KR20070071985A - Color filter substrate for a liquid crystal display device and a manufacturing method of the same - Google Patents

Abstract

A color filter substrate for an LCD(Liquid Crystal Display) and a manufacturing method thereof are provided to minimize a layer thickness change at a column spacer part and prevent a cell-gap change and a defective cell gap by removing a color filter layer and an overcoat layer at a portion where a column spacer is formed. A black matrix(222) is formed on a substrate and an opening corresponding to a pixel area. A column spacer(228) is formed on the black matrix. A color filter layer corresponds to the opening, includes red, green and blue color filters, and is spaced apart from the column spacer. An overcoat layer(226) is formed on the color filter layer, and is spaced part from the column spacer. The column spacer extends from the black matrix. The column spacer has a thickness ranging from about 4mum to about 5.5mum.

Description

Color filter substrate for a liquid crystal display device and a manufacturing method of the same}

1 is a cross-sectional view showing a part of a conventional liquid crystal display device.

2 is a plan view schematically illustrating a color filter substrate for a liquid crystal display device according to a first embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a liquid crystal display device corresponding to line III-III of FIG. 2.

4 is a schematic cross-sectional view of another liquid crystal display device according to a first embodiment of the present invention;

5 is a plan view schematically illustrating a color filter substrate for a liquid crystal display according to a second embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view of a liquid crystal display device corresponding to line VI-VI of FIG. 5.

7A to 7D are plan views sequentially illustrating a manufacturing process of a color filter substrate for a liquid crystal display device according to a second embodiment of the present invention.

8A to 8D are cross-sectional views taken along the line VIIIA-VIIIA of FIG. 7A, line VIIIB-VIIIB of FIG. 7B, line VIIIC-VIIIC of FIG. 7C and line VIIID-VIIID of FIG. 7D, respectively.

<Description of Symbols for Main Parts of Drawings>

210: first substrate 212: first thin film

214: second thin film 220: second substrate

222 black matrix 226 overcoat layer

226a: hole 228: column spacer

The present invention relates to a liquid crystal display device, and more particularly, to a color filter substrate for a liquid crystal display device including a column spacer and a manufacturing method thereof.

Recently, with the rapid development of the information society, there is a need for a flat panel display having excellent characteristics such as thinning, light weight, and low power consumption, among which a liquid crystal display has 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 is formed by arranging two substrates having electrodes formed on one side thereof so that the surfaces on which the two electrodes are formed face each other, injecting a liquid crystal material between the two substrates, and then applying voltage to the two electrodes. By moving the liquid crystal molecules by the electric field is a device that represents the image by the transmittance of light that varies accordingly.

Hereinafter, a structure of a conventional liquid crystal display device will be described with reference to the accompanying drawings.

1 is a cross-sectional view showing a part of a conventional liquid crystal display device.

As shown, the liquid crystal display includes first and second substrates 11 and 21, and a liquid crystal layer 30 is positioned between the first and second substrates 11 and 21.

A gate electrode 12 made of a conductive material such as a metal is formed on the first substrate 11, and a gate insulating film 13 made of a silicon nitride film (SiN _x ) or a silicon oxide film (SiO ₂ ) is formed thereon. 12) covering. An active layer 14 made of pure amorphous silicon is formed on the gate insulating layer 13 on the gate electrode 12, and an ohmic contact layer 15 made of amorphous silicon doped with impurities is formed thereon.

Source and drain electrodes 16a and 16b made of a conductive material such as a metal are formed on the ohmic contact layer 15. The source and drain electrodes 16a and 16b are formed of the gate electrode 12 and the active layer 14. Together to form a thin film transistor (T).

Although not shown, the gate electrode 12 is connected to the gate wiring, the source electrode 16a is connected to the data wiring, and the gate wiring and the data wiring cross each other to define the pixel region.

Subsequently, a passivation layer 17 made of a silicon nitride film, a silicon oxide film, or an organic insulating film is formed on the source and drain electrodes 16a and 16b, and the passivation layer 17 is a contact hole 17a exposing the drain electrode 16b. Has

A pixel electrode 18 made of a transparent conductive material is formed in the pixel area above the passivation layer 17, and the pixel electrode 18 is connected to the drain electrode 16b through the contact hole 17a.

