Magnetic Field‐oriented One‐step Fabrication of Metal‐grade Thermally Conductive Carbon Fiber Flexible Thermal Pad

Abstract As modern electronic devices trend toward miniaturization and integration, there is an urgent need for excellent thermal pads to facilitate efficient interface heat transfer. Carbon fibers (CFs), owing to their outstanding axial thermal conductivity and thermal stability, emerge as a promising high‐performance filler. However, the fabrication of high filler content composites using the inherent diamagnetic properties of CFs through magnetic orientation remains challenging. In this study, a solvent dilution method is employed to dilute the high‐viscosity PDMS with ethyl acetate, producing a PDMS dilute solution with a viscosity of only 2.28 mPa·s. This facilitated the vertical alignment of CFs in the solution at a low magnetic field (0.4 T) with a filler content as high as 60 wt.%. Specifically, completely vertical CFs achieved an alignment exceeding 93%. The prepared VCF/PDMS composite exhibited an exceptionally high through‐plane thermal conductivity of 141.57 W m ⁻¹ K ⁻¹ , reaching the level of metallic thermal conductivity. Furthermore, the thermal management application of the composite material as a thermal interface material for cooling electronic devices is demonstrated.