ABSTRACT Heat dissipation remains a formidable challenge for polytetrafluoroethylene (PTFE) based high‐frequency substrates, as the integration of thermally conductive fillers like hexagonal boron nitride (hBN) is often hindered by the intrinsic chemical inertness and ultra‐low surface energy of PTFE. Herein, a soluble fluoroalkyl end‐capped polyimide (FPI) precursor is developed. The amphipathic structure of FPI acts as an intermolecular bridge, facilitating the homogeneous dispersion of hydrop