KR100437594B1 - Liquid crystal display - Google Patents

Abstract

The present invention discloses a liquid crystal display device having a holding spacer as a cell gap holding means. In the disclosed liquid crystal display device, a lower substrate including several gate bus lines, data bus lines, and thin film transistors, and an upper substrate provided with a color filter and a black matrix include a sealing material having a line shape with a liquid crystal layer interposed therebetween. In the liquid crystal display device bonded to each other by a holding spacer to maintain a gap between the substrates, the holding spacer is made of a polymer material, and the black of the upper substrate corresponding to the gate bus line. It is located on the matrix, characterized in that arranged in a different density in the inner region and the outer region relative to the sealing line.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPLAY}

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 having a holding spacer as a cell gap holding means.

In general, a liquid crystal display device has a structure in which an upper substrate including a lower substrate and a color filter layer is bonded with a liquid crystal layer interposed therebetween. When a graphic signal is applied to a pixel electrode disposed on a lower substrate, the liquid crystal display generates an electric field between the counter electrode disposed on the upper substrate, thereby twisting the liquid crystal molecules, and twisting the liquid crystal molecules. By the transmittance of the polarized light is adjusted to display a graphic signal.

Therefore, in the liquid crystal display, optical properties vary greatly depending on the physical properties of the liquid crystal and the thickness of the liquid crystal layer. As a result, when the lower substrate and the upper substrate are completed, the liquid crystal display may spread spacers to maintain a constant cell gap before bonding them. do.

There are various methods of dispersing the spacers on the substrate, but among them, a dry method in which the same polarity is uniformly spread by the repulsive force between the spacers which are charged and charged while passing through the injection nozzle together with nitrogen gas is widely used.

However, with the recent trend toward larger and higher quality liquid crystal displays, conventional spacer spreading methods have many limitations.

First, the spacers should be uniformly distributed over a large area as the size is increased, and scattering nonuniformity occurs according to the conductivity uniformity of the stage on which the substrate is seated.

Second, the scattered spacers are also located in the openings of the unit pixel areas, causing light leakage.

Recently, in order to solve the above problems, a method of constantly forming a holding spacer made of a polymer material on an upper substrate or a lower substrate has been proposed. This method allows the spacers to be uniform and prevents the position from changing due to movement, thereby improving cell gap retention.

However, the spacer density in the substrate surface is important for the method of forming the strut spacer in order to maintain the cell gap. For example, when the spacer density is high, the bubble shrinks due to the difference in heat shrinkage between the glass substrate and the strut spacer at low temperature. There is a problem that occurs.

On the contrary, when the spacer density is low, there is a problem in that the cell gap is easily changed by external pressure in the subsequent hot press process, and the process margin is reduced.

Accordingly, the present invention has been made to solve the above problems, by changing the density of the holding spacer in the inner region and the outer region around the sealing region of the substrate, thereby preventing the low-temperature bubble phenomenon, cell gap It is an object of the present invention to provide a liquid crystal display device which can prevent this easily changing disadvantage.

1 schematically shows a substrate on which strut-shaped spacers are formed in accordance with the present invention;

FIG. 2 is an enlarged view of a portion “A” of FIG. 1. FIG.

3 is an enlarged view of a portion “B” of FIG. 2;

* Description of the symbols for the main parts of the drawings *

2: outer black matrix line 3: sealing line

5: Post type spacer 7: Black matrix line 9a: Red color filter layer 9b: Green color filter layer 9c: Blue color filter layer 10: Substrate

11: scribing line X: outer area of seal

Y: display area

In order to achieve the above object, a liquid crystal display device includes a lower substrate including several gate bus lines, data bus lines, and thin film transistors, and an upper substrate provided with a color filter and a black matrix. In the liquid crystal display device which is bonded by a sealing material in the form of a line between the two, and the holding spacer is interposed between the substrates to maintain the gap therebetween, the holding spacer is made of a polymer material, the gate bus line It is located on the black matrix of the upper substrate corresponding to and characterized in that arranged in a different density in the inner region and the outer region relative to the sealing line.

Here, the strut spacer is made of any one polymer material selected from the group consisting of acrylic, epoxy, aligning agent, and photosensitive film, wherein the strut spacer has a denser density than the inner region based on a sealing line. Wherein the strut spacers are arranged in one of three pixel sizes on the black matrix inside the sealing line, the strut spacers are arranged on the black matrix portion of the red color pixel, and the strut spacers are sealed. In the area outside the line, it is disposed at one density per unit pixel size from 0.2 mm in the scribing line to an area 10 mm from the edge of the disc substrate, and the strut spacer has a width (w) and a length (l) of 15 μm × It has a rectangular shape of 20 µm. In addition, the width of the black matrix has at least four times the width w of the post spacer.

According to the present invention, since the post spacers are arranged at different densities in the inner and outer regions of the sealing line, uniform cell gaps can be maintained and process margins can be increased.

(Example)

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

1 is a view schematically showing a substrate on which a post spacer is formed according to the present invention. As shown, the substrate 10 is divided into a display area Y on the inner side and a seal outer area X on the outer side with respect to the sealing line 3, and the outer black matrix line 2 It is formed inside the sealing line (3). On each of the outer black matrix lines 2 and the black matrix lines (not shown) in the display area Y, the strut spacers are formed of three unit pixels each having red, green, and blue color filter layers 9a, 9b, and 9c. It is formed one by one.

