Thermal Conductivity and Dielectric Behavior of Nanobrick Wall Thin Films: A New Generation of High-Performance Insulation

Various high voltage electronics for aerospace, defense, and energy storage and conversion have experienced a significant increase in their miniaturization, complexity, power draw, and heat generation. Current insulation systems are inadequate to meet the demands of these rapidly evolving electronics due to subpar thermal conductivities, dielectric properties, and conformability to complex part geometries. Little research has focused on creating novel insulation systems that excel at both dissipating heat and withstanding high voltages (i.e., have both high thermal conductivity and superior dielectric breakdown strength) due to the inverse relationship between the material’s thermal conductivity and insulating dielectric properties. Electronics often require specific combinations of thermal and dielectric properties that are difficult to obtain with one material. Layer-by-layer (LbL) deposition of polyelectrolytes and inorganic nanoplatelets, yields nanocomposite coatings with a high degree of conformality and ordered structures, with unique properties which rival Kapton. Properties can be controlled by adjusting solution concentration, chemistry, and pH, which directly alters the system’s nanostructure. Thermal conductivity as high as 1.87 W/m*K and impressive dielectric constant, losses, and breakdown strength (3, 0.05, and 140 kV/mm, respectively) have been achieved. These novel insulation systems also demonstrate impressive dielectric properties at elevated temperatures, with breakdown strengths ranging from 180-270 kV/mm and low dielectric losses (<<0.1). This unique application of LbL assembly provides a practical route for the precise production of high performance, thermally conductive insulation systems for high voltage electronics.