JPS6236545A - Defect inspection - Google Patents

Abstract

PURPOSE:To enable a defect of an object to be visually inspected in a moment, by a method wherein a liquid crystal is interposed between a transparent electrode substrate and an object to be inspected such as liquid crystal display substrate to assemble 1a liquid crystal display substrate to assemble a liquid crystal cell temporarily and a voltage is applied across the substrate and the object. CONSTITUTION:A transparent electrode film is deposited on the surface of polyethylene or the like, and an orienting film of polyimide or the like is applied and hardened thereon and is subjected to an orientation processing to form a transparent electrode substrate 2. The transparent electrode substrate 2 thus obtained is fixed on a stationary member 12 with two sides thereof kept curved and a gel host type liquid crystal 5 is interposed between the substrate 2 and a liquid crystal display substrate 4 to be inspected to assemble liquid crystal cell temporarily. To achieve this, the fixing member 12 is turned on a support member 13a. The base line of the orienting film 3 on the curved transparent substrate 2 first gets in linear contact with the substrate 4 and then shifts gradually to surface contact to accomplish a uniform distribution of the liquid crystal cell. This enables visual detection of point and linear defects of a simple matrix electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for inspecting objects to be inspected, such as liquid crystal display substrates and electrode substrates with color filters.

Conventional technology Conventional defect inspection equipment includes, for example, "Electronic Materials Separate Volume 1".
984 Edition VLSI Manufacturing/Testing Equipment Guidebook (1984)
8/11/16), Kogyo Kenkyukai, P196-P198J
There is a wafer flow bar as shown in . The wafer prober here is a device that serves as a testing medium by mechanically contacting input/output terminals on a wafer chip with a prober needle.

Therefore, the number of input/output terminals is approximately 60, like a liquid crystal display board.
If there are 0, it is relatively difficult to contact the input/output terminal with the prober needle and measure the electrical characteristic values, etc., and to determine the position of the defective location on the liquid crystal display board from the measured values.
And it requires a lot of time.

The problem that the invention aims to solve.

Inspection methods using such conventional defect inspection equipment require a precise micro-feeding mechanism for the prober needle, and processing must be performed to measure electrical characteristic values and determine the position of the defect location. Furthermore, it has been difficult to relatively shorten the time required to minutely feed the prober needle or the liquid crystal display substrate, and the time required to determine the position of the defective location from the measurement of electrical characteristic values.

The present invention has been made in view of the above, and an object of the present invention is to provide an inspection method using a defect inspection device that has a simple configuration and can visually inspect defects in objects to be inspected, such as liquid crystal display substrates and electrode substrates with color filters. It is said that

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention applies an alignment treatment to an alignment film formed on a transparent electrode substrate, and further cuts the transparent electrode substrate into rectangular shapes to form a curved shape. When the fixing member rotates around the supporting member of the fixing member, the generatrix of the alignment film formed on the curved transparent electrode substrate will be exposed to the surface of the liquid crystal display substrate, electrode substrate with color filter, etc. When the fixing member of the transparent electrode substrate first comes into line contact with the object to be inspected and then rotates around its support member, the alignment film formed on the curved transparent electrode substrate becomes the object to be inspected, such as a liquid crystal display substrate or an electrode substrate with a color filter. The liquid crystal that is in surface contact with the object and interposed between the object to be inspected and the alignment film on the transparent electrode substrate is almost uniformly distributed to form a liquid crystal cell, and the liquid crystal cell and the transparent electrode substrate are located between the light source and the measuring person. A voltage is applied to a liquid crystal cell through a polarizing plate to detect defects in an object to be inspected, such as a liquid crystal display substrate or an electrode substrate with a color filter, by visual inspection.

action The effect of this technical means is as follows.

That is, when temporarily assembling a liquid crystal cell with a liquid crystal interposed between a transparent electrode substrate and an object to be inspected such as a liquid crystal display substrate or an electrode substrate with a color filter, and applying a voltage between the transparent electrode substrate and the object to be inspected, Point defects and the like on the inspection object are detected visually. In the present invention, the transparent electrode substrate is flexible, and an alignment film is coated on the transparent electrode substrate and further subjected to alignment treatment, and two sides of the transparent electrode substrate are fixed with fixing members and curved. When rotated around , the curved transparent electrode substrate first comes into line contact with the object to be inspected, and when the fixing member of the transparent electrode substrate rotates around its supporting member, the alignment film on the curved transparent electrode substrate comes into line contact with the object to be inspected. The liquid crystal that is in surface contact with the object and interposed between the object to be inspected and the alignment film on the transparent electrode substrate is distributed almost uniformly, and a liquid crystal cell can be temporarily assembled. In addition, a guest-host type liquid crystal is used as the liquid crystal, and a liquid crystal cell and a polarizing plate are interposed between the light source and the measuring person, and the polarizing plate is placed only on the transparent electrode substrate side of the liquid crystal cell.

