| 摘要 |
<p>In Sn-plated copper or a Sn-plated copper alloy according to the present invention, a surface plating layer including a Ni layer, a Cu—Sn alloy layer, and a Sn layer which are deposited in this order is formed on a surface of a base material made of copper or a copper alloy. 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. The Cu—Sn alloy layer includes Cu—Sn alloy layers having two compositions, a portion thereof in contact with the Ni layer is formed of an &egr;-phase having an average thickness of 0.5 to 0.95 μm, and a portion thereof in contact with the Sn layer is formed of a &eegr;-phase having an average thickness of 0.05 to 0.2 μm.</p> |
