Carbonized Nanodots Modified Epoxy Resins With Low Permittivity, High Thermal Conductivity and Enhanced Breakdown...

To address the performance limitations of epoxy resin (EP) in electronic packaging applications, carbon nanodots (CDs) were synthesized and chemically incorporated into the EP matrix as a co-curing agent. The effects of CDs on curing behavior, dielectric properties, electrical breakdown resistance, thermal conductivity and mechanical properties of EP composites were systematically investigated. The results indicate that CDs with their multiple active sites can enhance the curing reactivity of EP and construct a more compact crosslinked network, which is verified by the increased glass transition temperature (T_g). The densified network suppresses polarization and dielectric loss. Meanwhile, it provides more covalent pathways for phonon transport. Compared to neat EP, the EP/CDs composite containing 0.5 wt% CDs exhibits superior comprehensive performance: low dielectric constant (ε ∼ 2.3 @10⁶ Hz), low dielectric loss (tanδ ∼ 0.009 @10⁶ Hz), significantly elevated electrical breakdown strength (E_b ∼ 89.9 MV m^-1), nearly double thermal conductivity (TC ∼ 0.61 W m^-1 K^-1) of neat EP. Additionally, the service stability of EP/CDs composites under hot-humid conditions has been evaluated and found to be superior to that of neat EP. This work demonstrates that EP/CDs composites have great application potential as electronic packaging materials for high-speed communication systems due to their excellent integrated properties.