JP3693136B2 - Method for overlaying liquid crystal panel and apparatus therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal panel superimposing method for superimposing two panel substrates constituting a liquid crystal display device used in, for example, a liquid crystal projector, and an apparatus therefor.
[0002]
[Prior art]
In recent years, with the spread of electronic devices with a liquid crystal display device typified by a liquid crystal projector and the like, the demand for higher performance of the liquid crystal display device has increased, and improvements for higher definition and higher brightness of the liquid crystal display device have progressed. are doing. This liquid crystal display device usually includes a substrate (hereinafter referred to as a drive substrate) on which a thin film transistor (hereinafter simply referred to as TFT), a storage capacitor, etc. formed on each pixel is formed, and a color filter (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 driving substrate and the counter substrate are bonded to each other after being overlapped (positioned) with an alignment mark as a reference by an overlapping device.
[0003]
In such a liquid crystal display device in which a color filter and a black matrix are formed on the counter substrate, it is necessary to precisely align the opening of the drive substrate and the functional portion of the counter substrate. In this case, when the color filter and the black matrix are formed on the counter substrate, alignment marks are also formed at the same time, and alignment is performed using the marks. By the way, as the aperture ratio decreases with the recent demand for smaller and higher-definition liquid crystal panels, a black matrix can be built on the drive substrate side, or a micro condensing lens (hereinafter simply referred to as “microlens”). (Abbreviated) is made in a counter substrate to improve brightness as a counter substrate integrated with a microlens. In such a configuration, only the microlens exists on the counter substrate side. Therefore, as a method of forming the alignment mark on the counter substrate side, a necessary mark is formed by using the lens shape when the microlens is formed. 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, sputtering method) after forming the microlens can be considered.
[0004]
[Problems to be solved by the invention]
However, in the method of forming a mark using the shape of the above-described microlens, there is a distance difference of several hundred microns between the mark on the counter substrate side and the mark on the driving substrate side. A special device (microscope) that can be viewed at the same time is necessary, and there was a problem with the visibility of the mark. On the other hand, in the method of forming a necessary mark using another means after forming the microlens, there is a possibility that a relative positional deviation occurs between the microlens and the microlens. There has been a problem that the positional deviation between the opening and the opening becomes large.
[0005]
The present invention has been made in view of such problems, and its object is to improve the overlay accuracy of two substrates such as a drive substrate and a microlens-integrated counter substrate and to automate the overlay. Another object of the present invention is to provide a liquid crystal panel superimposing method and an apparatus for the same.
[0006]
[Means for Solving the Problems]
The liquid crystal panel superimposing method according to the present invention includes a first substrate having a pixel portion composed of a plurality of pixels and having a first alignment mark as a reference for superimposing, and a pixel on the first substrate side. A plurality of micro condensing lenses corresponding to a portion and a second substrate provided with a second alignment mark serving as a reference for overlaying, with a predetermined gap. The shape of the second alignment mark is substantially hemispherical, and the shape of the first alignment mark is the same as the diameter of the spot light by the second alignment mark, while the maximum width of the central region is the same. width and narrower shape than the diameter of the spot light by the second alignment mark, to irradiate light toward the second alignment mark of the second substrate side Forming spot light having a shape related to the second alignment mark on the first alignment mark surface on the first substrate side, and the amount of light that passes through the first alignment mark or the first alignment mark The amount of light reflected from the first substrate is detected, and the relative positional relationship between the first substrate and the second substrate is adjusted according to the amount of light.
[0007]
The liquid crystal panel overlaying apparatus according to the present invention is configured to irradiate the second alignment mark from the light irradiating means for irradiating light toward the second alignment mark on the second substrate side. Spot forming means for collecting light and forming spot light having a shape related to the second alignment mark on the surface of the first alignment mark on the first substrate side, and spot light formed by the spot forming means Light quantity detection means for detecting the light quantity passing through the first alignment mark or the light quantity reflected by the first alignment mark, and according to the detection result of the light quantity detection means, the first substrate and the second substrate relative position and a substrate moving means for fine adjustment of the relationship, form a substantially hemispherical shape so as to have a light converging characteristic spot forming means by transparent material A second alignment mark that is, those shape of the spot light is circular corresponding to the planar shape of the second alignment mark.
