Recyclable Low Dielectric Polymers with High Thermal Conductivity for Copper‐Clad Laminated Film for High‐Frequency Applications

Abstract With the rapid increase in demand for next‐generation communication, the development of advanced dielectric materials has become imperative. To enhance the performance and reliability of miniaturized electronic devices, dielectric materials must exhibit high thermal conductivity (λ) while simultaneously fulfilling crucial criteria such as low dielectric permittivity (D_k) and dielectric loss (D_f). The synthesis of novel low dielectric polymers (LDPs) is newly reported by integrating fused aromatic mesogens and siloxane functions with silane linkers. Fused aromatic mesogenic building blocks undergo crosslinking via hydrosilylation with octavinylsilsesquioxane (OVS). The resulting LDPs exhibit excellent low dielectric properties (D_k of 1.79 and a D_f of 0.004) along with a high λ (0.89 W m⁻¹ K⁻¹). The cold crystallization of LDPs governs their molecular packing structure, which controls electron alignment and phonon transfer. A comprehensive understanding of the interplay between molecular packing structure and thermal properties of LDPs allows for precise tuning of signal transmission and heat conduction in dielectric polymers. Furthermore, the reprocessable and recyclable nature of LDPs highlights their potential as highly effective and environmentally sustainable materials for advanced dielectric applications.