KR101031760B1 - manufacturing method of array substrate for liquid crystal display device - Google Patents

Abstract

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display device.

Since a plurality of metal wires are formed in the display area of the array substrate, ions of the etching gas are bent toward the outer side of the substrate during the dry etching process, resulting in poor etching uniformity.

In the present invention, a dummy pattern having the same structure as that of the pixel on the display area is formed outside the array substrate to uniformly etch the thin film during dry etching, and the protective layer on the dummy pattern is removed to form a hole, thereby easily etching the protective layer. can do. In addition, the protective pattern may cover the holes of the protective layer to prevent foreign substances from entering the display area of the array substrate through the holes of the protective layer.

Description

Manufacturing method of array substrate for liquid crystal display device             

1 is a view showing a conventional array substrate for a liquid crystal display device.

2 is a schematic view of an array substrate for a liquid crystal display according to an embodiment of the present invention.

3 illustrates a cross-sectional structure for one pixel in the array substrate of the present invention.

4 is a view illustrating a dummy pattern forming unit according to an exemplary embodiment of the present invention.

5 is a view illustrating a dummy pattern forming unit according to another exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

210: dummy pattern 212: first wiring

214: second wiring 216: thin film transistor

220: shield 222: hole

232: Protective Pattern

The present invention relates to a liquid crystal display device, and more particularly, to a method of manufacturing an array substrate for a liquid crystal display device.

In general, a liquid crystal display device is formed by arranging two substrates having electrodes formed on one surface thereof so that the surfaces on which the two electrodes are formed face each other, injecting a liquid crystal material between the two substrates, and then applying a voltage to the two electrodes. By moving the liquid crystal molecules by an electric field, the device expresses an image by the transmittance of light that varies accordingly.

A liquid crystal display may have various forms. Currently, an active matrix liquid crystal display (AM-LCD) having a thin film transistor and pixel electrodes connected to the thin film transistors arranged in a matrix manner has excellent resolution and video performance. It is most noticed.

The liquid crystal display device has a structure in which pixel electrodes are formed on a lower array substrate, and a common electrode is formed on a color filter substrate, which is an upper substrate, and drives liquid crystal molecules by an electric field perpendicular to a substrate that is vertically stretched. to be. This is excellent in characteristics such as transmittance and aperture ratio, and the common electrode of the upper plate serves as a ground, thereby preventing the destruction of the liquid crystal cell due to static electricity.

An array substrate of a liquid crystal display device includes a plurality of thin film transistors and pixel electrodes, and is formed by repeatedly repeating a process of depositing a thin film and etching a photo using a mask.

Hereinafter, a conventional array substrate for a liquid crystal display device will be described with reference to the accompanying drawings.

1 is a view showing a conventional array substrate for a liquid crystal display device. As shown, a display area A in which an image is implemented is defined on the array substrate 1, and a plurality of gate wires 2 and data wires 4 are formed in the display area A. FIG. The gate wiring 2 and the data wiring 4 intersect to define a pixel region, and a thin film transistor 6 serving as a switching element is formed at a portion where the gate wiring 2 and the data wiring 4 cross each other. The pixel electrode 8 connected to the thin film transistor 6 is formed in the region.

The array substrate of the liquid crystal display is formed by repeatedly depositing a thin film and etching the photo using a mask. As described above, in the display area of the array substrate, a plurality of gate wirings, data wirings, and electrodes of a thin film transistor are formed of a metal material. Therefore, in the dry etching process using plasma, the ions of the etching gas used to etch the thin film are bent toward the outer side of the substrate having less metal material than the display area having more metal material. For this reason, the etching uniformity in a board | substrate falls, and the characteristic of a thin film transistor falls.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a method of manufacturing an array substrate for a liquid crystal display device which can increase the etching uniformity of a thin film and prevent the occurrence of defects.

