JP2007241183A - Display device and method for repairing display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably repair a point defect due to a foreign matter or the like generated during a manufacturing process of a display device.
A pixel electrode, a drain electrode, a source electrode disposed opposite to the drain electrode, a video signal line, a pixel electrode of an adjacent pixel in the video signal line direction, and an insulating film. An island formed of the conductive film of the same layer as the source electrode 4 and connected to the pixel electrode 8 at the overlapping portion of the scanning line 1 having the overlapping protruding part 11 and the protruding part 11 of the scanning line 1 and the pixel electrode 8. The pattern 13 is provided.
[Selection] Figure 1

Description

  The present invention relates to a display device that reliably repairs defective pixels and a method for repairing the display device, and is particularly suitable for application to a liquid crystal display device.

In an active matrix liquid crystal display device, a switching element such as a TFT (Thin Film Transistor) is connected to pixel electrodes arranged in a matrix on one insulating substrate in a pair of insulating substrates to be bonded. Each pixel electrode is selected or not selected by the switching operation of the switching element, and the display operation is performed. Since the above switching element generally has a multilayer structure in which a semiconductor layer, an insulating layer, and various electrodes for driving a liquid crystal are laminated on an insulating substrate, each layer is formed on the insulating substrate in order to manufacture the switching element. The patterning is repeated. For this reason, when a switching element is manufactured, a defective switching element that does not perform normal operation due to disconnection or a short circuit may occur. In this case, a pixel including a pixel electrode connected to the defective switching element is a defective element to which no voltage is applied. The pixel having this defective element is a bright spot defect in which light is always transmitted, particularly in a liquid crystal display device in a normally white mode, which is a display operation mode in which the display screen is set to white with the power off. As confirmed.

As a conventional technique for repairing bright spot defects in liquid crystal display devices, laser irradiation is applied to the overlap between the gate electrode and drain electrode of the thin film transistor, the gate insulating film is destroyed and the gate electrode and drain electrode are melted and electrically connected. Then, a scanning pulse is applied as a DC voltage to the liquid crystal through the pixel electrode connected to the drain electrode. As a result, dark display is obtained in the normally white mode, and the bright spot defect is not noticeable (for example, Patent Document 1). reference).

In addition, as a conventional technique for repairing other point defects, an overlapping portion of the gate wiring and the pixel electrode is separately provided to connect the gate wiring and the pixel electrode, the pixel electrode and the gate wiring are connected by laser irradiation, and the gate voltage is set. When applied, the defective pixel of the white spot is converted into a black spot to make it inconspicuous (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 5-210111 Japanese Patent No. 9-119366

  However, in the conventional method for repairing a bright spot defect of a display device described in Patent Document 1, a bright spot defect is detected and repaired after the insulating substrate on which the TFT is formed and the counter substrate are bonded together. In this case, laser irradiation is performed on the overlapping part of the drain electrode and the gate wiring from the back side of the insulating substrate on which the TFT is formed. In this case, the position of the overlapping part can be clearly confirmed. Therefore, there is a problem that it is difficult to reliably perform laser irradiation, the gate wiring and the drain electrode are not reliably connected, and the defect cannot be repaired.

Further, in the conventional bright spot defect repairing method disclosed in Patent Document 2, in the case of a display device in which an overlap portion is provided between the gate wiring and the pixel electrode, the laser irradiation position can be specified. And the method of connecting the pixel electrode by laser irradiation have a problem in that the pixel electrode is scattered at the time of laser irradiation because the transparent conductive film is mainly used for the pixel electrode, so that the pixel electrode cannot be reliably connected.

In the case of the liquid crystal display device described in Patent Document 2 in which an overlap portion is provided between the gate wiring and the pixel electrode, the laser irradiation position can be specified, but the gate electrode has an overlap portion with the pixel electrode. Further, the parasitic capacitance (Cgd) between the gate electrode and the drain electrode is increased, and there is a problem that display quality is deteriorated.

  The present invention has been made in view of such problems, and in a display device having a point defect, an increase in the parasitic capacitance of the pixel is suppressed and the brightness is accurately emitted from the back side of the insulating substrate on which the TFT is formed. An object of the present invention is to provide a display device having a pixel structure capable of correcting a point defect and a method for repairing the display device.

The present invention relates to a display device capable of repairing a defective pixel, and includes a scanning wiring having a protrusion overlapping with a pixel electrode of an adjacent pixel in an image signal line direction via an insulating film, and the protrusion of the scanning wiring and the pixel electrode And an island pattern formed of the same conductive film as the source electrode forming the TFT and connected to the pixel electrode.

  According to the present invention, a display device and a display device manufacturing method capable of reliably repairing point defects are obtained.

Embodiment 1 FIG.
A first embodiment of the present invention will be described with reference to FIGS. 1 is a plan view of substantially one pixel of a display device according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a method for repairing the display device according to Embodiment 1 of the present invention. FIG. 4 is a cross-sectional view taken along the line BB in FIG. 3.

