▎ 摘　　要

Thermal interface material (TIM) is a key component to dissipate the accumulated heat in the majority of power electronic systems. In this work, a facile and solid-state ball-milling method is adopted for the solvent-free reduction of exfoliated graphite nanoplatelets (EGNs) into high-quality ball-milled exfoliated graphite nano-platelet (BMEGN) fillers. In addition, BMEGN fillers are embedded and uniformly dispersed with polydimethylsiloxane (PDMS) matrix to make a highly stretchable BMEGN-embedded PDMS-TIMs (BMEGN/PDMS) with strongly enhanced thermal conductivity. Furthermore, material characterizations were thoroughly investigated using scanning electron microscopy, transmission electron microscope, Raman spectroscopy, thermogravimetric analysis, and x-ray diffraction. Improvements in the thermal conductivity of TIMs by adding BMEGN were compared, the thermal conductivity was observed for BMEGN fillers with 0- to 48-h ball-milling time, and an enhanced in-plane thermal conductivity of 15.04 to 16.91 W/mK and through-plane thermal conductivity of 1.03 to 1.19 W/mK can be experimentally measured. A strong anisotropy was observed in the range of 14.60 (BMEGN12h/PDMS) to 14.21 (BMEGN48h/PDMS). The results reveal that the ball-milled graphene filler network with branched morphology can effectively provide the synergetic effect of a thermally conductive pathway via diffusion of phonon vibration in flexible composites. The combination of thermal conductivity and thermal stability may facilitate the applications in thermal management. (C) 2018 Society of Photo-optical Instrumentation Engineers (SPIE)