Polymer nanofiber based continuous metal phase composite for thermal management applications

A new composite design approach for thermal interface materials is presented. A porous electrospun nanofiber network composed of temperature stable polyimide was infiltrated with liquid phase indium at a pressure of 30 MPa. The polymer phase defines composition and geometry, while the continuous metal phase gives binding to surfaces and high thermal conductivity. The composite was characterized by assembly of tri-layer copper/TIM/copper sandwich structures and subsequent xenon flash measurements extracting the thermal properties of the intermediate TIM layer. The interfacial contact resistance was found to be 8 Kmm²/W and the thermal conductivity was 28 W/mK, indicating the potential for use in thermal management applications.