According to another aspect of the present invention, there is provided a method of manufacturing an array substrate for a liquid crystal display device, the method including: providing a substrate defined by a display area and a non-display area; and forming a gate wiring on the display area of the substrate. Forming a data line crossing the gate line to define a pixel area; forming a thin film transistor connected to the gate line and the data line; forming a dummy pattern in the non-display area; Forming a passivation layer covering a wiring, a data line, and a thin film transistor and having a hole exposing the dummy pattern; forming a pixel electrode connected to the thin film transistor in a pixel area above the passivation layer; Forming a protective pattern covering the dummy pattern; The.

The dummy pattern includes first and second interconnections and a thin film transistor connected to the first and second interconnections.

The forming of the gate wiring may include forming the first wiring, and the forming of the data wiring may include forming the second wiring.

The forming of the protective pattern may be performed in the same process as forming the pixel electrode.

In addition, the dummy pattern may have a larger area than the hole, and the dummy pattern may be positioned on the top, bottom, left, and right sides of the display area.

Meanwhile, the forming of the passivation layer may use a dry etching method.

As described above, in the present invention, a protective pattern covering the hole of the protective film exposing the dummy pattern of the non-display area may be formed to prevent foreign matter from entering the display area of the array substrate through the hole of the protective film.

Hereinafter, an array substrate for a liquid crystal display device according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram schematically illustrating an array substrate for a liquid crystal display according to an exemplary embodiment of the present invention. As shown, the array substrate 100 according to the present invention includes a display area B in which an image is implemented and a non-display area C at the edge of the display area B.

In the display area B, a plurality of gate lines 112 are formed in the horizontal direction, and a plurality of data lines 132 are formed in the vertical direction. The gate line 112 and the data line 132 intersect to define a pixel area. A thin film transistor 116, which is a switching element, is formed at a portion where the gate line 112 and the data line 132 intersect, and a pixel electrode 152 connected to the thin film transistor 116 is formed in the pixel area. have.

In the non-display area C, a dummy pattern 170 is formed. The dummy pattern 170 is formed on the top, bottom, left, and right sides of the display area B, but may be formed only on a portion of the dummy pattern 170 depending on the width of the non-display area C. FIG. The dummy pattern 170 has a structure similar to that of the pixel of the display area B. FIG.

The cross-sectional structure of one pixel in the array substrate of the present invention is shown in FIG. As illustrated in FIG. 3, a gate electrode 114 is formed on the substrate 110, and the gate electrode 114 is connected to the gate wiring 112 (FIG. 2). A gate insulating layer 120 is formed on the gate electrode 114 to cover the gate electrode 114. An active layer 122 and an ohmic contact layer 124 are formed on the gate insulating layer 120 on the gate electrode 112. It is formed in turn. Source and drain electrodes 134 and 136 are formed on the ohmic contact layer 124. The source electrode 134 is connected to the data line 132 of FIG. 2, and the drain electrode 136 is a gate electrode ( 114 is spaced apart from the source electrode 134 at the top. A passivation layer 140 is formed on the source and drain electrodes 134 and 136, and the passivation layer 140 has a drain contact hole 142 exposing the drain electrode 136. The pixel electrode 152 is formed on the passivation layer 140, and the pixel electrode 152 is connected to the drain electrode 134 through the drain contact hole 142.

4 is a diagram illustrating a dummy pattern forming unit according to an exemplary embodiment of the present invention. As illustrated, the dummy pattern 170 includes a plurality of first wires 172 extending in the horizontal direction and a plurality of second wires 174 extending in the vertical direction. In addition, the dummy pattern 170 includes a thin film transistor 176 formed at a portion where the first and second wirings 172 and 174 intersect and connected to the first and second wirings 172 and 174. . The first wire 172 is formed of the same material and the same process as the gate wire 112 of FIG. 2, and the second wire 174 is formed of the same material and the same process as the data wire 132 of FIG. 2. The dummy pattern 170 is exposed by the hole 144 formed in the passivation layer 140.

Here, a dry etching method is used when etching the passivation layer 140 to form the drain contact hole (142 of FIG. 3), and the etching degree of the passivation layer 140 is measured by detecting the removed substance. However, since only the protective layer 140 of the drain contact hole 142 is removed in the display area (B of FIG. 2), the amount of detection is very small, and thus the degree of etching of the protective layer 140 is difficult to determine. Therefore, as shown in FIG. 4, by removing and detecting all of the passivation layer 140 of the dummy pattern 170, the etching degree of the passivation layer 140 may be easily measured.

