t 1 -t3) between the time (tl) at which said preheating is initiated (tl) and the time (t3) at which said locally heating (9, 9 1, 9_2, 9_3, 9_4) of the solder material is initiated, is in the range of 10 minutes to 90 minutes, such as in in the range of 15 minutes to 70 minutes or in the range of 20 minutes to 50 minutes.

9. The method according to any of the preceding claims, wherein a gate or door (105) is arranged between the preheating station (100) and the edge sealing station (200), and/or wherein the preheating station (100) and the edge sealing station (200) are consecutive stations.

10. The method according to any of the preceding claims, wherein the preheating target temperature (Tl) is above 260 °C, such as above 280 °C, such as above 300 °C,

11. The method according to any of claims 4 or 5, wherein the solder material (7) of the glass sheet assembly (1) is substantially free from solvent prior to processing of the glass sheet assembly (1) at the preheating station (100).

12. The method according to any of the preceding claims, wherein a chamber (201) in which the glass sheet assembly (1) is arranged during said locally heating (9, 9 1, 9_2, 9_3, 9_4) of the solder material (7), is heated, such as convection heated, by means of a heater (220), so as to maintain an elevated temperature of the glass sheet assembly during said local heating (9, 9 1, 9_2, 9_3, 9 4).

13. The method according to any of the preceding claims, wherein the average temperature of the glass sheets (3, 4), in a chamber (201) of at the edge sealing station (200), is maintained within ± 30 °C, such as within ± 20 °C, such as within ± 10 °C or within ± 5 °C of the preheating target temperature (Tl), such as by means of a heater (220).

14. The method according to any of the preceding claims, wherein the softening of the solder material (7) by locally heating the solder material (t3-t5) is be provided for a time period (t3- t5) that is within 10 to 130 seconds, such as within 30 to 100 seconds for example within 40 seconds to 90 seconds.

15. The method according to any of the preceding claims, wherein said softening of the solder material (7) by locally heating the solder material is provided for a time period (t3-t5) that is less than 5 minutes, such as less than 2 minutes, such as less than 100 seconds, before the local heating is stopped (t5).

16. The method according to any of the preceding claims, wherein the local heating is provided by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) that are swept along the longitudinal direction (LDS) of the solder material in order to provide a substantially uniform heating of the total longitudinal extent (2 ^solder ⁼ L_AB + L_BC + L_CD + L_DA ) of the solder material (7).

17. The method according to any of the preceding claims, wherein the heating by means of said one or more laser light beams comprises a plurality of consecutive, such as continuous, heating iterations along the longitudinal direction (LDS) of the solder material (7) so as to heat the total longitudinal extent (2 hsoider = L_AB + L_BC + L_CD + L_DA ) ofthe solder material (7).

18. The method according to any of the preceding claims, wherein said local heating is provided by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) which is/are moved in the lengthwise direction (LDS) of the solder material (7) at a combined speed of at least 20 m/s such as at least 40 m/s during the softening step (7).

19. The method according to any of the preceding claims, wherein said local heating is provided by means of one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) which each is moved in the lengthwise direction (LDS) of the solder material (7) at a speed of at least 20 m/s such as at least 40 m/s during the softening step (7).

20. The method according to any of the preceding claims, wherein the full extent (L_AB + L BC+ L CD + L_DA) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 10 times per second, such as at least 20 times per second, such as at least 30 times per second, during the step of softening the solder material by means of one or more laser light beams.

21. The method according to any of the preceding claims, wherein the power of each of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4,) is at least 500 W, such as at least 750 W, such as at least 1000W.

22. The method according to any of the preceding claims, wherein the full extent (L_AB + L_ BC, + L_CD + L_DA) of the solder material (7) of the glass sheet assembly is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 500 times, such as at least 1000 times, such as at least 1500 times during the step of softening the solder material.

23. The method according to any of the preceding claims, wherein the temperature of the solder material (7) is increased by means of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) by at least 30 °C, such as at least 50 °C, in less than 180 seconds, such as less than 120 seconds such as less than 100 seconds.

24. The method according to any of the preceding claims, wherein a mirror controller (16) controls a mirror (15) so as to move a redirected laser beam (9, 9 1, 9_2, 9_3, 9_4) along the longitudinal direction (LDS) of one or more solder material strips (A-B, B-C, C-D, D-E) of the solder material (7) so as to provide said local heating of the solder material (7).

25. The method according to any of the preceding claims, wherein a mirror controller (16) controls a mirror (15) so as to move a redirected laser beam (9, 9 1, 9_2, 9_3, 9_4) along the longitudinal direction (LDS) of more than one solder material strips (A-B, B-C, C-D, D- E) of the solder material (7) so as to provide said local heating of the solder material (7).

26 . The method according to claim 24 or 25, wherein said mirror (15) is located outside a chamber (201) of the edge sealing station (200) in which the glass sheet assembly (1) is arranged during said local heating.

