Copper alloy for electronic/electric device, copper alloy sheet/strip material for electronic/electric device, component for electronic/electric device, terminal, and busbar

Abstract

A copper alloy includes, by mass %: Mg: 0.15%-0.35%; and P: 0.0005%-0.01%, with a remainder being Cu and unavoidable impurities, wherein [Mg]+20×[P]<0.5 is satisfied. Among the unavoidable impurities, H is 10 mass ppm or less, O is 100 mass ppm or less, S is 50 mass ppm or less, and C is 10 mass ppm or less. In addition, 0.20<(NF/(1−NF))≤0.45 is satisfied where a proportion of J3, in which all three grain boundaries constituting a grain boundary triple junction are special grain boundaries, to a total grain boundary triple junctions is NF, and a proportion of J2, in which two grain boundaries constituting a grain boundary triple junction are special grain boundaries and one grain boundary is a random grain boundary, to the total grain boundary triple junctions is NF.