Next, the second substrate 21 is spaced apart from the first substrate 11 at a predetermined interval, and the black matrix 22 is disposed at a position corresponding to the thin film transistor T on the inner surface of the second substrate 21. Although not shown, the black matrix 22 is formed on the entire surface of the substrate with an opening in a portion corresponding to the pixel electrode 18. Accordingly, the black matrix 22 prevents light leakage caused by tilting the liquid crystal molecules in portions other than the pixel electrode 18, and also blocks light from being incident on the channel portion of the thin film transistor T, thereby preventing light leakage current. Serves to prevent the occurrence of

The color filter layer 23 is formed under the black matrix 22. The color filter layer 23 is a red, green, and blue sub-color filter arranged sequentially and one color is one pixel electrode 18. Corresponds to An overcoat layer 24 is formed under the color filter layer 23, and a common electrode 26 made of a transparent conductive material is formed under the overcoat layer 24.

Although not illustrated, first and second alignment layers are formed on the pixel electrode 18 and the common electrode 26, respectively, to determine the initial alignment direction of the liquid crystal molecules of the liquid crystal layer 30.

Meanwhile, a spacer 40 is provided between the two alignment layers to maintain a constant gap between the first and second substrates 11 and 21 and to secure an appropriate thickness of the liquid crystal layer 30.

A first substrate comprising a thin film transistor and a pixel electrode is often referred to as an array substrate, and a second substrate comprising a color filter layer and a common electrode is referred to as a color filter substrate.

The liquid crystal display device is formed through an array substrate manufacturing process, a color filter substrate manufacturing process, and a liquid crystal cell process including disposing two substrates, injecting and encapsulating a liquid crystal material, and attaching a polarizing plate.

Here, the spacers are scattered on any one of two substrates, for example, a color filter substrate, and the spacers can be divided into a wet dispersion method in which a spacer is mixed by spraying alcohol and the like and a dry dispersion method in which only a spacer is dispersed. Dry spraying is divided into electrostatic spraying using static electricity and antistatic spraying using gas pressure. Since liquid crystal displays have a structure that is vulnerable to static electricity, antistatic spraying is widely used.

However, since the scattered spacers are not controlled at a constant position, the scattered spacers may be positioned in the pixel area above the color filter layer, thereby reducing the image quality of the liquid crystal display.

In addition, in the color filter substrate, an alignment layer is formed on the uppermost portion, and a spacer is arbitrarily positioned thereon, and when the liquid crystal display is driven by rubbing of the alignment layer, the arrangement of liquid crystal molecules positioned at the boundary of the pixel region is different. The liquid crystal molecules may be different from each other so that defects such as light leakage may occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a color filter substrate for a liquid crystal display device and a method of manufacturing the same which can improve image quality.

Another object of the present invention is to provide a color filter substrate for a liquid crystal display device and a method of manufacturing the same, which can minimize the change in cell gap caused by the variation in the thickness of the column spacer portion and thus prevent defects.

A color filter substrate for a liquid crystal display device according to the present invention for achieving the above object is a substrate; A black matrix formed on the substrate and having an opening corresponding to the pixel region; A column spacer formed on the black matrix; A color filter layer corresponding to the opening and including a sub color filter of red, green, and blue and spaced apart from the column spacer; And an overcoat layer formed on the color filter layer and spaced apart from the column spacer.

The column spacer extends from the black matrix and has a thickness of about 4 μm to about 5.5 μm.

The overcoat layer has holes corresponding to the column spacers.

A method of manufacturing a color filter substrate in a liquid crystal display according to the present invention includes forming a black matrix and a column spacer having an opening in an upper portion of the substrate; Forming a color filter layer corresponding to the opening and spaced apart from the column spacer; And forming an overcoat layer formed on the color filter layer and spaced apart from the column spacer.

The forming of the black matrix and the column spacer may include applying an opaque photosensitive resin to form a black resin layer; Disposing a mask including a transmissive part, a transflective part, and a blocking part on the black resin layer; Exposing the black resin layer through the mask; And developing the exposed black resin layer.

The black resin layer is a negative type in which a portion exposed to light remains after development, and the transflective portion corresponds to the black matrix.

Forming the overcoat layer includes forming a hole corresponding to the column spacer, wherein the column spacer has a thickness of about 4 μm to about 5.5 μm.

Hereinafter, a liquid crystal display according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a plan view schematically illustrating a color filter substrate for a liquid crystal display according to a first embodiment of the present invention.

