DE202019005371U1 - Laser-treated heatable glazing - Google Patents

Abstract

Inorganic or organic substrate (1) which has a single-layer or multi-layer coating comprising at least one electrically conductive layer (2), obtainable by a process which involves depositing the electrically conductive layer (2) onto the substrate (1) and laser treatment of the deposited electrically conductive layer (2) with UV laser light to improve the conductivity of the electrically conductive layer (2).

Description

The invention relates to a substrate, preferably a glass substrate, which has a coating which comprises an electrically conductive layer and which e.g. can be used as heatable glazing for vehicles.

In order to achieve adequate comfort in sunlight, most coating packages for automotive and building applications have reflective IR properties. High IR reflection properties are directly related to high electrical conductivity. Also for the ohmic heating of substrates, e.g. heated windshields or rear windows, coatings with high electrical conductivity are desirable.

These coatings can e.g. be based on ITO or silver and the substrates can consist of both plastic and inorganic glass. A standard method for depositing such coatings is magnetron sputtering. Most industrial sputtering processes are carried out at room temperature. In order to achieve a higher conductivity of the coating and a higher light transmission, an additional heat treatment is necessary, typically at temperatures above 500 ° C.

This heat treatment step is, of course, for thermally sensitive substrates such as e.g. Plastics, not possible, as this would damage or melt the substrate.

Another method of increasing the conductivity is to increase the layer thickness, but this has a negative effect on the optical transmission and the product costs. The longer coating times are also disadvantageous.

In the case of plastic glasses such as Polycarbonate washers to achieve a heating function, the current solution consists of soldering tungsten wires. In the case of inorganic glass substrates, the coating is heat-treated, a high-temperature coating or a thicker coating in order to achieve improved conductivity. With 3D panes (i.e. curved panes, in particular panes curved along several spatial directions), it is difficult to solder the tungsten wire. In addition, e.g. Damage to the existing anti-scratch coating may occur.

An alternative option is to treat the layers in the visible or IR range. For example, concerns WO 2010/139908 A1 a method for producing a substrate which is coated on a first surface with at least one transparent and electrically conductive thin film which contains at least one oxide, which the deposition of the thin film on the substrate and the heat treatment of the thin film while irradiating the thin film with light of a wavelength between 500 and 2000 nm.

DE 102007052782 A1 describes a method for changing the properties of a TCO layer, the TCO layer being irradiated with the laser light of at least one laser device and the laser light on the TCO layer having a linear intensity distribution. The wavelength of the laser light can be in the range from 800 to 1800 nm.

WO 2008/096089 A2 relates to a method of treating a substrate, such as glass, coated on one side with a thin layer, the treatment comprising heating the thin layer to a temperature of at least 300 ° C while maintaining a temperature of no more than 150 ° C on the other Side of the substrate to increase the degree of crystallization of the thin film. The thin layer can be, for example, electrically conductive oxides or silver layers.

In WO 2015/055944 A1 describes a method for producing a material that contains a glass or glass ceramic substrate that is at least partially coated with a stack of thin layers, which is based on depositing the stack comprising at least one thin layer of an electrically conductive transparent oxide together with at least one homogenization layer on metal, metal nitride or metal carbide and then heat treating the stack under radiation. Laser radiation with a wavelength between 500 and 2000 nm can be used.

However, these alternative laser treatment methods in the visible or IR range are not very effective due to the lower absorption by the coating.

US20130320241A1 discloses laser treatment of a silver-containing coating on glass substrates with UV radiation. US20170167188A1 discloses laser treatment of a TCO layer Glass substrates with UV radiation. In both cases, the coating is treated exclusively with laser radiation, without additional heat treatment.

A laser treatment process in the sense of the invention is to be distinguished from laser coating processes in which the coating is removed in certain areas, in particular by producing insulating lines which structure the coating. Such processes are for example in WO03100513A1 and WO2014072137A1 disclosed. A distinction should also be made between laser drying processes based on sol-gel coatings, such as in DE102008001578A1 disclosed.