As a result, when inspecting objects to be inspected for defects such as liquid crystal display substrates and electrode substrates with color filters, it is no longer necessary to contact each electrode with a prober or the like to measure electrical characteristic values to determine defects. Defects can be detected visually by applying a voltage between the transparent electrode substrate and the object to be inspected.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

In FIG. 1, a transparent, highly insulating and flexible substrate is made of, for example, polyethylene with gold on the surface.

A transparent electrode substrate 2 produced by vapor-depositing a conductive transparent electrode film 1 of indium oxide, palladium, nichrome, etc. is cut into rectangles, and an alignment film 3 of polyimide or the like is applied onto the transparent electrode film 1 on the transparent electrode substrate. After curing, rubbing alignment treatment is performed, and a guest-host type liquid crystal 6 is interposed between the liquid crystal display substrate 4 and the transparent electrode substrate 2 to form a liquid crystal layer, and the liquid crystal is assembled. At this time, the gap between the liquid crystal layer, that is, the liquid crystal display substrate and the transparent electrode substrate can be obtained by including glass fiber spacers in the alignment film or by dispersing glass fiber spacers in the liquid crystal display substrate in advance. Furthermore, a voltage is applied to the liquid crystal cell temporarily assembled between the light source 6 and the measuring person 7, and a voltage is applied to the liquid crystal cell through the polarizing plate 8 or the polarizing filter located on the transparent electrode substrate side of the liquid crystal cell, and all switching transistors are turned on at once. If the rubbing direction of the alignment film and the polarization axis direction of the polarizing plate are parallel to each other due to a defect in the TPT element (a transistor element composed of a thin film transistor and used for switching the voltage applied to the pixel electrode) of the liquid crystal display substrate, a normal T
The pixels of the PT element become black dots, and the pixels due to defects become white dots, which can be detected visually, and by applying a voltage to the liquid crystal cell,
When all the switching transistors are turned on at once, if the rubbing direction of the alignment film and the polarization axis direction of the polarizing plate are perpendicular to each other, pixels of a normal TPT element become white dots, and pixels due to defects become black dots, which can be visually detected.

Furthermore, as shown in FIG. 2, when a voltage is applied to the liquid crystal cell to turn on all the switching transistors at once, the transparent electrode film of the transparent electrode substrate of the liquid crystal cell and the source 9 of the TPT element on the liquid crystal display substrate are connected. A voltage is applied to the gate 10.

However, unlike a prober inspection device, there is no need to apply voltage to all input/output terminals independently, and there is no need to apply voltage to all input/output terminals independently, and it is possible to avoid short-circuiting of adjacent terminals at the input/output terminals of the source or the input/output terminals of the gate. When a bias voltage corresponding to a signal is applied to all the gate lines, all the switching transistors are turned on at the same time, and defects in the TPT elements can be visually detected.

On the other hand, when a voltage is applied to the transparent electrode film of the transparent electrode substrate of the liquid crystal cell and the source of the TPT element of the liquid crystal display substrate, and a light beam is irradiated from the measuring person's side, a voltage equivalent to the gate voltage is applied to the TPT element, and defects can be visually checked. It can be detected by

The uniform distribution of liquid crystal will be explained as shown in FIGS. 3, 4, and 5. Transparent electrode substrate 202 cut into rectangles
The sides are fixed by the first fixing member 11, and the first fixing member 11, which is used to keep the transparent electrode substrate in a curved shape, is connected to the second fixing member 1.
2, the second fixing member 12 is fixed to the second fixing member 1
The generating line of the alignment film 3 on the curved transparent electrode substrate 2 first comes into line contact with the liquid crystal display substrate 4, and then the second fixing member rotates around the support member 13. Then, the alignment film 3 on the curved transparent electrode substrate 2 comes into surface contact with the liquid crystal display substrate, and the liquid crystal display substrate 4 and the transparent electrode substrate 2
The liquid crystal 6 interposed between the upper alignment films 3 is distributed almost uniformly.

As shown in FIG. 6, the liquid crystal display board 4 is vacuum-adsorbed to the fixing base 14 of the liquid crystal display board 4, and the applied voltage connector 16 is brought into contact with one side of the input/output terminal of the liquid crystal display board 4, and the liquid crystal display board 4 is placed on the liquid crystal display board 4. A few drops of liquid crystal are dropped using a syringe to bring the transparent electrode substrate and the liquid crystal display substrate into contact, and the liquid crystal is uniformly distributed to temporarily assemble the liquid crystal cell. The liquid crystal does not spread beyond the width of the transparent electrode substrate due to surface tension. Further, an acrylic protective member 17 is provided so that the transparent electrode substrate does not come into contact with the connector 16, and the transparent electrode substrate is tapered so as not to damage the curved shape of the curved transparent electrode substrate.

