An efficient thermal interface material with anisotropy orientation and high through-plane thermal conductivity

The rapid development of integrated circuits and electronic devices with increased power density and heat flux, requires effective heat dissipation for thermal management. Constructing a directional thermal pathway from the vertically aligned thermal conductive fillers in the thickness-direction of polymer-based thermal interface materials (TIMs) is a desirable strategy to form materials with high thermal conductivity. However, due to the complexity of vertical orientation technology, fillers with the poor orientation degree weaken the enhancement of through-plane thermal conductivity. In this work, we prepared short carbon fiber (CF)/olefin block copolymer (OBC) composites with high orientation degree via the melting extrusion method on a basis of sharing force induce alignment. Attributed to the high orientation degree of CF in the vertical direction, the as-prepared material shows a through-plane thermal conductivity (kappa(perpendicular to)) up to 15.06 W/m K at a 30 vol% CF content, which is similar to 10 times that of a parallel structure. The operating temperature difference between vertical and random reached 35.2 degrees C, surpassing the characters in most works of literature. This study provides an effective way to develop high-oriented degree and electrical insulation polymer composites with superior kappa(perpendicular to) for scalable thermal management applications in electronic devices.