Highly thermally conductive, superior flexible and surface metallisable boron nitride paper fabricated by a facile and scalable approach

Abstract

High thermal conductivity and high flexibility, required by advanced microelectronic devices, are hard to be combined in composites, because their dependences on components concentration often contradict each other. Here, the conflicting goals are achieved by preparing meter-level BN paper containing 82.6 wt% commercial micron BN sheets with dihydromyricetin (DMY) from herbal medicine as a novel surface modifier and high molecular weight acrylate copolymer as adhesive. Thanks to the polycyclic aromatic hydrocarbons of DMY coupled with abundant functional groups, which form conjugation with the inert BN and increase its hydrophilicity, tough interphases are established in the oriented nacre-like BN composite architecture when Mayer rod method is used. The resultant BN paper can be folded into complicated shapes, possessing decent tensile properties (strength = 8.49 MPa; failure strain = 3.8%), as well as excellent in-plane and through-plane thermal conductivities (8.97 and 2.14 W m−1 K−1). Besides, the DMY attached to BN sheets can further coordinate with Pd2+, catalyzing copper deposition and producing flexible copper-clad BN paper. Considering the cost-effective and easy-accessible raw materials and the simple assembly technique, which avoid the limitation of lab-scale BN nano-sheets, the present approach may be feasible for producing flexible electronic components with highly efficient thermal dissipation ability.