As shown, a black matrix 122 having an opening 122a corresponding to the pixel region is formed, and a color filter layer 124 is formed corresponding to the opening 122a. The color filter layer 124 is black. It also overlaps with the matrix 122. The color filter layer 124 includes red, green, and blue sub color filters 124a, 124b, and 124c sequentially arranged. In this case, the sub color filters 124a, 124b, and 124c having the same color are formed in the pixel areas vertically adjacent to each other in the drawing, and the color filter layers 124 have a stripe structure. Next, the column spacer 128 is formed to overlap the black matrix 122, and the column spacer 128 is formed to correspond to the black matrix 122 between the pixel regions adjacent in the vertical direction, and thus the red sub color filter ( Also overlap with 124a).

FIG. 3 is a schematic cross-sectional view of the liquid crystal display device corresponding to line III-III of FIG. 2.

As shown, the first and second substrates 110 and 120 are spaced apart at regular intervals, and the first thin film 112 and the second thin film 114 are sequentially formed on the inner surface of the first substrate 110. have. The first thin film 112 and the second thin film 114 may be an insulating layer formed on the array substrate for the liquid crystal display device, or may be a conductive layer. Although not illustrated, a thin film transistor including a gate electrode, an active layer, a source electrode, and a drain electrode is formed on an inner surface of the first substrate 110, and a pixel electrode connected to the thin film transistor is formed. In addition, the gate lines and the data lines are defined to cross each other to define pixel regions and to transfer signals to the thin film transistors.

A black matrix 122 is formed on the inner surface of the second substrate 120, and the color filter layer 124 in which the red, green, and blue sub color filters 124a, 124b, and 124c of FIG. The overcoat layer 126 is formed on the color filter layer 124. A column spacer 128 is formed on the overcoat layer 128 to uniformly maintain the cell gap d1, which is an interval between the first and second substrates 110 and 120.

Although not shown, a common electrode made of a transparent conductive material may be further formed between the overcoat layer 128 and the column spacer 128.

A liquid crystal layer (not shown) is positioned between the first and second substrates 110 and 120.

Accordingly, the thickness t1 of the column spacer 128 corresponds to the cell gap d1, that is, the thickness of the liquid crystal layer.

4 is a schematic cross-sectional view of another liquid crystal display device according to the first embodiment of the present invention, and has a structure similar to that of FIG. As shown in FIG. 4, a film under the column spacer 128, for example, a red sub color filter 124a, may be formed thicker than other portions. Therefore, the cell gap d2 is larger than the thickness t1 of the column spacer 128.

However, in this case, since the liquid crystal layer is formed based on the thickness t1 of the column spacer 128, a defect may occur. That is, since the supply amount of the liquid crystal material is determined according to the thickness t1 of the column spacer 128, the same amount of liquid crystal material is supplied even if the cell gap d2 is increased, so that the liquid crystal material is supplied in comparison with the actual cell gap d2. The thickness of the liquid crystal layer formed becomes small. Therefore, when an external pressure is generated outside the panel, the liquid crystal of the portion where the pressure is generated is not quickly recovered and staining occurs.

On the other hand, when the film under the column spacer 128 is thinner than other portions, the cell gap becomes smaller than the thickness t1 of the column spacer 128. In this case, since the liquid crystal material is supplied in the same amount as before, since the thickness of the liquid crystal layer to be formed becomes larger than the cell gap, defects due to unevenness may occur.

The second embodiment of the present invention proposes a structure of a color filter substrate to solve this problem.

5 is a plan view schematically illustrating a color filter substrate for a liquid crystal display according to a second embodiment of the present invention.

As shown, a black matrix 222 having an opening 222a corresponding to the pixel region is formed, and a color filter layer 224 is formed corresponding to the opening 222a. The color filter layer 224 is black. It also overlaps with the matrix 222. The color filter layer 224 includes red, green, and blue sub color filters 224a, 224b, and 224c sequentially arranged, and are separated for each pixel area. That is, the sub color filters 224a, 224b, and 224c having the same color and separated from each other in the vertically adjacent pixel areas are formed in the drawing. Next, a column spacer 228 is formed to overlap the black matrix 222, which corresponds to the black matrix 222 between pixel regions adjacent in the vertical direction. In addition, an overcoat layer (not shown) having a hole 226a corresponding to the column spacer 228 is formed on the entire surface of the substrate. Accordingly, the column spacer 228 according to the second embodiment of the present invention does not overlap the color filter layer 224 and the overcoat layer.

