KR101212144B1 - A liquid crystal display device and method for fabricating the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device and a method of manufacturing the same, which can reduce the number of processes and increase the flatness of a substrate, comprising: a substrate having a plurality of first to fourth pixel regions; A black matrix layer formed in an area excluding first to fourth pixel areas of the substrate; A first color filter layer formed in each first pixel region; A second color filter layer formed in each second pixel region; A third color filter layer formed in each third pixel region; And a fourth color filter layer formed on the entire surface of the substrate including each of the fourth pixel areas.

LCD, mask, color filter layer, level difference, flatness, overcoat layer, black matrix layer

Description

A liquid crystal display device and method for manufacturing the same {A liquid crystal display device and method for fabricating the same}

1 is a schematic configuration diagram of a conventional color filter substrate

FIG. 2 is a cross-sectional view of a conventional color filter substrate taken along the line I-I ′ of FIG.

FIG. 2 is a cross-sectional view of a conventional color filter substrate taken along the line I-I ′ of FIG.

3A to 3C are cross-sectional views of a conventional color filter substrate.

4 is a configuration diagram of another conventional color filter substrate

5 illustrates a color filter substrate of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 6 is a cross-sectional view taken along line II-II of FIG. 5.

7A to 7J are cross-sectional views of a color filter substrate in a liquid crystal display according to an exemplary embodiment of the present invention.

* Explanation of symbols on the main parts of the drawings

101a: first color filter layer 101b: second color filter layer

101c: third color filter layer 101d: fourth color filter layer

BM: Black Matrix Layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same, which can eliminate the step difference of the flat layer while reducing the number of processes.

As the information society develops, the demand for display devices is increasing in various forms.In recent years, liquid crystal display (LCD), plasma display panel (PDP), electro luminescent display (ELD), and vacuum fluorescent display (VFD) have been developed. Various flat panel display devices have been studied, and some have already been used as display devices in various devices.

Among them, LCD is the most used to replace the CRT (Cathode Ray Tube) for mobile image display because of the excellent image quality, light weight, thinness, and low power consumption, and mobile type such as notebook computer monitor. In addition, it is being developed in various ways, such as a television for receiving and displaying broadcast signals, and a monitor of a computer.

As described above, although various technical advances have been made in order for the liquid crystal display device to serve as a screen display device in various fields, the task of improving the image quality as the screen display device has many advantages and disadvantages.

Therefore, in order to use a liquid crystal display as a general screen display device in various parts, the key to development is how much high definition images such as high definition, high brightness and large area can be realized while maintaining the characteristics of light weight, thinness and low power consumption. It can be said.

Such a liquid crystal display device may be broadly divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel includes a first and second substrates having spaces, and It consists of a liquid crystal layer injected between the first and second substrates.

Here, the first substrate (TFT array substrate) is provided with a plurality of gate lines arranged at a predetermined interval in one direction, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, A plurality of pixel electrodes formed in a matrix form in each pixel region defined by intersecting lines and data lines and a plurality of thin film transistors switched by signals of the gate lines to transmit signals of the data lines to the pixel electrodes Respectively.

In addition, the second substrate (color filter substrate) includes a black matrix layer for blocking light in portions other than the pixel region, an R, G, and B color filter layers for expressing color colors, and a common electrode for implementing an image. Is formed.

The first and second substrates have a predetermined space by spacers and are bonded by a sealant to form a liquid crystal between the two substrates.

On the other hand, an alignment layer is formed on the facing surfaces of the first substrate and the second substrate, respectively, and is rubbed to align the liquid crystal layer.

Here, the color filter layer of the second substrate is generally composed of three color filter layers of R (red), G (green), and B (blue) when the unit pixel is composed of three subpixels. In some cases, in order to increase the luminance of an image displayed on the liquid crystal panel, the unit pixel may be configured by four subpixels.

That is, a transparent white (W) color filter layer is further provided in addition to the R, G, and B color filter layers, and four color filter layers of R, G, B, and W are used.

Hereinafter, a color filter substrate using a color filter layer of conventional R, G, B, and W will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a conventional color filter substrate, and FIG. 2 is a cross-sectional view of a conventional color filter substrate taken along lines I to I ′ of FIG. 1.

In the conventional color filter substrate, as illustrated in FIGS. 1 and 2, a substrate 10 repeatedly defined as a plurality of first, second, third, and fourth pixel regions, and a substrate except the pixel region A black matrix layer BM formed on the entire surface of the pixel 10 to block light in portions other than the pixel region, and first, second, third, and fourth color filter layers 11a formed in the pixel regions. And 11b, 11c, and 11d, and an overcoat layer 12 formed on the entire surface of the substrate 10 including the color filter layers 11a, 11b, 11c, and 11d.

