Patent ID: 8623194

Claim:
A method for plating a workpiece, said method comprising: forming, within a solution in a container, multiple overlapping anode layers comprising at least: a first anode layer comprising a plurality of discrete first anodes adjacent to a wall in said container opposite a workpiece, said first anodes comprising a first metal; and a second anode layer between said first anode layer and said workpiece and comprising a plurality of discrete second anodes, said second anodes comprising a second metal that is different from said first metal, being offset from said first anodes, and being spaced an approximately uniform distance apart, said uniform distance being less than a width of said first anodes such that each first anode in said first anode layer has a first side edge that is overlapped by a second side edge of one of said second anodes in said second anode layer; and, applying different voltages to said first anodes and said second anodes, respectively, in order to plate said workpiece with an alloy of said first metal and said second metal.