FIG. 6 is a schematic cross-sectional view of a liquid crystal display device corresponding to line VI-VI of FIG. 5.

As shown, the first and second substrates 210 and 220 are spaced apart at regular intervals, and the first thin film 212 and the second thin film 214 are sequentially formed on the inner surface of the first substrate 210. have. As mentioned above, the first thin film 212 and the second thin film 214 may be an insulating layer formed on the array substrate for the liquid crystal display device, or may be a conductive layer. Although not shown, a thin film transistor including a gate electrode, an active layer, a source electrode, and a drain electrode is formed on an inner surface of the first substrate 210, and a pixel electrode connected to the thin film transistor is formed. In addition, the gate lines and the data lines are defined to cross each other to define pixel regions and to transfer signals to the thin film transistors.

A black matrix 222 and a column spacer 228 are formed on the inner surface of the second substrate 220, and a part of the black matrix 222 overlaps the black matrix 222 so that the red, green, and blue sub color filters (224a, FIG. 5) are formed. A color filter layer (224 in FIG. 5) is formed in which 224b and 224c are sequentially arranged. In this case, the column spacer 228 extends from the black matrix 222. An overcoat layer 226 is formed on the color filter layer 224 of FIG. 5 and the black matrix 222. The overcoat layer 226 has a hole 226a corresponding to the column spacer 228. Accordingly, the column spacer 228 protrudes through the hole 226a of the overcoat layer 226 to contact the film 214 formed on the first substrate 210.

Although not shown, a common electrode made of a transparent conductive material may be further formed between the overcoat layer 226 and the column spacer 228, and the common electrode may be formed on the first substrate 210.

A liquid crystal layer (not shown) is positioned between the first and second substrates 210 and 220.

Here, the thickness t2 of the column spacer 228 is equal to the thickness (t1 in FIGS. 3 and 4) of the first embodiment equal to the thickness of the color filter layer 224 and the overcoat layer 226. All.

In the drawings, the column spacer 228 of the present invention may have a circular columnar shape, but may have other shapes such as a square column. Accordingly, the holes 226a of the overcoat layer 226 may also have other shapes.

As described above, in the second embodiment of the present invention, the column spacer 228 is formed to extend from the black matrix 222, and the color filter layer 224 and the overcoat layer 226 in the region where the column spacer 228 is located. To be removed. Therefore, a change in the cell gap caused by the film thickness variation in the region where the column spacer 228 is located can be minimized, thereby preventing a defect.

A method of manufacturing a color filter substrate for a liquid crystal display device according to a second exemplary embodiment of the present invention will be described in detail with reference to FIGS. 7A to 7D and 8A to 8D.

7A to 7D are plan views sequentially illustrating a manufacturing process of a color filter substrate for a liquid crystal display according to a second exemplary embodiment of the present invention, and FIGS. 8A to 8D are lines VIIIA-VIIIA of FIG. 7A and FIG. 7B, respectively. A cross-sectional view taken along the line VIIIB-VIIIB, the line VIIIC-VIIIC of FIG. 7C and the line VIIID-VIIID of FIG. 7D.

First, as shown in FIGS. 7A and 8A, an opaque photosensitive resin is coated on the transparent insulating substrate 220 to form a black resin layer 221 having a thickness of about 5 to 7 μm. Subsequently, a mask 300 including the blocking part 312, the transflective part 314, and the transmissive part 316 is disposed on the black resin layer 221, and the exposure is performed through the mask 300. At this time, the black resin layer 221 corresponding to the transmissive portion 316 is completely exposed, and only a part of the black resin layer 221 corresponding to the transflective portion 314 is exposed. Here, the black resin layer 221 is a negative type (negative type) is used to leave the light portion after development, the positive type (positive type) is removed may be used after development, in this case The positions of the blocking part 312 and the transmitting part 316 of the mask 300 are reversed. Meanwhile, in the present invention, the semi-transmissive portion 314 of the mask 300 includes a plurality of slits, but may be formed as a semi-transmissive layer that transmits only part of the light.

Next, as illustrated in FIGS. 7B and 8B, the exposed black resin layer (221 of FIGS. 7A and 8A) is developed to have a black matrix 222 and a black matrix having an opening 222a corresponding to the pixel region. Column spacers 228 extending in the vertical direction from 222 are formed. The black matrix 222 corresponds to the transflective portion 314 of the mask 300 of FIG. 8A, and the column spacer 228 corresponds to the transmissive portion 316 of the mask 300 of FIG. 8A. As mentioned above, since the column spacer 228 is preferably formed in consideration of the thicknesses of the color filter layer and the overcoat layer, the thickness t21 of the column spacer 228 is about 4 to 5.5 μm, and the black matrix ( The thickness t22 of 222 may be about 1 to 1.5 μm as in the prior art.

