JPH11249124A - Production of liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce irregular display caused by static electricity generated at the time of a polarizing film affixing process. SOLUTION: After a pair of transparent electrode substrates 1a and 1b having transparent electrodes are affixed through a peripheral seal member 6, liquid crystals are filled between these transparent electrode substrates 1a and 1b to form a panel element. Prior to affixing polarizing films 2 and 2 onto the surface of the above panel element, the panel element is heated above an ordinary temperature. Such an extremely simple method for previously heating the panel element before the polarizing film affixing process reduces line-shaped irregular display caused by static electricity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display panel, and more specifically, to reduce display unevenness caused by static electricity generated during the manufacture as much as possible and to increase production efficiency. And a method for manufacturing a liquid crystal display panel.

[0002]

2. Description of the Related Art FIG. 1 shows a well-known typical example of a liquid crystal display panel. FIG. 1 (A) is a plan view and FIG. 1 (B) is a longitudinal sectional view thereof. That is, the liquid crystal display panel includes a pair of transparent electrode substrates 1a and 1b having transparent electrodes formed on surfaces facing each other.

In the case of a dot matrix type display element, display electrodes are formed on one transparent electrode substrate 1a, for example, in the form of stripes along the X-axis direction, and on the other transparent electrode substrate 1b, Y electrodes perpendicular to the display electrodes are formed. The display electrodes are formed in stripes along the axial direction. Note that an alignment film is further provided on each display electrode.

In the example shown in FIG. 1, the transparent electrode substrates 1a and 1b are bonded to each other via a peripheral sealing material 6 with an in-plane spacer (not shown) arranged between the display electrodes. On one transparent electrode substrate 1a,
Terminal portions 3 projecting to the side of the other transparent electrode substrate 1b are continuously provided.

[0005] Although not shown, the terminal portion 3 includes:
An electrode terminal connected to the display electrode of each of the transparent electrode substrates 1a and 1b is formed. In this case, the other transparent electrode substrate 1b
Are electrically connected to predetermined electrode terminals of the terminal unit 3 via a transfer (not shown) in the peripheral sealing material 6.

After bonding the transparent electrode substrates 1a and 1b, a liquid crystal as an electro-optical medium is sealed in the sealing layer 4 between them. Thus, a panel element is formed, and then the polarizing films 2 and 2 are attached to the surface of the panel element.

In manufacturing a liquid crystal display panel, static electricity is generated in various steps to charge the panel, but the amount of charge when the polarizing film 2 is attached is the largest. The electric charge charged on the liquid crystal display panel is discharged, for example, when the terminal portion 3 comes into contact with a terminal having a relatively low volume specific resistance when the panel is sent to the next step. At that time, the charging state of the alignment film and the in-plane spacer in the region serving as the discharge path locally changes, so that the threshold voltage of the liquid crystal display panel locally changes. In the case of a dot-type electrode pattern, linear display unevenness occurs.

In order to prevent this, conventionally, a conductive tape 5 is attached so as to straddle each electrode terminal of the terminal portion 3 and each display electrode is set to the same potential, thereby preventing local discharge. , To reduce display unevenness based on this.

[0009]

However, since such a local discharge mainly occurs in the process up to the step of connecting the liquid crystal drive circuit, the conductive tape 5 is rather obstructive after the step of connecting the liquid crystal drive circuit. It will be.

[0010] In addition, a step of attaching the conductive tape and a step of removing the conductive tape are required, which is not preferable in terms of work. In addition, it has been pointed out that an adhesive containing a carbon material is generally used for the conductive tape, which causes problems such as a short circuit due to the remaining adhesive, and insufficient adhesion strength of TCP due to dirt. Furthermore, since the price of the conductive tape is high, this is a factor that increases the panel manufacturing cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a liquid crystal display panel capable of reducing display unevenness caused by static electricity without using a conductive tape or the like. It is to provide a manufacturing method of.

