JP4154981B2 - Substrate, manufacturing method thereof, and electro-optical device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate in a liquid crystal display panel and a manufacturing method thereof, and more particularly to a substrate manufactured by bonding a cover glass to a transparent substrate and a manufacturing method thereof.
[0002]
[Prior art]
As is well known, a liquid crystal panel such as a liquid crystal light valve is configured by sealing liquid crystal between two substrates made of a glass substrate, a quartz substrate, etc., and a thin film transistor (Thin Film Transistor, (Hereinafter referred to as TFT) are arranged in a matrix, a counter electrode is arranged on the other substrate, and the optical characteristics of the liquid crystal layer sealed between the two substrates are changed according to the image signal, thereby displaying an image. It is possible.
[0003]
In addition, the TFT substrate on which the TFT is disposed and the other substrate (hereinafter referred to as the counter substrate) disposed relative to the TFT substrate are manufactured separately, and both the substrates are highly accurate in the panel assembly process. After being bonded together, the liquid crystal is sealed.
[0004]
In this panel assembling process, first, when the TFT substrate and the counter substrate manufactured in the manufacturing process of each substrate are made to face each other, the opposing surface, that is, the counter substrate and the surface in contact with the liquid crystal layer of the TFT substrate are arranged. Then, an alignment film for aligning the liquid crystal molecules along the substrate surface is formed. This alignment film is formed, for example, by printing polyimide with a thickness of about several tens of nanometers. Thereafter, baking is performed, and a rubbing process is performed to determine the alignment of liquid crystal molecules when no voltage is applied. Next, a seal portion serving as an adhesive is formed on the edge of one substrate, and the TFT substrate and the counter substrate are bonded together using this seal portion, and are cured by pressure bonding while performing alignment, and then each manufactured TFT. A technique is used in which the substrate and the counter substrate are opposed to each other, and liquid crystal is sealed through a notch provided in a part of the seal portion.
[0005]
Here, the manufacturing method of the counter substrate will be further described. First, a concave curved surface portion for increasing the aperture ratio is provided by etching on the surface to be the pixel pattern of the transparent substrate made of glass, quartz or the like. Next, an uncured high-refractive resin is attached to the surface of the transparent substrate on which the concave curved surface portion is provided, and then cured to form a microlens. A cover glass of the same surface as the surface is bonded to the substrate surface, and then the surface of the cover glass is ground and polished to a predetermined thickness, and this ground and polished surface is exposed from the vicinity of the wiring. A light shielding film (hereinafter referred to as BM) is formed to prevent light leakage, and a transparent electrode (hereinafter referred to as ITO) for applying a voltage to the TFT substrate and the counter substrate is formed on the surface of the BM. Thus, a method for manufacturing the counter substrate is generally known. (For example, refer to Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-246599
[Problems to be solved by the invention]
However, in the conventional manufacturing method of such a counter substrate (hereinafter simply referred to as a substrate), the surface of the transparent substrate 100 provided with the concave curved surface portion 101 as shown in FIG. In the step of bonding the surfaces of the cover glass 120, since the surface of the cover glass 120 is formed to the same surface size as the surface of the transparent substrate 100, as shown in FIG. If the glass 120 is displaced and protrudes from the end surface of the transparent substrate 100, the edge 120a that protrudes from the cover glass 120 is shown in FIG. Chipping, cracking, and the like occur, resulting in a decrease in substrate manufacturing yield and product defects.
[0008]
The present invention has been made paying attention to the above-mentioned problems, and provides a substrate and a method for manufacturing the same that improve yield in manufacturing a substrate (counter substrate) used in an electro-optical device, and prevents product defects. With the goal.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a method of manufacturing a substrate according to the present invention includes a step of forming a plurality of hemispherical curved portions on the surface of a transparent substrate, a step of forming a resin layer on the surface of the transparent substrate, and a resin layer. A bonding step of bonding the cover glass to the transparent substrate as an adhesive, and a step of cutting the surface of the cover glass. The size of the cover glass is smaller than the surface of the transparent substrate. The glass is bonded so as not to protrude from the surface of the transparent substrate.
