JPH03203135A - Manufacture of electric contact - Google Patents

Abstract

PURPOSE:To manufacture a long-life electric contact by applying ion beam mixing treatment in which thin film development is used in combination with ion impregnation onto the surface of a contact material formed of either one of silver, silver alloys and silver-oxides. CONSTITUTION:An electric contact base material to be subjected to ion beam mixing treatment is mounted on a base holder 1. Ions such as N and Ar are emitted in the arrowed direction from an ion source, and an evaporated material for thin film formation is supplied from an evaporation source 3. The ion beam cleans the material surface held by the holder 1 by spattering and also piles the metal vapor from the evaporation source 3 into the atomic layer of the material surface by knock-on. An ion beam mixing device has shutters 4, 5, a gas vessel 6, a filament power source 7, an arc electrode 8, a draw power source, a decelerating power source 10, and a film thickness monitor 11. As the evaporated material of the thin film development, for example, materials having boiling points higher than that of silver such as Ti, Zr, Hf, and Pt are used.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing electrical contacts used in relays, switches, etc.

Prior Art and Its Problems Silver, silver alloy, and silver monoxide based contacts are used as conventional power switching contact materials.

The necessary conditions for a contact material are low contact resistance 2, electrical properties such as welding resistance, wear resistance, and transfer resistance, and workability that allows it to be formed into a shape according to the purpose. No matter how good the electrical properties are, if it is difficult to process, it cannot be used practically. For this reason, only a limited number of contact materials are in practical use. Furthermore, from the viewpoint of reliability and life, a comprehensive design that takes into account issues such as contact shape and surrounding heat radiation is required, but these are already reaching their limits.

However, on the other hand, as equipment that uses this type of electrical contact is used in conjunction with semiconductors, market demands for improved reliability and longevity are increasing, and conventional contact materials cannot meet these demands. I can't.

One possible solution to this problem is to form a thin film on the surface of the contact material by vapor deposition or sputtering in order to modify the surface of the contact material, but this method also has the following problems. . That is, although there is no limit to the evaporated material used to form a thin film, since a layer of evaporated material is basically formed on the surface of the contact material, the electrical characteristics of the contact material largely depend on the physical properties of the evaporated material. Furthermore, the adhesion between the thin film layer and the base material is insufficient.

SUMMARY OF THE INVENTION OBJECTS OF THE INVENTION The present invention provides a new manufacturing method capable of manufacturing electrical contacts with excellent electrical properties, high reliability, and long life.

Structure of the Invention 1 Functions and Effects The method for manufacturing an electrical contact according to the present invention is to apply an ion beam using a combination of thin film growth and ion implantation to the surface of a contact material made of silver, silver alloy, or silver monoxide. ◆It is characterized by performing mixing processing.

It is preferable to use a substance with a higher melting point than silver as the evaporator for thin film growth.

Further, it is preferable to simultaneously use a substance having a higher melting point than silver and a substance similar to the base material of the contact material as the evaporated product for thin film growth.

According to this invention, an electrical contact is manufactured by an ion beam mixing process that combines thin film growth and ion implantation on the surface of a contact material. Ion beam mixing completely mixes the thin film and the contact material matrix, so it
It is possible to form new mixed layers that are not possible with sputtering. In addition, a large implantation amount and thickness (depth) that cannot be obtained with ion implantability alone can be obtained. Since it is based on a thin film growth process, it is possible to use substances that are difficult to ion-implant into evaporated materials alone. In this way, a new layer can be formed on the surface of the electrical contact.

It is expected that electrical contacts with excellent electrical properties, high reliability, and long life will be realized. Furthermore, to perform the above processing after creating the desired contact shape.

It also becomes possible to inject substances that are difficult to process.

DESCRIPTION OF THE EMBODIMENTS Ion beam mixing can be used to increase the implantation dose and the thickness of the modified layer. ion·
The combination of thin film growth and ion implantation in beam mixing can thoroughly mix the thin film and material matrix to form a new mixed or alloy layer.

Figure 1 shows a diagram of the principle of the ion beam mixing device. A material to be subjected to ion beam mixing treatment (electrical contact base material) is attached to the substrate holder 1. From the ion source 2, N, Ar, and Ne are supplied.

Ions such as 0 and H are emitted in the direction of the arrow in the figure.

The evaporation source 3 supplies a substance (evaporated material) for forming a thin film. The ion beam cleans the surface of the material held in the holder by sputtering and
It functions to knock-on the metal vapor from the evaporation source 3 into the atomic layer on the surface of the material. In FIG. 1, reference numeral 4.5 indicates a gas container for the shutter 56, 7 for a filament power source, 8 for an arc power source, 9 for an extraction power source, 10 for a deceleration power source, and 11 for a film thickness monitor.

A substance with a higher melting point than silver is used as the evaporated material for thin film growth. For example, Ti, zr, Hf', VNb, W, Re
, Ru, Os, Rib, Ir, Pt, etc. Alternatively, the above-mentioned high melting point substance and a substance similar to the base material of the contact material may be generated from separate evaporation sources as evaporates for thin film growth, and the ion beam mixing process may be performed.

(Example 1) Ir was used as an evaporation source and Ar was ion-implanted into a silver-cadmium oxide silver monoxide contact material. The element distribution in the depth direction obtained at this time is shown in FIG. For comparison, FIG. 3 shows the element distribution in the depth direction when ion implantation is performed alone.

[A+r ion implantation conditions]

Energy: 6 (lKeV Injection amount: l x 10'ions/cj' Ar+ beam intensity: 800 μA Average degree of vacuum during implantation: 5 to 8 x 10-6 Torr (
Example 2) Adding Ir and A to the silver monoxide contact material of silver-oxidizing donium
g-Cd is evaporated from separate sources.

Ion implantation was performed at 0. The element distribution in the depth direction obtained at this time is shown in FIG.

[Ion implantation conditions for 0+] Energy: 55KeV Implantation amount: 2 x 101 ions/cdO+ beam intensity near 00μA Average degree of vacuum during implantation: 5 to 8 x 1O-6 Torr In this case, when ions are implanted with oxygen, Ag-Cd is It reacts with oxygen and is mixed in the ion beam in the form of Ag-Cd0.

Here, Ag-Cd may be evaporated as an alloy, or
It is also possible to evaporate g and Cd from separate evaporation sources and perform mixing during the ion◆ beam.

In addition, Ir and Ag-C are used as contact materials for silver-cadmium oxide.
The same effect as in Example 2 was obtained even when a contact material made by performing ion beam mixing treatment with Ne and Ar as ion sources was treated in an oxidizing atmosphere at 700°C for 15 minutes using d as an evaporation source and Ne and Ar as ion sources. can get.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an outline of the structure of an ion or beam mixing device. FIG. 2 is a graph showing the element distribution in the depth direction obtained in Example 1, and FIG. 3 is a comparative example. 7 is a graph showing the element distribution in the depth direction in the case of ion implantation alone. FIG. 4 is a graph showing the element distribution in the depth direction obtained in Example 2. that's all

Claims (3)

[Claims] (1) A method for manufacturing an electrical contact in which an ion beam mixing process using a combination of thin film growth and ion implantation is performed on the surface of a contact material made of silver, a silver alloy, or a silver monoxide system. (2) The method for manufacturing an electrical contact according to claim (1), characterized in that a substance having a higher melting point than silver is used as the evaporated material for thin film growth. (3) The method for manufacturing an electrical contact according to claim (1), characterized in that a substance having a higher melting point than silver and a substance similar to the base material of the contact material are simultaneously used as the evaporated product of thin film growth.