Silver nanowire array-polymer composite as thermal interface material

Silver nanowire arrays embedded inside polycarbonate templates are investigated as a viable thermal interface material for electronic cooling applications. The composite shows an average thermal diffusivity value of $1.89×10−5m2s−1$⁠, which resulted in an intrinsic thermal conductivity of $30.3Wm−1K−1$⁠. The nanowires’ protrusion from the film surface enables it to conform to the surface roughness to make a better thermal contact. This resulted in a 61% reduction in thermal impedance when compared with blank polymer. An $∼30nm$ Au film on the top of the composite was found to act as a heat spreader, reducing the thermal impedance further by 35%. A contact impedance model was employed to compare the contact impedance of aligned silver nanowire-polymer composites with that of aligned carbon nanotubes, which showed that the Young’s modulus of the composite is the defining factor in the overall thermal impedance of these composites.