KR20070069923A - Liquid crystal display device for preventin rubbing defect - Google Patents

Abstract

A liquid crystal display device for preventing rubbing defect is provided to compensate a stepped difference between data and gate link parts for preventing damage of a rubbing cloth, thereby preventing rubbing defect and improving screen quality. A liquid crystal display device for preventing rubbing defect includes first and second substrates defined with an image display area(113), a plurality of gate lines and data lines(108,109) formed on the image display area of the first substrate and respectively aligned in first and second directions for defining a plurality of pixels, switching elements formed at intersections between the gate and data lines for switching the pixels, a plurality of gate and data pads(114,115) formed outside the image display area for respectively supplying gate and data signals to the gate and data lines, gate and data link lines(145,125) for respectively connecting the gate lines to the gate pads and the data lines to the data pads, and stepped difference compensating patterns(127) for the data lines formed between the data lines. The compensating patterns are semiconductor patterns formed on a gate insulating film between the gate and data pads.

Description

Liquid crystal display device to prevent living defects {LIQUID CRYSTAL DISPLAY DEVICE FOR PREVENTIN RUBBING DEFECT}

1 is a cross-sectional view of a general liquid crystal display device.

2 is a flowchart illustrating a manufacturing process of a general liquid crystal display device.

3 is a plan view schematically showing a liquid crystal display device according to the present invention.

4 is an enlarged view of region A of FIG. 3;

FIG. 5 is a cross-sectional view taken along line II ′ of FIG. 4 when the step compensation pattern of the data link line is formed on a transparent substrate. FIG.

6 is a cross-sectional view taken along line II ′ of FIG. 4 when a step compensation pattern of a data link line is formed on the gate insulating film;

7 is a cross-sectional view showing a portion of a gate link portion having a stepped pattern of a gate link line;

*** Explanation of symbols for main parts of drawing ***

110: thin film transistor array substrate 120: color filter substrate

125: data link line 127: step compensation pattern of the data link line

131: gate insulating film 133: protective film

145: gate link line 147: step compensation pattern of the gate link line

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device to prevent the rubbing of the rubbing cloth due to the step of the pattern, thereby preventing rubbing defects.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, there is a growing demand for flat panel display devices for light and thin applications. Such flat panel displays are being actively researched, such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), FED (Field Emission Display), VFD (Vacuum Fluorescent Display), but mass production technology, ease of driving means, Liquid crystal display devices (LCDs) are in the spotlight for reasons of implementation.

1 schematically illustrates a cross section of a general liquid crystal display device. As shown in the figure, the liquid crystal display device 1 is composed of a lower substrate 5 and an upper substrate 3 and a liquid crystal layer 7 formed between the lower substrate 5 and the upper substrate 3. . Although the lower substrate 5 is a driving element array substrate, although not shown in the drawing, a plurality of pixels are formed on the lower substrate 5, and each pixel is driven such as a thin film transistor. An element is formed. The upper substrate 3 is a color filter substrate, and a color filter layer for real color is formed. In addition, a pixel electrode and a common electrode are formed on the lower substrate 5 and the upper substrate 3, respectively, and an alignment film for aligning liquid crystal molecules of the liquid crystal layer 7 is coated.

The lower substrate 5 and the upper substrate 3 are bonded by a sealing material 9, and a liquid crystal layer 7 is formed therebetween, and is driven by a driving element formed on the lower substrate 5. Information is displayed by controlling the amount of light passing through the liquid crystal layer by driving the liquid crystal molecules.

The manufacturing process of the liquid crystal display device can be largely divided into a driving element array substrate process of forming a driving element on the lower substrate 5, a color filter substrate process of forming a color filter on the upper substrate 3, and a cell process. However, the process of the liquid crystal display will be described with reference to FIG. 2.

First, a plurality of gate lines and data lines arranged on the lower substrate 5 to define a pixel region are formed by a driving element array process, and the gate line and the data are formed in each of the pixel regions. A thin film transistor which is a driving element connected to the line is formed (S101). In addition, the pixel electrode is connected to the thin film transistor through the driving element array process to drive the liquid crystal layer as a signal is applied through the thin film transistor.

