Transient Current Distribution with Paralleling Dies and Paralleling Half Bridges in Multichip Power Modules

Abstract:
This paper addresses the transient current distributions in the multichip half bridge power modules where two types of paralleling connections with different current commutation mechanisms are considered: paralleling dies and paralleling half bridges. It reveals that with paralleling dies, both the high side and low side paralleled devices experience the transient current imbalance due to the mismatched stray inductance. However, with paralleling half bridges, the high side paralleled devices have much smaller transient current imbalance even though with the same mismatched stray inductances. Theoretical analysis based on the circuit modelling elaborate the findings, which are then confirmed experimental results.