Graphene-epoxy composite with dual-function of excellent microwave absorption and efficient heat dissipation

Developing electronic packaging materials with both outstanding electromagnetic wave (EMW) absorption and efficient heat dissipation is crucial for addressing vital issues of electromagnetic interference and heat accumulation in modern integrated circuits. Herein, we present a graphene-epoxy composite with dual-function of excellent microwave absorption and efficient heat dissipation as a promising candidate. The composite was fabricated by immersing epoxy resin into graphene aerogel (GA) with precisely controlled directional pores. Before immersion, the GA was annealed at temperatures from 600 to 3000 °C to investigate the influence of oxygen content and defects in the graphene on wave absorbing and heat dissipating properties of the graphene-epoxy composite. The composite with the GA annealed at 1200 °C exhibits a minimum reflection loss of −35.67 dB at a frequency of 8.80 GHz with a sample thickness of 2.0 mm, and the thermal conductivity is 0.69 W m⁻¹ K⁻¹, 283 % improvement over the epoxy matrix. Furthermore, the composite with the GA annealed at 2500 °C demonstrates an impressive absorption bandwidth (7.76 GHz) spanning from 10.24 to 18.00 GHz (covering a part of X-band and all the Ku-band) with a sample thickness of 3.0 mm, and the thermal conductivity is 6.81 W m⁻¹ K⁻¹, 3683 % improvement over the matrix. The graphene-epoxy composite exhibits excellent EMW absorption performance and high thermal conductivity, highlighting promising applications as electronic packaging material in high-power integrated circuits.