Mixed monolithic-hybrid integration of multiphase power converter: preliminary evaluation of the 3-chip integration concept

The authors present a 3-chip mixed integration approach that combines monolithic silicon multi-terminal power chips and flip-chip assembly on a printed circuit board (PCB) for the realization of a multiphase power converter. The overall approach allows for taking advantage of the degrees of freedom offered by silicon and PCB technologies with a limited and well-mastered complexity. The multiphase converter is integrated within three multi-terminal chips that are judiciously packaged, using the partial flip-chip, on a PCB board so as to reduce the switching cell stray inductance as well as the impact of voltage variations on the common mode current that flows through the converter's PCB. Using Si and SiC dipole MOSFET and diode chips, converters based on the 3-chip approach were realized and compared to the conventional one. The obtained commutation loop inductance value is reduced by at least a factor of two as compared to that of the conventional one.