JPH01271704A - Color filter and production thereof - Google Patents

Abstract

PURPOSE:To enable the introduction of a photolithography technique of high accuracy to a sol-gel method technique which provides excellent flatness to the color filter by forming a colored layer consisting of at least an inorg. structural material and org. mordant on a transparent substrate. CONSTITUTION:An alumina sol is coated by using a spin coater on the transparent substrate 1 and is held by heating to form a porous alumina layer. A soln. prepd. by adding a diazonium salt as a crosslinking agent to an aq. soln. of polyacryl amide is coated on the porous alumina layer by a spray coater and the substrate 1 is rested still by maintaining the same level. After the acryl amide on the surface is wiped away by a cloth soaked with water, the surface is dried and is irradiated by UV rays, by which the colored layer 2 filled with the modified acrylic resin of the mordant in the pores of the porous alumina is formed. The introduction of the photography technique of high accuracy to the sol-gel method technique which provides the excellent flatness to the color filter is thereby enabled and the increase of the area and density is enabled.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a color filter for display devices.

[Conventional technology]

The following four types of conventional color filter manufacturing methods are known.

i) Providing a photosensitive mordant layer on the dyeing method substrate, aligning the photomask,
One color is completed by exposure, development, dyeing, and formation of a protective film. Repeat the same process below.

ii) Printing method One color printing is performed while aligning the original plate onto the substrate, and is fixed by firing. Repeat the same process below.

iii) An electrode pattern is formed on the electrodeposition substrate by photolithography. - One color is completed by printing conductive paste on the electrode corresponding to the color, electrodeposition, firing, and peeling off the paste. Repeat the same process below.

iv) Sol-gel method A finely divided inorganic gel layer is provided on the substrate. The metal window opening is finished in one color by diffusing the dye into the gel layer through a mask. Repeat the same process below.

[Problem to be solved by the invention]

However, with the exception of iv) the sol-gel method, conventional methods result in thickness unevenness of 0.1 μm or more between fair skins or colors. Therefore, when used in, for example, a simple matrix type liquid crystal display device, problems such as insufficient contrast and gradation occur.

On the other hand, in the sol-gel method, patterning for each color is performed by aligning metal masks, making it difficult to achieve dimensional and positional accuracy. In particular, the use of metal masks has become a big problem when increasing the area and increasing the density of patterns.

Although the problems of dimensional accuracy and positional accuracy can be solved by using photolithography technology, the photosensitive resist is diffused and fixed in the inorganic gel layer that has micropores, so the current sol-gel method is not suitable for photolithography. Unable to introduce lithography technology.

The present invention is intended to solve these problems, and its purpose is to provide a color filter structure that allows the introduction of highly accurate photolithography technology into sol-gel technology that has excellent flatness. In addition, the present invention provides a method for manufacturing color filters that can be made larger in area and in higher density using photolithography technology.

[Means to solve the problem]

The color filter of the present invention is characterized in that a colored layer made of at least an inorganic structural material and an organic mordant is formed on a transparent substrate.

In addition, the method for producing a color filter of the present invention includes forming an inorganic porous layer on a transparent substrate, filling the micropores of the inorganic porous material with an organic mordant to form a colored layer, and then performing at least the following steps. It is characterized in that patterning is performed for each color by repeating the process, and a protective layer is formed on the colored layer for each color or all at once.

a) Coating a photosensitive resist on the colored layer.

b) A step of exposing the resist layer to light through a photomask having a predetermined pattern to be colored.

C) Developing and opening windows in a predetermined pattern.

d) Diffusing the dye through the windowed resist layer into the colored layer.

e) Step of removing the resist layer.

〔Example〕

Example 1 FIGS. 1(a) to 1(f) are cross-sectional views schematically showing the manufacturing process of a color filter in Example 1 of the present invention.

Figure 1(a) shows a colored layer 2 on a transparent substrate 1, in which the micropores of porous alumina are filled with modified acrylic resin as a mordant.
This shows the state in which it has been formed. First, alumina sol-520 (manufactured by Nissan Chemical Industries, Ltd.) was applied onto a transparent substrate using a spin coater, heated to a maximum of 600°C, and held for 60 minutes. An alumina porous layer with a thickness of 3 μm was formed. Next, a solution prepared by adding a diazonium salt as a crosslinking agent to a 20% aqueous solution of polyacrylamide RWIOI (manufactured by Sekisui Fine Chemicals) was applied onto the porous alumina using a spray coater. The substrate was held horizontally and allowed to stand at room temperature for 2 hours.

Wipe off the acrylamide on the surface with a cloth soaked in water,
After drying at °C, it was irradiated with ultraviolet light. A colored layer was formed in which the micropores of porous alumina were filled with a modified acrylic resin as a mordant.

FIG. 1(b) shows a step in which a positive type photosensitive positive resist layer 3 is formed and exposed through a photomask 4. As shown in FIG.

After applying the resist layer using a spin coater,
It was formed by pre-baking at ℃. A mercury lamp is used as the light source for exposure, and the resist layer and photomask are brought into close contact.
Light was applied for 40 seconds.

FIG. 1(C) shows a state in which a window is opened in the photosensitive resist layer 3 after development. Development and rinsing were done at room temperature,
Bost baking was performed at °C.

FIG. 1(d) shows a state in which a dye is diffused through the resist layer 3 with an open window to form a colored pattern (for example, a red colored portion 11) on the colored layer 2. For dyeing, use 60 red dye
The substrate was heated to .degree. C., and the substrate was immersed and held for 10 minutes.

FIG. 1(e) shows a state in which the photosensitive resist layer 3 has been removed. Removal was performed by irradiating the entire surface with a mercury lamp for 40 seconds and then immersing it in a developer.

