KR20060053498A - Liquid crystal display panel - Google Patents

Abstract

The present invention relates to a liquid crystal display panel, comprising: an insulating substrate; A black matrix formed on the insulating substrate and having an opening region formed in a predetermined pattern; And a column spacer formed in the opening region on the insulating substrate. As a result, it is possible to provide a liquid crystal display panel having an improved structure such that the column spacers can stably and stably maintain the gap between both substrates forming the liquid crystal display panel.

Description

Liquid crystal display panel {LIQUID CRYSTAL DISPLAY PANEL}

1 is a cross-sectional view illustrating main parts of a liquid crystal display panel according to a first exemplary embodiment of the present invention;

FIG. 2 is a pattern model diagram of the black matrix of FIG. 1; FIG.

3 is a cross-sectional view illustrating main parts of a liquid crystal display panel according to a second exemplary embodiment of the present invention;

4 is a cross-sectional view illustrating main parts of a liquid crystal display panel according to a third exemplary embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: thin film transistor 100: first substrate

110: first insulating substrate 120: gate line

121: gate electrode 130: gate insulating film

140: semiconductor layer 161: source electrode

162: drain electrode 170: protective film

180 pixel electrode 200 second substrate

210: second insulating substrate 220: black matrix

221: first opening pattern 222: second opening pattern

230: color filter 250: column space

280: common electrode 300: liquid crystal layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly, to a liquid crystal display panel in which the gap between both substrates of the liquid crystal display panel is firmly maintained and the resistance to external pressure is improved.

The liquid crystal display panel displays a desired image by adjusting light transmittance of liquid crystal cells arranged in a matrix according to image signal information.

The liquid crystal display panel maintains a gap between the thin film transistor substrate, the color filter substrate mutually attached to face the thin film transistor substrate, the liquid crystal injected between the thin film transistor substrate and the color filter substrate, and the gap between the thin film transistor substrate and the color filter substrate. It comprises a spacer. Many column spacers are used as such spacers.

Conventional column spacers are generally formed in a shape similar to a cylinder, a truncated cone or a hemisphere on a color filter substrate, and are arranged to correspond to a thin film transistor or a gate line formed on the thin film transistor substrate.

However, in the conventional liquid crystal display panel, pressure is concentrated at a portion where column spacers are formed to maintain a gap between both substrates when a locally excessive external pressure is applied during the process. As a result, the low-strength organic films disposed below the column spacers are destroyed, so that the column spacers cannot properly maintain the gap between the two substrates. That is, when the column spacer is formed on the black matrix, the external pressure applied to the substrate is transferred to the black matrix through the column spacers which maintain the gap between the two substrates, and the black matrix formed of the organic material having a relatively low strength is first broken and the column spacer collapses. There arises a problem that it is impossible to properly maintain the gap between the two substrates.

Accordingly, an object of the present invention is to provide a liquid crystal display panel having an improved structure such that the column spacers can stably and stably maintain the gap between both substrates forming the liquid crystal display panel.

According to the present invention, there is provided a liquid crystal display panel comprising: an insulating substrate; A black matrix formed on the insulating substrate and having an opening region formed in a predetermined pattern; It is achieved by a liquid crystal display panel comprising a column spacer formed in the opening region on the insulating substrate.

The color filter may further include a color filter formed in the opening area on the insulating substrate, and the opening area may include a first opening pattern in which the color filter is formed and a second opening pattern in which the column spacer is formed.

In addition, it is preferable to further include an overcoat layer covering the black matrix.

Here, the overcoat layer preferably has a hole region corresponding to the opening region.                     

The overcoat layer is preferably formed of a photocurable material.

As a result, the column spacer can firmly and stably maintain the gap between the two substrates.

Hereinafter, a liquid crystal display panel according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, a liquid crystal display panel using an amorphous silicon (a-Si) thin film transistor (TFT) formed by a five-sheet mask process as an example is schematically illustrated.

