SiC MOSFET Die Sorting and Parallel for Optimal Module Design

Abstract:
SiC MOSFET power modules often have multiple dies connected in parallel inside the packages. Variation or mismatch of the dies’ Vth and Ron can degrade the power module performance, including output current capability and even reliability. This article proposes a new die sorting methods to arrange dies in Vth value sequence and screen out outlier dies in any designated consecutive die number. This sorting method and its die output arrangement facilitate module manufacturing. Die screen criteria are also discussed for optimal module design. HPD modules are built with this new die selection scheme and tests are designed to investigate the performance. The tests show that proper die sorting and combination can achieve a good current sharing and thermal balance.