JP2645590B2 - Method for repairing short-circuit defect of liquid crystal display - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting and repairing a short-circuit between electrodes or wirings of a thin-film liquid crystal display device.

[Conventional technology]

FIG. 5 is a configuration diagram showing a short-circuit defect repairing device for detecting and repairing a short-circuit defect between electrodes or wirings of the thin film semiconductor device, FIG. 6 is a plan view showing a pixel portion structure of the thin film semiconductor device, and FIG. Is a plan view showing the vicinity of the transistor of the thin-film semiconductor device, FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 7, and FIGS. 9 and 10 show the wiring intersection structure of the thin-film semiconductor device. FIG. 10 is a plan view and a cross-sectional view taken along line XX of FIG. 9.

5 to 10, (1) shows a thin film transistor (TFT) array substrate or a liquid crystal display (L) using the substrate.
A thin film device such as a CD) panel, (2) an XY stage on which the thin film semiconductor device (1) is mounted, and (3) and (4) X and Y drives for moving the XY stage (2) in the X and Y directions, respectively. And (5) are thin-film cutting devices for cutting short-circuit points between electrodes or wirings of the thin-film semiconductor device (1), and use a laser device or the like. (6) is a processor for controlling the driving of the X drive (3), the Y drive (4) and the thin film cutting device (5), and (7) is an insulating substrate made of glass or the like, and the insulating substrate (7) A gate electrode (9) constituting a thin film transistor (TFT) (8) thereon,
An insulating layer (10), a semiconductor layer (11), a source electrode (12), and a drain electrode (13) are formed by lamination. (14) is a pixel electrode formed on the insulating substrate (7), and the drain electrode (13) is electrically connected. (15) is a source wiring electrically connected to the source electrode (12), and (16) is a gate wiring electrically connected to the gate electrode (9).

Next, the operation will be described. First, when the thin film semiconductor device (1) is a TFT array substrate, another power supply (not shown)
An electric signal is sent to one of the source wirings (15) and one of the gate wirings (16), and the gate of one TFT (8) electrically connected to the source wiring (15) and the gate wiring (16) A short circuit between the electrode (9) and the source electrode (12) or between the source wiring (15) and the gate wiring (16) is electrically checked. This operation is sequentially performed for all combinations of the source wirings (15) and all the gate wirings (16), and the presence or absence of a short circuit is detected. When the thin-film semiconductor device (1) is an LCD panel, the LCD panel is turned on and a short-circuit point is estimated from a display defect appearing on the LCD panel. Next, using a thin film cutting device (5), a TFT (8) having a high probability of a short circuit occurring in a pair of a source line (15) and a gate line (16) where a short-circuit portion is detected as described above exists. Disconnect from source wiring (15) or gate wiring (16). If the short circuit is not recovered by the above operation, the both sides of the intersection of the source wiring (15) are electrically cut again using the thin film cutting device (5). At this time, the source line (15) is electrically divided on both sides of the cut portion, and an electric signal supplied from one side of the source line (15) is not transmitted to a portion after the cut portion. ), An electric signal is separately supplied from the terminal opposite to the terminal supplying the electric signal, and the repair of the short-circuit defect is completed.

[Problems to be solved by the invention]

Since the conventional short-circuit point detection is performed as described above, even if a short-circuited wire pair is found, the short-circuited position cannot be clearly determined, and in the subsequent repair process. There has been a problem that a normal part where no short circuit has occurred may be cut.

In addition, although a short-circuit defect can be repaired by accurately detecting a short-circuited portion and separating the short-circuited TFT from the wiring, there is a problem that a pixel corresponding to the separated TFT cannot be displayed and display performance is deteriorated.

The present invention has been made to solve the above-described problems, and it is intended to clearly detect a short-circuit position generated in a liquid crystal display device, electrically disconnect a short-circuited thin film transistor, and a pixel corresponding to the separated thin-film transistor. And to prevent display performance from deteriorating.

