Modeling Research And Characteristic Analysis Based On Parasitic Parameters Of SiC Devices

With the development boom of new energy power generation,photovoltaic inverter,electric vehicles,smart microgrid,power electronic conversion technology and control optimization have attracted people’s attention,among which power switching converter,as the core of power electronics technology,is subject to the constraints of materials,packaging and high temperature,and domestic and foreign scientific researchers have joined the cutting-edge team of science and technology such as device research and development,module packaging,and drive characteristic analysis.At present,in the semiconductor field,silicon(Si)-based MOSFETs,IGBTs and other power devices are still the mainstream,but limited by the performance factors of Si materials themselves,it is urgent to seek high-performance materials with high temperature resistance,bandwidth prohibition and fast switching rate.In this context,silicon carbide(SiC)has been widely promoted and applied with its excellent performance,which has led universities to focus on electromagnetic thermal fields such as model establishment,performance testing,drive design,module packaging and parasitic parameter analysis of SiC devices.Firstly,based on the inductive modeling method and the relevant research on the driving influence of parasitic parameters,this thesis takes the 1200V/450 A silicon carbide power module as the research object,proposes a modeling method based on semi-physical model and periodic oscillation method to obtain external parasitic parameters,builds an accurate model of nonlinear parameterization of the device based on PSPICE simulation software and fitting technology,and designs a double-pulse test circuit to verify the correctness of the modeling.Secondly,in view of the problem that the external test environment is different and easy to cause parasitic parameter changes,the environmental impact of the external test is removed,and the two research ideas of parametric analytical model and software simulation are proposed to verify the research of parasitic parameters on the switching characteristics,and analyze the turn-on and shutdown process of silicon carbide devices by parameter visualization.Finally,in view of the key problems of parasitic parameters caused by module packaging characteristics,Ansys Q3 D software simulation is used to focus on metal bonding wires and DBC copper clad layers,and simulate the influence of key factors such as bond wire length,width,and number of parallel connections on parasitic parameters.At the same time,the COMSOL software simulation method is used to simulate and study the thermal characteristics of different metal bonding wire connection positions.Aiming at the problem of power module failure and easy falling off of bonding wires,the method of drawing the map is used to analyze the module failure principle and propose solutions,which has guiding significance for the analysis of the cause of module failure.