In addition, prior to description, in the various embodiments, components having the same configuration will be described in the first embodiment by using the same reference numerals, and in other embodiments, only the configuration different from the first embodiment will be described. Let's do it.

In the liquid crystal display panel according to the first exemplary embodiment of the present invention, as shown in FIG. 1, a plurality of thin film transistors 10, which are switching elements, and a plurality of pixel electrodes 180 connected to the plurality of thin film transistors 10, respectively. The first substrate 100 having a formed first substrate 100, a black matrix having opening regions 221 and 222 formed in a predetermined pattern, and column spacers 250 formed in the opening regions 221 and 222. The liquid crystal layer 300 filled between the second substrate 200 disposed opposite to the first substrate 100 and the second substrate 200 is included.

First, the first substrate 100 will be described in detail. The first substrate 100 includes a plurality of matrixes formed on the first insulating substrate 110 made of an insulating material such as glass, quartz, ceramic, or plastic. A thin film transistor (TFT) 10, which is a switching element formed at an intersection of the gate line and the data line, a thin film transistor 10, a thin film transistor 10, and a gate line 120 and a plurality of data lines (not shown). The connected pixel electrode 180 is included. A signal voltage is applied to the liquid crystal layer 300 between the pixel electrode 180 and the common electrode 280 of the second substrate 200 to be described later through the thin film transistor 10, and the liquid crystal layer 300 receives this signal. It is aligned with the voltage to determine the light transmittance.

The thin film transistor 10 includes a gate electrode 121, a gate insulating layer 130, a semiconductor layer 140, ohmic contact layers 151 and 152, a source electrode 161, and a drain electrode 162. The gate electrode 121 is formed to branch from the gate line 120.

In addition, although not shown, the first substrate 100 further includes a driving circuit portion connected to the end of the gate line and the data line to supply a driving signal, and the thin film transistor 10 may also be formed in the driving circuit portion. Many may be formed and used as circuit elements.

The gate insulating layer 130 is made of an insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx), and is stacked on the entire surface of the first substrate 100 on which the gate line 120 and the gate electrode 121 are formed. On the gate insulating layer 130 where the gate electrode 121 is located, the semiconductor layer 140 made of amorphous silicon and the ohmic contact layers 151 and 152 made of n + hydrogenated amorphous silicon heavily doped with n-type impurities are sequentially formed. do. Here, the ohmic contacts 151 and 152 are separated at both sides with respect to the gate electrode 121. In addition, unlike the above-described embodiment, the semiconductor layer 140 may be formed of polysilicon.

The data line (not shown) and the source electrode 161 and the drain electrode 162 branched from the data line are formed on the gate insulating layer 130 and the ohmic contact layers 151 and 152.

Here, each wiring including the gate line 120, the gate electrode 121, the data line (not shown), the source electrode 161, the drain electrode 162, and the like is formed of a single layer of a metal or an alloy. However, in order to compensate for the shortcomings of each metal or alloy and to obtain desired physical properties, they are often formed in multiple layers. For example, aluminum or an aluminum alloy is used as the lower layer, and chromium or molybdenum is used as the upper layer. The lower layer uses aluminum or aluminum alloy with low specific resistance to prevent signal resistance due to wiring resistance, and the upper layer uses chemicals to compensate for the shortcomings of aluminum or aluminum alloy where corrosion resistance is weak and easily broken due to chemicals. The upper layer is formed of chromium or molybdenum, which is highly resistant to chemicals. In recent years, molybdenum, aluminum, titanium, tungsten, and the like are spotlighted as wiring materials, and most of them are used in multiple layers.

The passivation layer 170 made of a photosensitive material is stacked on the first substrate 100 on which the thin film transistor 10 is formed. In other words, the protective film 170 may be formed of silicon nitride (SiNx), plasma enhanced chemical vapor deposition (PECVD), or an a-Si: C: O film or an a-Si: C: F film (low dielectric constant CVD film) and an acrylic resin. An organic insulating film or the like. In the passivation layer 170, a contact hole 171 for exposing a portion of the drain electrode 162 of the thin film transistor 10 or a part of the source electrode 161 may be formed.

