Design and regulation of electromagnetic parameters of THz absorbing epoxy resin composite film for 6G electronic packaging

Abstract

Flexible electrically insulating packaging materials with high absorption performance are urgently indispensable in the wide applications for 6G electronic devices. Herein, direct modification of KH550 and low-filler loading of mSiO₂ are proposed to construct enhanced epoxy resin (EP) composite film. The resultant EP-F sample achieves an average total shielding effectiveness (SE_T) of 15.11 dB (0.2–2.5 THz) at a thickness of 1 mm, representing a 142 % improvement over the EP sample. At a thickness of 1.8 mm, EP-F exhibits effective THz wave absorption across 0.5–2.5 THz frequency range, with an average reflection loss (RL) value of −14 dB. The dielectric behavior and THz wave absorption of the KH550- and mSiO₂-modified EP samples were analyzed through dielectric constant spectra and Cole-Cole plots for the first time, elucidating the distinction and relationship between microwave-like polarization and infrared-like absorption mechanisms in polar dielectric polymer materials within the THz range. Moreover, the EP-F sample exhibits enhanced mechanical properties and thermal stability, with a volume resistivity of 8.75 × 10¹² Ω cm and a breakdown field strength of 37.59 kV/mm. Finally, the potential application of EP-F in practical THz circuit board packaging was demonstrated through Finite difference time domain (FDTD) simulation modeling. The enhanced epoxy resin material demonstrates enormous promise for in-situ shielding and packaging of THz devices, fabrication of efficient wave-absorbing layers, and various future applications.