Cu-Zn alloy heat Sn plating conditions that whisker has been suppressed

摘要

PROBLEM TO BE SOLVED: To provide a reflow-Sn soldered strip with Cu/Ni-double ground layers of Cu-Zn alloy, in which the generation of whiskers is suppressed.;SOLUTION: In the Sn soldered strip comprising, as a base material, a Cu-alloy containing Zn in an average concentration of 15-40 mass%, in which from the surface to the base metal, a plated film is composed of each layer of a Sn phase, a Sn-Cu alloy phase and a Ni phase, and the concentration of Zn in the outermost surface layer of the Sn phase is adjusted to be 0.1-5.0 mass%. The base material may further contain 0.005-3.0 mass% in total of arbitrary components selected from Sn, Ag, Pb, Fe, Ni, Mn, Si, Al and Ti. Alternately, the base material may be a copper-based alloy containing, by mass, 15-40% Zn, 8-20% Ni and 0-0.5% Mn, and the balance composed of Cu and inevitable impurities, and furthermore, the base material may contain 0.005-10 mass% in total of the above mentioned arbitrary components.;COPYRIGHT: (C)2008,JPO&INPIT