The pixel electrode 180 is formed on the passivation layer 170 and the contact hole 171. The pixel electrode 180 is connected to the drain electrode 162 through the contact hole 171 so that the thin film transistor 10 and the pixel electrode 180 are electrically connected to each other. The pixel electrode 180 is formed of a reflective conductive film having a high reflectance such as aluminum (Al) or silver (Ag) in the case of a reflective liquid crystal display panel, and indium tin oxide (ITO) or ITO in the case of a transmissive liquid crystal display panel. It is formed of a transparent conductive film such as indium zinc oxide (IZO). In the case of the reflective-transmissive liquid crystal display panel, the pixel electrode 180 is formed in a structure in which the transparent conductive film and the reflective conductive film are stacked.

Next, the second substrate 200 will be described in detail. Like the first substrate 100, the second substrate 200 may include a second insulating substrate made of an insulating material such as glass, quartz, ceramic, or plastic. Black mattress 220 having an opening region formed in a predetermined pattern on 210 and three primary colors of red, green and blue or cyan, magenta and yellow respectively formed in opening regions 221 and 222 of black matrix 220, respectively. The first substrate 100 and the first substrate 100 are formed in the color filter 230 having the structure, the black matrix and the common electrode 280 formed on the color filter, and the opening regions 221 and 222 of the black matrix 220. And a column spacer 250 for maintaining a gap between the two substrates 200.

The black matrix 220 distinguishes between colors of the color filter 230 having red, green, and blue (RGB) or cyan, magenta, and yellow colors to prevent light leakage between adjacent pixels, and light is applied to the thin film transistor 10. It prevents the incident and prevents the poor quality. The black matrix 220 may be made of a single or a combination of multiple metal layers such as chromium, chromium oxide, and chromium nitride, or may be made of a photosensitive organic material to which black pigment is added to block light. Here, carbon black or titanium oxide may be used as the black pigment.

As shown in FIG. 2, the opening regions 221 and 222 of the black matrix 220 include a first opening pattern 221 having a color filter 230 formed in a stripe or lattice shape, and a column spacer. And a second opening pattern 222 in which the 250 is formed.

The second opening pattern 222 may be formed at the position where the column spacer 250 is to be formed, that is, the thin film transistor 10, the gate line 120, the data line (not shown) of the first substrate 100, or the gate line and the data line. It is formed to correspond to the intersection of.

The color filter 230 is formed by repeating red, green and blue or cyan, magenta, and yellow colors in the first opening pattern 221 of the black matrix 220, respectively, and applies color to light passing through the liquid crystal layer 300. It will play a role. This color filter 230 is usually made using a pigment dispersion method known as a coloring photosensitive organic material.

The common electrode 280 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The common electrode 280 directly applies a signal voltage to the liquid crystal layer 300 together with the pixel electrode 180 of the first substrate 100.

The column spacer 250 is formed on the second opening pattern 222 of the black matrix 220 described above, and the photosensitive organic insulating layer formed by dissolving a photoreaction initiator and other additional solvents together in a thermosetting resin such as acryl and a second insulating substrate. It is formed to maintain the gap between the substrate (100, 200) by coating on the (210) and then patterned through a photo process. Here, the material of the column spacer 250 includes a material for blocking light, such as a carbon black pigment, to prevent problems such as light leakage that may occur in the second opening pattern 222 in which the black matrix 220 is opened. can do.

The first substrate 100 and the second substrate 200 completed as described above are arranged to face each other, and then bonded to each other by using a sealant (not shown), and a liquid crystal dropping method is performed between the two substrates 100 and 200. The liquid crystal layer 300 is filled using a vacuum injection method.