Further, the plurality of hemispherical curved surface portions are provided so as to be concave on the surface of the transparent substrate, and the resin layer having a refractive index different from that of the transparent substrate is filled in the plurality of curved surface portions in the bonding step. Thus, it is preferable to configure a plurality of microlenses.
Moreover, it is preferable to further include the process of forming a light shielding film on the surface of the cut cover glass, and the process of forming a transparent electrode in the upper layer of a light shielding film.
In order to achieve the above object, the substrate manufacturing method of the present invention includes a step of forming a plurality of hemispherical curved portions for each individual substrate on the surface of the transparent mother substrate, and a resin layer formed on the surface of the mother substrate. The size of the individual substrate, the step of bonding the large cover glass to the mother substrate using the resin layer as an adhesive, the step of cutting the surface of the large cover glass, and the mother substrate to which the large cover glass is bonded A large cover glass having a size smaller than the surface of the mother substrate, and in the bonding step, the large cover glass is bonded so as not to protrude from the surface of the mother substrate. And
[0010]
An electro-optical device according to the present invention includes a counter substrate made of the substrate manufactured by the manufacturing method described above, and an element substrate that sandwiches an electro-optical layer between the counter substrate. These pixels are provided, and each of the plurality of pixels is formed so as to overlap with a corresponding microlens.
[0011]
The substrate according to the present invention is a substrate formed by bonding a cover glass to a transparent substrate, and has a hemispherical curved surface on the surface of the transparent substrate, and thus has a surface smaller than the surface of the transparent substrate. The cover glass is bonded to the surface of the transparent substrate with a high refractive resin so as not to protrude from the surface of the substrate.
[0012]
Moreover, as one aspect of the substrate of the present invention, the cover glass is bonded to the transparent substrate to form a substrate, and then the surface is processed to have a predetermined thickness.
[0013]
According to this substrate, since the surface of the cover glass is made smaller than the surface of the transparent substrate, in the manufacturing process of the substrate in which the cover glass is bonded to the transparent substrate, the cover glass bites from the end surface of the transparent substrate. Since they can be bonded together without being taken out, it is possible to prevent the occurrence of product defects such as cracks and chips even if the cover glass is ground and polished to a predetermined thickness in the subsequent steps. Has an effect.
[0014]
Moreover, as one aspect of the substrate of the present invention, the cover glass protects the surface of the high refractive resin.
[0015]
Further, as one aspect of the substrate of the present invention, the cover glass is characterized in that the surface thereof is ground and polished to a predetermined thickness, and then a light shielding film and a transparent electrode are formed. To do.
[0016]
Furthermore, the high refractive resin functions as a microlens together with the hemispherical curved surface portion by changing the refractive index.
[0017]
According to this substrate, since the cover glass protects the surface of the high refractive resin, in the subsequent light shielding film and transparent electrode film forming process, a microlens is formed together with the hemispherical curved surface portion formed on the substrate. There is an effect that the surface of the functioning high refractive resin is not damaged.
[0018]
In one aspect of the substrate of the present invention, the surface of the hemispherical curved surface is an optical surface of the microlens.
[0019]
According to this substrate, since the surface of the hemispherical curved surface portion becomes the optical surface of the microlens, there is an effect that the light condensing property of the microlens composed of the high refractive resin can be enhanced.
[0020]
Moreover, as one aspect of the substrate of the present invention, the hemispherical curved surface portion is further located at a position corresponding to the curved surface portion provided on the transparent substrate, on the surface of the cover glass facing the transparent substrate. It is provided.
[0021]
According to this substrate, the condensing property of the substrate is further improved by providing the lens at a position corresponding to the hemispherical curved surface portion provided on the substrate on the surface of the cover glass facing the transparent substrate. Has the effect of being able to.
[0022]
Moreover, as one aspect of the substrate of the present invention, the hemispherical curved surface portion constitutes a microlens with at least the high refractive resin and the cover glass.
[0023]
According to this substrate, since the condensing property of the substrate can be improved by configuring the microlens on the substrate, the aperture ratio of the substrate can be increased.
[0024]
An electro-optical device according to the present invention includes a first substrate configured by the substrate according to any one of claims 1 to 9, and a plurality of electro-optical devices together with the first substrate arranged to face the first substrate. And a second substrate provided with a plurality of pixel electrodes constituting the pixel, and the electro-optical material sandwiched between the first substrate and the second substrate.
