Ultra-high-performance heat spreader based on a graphite architecture with three-dimensional thermal routing

Authors
Bin Xu, Yuxuan Liao, Zhenglong Fang, Keisuke Nagato, Takashi Kodama, Yasushi Nishikawa, Junichiro Shiomi

Summary
To meet the increasing demand for highly efficient heat dissipation in power electronics, a heat spreader that has significantly greater isotropic thermal conductivity than the commonly used copper (400 W/m·K) should be developed. Although graphite is a promising candidate because of its high basal-plane thermal conductivity, its application is restricted by its low c axis thermal conductivity. This issue can be resolved by transforming graphite into an isotropic thermal conductor by building a structure that can effectively route heat in all three dimensions. Herein, we develop a double-decker structure with differently oriented graphite layers to realize high heat dissipation from a local heat source. The critical issue of bonding the graphite layers is overcome by a high-temperature process using Cu as the binding layer. The graphite/Cu composite efficiently dissipates heat nearly isotropically and performs as well as an isotropic conductor with a thermal conductivity of 900 W/m·K.

Cell Reports Physical Science : https://www.sciencedirect.com/science/article/pii/S2666386421003398