Research On Package Of IGBT Module In Pulsed Power System

Pulse power source is one of the main research directions in the field of high power microwave.Compact and solid state is the important development direction of pulsed power technology,and the performance of pulsed power system is often affected by the performance of switches.As the main switch of the system,the semiconductor switch has gradually become the development direction of pulsed power source,and the power IGBT(Insulated Gate Bipolar Transistor)device has received extensive attention.The voltage and current of a single IGBT can not fulfill the requirements of pulsed power system.The series and parallel operation of the IGBT device will make the volume of the system bigger and loop inductance greater.With the development of semiconductor technology and manufacturing.By using bare core array packaging,the mentioned problems can be effectively solved.Therefore,the package design based on IGBT is one of the key issues in the development of pulsed power systems.In this thesis,based on the existing research,IGBT series and parallel package module is designed,and reliability simulation analysis is operated.Firstly,the research status of pulse power system Whose main switch is IGBT and the development course of IGBT bare core series and parallel connection package are introduced.The advantages and disadvantages and the key problems are analyzed.The basic characteristics of IGBT,Operating principle and the requirements of the drive circuit are introduced.The IGBT series voltage sharing and parallel current sharing circuits are investigated and analyzed,and the performance of the packaging materials and the characteristics of the chip surface interconnection materials are compared and analyzed.Secondly,the performance of the IGBT single tube is analyzed in detail,including the selection of the device,the limit current and voltage analysis.The fast driving circuit of IGBT with voltage driving mode based on planar transformer is designed,and the feasibility of the design is verified by experiment.The experimental results show that under the operating voltage 1kV and the load 3.8 ohms,the collector current rise rate di/dt(10%?90%)reaches 9.75A/ns.On this basis,a series voltage sharing circuit and a reverse voltage protection circuit in accordance with the switching requirements in the pulse power system are designed,and the selection of the middle element of the circuit is introduced.The internal structure with 5kv and 1kA of packaging module of IGBT,whose size if 68mm*55mm*5mm,is designed,parasitic parameters of packaging module are extracted,and its electrical insulation performance is analyzed.Finally,to evaluate the reliability of the package module,the IGBT module loss model and thermal simulation model are established,and the thennal analysis of the packaging module is carried out.The thermal stress analysis of the welding layer with less encapsulation module is carried out.It mainly includes the chip welding material and the deformation and inelastic strain of the base welding material,and Evaluation of the reliability of the welding material.Through the failure mechanism of the IGBT module,the life prediction of the IGBT module is carried out respectively from three aspects of chip bonding,lead,welding layer and encapsulation module.The simulation results show that the working cycle number of IGBT packaging module is 3.2e9.