The measurer can visually observe the measurement with the naked eye or use the IT on the liquid crystal cell.
A V-camera is installed and visually observed on a magnifying monitor.

Next, other embodiments of the present invention will be described. When the object to be inspected is a simple multi-IJ sock crystal display substrate, it is simple to temporarily assemble the transparent electrode substrate of the device of the present invention and the simple matrix liquid crystal display substrate of the object to be inspected into a liquid crystal cell, and then apply a voltage to the liquid crystal cell. Defects such as point defects and line defects in the matrix electrode can be detected visually.

Further, other embodiments of the present invention will be described.

When the object to be inspected is an electrode substrate with a color filter, the transparent electrode substrate of the device of the present invention and the electrode substrate with a color filter of the object to be inspected are temporarily assembled into a liquid crystal cell, and when a voltage is applied to the liquid crystal cell, the surface of the electrode substrate with a color filter changes. Defects in the transparent electrode film, missing color filters, etc. can be detected visually.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) By temporarily assembling the liquid crystal cell, defects in the liquid crystal display substrate and color filter-attached electrode substrate to be inspected can be instantly detected visually.

(2) When applying a voltage to a temporarily assembled liquid crystal cell, it is not necessary to take the time to measure electrical characteristic values and find the location of a defective location.

(31) Defects in the object to be inspected can be visually detected stably and accurately with an extremely simple mechanical configuration.

(4) Therefore, it is extremely useful in practice.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a defect inspection device to which the present invention is applied;
The figure is a cross-sectional view of a TPT element on a liquid crystal display substrate to be inspected.
Figure 3 is a configuration diagram of the fixing member and supporting member of the defect inspection device;
Figures 4 and 5 show the transparent electrode substrate, liquid crystal, and
FIG. 6, which is a relationship diagram of the liquid crystal display substrate, is a configuration diagram of the voltage application method of the defect inspection device. DESCRIPTION OF SYMBOLS 1...Transparent electrode film, 2...Transparent electrode substrate, 3...Alignment film, 4...Liquid crystal display substrate, 5... LCD, 6...Light source, a...
...Measuring person, 8...Polarizing plate, 9...
・Source, 1o...Gate, 11...
First fixing member, 12...Second fixing member, 1
32L, 13b...Supporting member, 14...
・Fixed stand, 16... Input/output terminal, 16...
... Connector, 17... Protective member. Name of agent: Patent attorney Toshi Nakao, 1 person, 4-
= 51L Todorosha Tsukuchi J 5-11 Qingryo 4 Figure 5 2-458ta 礒 (1 (Lime 4--j trace crystal A 6 day silence (mouth) f4- (branch) friend f5- output to one fg--]next f7., f'hy-image t[1 rod

Claims (7)

[Claims] (1) The alignment film formed on the transparent electrode substrate has been subjected to alignment treatment, and the flexible transparent electrode substrate is cut into rectangles.
The transparent electrode substrate is kept in a curved shape by fixing the sides with a fixing member, and when the fixing member rotates around the support member, the generatrix of the alignment film on the curved transparent electrode substrate first comes into line contact with the object to be inspected. Further, when the fixing member rotates around the support member, the alignment film on the curved transparent electrode substrate comes into surface contact with the object to be inspected, and the alignment on the object to be inspected and the transparent electrode substrate is improved. The liquid crystal interposed between the films is almost uniformly distributed to form a liquid crystal cell, and a voltage is applied to the liquid crystal cell between a light source and a measuring person through the liquid crystal cell and the polarizing plate located on the transparent electrode substrate side. A defect inspection method configured to detect defects in an object to be inspected. (2) The defect inspection method according to claim 1, which uses a guest-host type liquid crystal as the liquid crystal. (3) The defect inspection method according to claim 1, which uses a liquid crystal display substrate as the object to be inspected. (4) The defect inspection method according to claim 3, wherein applying voltage to the liquid crystal cell applies voltage to the source and gate of the thin film transistor on the liquid crystal display substrate. (5) The defect inspection method according to claim 3, wherein the voltage is applied to the liquid crystal cell only to the source of the thin film transistor on the liquid crystal display substrate, and the light beam is irradiated from the measuring person's side. (6) The defect inspection method according to claim 3, wherein applying a voltage to the liquid crystal cell applies a voltage to a matrix electrode on a liquid crystal display substrate. (7) The defect inspection method according to claim 1, using an electrode substrate with a color filter as the object to be inspected.