JPH0519294A - Line defect correcting method for active matrix display device - Google Patents

Abstract

PURPOSE:To correct the line defect caused by the disconnection of a signal line of an active matrix display device and to improve the yield of a product. CONSTITUTION:The tip part of a gate bus branch line 22 protruded toward a picture element electrode 41 from a gate bus line 21 becomes a gate electrode of a TPT 31, and the TFT 31 is formed by superposing a source electrode 32 and a drain electrode 33 by placing a gate insulating film between them thereon. On the other hand, in a source bus line 23, a source bus line protruding part 46 is formed toward the picture element electrode 41, and a redundant structure is formed by inserting and holding the gate insulating film and superposing a first conductive body piece 47 and a second conductive body piece 48 thereon. When a line defect caused by disconnection is detected, the base end part of the gate bus branch line 22, the superposed part of the gate bus branch line 22, the source electrode 32 and the drain electrode, a superposed part of the source bus line protruding part 46 and a first conductive body piece 47, and a superposed of a first and a second conductive body pieces 47, 48 are irradiated with a laser light, and by forming a bypass line on the side of a disconnection generated part, the line defect is obviated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line defect repairing method for a display device which executes display by applying a drive signal to a display pixel electrode through a switching element, and more particularly to a matrix of pixel electrodes. The present invention relates to a line defect repairing method for an active matrix display device, which repairs a line defect occurring in an active matrix driving type display device which is arranged in a matrix and performs high density display.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal display device, an EL display device, a plasma display device, etc., a display pattern is formed on a screen by selectively driving picture element electrodes arranged in a matrix. As a method of selecting display picture elements, an active matrix drive method is known in which individual picture element electrodes are arranged and a switching element is connected to each of the picture element electrodes to perform display driving. As a switching element for selectively driving the pixel electrode, a TFT (thin film transistor) element, MIM (metal-insulating layer-metal)
An element, a MOS transistor element, a diode, a varistor, or the like is generally used, and a voltage applied between a pixel electrode and a counter electrode facing the pixel electrode is switched by a switching element, and a liquid crystal is interposed between both electrodes. By optically modulating a display medium such as an EL light emitting layer or a plasma light emitter,
The optical modulation is visually recognized as a display pattern. Such an active matrix drive system is capable of high-contrast display, and has been put to practical use in liquid crystal televisions, word processors, terminal display devices of computers, and the like.

FIG. 6 shows a conventional example of an active matrix liquid crystal display device, in which gate bus lines 21, 21 ... Are horizontally arranged on one of a pair of substrates arranged opposite to each other. Source bus lines 23, 23 ... Are wired in the vertical direction orthogonal to the. A pixel electrode 41 is provided in each rectangular area surrounded by the adjacent gate bus lines 21 and 21 and source bus lines 23 and 23.

In addition, a TFT 31 functioning as a switching element is formed on the gate bus branch line 22 branched (projected) from the gate bus line 21. TF
The drain electrode 33 of T31 is electrically connected to the pixel electrode 41, and the source electrode 32 is connected to the source bus line 23.

[0005]

By the way, in the above active matrix display device, when the source bus line 23 adopts a signal transmission system for transmitting a drive signal to each pixel electrode 41 from only one direction, the source bus line 23
If a disconnection occurs midway, the drive signal that should be given originally is not input to the pixel electrode 41 located on the tip side of the disconnection portion, and as a result, it is recognized as a line defect on the display. Such line defects significantly impair the quality of the display device, which is a serious problem from the viewpoint of product yield.

The line defect is caused by T as a switching element.
If it is discovered during the manufacturing stage of the substrate on which FT31 is placed,
It can be corrected by laser trimming. However, it is extremely difficult to detect such line defects from a huge number of picture elements during the production of the substrate, and it may be impossible at the mass production level in view of the production time and the production cost.

On the other hand, there is a method of visually detecting a line defect by applying an inspection electric signal to the source bus line 23 when the opposite side substrate is attached to the substrate and the liquid crystal is sealed. For example, line defects can be easily detected. However, according to this method, since it is difficult to correct the line defect, the display device in which the line defect is detected must be discarded after all, which is a bottleneck in cost reduction.

For the above-mentioned reason, the conventional technique has a great limitation in improving the yield of products.

The present invention solves the above-mentioned drawbacks of the prior art, and can reliably correct line defects due to disconnection of signal lines, resulting in a marked improvement in product yield. It is an object of the present invention to provide a method for repairing line defects.

