JPH06242310A - Production of color filter for liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide a process for production of the color filters for liquid crystal display devices capable of greatly improving the smoothness of the surfaces of color filter layers by the simple method. CONSTITUTION:Conductive metallic layers 3 which shut off the transmitted light between pixel parts and pixel parts and three colors of colored resin layers 2, 2, 2 which are regularly arranged in the pixel parts and color the transmitted light to red (R), green (G) and blue (B) are successively formed by a photolithography method on a transparent substrate 1 and thereafter, the conductive metallic layers 3 are energized to electrodeposit electrodeposition resins 6 on these conductive metallic layers 3, by which the resins 6 are formed approximately flush with the colored resin layers 2, 2, 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color filter used in a liquid crystal display device such as a color liquid crystal TV.

[0002]

2. Description of the Related Art Conventionally, a photolithography method such as a dyeing method or a pigment dispersion method has been mainly used for forming a color filter. That is, in the case of the dyeing method, a hydrophilic resin solution such as gelatin, glue, polyvinyl alcohol, etc., which has been made photosensitive with dichromate, is applied on a glass substrate, and then a predetermined pattern is formed by a mask exposure method. Baking and development are performed to form a relief pattern, which is dyed with a dye of a desired color, and then subjected to post-treatments such as washing with water, fixing and fixing. This process is repeated by the number of colors to produce a color filter. On the other hand, in the case of the pigment dispersion method,
Instead of dyeing after development, a photosensitive resin containing a pigment of a desired color in advance is used.

FIG. 2 and FIG. 3 show the structure of the color filter manufactured in this way. The colored resin layers 2 and 2 of three colors of red (R), green (G) and blue (B) are shown. , 2 are regularly arranged in the pixel portion of the transparent substrate 1. Further, in order to improve the display quality of the liquid crystal display device, a black matrix pattern made of the conductive metal layer 3 that blocks the transmitted light between the pixel portions is formed.

When a color filter is manufactured by a photolithography method, it is formed depending on whether it is a dyeing method or a pigment dispersion method, or whether the photosensitive resin used is a negative type or a positive type. The cross-sectional shape of the colored resin layer 2 of each color may be a relatively steep taper shape as shown in FIG. 2 or an inverse taper shape as shown in FIG.

[0005]

However, I is formed on the entire surface including each colored resin layer 2 having such a cross-sectional shape.
Even if the TO film is formed by a sputtering method or the like, the film adhesion of the ITO film on the side surface of each colored resin layer 2 may be insufficient and the pixel electrode may be broken. This becomes a point defect when the module is turned on, and the quality on the image display is greatly impaired. Further, even if the pixel electrode is not broken, the edges of the colored resin layers 2 are sharp, so that even if the liquid crystal molecules are aligned by rubbing, the alignment disorder of the liquid crystal molecules is likely to occur at the edge portion. The reverse tilt phenomenon occurs, and the quality of the display device deteriorates.

Therefore, conventionally, as shown in FIG. 4, an overcoat layer 4 is applied and formed on the entire surface, and then ITO is formed thereon.
Although a method for solving the above-mentioned problems by forming the film 5 has been proposed, an ordinary method is particularly used when the cross section of the colored resin layer 2 as shown in FIG. Therefore, there is a problem in that even if overcoating is performed, the recesses are not sufficiently filled with resin. Further, by providing such an overcoat layer 4 on the entire surface, the reliability of the adhesive strength at the seal portion is lowered, and defects such as dust projections and uneven coating of the overcoat layer 4 are likely to occur. There is also a problem that wrinkles, blisters, cracks and the like of the overcoat layer 4 are likely to occur during heating when forming the ITO film 5.

The present invention has been made in view of the above conventional problems, and it is an object of the present invention to provide a method of manufacturing a color filter for a liquid crystal display device, which can greatly improve the smoothness of the filter layer surface by a simple method. To aim.

[0008]

In order to achieve the above object, the present invention provides a plurality of colored resin layers which are regularly arranged in a pixel portion of a transparent substrate to color transmitted light into respective colors, and the above pixel. And a smoothing resin layer provided on the conductive metal layer and substantially flush with the colored resin layer. In the method for producing a color filter for a liquid crystal display device, the conductive metal layer and the colored resin layer are sequentially formed on a transparent substrate, and then the conductive metal layer is energized to electrodeposit an electrodeposition resin to smooth the surface. It is characterized in that a resin layer is formed.

[0009]

According to the present invention, a pixel is formed by energizing a conductive metal layer provided on a transparent substrate in order to block light transmitted between pixel portions of the transparent substrate and electrodepositing an electrodeposition resin. The electrodeposition resin layer is formed so as to be substantially flush with the colored resin layer which is regularly arranged in the part. As a result, the smoothness of the filter layer surface is greatly improved, and ITO is directly applied to the surface.
Even if the film is formed, the disconnection does not occur and the reverse tilt phenomenon does not occur.

Further, even if the cross section of the colored resin layer is formed in an inverted taper shape, the resin can be sufficiently filled in the concave portion by electrodeposition, and the surface can be smoothed.

Furthermore, since it is not necessary to provide an overcoat layer, various problems caused by the conventional overcoat layer can be solved, the production yield is greatly improved, and an inexpensive color filter can be produced.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples.

FIG. 1 is a sectional view showing the structure of a color filter manufactured by the method of the present invention.

As is clear from the figure, red (R),
The colored resin layers 2, 2, 2 of three colors of green (G) and blue (B) are regularly arranged at pixel portions of the transparent substrate 1 such as glass. In addition, a black matrix pattern made of the conductive metal layer 3 is formed on the transparent substrate 1 in order to block the transmitted light between each pixel portion.

