JPH06258518A - Color filter substrate and its production - Google Patents

Abstract

PURPOSE:To provide a color filter substrate and its production method by which a patterning process and a mask for patterning of a light-shielding layer can be omitted, the process is simplified, the production cost is decreased, and the material for the light-shielding layer can be selected from a wider range of materials. CONSTITUTION:The color filter substrate consists of a color filter pattern 2 formed on the surface of a transparent substrate, a light-shielding layer pattern 3a, and a protective layer 4 formed on the color filter pattern 2 and the light- shielding pattern 3a. The light-shielding layer pattern 3a is obtd. by forming a light-shielding layer 3 between picture elements and side walls of picture elements of the color filter. The production process consists of steps of forming a color filter pattern 2 on the surface of a transparent substrate 1, forming a light-shielding layer 3 on the color filter pattern 2, removing the light-shielding layer 3 on the color filter pattern 2 and removing a part of the color filter pattern 2 by grinding and forming the protective layer 4 on the ground color filter pattern 2 and the light-shielding layer pattern 3a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter substrate for a liquid crystal panel having a light shielding layer pattern and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, it has become common to provide a light-shielding mask between pixels in order to improve the definition of a liquid crystal panel and improve the display quality. For example, Japanese Patent Publication No. 63-3868
No. 9 discloses a method in which a metal electrode, which is a leading electrode, is arranged in a ladder shape on a transparent display electrode on one substrate to hide the pixels on the opposite substrate side. Also, in the case of being equipped with a color filter, for example, Japanese Patent Publication No.
No. 653, a color filter is provided between light-shielding layers, and an opaque film is arranged at the boundary of the color filter, as in Japanese Patent Publication No. 2-1311, and a transparent film is arranged thereon. Things are disclosed.

An insulating layer is formed on the metal light-shielding mask as described above. As the insulating layer, inorganic oxides such as SiO ₂ , Ta ₂ O ₅ and Al ₂ O ₃ , oxides, polyimide and polyamide are used. There are various types such as those formed from organic materials such as organic metal oxide films.

A color filter or the like formed on the metal light-shielding mask is also considered as a kind of insulating film.
As the color filter, a coloring resin in which at least a coloring material is dispersed in a photosensitive resin is used, and in the color filter having a plurality of patterned coloring resins formed by repeating the photolithography process, the coloring material is provided on the surface of the coloring resin layer. It is dispersed from the bottom to the bottom.

However, as a method of providing a light-shielding mask between the pixels, the above-mentioned arrangement of the metal electrodes, which are the leading electrodes on the display electrodes, in the form of a ladder is, for example, when a ferroelectric liquid crystal is used, the metal electrodes are used. There is a defect that the orientation of the part surrounded by is disturbed.

As a means for compensating for such a defect, as shown in FIG. 6, there is also known a type in which a light-shielding mask is directly formed on a substrate such as glass and the above-mentioned insulating layer is formed thereon. Has been. In the case of such a type, from the viewpoint of shading which is the original purpose, it is usual that the area other than the effective area to be displayed is shaded.

Metals and colorant-dispersed resins are used as the light-shielding material, and the optical density is at least 2 (transmittance of 1% or less) as the light-shielding performance while satisfying the heat resistance and chemical resistance required in the liquid crystal manufacturing process. ), Preferably 3 or more, a metal vapor-deposited film of Cr, Mo, Al or the like having a film thickness of about 800 Å or more, and a carbon-dispersed resin film has a thickness of 1.5 to 5 in the same manner as a color filter.
Generally, the film thickness is set to 2.0 μm.

[0008]

However, in the above-mentioned conventional example, when a metal film is used as the light-shielding layer, for example, there are restrictions on the film-forming technique due to the increase in size of the liquid crystal panel, adhesion with the color filter pattern, and heat resistance, Even if Cr, which has a problem in chemical resistance and is relatively suitable, is used, it has problems such as difficulty in etching a fine pattern and strict waste liquid management.

