Simple Protein Foaming‐Derived 3D Segregated MgO Networks in Epoxy Composites with Outstanding Thermal Conductivity Properties

Abstract The miniaturization and high‐power density of electronic devices present new challenges for thermal management. Efficient heat dissipation in electrically insulating packaging materials is currently limited by the thermal conductivity of thermal‐interface materials (TIMs) and their ability to effectively direct heat toward heat sinks. In this study, MgO‐based composites with high thermal conductivities are fabricated to achieve excellent thermal performances by optimizing the heat‐transfer path. These composites are produced using a protein foaming method, which effectively forms interconnected ceramic‐filler networks. Additionally, the liquid phase formed during the sintering of MgO enhances the bonding with the epoxy matrix, thereby improving the thermal conductivity of the composites. As a result, the composites with 54.64 vol% MgO achieve a high thermal conductivity of 17.19 W m −1 K −1 , which is 101 times higher than that of pure epoxy, 3.7 times higher than that of randomly dispersed composites, and even superior to that of nitride‐based composites. Moreover, the composites also exhibited a low thermal‐expansion coefficient (27.76 ppm °C −1 ) and high electrical‐insulation strength (51.51 kV mm −1 ), ensuring good thermal and electrical performance for electronic‐packaging applications. The strategic design of the TIM microstructures for effectively directing heat offers a promising solution for efficient thermal management in integrated electronics.