JPH1068962A - LCD panel - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To manufacture a liquid crystal display panel by a simplified manufacturing process, and to enable a countermeasure against static electricity in an assembling process using the completed liquid crystal display panel. SOLUTION: Short-circuit bus lines 51 and 52 are superposed on an end of a scanning wiring 1 and an end of a signal wiring 2 via an insulating film to form MIM elements 61a, 62a, 61b and 62b. When a voltage due to static electricity is input, the MIM element 6
The insulating film portions 1a, 62a, 61b, and 62b are broken down, and charges due to static electricity are transferred to the short-circuit bus lines 51 or 5.
Spread to 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television set, a personal computer, a word processor or OA (Office Automation).
The present invention relates to a liquid crystal display panel used for equipment and the like.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing an equivalent circuit of a conventional liquid crystal display panel. In this liquid crystal display panel, an active matrix substrate in which a plurality of pixel electrodes 26 are provided in a matrix and a counter substrate in which a counter electrode 27 is provided over substantially the entire surface of the substrate are arranged to face each other with a liquid crystal layer interposed therebetween.
A liquid crystal cell 24 functioning as a capacitor is configured. A thin film transistor (hereinafter referred to as TFT) connected to each pixel electrode 26 on the active matrix substrate
23, and a gate bus line 21 and a source bus line 22 are provided so as to intersect with each other passing around the periphery of each pixel electrode 26. Each TFT 23 is connected to a gate bus line 21 and a source bus line 22. Each gate bus line 21 is provided with a gate electrode terminal 28, and on / off of the TFT 23 is controlled by a gate signal applied from the gate electrode terminal 28 to the gate bus line 21. In addition, each source bus line 22
Is provided with a source electrode terminal 29. When each TFT 23 is turned on, a source signal input from the source electrode terminal 29 via the source bus line 22 is supplied to the pixel electrode 2.
6.

[0003] Short-circuit bus lines 25 are all connected to the ends of the gate bus lines 21 and the ends of the source bus lines 22. The short-circuit bus line 25 is provided to prevent the TFT 23 from being destroyed by static electricity generated in a manufacturing process of the liquid crystal display panel. A non-linear element 10a is provided between the short-circuit bus line 25 and the gate bus line 21.
Short-circuit bus line 2 wired so that a becomes the reference potential
5, the voltage between the gate bus line 21 and the source bus line 22 can be controlled when a charge due to static electricity is generated in the gate bus line 21. The nonlinear element 10b is provided between the short-circuit bus line 25 and the source bus line 22, and the nonlinear element 10b is connected to the short-circuit bus line 25 as a nonlinear resistor. Occurs, the voltage between the gate bus line 21 and the source bus line 22 can be controlled. Conventionally, three-terminal elements such as TFTs are used as the nonlinear elements 10a and 10b.

The reason for providing the non-linear elements 10a and 10b in the above-mentioned conventional liquid crystal display panel is as follows. That is, in the manufacture of a normal liquid crystal display panel, when the liquid crystal display panel is completed, the short-circuit bus line is generally removed by dropping an end of the active matrix substrate. However, if the short-circuit bus line is removed, the voltage between the gate bus line 21 and the source bus line 22 is controlled even if static electricity is generated in an assembly process of a display device or the like performed using the completed liquid crystal display panel. Can not do it. Therefore, the insulating film between the gate bus line 21 and the source bus line 22 and the TFT 2
The gate insulating film 3 and the like are electrostatically destroyed, and the TFT array is destroyed. On the other hand, in the conventional liquid crystal display panel shown in FIG. 3, since the non-linear elements 10a and 10b are provided, the short-circuit bus line 2 is connected to the completed liquid crystal display panel.
5 can be left, and a countermeasure against static electricity can be taken in a subsequent assembly process using the completed liquid crystal display panel.

