JP2860973B2 - Active matrix display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix display device which drives a liquid crystal by a switching element such as a thin film transistor (hereinafter referred to as a TFT) to display an image.

[0002]

2. Description of the Related Art The display image quality of an active matrix liquid crystal display device has been greatly improved in recent years and has reached a level comparable to a CRT. However, in terms of mass productivity, production is not always performed at a sufficient yield due to problems in its configuration and process.

A typical defect mode of a liquid crystal display device is a line defect defect. The causes of line defects are:
Driver IC failures, disconnections, short-circuits between adjacent wirings, static electricity, etc. are present. Above all, line defects due to deterioration of TFT characteristics due to static electricity cannot be repaired basically, which is an important issue.

[0004] As a method of preventing line defects due to static electricity, a wiring for shorting all signal wirings is formed, and damage to one wiring is dispersed by increasing electric capacity.
Mitigation is a common practice.

The short wiring is removed immediately before a step for removing the short wiring such as an image inspection step. As a removing method, there are a method utilizing a chemical reaction such as etching, and a method of mechanically removing a wiring pattern, and the latter is generally selected from the viewpoint of workability and the like.

Here, it can be seen that if the short wiring is disposed near the end face of the substrate or near the fractured surface, it can be removed by chamfering the end face.

[0007]

However, usually,
The amount of chamfering is defined by the distance from the end face of the substrate or the cross section. However, it is difficult to precisely chamfer a necessary and sufficient amount due to variations in substrate size, pattern, and cutting position. When the short wiring cannot be completely removed, problems such as a short circuit between adjacent wirings and a resulting image defect due to a shortage of IC capability occur.

For this reason, it is necessary to visually inspect whether or not the short wiring has been removed as a management of the chamfer amount, and there is still a risk that a minute portion may be overlooked.

SUMMARY OF THE INVENTION An object of the present invention is to provide an active matrix display device in which there is no short wiring removal defect and no short circuit between adjacent wirings due to the short wiring failure taking into consideration such conventional problems.

[0010]

A switching element such as a thin film transistor and image signal wiring, scanning signal wiring and pixel electrode electrically connected to the switching element are arranged in a matrix on one main surface of a first substrate. Formed in
A display material such as a liquid crystal is sandwiched between the first substrate and a second substrate on which a transparent electrode opposed to the first substrate with a certain gap is formed, and the image signal wiring group or the scanning signal wiring group is electrically connected. After the first substrate and the second substrate are cut and divided into a plurality of pieces,
In an active matrix display device in which the short wiring is removed by chamfering an end face or a split cross section of the substrate, a mark indicating a chamfered state is formed on one main surface of the first substrate independently of the short wiring. The purpose is achieved.

The mark indicating the chamfered state is an active matrix display device including a first mark formed in a region removed by chamfering and a second mark formed in a region not removed by chamfering.

Further, the active matrix display device is characterized in that the mark is formed by a thin film layer forming the scanning signal wiring.

Further, in the active matrix display device, the mark is formed by a thin film layer forming the image signal wiring.

The distance from the first substrate end face or the split section to the second mark is a distance obtained by adding the distance from the first substrate end face or the split section to the short wiring and the width of the short wiring. Larger active matrix display device.

[0015]

According to the present invention, for example, a mark is formed on the inner side of the short wiring, that is, at a position larger than the distance from the substrate end face or the cross section to the short wiring and the distance of the width of the short wiring. Work while making sure to chamfer an appropriate amount. Thereafter, a short wiring removal failure can be selected by visual inspection of only the mark portion, thereby preventing the occurrence of a problem such as a short between adjacent wirings.

[0016]

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

FIG. 1 and FIG. 2 are diagrams for explaining a short wiring removal failure in this embodiment. FIG. 1 shows a case where a defective removal exists in a plane. That is, most of the short wiring 1 below has been removed, but there is a slightly removed defective portion 9 above. FIG. 2 shows a case where a removal defect exists in a three-dimensional manner. This is a removal defect that occurs because chamfering is performed diagonally.

As is clear from the description of the prior art, when determining whether or not a short wiring has been removed, a considerable amount of man-hour is required if the short wiring itself is visually checked, and a small part is required. There is a possibility that the remaining short wiring may be missed.

Further, when the chamfer is almost the required amount,
Even if there is some work variation or dimensional variation, short wiring remains.

In order to avoid this, in the present embodiment, marks are provided at portions other than the short wiring so that the chamfer amount can be defined and a margin for variation can be secured.