[0025]
According to this apparatus, it is possible to improve the product reliability of the electro-optical device by forming the first substrate used in the electro-optical device by bonding the cover glass smaller than the transparent substrate to the transparent substrate. It has the effect of being able to.
[0026]
The substrate manufacturing method according to the present invention is characterized in that, in the manufacturing process of a substrate formed by bonding a cover glass to a transparent substrate, the surface of the cover glass is made smaller than the surface of the transparent substrate.
[0027]
According to the substrate manufacturing method of the present invention, in the manufacturing process of the substrate in which the cover glass is bonded to the transparent substrate by making the surface of the cover glass smaller than the surface of the transparent substrate, the cover glass is the transparent substrate. Since it can be bonded together without protruding from the end face of this, there is an effect that there is no product defect.
[0028]
Further, as one aspect of the substrate manufacturing method of the present invention, a step of forming a hemispherical curved surface portion on the surface of the transparent substrate, and a highly refractive resin on the surface of the transparent substrate provided with the hemispherical curved surface portion are provided. A step of forming a microlens and a cover glass having a surface smaller than the surface of the transparent substrate on the surface of the transparent substrate on which the high-refractive resin is pasted via the high-refractive resin. And a step of bonding.
[0029]
Further, as one aspect of the substrate manufacturing method of the present invention, a step of forming a plurality of lenses corresponding to each pixel position in a plurality of element forming regions on the mother transparent substrate, and the lens of the mother transparent substrate A step of covering the plurality of element forming regions by bonding a cover glass having an area smaller than the surface area of the mother transparent substrate to the formation surface so as not to protrude from the mother transparent substrate, and the bonded cover After the surface processing of the glass, a step of cutting the bonded mother transparent substrate and the cover glass and cutting them out in units of the element forming regions is provided.
[0030]
According to the substrate manufacturing method of the present invention, in the step of attaching the cover glass to the mother transparent substrate via the high refractive resin, the surface of the cover glass is formed smaller than the surface of the transparent substrate. When bonding, the cover glass can be bonded without protruding from the end face of the transparent substrate. In the subsequent steps, the cover glass can be cracked even if it is ground and polished to a predetermined thickness. It is possible to prevent the occurrence of product defects such as chipping, and to improve the yield during manufacturing.
[0031]
Furthermore, a step of forming a plurality of lenses corresponding to each pixel position in one element formation region on the first transparent substrate, and a surface of the first transparent substrate on the lens formation surface of the first transparent substrate Bonding a second transparent substrate having an area smaller than the area so as not to protrude from the first transparent substrate, covering the element forming region, and bonding the surface of the second transparent substrate And a processing step.
[0032]
According to the substrate manufacturing method of the present invention, in the step of attaching the cover glass to the surface of the one element formation region of the first transparent substrate through the high refractive resin, the surface of the cover glass is more than the surface of the transparent substrate. Since the cover glass can be bonded without sticking out from the end face of the transparent substrate, the cover glass is ground to a predetermined thickness in the subsequent steps. Even if the polishing process is performed, it is possible to prevent the occurrence of product defects such as cracks and chips, and to improve the yield during manufacturing.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a longitudinal sectional view showing a configuration of an electro-optical device configured by two substrates.
As shown in FIG. 1, the electro-optical device 50 includes a second substrate (TFT substrate) 1, a first substrate (counter substrate) 2 disposed at a position facing the second substrate (TFT substrate) 1, the TFT substrate 1, and It is configured to include a seal portion 3 for joining both substrates at both ends of the counter substrate 2 and an electro-optic material 4 sealed between the substrates.
[0034]
The counter substrate 2 is formed of a transparent substrate 10 made of quartz or the like, a high refractive resin 14, and a cover glass 15. A surface of the transparent substrate 10 facing the electro-optic material 4 has a hemispherical concave shape. A predetermined number of curved surface portions 13 are formed, a high refractive resin 14 is formed on the surface of the transparent substrate 10 on which the concave curved surface portion 13 is formed, and a cover glass 15 is further pasted on the surface of the high refractive resin 14. BM 17 and ITO 18 are formed on the surface of the cover glass 15.