[0008]
In the method for overlaying liquid crystal panels according to the present invention, when light is irradiated toward the second hemispherical second alignment mark on the second substrate side, the surface of the first alignment mark on the first substrate side. In addition, spot light having a shape related to the second alignment mark is formed. The first alignment mark has a shape in which the maximum width of the central region is the same as the diameter of the spot light by the second alignment mark and the width of the other region is narrower than the diameter of the spot light by the second alignment mark. In this spot light, 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 first substrate and the second substrate are relative to each other according to the amount of light. The positional relationship is adjusted.
[0009]
In the liquid crystal panel overlaying apparatus according to the present invention, light is irradiated by the light irradiation means toward the second alignment mark on the second substrate side. The light emitted from the light irradiating means to the second alignment mark is condensed by the spot forming means , that is, the second alignment mark formed in a substantially hemispherical shape so as to have a condensing characteristic by the transparent material. Circular spot light corresponding to the planar shape of the second alignment mark is formed on the surface of the first alignment mark on the first substrate side. Of the spot light formed by the spot forming means, the light quantity that has passed through the first alignment mark or the light quantity reflected by the first alignment mark is detected by the light quantity detection means, and according to the detection result of the light quantity detection means. Fine adjustment of the relative positional relationship between the first substrate and the second substrate is performed by the substrate moving means.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
FIGS. 1A to 1C show an example of the configuration of a liquid crystal display device 10 used in the liquid crystal panel overlapping method according to the present invention. These drawings show a part of the liquid crystal display device 10 including the display area 10A and a non-display area (guard ring portion) 10B provided around the display area 10A. The liquid crystal display device 10 includes a drive substrate 11 as a first substrate on which TFTs for controlling each pixel and the like are formed, and a counter substrate 12 as a second substrate on which microlenses and the like are formed. FIG. 4A is a view of the counter substrate 12 and FIG. 4B is a view of the drive substrate 11 as viewed from the upper surface side. The liquid crystal display after the drive substrate 11 and the counter substrate 12 are overlaid. FIG. 2C shows a state where the device 10 is viewed from the side.
[0012]
The counter substrate 12 is directly and integrally formed with a lens group consisting of a number of microlenses 14 for condensing light in the opening 13 in the display area 10A on the drive substrate 11 side, so-called on-chip type microlens. (OCL). Each microlens 14 has, for example, a hexagonal shape when viewed from above. A second alignment mark 15 having a light condensing function is formed at an arbitrary position in the display area 10B of the counter substrate 12. That is, the second alignment mark 15 is made of a transparent body having a predetermined refractive index, and in this embodiment, is the same material (for example, transparent resin) and shape (substantially hemispherical shape) as the microlens 14 on the display area 10A side. It is a so-called lens shape.
[0013]
The second alignment mark 15 is created simultaneously at the same time in the formation process of the microlens 14 in the display area 10A, and the second alignment mark 15 can be obtained without adding a new process to the conventional process. An alignment mark 15 can be formed. In addition, the second alignment mark 15 can be formed without shifting the relative position with respect to the microlens 14 by this method.
[0014]
On the other hand, the drive substrate 11 has a TFT portion (not shown) for controlling each pixel and an opening 13 for projecting an image in the display area 10A, and the drive substrate 11 side in the non-display area 10B. For example, a cross-shaped first alignment mark 16 corresponding to the second alignment mark 15 is provided. The first alignment mark 16 is formed in the same process 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.
[0015]
FIG. 2 shows a conceptual configuration of an overlaying apparatus 20 for overlaying the drive substrate 11 and the counter substrate 12 having such a configuration. That is, the overlay apparatus 20 according to the present embodiment includes a light irradiation unit 201 for irradiating light toward the second alignment mark 15 on the counter substrate 12 side, and a second alignment mark from the light irradiation unit 201. 15 is collected, and a shape related to the second alignment mark 15 is formed on the surface of the first alignment mark 16 on the drive substrate 11 side (in this embodiment, the second alignment mark 15 (microlens The spot forming means 202 for forming a spot light having a shape similar to the outer shape of), and the amount of light passing through the first alignment mark 15 among the spot lights formed by the spot forming means 202 or the first alignment mark 15 for detecting the amount of light reflected by the light source 15 and detection by the light amount detecting means 203 It is obtained by a substrate moving means 204 for fine adjustment of the relative positional relationship between the drive substrate 11 and the counter substrate 12 depending on the result.