FIG. 3 shows an embodiment of the present invention. As a first mark, a line 2 indicating the position of the short wiring 1, a line 3 indicating a manufacturing variation range 8, and a line 4 indicating a maximum allowable chamfering position are provided as a second mark. The range in which the line 3 indicating the manufacturing variation range 8 is removed and the line 4 indicating the maximum allowable chamfering position can be confirmed is an appropriate chamfering amount. With this mark, it is possible to confirm at a glance whether the chamfering amount is appropriate. it can. It is desirable that these marks be arranged at both ends of the short wiring 1. 7 is a chamfer line.

FIG. 4 shows a second embodiment of the present invention. A block pattern 5 as a first mark and a pattern 6 indicating a maximum allowable chamfering position as a second mark are provided having a width in the range of manufacturing variation from the position of the short wiring 1. The range in which the block pattern 5 is removed and the pattern 6 indicating the maximum allowable chamfering position can be confirmed is the proper chamfering amount, and this mark allows the user to confirm at a glance whether the chamfering amount is appropriate. The pattern 6 is provided with a projection 61 on the side close to the block pattern 5 having a width of the manufacturing variation in order to clarify whether or not the chamfer is properly performed. Can be determined. In the case of this mark as well, it is desired to be arranged at both ends of the short wiring.

It is needless to say that the pattern indicating each position may be any shape such as a circle or an ellipse as long as it can indicate the above-mentioned position and range.

[0024]

As is apparent from the above description,
The present invention provides a first substrate on which a switching element such as a thin film transistor, an image signal wiring electrically connected to the switching element, a scanning signal wiring, and a pixel electrode are formed in a matrix, A short wiring for sandwiching a display material such as a liquid crystal between the second substrate on which a transparent electrode is formed and a second substrate opposed with a predetermined gap, and electrically short-circuiting the image signal wiring group or the scanning signal wiring group; An active matrix display manufactured by a method of cutting the first substrate and the second substrate, dividing the first substrate and the second substrate into a plurality of pieces, and chamfering an end face or a split cross section of the first substrate to remove the short wiring. In the apparatus, a mark indicating a chamfered state is provided on the first substrate,
Because it is formed independently of the short wiring,
Inconveniences such as short wiring removal failure and a short circuit between adjacent wirings can be eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a short wiring removal failure.

FIG. 2 is a cross-sectional view of a defective portion where a short wiring is removed.

FIG. 3 is a diagram showing a shape of a mark in one embodiment of the present invention.

FIG. 4 is a view showing a shape of a mark in a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Short wiring 2 Line indicating the position of short wiring 3 Line indicating the range of manufacturing variation 4 Line indicating the maximum allowable chamfering position 5 Block pattern having the width of the manufacturing variation range from the position of short wiring 6 Pattern indicating the maximum allowable chamfering position

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-221926 (JP, A) JP-A-6-82775 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02F 1/136 500 G02F 1/1343 G02F 1/1345

Claims (5)

(57) [Claims] 1. A first substrate on which a switching element such as a thin film transistor, an image signal wiring electrically connected to the switching element, a scanning signal wiring, and a pixel electrode are formed in a matrix, and the first substrate. A display material such as a liquid crystal is sandwiched between a transparent substrate and a second substrate on which a transparent electrode is formed, which is opposed to the second substrate with a predetermined gap, and electrically short-circuits the image signal wiring group or the scanning signal wiring group. An active matrix manufactured by a method having a wiring, cutting the first substrate and the second substrate, dividing the substrate into a plurality of pieces, and chamfering an end face or a cross section of the first substrate to remove the short wiring. In the display device, a mark indicating a chamfered state is formed on the first substrate independently of the short wiring. Display device. 2. A mark representing a chamfered state includes a first mark formed in a region removed by chamfering and a second mark formed in a region not removed by chamfering. The active matrix display device as described in the above. 3. The active matrix display device according to claim 1, wherein a mark indicating a chamfered state is formed by a thin film layer forming said scanning signal wiring. 4. The active matrix display device according to claim 1, wherein a mark indicating a chamfered state is formed by a thin film layer forming said image signal wiring. 5. The distance from the end face or the split section of the first substrate to the second mark is greater than the distance obtained by adding the distance from the end face or the split section of the first substrate to the short wiring and the width of the short wiring. 2. The active matrix display device according to claim 1, wherein the active matrix display device is also large.