JPH08106084A - Formation of black matrix made of resin - Google Patents

Abstract

PURPOSE: To obtain a black matrix pattern in which resist residues of protruding shape are not generated at corner parts of the pattern at the time of forming a black matrix of a color filter for a liquid crystal display device of a resin by providing a chamfer at a top end part of a corner of the pattern of a photomask for forming a pattern. CONSTITUTION: Chamfers 4 are previously provided at the top end parts of the corners of the patterns of the photomask 1 for forming a pattern in a forming process of the black matrix made of resin of the color filter for the liquid crystal display device on a transparent substrate. Consequently, corner parts of the pattern of the black matrix 2 are smooth and projections 3 are not generated. As to a chamfering quantity, the angle of the chamfer 4 is preferably 45 deg. and a distance between a corner apex of a pattern without forming a chamfer and both ends of a chamfering side is preferably 2 to 10μm for preventing a projection and maintaining numerical aperture. Shape of the chamfer 4 may be linear or circular arc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a resin black matrix in a color filter for a liquid crystal display device.

[0002]

2. Description of the Related Art When a color filter for a liquid crystal display device is formed on a transparent substrate, a black matrix (light-shielding film) is generally interposed between the color filters.
Conventionally, this black matrix is formed by vacuum-depositing chromium, and the formed chromium surface is patterned into a matrix by a photoetching process. However, this process is a costly and labor intensive method. Therefore, it has been proposed to use a material in which a light-absorbing pigment is dispersed in a photosensitive resin to form a resin black matrix in a simple process of a single pattern exposure and development process.

However, when a black matrix of a color filter for a liquid crystal display device is formed of a resin on a transparent substrate, a conventional method hardly allows a developer to enter a fine portion, and as shown in FIG. A resist residue having protrusions 3 is formed at the corner portion of the pattern. If there is a difference in the shape and size of the protrusions 3 on the display screen, a display pattern becomes uneven when a liquid crystal display device is used, and the display quality deteriorates.

[0004]

DISCLOSURE OF THE INVENTION According to the present invention, when a black matrix of a color filter for a liquid crystal display device is formed of a resin, a black matrix pattern in which no protruding resist residue is generated at the corners of the pattern is obtained. The purpose is to

[0005]

In order to solve the above problems, the present invention is shown in FIG. 1B in a step of forming a resin black matrix of a color filter for a liquid crystal display device on a transparent substrate. Thus, the chamfered portion 4 is provided in advance at the tip of the corner of the pattern of the pattern forming photomask. As a result, the corners of the pattern of the black matrix 2 become smooth, and no protrusions as in the conventional case are generated. Regarding the amount of chamfering, considering the prevention of protrusions and ensuring the aperture ratio, as shown in FIG. 2, the angle of the chamfered portion 4 is usually 45 °, and the apex of the corner of the pattern without the chamfered portion and both ends of the chamfered side. It is suitable to set the distance a between 2 and 10 μm. Further, the shape of the chamfered portion 4 is not limited to a straight line, and may be an arc having a radius of the distance a.

[0006]

According to the method of the present invention, since the sharp edge at the corner of the pattern of the photomask is eliminated, uneven development is less likely to occur, and no protrusion is generated at the corner of the black matrix pattern. . Moreover, the corners of the pattern become smooth due to optical factors.

[0007]

EXAMPLE An example of the process of forming the resin black matrix according to the present invention will be described. An ultraviolet curable photosensitive resin in which a black pigment is dispersed on a glass substrate forming a color filter for a liquid crystal display device, for example, Fuji Hunt Co., Ltd.
The product name "CK-2000" is evenly coated on the entire surface by a spin coater, polyvinyl alcohol is coated on the entire surface as an oxygen blocking film, prebaked, and then UV rays are irradiated through a photomask for forming a black matrix pattern. Irradiate 50 mJ / cm ² from the coated surface. The shape of one pixel of the pattern of the photomask used at this time is as shown in FIG.
Further, as shown in FIG. 3B, the chamfered portion 4 is provided at the tip of the corner of the pattern. Note that it is not necessary to make the sizes of the chamfered portions 4 uniform in the pattern as in the example given here.

Next, the exposed substrate is shower-developed with a dedicated developer, for example, "CD" manufactured by Fuji Hunt Co., Ltd., and the corners of the pattern of the black matrix are as shown in FIG. 1 (B). The whole pattern is rounded, and a stable display quality pattern can be obtained without generating uneven protrusions.

[0009]

According to the method of the present invention, projections are not generated at the corners of the black matrix pattern, and the pattern becomes smooth. Therefore, the occurrence of display pattern unevenness in the case of a liquid crystal display device is suppressed, and the display quality is improved.

[0010]

[Brief description of drawings]

FIGS. 1A and 1B are explanatory views showing states of a photomask and a black matrix in a conventional method and a method of the present invention, respectively.

FIG. 2 is a plan view showing an example of a chamfered shape used in the present invention.

FIG. 3 is a plan view showing an example of a pattern shape of a photomask according to the present invention.

[Explanation of symbols]

 1 Photomask 2 Black matrix 3 Protrusion 4 Chamfer

Claims (1)

[Claims] 1. A method for forming a resin black matrix of a color filter for a liquid crystal display device, characterized in that a chamfered portion is provided at a tip of a corner of a pattern forming photomask. Method.