An IC chip assembly includes a chip having an array of exposed contacts at a first face thereof, a substrate having an array of exposed contacts at a face thereof and a compliant interposer with exposed contacts at opposite faces thereof positioned between the chip and substrate so that contacts on the opposite faces of the interposer engage the contacts on said chip and substrate, respectively. A thermal transfer member contacts the opposite face of the chip and is engaged to the substrate so as to compress the interposer thereby simultaneously establishing relatively low inductance electrical connections between the chip contacts and the substrate contacts and good thermal contact between the chip and the thermal transfer member. The assembly is particularly adapted to provide power to the chip of a TAB-type integrated circuit assembly which includes a flexible lead frame connected between the chip and the substrate.