Analysis Of Electrothermal Characteristics Of Press-Pack SiC MOSFET

Power semiconductor devices are the core components of power electronics converters.The press-pack devices,with its advantages of high reliability and short circuit after failure,have been paid more and more attention.In this dissertation,the parasitic resistance,heat dissipation and current sharing characteristics of press-pack SiC MOSFET devices are mainly analyzed,and a method for optimizing the design of the press-pack device structures is discussed.First,the development of packaging technology in power semiconductor devices is introduced in this dissipation.And based on the core directions,the structural characteristics and related studies of press-pack IGBT and the press-pack SiC MOSFET are summarized.The main problem of large parasitic resistance in press-pack SiC MOSFET device is deeply studied in this dissertation.The method combining finite element simulation and actual measurement is used to find the main reason that affects the parasitic resistance of the module.And this dissertation discusses an improved press-pack SiC MOSFET structure.After that,a new bus bar structure is discussed for press-pack SiC MOSFET device,which reduces the stray inductance in the commutation circuit.Based on the improved press-pack SiC MOSFET structure,a single-phase inverter using press-pack SiC MOSFET devices is built,which proves the reliability for the presspack SiC MOSFET device on operating.Aim to press-pack power devices for high power applications,the purpose of this dissertation is to design the 1200V/1000 A high-power press-pack SiC MOSFETs.This dissertation sets up the model of parasitic inductance of press-pack SiC MOSFET devices.Then the influence of parasitic inductances on current sharing characteristics is analyzed by simulation.After that,the improved Kelvin source layout is proposed,which can verify a good dynamic current balancing between the paralleled chips in the high-power press-pack SiC MOSFET.A summary of this dissertation at last.The main contributions of this dissertation are summarized,and the future works are presented.