Thermal interface material (TIM) is applied at the interface between the high-performance microprocessors and heat sink to create a robust heat transfer path. Thermally speaking, TIM is typically characterized by a TIM tester and results are reported in terms of thermal impedance with bond line thickness (BLT) and/or averaged contact pressure. However, the characterization data collected from a TIM tester often cannot represent TIM’s behavior under usage conditions for high-performance microprocessors. The primary reason being the discrepancy in the contact conditions between TIM tester and microprocessor application, mainly including warpage of the microprocessor package and heat sink. In this paper, a Hertzian contact model is proposed to bridge this gap by incorporating in-situ warpage of the microprocessor package and heat sink in usage into the consideration. By applying the model, the thermal resistance of TIM under usage conditions for high performance microprocessors can be estimated from laboratory characterization data. A validation experiment is also presented, and good correlation has been obtained between the prediction and measurement.

在高性能微处理器和散热器之间的界面处应用了热界面材料（TIM），以创建可靠的传热路径。从热学角度来说，TIM通常由TIM测试仪表征，并以热阻抗，粘合线厚度（BLT）和/或平均接触压力报告结果。但是，从TIM测试仪收集的特性数据通常不能代表TIM在高性能微处理器使用条件下的行为。主要原因是TIM测试仪与微处理器应用之间的接触条件存在差异，主要包括微处理器封装和散热器的翘曲。在本文中，提出了一种赫兹接触模型，通过考虑使用中的微处理器封装和散热器的原位翘曲来弥合这一差距。通过应用该模型，可以根据实验室特征数据估算TIM在高性能微处理器使用条件下的热阻。还提出了一个验证实验，并且在预测和测量之间已经获得了良好的相关性。