CU-NI-SI-CO-BASE COPPER ALLOY FOR ELECTRONIC MATERIAL AND PROCESS FOR PRODUCING THE COPPER ALLOY

摘要

This invention provides a Cu-Ni-Si-Co-base alloy possessing excellent strength, electroconductivity and press punchability. The Cu-Ni-Si-Co-base alloy is a copper alloy for an electronic material and comprises Ni: 1.0 to 2.5% by mass, Co: 0.5 to 2.5% by mass, and Si: 0.30 to 1.2% by mass with the balance consisting of Cu and unavoidable impurities. The observation of a cross section parallel to the rolling direction of the copper alloy, for a variation in composition and the area ratio of second phase particles having a diameter of not less than 0.1 µm and not more than 1 µm, shows that the middle value ? (% by mass) of the amount of [Ni + Co + Si] is 20 (% by mass) = ? = 60 (% by mass), the standard deviation s(Ni + Co + Si) is s(Ni + Co + Si) = 30 (% by mass), and the area ratio S (%) is 1% = S = 10%.