JP2892894B2 - Inspection method of 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 inspection of a matrix display device in which a large number of pixels are arranged in a matrix, especially an active matrix display device in which a thin film transistor (hereinafter referred to as TFT) is used as a switching element to drive a liquid crystal.
It is about the method .

[0002]

2. Description of the Related Art In recent years, matrix display devices centering on liquid crystal, particularly active matrix display devices that drive liquid crystal by using TFTs as switching elements, have rapidly penetrated the market. Business and industrial use. Among them, for OA is the largest the market scale, not only on the screen of a personal computer, and spreads out applications to the workstation screen, there is an increasing demand of further large high-definition to a display device.

Accordingly, from the side of the matrix display device, the number of cross points between the X-direction signal wiring group and the Y-direction signal wiring group necessarily increases. Originally, the X-direction signal wiring group and the Y-direction signal wiring group should be electrically insulated through an interlayer insulating film. In the process, the electrical connection between the X-direction signal wiring group and the Y-direction signal wiring group
A short circuit (hereinafter referred to as a cross short) occurs. Therefore, an increase in cross points leads to an increase in cross shorts. From the viewpoint of manufacturing yield, it is necessary to take sufficient measures against both design and manufacturing processes. For example, from a design point of view, 1) minimize the cross point area, 2) optimize the configuration of the interlayer insulating film, and from a manufacturing process point of view, 1) reduce dust, 2) reduce particles during film formation. And other measures are taken.

On the other hand, it is also important that in the inspection process after the completion of the substrate, a sufficient inspection is performed, a substrate having a cross short is screened, and the substrate is not transferred to a subsequent process. This is because, if a failure occurs in a subsequent process, it is disadvantageous in terms of the manufacturing cost. Accordingly, from the viewpoint of manufacturing, it is extremely important to detect in a preceding process as much as possible.

[0005]

Normally, in the inspection process after the completion of the substrate, a single applied voltage of 10 V or less is applied due to various problems such as a power supply of an inspection voltage application device and a reduction in process time.
Crossing between X-direction signal wiring group and Y-direction signal wiring group by voltage
Inspection of shots is being performed. However, in actual driving of the matrix display device, the cross point between the X-direction signal wiring group and the Y-direction signal wiring group depends on the driving method,
A voltage of a maximum of 30 to 35 V is applied. As a result, cross shorts that are not detected in the substrate completion inspection process are detected in a later process or occur after the display device is completed, leading to problems such as a reduction in manufacturing yield and an increase in cost.

According to the present invention, when the substrate is completed, a voltage equal to or higher than the maximum voltage applied to the cross point between the X-direction signal wiring group and the Y-direction signal wiring group in actual driving is applied to the Y-direction signal wiring group. Apply to the cross point of the signal wiring group
In this way, cross shorts can be detected at the
It will be issued. Accordingly, it is an object of the present invention to suppress a cross-short between the X-direction signal wiring and the Y-direction signal wiring in a process after the completion of the substrate, which is a conventional problem.

[0007]

Means for Solving the Problems XY via an interlayer insulating film
When a maximum voltage difference between a drive signal supplied to the X-direction signal wiring group and a drive signal supplied to the Y-direction signal wiring group is A, the predetermined voltage V is at least A or more in the substrate manufacturing process. during the ₀ for a predetermined time T _0, is applied between the X-direction signal wiring group and Y direction signal wiring group.

[0008]

In the process of manufacturing a substrate, an interlayer insulating film is essentially used.
Therefore, the X direction signal wiring group to be electrically insulated and the Y direction
The cross points of the signal wiring groups
Use the above means
Thus, when the substrate is completed, a cross short which is likely to occur can be detected in advance. This is the post-process
This leads to a reduction in the rate of occurrence of cross shorts.

[0009]

Embodiments of the present invention will be described below. (Figure
1) is a flow chart of a board completion inspection process of one embodiment using the present invention. Conventionally, as shown in FIG. 4 , after the substrate is completed, a low voltage of 10 V is applied between the XY signal wirings.
As a result, a cross-short inspection of the X-direction signal wiring group and the Y-direction signal wiring group was performed. In the actual driving after the assembling process, the driving signal supplied to the X-direction signal wiring group and Y
The maximum voltage difference A of the drive signal supplied to the direction signal wiring group is 1
Since the voltage exceeds 0 V, a voltage of 10 V or more is not applied once after the completion of the substrate, and the substrate is put into processes after the assembly process.
Ing to be. When the substrate is completed, apply a voltage greater than or equal to the maximum voltage difference A between the drive signal supplied to the X-direction signal wiring group and the drive signal supplied to the Y-direction signal wiring group, and
Detection (hereinafter referred to as the screening step).
) Means low yield due to cross-short occurrence in the subsequent process
In addition to preventing the lowering, the reliability of the matrix evaluation device for the substrate can be improved .

FIG . 2 shows an embodiment of a matrix display device .
FIG. 4 is a driving waveform diagram of FIG. The maximum voltage difference A between the driving signal supplied to the X-direction signal wiring group and the driving signal supplied to the Y-direction signal wiring group is represented by Vs (H) -Vge (L). In this embodiment, Vs (H) = 7V and Vge (L) =-13V are adopted, and depending on the driving method, if the coupling variation is included, the X-direction signal wiring group and the Y-direction signal wiring group are used. A voltage of 30 to 35 V at the maximum is applied to the cross point for a short period of time. Crossing in the assembly process
If a short-circuit occurs, rescue by rescue wiring
It is possible, but the number of rescue
The number of skews is limited. Also, after the mounting process
Cross short relief is not possible.

