JPH04355729A - Method for manufacturing array substrate for liquid crystal display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-performance, high-yield liquid crystal display device and a method for manufacturing the same.

0002

2. Description of the Related Art In recent years, liquid crystal display devices have been actively approached for large-capacity displays, particularly image displays, and are attracting the most attention as displays that can realize low-cost devices.

FIGS. 6, 7A, and 7B are diagrams showing the structure of a matrix type liquid crystal display device, which is an example of a conventional liquid crystal display device.

First, FIG. 6 will be explained. FIG. 6 shows a cross-sectional configuration diagram of a conventional liquid crystal display device. In FIG. 6, a switching element group 1, a pixel electrode group 2, and an alignment film 3
and an array substrate 17 consisting of a transparent insulating substrate 7a having an image display area 5 consisting of a signal wiring electrode group 4, a signal input electrode group 6 from an external drive circuit, and an auxiliary wiring group 13, a transparent common electrode 8 and a light shielding layer. A spacer 10 made of glass fiber or resin fine particles is provided on a counter substrate 18 consisting of a transparent insulating substrate 7b having an alignment film 3 and a pixel electrode 2 facing each other, and the pixel electrode 2 and the transparent common electrode 8 are pasted with a resin adhesive 11 so as to face each other. The liquid crystal composition 12 is placed in the gap formed by the spacer 10.
It is filled with

[0005] The liquid crystal display device configured as described above has the following features:
By selectively applying a voltage to these pixel electrode groups 2 via the switching element 1, arbitrary information can be displayed.

FIG. 7A shows a plan view of the array substrate 17. As shown in FIG. 7A, in the switching elements constituting the image display area 5, the source electrode side and the gate electrode side are perpendicular to each other. For this reason, the signal input electrode from the external drive circuit is divided into a source side signal input electrode 6a and a gate side signal input electrode 6b. Auxiliary signal wiring 13a,
13b is formed at a location other than the image display area 5 on the array substrate 17 so as to connect the vicinity of both ends of the signal wirings 4a and 4b.

FIG. 7(B) is an enlarged plan view showing part 7B of the signal wiring and auxiliary wiring in FIG. 7(A). In the figure, an auxiliary wiring 13a having a connection electrode 14 and a signal wiring 4a having a connection electrode 15 are electrically separated via an insulating layer 16.

Next, a conventional method for manufacturing a liquid crystal display device will be explained. FIG. 8 is a manufacturing flowchart of a conventional liquid crystal display device. Array formation process (81)
After the array board was completed (82), the signal wiring in the image display area was inspected for disconnections (
83). Here, the products are sorted into non-defective products and defective products, and defective products, that is, products with disconnection, are repaired by wire bonding (84). In other words, Figure 7 (A
), the connection electrode 15 of the signal line and the auxiliary wiring 1 where the disconnection occurred
The connection electrode 14 of 3a is electrically connected using an aluminum wire. By performing this at both ends of the signal wiring where the disconnection has occurred, the disconnection can be repaired even in a liquid crystal display device in which a signal is input from only one side. The array substrate for which the disconnection has been repaired is inspected again, and then subjected to alignment film formation (85), alignment treatment (86), bonding with the counter substrate (87 to 91).
), the liquid crystal display device is completed (93) through the step of liquid crystal injection (92). Before the bonding step, the counter substrate is completed in the counter substrate process (87 to 90).

[0009]

[Problems to be Solved by the Invention] Wire bonding has been used as a means of repairing disconnections in conventional manufacturing methods. The following two conditions are well known for devices resulting from wire bonding. One is
The material of the wire and the material of the connecting electrode must be the same. Furthermore, in order to ensure adhesiveness in bonding, the thickness of the connection electrode is required to be about 1 μm. The above two conditions are constraints on the array configuration, and there is no flexibility in array design, which ultimately hinders improvements in productivity and yield.

[0010] In addition, in the conventional manufacturing method, when electrically connecting by bonding in the process of repairing disconnections, if the characteristics of the switching element deteriorate or new disconnections occur due to the difference in potential between different conductors, so-called static electricity Destruction occurred. Furthermore, since the signal wirings in which disconnections occur are random, it is extremely difficult to automate repair by bonding as a process.

