JPH11352510A - Liquid crystal display device and production therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a drive circuit testing element group so as not to be destroyed and scratched at the time of handling by improving the monitoring accuracy of characteristics and improving the changes in the characteristics of the group due to the changes with the lapse of time. SOLUTION: In a liquid crystal display device, in which liquid crystal is held between an array substrate on which pixel electrodes and thin film driving circuits are formed and a counter substrate, an extending part 11a is formed on the array substrate where a drive circuit testing element group 21 having the same operating functions as those of the drive circuits are formed. Moreover, an extending part 34a is also formed on the counter substrate, and the both extending parts are adhered with a sealing material so as to cover the upper part of the drive circuit testing element group 21 and the group 21 is separated from a device to be made for testing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display device having a thin film circuit such as a driving circuit on a substrate together with a display pixel electrode.

[0002]

2. Description of the Related Art As a liquid crystal display device for displaying characters, figures and the like, there is a matrix type in which address wiring and data wiring are crossed and each of the crossed sections is a pixel. The active matrix type liquid crystal display device includes a driving switching element corresponding to each of these pixels. Typical examples of the switching element include a thin film transistor and a metal-insulator-metal non-linear resistance element. Among them, the thin-film transistor has excellent high-speed response and is suitable for full-color display. Since such a liquid crystal display device can be made relatively thin, it is often mounted on a portable personal computer such as a notebook PC. Mobile phones need to be cheaper, smaller, and cheaper.

In order to cope with such a demand, a circuit for driving a liquid crystal has conventionally been provided externally as a flexible circuit board TCP (Tape Carrier Package) on an array substrate. There is a method in which the number of members is reduced and the cost is reduced by forming a thin film circuit at the same time as forming the address wiring, the data wiring and the pixel electrode.

In an array substrate in which a liquid crystal driving circuit is formed, the manufacturing method of a thin film transistor or the like is complicated and the practical conditions are severe. Therefore, it is necessary to confirm the operation life of the circuit. In order to confirm the operating life of the drive circuit on the array substrate, a reliability test may be performed using the liquid crystal display device itself. However, it takes time to manufacture a sample and the cost is increased because the number of components increases. Therefore, it is difficult to prepare a large number of samples.

FIG. 4 shows a drive circuit test element group TEG (Test Element) formed on an array substrate together with a liquid crystal display device.
nt Group). Test drive circuit 2 on insulating substrate 1, pad 3 for supplying power and logic signals to drive circuit 2, and electrically operating state of each circuit of a unit constituting drive circuit 2 Inspection pad 4 is formed. At this time, the inspection pad 4 is arranged at least in the periphery of the drive circuit 2 or in a circuit of a unit constituting the drive circuit 2.

[0006]

However, since the test drive circuit 2 is exposed, the following problems occur. As shown in FIG. 4, the driving circuit 2 has no counter substrate.
When the reliability test is performed, the same phenomenon as when the liquid crystal display device is driven is not necessarily reproduced because the opposing substrate exists in the drive circuit of the liquid crystal display device portion. That is, even if the drive circuit 2 has the same scale and the same structure as the liquid crystal display unit, changes in characteristics due to aging may be monitored in a state different from that of the liquid crystal display device.

Further, since there is no substrate, protective film, etc. for protecting the drive circuit 2 in particular, there is a problem that the drive circuit 2 is broken or damaged by touching it during handling so that it does not operate. .

The present invention has been made in view of such a problem, and instead of using a liquid crystal display device to evaluate changes in characteristics of a driving circuit due to aging, a large number of driving circuit test elements are used to easily and easily. An object of the present invention is to provide a method for manufacturing a liquid crystal display device so that evaluation can be performed in the same state as a liquid crystal display device.

[0009]

According to the present invention, a pixel electrode is arranged in a matrix on one surface of a display area, and a driving circuit for driving the pixel electrode is arranged in a non-display area around the pixel electrode.
A substrate, a second substrate opposed to the first substrate with a gap for sandwiching liquid crystal therebetween, a sealing material for bonding these substrates around the substrate so as to enclose the liquid crystal, and a sealing material outside the sealing material. A first substrate extension portion extending from the first substrate, a drive circuit test element group formed on the same surface of the first substrate extension portion as one surface of the first substrate, and The present invention provides a liquid crystal display device including a pad of this element group and a second substrate extension portion located on the drive circuit test element group so as to face the second substrate.

