JPH07318965A - Display device - Google Patents

Abstract

PURPOSE:To absorb the electrostatic damage of a display device in a manufacturing process. CONSTITUTION:The display device is provided with a panel structure provided with a drive substrate 1, a counter substrate and an electrooptical substance layer held between both substrates. A pixel array part 2 and a drive circuit part are accumulated and formed on the drive substrate 1. The drive circuit part is separated into a vertical drive circuit 3 and a horizontal drive circuit 4. A conductive guard ring belt 5 is formed so as to surround the pixel array part 2 and the drive circuit part. Terminal parts 6 for connecting with the outside are arranged on the outside of the guard ring belt 5. Wiring 7 are formed for connecting the outside terminal parts 6 to the inside drive circuit part while traversing the guard ring belt 5. The guard ring belt 5 is provided with small area parts 9 and large area parts 10 electrically separated each other by slits 8. The small area parts 9 attain a role as buffer areas for electrostatic charge by interposing between the large area parts 10 and the wiring 7.

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 display device. More specifically, the present invention relates to a structure of a guard ring band that surrounds a pixel array section and a driving circuit section that are integrated and formed on a substrate.

[0002]

2. Description of the Related Art A general structure of a conventional display device will be briefly described with reference to FIG. As shown, the display device has a panel structure including a driving substrate 101, a counter substrate 102, and an electro-optical material layer 103 held between the driving substrate 101 and the counter substrate 102.
A liquid crystal material or the like is widely used as the electro-optical material layer 103. A pixel array section 104 and a drive circuit section are integrally formed on the drive substrate 101. The drive circuit section is divided into a vertical drive circuit 105 and a horizontal drive circuit 106.
A terminal portion 107 for external connection is formed on the upper end of the peripheral portion of the drive substrate 101. The terminal portion 107 is the wiring 108
It is connected to the vertical drive circuit 105 and the horizontal drive circuit 106 via.

[0003]

FIG. 5 is a plan view of a drive substrate. In general, a conductive guard ring band 109 is formed along the peripheral portion on the surface of the driving substrate and surrounds the inner pixel array portion and the driving circuit portion (not shown). In order to connect the terminal portions 107a, 107b, 107c arranged outside the guard ring band 109 and the inner drive circuit portion to each other, the wirings 108a, 108b, 108c are formed so as to cross the guard ring band 109. The guard ring band 109 is formed in the shape of a window frame, and is provided along the seal region that bonds the pair of drive substrates and the counter substrate to each other. The guard ring band 109 is made of a metal film such as aluminum and shields external incident light so as to frame the pixel array portion. Also, the wiring 10
8a, 108b, and 108c are arranged so as to fill the steps, and the drive substrate surface is flattened along the seal region.

The guard ring band 109 is formed in an electrically floating state on the surface of the drive substrate having an insulating property, and is easily charged with static electricity. The guard ring band 109 has a relatively large area and accumulates a large amount of static electricity during the manufacturing process. For this reason, there is a problem in that discharge occurs between the adjacent wirings 108a and 108c during the manufacturing process, and electrostatic damage is likely to occur in the surroundings. For example, the discharge between the guard ring band 109 and the wirings 108a and 108c causes short-circuit breakdown of the input protection circuit connected to each wiring. Electrostatic damage is likely to occur on the wirings 108a and 108c adjacent to the guard ring band 109 having a large area, and the wiring 108b is not so affected.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to prevent electrostatic damage around the external connection terminals due to the charging of the guard ring band. The following measures have been taken in order to achieve this object. That is, the display device according to the present invention is based on a panel structure including a drive substrate, a counter substrate, and an electro-optical material layer held between the drive substrate and the counter substrate. A pixel array unit and a drive circuit unit are formed integrally on the drive substrate. Further, a conductive guard ring band that surrounds both of them and a terminal portion for external connection arranged outside thereof are also formed. Further, wiring is formed across the guard ring band to connect the outer terminal portion to the inner drive circuit portion. As a feature of the present invention, the guard ring band has a small area portion and a large area portion electrically separated from each other by a slit. The small area portion is interposed between the large area portion and the wiring, and serves as a buffer area for electrostatic charge. Preferably, the large area portion is electrically subdivided by an additional slit to disperse the charge. In an embodiment embodying the present invention,
For example, the electro-optical material layer is made of liquid crystal, and the surface of the driving substrate is subjected to a rubbing treatment to control the alignment of the liquid crystal. In such a configuration, the small area portion plays a role as a buffer area that protects the wiring against at least static electricity charged in the large area portion by the rubbing process.

