JP3265765B2 - Manufacturing method of color filter - Google Patents

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 for a liquid crystal display and an image sensor.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a black matrix (hereinafter referred to as BM) for a color filter, a method of patterning a metal chromium thin film by using an etching method has been generally used. In view of this, low reflectance is required, and non-chromium is required in view of environmental issues. A method of forming a BM using a resin in which a pigment is dispersed has been studied.

As a method of forming a BM using the pigment, a method using a colored resin having photosensitivity (for example, JP-A-2-144502, JP-A-2-181704)
JP-A-60-237403, JP-A-62-234103, and the like, and each is solved. There are issues to be addressed.

[0004] The former method has a problem of insufficient resolution. That is, a high optical density is required to satisfy the BM characteristics, and a large amount of exposure is required for patterning. As a result, the line width of the BM obtained by a phenomenon such as halation becomes large. It is.

Further, it is necessary to add a photosensitive monomer and a photosensitive agent in order to impart photosensitivity to the colored resin, and the film thickness of the formed BM becomes large. In addition, the BM layer may have a projection due to the overlap of the RGB layers, which may affect the alignment characteristics of the liquid crystal.

In the latter method, generally, Japanese Patent Application Laid-Open No.
As shown in Japanese Patent No. 237403, a polyimide resin is considered, but the polyimide resin is expensive and disadvantageous in cost. Also, compared with the former method, the number of steps is large, and a step of removing the resist with an organic solvent is required, which is disadvantageous in terms of steps and equipment.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to provide a method of forming a pattern by an etching method using an inexpensive acrylic resin. It is an object of the present invention to provide a method of manufacturing a color filter by forming a BM having a high optical density and a high resolution with a thin film.

[0008]

According to the present invention, there is provided a liquid crystal display device comprising: (1) an acrylic resin containing acrylic acid or methacrylic acid as a monomer containing a dispersant, a pigment, and a thermosetting resin on a substrate; (2) Step of forming a resist layer thereon (3) Step of performing resist patterning and etching of the colored resin layer with an alkali developer (4) Heating the resist and the colored resin pattern Baking Step (5) Step of Stripping Resist with Alkaline Stripping Solution Provided is a method of manufacturing a color filter characterized by forming a black matrix comprising the above steps.

Hereinafter, the present invention will be described in detail. As the acrylic resin used in the present invention, alkali developable,
When used as a color filter, sufficient resistance is required so as not to affect the characteristics of the liquid crystal display, and a material containing acrylic acid or methacrylic acid as a monomer is selected.

As the pigment, a resin-dispersed pigment having a high light-shielding property is used. For example, chromium oxide, titanium oxide, iron oxide, carbon black and the like can be used.

As the dispersing agent, a derivative of an organic dye is used, and as an organic dye serving as a base, azo, phthalocyanine, quinacridone, anthraquinone, perylene, perinone, thioindico, dioxazine,
There are isoindolinone type, quinophthalone type, triphenylmethane type, metal chain salt type and the like.

As the thermosetting resin, thermal reactivity and alkali resistance after curing are required, and an alkylated melamine resin such as a methylated melamine resin or a butylated melamine resin, or an alkylated benzoguanamine resin can be used.

These are dissolved in a solvent to form a uniform coating film. The solvents used are cyclohexanone, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, ethylbenzene, xylene, diglyme, propylene glycol monomethyl ether acetate, lactic acid, and the like. Ethyl, methyl ethyl ketone and the like are used.

[0014]

The operation of the formation of a BM according to the present invention will be described below in detail through steps. A spin coating method, a roll coating method, or the like can be used as a coating method for uniformly applying the coloring resin on a substrate.

Subsequently, the colored resin layer is dried by heating. As the heating conditions at this time, during the application of the resist in the next step, it is necessary to cure the colored resin layer to such an extent that the colored resin layer is not attacked by the solvent of the resist, and so as not to impair the alkali developability of the colored resin layer. In addition, it is necessary that the thermosetting resin is not excessively thermoset.

Next, a resist for patterning is applied on the colored resin layer. As the coating method, a spin coating method, a roll coating method, or the like can be used as described above.

