JPS5814006B2 - Selective removal method of oxidized conductive film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for selectively removing an oxidized tin conductive film.

In the past, attempts have been made to use an indium oxide film because of its strong chemical resistance, but it has not been used much because the etching method is difficult, and an indium oxide transparent conductive film is generally used.

There are various methods for etching suzu oxide, but each method has its own problems.

(1) Electrolytic etching: Etching is performed by gradually immersing Suzu oxide in an electrolytic etching solution such as hydrochloric acid as a negative electrode.

However, this method has problems such as not being able to form electrodes using patterns, being time consuming, and requiring a pattern forming process using photoresist.

(2) Zinc method: A photoresist pattern is created on the isuzu oxide film, and a paste-like zinc powder is further applied on top of this.
After drying, immerse it in an etching liquid such as hydrochloric acid.

However, this method has problems such as weak adhesion of the zinc powder, peeling in the etching solution, and non-uniform removal of the surface, leaving unevenly oxidized residue.

(3) Zinc evaporation method: A photoresist pattern is formed on the tin oxide film, zinc is evaporated thereon, and the pattern is immersed in an etching solution.

However, with this method, the upper temperature limit of the photoresist is low, the strength of the deposited film is low, and it is easy to peel off, and when zinc is deposited using a deposition mask, the accuracy is low due to the adhesion of the mask, etc. There is a problem.

The present invention is intended to solve the above problems,
By applying a paste made by kneading zinc powder onto the ISUZU oxide transparent conductive film in a desired pattern and heating it,
A selective method of oxidized tin oxide that eliminates the need for photoresist creation process and post-use resist stripping process, provides a homogeneous and clean removed surface, and allows for highly accurate oxidized tin transparent conductive patterns to be obtained in a short time. It provides a removal method.

Examples thereof will be described below.

The following two types of kneaded materials are used.

■ A mixture of zinc powder, acrylic ester, and starch; ■ A mixture of zinc powder, acrylic ester, nitrocellulose, and acetyl butyryl cellulose. These zinc powders have a particle size of 200 mesh or more (particle radius of approximately 70 μm or less). Good results can be obtained.

Any of these mixtures should have a viscosity of about 5,000 so that it can be easily printed with a silk screen on the glass substrate 1 having the tin oxide film 2 shown in FIG. Adjust and apply between centipoise and 200,000 centipoise.

The silk screen pattern 4 is made so that the above-mentioned mixture is printed and applied to the areas to be removed other than the desired oxidized tin pattern.

After printing, the substrate is heated to 100-150°C and further heated to 3500-450°C in an air atmosphere, for example 430°C.

The zinc powder thereby melts and forms a thin film on the tin oxide.

At this time, the resin creates a highly reducing atmosphere through thermal decomposition.

When the substrate is immersed in concentrated hydrochloric acid at 50 DEG C., only the patterned portion 3 made of zinc in FIG. 2 is dissolved, leaving the portion 2' in FIG. 3.

Further, since the resin residue is dissolved in the etching solution, only the desired oxidized Izuzu pattern 2' can be obtained after etching.

The effects of the present invention are listed below.

(1) No pattern creation process using photoresist is required.

(2) There is no need for a resist stripping process after etching.

(3) The thermal decomposition of the resin turns the residue into ash, which does not affect others, and the reducing atmosphere can prevent the oxidation of zinc.

(4) A homogeneous removed area can be obtained.

(5) As for accuracy, a silk screen accuracy of 100 microns can be obtained.

(6) Since it can be processed at relatively low temperatures, it does not affect glass or oxidized isuzu.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a glass substrate in a state where a tin oxide film is formed according to the present invention, FIG. 2 is a perspective view of a glass substrate after printing and heating a zinc mixture according to the present invention, and FIG. FIG. 2 is a perspective view of a glass substrate after etching according to the invention. 1... Glass substrate, 2... Suzu oxide film, 2'...
Tin oxide pattern (desired pattern), 3... Zinc mixture pattern, 4... Silk screen pattern.

Claims (1)

[Claims] 1. After applying a paste prepared by kneading zinc powder onto a transparent conductive film of Isuzu oxide in a desired pattern,
The zinc is melt-adhered onto the oxidized isocarbon and selectively removed by immersion in an etching solution. Selective removal method of oxidized tin conductive film,