Heat Dissipation Structure Optimization Topology Design Based On SIMP Power Device IGBT

With the development of science and technology,semiconductor integration technologies and processes have become more and more mature.Power device products tend to be miniaturized,the internal heat flux density of devices is increasing,so that the heat dissipation problem becomes more and more serious.Most of the traditional IGBT module heat dissipation structures uses the typical finned radiators.The topologies of different radiators are different,thus the cooling effect is obviously different.If the heat dissipation structure is not designed according to the heat flow path of the device,the heat dissipation function of the heat dissipation structure may be poor.Therefore,optimizing the heat dissipation topology is a hot spot in heat dissipation research.To solve the heat dissipation problem of power devices,this paper studies the optimal topology design of IGBT heat dissipation structure of power devices based on SIMP method.The main research work carried out are:1.Building a mathematical model.Based on the SIMP theory,establish the original design volume occupied by the solid material as the constraint condition,and optimize the overall heat dissipation uniformity of the structure as the objective function.The SIMP material interpolation model and optimization criterion method are derived in detail.Based on the optimization criterion method,the solving process and algorithm realization of the mathematical model are discussed,and using MATLAB software to discuss the influence of different boundary conditions,heat sources and different volume constraints on the topological configuration.Finally,a better topology optimized design structure was calculated,and a three-dimensional visualization model of the power device IGBT heat dissipation structure was obtained.2.Design heat dissipation structure based on SIMP method.The heat dissipation structure is simplified to a three-dimensional physical geometric model,and establish a three-dimensional simulation model of IGBT module.Then,the heat dissipation effect of the heat dissipation structure is explored by conducting a steady-state thermal analysis of the radiator structure,taking the junction temperature and thermal resistance as indicators.And the steady-state thermal analysis is carried out one by one by setting the liner material and liner thickness,solder layer thickness,and chip bonding material as variables.Moreover,through the horizontal and vertical comparison and discussion,to explore the influence trend of various factors on the heat dissipation performance.The influence trend of the heat dissipation design is proposed from three aspects: the requirements and measures of heat dissipation design,the choice of cooling method,and the optimization measures of the external environment.3.Analyze the equivalent thermal stress of the IGBT module.First,using the temperature field distribution,which obtained from the analysis of the heat dissipation performance of the IGBT module,is taken as the load,hence the cloud diagram of the equivalent thermal stress distribution of each layer of IGBT module material is obtained by simulation.Second,taking the maximum thermal stress as the index,set the liner material and liner thickness,solder layer thickness,and chip bonding material as variable factors to carry out thermal stress analysis one by one,and to explore the laws that each factor affects the equivalent thermal stress of each layer of the IGBT module.Finally,according to the rules obtained by the analysis,optimize the IGBT module heat dissipation structure,analyze the optimized IGBT module heat dissipation performance and the equivalent thermal stress of each layer material of the module.Therefore,to realize the topology optimization design of the power device IGBT heat dissipation structure.The research results show that,as expected,the mathematical model based on SIMP method can be solved by the optimization criterion method to obtain a better topology optimization configuration.When the volume fraction is set to 30%,the topology optimization details of the structure are better.For the heat dissipation structure,after carry out overall optimization of IGBT modules,the optimization results show that the maximum junction temperature of the module is reduced by 45.63% and the maximum equivalent thermal stress is reduced by 40.35%.In this work,the proposed method,has an important theoretical reference value for the optimization of the topology design of the heat dissipation structure of the power device and the improvement of the heat dissipation performance of the device.Therefore,it is beneficial to apply topology optimization theory to the engineering practice of the heat dissipation structure design.