Thermal conductivity of Ni-coated MWCNT reinforced 70Sn-30Bi alloy

The high thermal conductivity of thermal interface material (TIM) is essential since the heat dissipation of electronic chips in an integrated circuit is solely achieved through TIM, which forms the bottleneck of the heat conduction. In the current study, the efficiency of utilizing multi-walled carbon nanotubes (MWCNTs) to increase the thermal conductivity of a typical TIM 70Sn-30Bi alloy has been investigated. Encapsulation of carbon nanotubes (CNTs) with nickel by electroless deposition was used to prevent aggregation of CNTs and to enhance the interfacial bonding between CNTs and the metal matrix. The nickel encapsulation also allows avoiding the separation of CNTs from the molten metal due to the buoyancy effect. The dispersion of Ni-encapsulated CNTs was assisted by sonication. The thermal conductivity of 3 wt % Ni/MWCNTs reinforced 70Sn-30Bi alloy was found to be more than 170% greater than that of the base alloy.