Electric contact and connector terminal pair

Patent metadata

Field	Value
Publication number	US-9692162-B2
Application number	US-201415036883-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Dec 4, 2013
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

An electric contact includes a bulge-shaped contact having a bulge shape, and a plate-shaped contact that has a plate shape and comes into electrical contact with an apex portion of the bulge-shaped contact. The bulge-shaped contact has a silver-tin alloy layer and a silver coating layer that coats the surface of the silver-tin alloy layer and is exposed at an outermost surface. The plate-shaped contact has a silver layer that does not have a silver-tin alloy layer directly below and is exposed at the outermost surface. Also, a connector terminal pair has such an electric contact in a contacting portion.

First claim

The invention claimed is:

1. An electric contact comprising:
a bulge-shaped contact having a bulge shape; and a plate-shaped contact that has a plate shape and comes into electrical contact with an apex portion of the bulge-shaped contact, wherein
the bulge-shaped contact has a silver-tin alloy layer and a silver coating layer that coats a surface of the silver-tin alloy layer and is exposed at an outermost surface,
the plate-shaped contact has a silver layer that does not have a silver-tin alloy layer directly below and is exposed at the outermost surface, and
the silver layer formed at the plate-shaped contact is thicker than the silver coating layer formed at the bulge-shaped contact.

2. The electric contact according to claim 1 , wherein
the silver coating layer formed at the bulge-shaped contact is thinner than the silver-tin alloy layer.

3. The electric contact according to claim 1 , wherein
at the bulge-shaped contact, a primer metal layer that coats a surface of a base material and contains nickel or copper as a main component is formed, and the silver-tin alloy layer is formed in contact with the primer metal layer.

4. The electric contact according to claim 3 , wherein
the primer metal layer is made of nickel or a nickel alloy, and a portion of the nickel forms an alloy with tin included in the silver-tin alloy layer.

5. The electric contact according to claim 1 , wherein
at the bulge-shaped contact, a thickness of the silver-tin alloy layer is in a range of 1 to 45 μm and a thickness of the silver coating layer is in a range of 0.5 to 15 μm.

6. The electric contact according to claim 1 , wherein
a contact resistance between the bulge-shaped contact and the plate-shaped contact is not more than 0.4 mΩ, the contact resistance being measured after the bulge-shaped contact and the plate-shaped contact have been slid relative to each other.

7. The electric contact according to claim 1 , wherein
a change in a contact resistance between the bulge-shaped contact and the plate-shaped contact is not more than 0.2 mΩ when the bulge-shaped contact and the plate-shaped contact are slid relative to each other.

8. The electric contact according to claim 1 , wherein
an average value of frictional coefficients between the bulge-shaped contact and the plate-shaped contact is not more than 0.6, the frictional coefficients being measured while the bulge-shaped contact and the plate-shaped contact are slid relative to each other for 200 round trips over a 7 mm distance.

9. The electric contact according to claim 1 , wherein
at the bulge-shaped contact, a primer metal layer that coats the surface of the base material and is made of nickel or a nickel alloy is formed, and the silver-tin alloy layer is formed in contact with the primer metal layer, and
the base material of the bulge-shaped contact is not exposed after the bulge-shaped contact and the plate-shaped contact have been slid relative to each other.

10. The electric contact according to claim 1 , wherein
after the bulge-shaped contact and the plate-shaped contact have been slid relative to each other, metal of a layer below the silver layer is not exposed at the plate-shaped contact.

11. A connector terminal pair, comprising:
a pair of connector terminals that come into electrical contact with each other at a contacting portion, wherein
the contacting portion has the electric contact according to claim 1 .

Assignees

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

Inventors

• Sunaga Takahiro
• Saka Yoshifumi
• Saitoh Yasushi
• Kato Akihiro

Classifications

• C25D5/10

  Electroplating with more than one layer of the same or of different metals (for bearings C25D7/10) · CPC title

• H01R13/111

  co-operating with pins having a circular transverse section · CPC title

• H01R13/11

  Resilient sockets (carrying separate resilient parts H01R13/15) · CPC title

• C25D5/505

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

• H01R13/03 Primary

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