Connection terminal and method for producing connection terminal

Patent metadata

Field	Value
Publication number	US-10804632-B2
Application number	US-201716338224-A
Country	US
Kind code	B2
Filing date	Oct 6, 2017
Priority date	Oct 20, 2016
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

A connection terminal in which alloy particles made of an intermetallic compound containing tin and palladium are exposed on an outermost surface of a contact configured to electrically contact a mating conductor and distributed on a surface of a base material at least in the contact, wherein: a tin part made of pure tin or an alloy having a higher ratio of tin to palladium than the intermetallic compound is not exposed on a plane passing through a point where a height of the alloy particles from the surface of the base material is highest.

First claim

The invention claimed is:

1. A connection terminal in which alloy particles made of an intermetallic compound containing tin and palladium are exposed on an outermost surface of a contact configured to electrically contact a mating conductor and distributed on a surface of a base material at least in the contact, wherein:
a tin part made of pure tin or an alloy having a higher ratio of tin to palladium than the intermetallic compound is not exposed on a plane passing through a point where a height of the alloy particles from the surface of the base material is highest.

2. A connection terminal according to claim 1 , wherein the tin part is not present around the alloy particles.

3. A connection terminal according to claim 1 , wherein the surface of the base material is exposed between the alloy particles.

4. A connection terminal according to claim 1 , wherein:
the base material includes a layer of nickel or nickel alloy; and
the intermetallic compound has a composition of (Ni 0.4 Pd 0.6 )Sn 4 .

5. A connection terminal according to claim 1 , wherein a ratio of an area occupied by the alloy particles in the contact is 30% or higher.

6. A connection terminal according to claim 1 , wherein a dynamic friction coefficient between the contact and the mating conductor having a tin layer exposed on an outermost surface is 0.4 or lower.

7. A connection terminal according to claim 1 , wherein an average thickness of a layer occupied by the alloy particles is 0.1 μm or larger and 5.0 μm or smaller.

8. A method for producing a connection terminal, comprising:
fabricating a laminated structure in which a palladium layer and a tin layer are laminated in this order on a surface of a base material;
heating the laminated structure to form alloy particles made of an intermetallic compound containing tin and palladium; and
removing a tin part made of pure tin or an alloy having a higher ratio of tin to palladium than the intermetallic compound, the pure tin or the alloy deriving from excess tin having not formed the intermetallic compound.

9. A method for producing a connection terminal according to claim 8 , wherein removing the tin part is performed by chemically dissolving tin.

10. A method for producing a connection terminal according to claim 8 , wherein a ratio of palladium to the total amount of tin and palladium in the laminated structure is 2 atom % or higher.

11. A method for producing a connection terminal according to claim 8 , wherein a ratio of palladium to the total amount of tin and palladium in the laminated structure is below 20 atom %.

Assignees

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

Inventors

• Watanabe Hajime

Classifications

• 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

• H01B1/02 Primary

  mainly consisting of metals or alloys · CPC title

• C25D5/627

  Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance · CPC title

• C25D5/611

  Smooth layers · CPC title