JPS58199381A - Manufacture of liquid crystal display element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a liquid crystal display element, and an object of the present invention is to provide an inexpensive liquid crystal display element that has simple manufacturing equipment and manufacturing processes, and uses less precious metal. .

Transparent conductive thin films such as transparent electrodes and wiring parts normally used in liquid crystal display elements have an area resistance value of several tens of Q/R to several hundred Ω/R, and especially in narrow wiring parts, the resistance between both ends The value Fi may reach several hundred Ω.

In order to lower the resistance value, metal coatings such as gold and silver are used for wires with narrow widths that are not noticeable.

Normally, when forming a transparent conductive thin film on a glass substrate in this way, nichrome is often deposited as a base, and a noble metal such as ζ gold or silver is deposited on top of the base and then etched.

However, the prize of expensive gold and scissors is lAt? Full-surface vapor deposition on a glass substrate requires a large amount of precious metals, and the vapor deposition equipment itself as well as the work process are complicated, which increases the cost of liquid crystal cells. This is an attempt to improve the above conventional drawbacks,
It is characterized by forming a transparent conductive thin film consisting of a thin film of silver directly on the surface of the glass substrate by applying a paste containing organic noble metals such as gold or silver as the main component onto the glass substrate by screen printing method and baking it. That is.

Hereinafter, an example of the present invention will be described. First, an Indume tin transparent conductive film is formed on a soda glass substrate by vacuum deposition, and then A-3725 gold paste manufactured by ENGELH△ARD is screen printed on it. was printed on the entire surface of the substrate, and baked at 550°C for 220 minutes.

As a result, a gold film with a film thickness of 4000 angstroms was formed.

On this glass substrate, 0FPR-TYPE2 positive type photoresist (manufactured by Tokyo Ohka Co., Ltd.) tRcP-141,
Apply with a roll coater (manufactured by Dai Nippon Printing Co., Ltd.), and after drying, apply M-3LD mask aligner (manufactured by Mikasa Co., Ltd.)
After exposure, the gold film was etched to form transparent conductive thin films such as wiring portions and transparent electrodes.

Next, in order to ensure the strength of the adhesion of the gold transparent conductive thin film to the glass substrate, a paste mainly composed of organic metals such as aluminum, silicon, and indium is applied onto the glass substrate using a screen printing method. The coating was applied to the entire surface of the glass substrate except for the terminal portions, and baked at 550° C. for 15 minutes to cover the entire surface with a transparent insulating film made of the above metal oxide. After coating the surface with 5H6020 silane coupling agent (manufactured by Toshi Silicone Co., Ltd.), even if the surface of the glass substrate was rubbed strongly with absorbent cotton, the thin gold film on the transparent electrode, including the wiring, did not come off at all. .

When this glass substrate was used to assemble a cell tube and inject liquid crystal to create a liquid crystal display element, good alignment was obtained. This is a relatively easy process 1! As a result, it has become possible to manufacture a dot matrix liquid crystal display element using the gold film M1.

In addition, instead of the metal oxide coating mentioned above, a pK polyamic acid solution (Toshiku Co., Ltd. high purity trenice) was used as N-
It was diluted 5 times with methylpyrrolidone, applied to the entire surface of the glass substrate using a roll coater, dried at 150aC for 120 minutes, and heat-treated at 350@C for 30 minutes to cross-link and polymerize the polyamic acid to form a transparent insulating film of polyimide. Although I rubbed it with absorbent cotton, the narrow gold film wiring did not come off.

When a cell was assembled using this glass substrate and liquid crystal was injected to produce a liquid crystal display element, good alignment was obtained.

Although the above embodiments have been explained using a polyimide film as an organic polymer film which is a transparent insulating film, the present invention is not limited to this (a film such as PVA' may also be used).

As mentioned above, in the present invention, when forming a transparent conductive thin film, a paste containing an organic noble metal as a main component is applied by screen printing method and then baked, so the amount of precious metal used is reduced compared to the conventional vapor deposition method. It requires less metal and is easy to work with, so it is possible to reduce the cost of liquid crystal display elements assembled using metal substrates, and the electrical resistance can be reduced by forming narrow wiring parts with thin gold films. So complex Δ matrix wiring is possible (with calm effect).

Furthermore, if the transparent conductive thin film formed in advance by screen printing is coated with a transparent insulating film such as a metal oxide or organic polymer film, the transparent conductive thin film will be reliably protected and there will be no risks such as peeling. Use the following effects together.

Claims (1)

[Scope of Claims] (1) Paste yi whose main component is an organic noble metal - A thin noble metal film is formed by printing and baking on a glass substrate, and a transparent conductive thin film in a desired shape is formed by photo-etching or other methods on the bare precious metal thin film. A method for manufacturing a two-liquid crystal display element, comprising: forming a transparent conductive thin film, and further forming a transparent insulating film to cover the transparent conductive thin film. (i) The transparent insulation m is a metal oxide film obtained by printing and firing a paste containing an organic metal as a main component. (3) The method for manufacturing a liquid crystal display element according to item (1), wherein the transparent insulating film is an organic polymer film made of polyimide.