Simultaneously Enhanced Thermal Conductivity and Dielectric Breakdown Strength in Sandwich AlN/Epoxy Composites

Polymer-based composites with high thermal conductivity and dielectric breakdown strength have gained increasing attention due to their significant application potential in both power electronic devices and power equipment. In this study, we successfully prepared novel sandwich AlN/epoxy composites with various layer thicknesses, showing simultaneously and remarkably enhanced dielectric breakdown strength and thermal conductivity. The most optimized sandwich composite, with an outer layer thickness of 120 mu m and an inner layer thickness of 60 mu m (abbreviated as 120-60) exhibits a high through-plane thermal conductivity of 0.754 W/(m center dot K) (4.1 times of epoxy) and has a dielectric breakdown strength of 69.7 kV/mm, 8.1% higher compared to that of epoxy. The sandwich composites also have higher in-plane thermal conductivity (1.88 W/(m center dot K) for 120-60) based on the novel parallel models. The sandwich composites with desirable thermal and electrical properties are very promising for application in power electronic devices and power equipment.

Automated summary

This study successfully prepared novel sandwich AlN/epoxy composites with significantly enhanced dielectric breakdown strength and thermal conductivity, showing great potential for application in power electronic devices and power equipment. The optimized sandwich composite with specific layer thicknesses demonstrated high through-plane thermal conductivity and dielectric breakdown strength, making it promising for various industrial applications.