SiC Power Module with "hand in hand" structure for current sharing in parallel chips

Dynamic current imbalance in multi-chip Silicon Carbide (SiC) MOSFET power modules is a critical factor affecting both the power handling capability and reliability of these modules. This paper proposes an innovative layout approach aimed at improving current sharing in multi-chip power modules (MCPMs). The method utilizes the mutual inductance cancellation effect arising from the reverse coupling of currents between the DC power terminals within the power loop. The terminals of two adjacent parallel power loops are configured in a "hand-in-hand" closed-loop structure through reverse coupling. When current imbalance occurs in any given power loop, the adjacent parallel loops generate induced voltages that suppress the imbalance across these loops. Experimental validation through double pulse test demonstrates that the proposed SiC MOSFET power module achieves a maximum dynamic current variation of 5.33 A during the turn-on transient under test conditions of 600 V/100 A. Compared with the commercial module, the proposed power module design achieves a 78.1% decrease in dynamic current imbalance. Furthermore, the power loop parasitic inductance of the module is measured to be 4.5 nH.