Here, the first, second, and third color filter layers 11a, 11b, and 11c use a pigment or dye-dyed resist or resin.

That is, the first, second, and third color filter layers 11a, 11b, and 11c are formed using a resist or a resin in which red, green, and blue pigments are dyed, respectively, to represent each color.

In addition, the fourth color filter layer 11d is formed using a transparent resist and a resin in which no dye is dyed, and serves to increase luminance by passing all incident light.

Referring to the manufacturing process of the conventional color filter substrate configured as described above in detail.

3A to 3C are cross-sectional views of a conventional color filter substrate.

First, as shown in FIG. 3A, a substrate 10 having first, second, third, and fourth pixel regions is prepared, and chromium or resin is deposited on the substrate 10, and photo and etching are performed. By patterning, a black matrix layer BM is formed on the entire surface of the substrate 10 except for the pixel areas.

Subsequently, as shown in FIG. 3B, a red resist or a resin is applied to the substrate 10 on which the black matrix layer BM is formed, and patterned through photo and etching processes to form a first pixel region of the substrate 10. The first color filter layer 11a is formed on the substrate.

Next, as illustrated in FIG. 3C, a green resist or resin is applied to the substrate 10 on which the first color filter layer 11a is formed, and patterned through photo and etching processes to form a second layer of the substrate 10. The second color filter layer 11b is formed in the pixel region.

Subsequently, a blue resist or resin is applied to the substrate 10 on which the first and second color filter layers 11a and 11b are formed, and patterned through photo and etching processes to form a third pixel region of the substrate 10. Three color filter layers 11c are formed.

Subsequently, a transparent resist is applied to the substrate 10 on which the first, second, and third color filter layers 11a, 11b, and 11c are formed, and patterned through photo and etching processes to form the substrate 10. A fourth color filter layer 11d is formed in four regions, and an overcoat layer 12 is formed on the entire surface of the substrate 10 including the first to fourth color filter layers 11a to 11d to produce a color filter substrate. .

The overcoat layer 12 serves to planarize the substrate 10 by filling gaps between the color filter layers 11a to 11d.

In order to manufacture such a conventional color filter substrate, five mask processes are required. That is, a first mask process for forming the black matrix layer BM is required, and a first mask process for forming the first to fourth color filter layers 11a to 11d, respectively.

Meanwhile, in order to reduce the number of mask processes, the process of forming the fourth color filter layer 11d may be omitted. In this case, the overcoat layer 12 plays the same role as the fourth color filter layer 11d in addition to the planarization role as described above.

That is, FIG. 4 is a view showing another conventional color filter substrate, and as shown in the figure, the portion of the overcoat layer 12 formed in the fourth pixel region serves as the fourth color filter layer 11d.

Proceeding such a process can reduce one mask process.

However, since the first to third color filter layers 11a to 11c are formed in the first to third pixel areas, and the color filter layer 11d is not formed in the fourth pixel area, respectively, the first to third pixels. The portion of the overcoat layer 12 formed in the portion corresponding to the three pixel region and the portion of the overcoat layer 12 formed in the portion corresponding to the fourth pixel region have different thicknesses. That is, the portion of the overcoat layer 12 formed in the portion corresponding to the fourth pixel region has a lower thickness than the portion of the overcoat layer 12 formed in the portion corresponding to the first to third pixel regions. Therefore, the overcoat layer 12 shown in FIG. 4 has a problem in that it cannot properly perform its original role, that is, the planarization role.

Disclosure of Invention The present invention has been made to solve the above problems, and an object thereof is to provide a liquid crystal display device and a method of manufacturing the same, which can reduce the number of processes through back exposure and planarize the substrate.

According to an aspect of the present invention, a liquid crystal display device includes: a substrate having a plurality of first to fourth pixel areas; A black matrix layer formed in an area excluding first to fourth pixel areas of the substrate; A first color filter layer formed in each first pixel region; A second color filter layer formed in each second pixel region; A third color filter layer formed in each third pixel region; And a fourth color filter layer formed on the front surface of the substrate including each of the fourth pixel areas.

The fourth color filter layer may be formed in each of the fourth pixel areas to cover the black matrix layer and the first to third color filter layers.

The first to fourth color filter layers may be color filter layers representing red, green, blue, and white, respectively.

And an overcoat layer formed on the entire surface of the substrate including the fourth color filter layer.

