JPH09197117A - Production of color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form color filters of a uniform film thickness free from unevenness in streaks and irregularity in color over the region of the entire surface of a substrate when plural color filters are produced on a large-sized substrate by a spin coating method. SOLUTION: In order to form plural color filters on a substrate 1, a black matrix and a dummy pattern are simultaneously formed by combining a pattern of the black matrix 2 and the dummy pattern 3 separately made of resin materials. Color filters are then formed on the black matrix 2 and an overcoat film is formed on the color filters and the dummy pattern 3 of color filters.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter manufacturing method, and more particularly to a color filter manufacturing method for manufacturing a plurality of liquid crystal display devices from a large substrate.

[0002]

2. Description of the Related Art In recent years, among the members of liquid crystal display devices,
Since the color filter is expensive, a plurality of color filters are simultaneously formed on a large-sized substrate. And then, using splitting and defect-free color filters,
By assembling the liquid crystal display device, a manufacturing means for reducing the price of the liquid crystal display device is taken.

As a method of forming this color filter,
A method of forming the color filter substrate by a spin coating method or a roll coating method may be mentioned.

The former spin coating method has a drawback in that the amount of color filter base material used is large, but in comparison with the latter roll coating method, the undulation of the formed film thickness of the color filter base material and the unevenness of the roll are not uniform. It is excellent in uniformity of the formed film thickness. Moreover, since the filtered color filter substrate is formed by dropping it on each substrate, there is an advantage that the occurrence of dust defects, which are fatal damages of the color filter, is reduced.

However, when it is attempted to simultaneously form a plurality of color filters consisting of three layers of a black matrix of black resin, a color filter and an overcoat film on a large-sized substrate at the same time as a color filter of recent years, a step of each film thickness is formed. As a hindrance, uneven streaks occur, and a part where the film thickness becomes non-uniform occurs.

Before describing the method of manufacturing a color filter in the prior art, the structure of a color liquid crystal display device using a color filter will be described with reference to the sectional view of FIG.

As shown in FIG. 20, a seal 9 is provided between the upper and lower substrates 1 so as to seal the liquid crystal layer 11. Further, on the substrate 1 on the upper side, a lattice-shaped black matrix 2 made of a black resin material or a metal material is formed to shield light leakage from the gaps of the color filters 4 and improve the contrast. This Black Matrix 2
In order to exhibit the light-shielding property, the black resin material is required to have a film thickness of 1 μm or more, and the metal material is required to have a film thickness of 100 nm or more.

A color filter 4 is provided on the black matrix 2, and an overcoat film 7 for flattening the surface is further provided. A display electrode 8a is provided on the overcoat film 7, and the display electrode 8a is provided on the lower substrate 1 as well.
a is provided. The polarizing plates 10 and 10 are provided outside the substrate 1.
Are respectively arranged to form a liquid crystal display device.

A manufacturing method in the prior art will be described below with reference to FIG.
And FIG. 13 to FIG. FIG. 12 is a plan view showing a method of manufacturing a black matrix in the prior art, and FIGS. 13 to 19 are sectional views showing a section taken along the line AA of FIG. Here, a manufacturing method for forming the black matrix with a black resin will be described.

First, as shown in FIG. 14, a substrate 1
A black matrix base material 21 made of a black resin material having photosensitivity is dropped on the black matrix base material 21, and the black matrix base material 21 is spread on the substrate 1 by a spin coating method in which the substrate 1 is rotated.

Then, since there are no obstacles on the substrate 1, a black matrix substrate 22 having a uniform film thickness and a flat surface can be obtained as shown in FIG.

Next, the black matrix base material 22 is exposed and developed using a photomask to form the black matrix 2. Since the black matrix base material 22 which is a black resin film is formed flat, the black matrix 2 having a uniform film thickness on the entire surface of the substrate 1 can be formed.

