JP2002229471A - Substrate superposition equipment - Google Patents

Abstract

(57) Abstract: In an apparatus for superposing a pair of substrates in parallel and at a predetermined interval in a predetermined positional relationship, a gap is reduced, uniformity of alignment is improved, accuracy is improved, and the structure of the apparatus is simplified. The objectives are to increase costs, improve productivity, and reduce the generation of bubbles and dust. SOLUTION: After a pair of substrate holders 1 and 2 constituting a vacuum container hold a pair of substrates 91 and 92 and are closed by an opening / closing mechanism 5, the inside is exhausted by an exhaust system 41,
Gap setting and alignment are performed in a vacuum. The differential pressure applying mechanism 62 introduces gas into the closed space formed by the diaphragm 22 behind the one substrate 92 and presses the substrate 92, and the pressing mechanism 61 mechanically presses the one substrate 92. A gap is set. The gap length and the parallelism between the pair of substrates 91 and 92 are measured by the plurality of distance sensors 63, and the gap setting operation is feedback-controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus suitable for use in the manufacture of a liquid crystal display, a plasma display, or the like. The present invention relates to a substrate superposing apparatus.

[0002]

2. Description of the Related Art In the manufacture of a liquid crystal display, a plasma display, or the like, it is necessary to overlap a pair of substrates at a predetermined interval with a predetermined positional relationship. This point will be described using a liquid crystal display as an example. 2. Description of the Related Art A liquid crystal display is actively used for many uses including a display unit of a computer. The LCD display is
In this structure, liquid crystal is injected between a pair of substrates, and a driving circuit is formed on an inner surface of the substrates. When an electric field is applied to the liquid crystal by the drive circuit, the molecular arrangement of the liquid crystal changes, and light transmission and
Blocking is controlled and characters and images are displayed.

[0003] On inner surfaces of a pair of substrates facing each other,
Elements such as a transparent electrode (ITO) and a TFT (thin film transistor) forming a driving circuit are formed. Therefore, in order for the elements to function properly, it is necessary to overlap a pair of substrates so that the positional relationship of the substrates in the plate surface direction (hereinafter simply referred to as the plate surface direction) becomes a predetermined one. Further, in order for the driving circuit to operate properly and to control the liquid crystal normally, it is necessary to overlap a pair of substrates at a predetermined narrow interval. In the following description, the alignment of the pair of substrates in the plate surface direction is referred to as alignment, and the alignment in which the distance between the pair of substrates (hereinafter, gap length) is a predetermined value is referred to as gap setting.

A liquid crystal display is manufactured by enclosing liquid crystal between a pair of substrates thus superposed. The method of sealing the liquid crystal is divided into an injection type and a drop type. In the injection method, first, a light-curing or thermosetting sealing material is applied to one of the pair of substrates along the periphery of the plate surface. The application of the sealing material is not completely circumferential, but is provided with portions that are slightly interrupted. In this state, the other substrate is overlapped with a spacer interposed,
Perform alignment and gap setting. Then, the cured resin is cured by light or heat, and the pair of substrates is bonded.

[0005] The space between the pair of substrates thus bonded is a closed space other than the portion where the sealing material is interrupted. Then, the broken part of the sealing material (hereinafter, referred to as
Liquid crystal is injected into the inside through an injection hole). The container holding the liquid crystal and the pair of bonded substrates are placed in a vacuum, and the injection hole is immersed in the liquid crystal in the vacuum. In this state, the atmosphere is returned to the atmospheric pressure, and the liquid crystal is injected between the pair of substrates by the pressure difference. Thereafter, the injection hole is closed with a sealing material or the like.

In the case of the drop type, a sealing material is similarly applied to one of the pair of substrates in a circumferential manner. At this time, the coating is performed in a complete peripheral shape (non-terminal shape) without any interruption. Then, the substrate is kept in a horizontal position, and a predetermined amount of liquid crystal is dropped on the surface. The liquid crystal spreads inside the sealing material applied in a circumferential shape. Thereafter, the other substrate is superimposed on one substrate with the spacer interposed therebetween, and alignment and gap setting are performed. And when the sealing material is cured,
The sealing of the liquid crystal between the pair of substrates is completed.

[0007] Of the two methods described above, the injection method has often been adopted in the past, but the dropping method is considered to be superior when the size of the substrate is increased. In the case of the injection type, a pair of substrates bonded to each other must be lifted to immerse the injection holes in the liquid crystal. Also in the case of automation, it tends to be mechanically large. In addition, in the injection method, it takes a long time to inject the liquid crystal by the differential pressure, and there is a problem in productivity. This problem becomes more pronounced as the size of the substrate increases. Furthermore, in the injection type,
Since the liquid crystal is injected by the differential pressure, air or the like is mixed in the liquid crystal and bubbles are easily generated in the liquid crystal. The generation of bubbles also causes display defects and the like.

[0008]

However, the conventional method has the following problems whether it is a dropping type or an injection type. First, there are problems of accuracy and uniformity in gap setting. That is, a force in the thickness direction of the substrate (hereinafter simply referred to as the thickness direction) is applied to one substrate to press the one substrate against the other substrate, and the gap is formed while slightly crushing the sealing material. Is difficult to act uniformly, and the gap may differ from place to place. When the gap is non-uniform, display unevenness or the like is likely to occur. Such a problem is remarkable when the substrate is enlarged. In addition, in the case of the dropping type, a larger pressing force is required because the substrate is pressed with the liquid crystal inside. However, it is difficult to finely adjust the large pressing force, and there is a problem that the accuracy of the gap cannot be sufficiently increased.

Further, in the conventional method, the degree of the gap during the pressing is not detected, and the pressing is performed only with a predetermined pressing force. Then, after pressing and bonding, the size of the gap is measured with a measuring instrument, and it is checked whether the gap is within a specified range. And if they are not within the specified range, they do things like re-gap. That is, the feedback control is not used in the gap setting process, and is a kind of open loop control. For this reason, there is a problem that it takes a long time to obtain the required gap setting accuracy. In addition, from the viewpoint of preventing display unevenness and the occurrence of scratches caused by spacers at the time of forming a gap, it is necessary to overlap a pair of substrates with a sufficiently high degree of parallelism. However, even in the injection type,
There is no practical device that can superpose substrates with high parallelism even in the case of a dropping type.

In the conventional substrate superposition apparatus, the parallelism greatly depends on the mechanical or mechanical accuracy of the apparatus. That is, the degree of parallelism is determined by the degree of parallelism of the pair of members holding the pair of substrates and the accuracy of the moving mechanism that moves one of the pair of members. Depending on the processing accuracy and assembly accuracy of the member holding the substrate, sufficient parallelism may not be obtained, or sufficient parallelism may not be obtained due to reduced accuracy of the moving mechanism. There is no means in conventional devices to correct it during the overlay operation. In a conventional device, the parallelism of a pair of superposed substrates is inspected. If the parallelism is not a predetermined value, it is determined that there is a defect in a mechanical part or a mechanical part, and the device is checked. It only performs repairs and the like. For this reason, productivity is poor and it is not practical.

In the conventional method, the substrates are often superposed in the air. However, superposition in the atmosphere has the following problems. In the case of the injection method, after a pair of substrates are stacked and bonded in the air, the liquid crystal is injected into a vacuum vessel in a vacuum atmosphere, and the liquid crystal is injected. In some cases. In the case of the dropping type, such a problem does not occur. However, when the superposition is performed in the air, air or the like is trapped when the superposition is performed, which easily causes bubbles in the liquid crystal.

In order to prevent such a problem, Japanese Patent Laid-Open Publication No.
As disclosed in JP-A-00-66163, it is conceivable to use an apparatus for superposing substrates in a vacuum. However, the apparatus disclosed in the publication has a drawback that the vacuum container is enlarged because a moving mechanism for gap setting and alignment is provided in the vacuum container.

As the size of the vacuum vessel increases, the time required to exhaust the gas to a predetermined pressure becomes longer and the productivity decreases. In addition, an expensive vacuum pump or the like is required to improve the exhaust performance, There is a disadvantage that the running cost is increased because the vent gas is consumed. Also, if the pumping speed is increased to complete the evacuation in a short time, or the flow rate of the vent gas is increased to complete the venting in a short time, the dust easily rises in the vacuum container, and the dust is mixed into the liquid crystal. There is a disadvantage that it is easy to do.

SUMMARY OF THE INVENTION The invention of the present application has been made to solve the above-mentioned problem. In a substrate superimposing apparatus for superposing a pair of substrates in parallel and at a predetermined positional relationship at a predetermined interval, a gap estimating device is provided. The technical significance is that uniform and accurate alignment can be performed, the structure of the device can be simplified and the cost can be reduced, the productivity can be improved, and the generation of bubbles and the contamination of dust can be reduced. To bring.

[0015]

