JPH05265012A - Production of liquid crystal electro-optical device - Google Patents

Abstract

PURPOSE:To improve the productivity of a liquid crystal electrooptical device and to reduce its production cost. CONSTITUTION:In a production method for forming a liquid crystal display device by arranging ultra-violet curing sealing materials 2 at least on one of opposed electrode bases 1, 8, mounting a fixed quantity of liquid crystal 6 at least on the electrode base 1 e.g. and sticking the opposed bases 1, 8 to each other in vacuum, a part of the sealing materials 2 are cured to form a film prior to the contact of the liquid crystal 6 with the materials 2. Since reaction with the liquid crystal 6 can be prevented by the surface films of the materials 2 and single sealing can be attained without using convensional double sealing required for reliability and quality, the improvement of productivity and the reduction of cost can be attained.

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 electro-optical device such as an image display panel of a personal computer or a liquid crystal television.

[0002]

2. Description of the Related Art In a display device used as a small, lightweight and low power consumption display device, a liquid crystal display device is superior to other display devices and has been put into practical use in recent years. As disclosed in JP-A-62-89025 as a conventionally proposed method of manufacturing a liquid crystal display device, a sealing material is arranged on at least one of the opposing electrode substrates, and one kind is provided on at least one of the electrode substrates. There is a manufacturing method in which a certain amount of the above liquid crystal is placed and then the two electrode substrates are bonded together in a vacuum. In the conventional manufacturing method, a UV curable sealing material is practically used from the viewpoint that high productivity and a heat process are unnecessary, and there is nothing that can satisfy all the specifications required as a liquid crystal display device, and its purpose is Depending on the need to make a double seal. That is, FIG. 2 (A)
As shown in (E) to (E), the radical polymerization type sealing material 9 that does not adversely affect the liquid crystal is arranged on the substrate 1, and the cation polymerization type sealing material 2 having excellent moisture resistance is arranged on the outer side of the sealing material 9. There is a method of manufacturing a liquid crystal display electro-optical device in which an appropriate amount of is dropped, the spacer 7 is attached to the counter substrate 8 in a vacuum, pressure is applied, and ultraviolet rays are irradiated to cure the sealing materials 2 and 9.

[0003]

In the conventional manufacturing method,
From the viewpoint of high productivity and unnecessary heat stroke, it is practically most of the cases to use an ultraviolet-curable sealing material. However, as a liquid crystal electro-optical device, there is no ultraviolet curable sealant that can satisfy all the conditions in terms of reliability and quality. For example, when a cationic polymerization type ultraviolet curable sealant is used, it has excellent moisture resistance and adhesive strength. However, there is a problem in that it reacts with the liquid crystal before curing to increase the current consumption.

On the other hand, as a resin which does not react with the liquid crystal, there is a radical polymerization type such as epoxy acrylate, but these are not suitable as a sealing material due to problems such as moisture resistance. When using a UV-curable sealant in the conventional manufacturing method as in the above example, there is no UV-curable sealant that meets all the requirements in terms of reliability and quality when put to practical use. There is a need to. That is, it is necessary to prevent the inner seal material from reacting with the liquid crystal and to have strength and moisture resistance by the outer seal material. This method deteriorates productivity and cost as compared with the single seal.

Therefore, the manufacturing method of the present invention alleviates the restriction due to the reactivity with the liquid crystal as the specifications required for the sealing material, and provides a manufacturing method by a single seal.
In addition, under low pressure when the substrates are bonded together, defoaming may occur depending on the type and viscosity of the sealing material and the arrangement thereof may be disturbed, or the defoaming of the liquid crystal may cause the liquid crystal to come out of the sealing material. There is a problem in manufacturing.

[0006]

In order to solve the above-mentioned problems, in the present invention, a sealing material is arranged on at least one of the opposing electrode substrates, and one or more kinds of liquid crystals are fixed on at least one of the electrode substrates. In the method of manufacturing a liquid crystal display device in which the above-mentioned two electrode substrates are bonded together in a vacuum, when an ultraviolet-curable sealing material is used as the sealing material from the viewpoint of productivity, before the opposing electrode substrates are bonded together. That is, before the UV-curable sealing material was brought into contact with the liquid crystal, the vicinity of the surface of the portion of the sealing material which was in contact with the liquid crystal was subjected to a polymerization reaction by irradiation of ultraviolet rays to form a film on the surface of the sealing material.

