KR20070071795A - Liquid crystal display device - Google Patents

Abstract

An LCD(Liquid Crystal Display) is provided to minimize a bright spot generation region by minimizing a repair region through change of a gate line pattern, a drain electrode pattern and a pixel electrode pattern. A gate line(61) includes a gate electrode(61a) on a substrate and includes a protruding protrusion(61b) and a recess(61c). A data line(63) intersects the gate line to define a pixel region. A source electrode(63a) protrudes from the data line. A drain electrode(63b) is separated from the source electrode to overlap the protrusion of the gate line. A passivation layer includes a first contact hole(65) that is formed alternately with respect to the protrusion of the gate line so as to expose a portion of the drain electrode. A pixel electrode(66) is formed in the pixel region. The drain electrode extends in a right direction and the extending portion overlaps the protrusion of the gate line.

Description

Liquid Crystal Display Device

1 is an exploded perspective view showing a conventional liquid crystal display device

FIG. 2 is a plan view illustrating a bright point defect generated when observed in a black state in a conventional liquid crystal display device. FIG.

FIG. 3 is a cross-sectional view illustrating a bright spot failing part of FIG. 2 and adjacent pixels thereof; FIG.

4 is an enlarged plan view of a unit pixel of a liquid crystal display according to the related art.

FIG. 5 is a diagram illustrating a bright point generation of a unit pixel according to a lack of a repair margin in FIG. 4.

6 is an enlarged plan view of a unit pixel of a liquid crystal display according to the present invention;

7 is a diagram of a unit pixel after repairing when changing the unit pixel structure according to the present invention.

 Explanation of symbols on the main parts of the drawings

61 gate line 61a gate electrode

61b: protrusion 61c: groove

63: data line 63a: source electrode

63b: drain electrode 65: first contact hole

66 pixel electrode

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device suitable for minimizing the repair area to minimize the bright spot generation area.

As the information society develops, the demand for display devices is increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display panels (PDPs), electro luminescent displays (ELD), and vacuum fluorescent (VFD) Various flat panel display devices such as displays have been studied, and some of them are already used as display devices in various devices.

Among them, LCD is the most widely used as the substitute for CRT (Cathode Ray Tube) for mobile image display device because of its excellent image quality, light weight, thinness, and low power consumption. In addition to the use of the present invention has been developed in various ways such as a television and a computer monitor for receiving and displaying broadcast signals.

In order to use such a liquid crystal display as a general screen display device in various parts, it is a matter of how high quality images such as high definition, high brightness and large area can be realized while maintaining the characteristics of light weight, thinness and low power consumption. Can be.

Hereinafter, a liquid crystal display according to the related art will be described with reference to the accompanying drawings.

1 is an exploded perspective view showing a conventional liquid crystal display device.

The conventional liquid crystal display device 10 has the 1st board | substrate 1 and the 2nd board | substrate 2, and the said 1st board | substrate 1 and the 2nd board | substrate 2 which were bonded together with the fixed space as shown in FIG. It consists of the liquid crystal layer 3 injected in between.

In more detail, the first substrate 1 may have a plurality of gate lines 4 in one direction and constant in a direction perpendicular to the gate lines 4 at regular intervals to define the pixel region P. FIG. A plurality of data lines 5 are arranged at intervals. In addition, a pixel electrode 6 is formed in each pixel region P, and a thin film transistor T is formed at a portion where the gate line 4 and the data line 5 cross each other to form the gate line 4. A data signal of the data line 5 is applied to each of the pixel electrodes 6 according to a signal applied to the.

In addition, a black matrix layer 7 is formed on the second substrate 2 to block light in portions other than the pixel region P, and portions R corresponding to the respective pixel regions are formed to express colors. , G, B color filter layers 8 are formed, and a common electrode 9 for realizing an image is formed on the color filter layers 8.

In the liquid crystal display device as described above, the liquid crystal of the liquid crystal layer 3 formed between the first and second substrates 1 and 2 is aligned by an electric field between the pixel electrode 6 and the common electrode 9, The amount of light passing through the liquid crystal layer 3 may be adjusted according to the degree of alignment of the liquid crystal layer 3 to express an image.

Such a liquid crystal display is called a twisted nematic mode liquid crystal display, and in addition to the TN mode liquid crystal display, an in-plane switching (IPS) liquid crystal display using a horizontal electric field has been developed. In the transverse electric field (IPS) mode liquid crystal display, a pixel electrode and a common electrode are formed parallel to each other at a predetermined distance in a pixel area of the first substrate so that a transverse electric field (horizontal electric field) is generated between the pixel electrode and the common electrode. The liquid crystal layer is aligned by the lateral electric field.

Hereinafter, the causes of the bright spots in the conventional liquid crystal display will be described.

FIG. 2 is a plan view illustrating a bright spot defect generated when the black liquid crystal is observed in a conventional liquid crystal display, and FIG. 3 is a cross-sectional view illustrating the bright spot defect of FIG. 2 and an adjacent pixel thereof.