In addition, the manufacturing method of the liquid crystal display device according to the present invention for achieving the above object comprises the steps of preparing a substrate having a plurality of first to fourth pixel areas; Forming a black matrix layer in an area except for each of the first to fourth pixel areas of the substrate; Forming a first color filter layer in each of the first pixel areas; Forming a second color filter layer in each of the second pixel areas; Forming a third color filter layer in each of the third pixel areas; Forming a color resist on the entire surface of the substrate including the first to third color filter layers; And forming a fourth color filter layer on the front surface of the substrate including each of the fourth pixel areas by back exposing the color resist.

The first to fourth color filter layers may be color filter layers representing red, green, blue, and white colors, respectively.

The method may further include forming an overcoat layer on the entire surface of the substrate including the fourth color filter layer.

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

5 is a view illustrating a color filter substrate of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along lines II to II of FIG. 5.

The color filter substrate of the liquid crystal display according to the exemplary embodiment of the present invention includes a substrate 100 having a plurality of first, second, third, and fourth pixel regions, as shown in FIGS. 5 and 6. And a black matrix layer BM formed on the entire surface of the substrate 100 except for the first to fourth pixel regions to block light in portions except the first to fourth pixel regions, and the first pixel region. And a first color filter layer 101a formed in the second pixel filter, a second color filter layer 101b formed in the second pixel region, a third color filter layer 101c formed in the third pixel region, and the fourth pixel region. And a fourth color filter layer 101d formed on the entire surface of the substrate 100 and an overcoat layer 120 formed on the entire surface of the substrate 100 including the fourth color filter layer 101d.

Here, the first color filter layer 101a is a red color filter layer for expressing red color, the second color filter layer 101b is a green color filter layer for expressing green color, and the third color filter layer 101c is blue. A blue color filter layer for expressing the color filter layer, and the fourth color filter layer 101d is a white color filter layer for expressing white color.

In fact, the fourth color filter layer 101d is a colorless transparent color filter layer, and the fourth color filter layer 101d passes the incident light as it is.

According to an exemplary embodiment of the present invention, a liquid crystal display device includes a color filter substrate 100 configured as described above, a thin film transistor substrate 100 (not shown) bonded together with a space with the color filter substrate 100, and the And a liquid crystal layer (not shown) formed between the color filter substrate 100 and the thin film transistor substrate 100.

Here, the thin film transistor substrate 100 has a plurality of pixel regions, and has a plurality of gate lines and a plurality of data lines arranged to cross each other to define the pixel region.

A thin film transistor is formed near the intersection of the gate line and the data line, the gate electrode of the thin film transistor is electrically connected to the gate line, the source electrode of the thin film transistor is electrically connected to the data line, The drain electrode is electrically connected to the pixel electrode.

The manufacturing method of the liquid crystal display device according to the exemplary embodiment of the present invention configured as described above is as follows.

7A to 7J are cross-sectional views of a color filter substrate 100 in a liquid crystal display according to an exemplary embodiment of the present invention.

First, as shown in FIG. 7A, a substrate 100 having a plurality of first, second, third, and fourth pixel regions is prepared, and chromium or resin is deposited on the substrate 100, and a photo And patterning through an etching process to form a black matrix layer BM on the entire surface of the substrate 100 except for the first to fourth pixel areas.

Subsequently, as shown in FIG. 7B, the red resist 141 is applied to the substrate 100 on which the black matrix layer BM is formed, and the first mask M1 is aligned on the red resist 141. Let's do it.

Here, the opening of the first mask M1 exposing the first pixel area is formed.

In this state, an exposure step of irradiating ultraviolet rays to the red resist 141 exposed through the first mask M1 is performed.

Subsequently, when the development process is performed, only a portion of the red resist 141 positioned in the first pixel area is left as shown in FIG. 7C, and the rest is removed. That is, the first color filter layer 101a is formed in the first pixel area.

Subsequently, as shown in FIG. 7D, the green resist 142 is coated on the entire surface of the substrate 100 on which the first color filter layer 101a is formed, and the second mask M2 is disposed on the green resist 142. ).

Here, the opening of the second mask M2 exposing the second pixel area is formed.

In this state, an exposure process of irradiating ultraviolet rays to the green resist 142 exposed through the second mask M2 is performed.

Subsequently, when the development process is performed, only a portion of the green resist 142 positioned in the second pixel area remains as shown in FIG. 7E, and the rest is removed. That is, the second color filter layer 101b is formed in the second pixel area.

Subsequently, as shown in FIG. 7F, a blue resist 143 is coated on the entire surface of the substrate 100 on which the first and second color filter layers 101b are formed, and a third portion is formed on the blue resist 143. Align the mask M3.

