Electrical contact material, terminal fitting, connector, wire harness, and electrical contact material manufacturing method

Patent metadata

Field	Value
Publication number	US-11228127-B2
Application number	US-202016897356-A
Country	US
Kind code	B2
Filing date	Jun 10, 2020
Priority date	Jun 27, 2019
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

Provided is an electrical contact material that can suppress an increase in contact resistance even if contact pressure with a counterpart material is small. An electrical contact material that includes a base material made of metal, a metal layer provided on a surface of the base material, and an oxide layer provided on a surface of the metal layer. The metal layer is made of metal that contains zinc, copper, and tin, the oxide layer is made of an oxide that contains zinc, copper, and tin, and beneath the oxide layer, a ratio of the atomic concentration of copper to the atomic concentration of tin is less than 1.4.

First claim

What is claimed is:

1. An electrical contact material comprising:
a base material made of metal;
a metal layer provided on a surface of the base material; and
an oxide layer provided on a surface of the metal layer, wherein:
the metal layer is made of metal that contains zinc, copper, and tin,
the oxide layer is made of an oxide that contains zinc, copper, and tin,
beneath the oxide layer, a ratio of the atomic concentration of copper to the atomic concentration of tin is less than 1.4, and
in the oxide layer,
the atomic concentration of oxygen is more than 0 atom % and is equal to or less than 70 atom %,
the atomic concentration of zinc is more than 0 atom % and is equal to or less than 70 atom %,
the atomic concentration of copper is more than 0 atom % and is equal to or less than 30 atom %, and
the atomic concentration of tin is more than 0 atom % and is equal to or less than 30 atom %.

2. The electrical contact material according to claim 1 , wherein
the oxide layer has an average thickness of 1 nm to 1000 nm inclusive.

3. The electrical contact material according to claim 1 , wherein
the metal layer includes:
a first metal layer provided on the base material side; and
a second metal layer provided on the oxide layer side, and

the first metal layer is made of an alloy that contains two or more types of elements selected from a group consisting of zinc, copper, and tin, and
the second metal layer is made of tin or a tin alloy.

4. The electrical contact material according to claim 3 , wherein
the first metal layer has an average thickness of 0.1 μm to 5 μm inclusive.

5. The electrical contact material according to claim 3 , wherein
the second metal layer has an average thickness of 0.1 μm to 5 μm inclusive.

6. A terminal fitting made of the electrical contact material according to claim 1 .

7. A connector comprising
the terminal fitting according to claim 6 .

8. A wire harness comprising:
an electrical wire; and
the connector according to claim 7 that is attached to the electrical wire.

9. A wire harness comprising:
an electrical wire; and
the terminal fitting according to claim 6 that is attached to the electrical wire.

10. An electrical contact material manufacturing method, comprising:
a step of manufacturing a coated material by plating a first layer, a second layer, and a third layer on at least a part of a surface of a base material in the order from the surface of the base material; and
a step of subjecting the coated material to thermal treatment under oxygen atmosphere at a temperature of 232° C. to 500° C. inclusive,
wherein, in the step of manufacturing the coated material,
the first layer is made of metal that contains tin,
the second layer is made of metal that contains zinc,
the third layer is made of metal that contains copper,
the first layer has a thickness of 3.5 μm to 5 μm inclusive,
the second layer has a thickness of 0.1 μm to 0.6 μm inclusive, and
the third layer has a thickness of 0.05 μm to 0.4 μm inclusive, and

wherein, an oxide layer is formed on a surface of the coated material, and in the oxide layer,
the atomic concentration of oxygen is more than 0 atom % and is equal to or less than 70 atom %,
the atomic concentration of zinc is more than 0 atom % and is equal to or less than 70 atom %,
the atomic concentration of copper is more than 0 atom % and is equal to or less than 30 atom %, and
the atomic concentration of tin is more than 0 atom % and is equal to or less than 30 atom %.

Assignees

• Autonetworks Technologies Ltd
• Sumitomo Wiring Systems
• Sumitomo Electric Industries

Inventors

• Shirai Yoshimasa
• Saito Yasushi
• Furukawa Kingo
• Kumondai Mitsuhiro
• Hosoe Akihisa

Classifications

• C25D5/505

  of electroplated tin coatings, e.g. by melting · CPC title

• C25D7/00

  Electroplating characterised by the article coated · CPC title

• H01R13/03 Primary

  characterised by the material, e.g. plating, or coating materials · CPC title

• H01R4/185

  combined with a U-shaped insulation-receiving portion · CPC title

• C25D7/0607

  Wires · CPC title