High-Precision Thermal Characterization of Ultra-Low Thermal Resistance Copper Nano-Wire (Cunws)-Polydimethylsiloxane (Pdms) Composite Thermal Interface Materials (Tims) Tape

This paper details high-precision thermal characterization of CuNWs-PDMS composite TIMs using infrared (IR) cross-sectional microscopy. To enhance measurement sensitivity and to reduce the thermal resistances across TIM tester components and sample, we apply thin layers of high thermal conductivity gallium-based liquid metal (LM) to reduce the dry contact thermal interface resistances from ~10−4 to 1.4×10−6 m2KW-1. Application of the LM in combination with a 1 mm thick silicon wafer as the reference layer, yields thermal resistance of ~(3.23 ± 0.6)×10−6 m2KW-1 for the CuNWs/PDMS composite. Theoretical analyses suggest the potential for achieving even lower thermal resistance values with optimized LM wetting thickness.