The invention is therefore based on the object of overcoming the disadvantages described above in the prior art. The object is in particular to provide substrates with electrically conductive transparent coatings with very good transparency and conductivity, which are accessible by a process which is also suitable for thermally sensitive substrates such as plastic. The method should also be effective so that the laser light used is used effectively. Furthermore, the required outlay on equipment should be as low as possible.

According to the invention, this object is achieved by a substrate according to claim 1. Preferred embodiments of the invention are given in the dependent claims.

It was found that electrically conductive layers with excellent optical transmission and conductivity are obtained by the method. After UV laser treatment, the surface resistance of the coating improves e.g. by 25% or even 50%. The layers show increased crystallinity. Since the electrically conductive layers absorb UV radiation well, the treatment is highly effective. The process is relatively simple to carry out and is also suitable for thermally sensitive substrates.

The invention thus relates to an inorganic or organic substrate, preferably an inorganic or organic glass substrate, which has a single-layer or multilayer coating comprising at least one electrically conductive layer and which is obtainable by an improved method, the method being the deposition of the electrically conductive layer onto the Includes substrate and the laser treatment of the deposited electrically conductive layer with UV laser light. Before the coating is deposited, the substrate can be uncoated or already precoated.

The laser treatment according to the invention serves to improve the conductivity or the sheet resistance of the electrically conductive layer. An improvement in the surface resistance is understood to mean its reduction, which results in better conductivity. Laser treatment is full-area irradiation of the conductive layer, which leads to a material conversion, in particular an increase in crystallinity. The laser treatment according to the invention is in particular not a laser decoating, material being removed in certain areas.

1. 1. Abscheiden mindestens einer elektrisch leitfähigen Schicht auf das Substrat,
2. 2. Laserbehandlung der abgeschiedenen elektrisch leitfähigen Schicht mit UV-Laserlicht.

In other words, the invention comprises a coated pane, comprising a substrate and a coating with at least one electrically conductive layer. The disc can be obtained by a process which has the following steps:

1. 1. depositing at least one electrically conductive layer on the substrate,
2. 2. Laser treatment of the deposited electrically conductive layer with UV laser light.

According to the method, an inorganic or organic substrate is produced which has a single-layer or multilayer coating which comprises at least one electrically conductive layer.

The inorganic or organic substrate is preferably an inorganic or organic glass substrate or a ceramic substrate, preferably a transparent ceramic substrate.

The glass substrate can be made of inorganic glass or organic glass (polymers). Examples of inorganic glass are flat glass, quartz glass, borosilicate glass, soda-lime glass and / or alkali aluminum silicate glass. The inorganic glass is preferably soda-lime glass, quartz glass, borosilicate glass or chemically toughened glass.

Organic glass is glass made of plastic. Examples of organic glass are a glass made from polyethylene terephthalate (PET), polycarbonate (PC) or polymethyl methacrylate (PMMA), PMMA glass and PC glass being preferred and PC glass being particularly preferred.

The single-layer or multi-layer coating comprises at least one electrically conductive layer, preferably a transparent electrically conductive layer. In a preferred embodiment, the electrically conductive layer is formed from a transparent conductive oxide (TCO, “transparent conductive oxide”). Such TCO layers are well known to those skilled in the art.

Examples of transparent conductive oxides are tin-doped indium oxide (ITO, also known as indium tin oxide), zinc-doped indium oxide (IZO) with antimony or fluorine-doped tin oxide (SnO ₂ : Sb or SnO ₂ : F), gallium-doped zinc oxide or aluminum-doped zinc oxide (ZnO: Al), with ITO being preferred.

The thickness of the electrically conductive layer based on these transparent conductive oxides (TCO) is e.g. in the range of 10 nm to 1 μm, more preferably 30 nm to 200 nm and in particular 50 to 100 nm.

In another preferred embodiment, the electrically conductive layer, preferably the transparent electrically conductive layer, is formed from a metal layer or a stack of layers comprising at least one metal layer. Such metal layer systems are well known to the person skilled in the art.