The black matrix pattern consisting of the conductive metal layer 3 is formed by forming a thin film of a conductive metal such as chromium on the transparent substrate 1 and patterning it by photolithography.

After forming the black matrix pattern consisting of the conductive metal layer 3 on the transparent substrate 1, the colored resin layers 2, 2 and 2 of the three colors R, G and B are formed in the same manner as described above. The layers are sequentially formed by the photolithography method. That is, a photosensitive resin such as photosensitive gelatin is applied on the transparent substrate 1, and then a predetermined filter pattern is exposed by a mask exposure method and developed to form a relief pattern, which is formed with a desired red dye, for example. Dyeing, and then post-treatment such as washing with water and fixing. By repeating this process for green and blue as well,
The colored resin layers 2, 2, and 2 of three colors of R, G, and B are completed. The pigment dispersion method may be used instead of the dyeing method. Also, regarding the number of colors, R, G,
It is not limited to the three colors of B, and any number of colors may be used.

Thus, on the transparent substrate 1, the conductive metal layer 3 and the colored resin layers 2, 2, 2 of three colors R, G, B are sequentially formed.
After forming, the electroconductive metal layer 3 is energized to electrodeposit the electrodeposition resin 6.

That is, the electroconductive metal layer 3 is used as one of the electrodes and is immersed in an aqueous solution of a polymer resin for electrodeposition, and a direct current is passed between the opposing electrode plates, whereby the electrodeposition resin 6 is deposited on the electroconductive metal layer 3. By depositing and coating, the concave portions between the respective colored resin layers 2 are filled without any gap, and are formed substantially flush with the respective colored resin layers 2. As a result, as shown in FIG. 1, the sharp recesses between the colored resin layers 2 are not filled up, the surface smoothness is greatly improved, and the ITO film 5 can be formed directly on top of the recessed recesses. Problems such as disconnection will not occur.

The colored resin layers 2, 2 and 2 preferably have a film thickness of 1.0 to 3.0 μm in order to fill the recessed portion with the electrodeposition resin 6 without any gap so as to make the surface smooth. If the film thickness is too thin, the electrodeposition resin 6 is formed on the colored resin layers 2, 2, 2 too. On the other hand, if it is too thick, the recesses are not sufficiently filled and the colored resin layers 2, 2, 2 and the electrodeposition resin layer 6 are not formed. There remains a step between.

There are two electrodeposition methods, anion electrodeposition and cation electrodeposition.

In the anion electrodeposition method, an anionic water-soluble resin is used as the electrodeposition resin, and specifically, a polyester resin having a carboxyl functional group neutralized with an organic amine, polyamic acid, methacrylic acid, and acrylic resin are used. Examples thereof include copolymer resins of acid and various acrylates. on the other hand,
For the cation electrodeposition method, a cation type water-soluble resin is used, and examples thereof include a polymer having a basic functional group neutralized with an acid, such as an amine-modified epoxy resin. It is also possible to disperse a black pigment in the aqueous solution for electrodeposition to deposit a black coating film by electrodeposition.

In the case of the anion electrodeposition method, the conductive metal layer 3 is connected to the positive electrode side, and in the case of the cation electrodeposition method, the conductive metal layer 3 is connected to the negative electrode side, Perform electrodeposition processing. The applied voltage is preferably in the range of several tens of volts to several hundreds of volts. Although the electrodeposition time depends on the magnitude of the applied voltage, it is about 10 to 30 seconds, which is extremely short, and the conductive metal layer 3 is hardly damaged.

[0023]

As described in detail above, according to the present invention, the conductive metal layer provided on the transparent substrate is energized to block the transmitted light between the pixel portions of the transparent substrate. The electrodeposited resin layer is formed so as to be substantially flush with the colored resin layer regularly arranged in the pixel portion by electrodeposition of the electrodeposited resin, thereby improving the smoothness of the filter layer surface. It can be greatly improved. Therefore, even if the ITO film is directly formed without providing the overcoat layer on the surface, the disconnection does not occur and the reverse tilt phenomenon does not occur.

Further, the present invention is a very simple method in which even if the cross section of the colored resin layer is formed in a reverse tapered shape, for example, the resin can be sufficiently filled in the concave portions by electrodeposition to smooth the surface.

Further, according to the present invention, since it is not necessary to provide an overcoat layer on the surface, the reliability of the adhesive strength at the seal portion due to the conventional overcoat layer is reduced,
Adhesion of dust protrusions, uneven coating defects on the overcoat layer, IT
Since various problems such as wrinkles, blisters, and cracks in the overcoat layer can be solved when the O film is formed, the production yield is significantly improved, and an inexpensive color filter can be produced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a color filter manufactured by the method of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a conventional color filter.

FIG. 3 is a cross-sectional view showing the structure of a conventional color filter.

FIG. 4 is a cross-sectional view showing the structure of a color filter having a conventional overcoat layer on its surface.

[Explanation of symbols]

 1 transparent substrate 2 colored resin layer 3 conductive metal layer 4 overcoat layer 5 ITO film 6 electrodeposition resin

Claims (1)

[Claims] 1. A colored resin layer of a plurality of colors, which is regularly arranged in a pixel portion of a transparent substrate and colors transmitted light in each color, and a conductive metal which blocks transmitted light between the pixel portion and the pixel portion. Layer, and a method for producing a color filter for a liquid crystal display device, which is provided on the conductive metal layer and comprises a smoothing resin layer formed substantially flush with the colored resin layer, in order on a transparent substrate. After forming the conductive metal layer and the colored resin layer, an electric current is applied to the conductive metal layer to electrodeposit an electrodeposition resin to form the smoothing resin layer, thereby forming a color filter for a liquid crystal display device. Manufacturing method.