[0011] Therefore, the present invention provides relief from disconnection while
It is an object of the present invention to provide a liquid crystal display device that eliminates the above-mentioned drawbacks and has excellent display quality using a simple method, and also to obtain a method for manufacturing the liquid crystal display device.

0012

[Means for Solving the Problems] In order to achieve the above object, the liquid crystal display device of the present invention provides an area other than the image display area that is electrically connected to both ends of all signal wiring electrodes constituting the image display area. The structure has an auxiliary wiring that passes through.

Further, the liquid crystal display device of the present invention is provided with a diode between each signal wiring and the auxiliary wiring or within the auxiliary wiring in order to perform a disconnection test with the above configuration.

Furthermore, in the manufacturing method of the present invention, after the array substrate is completed, the signal wiring constituting the image display area is inspected for electrical disconnection, and then all signal wiring except where the disconnection is detected is inspected. is electrically disconnected from the auxiliary wiring using a laser beam.

[0015]

[Operation] In the liquid crystal display device configured as described above, while repairing disconnections as before, the material for the signal wiring in the array configuration is made of high-yield and highly reliable materials in the array process, and the display I was able to change the design to one with better quality. This made it possible to dramatically improve the yield and display performance of liquid crystal display devices.

Furthermore, in the manufacturing method of the present invention, it was possible to completely suppress the occurrence of defects due to static electricity, etc. in the process of repairing disconnections. Furthermore, the process could be easily automated and costs could be reduced.

[0017]

[Examples] Examples of the present invention will be described below. Figure 1
FIG. 1 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention. Thin film transistor (TFT) using amorphous silicon as a semiconductor
), a pixel electrode group 22 made of indium-tin oxide (hereinafter referred to as ITO), a polyimide alignment film 23, a two-layer structure of aluminum and chromium as a gate electrode, and a two-layer structure of aluminum and titanium as a source electrode. It has an image display area 25 consisting of a signal wiring electrode group 24, a signal input electrode group 26 from an external drive circuit having the same configuration as the signal wiring electrode 24, and an auxiliary wiring group 33 made of aluminum and titanium. A diode 3 made of amorphous silicon is provided between the electrode 24 and the auxiliary wiring group 33.
An array substrate 20 consisting of a glass substrate 27a on which 4 is formed.
a, and a counter substrate 2 consisting of a glass substrate 27b having a transparent common electrode 28 made of ITO, a black stripe layer 29 made of chromium, and a polyimide alignment film 23.
A spacer 30 made of glass fiber or resin fine particles was provided at 0b, the pixel electrode 22 and the transparent common electrode 28 were bonded together with a resin adhesive 31 so as to face each other, and the gap formed by the spacer 30 was filled with a liquid crystal composition 32. . Here, a TN type liquid crystal was used. The operation of the liquid crystal display device configured as described above is the same as the conventional one.

FIG. 2 shows a simplified equivalent circuit diagram of a liquid crystal display device according to an embodiment of the present invention. In the image display area 25, signal wirings 2, which are source electrodes orthogonal to each other,
4a and a signal wiring 24b which is a gate electrode. TFTs and pixel electrodes are omitted here. The signal input electrode 26a on the source electrode side is electrically connected to the other end of the signal line 24a via the diode 34 by the auxiliary line 33a on the source side. The signal wiring 24b on the gate electrode side is also connected via the diode 34, similarly to the source electrode side. For example, source wiring D-D' is 3
When a disconnection occurred in No. 5, only the auxiliary wiring 36 was left and the other auxiliary wirings were cut with a laser beam, thereby obtaining a liquid crystal display device with no display defects.

FIG. 3 is an equivalent circuit diagram of another embodiment of the present invention. The image display area 25 has a configuration similar to that of the embodiment described above. The same applies to the method for repairing disconnection. Here, a configuration is adopted in which a plurality of wiring electrodes are connected together to one auxiliary wiring 33a'. Although this configuration cannot repair all signal wiring disconnections, it is possible to reduce the size of the array substrate because the area occupied by the auxiliary wiring is reduced.

