KR100648218B1 - High aperture ratio color liquid crystal display - Google Patents

Abstract

The present invention discloses a high aperture color liquid crystal display. A high aperture color liquid crystal display device according to the present invention includes a lower substrate having a thin film transistor and a pixel electrode, an upper substrate disposed opposite to the lower substrate and having a counter electrode, and interposed between the lower substrate and the upper substrate. And a red, green, and blue color resin layer and a transparent resin layer are interposed between the thin film transistor and the pixel electrode to have a color filter on array (COA) structure. A plurality of holes (Hole) is provided in the corresponding portion. According to the present invention, the thickness of the color resin layer may be increased to reduce the coupling capacitance, but a plurality of holes may be formed in the color resin layer to prevent a decrease in transmittance, thereby implementing a high-aperture-rate COA structure.

High Opening Ratio, COA Structure, Color Resin Layer

Description

High aperture ratio color liquid crystal display

1 is a plan view showing a unit pixel of a high aperture color liquid crystal display according to the present invention;

2 is a cross-sectional view taken along line AA ′ of FIG. 1.

3 is a cross-sectional view taken along line BB ′ of FIG. 1.

4 is a cross-sectional view taken along the line B-B 'of FIG. 1 according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

1: glass substrate 2: gate line

2a: gate electrode 3: gate insulating film

4 active layer 5 source / drain electrodes

6: data line 7: protective film

8: color resin layer 9: transparent resin layer

10a: via hole 10b: hole

10c: groove 11: pixel electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device, and more particularly, to a high aperture color liquid crystal display device in which a color filter is formed on an array substrate.

Liquid crystal displays have been developed in place of the CRT (Cathode Ray Tube) based on the advantages of low weight, low voltage driving and low power consumption. In particular, thin film transistor liquid crystal displays (hereinafter referred to as TFT-LCDs) realize high quality, large size, and color that are comparable to CRTs, and thus have recently been used in various fields as well as in the notebook PC and monitor market.

The TFT-LCD has a structure in which a lower substrate including a thin film transistor and a pixel electrode and an upper substrate provided with a color filter and a counter electrode are bonded to each other under an intervening liquid crystal layer.

On the other hand, in such a TFT-LCD, in order to obtain a high quality display screen, improvement of the aperture ratio, which is the actual light transmission ratio with respect to the area of the pixel electrode, is prioritized. Accordingly, a top ITO structure has been proposed in which a pixel electrode made of a transparent metal such as indium tin oxide (ITO) is disposed over an entire unit pixel area, and in addition, a COA (coa) having a color filter of an upper substrate disposed on a lower substrate is proposed. Color filter On Array) structure has been proposed.

Here, in order to implement a high aperture COA structure, coupling capacitance between the data line and the pixel electrode must be reduced. Accordingly, the coupling capacitance is reduced by increasing the thickness of the color resin layer interposed between the data line and the pixel electrode.

However, if the thickness of the color resin layer is increased, the coupling capacitance between the data line and the pixel electrode may be reduced, but the transmittance of the light is decreased, thereby making it impossible to realize a high opening ratio. In addition, there is a need for the development of new pigments and new processes for them.

Meanwhile, Korean Patent Application No. 99-7387 discloses a color filter structure for increasing transmittance of a reflective liquid crystal display device. According to this patent, a part of each color subpixel is formed to be transparent by a predetermined length with the same width as each subpixel.

However, this simple distribution of the same width has the fatal drawback of lack of process margin. That is, the transmittance and color reproducibility of the color filter may be different from the first design due to misalignment occurring during the color resin exposure process and misalignment occurring during bonding between the upper and lower substrates. In addition, since a large area must be covered when coating the transparent resin layer on the color resin layer, flatness becomes poor, resulting in a difference in cell gaps.

As a result, there is a difficulty in implementing a high-aperture color liquid crystal display device having a COA structure in the related art.

Accordingly, an object of the present invention is to provide a high aperture color liquid crystal display device which prevents a decrease in transmittance while implementing a COA structure.

