KR20060080393A - Liquid crystal display panel and manufacturing method of the same - Google Patents

Abstract

The present invention relates to a liquid crystal display panel and a manufacturing method thereof, comprising: a first substrate; A second substrate disposed opposite the first substrate; A liquid crystal layer injected between the first substrate and the second substrate; And a column spacer formed on at least one of the first substrate and the second substrate and having a relatively hard lower first resin layer and a second resin layer softer than the first resin layer. . Accordingly, a liquid crystal display panel including a column spacer capable of elastically responding to external pressure, and a manufacturing method thereof may be provided.

Description

Liquid crystal display panel and its manufacturing method {LIQUID CRYSTAL DISPLAY PANEL AND MANUFACTURING METHOD OF THE SAME}

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

2 to 5 are cross-sectional views sequentially showing steps of manufacturing a column spacer according to the present invention.

Explanation of Signs of Major Parts of Drawings

10: thin film transistor 100: first substrate

120: gate line 200: second substrate

210: second insulating substrate 220: black matrix

230: color filter 240: overcoat layer

250: common electrode 260: first resin coating layer

270: second resin coating layer 280: column spacer

281: first resin layer 283: second resin layer

300: liquid crystal layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel and a method for manufacturing the same, and to a liquid crystal display panel and a method for manufacturing the same, which can flexibly respond to external pressure by improving the structure of a column spacer.

In general, a liquid crystal display (LCD) forms an image using light emitted from a backlight assembly by adjusting light transmittance of liquid crystal cells arranged in a matrix form according to image signal information.

The liquid crystal display panel includes a thin film transistor substrate, a color filter substrate disposed opposite the thin film transistor substrate, and a liquid crystal layer injected between the thin film transistor substrate and the color filter substrate.

A liquid crystal display device including a liquid crystal display panel injects a liquid crystal into a constant cell gap formed between a thin film transistor substrate and a color filter substrate prepared by a known method, and applies an electric voltage to the liquid crystal molecules to drive the optical. It is important to maintain the two substrates at regular intervals because they are devices. If the cell gap is not constant, the transmittance of light passing through the portion is changed, and thus uniformity defects appearing, which represent spatially nonuniform brightness.

Thus, column spacers are formed between the thin film transistor substrate and the color filter substrate in order to maintain an appropriate cell gap.

However, in the case where the column spacer is made of one resin, when an external pressure is applied to the liquid crystal display panel, the pressure is concentrated at a portion where the column spacer is formed to maintain the gap between the two substrates, thereby failing to flexibly cope with the external pressure. In particular, when the column spacer is not able to overcome the external pressure, there is a problem in that a defect in which the spacer of the portion under pressure is collapsed and the region is dark appears.

Accordingly, an object of the present invention is to provide a liquid crystal display panel and a method of manufacturing the same, which can flexibly respond to external pressure by improving the structure of the column spacer.

The object is a first substrate; A second substrate disposed opposite the first substrate; A liquid crystal layer injected between the first substrate and the second substrate; And a column spacer formed on at least one of the first substrate and the second substrate, the column spacer having a lower first resin layer that is relatively hard and an upper second resin layer that is softer than the first resin layer. It is achieved by a liquid crystal display panel.

Here, the glass transition temperature of the material constituting the first resin layer is higher than the glass transition temperature of the material constituting the second resin layer.

The glass transition temperature of the material forming the first resin layer is higher than room temperature, and the glass transition temperature of the material forming the second resin layer is lower than room temperature.

Moreover, it is preferable that the molecular weight of the substance which comprises a 1st resin layer is larger than the molecular weight of the substance which comprises a 2nd resin layer.

Another object of the present invention is to prepare a first substrate; Forming a common electrode on the second insulating substrate; Sequentially forming a lower hard first resin coating layer on the common electrode and an upper second resin coating layer softer than the first resin coating layer; Patterning a resin coating layer to form a column spacer composed of a first resin layer and a second resin layer to prepare a second substrate; And arranging a second substrate so as to face the first substrate, and bonding the second substrate to each other.

Hereinafter, a liquid crystal display panel and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the liquid crystal display panel according to the present invention includes a first substrate 100 including a plurality of thin film transistors 10, which are switching elements, and a passivation layer 170 covering the plurality of thin film transistors 10. ), A second substrate 200 facing the first substrate 100 and including a black matrix 220, a color filter 230, and a common electrode 250, a first substrate 100, and a second substrate 200. And a column spacer 280 that maintains a gap between the substrates 200, and a liquid crystal layer 300 filled between the first and second substrates 100 and 200.