[0035]
On the surface of the TFT substrate 1 facing the electro-optic material 4, a pixel switching TFT 1a and a pixel electrode 1b on which scanning lines, data lines, and capacitor lines (not shown) are formed are formed.
[0036]
The first substrate 2 in the electro-optical device 50 configured as described above is manufactured by the manufacturing method of the present invention. Next, a substrate and a manufacturing method thereof according to an embodiment of the present invention will be described below with reference to the drawings.
[0037]
2 to 11 are partial longitudinal sectional views showing a method for manufacturing the substrate 2 shown in FIG. 1, and FIG. 7 is a plan view showing the transparent substrate manufacturing method according to the embodiment of the present invention. FIG. 8 is a partial vertical cross-sectional view showing a state before the cover glass is bonded to the surface of the substrate, and FIG. 8 is a partial vertical cross-sectional view showing the state after the cover glass is bonded to the surface of the transparent substrate of FIG. Further, FIG. 12 is a perspective view of FIG. 8 as viewed obliquely from the upper front right, and FIG. 13 is a perspective view showing a state in which the transparent substrate and cover glass of FIG.
[0038]
First, as shown in FIG. 2, a mask layer 11 is formed on the entire surface of a transparent substrate 10 which is a mother glass substrate of a substrate 2 made of quartz or the like. The transparent substrate 10 is a large substrate of 8 inches or more. The mask layer 11 is formed by using, for example, an existing CVD method, a sputtering method, or the like using various materials whose etching rate is sufficiently smaller than the material constituting the transparent substrate in the etching process of the transparent substrate 10.
[0039]
Next, as shown in FIG. 3, a prescribed number of pinholes 12 are formed on the mask 11 formed on the entire surface of the substrate 10 at any position in the element formation region where the pixel pattern of the substrate 10 is to be formed. . The pinhole 12 is formed by, for example, coating a resist layer made of a photoresist on the mask layer 11 by a known photolithography method, and exposing and developing the resist layer to partially form pores. It can be formed by performing dry etching through.
[0040]
Further, as shown in FIG. 4, the same number of hemispherical concave curved surface portions 13 as the pinholes 12 are formed on the substrate 10 by performing wet etching based on the pinholes 12. The surface of the hemispherical concave curved surface portion 13 becomes an optical surface of a microlens described later. Here, the wet etching is a method of performing etching by applying to a chemical solution. Here, since a hydrofluoric acid-based etching solution such as a mixed aqueous solution of hydrogen fluoride and nitric acid that is isotropic with respect to the substrate 10 is used, the substrate 10 can be cut into a hemisphere. In addition, since the etching target can be changed by changing the type of the chemical solution, the mask 11 is not cut by the wet etching that forms the hemispherical concave curved surface portion 13.
[0041]
Subsequently, as shown in FIG. 5, the mask 11 is removed by wet etching. Also here, for example, a mixed aqueous solution of hydrofluoric acid and ammonium fluoride is used for removing the mask, so that the substrate 10 is not cut. In this way, the substrate 10 on which a prescribed number of hemispherical concave curved surface portions 13 are formed is produced.
[0042]
Next, as shown in FIG. 6, an uncured high refractive resin 14 is pasted on the surface of the substrate 10 on which the hemispherical concave curved surface portion 13 is provided by a known method. Further, as shown in FIG. 7, a cover glass 15 for protecting the microlens 16 formed of the high refractive resin 14 is bonded to the surface on which the high refractive resin 14 is pasted via the high refractive resin 14. . The high refractive resin 14 serves as an adhesive, and bonds the substrate 10 and the cover glass 15 by curing. By this curing process, the high refractive resin 14 forms the microlens 16 together with the concave curved surface portion 13, and as a result, the condensing property of the substrate is improved and the aperture ratio by the substrate is improved.
[0043]
The cover glass 15 is a large flat plate manufactured by semiconductor manufacturing in the same manner as the substrate 10.
Here, as shown in FIG. 16 to FIG. 18 described above, when the surface of the cover glass to be bonded has the same area as the surface of the transparent substrate, when the two surfaces are bonded to face each other, There was a problem that the cover glass slipped and protruded from the end of the transparent substrate.
