Copper alloy and fabrication method thereof

The invention relates to the field of a metal alloy, in particular to a Cu-Ni-Si alloy. A fabrication method of a copper alloy comprises the steps as follows: A) casting, B) hot rolling, C) face milling and D) cold rolling and annealing. The copper alloy comprises the following chemical components by mass percent: 1.8-2.1% of nickel, 0.4-0.68% of silicon, 0-0.2% of iron, 0-0.1% of manganese, 0-0.2% of zinc, 0-0.005% of cadmium, 0-0.02% of lead, 0-0.3% of other impurities and the balance of cooper, wherein iron, manganese, zinc, cadmium and lead are all impurities; the tensile strength Rm of the copper alloy is greater than or equal to 600MPa; the broken elongation A11.3 is greater than or equal to 8%; the Vickers hardness HV is greater than or equal to 180; and the electrical conductivity is greater than or equal to 46% IACS (International Annealed Copper Standard). The ideal performance of a copper alloy material for a lead frame can be obtained by the fabrication method for the copper alloy.