Suitable metals for the metal layer are e.g. Ag, Al, Pd, Cu, Pt, Mo, Au, Ni, Cr, W, Nb, Ta, Zr, Hf or mixtures of one or more of these metals, the metal preferably being selected from silver or niobium and particularly preferably from silver is.

The metal layer can be present as a single layer or the electrically conductive layer can be a layer stack of several layers comprising at least metal layer. The layer stack can e.g. are formed from one or more, preferably at least two, dielectric layers and one or more metal layers, in particular silver layers, the dielectric layer and metal layer preferably being arranged in an alternating sequence. The dielectric layer is also called an anti-reflective layer and is e.g. by oxides or nitrides, e.g. Silicon nitrides, zinc oxides, aluminum nitrides or titanium oxide.

Typical thicknesses of the individual layers for the metal layer or the layer stack comprising at least one metal layer are e.g. in the range from 1 to 20 nm, preferably 5 to 15 nm, the metal layer preferably being a silver layer. The total thickness of the layer stack comprising at least one metal layer is e.g. typically at least 50 nm and can be up to 500 nm for multilayer layers, the metal layer preferably being a silver layer.

The method comprises depositing the electrically conductive layer on the (uncoated or pre-coated) substrate, preferably a glass substrate, preferably a pre-coated glass substrate. The deposition can e.g. by physical vapor deposition (PVD), e.g. Sputtering, preferably magnetron sputtering, or by chemical vapor deposition (CVD), e.g. Plasma-assisted chemical vapor deposition (PECVD) or atomic layer deposition (ALD) take place.

In a preferred embodiment, the electrically conductive layer, in particular the transparent conductive oxide, is deposited by sputtering, in particular magnetron sputtering, or a CVD process. The metal layer and the layer stack comprising at least one metal layer are preferably deposited by sputtering, in particular magnetron sputtering.

The deposition of the electrically conductive layer is preferably carried out at a relatively low temperature, e.g. a temperature of not more than 100 ° C, preferably not more than 80 ° C or about ambient temperature.

Magnetron sputtering is a process that is frequently used on an industrial scale for the application of thin layers, in particular on glass substrates. In the industrial implementation of magnetron sputtering, the substrate usually remains at ambient temperature or is warmed slightly (less than 80 ° C).

The method further includes laser treatment of the deposited electrically conductive layer with UV laser light. The UV laser light can be broadband, multichromatic or monochromatic UV laser light, with monochromatic UV laser light being preferred.

Compared to treatment with IR laser light, e.g. in the wavelength range of about 1 µm, the electrically conductive coating, in particular the ITO layer and the layer comprising one or more silver layers, shows a high absorption in the UV range 400 400 nm, so that a very effective treatment is achieved. After UV laser treatment, the sheet resistance can be improved by up to 25% and even up to 50%.

The UV laser light can be generated by conventional lasers. The UV laser light is preferably generated by a solid-state laser. Compared to other lasers such as excimer lasers, UV solid-state lasers are particularly easy to integrate into the method according to the invention and are easy to maintain.

In the present application, light and radiation are used as synonymous terms. In the literature, there are different indications for the wavelength range of ultraviolet (UV) radiation, e.g. a wavelength range from 10 to 380 nm or a range from 1 to 400 nm. In the present application, UV light is understood to mean light in the wavelength range up to 400 nm, in particular from 100 nm to 400 nm.

The wavelength of the UV laser light for laser treatment of the electrically conductive layer is preferably in the range from 150 nm to 400 nm.

The coating is heated relatively little during the laser treatment. The temperature of the electrically conductive layer or coating remains e.g. advantageous during laser treatment at any point below 600 ° C. The electrically conductive layer advantageously reaches a temperature of at least 100 ° C. during laser treatment.

The laser treatment with UV laser light is preferably carried out with an energy density introduced into the electrically conductive layer or coating in the range from 150 to 300 mJ / cm ² .

Since laser light can usually only irradiate a small area, the UV laser light or the UV laser is usually moved over the electrically conductive layer or coating or the coated substrate is moved under the UV laser light to cover the entire area scanning the electrically conductive layer with the UV laser light.

