JPH103087A - Active matrix type liquid crystal display device and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active matrix type liquid crystal display device to which with a sufficient countermeasure for preventing a dielectric breakdown is applied. SOLUTION: This device includes a transparent substrate (an array substrate) consisting of row lines G1...G5 formed on the transparent substrate, plural column lines S1...S5 formed so as to cross with these row lines, thin film transistors Tr11 formed at intersection parts of the row lines and the column lines, a counter substrate having counter electrodes and arranged parallel with the array substrate and a liquid crystal layer. In this case, a short-circuited line S/R(short ring) being on the array substrate is formed at the outside of an area where the row lines and the column lines are formed so as to circulate the area and the short-circuited line is electrically insulated from the row lines and the column lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display device provided with measures against static electricity and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in the field of display devices, research and development of display devices which are small, light and have low power consumption in place of CRTs have been advanced. In particular, the development of the most common liquid crystal display device for flat panel displays is progressing rapidly. Among such liquid crystal display elements, the active matrix type liquid crystal display device has features that it can easily realize high-definition and full-color moving image display in addition to small size, light weight and low power consumption.

An active matrix type liquid crystal display device is
Display pixels are arranged at intersections of signal lines (row lines, column lines) for supplying drive signals, switching elements are provided for each pixel, and the driving of the switching elements is individually controlled. A switching element in such an active matrix type liquid crystal display device includes a non-linear element type such as a diode and a thin film transistor (thin f).
ilm transistor (hereinafter simply referred to as TFT) type. In particular, research and development of TFT-type liquid crystal display devices are progressing, and some of them have already been put to practical use, and the price has been rapidly reduced. For this reason, it is essential to improve the yield in the manufacturing process.

Next, the structure of an array substrate in which a plurality of TFTs are arranged in an array, which is a main part of a conventionally used active matrix display device, will be described. FIG. 6 is a plan view showing a schematic configuration of such an array substrate (hereinafter, may be simply referred to as a substrate).
The storage capacitor portion is shown in an equivalent circuit. FIG.
FIG. 7 is an enlarged explanatory view of a region including the end portions of the row lines G1 to G5, the cutting line B2, and the short-circuit line S / R in FIG. In FIG. 7, R is an electrostatic induction wire. G1, G
2,..., G5 are row lines (that is, gate wirings), and the subscripts 1 to 5 attached to the right side of G are for clarifying the positions of the respective row lines. .., 5 from top to bottom. S
1, S2,..., S5 are column lines (that is, source lines)
The subscripts 1 to 5 attached to the right side of S are for clarifying the position of each column line, and FIG.
, Are sequentially assigned from left to right. Tr11, Tr at the intersection of these row lines and column lines
12, Tr21 is a TFT, the left side of the subscript attached to Tr indicates the subscript of the row line to which each TFT is connected, and the right side indicates the subscript of the column line to which each TFT is connected. ing.

In FIG. 6, for simplicity of explanation,
Although five row lines and five column lines are shown and three TFTs are drawn, the row lines and the column lines are actually
VGA × 640 × 48
0 × 3 lines and 1024 × 768 × 3 lines are provided in XGA, and TFTs are provided by the number of intersections. As shown in FIG. 6, a signal is sent from a driving circuit to the formed row lines and column lines to drive TFTs, whereby a desired pixel portion is displayed.

[0006] The TFT elements used in the active matrix type liquid crystal display device described above are generally susceptible to static electricity, and the static electricity causes the TFT elements to not operate normally, that is, so-called electrostatic breakdown often occurs. In order to prevent the electrostatic breakdown, as shown in FIG. 6, a short ring S / R is provided on the outer periphery of the substrate so as to surround the outside of the region where the row lines and the column lines are formed. Neutralizing or reducing static electricity. Row and column lines and short-circuit line S
The arrangement with / R is shown in detail in FIG. That is, an electrostatic induction line R protruding in a comb-like shape from the short-circuit line S / R is provided so as to enter between the lines G1, G2,..., G5, and the electrostatic induction line R is connected to the line (G1, G2,
.., G5), and ends at a fixed interval from the row line. Column lines (S1, S2, ...)
.., S5) and the positional relationship between the static induction lines R are the same as the positional relationship between the row lines and the static induction lines. Here, the role of the electrostatic induction wire is as follows. That is, when the short-circuit line S / R is cut off from the array substrate, it is impossible to arrange the row line and the short-circuit line at a short distance.