After that, in order to form a color filter on the black matrix 2 formed on the substrate 1, first, a color filter base material 41 having a photosensitivity of the first color of the color filter is placed on the substrate 1 as shown in FIG. Drop it on
The substrate 1 is formed to a thickness of 1 μm to 2 μm by a spin coating method in which the substrate 1 is rotated.

As the color filter substrate 41, a color resist in which fine black, red, green and blue pigments are uniformly dispersed in an acrylic resin or an epoxy resin is excellent in heat resistance and light resistance. It is used as the color filter substrate 41.

Here, since a plurality of liquid crystal display devices are formed on one substrate, a black matrix pattern for forming a plurality of color filters on one substrate 1 is as shown in FIG. Black matrix 2a,
Black matrix 2b, black matrix 2
c, the black matrix 2d is independently arranged as a pattern.

As shown in the sectional view of FIG. 13, the substrate 1 and the black matrix 2 need to have a film thickness of 1 μm or more when a black resin material is used as the black matrix 2. For this reason, when the color filter substrate is formed on the black matrix by the usual spin coating method, the result shown in FIG.
As shown in FIG. 7, the black matrix 2 is formed on the outside of the substrate 1.
In the area near a and the black matrix 2d, the color filter substrate 42 has a portion where the film thickness is radially uneven from the center portion of the substrate 1 toward the outer peripheral portion due to a striation phenomenon from the corner portion.

The striation phenomenon is a phenomenon in which streak-shaped formation unevenness occurs radially from the center of the substrate by the spin coating method. The lower the vapor pressure of the solvent of the chemical solution to be formed, the more easily the clay of the chemical solution is likely to change, the more likely it is to occur, the higher the coating rotation speed, and the larger the size of the substrate, the stronger the centrifugal force at the outer peripheral portion becomes, which is remarkable.

Thereafter, when the substrate 1 is sequentially subjected to an exposure process, a development process and a baking process to form a color filter pattern for the first color, the non-uniform state of the film thickness remains as shown in FIG. , The color filter 4 is formed.

Next, the second and third color filter substrates are formed by the spin coating method similarly to the first color. As shown in the sectional view of FIG. 19, the second and third colors further include a black matrix 2 film. The thickness of the color filter 4 of the first color is added to the thickness, and the thickness difference with the substrate 1 increases. Therefore, in the area near the black matrix 2a and the black matrix 2d on the outer side of the substrate 1, the color filter substrate has a stronger striation phenomenon from the corner portion, and the film thickness is radially nonuniform from the substrate central portion to the outer peripheral portion. Sex increases.

After that, as shown in FIG. 19, after forming color filters 4 of three colors of red, green and blue, an overcoat having flatness, chemical resistance and indium tin oxide (ITO) sputtering resistance. The film 7 is formed by the spin coating method. Then, the film thickness of the black matrix 2 and the film thickness of the color filter 4 are added, and the film thickness difference further increases. Therefore, in the region near the black matrix 2a and the black matrix 2d outside the substrate 1,
The striation phenomenon intensifies from the corner portion, and the non-uniformity of the film thickness of the overcoat film 7 further increases radially from the central portion of the substrate 1 toward the outer peripheral portion.

[0021]

SUMMARY OF THE INVENTION In order to form the film thickness of a plurality of color filters 4 on a substrate 1 as uniformly as possible by the conventional manufacturing method, and to sufficiently obtain the color density of the color filters 4, When the film thickness of No. 4 is 1 μm or more, the film thickness is controlled by controlling the viscosity and the rotation speed of the color filter substrate 42 when forming the color filter substrate 42 by the spin coating method.

However, the pattern of the plurality of color filters 4 arranged on the large-sized and rectangular substrate 1 has a quadrangular plane pattern and has a corner, and further has a film thickness difference of 1 μm or more. Therefore, there is a drawback that a striation phenomenon is generated from the corners of the substrate, the centrifugal force increases toward the outer periphery of the substrate, and the formed film thickness cannot be formed uniformly.