[0016]
FIG. 3 shows a specific configuration of the superposition apparatus 20. The superimposing device 20 includes a driving substrate 11 placed on an XY-θ table 21 and a reflecting mirror 22a on the back surface above a counter substrate 12 fixedly disposed above and facing the driving substrate 11. A light source 22 is disposed, and a light receiving device 23 is disposed below the drive substrate 11 so as to face the light source 22. As the light receiving device 23, for example, a light receiving element that converts the amount of received light into an electrical signal is used. A control device 24 is connected to the light receiving device 23. The control device 24 receives the electrical signal output from the light receiving device 24 and calculates the amount of deviation between the first alignment mark 16 and the second alignment mark 15 (that is, the amount of deviation between the drive substrate 11 and the counter substrate 12). The XY-θ table 21 is driven according to the amount of deviation. The light source 22 is the light irradiation means 201 described above, the second alignment mark 15 (microlens) is the spot forming means 202, the light receiving device 23 is the light amount detecting means 203, and the XY-θ table 21 and the control device 24. Each of the substrate moving means 204 is configured.
[0017]
In the superimposing apparatus 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 16 is moved through the second alignment mark 15 of the light. The amount of light transmitted is detected by the light receiving device 23. The XY-θ table 21 is driven by the control device 24 in accordance with the amount of light received by the light receiving device 23, and the drive substrate 11 is moved, whereby the drive substrate 11 and the counter substrate 12 are overlapped.
[0018]
4 and 5 show the first alignment mark 16 and the second alignment mark 15 shown in FIG. 1 taken out and enlarged, respectively, and FIG. 6 shows a cross-sectional configuration when these marks 15 and 16 are overlapped. It represents. The light emitted from the light source 22 is collected by the lens effect of the microlens (second alignment mark 15) formed in the counter substrate 12, and on the surface of the first alignment mark 16 in the drive substrate 12, As shown in the planar state in FIG. 7, the spot light 18 has a predetermined size (φa). Of the spot light 18 formed on the surface of the first alignment mark 16, the light (region A) incident on a portion of the pattern of the first alignment mark 16 where there is no aluminum film (Al) passes through the drive substrate 11. However, the light (region B) incident on a part of the aluminum film (Al) cannot pass through the drive substrate 11.
[0019]
Here, in the present embodiment, as shown in FIG. 8, the amount of light that passes through the driving substrate 11 and is incident on the light receiving device 23 when there is no deviation in the overlapping of the driving substrate 11 and the counter substrate 112. Try to be the maximum. That is, the width b of each portion of the cross-shaped first alignment mark 16 is narrower 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). In addition, the width at the center of the first alignment mark 16 is the same as the diameter a of the spot light 18. The light that has passed through the first alignment mark 16 having such a configuration is received on the light receiving device 23 side 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. Thereby, precise alignment (superposition) of the liquid crystal panels (the driving substrate 11 and the counter substrate 12) is performed.
[0020]
As described above, in this embodiment, the driving substrate 11 and the counter substrate 12 are aligned with the first alignment mark 16 and the second alignment mark 15 as shown in FIG. In addition, each of the plurality of microlenses 14 on the counter substrate 12 side is accurately positioned on the corresponding opening 13 on the drive substrate 11 side. In the present embodiment, since 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 second alignment mark 15 is formed. 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 counter substrate 12 can be superimposed with higher accuracy.
[0021]
FIG. 9 and FIG. 10 each show a modification of the shape of the first alignment mark on the drive substrate 11 side according to the above embodiment, and each shows a state in which two marks overlap each other as viewed from above. 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 either case, the width b of each part of the first alignment mark 16 is narrower than the spot diameter a on the surface of the first alignment marks 31 and 32 by the second alignment mark 15 (a> b). The width at the center of the alignment mark 16 is the same as the spot diameter a, which is the same as in the above embodiment, and the operational effects thereof are also the same.
[0022]
Although the present invention has been described with reference to various embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made within the equivalent range. For example, in the above embodiment, the XY-θ table 21 is automatically driven while the received light amount is monitored by the control device 24. However, the operator manually checks the received light amount of the light receiving device 23. Then, the XY-θ table 21 may be driven. In this case, as the light receiving device 23, for example, a camera or a microscope can be used.
[0023]
Further, the negative / positive of the first alignment mark 16 on the drive substrate 11 side is reversed, and the light receiving device 23 is arranged on the counter substrate 12 side so that the reflected light from the first alignment mark 16 is received by the light receiving device 23. You may comprise. Needless to say, the shapes of the first alignment mark 16 and the second alignment mark 15 are not limited to those of the above-described embodiment, but may be other shapes.