[0006]

According to the present invention, the guard ring band is electrically separated into the small area portion and the large area portion by the slit. This slit is located in the vicinity of the wiring that connects the outside external connection terminal portion and the inside drive circuit portion to each other, so that the small area portion is interposed between the large area portion and the wiring. Become. The static electricity charged in the large area of the guard ring band during the manufacturing process is discharged to the adjacent small area, but the probability of jumping over this and discharging to the wiring is extremely low. Therefore, the possibility that the wiring is electrostatically damaged is significantly reduced. On the other hand, the small area portion is electrostatically damaged by the discharge, but since it is originally in a floating state, it does not adversely affect the operation itself of the display device. That is, the small area portion functions as a buffer area for protecting the wiring around the external connection terminal portion against static electricity charged in the large area portion of the guard ring band.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic plan view showing an embodiment of a display device according to the present invention. Generally, a display device has a panel structure including a driving substrate, a counter substrate, and an electro-optical material layer held between the driving substrate and the counter substrate. In order to facilitate understanding of the present invention, FIG. 1 particularly shows only the plane pattern of the drive substrate 1. A pixel array section 2 and a drive circuit section are integrally formed on the drive substrate 1. The drive circuit section includes a vertical drive circuit 3 and a horizontal drive circuit 4. Further, a conductive guard ring band 5 is patterned along the periphery of the drive substrate 1. The guard ring band 5 has a window frame shape and is patterned so as to surround the pixel array section 2 and the drive circuit sections (3, 4). The guard ring band 5 is made of a metal film such as aluminum or aluminum alloy,
The periphery of the pixel array section 2 is shielded from light. Further, it is in a floating state on the drive substrate 1 which is electrically insulating. A plurality of terminal portions 6 for external connection are formed on the outer upper portion of the guard ring band 5. In addition, a wiring 7 is formed across the guard ring band 5 to connect the outer terminal portion 6 to the inner drive circuit portion (3, 4). In the figure, five terminal portions 6 and five corresponding wires 7 are schematically shown.
Are shown, but in reality, 10 or more terminal portions 6
Is provided so that a predetermined power supply voltage, a clock signal, a video signal, etc. can be supplied to the vertical drive circuit 3 and the horizontal drive circuit 4.

As shown in the drawing, each wiring 7 is provided so as to cross the guard ring band 5, and the guard ring band 5 is divided along the path of each wiring 7. In this portion, the divided guard ring band 5 fills the step of the wiring 7 and flattens the surface of the drive substrate 1.

As a feature of the present invention, the guard ring band 5 has a small area portion 9 and a large area portion 10 electrically separated from each other by a slit 8. The small area portion 9 is interposed between the large area portion 10 and the wiring 7, and serves as a buffer area for electrostatic charging. That is, in the manufacturing process, the static electricity charged on the large area portion 10 of the guard ring band 5 is easily discharged toward the adjacent small area portion 9,
The probability of jumping over this and discharging to the wiring 7 becomes extremely low. Therefore, it is possible to remarkably prevent electrostatic damage around the terminal portion 6. For example, it is possible to effectively prevent a short circuit failure or the like of the input protection circuit provided corresponding to the terminal portion 6. On the other hand, electrostatic discharge is applied to the small area portion 9 by the discharge from the large area portion 10. However, the small area portion 9 is originally in a floating state and does not adversely affect the operation of the drive substrate 1. As can be easily understood from the figure, the two wirings 7 at both ends closest to the guard ring band 5 among the plurality of wirings 7 are provided.
The book is susceptible to electrostatic damage, and the three wirings 7 located in the center far from the guard ring zone 5 are originally less likely to be electrostatically damaged. Therefore, in this example, two small area portions 9 are provided on the left end side and the right end side as buffer regions for the two wirings 7 located on both sides. That is, in the present invention, it is essential to provide at least two small area portions 9.

For reference, the structure of the pixel array section 2 will be described. As shown in the figure, in the pixel array section 2, row-shaped gate lines 11 and column-shaped data lines 12 are arranged so as to intersect with each other. Each gate line 11 and data line 1
A thin film transistor 13 is formed at the intersection with the line 2.
The pixel electrode 14 is also formed. The gate electrode of each thin film transistor 13 is connected to the corresponding gate line 11, the source electrode is connected to the corresponding data line 12, and the drain electrode is connected to the corresponding pixel electrode 14. The row-shaped gate lines 11 are connected to the vertical driving circuit 3, while the column-shaped data lines 12 are connected to the horizontal driving circuit 4. The vertical drive circuit 3 has a terminal portion 6 for external connection.
The gate line 11 is line-sequentially scanned by operating in accordance with a clock signal supplied from. As a result, the thin film transistors 13 are turned on for each row. On the other hand, the horizontal drive circuit 4 operates in response to a clock signal supplied from the external connection terminal section 6, and samples the video signal also supplied from the external connection terminal section 6 to each data line 12. The sampled video signal is written in the pixel electrode 14 via the thin film transistor 13 in the conductive state, and desired image display is performed.

FIG. 2 is a schematic plan view showing another embodiment of the display device according to the present invention. The basic configuration is shown in Figure 1.
Similar to the embodiment shown in FIG. 6, corresponding parts are designated by corresponding reference numerals to facilitate understanding. The different point is that the large area portion 10 of the guard ring band 5 is electrically subdivided by the additional slits 15 to disperse the charging. In this example, the large U-shaped large area portion 10 is divided into five by four additional slits 15. As a result, the absolute amount of electrostatic charge accumulated in each of the large-sized subdivided large-area portions 10 becomes small, so that electrostatic damage can be reduced.