In the conventional inspection process, the voltage application time was as short as 7 ms when a low voltage of 10 V was applied.
A long voltage application time is required due to the rounding of the drive waveform and the problem of the power supply of the inspection voltage application device. However, considering the occurrence of cross shorts in the post-process , the yield
This embodiment is very effective in terms of the stowdown .

In this embodiment, as shown in FIG. 1, when the substrate is completed, a voltage of +50 V is first applied to the cross point of the X-direction signal wiring group and the Y-direction signal wiring group for 3 minutes, and the maximum drive voltage phase and the like are inspected in advance. A cross short is detected by the voltage, the detected cross short is cut, and +50 V is applied again.
Is applied for one minute, and the operation of cutting the detected cross-short is performed. As a result, the occurrence of cross-short in the subsequent process is suppressed, and the manufacturing yield at the time of completing the substrate is successfully improved. Note that OK (a) indicates a case where no cross-short has occurred by applying a voltage, and OK (b) indicates a case where the number of cross-shorts detected by applying a voltage can be rescued.

FIG . 3 is a plan view of the completed substrate. X direction
The cross point between the signal wiring group and the Y-direction signal wiring group is oblique.
Shown in the line. In FIG. 3, a voltage equal to or greater than the maximum voltage difference between the X-direction signal wiring (group) 1 and the Y-direction signal wiring (group) 2 in actual driving is applied to the X-direction signal wiring (group) 1 for a predetermined period.
When a cross short 8 occurs at the cross point 7 between the X-direction signal wiring (group) 1 and the Y-direction signal wiring (group) 2, the Y-direction signal wiring is applied. 2, the Y-direction signal wiring 2 is cut at a location 9, and a display signal is supplied from a side that has been floated by cutting using a rescue wiring (not shown) (not shown). Make it possible. In this embodiment, the applied voltage is +50 V, but the applied voltage is 100 V.
When the voltage exceeds V, a problem of elution of the scanning direction signal wiring (X) occurs. Therefore, it is preferable that the applied voltage is set to an upper limit of about 100 V. At this time, the application time is required to be at least 10 ^-6 seconds because the pulse width of the coupling variation in the scanning direction signal wiring is required. Since it is necessary to set the application time to such an extent that no scorching occurs, the upper limit is desirably about 300 seconds.

[0014]

As described above, according to the present invention, 1) after
The occurrence of cross shorts in the process is suppressed, 2) reliability,
There was no occurrence of cross shorts after completion of the matrix evaluation device, including actual use. As a result, the effects of reducing the manufacturing cost and improving the reliability of the matrix display device were observed, and were extremely useful in practice.

[Brief description of the drawings]

FIG. 1 is a process flow chart of a board completion inspection process of one embodiment using the present invention.

FIG. 2 is a driving waveform diagram shown in one embodiment used in the present invention .

FIG. 3 is a plan view when the substrate is completed.

FIG. 4 is a flowchart of a conventional board completion inspection process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 X (scanning) direction signal line (gate electrode) 2 Y (display) direction signal line (source electrode) 3 Drain electrode 4 Pixel electrode 5 Etching stopper 6 Contact window 7 Cross point of X direction signal line and Y direction signal line 8 Cross-short occurrence location 9 Cutting location

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiji Yamamoto 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Yasushi Narushige 1006 Kadoma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Tatsuhiko Tamura 1006 Oji Kadoma Kadoma, Osaka Pref. Document JP-A-3-200121 (JP, A) JP-A-63-289589 (JP, A)

Claims (4)

(57) [Claims] 1. A plurality of X-direction signal wiring groups and a plurality of Y-direction signal wiring groups are arranged in an XY matrix on one main surface of a substrate constituting a matrix display device via an interlayer insulating film. A driving signal to be supplied to the X-direction signal wiring group;
When the maximum voltage difference between the drive signals supplied to the Y-direction signal wiring group is A, at least a voltage V ₀ equal to or higher than A is applied to the X for a predetermined period T _0.
A step 1 of applying between the direction signal wiring group and the Y direction signal wiring group, a step 2 of measuring an electric short circuit between the X direction signal wiring group and the Y direction signal wiring group, and a step 2 When an electric short circuit is detected, a step 3 of cutting the both sides in the vicinity of at least one of the electric short circuits of the X-direction signal wiring group and the Y-direction signal wiring group to eliminate the electric short circuit is sequentially performed. A method for manufacturing a matrix display device. 2. The method of manufacturing a matrix display device according to claim 1, wherein the polarity of V ₀ coincides with the polarity giving the maximum voltage difference A. 3. A method for inspecting a matrix display device according to claim 1 or claim 2, wherein the V ₀ is _{30 ≦ V 0 ≦ 100 (V} ). Wherein T ₀ is 10 ^-6 ≦ T ₀ ≦ 300 claim 1 or claim 2 or method of manufacturing a matrix display device, wherein it is a (second).