  In FIG. 1 and FIG. 2, a video signal line 3 is formed through and intersecting a scanning wiring (gate wiring) 1 for inputting a scanning signal and an insulating film (gate insulating film) 2. The video signal line 3 includes a source electrode 4 formed integrally. Further, the drain electrode 5 formed facing the source electrode 4 is connected to a pixel electrode 8 made of a transparent conductive film such as ITO through a contact hole 7 formed in the interlayer insulating film 6. A TFT 9 that is a switching element is formed by the gate electrode formed from the source electrode, the drain electrode, and the scanning wiring, a semiconductor film (not shown), and the like. In addition, the drain electrode 5 includes an extending portion 10 in parallel with the scanning wiring 1 and covering an end portion of one side of the pixel electrode 8. Further, a projection 11 is formed on the scanning wiring 1 so as to overlap with the pixel electrode 8 of the pixel adjacent in the video signal line direction through the insulating film 2. The protrusion 11 includes an island pattern 13 connected to the transparent conductive film 8 by a contact hole 12 formed in the interlayer insulating film 6 at an overlapping portion with the pixel electrode 8 of the adjacent pixel. Since the island pattern 13 is formed between the protrusion and the pixel electrode formed integrally with the scanning wiring of the adjacent pixel as described above, it is possible to suppress the decrease in the aperture ratio as much as possible. Yes. Since the protrusion 11 is formed so as to overlap with the pixel electrode of the adjacent pixel as described above, the parasitic capacitance (Cgd) between the gate electrode and the drain electrode of the pixel may be increased. Absent.

A method for repairing point defect pixels in the pixels configured as described above will be described below with reference to FIGS. 3 and 4, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals. For example, when a so-called defective pixel in which a pixel does not perform a desired display occurs due to, for example, the TFT 9 not operating normally due to foreign matter generated during the manufacturing process, first, scanning of the pixel adjacent to the pixel electrode 8 of the pixel is performed. Laser irradiation is performed on the island-like pattern 13 formed in the overlapping portion with the protruding portion 11 of the wiring. In this case, the laser irradiation is performed after the insulating substrate on which the TFT is formed (hereinafter referred to as the array substrate) and the counter substrate disposed opposite to each other are bonded to each other. It is preferable to irradiate laser from the back side, but in the state of only the array substrate that has not yet bonded the counter substrate, laser irradiation is performed from either the surface of the array substrate where the TFT is formed or the back side where it is not formed. May be. By irradiating the laser in this way, the insulating film 2 between the island pattern 13 and the scanning wiring protrusion 11 is broken, and the island pattern 13 and the scanning wiring protrusion 11 are connected (FIG. 3). , See the connecting portion 14 in FIG. 4).

Next, a portion of the drain electrode 5 connected to the pixel electrode 8 (XX portion in FIG. 3) is cut by laser irradiation. By doing in this way, the malfunction by a video signal and a scanning signal being short-circuited can be eliminated.

With the above-described configuration, it becomes possible to constantly apply a scanning signal to a defective pixel caused by a foreign matter or the like generated during the manufacturing process while suppressing a decrease in the aperture ratio of the pixel, thereby ensuring a defect. It becomes possible to make it inconspicuous by making a black spot (dark display).

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIGS. 5 is a plan view of substantially one pixel of the display device according to the second embodiment of the present invention, FIG. 6 is a cross-sectional view taken along the line CC in FIG. 5, and FIG. 7 is a method for repairing the display device according to the second embodiment of the present invention. FIG. 8 is a cross-sectional view taken along the line DD in FIG. 7. 5 to 8, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals, and the differences will be described.

  5 and 6, the semiconductor film 15 connected to the extended portion 10 of the drain electrode is formed via the scanning wiring 1 and the insulating film 2. The semiconductor film 15 is formed to extend up to the scanning wiring 1 and is connected to an island pattern 16 formed of a conductive film in the same layer as the source electrode 4. Since the island pattern 16 is formed on the scanning wiring from the extended portion of the drain electrode of the same pixel through the semiconductor film as described above, it is possible to further suppress the decrease in the aperture ratio. Yes.

A method for repairing point defect pixels in the pixels configured as described above will be described below with reference to FIGS. 7 and 8, the same components as those in FIGS. 5 and 6 are denoted by the same reference numerals. For example, when a defective pixel in which a pixel does not perform a desired display due to, for example, the TFT 9 not operating normally due to foreign matter generated during the manufacturing process, first, the scanning wiring 1 of the pixel and the island pattern 16 are first connected. Laser irradiation is performed on the overlapping part. In this case, as in the first embodiment, laser irradiation is preferably performed from the back surface side where the TFT of the array substrate is not formed in a state after the array substrate and the counter substrate are bonded together. In a state where the counter substrate is not yet bonded, laser irradiation may be performed from either the surface of the array substrate where the TFT is formed or the back surface side where it is not formed. By irradiating the laser in this way, the insulating film 2 between the island pattern 16 and the scanning wiring 1 is broken, and the island pattern 16 and the scanning wiring 1 are connected (the connection portion in FIGS. 7 and 8). 17). As a result, the potential of the scanning wiring 1 is connected to the drain electrode extension 10 via the island pattern 16 and the semiconductor film 15, and further applied to the pixel electrode 8 via the contact hole 7 in FIG. Will be.