[0005]

In the conventional liquid crystal display panel shown in FIG. 3, the short-circuit bus line 25 is left, and the short-circuit bus line 25 is connected to the non-linear element 1.
Since the gate bus line 21 is connected via Oa and the source bus line 22 is connected via the non-linear element 10b, it is possible to take measures against static electricity in a subsequent assembly process performed using the completed liquid crystal display panel. Become. However, as the nonlinear elements 10a and 10b,
Conventionally, a three-terminal element such as a TFT is used. If the three-terminal element is used as a two-terminal element such as a diode, the gate and the source are connected or the gate and the drain are connected. Therefore, it is necessary to provide through holes, and there is a problem that the manufacturing process is complicated.

The present invention has been made to solve such problems of the prior art, and it is possible to take measures against static electricity in a subsequent assembling process performed using a completed liquid crystal display panel. It is an object to provide a liquid crystal display panel that does not become complicated.

[0007]

According to the liquid crystal display panel of the present invention, a plurality of pixel electrodes and a switching device connected to the pixel electrodes are provided on one of a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween. The elements are provided in a matrix, and a scanning wiring and a signal wiring are provided so as to cross each other through the vicinity of the periphery of the pixel electrode, and are provided on at least one wiring end of the scanning wiring and the signal wiring. One or two or more short-circuit bus lines are formed so as to overlap with each other via an insulating film, and the MIM element constituted by the overlapping portion of the wiring end and the insulating film and the short-circuit bus line has a voltage higher than a reference value. Is input, the insulating film portion is broken down and the electric charge is diffused to the short-circuit bus line, thereby achieving the above object.

[0008] The short-circuit bus line may
It may be cut on both sides of the IM element portion.

The insulating film is an anodic oxide film or SiN _x
It may consist of a membrane.

The operation of the present invention will be described below.

In the present invention, an MIM formed at an overlapping portion of an end portion of a scanning wiring, an insulating film and a part of a short-circuit bus line is provided.
(Metal layer-insulating film-metal layer) The element and the MIM element formed at the overlapping portion of the end of the signal wiring, the insulating film, and a part of the short-circuit bus line function as a fuse element, and have a voltage lower than a reference value. Is input, the insulating film portion is not broken down, but if a voltage higher than the reference value is input, the insulating film portion is broken down.

For example, when a voltage of about 30 V or less, which is a normal driving voltage of a liquid crystal display panel, is input to the MIM element, the insulating film portion of the MIM element is not broken down, and the driving signal is affected. Absent.

On the other hand, when a high voltage of about 100 V or more generated by static electricity is input to the MIM element,
The insulation of the insulating film portion of the MIM element is broken, and the charge due to static electricity is diffused to the short-circuit bus line.

As described above, since the MIM element having the above structure functions as a fuse element, even when the liquid crystal display panel is completed, the short-circuit bus line can be left, and the manufacturing process of the liquid crystal display panel and the completed liquid crystal display panel This makes it possible to take countermeasures against static electricity in the subsequent assembling process using the.
Further, since the MIM element having the above structure has a simple structure,
The manufacturing process can be simplified.

When the insulating film portion of the MIM element is broken down, the scanning wiring connected to the MIM element and the short-circuit bus line are connected, or the signal wiring and the short-circuit bus line connected to the MIM element are connected. Are connected, the pixel corresponding to the scanning wiring or signal wiring presents a linear defect. In this case, it is possible to correct the line-shaped defect by cutting the short-circuit bus line using a laser or the like on both sides of the MIM element portion where the dielectric breakdown has occurred.