After wiring necessary for a liquid crystal display device is provided on an array substrate, a counter substrate having a counter electrode is provided so as to face the array substrate, and a liquid crystal is sandwiched between the array substrate and the counter substrate. Enclose the material and assemble the panel.

After the panel assembly is completed, the panel is cut along cutting lines B1, B2, B3 and B4 indicated by alternate long and short dash lines in FIG. Make a connection with Here, after the panel is cut by the cutting line, the short-circuit line S / R is cut off, so that no short-circuit line exists inside the panel.

As described above, during the array substrate manufacturing process and the panel assembling process, the electrostatic breakdown due to the outside of the panel can be reduced. However, as shown in FIG. After the substrate is cut, the substrate outside the short-circuit line S / R is removed. Therefore, the prevention of electrostatic breakdown by the short-circuit line S / R performed until the step of cutting the panel is performed after the step of cutting the panel. It is very weak against static electricity from inside the panel and from outside the panel. This causes a reduction in yield after the panel assembly process.

[0010]

As described above, in the conventional active matrix type liquid crystal display device, the countermeasure for preventing electrostatic breakdown is completely against static electricity after disconnecting a short-circuit line for preventing electrostatic breakdown. It was not enough.

An object of the present invention is to provide an active matrix type liquid crystal display device which solves such a problem and takes sufficient measures for preventing electrostatic breakdown, and a method of manufacturing the same.

[0012]

In order to solve the above-mentioned problems, a short-circuit line for preventing electrostatic breakdown provided outside the array substrate of the active matrix type liquid crystal display device is kept on the surface of the array substrate even after the panel assembly is completed. To be kept inside. At this time, in order to guide static electricity from the outside of the array substrate to the short-circuit line S / R and prevent the static electricity from entering the panel surface, the row line and the short-circuit line are electrically insulated, and similarly, the column line is short-circuited with the column line. The wires are electrically insulated and located at close distances.
Further, since the row line and the short-circuit line are not connected, and similarly, the column line and the short-circuit line are not connected, there is no influence on the operation of the TFT element.

The liquid crystal display device according to the present invention comprises: (a) a transparent substrate, a plurality of row lines formed on the transparent substrate, a plurality of column lines formed to intersect the row lines, An array substrate comprising thin film transistors formed at intersections of lines and the column lines, (b) an opposing substrate having opposing electrodes and arranged in parallel with the array substrate, and (c) a liquid crystal layer. An active matrix type liquid crystal display device, wherein a short-circuit line is formed on the array substrate outside the region where row lines and column lines are formed so as to go around the region, and the short-circuit line is It is characterized by being electrically insulated from the row lines and the column lines.

Since the short-circuit line is formed of the same material as the conductive thin film forming the row line, the short-circuit line can be formed simultaneously with the row line, and the manufacturing cost can be reduced. preferable.

Since the short-circuit line is formed of the same material as the conductive thin film constituting the column line, the short-circuit line can be formed simultaneously with the column line, and the manufacturing cost can be reduced. preferable.

The width of the short-circuit line is 1.5 times the width of the row line.
It is preferable that the value be up to twice because the wiring resistance of the short-circuit line can be reduced.

It is preferable that the width of the short-circuit line is 50 to 100 μm, because the wiring resistance of the short-circuit line can be reduced and static electricity from the outside of the array substrate can be easily released to the short-circuit line.

The short-circuit line is formed at a position on the array substrate at a distance of 10 to 50 μm from an end of the array substrate and at a distance of 50 to 100 μm from an end of the row line and an end of the column line. Is preferable because static electricity can be easily released to the short-circuit line from the outside of the array substrate.

It is preferable that the end of the row line is formed to have a tapered shape toward the outer periphery of the array substrate, because static electricity can be easily released from the row line.

It is preferable that the width of the short-circuit line is formed wider at the four corners of the transparent substrate than at other portions, because the wiring resistance of the short-circuit line can be reduced.

