Patent ID: 8317948

Claim:
A copper alloy for electronic materials, consisting essentially of 0.5 to 2.5% by weight of Ni, 0.5 to 2.5% by weight of Co, 0.30 to 1.2% by weight of Si, 0.1 to 0.5% by weight of Cr, optionally in total about 2.0% or less by weight of one or more elements selected from the group consisting of P, As, Sb, B, Mn, Mg, Sn, Ti, Zr, Al, Fe, Zn and Ag, and the balance being Cu and unavoidable impurities, wherein the ratio of the total weight of Ni and Co to the weight of Si ([Ni+Co]/Si ratio) satisfies the formula: 4≦[Ni+Co]/Si≦5, and the ratio of Ni to Co (Ni/Co ratio) satisfies the formula: 0.5≦Ni/Co≦2; and wherein the alloy has a 0.2% yield strength of 800 MPa or more and an electrical conductivity of 45% IACS or more.