[0010]

According to a method of correcting a line defect of an active matrix display device of the present invention, scanning lines and signal lines are arranged in a grid pattern on an insulating substrate and surrounded by the scanning lines and the signal lines. A pixel electrode is arranged in each area, and connected to the scan line, the signal line, and the pixel electrode above or below a scan line branch line formed to project from the scan line toward the pixel electrode. An active matrix substrate having a switching element formed therein, wherein the switching element has a three-dimensional structure in which the scanning line branch line and the source electrode and the pixel electrode are superposed with an insulating film interposed therebetween, and from the signal line, A signal line projecting portion that is formed so as to project toward the pixel electrode and is not in electrical contact with the pixel electrode; and a first conductor piece having one end overlapping the signal line projecting portion with an insulating film interposed therebetween. , On the other end of the first conductor piece Fabrication of an active matrix substrate having a redundant structure which is overlapped with an edge film, is in electrical contact with the pixel electrode, and is formed of a second conductor piece that is not in electrical contact with the signal line protrusion. And a step of adhering a counter electrode side substrate having a counter electrode formed on the active matrix substrate, encapsulating a display medium between the two substrates to manufacture an active matrix display device, and a state of adhering the both substrates. A step of applying a signal voltage to the signal line to drive the switching element, thereby operating the active matrix display device to optically detect a malfunctioning signal line, and a malfunctioning signal in the detecting step. When a line break is detected, a region where the scan line branch line and the source electrode of the switching element that drives the picture element electrode closest to the break line overlap, the scan branch line and the drain electrode are A region to be folded, a portion of the scanning line branch line branched from the scanning line, an overlapping portion of the signal line protruding portion and the first conductor piece, and the first conductor piece and the second conductor piece Irradiating the overlapping portion with light energy, whereby the above object is achieved.

Further, according to the method of repairing line defects of an active matrix display device of the present invention, scanning lines and signal lines are arranged in a grid pattern on an insulating substrate, and picture elements are formed in a region surrounded by the scanning lines and signal lines. Switching elements, each of which is provided with an electrode, is connected to the scanning line, the signal line, and the pixel electrode above or below a scanning line branch line formed to project from the scanning line toward the pixel electrode. An active matrix substrate having: a switching element having a three-dimensional structure in which the scanning line branch line, the source electrode and the pixel electrode are superposed with an insulating film interposed therebetween, and the signal line is connected to the pixel electrode. A signal line projecting portion that is formed so as to project toward the picture element electrode and is not electrically in contact with the picture element electrode, and a projection line that projects toward the picture element electrode from the scanning line adjacent to the picture element electrode, and sandwiches the insulating film Superimposed under the signal line The scanning line projecting portion is superposed on the tip of the scanning line projecting portion with an insulating film interposed therebetween and is in electrical contact with the pixel electrode, and is not electrically in contact with the signal line projecting portion. A process of manufacturing an active matrix substrate having a redundant structure formed with body pieces and a counter electrode side substrate having a counter electrode formed on the active matrix substrate are bonded to each other, and a display medium is sealed between the two substrates to make active. A step of manufacturing a matrix display device, and a signal voltage is applied to the signal line in a state where both substrates are bonded to drive the switching element, and thereby the active matrix display device is operated to cause a malfunctioning signal line. And a scanning line branch line and a source of the switching element that drives the pixel electrode closest to the disconnection portion when a disconnection of the malfunctioning signal line is detected in the detecting step. A region in which the poles overlap, a region in which the scanning line branch line and the drain electrode overlap, a part of the scanning line branch line branched from the scanning line, a overlapping part of the signal line protruding portion and the scanning line protruding portion, and the first portion. 1) A step of irradiating the overlapping portion of the conductor piece and the scanning line projecting portion with light energy, whereby the above object is achieved.

[0012]

The method of detecting and correcting line defects in the active matrix display device manufactured as described above will be described below with reference to FIG. In an active matrix display device in which the gate bus lines (scanning lines) 21 and the source bus lines (signal lines) 23 are wired in a matrix, and the picture element electrodes 41 are arranged in a region surrounded by the bus lines 21 and 23, Assuming a state where a disconnection 90 occurs in the middle of the source bus line (signal line) 23 and a source signal is transmitted to the source bus line 23 in the direction of arrow C, the line is located on the tip side of the disconnection 90 in the signal transmission direction. Defects will occur. The line defect is detected by using a display medium such as a liquid crystal as T
A gate bus line (scanning line) 21 and a source bus line, which are wired to the TFT side substrate in a state of being enclosed between the TFT side substrate on which the FT31 (switching element) is arranged and the counter electrode side substrate on which the counter electrode is formed. 23, and an appropriate signal is applied to the counter electrode. That is, when the signal is applied, a display state corresponding to the line defect is obtained, and thus the line defect can be detected by visually observing the display state.

