KR100920339B1 - A color filter array panel and a method of fabricating thereof - Google Patents

Abstract

The color filter substrate according to the present invention includes a black matrix formed on an insulating substrate, a red, blue, green color filter formed on each of the regions defined by the black matrix, and a planarization formed on the black matrix positioned between the color filters. And a reference electrode formed on the pattern, the color filter, and the planarization pattern, wherein the planarization pattern is made of the same material as any one of the red, blue, and green color filters.

Color Filter Board, Flatten

Description

A color filter array panel and a method of fabricating

1 is a cross-sectional view of a color filter substrate according to a first embodiment of the present invention.

2A to 2C are diagrams sequentially illustrating a method of forming a color filter substrate according to a first embodiment.

3 is a cross-sectional view of a color filter substrate according to a second embodiment of the present invention.

4A to 4C are diagrams sequentially illustrating a method of forming a color filter substrate according to a second embodiment.

※ Explanation of code for main part of drawing ※

1: lower substrate 2: upper substrate

210: insulating substrate 230R, 230G, 230B: red, green, blue color filter

220: black matrix 231, 232: planarization pattern

270: reference electrode 310: sealing material

The present invention relates to a color filter substrate and a method of forming the same.                         

In general, a liquid crystal display device includes a lower substrate on which a plurality of thin film transistors, which are switching elements for turning on / off each pixel electrode, and an upper portion on which red, blue, and green color filters representing colors are formed. It consists of a substrate and a liquid crystal filled between these two substrates.

Pixel electrodes and thin film transistors are formed on the lower substrate. The upper substrate has a black matrix formed on the insulating substrate to prevent light leakage. In addition, red, green, and blue color filters are formed in a region defined by a black matrix, and a reference electrode made of a transparent conductive material such as indium tin oxide (ITO) or indiumzinc oxide (IZO) is formed on the color filter. .

A sealant is used at the edges of the upper and lower substrates to fix the two substrates and prevent liquid crystal leakage. In order to bond the upper substrate and the lower substrate using the sealing material, the sealing material is coated along the edge and then pressurized at high temperature.

Color filters are separated on the black matrix, and each color filter has a thickness of 1.3 ~ 1.6um. Therefore, a step occurs due to the thickness of the color filter. When the liquid crystal is injected to form a liquid crystal display, a region in which the arrangement of liquid crystal molecules positioned near the step is unstable or the continuity of the liquid crystal is broken occurs, thereby causing light leakage.

Such light leakage can suppress light leakage by adjusting the line width of the black matrix, but there is a limit to suppressing light leakage by adjusting the line width of the black matrix as the demand for high brightness and wide viewing angle is increased. Therefore, various methods have been implemented to reduce the step difference and obtain high brightness and wide viewing angle.                         

Among them, there is a method of reducing the gap between the color filter and the color filter, but it is difficult to accurately pattern. Another method is to form an overcoat layer to reduce the step. However, when the overcoat layer is formed, the step is reduced and the planarization effect is effective, but since the process of forming the overcoat layer is added, there is a problem in that productivity is reduced due to yield reduction, cost increase, and productivity decrease.

Accordingly, an object of the present invention is to provide a method for forming a color filter and a color filter substrate which can reduce the step difference caused by the color filter without forming the overcoat layer as a solution to the above problems.

The color filter substrate according to the present invention for achieving the above object is a black matrix formed on an insulating substrate, the red, blue, green color filter formed in each of the regions defined by the black matrix, the color filter is located between A planarization pattern formed on the black matrix, a color filter, and a reference electrode formed on the planarization pattern, wherein the planarization pattern is made of the same material as any one of the red, blue, and green color filters.

Here, the red, blue, green color filter and the planarization pattern have the same thickness, and the planarization pattern is preferably formed by the blue color filter. The top edge of the planarization pattern is formed with a stage.

Such a method of forming a color filter substrate includes forming a black matrix on an insulating substrate, forming a red color filter on a black matrix, forming a green color filter on a black matrix, and forming a blue color filter on a black matrix. Filling a region between the color filters in any one of the steps of: forming a reference electrode over the color filter, forming a red color filter, forming a green color filter, and forming a blue color filter. The planarization pattern is formed together.

In forming the planarization pattern together, an optical mask having a light shielding pattern including slits is used, and the slits are disposed at a boundary between the planarization pattern and the color filter during exposure. In addition, the planarization pattern may be formed together at the step of forming the blue color filter.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "on top" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Embodiments according to the present invention will now be described in detail with the accompanying drawings.                     

[First Embodiment]

1 is a cross-sectional view of a color filter substrate according to the present invention. As illustrated in FIG. 1, the black matrix 220 is formed on the transparent insulating substrate 210.

A color filter of red 230R, green 230G, and blue 230B is formed in a region defined by the black matrix 220. Color filters are arranged in the same color in the vertical direction, and red, green, and blue color filters are alternately arranged in the horizontal direction.

