JP3130073B2 - Method for manufacturing array substrate for liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-performance, high-yield
The present invention relates to a method for manufacturing an array substrate for a liquid crystal display .

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been actively approached particularly for large-capacity display represented by image display, and have attracted the most attention as displays capable of realizing low-cost devices.

FIGS. 4, 5A and 5B show an example of a conventional liquid crystal display device, and show the structure of a matrix type liquid crystal display device.

First, FIG. 4 will be described. FIG. 4 is a sectional view of a conventional liquid crystal display device. In FIG. 4 , an image display area 5 including a switching element group 1, a pixel electrode group 2, an alignment film 3, and a signal wiring electrode group 4, a signal input electrode group 6 from an external drive circuit, and an auxiliary wiring group 13 are provided. An array substrate 17 composed of an insulating substrate 7a, a transparent insulating substrate 7 having a transparent common electrode 8, a light shielding layer 9 and an alignment film 3;
b, a spacer 10 made of glass fiber or resin fine particles is provided on a counter substrate 18 made of b, and the pixel electrode 2 and the transparent common electrode 8 are bonded to each other with a resin adhesive 11 so as to face each other.
The gap formed by the spacer 10 is filled with a liquid crystal composition 12.

The liquid crystal display device configured as described above has
Arbitrary information can be displayed by selectively applying a voltage to the pixel electrode group 2 via the switching element 1.

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

FIG . 5B is an enlarged plan view showing an enlarged part 7B of the signal wiring and the auxiliary wiring in FIG. 5A. In the figure, the auxiliary wiring 13 a having the connection electrode 14 and the signal wiring 4 a having the connection electrode 15 are electrically separated via an insulating layer 16.

Next, a method for manufacturing a conventional liquid crystal display device will be described. FIG. 6 is a manufacturing flowchart of a conventional liquid crystal display device . After completion of the array substrate (82) by the array formation process (81), disconnection inspection (8) of the signal wiring in the image display area is performed by an electrical method.
Perform 3). Here, a good product and a defective product are selected, and a defective product, that is, a product in which a disconnection has occurred is repaired by wire bonding (84). That is, FIG.
Thus, the connection electrode 15 and the auxiliary wiring 13 of the disconnected signal line
The connection electrode 14a is electrically connected using an aluminum wire. By performing this at both ends of the signal wiring where the disconnection has occurred, the liquid with a structure in which the signal is input from only one side
The disconnection can be relieved also in the crystal display device . The array substrate for which the disconnection has been relieved is checked again by inspection, and then subjected to the steps of forming an alignment film (85), aligning (86), bonding with an opposite substrate (91), and injecting liquid crystal (92). The liquid crystal display device is completed (93). Before the bonding step, the counter substrate is completed by a counter substrate process (87 to 90).

[0009]

The remedy for disconnection in the conventional manufacturing method uses wire bonding. Here, the following two conditions are well known as conditions of the display device coming from wire bonding. One is
Wire material and connection electrode material must be of the same type. Further, the thickness of the connection electrode is required to be about 1 μm in order to secure the adhesiveness in bonding. The above two conditions are constraints on the array substrate structure, and there is no flexibility in the array substrate design .
In turn, this hindered productivity and yield.

Further, in the conventional manufacturing method, when electrical connection is made by bonding in a disconnection relieving process, when the characteristic of the switching element deteriorates or a new disconnection occurs due to a potential difference between different kinds of conductors, a so-called electrostatic discharge occurs. Destruction has occurred. Further, since the signal wiring in which the disconnection occurs is random, it has been extremely difficult to automate the remedy by bonding as a process.

Accordingly, the present invention provides a method for relieving a disconnection,
Provided is a method for manufacturing an array substrate for a liquid crystal display device which eliminates the above-mentioned disadvantages and has excellent display quality by a simple method.
It is intended to do so.

[0012]

In order to achieve the above object, a method of manufacturing an array substrate for a liquid crystal display device according to the present invention is characterized in that both ends of all signal lines constituting an image display area are electrically connected. Auxiliary wiring is formed in advance in an area other than the image display area to form a closed loop of signal wiring and auxiliary wiring.
After the disconnection inspection of the signal wiring,
If there is, close the signal wiring and auxiliary wiring in a closed loop.
There is no signal wiring that is also disconnected the other auxiliary wiring leaving
If all auxiliary wiring is electrically separated by a laser beam,
It is .

[0013]

The liquid crystal display device manufactured as described above is used.
In the ray board , while relieving the disconnection as before,
The material of the signal wiring on the array substrate is yielded by the array process, a highly reliable material can be used, and the design can be changed to a display with excellent display quality . This allows the LCD
Dramatic improvement in display device yield and display performance
it can.

Further, according to the manufacturing method of the present invention, it is possible to completely suppress the occurrence of defects due to static electricity or the like in the disconnection relief step . Moreover, the process can be easily automated, and the cost can be reduced .