Next, as in the first embodiment, a portion of the drain electrode 5 connected to the pixel electrode 8 (XX portion in FIG. 7) is cut by laser irradiation. By doing in this way, the malfunction by a video signal and a scanning signal being short-circuited can be eliminated.

By adopting the configuration as described above, as in the first embodiment, a scanning signal is always applied to a defective pixel caused by a foreign matter or the like generated during the manufacturing process while further suppressing a decrease in the aperture ratio of the pixel. It becomes possible to make the defect inconspicuous by surely blackening (darkening) the defect.

As mentioned above, although this invention was demonstrated by the said Embodiment 1, 2, this invention is not limited to the said embodiment, It cannot be overemphasized that it can change variously in the range which does not deviate from the summary. . The first and second embodiments may be applied not only to a display device using liquid crystal but also to repairing any display device having a pixel electrode and various signal lines.

It is a top view of substantially 1 pixel of the display apparatus in Embodiment 1 of this invention. It is AA sectional drawing in FIG. FIG. 5 is a plan view of substantially one pixel for explaining the display device repairing method according to the first embodiment of the present invention. It is BB sectional drawing in FIG. It is a top view of substantially 1 pixel of the display apparatus in Embodiment 2 of this invention. It is CC sectional drawing in FIG. FIG. 10 is a plan view of substantially one pixel for explaining a display device repairing method according to Embodiment 2 of the present invention. It is DD sectional drawing in FIG.

Explanation of symbols

1 Scanning wiring, 2 Insulating film, 3 Video signal line, 4 Source electrode, 5 Drain electrode, 6 Interlayer insulating film, 7 Contact hole, 8 Pixel electrode, 9 TFT, 10 Drain electrode extension, 11 Protrusion, 12 Contact hole, 13 island pattern, 14 connection, 15 semiconductor film, 16 island pattern, 17 connection

Claims (6)

A pixel electrode made of a transparent conductive film;
A drain electrode connected to the pixel electrode;
A source electrode disposed opposite the drain electrode;
A video signal line connected to the source electrode;
A scanning wiring having a protrusion that intersects with the video signal line through an insulating film and overlaps with a pixel electrode of an adjacent pixel in the video signal line direction through the insulating film;
An island pattern formed of a conductive film in the same layer as the source electrode and connected to the pixel electrode in an overlapping portion between the protrusion of the scanning wiring and the pixel electrode of the adjacent pixel;
A display device comprising: The island pattern and the projection of the scanning wiring are connected by a hole formed in the insulating film, and a portion of the drain electrode connected to the pixel electrode is cut. The display device according to claim 1. A pixel electrode made of a transparent conductive film;
A drain electrode connected to the pixel electrode;
A source electrode disposed opposite the drain electrode;
A video signal line connected to the source electrode;
A scanning wiring intersecting with the video signal line through an insulating film;
A semiconductor film connected to the drain electrode and extending to a position overlapping the scan line via the insulating film;
An island pattern connected to the semiconductor film on the scanning wiring and formed from the same conductive film as the source electrode;
A display device comprising: The island pattern and the scanning wiring are connected by a hole formed in the insulating film, and a portion of the drain electrode connected to the pixel electrode is cut. 3. The display device according to 3. A pixel electrode made of a transparent conductive film;
A drain electrode connected to the pixel electrode;
A source electrode disposed opposite the drain electrode;
A video signal line connected to the source electrode;
A scanning wiring having a protrusion that intersects with the video signal line through an insulating film and overlaps with a pixel electrode of an adjacent pixel in the video signal line direction through the insulating film;
An island pattern formed of a conductive film in the same layer as the source electrode and connected to the pixel electrode in an overlapping portion between the protrusion of the scanning wiring and the pixel electrode of the adjacent pixel;
A method for repairing a liquid crystal display device comprising:
Connecting the island pattern and the projection of the scanning wiring by laser irradiation;
Cutting the portion of the drain electrode connected to the pixel electrode by laser irradiation;
A method of repairing a display device, comprising: A pixel electrode made of a transparent conductive film;
A drain electrode connected to the pixel electrode;
A source electrode disposed opposite the drain electrode;
A video signal line connected to the source electrode;
A scanning wiring intersecting with the video signal line through an insulating film;
A semiconductor film connected to the drain electrode and extending to a position overlapping the scan line via the insulating film;
An island pattern connected to the semiconductor film on the scanning wiring and formed from the same conductive film as the source electrode;
A method for repairing a liquid crystal display device comprising:
Connecting the island pattern and the scanning wiring by laser irradiation;
Cutting the portion of the drain electrode connected to the pixel electrode by laser irradiation;
A method for repairing a display device, comprising:

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