Conductive member and method for producing the same

Abstract

Disclosed is a conductive member having a stable contact resistance, which is hardly separated and requires a small inserting / drawing force when used as a connector. The conductive member is characterized in that a Cu-Sn intermetallic compound layer (3) and an Sn surface layer (4) are formed in this order on the surface of a Cu substrate (1) through an Ni base layer (2); the Cu-Sn intermetallic compound layer (3) is composed of a Cu3Sn layer (5) arranged on the Ni base layer (2) and a Cu6Sn5 layer (6) arranged on the Cu3Sn layer (5); the Cu-Sn intermetallic compound layer (3) obtained by bonding the Cu3Sn layer (5) and the Cu6Sn5 layer (6) is provided with recesses and projections in the surface which is in contact with the Sn surface layer (4); thicknesses X at the recessed portions (7) are set to 0.05-1.5 [mu]m; the area coverage of the Cu3Sn layer (5) relative to the Ni base layer (2) is not less than 60%; the ratio of the thicknesses Y at the projected portions (8) to the thicknesses at the recessed portions (7) in the Cu-Sn intermetallic compound layer (3) is 1.2-5; and the average thickness of the Cu3Sn layer (5) is 0.01-0.5 [mu]m.

Description

technical field [0001] The present invention relates to a conductive member used for electrical connection connectors and the like, in which a plurality of plated layers are formed on the surface of a base material made of Cu or a Cu alloy, and a method for manufacturing the same. [0002] This application claims priority based on Japanese Patent Application No. 2009-9752 filed in Japan on January 20, 2009 and Japanese Patent Application No. 2009-39303 filed in Japan on February 23, 2009, the contents of which are incorporated herein. Background technique [0003] As conductive components such as connectors for electrical connection in automobiles or connection terminals of printed circuit boards, in order to improve electrical connection characteristics, etc., Sn-based metal plating is often applied on the surface of Cu-based substrates composed of Cu or Cu alloys. conductive parts. [0004] As such a conductive member, there exist the conductive members described in Paten...

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Problems solved by technology

[0009] However, when such a connector or terminal is used in a high-temperature environment such as around an automobile engine, for example, as high as about 150°C, due to long-term exposure to the high temperature, Sn and Cu will thermally diffuse into each other and the surface state will easily change over time. And there is a tendency to increase the contact resistance

In addition, there is also the risk of peeling off due to the formation of Kirkendall voids on the surface of Cu-based substrates due to the diffusion of Cu, and it is desired to solve these problems

[0010] On the other hand, the conductive member described in Patent Document 4 has the problem that the base plating layer of Fe-Ni or Fe has poor adhesion to Cu and is easily peeled off.

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