It is preferable to use an anodic oxide film as the insulating film. When the MIM element is provided on the scanning wiring side, this anodic oxide film can be formed by anodizing one of the scanning wiring and the short-circuit bus line which overlap each other with the insulating film interposed therebetween. In the case where the MIM element is provided, one of the signal wiring and the short-circuit bus line which are overlapped with an insulating film interposed therebetween can be formed by anodizing.
The anodic oxide film can be a film having few pinholes and high uniformity. Moreover, since the anodic oxide film is also used to prevent short-circuit failure occurring at the intersection of the scanning wiring and the signal wiring and short-circuit failure occurring at the TFT, the anodic oxide film and the insulating film of the MIM element are used. Simultaneous formation can simplify the manufacturing process. Further, a SiN _x film may be used as the insulating film. The SiN _X film is TF
Since it is also used as a T gate insulating film and other insulating films, the manufacturing process can be simplified by forming the SiN _x film and the insulating film of the MIM element at the same time.

[0017]

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

FIG. 1 shows an equivalent circuit of a liquid crystal display panel according to an embodiment of the present invention. In this liquid crystal display panel, an active matrix substrate in which a plurality of pixel electrodes 7 are provided in a matrix and a counter substrate in which a counter electrode 8 is provided over substantially the entire surface of the substrate are opposed to each other with a liquid crystal layer interposed therebetween. The liquid crystal cell 4 functioning as a liquid crystal cell is configured. On the active matrix substrate, TFTs 3 are provided in a matrix and connected to the respective pixel electrodes 6, and pass through the vicinity of each of the pixel electrodes 7 and pass through the vicinity of the gate electrode 1 as a scanning line and the source bus line 2 as a signal line.
Are provided to cross each other. Each TFT 3 is connected to a gate bus line 1 and a source bus line 2. Each gate bus line 1 is provided with a gate electrode terminal 11, and on / off of the TFT 3 is controlled by a gate signal applied from the gate electrode terminal 11 to the gate bus line 1. Each source bus line 2 is provided with a source electrode terminal 12. When each TFT 3 is turned on, a source signal input from the source electrode terminal 12 via the source bus line 2 is supplied to the pixel electrode 7. You.

An end of the gate bus line 1 and an end of the source bus line 2 are connected to double short-circuited bus lines 51 and 52 which are provided in double. These short-circuit bus lines 51 and 52 are provided in order to prevent the TFT 3 from being destroyed by static electricity generated in the manufacturing process of the liquid crystal display panel. An MIM element 61a is provided between the short-circuit bus line 51 and the gate bus line 1, and an MIM element 62a is provided between the short-circuit bus line 52 and the gate bus line 1. An MIM element 61b is provided between the short-circuit bus line 51 and the source bus line 2, and an MIM element 62b is provided between the short-circuit bus line 52 and the source bus line 2.
The short-circuit bus lines 51 and 52 are set at a common potential or the like.

FIG. 2A is a sectional view showing MIM elements 61a and 62a, and FIG. 2B is a sectional view showing MIM elements 61b and 6a.
It is sectional drawing which shows 2b. The MIM element 61a is connected to the end of the gate bus line 1 and the shorted bus line 5 wired on the insulating substrate 16 forming the active matrix substrate.
The MIM element 62a is provided between the end of the gate bus line 1 wired on the insulating substrate 16 and the short-circuit bus line 52. This is a two-terminal element having a configuration in which the insulating film 9 is interposed. The MIM element 61b is a two-terminal element having a configuration in which the insulating film 9 is interposed between the end of the source bus line 2 wired on the insulating substrate 16 and the short-circuit bus line 51.
The M element 62 b is a two-terminal element having a configuration in which the insulating film 9 is interposed between the end of the source bus line 2 wired on the insulating substrate 16 and the short-circuit bus line 52.

The MIM elements 61a and 62a can be manufactured as follows. The gate bus line 1 is formed on the insulating substrate 16 using an anodic oxidizable material such as Ta, and the surface of the portion overlapping with the short-circuit bus lines 51 and 52 is anodized by the anodic oxidation method. As a result, the insulating film 9 made of a Ta oxide film or the like is
Is formed. Short-circuit bus lines 51 and 52 made of Ti or the like are formed thereon so as to partially overlap. As described above, a nonlinear element 61a including the gate bus line 1, the insulating film 9, and the short-circuit bus line 51, and a nonlinear element 62a including the gate bus line 1, the insulating film 9, and the short-circuit bus line 52 are formed.

