JPH10123565A - Liquid crystal panel, its fault detection method and its fault correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform fault detection and fault correction in the state of a liquid crystal panel. SOLUTION: An active matrix substrate is provided with a pixel electrode 5 on an interlayer insulation film covering scan wiring 1, signal wiring 2 and a TET 4, and the pixel electrode 5 is connected to the TFT 4 passing the through hole 14 of the interlayer insulation film. A counter substrate is provided with a counter electrode and a color layer of a color filter, and BM(black matrix) is not provided between respective color layers and on the outermost fringe of the color filter. When a short circuit fault occurs between adjacent pixel electrodes, laser irradiation is performed from the counter substrate side, and a short-circuited part is cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an office automation (OA) such as a personal computer and a word processor.
The present invention relates to a liquid crystal panel used in a display device such as a ce Automation device or a liquid crystal television, a defect detection method thereof, and a defect correction method thereof.

[0002]

2. Description of the Related Art In recent years, flat display panels such as liquid crystal panels have become widespread as the above-mentioned display devices. Especially,
In applications requiring high resolution, such as VGA, S-VGA or XGA, an active matrix type liquid crystal panel is used because the number of electrodes is enormous.

This active matrix type liquid crystal panel has a configuration in which an active matrix substrate and a counter substrate are opposed to each other with a liquid crystal layer interposed therebetween. On the active matrix substrate, pixel electrodes and switching elements for switching the pixel electrodes are provided in a matrix, and a plurality of scanning wirings and a plurality of signal wirings are provided so as to cross each other near the switching elements. The counter electrode is provided on the counter substrate so as to face the pixel electrode.

In this liquid crystal panel, in order to obtain a bright display by improving the aperture ratio, a so-called POP (Pix) is used.
A configuration using an active matrix substrate having an "el On Passivation" structure is employed. The active matrix substrate having the POP structure includes scanning wiring,
An interlayer insulating film covering a thin film transistor (TFT) as a signal wiring and a switching element is formed, and a pixel electrode is provided on the interlayer insulating film. Further, in order to realize color display, a color filter (hereinafter, referred to as CF) is formed on a counter substrate, and R (red), G (green) and G (green) are opposed to each pixel electrode on the active matrix substrate.
A configuration in which (green) and B (blue) color layers are arranged is adopted. Generally, this CF is provided with a light-shielding layer (black matrix, hereinafter referred to as BM) between each color layer and covering the outermost contour of the CF in order to prevent color mixing and light leakage.

FIG. 5 is a plan view of a liquid crystal panel using a conventional active matrix substrate having a POP structure, and FIG. 6 is a sectional view taken along line CC 'of FIG.

In this liquid crystal panel, the active matrix substrate is provided with a plurality of scanning lines 1 and a plurality of signal lines 2 via a gate insulating film 19 so as to intersect each other on an insulating substrate 16a. A TFT as a switching element is provided in the vicinity of the intersection 21 of. This TFT is covered with a BM 12 described later, and is invisible from the counter substrate side. An interlayer insulating film 29 is provided so as to cover them, and the pixel electrode 5 has a POP structure provided thereon in a matrix. The gate electrode of the TFT is a part of the scanning wiring 1,
The TFT is driven by the signal input thereto. T
A signal wiring 2 is connected to the source electrode of the FT, from which a video signal or the like as a display signal is input. The drain electrode of the TFT is connected to the connection electrode 8. The connection electrode 8 is formed in the through hole 1 provided in the interlayer insulating film 29.
4 is connected to the pixel electrode 5 via
The FT and the pixel electrode 5 are connected. In addition, each scanning wiring 1
And a gate insulating film 19 between the gate insulating film 19 and the signal wiring 2.
The common line 3 is provided through the common line 3, and an overlapping portion of the common line 3 and the pixel electrode 5 is an additional capacitance. In addition, each scanning wiring 1
An insulating film 9 is formed on the surface of the common line 3.

On the other hand, the opposing substrate has an opposing electrode 10 provided on an insulating substrate 16b so as to oppose the pixel electrode 7, and has R, G, and B color layers. Further, a CF 27 having a BM 12 covering the outermost portion is provided.

[0008] The active matrix substrate and the opposing substrate are bonded together, and a liquid crystal layer 11 is sandwiched between the substrates.