When line defects are detected, 51, 52, 5 in the figure are detected.
A region shown by 3 and a region shown by 54, 55 are irradiated with laser light as an example of light energy. here,
A region 51 corresponds to the overlapping portion of the source electrode 32 of the TFT 31 and the gate bus branch line 22 (scan line branch line), and a region 52 is the gate bus branch line 22 and the drain electrode 33 of the TFT 31.
Corresponds to the overlapping portion of The region 53 corresponds to a portion of the gate bus branch line 22 branched from the gate bus line 21, that is, a base end portion of the gate bus branch line 22. Further, the regions 54 and 55 correspond to the redundant structure portion, more specifically, the region 54 corresponds to the overlapping portion of the first conductor piece 47 and the source bus line protruding portion (signal line protruding portion) 46, The region 55 corresponds to the overlapping portion of the first conductor piece 47 and the second conductor piece 48.

By irradiating the region 53 with laser light,
The gate bus branch line 22 is cut off from the gate bus line 21 at the irradiation portion, whereby the gate electrode of the TFT 31 becomes electrically floating. On the other hand, the area 51,
When the irradiation portion is shot through with a small spot by irradiating the laser beam to 52, the insulating film in the overlapping portion is destroyed, and the upper and lower conductors are electrically connected via the peripheral portion of the punched hole. That is, by irradiating the regions 51 and 52 with laser light, the gate bus branch line 22 and the source electrode 32 are electrically connected, and the gate bus branch line 22 and the drain electrode 33 are electrically connected. As a result, the TFT
The source bus line 23 and the pixel electrode 41 are electrically connected through 31. That is, the picture element electrode 41 is short-circuited with the source bus line 23 and always has the same potential as the source signal.

When the regions 54 and 55 are irradiated with laser light from this state, the source bus line protrusion 46 and the first conductor 47 and the first conductor piece 47 and the second conductor piece 48 are connected in the same manner as described above. To be done. Therefore, the region 54,
By irradiating the laser beam 55, the source bus line 23 and the pixel electrode 41 are electrically connected.

The source signal transmitted through the source bus line 23 in the direction of arrow C by the irradiation of the laser light at the above five locations is as follows: source electrode 32 → gate electrode of TFT 31 → drain electrode → pixel electrode 41 → first conductor. It is transmitted to the tip side of the portion of the source bus line 23 where the disconnection 90 has occurred via the piece 47 → the second conductor piece 48 → the source bus line protrusion 46. As a result, line defects caused by the disconnection 90 are eliminated.

As described above, according to the present invention, a redundant structure is provided on the side of the portion where the disconnection 90 is generated so that a bypass line utilizing the picture element electrode 41 can be formed by irradiation with laser light or the like, and the bypass line is passed through. Then source bus line 23
The correction principle is adopted to eliminate the line defect by transmitting the source signal to the tip side of the portion where the disconnection 90 occurs.

[0018]

EXAMPLES Examples of the present invention will be described below.

1 to 3 show an active matrix display device according to this embodiment, which displays a space between a pair of upper and lower transparent insulating substrates (in the drawing, only the substrate 1 on which a TFT 31 is formed is displayed). Liquid crystal is enclosed in the above).
A plurality of gate bus lines 21, 21 ... That function as scanning lines and a plurality of source bus lines 23, ... That function as signal lines are wired vertically and horizontally on the substrate 1, and are surrounded by both bus lines 21, 23. The pixel electrodes 41 are arranged in a matrix in each of the rectangular regions. A gate bus branch line 22 is formed on the gate bus line 21 so as to project toward the pixel electrode 41 side.
The TFT 31 is formed in a portion near the tip of 2. The tip portion of the gate bus branch line 22 becomes the gate electrode of the TFT 31. The gate electrode 22 has a source electrode 32 of a TFT 31.
And the drain electrode 33 is overlapped with the gate insulating film 11 (see FIGS. 2 and 3) interposed therebetween. The TFT 31 functions as a switching element and is connected to the picture element electrode 41.