The UV laser light is used in laser treatment e.g. at a speed in the range of 10 to 20 mm / s over the electrically conductive layer or coating.

If the coating over the electrically conductive layer comprises one or more further layers, the laser treatment of the electrically conductive layer can be carried out before or after the deposition of the one or more further layers above it.

Since layers applied over the electrically conductive layer are generally transparent to UV light, it is usually expedient to carry out the laser treatment after the entire coating has been completed. In particular in cases in which layers applied above the electrically conductive layer partially absorb or reflect UV light, it may be expedient or necessary to carry out the laser treatment after the deposition of the transparent electrically conductive layer and before the deposition of layers above it.

The UV laser light for the treatment of the deposited electrically conductive layer can e.g. be punctiform or linear UV laser light, with linear UV laser light being preferred. In the case of line-shaped UV laser light, the above-mentioned speed of the UV laser light relates to the direction perpendicular to the laser line irradiated on the coating. The line width of the line-shaped UV laser light is preferably greater than or equal to the width of the conductive coating perpendicular to the direction of movement of the laser radiation. As a result, the entire width of the coating is covered by the laser radiation and the laser treatment can be carried out in a single pass.

The substrates, in particular the glass substrates, can be flat or flat substrates (2D glass substrates) or curved or shaped substrates (3D glass substrates), for example flat or curved vehicle windows.

The thickness of the substrate, especially the glass substrate, can e.g. are in the range from 0.1 mm to 19 mm, preferably 0.1 to 10 mm. The substrates can be relatively large, in particular glass substrates, e.g. have at least one dimension (e.g. a length) of at least 1 m, at least 2 m or even at least 3 m.

The laser treatment can be adjusted depending on the substrate shape. In the case of flat substrates, preferably glass substrates, in particular large, flat glass substrates, a laser treatment with line-shaped UV laser light is suitable, with which the substrate surface to be treated is scanned. For 3D substrates, preferably 3D glass substrates, e.g. for plastic glazing with organic glass substrates, the laser can be installed on a robot or a multi-axis system in order to move the punctiform or linear laser beam of the UV laser light for processing the free-form surfaces, the linear laser beam e.g. has a line width of less than 10 mm.

In particular, if the substrate is an inorganic glass substrate or ceramic substrate, in particular transparent ceramic substrate, the method according to the invention after the laser treatment can include a tempering step in which the coated substrate is subjected to a heat treatment at elevated temperature, e.g. at a temperature of at least 500 ° C, more preferably at least 550 ° C and not more than 750 ° C, more preferably not more than 700 ° C. The heat treatment can be carried out as part of a glass bending process. An organic substrate can also be subjected to a heat treatment, but lower temperatures should then be used in order to avoid melting or softening of the substrate.

The coating on the substrate, preferably a glass substrate, can have one or more layers. If the coating has one or more additional layers in addition to the electrically conductive layer, the additional layers may e.g. are a UV-reflecting layer and / or a protective layer and / or a dielectric layer.

In a preferred embodiment, the substrate, in particular the organic glass substrate, is provided with a UV-reflecting layer prior to the deposition of the transparent electrically conductive layer, i.e. the transparent, electrically conductive layer is deposited on a precoated substrate, the precoating comprising a UV-reflecting layer. A suitable UV-reflecting layer is e.g. a titanium oxide layer or a zinc oxide layer. The UV reflective layer can e.g. applied by PVD or CVD processes. The UV reflective layer has e.g. a layer thickness of 1 to 100 nm, preferably of 5 to 50 nm.

The UV-reflecting layer can be useful as protection for UV-sensitive materials from damage during laser treatment if such UV-sensitive materials are present under the electrically conductive layer. Organic glass substrates can be UV sensitive and need such protection.

