JPH09127326A - Production of color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a flat color pattern with little steps. SOLUTION: A photosensitive resin layer 1 is formed on a transparent substrate 3 on which a black matrix(BM) or a color pattern 2 of one or more colors is formed in a specified position. The resin layer 1 is flattened by heat treatment and pressure treatment. Then the flattened photosensitive resin layer is exposed to light through a photomask having a specified pattern and developed to form a color pattern 2 to obtain a color filter. By this method, the obtd. color filter has a flat color pattern, so that it does not cause orientation defects or irregular colors in a liquid crystal.

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 or the like.

[0002]

2. Description of the Related Art Liquid crystal display elements are utilized for many purposes by utilizing the features of light weight, thinness, and low power consumption. In addition, since color display can be relatively easily performed by a combination of a backlight and a color filter, it is used as a display of a personal computer or a word processor. The color filter, which is an important component of colorization, has R (red), G (green), and B (blue) colored patterns arranged on a transparent substrate, and a black matrix (BM) between the colored patterns as necessary. The configuration is such that a pattern is formed. On the upper side of the black matrix (BM) pattern and each of the RGB colored patterns, a transparent conductive film or a transparent conductive film is appropriately formed via a protective film.

[0003] As a method of manufacturing the above color filter,
Various methods such as a dyeing method, a pigment dispersion method, a printing method, and an electrodeposition method have been developed and studied. Among them, the method of sequentially patterning the RGB coloring patterns by the photolithography method after forming the photosensitive resin layer in which the pigment is dispersed as in the pigment dispersion method is currently used because of the high accuracy of the manufacturing pattern. It is becoming mainstream. Furthermore, in addition to applying a photosensitive resin liquid in which a pigment is dispersed by a conventional spin coater or the like and then drying it to form a photosensitive resin layer, a transfer method using a photosensitive dry film in which a pigment is dispersed is used as a material. It has attracted attention because of its high utilization efficiency, low cost, and simple formation.

However, in the method of manufacturing a color filter by the transfer method of a pigment-dispersed photosensitive dry film, the pigment-dispersed photosensitive resin layer () is superposed on a coloring pattern or a BM (black matrix) pattern already formed at predetermined positions. (Hereinafter referred to as a photosensitive resin layer), the BM
Due to the influence of the (black matrix) pattern or the colored pattern, the photosensitive resin layer has unevenness having an inclination as shown in FIG. When the photosensitive resin layer is exposed and developed with the unevenness having an inclination, the formed colored pattern is not flat and has a nonuniform film thickness. FIG.
In the above, 1 is a photosensitive resin layer, 2 is a colored pattern already formed, 3 is a transparent substrate, and 4 is a base film.

Therefore, the shape may be flattened by polishing or pressing. Conventionally, such a flattening process is performed after forming a colored pattern, that is, by exposing and
It was done after development. However, by performing the exposure, crosslinking of the photosensitive resin proceeds, and the resin hardly flows, so that sufficient flattening is not performed, or high temperature and high pressure are required to perform sufficient flattening.

[0006]

The above-mentioned non-uniform shape generated in the colored pattern due to the photosensitive resin layer having the unevenness having the inclination finds the alignment of the liquid crystal and deteriorates the display quality of the color liquid crystal display device. Is causing The present invention provides a method for manufacturing a color filter that solves the above-mentioned problems of the prior art and easily forms a flat colored pattern having a sufficiently small step.

[0007]

The present invention provides R (red), G
A step of forming a photosensitive resin layer on a transparent substrate on which at least one pattern selected from (green), B (blue) colored patterns and a black matrix (BM) pattern is formed; A method of manufacturing a color filter comprising: a step of performing a flattening process; and a step of forming a colored pattern by exposing and developing the flattened photosensitive resin layer through a photomask.