The non-linear elements 61b and 62b are formed by forming an insulating film by anodizing the source bus line 2 instead of the gate bus line 1 and forming a short-circuit bus line 51 thereon.
52, the nonlinear elements 61a, 6a
1b.

Next, the operation of the liquid crystal display panel of this embodiment will be described. In this liquid crystal display panel, the MIM elements 61a, 61b, 62a, 62b function as fuse elements. That is, when a voltage of about 30 V or less, which is a normal driving voltage of the liquid crystal display panel, is applied, the MIM element 6
The insulating film portions 1a, 61b, 62a and 62b are not broken down and do not affect the drive signal. However, when a high voltage of about 100 V or more is applied by static electricity, the MIM
Since the insulating film portions of the elements 61a, 61b, 62a, 62b are broken down, charges are diffused to the short-circuit bus lines 51, 52. Thus, the MIM elements 61a, 61b, 6
Since the fuses 2a and 62b function as fuse elements, the insulating film between the gate bus line 1 and the source bus line 2 and the gate insulating film of the TFT 3 are not electrostatically damaged. Can be prevented.

For example, when a voltage of 100 V or more due to static electricity is input from the source electrode terminal 12 to the source bus line 2, the insulation film 9 constituting the MIM element 61b is broken down, and the charges due to the static electricity are short-circuited. Diffused to line 51. Since the short-circuit bus line 51 is grounded, the pixel portion corresponding to the source bus line 2 presents a linear defect. However, as shown in FIG. 1, the short-circuit bus line 51 is connected to both sides 14b, 1b of the MIM element 61b.
By cutting with a laser or the like in 5b, this linear defect can be corrected. In addition, instead of the insulating film 9 constituting the MIM element 61b, the insulating film 9 constituting the MIM element 62b may be broken down, and the charge due to static electricity may be diffused to the short-circuit bus line 52. In this case, similar line-like defects also occur, but as shown in FIG.
This line-shaped defect can be corrected by cutting using laser or the like on both sides 16b and 17b of the portion b.

When a voltage of 100 V or more due to static electricity is input from the gate electrode terminal 11 to the gate bus line 1, the insulation film 9 constituting the MIM element 61a is broken down, and the charges due to the static electricity are short-circuited. Diffused to line 51. Since the short-circuit bus line 51 is grounded, a line defect occurs in the gate bus line 1. However, as shown in FIG. 1, the short-circuit bus line 51 is formed by using a laser or the like on both sides 14b and 15b of the MIM element 61b. By cutting, this linear defect can be corrected. In addition, instead of the insulating film 9 forming the MIM element 61a, the insulating film 9 forming the MIM element 62a may be broken down, and the charge due to static electricity may be diffused to the short-circuit bus line 52. In this case as well, similar line-like defects occur, but as shown in FIG. 1, the short-circuit bus line 52 is connected to both sides 16b, 1b of the MIM element 62b.
By cutting with a laser or the like at 7b, this linear defect can be corrected.

As described above, in the liquid crystal display panel of the present embodiment, the MIM elements 61a, 61b, 62a, 6
Since 2b functions as a fuse element, it is possible to take countermeasures against static electricity in a subsequent assembling process using this liquid crystal display panel while maintaining good display characteristics during normal driving. Further, the MIM elements 61a, 61b, 62a, 6
Reference numeral 2b denotes an MIM element, which has a simple structure, so that the manufacturing process can be simplified and the cost can be reduced. Further, in the liquid crystal display panel of the present embodiment, since the short-circuit bus lines 51 and 52 are provided twice, even if the insulating film portion of the MIM element connected to one of the short-circuit bus lines is broken down, MIM connected to the other short-circuit bus line
Since the element can cope with static electricity generated later, static electricity countermeasures can be taken more reliably.