In order to solve the above-mentioned problems, the invention described in claim 1 of the present application is a substrate laminating apparatus for laminating a pair of substrates in vacuum with a predetermined gap therebetween. There is a pair of substrate holders for holding a pair of substrates, and at least one of the pair of substrate holders is moved in the thickness direction of the substrate to set a gap length between one substrate and the other substrate to a predetermined value. A gap-moving moving means for performing a gap-forming operation, and an alignment for moving at least one of the pair of substrate holders in the plate-surface direction of the substrate such that the positional relationship of the pair of substrates in the plate surface direction becomes a predetermined one. At least one of the pair of substrate holders constitutes a vacuum container in which the pair of substrates is located during the gap setting and the alignment. It has a configuration that a member.
According to a second aspect of the present invention, there is provided an opening and closing mechanism for opening and closing the vacuum container by moving at least one of the pair of substrate holders. The opening / closing mechanism is configured such that when the vacuum container is opened to the atmosphere, the pair of substrate holders is located at a long first distance, and when the vacuum container is evacuated to a vacuum, It is configured to be moved so as to be located at a second distance that is shorter than one distance. Further, in order to solve the above-mentioned problem, the present invention relates to claim 3.
According to the invention described in the first aspect, the alignment moving means moves a substrate holder, which is a member constituting a vacuum vessel, of the pair of substrate holders. Tool or a separate member constituting the vacuum vessel, a first vacuum seal means for maintaining a vacuum by contacting a member which moves integrally with the substrate holder is provided, and the first vacuum seal means is A vacuum is maintained even when the substrate holder is moved by the alignment moving means. According to a fourth aspect of the present invention, the first vacuum sealing means is configured to move the substrate holder or the another member by the alignment moving means. The predetermined distance is such that the elastic sealing member that comes into contact with the substrate holding member or the another member that is moved by the alignment moving means and the member that forms the vacuum container do not contact the non-moving member. And an interval maintaining mechanism for maintaining the predetermined interval, wherein the predetermined interval is an interval in which the elastic sealing member achieves a vacuum seal and reduces the amount of deformation thereof to a predetermined value or less. Further, in order to solve the above problem, according to a fifth aspect of the present invention, in the configuration of the fourth aspect, the distance maintaining mechanism comprises: the substrate holder or the another member moved by the alignment moving means; A mechanism for maintaining the gap by a slidable or rollable rigid body interposed between members constituting the vacuum vessel and not moving, a mechanism for maintaining the gap by magnetically repelling both, Or, it is configured to adjust the pressure of the fluid interposed between the two to maintain the interval.
According to a sixth aspect of the present invention, in order to solve the above problem, in the configuration of the third, fourth or fifth aspect, at least one of the pair of substrate holders is moved in a thickness direction of the substrate. An opening / closing mechanism for opening and closing the vacuum container is provided, and a second vacuum sealing means for vacuum-sealing a sealing portion that comes into contact with or separates from the opening and closing by this opening / closing mechanism is separate from the first vacuum sealing means. It has a configuration of being provided. In order to solve the above problem, an invention according to claim 7 is a substrate stacking apparatus for stacking a pair of substrates in a vacuum with a pair of substrates being parallel to each other with a predetermined gap, and holding the pair of substrates. A pair of substrate holders, and a gap setting movement for moving at least one of the pair of substrate holders in the thickness direction of the substrate to set a gap length between the one substrate and the other substrate to a predetermined value. Means, and an alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the positional relationship of the pair of substrates in the plate surface direction becomes predetermined. A vacuum vessel is provided in which the pair of substrates are located inside at the time of the gap setting and the alignment, and the volume of the space in the vacuum vessel is equal to the volume of the pair of substrates. It has a configuration that the sum is 50 times or less than one times the the volume. According to another aspect of the present invention, there is provided a substrate stacking apparatus for stacking a pair of substrates parallel to each other with a predetermined gap, wherein the pair of substrates hold the pair of substrates. Holding means, a gap-out moving means for moving at least one of the pair of substrate holders in the thickness direction of the substrate to make a gap of a predetermined value of the gap length between one substrate and the other substrate, An alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the positional relationship of the pair of substrates in the plate surface direction becomes predetermined. One of the holders has a diaphragm that partitions a space where the one substrate held by the substrate holder is located and a space behind the one substrate, and the diaphragm extends parallel to the substrate. When the gap is moved by the gap moving device, a pressure difference that increases the atmospheric pressure in the space behind the substrate is higher than the atmospheric pressure in the space where one of the substrates is located. A differential pressure applying mechanism for pressing the substrate is provided, and the diaphragm is capable of pressing one substrate and displacing in the thickness direction when a differential pressure is applied by the differential pressure applying mechanism. The gap moving means has a configuration in which the differential pressure applying mechanism and a pressing mechanism for mechanically applying a pressing force to one of the substrates are provided.
In order to solve the above problem, according to the ninth aspect of the present invention, in the configuration of the eighth aspect, the gap setting moving means controls the magnitude of the differential pressure given by the differential pressure applying mechanism to adjust the gap. The length is finally set to the predetermined value. According to another aspect of the present invention, there is provided a substrate stacking apparatus for stacking a pair of substrates parallel to each other with a predetermined gap, wherein the pair of substrates hold the pair of substrates. Holding means, a gap-out moving means for moving at least one of the pair of substrate holders in the thickness direction of the substrate to make a gap of a predetermined value of the gap length between one substrate and the other substrate, An alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the positional relationship of the pair of substrates in the plate surface direction becomes predetermined. One of the holders has a diaphragm having a space behind one of the substrates held by the substrate holder as a closed space, and the diaphragm is a member extending in parallel with the substrate, When the gap is moved out by the moving means, a pressure difference is applied to increase the atmospheric pressure of the closed space behind and to the ambient pressure of the space facing the other substrate by pressing one substrate against the other substrate. A pressure applying mechanism is provided, and the diaphragm has a flexibility capable of pressing one of the substrates and displacing in the plate pressure direction when a differential pressure is given by the differential pressure applying mechanism, and The alignment moving means moves one substrate holder having the diaphragm in the plate surface direction, and the diaphragm transmits a driving force in the plate surface direction by the alignment moving means to the substrate. And has a configuration in which it is not essentially deformed in the plate surface direction. According to another aspect of the present invention, there is provided a substrate stacking apparatus for stacking a pair of substrates parallel to each other with a predetermined gap, wherein the pair of substrates hold the pair of substrates. Holding means, a gap-out moving means for moving at least one of the pair of substrate holders in the thickness direction of the substrate to make a gap of a predetermined value of the gap length between one substrate and the other substrate, An alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the positional relationship of the pair of substrates in the plate surface direction becomes a predetermined one; A distance sensor for measuring a gap length of the substrate, wherein the gap determining means controls movement of the substrate in a thickness direction by a signal fed back from the distance sensor; It has a structure that has a main control unit. According to another aspect of the present invention, there is provided a substrate stacking apparatus for stacking a pair of substrates parallel to each other with a predetermined gap, wherein the pair of substrates hold a pair of substrates. Holding means, a gap-out moving means for moving at least one of the pair of substrate holders in the thickness direction of the substrate to make a gap of a predetermined value of the gap length between one substrate and the other substrate, An alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the positional relationship of the pair of substrates in the plate surface direction becomes a predetermined one; Each of the substrate holders has a surface parallel to the substrate to be held, and these surfaces are opposed to each other. A plurality of distance sensors for measuring the distance between the opposed surfaces and signals from the plurality of distance sensors are provided. It has a configuration that has a determining section for determining a more parallelism and / or distance between the pair of substrates. According to a thirteenth aspect of the present invention, in accordance with the twelfth aspect of the present invention, in accordance with the twelfth aspect, the gap-moving moving means determines whether the pair of substrates has the predetermined value based on a result of the determination by the determination unit. After facing at a longer distance and facing at a predetermined parallelism, at least one of the pair of substrates is moved in a direction perpendicular to the plate surface while maintaining the parallelism, so that the gap length is set to the predetermined value. It has a configuration that is. In order to solve the above-mentioned problem, the invention according to claim 14 is the invention according to any one of claims 8 to 13, wherein the vacuum vessel in which the pair of substrates is located at the time of the gap setting and the alignment is provided. And have a configuration in which they are superposed in a vacuum. In order to solve the above-mentioned problem, the invention according to claim 11 is the arrangement according to any one of claims 1 to 14, wherein, when performing the alignment, a displacement of a positional relationship between the pair of substrates in a plate surface direction is detected. A configuration is provided in which a displacement detection sensor is provided, and the alignment moving means moves at least one of the pair of substrate holders so as to correct the displacement according to a signal from the displacement detection sensor. Having.

[0016]

Embodiments of the present invention (hereinafter, embodiments) will be described below. In the following description, a description will be given of a substrate superposing apparatus similarly used for manufacturing a liquid crystal display.

FIG. 1 is a diagram schematically illustrating a manufacturing process of a liquid crystal display using a substrate overlaying apparatus according to an embodiment of the present invention. This manufacturing process employs a dropping method. That is, the sealing material 9 is placed on the surface of a substrate 91 (hereinafter, referred to as a lower substrate) located on the lower side during the superposition.
3 is applied (FIG. 1 (1)), and a predetermined amount of liquid crystal 94 is dropped inside the sealing material 93 (FIG. 1 (2)). And
The upper substrate 92 is superimposed on the lower substrate 91 by using a substrate superimposing device described later, and gap setting and alignment are performed in a vacuum (FIGS. 1 (3) and (4)). Thereafter, the pair of superposed substrates 91 and 92 is placed in an atmospheric pressure atmosphere (FIG. 1 (5)), and then the sealing material 93 is cured by light irradiation or heating (FIG. 1 (6)).

When returning from the vacuum to the atmosphere (FIG. 1)
(5)) Since the pair of substrates 91 and 92 are compressed by the atmospheric pressure, the gap length is further reduced, and the sealing material 93 is cured in this state (FIG. 1 (6)). Accordingly, the gap is set to a predetermined value slightly larger than the gap length when the gap is set in a vacuum so that the predetermined gap length is obtained when the sealing material 93 is cured.

FIG. 2 is a schematic perspective view of a manufacturing system for performing the manufacturing process shown in FIG. The manufacturing system shown in FIG. 2 includes a load station 901 for loading and collecting the substrates 91 and 92, a sealing material application device 902 for applying the sealing material 93 to the lower substrate 91, and a lower side on which the sealing material 93 is applied. A liquid crystal dropping device 903 for dropping the liquid crystal 94 on the surface of the substrate 91, a substrate overlapping device 904 of the embodiment in which the upper substrate 92 is overlapped on the lower substrate 91 after the liquid crystal is dropped, and a sealing material 93 cured to cure the liquid crystal 94. Substrate 91,
Sealing material curing device 905 for bonding
It comprises a transfer robot 906 for transferring 1,92.

The transfer robot 906 holds the substrate at the tip of the arm 907 in a horizontal posture, and performs the expansion and contraction movement of the arm 907, the rotation movement about a vertical rotation axis, the up-and-down movement, and the like, and the predetermined movement of the substrates 91 and 92. Is transported to the position. The arm 907 holds the substrates 91 and 92 while vacuum-sucking them. A vacuum suction hole (not shown) is provided on the substrate holding surface of the arm 907, and the transfer robot 906 includes a vacuum pump (not shown) that evacuates the vacuum suction hole.

The transfer robot 906 includes a substrate 91,
The upper and lower surfaces of the substrate 92 can be turned over while holding the substrates 91 and 92 so that they can be reversed. Specifically, it is possible to rotate the arm 907 by 180 degrees around a horizontal axis while sucking the substrates 91 and 92 under vacuum. The transfer robot 906 holds the arm 907 in contact with the back surfaces of the substrates 91 and 92. Substrate 91,
The back surface of 92 refers to the surface opposite to the surface on which elements such as transparent electrodes are formed. Since the substrates 91 and 92 cannot be held on the surface on which the element is formed (hereinafter, element surface),
The substrates 91 and 92 are held on the back surface.

FIG. 3 is a schematic front sectional view of the substrate superposing apparatus of the embodiment provided in the manufacturing system shown in FIG. The first major feature of the substrate superposing apparatus shown in FIG. 3 is that a pair of substrates 91 and 92 are superposed in parallel in a vacuum to perform gap setting and alignment. The second feature is that the pair of substrates 91 and 9
This is a point that a vacuum vessel for disposing 2 in a vacuum atmosphere is constituted by a pair of substrate holders 1 and 2 for holding a pair of substrates 91 and 92.

More specifically, the pair of substrate holders 1 and 2 hold the pair of substrates 91 and 92 in a horizontal posture as shown in FIG. Of the pair of substrate holders 1 and 2, the substrate holder 1 that holds the lower substrate 91 is called a “lower substrate holder”, and the substrate holder 2 that holds the upper substrate 92 is an “upper substrate holder”. Call.

The upper substrate holder 2 is, as shown in FIG.
A holder main body 21 having a concave portion formed on the lower surface, and a diaphragm 2 provided to partition a space of the concave portion of the holder main body 21.
2 and a holding head 23 fixed to the lower surface of the diaphragm 22. The upper holder main body 21 is formed of a highly rigid material such as duralumin or stainless steel. The diaphragm 22 presses the upper substrate 92 by a differential pressure applied by a differential pressure applying mechanism 62 described later.