[0015]

Embodiments of the present invention will be described below. FIG.
Used an array substrate obtained by the manufacturing method of the present invention .
It is sectional drawing of one Example of a liquid crystal display device . A switching element group 21 composed of thin film transistors ( abbreviated as TFT) using amorphous silicon as a semiconductor, a pixel electrode group 22 composed of indium-tin oxide (hereinafter abbreviated as ITO), a polyimide alignment film 23, and aluminum and chromium as gate electrodes Two-layer structure of aluminum and titanium as source electrodes
An image display area 25 comprising a signal wiring electrode group 24 having a layer structure; 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 comprising aluminum and titanium. A diode 34 made of amorphous silicon between the signal wiring electrode 24 and the auxiliary wiring group 33;
Array substrate 20a composed of glass substrate 27a formed with
And a counter substrate 20 composed 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.
b, a spacer 30 made of glass fiber or resin fine particles was provided, the pixel electrode 22 and the transparent common electrode 28 were attached to each other with a resin adhesive 31, and the gap formed by the spacer 30 was filled with a liquid crystal composition 32. . Here, a TN type liquid crystal was used. Liquid configured as above
The operation of the crystal display device is the same as the conventional one.

FIG. 2 is obtained by the manufacturing method of the present invention.
FIG. 3 shows a simplified equivalent circuit diagram of one embodiment of an array substrate . In the image display area 25, the signal wiring 24a as a source electrode and the signal wiring 24 as a gate electrode, which are orthogonal to each other,
b etc. Here, the TFT and the pixel electrode are omitted. The signal input electrode 26a on the source electrode side is electrically connected to the other end of the signal line 24a via a diode 34 via an auxiliary line 33a on the source side. The signal wiring 24b on the gate electrode side is also connected via a diode 34, similarly to the source electrode side. That is, two
Signal wiring is closed through a diode and auxiliary wiring, respectively.
Connected to loop. Therefore, for example, when the source wiring DD ′ is 35 and a disconnection occurs, it is possible to obtain an array substrate without display defects by leaving only the auxiliary wiring 36 and cutting the other auxiliary wiring with a laser beam.
did it. Note that the diode 34 is replaced with a metal
-If it is a unidirectional electrical element consisting of an insulator-metal structure
Good.

Next, it is obtained by the production method of the present invention.
An embodiment of a method for manufacturing a liquid crystal display device using an array substrate will be described. FIG. 3 is a flowchart of the manufacturing method. Laser cutting was used as a relief for disconnection. The disconnection inspection will be described in detail with reference to FIG. In the present embodiment, for example, in the disconnection inspection (83) of the source signal wiring,
A probe was connected to A of the signal input electrode 26a, which is one end of the source signal wiring, and the other A ', a power supply was connected to the A' probe, a positive potential was applied, and an ammeter was connected to the A probe. There are two paths through which the current flows, the signal wiring 24a and the auxiliary wiring 33a. The presence of the diode 34 makes it possible to detect the disconnection state of the signal wiring 24a. If a disconnection occurs, only the auxiliary electrode where the disconnection has occurred is left, and the other auxiliary electrodes are cut by a laser beam (94). Other processes are the same as the conventional process shown in FIG. If there is no disconnection in all signal wiring, all auxiliary wiring
Are electrically separated by a laser beam.

[0018]

As described above, according to the present invention, disconnection can be relieved simply without requiring any other member, and the array base can be relieved.
After the completion of the board , a disconnection inspection could be performed, and the yield and display performance could be improved. In addition, the material of the signal wiring on the array substrate is yielded by the array process, and a highly reliable material is used.
Further, the design could be changed to a display having excellent display quality. As a result, it was confirmed that the yield and display performance of the liquid crystal display device were dramatically improved. Further, the occurrence of defects due to static electricity or the like in the disconnection relief step could be completely suppressed . In addition, it was confirmed that the process can be easily automated and cost reduction can be achieved .

[Brief description of the drawings]

FIG. 1 shows an array substrate obtained by the manufacturing method of the present invention.
Sectional view of one embodiment of a liquid crystal display device used

FIG. 2 is an equivalent circuit diagram of an array substrate obtained by the manufacturing method of the present invention.

FIG. 3 is an array substrate obtained by the manufacturing method of the present invention.
Showing an embodiment of a method for manufacturing a liquid crystal display device using the same .

FIG. 4 is a sectional view of a conventional liquid crystal display device .

[5] Rights <br/> view of the array substrate in (A) the liquid crystal display device (B) Fig 5 an enlarged plan view showing an enlarged 7B portion of (A)

FIG. 6 is a flowchart showing a conventional method for manufacturing a liquid crystal display device.

DESCRIPTION OF SYMBOLS 20a Array substrate 20b Opposing substrate 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 (unidirectional electrical element) 35 disconnection 36 auxiliary wiring

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-210419 (JP, A) JP-A-62-147432 (JP, A) JP-A-62-147433 (JP, A) JP-A-2- 123333 (JP, A) JP-A-2-212811 (JP, A) JP-A-4-127127 (JP, A) JP-A-62-151523 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1345

Claims (1)

(57) [Claims] An image display area on one surface is provided with a plurality of signal arrangements.
Insulating substrate forming lines, pixel electrodes and switching elements
The plurality of signals are provided on the surface of the board other than the image display area.
Form the same number of auxiliary wirings and unidirectional electrical elements as wirings
It consists of multiple signal wires, unidirectional electrical elements, and auxiliary wires.
Forming a plurality of closed loops, and then the plurality of signal wirings
Check for broken wires, and if any signal wires are
Signal wiring and auxiliary wiring in a closed loop, leaving other auxiliary
If there is no signal wiring that is broken again, all auxiliary wiring
Are electrically separated by a laser beam.
Of manufacturing an array substrate for a liquid crystal display device.