Noncured Graphene Thermal Interface Materials for High-Power Electronics: Minimizing the Thermal Contact Resistance

We report on experimental investigation of thermal contact resistance, R-C, of the noncuring graphene thermal interface materials with the surfaces characterized by different degree of roughness, S-q. It is found that the thermal contact resistance depends on the graphene loading, xi, non-monotonically, achieving its minimum at the loading fraction of xi similar to 15 wt%. Decreasing the surface roughness by S-q similar to 1 mu m results in approximately the factor of x2 decrease in the thermal contact resistance for this graphene loading. The obtained dependences of the thermal conductivity, K-TIM, thermal contact resistance, R-C, and the total thermal resistance of the thermal interface material layer on xi and S-q can be utilized for optimization of the loading fraction of graphene for specific materials and roughness of the connecting surfaces. Our results are important for the thermal management of high-power-density electronics implemented with diamond and other wide-band-gap semiconductors.

Automated summary

The study found that the thermal contact resistance of noncuring graphene thermal interface materials with different surface roughness depends on the graphene loading. Decreasing surface roughness can significantly reduce the thermal contact resistance. These results are crucial for thermal management of high-power-density electronics.