Fabrication and performance of ultrathin and adhesive composite film with high out-of-plane thermal conductivity using 3D printing and microwire-cutting assistance

This study presents the development of a highly thermally conductive adhesive film based on an epoxy matrix filled with high-oriented graphite films (GFs). The film was fabricated using a 3D-printed framework to fix aligned GFs in a parallel configuration, followed by the infusion of liquid epoxy. A diamond microwire cutting technique was employed to obtain a 0.4 mm thick epoxy composite film. The resulting film exhibits an impressive apparent out-of-plane thermal conductivity of 20 Wm-1K-1 and a notable tensile shear strength of 5.91 MPa, with a GF volume fraction of 75 %. Finite element simulations were employed to accurately predict the TC, which is found to be in excellent agreement with experimental results. The unprecedented combination of high out-of-plane TC and adhesive performance in such a thin adhesive film opens up opportunities for its utilization in various thermal management applications, including electronic packaging, LED systems, etc.