In addition, the TFT 31 of the source bus line 23
A source bus line protrusion 46 is formed toward the pixel electrode 41 side at a position separated from the formation portion by an appropriate length. One end of the first conductor piece 47 is overlapped below the tip of the source bus line protrusion 46 with the gate insulating film 13 interposed therebetween. The second conductor piece 47 has a rectangular shape that is long in the wiring direction of the source bus line 23, and the second conductor piece 4 is formed above the other end.
8 are overlapped with the gate insulating film 12 sandwiched therebetween. With the above structure, a redundant structure is formed in this portion.

The details of each part will be described below in accordance with the production procedure. As shown in FIG. 2, first, the gate bus line 21 is formed on the substrate 1. This fabrication is generally done with Ta, Ti, A
It is manufactured by depositing a single-layer metal or a multi-layer metal such as Cr and Cr on the substrate 1 by a sputtering method and then patterning the metal. At this time, at the same time, the gate bus branch line 22 and the first conductor piece 47 in the redundant structure portion are manufactured. In this example, the glass substrate 1 was used as the substrate 1. Note that FIG.
Further, as shown in FIG. 3, an insulating film 10 such as Ta ₂ O ₅ may be formed as a base coat film under the gate bus line 21.

Next, the gate insulating film 12 is laminated on the gate bus line 21 (including the gate bus branch line 22).
In this embodiment, a SiN _x film is formed by plasma CVD method.
The gate insulating film 12 was deposited to a thickness of 00 nm. Before forming the gate insulating film 12, the gate bus line 21 may be anodized to form the oxide film 11 made of Ta ₂ O ₅ .

Next, the semiconductor layer 13 and the etching stopper layer 15 are formed on the gate insulating film 1 by the plasma CVD method.
2 is formed continuously. The semiconductor layer 13 is composed of an amorphous silicon (a-Si) layer, and the etching stopper layer 15 is composed of a SiN _x layer. The respective film thicknesses are 30 nm and 200 nm. Then, the etching stopper layer 15 is patterned, and thereafter, an n ⁺ -type a-Si layer 14 (contact layer) to which phosphorus is added is stacked with a thickness of 80 nm by a plasma CVD method. This n ⁺ type a
The -Si layer 14 is formed in order to improve the ohmic contact between the semiconductor layer 13 and the source electrode 32 or the drain electrode 33 that is subsequently formed by lamination.

Next, the n ⁺ type a-Si layer 14 is patterned, and then a source metal is laminated by a sputtering method. As the source metal, generally, Ti, Al,
Although Mo, Cr and the like are used, Ti is used in this embodiment. Then, the Ti metal layer is patterned to obtain the source electrode 32 and the drain electrode 33. As a result, the TFT 31 having the structure shown in FIG. 2 is produced. This time,
The source bus line 23, the source bus line protrusion 46, and the second conductor piece 48 are simultaneously formed.

Next, a transparent conductive material to be the pixel electrode 41 is laminated. In this embodiment, the transparent conductive material is I
TO (Indium tin oxide) is laminated by a sputtering method and patterned to obtain a pixel electrode 41. The pixel electrode 41 is in conduction with the drain electrode 33. However, the pixel electrode 41 is omitted in FIG.

A protective film 16 made of SiN _x is deposited on the entire surface of the glass substrate 1 on which the pixel electrodes 41 are formed.
The protective film 16 may have a window-like shape removed at the central portion of the pixel electrode 41.

A counter electrode side substrate having a counter electrode formed thereon is bonded to the active matrix substrate manufactured as described above, and the optical matrix is formed in response to a drive voltage applied to the pixel electrode 41 between the two substrates. Liquid crystal is enclosed as a display medium whose dynamic characteristics change. An alignment film is formed on the protective film 16 to align the liquid crystal molecules. The alignment film is also formed on the counter electrode made of ITO. The active matrix display device is manufactured as described above.

Next, a method of correcting a line defect caused by the disconnection 90 in the active matrix display device of this embodiment will be described. First, the detection of line defects
A gate bus line 21 and a source bus line 23,
It is performed by applying an appropriate signal to the counter electrode. That is,
When the signal is applied, a display state corresponding to the line defect is obtained, so that the line defect can be detected by visually observing the display state.

