JPH10123493A - Method for superposing liquid crystal panels and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for superposing liquid crystal panels which is capable of improving the superposition accuracy of two substrates (a driving substrate and a counter substrate of a type integrated with a microlens) and automating the superposition and a device therefor. SOLUTION: The light emitted from a light source 22 is condensed by the microlens (the second alignment mark) created into the counter substrate 12 and is made into spot light of a prescribed size on the surface of the first alignment mark in the driving substrate 11. Of such spot light, the incident light on the part where there is no pattern material (aluminum film) can pass the driving substrate 11 but the incident light on the part where the aluminum film exists cannot pass this part. The passed light is detected by a photodetector 23 and an X-Y-θ table 21 is driven by a controller 4 according to the received light quantity, by which the superposition of the driving substrate 11 and the counter substrate 12 is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of superposing a liquid crystal panel for superposing two panel substrates constituting a liquid crystal display device used for a liquid crystal projector or the like, and an apparatus therefor.

[0002]

2. Description of the Related Art In recent years, with the spread of electronic equipment having a liquid crystal display device such as a liquid crystal projector, demands for higher performance of the liquid crystal display device have increased, and the liquid crystal display device has been improved in definition and brightness. Improvements are in progress. This liquid crystal display device generally includes a substrate (hereinafter referred to as a driving substrate) on which a thin film transistor (hereinafter simply referred to as a TFT) for controlling each pixel, a storage capacitor, and the like are formed, and a color filter (a color liquid crystal panel). ) And a substrate on which a black matrix or the like is formed (hereinafter, referred to as a counter substrate). The drive substrate and the counter substrate are superimposed (positioned) on the basis of the alignment mark by a superposition device, and then bonded to each other.

In such a liquid crystal display device, when a color filter and a black matrix are formed on the opposite substrate, it is necessary to precisely align the opening of the drive substrate with the functional portion of the opposite substrate. In this case, when a color filter and a black matrix are formed on the opposing substrate, alignment marks are also formed at the same time, and alignment is performed using the marks. By the way, since the aperture ratio decreases with the recent demand for smaller and higher definition liquid crystal panels, a black matrix is formed on the drive substrate side, or a micro condenser lens (hereinafter simply referred to as a “micro lens”). (Abbreviated) in the counter substrate to improve the brightness as a micro lens integrated counter substrate. In such a configuration, since only the microlens exists on the counter substrate side, the method of forming the alignment mark on the counter substrate side is to form a necessary mark using the lens shape when forming the microlens. A method or a method of forming a necessary mark (for example, an aluminum film having a predetermined shape) by using another means (for example, a sputtering method) after forming the microlens can be considered.

[0004]

However, in the above-described method of forming a mark using the shape of a microlens, a distance difference of several hundred microns between the mark on the counter substrate side and the mark on the drive substrate side. Therefore, a special device (microscope) capable of simultaneously viewing two focal planes is required, and there is a problem in the visibility of the mark. on the other hand,
In the method of forming a necessary mark by using another means after forming the microlens, a relative displacement may occur between the microlens at the time of forming the mark, and as a result, the microlens and the opening may be formed. However, there has been a problem that the positional deviation between them has increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to improve the overlay accuracy of two substrates, such as a drive substrate and a counter substrate integrated with a microlens, and to improve the overlay accuracy. It is an object of the present invention to provide a method of overlaying liquid crystal panels and an apparatus therefor, which can also automate the operation.

[0006]

According to the present invention, there is provided a method of superposing a liquid crystal panel, comprising: a first substrate having a pixel portion including a plurality of pixels and having a first alignment mark formed thereon as a reference for superposition; A plurality of micro-condensing lenses are provided corresponding to the pixel portions on the first substrate side, and a second substrate provided with a second alignment mark serving as a reference for superposition is placed at a predetermined gap. And irradiating the second alignment mark on the second substrate side with light.
A spot light having a shape related to the second alignment mark is formed on the first alignment mark surface on the substrate side, and the spot light is reflected from the first alignment mark or the amount of light passing through the first alignment mark. The light amount is detected, and the relative positional relationship between the first substrate and the second substrate is adjusted according to the light amount.

