JPS63240527A - Thin film transistor array - Google Patents

Abstract

PURPOSE:To obtain thin film transistors having the structure in which the defective transistors and defective parts can be easily disconnected from scanning wire and signal wire by providing >=1 points of bridge parts to the scanning wires and signal wires with respect to one picture element of the thin film transistor array. CONSTITUTION:The bright part 9 of the signal wire is provided at the part intersecting with the scanning wire 1 to relay the signal wire 2 and the bridge parts 10 of the scanning wire are provided at two points on both sides of the juncture of the scanning wire 1 and gate electrodes 7. For example, the bridge parts 10a and 10b are cut by a laser beam 15 by which the defective part can be isolated when a short-circuiting 14 is generated by a counter electrode 12 and the scanning wire 1. The defectless display image is obtd. by impressing an input voltage to the scanning wire 1 from both sides thereof at this time. The short circuiting at the intersected part and the defect of the thin film transistors can be similarly corrected by selecting and cutting the cutting points of the scanning wire 1 and the signal wire 2 according to a defect mode. The defective image display by the defects of the thin film transistors are thereby decreased and the defects by cross-shortings and counter electrode-shortings are eliminated without increasing the line resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thin film transistor array used in an active matrix liquid crystal display device.

2. Description of the Related Art In recent years, new display devices to replace conventional CRTs have been actively developed. Among these, liquid crystal display devices are thin and can operate with low power, so they have high expectations in the markets of automobiles, watches, and home appliances.

Conventionally, liquid crystal display devices used a simple drive method and were often small, but the contrast was poor and the density was high.

Since it is difficult to increase the size, active matrix display devices, in which each picture element operates independently, are becoming promising. Among them, the market for liquid crystal display devices driven by thin film transistors, such as high-density compact televisions of 1 to 5 inches in size, is expanding. Furthermore, research and development is progressing on promising products such as projection televisions using liquid crystal light pulp that can enlarge images of 10 to 20 inches or small sizes.

An example of the conventional thin film transistor array mentioned above will be described below with reference to the drawings.

FIG. 8 shows a planar configuration diagram of a conventional thin film transistor array. In FIG. 8, 1 is a scanning line connected to the gate electrode 7. A signal line 2 is connected to the source electrode 6, and the intersection with the scanning line is insulated by an insulating film 3. 5 is a drain electrode connected to the picture element electrode 4. Reference numeral 8 denotes a semiconductor film and an insulating film, and the semiconductor film is connected to a source electrode and a drain electrode, and is insulated from a gate electrode by the insulating film 8.

When a control signal and a scanning voltage are applied to the thin film transistor array configured as described above, switching of each thin film transistor is performed and a signal is input to the picture element electrode 4.

Problems to be Solved by the Invention However, with the above configuration, problems may occur due to defects in the thin film transistors, short circuits with the opposing electrode (common short) that occur when the panel is assembled, or cross shorts at the intersections of scanning lines and signal lines. If a defect occurs in the displayed image, the panel will be defective, but it can be corrected by separating the transistor in the defective part or the scanning line or signal line in the defective part and supplying power to the scanning line or signal line on both sides. However, as the size of the panel increases, the scanning lines and signal lines need to be made lower in resistance, and the thickness of the scanning lines and signal lines has become several thousand people due to the use of Ant and the like. In an array state, thousands of A
It is possible to cut the l, but if a laser output that can cut the panel is applied, it will have a negative effect on the liquid crystal, counter electrode, etc. that stays, and will cause a sheet failure with the counter electrode, so it must be corrected. Since it is difficult, there is a major problem in that the yield is reduced.

In view of the above problems, the present invention provides a thin film transistor having a structure in which a defective transistor and a defective portion can be easily separated from a scanning line and a signal line.

Means for Solving the Problems In order to solve the above problems, the thin film transistor array of the present invention has a configuration in which a scanning line and a signal line are provided with one or more bridge portions for each pixel. It is.

Effects of the present invention With the above-described configuration, when a defect occurs in the thin film transistor, or when a short-circuit failure with the counter electrode occurs after forming a panel, the bridge portion that can be cut is cut with a laser beam, and the scanning line or By separating the defective portion from the signal line, defects can be eliminated or reduced.

EXAMPLE Hereinafter, a thin film transistor array according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows the first embodiment of the present invention.
FIG. 3 shows a plan configuration diagram of a thin film transistor array in an example. In FIG. 1, reference numeral 9 denotes a signal line prefix portion, which is made of Cr having a thickness of 1000 mm. The signal line bridge section is provided at the intersection with the scanning line and relays the signal line 2. Reference numeral 10 denotes a scanning line bridge portion, which is made of Cr having a film thickness of 1,000 yen, and is provided at two locations on both sides of the connection portion between the scanning wA1 and the gate electrode 7. The gate electrode is made of Cr with a film thickness of 1000 mm, and the scanning line and signal line drain electrodes are 5. The source electrode 6 is made of AJ and has a thickness of 8000 mm. 8
4 is a semiconductor film and an insulating film, and 4 is a picture element electrode.

A method for correcting defects in the thin film transistor array constructed as described above will be described below with reference to FIGS. 1 to 4.

First, Fig. 2 is a perspective view of Fig. 1, Fig. 3 is a cross-sectional view of the array as a panel, cut in the longitudinal direction from the center of scanning l1) 1), and Fig. 4 is an equivalent circuit diagram of the thin film transistor array. In Figure 3, when the array is made into a panel, the gap between the counter electrode and the counter electrode is as narrow as 10 μm or less, so if a vertical short occurs between the counter electrode and the electrode part of each array, it will be a display defect. Become. Furthermore, a short circuit at the intersection of the scanning line and the signal line or a short circuit between the electrodes of individual thin film transistors also results in a display defect. This defect can be corrected by separating the defective portion from the scanning line and signal line.

