Towards electrical insulation electromagnetic interference shielding materials: a magnetic network–microcapacitor framework for advanced electronic packaging

Abstract

To meet the challenges of Moore's law, next-generation chips have been constructed with increasingly complex multilayer architectures. Traditional electromagnetic interference (EMI) shielding materials designed with high electrical conductivity as the primary principle are prone to electrical reliability issues in electronic devices. To tackle this challenge, we propose a “magnetic network–microcapacitor” framework composed of magnetic particles decorated with electrical insulation shells, aiming to develop epoxy-based composites that provide EMI shielding yet electrical insulation. It is noteworthy that fine-tuning the state of the coating layer plays a critical role in blocking electron transport within the composite while preserving the continuity of the magnetic network pathways. Thus, the magnetic loss induced by the high-density magnetic network, along with the ohmic and polarization losses from a number of microcapacitors, endow the composite with integrated “electrical insulation-EMI shielding-thermal conductivity” functions targeting advanced electronic packaging. Guided by this framework, the novel designed and prepared FeSiAl@Al₂O₃/epoxy composites possess a wide-band EMI shielding efficiency (reaching 50 dB) and excellent thermal conductivity (4.14 W m⁻¹ K⁻¹) while maintaining electrical insulation at values exceeding 10¹³ Ω cm. Besides, the thermal management ability and near-field shielding performance demonstrate that this innovative design concept is expected to significantly advance the development of electrically insulating EMI shielding materials.