Study On Electro Thermal Mechanical Performance And Multi-objective Collaborative Optimization Design For Double-sided Cooling Power Module

With the continuous progress of power electronics technology,high power,high density and miniaturization have become the development direction of power modules,which puts forward higher requirements for the electrothermal performance of power modules.Doublesided cooling power modules have attracted much attention because of their excellent electrical and thermal performance.The key issue that needs to be urgently solved in research is how to further optimize their design and comprehensively improve their electrical,thermal and mechanical properties.This paper focuses on the packaging structure design,electrical,thermal,and mechanical performance of double-sided cooling IGBT power modules,and conducts multi-objective collaborative optimization research on double-sided cooling power modules packaging.The specific research content and conclusions are as follows:(1)The package structure is designed from the perspective of reducing the inductance,and the basic package structure of the module designed in this paper is determined.The three-dimensional simulation analysis model of double-sided cooling power module is established.The layout of direct bonding copper(DBC)copper layer is optimized by using P-Cell and N-Cell technology and magnetic field cancellation principle;The laminated terminal is designed by using the principle of magnetic field cancellation.The results show that the inductance of the optimized packaging structure in this design module is only about5 n H.The inductance reduction effect is very significant,effectively improving the electrical performance of the module(2)Conduct thermal performance analysis of the packaging structure of the double-sided cooling power module and select key packaging materials.The temperature and stress distribution of the design module are simulated.The influence of the materials and thickness of the structural layers on the chip temperature and stress is studied,and the key packaging materials are selected.The results shows that Al N is selected for DBC ceramic layer material,nano-silver solder paste is selected for welding layer material,and Mo80Cu20 is selected for buffer layer material.The thermal and mechanical properties of the module are significantly improved after optimizing the materials,and the junction temperature and maximum stress of the optimized design module chip decreased by 8.84% and 31.75% respectively.(3)Based on the response surface method and the third generation non-dominated sorting genetic algorithms(NSGA-III),a multi-objective collaborative optimization study is conducted on the packaging structure of the double-sided cooling power module in this design.Firstly,the influence of package size parameters on the chip junction temperature,chip maximum stress and loop inductance is investigated.It is found that no change in any parameter value can simultaneously achieve the optimal results of the three objectives,and collaborative optimization of all parameters is necessary;Then the response surface method is employed to construct the mathematical models for the three optimization objectives;Finally,the NSGA-III algorithm is used for collaborative optimization to obtain the optimal solution set.The optimization results show that within the feasible range that meets the constraint conditions,the maximum reduction ratios of single targets for loop inductance,chip junction temperature,and chip maximum stress are 34.95%,7.91%,and 38.00%,respectively.There should be a compromise between each target.This method has a good effect on the three objective collaborative optimization,and can comprehensively improve the electrical,thermal,and mechanical performance of the power modules.In addition,this method has high prediction accuracy.This paper designs a double-sided cooling IGBT power module packaging structure that can comprehensively improve electrical,thermal and mechanical performance,and conducts multi-objective collaborative optimization research on the power packaging structure.The research results have certain reference value for the optimization design of double-sided cooling power module packaging.