Sn-coated copper alloy strip having excellent heat resistance

摘要

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.

主权项

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.