JPH0511256A - Formation of spacer for liquid crystal panel - Google Patents

Abstract

PURPOSE:To form spacers having excellent reproducibility of line images with a simple stage without concentrating loads and without having the possibility of attacking oriented films, etc. CONSTITUTION:This method for forming the spacers for a liquid crystal panel which are interposed between two sheets of substrates constituting the liquid crystal panel and support the two substrates includes (1) a stage for laminating a photosensitive sheet constituted by providing an org. high-polymer layer which substantially shuts off oxygen at least at the time of exposing on a flexible base and a photopolymerizable resin layer which can be developed with an aq. developer thereon to at least one of substrates, (2) a stage for peeling the flexible base at need and exposing patterns to at least a part corresponding to the parts of the laminated photopolymerizable resin layer which do not exist on picture element electrodes or the parts which exist on the black stripes constituting color filters and (3) a stage for removing the unexposed parts by development.

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 spacer for a liquid crystal panel, which is interposed between two substrates constituting a liquid crystal panel and supports both substrates.

[0002]

2. Description of the Related Art In a liquid crystal panel, a lower substrate having pixel electrodes, thin film transistors, MIM forming elements, matrix wiring, and the like is opposed to an upper substrate having electrodes, color filters, etc., and liquid crystal is sealed between both substrates. Is configured. And conventionally, in order to determine the thickness of the liquid crystal layer, it is transparent on either substrate (or both substrates in some cases),
Cylindrical or granular minute spacers were scattered, and the spacers were sandwiched between both substrates.

However, according to this method, only a small number of spacers scattered on the convex portion (TFT, MIM type element, electrode wiring portion, etc.) of the lower substrate hits the upper substrate, so that it is supported by this small number of spacers. The load concentrates on the parts that are damaged, which may damage the elements and electrodes.

In order to reduce the load concentrated on the portion supported by the spacers, it is possible to increase the dispersion density of the spacers. In this case, however, many spacers are also scattered on the display section. There was a problem that the contrast was lowered.

As a method for solving these problems, Japanese Patent Application Laid-Open No. 3-89320 discloses that a substrate having a pixel electrode is coated with an ultraviolet curable resin so that a portion not located on the pixel electrode is exposed. A method of curing and then removing the uncured portion to form a spacer is disclosed. According to this method, destruction of elements and wirings can be prevented, and a liquid crystal panel with higher contrast can be obtained.

However, this method requires a long time for coating and drying and the process, and usually a protective layer is further provided to prevent the sensitivity from being lowered due to the influence of oxygen at the time of exposure, thereby avoiding the deterioration of the reproducibility of the image line. It is necessary to prevent a decrease in yield. Further, when the spacer is formed on the side having the black stripe, there is a risk that the solvent may attack the alignment film in contact with the photosensitive resin layer.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a spacer which is free from concentration of load and has excellent reproducibility of image lines in a simple process without fear of damaging an alignment film or the like. To provide.

[0008]

An object of the present invention is to provide an organic polymer layer on at least one of two substrates constituting a liquid crystal panel, which is on a flexible support and at least substantially blocks oxygen during exposure. A step of laminating a photosensitive sheet on which a photopolymerizable resin layer developable with an aqueous developing solution is laminated, the flexible support is peeled off if necessary, and the laminated photopolymerizable resin layer , A step of pattern-exposing and curing at least a part corresponding to a part not located on the pixel electrode or a part located on the black stripe forming the color filter, and removing the unexposed part by development And a step of forming a spacer for a liquid crystal panel. The present invention will be described in detail below.

As the flexible support used for the photosensitive sheet material, a flexible plastic film can be used. Among them, a polyethylene terephthalate film having a thickness of 20 to 200 μm is particularly preferable.

As the water-soluble resin layer that substantially blocks oxygen, various materials described in JP-B-56-40824 can be used.

As the photopolymerizable photosensitive layer, Japanese Patent Publication No. 56-4
Various photopolymerizable compositions described in Japanese Patent Application No. 0824, Japanese Patent Application No. 2-235362 and the publications cited therein can be used. A pigment or the like may be added to the photosensitive layer if necessary.

Further, if necessary, a protective cover film may be provided on the photopolymerizable layer, and an undercoat layer may be provided between the support and the water-soluble organic polymer layer. Hereinafter, the present invention will be described in more detail with reference to Examples.
It is not limited to these.

[0013]

【Example】

Example 1 Referring to JP-A-3-89320, a gate electrode, a pixel electrode, a source electrode, an insulating film,
A lower substrate having a structure such as a drain electrode and a passivation layer was prepared. On the other hand, a photosensitive sheet material having the following constitution was prepared. On a polyethylene terephthalate film of 100 μm, a dry film thickness of 1.5 μm,
Polyvinyl alcohol (PVA205: Kuraray Co., Ltd.)
Manufactured). On top of that, a photosensitive solution having the following formulation was applied so as to have a dry film thickness of 7 μm.

Benzyl methacrylate / methacrylic acid copolymer (molar ratio = 73/27, viscosity = 0.12 [in MEK, 25 ° C.]) 60 g pentaerythritol tetraacrylate 50 g Michler's ketone 2.4 g loffin dimer 2.5 g methyl cellosolve Acetate 560g Methyl ethyl ketone 280g

Furthermore, as a cover film, 1
A 2 μm polypropylene film was laminated.

Using this photosensitive sheet, spacers were prepared as follows. The cover film of the photosensitive sheet material is peeled off, and a laminator (VP-II type) manufactured by Taisei Laminator Co., Ltd. is used on the passivation film of the lower substrate, the heating temperature is 110 ° C., the roller pressure is 2 kg / cm,
The photosensitive layer was laminated at a conveying speed of 0.3 m / min, and the polyethylene terephthalate film was peeled off to form a smooth photosensitive layer. Next, the intersection of the gate electrode and the drain electrode was pattern-exposed through a mask having a diameter of 30 μm, and then developed with an alkaline aqueous solution of pH 10.8 to remove the unexposed portion. The pattern thus formed had a high accuracy of spacing as a spacer, sufficient strength, and had a sufficient area so as not to concentrate the weight.

[0017]

According to the method of the present invention, it is possible to prevent the destruction of elements and electrodes and the deterioration of contrast without concentrating the weight on a part of the spacer. Furthermore, by changing the shape of the spacer pattern, it is possible to facilitate the injection of liquid crystal due to the capillary phenomenon, reduce the amount of expensive liquid crystal, and increase the area of the panel.

Claims (1)

Claim: What is claimed is: 1. A method for forming a spacer for a liquid crystal panel, which supports both substrates by interposing them between two substrates constituting a liquid crystal panel, wherein at least one of the substrates has a flexible support. A step of laminating a photosensitive sheet having an organic polymer layer that substantially blocks oxygen at the time of exposure on the body and a photopolymerizable resin layer developable with an aqueous developer on the body, if necessary. At least a part of the laminated photopolymerizable resin layer, which is not located on the pixel electrode or is located on the black stripe forming the color filter, is peeled off from the flexible support. And a step of removing the unexposed portion by development, a method of forming a spacer for a liquid crystal panel, comprising: