PBGA封装芯片热环境适应性仿真分析

针对多数塑料焊球阵列（PBGA）封装芯片仅依据美军MIL标准进行高低温交变测试致使预测服役寿命偏差较大的情况，将微控制芯片任务状态时间谱转化为环境温度载荷谱，在综合考虑热传导、热对流的情形下，利用icepak完成芯片热电耦合仿真分析，并借助于Transient Thermal及Transient Structural完成芯片结温的获取及焊点应力、应变的计算求解。同时，依据Arrhenius模型及修正Coffin-Manson热疲劳模型分别预测芯片本身及焊点的寿命，从而实现对其热环境适应能力的定量分析。仿真结果表明:芯片的预测寿命约为6.26年，寿命预测偏差约为13.4%，符合GJB 4239-2001中单个关键环境因素预测寿命偏差标准，能够较为精确地反映其热环境适应性。 

Simulation analysis of PBGA packaged chips' thermal environment adaptability

In view of the fact that most Plastic Ball Grid Array (PBGA) packaged chips are only subjected to high and low temperature alternating tests in accordance with the US military MIL standard, resulting in a large deviation in predicted service life, this paper converts the microcomputer control chip mission time spectrum into ambient temperature parameters, and comprehensively considers the heat conduction and heat convection, so as to use icepak to complete the chip thermoelectric coupling simulation analysis, and use Transient Thermal and Transient Structural to complete the chip junction temperature acquisition and solder joint stress and strain calculation and solution. At the same time, the life of chip itself and the solder joint are predicted based on the Arrhenius model and the modified Coffin-Manson thermal fatigue model, so as to realize the quantitative analysis of its thermal environment adaptability. The simulation results show that the predicted life of the chip is about 6.26 years, and the life prediction deviation is about 13.4%, which complies with GJB 4239's single key environmental factor predicted life deviation standard and accurately reflects its thermal environment adaptability.