A liquid crystal panel superposition apparatus according to the present invention comprises: a light irradiating means for irradiating light to a second alignment mark on a second substrate side; Spot forming means for converging the irradiated light to form spot light having a shape related to the second alignment mark on the surface of the first alignment mark on the first substrate side; Light amount detecting means for detecting the amount of light passing through the first alignment mark or the amount of light reflected by the first alignment mark in the spot light, and the first substrate and the second substrate in accordance with the detection result of the light amount detecting means. Substrate moving means for finely adjusting the relative positional relationship with the substrate.

In the method for overlaying liquid crystal panels according to the present invention, when light is irradiated toward the second alignment mark on the second substrate, the surface of the first alignment mark on the first substrate is placed on the surface of the first alignment mark on the first substrate. A spot light having a shape related to the second alignment mark is formed. The amount of light that has passed through the first alignment mark or the amount of light reflected from the first alignment mark is detected from the spot light, and the relative positional relationship between the first substrate and the second substrate is determined according to the amount of light. Adjusted.

In the liquid crystal panel superposition apparatus according to the present invention, light is irradiated toward the second alignment mark on the second substrate side by the light irradiation means. Light emitted from the light irradiating means to the second alignment mark is condensed by the spot forming means, so that a spot having a shape related to the second alignment mark is formed on the surface of the first alignment mark on the first substrate side. Light is formed. The light amount passing through the first alignment mark or the light amount reflected by the first alignment mark among the spot lights formed by the spot forming unit is detected by the light amount detecting unit, and the light amount is detected according to the detection result of the light amount detecting unit. Fine adjustment of the relative positional relationship between the first substrate and the second substrate is performed by the substrate moving means.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1A to 1C show an example of the configuration of a liquid crystal display device 10 used in a method of superposing liquid crystal panels according to the present invention. These figures show the display area 10A and the display area 1 of the liquid crystal display device 10.
It shows a partial area including a non-display area (guard ring portion) 10B provided around 0A. The liquid crystal display device 10 has a first TFT in which a TFT and the like for controlling each pixel are formed.
And a counter substrate 12 as a second substrate on which micro lenses and the like are formed. FIG. 2A is a view of the counter substrate 12 and FIG. 2B is a view of the drive substrate 11 as viewed from above, and the liquid crystal display after the drive substrate 11 and the counter substrate 12 are superimposed. FIG. 3C shows the state of the device 10 as viewed from the side.

On the opposite substrate 12, a lens group consisting of a number of microlenses 14 for condensing light on an opening 13 in a display area 10A on the side of the driving substrate 11 is formed directly and integrally, so-called on-chip. Type micro lens (OC
L). Each micro lens 14 has, for example, a hexagonal shape when viewed from above. An arbitrary position in the display area 10B of the counter substrate 12 has a second light condensing function.
Are formed. That is, the second alignment mark 15 is made of a transparent material having a predetermined refractive index, in this embodiment, the same material (for example, transparent resin) and shape (substantially hemispherical shape) as the microlens 14 on the display area 10A side. In a so-called lens shape.

The second alignment mark 15 is formed simultaneously and collectively in the process of forming the microlenses 14 in the display area 10A. With this method, a new process is not added to the conventional process. The second alignment mark 15 can be formed.
Further, by this method, the second alignment mark 15 can be formed without shifting the relative position with respect to the microlens 14.

On the other hand, the driving substrate 11 is provided with a display area 10A.
A TFT portion (not shown) for controlling each pixel and an opening 13 for projecting an image are provided therein, and a non-display area 10B corresponding to the second alignment mark 15 on the drive substrate 11 side. For example, a cross-shaped first alignment mark 16 is provided. The first alignment mark 16 is formed in the same step when the metal layer 17 such as Al (aluminum) or Ti (titanium) as a wiring material or a light shielding material is formed in the manufacturing process of the drive substrate 11, for example.

