KR20050064753A - An array plate for lcd and the fabrication method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly, to an array substrate for a liquid crystal display device for repairing defective pixels and a manufacturing method thereof.

According to the present invention, when the liquid crystal display is manufactured, the redundancy electrode structure is shared with the sub-pixels of the same color, so that image quality can be improved by laser welding when dark spot defects occur, and the defective pixels are repaired. Repair can reduce product defects and increase reliability.

Description

An array substrate for a liquid crystal display device and a method of manufacturing the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly, to an array substrate for a liquid crystal display device for repairing defective pixels and a manufacturing method thereof.

Recently, with the development of the electronics industry, display devices, which have been limitedly used for TV CRTs, have been widely used in personal computers, notebooks, wireless terminals, automobile dashboards, electronic displays, etc. As a result, the importance of the next generation display device that can process and implement this is increasing.

Such next-generation display devices should be able to realize light and small size, high brightness, large screen, low power consumption and low price. And various flat panel display devices such as a vacuum fluorescent display (VFD) have been studied, and one of them has recently attracted attention.

The liquid crystal display device is superior in resolution to other flat panel display devices, and exhibits characteristics such that the response speed is faster than that of a CRT when a moving image is realized.

In addition, the liquid crystal display device has excellent characteristics such as high brightness, high contrast, low power consumption, and so is used in a wide range of fields such as a desktop computer monitor, a notebook computer monitor, a TV receiver, a vehicle-mounted TV receiver, and navigation.

In general, a liquid crystal display device is formed by arranging two substrates having electrodes formed on one side 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 voltage to the two electrodes. By moving the liquid crystal molecules by the electric field is a device that represents the image by the transmittance of light that varies accordingly.

Such a liquid crystal display device may be broadly divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel includes first and second substrates bonded to each other with a predetermined space; It consists of a liquid crystal layer injected between the two substrates.

Usually, the liquid crystal panel has a structure in which a liquid crystal is filled between two glass substrates or a transparent plastic substrate. A transparent electrode (common electrode, pixel electrode) is formed on the substrate so that voltage can be applied to the liquid crystal. The transparent electrode serves to control the on / off by applying a voltage to the liquid crystal.

That is, the light transmission amount of the liquid crystal display device is controlled by the voltage applied to the transparent electrode, and displays characters / images by the optical shutter effect.

Among such liquid crystal display devices, an active matrix liquid crystal display device having a switching element capable of controlling voltage on / off for each pixel is attracting the most attention due to its excellent resolution and ability to implement video.

FIG. 1 is a three-dimensional view of a portion of a general liquid crystal display, and is shown centering on an active region defined as a region in which a liquid crystal is driven.

As shown, the upper and lower substrates 110 and 130 are spaced apart from each other by a predetermined distance, and the liquid crystal layer 150 is interposed between the upper and lower substrates 110 and 130.

A plurality of gates and data lines 132 and 134 cross each other on the lower substrate 130, and a thin film transistor T is formed at a point where the gates and data lines 132 and 134 cross each other. The pixel electrode 146 connected to the thin film transistor T is formed in the pixel area P defined as an area where the gate and the data lines 132 and 134 intersect.

Although not shown in the drawing, the thin film transistor T includes a gate electrode to which a gate voltage is applied, a source and drain electrode to which a data voltage is applied, and a channel for controlling voltage on / off by a difference between the gate voltage and the data voltage ( ch; channel).

In addition, the color filter layer 112 and the common electrode 116 are sequentially formed below the upper substrate 110.

Although not shown in detail in the drawing, the color filter layer 112 includes a color filter for transmitting only light of a specific wavelength band and a black matrix positioned at a boundary of the color filter to block light on an area where the arrangement of liquid crystals is not controlled.

In addition, upper and lower polarizers 152 and 154 are disposed on each outer surface of the upper and lower substrates 110 and 130 to transmit only light parallel to the polarization axis, and a backlight is provided under the lower polarizer 154 as a separate light source. light) is placed.

