Circuit assembly with semiconductor expansion matched thermal path

摘要

A copper lead frame (16) has an aperture (18) through which a molybdenum layer (20) extends to directly contact a ceramic substrate (8) therebelow. A semiconductor chip (2) is mounted on the molybdenum layer (20). Thermal conductivity is improved because of the reduced number of thermal path conduction layers between the semiconductor chip (2) and the ceramic substrate (8). The arrangement also enables the chip-expansion-matched thermal conductor (20) to contact the semiconductor chip (2) and match expansion therewith.