KR20120075210A - A color filter substrate of liquid crystal displaly device and method of fabricating thereof - Google Patents

Abstract

PURPOSE: A color filter substrate of a liquid crystal display device and a manufacturing method thereof are provided to form an ununiform color filter layer. CONSTITUTION: A plurality of color filter patterns are formed on a substrate(110). An edge area is eliminated from the color filter pattern. A green resist(116) is coated on the central area of the substrate on which a red color filter pattern(117R) is formed. The green resist spreads from the central area of the substrate to the outside by a centrifugal force to rotate the substrate clockwise. An overcoat layer is formed on the color filter pattern.

Description

A color filter substrate for a liquid crystal display device and a method of manufacturing the same {A COLOR FILTER SUBSTRATE OF LIQUID CRYSTAL DISPLALY DEVICE AND METHOD OF FABRICATING THEREOF}

The present invention relates to a liquid crystal display device, and more particularly, to a color filter substrate of a liquid crystal display device and a method of manufacturing the same.

Recently, with the rapid development of the information society, the necessity of flat panel displays having excellent characteristics such as thinning, light weight, and low power consumption has emerged. Among them, liquid crystal displays have a resolution, It is excellent in color display and image quality, and is actively applied to notebooks and desktop monitors.

In general, a liquid crystal display device forms a liquid crystal layer between substrates and applies an electric field to the liquid crystal layer to align liquid crystal molecules by an electric field, and implements an image by adjusting light transmittance according to the alignment of the liquid crystal molecules.

Typically, the lower substrate of the liquid crystal display is formed of an array substrate including a thin film transistor for applying a signal to a pixel electrode, and the upper substrate includes a color filter layer in which a common electrode and a color filter of red, green, and blue are sequentially arranged. It consists of a substrate containing.

This color filter layer is formed by various methods, such as a pigment dispersion method, a dyeing method, an electrodeposition method, or a (thermal) transfer method. Pigment dispersion method of the various color filter layer forming method is as follows.

In other words, the pigment dispersion method is a method of forming a color filter layer by applying a pigment to the substrate by spin coating, and then developed through a photo process. In such a pigment dispersion method, a red, green, and blue color filter is produced by one step. Since each is formed all at once, three steps are repeated to form all the red, green, and blue color filters.

Thus, in the pigment dispersion method, since the color filter layer can be formed by coating of the pigment by spin coating and developing by the photo process, it is mainly used as a method of forming the color filter layer by a relatively simple process and a low cost process. have.

1A to 1G illustrate a method of forming a color filter layer by using a pigment dispersion method, which will be described below with reference to the method of forming a color filter layer.

First, as shown in FIG. 1A, a metal material or resin is deposited (coated) on the entire surface of the substrate 10, and then a black matrix 15 is formed through a photolithography process. do. The black matrix 15 is to prevent light leakage caused by abnormal action of the liquid crystal molecules in the portion other than the pixel electrode on the array substrate.

Subsequently, as shown in FIG. 1B, a red color resist is applied to the entire surface of the substrate by spin coating on the substrate 10 on which the black matrix 15 is formed. ), The mask 20 having a portion for passing light and a pattern for blocking light is positioned on the substrate 10 and then exposed.

Thereafter, as shown in Fig. 1C, the exposed color resist layer is developed and cured to form a red color filter pattern 17R.

Subsequently, as shown in FIG. 1D, the green color resist is again applied to the substrate 10 on which the red color filter pattern 17R is formed by spin coating, followed by a photo process using the mask 21 to FIG. 1E. As shown, a green color filter pattern 17G is formed.

Thereafter, as shown in 1f, the blue color resist is again applied by spin coating to the substrate 10 on which the red color filter pattern 17R and the green color filter pattern 17G are formed, and then the mask 22 is applied. The blue color filter pattern 17B is formed as shown in FIG. 1G through the used photo process.

