Preparation of magnetic-oriented electronic packaging composite materials with improved thermal conductivity and insulating properties by filling magnetic BN@Fe3O4 core-shell particles into epoxy

Epoxy resin (EP), as a resin material with excellent insulation performance, has been widely applied in fields such as electronics, coatings, ships etc. However, epoxy resins generally have poor thermal conductivity, which limits their application in the field of new generation of electronic packaging. To address the key issues mentioned above, the BN@Fe₃O₄ particles with positive out-of-plane thermal conductivity were successfully prepared in this study, having a core-shell structure with rough surfaces as well. As a thermal conductive powder, the disadvantage of hexagonal boron nitride being easily agglomerated in resin has been improved. By applying an external magnetic field, three-dimensional thermal conduction pathways were constructed in the matrix. The physical and chemical properties of the BN@Fe₃O₄ powder and its composite materials were analysed and tested. The experiment indicates that the thermal conductive magnetic powder BN@Fe₃O₄ had been successfully prepared. When the filling amount of BN@Fe₃O₄ reached 27.5 vol%, the out-of-plane thermal conductivity of the composite material was 1.758 W m⁻¹ K⁻¹, which was 982.12% that of pure EP. At this point, the mechanical behaviour and insulation performance of EP composite materials can be effectively guaranteed at the same order of magnitude as pure EP performance.