That is, according to the present invention, a step of forming a photosensitive resin layer on a transparent substrate on which a black matrix (BM) or a colored pattern of one or more colors is formed at a predetermined position, and a heating / pressurizing treatment are further performed. As shown in FIG. 1, a step of flattening the photosensitive resin layer is performed, and the flattened photosensitive resin layer is exposed and developed through a photomask having a predetermined pattern to form a colored pattern. The method for producing a color filter is characterized by including at least the step of: In FIG. 1, 1 is a photosensitive resin layer, 2
Is a colored pattern already formed, 3 is a transparent substrate, and 4 is a base film.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The flattening treatment of the photosensitive resin layer can be carried out by heating / pressurizing with a roll, sandwiching a smooth film between the roll and the substrate, and heating / pressurizing. The photosensitive resin layer is formed directly on the transparent substrate or via another layer.

More specifically, a method of manufacturing a color filter using a pigment-dispersed photosensitive dry film (hereinafter referred to as photosensitive dry film) will be described. However, this is an example, and is not limited to the following method. First, a photosensitive dry film colored R (red) is transferred onto a glass substrate on which a BM (black matrix) pattern is formed by using a heat roll to form a photosensitive resin layer. On the glass substrate, at least one of R (red), G (green), and B (blue) colored patterns is used instead of the BM (black matrix) pattern, or R (red), G (green), and B ( At least one of the blue) coloring patterns and the black matrix (B
M) A pattern may be formed. At this time, BM
Due to the influence of the (black matrix) pattern, the photosensitive resin layer has unevenness having an inclination. Exposure is performed by overlapping the respective ends so that there is no gap between adjacent portions of the BM (black matrix) pattern and the R (red) colored pattern. For this reason, if exposure and development are performed without any processing, as shown in FIG. 3, a bulge occurs in an overlap portion between a BM (black matrix) pattern and an R (red) colored pattern. This swelling is conspicuously exhibited in a thick BM such as the resin BM. In FIG. 3, 3 is a transparent substrate, 5 is a BM (black matrix) pattern, and 6 is a colored pattern having a bulge in an overlapping portion with the BM (black matrix) pattern.

Therefore, in the present invention, the photosensitive dry film is transferred, the photosensitive resin layer is formed, and then the photosensitive resin layer having unevenness having an inclination is flattened by heating and pressing. As a method of flattening, it is easy to sandwich the substrate with two rolls and apply heat and pressure, but the same effect can be obtained even if one of the plates is used as a platen. The substrate may be heated as needed. As the material of the roll, rubber, metal, resin, ceramic or the like can be considered. The photosensitive resin layer can be heated with a roll while the base film of the photosensitive dry film is attached or the base film is peeled off.
Apply pressure. Further, the film may be sandwiched between the roll and the substrate to perform heating / pressurization. In particular, at this time, it was also found that the film to be sandwiched was not peeled immediately after being pressed, but was peeled after being gradually cooled, so that the film was easily flattened. Examples of the material of the film sandwiched between the roll and the substrate include resin films such as polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, cellophane, polysulfone, and polyimide; metal films such as aluminum, nickel, and copper; and multilayer films thereof.

Next, after exposing only a predetermined position of the photosensitive resin layer through a photomask, development is performed and R (red) is developed.
Is formed. Then, similarly to the R (red) colored pattern, the photosensitive resin layer having unevenness having an inclined shape is flattened by a press, and then exposed and developed to perform G.
A (green) or B (blue) colored pattern is formed. G
Alternatively, when forming the photosensitive resin layer of B, a coloring pattern already formed, for example, R for the second color
(Red) In the case of the third color, the photosensitive resin layer has a concavo-convex shape having an inclination under the influence of the R (red) and G (green) colored patterns and the BM pattern. For this reason, when exposure and development are performed without processing, swelling occurs in the overlapping portion with the BM pattern as in the R (red) colored pattern. Further, the color pattern newly formed by exposure / development does not overlap with the color pattern already formed, but due to the inclination of the photosensitive resin layer, the cross-sectional view shows the second color as L as shown in FIG. The letter shape and the third color are M-shaped. On the other hand, after the flattening treatment of the present invention,
In the case of development, a flat colored pattern is obtained as shown in FIG.

