JPH0843618A - Production of color filter - Google Patents

Abstract

PURPOSE:To obtain a production method of color filter to prevent discontinuity in a transparent conductive film without forming a transparent resin layer by applying a photosensitive resin layer on a substrate, then heating the photosensitive resin layer from the lower side while cooling from the upper side in a prebaking process, and exposing for a pattern to form a smooth tapered shape of the cross section of color filter. CONSTITUTION:After a photosensitive resin layer 2 is applied on a glass substrate 1, the layer is subjected to a prebaking process. In the prebaking process, such a baking device is used that is equipped with a hot plate 3 to be in contact with the glass substrate 1 and a cool plate 4 disposed in the opposite side of the glass substrate 1 to the hot plate 3 having a space between the glass substrate 1. By producing temp. difference between the upper and lower sides of the photosensitive resin layer 2, a temp. gradient between the interface with the glass and the top surface of the photosensitive resin layer 2 is intently produced. Thereby, difference of the apparent sensitivity for exposure in the resist layer 1 is produced and the cross section of the layer after exposure and development is normally tapered.

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 incorporated in a color liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3A, a color filter for a liquid crystal display device has heretofore been prepared by first coating a glass substrate 1 with a photocurable photosensitive resin layer 2 in which a color pigment is dispersed, followed by drying. As shown in FIG. 3B, ultraviolet rays are radiated through the photomask 7 for exposure, and development is performed as shown in FIG. 3C to form a pattern of the colored resin layer 2a. However, since the cross-sectional shape of the colored resin layer 2a is a right angle or an inverted taper shape as shown in FIG. 3C, particularly in a color filter used in a thin film transistor type liquid crystal display device, ITO or the like is formed on the color filter. When the transparent conductive film is formed, disconnection occurs, which becomes a cause of conduction failure during panel assembly. As a solution to this problem, it is known to form a transparent conductive film by coating the surface of the color filter with a transparent resin to make the surface smooth. However, the manufacturing cost becomes high and the manufacturing yield is greatly affected, which is a practical problem.

[0003]

DISCLOSURE OF THE INVENTION The present invention is directed to a method for producing a color filter, in which the cross-sectional shape of the color filter has a gentle forward taper shape, and the transparent conductive film is prevented from being broken without forming a transparent resin layer, and the above-mentioned production. An object of the present invention is to provide a manufacturing apparatus used in the method.

[0004]

That is, the present invention provides a color filter in which a photocurable photosensitive resin layer in which a color pigment is dispersed is pattern-exposed, developed, and post-baked to obtain a color filter layer having a desired shape. In the manufacturing method of
The method for producing a color filter is characterized in that after the above-mentioned photosensitive resin layer is applied onto a substrate, pattern exposure is performed through a pre-baking step of heating from below the photosensitive resin layer and cooling from above.

Specifically, in the pre-baking step after coating the photosensitive resin layer 2 on the glass substrate 1, the baking device as shown in FIG.
By disposing the glass substrate 1 and the cool plate 4 which is disposed with a gap from the glass substrate 1 on the side opposite to the hot plate 3, a temperature difference is provided between the upper and lower sides of the photosensitive resin layer 2. The temperature gradient between the glass interface side and the surface side of the photosensitive resin layer 2 is intentionally set. This causes a difference in apparent exposure sensitivity in the resist 1 layer, and the cross-sectional shape after exposure and development is forward tapered as shown in FIG.

[0006]

By the above method, by intentionally providing a temperature gradient between the glass interface side and the surface side of the photosensitive resin layer 2,
A difference occurs in the residual amount of the solvent in the photosensitive resin layer 2, resulting in a difference in the speed of photocrosslinking during exposure. As a result, the photosensitive resin layer 2
On the glass interface side, the line width tends to thicken due to an apparent increase in sensitivity, and on the other hand, on the surface side, the line width tends to become relatively thin due to a decrease in sensitivity. Therefore, the cross-sectional shape after development is a forward tapered shape.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing a manufacturing process of a color filter used in a liquid crystal display device, which is constituted by a continuous automation line. The present invention is characteristically carried out in the pre-baking step after coating the resist surrounded by the double frame. As a part of the in-line device on the line, the baking device as shown in FIG. 1 is installed in the pre-baking step after coating the photosensitive resin layer 2 on the glass substrate 1. The glass substrate 1 coated with the photosensitive resin layer 2 is carried into the baking device through the opening of the partition wall 5 by a walking beam system or a robot carrying device.

A hot plate 3 similar to a conventional bake device is provided in the lower part of the baking device, and a cool plate 4 is installed on the side opposite to the hot plate 3 with respect to the glass substrate 1 placed thereon. There is. The cool plate 4 is of a cooling water circulation system or the like, and can be moved up and down by an elevating mechanism 6 to adjust the distance to the photosensitive resin layer 2. Further, if necessary, nitrogen gas or clean air may be blown instead of the cool plate 4.

Here, prebaking is performed while making a temperature difference between the hot plate 3 and the cool plate 4 to intentionally create a temperature gradient between the glass interface side and the surface side of the photosensitive resin layer 2. As for the conditions, the hot plate 3 is 60 to 120 depending on the difference in the solvent contained in the resist used.
℃ (80 ℃ in this embodiment), cool plate 4 is 10 ~ 30 ℃
(20 ° C. in this embodiment). The clearance between the cool plate 4 and the photosensitive resin layer 2 is 2 to 15 m.
It is set to m (4 mm in this embodiment). After this, when the exposure process was performed as shown in FIG. 4B, the developed colored resin layer 2a was in a forward tapered shape as shown in FIG. 4C.

[0010]

According to the manufacturing method using the manufacturing apparatus having the structure of the present invention, the cross-sectional shape of the color filter can be made into a forward taper shape, and the transparent conductive layer can be formed without forming the transparent resin layer on the color filter. Even if the film is directly formed, the breakage of the transparent conductive film can be prevented.

[0011]

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a baking apparatus of the present invention.

FIG. 2 is a flow chart showing a manufacturing process of a color filter.

3A to 3C are explanatory views showing a manufacturing process of a color filter according to a conventional technique in the order of processes.

4A to 4C are explanatory views showing a manufacturing process of a color filter according to the present invention in order of process.

[Explanation of symbols]

 1 Glass Substrate 2 Photosensitive Resin Layer 2a Colored Resin Layer 3 Hot Plate 4 Cool Plate 5 Partition 6 Lifting Mechanism 7 Photo Mask

Claims (1)

[Claims] 1. A method for producing a color filter, wherein a photocurable photosensitive resin layer having a color pigment dispersed therein is subjected to pattern exposure, development, and post-baking to obtain a color filter layer having a desired shape. A method for producing a color filter, which comprises applying a layer on a substrate, heating the photosensitive resin layer from below, and then performing a pre-baking step of cooling from above to perform pattern exposure.