JPH1031223A - Manufacturing method of liquid crystal display element - Google Patents

Abstract

(57) [Problem] To provide a method for manufacturing a liquid crystal display element capable of securing a uniform predetermined gap over the entire surface of a panel. SOLUTION: When the sealing material 13 formed on the bonded electrode substrates 11 and 12 is cured, a partition layer 16 is formed to partition the cell from the outside of the cell, and an environment in which the pressure is higher than the pressure in the bonded electrode substrate. The sealing material 13 is cured below, and at least a part of the partition layer is removed, and liquid crystal is injected into the cell. Due to the pressure difference between the inside and outside of the cell caused by the provision of the partition layer 16, the entire surfaces of the bonded electrode substrates 11 and 12 can be uniformly pressed. In this state, the gap uniformity can be obtained by curing the sealing resin. A liquid crystal display element excellent in quality can be manufactured.

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 Liquid crystal display devices include personal computers, word processors,
It has been applied to liquid crystal televisions, etc., and has recently been widely used as OA displays and projection TVs.
The display quality is improving year by year.

In general, characteristics such as response speed, contrast, viewing angle, and display uniformity of a liquid crystal display element are closely related to the thickness of a liquid crystal layer, that is, a cell gap. In a liquid crystal display element, a liquid crystal sandwiched between two electrode substrates is sealed with a sealing material, and a spacer for securing a gap of a liquid crystal cell exists in the sealing material and between the electrode substrates.

A general method of manufacturing such a liquid crystal cell is to seal or seal a liquid crystal by printing or dispensing a resin adhesive containing glass fiber on an electrode substrate while leaving a liquid crystal injection port. As a spacer for forming a material and securing a gap between the substrates, resin or silica spheres are uniformly dispersed in the electrode substrate, and the two electrode substrates are bonded to each other. Then, the sealing material is cured while pressing the electrode substrate to secure a predetermined cell gap, and unnecessary portions of the electrode substrate are cut to complete a liquid crystal cell,
Liquid crystal is injected into the liquid crystal cell by a conventional method such as a vacuum injection method, and finally the liquid crystal injection port is sealed to complete the liquid crystal display device.

[0005] Here, in order to ensure the uniformity of the cell gap, the bonded electrode substrate is pressed uniformly,
It is necessary to cure the sealing material. Conventionally, a spacer 43 is provided between a lower surface plate 41 and an upper surface plate 42 as shown in FIG.
Substrate 4 on which a sealing material 44 is printed and bonded by dispersing
5 and then pressurize the electrode substrate with the upper and lower stools 41 and 42 and simultaneously heat and cure the sealing material to form a liquid crystal display element.

FIG. 4 shows a thermocompression bonding method, while FIG. 5 shows a conventional compression bonding method using vacuum packaging. The electrode substrate 45 bonded with the spacers 43 dispersed and printed with the sealing material 44 is placed in a vacuum packaging bag 51, the vacuum packaging bag 51 is closed under vacuum, and the pressure is returned to atmospheric pressure. , And then the sealing material 44 is cured in a heating furnace, whereby a liquid crystal display element is formed.

[0007]

However, in the conventional thermocompression bonding method, if a foreign substance is mixed in when the electrode substrate is placed on the surface plate, the gap becomes uneven and the electrode substrate is damaged. In addition, generally used thermosetting sealing materials need to be cured for 1 hour or more at a high temperature of 150 ° C., and a pressurized / heated platen that requires high flatness even at a high temperature is required. is necessary. In terms of productivity, it is necessary to stack liquid crystal panels, and the
Due to thermal strain caused by the temperature gradient of the stacked liquid crystal panels, the gap becomes uneven, which is not suitable for mass production.

In the crimping method using vacuum packaging,
Although the sealing material can be cured with high productivity while the liquid crystal panel is uniformly pressed, a vacuum packaging facility and a step of opening the vacuum packaging are required. The problem is that the process becomes complicated and the cost increases due to the use of vacuum packaging bags.

In addition, a photo-curable resin is used as a sealing material. In this case, a hard plate of a light-transmitting portion or a light-transmitting vacuum packaging bag is required to cure the sealing material. The cost rises.

An object of the present invention is to provide a method of manufacturing a liquid crystal display element having high gap uniformity and suitable for mass production.