[0012]

In order to achieve the above object, according to the present invention, a pair of transparent electrode substrates each having a transparent electrode are bonded via a peripheral sealing material, and then a liquid crystal is sealed between the transparent electrode substrates. In the method for manufacturing a liquid crystal display panel including each step of attaching a polarizing film to the surface of the panel element, and before the polarizing film attaching step,
The method is characterized in that after the panel element is heated to a temperature higher than room temperature in advance, the same polarizing film attaching step is performed.

The reason why the adoption of this process drastically reduces the charge amount of the panel and suppresses display unevenness due to local discharge is not necessarily clear, but the molecular motion of the liquid crystal sealed in the panel element is activated by heating. It is considered that one of the causes is that the polarizability decreases.

The heating temperature of the panel element is preferably from 40 to 95 ° C., particularly preferably from 45 to 80 ° C., although it depends on the type of liquid crystal. If the temperature is too low, the effect of suppressing charging is reduced. If the temperature is too high, adverse effects such as breakage of the substrate or deterioration of the adhesive of the polarizing film occur. In addition, there are various means for heating the panel element. However, in terms of facility such as introduction cost, heating by infrared irradiation is preferable.

[0015]

Next, embodiments of the present invention will be described. Note that the configuration of the liquid crystal display panel itself is the same as that of the above-described conventional example, and therefore, please refer to FIG. 1 described above.

First, transparent electrode substrates 1a and 1b on which a transparent electrode and an alignment film are respectively formed are prepared, and in-plane spacers are scattered in the display area.
1b are opposed to each other and bonded to each other via a peripheral sealing material 6 to form a panel element.

After the liquid crystal as an electro-optical medium was sealed in the sealing layer 4 of the panel element, the panel element was heated to 70 ° C. by infrared heating means. With the heating temperature maintained, the panel element was sent to a polarizing film attaching step, and the polarizing films 2 and 2 were attached to the surface of the panel element.

By the way, when the conductive film 5 is not applied to the terminal portion 3 of the panel element and the polarizing film is applied without heating the panel element, 50% of the
As described above, line-shaped display unevenness caused by static electricity was observed. If this state is left as it is, the inspection process is not allowed, so that it is necessary to wait until the display unevenness disappears. However, since this takes a relatively long time, conventionally, the lead time for manufacturing the liquid crystal display panel has been long.

On the other hand, in the case of the present invention, in the polarizing film attaching step, line-shaped display unevenness caused by static electricity occurred less than 20%, and the lead time was shortened and the yield was improved. Is achieved.

In the above example, the panel shown in FIG. 1 is described in which the terminal portions are concentrated on one side by transfer, but the terminal portions of the segment electrode and the common electrode are formed on different substrates. A similar effect is exhibited in the panel. The present invention is also applicable to a single wafer line. Furthermore, it goes without saying that the preheating of the panel element is not limited to the step of attaching the polarizing film, but may be extended to the steps before and after.

[0021]

As described above, according to the present invention,
By a very simple method of heating the panel element before the polarizing film attaching step, it is possible to reduce line-shaped display unevenness caused by static electricity.

Therefore, the conventional process of attaching and detaching the conductive tape is not required, so that the productivity can be further improved and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view for explaining a general configuration of a liquid crystal display panel and a longitudinal sectional view thereof.

[Explanation of symbols]

 1a, 1b Transparent electrode substrate 2 Polarizing film 3 Terminal part 4 Encapsulation layer 6 Peripheral sealing material

Claims (3)

[Claims] After a pair of transparent electrode substrates having transparent electrodes are pasted together via a peripheral sealing material, liquid crystal is sealed between the transparent electrode substrates to form a panel element, and a polarizing film is provided on the surface of the panel element. In the method of manufacturing a liquid crystal display panel including each step of attaching, before the polarizing film attaching step,
A method for manufacturing a liquid crystal display panel, wherein the panel element is heated to a temperature higher than room temperature in advance, and then the same polarizing film attaching step is performed. 2. The heating temperature of the panel element is 40 to 95.
The method according to claim 1, wherein the temperature is ° C. 3. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the panel element is heated by infrared irradiation.