JPH05333370A - Active matrix type liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide the active matrix type liquid crystal display element improving the yield. CONSTITUTION:When an array board 26 is completed, the disconnection of a signal line 22 is inspected by measuring resistance at both of terminals of the signal line 22. Concerning the signal line 22 discovered the disconnection at a point X, a selecting voltage Vg is impressed between the gate and source of second thin film transistors at both of terminals connected to this signal line 22, and the respective second thin film transistors 27 are turned on. The disconnection of wiring 25 for repair is inspected by measuring resistance values at both of terminals of the signal line 22. When there is no problem as the result of the disconnection inspection, the crossing part of the signal line 22 having the disconnection and the wiring 25 for repair is irradiated with laser beams L from the side of an insulated board 21. Then, the signal line 22 and the wiring 25 for repair are short-circuited, the wiring 25 for repair is bypassed, and the disconnection of the signal line 22 is relieved.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a thin film transistor (Th
The present invention relates to an active matrix type liquid crystal display element that performs display using in film transistor as a switch element.

[0002]

2. Description of the Related Art In recent years, display devices using liquid crystals are directed to television displays and graphic displays, and active matrix type display devices of large capacity and high density have been developed and put to practical use.

In such a display device, high contrast display without crosstalk can be achieved.
A semiconductor switch is used as a means for driving and controlling each pixel. As this semiconductor switch, a transmissive display is possible and it is easy to increase the area.
Generally, a thin film transistor or the like formed on an insulating substrate is used.

Further, conventionally, as a display element of this type, a structure described in, for example, Japanese Patent Application Laid-Open No. 61-4095 is known. This Japanese Patent Application Laid-Open No. 61-4095 discloses a structure as shown in FIG.

Then, as shown in FIG. 6, a thin film transistor 2 is formed on an insulating substrate 1, and a display pixel electrode 3 made of a transparent conductive film is formed in an array so as to be connected to the thin film transistor 2. On the other hand, an insulating substrate 4 is provided so as to face the insulating substrate 1, and a counter electrode 5 made of a transparent conductive film is formed on the entire surface of the surface of the insulating substrate 4 facing the insulating substrate 1. The liquid crystal 6 is placed between the insulating substrates 1 and 4.
Are sandwiched, and the periphery of the liquid crystal 6 is sealed with a sealing agent 7.
Then, the array substrate 8 is configured by the insulating substrate 1 on which the thin film transistor 2 and the display pixel electrode 3 and the like are formed, and the opposing substrate 9 is formed by the insulating substrate 4 on which the counter electrode 5 is formed.
Is configured.

Further, as shown in FIG. 7, the array substrate 8
A plurality of signal lines 10 and a plurality of scanning lines 11 orthogonal to the signal lines 10 are formed on the top. In addition, for repairing to repair the disconnection of the signal line 10 in a U shape so as to surround the signal line 10 and the scanning line 11 in a portion outside the pixel region 12 formed of the thin film transistor 2 and the display pixel electrode 3 of the array substrate 8. Wiring 13
Is provided.

A signal line pad 15 for supplying a signal voltage from the driving circuit is provided at one end of each signal line 10, and a scanning line pad for supplying a gate voltage is similarly provided at one end of the scanning line 11. 16 are provided. In addition, as shown in FIG. 8, the signal line 10 and the repair wiring 13 are connected to the gate insulating film 14
Are crossed across.

If there is a break in the signal line 10, for example, at the point X, the broken signal line 10 and the repair wiring 13
Array substrate 8 at Y1 point and Y2 point, which are two intersections with
The laser beam L is irradiated from the side to short-circuit the signal line 10 and the repair wiring 13. Then, since the signal voltage is supplied to the pixel beyond the point X, which is the disconnection portion, through the repair wiring 13, the line defect defect caused by the disconnection of the signal line 10 is relieved.

[0009]

However, in this type of liquid crystal display element, the repair wiring 13 is also broken due to dust or the like generated during the manufacturing process. Therefore, for example, when the repair wiring 13 is broken at the Z point shown in FIG. 7, the signal line is made at the Y1 point and the Y2 point which are the intersections.
Despite shorting 10 and the repair wiring 13,
No signal voltage is supplied to the display pixel electrode 3 beyond the point X, and the defect of the signal line 10 cannot be repaired.