[0009]

In the above-mentioned liquid crystal panel having the POP structure, the interval between the pixel electrodes is reduced in order to obtain a bright display by enlarging the opening. Therefore, a short-circuit defect may occur between adjacent pixel electrodes in the active matrix substrate.

However, in the conventional liquid crystal panel shown in FIGS. 5 and 6, the BM 12 is provided on the opposite substrate side. It could not be detected or the short-circuit portion 13 could not be corrected. For example, even if an attempt is made to detect or correct the short-circuited portion 13 from the active matrix substrate side, since the short-circuited portion 13 is covered with the wiring such as the scanning wiring 1 and the signal wiring 2, when they are made of an opaque conductive film, Cannot detect or correct the short-circuit portion 13. Also,
BM1
2, the short-circuit portion 13 is covered by the short-circuit portion 1
3 cannot be detected or corrected. As described above, the conventional liquid crystal panel cannot detect or correct a defective portion in the state of the liquid crystal panel, and thus has a problem that the yield of the liquid crystal panel is reduced.

The present invention has been made to solve such problems of the prior art, and can detect and correct a defect in a state of a liquid crystal panel, and can obtain a bright display and a high quality. It is an object of the present invention to provide a liquid crystal panel which is good and can improve a non-defective rate, a defect detecting method thereof, and a defect correcting method thereof.

[0012]

The liquid crystal panel of the present invention comprises:
An active matrix substrate and a counter substrate that are arranged to face each other with the liquid crystal layer interposed therebetween, and the active matrix substrate is provided near a crossing portion between the plurality of scanning wirings and the plurality of signal wirings provided so as to intersect with each other and the two wirings; An interlayer insulating film is provided so as to cover the switching element provided in the semiconductor device, and pixel electrodes provided in a matrix on the interlayer insulating film are connected to the switching element via through holes in the interlayer insulating film. The counter substrate has a configuration in which a counter electrode is provided so as to face the pixel electrode, and a color filter in which a light shielding layer covering a plurality of color layers is omitted is provided. Thereby, the above object is achieved.

The method for detecting a defect in a liquid crystal panel according to the present invention is a method for detecting a defect in a liquid crystal panel according to the present invention, wherein after bonding the active matrix substrate and the counter substrate, the method starts from the counter substrate side. A short-circuit portion between adjacent ones of the pixel electrodes is detected, thereby achieving the above object.

A method of repairing a defect of a liquid crystal panel according to the present invention is a method of repairing a defect of a liquid crystal panel in which a defect is detected by the method of detecting a defect of a liquid crystal panel of the present invention. After bonding, the laser irradiation is performed on the short-circuited portion from the counter substrate side to correct the defect, thereby achieving the above object.

The operation of the present invention will be described below.

According to the present invention, a light-shielding layer (BM) for covering a space between CF color layers is not provided on a counter substrate which is disposed opposite to a POP structure active matrix substrate with a liquid crystal layer interposed therebetween. In the state of the liquid crystal panel, the space between adjacent pixel electrodes is not covered with the BM.

Even if a short-circuit defect occurs between the adjacent pixel electrodes, which is not covered with the BM, the short-circuit portion can be observed from the counter substrate side, so that the defect can be detected. . Further, since the short-circuit portion can be cut by irradiating the short-circuit portion with laser light from the counter substrate side, the defect can be corrected.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, portions having the same functions as those of the conventional liquid crystal panel are denoted by the same reference numerals.

FIG. 1 is a plan view of an active matrix type liquid crystal panel having a POP structure according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA 'of FIG.