In order to achieve the above object, the present invention, a lower substrate having a thin film transistor and a pixel electrode, an upper substrate disposed opposite to the lower substrate and having a counter electrode, and interposed between the lower substrate and the upper substrate And a red, green, and blue color resin layer and a transparent resin layer are interposed between the thin film transistor and the pixel electrode to have a COA structure, and the color resin layer includes a plurality of liquid crystal layers. Provided is a high aperture color liquid crystal display, characterized in that two holes are provided.

Here, the hole is formed in at least one shape in a portion corresponding to one pixel area, and characterized in that formed in the size of the resolution or more of the exposure equipment.

In addition, in order to achieve the above object, the present invention, a lower substrate having a thin film transistor and a pixel electrode, an upper substrate disposed opposite to the lower substrate and having a counter electrode, and between the lower substrate and the upper substrate A liquid crystal layer interposed therebetween, wherein a red, green, and blue color resin layer and a transparent resin layer are interposed between the thin film transistor and the pixel electrode so as to have a COA structure. Provided is a high aperture color liquid crystal display, characterized in that a plurality of grooves are provided in the groove.

Here, the depth of the grooves may be adjusted using a gray tone mask.

(Example)

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

1 to 3 are diagrams for describing a high-aperture color liquid crystal display device according to an exemplary embodiment of the present invention. FIG. 1 is a plan view thereof, FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1, and FIG. It is sectional drawing along the BB 'line | wire of FIG.

First, although not shown in detail, the liquid crystal display according to the present invention basically has a structure in which a lower substrate having a thin film transistor and a pixel electrode and an upper substrate having a counter electrode are bonded under the liquid crystal layer.

In addition, the liquid crystal display according to the present invention has a COA structure in which a color filter is disposed on a lower substrate rather than an upper substrate in order to realize a high opening ratio.

In the liquid crystal display according to the present invention, a color resin layer and a transparent resin layer are interposed between a data line and a pixel electrode to prevent a decrease in light transmittance while implementing a COA structure. It is provided with a plurality of holes (Hole) in the.

That is, as shown in FIG. 1, in the liquid crystal display according to the present invention, a plurality of holes 10b are formed in each color resin layer formed in the sub pixel areas of red (R), green (G), and blue (B). Has a formed structure. In this case, the hole 10b is formed in at least one shape in one pixel area, and the hole 10b is formed in a size larger than the resolution of the exposure apparatus.

In this case, as the thickness of the color resin layer is increased in order to reduce the coupling capacitance between the data line 6 and the pixel electrode 11, a decrease in transmittance may be caused, but a plurality of holes provided in the color resin layer ( Since the white light is transmitted through 10b), the light transmittance is increased, and thus the transmittance can be improved while achieving a high opening ratio according to the COA structure.

In FIG. 1, reference numeral 2 denotes a gate line.

The manufacturing method of such a high aperture color liquid crystal display device is as follows.

2 and 3, a gate metal film is deposited on the glass substrate 1, and then patterned to form a gate line 2 including the gate electrode 2a. Then, the doped amorphous silicon (hereinafter referred to as a-Si) film and the doped amorphous silicon (hereinafter referred to as n + a-Si) on the entire surface of the substrate 1 to cover the gate line 2. ) Films are sequentially deposited, and then the n + a-Si film and the a-Si film are patterned to form an active layer 4.

Next, a source / drain metal film is deposited on the gate insulating film 3 including the active layer 4, and then patterned to form a data line 6 including the source / drain electrode 5. Then, after the protective film 7 is coated on the entire area of the substrate 1 including the data line 6, the protective film 7 is etched to expose the source / drain electrodes 5 to expose the via holes 10a. ).

In this case, since the color resin layer formed afterwards may serve as a protective film, the etching process for coating the protective film and forming the via hole may be omitted, thereby simplifying the process.

Subsequently, on the substrate resultant up to this step, for example, a red (R) color resin is applied to a thickness of about 3 μm thick. Thereafter, the red color resin is exposed and developed, and then cured to form a red color resin layer 8 having a plurality of holes 10b in a corresponding sub-pixel region. In this case, the hole 10b is formed to have a size greater than or equal to the resolution of the exposure apparatus and is formed at a distance greater than or equal to an alignment margin from the edge of the sub pixel region so that the transmittance is not affected by misalignment of the exposure apparatus. In addition, the hole 10b may change its size, shape and number in order to adjust transmittance and color reproducibility.