[0011]

According to a method of manufacturing a liquid crystal panel of the present invention, a barrier layer is formed around an electrode substrate to cure the sealing material of the bonded electrode substrate. The sealing material is cured under an environment higher than the pressure in the bonded electrode substrate by partitioning the cell outside from the cell.

According to the present invention, the gap uniformity is high and the liquid crystal display device can be mass-produced.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In a method for manufacturing a liquid crystal panel according to the present invention, two electrode substrates are bonded to each other with a sealing material for sealing a liquid crystal therebetween, and the two electrode substrates are pressed. Curing the sealing material to form a liquid crystal cell,
In a method of manufacturing a liquid crystal display element in which liquid crystal is injected into a liquid crystal cell, when the sealing material is cured, a partition layer is formed around the bonded electrode substrate to form a cell formed between the electrode substrates with the outside of the cell. Partitioning, curing the sealing material under an environment higher than the pressure in the bonded electrode substrate,
Thereafter, at least a part of the partition layer is removed, and liquid crystal is injected into the cell.

According to this structure, the entire surface of the bonded electrode substrate can be uniformly pressed by the pressure difference between the inside and the outside of the cell caused by the provision of the partition layer, and the sealing resin is cured in this state. Thus, a liquid crystal display device having excellent gap uniformity can be manufactured.

In the case where the partition layer is formed under reduced pressure below atmospheric pressure and the sealing material is cured under atmospheric pressure,
The hardening of the sealing material can be performed with high productivity without requiring special equipment.

Further, a partition layer is formed under an environment of atmospheric pressure,
When the sealing material is cured in an environment exceeding atmospheric pressure, the introduction of a seal curing device in a high-pressure environment
The formation of the partition layer can be performed under the environment of the atmospheric pressure, and the production cost can be reduced.

Hereinafter, embodiments of the method for manufacturing a liquid crystal display device according to the present invention will be described with reference to FIGS. (Embodiment 1) FIGS. 1 and 2 show (Embodiment 1), and FIG. 2 shows a manufacturing process of the liquid crystal cell before liquid crystal injection shown in FIG.

In this liquid crystal cell, a sealing material 13 mixed with glass fiber 14 is printed on an electrode substrate 11, spacers 15 are dispersed, and an opposing electrode substrate 12 is attached. This is one in which a partition layer 16 is formed.

In the curing step of the sealing material 13, the pressure P _IN between the bonded electrode substrates 11 and 12 and the external pressure P _OUT
However, the sealing material is cured in a state of “ _PIN < _POUT ”.

More specifically, as shown in FIG.
Then, a glass fiber 1 of φ5 μm is placed on the electrode substrate 11.
4 is mixed with 2 wt% of the sealing material 13 (manufactured by Mitsui Toatsu Chemicals, Inc .: ES-5500) by screen printing, and 50 to 200 resin beads having a diameter of 5 μm are dispersed as spacers 15 to 200 / mm ² . The electrode substrates 11 and 12 are bonded together.

In the step (b), the electrode substrate 1
The substrates 1 and 12 are put in a decompression container 17 having an internal pressure of 0.1 Torr, and an ultraviolet-curable resin (manufactured by ThreeBond: 3502B) 18 is applied around the bonded substrates 11 and 12 by a dispenser 19, and then irradiated with ultraviolet rays. Was cured to form a partition layer 16. Therefore, the internal pressure of the panel at this point is “P _IN = 0.1 Torr”.

Then, in the step (c), 150
When the electrode substrates 11 and 12 are put in a high-temperature furnace 20 ° C., a state similar to that when the electrode substrates 11 and 12 are pressed as indicated by arrows 21 and 22 occurs due to a pressure difference between the inside and outside of the cell. Material 13 was cured.

Thereafter, the entire partition layer 16 is removed or only the portions necessary for injecting the liquid crystal are removed, and the electrode substrates 11 and 1 are removed.
2 is injected into the cell formed between
A liquid crystal display element was manufactured by closing the opening of the liquid crystal display.

According to this method, the entire surface of the bonded electrode substrate can be uniformly pressed, and by curing the sealing resin in this state, a liquid crystal display element having excellent gap uniformity can be manufactured.