The first substrate 100 includes a plurality of gate lines 120 and a plurality of data lines (not shown) formed in a matrix form on a 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 the intersection of the gate line 120 and the data line (not shown), and a pixel electrode 180 connected to the thin film transistor 10. do. A signal voltage is applied to the liquid crystal layer 300 between the pixel electrode 180 and the common electrode 250 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 branched from the gate line 120.

In addition, although not shown, the first substrate 100 may include a gate pad (not shown) and a data pad (not shown) connected to ends of the gate line 120 and the data line (not shown) to receive driving signals. City).

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 doped with n-type impurities are sequentially formed. It is. Here, the ohmic contacts 151 and 152 are separated from each other around the gate electrode 121. In addition, unlike the above-described embodiment, the semiconductor layer 140 may be formed of polysilicon.

The source electrode 161 and the drain electrode 162 branched from the data line (not shown) and the data line (not shown) 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 by chemicals is weak and easily oxidized to cause disconnection. 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 protective film 170 is formed of silicon nitride (SiNx), a-Si: C: O film or a-Si: C: F film (low dielectric constant CVD film) and acrylic organic film deposited by PECVD (Plasma Enhanced Chemical Vapor Deposition) method. And so on. A contact hole 171 is formed in the passivation layer 170 to expose the drain electrode 162 of the thin film transistor 10.

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, whereby the thin film transistor 10 and the pixel electrode 180 are electrically connected. The pixel electrode 180 is formed of a reflective conductive film having a high reflectivity such as aluminum (Al) or silver (Ag) in the case of a reflective liquid crystal display panel, and is formed of indium tin oxide (ITO) or 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 has 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. A black matrix 220 formed in a stripe or lattice shape to have an opening area on the 210, and a color having three primary colors of red, green and blue or cyan, magenta, and yellow respectively formed in the opening area of the black matrix 220. The filter 230 includes a black matrix 220 and a common electrode 250 formed on the color filter 230.

The overcoat layer 240 may be included between the black matrix 220 and the color filter 230 and the common electrode 250.

The black matrix 220 distinguishes between the colors of the color filter 230 having three primary colors of red, green, and blue (RGB) or three primary colors of cyan, magenta, and yellow to prevent light leakage between adjacent pixels, and thin film transistors. Light is prevented from entering the light source 10 to prevent poor image 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 a black pigment is added to block light. Here, carbon black, titanium oxide, or the like may be used as the black pigment.

The color filter 230 is formed by repeating red, green and blue or cyan, magenta and yellow colors in the opening regions of the black matrix 220, respectively, and provides color to light passing through the liquid crystal layer 300. . The color filter 230 is a colored photosensitive organic material and is made using a known pigment dispersion method.

The overcoat layer 240 protects the color filter 230, planarizes the second substrate 200, and is mainly made of an acrylic epoxy material.

The common electrode 250 is made of indium tin oxide (ITO) or indium zinc oxide (IZO). The common electrode 250 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 280 includes a lower first resin layer 281 and a second upper resin layer 283 that is softer than the first resin layer 281. The color spacer 280 is formed on the second substrate 200 in a substantially cylindrical, truncated cone or hemispherical shape, and includes the thin film transistor 10, the gate line 120, and the data line formed on the first substrate 100. (Not shown) and corresponding to the intersection of the gate line 120 and the data line (not shown).

Here, the glass transition temperature of the material constituting the first resin layer 281 is preferably higher than the glass transition temperature of the material constituting the second resin layer 283. In addition, the glass transition temperature of the material constituting the first resin layer 281 is higher than room temperature, and the glass transition temperature of the material constituting the second resin layer 283 is preferably lower than room temperature. The molecular weight of the material forming the first resin layer 281 is preferably larger than the molecular weight of the material forming the second resin layer 283.

The second resin layer 283 of the formed column spacer 280 may be made of a material having a lower strength or rigidity than that of the first resin layer 281 to flexibly respond to pressure applied from the outside. The first resin layer 281 is made of a material having a stronger strength or rigidity than the second resin layer 283, so that an appropriate cell gap can be maintained even when an external pressure is applied.

The external pressure applied to the liquid crystal display panel is elastically absorbed by the second resin layer 283 of the column spacer 280 to increase resistance to external pressure, and the first resin layer 281 allows both substrates 100, It is possible to maintain a suitable cell gap between 200). In addition, the column spacer 280 according to the present invention can secure a sufficient amount of variation and elastic force, so that it can endure a larger load and improve liquid crystal amount margin. Thereby, the defect which looks dark while a spacer collapses by external pressure can be prevented.

