Dynamic Current Balancing Optimization of Cu Clip-Bonded SiC power module Based on Layout-Dominated Parasitic Inductance

Abstract:
Cu clip-bonding has lower resistance and lower inductance than wire-bonding, but unbalanced dynamic current still exists between paralleled silicon carbide (SiC) MOSFETs, limiting the available current capacity of Cu clipbonded SiC power modules. This paper presents a parasitic inductance equivalent circuit model at switching transients, and a dynamic current balancing optimization guideline based on self- and mutual inductance of main current path segments is determined. The mismatch of the equivalent power source parasitic inductances is reduced by adjusting the bonding positions and shape parameters of Cu clips. Simulation results show that the dynamic current sharing performance is greatly improved.