JPH0943417A - Production of color 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 is formed by using a carbon dispersion liquid. SOLUTION: A glass substrate 101 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 spin coating method and dried. The substrate is dipped in an alkali peeling soln. to dissolve the resist, then unnecessary part is forcedly removed by water pressure. Then the substrate is dried and cured to form a black matrix 102. In order to remove projections 103, roll press method is used to complete a black matrix 102 having no projection defects.

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 FIG. 3, 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 grid 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]

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, a carbon dispersion liquid in which a black material such as carbon is dispersed in a resin has been studied. However, the average particle size of carbon particles is
Since about 20% of 0.1 μm particles are dispersed, the carbon particles agglomerate to form protrusions of several μm when formed into a coating film, which is unsatisfactory. If the protrusions are present in the black matrix, the carbon itself has conductivity, and thus when assembled into a liquid crystal panel, there is a problem that the protrusions come into contact with a transparent electrode which is a counter electrode and cause a short circuit. The present invention removes this protrusion to prevent a short circuit defect.

[0008]

SUMMARY OF THE INVENTION The present invention is a method of manufacturing a color filter in which a light-shielding layer and colored pixels arranged regularly on a transparent substrate are formed, and the transparent substrate on which the light-shielding layer is formed is pressed. It is a method of manufacturing a color filter, which is characterized by adding steps. That is, in the present invention, the protrusions are removed by crushing with a press.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As a pressing method, a roll press,
Either a press using a surface plate may be used, but a roll press is preferable in consideration of workability. FIG. 1 shows a method of removing protrusions of a light shielding layer by roll pressing, 101 is a substrate, 102 is a black matrix as a light shielding layer, 10
3 is a protrusion and 104 is an iron roll. FIG. 2 shows a method of removing the protrusions of the light shielding layer by a platen press.
5 is a surface plate. The pressing step may be performed after the black matrix is formed, or after the carbon dispersion is applied and dried.

[0010]

Example As the carbon dispersion, a black matrix material GA66MA for cathode ray tubes manufactured by Hitachi Powder Metallurgy was applied, and the forming method was a lift-off method. First, as a transparent substrate, Corning # 7059 glass substrate length 200 mm,
A size of 300 mm in width and 1.1 mm in thickness 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, a positive photoresist AZ-1350 manufactured by Shipley Co., Ltd. was applied to a thickness of 1.0 μm by a spinner method.
And prebaking at 90 ° C. for 20 minutes.
Next, 100 mj / cm2 exposure through a photomask,
Develop with an alkaline developer. Next, the GA66MA spinner method is applied at 700 rpm for 20 seconds, and the blast dryer is used for 100
Drying at 5 ° C. for 5 minutes gives a thickness of 0.6 μm. 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. As it is, it cannot be used because the projection of several μm exists in the black matrix portion. In this embodiment, a roll pressing method is applied to remove this protrusion. 150φ for roll
Cylinder pressure 5kg / c using iron roll polished by
It was pressed at m2 and a conveying speed of 1 m / min. as a result,
The average protrusion height was 3.6 μm and σ1.4 μm, but the average protrusion height could be reduced to 1.5 μm and σ0.25 μm.

[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 pressing method of the present invention.

FIG. 2 is a side view showing a surface plate pressing method of the present invention.

FIG. 3 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 101. Substrate 102. Black matrix 103. Protrusion 104. Iron roll 105. Surface plate

Claims (2)

[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 of manufacturing a color filter, comprising a step of pressing a transparent substrate having a light shielding layer formed thereon. 2. The light shielding layer is made of carbon particles.
A method for producing the described color filter.