The holding head 23 is a member that contacts the upper substrate 92 and directly holds the upper substrate 92. The holding head 23 holds the upper substrate 92 by vacuum suction in the air and electrostatic suction in the vacuum. The electrostatic suction mechanism applies a DC voltage having the same magnitude and different polarities or the same polarity to a pair of suction electrodes (not shown) provided in the holding head 23 by a suction power supply (not shown). It is. The holding head 23 is entirely formed of a dielectric material such as alumina. When the adsorption power supply is operated and DC voltages having different polarities are applied to the pair of adsorption electrodes,
Dielectric polarization occurs in the holding head 23, and static electricity is induced on the lower surface. The upper substrate 92 is electrostatically attracted by the static electricity.

The lower substrate holder 1 is also formed of a material having high rigidity, such as duralumin or stainless steel. The lower substrate holder 1 is supported by a sturdy base (not shown). Similarly, the lower substrate holder 1 is provided with an electrostatic suction mechanism. Specifically, a concave portion is provided on the upper surface of the lower substrate holder 1, and an electrostatic suction plate 11 is provided so as to be fitted into the concave portion. The electrostatic attraction plate 11 is made of a dielectric material, and electrostatically attracts the lower substrate 91 by a similar configuration.

As described above, the pair of substrate holders 1 and 2 are members constituting a vacuum container. More specifically, the vacuum container includes a pair of substrate holders 1 and 2 and an intermediate ring 3 located between the pair of substrate holders 1 and 2. The lower substrate holder 1 has an exhaust path 12, and an exhaust system 41 is provided in the exhaust path 12. The exhaust system 41 includes an exhaust pipe 412 connecting the exhaust path 12 and the vacuum pump 411, and a valve 41 provided on the exhaust pipe 412.
3 and an exhaust speed adjuster (not shown). The upper substrate holder 2 has a vent gas introduction path 25, and a vent gas introduction system 42 is provided in the vent gas introduction path 25. Cleaned dry air (dry air), nitrogen, or the like is used as the vent gas. Note that the upper surface of the lower substrate holder 1 has a step in the peripheral portion and is slightly lower. This lowered portion extends circumferentially, and the intermediate ring 3 is located at this portion.

The pair of substrate holders 1 and 2 are separated by the opening / closing mechanism 5 at a long first distance when the vacuum container is opened to the atmosphere, and when the vacuum container is evacuated to vacuum. It is adapted to be located a short second distance apart. Specifically, the opening / closing mechanism 5 moves the upper substrate holder 2 up and down. In the following description, the position of the upper substrate holder 2 where the distance between the pair of substrate holders 1 and 2 is the first distance is referred to as the upper limit position, and the upper substrate holder 2 where the distance is the second distance. Is called the lower limit position.

The opening / closing mechanism 5 mainly includes a holding member 51 holding the upper substrate holder 2 as a whole, and an opening / closing drive source 52 having a drive shaft fixed to the holding member 51. A servomotor or the like is used as the opening / closing drive source 52, and a configuration is adopted in which a ball screw is rotated to convert the rotation into a vertical movement. The opening / closing mechanism 5 positions the upper substrate holder 2 at the upper limit position when opening to the atmosphere and at a predetermined lower position when evacuating. When the upper substrate holder 2 is at the lower limit position, the upper substrate holder 2 comes into contact with the intermediate ring 3. When the vacuum container is constituted only by the pair of substrate holders 1 and 2, the opening / closing mechanism 5 moves the pair of substrate holders 1 and 2 so that they come into contact with each other.

Such a structure comprises a pair of substrates 91 and 92
This takes into consideration the loading and unloading of the equipment and maintenance.
It is sufficient to provide the vent gas introduction system 42 just to open to the atmosphere. However, a pair of substrate holders is used to carry the substrates 91 and 92 into and out of the vacuum container. 1 and 2 are opposed to each other at a long distance. As a configuration for loading and unloading the substrates 91 and 92, there is a configuration in which an opening is provided in a vacuum container and a gate valve for opening and closing the opening is provided. In this configuration, maintenance work such as cleaning of an inner wall surface is performed. It is hard to remove.

The apparatus of the present embodiment comprises a pair of substrates 91 and 9
2 is provided with an alignment moving means 7 for performing alignment by moving at least one of the pair of substrate holders 1 and 2 in the plate surface direction so that the positional relationship in the plate surface direction becomes predetermined. In the present embodiment, the lower substrate 91 does not move in the plate surface direction, and the stationary lower substrate 91 does not move.
The alignment is performed by moving the upper substrate 92 in the plate surface direction. That is, the alignment moving means 7 performs the alignment by moving the upper substrate 92 in the plate surface direction. Since the pair of substrates 91 and 92 are held in the horizontal direction, the plate surface direction is the horizontal direction.

The structure of the alignment moving means 7 will be described with reference to FIGS. FIG. 4 is a schematic perspective view showing the configuration of the alignment moving means 7 provided in the apparatus of FIG. FIG. 5 is a schematic perspective view of a main part of the alignment moving means 7 shown in FIG. As shown in FIG. 3, the alignment moving means 7 is configured to move the intermediate ring 3 directly. The upper substrate holder 2 is pressed against the intermediate ring 3 with a large force by a differential pressure between the inside and outside of the vacuum vessel. Alignment moving means 7
In this state, by moving the intermediate ring 3 in this state, the upper substrate holder 2 is moved integrally with the intermediate ring 3, whereby the upper substrate 92 is moved.

As shown in FIGS. 4 and 5, the alignment moving means 7 includes a bracket 701 fixed to the intermediate ring 3, a linear drive source 702 for moving the intermediate ring 3 via the bracket 701, and a linear drive A fulcrum pin 703 provided on the output shaft of the source 702, a connector 704 connected to the fulcrum pin 703, the connector 704 and the bracket 7
01 and a linear guide 705 provided between them. As shown in FIG. 4 and FIG.
01, units 71, 72, 73, 74 comprising a linear drive source 702, a fulcrum pin 703, and a linear guide 705
Are provided on each side of the intermediate ring 3.
Hereinafter, for convenience of explanation, each unit is referred to as a first unit 71,
Second unit 72, third unit 73, fourth unit 7
4 is assumed. As shown in FIG. 4, the first unit 71 and the third unit 73, and the second unit 72 and the fourth unit 74 are located on opposite sides of the intermediate ring 3, respectively.

In each of the units 71, 72, 73 and 74, the linear drive source 702 is constituted by a motor such as a servomotor or a pulse motor, and a motion conversion mechanism including a ball screw for converting the output of the motor into a linear motion. I have. Each linear drive source 702 is fixed to a fixed plate (not shown) and does not move. The connecting member 704 has a U-shaped cross section as shown in FIG.
It is arranged toward the side 2. The fulcrum pin 703 is arranged so that the vertical direction is the axial direction. Connector 70
Reference numeral 4 has holes for inserting fulcrum pins 703 in the upper part and the lower part. The fulcrum pin 703 has an upper end and a lower end inserted into this hole. The fulcrum pin 703 and the connecting tool 704 are not fixed, and the connecting tool 704 can rotate around the stationary fulcrum pin 703.

As shown in FIGS. 4 and 5, the bracket 701 has a right triangle in plan view. Bracket 70
In 1, one of a pair of sides forming a right angle is parallel to the side surface of the intermediate ring 3, and the side portion is fixed to the side surface of the intermediate ring 3. The linear guide 705 is fixed to the other right side of the bracket 701 at a right angle. The linear guide 705 is an intermediate ring 3 provided with the units 71, 72, 73, 74 to which the linear guide 705 belongs.
Long in the horizontal direction perpendicular to the direction of the side of
It guides linear movement in this direction. Connector 7
Numeral 04 is long in the same direction as the linear guide 705 and has a concave portion or a step adapted to the shape of the linear guide 705. The linear guide 705 guides linear movement while sliding along the concave portion or the step.

The operation of the alignment moving means 7 shown in FIGS. 4 and 5 will now be described. The alignment moving means 7 shown in FIG. 4 and FIG.
By operating the 2, 73, 74 linear drive sources 702 arbitrarily, a linear movement (X
(Movement in the direction and the Y direction) and movement in the circumferential direction (movement in the θ direction) on a horizontal plane centered on an arbitrary position.

This will be described more specifically. As shown in FIG. 4, the X direction is the direction of the side where the first and third units 71 and 73 are arranged, and the Y direction is the direction of the second and fourth units 72 and 7.
The direction of the side where 4 is arranged is assumed. First, to linearly move the intermediate ring 3 in the X direction, the linear drive sources 702 of the first unit 71 and the third unit 73 are simultaneously operated,
Linear drive source 7 for second unit 72 and fourth unit 74
02 is not operated. At this time, the linear drive sources 702 of the first unit 71 and the third unit 73 are driven so that each bracket 701 moves by the same distance. For example, when the motor is a pulse motor, it is driven by the same number of pulses. As a result, the intermediate ring 3 also moves linearly in the X direction by this driving distance. Note that the linear drive source 702
Not operating means that when the motor is like a servo motor, the position is maintained and not moved (operates).

When moving in the Y direction, the linear drive sources 702 of the second unit 72 and the fourth unit 74 are simultaneously operated, and the first unit 71 and the third unit 7 are moved.
The third linear drive source 702 is not operated. Also in this case, the driving distances of the linear drive sources 702 of the second unit 72 and the fourth unit 74 are set to be the same. As a result, the intermediate ring 3 linearly moves by the driving distance in the Y direction.

In the movement in the X and Y directions, the linear guide 705 of each unit 71, 72, 73, 74
Has a function to guide movement. That is, when moving in the X direction, each bracket 701 also moves in the X direction integrally with the intermediate ring 3. At this time, the linear guide 705 provided on the bracket 701 of the second unit 72 and the fourth unit 74 slides along the concave portion or the step of the connecting member 704 and guides the movement in the X direction. That is, the linear guide 705 of the second and fourth units 72 and 74
Is to prevent the driving force in the X direction from being transmitted to the linear drive source 702 or the like. Further, when moving in the Y direction, the linear guide 705 provided on the bracket 701 of the first unit 71 and the third unit 73
4 slides along the concave portion or step to guide the movement in the Y direction.

Next, the case of moving in the θ direction will be described. For example, movement when the rotation axis is coaxial with the intermediate ring, that is, at the center axis of the intermediate ring 3 will be described. In this case, for example, the linear drive source 70 of the first unit 71
The linear drive sources 702 of the second and third units 73 are operated simultaneously, and the linear drive sources 702 of the second unit 72 and the linear drive sources 702 of the fourth unit 74 are not operated. At this time, the linear drive source 702 of the first unit 71 and the linear drive source 702 of the third unit 73 are driven in different directions (forward and backward) by the same distance. As a result, the intermediate ring 3
Moves in a horizontal circumferential direction around the center axis (in Figure 4 indicated by theta _1).

[0041] During the movement of the θ ₁ direction, each bracket 7
01 is also moved in the theta ₁ direction integrally with the intermediate ring 3. At this time, the fulcrum pins 703 and coupler 704 of the second fourth unit 72, 74 to discharge driving force of the theta ₁ direction has a function to prevent transmitted to the linear drive source 702. That is, when the bracket 701 of the second fourth unit 72, 74 is moved in the theta ₁ direction, the linear guide 705 coupler 704 via the also moved in the θ1 direction together. However, the fulcrum pin 703 is fixed to the output shaft of the linear drive source 702 and does not move. Accordingly, when the bracket 701 is moved in the theta ₁ direction, coupler 704 slightly rotates about the pivot pin 703, to escape the driving force of the theta ₁ direction so as not to transmit the linear drive source 702 and the like.

