JP2000193987A - Formation of seal of liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a substrate spacing uniform and to enhance the display grade of a liquid crystal panel by making the dispersion density in the sealing material in a gap forming material uniform by heating the sealing material. SOLUTION: The sealing material 8 heated by a heater 7 is formed on a substrate 4 by using a screen 5 and a squeegee 6. Thermosetting resins, such as epoxy resins, acrylic resins and phenolic resins, are used for the sealing material 8 and fillers, hardeners, polymerization initiators, etc., are used as additives. Glass fibers and silica balls are added as gap forming materials to such thermosetting resins to exhibit the function as the sealing material 8. The sealing material 8 which is increased in the amount of the fillers to be added into the thermosetting resins and is increased in viscosity is used. In such a case, the environment of screen printing is heated by a heater 7 to heat the sealing material 8 at temperature higher than ordinary temperature, by which the viscosity of the sealing material 8 is lowered and the dispersion density of the gap forming materials in the sealing material 8 is made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a seal for a liquid crystal display panel in which a liquid crystal material is sealed off from outside air in a cell between substrates stacked at a constant interval.

[0002]

2. Description of the Related Art Conventionally, two substrates are maintained at a constant interval,
There are screen printing method, dispenser method, etc. as a method of forming a sealant on the inner surface of the opposing substrate in order to seal the liquid crystal material in the cell by making the substrates adhere to each other. As a sealing agent, a curing agent, a polymerization initiator, a filler, etc. are mixed with a thermosetting resin such as an epoxy resin, an acrylic resin, and a phenol resin, and a gap is formed in the resin to keep a constant distance between substrates. As a material, there is one mixed with glass fiber and silica sphere.

[0003]

In the formation of a seal for a liquid crystal panel, when a sealant is formed on the inner surface of an opposing substrate so that the distance between the substrates is uniform, the positional accuracy of the substrates to be bonded is improved. Therefore, if the amount of the filler mixed with the sealant is increased, the viscosity of the sealant increases, and the gap forming material mixed in the sealant is not uniformly dispersed in the sealant. As shown in the conceptual diagram of the seal formation, when the sealant 2 is screen-printed on the substrate 1, the density of the gap forming material 3 in the sealant 2 is low on the printing start side 2 a of the sealant, and the printing end side of the sealant 2 is low. In the case 2b, the density of the gap forming material 3 in the sealant 2 increases, so that the distance between the substrate 1 and the substrate (not shown) becomes non-uniform.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a seal in which the distance between opposing substrates does not become uneven in forming a seal by a screen printing method.

[0005]

In order to solve this problem, the present invention provides a method in which two substrates are stacked at a constant interval.
When a sealant is formed by screen printing on the inner surface of an opposing substrate to form a cell between the substrates and seal the liquid crystal material in the cell, the distance between the substrates is kept constant by heating the sealant. This is a method for forming a seal for a liquid crystal display panel in which the dispersion density of a gap forming material added to maintain the sealant is uniform, and a liquid crystal panel with a uniform substrate interval can be obtained.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, two substrates are stacked at a constant interval, a cell is formed between the substrates, and a liquid crystal material is sealed in the cell.
When forming the sealant on the inner surface of the opposing substrate by screen printing, by heating the sealant,
This is a method of forming a seal for a liquid crystal display panel in which the dispersion density of the gap forming material added to keep the substrate spacing constant in the sealant is uniform, and the sealant is heated by heating the sealant when forming the sealant. This has the effect that the viscosity of the agent decreases, the dispersion density of the gap forming material in the sealant becomes uniform, and the distance between the substrates becomes constant.

According to a second aspect of the present invention, in the liquid crystal display according to the first aspect, the viscosity of the sealant is set to 100 to 1000 p while maintaining the temperature of the sealant at 10 to 25 ° C. higher than room temperature. This is a method for forming a seal for a panel, and has an effect of keeping the intervals between substrates uniform.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment) FIG. 1 is a conceptual perspective view of an apparatus for implementing a method of forming a seal of a liquid crystal display panel by a screen printing method according to one embodiment of the present invention. A screen 5 and a squeegee 6 are mounted on a substrate 4. A state is shown in which the sealant 8 heated and heated by the heater 7 is used.

In this case, the sealant 8 is made of epoxy resin,
A thermosetting resin such as an acrylic resin or a phenol resin is used, and a filler, a curing agent, a polymerization initiator, or the like is used as an additive. To this thermosetting resin, glass fiber and silica spheres are added in an amount of 1 to 3% by weight as a gap forming material to generate a function as the sealant 8. The sealant 8 is used in which the amount of the filler added to the thermosetting resin is increased and the viscosity is increased in order to improve the accuracy of the bonding position between the two substrates. Although the viscosity is 1500 to 2000 p, when the sealant 8 is applied as it is on the substrate 4 by screen printing, the dispersion density of the gap forming material in the sealant 8 becomes uneven during the application, and the seal is formed in that state. Even when the substrates are overlapped, the substrate spacing becomes non-uniform.

In the method for forming a seal according to the present embodiment,
The environment of the screen printing is heated by the heater 7, and the viscosity of the sealing agent 8 is reduced to 100 to 1000 p by heating the sealing agent 8 to a temperature higher by 10 to 25 ° C. than the normal temperature. This is to make the dispersion density of the gap forming material uniform.

[0011] As described above, the seal on the substrate formed by screen-printing the sealant having a uniform dispersion density of the gap forming material on the substrate is overlapped by two.
It has the function of making the distance between the substrates uniform.

[0012]

As described above, according to the method of forming a seal for a liquid crystal display panel of the present invention, the distance between two superposed substrates becomes uniform, and a liquid crystal panel with good display quality can be obtained. .

[Brief description of the drawings]

FIG. 1 is a conceptual perspective view of an apparatus for performing a method for forming a seal of a liquid crystal display panel according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of forming a seal by a conventional method of forming a seal for a liquid crystal display panel.

[Explanation of symbols]

 1, 4 Substrate 2, 8 Sealing agent 2a Printing start side of sealing agent 2b Printing end side of sealing agent 3 Gap forming material 5 Screen 6 Squeegee 7 Heater

Claims (2)

[Claims] 1. A method in which two substrates are stacked at a constant interval,
When a sealant is formed by screen printing on the inner surface of the opposing substrate to form a cell between the substrates and seal the liquid crystal material in the cell, the distance between the substrates is kept constant by heating the sealant. A method for forming a seal for a liquid crystal display panel in which a dispersion density of a gap forming material added for maintaining the dispersion in a sealant is made uniform. 2. The heating of the sealant is performed at a temperature of 10 to 10 from normal temperature.
Keeping the temperature at 25 ° C. higher, the viscosity of the sealant is 100 to
2. The method for forming a seal for a liquid crystal display panel according to claim 1, wherein the pressure is 1000p.