FIG. 2 shows a driving board 1 having such a structure.
1 illustrates a conceptual configuration of a superposition apparatus 20 for superposing a counter substrate 1 and a counter substrate 12. That is, the superposing apparatus 20 according to the present embodiment
Light irradiating means 201 for irradiating light toward the second alignment mark 15 on the side, and condensing light irradiated from the light irradiating means 201 onto the second alignment mark 15, and A spot for forming a spot light having a shape related to the second alignment mark 15 (in this embodiment, a shape similar to the outer shape of the second alignment mark 15 (microlens)) on the surface of the first alignment mark 16 Forming means 202; and a light amount detecting means 203 for detecting a light amount passing through the first alignment mark 15 or a light amount reflected by the first alignment mark 15 in the spot light formed by the spot forming means 202. , This light amount detecting means 203
Moving means 20 for finely adjusting the relative positional relationship between drive substrate 11 and counter substrate 12 according to the detection result of
4 is provided.

FIG. 3 shows a specific configuration of the superposing apparatus 20. This superimposing device 20 has X
A drive board 11 placed on a -Y-θ table 21;
A light source 22 having a reflecting mirror 22a on the back is disposed above the counter substrate 12 fixed and disposed above and opposed thereto, and a light receiving device 23 is disposed below the driving substrate 11 so as to face the light source 22. It is arranged. As the light receiving device 23, for example, a light receiving element that converts a received light amount into an electric signal is used. The control device 24 is connected to the light receiving device 23. The control device 24 receives the electric signal output from the light receiving device 24 and receives the first alignment mark 16 and the second alignment mark 16.
Of the alignment mark 15 (that is, the amount of displacement between the driving substrate 11 and the counter substrate 12), and drives the XY-θ table 21 according to the amount of deviation. In addition, the light source 22 is the light irradiation unit 201 described above,
The second alignment mark 15 (microlens) is the spot forming means 202 and the light receiving device 23 is the light quantity detecting means 2
03, the XY-θ table 21 and the control device 24
Constitute the substrate moving means 204, respectively.

In the superposing device 20, light is emitted from the light source 22 toward the second alignment mark 15 and the first alignment mark 16, and the first alignment mark 15 of the light is irradiated through the second alignment mark 15. The amount of light transmitted through the mark 16 is detected by the light receiving device 23. According to the amount of light received by the light receiving device 23, X
The -Y-θ table 21 is driven, and the drive substrate 11 moves, whereby the drive substrate 11 and the counter substrate 12 are overlapped.

FIGS. 4 and 5 show the first alignment mark 16 and the second alignment mark 15 shown in FIG. 1 taken out and enlarged, respectively.
Represents the cross-sectional configuration of the marks 15 and 16 when they are superimposed. The light emitted from the light source 22 is transmitted to the opposite substrate 1.
The light is condensed by the lens effect of the microlenses (second alignment marks 15) formed in the substrate 2, and on the surface of the first alignment marks 16 in the drive substrate 12, as shown in a planar state in FIG. The spot light 18 has a predetermined size (φa). This first alignment mark 1
6 of the spot light 18 formed on the surface of the aluminum film (A) of the pattern of the first alignment mark 16.
The light (region A) incident on the part without l) is
However, light (region B) incident on a portion of the aluminum film (Al) cannot pass through the drive substrate 11.

Here, in this embodiment, as shown in FIG. 8, when there is no shift in the superposition of the driving substrate 11 and the counter substrate 112, the light passing through the driving substrate 11 and entering the light receiving device 23 Is to be maximized. That is,
The width b of each part of the first alignment mark 16 having a cross shape
Is smaller than the diameter a of the spot light 18 on the surface of the first alignment mark 16 by the second alignment mark 15 (a> b), and the width at the center of the first alignment mark 16 is the spot. Diameter a of light 18
It is the same size as. The light passing through the first alignment mark 16 having such a configuration is received by the light receiving device 23 as described above. The control device 24 monitors the amount of light received by the light receiving device 23 and drives the XY-θ table 21 to move the drive substrate 11 so that the amount of light is maximized. As a result, the liquid crystal panels (the drive substrate 11 and the opposing substrate 12) are precisely aligned (overlaid).