In addition, the upper substrate 3 is formed with a color filter layer and a common electrode of R, G, B to implement the color by the color filter process (S104).

Subsequently, an alignment layer is applied to the upper substrate 3 and the lower substrate 5, respectively, and then the alignment control force or surface fixing force (ie, the liquid crystal molecules of the liquid crystal layer formed between the upper substrate 3 and the lower substrate 5). In order to provide a pretilt angle and an orientation direction, the alignment layer is rubbed (S102 and S105). Subsequently, a spacer is disposed on the lower substrate 5 to maintain a constant cell gap, and a sealing material is applied to an outer portion of the upper substrate 3. Then, the lower substrate 5 and the upper substrate are dispersed. Pressure is applied to (3), and it adheres (S103, S106, S107). On the other hand, the lower substrate 5 and the upper substrate 3 is made of a large area glass substrate. In other words, a plurality of panel regions are formed on a large area glass substrate, and a TFT and a color filter layer, which are driving elements, are formed in each of the panel regions. Must be processed (S108). Thereafter, the liquid crystal is injected into the liquid crystal panel processed as described above through the liquid crystal inlet, and the liquid crystal inlet is encapsulated to form a liquid crystal layer. Then, the liquid crystal display is manufactured by inspecting each liquid crystal panel (S109 and S110). .

The liquid crystal display device fabricated through the above process uses the electro-optic effect of the liquid crystal. The electro-optic effect is determined by the anisotropy of the liquid crystal itself and the molecular arrangement state of the liquid crystal. The rubbing process has a great influence on the stabilization of the display quality of the liquid crystal display device.

The rubbing process is a process of forming a fine groove on the alignment film by uniformly applying the alignment film on the substrate and then passing the roller wrapped with the rubbing cloth through the alignment film. In this case, when there is a step on the substrate, the rubbing cloth may be damaged to generate a rubbing defect. In particular, the rubbing cloth may be damaged at the beginning of rubbing due to the step of the data / gate link lines connecting the data / gate pad and the data / gate line. If damaged, the damaged rubbing cloth passes through the image display area, causing rubbing defects. Such rubbing defects cause a driving failure of the liquid crystal molecules and cause a poor image quality such as light leakage.

Accordingly, the present invention has been made to solve the above-described problem, and an object of the present invention is to compensate for the step of the data and gate link portions, thereby preventing the damage of the rubbing cloth generated from the step of the data and gate link portions. It is to provide a display element.

Another object of the present invention is to provide a liquid crystal display device capable of further improving image quality by preventing rubbing defects.

In addition, the objects and features of the present invention will be described in detail in the configuration and claims of the invention below.

According to an aspect of the present invention, there is provided a liquid crystal display device including: first and second substrates having an image display area defined therein; A plurality of gate lines arranged in a first direction on an image display area of the first substrate; A plurality of data lines arranged in a second direction perpendicular to the gate lines in the image display area of the first substrate to define a plurality of pixels together with the gate lines; A switching element formed at an intersection of the gate line and the data line to switch each pixel; A plurality of gate pads formed outside the image display area to supply gate signals to the gate lines; A plurality of data pads formed outside the image display area to supply data signals to the data lines; A gate link line connecting the gate line and a gate pad; A data link line connecting the data line and a data pad; And a step compensation pattern of the data link lines provided between the data link lines.

A gate insulating film is interposed between the gate pad and the data pad. In this case, the step compensation pattern of the data link line may be formed on the gate insulating layer, and may be formed of a semiconductor pattern.

In addition, the step compensation pattern of the data link line may be formed on the same layer as the gate pad, wherein the step compensation pattern is formed of the same material as the gate pad.

