Nobumitsu Tada

The module type power device united with a heat sink

The size of inverter equipment using conventional module type power devices becomes large in the consequence of large steady-state and transient thermal resistance by the following two reasons. (1) Because of the curvature of the base plate, contact thermal resistance of the conventional module type power device is relatively large, and steady-state thermal resistance also becomes large. (2) Since module type power devices are manufactured aiming at low cost and low steady-state thermal resistance, generally their heat capacity becomes small and their transient thermal resistance becomes large. We propose a new structure of a module type power device. The structure is that a semiconductor chip soldered on an electrode is united with a heat sink by using an epoxy resin. It is confirmed that the steady-state and the transient thermal resistance of the proposed module type power device is decreased to about 50% compared to conventional type.