Sn-coated copper alloy strip having excellent heat resistance

Patent metadata

Field	Value
Publication number	US-9508462-B2
Application number	US-201314012416-A
Country	US
Kind code	B2
Filing date	Aug 28, 2013
Priority date	Aug 29, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A Sn-coated copper alloy strip including a surface coating layer containing a Ni layer, a Cu—Sn intermetallic compound layer, and a Sn layer formed in this order over the surface of a base material containing a copper alloy strip, in which an average thickness of the Ni layer is from 0.1 to 3.0 μm, an average thickness of the Cu—Sn intermetallic compound layer is from 0.02 to 3.0 μm, an average thickness of the Sn layer is from 0.01 to 5.0 μm, and the Cu—Sn intermetallic compound layer contains only an η-phase or the η-phase and an ε-phase.

First claim

What is claimed is:

1. A Sn-coated copper alloy strip, comprising:
a surface coating layer comprising a Ni layer, a Cu—Sn intermetallic compound layer, and a Sn layer formed in this order, and
a base material comprising a copper alloy strip,
wherein
the surface coating layer covers over a surface of the base material,
an average thickness of the Ni layer is 0.6 to 3.0 μm,
an average thickness of the Cu—Sn intermetallic compound layer is 0.2 to 3.0 μm,
an average thickness of the Sn layer is 0.01 to 5.0 μm,
the Cu—Sn intermetallic compound layer comprises an η-phase and does not comprise an ε-phase,
a portion of the η phase is exposed to a surface of the surface coating layer with a ratio of surface exposure area of from 3 to 75%, and
the surface coating layer has a surface roughness such that an arithmetic mean roughness Ra in at least one direction is 0.15 μm or more and an arithmetic mean roughness Ra in all directions is 3.0 μm or less.

2. The Sn-coated copper alloy strip according to claim 1 , wherein
a Co layer or a Fe layer is formed instead of the Ni layer, and
an average thickness of the Co layer or the Fe layer is 0.1 to 3.0 μm.

3. The Sn-coated copper alloy strip according to claim 1 , wherein
a Co layer or a Fe layer is formed between the surface of the base material and the Ni layer or between the Ni layer and the Cu—Sn intermetallic compound layer, and
an average thickness of the Ni layer and the Co layer in total or the Ni layer and the Fe layer in total is 0.7 to 3.0 μm.

4. The Sn-coated copper alloy strip according to claim 1 , wherein
Cu 2 O is not present at a depth of 15 nm or more from an uppermost surface of the Sn-coated copper alloy strip after heating at 160° C. for 1,000 hours in the air.

5. A Sn-coated copper alloy strip, comprising:
a surface coating layer comprising a Ni layer, a Cu—Sn intermetallic compound layer, and a Sn layer formed in this order, and
a base material comprising a copper alloy strip,
wherein
the surface coating layer covers over a surface of the base material,
an average thickness of the Ni layer is 0.6 to 3.0 μm,
an average thickness of the Cu—Sn intermetallic compound layer is 0.2 to 3.0 μm,
an average thickness of the Sn layer is 0.01 to 5.0 μm,
the Cu—Sn intermetallic compound layer comprises an ε-phase and an η-phase,
the ε-phase is present between the Ni layer and the η-phase,
a ratio of a length of the ε-phase to a length of the Ni layer in a cross section of the surface coating layer is 50% or less, and
a ratio of an average thickness of the ε-phase to an average thickness of the Cu—Sn intermetallic compound layer is 30% or less.

6. The Sn-coated copper alloy strip according to claim 5 , wherein
a portion of the η-phase is exposed to a surface of the surface coating layer with a ratio of surface exposure area of from 3 to 75%, and
the surface coating layer has a mean roughness Ra in a direction perpendicular to a rolling direction of the base material of 0.03 μm or more and less than 0.15 μm.

7. The Sn-coated copper alloy strip according to claim 6 , wherein
a Co layer or a Fe layer is formed instead of the Ni layer, and
an average thickness of the Co layer or the Fe layer is 0.1 to 3.0 μm.

8. The Sn-coated copper alloy strip according to claim 6 , wherein
a Co layer or a Fe layer is formed between the surface of the base material and the Ni layer or between the Ni layer and the Cu—Sn intermetallic compound layer, and
an average thickness of the Ni layer and the Co layer in total or the Ni layer and the Fe layer in total is 0.7 to 3.0 μm.

9. The Sn-coated copper alloy strip according to claim 6 , wherein
Cu 2 O is not present at a depth of 15 nm or more from an uppermost surface of the Sn-coated copper alloy strip after heating at 160° C. for 1,000 hours in the air.

10. The Sn-coated copper alloy strip according to claim 5 , wherein
a portion of the η phase is exposed to a surface of the surface coating layer with a ratio of surface exposure area of from 3 to 75%, and
the surface coating layer has a surface roughness such that an arithmetic mean roughness Ra in at least one direction is 0.15 μm or more and an arithmetic mean roughness Ra in all directions is 3.0 μm or less.

11. The Sn-coated copper alloy strip according to claim 10 , wherein
a Co layer or a Fe layer is formed instead of the Ni layer, and
an average thickness of the Co layer or the Fe layer is 0.1 to 3.0 μm.

12. The Sn-coated copper alloy strip according to claim 10 , wherein
a Co layer or a Fe layer is formed between the surface of the base material and the Ni layer or between the Ni layer and the Cu—Sn intermetallic compound layer, and
an average thickness of the Ni layer and the Co layer in total or the Ni layer and the Fe layer in total is 0.7 to 3.0 μm.

13. The Sn-coated copper alloy strip according to claim 10 , wherein
Cu 2 O is not present at a depth of 15 nm or more from an uppermost surface of the Sn-coated copper alloy strip after heating at 160° C. for 1,000 hours in the air.

Assignees

• Kobe Steel Ltd
• Kobe Steel Ltd

Inventors

• Tsuru Masahiro

Classifications

• C25D5/12

  at least one layer being of nickel or chromium · CPC title

• H01B1/026 Primary

  Alloys based on copper · CPC title

• Y10T428/12715

  Next to Group IB metal-base component · CPC title

• C23C28/021

  including at least one metal alloy layer · CPC title

• C25D5/505

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