JP2001350149A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable method for manufacturing liquid crystal display device that can certainly and efficiently inject an adequate amount of a liquid crystal into a liquid crystal cell. SOLUTION: The liquid crystal is brought into contact with the liquid crystal cell in a state swollen by surface tension by using a material with the maximum value of critical surface tension γc to be 20 (mN/m) as the upper limit of a liquid crystal boat 5, for example, a Teflon (registered trademark) (PTFE) material or a material coated with a Teflon material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a liquid crystal display device is shown in FIG.
And a method shown in FIG.

First, there is a method shown in FIG. 5 in which the entire lower portion of a liquid crystal cell is immersed in a liquid crystal tank 7 containing a relatively large amount of liquid crystal. However, in this method, a large amount of liquid crystal adheres not only to the lower part of each liquid crystal cell but also to the magazine 4 holding the liquid crystal cell, which may cause waste of the liquid crystal or cause impurities to be mixed into the liquid crystal.

Therefore, as shown in FIG. 6, liquid crystal is supplied to a liquid crystal boat 5 having a narrow groove shape, the liquid surface of the liquid crystal is raised by surface tension, and only the inlet of each liquid crystal cell is brought into contact. In addition, the adhesion of the liquid crystal can be reduced, the liquid crystal can be saved, and the contamination of the liquid crystal with impurities can be further reduced.

[0005]

However, in such a conventional method of manufacturing a liquid crystal display device, the liquid crystal boat 5
There is a problem in that the liquid crystal that has been raised in contact with the liquid crystal cell comes out of the liquid crystal boat 5 at the moment of contact with the liquid crystal cell, and spills, resulting in poor injection due to insufficient liquid crystal.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a method of manufacturing a stable liquid crystal display device with less injection failure.

[0007]

In order to solve the above-mentioned problems, the present invention is to reduce the material of the liquid crystal holding surface, that is, the upper surface of the liquid crystal boat, as much as possible so that the upper limit of the critical surface tension γc is 20 (mN / m). Material, for example, Teflon tetrafluoride (P
TFE) makes it easy to raise the liquid level by increasing the contact angle of the liquid crystal.

According to the above manufacturing method, the liquid crystal raised by the surface tension can be maintained on the upper surface of the liquid crystal holding surface, and the liquid crystal cell hardly spills from the outside of the liquid crystal boat even at the moment of contact with the liquid crystal. A stable injection operation with few defects can be performed.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. Embodiment 1 FIG. 1 shows a method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a liquid crystal cell in a vacuum apparatus, which is sealed with a sealing material 2 provided with a liquid crystal injection port 3, and liquid crystal is injected therein. The liquid crystal cell 1 is held by a magazine 4 so that the inlet 3 faces downward, and a narrow groove-shaped liquid crystal boat 5 is placed under the inlet 3 so that the liquid crystal 6 rises due to surface tension. Or made of stainless steel or aluminum coated with a Teflon material, and the liquid crystal 6 is supplied into the groove with a dispenser or the like. After evacuation in this state, the magazine 4 is lowered or the liquid crystal boat 5 is raised to bring the inlet 3 into contact with the liquid crystal 6. Thereafter, the liquid crystal 6 is injected into the liquid crystal cell 1 by releasing the vacuum pressure to the atmospheric pressure.

FIGS. 2 and 3 are cross-sectional views of the liquid crystal 6 before the liquid crystal is injected. The liquid crystal boat 5 has grooves formed at the center and both sides, respectively, and supplies the liquid crystal 6 to the center groove. However, even if the liquid crystal 6 spills to the outside, it stops at the grooves on both sides and does not spill further. So consider
In FIG. 2, the liquid crystal is raised inside the center groove,
The rising amount A of the liquid crystal 6 from the upper surface of the liquid crystal boat 5 is 0.
About 2 mm to 0.8 mm is desirable. If you try to raise it further, it will travel along the upper part of the outer wall of the central groove and
Is unstable because it spreads.

On the other hand, FIG. 3 shows a method in which the liquid crystal is raised outside the central groove and the outer wall. Since the contact angle can be increased in this case, the rising amount B of the liquid crystal 6 is wide from 0.2 mm to 1.5 mm. A stable state can be realized in the region.

The width and depth of the central groove are appropriately set according to the required amount of liquid crystal according to the size of the liquid crystal cell to be used and the design dimensions of the width of the injection port formed of the sealing material.

Next, FIG. 4 is a sectional structural view at the moment when the liquid crystal cell is brought into contact with the liquid crystal after evacuation in the vacuum device. Normally, the liquid crystal cell is made of glass and has better wettability than Teflon, so that the liquid crystal 6 spreads along the lower surface of the glass, but the outermost upper surface of the liquid crystal boat 5 is slightly spaced from the lower surface of the glass. It is. Therefore, there is no fear that the liquid crystal will be transmitted to the outside of the liquid crystal boat 5 and spilled, and poor injection can be prevented.

As described above, according to the manufacturing method of the first embodiment of the present invention, a more stable injection operation with less injection failure can be performed.

[0015]

As described above, according to the method of manufacturing a liquid crystal display device of the present invention, a required minimum amount of liquid crystal can be more efficiently injected, and a stable injection operation with less injection failure can be performed.

[Brief description of the drawings]

FIG. 1 shows a method for manufacturing a liquid crystal display device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a configuration example in which a part of the embodiment shown in FIG. 1 is enlarged.

FIG. 3 is a diagram showing another configuration example in which a part of the embodiment shown in FIG. 1 is enlarged.

FIG. 4 is a diagram showing still another configuration example in which a part of the embodiment shown in FIG. 1 is enlarged.

FIG. 5 is a diagram showing an example of a conventional liquid crystal injection method.

FIG. 6 is a diagram showing another example of a conventional liquid crystal injection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal cell 2 Sealing material 3 Inlet 4 Magazine 5 Liquid crystal boat 6 Liquid crystal 7 Liquid crystal tank

Claims (3)

[Claims] 1. A liquid crystal display device comprising: holding means for holding a liquid crystal cell; a liquid crystal holding surface partially immersed in liquid crystal; and vertical driving means for relatively vertically moving the holding means and the liquid crystal holding surface. A liquid crystal injection device into a liquid crystal cell including the holding unit, the liquid crystal holding surface, and the vertical driving unit, and further including a vacuum container capable of changing an internal pressure; The upper limit of the surface tension γc is 20
(MN / m),
A method for manufacturing a liquid crystal display device. 2. The method for manufacturing a liquid crystal display device according to claim 1, wherein the material of the liquid crystal holding surface is a Teflon tetrafluoride (PTFE) material or a material coated with a Teflon material. 3. The liquid crystal is 0.2 mm from the upper surface of the liquid crystal holding surface.
2. The method for manufacturing a liquid crystal display device according to claim 1, wherein the liquid crystal display device is held in a state of being raised by 1.5 mm from the height.