US 2007/0176267 A1 · Aluminum leadframes for semiconductor QFN/SON devices

Abstract

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.

Claims20

Dependent claims

A semiconductor device without cantilevered leads, comprising:

a leadframe made of aluminum alloy and having a structure including a chip mount pad and a plurality of lead segments;
a semiconductor chip attached to the chip mount pad;
conductive connections spanning from the chip to the aluminum surface of the lead segments;
polymeric encapsulation material covering the chip, the connections, and portions of the aluminum lead segments;
a zinc layer on the aluminum of those lead segment portions, which are not covered by the encapsulation material;
a nickel layer on the zinc layer;
and
a layer of noble metal on the nickel layer.

5 more elements

Dependencies are inferred from the claim text.

Aluminum leadframes for semiconductor QFN/SON devices

Life of this patent

Aluminum leadframes for semiconductor QFN/SON devices

Life of this patent

Abstract

Claims20