PROBLEM TO BE SOLVED: To provide a copper alloy sheet having high strength, high conductivity and excellent stress relaxation resistance, and an electronic component for large current and an electronic component for heat release using the copper alloy sheet.SOLUTION: There is provided a copper alloy sheet containing one or more kinds of Ni and Co of total 0.8 to 5.0 mass%, Si of 0.2 to 1.5 mass% and the balance copper with inevitable impurities, having 0.2% bearing force &sgr;of 500 MPa or more and conductivity of 30%IACS or more, a relationship between spring deflection limit kb(MPa) and 0.2% bearing force &sgr;(MPa) of Kb≥(&sgr;-100) and I/Iof 5.0 or less, where Iis diffraction integrated intensity of a (hkl) face in a thickness direction on a surface determined by an X-ray diffraction method.
