JPH1039128A - Color filter - Google Patents

Abstract

(57) Abstract: In a color filter for a liquid crystal display device, the surface of the transparent conductive film is smoothed in order to reduce the resistance of the transparent conductive film and to eliminate tilde reverse. An overlapping amount between a black matrix and a color filter pixel is formed to be 3 μm or less to increase a contact area between the black matrix and a transparent conductive film, and
After forming the transparent conductive film, an overcoat layer having a thickness of 0.5 μm or less is formed thereon to smooth the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter built in for a color display of a liquid crystal display device.

[0002]

2. Description of the Related Art In a liquid crystal display (LCD), it is important to reduce the resistance of a transparent electrode (opposite electrode) on a color filter forming substrate side in order to improve display quality. Various attempts have been made, such as examining conditions. By the way, under the present circumstances, the disorder of the alignment of the liquid crystal sealed in the LCD (tilt) due to the disorder of the shape of the pixel end of the color filter 3 and the influence of the steep protrusion 6 (so-called horn) as shown in FIG. (Reverse), an afterimage phenomenon may occur, and display quality may be degraded. Therefore, in order to prevent the influence of the tilt reverse, as shown in FIG. 3, a large amount of overlap (superposition) between the color filter 3 and the black matrix 2 (using a chromium film) is taken so that the pixels of the color filter 3 It has been practiced to smooth the edges or to form a four-layer overcoat on the three layers of the color filter after the formation of the three layers to flatten the surface.

However, when the surface of the color filter forming substrate is flattened as described above, the transparent conductive film of the counter electrode (currently, usually indium tin oxide (IT)
O) film is used, the contact value of chromium with the black matrix decreases or disappears, so that the resistance value increases.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and to reduce the resistance of the transparent conductive film, and to smooth the surface of the transparent conductive film in order to eliminate tilde reverse. Aim.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a color filter for a liquid crystal display device comprising a black matrix using a chromium film, a color filter of any material, and a transparent conductive film. The contact area between the black matrix and the transparent conductive film is increased by forming the amount of overlap with the pixel to 3 μm or less, and the surface is formed by forming an overcoat layer having a thickness of 0.5 μm or less on the transparent conductive film. Is a color filter characterized by smoothing.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. First, as shown in FIG. 1, a substrate with a film in which a single-layer thin film of chromium metal or a laminated thin film of chromium metal and chromium oxide is formed on a glass substrate 1 is patterned by photolithography to form a pattern of a black matrix 2. . That is, for example, a positive resist manufactured by Hoechst Japan KK, “AZ-TFP61
0F "is spin-coated, and a mask pattern for a black matrix is collectively exposed by a collective exposure machine (aligner).
Develop with a special developer. Next, the metal chromium film exposed by dissolving the resist is dissolved and removed with a ceric ammonium nitrate solution, and the resist film is stripped with a 5% aqueous NaOH solution at 35 ° C. Thereby, the black matrix 2 was formed on the glass substrate 1.

Next, for example, a pigment dispersion photoresist manufactured by Fuji Hunt Co., Ltd., trade names "CR-2000", "CG-200"
0 "and" CB-2000 ", R (red), G (green),
Each color of B (blue) is patterned. The coating conditions of the pigment-dispersed photoresist were 1000 rpm, 10 seconds, the film thickness was about 1.2 μm, the pre-bake temperature was 70 ° C., 20 minutes, the mask exposure amount was 120 mJ / cm ² , and the development was performed using a special developer for the resist. Post baking is performed at 230 ° C. for 60 minutes.

Here, regarding the patterning region of the color filter 3, the overlap width of the overlap portion between the black matrix 2 and the color filter 3 is set to 3 μm or less. The reason for this is to increase the contact area between the black matrix and the transparent conductive film formed thereafter. The width of the black matrix 2 is usually 20 to 40 μm. The pixel end of the color filter 3 has a gentle taper shape so that a transparent conductive film to be formed thereafter will not be disconnected. Next, five layers of a transparent conductive film such as ITO are formed by sputtering or the like.

Thereafter, an overcoat layer is formed thereon to smooth the surface. This overcoat layer
The thickness should be 0.5 μm or less so that the voltage applied to the liquid crystal does not cause a problem due to the thinness.
Is high (ε ≧ 3) and a material having good leveling property is used. For example, the product name “ROC-2” manufactured by Nippon Kayaku Co., Ltd.
09 "acrylic-epoxy overcoating agent is applied by a spin coating method or the like, prebaked at 100 ° C. for 10 minutes, and then through a pattern mask for masking the electrode terminal portions to expose the electrode terminal portions. 200 mJ / cm ² by irradiating ultraviolet rays to cure the parts other than the electrode terminals and dissolve and remove the uncured parts.
Perform a 60 minute post bake. Alternatively, the above-mentioned overcoat may be directly patterned by flexographic printing, or an anti-adhesion layer may be applied to the electrode terminal portion by flexographic printing, and then the overcoat layer is spin-coated and then the anti-adhesion layer is dissolved and peeled off. A lift-off method of patterning the overcoat layer by removing it may be used.

[0010]

When the color filter of the present invention is used, the sheet resistance of the electrode on the color filter forming side is 15 Ω / □.
The following low resistance values are obtained. In addition, since the surface is smoothed by the overcoat layer, display defects due to liquid crystal tilt reverse are eliminated.

[0011]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an example of a color filter of the present invention.

FIG. 2 is an explanatory diagram illustrating an example of a conventional color filter.

FIG. 3 is an explanatory diagram illustrating an example of a conventional color filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Black matrix 3 Color filter 4 Overcoat 5 Transparent conductive film 6 Projection

Claims (1)

[Claims] 1. A black matrix using a chromium film,
In a color filter for a liquid crystal display device provided with a color filter of an arbitrary material and a transparent conductive film, the amount of overlap between the black matrix and the color filter pixel is 3
μm or less to increase the contact area between the black matrix and the transparent conductive film, and to have a thickness of 0.1 μm on the transparent conductive film.
A color filter characterized by forming an overcoat layer of 5 μm or less and smoothing the surface.