Enhanced thermal performance from liquid metal in copper/graphite filled elastomer

Abstract

With the increasing integration level of modern electronics, thermal management becomes an urgent issue for guaranteeing the work efficiency and lifespan of electronics. On the basis of intrinsic high thermal conductivity nature, highly ordered graphite and copper stripes are densely aligned in the silicone gel pads in vertical (VCuGr) and oblique (@15°CuGr) directions to couple the high thermal conductivity and mechanical softness. The wetting nature of liquid metal (LM) on the chemically treated Cu surface is utilized to form a LM layer on the two surfaces of thermal pads. The obtained LM-pad TIMs possessed ultrahigh through-plane thermal conductivity (VCuGr: 71.4 W/(m K), @15°CuGr: 62.5 W/(m K)) under the normal packaging pressure. The thermal resistance decreased from 0.69 cm2 K/W to 0.25 cm2 K/W with the surface modification with LM. Theoretical simulation and practical thermal dissipation test results further demonstrate the excellent thermal management capability of these composites in high-power electronics.