Effective Thermal Conductivity of Flexible Two‐Layer Aluminum Nitride/Polytetrafluoroethylene Structure

In this study, the thermal conductivity of polytetrafluoroethylene (PTFE) coated with thin layer of aluminum nitride (AlN) deposited using a hybrid helicon‐arc ion‐plasma reactor is investigated. The thermal conductivity flexible two‐layer AlN/PTFE structure is measured using the 3 ω method. In the results, it is indicated that two‐layer PTFE structure with a ≈2 μm thickness layer of the AlN coating exhibits effective coefficient thermal conductivity of λ = 0.7031 W m −1 K −1 , which is nearly three times higher than that of non‐coated PTFE (0.2–0.3 W m −1 K −1 ). This is attributed to the increased inelastic mean free path of phonons due to high adhesion and the effective heat dissipation properties of the AlN coating. Pretreating PTFE in helicon plasma significantly improves adhesion of AlN coatings, with adhesion strength reaching σ ≥ 10 MPa compared to σ ≈ 0.45 MPa on untreated surfaces. In this study, the potential of AlN coatings to enhance the thermal properties of polymer‐based materials is highlighted. Specifically, AlN/PTFE structure can be applied for the input windows of cryogenic ultrasensitive receivers in next‐generation navigation systems, providing improved protection against harmful environmental thermal radiation.