Optimization And Reliability Research Of Bonding Wires For High-power IGBT Module

IGBT(Insulated Gate Bipolar Transistor)is a fully controlled voltage-driven power semiconductor device composed of BJT(Bipolar Transistor)and MOS(Insulated Gate Field Effect Transistor).It has the dual advantages of MOS with low driving energy and high input impedance and high frequency BJT.With the increasing demand for IGBT modules in China,domestic manufacturers have been actively studying relevant IGBT module technologies to fill the technical gap with foreign manufacturers,and have made certain achievements in low-power IGBT modules.However,there is still a large gap between the packaging and chip design technology of high-power IGBT modules and foreign manufacturers.This paper focuses on the packaging technology of high-power IGBT module,which has an important impact on the reliability of the module.Based on the packaging technology and reliability of high-power IGBT modules,the following research has been done in this paper:Firstly,a high-power IGBT module is produced according to the requirements of the research project.Through the structural disassembly of the power module,the key technologies in the module packaging are analyzed,and the internal structure of the module is deeply understood.According to the characteristics of the module structure,the research object is determined as the bonding line.The data obtained by disassembling the module is used to build a three-dimensional digital model.The 3D digital model is imported into the finite element software,and the optimal substrate material is finally determined by changing the properties and thickness of the substrate material by simulating the experimental conditions of the temperature cycle in the finite element software,taking the stress condition of the bonding line as the reference standard.By changing the thickness of solder,the optimal thickness of solder is determined according to the stress of solder.After that,the lead bonding process parameters are optimized,with the bonding power and bonding time as the parameter research objectives,the bonding strength of the first and second bonding points as the assessment indicators,and the optimal process parameters are selected through the single factor exploration experiment,and then the orthogonal experiment is carried out on the selected process parameters to obtain the relationship between the two parameters and the bonding strength,and the influence factors of the strength of the first bonding point are obtained,The influence of bonding power is greater than that of bonding pressure.Among the factors affecting the strength of the second bonding point,the influence of bonding pressure is greater than that of bonding time.It is inferred from the research results that the two process parameters of the two bonding points in the bonding process should be adjusted to improve the life of the bonding line and the overall life of the module.The overall packaging process of the module is studied.Finally,the design route of the high-power IGBT module is verified in production practice.Through TGA/DSC experiments,the optimal temperature environment of the nano-silver paste is obtained,which provides guarantee for the reliable packaging of the module and improves the reliability of the module.