Thus, in the pigment dispersion method, since the color filter layer can be formed by coating of the pigment by spin coating and developing by the photo process, it is mainly used as a method of forming the color filter layer by a relatively simple process and a low cost process. have.

However, the following problems arise in such a pigment dispersion method. As described above, the green color filter pattern 17G and the blue color filter pattern 17B are formed after the red color filter pattern 17R and after the red color filter pattern 17R and the green color filter pattern 17G, respectively. It is formed by applying a resist onto a substrate by spin coating. However, since the color filter patterns 17R, 17G, and 17B are formed to have a thickness of about several μm, the color filter patterns 17R, 17G, and 17B are formed on the substrate because of the color filter patterns already formed when the green color resist or the blue color resist is applied to the substrate by spin coating. The resist is not evenly applied.

That is, as shown in FIG. 2, after applying the color resist to the center of the substrate 10 on which the color filter pattern 17 is formed, rotating the substrate 10 causes the color resist to be entirely rotated by the rotational force. The color resist is spread over the entire substrate 10. By the way, the rotational force of the color filter pattern on the flow direction side of the color resist acts as an obstacle to the flow. This phenomenon is mainly caused in the corner region (area A in the drawing) of the color filter pattern having a high obstacle angle. As a result, the flow of the color resist in this area is different from the flow in other areas. In other words, the speed of the flow of the color resist in the edge region of the color filter pattern is slowed in other regions.

On the other hand, since the color resist is a material having a high viscosity, when a difference occurs in the flow of the color resist, the thickness of the color filter pattern in area A becomes thinner than the thickness of the color filter pattern in other areas due to the difference in speed. do.

In the case of such a conventional color filter, since a plurality of color filter patterns 17 are typically arranged in a matrix on a substrate, the edge area A of each color filter pattern 17 is thinner than other areas. In the case of realizing the image of the liquid crystal display device, there is a problem that a stain occurs in the diagonal direction of the screen.

An object of the present invention is to provide a color filter substrate and a method for manufacturing the same, in which a color filter layer is uniformly formed over the entire substrate.

In order to achieve the above object, the color filter substrate according to the present invention is a substrate; And a plurality of color filter patterns formed on the substrate, wherein the color filter patterns have edge areas removed. The color filter pattern includes a red color filter pattern, a green color filter pattern, and a blue color filter pattern, and the removed corner area is a corner area on the side of the substrate facing the center area. At this time, the corner region is removed at an angle with the upper end of the color filter pattern, and the angle increases from the central region of the substrate toward the upper and lower regions.

In addition, the color filter substrate manufacturing method according to the present invention comprises the steps of providing a substrate; Forming the black matrix on the substrate; Applying a first color resist to the center of the substrate on which the black matrix is formed, and rotating the substrate to form a first color resist layer over the entire substrate; Developing the first color resist layer to form a first color filter pattern; Applying a second color resist to the center of the substrate on which the first color filter pattern is formed, and rotating the substrate to form a second color resist layer over the entire substrate; Developing the second color resist layer to form a second color filter pattern; Applying a third color resist to a center of the substrate on which the first color filter pattern and the second color filter pattern are formed, and rotating the substrate to form a third color resist layer over the entire substrate; And developing a third color filter pattern by developing the third color resist layer, wherein the first color filter pattern and the second color filter pattern comprise a second color resist and a third color resist when the substrate is rotated. It is characterized in that the edge on the spreading direction side is removed.

According to the present invention, when the color filter pattern removes a part of the region and spin coating the color resist, the color filter pattern is prevented from being applied unevenly by the color filter pattern, thereby preventing formation of an uneven color filter layer. It is possible to prevent spots from occurring on the screen.

1A to 1G illustrate a conventional method for manufacturing a color filter layer.
2 is a diagram showing application of a conventional color resist onto a substrate.
3A and 3B show the structure of a color filter substrate according to the present invention;
4 is a view showing coating of a color resist on a substrate on which a color filter pattern is formed in an upper region;
5A and 5B illustrate application of color resist to a substrate having color filter patterns formed in a central region and a lower region, respectively.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

3A and 3B are views illustrating a color filter substrate of a liquid crystal display according to the present invention. FIG. 3A is a cross-sectional view illustrating a structure of a color filter substrate, and FIG. 3B is a view showing an arrangement of color filter layers formed on a substrate.