27. The method according to any of the preceding claims, wherein a force clamping so as to force the first glass sheet (3) and the second glass sheet (4) towards each other is provided during said local heating of the solder material at the edge sealing station (200).

28. The method according to claim 27, wherein said force clamping comprises providing (t4) a pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (1) so as to force the first glass sheet (3) and the second glass sheet (4) towards each other.

29. The method according to claim 28, wherein the providing of the pressure difference includes a step of evacuating (8) the gap (5), such as by means of an evacuation cup.

30. The method according to any of claims 28-29, wherein the force clamping, such as the pressure difference, is initiated (t4) during (t3-t5) the softening the solder material (7) by means of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4).

31. The method according to any of claims 28-30, wherein said providing of the pressure difference, is initiated at a time (t4) after the local heating of the solder material (7) has been initiated (t3).

32. The method according to any of claims 28-31, comprising the step of eliminating (t6) the pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly.

33. The method according to claim 32, wherein said elimination of the pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (20) is provided at a time (t6) after said locally heating of the solder material (7) is stopped (t5), such as wherein the elimination of the pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (20) is provided at least 2 seconds after, such as at least 5 seconds after, such as at least 10 seconds after, after said locally heating of the solder material (7) is stopped (t5).

34. The method according to any of the preceding claims, further comprising the subsequent, consecutive steps of e) removing the edge sealed glass sheet assembly (20) from the edge sealing station (200) of the production line (10), f) positioning the edge sealed glass sheet assembly (1) at an evacuation station (300) of the production line (10), g) evacuating the gap (5) to a substantially vacuum, and h) sealing off (6a) the gap (5) from the surroundings.

35. The method according to claim 34, wherein a gate or door (205) is opened so as to allow moving the edge sealed glass sheet assembly (20) into a chamber (301) of the evacuation station (300), and is (205) thereafter closed again.

36. The method of any of claims 34-35, wherein the gap (5) is evacuated at the evacuation station (300) to a pressure below 0.05 mbar, such as below 0.005 mbar, such as 0.003 or 0.001 mbar or below by means of an evacuation pump.

37. The method according to any according to any of claims 28-32 and according to any of claims 34-36, wherein the maximum pressure difference between the pressure (P2) in the gap (5) and the pressure (Pl) surrounding the glass sheet assembly (1) at the edge sealing station (200) is less, such as at least ten times less, such as at least 100 times less, than the pressure difference between the pressure in the gap (5) and the pressure surrounding the edge sealed glass sheet assembly (20) at the evacuation station (300) after sealing off (6a) the gap (5) from the surroundings.

38. The method according to any of claims 34-38, wherein the preheating station (100), the edge sealing station (200) and the evacuation station (300) are consecutive stations of the production line (10).

39. The method according to any of claims 34-38, wherein the evacuation of the gap (5) at the evacuation station (300) is provided for at least 10 minutes, for example at least 20 minutes or for at least 25 minutes, such as wherein the evacuation of the gap (5) at the evacuation station (300) is provided for less than 60 minutes, such as less than 40 minutes, for example less than 30 minutes.

40. The method according to any of claims 34-39, wherein the solder material (7) is a low melting point glass solder frit material, and wherein the temperature in the evacuation station (300) chamber (301) is, such as is maintained, larger than 100 °C, such as larger than 200 °C or larger than 250 °C, but is lower than the glass transition temperature (Tg) of the solder material (7), while the gap (5) evacuation and sealing off is provided (S98-S99).

41. The method according to any of claims 4-5 and according to any of claims 34-40, wherein the temperature in the evacuation station (300) chamber (301) is maintained, such as by convection heating, at a temperature above 150°C, such as above 200 °C, such as above 250 °C, while the gap (5) evacuation and sealing off (6a) is provided.

42. The method according to any of the preceding claims, wherein the distance (DIS1) between neighboring support structures (2) in the gap (5) is between 20 mm and 70 mm, such as between 25 mm and 65 mm, such as between 35 mm and 45 mm.

43. The method of any of the preceding claims, wherein one or both glass sheets (3, 4) has/have a thickness (TH1, TH2) between 2 mm and 6 mm, such as between 2.5 mm and 6 mm, for example between 2.5 mm and 3.5 mm including both end points and/or wherein the glass sheet assembly (1) is configured so that the distance (H2) between the major glass sheet surfaces (3a, 4a) facing the gap of the final vacuum insulated glass unit (30) is 0.5 mm or below, such as 0.3 mm or below, for example 0.2 mm or below.

44. The method of any of the preceding claims, wherein the final VIG unit (30) is transparent to at least visible light.

45. The method of any of the preceding claims, wherein the solder material (7) width (Wl), due to the processing by means of the local heating (9, 9 1, 9_2, 9_3, 9_4) at the edge sealing station (200), is deformed to have a final solder material width (Wl) of between 4 mm and 16 mm, such as between 5 mm and 11 mm, for example between 7 mm and 9 mm.