On the other hand, in the seal outer area X, the post spacers 5 are formed at one density per unit pixel size.

FIG. 2 is an enlarged view of a portion “A” of FIG. 1. As shown in the figure, in consideration of the process of forming the strut spacer 5 from the edge of the substrate 10, the strut spacer 5 is placed in the room outer region X with a distance a of about 10 mm. The density is uniformly formed at about one density per unit pixel size. In the post spacer 5 formed in the seal outer region X, the post spacer 5 is formed only up to an area 0.2 mm (b) away from the scribing line 11. This is to prevent the holding spacer 5 from being present in the scribing line 11. The scribing line 11 is about 0.5 mm (c) away from the sealing line 3. The display area Y formed of the color filter layers 9a, 9b and 9c and the black matrix line 7 inside the sealing line 3 and the outer black matrix line 2 outside the display area Y. This exists. The outer black mattress line area is located up to a distance of 0.5 mm from the display area to the scribing line. The post spacer formed on the outer black matrix line 2 is separated from the sealing line 3 by 0.98 mm to 1.15 mm (e: 1.15 mm, f: 0.98 mm). Although shown in the figure, d which is not described is 1.5 mm as the width of the sealing line.

In this way, the post spacer 5 is formed at one density per three unit pixel sizes at the overlapping portion of the outer black matrix line 2 and the black matrix line 7 with the red color filter layer 9a. . On the outer periphery area X outside the sealing line 3, the strut-shaped spacer 5 is constantly formed at one density per unit pixel size.

The reason for differently forming the density of the post-shaped spacers 5 around the sealing line 3 as described above is that after the spacers are formed, a hot press process, a pressurized end seal process, and a tape of the upper and lower substrates are formed. This is to ensure a wide process margin, such as maintaining cell gap uniformity due to more strut spacers when undergoing a tape cleaning or polarizer attachment process.

FIG. 3 is an enlarged view of a black matrix line corresponding to the gate bus line of the portion “B” of FIG. 2. As shown in FIG. 3, a rectangular shape formed in the center of the black matrix line 7 of the red color filter layer 9a is illustrated. The size of the post spacer 5 is determined in consideration of the prevention of damage to the alignment layer of the opening of the pixel, which is influenced by the post spacer when rubbed and is not covered by the black matrix. The width of the black matrix line 7 is four times greater than the width w of the strut spacer 5. The preferred size of the post spacer 5 is 15 m in width w and 20 m in length l. Thus, the width of the black matrix should be at least 60 μm, four times 15 μm. However, in view of the aperture ratio problem, it is limited in an appropriate width.

In addition, although the shape of the post-shaped spacer 5 is limited to a rectangle, any person having ordinary skill in the art may include a form which can be modified and implemented.

Therefore, the present invention described above has the disadvantages such as lack of process margins such as cell gap unevenness caused by external pressure generated by a pressurization process and heat pressure applied when the upper substrate formed with the sealing line and the holding spacer is bonded to the lower substrate. In order to prevent low temperature bubble generation in the panel reliability test due to the dense spacer formed inside the sealing line, the formation density of the post spacer was modified according to each region.

As described in detail above, according to the present invention, in the low temperature reliability test generated in the conventional display area due to the dense strut spacer inside the sealing line, the low temperature bubble phenomenon due to the difference in shrinkage between the substrate and the strut spacer is prevented. There is an advantage to this.

In addition, the formation density of the strut-type spacers was increased in the outer region of the sealing line so that the cell gap did not easily change even in the external pressure in the hot pressure, the pressurized end seal process and the like.

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the invention claimed in the claims. will be.

Claims (9)

A lower substrate including several gate bus lines, data bus lines, and thin film transistors, and an upper substrate provided with a color filter and a black matrix are bonded by a sealing material in line form with a liquid crystal layer interposed therebetween, In the liquid crystal display device is provided with a holding spacer to maintain the gap therebetween, The holding spacer is made of a polymer material, and is positioned on a black matrix of an upper substrate corresponding to the gate bus line, and is disposed at different densities in an inner region and an outer region with respect to a sealing line. . The method of claim 1, The holding spacer is any one of a polymer material selected from the group consisting of acrylic, epoxy, aligning agent and photosensitive film. The method of claim 1, And the outer spacer is disposed at a denser density than the inner region based on the sealing line. The method of claim 1, And one of the columnar spacers is arranged on the black matrix inside the sealing line for every three pixel sizes. The method of claim 4, wherein And the post spacer is disposed on a black matrix portion of a red color pixel. delete The method of claim 1, And the strut spacer is disposed at a density per unit pixel size from an area of 0.2 mm to an area of 10 mm from the edge of the disc substrate in an area outside the sealing line. The method of claim 1, And said columnar spacer has a rectangular shape having a width (w) and a length (l) of 15 mu m x 20 mu m. The method of claim 1, And the width of the black matrix is at least four times the width (w) of the strut spacer.