Subsequently, although not described in detail, green and blue color resin layers are also formed in the respective sub-pixel areas according to the same process as described above.

Meanwhile, the black matrix for preventing color mixing may be formed of a resin or a metal separately from the formation of the color resin layers, and may also be formed through the lamination of the color resin layers described above.

Next, after applying the transparent resin layer 9 on the color resin layer 8 to remove the step by the color resin layer 8 of red (R), green (G) and blue (B). Then, patterning is performed, and then curing is performed. At this time, since the transparent resin layer 9 fills the plurality of holes 10b, the transparent resin layer 9 is easier to planarize than the wide area, and also has excellent thickness uniformity, and thus, excellent cell gap uniformity.

Next, the transparent resin layer 9 and the color resin layer 8 are etched to form via holes 10a exposing the source / drain electrodes 5. Thereafter, a transparent metal film, for example, an ITO metal film, is deposited on the via hole 10a and the transparent resin layer 9, and then patterned and disposed throughout the pixel region, so as to provide a source / through the via hole 10a. The pixel electrode 11 in contact with the drain electrode 5 is formed, thereby completing the formation of a lower substrate having a high opening ratio COA structure.

Subsequently, the lower substrate is bonded to the upper substrate having a counter electrode under the liquid crystal layer to complete the high aperture color liquid crystal display according to the present invention.

4 is a cross-sectional view taken along line B-B 'of FIG. 1 for explaining a high-aperture color liquid crystal display according to another exemplary embodiment of the present invention. Here, the same parts as in Fig. 3 are designated by the same reference numerals.

As shown, in this embodiment, when the color resin layer 8 is formed, a groove 10c, not a hole, is formed in a portion corresponding to the pixel region by using a gray tone mask. Form.

In this case, although the transmittance is slightly lower than that of the previous embodiment, better thickness uniformity can be obtained after formation of the transparent resin layer, thereby making the cell gap more uniform.

As described above, the present invention can increase the transmittance while reducing the coupling capacitance by forming a plurality of holes in the color resin layer while increasing the thickness of the color resin layer, thereby realizing a high aperture COA structure. have.

In addition, since the present invention forms a plurality of holes in the pixel rather than merely distributing the color, the color reproducibility and transmittance change due to misalignment can be prevented.

In addition, the present invention can have excellent flatness because it fills small holes in the application of the transparent resin layer, so that the cell gap can be kept uniform.

Although the preferred embodiments of the present invention have been described above, it is clear that the present invention can use various changes, modifications, and equivalents, and that the above embodiments can be appropriately modified and applied in the same manner. Accordingly, the above description does not limit the scope of the invention as defined by the following claims.

Claims (5)

A lower substrate including a thin film transistor and a pixel electrode, an upper substrate disposed opposite to the lower substrate and having a counter electrode, and a liquid crystal layer interposed between the lower substrate and the upper substrate, A red, green, and blue color resin layer and a transparent resin layer are interposed between the thin film transistor and the pixel electrode so as to have a color filter on array (COA) structure. High aperture color liquid crystal display, characterized in that provided with a hole (Hole). The high-ratio color liquid crystal display of claim 1, wherein the hole is formed in at least one shape in a portion corresponding to one pixel area. The high aperture color color liquid crystal display of claim 1, wherein the hole is formed to have a size equal to or greater than a resolution of an exposure apparatus. A lower substrate including a thin film transistor and a pixel electrode, an upper substrate disposed opposite to the lower substrate and having a counter electrode, and a liquid crystal layer interposed between the lower substrate and the upper substrate, A red, green, and blue color resin layer and a transparent resin layer are interposed between the thin film transistor and the pixel electrode to have a color filter on array (COA) structure, and the color resin layer includes a plurality of color resin on the portion corresponding to the pixel region. High aperture color liquid crystal display, characterized in that provided with a groove (groove). The liquid crystal display of claim 4, wherein the depth of the groove is adjusted using a gray tone mask.

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