Research On High Reliability Packaging Technology Of IGBT High Power Module

Insulated gate bipolar transistor(IGBT)is a device composed of MOSFET and bipolar transistor.It combines the advantages of easy driving,simple control and high switching frequency,low on voltage,large on state current and low switching loss.With the development of IGBT module and the increase of IGBT demand,domestic manufacturers are actively developing and studying IGBT related technologies to fill the technical gap with foreign manufacturers.So far,domestic low-power IGBT module technology has been able to compete with foreign countries,but for high-power IGBT,there is still a gap with foreign countries in chip technology and packaging technology.This paper focuses on the packaging technology of high-power IGBT module,which plays a vital role in the reliability of the whole module.In this paper,the module based packaging technology and reliability are studied as follows:Firstly,the project requirements are analyzed to clarify the overall structure design route of this subject.Through disassembly analysis,the basic information such as the composition of module packaging structure and the selection range of parts and materials are determined.After considering the layout of the overall structure of the module,the module outline drawing and internal connection drawing are obtained,and the digital model based on ANSYS finite element simulation is established.Then study the heat dissipation performance of different packaging materials,carry out finite element simulation according to the established digital model,calculate the maximum junction temperature of IGBT module under normal working state through steady-state thermal simulation,and compare the maximum junction temperature to get the heat dissipation performance of several packaging materials.After the finite element simulation,the temperature cycle test is carried out,and the packaging materials with heat dissipation performance and mechanical performance can meet the requirements are selected through the test.Then the sintering process of IGBT module is optimized,mainly the sintering temperature curve,including formic acid reduction time,formic acid reduction temperature,heating peak temperature and peak temperature time.The influence of different sintering temperature curves on the void rate of IGBT module is analyzed.By comparing the void rate after sintering,the optimal sintering curve of this module is obtained.Finally,the reliability of IGBT module is tested,including static test,dynamic test and thermal resistance test.Through the results of these three tests,it is concluded that the parameters of this design module meet the project requirements.