Epoxy‐Based Ceramic‐Polymer Composite with Excellent Millimeter‐Wave Broadband Absorption Properties by Facile Approach

The development of polymer‐based absorbers in millimeter‐wave frequency range has triggered a surge of interest due to the ever‐growing demands of 5G communication applications. Herein, a systematic investigation on a novel biphase composite, i.e., BaNb0.6Fe11.4O19 (BNFO)/epoxy, is presented. BNFO is the only filler phase that can generate dielectric loss and magnetic loss simultaneously, and epoxy is used as matrix phase for its advantages as a widely used electronic packaging material. The millimeter‐wave broadband absorption properties of the composite and related mechanisms are investigated both experimentally and theoretically. When the BNFO content is higher than 60 wt%, a millimeter‐wave broadband absorption performance is observed with a decreased matching thickness and a wider effective bandwidth covering the entire R band. The maximum reflection loss of the composite can achieve −28.74 dB at 31.43 GHz and −44.36 dB at 27.18 GHz with a matching thickness of only 0.98 and 0.97 mm when the BNFO contents are 60 and 75 wt%, respectively. The comprehensive advantages of the composite, including millimeter‐wave broadband absorption properties, facile manufacturing processes, small matching thickness, and good compatibility with current electronic packaging materials, facilitate it to be utilized in next‐generation electronic devices. An epoxy‐based ceramic‐polymer composite BaNb0.6Fe11.4O19 (BNFO)/epoxy by facile approach is proposed for electromagnetic interference (EMI) shielding in electronic packaging applications. The composites exhibit comprehensive advantages, including millimeter‐wave broadband absorption properties, facile manufacturing processes, small matching thickness, and good compatibility with current electronic packaging materials. The origination of dielectric loss, magnetic loss, and resultant electromagnetic wave absorption properties is also revealed.