A transparent substrate, a plurality of row lines formed on the transparent substrate, a plurality of column lines formed so as to intersect with the row lines, and an intersection of the row lines and the column lines, respectively. An array substrate including a formed thin film transistor and a short-circuit line provided around a region where the row line and the column line are formed, a counter substrate having a counter electrode and arranged in parallel with the array substrate, and A method for manufacturing an active matrix type liquid crystal display device including a liquid crystal layer, comprising: (a) sequentially forming the row lines and column lines on the transparent substrate;
Forming the thin film transistor at the intersection of the row line and the column line; (c) providing the short-circuit line around the region;
(D) cutting the array substrate outside the short-circuit line.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a plan view of an array substrate according to a first embodiment of the active matrix type liquid crystal display device of the present invention. In FIG. 1, G1, G2, G3, G4, and G5 are C
It is a plurality of row lines (gate wiring) made of r, Ta, Al, etc., and the subscripts 1 to 5 attached to the right side of G are for clarifying the position of each row line. 1, 2,..., 5 in order from the top to the bottom of 1. S1, S2, S3, S4, S5 are Cr, Ta, Al
The subscripts 1 to 5 attached to the right side of S are for clarifying the position of each column line, and are shown in FIG. 1 from left to right. .., 5 in that order. These row lines and column lines are formed on a transparent substrate. Glass or plastic can be used as the transparent substrate. Tr1
Reference numerals 1, Tr12, Tr21, and Tr22 denote TFTs as switching elements. The left side of the subscript attached to Tr indicates the subscript of the row line, and the right side indicates the subscript of the column line. In the present invention, an array substrate refers to a transparent substrate on which row lines, column lines, thin film transistors and short-circuit lines are formed, and a panel refers to an array substrate and a transparent substrate on which a color filter having a counter electrode is formed. The liquid crystal is sealed between them, and a display is performed by an electric signal applied to the array substrate.

In FIG. 1, for the sake of simplicity of description, line lines,
Although five column lines and four TFTs are illustrated, the row lines and the column lines are actually different depending on the display capability of the TFTs. In general, a VGA is 640 × 480 × 3.
In XGA, 1024 × 768 × 3 are provided for each,
The TFTs are provided by the number of the intersections. Further, B1, B2, B3 and B4 are cutting lines, and S /
R is a short-circuit line. The plurality of row lines are arranged parallel to each other and at equal intervals. Similarly, the plurality of column lines intersect with the row lines, and the column lines are arranged parallel to each other and at equal intervals. At the intersections of these row lines and column lines, TFTs as switching elements, ie, Tr11, Tr12, Tr21,
And Tr22 are provided. Actually, the short-circuit line S / R formed in a ring shape is grounded, and the static electricity escaping from the outside of the array substrate to the short-circuit line S / R is reduced to the short-circuit line S / R.
It flows further from R to the earth.

On the array substrate, short lines S / Cr made of Cr, Ta, or Al are formed so as to go around the regions simultaneously with the formation of the row lines outside the regions where the row lines and the column lines are formed.
R is 1000-3000mm thick and 30-50μm wide
Is the same as the conventional one. The short-circuit line S / R in the present embodiment is apart from the row line and the column line by a certain distance. Therefore, the short-circuit line S / R and the row line,
The short-circuit line S / R and the column line are electrically insulated. In addition, there is no need for the array substrate to separate the short-circuit line S / R, so there is no static induction line conventionally provided. In the present embodiment, the short-circuit line is formed at the same time as the row line, and is formed of Cr, which is a material of the conductive thin film forming the row line, in order to reduce the manufacturing cost. The column lines may be formed of Cr, which is a material of the conductive thin film. After the panel is assembled, the panel is cut along the cutting lines B1 to B4.
Remains in the panel surface even after the panel is assembled.

FIG. 2 is an enlarged view of a region including the end portions of the row lines G1 to G5, the cutting line B2, and the short-circuit line shown in FIG. The short-circuit line S / R is arranged at a certain short distance from the terminal end of the row line, specifically, a distance of about 50 to 100 μm. On the other hand, the short-circuit line S / R is 10 to
They are arranged at a distance of 50 μm. The cutting of the array substrate serving as a panel is performed at the positions of cutting lines B1 to B4 indicated by dashed lines immediately outside the short-circuit line S / R. Therefore, the short-circuit line is formed at a position 10 to 50 μm away from the end of the array substrate. Since the short-circuit line S / R remains in the array substrate surface as described above, the S / R serves as a lightning rod for the ingress of static electricity from the outside after the panel is assembled. The element has much less electrostatic damage than the conventional one.

An active matrix liquid crystal display device resistant to external static electricity can be obtained by sandwiching a liquid crystal layer between a counter substrate having a counter electrode and the array substrate using the array substrate thus configured. Can be.

Embodiment 2 FIG. 3 is an enlarged explanatory view of a region including a short-circuit line S / R and an end of a row line in a liquid crystal display device according to a second embodiment of the present invention. 3, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as in FIG. 1, and H is the line width of the short-circuit line S / R, which is 30 to 50 μm. Is formed. The points that are not particularly described are configured according to the first embodiment.

