COPPER ALLOY FOR ELECTRONIC/ELECTRICAL DEVICE, COPPER ALLOY PLASTICALLY WORKED MATERIAL FOR ELECTRONIC/ELECTRICAL DEVICE, COMPONENT FOR ELECTRONIC/ELECTRICAL DEVICE, TERMINAL, AND BUSBAR

A copper alloy for an electronic and electric device is provided. The copper alloy includes: Mg in a range of 0.15 mass% or more and less than 0.35 mass%; and a Cu balance including inevitable impurities, wherein the electrical conductivity of the copper alloy is more than 75%IACS, and a strength ratio TS TD /TS LD , which is calculated from strength TS TD obtained in a tensile test performed in a direction perpendicular to a rolling direction and strength TS LD obtained in a tensile test performed in a direction parallel to a rolling direction, is more than 0.9 and less than 1.1. The copper alloy may further include P in a range of 0.0005 mass% or more and less than 0.01 mass%.