| 摘要 |
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.
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