基于双热阻模型的典型芯片封装热分析及评估方法

目的研究基于双热阻模型的芯片封装热分析及评估方法,并对比分析芯片封装不同建模方式对热分析结果的影响。方法采用双热阻模型建立某ECU产品的芯片封装模型,并与"集总参数法"建模法的计算结果进行对比分析与评价。根据案例中典型的实测环境(试验箱),建立等效环境模型,并进行对比分析。结果采用双热阻模型建模的器件热仿真结果更精确,且能较好地反映芯片封装的实际热分布,从而便于发现芯片散热措施的热设计缺陷。集总参数法在应用与芯片封装建模分析时,计算误差相对较大,且无法准确表现芯片的实际散热情况。另一方面,是否建立实测环境的等效模型对计算结果影响较大。结论双热阻模型能较好地适用于芯片封装简化建模,在应用于封装芯片热分析时具有更高的精确度,且参数获取难度不大,具备较大的工程应用价值。

Thermal Analysis and Evaluation Method of Typical Chip Package Based on Double Thermal Resistance Model

Objective To study thermal analysis and evaluation method of chip packaging based on double thermal resistance model, compare and analyze influences of different modeling methods on thermal analysis results. Methods The double thermal resistance model was used to establish a chip package model of ECU product and compare with calculation results of the "lumped parameter method" modeling method. An equivalent environment model was established according to the typical measured environment in this case, and the comparative analysis was carried out. Results The thermal simulation results of the device modeled by the double thermal resistance model were more accurate, and it could better reflect the actual thermal distribution of the chip package, thus it was easy to find the thermal design defects of the chip''s heat dissipation measures. When the lumped parameter method was applied for modeling and analysis of chip package, the calculation error was relatively large, and the actual heat dissipation of the chip could not be accurately represented. On the other hand, the establishment of equivalent model of measured environment had great influence on the calculation results. Conclusion The double thermal resistance model can be better suitable for the simplified modeling of chip packaging. It has higher accuracy in the application of chip thermal analysis, and it is not difficult to obtain the parameters, so it has great engineering application value.