The end portions of the row lines are the same as those in the conventional and the first embodiment.
In FIG. 3, the end of each row line is tapered toward the outer periphery of the array substrate as shown in FIG. 3A. Formed as follows. That is, the row line G1 was formed such that the tip of the row line G1 became thinner (pointed) toward the short-circuit line S / R. In FIG. 3A, only the row line G1 is shown, but all other row lines are formed so as to be tapered.

The tapered shape was formed so that, of the sides of the isosceles triangle, a pointed portion consisting of two sides of the same length was the end of the row line. The angle θ formed by the terminal part is 3
It is easy to form 0 to 60 °. By forming the end portion of the row line to be sharpened, static electricity generated in the surface of the array substrate is transmitted to the outside of the array substrate through the row line, that is, the short-circuit line S / R.
It became easier to escape to.

As described above, by making the shape of the end of the row line taper toward the outer periphery of the array substrate, the rate of occurrence of TFT breakdown due to static electricity generated in the panel surface can be reduced. .

In the second embodiment, for ease of formation, of the isosceles triangular sides, a convex portion having two sides of the same length is used as the tapered shape.
It is also possible to use the shape of a right triangle as shown in FIG.

Third Embodiment FIG. 4 is an enlarged view of a region including a short-circuit line S / R and an end of a row line according to a third embodiment of the liquid crystal display device of the present invention. 4, the same portions as those shown in FIG. 1 are denoted by the same reference numerals as those in FIG. The points that are not particularly described are configured according to the first embodiment.

The line width H of the short-circuit line S / R is the same as that of the conventional and the first.
Alternatively, in the second embodiment, as shown in FIG. 2, the line width of the row line is 30 to 50 μm, which is almost the same as the line width, but in the third embodiment, the width H of the short-circuit line S / R is
Is formed at 50 to 100 μm, which is 1.5 to 2 times the line width of the row line, and reduces the wiring resistance of the short-circuit line S / R so that external static electricity can be easily picked up by the short-circuit line S / R.

As described above, by increasing the line width of the short-circuit line S / R, static electricity from the outside of the array substrate can easily escape to the short-circuit line S / R. Defects due to electrostatic breakdown of the transistor could be reduced as compared with the related art. In this case, the end of the line
As shown in the second embodiment, the pointed shape makes it possible to reduce the rate of occurrence of electrostatic breakdown due to static electricity generated in the plane of the array substrate, so that the measures for preventing electrostatic breakdown can be taken reliably.

Fourth Embodiment FIG. 5 is a pattern diagram of a short-circuit line S / R according to a fourth embodiment of the present invention. In FIG. 5, the same portions as those shown in FIG. 1 are denoted by the same reference numerals as those in FIG. Further, in FIG. 5, the row lines are shown up to G6.

In the fourth embodiment, as shown in FIG. 5, the line width of the short-circuit line S / R up to the outer line L in the region where the row line and the column line are formed is the same as that of the first embodiment. Is 30 to 50 μm or 50 to 100 μm as in the third embodiment. Further, the short-circuit line S / R at a portion not approaching the row line (four corners, which are four corners of the region surrounded by cutting lines B1, B2, B3, and B4 in FIG. 5) is, for example, stepped. And the width of the short-circuit line at the four corners is formed significantly wider than the other portions.
By partially increasing the line width of the short-circuit line S / R in this manner, the wiring resistance of the entire short-circuit line S / R becomes smaller than that of the row line or the column line. Therefore, static electricity from the outside of the array substrate is easily released to the short-circuit line S / R,
No static electricity flows through the transistor. Therefore, transistor defects due to electrostatic breakdown can be further reduced.

Further, in order to reduce the wiring resistance, instead of using Cr as the short-circuit line S / R, a wiring material having a lower resistance than Cr, such as Al or Ta, may be applied.

The most preferred embodiment according to the present invention will be described. In the present invention, the most preferred embodiment from the viewpoint of improving the yield is that, based on the fourth embodiment, Al is used as the wiring material instead of Cr, and the line width 30 to 50 μm of the short-circuit line S / R is changed to 50 to 100 μm. It was done.

That is, 640 × 480 × 3 VGA and XG
In A, 1024 × 768 × 3 column lines are arranged, 10 to 50 μm from the end of the array substrate, and 50 to 50 μm from the end of the row line.
A short-circuit line having a line width of 50 to 100 μm was formed at a position of 100 μm using Al. The end of the row line has a pointed shape, and the line width of the row line is 50 at the four corners of the array substrate.
0 to 1000 μm. With this configuration, in the most preferred embodiment, electrostatic breakdown of the TFT could be prevented.

