JPS59111290A - Method of forming electrode of semiconductor heater - 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 Technical Field The present invention relates to a method of forming electrodes by spraying metal onto a ceramic semiconductor element.

BACKGROUND ART Conventionally, when forming an electrode on a surface of a ceramic semiconductor porcelain having many through holes, for example when configuring a semiconductor heater with positive temperature characteristics, a metal spraying method is used in which metal such as aluminum or brass is sprayed at a high temperature. It is known that it is good to apply (Japanese Patent Publication No. 54-30133).

However, in this metal spraying method, the metal is simply sprayed and the electrodes are formed by pricking, so the adhesion strength of the electrode layer is weak and the specific resistance of the electrodes is large, resulting in poor performance as a semiconductor heater, for example, and making it difficult to use. It ends up lacking in durability.

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a method for forming electrodes of a semiconductor heater that can eliminate the above-mentioned drawbacks.

That is, in the method for forming an electrode according to the present invention, after the metal forming the electrode is deposited by thermal spraying, the metal layer is heated and baked at an appropriate temperature.

BEST MODE FOR CARRYING OUT THE INVENTION The following is a description of the best mode for carrying out the invention based on illustrated embodiments.

This embodiment constitutes a semiconductor heater, and electrodes 2 are formed on the surface of a ceramic semiconductor element 1 in the shape of a hollow disk, which has a large number of through holes.

This electrode 2 is formed as a metal layer by heating a metal such as aluminum or brass to a high temperature and spraying it on the surface of the semiconductor element l having the through hole using a thermal spraying device.This thermal spraying process is carried out inside the through hole. In order to prevent the metal from sticking to the surface, it is desirable to spray the metal from an angle of 10° to 60°.After the spraying process, the metal layer is baked in a heating furnace. The heat treatment is preferably carried out at a level that does not oxidize the metal layer, specifically at 450°C to 600°C.
It is sufficient to heat and bake for about 10 minutes at a temperature of .

When baked in this way, the metal layer becomes denser,
By solid-phase sintering of metal, it is possible to firmly adhere to the surface of the semiconductor element 1 and reduce the specific resistance by half.

This ceramic semiconductor A is sandwiched by bringing the electrodes on both sides into contact with power supply plates B and C made of metal plates, respectively, and is fixed to a frame plate made of a heat-resistant insulating resin. It can be used to construct a heater. In this semiconductor heater, a power supply plate B,
The heat generated by the ceramic semiconductor A can be utilized by blowing air through the openings in the C and frame plate and using a hot air heater, etc. However, even in this case, the electrodes are firmly attached to the surface of the semiconductor element 1. Therefore, even if the conductor A is placed on the ceramic plate so that the electrode is located on the air blowing side, the electrode layer will not peel off due to wind pressure.

Effects of the Invention As described above, according to the electrode forming method according to the present invention, the adhesion strength of the electrode can be improved and the specific resistance can be halved.
The performance as a semiconductor heater or the like can be improved and the durability in use can be increased.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a method for forming an electrode according to the present invention, and FIG. 2 is a perspective view of a semiconductor heater incorporating a semiconductor element obtained by the same method. 1 - semiconductor element r forming an electrode; 2: metal electrode layer;

Claims (1)

[Claims] 1. A method for forming an electrode for a semiconductor heater, which comprises depositing a metal to form an electrode by thermal spraying on a desired surface of a ceramic semiconductor element, and then heating and burning the metal layer at a temperature that does not oxidize it.