The liquid crystal display device uses a substrate that has undergone an array substrate manufacturing process for forming a switching element and a pixel electrode and a color filter substrate manufacturing process for forming a color filter and a common electrode, and a liquid crystal cell process that interposes liquid crystal between the two substrates. Completed through

The liquid crystal cell process may be characterized in that the process is relatively little compared to the array process or the color filter process. The whole process can be largely divided into an alignment layer forming process for forming the liquid crystal molecules, a cell gap forming process, a cell cutting process, and a liquid crystal injection process. After attaching the polarizing plates to the outside of the liquid crystal panel, the liquid crystal display device is completed by connecting the driving circuits.

In the liquid crystal display, when a liquid crystal in a normally black mode is used, if a defect occurs in a channel between the source electrode and the drain electrode in the thin film transistor T, a voltage is not applied to the pixel electrode. This pixel cell appears as a dark spot.

That is, since the bad pixel cell in which the drain electrode and the source electrode are opened cannot actually input desired data, the liquid crystal display cannot implement full color and thus has poor quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide an array substrate for a liquid crystal display device and a method of manufacturing the same, which are capable of improving image quality when dark spot defects are generated by sharing a redundancy electrode structure with subpixels of the same color in manufacturing a liquid crystal display device. There is this.

In order to achieve the above object, an array substrate for a liquid crystal display according to the present invention comprises: a substrate in which first and second sub-pixels of the same color are defined; A plurality of gate lines arranged in a first direction on one side of the sub pixel and a plurality of data lines arranged in a second direction crossing the gate lines; A thin film transistor including a gate electrode, an active layer, a source electrode, and a drain electrode in the subpixel; A pixel electrode connected to the drain electrode; A storage electrode connected to the pixel electrode; And a redundancy electrode overlapping a predetermined region with the drain electrode of the first subpixel, the storage electrode of the second subpixel, and the insulating layer interposed therebetween.

The display device may further include a common electrode configured to cross the pixel electrode and formed in the first direction.

The material constituting the pixel electrode is characterized in that the transparent conductive material.

The transparent conductive material is any one material selected from indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO).

The redundancy electrode is made of the same material as the pixel electrode.

The redundancy electrode is characterized in that the pixel electrode of the first sub-pixel and the storage electrode of the second sub-pixel are electrically connected by laser welding.

In addition, to achieve the above object, a method of manufacturing an array substrate for a liquid crystal display device according to the present invention comprises the steps of preparing a substrate in which the first sub-pixel of the same color is defined; Forming an active layer and an ohmic contact layer in the subpixel with a gate electrode extending from a gate wiring and a first insulating layer interposed therebetween; Forming a source electrode extending from the data line, a drain electrode spaced apart from the predetermined gap, and a storage electrode on the active layer; Forming a pixel electrode connected to the drain electrode; And forming a redundancy electrode overlapping a predetermined region with the drain electrode of the first sub pixel, the storage electrode of the second sub pixel, and the second insulating layer interposed therebetween.

The redundancy electrode is formed of the same material when the pixel electrode is formed.

The redundancy electrode may further include electrically connecting a region overlapping the pixel electrode of the first subpixel and the storage electrode of the second subpixel by laser welding.

The display device may further include a common electrode configured to cross the pixel electrode.

Hereinafter, a liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic plan view of an array substrate of a transverse electric field type liquid crystal display device according to an embodiment of the present invention, in which sub-pixels P ₁ and P ₂ of the same color are formed adjacent to each other. have.

As shown in FIG. 2, an array substrate for a transverse electric field type liquid crystal display device includes a plurality of gate lines 208 configured in one direction in parallel with a predetermined interval and one direction in parallel with the gate lines 208. The common wiring 231 is configured to intersect the two wirings, and in particular, the data wiring 210 is defined between the gate wiring 208 and the pixel regions P ₁ and P ₂ .

In this case, the gate wiring 208 and the data wiring 210 are formed by depositing and patterning a metal such as Al, Cu, Ta, Ti, Mo, Mo alloy, Al alloy, and the like.

A thin film transistor (TFT) including a gate electrode 209, a semiconductor layer 215, a source electrode 216, and a drain electrode 217 is formed at an intersection point of the gate wiring 208 and the data wiring 210. The source electrode 216 is connected to the data line 210 and the gate electrode 209 is connected to the gate line 208.

A pixel electrode 214 connected to the drain electrode 217 and a common electrode 213 connected in parallel with the pixel electrode 214 and connected to the common wiring 231 are formed on the pixel region. .