Subsequently, when a line defect is detected, first, as an example of light energy, an area 53 on the gate bus branch line 22 is provided.
Irradiate YAG laser light. By this irradiation, the gate conductors in the irradiation part are scattered and the gate bus branch line 22 is separated from the gate bus line 21 with the irradiation part as a boundary. As a result, the tip end side of the irradiation portion of the gate bus branch line 22, that is, the TFT 31 is electrically insulated from the gate bus line 21.

Irradiation of the laser light may be performed from the back side of the substrate 1 on the TFT 31 side or from the front side of the counter side substrate. However, in this example, since the counter substrate was covered with the light-shielding conductor and the laser beam could not be directly irradiated, the laser beam was irradiated from the back side of the substrate 1 as shown by the white arrow in FIG.

Next, the regions 51 and 52 are irradiated with laser light in the same direction as the above. Here, the region 51 is the overlapping portion of the gate electrode 22 and the source electrode 32 of the TFT 31, and the region 52 is the overlapping portion of the gate electrode 22 and the drain electrode 33 of the TFT 31. When the irradiated portion is shot through with a small spot by irradiating the regions 51 and 52 with a laser beam, the gate insulating film 12 in the overlapping portion is destroyed, and the upper and lower conductors are electrically connected through the peripheral portion of the punched hole. Connected to. That is, by irradiating the regions 51 and 52 with laser light, the gate bus branch line 22 and the source electrode 32 are electrically connected, and the gate bus branch line 22 and the drain electrode 33 are electrically connected. As a result, the TFT
The source bus line 23 and the pixel electrode 41 are electrically connected through 31. That is, the picture element electrode 41 is short-circuited with the source bus line 23 and always has the same potential as the source signal.

Then, when the regions 54 and 55 are irradiated with laser light, the source bus line protrusions 46 are formed in the same manner as above.
And the first conductor 47 and the first conductor piece 47 and the second conductor piece 48 are connected, respectively. Therefore, the regions 54, 55
By irradiating the laser beam to the source bus line 23
And the pixel electrode 41 is electrically short-circuited.

The source signal transmitted in the direction of arrow C through the source bus line 23 by the irradiation of the laser light at the above-mentioned five locations is as follows: source electrode 32 → gate electrode of TFT 31 → drain electrode → pixel electrode 41 → first conductor. It is transmitted to the tip side of the portion of the source bus line 23 where the disconnection 90 has occurred via the piece 47 → the second conductor piece 48 → the source bus line protrusion 46. That is, it is adapted to be transmitted to the tip side through the bypass line that follows the above path. As a result, line defects caused by the disconnection 90 are eliminated.

The region 53 is irradiated with the laser beam to cut the gate bus branch line 22, and the other regions are irradiated to melt the conductor. This is the laser beam irradiation. This is achieved by setting the conditions appropriately. Moreover, the irradiation order of the laser light is not limited to the above order.

Further, according to the experimental results of the inventors of the present invention, it has been confirmed that the connection resistance of the overlapping portion is several hundred Ω or less, and a resistance of this level is also used as a bypass line. No problem.

Next, according to FIG. 4, the TF when the pixel electrode 41 and the source bus line 23 are short-circuited as described above.
The operation of T31 will be described. In FIG. 4, Gn is a signal (voltage signal) on the n-th gate bus line 21, S
m is the signal of the m-th source bus line 23, Pn and m are n
The signal given to the pixel electrode 41 existing at the intersection of the th-th gate bus line 21 and the m-th source bus line 23 is schematically shown.

As shown in FIG. 4A, when the potential of the signal on the gate bus line 21 is Vgh (high level), the TFT
When 31 is selected and the potential is Vgl (low level), TF
T31 enters the non-selected state. As shown in FIG. 4 (c),
When the TFT 31 is selected, the pulsed signal V0 is charged in the pixel electrode 41. When the picture element electrode 41 is operating normally, this signal is set to the non-selection time T shown in FIG.
The signal is held for off and the -V0 signal is written to the source bus line 23 at the next selection time Ton.

Gn + 1 shown in FIG. 4B represents a signal given to the (n + 1) th gate bus line 21, and the signal Gn + 1 is the selection time of the nth gate bus line 21. To
When n ends, the selected state is started, and at this time, the signal -V1 is written to the source bus line 21 (see FIG. 4C). As can be seen from FIGS. 4A and 4B, the signal input to the gate bus line 21 sequentially delays with the line number until the selected state circulates to the nth gate bus line 21 next. The non-selected state continues for the time Toff. Even in this non-selected state, the signal to be written for each picture element electrode 41 is continuously input to the source bus line 21.

