Abstract: The effect of silane coupling agent (SCA) interfacial modification on the properties of silica particles/epoxy composites was systematically investigated to address the performance bottlenecks of epoxy resin-based electronic packaging materials in terms of high thermal conductivity, low dielectric loss, and moisture and thermal stability. The successful grafting of silane coupling agents onto the silica particle surface was verified by surface energy spectroscopy analysis, and epoxy resin-based packaging films with high filler content(50%, mass fraction) were prepared to compare the overall performance of the composites before and after modification. The incorporation of γ-glycidyloxypropyltrimethoxysilane(KH-560) enhanced the interfacial bonding strength of resin through the participation of epoxy groups in the cross-linking reaction. The resultant composites exhibited an optimal glass transition temperature of 170.38 °C, a thermal conductivity of 0.15 W/mK, and a tensile strength of 102 MPa. The resin prepared by using N-phenyl-3-aminopropyltrimethoxysilane (KBM-573)-modified silica particles exhibited a water contact angle of 114.9° and slightly lower mechanical properties due to the hydrophobicity of the benzene ring and conjugation effect. The γ-aminopropyltrimethoxysilane (KH-540)-modified system demonstrated limited improvement in dielectric properties and hydrophobicity due to the amine polarity. The present study elucidated the synergistic effect of modified silica particles on the mechanical, thermal, and electrical properties. This finding provides a theoretical basis for the targeted optimization of electronic packaging materials.

Key words: Silane coupling agent, Silica particle modification; Electronic packaging, Epoxy resin, Dielectric loss