The first substrate 100 and the second substrate 200 provided by the present invention are coupled to each other using a sealant (not shown), and the liquid crystal is injected into the space between the two substrates 100 and 200 by a vacuum injection method. The liquid crystal layer 300 may be formed, or the liquid crystal layer 300 may be formed through a liquid crystal dropping method.

According to the present invention, a method of manufacturing a liquid crystal display panel having the structure shown in FIG. 1 will be described. The first substrate 100 is manufactured by a known method, and the second substrate 200 is manufactured in the following method. Is manufactured by.

As shown in FIG. 2, first, a black matrix 220 is formed on the second insulating substrate 210. The black matrix 220 is formed by adding a black pigment such as carbon black or oxide to the photosensitive organic material to form a black matrix photoresist, and then applying the black matrix photoresist on the second insulating substrate 220 and exposing the photoresist. The black matrix 220 having openings is completed through a developing and baking process.

Subsequently, a color filter photoresist having any one of red, green, and blue colors is applied onto the second insulating substrate 210 on which the black matrix 220 and the black matrix 220 are not formed, and then the exposure, Through the development and baking process, the color filter 230 having any one of red, green, and blue colors is formed. Thereafter, the above-described process is repeated with the color filter photoresist having the remaining colors, thereby completing the color filter 230 in which red, green, and blue RGB colors are formed in the openings of the black matrix 220, respectively. Here, the red, green, and blue color filters 230 may be exposed using the same mask.

Next, an overcoat layer 240 is formed on the black matrix 220 and the color filter 230. The overcoat layer 240 protects the color filter 230 and planarizes the second substrate 200, and is mainly made of an acrylic epoxy material. Subsequently, the common electrode 250 is formed on the overcoat layer 240. The common electrode 250 directly applies a signal voltage to the liquid crystal layer 300 together with the pixel electrode 180 of the first substrate 100.

Next, as shown in FIG. 3, the first resin coating layer 260 is formed by applying a relatively hard first resin material on the common electrode 250. As shown in FIG. 4, the second resin material layer 270 of the upper portion is formed by sequentially applying a second resin material that is softer than the first resin material.

As shown in FIG. 5, the stacked resin coating layers 260 and 270 are patterned through a photo process to form a column spacer 280 having a predetermined shape. Here, the lower first resin layer 281 is made of a hard resin material as compared to the second resin layer 283, and should be manufactured to a thickness sufficient to maintain a basic cell gap between the two substrates. do. The second resin layer 283 should be made of a soft resin material or a resin material having a lower strength and rigidity than the first resin layer 281 so as to flexibly respond to pressure applied from the outside.

As a result, the second resin layer 283 of the column spacer 280 elastically absorbs the external pressure applied to the liquid crystal display panel, thereby increasing resistance to the external pressure, thereby increasing both substrates by the first resin layer 281. A suitable cell gap can be maintained between (100, 200). And, by the column spacer 280 according to the present invention can ensure a sufficient amount of variation and elastic force to withstand a greater load and improve the liquid crystal amount margin. It is also possible to prevent the spacers from collapsing due to external pressure and appear dark.

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 using a sealant (not shown), and a liquid crystal dropping method or a vacuum injection method is used between the two substrates. The liquid crystal layer 300 is filled to complete the liquid crystal display panel.

Unlike the embodiment of the present invention, a column spacer composed of three or more layers having different strengths may be manufactured.

As described above, according to the present invention, a liquid crystal display panel including a column spacer capable of elastically responding to an external pressure and a method of manufacturing the same can be provided.

Claims (5)

A first substrate; A second substrate disposed opposite the first substrate; A liquid crystal layer injected between the first substrate and the second substrate; And A column spacer formed on at least one of the first substrate and the second substrate, the column spacer having a lower first resin layer that is relatively hard and an upper second resin layer that is softer than the first resin layer. LCD panel. The method of claim 1, The glass transition temperature of the material forming the first resin layer is higher than the glass transition temperature of the material forming the second resin layer. The method of claim 1, The glass transition temperature of the material constituting the first resin layer is higher than room temperature, and the glass transition temperature of the material constituting the second resin layer is lower than room temperature. The method of claim 1, The molecular weight of the material constituting the first resin layer is greater than the molecular weight of the material constituting the second resin layer. Providing a first substrate; Forming a common electrode on the first insulating substrate; Sequentially forming a lower hard first resin coating layer on the common electrode and an upper second resin coating layer softer than the first resin coating layer; Patterning the resin coating layer to form a column spacer composed of a first resin layer and a second resin layer to prepare a second substrate; And And arranging the second substrate to face the first substrate and bonding the second substrate.

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