Volumetric heat capacity enhancement in ultrathin fluorocarbon polymers for capacitive thermal management

Abstract

Capacitive thermal management in electronics requires an enhancement in the volumetric storage density of compatible materials to approximately 1 GJ/m3. We investigate potential enhancement in sensible storage density arising from size e ects in thin polymer lms. We design and fabricate a micro-calorimeter to measure the volumetric heat capacity of nanometer scale thin uorocarbon polymer lms. The storage density increases approximately three times as the lm thickness decreases from 27 nm to 12 nm. Using the Debye theory of phonons, we relate this behavior to an increase in the Gr uneisen parameter with decreasing lm thickness. This work advances the understanding of size dependence in the heat capacity of amorphous polymers as well as highlights their potential for capacitive thermal management.