A lightweight Co₁Ni_0.5@NC/SiC_f filler with excellent low-frequency electromagnetic wave absorption and heat dissipation for electronic packaging

The rapid advancement of highly integrated and high-power electronic devices has intensified the inherent challenges of low-frequency electromagnetic interference and heat accumulation. To mitigate these issues, a lightweight Co₁Ni_0.5@NC/SiC_f filler with a density of 3.01 g cm⁻³ was prepared via electrostatic self-assembly followed by high-temperature heat treatment. By introducing CoNi-Zeolitic Imidazolate Frameworks, both magnetic and dielectric losses are enhanced, thereby improving the impedance matching and EMW absorption performance in the low-frequency band. When incorporated into an Epoxy Resin (EP) substrate, the composite forms a continuous heat transfer network constructed by the SiC_f, significantly improving heat dissipation performance. Specifically, at a filler mass ratio of 30 wt%, the Co₁Ni_0.5@NC/SiC_f/EP achieves an effective absorption bandwidth (EAB) of 2.1 GHz (4.4–6.5 GHz) at a thickness of 4.8 mm, fully covering the n79 band (4.4–5.0 GHz) used in 5G communications. Moreover, the thermal conductivity (λ) was enhanced to 0.7842 W m⁻¹ K⁻¹, which is 3.8 times that of EP. This work demonstrates a promising filler candidate for high-performance thermal interfacial materials (TIMs), advancing the development of advanced electronic packaging technology.