As shown in FIG. 4D, the normal pixel electrode 41 is connected to the pixel electrode 41 according to the signal Sm input from the source bus line 23 when the gate signal Gn is in the selected state. The counter electrode 3 on the side of the substrate 2 that is charged with electric charges
The potential difference between and changes the molecular alignment of the liquid crystal, and fulfills the display function. At this time, the signal Sm input to the source bus line 23 within the non-selection time Toff of the gate bus line 21 does not contribute to the display at all.

On the other hand, as described above, in the state where the pixel electrode 41 and the source bus line 23 are short-circuited by the irradiation of the laser beam, the pixel electrode 41 is not affected by the selection or non-selection of the gate bus line 21. It reacts to all of the signal Sm input from the source bus line 23, and charges / discharges the charge. The signal at this time is shown by P'n, m in FIG. Picture element electrode 41 modified by laser light irradiation
Since the signal Sm of the source bus line 23 is input as it is during the non-selection time Toff, the voltage acting on the liquid crystal becomes the effective value of the applied signal Sm. Therefore, the effective value of the signals P'n, m cannot be V0 except when all the signals Sm given to the source bus line 23 are V0, but The effective voltage is an average value of all the pixel electrodes 41 connected to the m-th source bus line 23. This means that the display device lights up with the average brightness of the picture element electrodes 41 arranged along the m-th source bus line 23, and in a normal display state, the picture element electrodes are turned on. The brightness of 41 hardly impairs the display quality. Therefore, although the corrected picture element is not operating normally, it is extremely difficult to identify it as a defect.

FIG. 5 shows another embodiment of the present invention.
In this embodiment, in place of the first conductor piece 47, the gate bus line protrusion 49 formed so as to protrude from the adjacent gate bus line 21 toward the pixel electrode 41 is replaced with the source bus line protrusion 46 and the conductor piece 48. ′ And a redundant structure is formed by overlapping with ′.

This embodiment has the following advantages in addition to the effects of the above embodiment. That is, according to this embodiment, at the stage of forming the anodic oxide film on the gate bus line 21, the gate bus line protrusion 49 is formed on the gate bus line 2.
When electrically connected to 1, the anodic oxide film can be formed also on the gate bus line protruding portion 49, so that a two-layer insulating film can be formed. Therefore, the insulating property can be improved, and the probability that the gate bus line projecting portion 49, the conductor piece 48 ′, the gate bus line projecting portion 49, and the source bus line projecting portion 46 will be leaked from the beginning due to a defective insulating film. It can be reduced. Therefore, it is more convenient for improving the yield of the active matrix display device.

In the correction of the line defect in this embodiment, laser light is applied to the base end portion of the gate bus line projecting portion 49 in addition to the regions 51, 52, 53, 54 and 55, and the gate is removed. It is necessary to separate the bus line protrusion 49 from the gate bus line 21. The irradiation method is the same as that in the above-mentioned embodiment, and therefore the explanation is omitted.

Although the whole of the illustrated embodiment is as described above, the present invention can be variously modified as described below.
That is, a display device provided with an additional capacitance in order to improve the display characteristics of the display device is known, but the present invention can be similarly applied to a display device provided with such an additional capacitance.

Further, although the TFT is used as the switching element for driving the pixel electrode in the above embodiment, the invention is not limited to this, and an MIM element, a MOS transistor element, a diode or a varistor may be used. Also, TF
The structure of T is not limited to that in the above embodiment, and may be a structure in which the source bus line is arranged on the lower surface and the gate bus line is arranged on the upper surface.

[0046]

According to the line defect repairing method of the active matrix display device of the present invention as described above, it is of course possible to easily detect the line defect caused by the disconnection of the signal line, and by applying the light energy such as laser light, The line defect can be reliably corrected. Therefore, according to the present invention, the yield of the active matrix display device can be remarkably improved, and the cost reduction can be greatly reduced.

In particular, according to the line defect repairing method of the active matrix display device of the second aspect, there is an advantage that the yield of the display device can be further improved.

[Brief description of drawings]

FIG. 1 is a plan view of an active matrix display device to which a line defect correcting method of the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a timing chart showing signals input to gate bus lines, source bus lines, and picture element electrodes.

FIG. 5 is a plan view showing another embodiment of the present invention.

FIG. 6 is a plan view showing a conventional example of active matrix display.

