Semiconductor device having copper alloy leads

Abstract

A semiconductor device having leads of high strength and elongation and which consist essentially of a copper alloy that contains 0.05-1% of Cr, 0.005-0.3% of Zr, 0.001-0.05% of Li, 0-1% of Ni, 0-1% of Sn, 0-1% of Ti, 0-0.1% of Si and 0.001-0.3% of at least one element selected from the group consisting of P, Mg, Al, Zn and Mn, with the balance being Cu and no more than 0.1% of incidental impurities, the percent being on a weight basis. The invention also provides a semiconductor device having leads of high strength and elongation and which consist essentially of a copper alloy that contains either 0.05-1% of Cr or 0.005-0.3% of Zr or both, 0.001-0.05% of Li, 0-1% of Ni, 0-1% of Sn, 0-1% of Ti, 0-0.1% of Si and which further contains one or more of 0-2% of a metal selected from the group consisting of Fe, Co and Be, 0-1% of a metal selected from the group consisting of Mg, Al, Zn, Mn, B, P, Y and a rare earth element, and 0-2% of a metal selected from the group consisting of Nb, V, Ta, Hf, Mo and W, the percent being on a weight basis, with the balance being copper and incidental impurities, and which has a structure wherein the average grain size of any eutectic crystal present is no more than 10 .mu.m, the average grain size of any precipitate present is no more than 0.1 .mu.m, and the average size of any crystalline grains present is no more than 50 .mu.m.