Further, according to the present invention, pixel electrodes are arranged in a matrix on one surface of a display area of a first substrate, and a driving circuit for driving the pixel electrodes is arranged in a non-display area around the pixel electrodes.
Arranging a drive circuit test element group on a first substrate extending portion extending from the first substrate; and opposing the second substrate to the first substrate with a gap for sandwiching liquid crystal therebetween; A step of causing a second substrate extending portion extending from the second substrate to face the drive circuit test element group; and a step of enclosing the first and second substrates around these substrates so as to encapsulate the liquid crystal. A liquid crystal display device comprising: a step of bonding with a sealant; and a step of separating the first substrate extension and the second substrate extension from the first substrate and the second substrate while keeping the first substrate extension and the second substrate extension together. Is obtained.

Further, the present invention provides a method of manufacturing an active matrix type liquid crystal display device, wherein the first substrate is an array substrate having a thin film transistor, and the second substrate is a counter substrate having a counter electrode.

Further, the drive circuit test element group has a function equivalent to that of the drive circuit and provides a method of manufacturing a liquid crystal display device.

Further, the driving circuit test element group is arranged near the driving circuit to obtain a method of manufacturing a liquid crystal display device.

Further, the driving circuit test element group includes:
An object of the present invention is to provide a method of manufacturing a liquid crystal display device, which has an inspection pad for electrically inspecting an operation state for each circuit of a unit constituting a circuit.

By arranging the opposing substrate on the drive circuit test element group, the drive circuit test element group approaches the environmental condition of the drive circuit of the liquid crystal display device. Therefore, as a substitute for the reliability test of the drive circuit of the liquid crystal display device. It can be carried out in large quantities and simply. Therefore, it is possible to monitor a change in characteristics due to a change with the lapse of time without the cost as the same state as the liquid crystal display device.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the liquid crystal display device according to the present invention will be described in detail. 1 to 3
1 shows a polysilicon type liquid crystal display device and a manufacturing method according to an embodiment of the present invention.

In the figure, the size is 300 mm × 400 m
m, an address / data line including a switching polysilicon thin film transistor (TFT) 12 and a pad 13 in a matrix in a display area (A) by repeating film formation and patterning on one surface of a glass substrate 11 having a thickness of 0.7 mm. 14. A drive circuit 16 including a polysilicon TFT for forming a pixel electrode 15 and applying a drive voltage to the pixel electrode in a non-display area (B) around the display area, and a drive circuit further around the drive circuit. A drive circuit built-in array substrate 20 having a drive circuit test element group (TEG) 21 having the same circuit configuration is formed.

As shown in FIG. 2, a polysilicon thin film transistor 12 is formed by continuously forming a silicon nitride film 22, a silicon dioxide film 23, and an amorphous silicon film (24) on a glass substrate 11 and then irradiating the film with a laser. The amorphous silicon film is changed to a polysilicon film 24. The polysilicon film 24 is patterned into a predetermined shape, and a gate insulating film 25 is formed thereon.

Thereafter, a gate electrode 26 is formed of a metal such as molybdenum in contact with the gate insulating film 25, and then source / drain regions 29 are formed by ion doping using the gate electrode as a mask with the channel region 28 interposed therebetween.

Further, an interlayer insulating film 30 of a silicon oxide film is formed, a transparent conductive film of ITO is formed thereon, and a predetermined pattern is obtained by etching to obtain the pixel electrode 15. Next, a signal line electrode 14 is formed, and a switching polysilicon thin film transistor 12 is formed.

The thin film transistor in the drive circuit 16 and the thin film transistor in the drive circuit test element group 21 are formed in the same process by the same film formation and patterning.

On the side of the array substrate 20, an electrode pad 13 for supplying power and a logic signal to the drive circuit 16 and a test for electrically checking an operation state for each circuit of a unit constituting the drive circuit 16 It has a pad 13a.

Next, a counter substrate 33 having a color filter 35 and a counter electrode 36 formed on a 0.7 mm glass substrate 34
Are sealed with a sealing material 40 so as to seal the liquid crystal 37 with a gap for holding the liquid crystal facing the array substrate 20.
Glue with

The sealing material for enclosing the liquid crystal passes inside the drive circuit test element group 21 and, at the final stage of the manufacturing process,
The glass substrate portions 11a and 34a on which the drive circuit test element group 21 is formed are cut along the cutting lines aa as the extended portions 41 of the substrate.
It is cut off along. Even after the separation, the sealing member 42 surrounds the periphery of the drive circuit test element group 21 separately from the sealing material so that the extending portion 11a of the array substrate 20 and the extending portion 34a of the counter substrate 33 are integrated. To do. It is desirable to form a gap in which liquid crystal can be sealed.