[Means for solving the problem]

A method for repairing a short-circuit defect of a liquid crystal display device according to the present invention is to form a plurality of driving display thin film transistors in parallel with the same gate line and the same source line for each pixel electrode in an array. After the arrangement, the liquid crystal device is configured, and the following steps (a), (b), and (c) are performed.

(A) Among a plurality of thin film transistors formed in parallel in one pixel, the position of the short-circuited thin film transistor is detected and specified by optical means for detecting microplasma emission or infrared light emitted from the short circuit portion. b) Electrically disconnecting the thin film transistor in which the short circuit has occurred in the beam device. (c) Step of driving the pixel electrode corresponding to the disconnected thin film transistor with a normal thin film transistor. Alternatively, since infrared light is detected by using an optical means for detecting the infrared light, the position of the short-circuited thin film transistor among the thin film transistors formed in parallel in one pixel can be accurately specified.

The short-circuit defect is repaired by electrically disconnecting the short-circuited thin film transistor.

Since a plurality of thin film transistors are provided in parallel with the pixel electrode of each pixel, even if one thin film transistor is short-circuited and disconnected, the remaining normal thin film transistor is operated by the original wiring (signal), thereby The pixel electrode can be driven to display a pixel.

(Example of the invention)

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, (1) is a TFT array substrate of a liquid crystal display device, (5) is a thin film cutting device, here a laser device,
(17) is a short-circuit detection device, which comprises a high-sensitivity camera (18) for detecting microplasma emission and a television monitor (19). (20) shows a drive circuit for supplying an electric signal to the TFT array substrate (1). The other components are the same as those in FIG.

Next, the operation will be described. First, the TFT array substrate (1) is set on the stage (2), and an electric signal is supplied from the drive circuit (20). At this time, the TFT array substrate (1)
If there is a short circuit between the inner electrodes or between the wires, microplasma emission is generated from the short circuit. Scan the stage (2) with the X drive (3) and the Y drive (4), and use the high sensitivity camera (18) and the TV monitor (19) for TFT.
Detects microplasma emission from a short-circuit point on the array substrate (1) and detects a short-circuit point between the gate electrode and the source electrode, a short-circuit point between the gate electrode and the drain electrode, and a short-circuit point at the intersection of the source line and the gate line in the TFT. Are detected separately. Next, if the detected short-circuit point is caused by the TFT, the gate electrode is moved from the gate wiring to the laser device (5).
When a short circuit occurs at the intersection of the source wiring and the gate wiring, the source wiring or the gate wiring is connected to the laser device (5) on both sides of the intersection.
To electrically disconnect and repair the short-circuit defect.

In the above embodiment, the short-circuit point detecting device (17)
The laser device (5) is located on the side opposite to the TFT array substrate (1), but may be located on the same side, or on either the front side or the back side of the TFT array forming surface of the substrate. The same effect can be expected even if it is located.

In the above embodiment, a high-sensitivity camera capable of detecting microplasma emission is used as the short-circuit point detecting device (17). The same effects as in the above embodiment can be obtained.

In the above embodiment, an ion beam device may be used instead of the laser device (5).

The following effects can be obtained by using the method for repairing short-circuit defects of a liquid crystal display device according to the present invention.

In the conventional method, when a short circuit occurs between the electrodes of the TFT liquid crystal display device, pixels connected to the TFT electrically separated by the laser device do not operate, and a dot-like display defect remains. In the embodiment of the present invention, the structure of the pixel portion of the liquid crystal display device is such that a pixel electrode (14) corresponding to one pixel as shown in FIG. 2 is divided into a plurality of pixel electrodes and driven by a plurality of TFTs. Formed. The short-circuit location detection device (17) accurately detects the short-circuit position, separates the TFT (18) where the short-circuit occurred, and performs pixel display with the remaining normal TFT to reduce display defects due to the repair of short-circuit defects. Can be fastened to parts. At this time, as shown in FIG.
TFT has the same source wiring (15) and the same gate wiring (1
Since it is connected in parallel to 6), it is driven by the original signal no matter which TFT remains. Further, as shown in FIG. 3, a pixel portion structure in which a plurality of TFTs (18) are connected in parallel to a pixel electrode (14) corresponding to one pixel of the liquid crystal display device is short-circuited by a short-circuit point detecting device (17). By accurately detecting the position and separating the short-circuited TFT (8), the pixel electrode (14) is driven by the remaining normal TFT (8) to leave a defect on all or a part of the pixel. And short-circuit defects can be repaired.

