基于GaN功率器件的热仿真技术研究

Study of Thermal Simulation Technology for GaN Power Devices

针对大功率器件散热瓶颈问题,基于GaN功率芯片,利用有限元分析方法开展了芯片近结区热特性模拟方法的研究。建立了芯片近结区散热能力仿真评估的三维理论模型,系统地研究了不同的初始条件、边界条件、晶格热效应及结构理论假设等因素对仿真精度的影响,分析了理论建模因素对计算结果的影响的原因。同时采用红外热成像仪对不同功率下的GaN芯片结温进行测试验证,模拟计算的结果和测试值的偏差在10%之内,表明合理建模的热仿真技术可有效评估器件散热能力。

In view of the bottleneck of heat dissipation in high power devices,the research on thermal analysis technology for near-junction region of GaN power chip was carried out by the finite element method.The theoretical thermal model for calculating heat dissipation capacity of near-junction region was established,the effects of theoretical modeling factors including boundary condition,initial condition,lattice thermal impact,and structural hypothesis on simulation precision were studied systemically,and the causes of the above effects were analyzed.Meanwhile,infrared thermography technique was used to determine the junction temperature of GaN chip with different power density.It is found that the deviations between calculated values and experimental data of junction temperature are all less than 10%,indicating that thermal simulation technology based on proper modeling is applicable to quantitatively evaluate the heat dissipation capacity of power devices.