KR101055190B1 - Manufacturing Method of Liquid Crystal Display Panel - Google Patents

Abstract

The present invention relates to a method of manufacturing a liquid crystal display panel which can simplify the process and reduce the cost.

A method of manufacturing a liquid crystal display panel according to the present invention includes forming a black matrix on a substrate; Forming a color filter in a region partitioned by the black matrix; Forming a planarization layer and a spacer at the same time by coating the organic material on the color filter and then molding the organic material into a soft mold, wherein the organic material is applied to the sum of the heights of the heights of the planarization layer and the spacer. The mold is characterized in that it uses a poly dimethyl siloxane (Poly dimethyl siloxane), polyurethane (Polyurethane).

Description

Manufacturing method of liquid crystal display panel {Method for Fabricating Liquid Crystal Display Pane}             

1 is a cross-sectional view showing a conventional liquid crystal display panel.

2A through 2F are cross-sectional views illustrating a method of manufacturing an upper array substrate of a liquid crystal display panel in a conventional IPS mode.

3 is a cross-sectional view illustrating a liquid crystal display panel according to an exemplary embodiment of the present invention.

4A to 4E are views illustrating a method of manufacturing the upper array substrate of the liquid crystal display panel illustrated in FIG. 3.

5A to 5C are diagrams illustrating formation of a spacer and a planarization layer using a soft mold.

         <Explanation of symbols for the main parts of the drawings>

2,102: upper substrate 4,104: black matrix

18,118: common electrode 32,132: lower substrate

6,106 color filter 7,107 flattening layer

134: Soft mold 113: spacer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly, to a method for manufacturing a liquid crystal display panel in which the planarization layer and the spacer of the liquid crystal display panel can be patterned without using a photolithography process.

In general, a liquid crystal display (LCD) displays an image corresponding to a video signal on a liquid crystal display panel in which liquid crystal cells are arranged in a matrix form by adjusting light transmittance of liquid crystal cells according to a video signal. To this end, the liquid crystal display device includes a liquid crystal display panel in which liquid crystal cells are arranged in an active matrix form, and driving circuits for driving the liquid crystal display panel.

Such liquid crystal displays are roughly classified into twisted nematic (TN) mode and in plan switch (IPS) mode using a vertical electric field according to the electric field driving the liquid crystal.

The TN mode is a mode in which a liquid crystal is driven by a vertical electric field between a pixel electrode and a common electrode arranged to face the upper substrate. The TN mode has an advantage that the aperture ratio is large while the viewing angle is folded. The IPS mode is a mode in which a liquid crystal is driven by a horizontal electric field between a pixel electrode and a common electrode disposed side by side on a lower substrate.

1 is a cross-sectional view showing a liquid crystal display panel of a conventional IPS mode.                         

Referring to FIG. 1, the liquid crystal display panel of the IPS mode has a black matrix 4, a color filter 6, and a planarization sequentially formed on an upper substrate 2 having a transparent electrode layer 3 thereon to prevent static electricity and the like on the back side. An upper array substrate (or color filter array substrate) composed of a layer 7, a spacer 13, and an upper alignment layer 8, and a thin film transistor (hereinafter referred to as “TFT”) formed on the lower substrate 32 in common. Liquid crystal (not shown) injected into an inner space between the lower array substrate (or thin film transistor array substrate) composed of the electrode 18, the pixel electrode 16 and the lower alignment layer 38, and the upper array substrate and the lower array substrate. ).

In the upper array substrate, the black matrix 4 is formed to overlap the TFT region of the lower substrate 2 with the gate line and data line regions (not shown) and partitions the cell region where the color filter 6 is to be formed. . The black matrix 4 prevents light leakage and absorbs external light to increase contrast. The color filter 6 is formed in the cell region separated by the black matrix 4. The color filter 6 is formed for each of R, G, and B to implement R, G, and B colors. The planarization layer 7 is formed to cover the color filter to planarize the upper substrate 2. The column spacer 13 maintains a cell gap between the upper substrate 2 and the lower substrate 32.

