Polyarylene ether nitrile dielectric material with a thermally conductive network connected by crystals and boron nitride nanosheets

Abstract The localized heat accumulation in electronic components not only restricts the further miniaturization and integration of electronic devices but also severely impacts their performance and longevity. This thesis develops a high‐temperature‐resistant, insulating, and thermally conductive composite material, which can be applied in electronic fields such as encapsulation materials and flexible copper clad laminate substrate materials. Boron nitride nanosheets (BNNS) are utilized as both nucleating agents and thermal conductive additives. This dual‐role approach synergistically enhances thermal and electrical properties. Results show that the out‐of‐plane thermal conductivity (λ ⊥ ) of crystallized poly(aryl ether nitrile) (PEN) reaches 0.255 W/(m K), a 54.55% increase over untreated PEN. Furthermore, the BNNS‐filled PEN composite exhibits an λ ⊥ of 0.831 W/(m K), representing a significant 403.64% enhancement. The composite also demonstrates improved overall performance, including a dielectric breakdown strength of 249.59 kV/mm, a thermal expansion coefficient of 18.03 ppm/°C, an elevated glass transition temperature of 209.5°C, and a thermal decomposition temperature of 441.3°C. Highlights BNNS plays the roles of both a nucleation agent and a heat‐conductive filler. The λ ⊥ of BNNS‐filled PEN composite increases by 403.64% compared to pure PEN film. Thermal conductivity increases through the regulation of condensed matter structure.