[0044]
Therefore, in the present invention, the surface of the cover glass 15 is formed smaller than the surface of the substrate 10 as shown in FIG. In this way, when the surface of the cover glass 15 is bonded to the surface of the substrate 10 via the high refractive resin 14, the cover glass 15 bites from the end of the substrate 10 as shown in FIG. I do not put out. What was bonded in this way is shown in FIG.
[0045]
Subsequently, as shown in FIG. 9, the cover glass 15 is cut and polished to a necessary thickness (for example, 100 μm or less) as the substrate 2 (see FIG. 1). At this time, as described above, since the cover glass 15 is bonded without protruding from the end portion of the substrate 10, even if the end portion of the cover glass 15 is cut and polished, chipping or cracking is caused. Etc. does not occur.
[0046]
Next, as shown in FIG. 11, BMs 17 are formed at intervals of the microlenses 16 on the surface opposite to the surface of the cover glass 15 bonded to the high refractive resin 14 by the existing method. 11, ITO 18 is formed on the surface of the BM 17 by an existing method. After that, as shown in FIG. 13, the substrate 2 having the microlenses 16 is manufactured by cutting the substrate 10 formed through these steps into a predetermined size (each element formation region 30). .
[0047]
As described above, in the substrate and the manufacturing method thereof according to the embodiment of the present invention, since the surface of the cover glass 15 is formed smaller than the surface of the transparent substrate 10, the cover glass 15 is transparent through the high refractive resin 14. When the cover glass 15 is bonded to the substrate 10, the cover glass 15 can be bonded without protruding from the end surface of the transparent substrate 10, so that the cover glass 15 is ground and polished in a later step, and chipped. Generation of cracks and the like can be prevented.
[0048]
FIG. 14 shows a modification of the present embodiment. The cover glass 25 is also formed on the hemispherical concave curved surface portion 23 formed on the transparent substrate 20 by the same method as the wet etching described above. A hemispherical concave curved surface portion 26 is formed by etching at an opposing position, and then the cover glass 25 is bonded to the transparent substrate 20 with the curved surface portion 23 etched through a high refractive resin 24, and the curved surface portion 23 is bonded. If the microlens 27 is formed by the high refractive resin 24 and the curved surface portion 26, the aperture ratio of the substrate can be further increased.
[0049]
Further, in the step of manufacturing the counter substrate by bonding the cover glass and the transparent substrate described above, a hemispherical concave curved surface portion is formed on the transparent substrate, but not limited thereto, a hemispherical concave curved surface portion is formed. You may apply to the said transparent substrate which does not form.
[0050]
In the above-described embodiment, the cover glass 15 that is slightly smaller than the surface of the transparent substrate 10 is bonded to the entire surface of the transparent substrate 10 that is the mother substrate of the substrate 2, and then cut out to a predetermined size to obtain the substrate 2. However, the present invention is not limited to this, and as shown in FIG. 15, the transparent substrate 10 and the cover glass 15 are cut into a predetermined size (each element formation region 30) in the first step, and then the above-described steps. Of course, the cover glass 15 cut out on the transparent substrate 10 may be bonded together.
[0051]
Furthermore, although the counter substrate facing the TFT substrate and the manufacturing method thereof have been described, the present invention is not limited to this, and the present invention may be applied to a substrate formed facing the TFD substrate.
[0052]
In addition, although it has been shown that the microlens is formed by at least the hemispherical concave curved surface portion formed on the transparent substrate and the cover glass and the high refractive resin, it is not limited to this, and at least the microlens is formed on the transparent substrate and the cover glass The hemispherical curved surface portion may constitute a microlens by the convex curved surface portion and the biconvex curved surface portion.
[0053]
Furthermore, although the above description is an example of a liquid crystal display device, the present invention can also be applied to an organic EL (electroluminescence) display device, an electrophoretic display device, or the like having a matrix configuration.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a configuration of an electro-optical device,
FIG. 2 is a longitudinal sectional view showing a state in which a mask is formed on the entire surface of a transparent substrate in the substrate manufacturing method;
FIG. 3 is a partial longitudinal sectional view showing a state where an opening is formed in the mask of FIG.