By such a configuration, the operation and effects of the liquid crystal display panel according to the first exemplary embodiment of the present invention will be described. A column spacer 250 having a higher strength than that of the black matrix 220 is not formed on the black matrix 220. Without being directly formed on the second insulating substrate 210, resistance to external pressure applied to the liquid crystal display panel is improved. That is, since the column spacer 250 is directly formed on the second insulating substrate 210, the column spacer 250 may withstand the breakdown strength of the column spacer 250 against external stress applied to the liquid crystal display panel, and thus may be applied to the external pressure of the liquid crystal display panel. Improved resistance to

As illustrated in FIG. 3, the second substrate 200 of the liquid crystal display panel according to the second embodiment of the present invention includes an overcoat layer 240 covering the black matrix 220 on the second insulating substrate 210. It includes more.

The overcoat layer 240 includes both the black matrix 220, the color filter 230 formed in the first opening pattern 221 of the black matrix 220, and the second opening pattern 222 of the black matrix 220. The surface is planarized. In addition, the overcoat layer 240 serves to protect the color filter 230, and an acrylic epoxy material is used as a material, and has a stronger strength than the black matrix 220 and the color filter 230.

The column spacer 250 is formed for the overcoat layer 240 formed in the second opening pattern 222 of the black matrix 220 in the second embodiment according to the present invention.

As described above, even when the column spacer 250 is formed on the overcoat layer 240, the black matrix 220 having low strength is not formed under the overcoat layer 240 under the column spacer 250. The load due to the external pressure is tolerate the column spacer 250 and the overcoat layer 240 having a relatively high strength to improve the resistance to the external pressure of the liquid crystal display panel.

As illustrated in FIG. 4, the second substrate 200 of the liquid crystal display panel according to the third embodiment of the present invention has a hole region 242 corresponding to the second opening pattern 222 of the black matrix 220. And an overcoat layer 240 covering the black matrix 220 on the second insulating substrate 210. That is, the overcoat layer 240 covers the black matrix 220 and the color filter 230 formed in the first opening pattern 221 of the black matrix 220, but does not cover the second opening pattern 222.

Here, in order to form the hole region 242 in the overcoat layer 240, it is preferable to form the overcoat layer 240 using a photocurable material. In the process of making the overcoat layer 240 with the photocurable material, the hole region 242 may be formed by adjusting the supply of light.

The column spacer 250 is, in the third embodiment according to the present invention, the second insulating substrate 210 through the hole region 242 of the overcoat layer 240 and the second opening pattern 222 of the black matrix 220. Is formed directly on the

As such, since the column spacer 250 is directly formed on the second insulating substrate 210, the load due to the external pressure applied to the liquid crystal display panel is tolerated by the column spacer 250 having a relatively high strength, so that the outside of the liquid crystal display panel It can improve the resistance to pressure. Therefore, the liquid crystal display panel according to the third embodiment of the present invention can withstand higher loads than the case of the second embodiment, but the manufacturing process becomes complicated.

Also, as in the case of the first and third embodiments of the present invention, when the column spacer 250 is directly formed on the second insulating substrate 210, the column spacer 250 is overcoat 240 as in the case of the second embodiment. Have a length longer than that formed on the layer. Accordingly, the column spacer 250 may secure a sufficient amount of variation and elastic force to withstand higher loads, or to withstand loads even with a small diameter, thereby improving liquid crystal margin.

In addition, the present invention is not limited to the above-described embodiments, and may be applied to any kind of liquid crystal display panel as long as the distance between the two substrates 100 and 200 is maintained by the column spacer 250. .

As described above, according to the present invention, it is possible to provide a liquid crystal display panel having an improved structure such that the column spacers can stably and stably maintain the gap between both substrates forming the liquid crystal display panel.

Claims (5)

In a liquid crystal display panel, An insulating substrate; A black matrix formed on the insulating substrate and having an opening region formed in a predetermined pattern; And a column spacer formed in the opening region on the insulating substrate. The method of claim 1, Further comprising a color filter formed in the opening area on the insulating substrate, The opening area may include a first opening pattern in which the color filter is formed and a second opening pattern in which the column spacer is formed. The method of claim 1, And an overcoat layer covering the black matrix. The method of claim 3, And the overcoat layer has a hole region corresponding to the opening region. The method of claim 4, wherein The overcoat layer is formed of a photocurable material.

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