As shown in FIG. 2 and FIG. 3, the liquid crystal display device implemented in the TN mode includes the first and second substrates 1 and 2 facing each other and each pixel of the first substrate 1 as described with reference to FIG. 1. And a common electrode 9 formed on the entire surface of the second substrate 2. In addition, the black matrix layer 7 corresponds to the non-pixel region on the second substrate 2, and the color filter layer 8 corresponds to the pixel region.

Although not shown, an alignment film (not shown) is formed on the uppermost surfaces of the first and second substrates 1 and 2 that face each other.

In the liquid crystal display of the TN mode formed as described above, the patterning between the source / drain electrodes of the thin film transistor is not normally performed, so that the source / drain electrodes cannot be separated, or conductive foreign substances remain in the thin film transistors to drive the thin film transistors. In the black state, the bright spots 15 may occur due to defects or disconnections.

In general, when a high gray (white state) is implemented, the dark point is that one region is dark due to light leakage, and when a low gray (black state) is implemented, the bright point is shown by the light leakage. In this case, the human eye is sensitive to bright spots in a relatively dark state rather than dark spots in a bright state, thereby imparting stricter criteria to bright spot defects than dark spots when determining whether the liquid crystal panel is poor. Accordingly, a method for minimizing the defective rate of the panel due to bright spots is required.

When defects occur in each of the thin films of the first substrate 1 and the second substrate 2 of the conventional liquid crystal display device, a process of repairing such as a rework process and a deposition process of the thin film is performed again. Proceed.

However, even when the above-described rework process is performed, foreign materials remain in the thin film transistor on the first substrate 1 as shown in FIGS. 2 and 3, so that the normal driving of the thin film transistor may not be performed. In the state where the first and second substrates 1 and 2 are bonded while the foreign material 21 remains, rework is not possible and repair is not easy.

In addition, in FIG. 4, when the data line 43 and the source / drain electrodes 43a and 43b are patterned, separation between the source electrode 43a and the drain electrode 43b may not be normally performed, or the source electrode 43a and the drain may not be properly formed. In this case, a foreign material or other defect is generated between the electrodes 43b. In this case, the thin film transistor to which the source electrode 43a and the drain electrode 43b are connected does not have a normal switching function. As a result, a normal signal is not applied to the pixel electrode 46 connected to the thin film transistor so that the pixel region is abnormally driven.

Such abnormal driving can be observed as a bright point in the black state and a dark point in the white state.

As a result, as shown in FIGS. 4 and 5, the thin film transistor in which the defect is generated is darkened by laser cutting and repairing the drain electrode 43b to be cut.

However, even if the darkening is performed due to the large repair area that is laser cut for darkening, that is, the lack of margin for repairing, there still remains a problem that the bright area occurs in the partial region as shown in FIG. 5.

The present invention has been made to solve the above problems, and in particular, an object of the present invention is to provide a liquid crystal display device suitable for minimizing the repair area by minimizing the repair area.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a gate line having a gate electrode on a substrate and having a protrusion and a groove at one side thereof; A data line crossing the gate line to define a pixel area; A source electrode protruding from the data line; A drain electrode spaced apart from the source electrode and overlapping the protrusion of the gate line; A passivation layer including a first contact hole at a position intersected with the protrusion of the gate line to expose a region of the drain electrode; And a pixel electrode formed in the pixel area.

The drain electrode extends to the right and overlaps the protrusion of the gate line at the extended portion.

The groove portion of the gate line is formed on one side adjacent to the drain electrode.

The groove portion of the gate line is characterized in that about 5 ~ 6㎛ dug.

The pixel electrode is shifted to the right in order to secure a repair starting point, that is, to secure a gap between the gate electrode and the gate electrode.

The pixel electrode may be shifted by about 2 μm.

Hereinafter, a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 6 is an enlarged plan view of a unit pixel of the liquid crystal display according to the present invention, and FIG. 7 is a view of the unit pixel after repair when changing the unit pixel structure according to the present invention.

As shown in FIG. 6, the liquid crystal display according to the present invention includes a gate line 61 and a data line 63 and pixel lines intersecting each other on a first substrate (not shown), and the gate line ( 61 and a thin film transistor TFT formed at each intersection of the data line 63 and a pixel electrode 66 formed in each pixel area and overlapping a predetermined portion of the front gate line (not shown).

In the thin film transistor, a channel is defined in a region between the source electrode 63a and the drain electrode 63b, and the source electrode 63a is formed in a 'U' shape to secure a channel region. Thereby, the channel is also defined as U 'shape along the inside of the shape of the source electrode 63a.

The thin film transistor includes a gate electrode 61a protruding from the gate line 61, a U ′ shaped source electrode 63a protruding from the data line 63, and the U ′ shaped source electrode ( It is formed to include a drain electrode 63b spaced apart from the predetermined interval 63a) into the U'-shaped source electrode 63a.

In this case, the gate line 61 has a protrusion 61b to partially overlap the pixel electrode 66, and a recessed groove 61c is formed in one side adjacent to the drain electrode 63b.