Therefore, there is a problem in that the film thickness of the pattern near the corners of the four corners of the large-sized and square substrate 1 is unevenly formed, resulting in variation in thickness within the same substrate. As a result, when a color liquid crystal display device is assembled from a plurality of color filters manufactured from a large substrate 1, liquid crystal cell defects such as display unevenness and color unevenness occur.

An object of the present invention is to solve this problem, and when a plurality of color filters are manufactured on a large-sized substrate by a spin coating method, a uniform unevenness and color nonuniformity are obtained over the entire area of the substrate. It is an object of the present invention to provide a color filter manufacturing method capable of forming a color filter having a film thickness.

[0025]

In order to achieve the above object, the method of manufacturing a color filter of the present invention employs the following steps.

In the method for manufacturing a color filter of the present invention, a step of simultaneously forming a black matrix and a dummy pattern on a substrate by connecting a plurality of independent black matrix patterns made of a black resin material and a dummy pattern. A step of forming a color filter on the black matrix and a step of forming an overcoat film on the color filter and the dummy pattern of the color filter are performed, and a plurality of color filters are formed on the substrate.

In the method of manufacturing a color filter according to the present invention, a step of simultaneously forming a black matrix and a dummy pattern on a substrate by connecting a plurality of independent black matrix patterns and dummy patterns made of a metal material, A step of forming a color filter on the black matrix and a step of forming an overcoat film on the color filter and the dummy pattern of the color filter are performed, and a plurality of color filters are formed on the substrate.

When a plurality of color filters are formed on a large-sized substrate, red, green and blue color filter base materials are uniformly formed on the entire surface of the large-sized substrate to provide excellent flatness over the entire surface of the large-sized substrate. It is desirable to form a color filter having a uniform film thickness.

Therefore, as a method for forming the color filter substrate, there are a spin coating method and a roll coating method. The former spin coating method has a low dust defect generation rate and is excellent in the uniformity of the formed film thickness. However, even though the formed film thickness is excellent on a flat substrate, 1 μm
In a manufacturing process for forming a color filter having a film thickness of up to 2 μm, even if a single-piece pattern is formed by dropping black resin or a color filter substrate at the center of the pattern, it is a single-piece pattern. A uniform film thickness can be formed.

However, if there are a large number of independent color filter patterns, it is 1 μm to 2 μm.
Since there is a film thickness difference of m, the film thickness difference plays a role of an obstacle in the pattern on the outside of the substrate, and a streak phenomenon is generated in the corner portion due to the striation phenomenon, and the film thickness becomes uneven. Become.

Further, when an overcoat film for improving flatness, chemical resistance and ITO sputtering resistance of the color filter is formed by a spin coating method, the film thicknesses of the black matrix and the color filter are added, There will be a film thickness difference of 2 μm to 3 μm.
As a result, when there are many independent color filter patterns, the film thickness difference acts as an obstacle in the pattern on the outside of the substrate, and the striation phenomenon occurs from the corner of the independent color filter pattern. Streaks occur in the overcoat film and the film thickness becomes uneven.

When a color filter substrate is formed by the spin coating method of the manufacturing method of the present invention to manufacture a plurality of color filters on a large-sized substrate, the thickness of the plurality of color filters is formed uniformly. In order to do so, the manufacturing method described below is adopted. A black matrix pattern and a black matrix pattern, which are independently formed on the substrate, are formed by connecting with a dummy pattern. As a result, the gap between the plurality of patterns is eliminated so that the film thickness difference between the substrate and the black matrix does not occur.

Next, when a color filter substrate of the first color, for example, red, is formed on the black matrix and the dummy pattern by the spin coating method, the pattern of the black matrix and the dummy pattern are connected to each other on the substrate, and there is a gap between the patterns. There is no. Since there is no film thickness difference due to the substrate and the black matrix as described above, even if a plurality of patterns are formed on one substrate, a plurality of patterns formed on the entire surface of the substrate are as if they were one pattern. The film thickness can be made uniform.

