JPH0961621A - Production of black matrix for color filters - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a blak matrix (light shielding layer) having a high optical density with a thin film. SOLUTION: The light shielding layer is formed on a transparent substrate, such as glass, and and intermediate layer consisting essentially of a material which is insoluble in a solvent for the photosensitive resin compsn. and is soluble in a developer for the photosensitive resin compsn. is formed thereon. Further, a photosensitive resin compsn. layer is formed thereon and is then exposed and developed, by which the photosensitive resin compsn. layer of the exposed parts or un-exposed parts is removed together with the intermediate layer thereunder and the light shielding layer of the removed parts is peeled with a liquid which does not attack the photosensitive resin compsn. layer and the inpermediate layer; thereafter, the remaining photosensitive resin compsn. layer and the intermediate layer are removed, by which the black matrix for color filters is formed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a black matrix for a color filter used in a color liquid crystal display device.

[0002]

2. Description of the Related Art Liquid crystal displays (hereinafter abbreviated as LCDs).
Utilizing features such as thinness, small size, and low power consumption, is currently used for display units such as watches, calculators, TVs, and personal computers. In recent years, color LCDs have been developed and OA / AV
It has begun to be used in many applications such as navigation systems and viewfinders, mainly in equipment, and the market is expected to expand rapidly in the future.

As shown in FIG. 1, a color filter for displaying an LCD in color is R (red) G (green) on a substrate 2 such as a glass plate on which a BM (black matrix) 1 having a lattice pattern is formed. ) B (blue) color pixels 3 (about 100 × 100 × 2 μm) are sequentially formed, and a transparent overcoat layer (OC) 4 is formed thereon. 5 is a polarizing plate and 6 is an ITO electrode.

[0004] In the color LCD, the color filter 7 has an LC
D, the display screen can be colored by transmitting backlight light through a color filter. 8 is an alignment film, 9 is a liquid crystal, 10 is a seal material, 11 is a top coat layer, 12 is an ITO electrode, 13 is a substrate such as a glass plate, 14
Is a polarizing plate.

At present, color filters are mainly manufactured using a dyeing method. However, in this method, a step of forming a pixel by applying a transparent photosensitive resin on a glass substrate, drying, exposing, and developing, dyeing with a dye, and then forming a color mixing prevention layer is required to be repeated three times. Therefore, the number of steps is large and the cost is high. Further, since a dye is used as a coloring agent, there is a disadvantage that reliability (weather resistance and heat resistance), which is an important issue of a color filter, is inferior.
Therefore, some color filters using a pigment as a coloring agent have been proposed, among which are an electrodeposition method, a printing method, and a photolithography method (photolithography method).

However, the electrodeposition method requires the formation of an electrode pattern. (1) The degree of freedom of the pattern is small.
(2) The cost is high, and the printing method has problems such as (1) it is difficult to align a large substrate and the resolution is low, so it is difficult to cope with miniaturization, and (2) the flatness of the pattern is poor. The photolithography method is considered to be the mainstream. For photolithography, liquid resists and films are contemplated. In the liquid resist, color pixels are formed by applying a varnish in which a pigment is dispersed in a photosensitive resin on a glass substrate with a spinner, drying, exposing, and developing. On the other hand, the film is a varnish formed into a film like the photosensitive film for printed boards, and after being laminated on a substrate, color pixels are formed by exposure and development.

[0007]

Since the photosensitive resist material containing a black material cannot increase the concentration of the black material, there is a limit in thinning the film. On the other hand, when the black matrix is produced by the etching method, it is not necessary to impart photosensitivity to the light-shielding layer, and thus the black material can be highly concentrated, but it is necessary to apply a resist layer on the light-shielding layer. The material of the light-shielding layer is limited to those which are insoluble in the solvent of the resist.
The present invention provides a method for producing a thin film and high optical density black matrix (light shielding layer).