Further, when a colorant-dispersed resin is used as the light-shielding layer, the required film thickness becomes thicker and the color filter pattern overlaps with the light-shielding layer which is generally softer than the color filter pattern. Because of the format, there was a drawback that it was difficult to grasp the conditions for flattening the color filter pattern and polishing.

The present invention has been made in order to improve the above drawbacks of the prior art. A light-shielding layer is formed on a color filter pattern, and the light-shielding layer is polished to flatten the color filter and simultaneously shield the light-shielding pattern. By forming the light-shielding layer, the patterning step of the light-shielding layer and the exposure mask for patterning are not required, the process can be simplified and the cost can be reduced, and the selection range of the light-shielding layer material is widened, and the manufacturing method thereof. It is intended to provide.

[0011]

That is, according to the present invention, a color filter pattern is formed on the surface of a transparent substrate, and a light shielding layer is provided between pixels of the color filter and on the side surface of each pixel to form a light shielding layer pattern. And a protective layer formed on the color filter pattern and the light-shielding layer pattern.

The present invention also provides a step of forming a color filter pattern on the surface of a transparent substrate, a step of forming a light-shielding layer on the color filter pattern, and a step of forming a light-shielding layer and a color filter pattern on the color filter pattern by polishing. A method of manufacturing a color filter substrate, which comprises a step of removing a part, a step of forming a protective layer on the polished color filter and the light shielding layer pattern.

In the present invention, a metal or a colorant-dispersed resin or the like is used as the light-shielding layer material, and this is formed by vapor deposition, spin coating, printing or the like to a thickness capable of obtaining the required optical density. The metal is preferably aluminum (Al), molybdenum (Mo) tantalum (Ta), and a multilayer structure or mixture of the metals.

The polishing in the present invention has been studied as a method for flattening a color filter in the past. Lapping and polishing polishing (see, for example, JP-A-2-287403).
However, tape polishing is preferably used, which has the effect of simultaneously obtaining the effect of eliminating the step between the colors of the color filter pattern.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 FIGS. 1 to 3 are sectional views schematically showing a manufacturing process of a color filter in Example 1 of the present invention. In FIG. 1, after forming the color filter pattern 2 on the transparent substrate 1,
The state which formed the light shielding layer 3 is shown.

Here, the color filter pattern 2 was sequentially formed by a photolithography method using a pigment dispersion resin. The thickness was about 1.5 μm, the step difference between colors was 0.2 μm at the maximum, and the surface roughness R _max was 0.1 to 0.15 μm. Further, as the light-shielding layer 3, a 1000 Å thick Al film is formed by the sputter deposition method.
Layers were formed.

FIG. 2 shows a state in which the light shielding layer on the color filter pattern 2 portion is removed by a polishing method and the light shielding layer pattern 2a is formed outside the color filter pattern portion by self-alignment. Polishing is performed using a foamed urethane surface plate and an alumina polishing liquid with a particle size of 0.3 μm at 50 g / cm.
It was performed by rotating and rocking for 3 minutes under the load of ² .

As a result, the light-shielding layer on the color filter pattern portion is completely removed, and as shown in FIG. 3, self-alignment is performed between the pixels 13 of the color filter outside the color filter pattern portion and on the side surface 14 of each pixel. A light shielding pattern was formed. Also, the surface roughness of the color filter pattern was R _max = 0.05 to 0.10 μm, and good smoothness was obtained. However, the maximum step difference between each color is 0.15μ
It was only a slight improvement.

Then, as shown in FIG.
A protective layer having a thickness of μm was formed to produce a color filter substrate.

Example 2 In the same manner as in Example 1, a color filter pattern as shown in FIG. 1 and a light shielding layer thereon were formed. Figure 2
Shows a state in which the light shielding layer on the color filter pattern 2 part is removed by a polishing method and the light shielding pattern is formed outside the color filter pattern part by self-alignment.

FIG. 4 is a sectional view schematically showing a method of removing the light shielding layer by polishing. Polishing conditions are Al ₂ O ₃ system #
Using the polishing tape 5 of 6000, the substrate feed speed is 75 m
m / min, tape feeding speed 300 mm / min, tape pressing pressure 5 kgf / cm ² , and number of polishing 5 times.

