An advanced FWD design concept with superior soft reverse recovery characteristics

In this paper an improved FWD design concept has been investigated having superior soft reverse recovery behavior, for the first time. The basic concept of the FWD design is a combination of low anode injection efficiency (MPS structure) and inhomogeneous lifetime controlling (platinum) in order to achieve the optimum carrier distributions. From experimental results, the rate of the rise in the cathode voltage (dV/dt) can be dramatically reduced. The new diode exhibits superior characteristics of the soft recovery than that of the conventional MPS diode, especially in the low current turn-on of the IGBT.