[0042] Incidentally, the movement of the theta ₁ direction, a linear drive source 702 of the first third unit 71, 73 leave not operate, the same linear drive source 702 of the second fourth unit 72, 74 in a different orientation It can also be performed by driving only a distance. In this case, coupler 704 and the fulcrum pin 703 of the second fourth unit 72 is operated so as to release the driving force of the theta ₁ direction. θ In the circumferential direction other than the ₁ direction,
Linear drive source 702 for each unit 71, 72, 73, 74
Can be freely performed by appropriately selecting the driving method (driving distance and driving direction). For example, in FIG.
_As shown by ₂ , it can be moved in the direction on the circumference around the position of the square corner of the substrate 91, 92 or the intermediate ring 3.

The moving distance during the above alignment is quite short. For linear movements such as X and Y, ±
It is about 2 mm. In the case of the movement in the θ direction, the angle is about ± 1 degree. Further, the apparatus according to the present embodiment includes a position shift detection sensor 75 that detects a shift in the positional relationship between the pair of substrates 91 and 92 in the plate surface direction when performing alignment. The displacement detection sensor 75 is provided on the lower substrate holder 1.
Attached to.

More specifically, the lower substrate holder 1 has a detection through-hole 14 extending vertically. The displacement detection sensor 75 is attached at a position facing the lower end opening of the detection through-hole 14. A plurality of detection through holes 14 are provided, and each of the
Is attached. The lower end opening of the detection through-hole 14 is airtightly closed by the optical window 15. Each displacement detection sensor 75 is specifically an image sensor such as a CCD camera. Each of the pair of substrates 91 and 92 includes
An alignment mark is provided at a predetermined position on the plate surface. The pair of substrates 91 and 92 are transparent and have the same shape and size. The alignment marks are provided at the same position on the pair of substrates 91 and 92.

As described above, when the lower substrate 91 is carried in by the transfer robot 906, the transfer robot 906
The lower substrate 91 is placed on the lower substrate holder 1 with high accuracy so that the alignment mark is positioned at the upper end opening of the through hole 14 for detection. At the time of alignment, the displacement detection sensor 75
Is configured to image the alignment mark of the lower substrate holder 1 and the alignment mark of the upper substrate 92 through the detection through hole 14.

In this embodiment, a gap is formed by pressing the upper substrate 92 toward the lower substrate 91. That is, there is provided a gap moving unit for moving the upper substrate 92 toward the lower substrate 91 to perform a gap. The structure of the moving means for gap generation is the third major feature of the present embodiment. That is, the moving means for gap generation includes a mechanism (hereinafter referred to as a pressing mechanism) 61 for mechanically applying a pressing force to the upper substrate 92 and a mechanism (hereinafter referred to as a differential pressure application) for applying a pressing force to the upper substrate 92 by a gas differential pressure. This is a major feature point.

The pressing mechanism 61 includes a plurality of pressing rods 611 fixed to the upper substrate holder 2 and each pressing rod 611.
And a pressing drive source 612 provided for each of them. Each of the pressing rods 611 has a vertical posture, and a lower end thereof is fixed to the diaphragm 22 and extends upward, and penetrates the upper substrate holder 2 in an airtight manner. Each pressing drive source 612
Is connected to the upper end of the pressing rod 611. Each pressing drive source 612 is a motor for position control such as a servomotor, and its rotational motion is converted into linear motion by a motion converting mechanism using a ball screw or the like.

Incidentally, the penetrating portion of each pressing rod 611 includes
There is provided a vacuum sealing means 613 for performing vacuum sealing while allowing vertical movement of each pressing rod 611. A mechanical seal using a magnetic fluid can be used for the pressing vacuum sealing means 613. A bellows may be provided between each pressing rod 611 and the upper substrate holder 2.

Of the space partitioned by the diaphragm 22,
The upper space is a closed space 26 surrounded by the upper holder main body 21 and the diaphragm 22. This closed space 26
Are located behind the upper substrate 92. Differential pressure application mechanism 62
Is designed to introduce a gas into the closed space 26 and apply a pressure difference to the space where the upper substrate 92 is located.
That is, the differential pressure applying mechanism 62 includes: It is mainly composed of a main valve 622 for differential pressure provided. The upper holder main body 21 has a gas introduction path 27 at a location where the differential pressure pipe 621 is connected. The closed space 26 means that the space other than the gas introduction path 27 is basically a closed space.

The differential pressure applying mechanism 62 has a pressure regulator (not shown) for adjusting the pressure in the closed space 26. The pressure regulator (not shown) uses an electro-pneumatic regulator that adjusts the pressure in accordance with the input of an electric signal for control. An electro-pneumatic regulator is a device that controls pressure by an electric signal (voltage or current). For example, a configuration is used in which a diaphragm (diaphragm) is controlled by a piezoelectric element, and thereby the internal valve is adjusted to control the pressure. Such electro-pneumatic regulators are commercially available from various companies, and are appropriately selected and used. As shown in FIG. 3, an auxiliary exhaust pump 6 for exhausting the inside of the closed space 26 is provided.
26 are provided. The auxiliary exhaust pump 626 includes a differential pressure pipe 621, valves 622 and 624, and an auxiliary exhaust pipe 6
The inside of the closed space 26 is exhausted through 23.

In the apparatus of the present embodiment, many measures are taken so that the gap can be formed with high accuracy. First,
When the upper substrate 92 is pressed against the lower substrate 91 for gap setting, a distance sensor 63 for indirectly measuring the distance between the upper substrate 92 and the lower substrate 91 is provided. Is controlling. More specifically, a plurality of distance sensors 63 are provided and attached to the lower substrate holder 1. On the upper surface of the lower substrate holder 1, a concave portion is provided outside a portion for holding the lower substrate 91, and the distance sensor 63 is provided to fill the concave portion.

As shown in FIG. 3, the substrate holding surface of the lower substrate holder 1 (the upper surface of the electrostatic attraction plate 11) and the substrate holding surface of the upper substrate holder 2 (the lower surface of the holding head 23) are parallel. is there. The thickness of the lower substrate 91 and the thickness of the upper substrate 92 are known. Therefore, if the distance between the substrate holding surface of the lower substrate holder 1 and the substrate holding surface of the upper substrate holder 2 is known,
The gap length (separation distance) between the pair of substrates 91 and 92 can be determined. Since the positional relationship of the substrate holding surface of the lower substrate holder 1 with respect to the distance sensor 63 is invariable, by measuring the distance from the distance sensor 63 to the lower surface of the holding head 23,
The gap length between the pair of substrates 91 and 92 is indirectly determined.

As the distance sensor 63, for example, a sensor that detects an eddy current can be used. That is, one of the sensors is configured to generate an AC magnetic field, and the other is configured to detect an eddy current generated by the AC magnetic field. The distance is determined by the magnitude of the eddy current. In addition, a sensor that measures a distance based on a magnetic field strength, a distance sensor that uses a laser interferometer, or the like can be used. Further, an electric contact type micrometer may be used.

FIG. 6 shows a distance sensor 63 in the plate surface direction.
It is a figure explaining the arrangement position of. Still another major feature of the present embodiment is that the distance sensor 63 is arranged so as to form a pair with each of the pressing rods 611 of the gap moving unit. That is, as shown in FIG. 6, in this embodiment, four pressing rods 611 are provided.
Each pressing rod 611 is disposed at a position of a virtual rectangle or square corner coaxial with the upper substrate holder 2. Similarly, four distance sensors 63 are also provided, and each pair is located below each pressing rod 611. More precisely, the square connecting the four pressing rods 611 and the square connecting the four distance sensors 63 are similar and coaxial. Then, each pair of pressing rods 6
11 and the distance sensor 63 are located at the same vertex position of the rectangle.

The diaphragm 22 of the upper substrate holder 2
Transmits the driving force in the plate surface direction by the alignment moving means 7 to the upper substrate 92. That is,
As described above, the alignment moving means 7 moves the upper substrate holder 2 via the intermediate ring 3 in the plate surface direction. The force of this movement is transmitted to the holding head 23 via the diaphragm 22 and the pressing rod 611. As a result, the upper substrate 92 electrostatically attracted to the holding head 23 moves.

As described above, the diaphragm 22 is expanded in the thickness direction by the differential pressure applying mechanism 62 of the gap moving means, and applies a pressing force to the upper substrate 92. On the other hand, during alignment, the force in the plate surface direction is applied to the upper substrate 92.
Tell In this case, it is important that the diaphragm 22 is deformable in the thickness direction, but is essentially deformed in the plate surface direction due to the rigidity of the pressing rod 611 and its own rigidity. That is what we do not do. If it is deformed in the plate surface direction, the alignment becomes unstable, and the reproducibility and accuracy may be deteriorated. [Delta] T of the time as "essentially unchanged", e.g., an amount of deformation when a force F ₁ is applied in the thickness direction and [Delta] T _1, the same force F ₂ of magnitude the plate surface direction is applied ₂ and ΔT ₂ /
It refers to the case where ΔT ₁ ≦ 0.1. The diaphragm 22 has a thin sheet shape and is made of a material such as carbon fiber reinforced plastic (CFRP) or a metal. The thickness of the diaphragm 22 is, for example, 1 mm to 2 mm.
It is about.

Further, in the apparatus of this embodiment, a special bearing mechanism (not shown in FIG. 3) is provided at the lower end of the pressing rod 611 in consideration of the function of the diaphragm 22 for transmitting the force in the plate surface direction to the upper substrate 92. Have. FIG. 7 is a schematic sectional view of a bearing mechanism provided at a lower end of the pressing rod 611 shown in FIG. The bearing mechanism includes a bearing 614 fixed to the diaphragm 22, a main bearing 615 interposed between the bearing 614 and the lower end of the pressing rod 611, and a pressing rod 61.
1 and a sub bearing 616 interposed between the lower end side surface of the bearing 1 and the inner side surface of the bearing 614.

As described above, when a force in the direction of the plate surface is applied to the diaphragm 22 by the alignment moving means 7, the diaphragm 22 is very thin, and in some cases, the diaphragm 22 is easily deformed in a wavy manner. . When such deformation occurs, the force in the plate surface direction is not transmitted well to the upper substrate 92,
Alignment may not be successful or accuracy may be reduced.

For this reason, in the present embodiment, deformation such as waving is prevented by the bearing mechanism shown in FIG. That is, when deformation such as waving occurs, the diaphragm 22 is locally locally inclined as shown by a dotted line in FIG. In this state, the diaphragm 22 tends to return to the original horizontal state due to the tension of the diaphragm 22 itself.
The main bearing 615 functions to assist the movement of the diaphragm 22. The auxiliary bearing 616 is designed to prevent play (backlash) between the bearing 614 and the pressing rod 611 in the plate surface direction. If there is play, the alignment accuracy will be reduced.