The pixel electrode 214 is electrically connected to the drain electrode 217 through the drain electrode 217 and the drain contact hole 233 to be spaced apart from each other by a plurality of vertical portions 214b and the vertical portion ( It is composed of a horizontal portion (214a) connecting the 214b.

The common electrode 213 extends vertically downward from the common wiring 231, and includes a plurality of vertical portions 213b interposed with the vertical portions 214b of the pixel electrode 214, and the vertical portions 213b. It consists of a horizontal part 213a which connects 213b to one.

At this time, the vertical portion 213b of the common electrode 213 and the vertical portion 214b of the pixel electrode 214 are configured in a zigzag shape and are alternately formed.

A storage electrode is formed on the common line with a gate insulating layer interposed therebetween, and the storage electrode is connected to the pixel electrode to form a storage capacitor.

In addition, a redundancy electrode made of a pixel electrode material is overlapped and connected over the gate wiring between the same color subpixels P ₁ and P ₂ .

In this case, the redundancy electrode may overlap the storage electrode and a predetermined area in the neighboring upper and lower subpixels (P _1, P ₂₎ the upper pixel (P ₁₎ the drain electrode and the lower pixel (P ₂₎ in which.

Therefore, in the liquid crystal display having the structure described above, when a dark spot occurs due to a defect in the thin film transistor, when the both ends of the redundancy electrode formed on the defective pixel are laser welded, the redundancy electrode causes the defective pixel. Is charged by applying signals from adjacent normal thin film transistors, thereby minimizing distortion of an image due to a dark spot defect.

3 is a cross-sectional view taken along line II ′ of FIG. 2, and FIG. 4 is a cross-sectional view illustrating an array substrate in which pixels are repaired in the transverse electric field type liquid crystal display of FIG. 3.

3 and 4 are basically the same configuration, the description and reference numerals will be omitted for the repeated structure.

As shown in FIG. 3, the array substrate for a transverse electric field type liquid crystal display device according to the present invention is formed by depositing a metal on the substrate 200 and patterning the plurality of gate wirings 208 and the gate wirings 208. Branched at, the gate electrode 209 is formed at the thin film transistor position.

In addition, the common wire 231 and the common electrode 213 are formed vertically downward from the common wire 231 so as to be parallel to the gate wire 208.

Next, the gate insulating layer 220 is formed on the entire surface including the gate electrode 209, and the semiconductor layer 215 forming the active layer 215a and the ohmic contact layer 215b is formed on the gate insulating layer 220. Is formed.

The data line 210 is formed on the gate insulating layer 220 to form a matrix structure with the gate line 208.

At this time, when the data line 210 is formed, the source electrode and the drain electrode 216 and 217 of the thin film transistor are simultaneously formed.

The storage electrode 265 is formed on the common wiring 231.

Subsequently, a protective film 228 is formed on the entire surface of the substrate 200 formed as described above.

The passivation layer 228 may be formed by depositing an organic insulating material including benzocyclobutene and an acrylic resin or one selected from a group of inorganic insulating materials such as silicon nitride (SiN _X ) or silicon oxide (SiO ₂ ).

Thereafter, the pixel electrode 214 is formed to be electrically connected to the drain electrode 217 and the drain contact hole 233 and parallel to the data line 210.

In addition, the pixel electrode 214 is electrically connected to the storage electrode 265 in the storage contact hole 266 to form a storage capacitor.

In this case, a redundancy electrode 275 structure is further formed of the same material when the pixel electrode 214 is formed, and the redundancy is made by pairing neighboring subpixels P ₁ and P ₂ having the same color. The electrode 275 is shared.

Here, the redundancy electrode 275 is formed by overlapping the gate wiring 208 between subpixels P ₁ and P ₂ of the same color, one end of which is connected to the drain electrode 217 of the upper sub pixel P ₁ . The predetermined area overlaps, and the other end overlaps with the storage electrode 265 of the lower subpixel P ₂ .

Therefore, as shown in FIG. 4, when a bad pixel is generated during driving of the liquid crystal, laser welding is performed at both ends of the redundancy electrode 275 overlapping the drain electrode 217 and the storage electrode 265. By connecting the drain electrode 217 and the redundancy electrode 275 overlapping with each other, and through the protective film 228 of each portion overlapping the storage electrode 265 and the redundancy electrode 275, Signals of the upper subpixel P ₁ and the lower subpixel P ₂ may be shared.

