What are the challenges in paralleling power semiconductors?

Paralleling increases current capacity but introduces challenges: current sharing (unequal current due to parameter spread, layout differences), thermal coupling (hotter device takes less current, potentially unstable), dynamic imbalance (faster device takes more current during switching), and gate drive requirements. Solutions include: matched devices, symmetric layout, individual gate resistors, common-mode chokes, active current sharing, and derating. For IGBTs, positive temperature coefficient of Vce helps static sharing but switching balance remains critical. Module-level paralleling is easier than discrete paralleling.