In this liquid crystal panel, the active matrix substrate is provided with a plurality of scanning wirings 1 and a plurality of signal wirings 2 via a gate insulating film 19 so as to cross each other on an insulating substrate 16a. The TFT 4 as a switching element is provided in the vicinity of the intersection of. An interlayer insulating film 29 is provided so as to cover them, and the pixel electrodes 5 are provided thereon in a matrix. TFT4
The gate electrode 6 is a part of the scanning wiring 1 and the TFT 4 is driven by a signal input thereto. The signal wire 2 is connected to the source electrode 7 of the TFT 4, from which a video signal or the like as a display signal is input. The drain electrode of the TFT 4 is connected to the connection electrode 8. The connection electrode 8 is connected to the pixel electrode 5 via a through hole 14 provided in the interlayer insulating film 29, and thereby the TFT
And the pixel electrode 5 are connected. In addition, a common line 3 is provided in parallel with each scanning line 1 and between the signal line 2 via a gate insulating film 19, and a superimposed portion of the common line 3 and the pixel electrode 5 becomes an additional capacitance. I have. An insulating film 9 is formed on the surface of each of the scanning lines 1 and the common line 3. The TFT 4 has a semiconductor layer (not shown) on the gate electrode 6 having the insulating film 9 formed on the surface via the gate insulating film 9.
Are overlapped, a channel protective film (not shown) is provided at the center thereof, and two contact layers (not shown) are provided on the channel protective film in a state of being separated on the channel protective film. This is an inverted staggered configuration in which a source electrode 7 overlaps a layer and a drain electrode overlaps the other contact layer.

On the other hand, as the counter substrate, a counter electrode 10 is provided on an insulating substrate 16b so as to face the pixel electrode 7, and a CF 17 having R, G and B color layers is provided.
Is provided. Between each color layer of CF17 and C
No BM covering them is provided at the outermost periphery of F17, and light is shielded by providing each color layer of CF17 in an overlapping manner.

The active matrix substrate and the counter substrate are bonded together, and a liquid crystal layer 11 is sandwiched between the two substrates.

This liquid crystal panel can be manufactured, for example, as follows.

First, as an active matrix substrate, a scanning wiring 1, a gate electrode 6, and a common line 3 are pattern-formed on a transparent insulating substrate 16a made of a glass substrate or the like, and an insulating film 9 covering them is formed.

Next, the gate insulating film 1 is formed so as to cover them.
9 is formed thereon, and a semiconductor layer (not shown) of the TFT is formed thereon.
A channel protective film (not shown) and a contact layer (not shown) are sequentially formed.

Subsequently, the signal wiring 2, the source electrode 7, the drain electrode and the connection electrode 8 are formed by patterning.

Thereafter, the scanning wiring 1, the signal wiring 2 and the T
An interlayer insulating film 29 is formed so as to cover the FT 4 and the through hole 14 is formed.

Next, the pixel electrode 5 is patterned so as to partially overlap the scanning wiring 1 and the signal wiring 2 and cover the TFT 4. As a result, the pixel electrode 5 and the connection electrode 8 are connected via the through hole 14 penetrating the interlayer insulating film 29, and the drain electrode of the TFT and the pixel electrode 5 are connected. Thus, an active matrix substrate having a so-called POP structure is obtained.

On the other hand, in the counter substrate, the color layers R, G, and G of CF 17 are pattern-formed on the insulating substrate 16b, and the counter electrode 10 is pattern-formed thereon.

Thereafter, if necessary, an alignment film for aligning the liquid crystal layer is formed on both substrates.

The liquid crystal panel is obtained by bonding the active matrix substrate and the opposing substrate manufactured as described above and sealing the liquid crystal 11 in the gap between the two substrates.

In this liquid crystal panel, FIGS.
As shown in (1), when a short-circuit defect 13 occurs between a certain pixel electrode 5a and a pixel electrode 5b adjacent thereto, a point defect occurs in display due to the short-circuit defect 13. In such a case, the short-circuit portion 13 can be detected as follows.

For example, when observing the liquid crystal panel with a microscope from the counter substrate side, since the BM for covering between the color layers of CF 17 is not provided on the counter substrate side, the short-circuit portion 13 can be directly visually observed. Thus, the short-circuit portion and the normal portion can be distinguished. In order to enable detection of such a short-circuit defect 13 of the pixel electrode 5, the above-described counter electrode 1 is required.
For 0, it is necessary to use a transparent conductive film such as ITO. When the pixel electrode 5 uses an opaque conductive film such as a metal film, the short-circuit defect 13 can be easily detected.
Even when a transparent conductive film such as a TO film is used, it is sufficiently possible to distinguish a short-circuited portion from a normal portion by microscopic observation. At this time, when the short-circuit portion 13 is detected in a state where the liquid crystal has been injected, the light transmittance of the liquid-crystal portion in contact with the short-circuit portion 13 changes due to the application of the voltage, so that the short-circuit portion 13 can be distinguished. .