As shown in FIG. 3A, a plurality of black matrices 115 are formed on a transparent substrate 110 such as glass, and color filter layers 117R, 117G, and 117B are formed therebetween. The black matrix 115 is for preventing the light from being deteriorated by blocking light leakage into an area where an image is not displayed when a liquid crystal display device is manufactured. The black matrix 115 is formed of a metal oxide such as CrO, a black resin, or the like. After coating on 110), it is formed by etching by a photo process using a mask and a photoresist.

In this case, as shown in FIG. 3B, the color filter layers 117R, 117G, and 117B arranged on the substrate 110 have a red color filter pattern 117R, a green color filter pattern 117G, and a blue color in the vertical direction. The filter patterns 117B are arranged in a line, respectively, and the red color filter pattern 117R, the green color filter pattern 117G, and the blue color filter pattern 117B are alternately arranged in the horizontal direction. In addition, the color filter layers 117R, 117G, and 117B have a red color filter pattern 117R, a green color filter pattern 117G, and a blue color filter pattern 117B arranged in a row in a vertical direction and alternately in a horizontal direction. May be arranged as:

In addition, the red color filter pattern 117R, the green color filter pattern 117G, and the blue color filter pattern 117B may be alternately arranged in the horizontal direction and the vertical direction, or the red color filter pattern 117R and the green color. The filter pattern 117G and the blue color filter pattern 117B may be arranged in a delta form.

The color filter layers 117R, 117G, and 117B are made of photosensitive color resist. Accordingly, the specific color filter pattern can be formed by applying the photosensitive color resist sheet, irradiating light using a mask, and developing the developer with a developer.

In this case, the photosensitive color resist may be a positive color resist or a negative color resist, and the color filter layers 117R, 117G, and 117B are formed through the process of FIGS. 1A to 1G.

As shown in FIG. 3A, an overcoat layer 130 is formed on the color filter layers 117R, 117G, and 117B to protect the color filter layers 117R, 117G, and 117B and to flatten the surface thereof. A transparent conductive layer such as Indium Tin Oxide is applied to form a common electrode 132 to complete the color filter substrate.

The color filter substrate configured as described above is bonded to the thin film transistor array substrate on which the thin film transistor is formed with the liquid crystal layer interposed therebetween to complete the liquid crystal display device.

Meanwhile, as shown in FIG. 3B, the red color filter pattern 117R, the green color filter pattern 117G, and the blue color filter pattern 117B are each formed in a substantially rectangular shape. Although not shown in the drawing, the shapes of the red color filter pattern 117R, the green color filter pattern 117G, and the blue color filter pattern 117B are formed in the same shape as the pixel of the liquid crystal display device. Accordingly, the shape of the red color filter pattern 117R, the green color filter pattern 117G, and the blue color filter pattern 117B may be variously formed according to the shape of the pixel of the liquid crystal display.

One corners of the red color filter pattern 117R, the green color filter pattern 117G, and the blue color filter pattern 117B formed in a quadrangular shape are chamfered. At this time, the direction of the chamfer is formed in the thin direction on the corner region side from the center of the substrate 110. As such, forming the chamfer in the thin direction from the center of the substrate 110 to the edge region side may require the flow of the color resist in this direction when applying the color resist to the substrate by spin coating to form the color filter layer. This is to uniformly apply the color resist throughout the substrate 110.

4 illustrates a method of applying a color resist when the color filter pattern 117G formed on the substrate 110 is formed. In this case, although only one red color filter pattern 117R is illustrated for convenience of description, the same phenomenon will occur when the color resist is applied to the substrate 110 on which the other color filter turns are formed.

