Patent ID: 8070893

Claim:
A Cuâ€”Niâ€”Siâ€”Coâ€”Cr copper alloy for electronic materials, containing about 0.5-about 2.5% by weight of Ni, about 0.5-about 2.5% by weight of Co, about 0.30-about 1.2% by weight of Si, and about 0.09-about 0.5% by weight of Cr, and the balance being Cu and unavoidable impurities, including carbon, wherein the ratio of the total weight of Ni and Co to the weight of Si ([Ni+Co]/Si ratio) in the alloy composition satisfies the formula: about 4â‰¦[Ni+Co]/Siâ‰¦about 5, and the ratio of Ni to Co (Ni/Co ratio) in the alloy composition satisfies the formula: about 0.5â‰¦Ni/Coâ‰¦about 2, and wherein Pc is about 1/1000 Î¼m 2 to about 7/1000 Î¼m 2 , and Pc/P is about 0.09 to about 0.25 wherein P is the number of inclusions dispersed in the alloy and having the size of 1 Î¼m or more, and Pc is the number of inclusions, among those having the size of 1 Î¼m or more, whose carbon concentration is 10% or more by weight.