The use of a photosensitive dry film in which the photosensitive resin layers for the second and third colors are thinner than the film thicknesses for the first and second colors, respectively, can further flatten the photosensitive resin layers.

[0014]

【Example】

Example 1 35 parts by weight of 2-2′-bis [4-methacryloxy, polyethoxyphenyl] propane, γ-chloro-β-hydroxypropyl-β′-methacryloyloxyethyl-o
15 parts by weight of phthalate, 50 parts by weight of methacrylic acid / ethyl acrylate / ethyl acrylate (18/30/53 weight ratio) copolymer resin, 2 parts by weight of 1,7bis (9-acridinyl) heptane, hexamethoxymethylmelamine, methyl ethyl ketone Then, the anthraquinone-based red pigment was homogenized to obtain a red photosensitive resin layer coating solution. Further, a green or blue photosensitive resin layer coating solution was obtained using a phthalocyanine green pigment or a phthalocyanine blue pigment instead of anthraquinone in the above coating solution. The solution was coated on a base film (polyethylene terephthalate film having a thickness of 6 μm) with a gravure coater (manufactured by Hirano Seiki Co., Ltd.) to give a protective film of 30 μm.
A polyethylene dry film was attached to obtain a photosensitive dry film. The thickness of the photosensitive resin layer is R (red): 2.
0 μm, G (green): 2.0 μm and 1.5 μm, B
(Blue): 2.0 μm and 1.0 μm.

Next, using a black photosensitive resin coating liquid, the film thickness of 0.
Using a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd.) on a glass substrate (1.1 mm × 200 mm × 300 mm, manufactured by Corning) on which a 7 μm black matrix is formed, a substrate temperature of 110 ° C. and a roll temperature of 110
° C, roll pressure 5 kg / cm ² , speed 0.5 m / min.
A red photosensitive film having a thickness of 2.0 μm was laminated while peeling off the protective film so that the colored photosensitive resin faced the substrate to form a photosensitive resin layer. The photosensitive resin layer on the BM pattern rises, and the maximum and minimum are 0.7μ.
There is a step of m. On top of this, a 125 μm thick PE
A T film (manufactured by Teijin Limited, Teijin Tetron Film) is placed, and a roll press (manufactured by Hitachi Chemical Technoplant Co., Ltd.) is used.
The heating and pressurizing treatment was performed at a temperature of 0.2 ° C., a roll pressure of 6.5 kg / cm ² , and a speed of 0.2 m / min. After cooling after heating and pressurizing treatment, the 125 μm PET film was peeled off, and the surface step shape of the photosensitive resin layer was measured.
m or less.

Further, this was passed through a predetermined negative mask and a parallel light exposure machine (manufactured by Dainippon Screen Co., Ltd.)
After exposure to 00 mJ / cm ² , the base film of 6 μm was removed, and 0.2% by weight of Na ₂ was added at 25 ° C. using a spray type developing device DVW911 (manufactured by Dainippon Screen Co., Ltd.).
B ₂ O ₅ solution was 20 seconds spray unexposed portion was removed, a clean oven CSO-402 (manufactured by Kusumoto Chemicals)
At 150 ° C. for curing to form a red colored pattern. The formed R (red) colored pattern had a flat shape with a step of 0.1 μm or less with no swelling in the overlapping portion with the BM pattern.

Comparative Example 1 A colored pattern of R (red) was formed in the same manner as in Example 1 except that the heating / pressurizing treatment steps before exposure and development were omitted. The formed R (red) colored pattern had a protrusion of 0.3 μm in the overlapping portion with the BM pattern.

