JPS62220902A - Optical bonding method of transparent substrate to substrate with color filter - Google Patents

Abstract

PURPOSE:To remove an excessive adhesive and air bubbles and to perform efficient adhering operation by putting a liquid adhesive between a color filter substrate and a transparent substrate and rotating a spinner head. CONSTITUTION:The color filter substrate 2 is set on the spinner head 1 and the transparent substrate 4 is fixed temporarily across the liquid adhesive 3; and then the spinner head 1 is rotated to remove the excessive adhesive 3 and air bubbles and thus the substrates are adhered together. The adhesive 3 has 300-500cps viscosity and means transmissivity in the visible light range suitably to optical adhesion and is an insoluble type preferably. An ultraviolet-ray irradiation setting type adhesive is small in setting man-hour, so that operation is efficient. Further, when an epoxy thermosetting adhesive is used, its adhesive strength is large, so the yield at the time of the subsequent cutting of the glass substrate is high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a manufacturing method for bonding a color filter-equipped substrate and a transparent substrate.

[Conventional technology]

When color display is performed by combining a color filter and a liquid crystal display element, the electro-optical characteristics of the liquid crystal display element are not deteriorated, and the parallax between the color filter and the lit part when viewed from an oblique direction is reduced. As shown in FIG. 2, a structure has been proposed in which a transparent electrode substrate 7 having a thickness that can reduce the parallax to a practically acceptable level is fixed to a filter-equipped substrate 5 via an adhesive layer 6.

Conventional methods for bonding color filter substrates and transparent substrates include: 1. A method in which a film adhesive is sandwiched between the color filter substrate and the transparent substrate, heat-compressed with a hot roller or press, and then processed in an autoclave. 2. Color filter substrate and A method has been considered in which transparent substrates are bonded together via a liquid adhesive 3 in vacuum or air, and then excess adhesive is pushed out from the adhesive layer using a rubber roller or the like. But 1. In this method, when a thermoplastic film such as PVB is used as the film adhesive, it is very difficult to cut the substrate. Furthermore, when using a thermosetting film adhesive such as an epoxy adhesive, it is necessary to press at high temperature and pressure, which may adversely affect the optical properties of the color filter. For the above reasons, usually Z
The most common method is to use an ultraviolet-curing or thermosetting liquid adhesive, as in It was unsuitable for mineral production.

[Problem that the invention seeks to solve]

The present invention eliminates the need for wiping off excess adhesive when bonding a color filter substrate and a transparent substrate using a liquid adhesive, and achieves an inexpensive color liquid crystal display device with good display quality. The goal is to provide the following.

[Means for solving problems]

In order to solve the problems of the prior art as described above, the present invention sets a color filter substrate on a spinner head, temporarily fixes the transparent substrate with liquid adhesive, and then rotates the spinner head to remove excess adhesive. By removing the agent and air bubbles and adhering, the adhesive work can be performed efficiently.

[Effect]

It is desirable that the adhesive used in carrying out the present invention 2 satisfies the following conditions.

α: The viscosity is 300 to s o c'ps or less.

b: The average transmittance in the visible light range is a characteristic suitable for optical adhesives.

C: Must be solvent-free.

In addition, as the adhesive actually used, an ultraviolet curable adhesive is more efficient because it requires fewer steps for curing. or,
When an epoxy thermosetting adhesive is used, the adhesive strength is high, so the yield when cutting the glass substrate later is good.

〔Example〕

The present invention will be explained using examples.

Example 1: To explain the process of bonding 0.1t glass with lTO to a color filter substrate, referring to FIG.
1.1 t) Fix 2 by vacuum suction. Drop UV curable adhesive 3 (1500P20) there. Furthermore, place Q with engineering TO and 1t glass 4 on top of it and temporarily fix the square. and 50s at 2500 rpm
et: Rotate. After this, ultraviolet rays are irradiated from the TO side to complete the bonding. Thereafter, the 170th surface is coated with photoresist, and the TO is patterned using alignment marks previously made in the 2-filter pattern.

Example 2 A color filter-attached substrate is fixed to a spinner head by vacuum suction, and an epoxy thermosetting adhesive is dropped thereon. Hereinafter, in the same manner as in Example 1, the spinner head was rotated with the TO substrate placed on it, and after temporary bonding, the temperature was 160°C to 180°C.
It was dried for about an hour.

〔Effect of the invention〕

According to the present invention, the adhesive sandwiched between the substrates is blown off from between the substrates to the periphery by the centrifugal force of rotation, so that the surface portions of the two substrates to be bonded together are not contaminated. Furthermore, if an ultraviolet curable adhesive is used as the adhesive, high temperature, high pressure equipment, etc. are not required, and the energy costs necessary for pasting can be reduced. Roughly speaking, according to the present invention, the thickness of the adhesive layer can be set to a desired value by controlling the rotation speed and rotation time of the spinner. Therefore, even adhesives that are slightly colored can be used by reducing the thickness of the adhesive layer sufficiently.

As described above, according to the present invention, a transparent substrate can be easily attached to a color filter-equipped substrate, so that a highly reliable color liquid crystal display device with good display quality can be provided by applying the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1(a) to 1(C) are diagrams showing the process of attaching TO glass to a color filter-equipped substrate according to the present invention. FIG. 2 is a diagram showing an example of a color liquid crystal display element in which a TO electrode is formed on a CF according to the present invention. In Fig. 1, 1...Spinner head 2...Substrate with color filter 3...Ultraviolet curable adhesive 4...2nd α1T glass with ITo In the figure, 5... Force 2 - Substrate with filter 6... Adhesive layer 7... Substrate with TO electrode Above Figure 1

Claims (1)

[Claims] Optical adhesion of a transparent substrate to a substrate with a color filter, which is characterized by the following steps a and b when bonding the transparent substrate to the substrate with a color filter using a liquid adhesive: Method. (a): A substrate with a color filter is fixed to a spinner head, and an adhesive is dropped onto the surface of the color filter. (b): Above (a): Temporarily fix the transparent substrate to be attached onto the substrate and rotate the spinner head to remove excess adhesive and air bubbles from the adhesive layer and adhere.