As shown in FIG. 3, the drive circuit test element group 21 includes an electrode pad 43 for supplying power and a logic signal to the drive circuit 21 on the extension portion 11a and the drive circuit 2
1 has a test pad 44 for electrically testing the operation state of each circuit of the unit constituting the unit 1 and is drawn out to the edge of the extending portion 11a of the array substrate. The size of the glass substrate of the opposing substrate is formed smaller than the size of the glass substrate of the array substrate so that the extended portions 34a of the opposing substrate do not cover the pads 43 and 44.

The drive circuit test element group 21 has the same scale, the same structure, and the same drive circuit as the drive circuit 16 of the liquid crystal display device formed on the same array substrate, and is formed near the liquid crystal display device. The operation of the liquid crystal display device can be reproduced.
The pads 43 and 44 for supplying power to the drive circuit test element group have the same structure and shape as the pads of the drive circuit of the liquid crystal display device, so that a flexible substrate (FPC) used in a module is used. To connect to the pads to drive the test element group.

Further, by holding the liquid crystal between the driving circuit test element group 21 and the opposing substrate 33, the same state as that of the driving circuit of the liquid crystal display device can be reproduced to perform a reliability test. Can be.

[0028]

According to the present invention, an opposing substrate is arranged on a drive circuit test element group formed on an array substrate, and the drive circuit test element group has the same scale, the same structure, and the same shape as the liquid crystal display device. By doing so, instead of evaluating the change over time of the drive circuit with a liquid crystal display device, a large number of drive circuit test elements
The evaluation can be performed simply and without any cost in the same state as the liquid crystal display device.

[Brief description of the drawings]

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

FIG. 2 is a partial cross-sectional view showing a structure of a polysilicon thin film transistor according to one embodiment of the present invention;

FIG. 3 is a plan view and a cross-sectional view showing an extended portion of a substrate on which a drive circuit test element group is formed;

4A and 4B are a plan view and a cross-sectional view illustrating an extended portion of a substrate on which a conventional drive circuit test element group is formed.

[Explanation of symbols]

 11: Glass substrate 11a: Extension portion 12: Polysilicon thin film transistor 13: 14: Address / data wiring 15: Pixel electrode 16: Driving circuit 20: Array substrate 21: Driving circuit test element group 33: Counter substrate 34: Glass substrate 34a: extending portion 37: liquid crystal 40: sealing material 43: electrode pad 44: inspection pad

Claims (6)

[Claims] 1. A first substrate in which pixel electrodes are arranged in a matrix on one surface of a display region, and a driving circuit for driving the pixel electrodes is disposed in a non-display region around the first substrate, and a liquid crystal is formed on the first substrate. A second substrate facing the substrate with a gap between the substrates,
A sealing material for adhering these substrates around the substrate so as to enclose the liquid crystal, a first substrate extending portion extending from the first substrate outside the sealing material, and a first substrate extending portion; A driving circuit test element group formed on the same surface as one surface of the first substrate and a pad of this element group; A liquid crystal display device comprising an extended second substrate extension. 2. A pixel substrate is arranged in a matrix on one surface of a display area of a first substrate, and a driving circuit for driving the pixel electrode is arranged in a non-display area around the pixel electrode, and extends from the first substrate. Disposing a drive circuit test element group on the first substrate extending portion, and extending the second substrate from the second substrate with the second substrate facing the first substrate with a gap interposing liquid crystal therebetween. Making the second substrate extending portion face the drive circuit test element group, and bonding the first and second substrates around the substrates with a sealing material so as to encapsulate the liquid crystal; A method of manufacturing a liquid crystal display device, comprising: a step of separating the first substrate extension and the second substrate extension from the first substrate and the second substrate while keeping the first substrate extension and the second substrate extension together. 3. An active matrix type wherein the first substrate is an array substrate having a thin film transistor and the second substrate is a counter substrate having a counter electrode.
The manufacturing method of the liquid crystal display device according to the above. 4. The method according to claim 2, wherein the driving circuit test element group has a function equivalent to that of the driving circuit. 5. The method according to claim 2, wherein the driving circuit test element group is arranged near the driving circuit. 6. The drive circuit test element group according to claim 2, wherein the drive circuit test element group has an inspection pad for electrically inspecting an operation state for each circuit of a unit constituting the circuit. A method for manufacturing the liquid crystal display device according to any one of the above.