Construction and the performance of the combination heat transfer mode of Dots-and-Plane based on liquid metal and AlN

Abstract

High-efficiency thermal conductivity is highly needed for highly-speed developed communication and integrated circuit. Gallium (Ga)-based liquid metal (LM) is a classic of metal with low melting point, and is concerned as a potential thermal interface material (TIM) due to high thermal conductivity (Tc, 16.5 W m−1 K−1). However, the leakage of LM can lead to the serious risk of short circuit and corrosion. This work proposes a strategy where the high-Tc powders of aluminum nitride (AlN) are mixed with LM to construct the heat conduction path combining dots (AlN) and plane (LM) and further to constrain the LM leakage. Specially, a LM-AlN composite paste filled with bimodal size particles displays a high Tc of 68 W m−1 K−1. Based on the simulation result, the bimodal size particles can construct more efficient thermal conductive path combining dots-and-plane, and the high Tc LM is speculated to help build heat transfer pathways among particles through particle-LM-particle. The LM successfully avoided the trouble of leakage during the process of testing, printing, and application. The high thermal conductivity of LM-AlN composite is further demonstrated by a light-emitting diode (LED) heat management test. This research will open a new direction for the development of high-performance TIM.