Further, defoaming was performed before disposing the sealing material, and defoaming was performed before the liquid crystal was placed on the electrode substrate.

[0008]

By forming a coating film on the surface of the sealing material before the sealing material comes into contact with the liquid crystal as described above, the cationic polymerization type sealing material, which has conventionally required double sealing, is formed by the coating film on the surface. Since there is no reaction, it can be used as a single sealing material, and productivity and cost are greatly improved. Further, by defoaming before placing the sealing material and degassing before placing the liquid crystal on the electrode substrate, the arrangement of the sealing material under low pressure and the outflow of the liquid crystal to the outside of the seal disappeared. As described above, in the present invention, the sealing material is disposed on at least one of the opposing electrode substrates, one or more kinds of liquid crystals are placed on the at least one of the electrode substrates in a certain amount, and then the two electrode substrates are vacuumed. In the manufacturing method for bonding inside, when an ultraviolet curable resin is used as the sealing material, a manufacturing method with higher productivity by a single seal, which could not be practically applied by conventional techniques, is provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1A to 1F are cross-sectional views of the manufacturing method of the present invention. In FIG. 1A, an ultraviolet-curable sealing material 2 is screen-printed on a substrate 1 (a transparent electrode and an alignment film are omitted in FIG. 1) having a transparent electrode and an alignment film formed on glass. It was formed on the square shape. For example, a cationic polymerization type epoxy resin was used as the ultraviolet curing type sealing material. FIG. 1B is a diagram in which an appropriate amount of ultraviolet rays 4 is selectively irradiated through the light-shielding mask 3, and the portion of the sealing material 2 which is in contact with the liquid crystal 6 undergoes a polymerization reaction of the sealing material 1 by the above step (B). The deposited coating 5 was formed.

Thereafter, as shown in FIG. 1D, an appropriate amount of liquid crystal 6 is dropped on the substrate 1 by a dispenser,
As shown in (E), the sealant 2 was cured by bonding it to the counter substrate 8 on which the spacers 7 were previously sprayed in a vacuum and applying pressure, and irradiating with ultraviolet rays (FIG. 1 (F)). The bonding in FIG. 1 is performed at a low pressure. By defoaming before placing the sealing material 2 and defoaming before placing the liquid crystal 6 on the electrode substrate, the placement of the sealing material is disturbed. It was possible to prevent the liquid crystal from flowing out of the seal.

[0011]

According to the present embodiment, a sealing material is arranged on at least one of the opposing electrode substrates, a certain amount of one or more liquid crystals is placed on at least one of the electrode substrates, and then 2
In the method for manufacturing a liquid crystal electro-optical device in which the above electrode substrates are bonded together in a vacuum, when an ultraviolet curing sealing material is used as the sealing material, a film is formed on a portion of the sealing material that contacts the liquid crystal, Due to the reaction of the above, the cationic polymerization type sealing material, which had conventionally required double sealing, does not react with the liquid crystal due to the film on the surface and can be used as a single sealing material, greatly improving productivity and cost. Improved.

Further, the film on the surface prevents the sealing material and the liquid crystal from being mixed with each other, the interface between the sealing material and the liquid crystal is cleaned, and the display quality is improved.

[Brief description of drawings]

1A to 1F are cross-sectional views of a manufacturing method of the present invention.

2A to 2E are cross-sectional views of a conventional manufacturing method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2, 9 UV curable sealing material 3 UV light shielding mask 4 UV 5 coating (a part of UV curable sealing material is cured) 6 Liquid crystal 7 Spacer 8 Counter substrate

Claims (3)

[Claims] 1. A step of disposing an ultraviolet-curable sealing material on the periphery of one electrode substrate, a step of placing a certain amount of liquid crystal on the electrode substrate, and the other electrode facing the electrode substrate. In a method for manufacturing a liquid crystal electro-optical device, which includes a step of bonding a substrate in vacuum and a step of curing the sealing material with ultraviolet rays, at least in a step before the step of bonding both electrode substrates in a vacuum, A method of manufacturing a liquid crystal electro-optical device, comprising a step of irradiating an ultraviolet ray on a surface of a sealing material in which the liquid crystal and the sealing material are in contact with each other to cure the surface. 2. A step of defoaming the sealing material before the step of disposing the sealing material is included.
A method for manufacturing the liquid crystal display device described. 3. The method of manufacturing a liquid crystal display device according to claim 1, further comprising a step of defoaming the liquid crystal before the step of placing the liquid crystal on the electrode substrate.