PCB-Embedding of Power Dies Using Pressed Metal Foam

This paper presents a new technique to manufacture the top-side contact of a PCB-embedded power die, using a pressed piece of metal foam. The manufacturing process is detailed, prototypes are manufactured and electrically characterized, and the technique is used to embed a switching cell with a 1.7 nH switching loop. This process is easy to make and highly cost-effective; the electric resistance of the assembly is close to that of a state-of-the-art industrial package using bond wires, moreover the stray inductance is minimized.