JPH0540259A - Production of color filter substrate - Google Patents

Abstract

PURPOSE:To allow the formation of the peripheral part of a top coat layer to a tapered shape and the consequent sure formation of electrodes thereon. CONSTITUTION:This process for production of the color filter substrate 14 provided with the color filters 22 on the surface of a substrate and provided with an electrode film 18 via the top coat layer 24 on the color filters 22 consists in providing the color filters 22 on the surface of the substrate, applying the top coat layer 24 consisting of a thermoplastic material so as to cover the region where the color filters 22 are formed, and applying heat to the top coat layer 24 to soften the layer, thereby fluidizing the peripheral part of the top coat layer to the tapered shape.

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 substrate of a liquid crystal display, for example, and more particularly to formation of a top coat layer of a color filter.

[0002]

2. Description of the Related Art In a liquid crystal display, for example, a liquid crystal 10 has a pair of transparent substrates 12 and 14 as shown in FIG.
And is sealed by a peripheral seal 16.
Electrodes 18 and 20 are provided on the inner surfaces of these substrates 12 and 14, respectively. One electrode 18 is a common electrode, and the other electrode 20 is provided for each minute pixel area.
It is designed to be driven by the active matrix of the FT.

For color display, one substrate 1
4 is provided with a color filter (this substrate is called a color filter substrate). FIG. 5 shows the color filter substrate 14 provided with the color filter 22. The color filter 22 is a minute film of resin containing R, G, and B components for each pixel, and a top coat layer 24 is formed thereon to protect the color filter 22. The electrode 18 is formed on the top coat layer 24.

[0004]

In the manufacture of such a color filter substrate 14, conventionally, the top coat layer 24 and the electrode 18 are made of an acrylic material and IT, respectively.
It is formed by vapor deposition of O. First, the color filter 22 is provided on the surface of the color filter substrate 14, and the top coat layer 24 is applied to the entire surface of the color filter substrate 14 so as to cover the formation region of the color filter 22. At this stage, the top coat layer 24 includes an outer peripheral portion 24a indicated by a broken line. Next, the outer peripheral portion 24a is removed by etching. Then, the electrode 18 is deposited on the entire surface of the color filter substrate 14. The color filter substrate 14 manufactured in this manner is sealed with the peripheral seal 16 together with the other substrate 12 (FIG. 4).

Of the top coat layer 24 vapor-deposited on the entire surface of the color filter substrate 14, the outer peripheral portion 24a outside the formation region of the color filter 22 is removed by etching in order to secure the adhesiveness of the peripheral seal 16 to the substrate 14. It is desirable to do this. Further, the electrode 18 extends to the outside of the peripheral seal 16 for electrical connection with the outside, but has little influence on the adhesiveness of the peripheral seal 16.

However, the outer peripheral portion 2 of the top coat layer 24
When 4a is removed by etching, the shape of the peripheral portion 24b of the topcoat layer 24 after etching becomes acute, and when the electrode 18 is formed thereon, the electrode of the portion covering the peripheral portion 24b of the topcoat layer 24 is formed. There is a problem that the film thickness of 18 becomes extremely thin and causes a disconnection in the subsequent use. An object of the present invention is to provide a method for manufacturing a color filter substrate in which the peripheral portion of the topcoat layer can be formed in a tapered shape, and thus an electrode can be reliably formed thereon.

[0007]

A method for manufacturing a color filter substrate according to the present invention is a color filter in which a color filter is provided on the surface of the substrate and an electrode film is provided on the color filter via a top coat layer. A method for manufacturing a substrate, comprising providing a color filter on the surface of the substrate, applying a topcoat layer made of a thermoplastic material so as to cover the formation region of the color filter, and applying heat to the topcoat layer to soften the topcoat layer. It is characterized by comprising a procedure of causing the peripheral portion of the top coat layer to flow in a tapered shape.

[0008]

According to the above method, the top coat layer is applied so as to cover the area where the color filter is formed, and then the top coat layer is heated. Then, the top coat layer made of a thermoplastic material is softened and flows particularly in the peripheral portion. The top coat layer is applied so as to substantially coincide with the color filter formation region, and the peripheral portion thereof is fluidized to be tapered from the peripheral portion of the color filter formation region toward the surface of the substrate. After the completion of such treatment, the top coat layer is irradiated with ultraviolet rays and cured. Since the peripheral portion of the top coat layer is formed in a tapered shape, when the electrode is formed thereafter, the material of the electrode spreads over the top coat layer and the possibility of disconnection is reduced.

[0009]

EXAMPLE The color filter substrate 14 shown in FIG.
It can be used as one transparent substrate 14 of the liquid crystal display. In FIG. 4, as described above, the liquid crystal 1
0 is enclosed between a pair of transparent substrates 12 and 14, and is sealed by a peripheral seal 16. Electrodes 18 and 20 are provided on the inner surfaces of the substrates 12 and 14, one electrode 18 is a common electrode, and the other electrode 20 is a minute pixel electrode driven by an active matrix of a TFT.

In the color filter substrate 14 shown in FIG.
The color filter 22 is provided on the surface of the substrate. The color filter 22 is a minute film of resin containing R, G, and B components for each pixel, and is formed by, for example, a pigment dispersion method or a dye printing method. A top coat layer 24 is formed on the color filter 22, and a peripheral portion 24x thereof is formed in a tapered shape. Therefore, the ITO electrode 18 is reliably formed on the top coat layer 24. In particular, the peripheral part 24
Since x has a tapered shape, the material of the electrode 18 is easier to ride on the peripheral portion 24x as compared with the case where this portion is vertical or acute-angled, thereby eliminating an extremely thin portion, The likelihood of electrode 18 disconnection is reduced.

