Electrical contact material, method of producing an electrical contact material, and terminal

Patent metadata

Field	Value
Publication number	US-2017076834-A1
Application number	US-201615363518-A
Country	US
Kind code	A1
Filing date	Nov 29, 2016
Priority date	May 30, 2014
Publication date	Mar 16, 2017
Grant date	—

Abstract

An electrical contact material ( 10 ) having: a conductive substrate ( 1 ) formed from copper or a copper alloy; a first intermediate layer ( 2 ) provided on the conductive substrate ( 1 ); a second intermediate layer ( 3 ) provided on the first intermediate layer ( 2 ); and an outermost layer ( 4 ) formed from tin or a tin alloy and provided on the second intermediate layer ( 3 ), wherein the first intermediate layer ( 2 ) is constructed as one layer of grains extending from the conductive substrate ( 1 ) side to the second intermediate layer ( 3 ) side, and wherein, in the first intermediate layer ( 2 ), the density of grain boundaries ( 5 b ) extending in a direction in which the angle formed by the grain boundary in interest and the interface between the conductive substrate and the first intermediate layer is 45° or greater, is 4 μm/μm 2 or less; a method of producing the same; and a terminal.

First claim

1 . An electrical contact material having: a conductive substrate formed from copper or a copper alloy; a first intermediate layer provided on the conductive substrate; a second intermediate layer provided on the first intermediate layer; and an outermost layer formed from tin or a tin alloy and provided on the second intermediate layer,
wherein the first intermediate layer is constructed as one layer of grains extending from the conductive substrate side to the second intermediate layer side, and wherein, in the first intermediate layer, the density of grain boundaries extending in a direction in which the angle formed by the grain boundary in interest and the interface between the conductive substrate and the first intermediate layer is 45° or greater, is 4 μm/μm 2 or less.

2 . The electrical contact material as claimed in claim 1 , wherein the first intermediate layer is formed from any of nickel, a nickel alloy, cobalt, or a cobalt alloy.

3 . The electrical contact material as claimed in claim 1 , wherein the second intermediate layer is formed from copper or a copper alloy.

4 . A method of producing the electrical contact material as claimed in claim 1 , comprising:
plating the first intermediate layer on the conductive substrate at a current density of 10 A/dm 2 or higher; plating the second intermediate layer on the first intermediate layer; and plating the outermost layer on the second intermediate layer; followed by subjecting the resultant electrical contact material to a heat treatment at 100° C. to 700° C. for 30 minutes to 7 seconds.

5 . A method of producing the electrical contact material as claimed in claim 1 , comprising:
plating the first intermediate layer on the conductive substrate at a current density of 5 A/dm 2 or higher; plating the second intermediate layer on the first intermediate layer; and plating the outermost layer on the second intermediate layer, followed by performing area reduction working from above the outermost layer, and subjecting the resultant electrical contact material to a heat treatment at 100° C. to 700° C. for 30 minutes to 7 seconds.

6 . The method of producing the electrical contact material as claimed in claim 5 , wherein the working ratio for the area reduction working is 30% to 70%.

7 . A method of producing the electrical contact material as claimed in claim 1 , comprising:
plating the first intermediate layer on the conductive substrate at a current density of 5 A/dm 2 or higher, followed by performing area reduction working from above the first intermediate layer; plating the second intermediate layer on the first intermediate layer; and plating the outermost layer on the second intermediate layer, followed by subjecting the resultant electrical contact material to a heat treatment at 100° C. to 700° C. for 30 minutes to 7 seconds.

8 . The method of producing the electrical contact material as claimed in claim 7 , wherein the working ratio for the area reduction working is 30% to 70%.

9 . A method of producing the electrical contact material as claimed in claim 1 , comprising:
plating the first intermediate layer on the conductive substrate at a current density of 5 A/dm 2 or higher; plating the second intermediate layer on the first intermediate layer, followed by performing area reduction working from above the second intermediate layer; and plating the outermost layer on the second intermediate layer, followed by subjecting the resultant electrical contact material to a heat treatment at 100° C. to 700° C. for 30 minutes to 7 seconds.

10 . The method of producing the electrical contact material as claimed in claim 9 , wherein the working ratio for the area reduction working is 30% to 70%.

11 . A terminal formed from the electrical contact material as claimed in claim 1 .

Assignees

• Furukawa Electric Co Ltd
• Furukawa Automotive Systems Inc

Inventors

• Okuno Yoshikazu
• Kobayashi Yoshiaki
• Nakatsugawa Tatsuya
• Mitose Kengo
• Tachibana Akira
• Kawata Shingo

Classifications

• H01H1/025

  having copper as the basic material · CPC title

• C25D3/12

  of nickel or cobalt · CPC title

• C25D3/30

  of tin · CPC title

• B21D53/00

  Making other particular articles (making wire fabrics B21F; making chains or chain parts B21L) · CPC title

• H01H1/04

  Co-operating contacts of different material · CPC title