In the lower array substrate, the TFT overlaps the gate electrode 9 formed on the lower substrate 32 with the gate line (not shown), and the gate electrode 9 and the gate insulating film 44 interposed therebetween. The semiconductor layers 14 and 47 and the source / drain electrodes 40 and 42 formed together with the data lines (not shown) with the semiconductor layers 14 and 47 interposed therebetween. This TFT supplies a pixel signal from the data line to the pixel electrode 16 in response to a scan signal from the gate line. The pixel electrode 16 is a transparent conductive material having a high light transmittance and is in contact with the drain electrode 42 of the TFT with the protective film 50 therebetween. The common electrode 18 is formed in a stripe shape so as to alternate with the pixel electrode 16. The common electrode 18 supplies a common voltage which is a reference when driving the liquid crystal. The liquid crystal rotates with respect to the horizontal direction by the horizontal electric field between the common voltage and the pixel voltage supplied to the pixel electrode 16.

The upper and lower alignment layers 8 and 38 for liquid crystal alignment are formed by applying an alignment material such as polyimide and then performing a rubbing process.

2A through 2F are cross-sectional views illustrating a method of manufacturing an upper array substrate of a conventional liquid crystal display panel.

First, the transparent conductive layer 3 is formed on the back surface of the upper substrate 2 by a deposition method such as sputtering. Subsequently, after the opaque resin is applied to the entire surface of the upper substrate 2, the black matrix 4 is formed as shown in FIG. 2A by patterning the photolithography process and the etching process using the first mask. Here, chromium (Cr) or the like may be used as the black matrix 4 material.

After the red resin is deposited on the upper substrate 2 on which the black matrix 4 is formed, the red resin R is patterned by a photolithography process and an etching process using a second mask, thereby providing red color as shown in FIG. 2B. The color filter R is formed.

After the green resin is deposited on the upper substrate 2 on which the red color filter R is formed, the green resin is patterned by a photolithography process and an etching process using a third mask, thereby displaying the green color filter as shown in FIG. 2C. (G) is formed. After the blue resin is deposited on the upper substrate 2 on which the green color filter G is formed, the blue resin is patterned by a photolithography process and an etching process using a fourth mask, thereby as shown in FIG. 2D. By forming (B), the red, green and blue color filters 6 are formed.

The organic material is entirely deposited on the upper substrate 2 on which the red, green, and blue color filters 6 are formed, thereby forming the planarization layer 7 as shown in FIG. 2E. The planarization layer 7 prevents the phenomenon of disclination due to the step generated by the black matrix 2 formed of the opaque resin.

After the spacer material is deposited on the upper substrate 2 on which the planarization layer 7 is formed, the spacer material is patterned by a photolithography process and an etching process using a fifth mask, so that the column spacer 13 is shown in FIG. 2F. ) Is formed.

As described above, in order to form the upper array substrate of the conventional liquid crystal display panel, at least five or more mask processes are required. Each mask process includes a photolithography process and the photolithography process is a series of photographic processes including application of photoresist, mask alignment, exposure and development. The photolithography process requires a long process time, a large waste of photoresist and a developer for developing a photoresist pattern, and requires expensive equipment such as an exposure apparatus. As a result, the manufacturing process is complicated and there is a problem of increasing the manufacturing cost of the liquid crystal display panel.

Accordingly, an object of the present invention is to provide a method of manufacturing a liquid crystal display panel which can simplify the process and reduce the cost by patterning without using a photolithography process.

In order to achieve the above object, a method of manufacturing a liquid crystal display panel according to an embodiment of the present invention comprises the steps of forming a black matrix on the substrate; Forming a color filter in a region partitioned by the black matrix; Forming a planarization layer and a spacer at the same time by coating the organic material on the color filter and then molding the organic material into a soft mold, wherein the organic material is applied to the sum of the heights of the heights of the planarization layer and the spacer. The mold is characterized in that it uses a poly dimethyl siloxane (Poly dimethyl siloxane), polyurethane (Polyurethane).

Simultaneously forming the planarization layer and the spacer comprises applying the organic material on the color filter; And pressing the organic material into a soft mold having a groove to form a spacer corresponding to the groove and a planarization layer corresponding to a region other than the groove.