Next, the resist layer is dried by heating. As the heating conditions at this time, for example, when the resist is a positive resist, the unexposed portions need to have sufficient resistance to the developer, and, similarly to the heating and drying of the colored resin layer, It is necessary that the thermosetting resin is not excessively thermoset so as not to impair the alkali developability of the colored resin layer.

Subsequently, the resist is exposed through a predetermined mask, and in the case of a positive resist, the exposed portion of the resist is developed with an alkali developing solution which is a weak alkaline aqueous solution. At this time, since the underlying colored resin layer also has alkali developability, it is simultaneously etched with a developer using the resist pattern as a mask to obtain a required pattern.

Next, the pattern consisting of the colored resin layer and the resist layer is heated and baked to improve the alkali resistance of the underlying colored resin layer. The heating conditions at this time are such that the thermosetting resin component of the colored resin layer is sufficiently cured by heat, and that the upper resist layer is thermally cured more than necessary and cannot be separated. is necessary.

Next, the resist layer is stripped using an alkaline stripping solution, which is a strong alkaline aqueous solution. However, since the colored resin layer has alkali resistance due to the curing of thermosetting water, only the resist layer is stripped and the colored resin layer is stripped. Is obtained.

Further, when the pattern is entirely exposed to light before the stripping step to increase the solubility of the resist, the stripping step becomes easier.

[0022]

EXAMPLE An allyl resin (20 parts by weight of methacrylic acid, 30 parts by weight of butyl acrylate, 5 parts of butyl methacrylate)
0 parts by weight were dissolved in 300 parts by weight of ethyl cellosolve, and 0.75 parts by weight of azobisisobutylnitrile was added thereto under a nitrogen atmosphere, and the mixture was reacted at 70 ° C. for 5 hours) to give a resin concentration of 5% with ethyl cellosolve. Diluted.

For 88.8 g of the diluted resin, 8.0 g of carbon black, 0.8 g of a copper phthalocyanine derivative as a dispersant, and a methoxylated melamine resin (trade name)
2.4 g of MS-21 (manufactured by Sanwa Chemical Co., Ltd.) was added and kneaded sufficiently with a three-roll mill to obtain a black colored resin.

First, this colored resin is put on a substrate for 1000 r.
Spin coating was performed under the conditions of pm × 30 seconds. Next, it was dried by heating at 90 ° C. for 20 minutes using a clean oven. Then, a resist (Tokyo Ohka Co., Ltd.) is formed on the colored resin layer.
OFPR-2 was spin-coated at 2000 rpm × 30 seconds, and dried by heating at 90 ° C. for 30 minutes. Next, using a super-high pressure mercury lamp, mask exposure was performed at 30 mJ, and NaOH 0.5
The development of the resist and the etching of the colored resin layer were performed at the same time with a 10% aqueous solution. Then use a clean oven for 150
The melamine resin was thermally cured by heating at 30 ° C. for 30 minutes. Subsequently, the resist was stripped using a 3.0% aqueous solution of NaOH to obtain a BM pattern.

The BM pattern thus obtained is
The film thickness was 0.6 μm, and the optical density was 2.0.
The resolution was 10 μm or less in line and space.

[0026]

As described above, according to the present invention, it is possible to obtain a color filter in which a BM having a high optical density and a high resolution is formed in a thin film. Further, since an acrylic resin that can be alkali-developed is used, the development of the resist and the etching of the colored resin can be performed in the same step, and the steps can be simplified. In addition, since the alkali resistance of only the colored resin layer can be improved by heating and baking after development and etching, the resist film can be removed using an alkaline aqueous solution without using an organic solvent. Excellent in terms of surface.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 5/20-5/28

Claims (1)

(57) [Claims] (1) A step of forming a colored resin layer comprising a dispersant, a pigment, and a thermosetting resin in an acrylic resin containing acrylic acid or methacrylic acid as a monomer on a substrate. (3) Step of patterning the resist layer and etching of the colored resin layer with an alkaline developer (4) Step of heating and baking the resist layer and the colored resin layer (5) Alkaline stripper for removing the resist layer A method of manufacturing a color filter, characterized by forming a black matrix comprising the above steps.