Patternable thermal conductive interface materials enabled by vitrimeric phase change materials

Abstract

Thermal interface materials (TIMs) with mechanical integrity and interfacial adaptability over rough surfaces without applying high pressure to the sandwiched thermal interfaces are challenging. Herein, patternable thermal conductive interface materials enabled by vitrimeric phase change materials (PCMs) for reconfigurable package procedures and reduction in thermal contact resistance are proposed. The incorporated dynamic crosslinked network in paraffin wax/polyolefin elastomer (PW/POE) PCMs forms a robust 3D supporting skeleton, giving rise to the PCMs with mechanical integrity even when POE is melted. Lowered modulus by solid–liquid phase change of PW and activated exchange of dynamic covalent bonds when POE is melted allow for reconfigurable package procedures by plastic deformation with small stress. Hybrid fillers with different sizes and dimensions form effective heat conduction pathways in the vitrimeric PW/POE PCMs. Notably, the resulting composites can still conformally adapt to the rough surfaces of the heat sink and heat source at 80 °C and 13 KPa, resulting in an interlocked structure, which can essentially reduce the thermal contact resistance and promote thermal transport. The prepared composites as TIM demonstrate better heat dissipation performance than the commercial thermal pad. The strategy of vitrimeric PCMs combines mechanical integrity and thermally triggered interfacial adaptability through reconfigurable package procedures, providing inspiration for the bulk compliance of TIMs that can adapt to rough surfaces.