Patent ID: 7220657

Claim:
A method of producing a semiconductor wafer provided with columnar electrodes having electrode terminals formed on its surface, an insulation film formed so as to expose the top of the electrode terminal, patterned wiring lines formed on the insulation film, each of the patterned wiring lines being connected, at one end, with the electrode terminal, and provided with a columnar electrode formed on the other end, and an encapsulating layer formed so as to cover the electrode-formed face of the wafer while exposing the top faces of the columnar electrodes, the columnar electrodes being provided with plated nickel, palladium, and gold films successively formed at their top, the method comprising: forming an insulation layer on the surface of a semiconductor wafer on which electrode terminals have been formed, so as to expose the top of the electrode terminals, forming a conductor layer on the electrode terminals and the insulation layer, forming a resist pattern on the conductor layer, plating the conductor layer with copper using the resist pattern as a mask and using the conductor layer as an electric power supply layer to thereby form a patterned copper layer having an end connected with the electrode terminal through the underlying conductor layer, removing the resist pattern, forming a further resist pattern on the patterned copper layer and the conductor layer, the further resist pattern having openings for formation of columnar electrodes on the other ends of the patterned copper layer, forming columnar electrodes of copper on the other ends of the copper layer in the openings by plating using the conductor layer as an electric power supply layer, forming a plated nickel film or plated nickel alloy film on the top face of the columnar electrodes, forming a plated palladium film and a plated gold film successively on the nickel or nickel alloy film, removing the further resist pattern, removing the exposed conductor layer, and encapsulating the electrode terminal-formed face of the wafer so as to expose the gold film at the top of the columnar electrode.