Further, since the partition layer 16 is formed under reduced pressure below the atmospheric pressure and the sealing material 13 is cured under the atmospheric pressure environment, the curing of the sealing material 13 can be performed with high productivity without requiring special equipment. It can be carried out.

(Embodiment 2) FIG. 3 shows (Embodiment 2)
Is shown. In the first embodiment, the partition layer 16 is formed in an environment where the pressure is lower than the atmospheric pressure.
In this method, a partition layer is formed under an environment of atmospheric pressure, and the sealing material is cured under an environment exceeding atmospheric pressure.

Specifically, in the step (a), the electrode substrate 11
Material 14 mixed with 2 wt% of a glass fiber of φ5 μm on the surface (Mitsui Toatsu Chemical Co., Ltd .: ES-550)
0) is screen printed, and the spacer 13 is φ5 μm.
After dispersing 50 to 200 beads / mm ² of resin beads of
The two electrode substrates 11 and 12 are bonded.

In the step (b), the bonded electrode substrate 1
UV curable resin 1 around the substrate under atmospheric pressure
8 (manufactured by ThreeBond: 3502B) with dispenser 19
Then, the resin was cured by irradiating ultraviolet rays to form a partition layer 16.

Then, in the step (c), 150 ° C., 2 kg
/ Cm ² high temperature / high pressure furnace 23, electrode substrate 1
Arrows 21 and 12 are indicated by arrows 21 and 12 depending on the pressure difference between the inside and outside of the cell.
A state similar to that when pressing was performed as shown in FIG. 2 occurred, and the sealing material 13 was cured by being left in this state for 2 hours.

Thereafter, the entire partition layer 16 is removed or only the portions necessary for injecting the liquid crystal are removed.
2 is injected into the cell formed between
A liquid crystal display element was manufactured by closing the opening of the liquid crystal display.

The cell gap of the obtained liquid crystal display element was measured with an interference gap measuring device (MS-200, manufactured by Otsuka Electronics Co., Ltd.).
, The average cell gap was 5.015 μm
And the deviation against it was 0.005 μm.

According to this method, the partition layer is formed under the environment of the atmospheric pressure, and the sealing material is cured under the environment exceeding the atmospheric pressure. The formation can be performed in an environment of atmospheric pressure, and the production cost can be reduced.

[0033]

As described above, according to the present invention, a partition layer is formed around the bonded electrode substrate to partition the cell formed between the electrode substrates from the outside of the cell, and to control the pressure difference between the inside and outside of the cell. The entire surface of the electrode substrate can be uniformly pressed, a special device is not required at the time of curing the seal, and a large amount of liquid crystal display elements excellent in uniformity of a predetermined gap at low cost can be manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a liquid crystal cell in a manufacturing process of a first embodiment.

FIG. 2 is a manufacturing process diagram of a main part of the embodiment.

FIG. 3 is a manufacturing process diagram of main parts of (Embodiment 2);

FIG. 4 is an explanatory view of a manufacturing method using a conventional thermocompression bonding method.

FIG. 5 is an explanatory view of a manufacturing method using a conventional vacuum packaging method.

[Explanation of symbols]

11, 12 Electrode substrate 13 Seal material 14 Glass fiber 15 Spacer 16 Partition layer _PIN Pressure between bonded substrates (inside partition layer) _POUT Pressure outside bonded substrate (outside partition layer)

Claims (3)

[Claims] 1. A liquid crystal display device comprising a sealing material for enclosing a liquid crystal.
A method for manufacturing a liquid crystal display element, in which two electrode substrates are bonded to face each other and the sealing material is cured while the two electrode substrates are pressed to form a liquid crystal cell and inject liquid crystal into the liquid crystal cell, When curing the sealing material, a partition layer is formed around the bonded electrode substrate to partition the cells formed between the electrode substrates from the outside of the cell, and in an environment higher than the pressure in the bonded electrode substrate. And curing the sealing material, then removing at least a part of the partition layer, and injecting a liquid crystal into the cell. 2. A partition layer is formed under reduced pressure below atmospheric pressure.
2. The method according to claim 1, wherein the sealing material is cured under an atmospheric pressure environment. 3. The method for manufacturing a liquid crystal display device according to claim 1, wherein the partition layer is formed under an environment of atmospheric pressure, and the sealing material is cured under an environment exceeding atmospheric pressure.