Patent ID: 11047023

Abstract:
A copper alloy sheet material that is excellent in surface smoothness of an etched surface has a composition containing, (mass %), from 1.0 to 4.5% of Ni, from 0.1 to 1.2% of Si, from 0 to 0.3% of Mg, from 0 to 0.2% of Cr, from 0 to 2.0% of Co, from 0 to 0.1% of P, from 0 to 0.05% of B, from 0 to 0.2% of Mn, from 0 to 0.5% of Sn, from 0 to 0.5% of Ti, from 0 to 0.2% of Zr, from 0 to 0.2% of Al, from 0 to 0.3% of Fe, from 0 to 1.0% of Zn, the balance Cu and unavoidable impurities. A number density of coarse secondary phase particles has a major diameter of 1.0 μm or more of 4.0×103 per square millimeter or less. KAM value measured with a step size of 0.5 μm is more than 3.00.