JP2648988B2 - Method of forming spacer for liquid crystal panel - Google Patents

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 provided with pixel electrodes, thin film transistors, MIM forming elements, matrix wiring, and the like is opposed to an upper substrate provided with electrodes, color filters, and the like, and liquid crystal is sealed between the two substrates. It is configured. And conventionally, in order to determine the thickness of the liquid crystal layer, it is transparent on one of the substrates (in some cases, both substrates),
A small cylindrical or granular spacer was sprayed, and both substrates were bonded together with the spacer interposed therebetween.

However, according to this method, only a small number of spacers scattered on the projections (TFT, MIM type element, electrode wiring portion, etc.) of the lower substrate hit the upper substrate, and are supported by the small number of spacers. The load concentrated on the part where it was damaged, which could damage the element and the electrode.

[0004] In order to reduce the load concentrated on the portion supported by the spacers, it is conceivable to increase the scattering density of the spacers. In this case, however, since a large number of spacers are also sprayed on the display portion. There is a problem that the contrast is reduced.

As a method for solving these problems, Japanese Unexamined Patent Publication No. 3-89320 discloses a method in which an ultraviolet-curing resin is applied to a substrate provided with a pixel electrode, and a portion not located on the pixel electrode is removed. A method is disclosed for curing and then removing the uncured portions to form a spacer. According to this method, destruction of elements and wirings is 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. Usually, a protective layer is further provided to prevent a decrease in sensitivity due to the influence of oxygen at the time of exposure, to avoid a deterioration in image reproducibility, and to manufacture the device. It is necessary to prevent the yield from decreasing. In the case where a spacer is formed on the side having the black stripe, there is a risk that the solvent may damage the alignment film in contact with the photosensitive resin layer.

[0007]

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

[0008]

SUMMARY OF THE INVENTION 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, on a flexible support, at least substantially blocking oxygen during exposure. Laminating a photosensitive sheet provided thereon with a photopolymerizable resin layer developable with an aqueous developer, optionally peeling off the flexible support, and laminating the laminated photopolymerizable resin layer. A step of exposing and curing at least a portion corresponding to a portion not located on the pixel electrode or a portion located on the black stripe constituting the color filter, and removing an unexposed portion by development And a step of forming a spacer for a liquid crystal panel. Hereinafter, the present invention will be described in detail.

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

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

The photopolymerizable photosensitive layer is disclosed in JP-B-56-4980.
Various photopolymerizable compositions described in JP-A-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 as needed.

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 based on examples, the present invention,
It is not limited to these.

[0013]

【Example】

Example 1 With reference to JP-A-3-89320, a gate electrode, a pixel electrode, a source electrode, an insulating film,
A lower substrate having a configuration such as a drain electrode and a passivation layer was prepared. On the other hand, a photosensitive sheet material having the following composition was prepared. On a 100 μm polyethylene terephthalate film, a dry film thickness of 1.5 μm
Polyvinyl alcohol (PVA205: Kuraray Co., Ltd.)
Co.) was applied. A photosensitive solution having the following formulation was applied thereon 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 lofin dimer 2.5 g methyl cellosolve Acetate 560 g Methyl ethyl ketone 280 g

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

Using this photosensitive sheet, a spacer was prepared as follows. The cover film of the photosensitive sheet material was peeled off, and a laminator (VP-II type, manufactured by Taisei Laminator Co., Ltd.) was used on the passivation film of the lower substrate at a heating temperature of 110 ° C. and a roller pressure of 2 kg / cm.
The photosensitive layer was laminated at a transport speed of 0.3 m / min, and the polyethylene terephthalate film was peeled off to provide a smooth photosensitive layer. Next, the intersection of the gate electrode and the drain electrode was subjected to pattern exposure through a mask having a diameter of 30 μm, and then developed with an aqueous alkaline solution having a pH of 10.8 to remove unexposed portions. The pattern formed in this way had a high accuracy of spacing and sufficient strength as a spacer, and had a sufficient area to prevent concentration of load.

[0017]

According to the method of the present invention, it is possible to prevent the destruction of elements, electrodes and the like and to prevent the reduction of contrast without concentration of the load on a part of the spacer. Further, by changing the shape of the spacer pattern, it is possible to easily inject liquid crystal due to the capillary phenomenon, reduce the amount of expensive liquid crystal, and increase the area of the panel.

Claims (1)

(57) [Claims] 1. A method of forming a spacer for a liquid crystal panel, which is interposed between two substrates constituting a liquid crystal panel and supports both substrates, wherein at least one of the substrates is provided on a flexible support at least during exposure. A step of laminating a photosensitive sheet having an organic polymer layer that substantially blocks oxygen and a photopolymerizable resin layer developable with an aqueous developer on the organic polymer layer, and, if necessary, peeling off the flexible support Then, at least a portion of the laminated photopolymerizable resin layer corresponding to a portion not located on the pixel electrode or a portion located on the black stripe constituting the color filter is cured by pattern exposure. A method for forming a spacer for a liquid crystal panel, comprising: a step of removing unexposed portions by developing.