JPH02190824A - Manufacture of liquid crystal display element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] A method for manufacturing a liquid crystal display element free from defects caused by sparks caused by static electricity generated during the manufacturing process, particularly during the rubbing process.

[Conventional technology]

In particular, the substrate of a TN type liquid crystal display cell is subjected to alignment treatment,
The orientation direction of the liquid crystal molecules is thereby defined, and one method for the above-mentioned orientation treatment is the rubbing method. An example procedure will be described below.

(1) Upper and lower glass substrates having display electrodes (patterned with a TTO film or the like) are prepared.

(2) Print coating a polyimide film or the like on the display electrode, or coat the display electrode with a dielectric material such as MgO1MgFz.
! After vacuum deposition, etc., the surface is rubbed in a specific direction with silk cloth, synthetic fiber cloth, wool cloth, etc.

By doing the above, the long axis direction of the liquid crystal molecules is aligned in the rubbing direction. The disadvantage here is that during the above-mentioned rubbing, a large amount of static electricity is generated on the substrate surface, and as a result, sparks are generated in the display electrodes where the mutual spacing is narrow, and the sparks disturb the surface of the alignment film, which causes the liquid crystal molecules to There was a drawback that the orientation was not good.

On the other hand, in Japanese Patent Publication No. 57-56044, a means for short-circuiting the display electrode pattern is provided.
Prevents potential difference from occurring in the 11-pole rjU.

A method for removing the short circuit pattern after the rubbing orientation process is completed is disclosed.

[Problem to be solved by the invention]

However, the above conventional technology has the following drawbacks.

Before the rubbing alignment process, it is necessary to check whether there is a touch defect between the electrodes, and to eliminate a substrate with a touch defect. However, in the prior art described above, this check is impossible because each electrode is short-circuited in advance.

The present invention prevents the occurrence of defects in the alignment film due to sparks caused by static electricity generated during the rubbing alignment process, and also makes it possible to inspect the presence or absence of poor touch between electrodes before the element is completed. It is.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a discharge electrode capable of discharging at a voltage lower than that of the display part in a place other than the display part for one display electrode before the rubbing treatment, and after the rubbing alignment treatment, this discharge electrode It is intended to remove.

[Effect]

Even if static electricity is generated during the rubbing alignment process and a potential difference occurs between the electrodes, the discharge occurs at the discharge electrodes before the discharge occurs between the display electrodes, so there is no adverse effect on the alignment film of the display section.

〔Example〕

FIG. 1 shows one embodiment of the invention. In the same figure (
(a) is a plan view of the liquid crystal display element with the discharge electrodes, (b) is a cross-sectional view thereof, (C) is a cross-sectional view of the liquid crystal display element with the discharge electrodes removed, and (d) is the discharge electrode section with the discharge electrodes removed. shows. 1
, 2 are glass substrates, and a liquid crystal 5 is sealed in a space formed between the glass substrates with a spacer 6 interposed therebetween. 3 is a display electrode, which is made of ITO (In,
Sn.

Alloy of ○) is a thin film patterned.

4 is an alignment film for aligning the liquid crystal 5; The alignment film is an organic film such as a printed polyimide film, or MgO, M, etc. that is vacuum-deposited or sputtered.
A dielectric thin film such as gFz, SiOx, CeOz, etc. is used. The alignment film 4 is formed to cover the display electrode 3 and is in contact with the liquid crystal 5 . Reference numeral 7 denotes a discharge electrode, which consists of a discharge pattern 8 and a short circuit pattern 9. In Figure 1, it is assumed that the same potential will be applied to the four electrodes after the liquid crystal display element is completed, and these electrodes are connected to a short circuit pattern, but this is not essential and all electrodes are A discharge electrode may be formed for.

In order to align the long axes of liquid crystal molecules in a predetermined direction, it is necessary to rub the surface of the alignment film 4 with silk cloth, synthetic fiber cloth, woolen cloth, etc. to align it in a specific direction.

Static electricity is generated at this time. Conventionally, the voltage between the electrodes caused by static electricity causes discharge in areas where the spacing between the display electrodes is small, as shown by 9 in FIG. 1, which has the disadvantage of causing defects in the alignment film 4. Incidentally, in a fine pattern of display electrode spacing, the spacing is about 30 μm.

In contrast, in the present invention, by providing the f11m pole 7, even if a potential difference occurs between the electrodes due to static electricity, discharge in one display area can be prevented.

After finishing the rubbing alignment treatment of the alignment film 4, the discharge electrodes are removed as shown in FIG. 1(d).

(d) in FIG. 1 is an example of cutting along the cutting line 11 in (a), but the cutting line is not limited to this, and the cutting line is not limited to this. Alternatively, the cut may be made between the discharge pattern and the short-circuit pattern; in any case, the short-circuit pattern may be removed.

FIG. 2 is a modification of FIG. 1. The feature of this embodiment is that the connecting portion 33 between the short circuit pattern and the display electrode is made thinner. Not only the connecting portion 33 with the short circuit pattern but also the discharge pattern portion 34 may be made thinner. This can be determined by considering the appearance.

Figure 3(a) is an enlarged view of the discharge electrode shown at 7 in Figure 1(a).
). The cutting lines 11, 12, and 13 shown in FIG.
This corresponds to the cutting lines 11, 12, and 13 in Figure (a). The shape of the discharge electrode is not limited to that shown in Fig. 3(a).
It suffices if it is easier to discharge than the display electrode, such as in FIGS. (b), (Q), or (d). Furthermore, it is desirable that the discharge starting voltage of the discharge electrode be 1/2 or less of the firing voltage of the display electrode. The reason is that for a pair of display electrodes, f! ! This is because two electrodes are connected in series. In order to lower the discharge starting voltage of the discharge electrode portion, the shape of the electrode may be selected to facilitate discharge, or the gap between the electrodes may be made smaller. However, although the discharge voltage can be lowered by making the protrusion 43 shown in FIG. 3(a) sharper, for example, there is a limit to how sharp the protrusion can be made due to patterning restrictions such as etching. Therefore, it is necessary to reduce the gap between the electrodes. According to experiments.

When the electrodes have a shape as shown in FIG. 3(a), it is desirable that the inter-electrode gap Q in the figure be 1/2 or less of the minimum gap of the display electrode portion.

Although FIG. 1 shows a relatively simple shape of the display section, a similar effect can be obtained even in a complicated pattern with a large number of electrodes, such as a dot matrix. Furthermore, although the terminals are present only on one side of the substrate in FIGS. 1 and 2, the above explanation is exactly the same when terminals are present on both sides or on all four sides.

〔Effect of the invention〕

According to the present invention, it is possible to prevent defects in the alignment film due to sparks caused by static electricity generated during rubbing alignment treatment. Furthermore, since the display electrodes can be inspected for touch defects before the liquid crystal display element is completed, only good parts or products can be processed, and the yield of the final product can be improved.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view of an embodiment of the present invention, and FIG. 1(b) is a plan view of an embodiment of the present invention.
) is a sectional view, FIG. 1(c) is a plan view with the discharge electrode section removed, FIG. 1(d) is a plan view of the removed discharge electrode section, and FIG. 2(a) is the present invention. FIG. 2(b) is a plan view of another embodiment with the discharge electrode section removed, and FIG. 3(a), (b), (c), and (d) are the plan views of the discharge electrodes. It is a figure showing an example of. 1.2... Glass substrate, 3... Display electrode, 4...
Alignment film, 5... Liquid crystal, 6... Spacer, 7... Discharge electrode, 8... Discharge pattern, 9... Short circuit pattern, 1o... Close display electrode, 11.12.13・・・
- Cutting line, 43...Fig. 3 α) (Mu

Claims (1)

[Claims] 1. In a method for manufacturing a liquid crystal display element in which alignment treatment is performed by a rubbing method, a discharge is caused between electrodes at a voltage lower than a discharge starting voltage between adjacent electrodes in a display portion before the rubbing treatment. 1. A method for manufacturing a liquid crystal display element, comprising: means for disabling the means for causing discharge after rubbing treatment, the means for producing a discharge on the same substrate. 2. As a means for causing the discharge, a discharge electrode is patterned on the same substrate using the same material as the display electrode, and the discharge electrode consists of a short line and a discharge pattern connected to each display electrode. A method for manufacturing a liquid crystal display element according to claim 1, characterized in that: 3. The method of manufacturing a liquid crystal display element according to claim 2, wherein the shorting line is connected to one or more display electrodes. 4. The method for manufacturing a liquid crystal display element according to claim 2, wherein the distance between the discharge electrode and the shorting line is 1/2 or less of the minimum value of the distance between the electrodes in the display section. .