Patent attributes
A semiconductor device has a leadframe with a structure made of a base metal (105), wherein the structure consists of a chip mount pad (402) and a plurality of lead segments (403). Covering the base metal are, consecutively, a nickel layer (301) on the base metal, and a continuous layer of noble metal, which consists of a gold layer (201) on the nickel layer, and an outermost palladium layer (202) on the gold layer. A semiconductor chip (410) is attached to the chip mount pad and conductive connections (412) span from the chip to the lead segments. Polymeric encapsulation compound (420) covers the chip, the connections, and portions of the lead segments. In QFN devices with straight sides (501), the compound forms a surface (421) coplanar with the outermost palladium layer (202) on the un-encapsulated leadframe surfaces.
