From interfacial contact to thermal transport: a molecular dynamics simulation of SiO₂/epoxy resin composites

A high-frequency working environment makes the heat generated by electronic components increase rapidly. The atomic level of interfacial thermal transfer between epoxy (EP) resin and various functionalized silica (SiO 2 ) in underfill was investigated by molecular dynamics simulation (MDS) methods. The interfacial thermal transfer mechanism was examined by calculating the interfacial binding energy, atomic density distribution, phonon vibrational power spectrum (VPS), and interfacial thermal resistance (ITR) studies. This work revealed the generalized relationship between interfacial thermal transport and SiO 2 /EP interface interaction, which was regulated by coupling agents and the grafting ratio in chemical modification processes. The calculation results showed that interfacial thermal resistance was strongly correlated with the calculated binding energy. The interfacial contact and phonon coupling in composites were improved when SiO 2 was functionalized by 3-glycidyloxypropyltrimethoxysilane (GOTMS) and 3-aminopropyltriethoxysilane (APTES). The binding energies of the two interfaces above exceeded −350 kcal/mol and relatively low ITRs of 5.05×10 −9 m 2 KW −1 and 5.03×10 −9 m 2 KW −1 were observed. In addition, 12% was the optimal grafting rate for SiO 2 in GOTMS-modified SiO 2 /EP composites, and the highest interfacial binding energy of −386.88 kcal/mol in this work was obtained.