Research On SiC Power Module And Application Based On PCB Embedded Package

SiC power devices are gradually becoming mature,but their mainstream packaging technology still adopts aluminum wire bonding packaging,and the development is relatively lagging.It has become a " being hit in the throat" technology that restricts the performance of SiC power devices.In order to make full use of the advantages of SiC power devices,the development and application of new packaging technologies is critical.Currently,many new packaging technologies have been studied at home and abroad.Due to the additional advantages of lightness,thinness,and miniaturization,PCB embedded packaging has become a highly potential SiC power device packaging technology.However,at present,PCB embedded packaging mostly adopts asymmetrical structure design,and the module packaging structure and terminal interface are not unified.This project developed a fan-out PCB embedded package SiC power module and application research,which are as follows:Since the half-bridge module is the most basic unit of the power electronic converter,this paper designs a PCB-embedded SiC MOSFET power half-bridge module,and carries out chip selection,material selection,parasitic inductance extraction and packaging process development for this.The study found that the maximum parasitic inductance of the designed PCB embedded SiC half-bridge power module is 1.24 n H.Compared with the TO-247 discrete SiC device,the drain parasitic inductance is reduced by 85.8%.In terms of electrical static characteristics,the extracted parasitic inductance was added to the PSpice simulation circuit for DC scan analysis,and the static characteristics of the PCB embedded SiC power module were verified by experiments using the B1505 A power device analyzer.Research have shown that under the same driving voltage and the same drain-source voltage,the forward conduction current of the PCB-embedded SiC power module is 5A smaller than that of the SiC power die on average.Moreover,when vgs>10V,the required driving voltage of the PCB-embedded SiC power module is 2V larger than the SiC die on average,and the threshold voltage of the PCB-embedded SiC power module is equal to Same as SiC die.In terms of dynamic characteristics,first establish a mathematical model of switching characteristics considering parasitic inductance,and import the stray inductance extracted from the simulation into PSpice for transient switching waveform analysis,and then build a double-pulse test platform to verify the theoretical model and simulation experiments.Research shows that under a typical600 V bus voltage,compared to TO-247 discrete SiC MOSFETs,the PCB embedded SiC power module voltage overshoot is reduced by 3 V(50%),the voltage change rate is increased by 33.3%,and the current change rate is increased by 5%,the turn-on loss decreases by 10%,and the turnoff loss decreases by 36%.In terms of module application,the PCB embedded SiC module was applied to the Boost photovoltaic power optimizer circuit to realize the 60 V to 120 V voltage conversion function and the maximum power point tracking(MPPT)function.The peak efficiency of the Boost circuit is 90.89%,and the MPPT efficiency is 99.59%.Finally,based on the study of electrical characteristics,an optimized design method for PCB embedded packaging structure is proposed,which provides guidance for subsequent embedded package module design.A long drain interconnection layer line can be selected to balance the turn-on loss and current stress of the chip.Moreover,the electrodes of the module should be distributed on the outboard to facilitate the layout of the driving circuit during application.In terms of driving parameter selection,a trade off value should be selected between device stress and switching loss according to the double-pulse test under actual operating conditions.