Spatial Thermal Conductivity Variation of Particulate-Filled Thermal Interface Materials

Thermal interface materials (TIMs) are widely used in electronic devices owing to their ability to thermally bridge gaps and voids at the interface between heat-producing chips and heat removal devices. The design goal of TIMs is to minimize the thermal interface resistance during the device’s service lifetime. Previous reports from the industry focus on the average thermal properties of TIMs. We explored how the thermal properties of different polymeric TIMs vary spatially, using a setup with a spatial resolution as fine as 10μm. This resolution enables quantification of spatial variability, which is important to prevent hot spots. Complementary characterizations of thermal interface materials made via electron microscopy, electron dispersive x-ray spectroscopy, x-ray imaging, differential scanning calorimetry, and mechanical testing will be shared. TIMs thermal properties measured with frequency-domain thermoreflectance (FDTR) will be related to these non-thermal characterizations.