The protective layer can comprise one or more protective layers for the electrically conductive layer. The protective layer can be at least one ion diffusion barrier layer and / or at least one oxygen barrier layer. The ion diffusion barrier layer can be arranged between the substrate, preferably glass substrate, and the electrically conductive layer, preferably transparent, electrically conductive layer, as a pre-coating in order to prevent the migration of alkaline ions, e.g. to prevent from the substrate, especially inorganic glass substrate. The oxygen barrier layer can be deposited over the electrically conductive layer to serve as a barrier against oxygen and to protect the electrically conductive layer from oxidation.

In a preferred embodiment, the precoated substrate, preferably the precoated glass substrate, comprises at least one ion diffusion barrier layer in the precoating and / or at least one oxygen barrier layer is deposited over the electrically conductive layer.

For the oxygen barrier layers and ion diffusion barrier layers serving as protective layers, essentially the same materials can be used, for example nitrides or carbides. Such protective layers and their formation are well known in the art. For the application of these protective layers the usual methods or gas phase deposition methods can be used, for example PVD, in particular sputtering, preferably magnetron sputtering, CVD and ALD.

The ion diffusion barrier layer and oxygen barrier layer can be formed, for example, from silicon carbide, silicon nitride, silicon oxynitride, metal nitride, metal carbide or a combination thereof, silicon nitride, in particular Si ₃ N ₄ and / or doped Si ₃ N ₄ , metal nitride, metal carbide or a combination thereof, being particularly preferred . In the case of the metal nitrides and metal carbides, the metal can be, for example, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten.

The oxygen barrier layer preferably has a layer thickness of 10 to 100 nm, preferably 20 to 80 nm, particularly preferably 30 to 80 nm. The ion diffusion barrier layer has e.g. a layer thickness of 1 to 100 nm, preferably of 5 to 50 nm.

The coating may optionally comprise one or more dielectric layers, e.g. have an anti-reflective effect. Typical dielectric layers contain oxides or nitrides, for example silicon nitride, silicon oxide, aluminum nitride, aluminum oxide, zinc oxide or titanium oxide. Dielectric layers can also be applied by PVD or CVD processes. The layer thickness can e.g. are in the range from 1 to 100 nm.

The substrate, preferably the glass substrate, can be coated over the entire surface or over part of the surface with the electrically conductive layer. The electrically conductive layer can e.g. be applied in a pattern and form part of a heating system. In a preferred embodiment, the single-layer or multi-layer coated substrate or glass substrate serves as heatable glazing.

In a preferred embodiment, the inorganic or organic substrate according to the invention, preferably glass substrate, is a vehicle window, in particular an automobile window, building glazing or a window window, in particular a heatable vehicle window.

• 1 einen schematischen Querschnitt eines erfindungsgemäß beschichten Glassubstrats;
• 2 einen schematischen Querschnitt eines weiteren erfindungsgemäß beschichten Glassubstrats;
• 3 XRD-Kurven einer ITO-Beschichtung gemäß Beispiel 1;
• 4 XRD-Kurven einer silberbasierten Beschichtung gemäß Beispiel 2.

The invention is explained below with reference to the attached figures and with the aid of non-restrictive exemplary embodiments. In these shows:

• 1 a schematic cross section of a glass substrate coated according to the invention;
• 2nd a schematic cross section of another glass substrate coated according to the invention;
• 3rd XRD curves of an ITO coating according to Example 1;
• 4th XRD curves of a silver-based coating according to example 2.

1 shows a schematic cross section of a glass substrate coated according to the invention with a glass substrate 1 , for example a soda-lime glass covered with a transparent electrically conductive layer 2nd is provided as a coating. With the transparent, electrically conductive layer 2nd it can be, for example, a layer stack comprising a silver layer.

2nd shows a schematic cross section of a further glass substrate coated according to the invention. The glass substrate 1 is a PC glass or an inorganic glass, eg a soda lime glass, which has a multi-layer coating. In this order, the coating has a UV-reflecting layer made of titanium oxide (TiOx), a dielectric layer made of SiO ₂ , an indium tin oxide layer (ITO) as a transparent, electrically conductive layer 2nd , an oxygen barrier layer made of silicon nitride (Si ₃ N ₄ ) and a further dielectric layer made of SiO ₂ .

example 1

ITO coating on plastic glazing

For a heated pane with a supply voltage of 24 - 48 V, a coating is required that can achieve a surface resistance of less than approximately 34 Ω / □. It was a multi-layer coating as in 2nd shown produced, a polycarbonate (PC) glass was used as the glass substrate.