After that, the red color filter substrate formed on the dummy pattern connected to the black matrix pattern is exposed, and then developed to simultaneously form the red color filter pattern on the connected dummy pattern. To do. Similarly, if the second color green and the third color blue color filter base materials are formed by the spin coating method and the dummy patterns connected to the color filter patterns are formed at the same time, a plurality of color filter patterns on the substrate and the substrate Since there is no film thickness step, the film thickness of the plurality of color filter patterns can be formed uniformly over the entire surface of the substrate.

Further, when the overcoat film is formed on the entire surface of the substrate by the spin coating method on the color filter, there is no gap between the dummy patterns made of the color filters formed in connection with the color filter pattern, and the film thickness difference is not generated. Therefore, the overcoat film can also be formed with a uniform film thickness, and a color filter having a uniform film thickness of a plurality of films can be manufactured on a large-sized substrate and can be manufactured.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION The best embodiment of the method for manufacturing a color filter of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described. 1 and 2 are a plan view and a cross-sectional view showing a black matrix showing a method of manufacturing a multi-color filter according to an embodiment of the present invention, and FIGS. 3 to 7 show a method of manufacturing a color filter. It is sectional drawing which expands and shows a partial area | region of FIG. 1 and FIG.

First, as shown in FIG. 1, CFPR-BK-53 made by Tokyo Ohka Co., Ltd., which is a negative black resin having photosensitivity as a black matrix base material on a substrate 1.
A film having a thickness of 1.5 μm is formed by a spin coating method in which 0S is dropped on the center of the substrate 1 and the substrate 1 is rotated.

When black resin as a black matrix base material is dropped on the substrate 1 and the spin coating method of rotating the substrate 1 is applied, there is no obstacle on the substrate, so that the film thickness is uniform over the entire surface of the substrate 1. It is possible to form a simple black matrix substrate.

After that, a plurality of black matrices 2
And a black mask 2 for connecting the black matrix 2 and a black resin dummy pattern 3 are used to perform an exposure process using a photomask on which alignment marks for alignment are formed. Then, it is developed in N-AK developer manufactured by Tokyo Ohka Co., Ltd. as an alkali developer for 1 minute to form a black matrix 2. After that, the substrate 1 on which the black matrix base material is formed is baked at a temperature of 200 ° C. to improve the adhesion between the black matrix 2 and the substrate 1 and the chemical resistance.

After that, as shown in FIG. 2, in order to form a color filter of the first color on the black matrix 2 and the dummy pattern 3, a red color filter substrate having photosensitivity is formed by a spin coating method. Then, as shown in FIG. 3, since the dummy patterns 3 are arranged between the patterns of the black matrix 2, there is no film thickness difference between the patterns of the black matrix 2 and the film thickness of the black matrix can be formed uniformly. Therefore, the film thickness of the color filter substrate can be formed uniformly over the entire surface of the substrate.

After that, an exposure process is performed using a photomask and an alkali development process is performed to form a red color filter pattern 4a. As shown in FIG. 4, a red (R) color filter 4a in the black matrix 2 region,
In the dummy pattern 3 region, the dummy pattern 3a is simultaneously formed by the red color filter.

Thereafter, by the same process as the red color filter 4b, the green (G) color filter pattern 4 is formed in the black matrix 2 area as shown in FIG.
b is formed, and the dummy pattern 3b is simultaneously formed in the dummy pattern 3 region with a green color filter.

Further, as shown in FIG. 6, a blue (B) color filter pattern 4 is formed in the black matrix 2 region.
c and the dummy pattern 3c are simultaneously formed in the dummy pattern 3 region with a blue color filter. These red, green and blue color filters are formed with a film thickness of 1.5 μm. As a result, as shown in FIG. 6, there is no step between the color filter and the dummy pattern of the color filter, and the film thickness of the color filter can be formed uniformly over the entire surface of the substrate.

Next, as shown in FIG. 7, JSS-6777 manufactured by Japan Synthetic Rubber Co., Ltd. is formed as a transparent thermosetting type overcoat film on the color filter having a uniform film thickness by a spin coating method. Since the overcoat film 7 has no film thickness difference between patterns, the film thickness can be formed uniformly. This overcoat film is formed with a film thickness of 2 μm.