In addition, the step difference compensation pattern of the gate pad formed between the gate link lines may be further included. In this case, the step compensation pattern of the gate pad may be formed on the gate insulating layer, and may be formed of the same material as the semiconductor pattern or the data pad.

In the liquid crystal display of the present invention, at least one pair of common electrodes and pixel electrodes for generating a horizontal electric field are formed on each pixel of the first substrate, and the second substrate includes a horizontal electric field including a black matrix and a color filter. The pixel electrode is formed over the entire surface of each pixel of the first substrate, and the second substrate comprises: a black matrix; Color filters; And a vertical electric field method including a common electrode formed over the entire color filter.

In addition, the liquid crystal display device according to the present invention comprises: first and second substrates in which an image display area is defined; A plurality of gate lines arranged in a first direction on an image display area of the first substrate; A plurality of data lines arranged in a second direction perpendicular to the gate lines in the image display area of the first substrate to define a plurality of pixels together with the gate lines; A switching element formed at an intersection of the gate line and the data line to switch each pixel; A plurality of gate pads formed outside the image display area to supply gate signals to the gate lines; A plurality of data pads formed outside the image display area to supply data signals to the data lines; A gate link line connecting the gate line and a gate pad; A data link line connecting the data line and a data pad; And a step compensation pattern of the gate link line provided between the gate link lines to compensate for the step difference of the gate link line.

As described above, the present invention provides a liquid crystal display device having a step compensation pattern between data link lines or gate link lines. That is, the present invention forms a step compensation pattern between the data / gate link lines, thereby preventing the rubbing cloth from being damaged by the step of the link lines in the rubbing process, thereby solving the rubbing defect.

As mentioned in the prior art, if the rubbing cloth is damaged due to the step of the data link line or the gate link line at the beginning of rubbing, rubbing defects are generated in the screen display area due to the damaged rubbing cloth. It prevents deterioration of image quality due to poor rubbing.

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

3 is a plan view schematically showing a liquid crystal display device according to the present invention.

As shown in the figure, the liquid crystal display device 100 according to the present invention includes a thin film transistor array substrate 110 and a color filter substrate 120 and a liquid crystal layer (not shown) interposed therebetween.

The thin film transistor array substrate 110 includes liquid crystals defined by a plurality of gate lines 108 arranged in a first direction and a plurality of data lines 109 crossing in a second direction perpendicular to the gate line 108. An image display region 113 in which cells are arranged in a matrix, a gate pad 114 connected to a gate line 108 of the image display region 113, and transmitting an external signal, and the data lines 109. And a data pad 115 to be connected to the. Each gate pad 114 is connected to the gate line 108 through gate link lines 145, and the data pad 115 is connected to the data line 109 through data link lines 125. A step compensation pattern 127 of the data link line is formed between the data link lines 125 to compensate for the step difference of the data link line 125, which will be described later.

After the gate pad part 114 and the data pad part 115 are cut into unit panels, the gate pad part 114 and the data pad part 115 are formed in the edge region of the thin film transistor array substrate 110 that does not overlap the color filter substrate 120. ) Supplies a gate signal supplied from a gate driver circuit (not shown) to the gate lines 108 of the image display unit 113, and the data pad unit 115 supplies data supplied from a data driver circuit (not shown). The signal is supplied to the data lines 109 of the image display area 113. In this case, the gate driving circuit may be formed separately on the outside or on the substrate.

Although not shown in the drawings, a thin film transistor is formed as a switching element for switching each liquid crystal cell in an area where the gate line 108 and the data line 109 cross each other. The thin film transistor includes a gate electrode, a semiconductor layer, and a source / drain electrode, and the gate electrode and the semiconductor layer are insulated by a gate insulating film (not shown) interposed therebetween. In this case, the gate insulating film (not shown) is formed over the entire surface of the thin film transistor array substrate 110, and a protective film (not shown) for protecting the thin film transistor is formed over the entire surface of the substrate. Therefore, a gate insulating film and a protective film are stacked on the thin film transistor array substrate 110 on the outside of the image display unit 113.