As described above, in the present invention, the black matrix 222 and the column spacer 228 may be simultaneously formed in one photolithography process. In addition, although the photosensitive black resin was exposed and developed here, a separate photosensitive film may be formed and the black resin may be patterned after exposure and development.

Next, as illustrated in FIGS. 7C and 8C, a color filter layer 224 including red, green, and blue sub color filters 224a, 224b, and 224c is formed on the opening 222a of the black matrix 222. . The color filter layer 224 partially overlaps the black matrix 222. In this case, each of the sub color filters 224a, 224b, and 224c may be formed by applying a photosensitive color resin and then exposing and developing the color filters. Alternatively, it may be formed by a method such as printing. Here, each of the sub color filters 224a, 224b, and 224c is removed from the portion where the column spacer 228 is formed. Therefore, as shown in FIG. 7C, the sub color filters 224a, 224b, and 224c of the pixel area adjacent in the vertical direction are separated from each other. In this case, the sub color filters 224a, 224b, and 224c may be removed only at a portion where the column spacers 228 are formed. In this case, the green sub color filter 224b and the blue sub color filter 224c of the pixel area adjacent in the vertical direction may be removed. ) May be connected to each other.

Next, as shown in FIGS. 7D and 8D, the overcoat layer 226 is formed and patterned on the entire surface of the substrate 220 including the color filter layer 224, thereby forming a hole 226a corresponding to the column spacer 228. To form. Thus, the column spacer 228 protrudes through the hole 226a.

A common electrode made of a transparent conductive material may be further formed on the overcoat layer 226. In this case, the common electrode has holes corresponding to the column spacer 228, like the overcoat layer 226, so that the column spacer 228 is formed. To protrude through the hole of the common electrode.

As such, the color filter substrate for the liquid crystal display device according to the second embodiment of the present invention can be manufactured. In the second embodiment of the present invention, in order to reduce the process, the column spacer 228 is formed in the same process as the black matrix 222, but the column spacer 228 is formed through a process separate from the black matrix 222. It may be formed.

The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit of the present invention.

In the color filter substrate for the liquid crystal display device and the method of manufacturing the same according to the present invention, the color filter layer and the overcoat layer are removed at the portion where the column spacer is formed. Therefore, it is possible to minimize the change in the film thickness of the column spacer portion, thereby preventing cell gap variations and defects. In this case, the column spacer may be formed in the same process as the black matrix, thereby reducing manufacturing process and cost.

Claims (10)

A substrate; A black matrix formed on the substrate and having an opening corresponding to the pixel region; A column spacer formed on the black matrix; A color filter layer corresponding to the opening and including a sub color filter of red, green, and blue and spaced apart from the column spacer; And An overcoat layer formed on the color filter layer and spaced apart from the column spacer Color filter substrate for a liquid crystal display device comprising a. The method of claim 1, And the column spacer extends from the black matrix. The method of claim 1, The overcoat layer is a color filter substrate for a liquid crystal display device having a hole corresponding to the column spacer. The method of claim 1, The column spacer has a thickness of about 4 μm to about 5.5 μm. Forming a black matrix and a column spacer having an opening on the substrate; Forming a color filter layer corresponding to the opening and spaced apart from the column spacer; And Forming an overcoat layer formed on the color filter layer and spaced apart from the column spacer. Method of manufacturing a color filter substrate for a liquid crystal display device comprising a. The method of claim 5, Forming the black matrix and column spacers, Applying an opaque photosensitive resin to form a black resin layer; Disposing a mask including a transmissive part, a transflective part, and a blocking part on the black resin layer; Exposing the black resin layer through the mask; And Developing the exposed black resin layer Method of manufacturing a color filter substrate for a liquid crystal display device comprising a. The method of claim 6, And the black resin layer is a negative type in which a portion exposed to light remains after development. The method of claim 6, And the transflective portion corresponds to the black matrix. The method of claim 5, The forming of the overcoat layer includes forming a hole corresponding to the column spacer. The method of claim 5, The column spacer has a thickness of about 4 μm to about 5.5 μm.

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