In the above-described embodiment, the short-circuited bus line 51 is formed on the end of the gate bus line 1 via the insulating film 9.
Although the MIM element is configured by superimposing 52, the MIM element may be configured by superimposing the end of the gate bus line 1 on the short-circuit bus lines 51 and 52 via an insulating film. Further, the MIM element is formed by superimposing the short-circuit bus lines 51 and 52 on the end of the source bus line 2 via the insulating film 9. However, the MIM element is formed on the short-circuit bus lines 51 and 52 via the insulating film. An MIM element in which two end portions are overlapped may be used. In this case, the insulating film 9 can be formed by anodizing the short-circuit bus lines 51 and 52. The anodic oxidation may be performed only on the portion constituting the MIM element, and the gate bus line 1, the source bus line 2, or the short-circuit bus line 51,
Anodization may be performed on the entire surface of the substrate 52. Further, as the insulating film 9 is not limited to the anodic oxide film may be an insulating film made of other materials such as SiN _X. Although Ta is used as a material for the gate bus line 1 and the source bus line 2, another material may be used, and different materials may be used for the gate bus line 1 and the source bus line 2. The material of the short-circuit bus lines 51 and 52 is T
Although i is used, other materials may be used. However, as the material of the gate bus line 1, the source bus line 2, and the short-circuit bus lines 51 and 52, it is preferable to use a combination of materials that can effectively secure the function as the MIM element.

Although the two short-circuit bus lines 51 and 52 are superimposed on each gate bus line 1 and each source bus line 2 via an insulating film, only one short bus line may be superposed. Alternatively, three or more short-circuit bus lines may be superimposed.

[0029]

As is apparent from the above description, according to the present invention, the MIM element and the end of the signal wiring formed at the overlapping portion of the end of the scanning wiring, the insulating film and a part of the short-circuit bus line. Since the MIM element formed at the overlapping portion of the portion, the insulating film, and a part of the short-circuit bus line functions as a fuse element, the TFT array can be protected. Therefore, according to the present invention, not only the manufacturing process of the liquid crystal display panel,
In the subsequent assembling process using the completed liquid crystal display panel, it is possible to take measures against static electricity. Further, since the MIM element has a simple structure, the manufacturing process can be simplified.
Therefore, a liquid crystal display panel excellent in yield and productivity can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an equivalent circuit of a liquid crystal display panel according to a first embodiment.

FIG. 2A is a cross-sectional view showing MIM elements 61a and 62a in the liquid crystal display panel according to the first embodiment, and FIG.
Is a sectional view showing MIM elements 61b and 62b.

FIG. 3 is a diagram showing an equivalent circuit of a conventional liquid crystal display panel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Gate bus line 2 Source bus line 3 TFT 4 Liquid crystal cell 7 Pixel electrode 8 Counter electrode 11 Gate electrode terminal 12 Source electrode terminal 14a, 14b, 15a, 15b, 16a, 16b, 1
7a, 17b Cutting section 51, 52 Short-circuit bus line 61a, 61b, 62a, 62b MIM element

Claims (3)

[Claims] 1. A plurality of pixel electrodes and switching elements connected to the pixel electrodes are provided in a matrix on one of a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween. Scanning lines and signal lines are provided so as to intersect each other through the vicinity of one of the lines, and one or more short-circuit bus lines are insulated on at least one of the wiring ends of the scanning lines and the signal lines. An MIM element formed by overlapping with a film, and configured by an overlapping portion of the wiring end, the insulating film, and the short-circuit bus line,
A liquid crystal display panel having a configuration in which, when a voltage equal to or higher than a reference value is input, the insulating film portion breaks down and charges are diffused to the short-circuit bus line. 2. The liquid crystal display panel according to claim 1, wherein the short-circuit bus line is cut off on both sides of a portion of the MIM element whose insulation has been broken. 3. The method according to claim 1, wherein the insulating film is an anodic oxide film or SiN.
3. The liquid crystal display panel according to claim 1, comprising an _X film.