Thereafter, the position of the photomask was moved and the steps from FIG. 1(b) to FIG. 1(e) were repeated to form blue and green colored patterns. FIG. 1(f) shows a state in which a protective layer 5 is formed on a colored layer 2 having a colored pattern of red, blue, and green. The protective layer was formed by applying an acrylic resin using a spin coater and heating it to 150°C.

The surface level difference was 0.05 μm or less, and the flatness was extremely good, and it was possible to increase the size of the substrate to 300×300 mm. The pattern could be made finer down to 50 μm, and a high positional accuracy of 5 μm or less was achieved.

Example 2 FIGS. 2(a) and 2(b) are cross-sectional views schematically showing a part of the manufacturing process of a color filter in Example 2 of the present invention. The steps from forming the colored layer to dyeing through the resist layer with the window open are the same as in FIGS. 1(a) to (d),
The completed color filter has a cross-sectional view exactly the same as that shown in FIG. 1(f).

The inorganic porous colored layer was formed by mixing three components: silica, alumina, and boric acid. Snowtex-0 and Alumina Sol-100 (both manufactured by Nichijo Kagaku Co., Ltd.), and boric acid in calculated amounts (SiO□:Al1.03:BzOi=(4:
5:1) (7) Mixed proportions.

The sol was applied to a transparent substrate using a roll coater, heated to a maximum of 500°C, and held for 60 minutes.

An inorganic porous layer with a thickness of 5 μm was obtained. Next, ammonium dichromate was added to a 1% aqueous solution of low molecular weight gelatin, and the mixture was applied onto the inorganic porous material using a spray coater. The substrate was held horizontally and allowed to stand at room temperature for 2 hours. After wiping off the gelatin on the surface with a cloth soaked in water and drying it at 60°C,
Irradiated with ultraviolet light.

A colored layer was formed in which the inorganic micropores were filled with gelatin, a mordant.

Thereafter, resist layer formation, exposure through a photomask, development, and dyeing were performed in the same manner as in Example 1. Figure 2 (g
) shows a state in which a colored pattern 11 is formed on the colored layer 2 and a protective layer 5 is formed without removing the photosensitive resist layer 3 with the window. The protective layer was formed by applying an inorganic mixed resin using a spin coater and heating it to 170°C to have a thickness of 0.3 μm.

FIG. 2(c) shows a state in which the photosensitive resist layer 3 has been removed together with the protective layer on the resist. For example, red colored part 1
A protective layer 5 is formed only on top of the protective layer 1 . The resist was removed by irradiating the entire surface of the substrate with a mercury lamp for 40 seconds and then immersing it in a developer.

The steps from forming the resist layer are repeated, and the steps shown in FIG. 1 (f) are repeated.
) as shown in red colored part 11, blue colored part 12,
A color filter was obtained in which the protective layer 5 was formed on the colored pattern of the green colored portion 13.

Although the embodiments have been described above, the number of colors to be colored and the coloring pattern are not limited at all.

Further, the inorganic porous layer is not limited in any way, and titania or zirconia, for example, can exhibit similar effects. The organic mordant is not similarly limited.

〔Effect of the invention〕

As described above, according to the present invention, a colored layer made of at least an inorganic structural material and an organic mordant is formed on a transparent substrate, thereby adding precision to the sol-gel method, which has excellent flatness. We were able to provide a color filter structure that allows the introduction of excellent photolithography technology.

Furthermore, after forming an inorganic porous layer on a transparent substrate and filling the micropores of the inorganic porous material with an organic mordant to form a colored layer, patterning of each color is performed by repeating at least the following steps. By forming a protective layer on the colored layer for each color or all at once, it was possible to provide a method for manufacturing a color filter that can be made larger in area and more dense using photolithography technology.

a) Coating a photosensitive resist on the uncolored layer.

b) A step of exposing the resist layer to light through a photomask having a predetermined pattern to be colored.

C) Developing and opening windows in a predetermined pattern.

d) Diffusing the dye through the windowed resist layer into the inorganic porous layer.

e) Step of removing the resist layer.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(f) are cross-sectional views schematically showing the manufacturing process of a color filter in Example 1 of the present invention. (a) is a step in which a colored layer is formed on a transparent substrate. Φ) is the process of forming a resist layer and exposing it to light through a photomask. (C) is the developing process. (d) is the dyeing process. (e) is the process of removing the resist. (f) shows the step of forming a protective layer after coloring. FIG. 2(a) (bl) is a sectional view schematically showing a part of the manufacturing process of a color filter in Example 2 of the present invention.(a) is a step in which a protective layer was formed after coloring. .(
b) shows the process in which the resist was removed together with the protective layer. 1. Transparent substrate 2, colored layer 3, photosensitive resist layer 4, photomask 5, protective layer 11, red colored part 12, blue colored part 13, green colored part Applicant: Seiko Epson Corporation Attorney Master Kizobe Suzuki and 1 other person

Claims (2)

[Claims] (1) A color filter characterized in that a colored layer made of at least an inorganic structural material and an organic mordant is formed on a transparent substrate. (2) After forming an inorganic porous layer on a transparent substrate and filling the micropores of the inorganic porous material with an organic mordant to form a colored layer, patterning of each color is performed by repeating at least the following steps. A method for producing a color filter, comprising: forming a protective layer on the colored layer for each color or all at once. a) Coating a photosensitive resist on the colored layer. b) A step of exposing the resist layer to light through a photomask having a predetermined pattern to be colored. c) Developing and opening windows in a predetermined pattern. d) Diffusing the dye through the windowed resist layer into the colored layer. e) Step of removing the resist layer.