As a result, the light-shielding layer on the color filter pattern portion was completely removed, and the surface roughness R _max of the color filter was improved to 0.05 to 0.10 μm and the step difference between colors was improved to 0.05 μm at the maximum.

As shown in FIG. 3, the final thickness is 1.5 μm.
A color filter substrate having a protective layer of m was formed. A color liquid crystal panel produced by using the substrate by a predetermined method had a contrast of 40 or more, a wide driving temperature range, and a large display area and uniform display characteristics.

Example 3 After forming a color filter pattern in the same manner as in Example 1, a carbon dispersion type resin light-shielding layer 3b having a thickness of 1.5 μm, which is the same as the color filter layer, is formed by a printing method as shown in FIG. Formed. This is done on the # 3000 firing PVA surface plate with a flat reference surface as a lapping process.
A load of g / cm ² was applied and the mixture was rotated and rocked for 30 seconds.

At this point, although the light-shielding layer on the color filter pattern portion was removed and the light-shielding pattern was formed, no improvement was seen in the surface roughness of the color filter pattern and the step difference between colors. Further, additional polishing was performed by the tape polishing method shown in the schematic view of FIG.

The polishing conditions are Al ₂ O ₃ system and a # 6000 polishing tape is used. The substrate feeding speed is 75 mm / min, the tape feeding speed is 300 mm / sec, and the tape pressing pressure is 5.
The number of times of polishing was 5 kgf / cm ² . As a result, the surface roughness R _max of the color filter is 0.05 to 0.10.
.mu.m, and the step difference between colors was improved to a maximum of 0.05 .mu.m.

As shown in FIG. 3, the final thickness is 1.5.
The color liquid crystal panel manufactured by using the color filter substrate having the protective layer of μm provided a display characteristic of large area and uniform over a wide driving temperature range with a contrast of 40 or more.

[0029]

As described above, according to the present invention, it is possible to form a light-shielding layer on a color filter pattern and polish it to form a light-shielding pattern at the same time as flattening the color filter. The layer patterning step and the exposure mask for patterning are not required, which simplifies the steps and reduces the cost, and also has the effect of broadening the selection range of the light shielding layer material and facilitating the process design of the color filter substrate.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a manufacturing process of a color filter in Example 1 of the present invention.

FIG. 2 is a cross-sectional view that schematically shows the manufacturing process of the color filter in Example 1 of the present invention.

FIG. 3 is a cross-sectional view that schematically shows the manufacturing process of the color filter in Example 1 of the present invention.

FIG. 4 is a cross-sectional view schematically showing a method of removing a light shielding layer by polishing in Example 2.

FIG. 5 is a cross-sectional view showing a formation state of a light shielding layer on a color filter pattern in Example 3.

FIG. 6 is a cross-sectional view of a liquid crystal panel using a conventional color filter substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Color filter pattern 3 Light-shielding layer 3a Light-shielding layer pattern 4 Protective layer 5 Polishing tape 7 Transparent electrode 8 Metal routing electrode 9 Insulating film 10 Alignment film 11 Cell gap 12 Liquid crystal 13 Pixel 14 Side surface

Claims (4)

[Claims] 1. A color filter pattern is formed on the surface of a transparent substrate, and a light-shielding layer is provided between each pixel of the color filter and on the side surface of each pixel to form a light-shielding layer pattern,
A color filter substrate comprising a protective layer formed on the color filter pattern and the light shielding layer pattern. 2. A step of forming a color filter pattern on the surface of a transparent substrate, a step of forming a light shielding layer on the color filter pattern, and a part of the light shielding layer and the color filter pattern on the color filter pattern removed by polishing. And a step of forming a protective layer on the ground color filter and the light-shielding layer pattern, the method of manufacturing a color filter substrate. 3. The method for producing a color filter substrate according to claim 2, wherein the polishing step is tape polishing or a step including tape polishing. 4. The light shielding layer is made of a metal film, and the metal is A
The method for producing a color filter substrate according to claim 2, which comprises a multilayer structure or a mixture of 1, 1, Mo, Ta and the metal.