JPS58207342A - Electrical contact material for encapsulation - Google Patents

Abstract

PURPOSE:To obtain a composite electrical contact material for sealing consisting of a prescribed percentage of phosphorus nitride and the balance copper, superior to a conventional composite electrical contact material contg. copper-nitride in contact performance, and having especially stable low contact resistance. CONSTITUTION:This composite electrical contact material for sealing contains 1-15wt% phosphorus nitride in copper. Copper powder is mixed with phosphorus nitride powder in a V-shaped mixer for a prescribed time. The powdered mixture is filled into a crucible, and it is repeatedly sintered and compressed until a prescribed density is provided. The resulting material is hot extruded, formed into a wire rod with a drawer, and worked with a header to obtain a rivet type contact or the like. This copper-nitride material shows much superior welding resistance when used in a nitrogen atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrical contact materials for the encapsulation of copper nitride threads. Conventionally, electrical contact materials for encapsulation include silver thread alloy, gold thread alloy,
Composite electrical contact materials made of noble metals such as palladium-based alloys, for example silver-cadmium oxide 12%, have been widely used in various directions because they exhibit excellent contact characteristics in the small to medium current range. However, in recent years, due to the miniaturization of electrical equipment and electronic equipment, the contact characteristics required of electrical contact materials have become more severe, and the conventional silver-oxidizing power
Ram-based composite electrical contact materials have poor welding resistance and are no longer usable. For this reason, there has been a demand for electrical contact materials for encapsulation that have excellent welding resistance (1:1).

On the other hand, in order to reduce the use of precious metals and provide inexpensive contact materials (1), we focused on copper, which has the second highest electrical conductivity after silver and has a melting point higher than silver, and attempted to use contact materials using this as a mother alloy. Attempts have been made to do so.

When copper is used as a bonding material, the corrosion resistance of copper becomes a problem, but this problem is solved by using copper in a vacuum or neutral gas, compared to when precious metals are used as the mother alloy. It has the same characteristics as a 4th grader. In particular, many nitrides have a low melting point, and when a melting point material such as titanium nitride or zirconium nitride is used as a dispersion reinforcing material for copper, the amount of wear is small and it also exhibits excellent welding strength. However, materials such as these whose melting point is low and whose composition changes little due to melting, evaporation, etc., have unstable contact resistance due to an agglomerated layer of dispersion reinforcing material that is generated on the surface layer as the contact is repeatedly opened and closed. It is something that has a tendency to bring about.

The present invention is based on the above circumstances and aims to provide a composite electrical contact material having superior contact performance, especially stable and low contact resistance, than the conventional composite electrical contact material of copper nitride yarn. It's a thing (2).

The electrical contact material for encapsulation of the present invention has 1-15 phosphorus nitride in the body.
The reason why phosphorus nitride was added to the body is that phosphorus nitride has an unstable property of dissociating at 750'C, which prevents the formation of nitride agglomeration bands on the surface of the contact. This is because it has the function of preventing contact resistance and stabilizing contact resistance.

In the electrical contact material of the present invention, the phosphorus nitride that is cooled in the body is set at 1-15% by weight because if it is less than 1%, the copper base will not be sufficiently strengthened, so it will not be resistant to wear. Good results cannot be obtained in terms of properties or welding resistance. Also 1
If the composition exceeds 5% by weight, processing becomes difficult and the electrical conductivity of the material becomes low, so that good results cannot be obtained. For the above reasons, the compositions set forth in the claims are limited, and when these copper-nitride materials are used in a nitrogen atmosphere, they exhibit even better welding resistance.

〔Example〕

Copper powder with an average particle size of 4 μm and phosphorous nitride powder were mixed in a V-type mixer (3) for 3 hours, then the powder was filled into a crucible, and the material 1/1, which was sintered and contracted 1F repeatedly until it reached a predetermined density, was heated. Extruded between. After making this into a wire rod with a wire drawing machine, -2
7D is added by one machine and has the composition shown in Table 1.The diameter of the four parts is 4φ.
Dragon, head ^1.1ms, leg diameter 2.8φ■1, leg J41.
A 6s■ rivet type contact was obtained.

[Conventional Example 1] Copper powder with an average particle size of 4p and titanium nitride were mixed for 3 hours in a type mixer, then the powder was filled into a crucible, and sintering was repeated until a predetermined density was reached. Depending on the machine, the diameter of the four parts is 4φs1, the head is AlIn with the composition shown in the table.
, the leg part was 142.8φ, and a rivet type contact of 1, b s own was obtained on the leg.

[Conventional Example 2] After casting 1 mm silver gold, wire drawing was carried out.
．． 1 dragon, leg diameter 2.8φ crane, leg +, after forming into 6 fl rivet shape, it is 5 air: String that does not undergo internal oxidation at 800℃ - oxidized copper 1 mm, ram 12 weight 9% .

However, the electrical contacts of Conventional Examples 1 and 2 were subjected to a switching test under the test conditions described in (4) F, and the number of openings and closings at the welding point was measured, and the contact resistance and wear were measured as aI. As a result, we obtained the results shown in the right column of the table below.

Test conditions Voltage ^, C, 100V 50Hz Current Supply current 40A, steady current 10A Switching frequency 20 times/min Negative resistance switching number of times Atmosphere until welding occurs Nitrogen atmosphere) Kumi I (column in the table shown in (5) As is clear from the numerical values, the electrical contacts made with the electrical contact material of Example 1 have excellent wear resistance and welding resistance as well as stable and low contact compared to the electrical contact materials of Conventional Example 1.2. I understand that you are showing resistance.

[As described in detail, the composite electrical contact material according to the present invention has superior f#4 weldability and wear resistance compared to conventional electrical contact materials made of string, cadmium oxide, copper nitride, and thread. IS has excellent contact resistance characteristics, so it has contact performance that can withstand harsh usage conditions as electric and electronic devices become smaller. It is considered to be an innovative electrical contact material for encapsulation.

(6)

Claims (1)

[Claims] An electrical contact material for encapsulation that contains 1 to 15% phosphorus nitride (by weight) and the balance is steel.