In Situ Generated Silver Nanoparticles on Boron Nitride Nanosheets Followed by Silane Modification in High-Performance Epoxy Nanocomposites for Advanced Packaging Applications

Abstract

The increasing power density and miniaturization of modern electronic devices have underscored the critical need for efficient thermal management solutions. Boron nitride nanosheets (BNNS) have emerged as promising fillers for thermally conductive epoxy based composite. However, the improvement of composite thermal conductivity is often constrained by interfacial thermal resistance (ITR) at filler-filler and filler-matrix interfaces. The smooth and inert surface of BNNS exacerbates this challenge. To address these issues, silver nanoparticles (AgNPs) are in situ synthesized on BNNS surfaces through a simple annealing process. The BNNS-Ag fillers are subsequently modified using 3-(Mercaptopropyl)triethoxysilane (MPTS) to enhance filler-polymer matrix interactions through thiol-silver and silane-epoxy reaction. This dual modification strategy reduces ITR at both filler-filler and filler-matrix interfaces, enabling the epoxy nanocomposite to achieve a thermal conductivity of 1.64 W (m·K)⁻¹ at 30 wt.% filler loading, representing an 811.1% improvement compared to neat epoxy. Furthermore, the BNNS-AgNPs@MPTS nanocomposite exhibits excellent electrical properties. Meanwhile, both experimental studies and simulations have demonstrated the promising potential of epoxy nanocomposites as high-performance thermal interface materials (TIMs). These findings provide a novel approach to overcoming interfacial thermal resistance while maintaining high electrical insulation, advancing the design of polymer composites for next-generation advanced electronic packaging applications.