JPH1048621A - Color filter, liquid crystal display device using it and black matrix photosensitive material used for production of the color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily give a projecting part having a gap controlling function to a color filter by using a spacer material of a uniform shape dispersed in a black matrix photosensitive material to form projections. SOLUTION: The color filter essentially consists of a transparent substrate 2, black matrix layer 5 formed on the substrate 2, color layer 3 which constitutes pixels, and transparent conductive film layer 4 on the color layer, and if necessary, the filter has an overcoat layer. The black matrix layer is formed in a hatched part in the figure and in the area outside of the frame shown as a dashed line inside of the color layer 3. In this case, a spacer member which is used as a projecting part 7 to control the gap is preliminarily dispersed in the black matrix photosensitive material so that the projecting part 7 as an alternative of a spacer is formed only in the area where the black matrix layer is formed, but no projecting part is formed in the area where only a color layer is formed. It is preferable that the spacer material used in the black matrix photosensitive material has a uniform shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device represented by a personal computer, and more particularly to a color filter characterized by forming a projection for controlling a gap between the color filter and a counter substrate, and using the color filter. The present invention relates to a liquid crystal display device and a black matrix light-sensitive material used for manufacturing a color filter.

[0002]

2. Description of the Related Art In a liquid crystal display device, as shown in FIG. 5, a color filter substrate 1 and a counter substrate 10 are arranged so as to face the color filter substrate 1, and a liquid crystal material 15 is sealed between them. The liquid crystal performs a shutter function of a light source from a backlight with a voltage applied between the two substrates. Since the liquid crystal is thus sandwiched between the two substrates, if the gap (interval) between the color filter substrate and the opposing substrate is not uniform, the above-described shutter function does not work sufficiently, and the display is not performed. Causes unevenness. From these points, in order to keep the gap formed between the color filter substrate and the opposing substrate uniform, spherical plastic particles usually called spacers 8 or fiber-like silica particles are dispersed as a gap control powder on one substrate. A process is taking place.
These particles need to have a uniform shape, and those having a size of 1.5 to 8.0 μm are often used depending on the thickness of the liquid crystal.

[0003]

However, since the spacer is a powder as described above, it is easy to form an agglomerate, and if this agglomeration occurs in the cell thickness direction in the spraying process, the gap amount at that portion changes. In the same way as the semiconductor manufacturing process, the LCD manufacturing process must be provided in a clean room, but must be provided with a process that causes dust generation, such as “spraying powder”, and “spraying”.
In this process, the spacers are scattered over the entire surface of the substrate, and there is no distinction between the colored pixel portion and the black matrix portion. Invite
There is a problem. From these points, a color filter having a gap control function similar to that of the spacer has been required by omitting the spacer dispersing step for lowering the yield, preventing the scattering of the spacer particles to the colored pixel portion, and the like.

Accordingly, the present invention has been made to provide a color filter and a liquid crystal display device using the same, which solve the above-mentioned problems, and disperse a spacer material in a black matrix photosensitive material in advance. Then, they came up with the idea of manufacturing a color filter using the light-sensitive material, and forming a projection part that functions as a substitute for the spacer.

[0005]

An embodiment of the color filter according to the present invention is a color filter having a projection for controlling a gap with an opposing substrate, wherein the projection is dispersed in a black matrix photosensitive material. A color filter formed of a spacer material having a uniform shape. In this color filter, since the protrusion for controlling the gap is formed only in the black matrix portion, it is possible to solve the problem that the colored pixel portion is affected by light scattering or the contrast is reduced.

An embodiment of the liquid crystal display device according to the present invention is directed to a color filter in which a projection for controlling a gap with the counter substrate is formed of a spacer material having a uniform shape dispersed in a black matrix photosensitive material, and a counter substrate. The liquid crystal display device is characterized in that a liquid crystal is filled in a gap formed by bringing the projection into contact with the projection as an inner side.
In this liquid crystal display device, since the projection for controlling the gap with the counter substrate is formed only in the black matrix portion, light scattering of the screen by the spacer does not occur, and the contrast does not decrease.

An embodiment of the black matrix light-sensitive material for a color filter according to the present invention is a black matrix light-sensitive material for a color filter, wherein a black pigment and fine spherical particles having a uniform diameter are dispersed in a photosensitive resin. ,It is in.
Since such a black matrix photosensitive material is used, it is possible to form a highly accurate gap control projection on the black matrix portion of the color filter.