That is, when a failure occurs in the lower sub pixel P ₂ , an image signal applied from the driving circuit is transferred from the drain electrode 217 of the upper sub pixel P ₁ to the storage electrode 265 through the redundancy electrode 275. The pixel is repaired by being applied to the pixel electrode 214 of the lower sub-pixel P ₂ through the storage electrode 265.

In the above, the transverse electric field type liquid crystal display device is described in detail by way of examples. However, the present invention is not limited thereto, and the present invention relates to a dark spot pixel repair method in a liquid crystal display device in a normally black mode.

As described above, the present invention has been described in detail through specific embodiments, which are intended to specifically describe the present invention, and the array substrate and manufacturing method for a liquid crystal display device according to the present invention are not limited thereto. It is apparent that modifications and improvements are possible by one of ordinary skill in the art within the technical idea.

According to the present invention, a dark spot defect of a pixel due to a channel defect is shared with a neighboring pixel of the same color in a liquid crystal display to repair a pixel by laser welding, thereby reducing product defects. Not only does it increase reliability, but it also improves product yield.

1 is a schematic stereoscopic view of a partial region of a general liquid crystal display.

2 is a schematic plan view of an array substrate of a transverse electric field type liquid crystal display device as one embodiment according to the present invention;

3 is a cross-sectional view taken along the line II ′ of FIG. 2.

4 is a cross-sectional view illustrating an array substrate in which pixels are repaired in the transverse electric field type liquid crystal display of FIG. 3.

<Description of Signs of Major Parts of Drawings>

200: substrate 208: gate wiring

209: gate electrode 210: data wiring

213: common electrode 214: pixel electrode

215: semiconductor layer 215a: active layer

215b: ohmic contact layer 216: source electrode

217: drain electrode 220: gate insulating film

231: common wiring 233: drain contact hole

228 protective film 265 storage electrode

266: storage contact hole 275: redundancy electrode

Claims (10)

A substrate in which first and second sub-pixels of the same color are defined; A plurality of gate lines arranged in a first direction on one side of the sub pixel and a plurality of data lines arranged in a second direction crossing the gate lines; A thin film transistor including a gate electrode, an active layer, a source electrode, and a drain electrode in the subpixel; A pixel electrode connected to the drain electrode; A storage electrode connected to the pixel electrode; And a redundancy electrode overlapping a predetermined region with the drain electrode of the first subpixel, the storage electrode of the second subpixel, and an insulating layer interposed therebetween. The method of claim 1, And a common electrode configured to cross the pixel electrode and formed in a first direction. The method of claim 1, The material of the pixel electrode is a transparent conductive material, the array substrate for a liquid crystal display device. The method of claim 1, The transparent conductive material is any one material selected from indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). The method of claim 1, The redundancy electrode is an array substrate for a liquid crystal display device, characterized in that the same material as the pixel electrode. The method of claim 1, The redundancy electrode is an array substrate for a liquid crystal display device, characterized in that the pixel electrode of the first sub-pixel and the storage electrode of the second sub-pixel are electrically connected by laser welding. Preparing a substrate in which first and second sub-pixels of the same color are defined; Forming an active layer and an ohmic contact layer on the gate electrode with a gate electrode extending from the gate wiring in the sub-pixel, and a first insulating layer interposed therebetween; Forming a source electrode extending from the data line, a drain electrode spaced apart from the predetermined gap, and a storage electrode on the active layer; Forming a pixel electrode connected to the drain electrode; And forming a redundancy electrode overlapping a predetermined region with the drain electrode of the first subpixel, the storage electrode of the second subpixel, and the second insulating layer interposed therebetween. Method of manufacturing an array substrate. The method of claim 7, wherein The redundancy electrode is formed of the same material when the pixel electrode is formed, the manufacturing method of the array substrate for a liquid crystal display device. The method of claim 7, wherein The redundancy electrode further comprises electrically connecting a region overlapping the pixel electrode of the first subpixel and the storage electrode of the second subpixel by laser welding. Method of preparation. The method of claim 7, wherein A method of manufacturing an array substrate for a liquid crystal display device, further comprising a common electrode that is alternated with the pixel electrode.