Next, the structure of the vacuum sealing means 81, 82 which constitutes the fourth major feature of this embodiment will be described with reference to FIG. As described above, since the pair of substrate holders 1 and 2 and the intermediate ring 3 constitute a vacuum container, their contact portions need to be vacuum-sealed. The configuration of the vacuum sealing means 81 and 82 for performing the vacuum sealing is also a major feature of the apparatus of the present embodiment.

First, a first vacuum sealing means 81 is provided between the intermediate ring 3 and the lower substrate holder 1.
A characteristic point is that the first vacuum sealing means 81 maintains a vacuum seal even when the upper substrate holder 2 and the intermediate ring 3 move integrally for the above alignment. is there. More specifically, the first vacuum sealing means 81 includes an elastic sealing tool 811 that comes into contact with the intermediate ring 3 moved by the alignment moving means 7,
The elastic sealing member 811 includes a rigid body 812 that limits the amount of deformation.

The elastic seal 811 is typically a vacuum seal such as an O-ring. A circumferential groove is formed in the lower part of the upper surface of the lower substrate holder 1 at the peripheral portion, and an elastic seal member 811 is inserted into the groove. On the other hand, in the intermediate ring 3, a convex portion is formed circumferentially along the inner edge of the lower surface, and the convex portion comes into contact with the elastic seal member 811 to perform vacuum sealing. On the other hand, the rigid body 812 has a spherical shape and is formed of a highly rigid material such as bearing steel. Rigid body 812
Are provided, and are locked by a locking tool (not shown) so as to be able to roll in an arbitrary direction. The rigid body 812
Are provided at equal intervals around the periphery of the elastic sealing member 811.

In a usual structure of the vacuum sealing means, an elastic sealing member such as an O-ring is interposed between members to be vacuum-sealed, and in this state, both are brought into contact with each other to perform screwing or the like. The contact between the two is not complete and the vacuum sealing is not performed only by screwing or the like. However, the vacuum sealing is achieved by the airtight sealing of the elastic sealing member between the two.

However, such a configuration cannot be adopted in this embodiment. This is because it is necessary to move the intermediate ring 3 in the horizontal direction with respect to the fixed lower substrate holder 1 during alignment. In the present embodiment, the lower substrate holder 1 corresponds to “a member that forms a vacuum vessel and does not move”. In the case where the lower substrate holder 1 and the intermediate ring 3 are in contact with each other, alignment is performed by moving the intermediate ring 3 while rubbing the intermediate ring 3 against the lower substrate holder 1. Become. When such a thing is performed, there is a problem that dust or the like is generated by rubbing, in addition to a problem that a large force is required for movement.

A configuration is also conceivable in which contact between the intermediate ring 3 and the lower substrate holder 1 is prevented by optimizing the elastic force of the elastic seal 811. However, in this case, the pressure due to the pressure from the upper substrate holder 2 and the pressure difference between the atmospheric pressure and the vacuum pressure when the gap is formed are applied only to the elastic seal member 811.
For this reason, the elastic force of the elastic sealing member 811 must be made considerably large, and it may be difficult to obtain an appropriate vacuum sealing action. Also, when the elastic force is small, a large force is applied to the elastic body sealing tool 811,
The deformation amount of the elastic sealing member 811 gradually increases, and there is a possibility that the intermediate ring 3 and the lower substrate holder 1 may eventually come into contact with each other. As described above, the elastic sealing member 811
If it is only, the range of the optimal elastic force is narrow, and it is very difficult to select.

On the other hand, when the deformation of the elastic seal 811 is limited by the rigid body 812 as in the present embodiment, the deformation of the elastic seal 811 is limited to a range where the intermediate ring 3 and the lower substrate holder 1 are not in contact with each other. It can be easily limited. That is, the diameter of the spherical rigid body 812 may be set to an appropriate value.

Further, the elastic sealing member 8 made of the rigid body 812
The limitation of the eleventh modification has great technical significance also in terms of alignment while maintaining a vacuum seal. Specifically, when the intermediate ring 3 moves during alignment,
The elastic sealing member 811 is in a state of being rubbed against the intermediate ring 3. That is, the intermediate ring 3 moves while sliding the elastic seal 811 on the lower surface thereof. In this case, when a large force is applied to the elastic sealing member 811 and the amount of deformation increases, the frictional force increases, and the intermediate ring 3 cannot move sufficiently, requires a large force to move, or controls the moving distance. Accuracy may be reduced. In addition, as a result of forcible movement, the elastic seal 81
There is also a risk that the wear of No. 1 will be severe, and a lot of dust such as dust will be generated. Furthermore, if the elastic force is increased so that the deformation of the elastic sealing member 811 is reduced, the vacuum seal may not be maintained.

According to the structure of this embodiment, since the rigid body 812 is provided, the deformation of the elastic seal 811 is limited, and the pressure between the intermediate ring 3 and the lower substrate holder 1 is dispersed. Therefore, there is no problem as described above, and the intermediate ring 3
Can be easily moved with sufficiently high controllability, and there is no problem such as generation of dust.

In this embodiment, measures are taken to further enhance the effect of reducing the generation of dust due to friction. First, the elastic sealing member 811 is made of silicone rubber or the like, and the one whose surface is coated with a lubricant such as Teflon (registered trademark) is used. The rigid body 812
Is also coated with a lubricant. The lower surface of the intermediate ring 3 that comes into contact with the elastic sealing member 811 or the rigid body 812 is mirror-finished, and a lubricant is provided on the surface. This lubricant is specifically a lubricating oil, and is applied to the lower surface of the intermediate ring 3. Due to such a configuration, the intermediate ring 3 can be moved with a small force, the control is easy, and the effect of reducing generation of dust due to friction is further enhanced.

As shown in FIG. 3, the rigid body 812
It is located outside the elastic seal 811 (farther from the central axis of the substrate holders 1 and 2). Therefore, even if dust is generated at the contact point of the rigid body 812, the dust is blocked by the elastic sealing member 811 and the substrates 91, 9
It does not enter the space where 2 is superimposed. In other words, the point where the rigid body 812 is located outside the elastic sealing tool 811 also contributes to preventing dust from being mixed into the liquid crystal 94 and adhesion of dust to the element surfaces of the substrates 91 and 92. .

In the structure of the first vacuum sealing means 81, the rigid body 812 rolls, but may slide. That is, the rigid body 812 is a block having a shape of a rectangular parallelepiped or the like, and may have a surface coated with a lubricant such as a fluororesin. In this case, the rigid body 812 slides relatively to the intermediate ring 3. The first vacuum sealing means 81 has a rigid body 81
Instead of 2, a mechanism may be used in which the intermediate ring 3 and the lower substrate holder 1 are magnetically repelled to maintain an interval therebetween. In this case, magnets are provided on the intermediate ring 3 and the lower substrate holder 1 so that magnetic poles of the same polarity face each other. The magnet is constituted by an electromagnet, and a current is controlled so that a predetermined interval is maintained.

Further, a mechanism for adjusting the pressure of the fluid interposed between the intermediate ring 3 and the lower substrate holder 1 to maintain the interval can be employed. In this case, a closed space is formed while connecting the intermediate ring 3 and the lower substrate holder 1 with bellows or the like, and gas is introduced into this space. The distance between the two is maintained at a predetermined value by adjusting the pressure of the gas to be introduced. In any case, by maintaining such an interval, the elastic sealing member 81
1 can be reduced to a predetermined value or less, and the contact between the intermediate ring 3 and the lower substrate holder 1 can be prevented. Absent.

Another major feature of the present embodiment relating to the vacuum seal is that the second vacuum sealing means 82 for vacuum-sealing the seal portion which comes into contact with or separates from the opening / closing mechanism by the opening / closing mechanism 5 is provided by the first vacuum sealing means 82 described above. This is a point provided separately from the vacuum sealing means 81. Hereinafter, this point will be described. In the present embodiment, the members that come into contact with or separate from each other at the time of opening and closing by the opening and closing mechanism 5 are the upper substrate holder 2 and the intermediate ring 3. Therefore, the second vacuum seal member performs a vacuum seal between the upper substrate holder 2 and the intermediate ring 3.

The second vacuum sealing means 82 is different from the first vacuum sealing means 81, and is constituted only by the elastic sealing member 821. This elastic seal 821 is also typically an O-ring or the like. On the upper surface of the intermediate ring 3, FIG.
A groove with a trapezoidal cross section as shown in is provided in the circumference,
An elastic seal member 821 is inserted into the groove.
The elastic sealing member 821 has a shape that slightly protrudes from the groove when vacuum sealing is not performed. However, at the time of vacuum sealing, the elastic sealing member 821 is crushed by the upper substrate holding member 2 and contacts the upper substrate holding member 2 to secure a vacuum seal. It is supposed to.

The configuration employing the second vacuum sealing means 82 has the following technical significance. In the configuration of the present embodiment, it is not impossible not to provide the second vacuum sealing means 82. For example, if the intermediate ring 3 is integrated with the upper substrate holder 2 (if the intermediate ring 3 is not provided), the second vacuum sealing means 82 is unnecessary. However, in this case, when the opening and closing mechanism 5 opens and closes, the upper substrate holder 2 and the lower substrate holder 1 come into contact with or separate from each other. That is,
In the first vacuum sealing means 81, opening to the atmosphere and vacuum sealing are repeated.

However, if the portion of the first vacuum sealing means 81 is opened to the atmosphere, the problem of dust adhesion is likely to occur. If dust adheres to the surface of the elastic sealing tool 811,
As a result of being rubbed against the intermediate ring 3 at the time of alignment, the surface of the elastic sealing member 811 is damaged, and the performance of the elastic sealing member 811 is reduced, so that leakage (vacuum leakage) is likely to occur. Further, if dust adheres to the lower surface of the intermediate ring 3, the elastic body sealing tool 811 is rubbed,
The dust may scratch the mirror surface and cause problems such as an increase in frictional force. Further, each time the opening and closing is performed, the intermediate ring 3 is attached to the elastic sealing member 811 and the rigid body 812.
As a result of repeated contact and separation, the lubricant may be worn or the lubricant may be scraped to become dust.

According to the structure of this embodiment, since the second vacuum sealing means 82 is provided, it is not necessary to open and close the first vacuum sealing means 81, and a vacuum sealing structure can be always used. Therefore, the above-described problem does not exist in the present embodiment. The apparatus has a main control unit (not shown) that controls each unit. The main control unit includes a determination unit that determines a gap length and a parallelism between a pair of substrates according to signals from a plurality of distance sensors. The judging section judges the parallelism by comparing the signals from the distance sensors and judges the gap length by averaging the signals from the distance sensors. Further, the main control unit also includes a determination unit that determines whether the positional relationship between the pair of substrates in the plate surface direction is a predetermined one according to a signal from the displacement detection sensor. The main control unit sends a control signal to the gap moving unit and the alignment moving unit.

Next, the operation of the apparatus according to this embodiment having the above configuration will be described. 8 and 9 are diagrams illustrating the operation of the device according to the present embodiment. (1) of FIG.
(2), (3), and subsequently, the operation proceeds in the order of (1), (2), and (3) in FIG. 8 and 9.
Shows a substantially right half of the apparatus shown in FIG.