Also, at the intersection of the source wiring (15) and the gate wiring (16) of the thin film semiconductor device as shown in FIG.
The source wiring (15) in which the short-circuit has occurred in the short-circuit point detecting device (17) of the present invention has a wiring structure in which 5) is branched into a plurality.
Branch is detected correctly, and that branch is identified as source wiring (15)
By repairing the short circuit by disconnecting from the source line, the source line (15) is not electrically disconnected at the cut portion, and
Even if a short circuit occurs at a plurality of locations on the same wiring, the repair can be performed without leaving an electrically divided defect portion.

〔The invention's effect〕

In the method for repairing a short-circuit defect in a liquid crystal display device according to the present invention, the pixel electrodes of each pixel are formed in an array by driving the pixel electrodes with a plurality of thin film transistors connected in parallel to the same gate wiring and the same source wiring. Thus, the position of the short-circuited thin film transistor among a plurality of thin film transistors formed in parallel in one pixel is determined by micro-plasma emission or infrared light emitted from the short-circuit portion by optical means. The short-circuit position can be accurately detected by the detection, and the pixel electrode corresponding to the short-circuited and separated thin-film transistor can be driven by the normal thin-film transistor operating with the remaining original signal, so that the display is not deteriorated. Play.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a short-circuit defect repairing apparatus used in the method for repairing a short-circuit of a liquid crystal display device according to the present invention. FIGS. FIG. 4 is a plan view showing a pixel portion structure for keeping a remaining display defect in a small portion and a pixel portion structure employed in the present invention for leaving no display defect, and FIG. 4 is a short circuit generated between wirings of a thin film liquid crystal display device. FIG. 5 is a plan view showing a wiring intersection portion structure for preventing an electrical defect portion from remaining in a wiring after repairing, FIG. 5 is a configuration diagram showing a conventional short-circuit defect repairing device of a thin film liquid crystal display device, and FIG. FIG. 7 is a plan view showing a pixel portion structure of the thin film liquid crystal display device, FIG. 7 is a plan view showing the vicinity of the thin film transistor of the thin film liquid crystal display device, and FIG.
FIG. 9 is a cross-sectional view taken along line VIII-VIII, FIG. 9 is a plan view showing a wiring intersection structure of a conventional thin film liquid crystal display device, and FIG.
It is sectional drawing along the XX line in a figure. In the figure, (17) is a short-circuit point detecting device. In the drawings, the same reference numerals indicate the same or corresponding parts.

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication H01L 21/82 H01L 21/82 R (72) Inventor Masahiro Hayama 8-1-1 Honcho Tsukaguchi, Amagasaki City, Hyogo Prefecture (56) References JP-A-59-94467 (JP, A) JP-A-62-232144 (JP, A) JP-A-61-121034 (JP, A) JP-A-61-264 30777 (JP, A) JP-A-50-141278 (JP, A) JP-A-63-150675 (JP, A) JP-B-7-78673 (JP, B2)

Claims (1)

(57) [Claims] 1. A thin film is laminated on a substrate via an insulating layer,
A pixel electrode and a plurality of thin film transistors connected in parallel to the same gate wiring and the same source wiring, each of which is formed in parallel with the same gate wiring and the same source wiring. A restoration method including the following steps (a) to (c). (A) detecting the position of the short-circuited thin film transistor among the plurality of thin film transistors formed in parallel with each pixel by detecting the microplasma emission or infrared light emitted from the short-circuit portion by optical means; (B) a step of electrically disconnecting the thin film transistor in which the short circuit has occurred in the beam device; and (c) a step of driving a pixel electrode corresponding to the disconnected thin film transistor with a normal thin film transistor.