Cu-Ag bimetallic-coated polyamide microfiber array: construction of continuous thermal channels for high-performance thermal Interface materials.

Constructing continuous high-thermal-conductivity channels that penetrate through the polymer matrix is one of the key approaches to achieving next-generation high-performance composite thermal interface materials (TIMs). Currently, the only reported metal copper microarray-based TIMs fabricated via porous sacrificial templating are costly and cumbersome. In this work, a novel and facile route is developed for constructing flexible, metallic array TIMs based on electroless plating of polyamide fiber arrays. The resulting CuAg bimetallic-coated (PA@Cu@Ag) fiber structures provide high-thermal-conductivity and performance-stable flexible channels for high-performance TIMs. The composite TIM, with the PA@Cu@Ag fiber array serving as the skeleton, exhibits a thermal conductivity as high as 69.3 W/m·K and a Young's modulus as low as 32.5 MPa. Its performance remains stable even after 1000 compression cycles and LED device on/off cycling. When assembled in LED devices, it significantly reduces the steady-state operating temperature to 58.0 °C, far outperforming conventional particle-filled composite materials.