A study on wafer scalable, industrially applicable CNT based nanocomposites of Al-CNT, Cu-CNT, Ti-CNT, and Ni-CNT as thermal interface materials synthesised by thin film techniques

Abstract

Heat dissipation is one of the major factors that inhibit the miniaturisation of electronic components. Thermal interface materials (TIMs) that dissipate heat help in improving device performance. Commercially available conformal TIMs such as indium foils, thermal pads, polymer matrix with thermal conductive films are not very useful in heat transfer due to low thermal conductivity and high thermal expansion coefficient. This research focuses on developing novel thin-film nanocomposites consisting of Carbon nanotubes (CNTs) as TIMs. CNTs based nanocomposites behave as nano fins for heat dissipation. CNTs that are almost vertically aligned are deposited on silicon (Si) substrates using Radio Frequency Plasma Enhanced Chemical Vapor Deposition (RF-PECVD). Metallic thin films of Aluminium, Copper, Titanium, and Nickel are sputtered using a Direct Current Magnetron target-based Physical Vapour Deposition on the CNT films to form a nanocomposite sandwich. The nanocomposite morphology is studied using SEM, structure using TEM, polycrystalline and elemental determination using XRD. The produced nanocomposite is modelled using Solid Works software, and thermal simulation of the same is performed using ANSYS. The equivalent thermal conductivity of Ni/CNT/Si, Al/CNT/Si, Cu/CNT/Si, and Ti/CNT/Si network is 1045.6 W/mK, 1120.8 W/mK, 886.56 W/mK and 463.6 W/mK when derived using mathematical modelling. The thermal conductivity values after experimentation for CNT/Si, Al/CNT/Si, Cu/CNT/Si, Ti/CNT/Si and Ni/CNT/Si nanocomposites were found to be 255–282 W/mK, 52–15 W/mK, 195–236 W/mK, 15–20.5 W/mK and 7.7–9.1 W/mK, respectively.