FIGS. 8 and 9 partially show the detailed structure of the apparatus not shown in FIG. First, as shown in FIGS. 8 (1) to 8 (3), a pair of substrate holders 1,
2 are provided with lift pins 16 and 28 for transferring substrates 91 and 92, respectively. Each board holder 1,
2 is provided with through holes for the lift pins 16 and 28. The through holes are long in the vertical direction, and the lift pins 16 and 2
8 is also disposed in the through hole in a vertical posture. The through holes and the lift pins 16 and 28 are provided in plural (for example, four) in each of the substrate holders 1 and 2.

Each of the lift pins 16 and 28 is provided with a lifting mechanism (not shown) for moving the lift pins 16 and 28 up and down. In addition, the lift pins 28 are formed in a tubular shape so that the substrate can be vacuum-sucked at the opening at the tip. That is, a vacuum pump (not shown) that sucks vacuum through the lift pins 28 is provided. Further, as shown in FIG. 9 (3), the lower substrate holder 1 is provided with a light irradiation unit 17 for temporary fixing. The light irradiating section 17 is the tip of the optical fiber 171 in the present embodiment. Optical fiber 17
Numeral 1 is for guiding light from the ultraviolet lamp 172 to irradiate the sealing material. The tip of the optical fiber 171 is branched into a plurality of parts, and the plurality of light irradiation parts 17 are provided evenly on the lower substrate holder 1.

First, the loading operation of the pair of substrates 91 and 92 will be described with reference to FIGS. First,
The upper substrate 92 is transported while being held while being vacuum-sucked by the arm 907 of the transport robot 906, and stops at a predetermined position. Since the lower side of the upper substrate 92 is the element surface, the upper substrate 92 is conveyed while being vacuum-sucked on the upper surface. Then, as shown in FIG. 8A, the lift pins (hereinafter, upper lift pins) 28 of the upper substrate holder 2 are lowered, and the upper substrate 92
Is vacuum-adsorbed. At this time, the upper lift pin 28 is lowered at a position where the upper lift pin 28 does not interfere with the arm 907 and is sucked by vacuum. After the vacuum suction of the arm 907 is released, as shown in FIG.
Stops at a position where it contacts the holding head 22. And
The vacuum suction mechanism operates and the upper substrate 92
Is adsorbed in vacuum. Thereafter, the upper lift pin 28 further releases the vacuum suction and then further rises and stops at a predetermined standby position.

Next, the lower substrate 91 is similarly held and conveyed while being vacuum-sucked by the arm 907 of the transfer robot 906, and stopped at a predetermined position. Since the upper side of the lower substrate 91 is the element surface, the lower substrate 91 is vacuum-sucked on the lower side. Then, after the vacuum suction of the arm 907 is released, the lift pins (hereinafter referred to as “lower lift pins”) 16 of the lower substrate holder 1 rise and come into contact with the lower surface of the lower substrate 91, and then lower by a predetermined distance. As a result, as shown in FIG. 8C, the lower substrate 91 is placed on the electrostatic attraction plate 11. afterwards,
The vacuum suction mechanism of the electrostatic suction plate 11 is operated, and the lower substrate 91 is vacuum-sucked to the electrostatic suction plate 11. The lower lift pin 28 further descends and stops at a predetermined standby position.

Next, the opening / closing mechanism 5 shown in FIG. 3 operates to lower the upper substrate holder 2 by a predetermined distance so as to be at the lower limit position. Thereby, as shown in FIG. 9A, the upper substrate holder 2 and the intermediate ring 3 come into contact with each other, and the second vacuum sealing means 82 achieves vacuum sealing. In this state,
The evacuation system 41 operates to evacuate the inside of the vacuum container including the pair of substrate holders 1 and 2 and the intermediate ring 3 to a predetermined pressure. At this time, the inside of the closed space 26 behind the diaphragm 22 is similarly evacuated to a vacuum pressure equivalent to that in the vacuum vessel. At the same time as the start of evacuation, the electrostatic suction mechanism is operated to operate the substrate 9.
1, 92 are electrostatically adsorbed and the vacuum adsorption is released. After the upper substrate holder 2 and the intermediate ring 3 come into contact with each other so that the alignment operation described later is not hindered,
The holding member 51 is separated from the opening / closing drive source 52 by a mechanism (not shown).

Next, the gap setting moving means and the alignment moving means 7 operate to perform gap setting and alignment. First, a predetermined value (hereinafter, referred to as a gap length) that is finally set as a gap length to be achieved in the present apparatus.
The gap length is set slightly larger than the gap length setting value (hereinafter, gap length standby value). That is, the gap-moving moving means operates the pressing drive source 612 to lower the upper substrate holder 2, and the pair of substrates 9
The gap length of 1,92 is set to the gap length standby value. In the state of the gap length standby value,
The upper substrate 92 does not contact the sealing material on the lower substrate 91. That is, the gap length standby value is a value sufficiently larger than the application height of the sealing material.

In this state, first, an operation of setting the parallelism to a predetermined high value is performed. That is, the main control unit (not shown) obtains the parallelism based on the signal from each distance sensor 63, and the determination unit (not shown) determines whether the parallelism is a predetermined high value. If it is determined that the degree of parallelism is not a predetermined high value, the main control unit proceeds to each pressing drive source 61 of the gap moving unit 6.
2 to control the pressing drive sources 612 so that the pair of substrates 91 and 92 are parallel to each other. That is, the distance measured by the specific distance sensor 63 is different from that of another distance sensor 63.
If the distance is longer than the distance measured by
Push rods 61 (paired) located above 3
A control signal is sent to a pressing drive source 612 that drives the pressing rod 611 so that 1 is displaced slightly downward. In this way, each pressing drive source 612 is controlled, and each distance sensor 63 is controlled.
Compare the magnitude of the signal from And each distance sensor 6
If it is determined that the difference in the magnitude of the signal from No. 3 is within a predetermined small range, it is determined that the parallelism between the pair of substrates 91 and 92 is a predetermined high value.

Next, alignment is performed. That is, two alignment marks are imaged by the displacement detection sensor 75. The captured image data is processed and digitized in the main control unit, and a position shift is calculated. Then, the main control unit operates the units 71, 72, 73, 7 of the alignment moving means 7 so as to correct the positional deviation.
The control signal is sent to the fourth linear drive source 702. The linear drive source 702 is driven according to the control signal, and the X, Y and / or θ
The upper substrate 92 moves in each direction. Subsequently, when the main control unit determines that the displacement has been corrected from the image data of the two alignment marks sent from the displacement detection sensor 75, the alignment is completed.

In this state, next, the gap moving means operates again to move the upper substrate 92 toward the lower substrate 91 in the plate surface direction so that the gap length becomes the gap length set value. . That is, the main control unit similarly sends control signals to the four pressing drive sources 612 so that the gap length becomes the gap length set value. However, each pressing drive source 61
In many cases, the pressing force alone is not sufficient, and the gap length does not become the gap length set value even after the lapse of a predetermined time. In this case, the main control unit closes the auxiliary valve 624 on the auxiliary exhaust pipe 623, and the valve 625 connected to a cylinder (not shown).
The main valve 622 for differential pressure is opened, and the inside of the closed space 26 is pressurized. As a result, in addition to the differential pressure between the vacuum and the atmospheric pressure, the upper substrate 92 is pressed toward the lower substrate 91 by the differential pressure between the pressure higher than the atmospheric pressure and the vacuum.

Then, a signal is sent to a pressure regulator (not shown) so that the gap length obtained by averaging the outputs from the four distance sensors 63 becomes the gap length set value, and the differential pressure applying mechanism 62 is negatively fed back. Control. If it is determined that the gap length matches the gap length set value, the position shift detection sensor 75
The main control unit determines again whether there is a position shift based on the signal from the controller.

When it is determined that there is a positional shift, alignment is performed again. At this time, the upper substrate 92 is slightly raised. In the state of the gap length set value, the upper substrate 92 is in contact with the sealing material on the lower substrate 91. When the alignment is performed again in this state, a very large force is required to move the upper substrate 92 because the alignment member is in contact with the highly viscous sealing material. In the case of the drop type, this problem is remarkable because liquid crystal exists in the gap. Further, when the alignment is performed in the state of the gap length setting value, the upper substrate 92 may drag the spacer, and the surfaces of the substrates 91 and 92 may be damaged.

For this reason, in the present embodiment, the upper substrate 92 is slightly lifted from the state of the gap length set value,
In that state, alignment is performed again. The gap length at this time may be a gap length standby value or a length that is shorter than the gap length standby value but allows the upper substrate 92 to be separated from the sealing material.

After the alignment is performed again in this manner, the upper substrate 92 is lowered again to form a gap. It is preferable to confirm the parallelism once again before performing the gap setting again. If the parallelism is not a predetermined high value, as described above, each of the pressing drive sources 6
The operation of controlling the parallelism 12 is performed to obtain the parallelism.

When the gap is determined again and it is determined that the gap length has been set to the gap length and no displacement has occurred, the sealing material is temporarily fixed as shown in FIG. 9 (3). . That is, ultraviolet rays are spot-irradiated from the light irradiation unit 17 to partially cure the sealing material. Thereafter, the operation of the electrostatic attraction mechanism of the upper substrate holder 2 is stopped, and the holding of the upper substrate 92 by the upper substrate holder 2 is released. Then, the inside of the closed space 26 is evacuated to the same pressure as the inside of the vacuum container, and the pressing drive source 612 is operated to raise the holding head 22 to the initial position.

Next, a gas is introduced into the vacuum chamber and the closed space 26 to make it atmospheric pressure, and the opening and closing mechanism 5 is operated to raise the upper substrate holder 2 to the upper limit position. Thereafter, the electrostatic suction mechanism of the lower substrate holder 1 is stopped, and the lower lift pins 28 are turned off.
To rise. As a result, the pair of substrates 91 and 92 are lifted by the lower lift pins 28 and separated from the lower substrate holder 1. Then, the arm 9 of the transfer robot 906
07 enters, holds the pair of substrates 91 and 92 while vacuum-sucking them, and carries them out of the apparatus. A pair of substrates 91 and 92
Is transferred to the collection cassette 913 by the transfer robot 906.

According to the substrate stacking apparatus of the present embodiment having the above-described structure and operation, the gap moving means and the alignment moving means 7 are arranged outside the vacuum vessel, so that the space inside the vacuum vessel is reduced. The volume can be reduced. For this reason, the time required for exhaust and venting can be shortened, which can contribute to an improvement in productivity. In addition, since it is not necessary to increase the exhaust speed or the vent speed, dust and dust in the vacuum container are not sowed up, and dust and dust are less mixed into the liquid crystal 94. Further, since there is no need to increase the pumping speed, an expensive vacuum pump is not required, which contributes to suppressing an increase in the cost of the apparatus.