As described above, in the present invention, a dummy pattern 170 having the same structure as that of the pixel of the display area B is formed on the outer side of the substrate so that the thin film may be uniformly etched during the photolithography process of the thin film using dry etching.

However, as shown in FIG. 4, when the protection layer corresponding to the dummy pattern is removed to form a hole, a foreign material enters the display area through the hole of the protection layer in a subsequent process, causing a problem. In order to solve this problem, another embodiment of the present invention further forms a protective pattern covering the hole of the protective film.                     

5 is a diagram illustrating a dummy pattern forming unit according to another exemplary embodiment of the present invention. As shown, the thin film transistors 216 connected to the first and second wirings 212 and 214 and the first and second wirings 212 and 214 that cross the outer portion of the substrate, that is, the non-display area, may be disposed. A dummy pattern 210 is formed. The dummy pattern 210 is exposed through the hole 222 formed in the passivation layer 220, and the hole 222 of the passivation layer 220 is covered with the passivation pattern 232. Since the protective pattern 232 has a larger area than the hole 222 of the protective layer 220 and covers the hole 222, foreign matter may be prevented from entering the display area through the hole 222 of the protective layer 220. In addition, the protection pattern 232 compensates the level difference caused by the hole 222 of the protection layer 220 to some extent. Therefore, it is possible to reduce the defect that may be caused by the step in the process of printing and rubbing the alignment film afterwards. The protection pattern 232 may be formed of the same material and the same process as the pixel electrode.

The array substrate is then subjected to a cell manufacturing process. That is, after forming an alignment layer for determining the initial alignment direction of the liquid crystal molecules on the array substrate and the color filter substrate, each of the two substrates to form a gap for the liquid crystal injection to prevent leakage of the injected liquid crystal A seal pattern is formed, and other substrates are provided with spacers for precisely maintaining a gap between the array substrate and the color filter substrate. Subsequently, the array substrate and the color filter substrate are disposed, and the seal pattern is pressed and bonded.

In general, in order to improve manufacturing efficiency and reduce manufacturing cost, since a plurality of liquid crystal cells to be a liquid crystal display device are formed on a single substrate, the array substrate and the color filter substrate are bonded together, and then cut into individual cells. Separation process is performed. In the cell separation process, the portion where the dummy pattern is formed is also cut and removed. Thereafter, liquid crystal is injected and encapsulated between the two substrates, and then a polarizing plate and a driving circuit are attached to complete the liquid crystal display.

The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit of the present invention.

In the present invention, the thin film may be uniformly etched during the dry etching by forming a dummy pattern having the same structure as the pixel on the display area outside the array substrate. In addition, the protection layer on the dummy pattern may be removed to form a hole to facilitate etching of the protection layer, and the protection pattern may be formed to cover the hole of the protection layer, and may be generated as a foreign material is injected into the display area through the hole of the protection layer. It can prevent the defective.

Claims (8)

Providing a substrate defined by a display area and a non-display area; Forming a gate wiring on the display area of the substrate; Forming a data line crossing the gate line to define a pixel area; Forming a thin film transistor connected to the gate line and the data line; Forming a dummy pattern in the non-display area; Forming a passivation layer covering the gate line, the data line, and the thin film transistor and having a hole exposing the dummy pattern; Forming a pixel electrode connected to the thin film transistor in a pixel area above the passivation layer; And Forming a protective pattern covering the dummy pattern on the protective layer; Including, The dummy pattern includes a thin film transistor connected to the first and second wirings and the first and second wirings that cross each other. Forming the gate wiring includes forming the first wiring; And the forming of the data line comprises forming the second line. delete delete delete The method of claim 1, The forming of the protective pattern is performed in the same process as forming the pixel electrode. The method of claim 1, And the dummy pattern has a larger area than the hole. The method of claim 1, And the dummy pattern is positioned on top, bottom, left and right of the display area. The method of claim 1, The forming of the passivation layer is a method of manufacturing an array substrate for a liquid crystal display device using a dry etching method.

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