Example 2 A green photosensitive resin layer was laminated on the substrate on which R (red) pixels were formed in Example 1 using a green photosensitive dry film having a thickness of 2.0 μm in the same manner. Further, heating and pressing were performed three times using a metal roll from above the temporary support of the green dry film. The conditions were a roll temperature of 140 ° C., a substrate temperature of 100 ° C., a roll pressure of 6.5 kgf / cm ² , and a speed of 0.2.
m / min. Thereafter, exposure and development were performed in the same manner as in the first color to form a second color pixel. Furthermore, using a blue dry film with a film thickness of 2.0 μm, similarly laminating, heating,
Pressure treatment, exposure and development were performed to form a third color. The resulting RGB colored pattern had a good level difference of 0.2 μm or less. However, the height of the colored patterns of the second and third colors was higher than that of the first color, and the step difference between the pixels was 0.8 μm at the maximum.

Comparative Example 2 The same procedure as in Example 2 was carried out except that the second and third colors were formed without performing the heating / pressurizing treatment. The cross-sectional shape of the colored pattern was that the second color was L-shaped and the third color was The shape was M-shaped, and the step difference in the pixel was as large as about 0.5 μm.

Comparative Example 3 RG formed in Comparative Example 2 having a step difference of about 0.5 μm in the pixel
The colored pattern of B was placed on the colored pattern by placing a PET film having a thickness of 6 μm, which is the same as the temporary support of the colored dry film, on which a heating / pressurizing treatment was performed 3 times using a metal roll as in Example 2. went. The step difference in the pixel was hardly reduced.

Example 3 A green photosensitive dry film having a film thickness of 1.5 μm for the second color,
When the same procedure as in Example 2 was carried out except that a blue photosensitive dry film having a film thickness of 1.0 μm was used for the third color, the resulting RGB colored pattern had a good step difference of 0.2 μm or less. Further, the height of the colored pattern of each color was also uniform, and the step between pixels was 0.2 μm or less.

Example 4 A rubber roll was used, and the thickness between the roll and the substrate was 125 μm.
Example 3 except that the heating and pressurizing treatment was performed once by sandwiching a PET film (manufactured by Teijin Limited, Teijin Tetron film) and the resin film was peeled off after the substrate was cooled.
When the same procedure as described in 1. was performed, the resulting RGB colored pattern had a good step difference of 0.2 μm or less. Further, the height of the colored pattern of each color was also uniform, and the step between pixels was 0.2 μm or less.

[0023]

In the method for manufacturing a color filter of the present invention, the photosensitive resin layer having the unevenness having the inclination is flattened, and then exposed and developed, so that the flattening method is simple. Further, according to the manufacturing method of the present invention, since the obtained color filter has a flat colored pattern, there is an effect that it is possible to manufacture a good color filter without liquid crystal misalignment or color unevenness.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a photosensitive resin layer after a flattening process according to the present invention.

FIG. 2 is a cross-sectional view of a photosensitive resin layer before a flattening process of the present invention is performed.

FIG. 3 is a cross-sectional view showing a bulge generated in an overlap portion between a BM (black matrix) and a colored pattern.

FIG. 4 is a graph showing a cross section of a colored pattern formed without performing the flattening treatment of the present invention.

FIG. 5 is a graph showing a cross section of a colored pattern obtained by the present invention.

[Explanation of symbols]

1 ... Photosensitive resin layer 2 ... Colored pattern already formed 3 ... Transparent substrate 4 ... Base film 5 ... BM (black matrix) pattern 6 ... BM (black matrix) pattern Colored pattern with a swell in the overlapping part with

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Nobuaki Takane 48 Wadai, Tsukuba, Ibaraki Prefecture Within Tsukuba Development Laboratory, Hitachi Chemical Co., Ltd.

Claims (1)

[Claims] 1. A photosensitive resin layer is formed on a transparent substrate on which at least one pattern selected from a colored pattern of R (red), G (green), B (blue) and a black matrix (BM) pattern is formed. And a step of flattening the photosensitive resin layer with a press, and a step of exposing and developing the flattened photosensitive resin layer through a photomask to form a colored pattern. And a method of manufacturing a color filter.