Preparation of polymer-metal nanocomposite films and performance evaluation as thermal interface material

An urgent need for improved thermal management of microelectronic systems has emerged as a direct consequence of increasing integration densities, both at chip and packaging level. Current thermal interface materials have been identified as a major bottleneck, hindering reduction of junction to ambient thermal resistance to future required levels (< 0.2 KW^-1). In this paper we introduce and characterize the thermal performance of a nanostructured polymer-metal composite aimed at thermal interface material applications. The composite consists of a high porosity polymer nanofiber network infiltrated with a low melting temperature alloy. The inherent structure of the composite provides all-metal high thermally conductive pathways from surface to surface in assemblies. Results indicate total thermal resistances as low 8.5 Kmm²W^-1 at bondline thicknesses of approximately 70 mum, corresponding to an effective thermal conductivity of up to 8 Wm^-1K^-1.