Each color filter 230R, 230G, 230B is divided on the black matrix 220, and a planarization pattern 231 is formed on the black matrix 220 positioned between the color filter and the color filter. The planarization pattern 231 is formed of the same material as the blue color filter 230B. The reference electrode 270 is formed of a transparent conductive metal such as ITO or IZO on the color filters 230R, 230G, and 230B.

A method of forming such a color filter substrate will be described in detail with reference to FIGS. 2A to 2B.

As shown in FIG. 2A, the black matrix 220 is formed on the transparent insulating substrate 210. The black matrix 220 is to prevent light leakage between the color filters to be formed later. The black matrix 220 is generally formed of a metal such as chromium, but may be formed of an organic material mixed with black pigment.

As shown in FIG. 2B, a red color filter 230R is formed by coating and patterning a photosensitive layer in which a red pigment is mixed in a region defined by the black matrix 220. The green color filter 230G is formed in the same process.

The green color filter 230G may be formed by moving the optical mask used to form the red color filter 230R, or may use an optical mask having a light shielding pattern different from that of the red color filter 230R.

As illustrated in FIG. 2C, the photoresist layer PR including the blue pigment is mixed on the red and green color filters 230R and 230G, and then patterned to form the blue color filter 230B and the planarization pattern 231. do.

The planarization pattern 231 is formed on the black matrix 220 where the color filters 230R, 230G, and 230B are divided to fill the gap between the color filter and the color filter, thereby reducing light leakage.

Thereafter, a transparent conductive metal such as ITO or IZO is deposited on the color filters 230R, 230G, and 230B to form the reference electrode 270 (see FIG. 1).

Second Embodiment

3 is a cross-sectional view of a color filter substrate according to a second embodiment of the present invention, and FIGS. 4A to 4C are diagrams sequentially showing a method for forming the second embodiment. As shown in FIG. 3, the flattening pattern 232 of the second embodiment has a stage formed at an upper edge of the flattening pattern 232.

As described above, the method of forming the flattening pattern 232 having the stage formed thereon is as follows.

First, as shown in FIG. 4A, the black matrix 220 is formed on the transparent insulating substrate 210. After the black matrix 220 is formed, green and red color filters are formed. This is formed in the same process as in the first embodiment.

As shown in FIG. 4B, the photomask MP having the light shielding pattern including the slit S is applied after applying the photosensitive layer PR mixed with the blue pigment on the red and green color filters 230R and 230G. Place it.

As shown in FIG. 4C, the photosensitive layer is exposed through the photomask MP, and then developed to form a planarization pattern 232 having a stage formed at an upper edge thereof. Since the slit S reduces the exposure amount of the photosensitive layer MP, only part of the photosensitive layer MP is removed during development. That is, when the planarization pattern 231 of the first embodiment is formed, a gap may be formed due to the misalignment of the light blocking pattern at the boundary portion where the planarization pattern 232 and the color filters 230R, 230G, and 230B are in contact with each other. However, forming the slit increases the process margin because the amount of exposure at the boundary can be reduced to prevent the formation of gaps.

Thereafter, a transparent conductive metal such as ITO or IZO is deposited on the color filters 230R, 230G, and 230B to form the reference electrode 270 (see FIG. 3).

When light is incident on the liquid crystal display including the color filter substrate according to the present invention, the incident light passes through the liquid crystal and is transmitted to the black matrix 220. The light incident on the black matrix 220 is reflected, but the reflected light is absorbed by the planarization pattern 231 so that the reflected light is reduced and light leakage is reduced.

The color filter forming the planarization patterns 231 and 232 may be formed of any one of red, green, and blue, but is preferably a blue color filter having good light absorption.                     

Although the preferred embodiments of the present invention have been described in detail as described above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the present invention.

As described above, according to the present invention, a flattening pattern is formed in the gap between the color filter and the color filter to reduce the step caused by the color filter. Therefore, it is possible to prevent light leakage that may occur due to the step of the color filter.

In addition, when the light shielding pattern in which the slit is formed is used when forming the flattening pattern, it is possible to prevent the gap from being formed more reliably.

Claims (7)

A black matrix formed on an insulating substrate, Red, blue, and green color filters respectively formed in the area defined by the black matrix, A planarization pattern formed on the black matrix positioned between the color filters; A reference electrode formed on the color filter and the planarization pattern Including, The flattening pattern may be formed of the same material as any one of the red, blue, and green color filters, and an upper edge of the flattening pattern may have a stage. In claim 1, And the planarization pattern is formed of the blue color filter. In claim 1, The red, blue, green color filter and the planarization pattern have the same thickness. delete Forming a black matrix on the insulating substrate, Forming a red color filter on the black matrix, Forming a green color filter on the black matrix, Forming a blue color filter on the black matrix, Forming a reference electrode on the color filter; Forming the red color filter, Forming a flattening pattern that fills an area between the color filters in any one of forming the green color filter and forming the blue color filter; The forming of the planarization pattern together uses a photomask in which a light shielding pattern including a slit is formed, and during exposure, the slit is disposed at a boundary between the planarization pattern and the color filter. delete In claim 5, And the planarization pattern is formed together in the forming of the blue color filter.

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