FIG. 3 shows a sectional structure of a display device according to the present invention. As shown, the display device has a panel structure including a lower drive substrate 1, an upper counter substrate 21, and an electro-optical material layer 22 held between the two. As the electro-optical material layer 22, twisted nematic liquid crystal or the like is widely used. The drive substrate 1 and the counter substrate 21 are bonded to each other by a sealing material 23. As described above, on the inner surface of the drive substrate 1, the pixel array section, the drive circuit section, and the guard ring band 5 surrounding the both are formed. In the drawing, only one pixel electrode 14 corresponding to one thin film transistor 13 included in the pixel array portion is shown. On the other hand, a counter electrode 24 is formed on the inner surface of the counter substrate 21.

The thin film transistor 13 has a semiconductor thin film 25, which is patterned in a predetermined shape, as an element region, and a gate electrode G is patterned on the semiconductor thin film 25 via a gate insulating film 26. The gate electrode G comprises a part of the gate line 11 shown in FIG. The thin film transistor 13 having such a configuration is covered with the interlayer insulating film 27. The pixel electrode 14 is patterned on the interlayer insulating film 27 and communicates with the drain region of the thin film transistor 13. The data line 12 is also formed and communicates with the source region of the thin film transistor 13.

A guard ring band 5 is formed in a window frame pattern so as to surround the inner pixel array portion along the periphery of the drive substrate 1. The guard ring band 5 is made of a metal film such as aluminum or aluminum alloy and is formed on the interlayer insulating film 27. It is electrically floating and easily charged with static electricity. For example, when a liquid crystal material is used for the electro-optical material layer 22, the inner surface of the drive substrate 1 is subjected to a rubbing process for controlling the alignment of the liquid crystal. In this rubbing process, a cotton cloth or the like is used to rub the substrate surface in a certain direction, and a large amount of static electricity is generated and accumulated in the guard ring band 5. In view of this point, in the present invention, the guard ring band 5 is used.
Is divided into a small area portion and a large area portion as described above. The small area portion is interposed between the wiring connected to the external connection terminal and the large area portion. A large amount of static electricity charged in the large area portion by the rubbing process is discharged to the small area portion to prevent electrostatic damage to the wiring. The cause of static electricity charging during the manufacturing process is not limited to the rubbing treatment, and the small area portion provided in the guard ring zone constitutes an effective buffer area for all kinds of electrification.

[0015]

As described above, according to the present invention, the guard ring band has the small area portion and the large area portion electrically separated from each other by the slit, and the small area portion is the large area portion. It acts as a buffer region for static electricity due to being interposed between the wiring and the connection wiring. As a result, it is possible to effectively protect the periphery of the connection wiring against static electricity charged in the guard ring band during the manufacturing process, and it is possible to achieve a significant improvement in manufacturing yield.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an embodiment of a display device according to the present invention.

FIG. 2 is a schematic plan view showing another embodiment of the display device according to the present invention.

FIG. 3 is a schematic sectional view showing a panel structure of a display device according to the present invention.

FIG. 4 is a schematic perspective view showing a configuration of a general display device.

FIG. 5 is a schematic plan view showing a pattern configuration example of a conventional display device.

[Explanation of symbols]

 1 Drive Substrate 2 Pixel Array Part 3 Vertical Drive Circuit 4 Horizontal Drive Circuit 5 Guard Ring Band 6 Terminal Part 7 Wiring 8 Slit 9 Small Area Part 10 Large Area Part 11 Gate Line 12 Data Line 13 Thin Film Transistor 14 Pixel Electrode 15 Additional Slit 21 Facing Substrate 22 Electro-optical material layer 23 Sealing material 24 Counter electrode

Claims (3)

[Claims] 1. A panel structure comprising a driving substrate, a counter substrate, and an electro-optical material layer held between the driving substrate and the counter substrate, wherein the driving substrate surrounds a pixel array portion, a driving circuit portion, and both. A display device in which a conductive guard ring band, a terminal portion for external connection arranged outside the guard ring band, and a wiring that crosses the guard ring band and connects the outer terminal portion to the inner drive circuit portion are formed. The guard ring band has a small area portion and a large area portion electrically separated from each other by a slit, and the small area portion is interposed between the large area portion and the wiring. A display device that is a buffer area against static electricity. 2. The display device according to claim 1, wherein the large area portion is electrically subdivided by an additional slit to disperse the charge. 3. The electro-optical material layer is made of liquid crystal, the surface of the drive substrate is subjected to a rubbing treatment to control the alignment of the liquid crystal, and the small area portion is at least electrostatically charged to the large area portion by the rubbing treatment. The display device according to claim 1, wherein the display device is a buffer region for protecting the wiring.