Further, the fact that the pair of substrate holders 1 and 2 themselves constitutes a vacuum container contributes to further reducing the volume of space in the vacuum container. When the substrate holders 1 and 2 do not form a vacuum container, the structure is such that the substrate holders 1 and 2 are accommodated in the vacuum container. With this structure, a large space volume in the vacuum vessel is required by the space occupied by the substrate holders 1 and 2. In the above embodiment, the pair of substrates 91 and 92 are overlapped in a horizontal state. Therefore, the pair of substrate holders 1 and 2 are the upper substrate holder 2 and the lower substrate holder 1. , But is not limited to this. In the case of the injection type, a pair of substrates 91, 92
May be superimposed in a state of being set up vertically. In this case, it becomes a left substrate holder and a right substrate holder.

The technical significance of the reduction of the space volume in the vacuum vessel is that if one of the pair of substrate holders 1 and 2 forms a vacuum container, the pair of substrate holders 1 and 2 does not form a vacuum container. can get. FIG. 10 is a diagram illustrating this point, and is a diagram illustrating a case where only one of the substrate holders 1 and 2 constitutes a vacuum container. As shown in FIG. 10 (1), only the upper substrate holder 2 may constitute a vacuum container, and as shown in FIG. 10 (2), the lower substrate holder 1
Only the vacuum container may be included.

In the structure of the above-described vacuum vessel,
The space volume in the vacuum vessel is one of the sum of the volume of the pair of substrates 91 and 92 and the volume of the gap (hereinafter, referred to as substrate volume).
It is preferably at least twice and at most 50 times. The space volume in the vacuum vessel is, for example, the product of the height, width, and height when the shape of the inner wall surface of the vacuum vessel is a rectangular parallelepiped. The “gap volume” is the volume after the gap is formed, that is, the volume at the gap length set value.

If the volume of the space in the vacuum vessel is larger than 50 times the volume of the substrate, the technical significance of shortening the time required for the above-described evacuation and venting cannot be obtained. If the space volume in the vacuum container is smaller than one time the substrate volume, the upper substrate 91 may come into contact with the sealing material or the liquid crystal, or the vacuum between the substrates 91 and 92 may be maintained at the gap length standby value. The problem that exhaust cannot be performed sufficiently occurs.

The opening / closing mechanism 5 includes a pair of substrate holders 1 and
As described above, the structure that opens and closes the opening and closing of the substrates 91 and 92
There is a technical significance that makes it easy to carry out the operation at the time of loading and unloading. Although the opening / closing mechanism 5 is opened and closed by moving the upper substrate holder 2 up and down, the lower substrate holder 1 may be moved up and down.

Further, the first vacuum sealing means 81 for maintaining a vacuum seal during alignment has a technical significance to enable alignment in a vacuum. If there is no first vacuum sealing means 81, the pressure will be atmospheric pressure during alignment. In this case, if the gap is set in a vacuum or the like, the substrates 91 and 9 may be removed due to a difference in atmospheric pressure.
The position 2 may slightly deviate from the alignment. The first vacuum sealing means 81 has technical significance for preventing such a problem.

Further, the configuration using both mechanical pressing and pressing by gas differential pressure has the following technical significance. In other words, a considerably large pressing force is required to make the gap, and this tendency is strong in the case of a dropping process in which liquid crystal is sandwiched inside. In this case, only the mechanical pressing using the pressing drive source 612 such as a servomotor results in insufficient pressing force, and in many cases, the pressing cannot be performed to the required gap length. If an attempt is made to produce a gap only by mechanical pressing, the pressing drive source 612 having a very large output will be used. It becomes difficult to adjust. Further, there is also a problem that the pressing force becomes non-uniform only by mechanical pressing, and as a result, the gap length tends to become non-uniform in the plate surface direction.

As in the present embodiment, when the pressing by the differential pressure of the gas is used in addition to the mechanical pressing, the insufficient pressing force can be compensated, and the fine pressing force can be easily adjusted. Further, since the pressing is performed by the gas differential pressure, there is an advantage that the pressing force can be applied uniformly and the gap length can be made uniform.

In this embodiment, the differential pressure applying mechanism 62
Was to introduce a gas into the closed space 26 and apply a differential pressure. However, the pressure in the space in which the upper substrate 92 was disposed was changed by the pressure in the space behind the upper substrate 92 partitioned by the diaphragm 22. High pressure is enough. Therefore, the space behind is not the closed space 26 but simply an open space of the atmospheric pressure, and the exhaust system 41 that exhausts the inside of the vacuum vessel can be used as the differential pressure applying mechanism 62. Further, when the gap is set in the atmosphere, the differential pressure applying mechanism 62 is configured to introduce gas into the closed space 26 behind the upper substrate 92 to make the pressure higher than the atmospheric pressure. Further, the differential pressure applying mechanism 62 is configured to set the pressure in the closed space 26 behind to a vacuum pressure higher than the vacuum pressure in the vacuum container, for example, to perform differential evacuation when performing gap generation in a vacuum. But it is good. Further, as the differential pressure applying mechanism 62, a mechanism that applies a differential pressure by introducing a gas other than a gas such as a liquid, and a mechanism that applies a differential pressure by introducing a fluid other than a gas such as a liquid may be adopted in addition to the mechanism that applies the differential pressure by introducing the gas as described above.

Further, a distance sensor 63 for measuring the gap length between the pair of substrates 91 and 92 is provided, and the gap determining means controls the movement in the thickness direction by controlling the negative feedback from the distance sensor 63. Has a technical significance that enables the gap to be formed with high accuracy and in a short time. Conventionally, as described above, after pressing a predetermined pressure, the size of the gap is measured by a measuring instrument, and if the gap is not within a specified range, the gap is simply retried. Compared with this, according to the configuration of the present embodiment, the gap setting can be completed with high accuracy and in a short time.

The fact that a plurality of distance sensors 63 are provided, and the above-described negative feedback control is performed by the plurality of distance sensors 63 has the technical significance of improving the measurement accuracy and further enabling high-precision gap setting. The point of detecting the parallelism of the pair of substrates 91 and 92 from the measurement data of the plurality of distance sensors 63 contributes to overlapping the pair of substrates 91 and 92 with a high degree of parallelism. It has the technical significance of making the gap setting more uniform in the plate surface direction.

Further, a displacement detection sensor 75 for detecting a displacement of the pair of substrates 91 and 92 in the plate surface direction is provided. The fact that at least one of the pair of substrate holders 1 and 2 is moved so as to perform the correction has a technical significance that the alignment can be performed with higher accuracy. In the above embodiment, the alignment is performed by moving the upper substrate holder 2 in the plate surface direction. However, the lower substrate holder 1 may be moved, or both may be moved. The opening / closing mechanism 5 is configured to open and close by linearly moving the upper substrate holder 2 in the thickness direction, but may be opened and closed by linearly moving the lower substrate holder 1. In addition to the linear movement, the door may be opened and closed like a hinged door.

[0107]

Next, examples of the invention of the above embodiment will be described. Similarly, an embodiment will be described with reference to an example in which substrates are overlapped in a liquid crystal display manufacturing process. In a TFT type liquid crystal display, a color filter is formed on one of a pair of substrates 91 and 92, and a TFT is formed on the other as a driving element. When the apparatus of the above embodiment is used, for example, the substrate on which the color filter is formed is the upper substrate 92, and the substrate on which the TFT is formed is the lower substrate 91. The size of the substrate is similar to what is called a large substrate, and is about 730 mm × 920 mm.

When such a pair of substrates 91 and 92 are overlaid, the alignment accuracy is ± 1 μm, and the final gap length is about 5 μm. When the gap length is set to 5 μm in vacuum, the pressing force by the gap setting means is about 5 × 10 ⁻⁴ N / m ² . The vacuum pressure is
It may be about 0.1 Pa. In the case of this vacuum pressure, the pressure in the closed space when the gap is finally formed is about 50 kPa
It is.

In the above embodiments and examples, the description has been made exclusively on the superposition of the substrates in the liquid crystal display manufacturing process. However, the apparatus of the present invention can also be used in the plasma display manufacturing process and the like.

[0110]

As described above, according to the first aspect of the present invention, since at least one of the pair of substrate holders constitutes a vacuum container, the space volume in the vacuum container can be reduced. Can be. For this reason, the time required for exhaust and venting can be shortened, which can contribute to an improvement in productivity. In addition, since it is not necessary to increase the exhaust speed or the vent speed, dust and dust in the vacuum vessel are not sowed up, and the entry of dust and dust into the liquid crystal is reduced. Further, since there is no need to increase the pumping speed, an expensive vacuum pump is not required, which contributes to suppressing an increase in the cost of the apparatus.
According to the second aspect of the present invention, in addition to the above effects,
Since the opening / closing mechanism opens and closes the vacuum vessel, there is a technical significance to achieve both minimization of the space volume in the vacuum vessel and facilitation of maintenance and operations at the time of loading and unloading the substrate. According to the third aspect of the present invention, in addition to the above-described effects, the first vacuum sealing means maintains the vacuum seal even during alignment, thereby enabling alignment in a vacuum. For this reason, there is an advantage in that even when the gap is set in a vacuum, it is difficult to generate a positional shift. And, these points, in the case of the process adopting the drop type,
This has the advantage that bubbles can be effectively prevented from entering the liquid crystal. According to the fourth or fifth aspect of the present invention, in addition to the above-described effects, it is possible to effectively maintain the vacuum seal while preventing the contact of the vacuum vessel constituent members. For this reason, it is possible to prevent a problem that a large force is required for the alignment and that dust is generated. According to the invention as set forth in claim 6, in addition to the above effects, the second vacuum sealing means for vacuum-sealing the sealing portion which comes into contact with or is separated from the opening and closing by the opening and closing mechanism is the same as the first vacuum sealing means. Since it is provided separately, the first vacuum sealing means can always be a vacuum seal. Therefore, technical significance such as prevention of deterioration of the first vacuum sealing means and stabilization of the vacuum seal can be obtained. According to the seventh aspect of the present invention, in addition to the above-described effects, the volume of the space in the vacuum vessel is at least one time larger than the volume of the substrate.
Since it is less than twice, the technical significance of shortening the time required for exhaust and venting can be sufficiently obtained, and the stroke at the time of opening the gap is not sufficiently obtained, so that control becomes difficult, and the operation of loading and unloading the substrate is performed. There is no problem that it becomes difficult. According to the eighth aspect of the present invention, in addition to the above effects, the moving means for gap setting is
Since the pressing by the gas differential pressure is used in addition to the mechanical pressing, the shortage of the pressing force can be compensated and the fine pressing force can be easily adjusted. Further, since the pressing is performed by the gas differential pressure, there is an advantage that the pressing force can be applied uniformly and the gap length can be made uniform. According to the ninth aspect of the present invention, in addition to the above effects, the gap is finally formed by controlling the magnitude of the differential pressure applied by the differential pressure applying mechanism. Even in this case, it is possible to improve the accuracy of gap setting. According to the tenth aspect, in addition to the above effects,
During alignment, the diaphragm transmits the force in the direction of the plate surface to the substrate, and is essentially not deformed in the direction of the plate surface, so that the alignment becomes unstable and the reproducibility and accuracy deteriorate. There is no fear of doing. According to the eleventh aspect of the present invention, in addition to the above effects, a distance sensor for measuring a gap length between the pair of substrates is provided, and the movement in the thickness direction is controlled by a signal fed back from the distance sensor. Therefore, it is possible to perform the gap setting with high accuracy and in a short time. According to the twelfth aspect of the present invention, in addition to the above effects, a plurality of distance sensors are provided, and the measurement of the parallelism and / or the gap length is measured by the plurality of distance sensors. Is performed while controlling the gap, it is possible to perform the gap removal with higher precision and to make the gap removal more uniform in the plate surface direction. According to the invention of claim 13, in addition to the above effects, after the pair of substrates are opposed to each other with a predetermined parallelism, at least one of the pair of substrates is oriented in a direction perpendicular to the plate surface while maintaining the parallelism. Since the gap is set by moving the gap, the parallelism is maintained high even after the gap is set. Therefore, the gap can be always formed with a high degree of parallelism regardless of the mechanical or mechanical elements of the device. Further, according to the fourteenth aspect, it is possible to perform gap setting and alignment in a vacuum while obtaining the effects of the seventh, eighth, ninth, or tenth aspects. For this reason, a process employing a dropping method is preferable because it is possible to effectively prevent air bubbles from entering the liquid crystal. According to the fifteenth aspect of the present invention, in addition to the above-described effects, the alignment moving means moves at least one of the pair of substrate holders so as to correct the position shift in accordance with a signal from the position shift detection sensor. Therefore, there is an advantage that alignment can be performed with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a manufacturing process of a liquid crystal display using substrate superposition according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a manufacturing system that performs the manufacturing process shown in FIG.

