Thermal conductivity and electrical properties of three-dimensional porous aluminum nitride/epoxy composites

Epoxy resin (EP) is a typical insulating material for electronic packaging, but its thermal conductivity (less than 0.2 W/(m·K)) is low, and improving its thermal conductivity is an effective way to solve the heat dissipation problem of electronic devices. In this paper, 3D-AlN/EP composites were prepared by constructing a three-dimensional porous aluminum nitride skeleton (3D-AlN). The SEM morphology and XRD phase characterization results confirmed the successful preparation of 3D-AlN skeleton and 3D-AlN/EP composites. The mass fraction of the composite accounted for by the 3D-AlN skeleton was precisely measured using TGA, and by comparing with different contents of random distribution AlN/EP (Random AlN/EP) composites, it was found that the thermal conductivity of 3D-AlN/EP composites was higher than that of Random AlN/EP composites, the thermal conductivity of the 45.48wt%3D-AlN/EP composite at room temperature (25℃) was 1.00 W/(m·K), which was 5.6 times higher than that of pure EP (0.18 W/(m·K)). The interfacial thermal resistance of the composites was calculated using the theoretical model (Fogyel, Agari), and it was found that the 3D-AlN/EP composites had lower filler-to-filler interfacial thermal resistance compared to Random AlN/EP, with 2.704×10⁵ K·W⁻¹ and 4.019×10⁵ K·W⁻¹, respectively. The electrical properties showed that the 45.48wt%3D-AlN/EP composite had good dielectric and insulating properties (volume resistivity is 4.16×10¹¹ Ω·cm). This study provides an effective solution to the heat dissipation problem of electronic devices from the perspective of package insulation material modification.