As a result, the color filters 4a, 4b, 4 having a uniform film thickness on the large-sized substrate 1 and having no unevenness or color unevenness.
c can be formed.

Next, a method of manufacturing a color filter according to the second embodiment of the present invention will be described with reference to the drawings. 8 is a plan view showing a method of manufacturing a color filter according to an embodiment of the present invention, FIG. 9 is a cross-sectional view showing a cross section taken along the line AA of FIG. 8, and FIG. 10 is a cross section taken along the line BB of FIG. It is sectional drawing which shows the cross section in a line. Then, FIG. 11 is a sectional view showing a method of manufacturing a color filter pattern in which a transparent electrode is formed on a color filter, and enlarging FIGS. 9 and 10.

First, a metal material such as chromium or molybdenum is formed as a black matrix material on the substrate 1 by sputtering to have a film thickness of 100 nm.

Then, a positive type resist ZPP-1700 manufactured by Nippon Zeon Co., Ltd. is formed to a thickness of 1.2 μm on the substrate 1 on which the metal material is formed by a spin coating method. Then, FIG.
As shown in FIG. 3, a black matrix pattern is formed using a photomask having a plurality of black matrices 2 and a dummy pattern 3 connecting the corners of the black matrix 2.

After that, the substrate 1 on which the black matrix pattern is formed is etched with a cerium-ammonium nitrate-based etching solution when the black matrix material is a chromium film, and with a phosphoric acid-based etching solution when the black matrix material is molybdenum. Then, when the resist is peeled off, the black matrix 2 having a film thickness difference from the substrate of 100 nm can be formed.

Then, first, a red (R) color filter substrate is formed to a thickness of 1.5 μm by a spin coating method.
Here, unlike the first embodiment, the film thickness difference of the black matrix pattern is only about 100 nm, and
Since the corner portions of the patterns of the plurality of black matrices 2 are connected by the dummy patterns 3, the color filter substrate film thickness can be formed uniformly as shown in FIG.

Next, as shown in FIG. 8, the dummy pattern 3 in which the corner portions of the color filter pattern and the color filter pattern are connected, and the dummy pattern and the corner portion of the cross-shaped color filter provided in the central portion of the substrate are formed. The color filter 1 shown in FIG. 9 is subjected to exposure processing and development processing using a photomask having a pattern in which
And dummy pattern 2 are formed.

A second color green (G) and a third color blue (B) color filter substrate are formed by a spin coating method by the same processing steps as for the red color filter. Here, FIG.
As shown in the plan view of FIG. 8, the corner portion of the color filter pattern is a dummy pattern even though the film thickness step size of the red color filter pattern formed in the first color is 1.5 μm as shown in FIG. As shown in FIG. 9, there is no film thickness difference between the black matrix 2 and the dummy pattern 3 because they are connected with each other. As a result, the film thickness of the second color filter substrate and the third color filter substrate can be formed to be uniform without causing uneven streaks due to the striation phenomenon.

After that, when the second color and the third color are subjected to the exposure process and the development process in the same manner as the first color to form the color filter, the color filter film thickness can be made uniform as in the first embodiment.

After that, as a negative type overcoat film having photosensitivity, V-259PA resin manufactured by Nippon Steel Chemical Co., Ltd. is formed on the substrate by a spin coating method to a film thickness of 3 μm. Here, since the corner portions of the black matrix are connected by the dummy pattern 2 and there is no film thickness difference at the corner portions of the color filter, the overcoat film 7 is formed to have a uniform film thickness without the occurrence of streaks due to the striation phenomenon. can do.

Then, after baking at a prebaking temperature of 80 ° C. to remove the solvent in the photosensitive resin, alignment is performed with a black matrix pattern and exposure is performed with a photomask.