4 is a partial longitudinal sectional view showing a state in which a lens is formed on the transparent substrate of FIG.
5 is a partial longitudinal sectional view showing a state where the mask on the entire transparent substrate in FIG. 4 is removed;
6 is a partial longitudinal sectional view showing a state in which a high refractive resin is pasted on the transparent substrate surface of FIG.
7 is a partial longitudinal cross-sectional view showing a state before a cover glass is bonded to the transparent substrate surface of FIG. 6 in the substrate manufacturing method showing an embodiment of the present invention;
FIG. 8 is a partial longitudinal sectional view showing a state after a cover glass is bonded to the surface of the transparent substrate of FIG.
9 is a partial longitudinal sectional view showing a state where the cover glass bonded to the transparent substrate surface of FIG.
10 is a partially enlarged longitudinal sectional view showing a state in which BM is formed on the surface of the cover glass bonded to the transparent substrate surface of FIG.
11 is a partially enlarged longitudinal sectional view showing a state in which ITO is formed on the surface of the cover glass bonded to the transparent substrate surface of FIG. 10,
FIG. 12 is a perspective view of FIG.
13 is a perspective view showing a state in which the transparent substrate and the cover glass of FIG.
FIG. 14 is a partial longitudinal sectional view showing a modification of the substrate manufacturing method according to one embodiment of the present invention;
FIG. 15 is a perspective view showing a modification of the substrate manufacturing method according to the embodiment of the present invention;
FIG. 16 is a partial longitudinal sectional view showing a state before a cover glass is bonded to the surface of a transparent substrate in a conventional substrate manufacturing method;
FIG. 17 is a partial longitudinal sectional view showing a state after a cover glass is bonded to the surface of a transparent substrate in a conventional substrate manufacturing method;
FIG. 18 is a partial vertical cross-sectional view showing a state in which, after a cover glass is bonded to the surface of a transparent substrate, chipping, cracking, or the like occurs at the end in a conventional substrate manufacturing method.
[Explanation of symbols]
2 ... Substrate (opposite substrate)
10, 20, 100 ... transparent substrates 13, 23, 26, 101 ... curved surface portions 14, 24, 110 ... high refractive resins 15, 25, 120 ... cover glass 16, 27 ... micro lens 17 ... light shielding film (BM)

Claims (5)

Forming a plurality of hemispherical curved surfaces on the surface of the transparent substrate;
Forming a resin layer on the surface of the transparent substrate;
An adhesion step of adhering a cover glass to the transparent substrate using the resin layer as an adhesive;
Cutting the surface of the cover glass,
The size of the cover glass is smaller than the surface of the transparent substrate,
In the bonding step, the cover glass is bonded so as not to protrude from the surface of the transparent substrate . The plurality of hemispherical curved surface portions are provided so that each is concave on the surface of the transparent substrate,
2. The substrate according to claim 1, wherein in the bonding step, the resin layer having a refractive index different from that of the transparent substrate forms a plurality of microlenses by filling the plurality of curved surface portions. Production method. Forming a light-shielding film on the surface of the cut cover glass;
The method for manufacturing a substrate according to claim 1, further comprising a step of forming a transparent electrode on an upper layer of the light shielding film. Forming a plurality of hemispherical curved surfaces for each individual substrate on the surface of the transparent mother substrate;
Forming a resin layer on the surface of the mother substrate;
Adhesion step of adhering a large cover glass to the mother substrate using the resin layer as an adhesive;
Cutting the surface of the large cover glass;
Cutting the mother substrate to which the large format cover glass is bonded into the size of the individual substrate,
The size of the large format cover glass is provided smaller than the surface of the mother substrate,
In the bonding step, the large-sized cover glass is bonded so as not to protrude from the surface of the mother substrate. A counter substrate comprising a substrate manufactured by the manufacturing method according to claim 3;
  An element substrate that sandwiches an electro-optic layer between the counter substrate, and
  The element substrate is provided with a plurality of pixels,
  The electro-optical device, wherein each of the plurality of pixels is formed so as to overlap with the corresponding microlens.

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