As shown in FIG. 4, after the green resist 116 is applied to the central region of the substrate 110 on which the red color filter pattern 117G is formed, the substrate 110 is rotated in a clockwise direction. The resist 116 spreads to the outside in the central region of the substrate 110.

In this case, the red color filter pattern 117G formed on the upper right side of the substrate 110 is formed in a quadrangular shape, and the corners of the upper left region are chamfered. The corner of the upper left region is formed on the side in which the green resist 116 spreads when the substrate 110 rotates, and thus acts as an obstruction to prevent the spread of the resist 116 when the green resist 116 spreads. Thus, by chamfering the edges of the upper left region, obstructions in this region are removed, which results in a smooth spread of the green resist 116 in this region, which is the same as the spread rate in other regions. Therefore, the green resist 116 is uniformly applied in this corner region and other regions to prevent staining due to the thickness difference of resist coating.

Meanwhile, when the red color filter pattern 117G formed on the upper left side of the substrate 110 is formed, unlike the case formed on the upper right side, the right edge of the red color filter pattern 117G acts as an obstacle to the flow of the resist. Therefore, when the red color filter pattern 117G formed on the upper left side of the substrate 110 is formed, the right edge of the red color filter pattern 117G is chamfered.

That is, when the red color filter pattern 117G is formed on the upper left and right sides of the substrate 110, the resist flow is disturbed by the right and left edges of the red color filter pattern 117G, respectively. By chamfering the corners, the resist is uniformly applied in the upper region of the substrate 110.

5A and 5B illustrate a green resist spreading in other regions of the substrate 110.

As shown in FIG. 5A, the red color filter pattern 117R formed in the center area on the right side of the substrate 110 has a substantially rectangular shape, and both upper and lower edges are chamfered. At this time, the chamfer is a corner of the upper left and lower portions of the red color filter pattern 117R, that is, the center region of the upper and lower portions.

After the green resist is applied to the center of the substrate 110 having such a structure, and the substrate 110 is rotated in the clockwise direction, the green resist applied to the center is spread outward by the centrifugal force of the substrate 110. At this time, the spread path of the resist in the left or right direction of the center is substantially parallel to the transverse direction of the substrate 110. Accordingly, in the case of the red color filter pattern 117R formed in the center region on the left or right side of the center, the upper and lower edges act as obstacles when the resist spreads.

Accordingly, in the color filter layer having such a structure, the upper and lower edges serving as obstacles are chamfered to facilitate the spreading of the resist in this region so that the resist is uniformly applied throughout the substrate 110.

On the other hand, when the red color filter pattern 117R is formed in the center region on the left side of the substrate 110, the red color filter pattern is formed as the corner in the opposite direction as the obstacle is formed as the red color filter pattern 117R is formed on the right side. (117R) Chamfer the upper and lower right corners.

As shown in FIG. 5B, when the red color filter pattern 117R is formed in the lower right region of the substrate 110, the lower left corner is chamfered. When the red color filter pattern 117R is formed in the lower right region of the substrate 110, when a resist is applied and rotated in the center of the substrate 110, the lower left corner of the red color filter pattern 117R is formed to flow in the resist. It acts as the main obstruction to disturb. Therefore, by removing the edges of the region, the obstacles can be removed, and the resist can be uniformly applied to the entire substrate 110 at the same flow rate as the resist in the other region.

On the other hand, when the red color filter pattern 117R is formed in the lower right region of the substrate 110, the resist flow in this region is smoothed by chamfering the lower right corner formed in the flow direction of the resist.

As described above, in the present invention, a portion of the red color filter pattern 117R formed on the substrate 110 is removed to uniform the flow of the resist throughout the substrate 110, thereby uniformizing the entire substrate 110. It is possible to form a color filter layer of one thickness.

