JPH05165023A - Color filter base board - Google Patents

Abstract

PURPOSE:To prevent a clear electrode from such defects as exfoliation and conductor severance. CONSTITUTION:A color filter base board includes a clear base board 12, color filtration layer 13 formed thereupon, top coat layer formed as enclosing the color filtration layer 13, and clear electrode 15 formed over the top coat layer. wherein the top coat layer is split into two or more fragments 14a, 14b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter substrate used in, for example, a liquid crystal display device capable of full color display, and more particularly to improvement of its topcoat layer.

[0002]

2. Description of the Related Art Generally, liquid crystal display devices are used for displays such as portable computers and word processors, and flat-screen televisions. In recent years, full-color display devices have been introduced.

A color filter substrate 1 used in such a liquid crystal display device is conventionally constructed as shown in FIGS. 2A and 2B, and a color filter layer 3 is formed on a transparent substrate 2. Has been done. In this case, it is deposited by a dyeing method or an electrodeposition method, and is patterned on the transparent substrate 2 by using a photolithography technique or the like.

The color filter layer 3 thus formed
In particular, in the case of a dot matrix type, which has R, G, and B colors, the colors are formed individually, so that a step 6 is formed in the adjacent portion of the pixel. When such a step 6 occurs, the distance (cell gap) from the counter substrate in the liquid crystal display device changes, and the threshold voltage of the liquid crystal changes. In order to solve this problem, by providing a top coat layer (flattening layer) 4 on the color filter layer 3,
This step 6 is made small.

In general, the material of the color filter layer 3 is
It is an organic agent which is unstable to liquid crystals and other solvents, cannot be used in an exposed state, and inevitably the top coat layer 4 also has a role of protecting the color filter layer 3. Topcoat layer 4
Although various materials are used as the material of (1), a material having high wettability to the color filter layer 3 and high transmittance is a selection condition, and at present, an acrylic polymer is often used, It is applied on the color filter layer 3 by a spin coat method or the like.

In such a color filter substrate 1, a transparent electrode 5 is generally formed on the top coat layer 4 by a sputtering method of ITO or a vacuum deposition method. Although it is easy to manufacture that the application area of the transparent electrode 5 is the whole area of the substrate, since the top coat material is an organic material, the adhesion strength with the transparent electrode 5 which is an inorganic material is a normal glass substrate. Weaker than that. Therefore, it is usual that the portion which becomes the connection terminal at the time of the product is subjected to a masking process or the like to form an uncoated region in the peripheral portion as shown in FIG.

[0007]

However, regarding the heat resistance of the color filter substrate, when the color filter substrate 1 shown in FIG. 2 is put into the manufacturing process of a liquid crystal display having many heating steps, the top coat layer 4 and the transparent layer are transparent. Stress is generated due to the difference in the coefficient of thermal expansion of the electrode 5, and the transparent electrode 5 formed on the top coat layer 4 is adjacent to the R, G and B pixels of the color filter layer shown in FIG. Part that has a step 6
Therefore, peeling and disconnection defects occur. The present invention has been made in view of the above circumstances, and an object thereof is to provide a color filter substrate in which peeling of a transparent electrode and disconnection failure are prevented.

[0008]

The present invention provides a transparent substrate, a color filter layer formed on the transparent substrate,
In a color filter substrate including a topcoat layer formed so as to cover the color filter layer and a transparent electrode formed on the topcoat layer, the topcoat layer is divided into two or more. This is a color filter substrate that is formed.

[0009]

According to the present invention, the stress caused by the difference in the coefficient of thermal expansion between the top coat layer and the transparent electrode formed thereon due to the heating of the color filter substrate is relieved, and as a result, the transparent electrode Peeling and disconnection defects are prevented in advance.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The color filter substrate 11 according to the present invention is configured as shown in FIGS. 1 (a) and 1 (b),
(A) is a plan view and (b) is a sectional view.

Reference numeral 12 in the drawing is a transparent substrate made of, for example, glass, and a color filter layer 13 is formed on the transparent substrate 12. The top coat layers 14a, 14 having a thickness of several μm are formed so as to cover the color filter layer 13.
b is formed, and the transparent electrode 15 is formed on the top coat layers 14a and 14b.

In this case, as is apparent from the figure, there are two or more top coat layers, and in this embodiment, two top coat layers.
It is divided into two layers 14a and 14b. At the time of division, a 5 μm gap 16 is formed laterally in the central portion of the top coat layer by a photolithography method and divided into two.

In this way, the top coat layer 14a,
When divided into 14b, the color filter substrate 11
Even when heated, the stress due to the difference in coefficient of thermal expansion between the top coat layers 14a and 14b and the transparent electrode 15 formed thereon is relieved by the gap 16, and as a result, peeling or disconnection of the transparent electrode 15 is eliminated. It is possible to obtain the color filter substrate 11 having extremely strong durability.

[0014]

According to the present invention, the topcoat layer has two layers.
Since it is divided into two or more parts, when the color filter substrate is heated, the stress caused by the difference in the coefficient of thermal expansion between the top coat layer and the transparent electrode is relieved, and as a result, peeling of the transparent electrode and defective disconnection occur. Prevented in advance.

[Brief description of drawings]

1A and 1B are a plan view and a sectional view showing a color filter substrate according to an embodiment of the present invention.

2A and 2B are a plan view and a cross-sectional view showing a conventional color filter substrate.

3 (a) and 3 (b) are a plan view and a sectional view showing another conventional color filter substrate.

FIG. 4 is an enlarged plan view showing a pixel portion of a color filter substrate.

[Explanation of symbols]

11 ... Color filter substrate, 12 ... Transparent substrate, 13 ... Color filter layer, 14a, 14b ... Top coat layer, 1
5 ... Transparent electrode, 16 ... Gap.

Claims (1)

[Claims] 1. A transparent substrate, a color filter layer formed on the transparent substrate, a topcoat layer formed so as to cover the color filter layer, and a topcoat layer formed on the topcoat layer. A color filter substrate provided with a transparent electrode, wherein the top coat layer is divided into two or more.