46. The method according to any of claims 4-5, wherein the preheating target temperature (Tl) is within the range of Tg to Tg x 1.1, such as within the range of Tg to Tg x 1.05, such as within the range of Tg to Tg x 1.02, where Tg is the rated glass transition temperature of the solder material (7).

47. The method according to any of the preceding claims, wherein one or more of said one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) is/are moved in the lengthwise direction (LDS) of the solder material (7) at a speed of at least 2 m/s such as at least 5 m/s, such as at least 9 m/s, during said softening (t3-t5) of the solder material (7).

48. The method according to any of the preceding claims, wherein the full longitudinal (LDS) extent (£ L_soider= L AB + L_ BC, + L CD + L_DA, , AR1+AR2) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least one time every fourth second, such as at least 1 time per second, such as at least 2 times per second during said softening (t3-t5) of the solder material (7).

49. The method according to any of the preceding claims, wherein the full longitudinal (LDS) extent (£ L_soider, L AB + L_ BC, + L CD + L_DA, , AR1+AR2) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 5 times per second, such as at least 9 times per second, such as at least 14 times per second during said softening (t3-t5) of the solder material (7).

50. The method according to any of claims 20, 48 or 49, wherein the full longitudinal (LDS) extent (2 L_soider, L_AB + L_ BC, + L_CD + L_DA) of the solder material (7) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) said amount of times per second during at least 30%, such as at least 60%, such as at least 90% of the heating time (t3-t5) where the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) heat and soften the solder material (7).

51. The method according to any of the preceding claims, wherein the full longitudinal (LDS) extent ( L_soider, L AB + L_ BC, + L CD + L_DA, , AR1+AR2) of the solder material (7) of the glass sheet assembly (1) is exposed to a laser light beam (9, 9 1, 9_2, 9_3, 9_4) at least 20 times, such as at least 100 times, such as at least 250 times, during said softening (t3-t5) of the solder material (7).

52. The method according to any of the preceding claims, wherein the sum of the power of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4,) is at least 400 W, such as at least 1000 W or at least 2000 W.

53. The method according to any of the preceding claims, wherein the sum of the power of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) is at least 250W per meter of solder material, such as at least 500W per meter of solder material, such as at least 750W per meter of solder material.

54. The method according to any of the preceding claims, wherein the power of the one or more laser light beam(s) and/or the movement speed of the one or more laser light beams is regulated (HP1, HP2, HP3, HP4, Itl, It2, It3, It4), such as increased and/or decreased, during the softening (t3-t5) the solder material (7) at the edge sealing station (200), such as wherein said regulation is provided according to one or more predefined heating profiles (HP1-HP4).

55. The method according to any of the preceding claims, wherein the power of one or more of the one or more laser light beams (9, 9 1, 9_2, 9_3, 9 4,), such as each of the one or more laser light beams, is at least 250W, such as at least 500 W.

56. The method according to any of the preceding claims, wherein the heating of a local area (18) of the solder material (7) by means of the one or more laser light beams (9, 9 1, 9_2,

9 3, 9 4) during a heating iteration comprises a heating time (HETI) followed by a soaking time (SOTI) for said local area (18) before a laser light beam revisit the local area (18).

57. The method according to claim 56, wherein the soaking time (SOTI) from a local peak temperature (Pt) is reached, and to a new consecutive heating is started (HIS2) at the local area (18), is at least four times larger, such as at least six times larger, such as at least 10 times larger, than the time (HETI) it takes for a laser light beam to heat the solder material at the local area (18) to the peak temperature (Ptl) obtained during a heating iteration.

58. The method according to any of the preceding claims, wherein the heating time (HETI) it takes for a laser light beam to increase (Til) the solder material temperature to a local (18) peak temperature (Ptl) during a heating iteration is less than 1 second, such as less than 0.5 second, such as less than 0.05 second.

59. The method according to any of the preceding claims, wherein the heating time (HETI) it takes for a laser light beam to increase (TH) the solder material temperature to a local (18) peak temperature (Ptl) during a heating iteration is less than 0.2 second, such as less than 0.1 second, such as less than 0.05 second.

60. The method according to any of claims 18, 19 or 47, wherein said one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) each is/are moved in the lengthwise direction (LDS) of the solder material (7) at said speed during at least 30%, such as at least 60%, such as at least 90% of the heating time (t3-t5) where the one or more laser light beams (9, 9 1, 9_2, 9_3, 9_4) heat and soften the solder material (7).

61. The method according to any of the preceding claims, wherein the vacuum insulated glass (VIG) unit (30) is for, such as for use in, a building window, such as a roof window.

62. The method according to any of the preceding claims, wherein the first glass sheet (3) as well as the second glass sheet (4) are tempered glass sheets such as thermally tempered glass sheets.

63. A building window, such as a roof window, comprising a vacuum insulated glass (VIG) unit (30), wherein the vacuum insulated glass (VIG) unit (30) is manufactured by means of a method according to any of the preceding claims.