[0024]
【The invention's effect】
As described above, according to the method for overlaying a liquid crystal panel and the apparatus therefor according to the present invention, the first alignment mark is irradiated by irradiating light toward the second hemispherical second alignment mark on the second substrate side. A spot light having a shape related to the second alignment mark is formed on the surface of the first alignment mark on the substrate side, and the spot light is reflected from the amount of light passing through the first alignment mark or from the first alignment mark. Since the relative positional relationship between the first substrate and the second substrate is adjusted according to the amount of light, the overlay accuracy of the two substrates is improved, and the pixel portion and the micro In addition to achieving alignment with the condenser lens, the aperture ratio and the lens condenser ratio can be improved, and the overlay can be automated. That.
[Brief description of the drawings]
1A and 1B show a schematic configuration example of a liquid crystal display device used in a liquid crystal panel overlaying method according to the present invention. FIG. 1A is a top view showing a counter substrate, and FIG. 1B shows a drive substrate. FIG. 4C is a side view showing a state in which the counter substrate and the driving substrate are overlaid.
FIG. 2 is a block configuration diagram for explaining a basic principle of a superposition apparatus according to an embodiment of the present invention.
FIG. 3 is a configuration diagram illustrating a specific example of the superimposing 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 showing a cross-sectional structure when the first alignment mark and the second alignment mark are overlaid.
FIG. 7 is a top view for explaining the state of the spot light collected by the second alignment mark on the surface of the first alignment mark.
FIG. 8 is a top view showing a state when a first alignment mark and a second alignment mark overlap each other.
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. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device, 11 ... Drive board | substrate (1st board | substrate), 12 ... Opposite board | substrate (2nd board | substrate), 13 ... Opening part, 14 ... Micro lens, 15 ... 2nd alignment mark, 16 ... 1st Alignment mark, 20 ... overlay device, 21 ... XY-θ table, 22 ... light source, 23 ... light receiving device, 24 ... control device

Claims (6)

A first substrate having a pixel portion composed of a plurality of pixels and formed with a first alignment mark serving as a reference for superposition, and a plurality of micro condensing lenses corresponding to the pixel portion on the first substrate side And a second substrate provided with a second alignment mark serving as a reference for overlaying, with a predetermined gap,
The shape of the second alignment mark is a substantially hemispherical shape, and the shape of the first alignment mark is the same as the diameter of the spot light by the second alignment mark, while the maximum width of the central region is the same. The width is narrower than the diameter of the spot light by the second alignment mark,
By irradiating light toward the second alignment mark on the second substrate side, spot light having a shape related to the second alignment mark is formed on the first alignment mark surface on the first substrate side. The amount of light that the spot light passes through the first alignment mark or the amount of light reflected from the first alignment mark is detected, and the relative positional relationship between the first substrate and the second substrate is determined according to the amount of light. A liquid crystal panel superimposing method characterized by adjusting.   2. 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. A method for overlaying the liquid crystal panel as described. How superposition of the liquid crystal panel according to claim 1, wherein the forming the second alignment mark by a transparent body of the same material as the micro-condenser lens. 4. The liquid crystal panel overlaying method according to claim 3, wherein the second alignment mark is formed in the same process as the micro condensing lens by using a transparent body made of the same material as the micro condensing lens. A first substrate having a pixel portion composed of a plurality of pixels and having a first alignment mark formed thereon is provided with a plurality of micro condensing lenses corresponding to the pixel portion on the first substrate side and superimposed. An overlaying device for overlaying a second substrate provided with a second alignment mark serving as a reference with a predetermined gap,
Light irradiation means for irradiating light toward the second alignment mark on the second substrate side;
A spot for condensing the light irradiated to the second alignment mark from the light irradiation means 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. Forming means;
A light amount detection means for detecting a light amount that has passed through the first alignment mark or a light amount reflected by the first alignment mark among the spot light formed by the spot forming means;
Substrate moving means for finely adjusting the relative positional relationship between the first substrate and the second substrate in accordance with the detection result of the light amount detecting means;
The spot forming means is a second alignment mark formed in a substantially hemispherical shape so as to have a condensing characteristic by a transparent material, and the shape of the spot light corresponds to the planar shape of the second alignment mark. A liquid crystal panel overlaying device characterized by being circular . Further, a control means for detecting a relative deviation amount between the first alignment mark and the second alignment mark based on the detection result of the light amount detection means and driving the substrate moving means according to the deviation amount. 6. The apparatus for superimposing a liquid crystal panel according to claim 5, further comprising:

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