When the liquid crystal display is a twisted nematic (TN) method, a pixel electrode is formed on the thin film transistor array substrate 110 and becomes a common electrode on the upper substrate. On the other hand, in the case of the in-plane switching (IPS) method, the common electrode and the pixel electrode for generating a horizontal electric field are formed together on the thin film transistor array substrate 110.

In addition, the color filter substrate 120 includes a color filter coated separately for each cell region, a switching element of the thin film transistor array substrate 110, a gate line 108, a data line 109, and an image display unit 113. A black matrix (not shown) is formed between the pad parts 114 and 115 to prevent light leakage. In addition, an overcoat layer may be formed on the entire surface of the substrate including the black matrix and the color filter.

On the other hand, a sealing material 116 is formed on the upper substrate (color filter substrate; 120) corresponding to the outside of the thin film transistor array substrate 110 for bonding with the thin film transistor array substrate 110. On the opposing surfaces of the thin film transistor array substrate 110 and the color filter substrate 120, alignment layers for setting the initial alignment direction of the liquid crystal molecules are formed.

In the alignment layer, a rubbing direction in a predetermined direction is determined through a rubbing process using a rubbing cloth. At this time, the rubbing cloth is often damaged due to a step on the substrate.

Accordingly, the present invention has been made to solve such a problem, and has a step compensation pattern that can compensate for the step difference of the thin film transistor array substrate. In particular, the present invention compensates for the step of the data link line 125, which is a factor that damages the rubbing cloth at the beginning of the rubbing process, thereby preventing damage to the rubbing cloth.

However, since the rubbing direction varies depending on the driving mode of the liquid crystal molecules or the arrangement and structure of the common electrode and the pixel electrode, the initial state of the rubbing cloth may be changed at any position as well as the data link line portion.

3 illustrates an example in which rubbing is performed in parallel with the data line 109. When rubbing is performed alongside the data line 109, the rubbing cloth will move in parallel along the data line 109 with the data link line 125 as a starting point. At this time, if the rubbing cloth is damaged due to the step of the data lines 109, the rubbing cloth will continue to generate rubbing defects while passing through the pixel display region 113. However, in the present invention, the step compensation pattern 127 of the data link line is provided between the data link lines 125 to compensate for the step of the data link line 125, thereby preventing damage to the rubbing cloth due to the step. .

4 is an enlarged view of area A of FIG. 3, and as shown in the drawing, a step compensation pattern 127 of a data link line is formed between the data link lines 125 to form the data link line 125. Compensate for the step. In this case, the step compensation pattern 127 of the data link line may be formed of the same material as the gate line 108 and the gate pad 114, or may be formed on the same plane as the data link line 125. have.

5 and 6 are cross-sectional views taken along line II ′ of FIG. 3, as shown in the drawing.

First, as shown in FIG. 5, when the step compensation pattern 127 of the data link line is formed in the process of the gate line and the gate pad, the step compensation pattern 127 of the data link line is formed on the transparent substrate 111. The gate insulating layer 131 is formed between the step compensation pattern 127 and the data link line 125, and a passivation layer 133 is formed on the substrate including the data link line 125. An alignment layer is coated on the passivation layer 133 and a rubbing process is performed. The step difference on the surface of the passivation layer 133 is alleviated due to the step compensating pattern 127 of the data link line. The damage can be greatly reduced.

In addition, as shown in FIG. 6, when the step compensation pattern 127 of the data link line is formed on the same plane as the data link line 125, they are all formed on the gate insulating film 131 formed on the transparent substrate 111. The passivation layer 133 is formed on the substrate including the step compensation pattern 127 and the data link line 125. In this case, the step compensation pattern 127 may be formed together when the semiconductor layer of the thin film transistor is formed, and the step compensation pattern 127 is formed of a semiconductor pattern.

On the other hand, although not shown in the drawing, when the rubbing direction is parallel to the gate line, since the rubbing is performed starting from the gate link line, a step compensation pattern of the gate link line may be formed between the gate link lines. Can be.

