Research On Integrated Heat Dissipation Technology Of Silicon Carbide MOSFET Based On Micro TEC

Compared with traditional silicon(Si),silicon carbide(SiC)have wide band gaps,high dielectric constants,high thermal conductivity,and high breakdown voltage.SiC devices have received extensive research and attention in academia and industry.The power electronic devices represented by SiC power MOSFET have the advantages of low on-resistance,high voltage resistance,high switching frequency,and high temperature resistance.Therefore,it is favored in the application of modern high-power switching equipment and high-performance power electronic devices.However,it cannot be ignored that the improvement of power performance will bring about an increase in power density,which will cause the power device to generate more heat during the work process.Even if the SiC MOSFET has high temperature resistance characteristics,the dynamic and static performance of the device will still be affected if it is operated in a high temperature environment for a long time.At present,the high-temperature packaging technology required for SiC MOSFET is still immature.Too high a junction temperature of the chip will cause the microstructure inside the chip and the device package to undergo more significant thermal mismatch stress,leading to device failure and failure.In the absence of reliable high-temperature packaging technology for SiC MOSFET,finding a reasonable and effective heat dissipation method has become an inevitable choice for the development of SiC MOSFET.In view of the above problems,this thesis uses thermoelectric cooling technology to conduct thermal management of SiC MOSFETs.By independently designing and manufacturing a micro thermoelectric cooler(TEC),the SiC MOSFET containing the micro TEC is integrated and packaged.First,the analytical parameters and finite element calculations were used to design the structural parameters of the thermocouple arm of the micro TEC,and the effect of the electrode Joule thermal effect as a non-ideal factor was analyzed to determine the size range of each structural parameter.Then the semiconductor microfabrication technology was used to manufacture the micro TEC single-pair thermocouple arm,which verified the feasibility of the structural design scheme in the manufacturing process.Finally,the complete micro TEC and the bare chip of the SiC MOSFET are packaged,and the packaged SiC MOSFET is subjected to a temperature test and an electrical performance test.The experimental results show that the micro TEC can reduce the chip surface temperature and the case temperature of the SiC MOSFET,and can also reduce the on-resistance and the conduction loss,but it has little effect on the switching loss.Overall research shows that to a certain extent,micro TEC with integrated packaging can perform thermal management of SiC MOSFET,and can reduce the conduction loss of SiC MOSFET.