High-Temperature Pressure Mapping of TIM Interfaces for Improved Thermal Simulation Accuracy

Thermal interface material (TIM) performance depends on pressure distribution at the package-heatsink interface. Conventional thermal models assume uniform pressure, neglecting local variations and resulting in erroneous junction temperature predictions. Extracting pressure distribution of molten TIM at the interface is challenging. This study addresses extraction of pressure maps of the interface, by introducing a Tekscan sensor-based pressure mapping method to capture non-uniform distributions at high temperatures up to 80° C. The measured pressure maps are converted into discretized thermal resistance maps and imported into CFD simulations through an ECXML-based modeling framework. Simulations with measured non-uniform pressure map predict 13.3 % higher junction temperature than uniform-pressure map. The proposed workflow integrates experimental pressure mapping, thermal resistance and CFD thermal modeling. Enabling accurate prediction of TIM performance under operating conditions. The study also characterizes temperature-dependent TIM pressure distribution to examine load redistribution behavior