FIG. 7 is a cross-sectional view illustrating a portion of a gate link unit having a step compensation pattern formed on the gate link line. As shown in the drawing, the step compensation pattern of the gate link lines is also provided between the gate link lines 145 according to the set rubbing direction. 147 can be formed.

In this case, the step compensation pattern 147 of the gate link line may be formed on the gate insulating layer 131 formed on the gate link line 145, and the step compensation pattern 147 may form a data line and a data pad. It may be formed together in the forming process, or may be formed together when forming the semiconductor layer of the thin film transistor.

As described above, the present invention is to prevent the damage of the rubbing cloth caused by the step at the beginning of the rubbing start, and to compensate the step by providing a separate step compensation pattern in the data link section or the gate link section It is. Therefore, according to the present invention, the step compensation pattern may be formed in the gate link unit or the data link unit according to the direction in which the rubbing cloth moves, that is, the rubbing direction, and the step compensation pattern may be formed at any position under the condition that the link lines are not shorted. can do.

As described above, according to the present invention, by providing the step compensation pattern in the data link section or the gate link section, the damage of the rubbing cloth caused from the step difference of the pattern is prevented.

As described above, the present invention prevents damage to the rubbing cloth, thereby preventing deterioration in image quality due to poor rubbing, thereby providing a liquid crystal display device with uniform image quality, and further improving production efficiency.

Claims (15)

First and second substrates on which image display areas are defined; A plurality of gate lines arranged in a first direction on an image display area of the first substrate; A plurality of data lines arranged in a second direction perpendicular to the gate lines in the image display area of the first substrate to define a plurality of pixels together with the gate lines; A switching element formed at an intersection of the gate line and the data line to switch each pixel; A plurality of gate pads formed outside the image display area to supply gate signals to the gate lines; A plurality of data pads formed outside the image display area to supply data signals to the data lines; A gate link line connecting the gate line and a gate pad; A data link line connecting the data line and a data pad; And And a step compensating pattern of the data link line provided between the data link lines to compensate for the step difference of the data link line. The method of claim 1, And a gate insulating film interposed between the gate pad and the data pad. The method of claim 2, And the step compensation pattern of the data link line is formed on the gate insulating layer. The method of claim 3, And the step compensation pattern of the data link line is formed of a semiconductor pattern. The method of claim 2, And the step compensation pattern of the data link line is formed on the same layer as the gate pad. The method of claim 5, And the step compensation pattern of the data link line is formed of the same material as the gate pad. The method of claim 1, And a step compensation pattern of gate link lines formed between the gate link lines. The method of claim 7, wherein And the step compensation pattern of the gate link line is formed on the gate insulating layer. The method of claim 8, And the step compensation pattern of the gate link line is formed of a semiconductor pattern. The method of claim 9, And the step compensation pattern of the gate link line is made of the same material as that of the data pad. The method of claim 1, And at least one pair of common electrode and pixel electrode for generating a horizontal electric field in each pixel of the first substrate. The method of claim 11, The second substrate, A liquid crystal display device comprising a black matrix and a color filter. The method of claim 1, And a pixel electrode is formed over the entire surface of each pixel of the first substrate. The method of claim 13, The second substrate, Black matrix; Color filters; And And a common electrode formed over the entire color filter. First and second substrates on which image display areas are defined; A plurality of gate lines arranged in a first direction on an image display area of the first substrate; A plurality of data lines arranged in a second direction perpendicular to the gate lines in the image display area of the first substrate to define a plurality of pixels together with the gate lines; A switching element formed at an intersection of the gate line and the data line to switch each pixel; A plurality of gate pads formed outside the image display area to supply gate signals to the gate lines; A plurality of data pads formed outside the image display area to supply data signals to the data lines; A gate link line connecting the gate line and a gate pad; A data link line connecting the data line and a data pad; And And a step compensating pattern of the gate link line provided between the gate link lines to compensate for the step difference of the gate link line.

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