Patent ID: 8142906
Filing Date: 2012-03-27
Classification: C25D,Y10S,Y10T

Abstract:
1. Sn-plated copper or a Sn-plated copper alloy, comprising: a base material made of copper or a copper alloy; and a surface plating layer including a Ni layer, a Cu—Sn alloy layer, and a Sn layer which are formed in this order on a surface of the base material, wherein an average thickness of the Ni layer is 0.1 to 1.0 μm, an average thickness of the Cu—Sn alloy layer is 0.55 to 1.0 μm, and an average thickness of the Sn layer is 0.2 to 1.0 μm, said Cu—Sn alloy layer includes Cu—Sn alloy layers having two compositions, and, in said two types of Cu—Sn alloy layers, a portion in contact with the Sn layer is formed of a η-phase having an average thickness of 0.05 to 0.2 μm, and a portion in contact with the Ni layer is formed of an ε-phase having an average thickness of 0.5 μm to 0.95 μm.