As described above, in the present embodiment, the driving substrate 1
As shown in FIG. 1C, a plurality of microlenses on the counter substrate 12 side are aligned with each other by superposing the first alignment mark 16 and the second alignment mark 15 on the counter substrate 12. 14 will be accurately positioned on the corresponding opening 13 on the drive substrate 11 side. Further, in the present embodiment, the second alignment mark 15 on the counter substrate 12 side is formed integrally with the counter substrate 12 in the same process as the micro lens 14 on the display area 10A side. The mark 15 can be formed without adding a new process to the conventional process, and can be formed without shifting the relative position with respect to the microlens 14. Therefore, the driving substrate 11 and the opposing substrate 12 can be superimposed more accurately.

FIGS. 9 and 10 each show a modification of the shape of the first alignment mark on the side of the drive substrate 11 according to the above-described embodiment. FIG. 9 and FIG. It is. Here, the first alignment mark 15 on the counter substrate 12 side is the same as in the above embodiment. The first alignment mark 31 in FIG. 9 has an L shape, and the first alignment mark 32 in FIG. 10 has a radial shape. In each case, the width b of each part of the first alignment mark 16 is equal to the first alignment marks 31 and 32 by the second alignment mark 15.
Smaller than the spot diameter a on the surface of (a> b), and
The fact that the width at the center of the first alignment mark 16 is the same as the spot diameter a is the same as in the above embodiment, and the operation and effect are also the same.

Although the present invention has been described with reference to various embodiments, the present invention is not limited to the above-described embodiments, and can be variously modified within an equivalent range. For example, in the above-described embodiment, the XY-θ table 21 is automatically driven while the control device 24 monitors the amount of received light. May drive the XY-θ table 21. In this case, for example, a camera or a microscope can be used as the light receiving device 23.

In addition, the negative / positive of the first alignment mark 16 on the driving substrate 11 is reversed, and the light receiving device 23 is disposed on the counter substrate 12, and the light reflected from the first alignment mark 16 is reflected by the light receiving device 23. It may be configured to receive light. In addition, the shapes of the first alignment mark 16 and the second alignment mark 15 are not limited to those in the above-described embodiment, but may be other shapes.

[0024]

As described above, according to the method and apparatus for superposing liquid crystal panels of the present invention,
By irradiating light toward the second alignment mark on the substrate side of the first substrate, a spot light having a shape related to the second alignment mark is formed on the surface of the first alignment mark on the first substrate side. Detecting the amount of spot light passing through the first alignment mark or the amount of light reflected from the first alignment mark, and adjusting the relative positional relationship between the first substrate and the second substrate according to the amount of light Therefore, the overlay accuracy of the two substrates is improved, the pixel unit and the micro condenser lens are matched, the aperture ratio and the lens condenser ratio can be improved, and This has the effect that automation can be achieved.

[Brief description of the drawings]

FIGS. 1A and 1B show a schematic configuration example of a liquid crystal display device used for a method of superposing liquid crystal panels according to the present invention, wherein FIG. 1A is a top view showing a counter substrate, and FIG. FIG. 3C is a side view showing a state in which the opposing substrate and the driving substrate are overlaid.

FIG. 2 is a block diagram for explaining the basic principle of the superposing apparatus according to one embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating a specific example of the superposition apparatus in FIG. 2;

FIG. 4 is a plan view illustrating an example of a second alignment mark on the counter substrate side.

FIG. 5 is a plan view illustrating an example of a first alignment mark on a driving substrate side.