FIGS. 3 and 4 show examples of defects in which a vertical short circuit 14 occurs between the counter electrode 12 and the scanning line 1. To correct this, the bridge portions 10a and 10b are cut by the laser beam 15, thereby making the defective portion independent. At this time, a display image free of defects can be obtained by applying input voltages from both sides of the scanning line. Similarly, short circuits at intersections and defects in thin film transistors can be corrected by selecting and cutting the scanning lines and signal lines according to the defect mode. Note that correction of thin film transistor defects ÷ means that constant lighting due to line defects or pixel defects is reduced to constant non-lighting due to pixel defects, but it does not mean that there are no defects. However, by making the configuration 1 pixel and 2 transistors, Can be defective.

As described above, according to this embodiment, by providing one or more bridge portions in the scanning line and the signal line for each pixel, defective portions can be easily isolated from the scanning line and the signal line even in a paneled state. Can be separated from the signal line.

A thin film transistor array according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 is a partial plan view of a thin film transistor array showing a second embodiment of the present invention. FIG. 6 is an equivalent circuit diagram.

In the figure, 1 is a scanning line, 2 is a signal line, 3 is an insulating film,
4 is a picture element electrode, 5 is a drain bridge, 6 is a source electrode, 8
9 is a semiconductor film and an insulating film, 9 is a signal line bridge portion, and 10 is a semiconductor film and an insulating film.
1 is a scanning line bridge section, and the above structure is similar to that shown in FIG. The difference from the configuration shown in FIG. 1 is that there are two connecting portions between the gate electrode 7 and the scanning electrode, and a bridge portion is provided between the connecting portions.

A method for modifying the thin film transistor array configured as described above will be described below.

In the first embodiment shown in FIG. 1, there are bridge parts on both sides of the connection part between scan &1) and the gate electrode 7, and when a defective part where a short circuit with the counter electrode occurs between the bridge parts is separated, the gate No voltage can be applied, resulting in a pixel defect. In the second embodiment, even if a sheet with the opposing electrode occurs at point B in FIG. 5, voltage can be applied to the gate electrode with power supply on both sides by disconnecting the gate electrode and point A of the bridge part. becomes possible. Similarly, even when a defect occurs at the 0 point, it can be corrected by selecting the cutting location while voltage can be applied to the gate electrode.

As described above, by providing two connection parts between the gate electrode and the scanning line and providing a scanning line bridge part between the connection parts, it is possible to determine at which part of the scanning line the seat with the counter electrode occurs. can also be modified without impairing the functionality of the thin film transistor.

A thin film transistor array according to a third embodiment of the present invention will be described below with reference to the drawings.

FIG. 7 is a partial plane configuration diagram of a fil film transistor array showing a third embodiment of the present invention.

In the figure, 1 is a scanning line, and 10 is a bridge portion connected to a gate electrode or a source electrode.

The operation of the thin film transistor array configured as described above will be explained.

The defective part is cut off in the same way as the repair method in the second embodiment, but the same effect as in the second embodiment can be obtained by selecting the cutting part A on the right or left side of the connection part between the bridge part and the gate electrode or source electrode. is obtained.

As described above, the bridge portion of the scanning line is connected to the gate electrode or the source electrode, and by providing cut portions in the bridge portions on both sides of the connection portion, defects can be repaired by reducing the number of cut portions.

Effects of the Invention As described above, the present invention provides one or more bridge portions in the scanning line and signal line for each pixel of a thin film transistor array, thereby eliminating image display failures caused by defects in thin film transistors without increasing line resistance. It is possible to reduce defects caused by cross shorts and opposing electrode sheets.

[Brief explanation of drawings]

FIG. 1 is a plan configuration diagram of a thin film transistor according to a first embodiment of the present invention, FIG. 2 is a perspective view of FIG. 1, and FIG. Determined disconnection, Figure 8 is the conventional III)
FIG. 2 is a plan configuration diagram of a transistor array. l...Scanning line, 2...Signal line, 3...
... Insulating film, 4 ... Picture element electrode, 5 ...
...Drain electrode, 6...Source electrode, 7...
... Gate electrode, 8 ... Semiconductor film and insulating film, 9 ... Signal line bridge portion, 10 ...
・・Scanning line pre-fuji part, 1)・・・・Substrate, 12・
...Counter electrode, 13...Liquid crystal. Name of agent: Patent attorney Toshio Nakao 1 (Ku 1 - 4 to 9 purple Fig. 1 3 - Horse stock R 笈 4 - 饋本實厭 5 - Ridley Doo Soo Kuji Rippan 6 - North Ge 7 - pu° - k17 δ - -4 *sbp pi* **y+xδ 7 Figure 2 13-Shi prostitute faction change

Claims (4)

[Claims] (1) A thin film transistor array for an active matrix display device, characterized in that one or more bridge portions are provided in a scanning line and a signal line for one picture element. (2) The thin film transistor array according to claim (1), wherein the output power that can cut the bridge portion of the scanning line or the signal line with the laser beam is smaller than the output power that can cut the scanning line or the signal line. (3) Each transistor has two connection points between the scanning line or signal line and the gate electrode or source electrode of the thin film transistor, and a bridge portion of the scanning line or signal line is provided between the two connection points. The thin film transistor array according to claim (1) or (2), characterized in that: (4) A bridge portion of a scanning line or a signal line is connected to a gate electrode or a source electrode of a thin film transistor, and cutting portions are provided on both sides of the bridge portion of the connection portion. The thin film transistor array according to item (1) or item (2).