Dual-direction thermal conductive FG-based composite manufactured by rotating magnetic-field assisted casting

Abstract

With the miniaturization of electronic components and the complication of packaging processes, operating environments with high power density are bound to generate large amounts of heat. Conventional thermal interface material (TIM) typically aims to enhance thermal conductivity (TC) in only one direction (either through-plane or in-plane), which is insufficient to meet the growing requirement for heat dissipation. Here, highly oriented and tightly fitted flake graphite (FG)-based TIM with dual-direction thermal conductive pathways were prepared via rotating magnetic field assisted casting (RMAC), which can dissipate heat quickly in both directions. The results revealed that at 50 wt% filler and 30 r/min magnetic field rotation rate, the composites with dual-direction thermal conductive pathways exhibited in-plane and through-plane TC of 12.8 and 10.1 W/mK, respectively. Notably, these values represent significant improvements of 415.4 % and 134.1 % over random composites and also demonstrate outstanding advantages over composites with filler orientation in only one direction, horizontal or vertical. This also has been confirmed by finite element simulations and actual thermal characterization. The rational structural design of the filler in TIM can efficiently direct heat away from specific directions, which provides a feasible solution to the heat dissipation problem of high-power-density electronic devices.