JPH0943415A - Production of colro filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter in which a black matrix having uniform film thickness distribution without projection defects due to aggregated particles by using a carbon dispersion liquid. SOLUTION: A glass substrate 105 is cleaned, dried and treated with hexamethyldisilazane, on which a positive photoresist is applied, exposed through a photomask and developed. A carbon dispersion liquid 104 is applied by roll coating method and dried. The substrate is dipped in an alkali peeling soln. to dissolve the resist, and unnecessary part is forcedly removed by water pressure. Then the substrate is dried and cured to complete a black matrix.

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 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 the figure, a color filter for displaying an LCD color is R (red) G (green) on a substrate 2 such as a glass plate on which a BM (black matrix) 1 having a grid pattern is formed. A color pixel 3 (about 100 × 100 × 2 μm) of B (blue) is 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]

Conventionally, a metal thin film of chromium or the like is applied to the black matrix (BM) of a color filter for liquid crystal, but since the reflectance is high, the visibility is poor and the vacuum evaporation method is used. Since the film is formed, there are problems such as high cost. In order to solve this problem, an organic material in which a black material such as carbon is dispersed in a resin and a photosensitizer is added to have photosensitivity is applied. However,
20% if the average particle size of carbon particles is 0.1 μm
Since the particles are dispersed to some extent, the carbon particles aggregate to form protrusions of several μm when formed into a coating film, which is unsatisfactory. Further, although it is usually applied by a spinner method, there is a problem that the film thickness distribution in the central portion and the peripheral portion of the substrate becomes poor because the liquid has thixotropic properties. The present invention improves the protrusion failure and the film thickness distribution due to the aggregated particles.

[0008]

The present invention relates to a method of manufacturing a color filter for forming regularly arranged light-shielding layers and colored pixels on a transparent substrate, in which carbon particles are dispersed in the light-shielding layers. It is a method for producing a color filter, which is characterized in that it is formed by applying a liquid by a roll coating method. That is, according to the present invention, when the spinner method deposits agglomerated particles in the BM liquid as it is on the film, the spinner method is applied by the roll coater method.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The roll coater method comprises a coating roll 101 having fine grooves as shown in FIG. 1, a doctor bar 102, and a substrate carrying system 103 such as a carrying conveyor. The carbon dispersion liquid 104 to be applied to the doctor bar 103 is stored, the liquid is transferred to the groove of the coating roll 101, further transferred from the coating roll 101 to the substrate 105, and leveled to form a coating film. The coating roll 101 rotates and is pressed against the doctor bar 102, the liquid is filtered, and even if there are aggregated particles in the liquid, they are destroyed.
Further, since the coating roll 101 is pressed against the substrate 105 with a predetermined pressure, even if the aggregated particles fall off in the previous step, the aggregated particles can be crushed at the time of transferring the substrate. Further, since this coating method is a coating method utilizing the leveling of the liquid, uniform coating is possible without being affected by the thixotropy of the liquid.

[0010]

EXAMPLES As a BM material, a black matrix material GA66MA for cathode ray tubes manufactured by Hitachi Powder Metallurgy was applied, and a forming method was a lift-off method. First, as a transparent substrate, Corning # 7059 glass substrate 200 mm long and 300 horizontal
mm, and a thickness of 1.1 mm was used. The glass substrate is washed with an ultrasonic method using acetone and dried. Next, the surface of the glass substrate is treated with hexamethyldisilazane in order to improve the adhesion between the photoresist and the glass substrate. Next, positive photoresist AZ-1350 manufactured by Shipley Co., Ltd. is applied by a spinner method so as to have a thickness of 1.0 μm, and prebaked at 90 ° C. for 20 minutes. Next, it is exposed to 100 mj / cm 2 through a photomask and developed with an alkaline developer. Next, GA66MA is applied by a roll coater method. As the roll coater, a roll coater MRC-450 manufactured by Pilot Seiko Co., Ltd. was used. The pushing amount of the doctor bar is 100 μm, the clearance between the coating roll and the transfer conveyor is 0.9 mm, and the transfer speed is 1.0 m / mi.
It is applied under the condition of n, and the drying is performed by a blow dryer at 100 ° C. for 5 minutes. Next, the substrate is immersed in an alkaline stripping solution to dissolve the resist first. Next, the unnecessary portion is forcibly removed with a water pressure of 1.5 kg / cm 2, and the material is dried and cured to complete the black matrix. FIG. 2 shows a graph showing the film thickness distribution of the black matrix. FIG. 3 is a graph showing the film thickness distribution of the black matrix formed by the conventional spinner method.

[0011]

According to the present invention, a carbon dispersion can be used to form a BM having no protrusion defect due to agglomerated particles and having a uniform film thickness distribution.

[Brief description of drawings]

FIG. 1 is a side view showing a roll coater method of the present invention.

FIG. 2 is a graph showing a film thickness distribution of a black matrix formed according to the present invention.

FIG. 3 is a graph showing a film thickness distribution of a black matrix formed by a conventional spinner method.

FIG. 4 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. Polarizing plate 100. Coating roll 102. Doctor bar 103. Substrate transport system 104. Carbon dispersion 105. substrate

Claims (1)

[Claims] 1. A method of manufacturing a color filter for forming light-shielding layers and colored pixels, which are regularly arranged on a transparent substrate, comprising:
A method for manufacturing a color filter, characterized in that the light shielding layer is formed by applying a liquid in which carbon particles are dispersed by a roll coating method.