[0008]

FIG. 1 is a schematic diagram showing an example of the color filter of the present invention. FIG. 1A is a plan view thereof, and FIG. 1B is a cross-sectional view taken along line 1-1 of FIG. 1A. As shown in FIG. 1, a color filter substrate according to the present invention includes a black matrix layer 5 formed on a transparent substrate 2, a colored layer 3 (R, G,
B) and a transparent conductive film layer 4 on the colored layer as a basic structure, and if necessary, an overcoat layer (FIG. 1).
In the figure, the overcoat layer is omitted. ). The black matrix layer includes a hatched portion in FIG.
And is formed outside the frame indicated by the dotted line inside. Accordingly, the black matrix layer 5 and the coloring layer 3 are formed in two layers outside of the frame of the dotted layer in the portion of the coloring layer 3.

In the present invention, since the spacer material serving as the projection 7 for controlling the gap is dispersed in the black matrix photosensitive material in advance, only the region where the black matrix layer exists serves as a substitute for the spacer. A projection is formed, and no projection is formed in a portion of only the coloring layer. In FIG. 1A, the black matrix layer is covered with a hatched portion between the colored layers 3 and between the colored layers and the colored layer, but is surrounded by a region where the black matrix layer exists, that is, surrounded by a dotted line. The protrusions appear in those regions because they are present outside the colored layer.

The height of the projection 7 is 5 μm from the surface of the pixel.
m or less is desirable. This is to make the thickness correspond to the thickness of a normal liquid crystal layer. For flatness, an accuracy of 0.3 μm or less is required. Further, it is preferable to form one or more protrusions 7 in one pixel. The reason is that the force applied to the opposing substrate surface is dispersed evenly. Further, from the viewpoint of maintaining an appropriate intensity, it is more preferable that two or three pixels exist in one pixel. In order to keep the number of projections at an appropriate number, when adjusting the black matrix photosensitive material, it is necessary to consider dispersing an appropriate amount of spacer material calculated from the particle diameter of the spacer material and its specific gravity. It does not involve difficulties. It is desirable to use a spacer material in which the spacer itself is colored black. This is to emphasize the light shielding properties of the black matrix. Therefore, in the case of a normal transparent spacer, it is preferable to sufficiently stir the black matrix colored photosensitive material and the spacer so that the black photosensitive material covers the spacer surface.

Various spacer materials can be used for the black matrix light-sensitive material of the present invention. Fiber-like or spherical ones can be used, but preferably have a uniform shape. Spherical ones include spacers of plastic, silica and metal particles. As described above, those having a diameter of 1.5 to 8.0 μm are often used depending on the thickness of the liquid crystal.

FIG. 2 is a diagram showing a method of manufacturing a color filter according to the present invention. In particular, a portion where the black matrix layer and the coloring layer are formed so as to overlap with each other is shown. In the present invention, the black matrix layer 5 and the projection 7
It is formed by a normal process (photolithography process). That is, first, as shown in FIG. 1A, a black photosensitive material that has been adjusted in advance to a predetermined thickness is formed on a transparent substrate 2 by means such as a spin coater or a roll coater. Drying is performed to leave a required portion of the black matrix pattern (FIG. 2A). Since the spacer material is dispersed in the black light-sensitive material, the projection 7 is inevitably formed. Next, the R, G, and B colored layers 3 are repeated by repeating the normal process to form a portion to be a predetermined colored pixel. However, when the colored layer 3 is formed on the protrusion of the black matrix layer, FIG.
As shown in (B), the colored layer has an uneven shape. If the transparent conductive film 4 is formed by sputtering after forming the colored layer, the spacers are fixed and the color filter substrate is completed (FIG. 2C).

FIG. 3 is a diagram showing a typical pattern of a colored layer constituting a color filter substrate. The color filter of the present invention is applicable to any pattern ((A) mosaic type, B) Stripe type,
(C) triangle type and (D) four-pixel arrangement type). Hereinafter, the embodiment will be described using a stripe type represented by a laptop personal computer.

[0014]

【Example】

(Example) (1) Adjustment of photosensitive material Transparent substrate (Corning “7059 glass”) 300
× 400 mm and a thickness of 1.1 mm were placed on an electronic balance, and the weight was measured. Next, on this transparent substrate, a black photosensitive material (“Color Mosaic CK-S171” manufactured by Fuji Hunt Co., Ltd.) was rotated at 1,000 rpm using a spin coater.
Immediately after coating, the sample was placed on an electronic balance and its weight was measured. This step was repeated five times, and the average value of the weight difference was defined as the coating weight. The measured values of the weight and the film thickness were 0.5 g and 1.28 μm as shown in Table 1.

[0015]

[Table 1]

Next, the weight per one piece was calculated from the specific gravity and the particle diameter (7 μm) of a spacer material (“Micropearl SPN-207” manufactured by Sekisui Fine Chemical Co., Ltd.) which is usually commercially available as polymer fine particles. calculating the weight to be 100 per 1mm ^2, 300 × 400mm
The weight required for the substrate was calculated. <Calculation method> The specific gravity of Micropearl SPN-207 is 1.
In No. 19, the average particle diameter is 7 μm. Assuming that the micropearl is a true sphere, volume = (4/3) · π · r ³ = 1.436 x 10 ^-9 cm
³ The weight per micropearl is: 1.436 × 10 ⁻⁹ × 1.19 = 1.71 × 10
^-9 g. Here, 1 mm
^In order for micropearls to be distributed at a ratio of 100 per ² , 300 × 400 × 100 × 1.71 × 10 ⁻⁹ g = 2.0
It is necessary that 5 × 10 ⁻² g of micropearls be contained in the black light-sensitive material having a coating weight of 0.5 g, and the following light-sensitive material adjustment is made based on this calculation.

From these results, the photographic materials were adjusted as follows. Black Sensitive Material 1000g (Color Mosaic CK-S17 manufactured by Fuji Hunt Co., Ltd.
1)) Fine polymer particles 41 g (“Micropearl SP” manufactured by Sekisui Fine Chemical Co., Ltd.)
N-207 ") 1000 g of the black light-sensitive material was weighed into a beaker, and the polymer fine particles were added little by little to the above amount while stirring with a stirrer. After the addition was completed, stirring was further continued for 30 minutes with a stirrer.

(2) Preparation of Black Matrix After applying a black photosensitive material adjusted at a rotation speed of 1500 rpm to a transparent substrate (“7059 glass” manufactured by Corning) having a size of 300 × 400 mm and a thickness of 1.1 mm using a spin coater. And dried in a clean oven at 100 ° C. for 10 minutes. The film thickness after prebaking was 1.1 μm.

Next, an ultraviolet ray having a wavelength of 405 nm was irradiated at an irradiation amount of 400 mj / cm ² using an ultra-high pressure mercury lamp through a photomask for black matrix. Thereafter, the substrate was placed in a 1 wt% aqueous solution of sodium carbonate at room temperature for 2 hours.
After immersion for 1 minute, followed by shower rinsing with ultrapure water for 1 minute to remove the unexposed portions of the photosensitive material, followed by air drying. Then, it was dried in a clean oven at 200 ° C. for 30 minutes to form a black matrix pattern. In the black matrix pattern, two to three projections were formed on one pixel on average. In addition, when the portion having the protrusion and the portion not having the protrusion of the black matrix pattern were measured with a stylus type film thickness meter (“Alpha Step 300” manufactured by Tencor Corporation), the portion having the protrusion was the height from the glass surface. Was 7 μm, and the portion not having it was 1 μm.

(3) Preparation of Color Filter Using the above black matrix substrate, an R colored sensitizing material was applied to form an R color filter layer. In the application condition of the coloring photosensitive material, the number of rotations of the spin coater was set to 100.
It was set to 0 rpm. The mask pattern used was an R-colored stripe mask, and the other conditions were the same as in the preparation of the black matrix. continue,
Pattern formation was performed for the G and B photosensitive materials in the same manner as for R. The thickness of each colored layer was 2 μm. The colored light-sensitive material is a light-sensitive material manufactured by Fuji Hunt Co., Ltd. and includes a red light-sensitive material "Color Mosaic CR-7000", a green light-sensitive material "Color Mosaic CG-7000", and a blue light-sensitive material "Color Mosaic CB-7000". It was used.

The film thickness of the R stripe pattern riding on the black matrix pattern was measured with a stylus type film thickness meter ("Alpha Step 300" manufactured by Tencor Corporation) (along the dotted line m in FIG. 1A). By moving the measuring needle), the portion having the protrusion was 4.5 μm from the surface of the colored layer in the portion without the black matrix layer.
This is slightly leveled by the colored sensible material, and the total height of the protrusions is 6.5 μm. In addition,
The height of the projections can be controlled by the diameter of the polymer fine particles dispersed in the black light-sensitive material. Thereafter, a transparent conductive film (ITO) is formed to a thickness of 0.15 μm by a sputtering method,
A color filter substrate was manufactured.

(Comparative Example) A color filter substrate was produced in exactly the same manner as in the example except that polymer fine particles were not dispersed in the black light-sensitive material.

(Embodiment relating to liquid crystal display device) A liquid crystal display device 10 was assembled as shown in FIG. 4 using the liquid crystal color filters obtained in the above embodiments. First, a transparent conductive film layer 4 (ITO) is formed to a thickness of 0.15 μm on a transparent substrate by a sputtering method, and a polyimide-based alignment film (not shown) is applied thereon via an insulating layer 12. An orientation treatment was performed to form a counter substrate 11. Similarly, a polyimide-based alignment film (not shown) is applied to the color filter side and subjected to an alignment treatment, and then the opposing substrate 11 and the color filter 1 are pressure-bonded so that the projection 7 of the color filter contacts the opposing substrate. The periphery was sealed with a sealant 13 except for a liquid crystal introduction part. Finally, a liquid crystal 15 was filled in a gap formed between the color filter and the counter substrate and sealed, thereby completing a liquid crystal display device.

(Comparative Example Related to Liquid Crystal Display Device) With respect to the color filter manufactured in the comparative example, after a spacer material (“Micropearl SPN-207” manufactured by Sekisui Sine Chemical Co., Ltd.) was sprayed on the color filter substrate. A liquid crystal display device was assembled in the same manner as in the example.

Function tests were performed on the liquid crystal display devices of the completed example and the comparative example. As a result, the liquid crystal display device of the example maintained an accurate constant distance between the opposing substrate and the color filter, and reduced the light scattering of the image display portion. Good results were obtained without being seen.

[0026]

According to the present invention, it is possible to add a projection having a gap control function to a color filter without having to change a mask pattern or to provide a special step, thereby providing the same function as a conventional spacer. Can be provided. Therefore, the spacer dispersing step in the LCD manufacturing process can be omitted, which can contribute to maintaining the environment of the clean room. In addition, since the protrusion serving as a spacer is formed only in the region where the black matrix exists and is not formed in the display pixel portion, there is a remarkable effect that light scattering and a decrease in contrast due to the spacer do not occur.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of a color filter of the present invention.

FIG. 2 is a view illustrating a process of manufacturing the color filter of the present invention.

FIG. 3 is a view showing a typical pattern of a coloring layer constituting a color filter substrate.

FIG. 4 is a diagram showing a liquid crystal display device of the present invention.

FIG. 5 is a diagram showing a conventional liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 1 color filter for liquid crystal 2 transparent substrate 3 colored layer 4 transparent conductive film layer 5 black matrix layer 6 overcoat layer 7 protrusion 8 spacer 10 liquid crystal display device 11 counter substrate 12 insulating layer 13 sealant 15 liquid crystal

Claims (7)

[Claims] 1. A color filter having a projection for controlling a gap with a counter substrate, wherein the projection is formed of a spacer material having a uniform shape dispersed in a black matrix photosensitive material. Color filter to be used. 2. The color filter according to claim 1, wherein the spacer material is a spherical plastic fine particle having a uniform diameter. 3. The color filter according to claim 1, wherein the spacer material is plastic fine particles colored black. 4. A color filter made of a uniform-shaped spacer material dispersed in a black matrix photosensitive material and a projection for controlling a gap with the counter substrate are brought into contact with the counter substrate with the projection being on the inside. A liquid crystal display device, wherein a liquid crystal is filled in a gap formed by the liquid crystal display. 5. The liquid crystal display device according to claim 4, wherein the spacer material is a spherical plastic fine particle having a uniform diameter. 6. A black matrix light-sensitive material for a color filter, wherein a black pigment and fine spherical particles having a uniform diameter are dispersed in a photosensitive resin. 7. The black matrix light-sensitive material for a color filter according to claim 6, wherein the fine particles are made of plastic, silica, glass, and metal particles.