An Improved Double-layer Spacer in Double-sided Cooling Power Module

Abstract:
This paper focuses on enhancing the thermal performance and reliability of double-sided cooling (DSC) power modules by introducing an improved double-layer spacer. The proposed spacer aims to minimize thermal resistance and improve reliability. The lower layer of the spacer facilitates the connection of bonding wires, while the upper layer maximizes heat dissipation by effectively utilizing the surface area of the top DBC (direct bonding copper), which is typically underutilized. Through simulation verification and experiments, the study demonstrates that implementing the improved spacer results in a significant 24% reduction in thermal resistance and longer lifetime compared to conventional power modules. Additionally, this paper explores the impact of changing the spacer material from copper to Molybdenum copper (MoCu). This material substitution shifts the solder layer in which solder failure is most likely to occur, with the new layer being predominantly influenced by the size of the spacer.