[Explanation of symbols]

1 Substrate on which the TFT is installed 12 Gate insulating film 21 gate bus line 22 gate bus line 23 Source Bus Line 31 ... TFT 32 ... Source electrode 33 ... Drain electrode 41 ... Picture element electrode 46 ... Source bus line protrusion 47 ... First conductor piece 48 ... Second conductor piece 49 Gate bus line protrusion 49 'Conductor piece 51, 52, 53, 54, 55 ... Laser light irradiation area 90 disconnection C Source signal transmission direction

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication H01L 27/12 A 8728-4M 29/784 (72) Inventor Eiji Marumoto 22 Nagaike-cho, Abeno-ku, Osaka No.22 Sharp Corporation

Claims (2)

[Claims] 1. A scanning line and a signal line are arranged in a grid pattern on an insulating substrate, and a pixel electrode is arranged in a region surrounded by the scanning line and the signal line. An active matrix substrate having switching elements connected to the scanning lines, the signal lines, and the pixel electrodes above or below a scanning line branch line protruding toward the element electrodes, wherein the switching elements are The scanning line branch line and the source electrode and the picture element electrode have a three-dimensional structure in which they are overlapped with each other with an insulating film interposed therebetween, and are formed so as to project from the signal line toward the picture element electrode and electrically connected to the picture element electrode. A non-contact signal line projecting portion, a first conductor piece whose one end is superposed on the signal line projecting portion with an insulating film sandwiched therebetween, and an other end portion of the first conductor piece is superposed with an insulating film sandwiched therebetween. Are electrically contacted with the pixel electrodes, and are electrically connected to the signal line protrusions. A step of producing an active matrix substrate having a redundant structure formed of a non-contact second conductor piece, and a counter electrode side substrate having a counter electrode formed thereon is bonded to the active matrix substrate, A step of manufacturing an active matrix display device by encapsulating a display medium, and applying a signal voltage to the signal line in a state where both substrates are bonded to drive the switching element, thereby operating the active matrix display device. Optically detecting the malfunctioning signal line by performing the scanning, and when the disconnection of the malfunctioning signal line is detected in the detecting step, the scanning of the switching element that drives the pixel electrode closest to the disconnection portion. A region where the line branch line and the source electrode overlap, a region where the scan branch line and the drain electrode overlap, a portion of the scan line branch line branched from the scan line, and the signal line protruding portion First
A line defect repairing method for an active matrix display device, comprising: irradiating light energy to an overlapping portion with a conductor piece and an overlapping portion with the first conductor piece and the second conductor piece. 2. A scanning line and a signal line are arranged in a grid pattern on an insulating substrate, and a pixel electrode is arranged in a region surrounded by the scanning line and the signal line. An active matrix substrate having switching elements connected to the scanning lines, the signal lines, and the pixel electrodes above or below a scanning line branch line protruding toward the element electrodes, wherein the switching elements are The scanning line branch line and the source electrode and the picture element electrode have a three-dimensional structure in which they are overlapped with each other with an insulating film interposed therebetween, and are formed so as to project from the signal line toward the picture element electrode and electrically connected to the picture element electrode. A non-contact signal line projecting portion, and a scanning line projecting portion which is formed to project from the scanning line adjacent to the pixel electrode toward the pixel electrode and is overlapped under the signal line with an insulating film interposed therebetween. , An insulating film is sandwiched at the tip of the scanning line protruding portion, A step of manufacturing an active matrix substrate having a redundant structure formed by a first conductor piece that is in electrical contact with the pixel electrode and is not in electrical contact with the signal line protruding portion; A step of adhering a counter electrode side substrate having a counter electrode formed on a matrix substrate and encapsulating a display medium between the two substrates to manufacture an active matrix display device, and a signal to the signal line in a state where the both substrates are adhered. A step of applying a voltage to drive the switching element, thereby operating the active matrix display device to optically detect a malfunctioning signal line, and a disconnection of the malfunctioning signal line is detected in the detecting step. When done,
A region where the scanning line branch line and the source electrode of the switching element that drive the pixel electrode closest to the disconnection portion overlap, a region where the scanning line branch line and the drain electrode overlap, and a branch from the scanning line of the scanning line branch line Active matrix display device, including: a light-exposed portion, an overlapping portion of the signal line protruding portion and the scanning line protruding portion, and a step of irradiating light energy to an overlapping portion of the first conductor piece and the scanning line protruding portion. Line defect repair method.