The short-circuit portion 13 thus detected
Can be corrected for defects as follows.

For example, as shown in FIG. 4, when the short-circuit portion 13 is irradiated with an energy beam such as a laser beam from the counter substrate side, no BM is provided between the CF color layers on the counter substrate side. The short-circuit portion 13 is irradiated with a laser beam. The pixel electrode 5 is irradiated by the laser irradiation.
Trimming is performed on the short-circuit portion 13 between the pixel electrode 5 a and the adjacent pixel electrode 5 b, and that portion becomes the trimming portion 15.
Thereby, the point defect of the display is corrected.

As described above, in the liquid crystal panel of the present embodiment, since the light-shielding layer is not provided between the CF color layers formed on the counter substrate side, the liquid crystal panel is short-circuited from the counter substrate side even in the liquid crystal panel state. Part detection could be performed. In addition, by irradiating laser light to the short-circuited portion from the counter substrate side, the short-circuited portion could be cut and defect repaired even in the state of the liquid crystal panel.

In the above embodiment, the detection of the defective portion and the correction of the defective portion were performed in the state of the liquid crystal panel. However, the state of the active matrix substrate before bonding, or both substrates were bonded before liquid crystal injection. Even in the state, it is possible to detect and correct the short-circuited portion.

In the above embodiment, the BM is not provided between the color layers of CF formed on the counter substrate and at the outermost periphery. However, the present invention is not limited to this. That is, in order to detect a short-circuit defect between adjacent pixel electrodes from the counter substrate side and perform defect correction, it is sufficient if the light-shielding layer is not provided between the CF color layers. The present invention is also applicable to a liquid crystal panel having a configuration in which a light shielding layer is provided.

[0039]

As is apparent from the above description, according to the present invention, in the liquid crystal panel having the POP structure, no light-shielding layer is provided between the CF color layers formed on the opposing substrate. Even in the state described above, it is possible to detect a short-circuited portion between adjacent pixel electrodes and to correct the short-circuited portion. Therefore, it is possible to improve the quality of the liquid crystal panel capable of obtaining a bright display and to improve the reliability of the liquid crystal panel. Further, the non-defective rate of the liquid crystal panel can be improved and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing an active matrix type liquid crystal panel having a POP structure according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line A-A 'of FIG.

FIG. 3 is a plan view of the liquid crystal panel for explaining a defect correcting method of the liquid crystal panel according to one embodiment of the present invention.

FIG. 4 is a sectional view taken along line B-B ′ of FIG. 3;

FIG. 5 is a plan view showing a conventional active matrix type liquid crystal panel having a POP structure.

FIG. 6 is a sectional view taken along line C-C ′ of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scan wiring 2 Signal wiring 3 Common line 4 TFT 5 Pixel electrode 6 Gate electrode 7 Source electrode 8 Connection electrode 9 Insulating film 10 Counter electrode 11 Liquid crystal layer 13 Short-circuit part 14 Through hole 15 Trimming 16a, 16b Insulating substrate 17 CF19 Gate Insulating film 29 Interlayer insulating film

Claims (3)

[Claims] An active matrix substrate opposed to the liquid crystal layer and a counter substrate, wherein the active matrix substrate is provided with a plurality of scanning wirings and a plurality of signal wirings provided so as to intersect each other. An interlayer insulating film is provided so as to cover the switching element provided in the vicinity of the intersection of the wiring, and pixel electrodes provided in a matrix on the interlayer insulating film are connected to the switching element via through holes in the interlayer insulating film. The opposing substrate is provided with an opposing electrode facing the pixel electrode and a color filter in which a light-shielding layer covering a plurality of color layers is omitted. LCD panel. 2. The method for detecting a defect of a liquid crystal panel according to claim 1, wherein after bonding the active matrix substrate and the counter substrate, the pixel electrode is adjacent to the pixel electrode from the counter substrate side. A defect detection method for a liquid crystal panel that detects a short-circuit portion generated between objects. 3. A method for correcting a defect in a liquid crystal panel in which a defect is detected by the method for detecting a defect in a liquid crystal panel according to claim 2, wherein the active matrix substrate is bonded to the counter substrate. A defect correction method for a liquid crystal panel, in which the short-circuited portion is irradiated with laser from the counter substrate side to correct the defect.