A review of the thermal conductivity of silver-epoxy nanocomposites as encapsulation material for packaging applications

Thermal management has been playing an important role in electronic encapsulation because large heat fluxes need to be dissipated from high density/high-power integrated circuits (ICs) for better performing electronic devices with longer lifetimes. Thus, encapsulant materials with very high thermal conductivity are critical for the development of packaging technologies with efficient thermal management solutions. Silver-epoxy nanocomposites have been widely applied in many electronic packaging industries because silver has the highest thermal conductivity (427 W/mK) among all metals as a bulk material which also exhibits resistant to oxidation. In addition, nanomaterials consisting of silver have weak phonon scattering and can be sintered at low temperature compared to other nanofillers, which will reduce the contact resistance and thereby improve the thermal conductivity. In this mini review, a comprehensive understanding of the thermal conductivity of epoxy resins based on different kinds of silver nanomaterials, such as silver nanoparticles, silver nanowires, silver nanoflakes, etc., is provided and discussed. Furthermore, the dependence of thermal conductivity of silver-epoxy nanocomposites on the particle size of silver, its atomic structure, surface modification, dispersion, interfacial resistance, etc. are summarized and discussed. Finally, an outlook on thermally conductive silver-epoxy nanocomposites for electronic encapsulation is discussed.