Here, the third mask M3 has an opening that exposes the third pixel region.

In this state, an exposure step of irradiating ultraviolet rays to the blue resist 143 exposed through the third mask M3 is performed.

Subsequently, when the development process is performed, only the portion of the blue resist 143 positioned in the third pixel region remains and the rest are removed, as shown in FIG. 7G. That is, a third color filter layer 101c is formed in the third pixel area.

Subsequently, as shown in FIG. 7H, a white resist 144 is coated on the entire surface of the substrate 100 on which the first to third color filter layers 101a to 101c are formed, and the white resist 144 is exposed. .

In this case, the exposure method uses a back exposure method for exposing the back surface of the substrate 100. That is, ultraviolet rays are irradiated to the back surface of the substrate 100.

The ultraviolet light then reaches the white resist 144 through two paths.

That is, the first path through which the ultraviolet rays reach the white resist 144 via the substrate 100 and the ultraviolet rays pass through the substrate 100 and the color filter layers 101a, 101b, or 101c. There is a second route to 144.

Here, since the ultraviolet rays of the second path further pass through the color filter layers 101a, 101b, or 101c, they have a weaker intensity than the ultraviolet rays of the first path. Accordingly, the portion of the white resist 144 irradiated with the ultraviolet rays of the second path is weakly exposed than the portion of the white resist 144 irradiated with the ultraviolet rays of the first path.

Accordingly, a portion of the white resist 144 located on the first to third pixel areas where the color filter layers 101a, 101b, or 101c are present is weakly exposed, and the color filter layers 101a, 101b, or 101c are present. The portion of the white register 144 located on the fourth pixel region that is not is exposed at the original intensity.

Subsequently, when the substrate 100 is immersed in a developing solution, a portion of the white resist 144 on the fourth pixel region is left as it is and half of the portion of the white resist 144 on the first to third pixel regions is removed. In fact, the thickness of the portion of the white resist 144 formed on the remaining portion of the substrate 100 except for the fourth pixel region is about half removed.

Then, as illustrated in FIG. 7I, a fourth color filter layer 101d is formed on the entire surface of the substrate 100 including the fourth pixel region to express white color.

Here, the fourth color filter layer 101d serves to planarize the substrate 100 in addition to expressing the white color described above.

At this time, as described above, since the thickness of the portion of the white resist 144 formed on the remaining portion of the substrate 100 except for the fourth pixel region is about half removed, the fourth color formed from the portion of the white resist 144 is removed. The portion of the filter layer 101d is also half in thickness. On the other hand, the thickness of the portion of the fourth color filter layer 101d formed in the fourth pixel region is maintained at the thickness of the first white resist 144. Accordingly, the step difference between the portion of the fourth color filter layer 101d formed in the fourth pixel region and the portion of the fourth color filter layer 101d formed in the remaining portion of the substrate 100 except for the fourth pixel region is reduced. That is, d2 of FIG. 7I is smaller than d1 of FIG. 4.

Meanwhile, as shown in FIG. 7I, the flatness may be further increased by further forming an overcoat layer 120 on the entire surface of the substrate 100 on which the fourth color filter layer 101d is formed.

When the process of the present invention proceeds, only four mask processes are required, and the flatness of the substrate 100 can be increased.

That is, only the first mask M1 process for forming the black matrix layer BM and the first masks M1 to M3 for forming the first to third color filter layers 101a to 101c are performed. need.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

As described above, the liquid crystal display device and the manufacturing method thereof according to the present invention have the following effects.

In the present invention, by forming the overcoat layer and the white color filter layer using the back exposure method, it is possible to reduce the step of the overcoat layer while reducing the number of masks.

Claims (7)

delete delete delete delete Preparing a substrate having a plurality of first to fourth pixel regions; Forming a black matrix layer in an area except for each of the first to fourth pixel areas of the substrate; Forming a first color filter layer in each of the first pixel regions by exposing the first color resist to the entire surface using a first mask; Forming a second color filter layer in each of the second pixel areas by exposing the second color resist to the entire surface using a second mask; Forming a third color filter layer in each of the third pixel areas by exposing the third color register to the entire surface using a third mask; Forming a fourth color resist on the entire surface of the substrate including the first to third color filter layers; And Back exposing the fourth color resist to form a fourth color filter layer on the entire surface of the substrate including the respective fourth pixel regions; And, And the first to fourth color filter layers are color filter layers representing red, green, blue, and white colors, respectively. delete 6. The method of claim 5, And forming an overcoat layer on the entire surface of the substrate including the fourth color filter layer.

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