Further, depending on the position of the Z point of the repair wiring 13, the signal line 10 which can be repaired by disconnection is limited. Since it is impossible to inspect these repair wirings 13 during the process of the array substrate 8 and at the time of completion thereof, the laser beam L is applied to the intersecting portions corresponding to the Y1 point and the Y2 point of the broken signal line 10. However, there is a problem that cannot be understood until the liquid crystal display element is actually driven and an image output inspection is performed after the short circuit is made by such as.

Further, the scanning line 11 side has the same problem as the signal line 10.

The present invention has been made in view of the above problems, and an object thereof is to provide an active matrix type liquid crystal display device having an improved yield.

[0013]

According to the present invention, a plurality of scanning lines and signal lines are arranged in a matrix on one main surface of an insulating substrate, and the scanning lines and the signal lines are provided in the vicinity of the intersections thereof. A pixel region in which one pixel including a first thin film transistor and a display pixel electrode connected to the first thin film transistor is arranged, and a repair wiring for repairing the disconnection of the scanning line or the signal line is provided outside the pixel region. An array substrate having; a counter substrate in which a counter electrode is formed on one main surface of the insulating substrate; and a liquid crystal layer sandwiching the array substrate and the counter substrate so that the one main surface sides face each other. In an active matrix type liquid crystal display device provided with the second thin film transistor, a second thin film transistor is provided near an intersection of the repair wiring and at least one of the scanning line and the signal line. Which are connected to at least one of the source electrode and the drain electrode of the thin film transistors each said repair wire the scanning lines and the signal lines.

[0014]

According to the present invention, the second thin film transistor is provided near the intersection of the repair wiring and the scanning line or the signal line, and the source electrode and the drain electrode of the second thin film transistor are respectively the repair wiring, the scanning line and the signal line. By connecting to at least one of the lines, when the second thin film transistor is turned on, the signal line or the scanning line and the repair wiring are electrically connected, and therefore both ends of the broken signal line or the scanning line are connected. By conducting a continuity test between the two, it is possible to inspect the success or failure of the disconnection repair, so that it is possible to inspect the signal line or the scanning line defect due to the disconnection of the repair wiring during the manufacturing process, and it is possible to prevent the yield from decreasing. it can.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the active matrix type liquid crystal display device of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 4, the insulating substrate 21
A plurality of parallel scanning lines 23 and a plurality of parallel signal lines 22 are arranged in a matrix on one main surface so as to intersect each other. Then, in the vicinity of the intersection of the scanning line 23 and the signal line 22, one pixel including a first thin film transistor (not shown) and a display pixel electrode connected to the first thin film transistor is arranged. The portion where the display pixel electrode is provided is referred to as a pixel region 24. Then, in a portion outside the pixel area 24,
Parallel to the scanning line 23 near both ends of the signal line 22, and
An array substrate 26 is formed by forming repair wiring 25 for repairing disconnection of the signal line 22 which is formed in a substantially U shape in parallel with the signal line 22 on one end side of 22.

A second thin film transistor 27 is formed near the intersection of the signal line 22 and the repair wiring 25.
The signal line 22 is connected to the source electrode 28 of the thin film transistor 27, and the repair wiring 25 is connected to the drain electrode 29.

The array substrate 26 is provided with a counter substrate (not shown) so as to face it. Further, a counter electrode is formed on one main surface of the insulating substrate, and a liquid crystal layer is sandwiched between the two main surfaces of the array substrate 26 and the counter substrate which face each other.

In the second thin film transistor 27, as shown in FIG. 4, a gate electrode 31 is formed on an insulating substrate 21,
A gate insulating film 32 is formed on the entire surface including the gate electrode 31. Further, the semiconductor layer 33 and the insulator layer 34 are sequentially formed on the gate electrode 31 of the gate insulating film 32. Further, ohmic layers 35 and 36 are formed on the semiconductor layer 33, and the source electrode 28 is formed on the ohmic layers 35 and 36, respectively.
And the drain electrode 29 is formed. Then, the protective layer 37 is formed on the entire surface. The first thin film transistor (not shown) is also formed in the same manner as the second thin film transistor 27.

On the other hand, as for the repair wiring 25, as shown in FIG. 5, the repair wiring 25 is formed on the insulating substrate 21, and the gate insulating film 32 is formed on the repair wiring 25. A signal line 22 is formed on the film 32 in a direction intersecting with the repair wiring 25, and a protective layer 37 is formed on the entire surface.

Further, as shown in FIG. 3, a source electrode 41 for inspection is formed on the source electrode 28 and the repair wiring 25, and a gate pad 42 for inspection is formed on the gate electrode 31.