After the coating was produced by magnetron sputtering and before the laser treatment, the ITO layer had a thickness of <100 nm and a sheet resistance of> 50 Ω / □.

The plastics, such as polycarbonate, have good absorption in the UV range; therefore, a TiOx layer is added especially for plastic substrates, which reflects part of the UV light (-40%) in order to protect UV-sensitive substrates during the treatment process.

The coating was then subjected to laser treatment by irradiation with UV laser light. The linear laser light generated by a solid-state laser had a wavelength of 355 nm and the coating was scanned with it. The energy density introduced was in the range from 100 to 300 mJ / cm ² , the laser speed in the range from 10 to 20 mm / s.

After the laser treatment, the conductivity of the coating was improved by almost 50%, so that a heatable coating can be provided on the plastic glazing. The UV laser treatment has a low depth of heat, there is no damage or deformation of the substrates.

ITO coating on inorganic glazing

It was a multi-layer coating as in 2nd shown and produced as in variant A), but an inorganic glass was used as the glass substrate instead of a PC glass.

The coating was then subjected to laser treatment by irradiation with UV laser light. The linear laser light generated by a solid-state laser had a wavelength of 355 nm and the coating was scanned with it.

After the laser treatment, the coated substrate was annealed at a temperature of 680 ° C.

Three coatings A, B and C were prepared in this manner, the laser treatment being varied in terms of energy density and laser speed as shown in the table below. A reference coating was also prepared in the same manner for comparison purposes, except that the laser treatment was not performed on the reference coating. The table below also shows the results of the resistance measurements after the individual steps.

Comparison of resistance before and after laser treatment and annealing

sample Energy density Laser speed Surface resistance after Surface resistance after laser treatment [mJ / cm ² ] [mm / s] Laser treatment and tempering [Ω / □] [Ω / □] A 250 20 22.1 18.05 B 200 20 25th 18th C. 250 10th 22 18.05 reference - - 49.6 * 17.5 ** * after deposition, no laser treatment, ** after tempering, no laser treatment

In 3rd the results of an X-ray diffraction measurement (XRD measurement) on the coating after the individual steps are also shown. The figure shows the signal from ITO. The curves obtained were somewhat smoothed out for reasons of clarity.

In 3rd is the XRD curve 3rd that of the coating or the ITO layer after deposition; is the XRD curve 4th that of the deposited coating or ITO layer after laser treatment; is the XRD curve 5 that of the deposited coating or ITO layer after annealing (no laser treatment); and is the XRD curve 6 that of the deposited ITO layer after laser treatment and annealing.

The laser-treated coating has a higher crystallinity (comparison of the XRD curve 3rd before laser treatment and the XRD curve 4th after laser treatment), better conductivity and higher optical transmission.

Example 2

Silver-based coating on inorganic glass

A silver-based layer stack of 3 silver layers with dielectric layers (SiO ₂ ) between the silver layers (so-called kappa coating) was deposited on an inorganic glass by magnetron sputtering.

The deposited coating had a sheet resistance of approximately 1.2 Ω / □. For a heated windshield with a supply voltage of 14 V, a sheet resistance of less than 0.9 Ω / □ is required.

The coating was then subjected to laser treatment by irradiation with UV laser light. The linear laser light generated by a solid-state laser had a wavelength of 355 nm and the coating was scanned with it.

After the laser treatment, the coated substrate was annealed at a temperature of 680 ° C.

Three coatings A, B and C were prepared in this manner, the laser treatment being varied in terms of energy density and laser speed as shown in the table below. A reference coating was also prepared in the same manner for comparison purposes, except that the laser treatment was not performed on the reference coating. The table below also shows the results of the resistance measurements after the individual steps.