In addition, an active layer (not shown) and an ohmic contact layer may be disposed below the data line 63, the source electrode 63a, the drain electrode 63b, and the channel region between the source electrode 63a and the drain electrode 63b. Not shown) is laminated. In this case, the ohmic contact layer is removed in the channel region corresponding to the region between the source electrode 63a and the drain electrode 63b.

For reference, the active layer may be selectively formed only under the source / drain electrodes 63a and 63b and the region therebetween, and the ohmic contact layer may include the source electrode 63a and the drain electrode 63b except for the channel region. It may be formed on the lower side.

On the other hand, as shown, the shape of the source electrode (63a) is U ', the liquid crystal display having a' U'-shaped channel has been described, the liquid crystal display of the present invention is characterized in that the source electrode (63a) Applicable in any case, whether the shape is a date ('-').

A gate insulating layer (not shown) is formed between the gate line 61 and the data line 63, and a passivation layer (not shown) is formed between the data line 63 and the pixel electrode 66. Here, the first contact hole 65 is formed in the passivation layer so that a predetermined portion of one region of the drain electrode 63b of the thin film transistor is exposed.

In the liquid crystal display according to the present invention having the above structure, as shown in FIG. 6 to reduce the occurrence of bright spots when a defect is repaired, the gate line 61 pattern, the drain electrode 63b pattern, and the pixel electrode 66. ) Pattern was changed.

In more detail, first, the pattern of the gate line 61 is changed. The gate line 61 has a gate electrode 61a protruding from one side thereof, and is partially overlapped with the drain electrode 63b. A protruding portion 61b is provided, and a groove portion 61c in which one side adjacent to the drain electrode 63b is recessed is formed.

In this case, the protrusion 61b is a compensation pattern for securing the capacitance, and is formed to cross the region in which the first contact hole 65 is formed in the drain electrode 63b. In this way, the shift margin of the first contact hole 65 is additionally secured, thereby preventing short circuits from occurring.

The groove 61c on one side of the gate line 61 is formed in order to sufficiently secure a margin during laser cutting later, and the groove is 5 to 6 µm or more.

Next, the drain electrode 63b pattern was lengthened along the gate line 61.

As a result, a configuration in which the protrusion 61b on one side of the gate line 61 is shifted in the right direction so as to cross the first contact hole 65 is facilitated.

The reason for increasing the length of the drain electrode 63b pattern is to reduce the bright point by laser cutting a portion as close as possible to the source electrode 63a and the gate electrode 61a.

Next, the pattern of the pixel electrode 66 is changed, and the pixel electrode 66 is shifted to the right to have a distance of 'L2' larger than the conventional 'L1' in the region adjacent to the gate electrode 61a. That is, the pattern of the pixel electrode 66 is changed to secure a repair starting point. At this time, the pixel electrode 66 is shifted by about 2 μm.

As described above, when the gate line 61 pattern, the drain electrode 63b pattern, and the pattern of the pixel electrode 66 are changed, the repair area can be minimized. Thus, as shown in FIG. Can be.

Although not shown in the drawing, when a defect occurs between the source and drain electrodes 63a and 63b, after cutting the drain electrode 63b, the pixel electrode 66 is lasered to the gate electrode of the previous stage. It was welded using and darkening was carried out as shown in FIG. At this time, since the bright spot region appears only in the thin film transistor formation region, repair with little bright spot can be performed.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the above embodiments, but should be defined by the claims.

The liquid crystal display according to the present invention as described above has the following effects.

First, when the gate line 61 pattern, the drain electrode 63b pattern, and the pattern of the pixel electrode 66 are changed, the repair area can be minimized. Thus, as shown in FIG. 7, the partial bright spot generating area can be minimized. have.

Second, it is possible to reduce the occurrence of defects due to the repair failure through the repair margin compared to the conventional structure.

Third, the occurrence of defects can be reduced due to the shortening of the repair line (laser cutting).

Fourth, by configuring the protrusions of the first contact hole and the gate line which is the capacitance compensation pattern, the occurrence of automatic dark spot failure due to a short can be reduced.

Claims (6)

A gate line having a gate electrode on the substrate, the gate line having a protrusion and a groove on one side; A data line crossing the gate line to define a pixel area; A source electrode protruding from the data line; A drain electrode spaced apart from the source electrode and overlapping the protrusion of the gate line; A passivation layer including a first contact hole at a position intersected with the protrusion of the gate line to expose a region of the drain electrode; And a pixel electrode formed in the pixel area. The method of claim 1, And the drain electrode extends to the right and overlaps the protrusion of the gate line at the extended portion. The method of claim 1, And a groove portion of the gate line is formed on one side adjacent to the drain electrode. The method of claim 1, And a groove portion of the gate line is approximately 5 to 6 µm. The method of claim 1, And the pixel electrode is shifted to the right to secure a repair starting point, that is, to secure a gap between the gate electrode and the gate electrode. The method of claim 5, And the pixel electrode is shifted by about 2 μm.

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