Further, the drain electrode 29 is a gate insulating film 32.
The gate electrode 31 is connected to the repair wiring 25 through the through hole 43 formed in the gate electrode 31 and is exposed on the surface by the through hole 44 formed in the gate insulating film 32.

The repair wiring may be similarly formed for the scanning line 23.

Next, a method of using the above embodiment will be described.

First, when the array substrate 26 is completed,
Signal line 22 is measured by measuring the resistance across signal line 22.
Check for disconnection. Then, for example, for the signal line 22 in which the disconnection is found at the point X, the selection voltage Vg is applied between the gate and the source of the second thin film transistors 27 at both ends connected to the signal line 22, and each of the second thin film transistors 27 is supplied with the selection voltage. The second thin film transistor 27 is turned on. The resistance value at both ends of the signal line 22 is measured again to perform a disconnection inspection of the repair wiring 25. Then, if there is no problem in this disconnection inspection, as shown in FIG. 5, the intersection of the signal line 22 having the disconnection and the repair wiring 25 is irradiated with the laser beam L from the insulating substrate 21 side. Thus, by short-circuiting the signal line 22 and the repair wiring 25, the repair wiring 25 is bypassed and the disconnection of the signal line 22 is repaired.

Then, as shown in FIG. 2, a signal hold circuit 51 is connected to each signal line 22 and a scanning circuit 52 is connected to each scanning line 23.
Connect and complete.

According to the above embodiment, the repair wiring 25 for repairing the disconnection of the signal line 22 or the scanning line 23, and the signal line 22.
Alternatively, the second thin film transistor 27 is provided near the intersection of the scanning lines 23.
By providing the above, it becomes possible to inspect the repair wiring 25 for disconnection when the array substrate 26 is completed. Therefore,
Since it is possible to prevent the defective array substrate, which has failed to repair the disconnection of the signal line 22 or the scanning line 23, from flowing into the cell process, it is possible to improve the cell process yield and provide an inexpensive liquid crystal display device. .

Since the second thin film transistor 27 is also formed in the same manner as the first thin film transistor, the manufacturing process does not become complicated.

[0029]

According to the active matrix type liquid crystal display element of the present invention, a second thin film transistor is provided near the intersection of the repair wiring and the scanning line or the signal line.
Since the source electrode and the drain electrode of the thin film transistor are connected to at least one of the repair wiring, the scanning line and the signal line, when the second thin film transistor is turned on, the source electrode and the drain electrode are connected to the signal line or the scanning line. Since the repair wiring is electrically connected, the success or failure of the disconnection repair can be inspected by conducting a continuity test between both ends of the broken signal line or scanning line. Scan line defects can be inspected during manufacturing, and a decrease in yield can be prevented.

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram showing a test time of an embodiment of an active matrix type liquid crystal display device of the present invention.

FIG. 2 is an equivalent circuit diagram showing the same as above.

FIG. 3 is a plan view showing a structure of a thin film transistor provided in the vicinity of an intersection of a signal line and a repair wiring as above.

4 is the same as the second thin film transistor of FIG.
It is an IV sectional view.

5 is a sectional view taken along line VV of FIG. 3 showing the signal line and the repair wiring.

FIG. 6 is a cross-sectional view showing a conventional active matrix type liquid crystal display element.

FIG. 7 is an equivalent circuit diagram showing the same as above.

FIG. 8 is a cross-sectional view showing the signal line and the repair wiring of the above.

[Explanation of symbols]

 22 signal line 23 scanning line 24 pixel region 25 repair wiring 26 array substrate 27 second thin film transistor

Claims (1)

[Claims] 1. A plurality of scanning lines and signal lines are arranged on a main surface of an insulating substrate so as to intersect each other in a matrix, and a first thin film transistor and the first thin film transistor are provided in the vicinity of an intersection of these scanning lines and signal lines. An array substrate having a pixel region in which one pixel including a display pixel electrode connected to the thin film transistor is arranged, and a repair wiring for repairing the disconnection of the scanning line or the signal line outside the pixel region; and the insulating substrate. An active matrix type liquid crystal display device comprising: a counter substrate having a counter electrode formed on one principal surface thereof; and a liquid crystal layer sandwiching the array substrate and the counter substrate so that the one principal surface sides thereof face each other. In the above, a second thin film transistor is provided in the vicinity of an intersection of the repair wiring and at least one of the scanning line and the signal line. Active matrix liquid crystal display element characterized scan electrode and the drain electrode respectively and the repair wiring that connects the to at least one of the scanning lines and the signal lines.