FIG. 6 is a configuration diagram illustrating a cross-sectional structure when a first alignment mark and a second alignment mark are superimposed.

FIG. 7 is a top view for explaining the state of the spot light condensed by the second alignment mark on the surface of the first alignment mark.

FIG. 8 is a top view illustrating a state where a first alignment mark and a second alignment mark overlap each other.

FIG. 9 is a top view for explaining a modification of the second alignment mark of the embodiment shown in FIGS. 1 and 5;

FIG. 10 is a top view for explaining another modification of the second alignment mark of the embodiment shown in FIGS. 1 and 5;

[Explanation of symbols]

10: liquid crystal display device, 11: drive substrate (first substrate),
12 ... counter substrate (second substrate), 13 ... opening, 14 ...
Microlens, 15 second alignment mark, 1
6: first alignment mark, 20: superposition device, 21: XY-θ table, 22: light source, 23: light receiving device, 24: control device.

Claims (8)

[Claims] A first substrate having a pixel portion composed of a plurality of pixels and having a first alignment mark serving as a reference for superposition formed thereon, and a plurality of pixels corresponding to the pixel portion on the first substrate side. A second substrate provided with a micro-condenser lens and a second alignment mark serving as a reference for superposition, the second substrate being superimposed at a predetermined gap, wherein the second substrate By irradiating light toward the second alignment mark on the side, a spot light having a shape related to the second alignment mark is formed on the first alignment mark surface on the first substrate side, and the spot light is The amount of light passing through the first alignment mark or the amount of light reflected from the first alignment mark is detected, and the relative position between the first substrate and the second substrate is determined according to the amount of light. How superposition liquid crystal panel and adjusting a relationship. 2. The method according to claim 1, wherein the positional relationship between the first substrate and the second substrate is adjusted so that the amount of light transmitted through the first alignment mark or reflected from the first alignment mark is maximized. The method for superimposing liquid crystal panels according to claim 1, wherein 3. The shape of the second alignment mark is substantially hemispherical, and the shape of the first alignment mark is
The maximum width of the central area is the same as the diameter of the spot light by the second alignment mark, and the width of the other areas is smaller than the diameter of the spot light by the second alignment mark. Item 3. A method for superposing liquid crystal panels according to Item 2. 4. The method according to claim 3, wherein the second alignment mark is formed of a transparent material of the same material as the micro condenser lens. 5. The method according to claim 4, wherein the second alignment mark is formed of a transparent material of the same material as the micro condenser lens in the same step as the micro condenser lens. 6. A first substrate having a pixel portion composed of a plurality of pixels and having a second alignment mark formed thereon, and a plurality of micro condenser lenses corresponding to the pixel portion on the first substrate side. A superimposing apparatus for superposing a second substrate provided with a second alignment mark serving as a superimposition reference at a predetermined gap, comprising: Light irradiating means for irradiating light toward the alignment mark, and condensing light irradiated from the light irradiating means onto the second alignment mark, and the surface of the first alignment mark on the first substrate side Forming a spot light having a shape related to the second alignment mark, and passing the first alignment mark out of the spot light formed by the spot forming means. Amount of light or first
Light amount detecting means for detecting the amount of light reflected by the alignment mark; and fine adjustment of the relative positional relationship between the first substrate and the second substrate in accordance with the detection result of the light amount detecting means. What is claimed is: 1. An apparatus for superposing liquid crystal panels, comprising: substrate moving means. 7. A spot forming means which is formed in a substantially hemispherical shape by a transparent material so as to have a light collecting characteristic.
Alignment mark, and the shape of the spot light is
7. The apparatus according to claim 6, wherein the alignment mark has a circular shape corresponding to the planar shape of the alignment mark. 8. A relative displacement amount between the first alignment mark and the second alignment mark is detected based on a detection result of the light amount detection unit, and the substrate moving unit is driven according to the displacement amount. 8. A liquid crystal panel superposition apparatus according to claim 7, further comprising control means for performing the operation.