A post-mold plated semiconductor device has an aluminum leadframe (105)
with a structure including a chip mount pad and a plurality of lead
segments without cantilevered lead portions. A semiconductor chip (210)
is attached to the chip mount pad, and conductive connections (212) span
from the chip to the aluminum of the lead segments. Polymeric
encapsulation material (220), such as a molding compound, covers the
chip, the connections, and portions of the aluminum lead segments without
leaving cantilevered segment portions. Preferably by electroless plating,
a zinc layer (301) and a nickel layer (302) are on those portions of the
lead segments, which are not covered by the encapsulation material
including the aluminum segment surfaces (at 203b) formed by the device
singulation step, and a layer (303) of noble metal, preferably palladium,
is on the nickel layer.