Comparison of resistance before and after laser treatment and annealing

sample Energy density [mJ / cm ² ] Laser speed [mm / s] Surface resistance after laser treatment [Ω / □] Surface resistance after laser treatment and annealing [Ω / □] A 250 20 0.99 0.85 B 200 20 1.06 0.86 C. 250 10th 0.99 0.87 reference - - 1.17 * 0.89 ** * after deposition, no laser treatment, ** after tempering, no laser treatment

After the UV laser treatment, an improvement in the sheet resistance of about 15% was achieved, whereby a more effective treatment than with IR lasers with the wavelength of about 1 μm can be achieved. With such an IR laser light treatment, the improvement is only <10% with the same procedure.

In combination with the bending / heating process for the production of car glazing, an improvement in surface resistance of> 25% can be achieved, even higher than just the bending / heating process without laser treatment (<25%). The laser treatment according to the invention with UV laser light can be a simple way to achieve a lower resistance without having to increase the thickness of the silver, which is more expensive and has a negative influence on the optical transmission.

In 4th the results of an X-ray diffraction measurement (XRD measurement) on the electrically conductive layer (silver-based layer) are also reproduced after the individual steps.

In 4th is the XRD curve 3rd that of the silver-based layer after deposition; is the XRD curve 4th that of the deposited silver-based layer after laser treatment; is the XRD curve 5 that of the deposited silver-based layer after annealing (no laser treatment); and is the XRD curve 6 that of the deposited silver-based layer after laser treatment and annealing.

The coating treated with UV laser light has a higher crystallinity (comparison of the XRD curve 3rd before laser treatment and the XRD curve 4th after laser treatment), better conductivity and higher optical transmission. After the tempering / bending process, an even higher crystallinity can be achieved can be achieved (comparison of the XRD curve 4th after the laser treatment and the XRD curve 6 after laser treatment and annealing).

An additional example of a silver-based coating on inorganic glass was carried out as above, except that a silver-based layer stack of 4 silver layers with dielectric layers between the silver layers was deposited by magnetron sputtering. Three coatings D, E and F were prepared in this way, the laser treatment at a wavelength of 355 nm in terms of energy density and laser speed for D as for coating A, for E as for coating B and for F as for coating C was varied. A reference coating was also prepared in the same manner for comparison purposes, except that the laser treatment was not performed on the reference coating. The table below shows the results of the resistance measurements before tempering, ie after laser treatment or in the reference without laser treatment after deposition, and after tempering. The improvement after annealing in percent is also included. reference D E F Surface resistance [Ω // □] before tempering 0.93 0.816 0.874 0.849 Surface resistance [Ω // □] after annealing 0.764 0.703 0.729 0.708 Improvement [%] 17.85 24.41 21.61 23.87

Example 3

1. I. keine Laser- oder Wärmebehandlung
2. II. nur Wärmebehandlung
3. III. nur Laserbehandlung
4. IV. Wärmebehandlung, anschließend Laserbehandlung
5. V. Laserbehandlung, anschließend Wärmebehandlung

Lime-soda glass substrates with a coating comprising several conductive silver layers were treated differently. Then their sheet resistance was determined. The different treatments were:

1. I. no laser or heat treatment
2. II. Only heat treatment
3. III. only laser treatment
4. IV. Heat treatment, followed by laser treatment
5. V. Laser treatment, followed by heat treatment

The laser treatment was carried out in each case with a UV laser (343 nm), with a movement speed over the coating of 100 mm / s and a power density of 200 mJ / cm ² . The temperature treatment was carried out at a temperature of 540 ° C. in each case.

The measured surface resistances are summarized in the following table. treatment Surface resistance / Ω / □ I. 0.927 II 0.676 III 0.815 IV 0.700 V 0.648

The table shows in particular that the sequence of laser treatment and heat treatment has a significant influence on the surface resistance. If the heat treatment is carried out after the laser treatment (V), then a lower surface resistance is achieved than with the reverse procedure (IV). This was very surprising for the expert.

