Characterization of a dielectric microdroplet thermal interface material with dispersed nanoparticles

This work presents the fabrication and characterization of a dielectric microdroplet thermal interface material (TIM). Glycerin droplets, 1 mu L, were tested as TIMs in this study. Copper nanoparticles having a diameter of 25 nm were dispersed in glycerin at different volume fractions to enhance its thermal conductivity. An increase of 57.5 % in the thermal conductivity of glycerin was measured at a volume fraction of 15 %. A minimum thermal interface resistance of 30.37 mm(2) K/W was measured for the glycerin microdroplets at a deformed droplet height of 10.2 mu m. Good agreement between experimental measurements and the predictions of a model based on Maxwell's equation of rules of mixtures was obtained. The effect of nanoparticles' size on the effective thermal conductivity of glycerin was studied. Nanoparticles with diameters of 60-80 and 300 nm were dispersed in glycerin at a volume fraction of 5 %, and their results were compared to those of the 25 nm particles.