After that, when development processing is performed in an alkaline developing solution, as shown in FIG. 11, the negative type overcoat film 7 is formed.
The overcoat film 7 can be formed only on the color filter region irradiated with the light. After that, the substrate on which the photosensitive overcoat film is formed is heated at a temperature of 250 in a nitrogen atmosphere.
Calcination is performed for 1 hour.

After that, a transparent conductive film made of indium tin oxide (ITO) was formed on the entire surface of the substrate 1 at a substrate temperature of 22.
It is formed by a sputtering method at 0 ° C. Then, as shown in FIG. 11, the transparent conductive film is patterned to form the display electrode 8a on the color filter and the extraction electrode 8b on the substrate 1.

As a result, unlike the first embodiment, only the color filter portion is covered with the overcoat film 7,
It is possible to simultaneously form a plurality of color filters having the extraction electrode 8b on the substrate 1 and having a uniform film thickness and excellent flatness.

[0059]

As described above, according to the present invention, when a plurality of color filters are manufactured on a large-sized substrate by a spin coating method, a uniform film having no unevenness or uneven color is formed over the entire area of the substrate. A thick color filter can be formed. Therefore, it is possible to simultaneously manufacture a plurality of liquid crystal color display devices without the display unevenness and color unevenness of STN type, ferroelectric type, or antiferroelectric type liquid crystal cells that require flatness of color filters at a high yield. It will be possible.

[Brief description of drawings]

FIG. 1 is a plan view showing a method of manufacturing a color filter according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the method of manufacturing a color filter according to the embodiment of the invention.

FIG. 3 is a cross-sectional view showing the method of manufacturing the color filter according to the embodiment of the invention.

FIG. 4 is a cross-sectional view showing the method of manufacturing the color filter according to the embodiment of the invention.

FIG. 5 is a cross-sectional view showing the method of manufacturing the color filter according to the embodiment of the invention.

FIG. 6 is a cross-sectional view showing the method of manufacturing the color filter according to the embodiment of the invention.

FIG. 7 is a cross-sectional view showing the method of manufacturing the color filter in the embodiment of the present invention.

FIG. 8 is a plan view showing the method of manufacturing the color filter according to the embodiment of the invention.

FIG. 9 is a cross-sectional view showing the method of manufacturing the color filter in the embodiment of the present invention.

FIG. 10 is a cross-sectional view showing the method of manufacturing the color filter in the embodiment of the present invention.

FIG. 11 is a cross-sectional view showing the method of manufacturing the color filter in the embodiment of the present invention.

FIG. 12 is a plan view showing a method of manufacturing a color filter in the related art.

FIG. 13 is a cross-sectional view showing a method of manufacturing a color filter in the related art.

FIG. 14 is a cross-sectional view showing a method of manufacturing a color filter in the related art.

FIG. 15 is a cross-sectional view showing a method of manufacturing a color filter in the related art.

FIG. 16 is a cross-sectional view showing a method of manufacturing a color filter in the related art.

FIG. 17 is a cross-sectional view showing a method of manufacturing a color filter in the related art.

FIG. 18 is a cross-sectional view showing a method of manufacturing a color filter in the related art.

FIG. 19 is a cross-sectional view showing a method of manufacturing a color filter according to a conventional technique.

FIG. 20 is a cross-sectional view showing a color liquid crystal display device.

[Explanation of symbols]

 1 substrate 2 black matrix 3 dummy pattern 4 color filter 7 overcoat film

Claims (2)

[Claims] 1. A step of simultaneously forming a black matrix and a dummy pattern by connecting a plurality of independent black matrix patterns made of a black resin material and a dummy pattern on a substrate, and forming a color filter on the black matrix. And a step of forming an overcoat film on the color filter and a dummy pattern of the color filter, wherein a plurality of color filters are formed on the substrate. 2. A step of simultaneously forming a black matrix and a dummy pattern by connecting a pattern of a black matrix and a dummy pattern made of a plurality of independent metal materials on a substrate, and forming a color filter on the black matrix. A method of manufacturing a color filter, comprising: forming a plurality of color filters on a substrate; and forming an overcoat film on the color filter and a dummy pattern of the color filter.