[0041]

According to the active matrix type liquid crystal display device of the present invention, the distance between the row line and the short-circuit line, the distance between the column line and the short-circuit line, the arrangement thereof and the shape of the short-circuit line are adjusted. It is possible to prevent the TFT element from being damaged by external static electricity after the array substrate manufacturing process, the panel assembling process, and the panel assembling process without hindering the operation of the TFT device.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view showing an array substrate according to a first embodiment of an active matrix liquid crystal display device of the present invention.

FIG. 2 is an enlarged explanatory view of a region including a short-circuit line, an end portion of a row line, and a cutting line in the array substrate of FIG. 1;

FIG. 3 shows a short-circuit line, a terminal end of a row line, and a terminal according to a second embodiment of the active matrix type liquid crystal display device of the present invention;
It is an enlarged explanatory view showing a region including a cutting line.

FIG. 4 shows a short-circuit line, a terminal end of a row line, and a terminal according to a third embodiment of the active matrix liquid crystal display device of the present invention;
It is an enlarged explanatory view showing a region including a cutting line.

FIG. 5 is an explanatory diagram showing a wiring pattern of a short-circuit line according to a third embodiment of the active matrix type liquid crystal display device of the present invention.

FIG. 6 is an explanatory plan view of an array substrate in an example of a conventional active matrix liquid crystal display device.

FIG. 7 is an enlarged explanatory view of a region including a short-circuit line, an end portion of a row line, and a cutting line in the array substrate of FIG. 6;

[Explanation of symbols]

 S / R short-circuit line B1, B2, B3, B4 Cutting line G1, G2, G3, G4, G5, G6 Row line S1, S2, S3, S4, S5 Column line Tr11, Tr12, Tr21, Tr22 TFT element

Claims (9)

[Claims] (A) a transparent substrate, a plurality of row lines formed on the transparent substrate, a plurality of column lines formed to intersect the row lines, and the row lines and the column lines. An array substrate comprising thin film transistors formed at the intersections of
(B) an active matrix type liquid crystal display device including a counter electrode having a counter electrode and arranged in parallel with the array substrate; and (c) an active matrix liquid crystal display device including a liquid crystal layer. An active matrix, wherein a short-circuit line is formed outside the region where the column line is formed so as to go around the region, and the short-circuit line is electrically insulated from the row line and the column line. Liquid crystal display device. 2. The active matrix type liquid crystal display device according to claim 1, wherein the short-circuit line is formed of the same material as a conductive thin film forming the row line. 3. The active matrix type liquid crystal display device according to claim 1, wherein the short-circuit line is formed of the same material as the conductive thin film forming the column line. 4. The width of the short-circuit line is equal to 1.1 of the width of the row line.
2. The active matrix type liquid crystal display device according to claim 1, wherein the ratio is 5 to 2 times. 5. The active matrix type liquid crystal display device according to claim 1, wherein the width of the short-circuit line is 50 to 100 μm. 6. The short-circuit line is formed at a position on the array substrate at a distance of 10 to 50 μm from an end of the array substrate and at a distance of 50 to 100 μm from an end of the row line and an end of the column line. The active matrix type liquid crystal display device according to claim 1, wherein 7. The active matrix type liquid crystal display device according to claim 1, wherein the end portion of said row line is formed to have a tapered shape toward an outer periphery of said array substrate. 8. The active matrix type liquid crystal display device according to claim 1, wherein the width of the short-circuit line is formed wider at four corners of the transparent substrate than at other portions. 9. A transparent substrate, a plurality of row lines formed on the transparent substrate, a plurality of column lines formed so as to intersect the row lines, and an intersection between the row lines and the column lines. An array substrate, comprising a thin film transistor formed in each of the above, and a short-circuit line provided around a region where the row line and the column line are formed, and a counter substrate having a counter electrode and arranged in parallel with the array substrate. And a method of manufacturing an active matrix type liquid crystal display device including a liquid crystal layer, wherein (a) the row lines and the column lines are sequentially formed on the transparent substrate,
(B) forming the thin film transistor at the intersection of the row line and the column line; (c) providing the short-circuit line around the region; and (d) cutting the array substrate outside the short-circuit line. Characteristic manufacturing method of active matrix type liquid crystal display device.