Reference list

1

Glass substrate

2nd

electrically conductive layer

3rd

XRD curve of coating after deposition

4th

XRD curve from coating after laser treatment

5

XRD curve from coating to tempering (reference)

6

XRD curve of coating after laser treatment and annealing

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2010/139908 A1 [0007]
• DE 102007052782 A1 [0008]
• WO 2008/096089 A2 [0009]
• WO 2015/055944 A1 [0010]
• US 20130320241 A1 [0012]
• US 20170167188 A1 [0012]
• WO 03100513 A1 [0013]
• WO 2014072137 A1 [0013]
• DE 102008001578 A1 [0013]

Claims (14)

Inorganic or organic substrate (1) which has a single-layer or multilayer coating comprising at least one electrically conductive layer (2), obtainable by a process which involves depositing the electrically conductive layer (2) onto the substrate (1) and laser treatment of the deposited electrically conductive layer (2) with UV laser light to improve the conductivity of the electrically conductive layer (2). Inorganic or organic substrate (1) according to Claim 1 , wherein the substrate (1) is an inorganic or organic glass or a transparent ceramic and / or the electrically conductive layer (2) is a transparent electrically conductive layer. Inorganic or organic substrate (1) according to Claim 1 or 2nd , wherein the organic substrate (1) is selected from polycarbonate glass or polymethyl methacrylate glass or the inorganic substrate is selected from soda-lime glass, borosilicate glass, quartz glass or a transparent ceramic. Inorganic or organic substrate (1) according to one of the Claims 1 to 3rd The substrate (1) with the electrically conductive layer (2) is subjected to a heat treatment after the laser treatment, preferably at a temperature of at least 500 ° C. Inorganic or organic substrate (1) according to one of the Claims 1 to 4th , wherein the electrically conductive layer (2) is formed from a transparent conductive oxide (TCO) or a metal layer or a layer stack comprising at least one metal layer, the TCO preferably being tin-doped indium oxide (ITO) and the metal layer preferably being a silver layer. Inorganic or organic substrate (1) according to one of the Claims 1 to 5 The electrically conductive layer (2) is deposited by sputtering, in particular magnetron sputtering, or a CVD process. Inorganic or organic substrate (1) according to one of the Claims 1 to 6 , wherein the UV laser light is generated by a solid-state laser or an excimer laser. Inorganic or organic substrate (1) according to one of the Claims 1 to 7 , the wavelength of the UV laser light being in the range from 150 nm to 400 nm. Inorganic or organic substrate (1) according to one of the Claims 1 to 8th , wherein the electrically conductive layer is irradiated with UV laser light with an energy density in the range from 100 to 300 mJ / cm ² and / or wherein the UV laser light is moved during the treatment at a speed in the range from 10 to 20 mm / s . Inorganic or organic substrate (1) according to one of the Claims 1 to 9 , wherein the coating over the electrically conductive layer (2) comprises one or more further layers and wherein the laser treatment of the electrically conductive layer (2) is carried out before or after the deposition of the overlying one or more further layers. Inorganic or organic substrate (1) according to one of the Claims 1 to 10th , wherein the UV laser light for the treatment of the deposited electrically conductive layer is linear UV laser light. Inorganic or organic substrate (1) according to one of the Claims 1 to 11 , wherein the substrate (1) is already precoated before the deposition of the electrically conductive layer (2), preferably with a UV-reflecting layer, preferably a titanium oxide layer or a zinc oxide layer, and wherein the substrate is preferably an organic glass. Inorganic or organic substrate (1) according to one of the Claims 1 to 12th , wherein the coating comprises one or more protective layers for the transparent electrically conductive layer, wherein preferably the precoating of the precoated substrate comprises at least one ion diffusion barrier layer and / or at least one oxygen barrier layer is deposited over the electrically conductive layer. Inorganic or organic substrate (1) according to one of the Claims 1 to 13 , The substrate being coated over the entire surface or over part of the surface with the electrically conductive layer (2) and / or wherein the single-layer or multi-layer coated substrate (1) is heatable glazing.

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