Design Of A Fast Recovery Diode For Inverter Modules

With the continuous development of power electronic systems,the importance of the inverter module is increasing dramatically.The effect of the inverter module is to convert DC into AC.In the inverter module,fast recovery diode in parallel with switching device is needed for conducting freewheeling current.This paper aims to design a high-performance high-voltage fast recovery diode for inverter modules.In this thesis,the function of the fast recovery diode in the inverter circuit is introduced,and the relationship between it and the switching device is analyzed.Then,the static and dynamic performance parameters of the fast recovery diodes are introduced,and the contradictory relationship between the forward conduction voltage and the reverse recovery characteristic is analyzed.The key to the contradictory relationship lies in the forward carrier distribution in the drift region.In this paper,we introduce some technologies to optimize the carrier distribution.On this basis,the fast recovery diodes with stepped doping concentration and metal trench structure are proposed and designed.Based on the basic technological conditions of the semiconductor manufacturing platform,this paper designs the suitable process for the fast recovery diodes described in this paper.On the basis of the process,the cell design and terminal design of the fast recovery diode are completed by optimizing the process parameters and structural parameters.Finally,the layout design are completed.In this thesis,the fast recovery diode cell reverse breakdown voltage is 1437 V,and current capacity is 100 A,and forward conduction voltage is 1.61V@200A / cm2.Reverse recovery peak current IRRM is 60% lower than conventional fast recovery diodes,and reverse recovery charge QRR and reverse recovery loss EOFF are lower than conventional fast recovery diodes.The contradictory relationship of forward voltage drop and reverse recovery characteristics is much better than traditional fase recovery diodes.Finally,the fast recovery diodes in this thesis is not prone to dynamic breakingdown.