FIG. 4(A) is a plan view of an array substrate according to still another embodiment of the present invention, and FIG. 4(B) is an enlarged plan view of the periphery 4B of the diode in FIG. 4(A). In this embodiment, for the signal wiring 24c in which no disconnection was detected, the portion 3 between the diode 34 and the auxiliary wiring 33a'
7 was cut by laser beam and electrically disconnected.

Next, a method for manufacturing a liquid crystal display device according to the present invention will be explained. FIG. 5 is a flowchart of an embodiment of the manufacturing method of the present invention. Laser cutting was used to repair the disconnection. The disconnection inspection will be explained in detail using FIG. 2. In this embodiment, for example, disconnection inspection of source signal wiring (
83), connect a probe to A of the signal input electrode 26a, which is one end of the source signal wiring, and A' of the other end, connect a power supply to the probe of A' and apply a positive potential, and connect an ammeter to the probe of A. Connected. The path through which the current flows is signal wiring 2
There are two types, 4a and auxiliary wiring 33a, and since the diode 34 is provided, it is possible to detect a disconnection state of the signal wiring 24a. If a disconnection occurs, only the auxiliary electrode with the disconnection is left, and the other auxiliary electrodes are cut with a laser beam (94). Other steps are similar to the conventional steps shown in FIG.

[0022]

[Effects of the Invention] As described above, the present invention improves the yield of the signal wiring in the array process, uses materials with high reliability, and improves the display quality while repairing disconnections as before. I was able to change it to a better design. It was confirmed that this dramatically improved the yield and display performance of the liquid crystal display device.

Furthermore, with the manufacturing method of the present invention, it is possible to completely suppress the occurrence of defects due to static electricity, etc. in the process of repairing disconnections. Furthermore, it can be confirmed that the process can be easily automated and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of a liquid crystal display device according to an embodiment of the present invention.

FIG. 3 is an equivalent circuit diagram of a liquid crystal display device according to another embodiment of the present invention.

4(A) A plan view of a liquid crystal display device according to still another embodiment of the present invention. FIG. 4(B) An enlarged plan view of 4B in FIG. 4(A).

[Figure 5]
Flowchart showing a method for manufacturing a liquid crystal display device according to an embodiment of the present invention

[Figure 6] Cross-sectional configuration diagram of a conventional liquid crystal display device

[Figure 7] (A
) Same plan view (B) Enlarged plan view of 7B in Fig. 7 (A)

[Figure 8]
Flowchart showing a conventional method for manufacturing a liquid crystal display device

[Explanation of symbols]

21 Switching element group 22 Pixel electrode 23 Polyimide alignment film 24 Signal wiring electrode 24a, 24b Signal wiring 26 Signal input electrode group 27a, 27b Glass substrate 30 Spacer 32 Liquid crystal composition 33 Auxiliary wiring group 33a Auxiliary wiring 34 Diode 35 Disconnection 36 Auxiliary electrode

Claims (7)

[Claims] Claim 1: A pair of substrates with electrodes, at least one of which is transparent, with their electrode surfaces facing each other, and
A liquid crystal display device that is arranged with a predetermined gap and filled with a liquid crystal composition, and is electrically connected to both ends of all the signal wirings that make up the image display area of the electrode-equipped substrate. A liquid crystal display device having auxiliary wiring passing through an area other than the image display area. 2. The liquid crystal display device according to claim 1, further comprising a diode between each signal wiring and the auxiliary wiring or within the auxiliary wiring. 3. The liquid crystal display device according to claim 1, wherein the signal wiring constituting the image display area is divided into a plurality of groups, and each group has one auxiliary wiring. 4. The liquid crystal display device according to claim 1, further comprising a matrix-shaped image display area comprising a switching element group and a wiring electrode group forming the switching elements on the side of the electrode-equipped substrate that is in contact with the liquid crystal composition. 5. The liquid crystal display device according to claim 4, wherein the switching element group is formed of thin film transistors. [Claim 6] The switching element group is metal-insulator-
5. The liquid crystal display device according to claim 4, comprising a two-terminal circuit such as a metal structure and a diode structure. 7. After manufacturing the substrate with electrodes, the signal wiring constituting the image display area is inspected for electrical disconnection, and then all signal wiring electrodes other than those where the disconnection is detected are exposed to laser beams from the auxiliary wiring. A method for manufacturing a liquid crystal display device that is electrically disconnected.