Baking the organic material pressed by the soft mold is characterized in that it further comprises.

The organic material is characterized in that it is cured by at least one of heat and light.

The method may further include forming a common electrode on the spacer and the planarization layer.                     

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 5C.

3 is a cross-sectional view illustrating a liquid crystal display panel in an IPS mode according to the present invention.

The liquid crystal display panel of the IPS mode shown in FIG. 3 is a black matrix 104, a color filter 106, and a planarization layer sequentially formed on the upper substrate 102 having the transparent electrode layer 103 on the back side to prevent static electricity. 107, an upper array substrate (or color filter array substrate) composed of a spacer 113 and an upper alignment layer 108, a thin film transistor (hereinafter referred to as "TFT") formed on the lower substrate 132, and a common electrode 118, a lower array substrate (or a thin film transistor array substrate) composed of a pixel electrode 116 and a lower alignment layer 138, and a liquid crystal (not shown) injected into an internal space between the upper array substrate and the lower array substrate. It is provided.

In the upper array substrate, the black matrix 104 is formed to overlap the TFT region of the lower substrate 132 and the gate line and data line regions (not shown) and partitions a cell region in which the color filter 106 is to be formed. . The black matrix 104 prevents light leakage and absorbs external light to increase contrast. The color filter 106 is formed in the cell region separated by the black matrix 104. The color filter 106 is formed for each of R, G, and B to implement various colors when driving the liquid crystal.

The planarization layer 107 is formed to cover the color filter 106 to planarize the upper substrate 102. The column spacer 113 serves to maintain a cell gap between the upper substrate 102 and the lower substrate 132.

The planarization layer 107 and the column spacer 113 are simultaneously formed by a press molding method using a soft mold (not shown). Here, as the planarization layer 107 and the column spacer 113 material, an organic material curable by heat or light is used.

In the lower array substrate, the TFT overlaps the gate electrode 109 formed on the lower substrate 132 with the gate line (not shown), and the gate electrode 109 and the gate insulating film 144 interposed therebetween. The semiconductor layers 114 and 147 and the source / drain electrodes 140 and 142 formed together with the data lines (not shown) are disposed between the semiconductor layers 114 and 147. The TFT supplies a pixel signal from the data line to the pixel electrode 116 in response to a scan signal from the gate line. The pixel electrode 116 is a transparent conductive material having a high light transmittance and contacts the drain electrode 142 of the TFT with the passivation layer 150 therebetween. The common electrode 118 is formed in a stripe shape so as to alternate with the pixel electrode 116. The common electrode 118 supplies a common voltage which is a reference when driving the liquid crystal. The liquid crystal rotates with respect to the horizontal direction by the horizontal electric field between the common voltage and the pixel voltage supplied to the pixel electrode 116.

The upper and lower alignment layers 108 and 138 for liquid crystal alignment are formed by applying an alignment material such as polyimide and then performing a rubbing process.

4A through 4E are cross-sectional views illustrating a method of manufacturing an upper array substrate of a conventional liquid crystal display panel.                     

First, the transparent conductive layer 103 is formed on the back surface of the upper substrate 102 by a deposition method such as sputtering. Subsequently, after the opaque resin is coated on the entire surface of the upper substrate 102, the black matrix 104 is formed as shown in FIG. 4A by patterning the photolithography process and the etching process using the first mask. Here, chromium (Cr) or the like may be used as the black matrix 104 material.

After the red resin is deposited on the upper substrate 102 on which the black matrix 104 is formed, the red resin R is patterned by a photolithography process and an etching process using a second mask, thereby redding the red resin as shown in FIG. 4B. The color filter R is formed.

After the green resin is deposited on the upper substrate 102 on which the red color filter R is formed, the green resin is patterned by a photolithography process and an etching process using a third mask, so that the green color filter as shown in FIG. 4C. (G) is formed. After the blue resin is deposited on the upper substrate 102 on which the green color filter G is formed, the blue resin is patterned by a photolithography process and an etching process using a fourth mask, as shown in FIG. 4D. By forming (B), the red, green, and blue color filters 106 are formed.

