JPS603724B2 - Method for forming transparent conductive pattern - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing glass with a transparent electrode pattern used in various display elements such as liquid crystal panels, plasma displays, electroluminescence, and the like.

Conventionally, as a method for forming a transparent electrode pattern on glass, {1} After coating the entire surface with a transparent conductive film, a pattern is formed by photoetching.

[2] After coating the entire surface with a transparent conductive film, a resist ink is printed and etched to form a pattern.

'31 After printing with printing ink containing metal oxide, a transparent conductive film is coated, and the printing ink is removed to form a transparent conductive film.

There was a method like this.

However, the method of {11] has the disadvantage that the photo-etching process is very complicated, requires many techniques, and the manufacturing cost is very high.

Method (2) has a considerably simpler process and lower manufacturing costs than method '1', but since it involves an etching process, it poses a pollution problem and is also quite difficult to automate. The '31 method is the method described in Showa No. 113573, but compared to {1} and {2' method, the process is very simple and there is no etching process. Although this method is good and does not cause any pollution, since powdered metal oxides are used as the shielding composition, due to its hygroscopicity and compatibility with other mixtures, when it is synthesized as a printing ink, it may cause sudden changes in viscosity properties. Precipitation of metal oxides occurs, and even if it is possible to print temporarily, it is impossible to print many times continuously, and it cannot be used to significantly reduce the number of steps when manufacturing transparent electrode patterns.

The present invention was carried out in order to eliminate the above-mentioned conventional drawbacks, and aims to provide a method for stably manufacturing products with uniform quality while reducing the number of steps.

Examples of the present invention will be described in detail below.

In the present invention, the characteristics of the printing ink are the most important point in order to manufacture products with uniform and stable quality.

The properties necessary for a stable printing ink are as follows. '1' There should be no change in ink properties for a long period of time after ink synthesis.

In particular, there should be no change in viscosity. [2] Screen printing should not cause any self-curing.

Rigidity The ability to make the edges of a printed pattern sharp. '
4- Must have sufficient heat resistance, chemical stability, and shielding effect at a temperature of around 500°C when coating the transparent conductive film.

Various inks have been synthesized as printing inks that satisfy the above-mentioned characteristics, but all of the printing inks that use shelchloride nitride as the optimum heat-resistant particles, nitrified wire as the binder, and butyl carbitol as the solvent have all the above-mentioned characteristics. Satisfied.

The blending ratio was approximately 10:10:1 (nitrification line: 1) by weight.

The nitride column used here as a shielding substance is chemically stable at temperatures below 900°C, does not react with other mixtures, provides long-term stability of the ink, and shows no reaction when coated with a transparent conductive film. Moreover, since particles with an average particle size of 2 to 3 peaks are used, sharp edges can be obtained during printing.

Butylcarpitol used as a solvent has the lowest vapor pressure among the various solvents for nitrified cotton, so there is no drying during printing and no clogging occurs.

Furthermore, stable printing can be achieved by appropriately varying the mixing ratio to facilitate printing. It goes without saying that in the process of printing this printing ink mainly composed of shelchloride nitrides onto a transparent substrate, screen printing is performed to obtain a negative of the desired pattern to be finally obtained. The ink after printing on glass does not solidify for a long time at room temperature, but if you want to preserve it before coating with a transparent conductive film, please use 1.
By heating at 50 qo for several minutes, the butyl carbitol evaporates and the printing ink solidifies. In other words, if the coating process described below is performed immediately after the printing process,
Coating may be performed directly after printing, but if the printed substrates are to be stored for a long time, the drying step described above is necessary to prevent ink from spreading. The glass substrate after printing is heated to about 500° C. and coated with a transparent conductive film of tin oxide.

During this heating, butyl carbitol evaporates and the nitrification line is completely burned.

The exhaust gas generated at this time has an adverse effect on the tin oxide coating film, so this exhaust gas is removed. In this way, the printing ink is burned and only the powdered chloride is deposited on the glass substrate as a residue. Therefore, when heated at 500° C., only the indoor shelving elements remain in a pattern, and the transparent conductive film is shielded. After the glass coated with the transparent conductive film is cooled, the shielding material thereon is removed.

At this time, the coating film on the shielding material (shelf nitride) is also naturally removed. This peeling is very easy because the shielding material is completely composed of nitrided shelphic particles, and can be done by any method such as ultrasonic cleaning, peeling with a brush, or gently rubbing by hand. In this way, the printed pattern (negative pattern) is completely removed, and a desired pattern shape is formed using the transparent conductive film. As described above, according to the method for manufacturing a transparent electrode pattern of the present invention, by using a continuous type transparent electrode coating device, there is no need for a batch process at all, and the entire process can be made continuous. It is possible to significantly reduce the cost of manufacturing display devices such as liquid crystal panels.

Claims (1)

[Claims] 1 A process of screen printing a printing ink mainly composed of boron nitride on a transparent substrate, a process of coating a transparent conductive film on the printed transparent substrate while heating it to about 500 ° C., and a process of burning the printing ink. A method for forming a transparent conductive pattern, comprising a step of removing generated residue.