In this case, the removed region is an edge formed in a path of a resist that spreads to the outside from the center region of the substrate 110 when the substrate 110 is rotated, and the red color filter pattern formed in the upper left and right regions of the substrate 110 ( In the case of 117R, the upper right and left edges are removed, respectively. In the case of the red color filter pattern 117R formed in the left and right regions of the center of the substrate 110, the upper and lower edges of the right and left sides are removed, respectively. In addition, in the case of the red color filter pattern 117R formed in the lower left and right regions of the substrate 110, upper left and right edges are removed.

At this time, the corner is removed from the upper disconnection of the red color filter pattern 117R at a predetermined angle θ, the angle θ is removed from the upper region to the center region, and the angle ( θ) decreases. The reason is that the path of the resist spreading when the substrate 110 rotates is directed toward the edge of the substrate 110 in the upper and lower regions, so that the angle is different from the upper end of the red color filter pattern 117R in the upper and lower regions. This is because the path of the resist is almost parallel to the end of the red color filter pattern 117R in the center region while being about 45 degrees.

Meanwhile, in the above description, a method of applying green resist to the substrate 110 on which the red color filter pattern 117R is formed is illustrated, but a blue resist is applied to the substrate 110 on which the red color filter pattern and the green color filter pattern are formed. Even in the case of forming, a part of the red color filter pattern and the green color filter pattern may be removed to smooth the flow of the blue resist, thereby forming a color filter layer having a uniform thickness.

As described above, in the present invention, a part of the color filter pattern is removed to remove obstacles that hinder the flow of the resist during spin coating of the resist so that the resist is uniformly applied over the entire substrate. It is to be formed to a uniform thickness. Therefore, the color filter layer can be prevented from occurring unevenness in the diagonal direction of the substrate by non-uniformity.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

Accordingly, the scope of the present invention is not limited thereto, but various modifications and improvements of those skilled in the art using the basic concept of the present invention as defined in the following claims are also within the scope of the present invention.

110 substrate 116 color resist
117R, 117G, 117B: Color Filter

Claims (11)

Board; And
It is composed of a plurality of color filter patterns formed on the substrate,
The color filter pattern is a color filter substrate, characterized in that the edge area is removed. The color filter substrate of claim 1, wherein the color filter pattern comprises a red color filter pattern, a green color filter pattern, and a blue color filter pattern. 2. The color filter substrate of claim 1, wherein the removed edge region is an edge region of a side that is directed toward the center region of the substrate. The color filter substrate of claim 1, wherein the edge area is removed at an angle with an upper end of the color filter pattern. The color filter substrate of claim 4, wherein the angle increases from the central area of the substrate toward the upper and lower areas. The method of claim 1,
An overcoat layer formed on the color filter pattern; And
The color filter substrate further comprises a common electrode formed on the overcoat layer. Providing a substrate;
Forming the black matrix on the substrate;
Applying a first color resist to the center of the substrate on which the black matrix is formed, and rotating the substrate to form a first color resist layer over the entire substrate;
Developing the first color resist layer to form a first color filter pattern;
Applying a second color resist to the center of the substrate on which the first color filter pattern is formed, and rotating the substrate to form a second color resist layer over the entire substrate;
Developing the second color resist layer to form a second color filter pattern;
Applying a third color resist to a center of the substrate on which the first color filter pattern and the second color filter pattern are formed, and rotating the substrate to form a third color resist layer over the entire substrate; And
Developing the third color resist layer to form a third color filter pattern;
The first color filter pattern and the second color filter pattern is a color filter manufacturing method, characterized in that the edge of the direction in which the second color resist and the third color resist spreads when the substrate is rotated. The method of claim 7, wherein the first, second, and third color resists are red, green, and blue color resists, respectively. The method of claim 7, wherein the edge is removed at an angle with an upper end of the color filter pattern. 10. The method of claim 9, wherein the angle increases from the central area of the substrate toward the upper and lower areas. The method of claim 7, wherein
Forming an overcoat layer on the color filter pattern; And
Forming a common electrode on the overcoat layer, characterized in that it further comprises a color filter substrate.

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