[0008]

Means for Solving the Problems The present invention comprises forming a light-shielding layer containing a material for shielding visible light on a surface of a light-transmitting substrate, and then forming a light-shielding layer on the surface of the light-transmitting substrate, which is insoluble in a solvent of a photosensitive resin composition,
Further, after forming an intermediate layer containing a material soluble in a developing solution of the photosensitive resin composition as a main component, and further forming a photosensitive resin composition layer on the intermediate layer, the exposed portion or unexposed portion is exposed or exposed. Part of the photosensitive resin composition layer is removed together with the underlying intermediate layer, and the removed light-shielding layer is peeled off with a liquid that does not attack the photosensitive resin composition layer and the intermediate layer, and the remaining photosensitive resin is then removed. The composition layer and the intermediate layer are removed to prepare a black matrix for a color filter.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, by providing an intermediate layer which is insoluble in a resist solvent between a light-shielding layer and a resist layer, it is possible to increase the concentration of a black material and it is excellent in light-shielding property. Even if a material that melts is used, the light shielding layer can be formed. In the present invention, the black matrix is produced by an etching method, and an intermediate layer is provided between the BM layer and the resist layer to prevent the BM layer from being dissolved when the resist layer is applied.

[0010]

[Example] Carbon black REAGA manufactured by CABOT
9.6 g of L-250R (trade name), a copolymer of methyl methacrylate / n-butyl acrylate / N, N′-dimethylaminoethyl methacrylate (copolymerization ratio 60
/ 20/20), 4.3 g of dipentaerythritol pentaacrylate, and 84 g of ethyl cellosolve acetate were dispersed in a planetary mill for 2 hours to obtain a dispersion paste. This dispersion paste was spin-coated on a washed and dried glass substrate and dried at 120 ° C. for 10 minutes to 0.8.
A μm coating was obtained. An aqueous polyvinyl alcohol solution (Kuraray, Poval # 224, trade name) was spin-coated on this, and dried at 90 ° C. for 10 minutes to provide a 0.2 μm intermediate layer. Further, a positive resist PMERP-6005C-3 (trade name) manufactured by Tokyo Ohka Kogyo Co., Ltd. was spin-coated thereon, and dried at 90 ° C. for 10 minutes to form a resist layer of 1.5 μm. After exposing to ultraviolet light (60 mJ) of a high-pressure mercury lamp through a mask having a light-shielding pattern, 0.5% Na
The resist layer and the intermediate layer were developed with an aqueous OH solution. After that, the light shielding layer was etched with a 20% acetic acid aqueous solution, and after the entire surface was exposed, the resist layer remaining on the light shielding layer pattern was peeled off with a 2% NaOH aqueous solution. Finally, the obtained light-shielding layer pattern was heat-treated at 200 ° C. for 30 minutes to be cured, and a black matrix was produced. The optical density was 2.0.

[0011]

According to the present invention, it is possible to produce a black matrix (light-shielding layer) with a thin film and high optical density.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid crystal display.

[Explanation of symbols]

 1. 1. BM (black matrix) Glass substrate 3. Color pixels 4. 4. Overcoat layer (OC) Polarizing plate 6. ITO electrode 7. Color filter 8. Alignment film 9. Liquid crystal 10. Seal material 11. Top coat layer 12. ITO electrode 13. Glass substrate 14. Polarizer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Sato 14 Goi Minami Coast, Ichihara City, Chiba Hitachi Chemical Co., Ltd. Goi Factory

Claims (1)

[Claims] 1. A light-shielding layer containing a material for shielding visible light is formed on the surface of a light-transmissive substrate, and a light-shielding layer which is insoluble in the solvent of the photosensitive resin composition and is formed on the light-shielding layer. An intermediate layer containing a material soluble in a developing solution as a main component is formed, and a photosensitive resin composition layer is further formed on the intermediate layer, and then the exposed or unexposed portion of the photosensitive resin composition is exposed or developed. The layer is removed together with the intermediate layer thereunder, the light-shielding layer in the removed portion is peeled off with a liquid that does not attack the photosensitive resin composition layer and the intermediate layer, and then the remaining photosensitive resin composition layer and the intermediate layer are removed. A method for producing a black matrix for a color filter, which comprises: