Heat Transfer Performance Of Thermal Interface Materials Based On Radially Aligned Graphene Framework

With the miniaturization and multi-functionalization of modern electronics,the power density per unit area(up to 200 W cm^-2)rises rapidly,which will result in a dramatic increase of generated heat or even thermal failure problems.Therefore,efficient heat dissipation has become one of the most imperative issues in determining the working performance and long-term reliability of microelectronics.Thermal interfacial materials（TIM）,composed of polymer matrix and thermal conductive fillers,are commonly used to fill the microgaps between heat sink and electronic devices for efficient heat dissipation,while their low thermal conductivity still remains in the lower regime and cannot meet the criteria for thermal management of next generation microelectronics.Graphene is a 2D honeycomb structure that has been extensively studied for its extremely high thermal conductivity and excellent chemical and physical properties.In this paper,the thermal conductivity of graphene TIM in various forms is experimentally studied,and the tree structure in nature is used to propose a graphene skeleton structure with Fin（RG-Fin）arranged radially.Radially aligned network achieves efficient and isotropic heat transfer.The interconnected RG skeleton prepared by the radial freezing method is the main channel for heat isotropic conduction.The fin-shaped graphene nanosheets（Fin）grown vertically on the surface of the RG skeleton by the plasma chemical vapor deposition method not only have very high thermal conductivity itself,but also increase the surface roughness and interface binding ability of the RG skeleton,so that It can be more effectively combined with the polymer,thereby reducing the interface thermal boundary resistance at the interface between the RG backbone and the polymer.In addition,the growth of Fin also provides additional motion channels for the movement of phonons in the RG skeleton,and realizes a more effective dual-channel heat transfer mode without affecting the heat transfer performance of the skeleton.Finally,the actual thermal management of the CPU module in operation was demonstrated by the principle of infrared imaging,and the efficient heat transfer ability of the composite material with RG-Fin as filler was verified in practical applications.This paper provides a new research idea for the realization of high thermal conductivity TIM for thermal management.