Patent ID: 9059185
Filing Date: 2015-06-16
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device comprising: providing a leadframe having a base metal including copper and a stack of a plated first layer of nickel in contact with the base metal, wherein the thickness of the first layer is in the range from about 0.5 to 2.0 μm and a plated outermost second layer of a noble metal in contact with the nickel layer, the leadframe including a chip pad and a lead having a first end proximate to the pad and a second end remote from the pad; forming a ball bond of a copper wire on a semiconductor chip attached to the chip pad; forming a stitch bond of the copper wire on the first lead end, penetrating the second layer; encapsulating chip and wire in a packaging compound, while leaving the second lead end un-encapsulated; removing the second layer of a noble metal from the un-encapsulated second lead ends wherein the noble metal is gold with a thickness of the second layer in the range from about 0.003 to 0.009 μm; plating a third layer of solder on the un-encapsulated second lead end; trimming the second lead end; and forming the second lead end.