FIG. 3 is a schematic front sectional view of a substrate superposing apparatus according to an embodiment provided in the manufacturing system shown in FIG. 2;

FIG. 4 is a schematic diagram illustrating a configuration of an electrostatic attraction mechanism provided on a holding head 23 illustrated in FIG. 3;

FIG. 5 is a schematic perspective view illustrating an operation of loading and unloading substrates 91 and 92 to and from the substrate stacking apparatus.

FIG. 6 is a diagram illustrating an arrangement position of a distance sensor 63 in a plate surface direction.

7 is a schematic sectional view of a bearing mechanism provided at a lower end of a pressing rod 611 shown in FIG.

FIG. 8 is a diagram illustrating the operation of the device of the present embodiment.

FIG. 9 is a diagram for explaining the operation of the device of the present embodiment.

FIG. 10 is a diagram illustrating a case where only one substrate holder constitutes a vacuum container.

[Explanation of symbols]

 Reference Signs List 1 lower substrate holder 22 diaphragm 2 upper substrate holder 3 intermediate ring 41 exhaust system 42 vent gas introduction system 5 opening / closing mechanism 61 pressing mechanism 62 differential pressure applying mechanism 63 distance sensor 7 alignment moving means 701 bracket 702 linear drive source 703 fulcrum Pin 704 Connector 705 Linear guide 75 Position shift detection sensor 81 First vacuum seal 811 Elastic seal 812 Rigid 82 Second vacuum seal 91 Lower substrate 92 Upper substrate

Claims (15)

[Claims] 1. A substrate laminating apparatus for laminating a pair of substrates in vacuum with a predetermined gap therebetween, comprising: a pair of substrate holders for holding a pair of substrates; and a pair of substrate holders A gap-moving means for moving at least one of the substrates in the thickness direction of the substrate to make a gap length between the one substrate and the other substrate to a predetermined value, and a position of the pair of substrates in the plate surface direction. Alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the surface of the substrate so that the relationship becomes a predetermined one, and at least one of the pair of substrate holders is A substrate stacking apparatus, wherein the pair of substrates is a member constituting a vacuum container in which the pair of substrates are positioned at the time of gap setting and the alignment. 2. An opening / closing mechanism for opening and closing the vacuum container by moving at least one of the pair of substrate holders, the opening / closing mechanism is provided when the vacuum container is opened to the atmosphere. The pair of substrate holders are located at a long first distance, and when the vacuum container is evacuated to vacuum, the pair of substrate holders are moved to be located at a second distance shorter than the first distance. The apparatus according to claim 1, wherein: 3. The alignment moving means for moving a substrate holder, which is a member constituting a vacuum container, of the pair of substrate holders, and separates the substrate holder or the vacuum container. And a first vacuum sealing means for maintaining a vacuum by contacting a member which moves integrally with the substrate holder, and wherein the first vacuum sealing means holds the substrate by the alignment moving means. 2. The substrate stacking apparatus according to claim 1, wherein a vacuum is maintained even when the tool moves. 4. The substrate holding member moved by the alignment moving means, wherein the first vacuum sealing means is an elastic sealing member contacting the substrate holder or the another member moved by the alignment moving means. Tool or the other member and a member that constitutes the vacuum container, and a distance maintaining mechanism that maintains a predetermined distance that does not come into contact with a member that does not move, wherein the predetermined distance is the elasticity. 4. The substrate stacking apparatus according to claim 3, wherein the body sealing member has an interval of not more than a predetermined amount of deformation while achieving vacuum sealing. 5. The interval maintaining mechanism is interposed between the substrate holder or the another member moved by the alignment moving means and a member constituting the vacuum vessel but not moving. A mechanism for maintaining the gap by a slidable or rollable rigid body, a mechanism for maintaining the gap by magnetically repelling the two, or adjusting the pressure of the fluid interposed between the two to maintain the gap 5. The apparatus according to claim 4, wherein the apparatus is a mechanism. 6. An opening / closing mechanism for opening and closing the vacuum container by moving at least one of the pair of substrate holders in the thickness direction of the substrate, wherein the opening / closing mechanism contacts the opening and closing of the vacuum container. 6. The substrate stacking apparatus according to claim 3, wherein a second vacuum sealing means for vacuum-sealing the sealing portion which is separated or separated is provided separately from the first vacuum sealing means. 7. A substrate stacking apparatus for stacking a pair of substrates in a vacuum with a pair of substrates being parallel to each other and with a predetermined gap, comprising: a pair of substrate holders for holding a pair of substrates; Moving means for moving at least one of them in the thickness direction of the substrate to make a gap length between the one substrate and the other substrate to a predetermined value, and a position of the pair of substrates in the plate surface direction Alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the surface of the substrate so that the relationship becomes a predetermined relationship. A vacuum vessel in which the substrate is located is provided, and the volume of the space in the vacuum vessel is 1 to 50 times the sum of the volume of the pair of substrates and the volume of the gap. Substrate overlay and wherein the Rukoto. 8. A substrate superposing apparatus for superposing a pair of substrates in parallel with each other and with a predetermined gap, wherein at least one of a pair of substrate holders holding the pair of substrates and a pair of substrate holders Moving means in the thickness direction of the substrate to perform a gap setting to set a gap length between one substrate and the other substrate to a predetermined value, and a positional relationship between the pair of substrates in the plate surface direction is predetermined. Alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the one of the pair of substrate holders is one of the substrate holders. Has a diaphragm that partitions a space in which the one substrate held by the substrate is located and a space behind the one substrate, and the diaphragm is a member extending in parallel with the substrate, and the gap moving means A differential pressure application mechanism that applies a differential pressure that raises the atmospheric pressure in the space behind it compared to the atmospheric pressure in the space where one substrate is located, and presses one substrate toward the other substrate when the gap is formed. The diaphragm has a flexibility capable of pushing one of the substrates and displacing in the thickness direction when a differential pressure is applied by a differential pressure applying mechanism, The moving means includes this differential pressure applying mechanism,
A substrate superposing apparatus, comprising: a pressing mechanism for mechanically applying a pressing force to one of the substrates. 9. The apparatus according to claim 9, wherein the gap setting moving means controls the magnitude of the differential pressure applied by the differential pressure applying mechanism to finally make the gap length the predetermined value. The substrate superposition apparatus according to claim 8. 10. A substrate stacking apparatus for stacking a pair of substrates in parallel with each other and at a predetermined gap, wherein at least one of the pair of substrate holders holding the pair of substrates and the pair of substrate holders Moving means in the thickness direction of the substrate to perform a gap setting to set a gap length between one substrate and the other substrate to a predetermined value, and a positional relationship between the pair of substrates in the plate surface direction is predetermined. Alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the one of the pair of substrate holders is one of the substrate holders. Has a diaphragm with a space behind one of the substrates held as a closed space, the diaphragm is a member extending parallel to the substrate,
At the time of gap setting by the gap setting moving means,
A differential pressure application mechanism for applying a differential pressure that raises the atmospheric pressure of the closed space behind to the ambient pressure of the space facing the other substrate in front and pressing one substrate against the other substrate is provided; The diaphragm has a flexibility capable of pushing one of the substrates to be displaced in the direction of the plate pressure when a differential pressure is applied by the differential pressure applying mechanism. Moving one of the substrate holders in the direction of the plate surface, wherein the diaphragm transmits driving force in the direction of the plate surface to the substrate by the moving means for alignment, and is essentially in the direction of the plate surface. A substrate superposing apparatus characterized in that it is not deformed. 11. A substrate stacking apparatus for stacking a pair of substrates parallel to each other with a predetermined gap, wherein at least one of the pair of substrate holders holding the pair of substrates and the pair of substrate holders Moving means in the thickness direction of the substrate to perform a gap setting to set a gap length between one substrate and the other substrate to a predetermined value, and a positional relationship between the pair of substrates in the plate surface direction is predetermined. Alignment means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so as to have a distance sensor for measuring a gap length between the pair of substrates. Wherein the gap setting means has a main control section for controlling the movement of the substrate in the thickness direction by a signal fed back from a distance sensor. Plate overlay devices. 12. A substrate stacking apparatus for stacking a pair of substrates in parallel with each other with a predetermined gap, wherein at least one of the pair of substrate holders holding the pair of substrates and the pair of substrate holders Moving means in the thickness direction of the substrate to perform a gap setting to set a gap length between one substrate and the other substrate to a predetermined value, and a positional relationship between the pair of substrates in the plate surface direction is predetermined. Alignment moving means for performing alignment for moving at least one of the pair of substrate holders in the direction of the plate surface of the substrate so that the pair of substrate holders each have a surface parallel to the substrate to be held. A plurality of distance sensors that measure the distance between the facing surfaces, and a parallelism and / or a distance between a pair of substrates based on signals from the plurality of distance sensors. Substrate overlay apparatus characterized by and a determining section for determining. 13. The gap moving device according to claim 1, wherein the pair of substrates are opposed to each other at a distance longer than the predetermined value and have a predetermined degree of parallelism. 13. The apparatus according to claim 12, wherein at least one of the pair of substrates is moved in a direction perpendicular to the plate surface while maintaining the degree, so that the gap length is set to the predetermined value. 14. A vacuum container in which said pair of substrates is positioned inside at the time of said gap setting and said alignment, wherein said vacuum containers are superposed in a vacuum. 14. The apparatus for superimposing substrates according to any one of 13). 15. A displacement detection sensor for detecting a displacement of a positional relationship between a pair of substrates in a plate surface direction when performing the alignment, wherein the alignment moving means includes 2. The apparatus according to claim 1, wherein at least one of the pair of substrate holders is moved so as to correct the displacement according to the signal.
15. The apparatus for superimposing a substrate according to any one of claims 14 to 14.