Transferable Percolated Particle Monolayers Derived from Marangoni Flows for Thermally Conductive Dielectric Coatings

Thermal management is becoming one of the most significant design and size limitations for high power density electronics, including motherboards, power converters, and phased array antennas for 5G communications. There are few options for conducting heat away with dielectric materials that avoid shortening or distorting the performance of these electronics. Certain highly thermally conductive 2D and 3D materials, including hexagonal boron nitride and diamond, offer ideal material properties to address these issues but are extremely challenging to process. This work studies highly oriented single-particle thick films of hexagonal boron nitride, manufactured through a modified Langmuir-Blodgett process and densified further using the Marangoni effect to attain remarkable thermal conductivity enhancement with minimal coating thickness. High loadings of hexagonal boron nitride (∼60 vol %) in dense, castable films are also produced to compare thermal spreading ability in a comparatively simpler but less-coordinated percolated system to the highly percolated particle monolayers. These procedures were applied to glass fiber reinforced polymers used in aerospace and radome applications as well as to a single-board computer to demonstrate enhanced thermal management.