After the organic material is formed on the upper substrate 102 on which the red, green, and blue color filters 106 are formed, the flattening layer 107 and the spacer (as shown in FIG. 113 is formed at the same time. Here, the organic material may be molded by the weight of the soft mold without applying a separate pressure when the soft mold and the organic contact.

This will be described in detail with reference to FIGS. 5A to 5C as follows.                     

As illustrated in FIG. 5A, the organic material is coated on the upper substrate 102 having the color filter 106 formed thereon by a coating method such as a nozzle or spin coating.

Here, the organic material is applied to have a predetermined thickness in consideration of the height of the planarization layer and the spacer. For example, when designing a spacer having a height of about 4 μm and a planarization layer of about 2 μm, the organic material 107a is coated to have a thickness of about 6 μm.

The soft mold 134 having the groove 134a and the protrusion 134b is aligned with the organic material 107a as shown in FIG. 5B. The groove 134a of the soft mold 134 corresponds to the region where the spacer is to be formed. The soft mold 134 may be made of a highly elastic rubber material such as poly dimethyl siloxane (PDMS), polyurethane, cross-linked Novolac Resin, or the like. .

The soft mold 134 is in contact with the surface of the protrusion 134b of the soft mold 134 and the color filter 106 and the black matrix 104 at a weight of its own weight for a predetermined time, for example, For example, pressurized for about 10 minutes to 2 hours. At this time, the upper substrate 102 is baked at a temperature of about 130 ℃ or less. Then, a part of the organic material 107a is caused by capillary force generated by the pressure and surface tension between the soft mold 134 and the substrate 102 and the repulsive force between the soft mold 134 and the organic material 107a. Move into groove 134a of soft mold 134. As a result, as shown in FIG. 5C, the planarization layer 107 and the groove 134a of the soft mold 134 and the spacer 113 in the form of reverse transfer are simultaneously formed.

That is, the organic material 107a moved into the groove 134a of the soft mold 134 by applying the organic material to a sufficient thickness is formed by the spacer 113, and is not moved into the groove 134a of the soft mold 134. The organic material 107a is formed of the planarization layer 107.

After that, an alignment layer is formed on the planarization layer 107 and the spacer 113.

Meanwhile, a common electrode for forming a vertical electric field with the pixel electrode positioned on the lower array substrate may be formed on the planarization layer 107 and the spacer 113.

As described above, the manufacturing method of the liquid crystal display panel according to the present invention eliminates exposure and development by eliminating the formation of a spacer and a planarization layer by pressing an organic material with a soft mold, thereby eliminating the need for expensive equipment such as exposure equipment. This simplifies the manufacturing process and reduces costs.

As such, the method of simultaneously forming the spacer and the planarization layer using a soft mold without using a photo process is not only an IPS mode liquid crystal display panel and a TN mode liquid crystal display panel, but also ECB (Electric Controlled Birefringence), and VA (Vertical Alignment). It can also be easily applied to the liquid crystal display panel of the mode.

As described above, in the method of manufacturing the liquid crystal display panel according to the embodiment of the present invention, the spacer and the planarization layer are simultaneously formed, and the spacer and the planarization layer are formed using the soft mold without using a photo process. This simplifies the manufacturing process and reduces costs.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

Forming a black matrix on the substrate; Forming a color filter in a region partitioned by the black matrix; Coating the organic material on the color filter and then molding the organic material into a soft mold to simultaneously form a planarization layer and a spacer; The organic material is applied to the thickness of the sum of the height of the planarization layer and the spacer, The soft mold is a method of manufacturing a liquid crystal display panel, characterized in that the use of poly dimethyl siloxane (Poly dimethyl siloxane), polyurethane (Polyurethane). The method of claim 1, Simultaneously forming the planarization layer and the spacer Applying the organic material on the color filter; And pressing the organic material into a soft mold having grooves to form a spacer corresponding to the grooves and a planarization layer corresponding to a region other than the grooves. The method of claim 2, And baking the organic substance pressed by the soft mold. The method of claim 1, And the organic material is cured by at least one of heat and light. The method of claim 1, And forming a common electrode on the spacer and the planarization layer.

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