The color filter substrate 14 shown in FIG.
Can be used as one of the transparent substrates 14 of the liquid crystal display of FIG. 4, and the peripheral portion 24x of the top coat layer 24 is tapered as in the case of FIG. Figure 2
The color filter substrate 14 shown in FIG.
2 and the top coat layer 24 between the auxiliary top coat layer 26
Are formed. The auxiliary top coat layer 26 is made of an acrylic resin having a film thickness similar to that of the color filter 22, and is formed in a pattern substantially matching the formation region of the color filter 22.

FIG. 3 is a diagram showing a method of manufacturing the color filter substrate 14 of FIG. Further, this manufacturing method can be applied to the manufacture of the color filter substrate 14 of FIG. 1 except for the formation of the auxiliary top coat layer 26. In FIG. 3A,
A color filter 22 is provided on the surface of the substrate 14. This can be performed by the pigment dispersion method or the dye printing method as described above. Next, as shown in (B), an auxiliary top coat layer 26 is provided on the surface of the substrate 14 so as to cover the color filter 22.

The auxiliary top coat layer 26 is made of a transparent acrylic resin resist and is formed on the entire surface of the substrate 14 so as to have a film thickness similar to that of the color filter 22. When the auxiliary top coat layer 26 is formed to have a uniform thickness, a step is formed between the portion above the color filter 22 and the portion outside the color filter 22. Next, as shown in (C), the auxiliary top coat layer 26 is patterned by etching so that the pattern substantially coincides with the formation region of the color filter 22. That is, the low step portion outside the color filter 22 is removed by developing along the contour of the color filter 22.

Next, as shown in (D), a top coat layer 24 is formed. The top coat layer 24 is made of a thermoplastic material, and particularly preferably made of an ethylene oligomer-based material that is cured by being irradiated with ultraviolet rays. In the present invention, the top coat layer 24 is applied so as to cover the formation region of the color filter 22 and the outside of the formation region of the color filter 22 is not coated. In the embodiment, the top coat layer 24 is formed on the auxiliary top coat layer 26 by a printing method. Therefore, at this stage, the top coat layer 2
4 is formed in a stepped manner so as to exactly overlap the auxiliary top coat layer 26.

Then, as shown in (E), heat is applied to the top coat layer 24 to soften it. As a result, the topcoat layer 24 is softened, but practically most of the area of the topcoat layer 24 does not substantially flow, remains a substantially flat surface, and only the peripheral portion 24x substantially flows. .. When the peripheral portion 24x of the top coat layer 24 flows, the tip of the flow hangs down toward the surface of the color filter substrate 14, and the step portion of the auxiliary top coat layer 26 and the step portion between the auxiliary top coat layer 26 and the substrate 14 are formed. To fill in a taper shape. When the peripheral portion 24x of the top coat layer 24 is formed in a taper shape in this manner, the surface of the color filter substrate 14 is left exposed outside the tapered peripheral portion 24x. Finally, it is not necessary to remove the outer peripheral portion of the top coat layer 24 by etching.

Therefore, when the top coat layer 24 is irradiated with ultraviolet rays and cured after completion of such treatment, the peripheral portion 24x of the top coat layer 24 is in a tapered state. After that, when the electrode 18 is formed, the material of the electrode 18 spreads over the top coat layer 24, and the possibility of disconnection is reduced because there is no extremely thin portion.

[0017]

As described above, according to the present invention,
The periphery of the top coat layer that covers the color filter is formed in a taper shape, and the surface of the color filter substrate is left exposed outside the top coat layer. The material spreads over the topcoat layer, reducing the potential for wire breaks.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram showing an example of the present invention.

FIG. 3 is a diagram for explaining the manufacturing process of the color filter substrate according to the present invention from (A) to (E).

FIG. 4 is a cross-sectional view showing a liquid crystal display.

FIG. 5 is a diagram showing a conventional color filter substrate.

[Explanation of symbols]

 14 ... Color filter substrate 18 ... Electrode 22 ... Color filter 24 ... Top coat layer 26 ... Auxiliary top coat layer

Claims (3)

[Claims] 1. A color filter (22) is provided on a surface of a substrate, and a top coat layer (2) is provided on the color filter.
4) A method for manufacturing a color filter substrate (14) having an electrode film (18) provided therebetween, wherein a color filter (22) is provided on the surface of the substrate, and a top coat layer (24) made of a thermoplastic material is provided. ) Is applied to cover the area where the color filter (22) is formed, and heat is applied to the top coat layer (24) to soften the top coat layer (24) to make the peripheral portion of the top coat layer flow in a tapered shape. Method. 2. An auxiliary top coat layer (26) made of an acrylic resin is formed in a pattern which substantially coincides with a color filter forming region before the application of the top coat layer made of the thermoplastic material, The method for producing a color filter substrate according to claim 1, wherein the top coat layer (24) made of a plastic material is applied onto the acrylic resin by a printing method. 3. The method of manufacturing a color filter substrate according to claim 1, wherein the top coat layer (24) made of a thermoplastic material is made of a styrene oligomer-based material having thermoplasticity.