Investigation of Aromatic Voltage Stabilizers for Enhancing High Voltage Stability of Epoxy for Power Electronics

Drive train electrification in automotive industry has become the general trend in recent years. As crucial components in the encapsulation and isolation of future wide-bandgap semiconductor-based power cards, epoxy resin and its composites face great challenges from the high voltage operation. This work provides an exploration into employing a group of polycyclic aromatic hydrocarbon molecules with varied number of aromatic rings, namely naphthalene, anthracene and pyrene, as voltage stabilizers in epoxy resin. The conjugated $\pi$ system can be excited by the incoming high energy electrons, thus absorbing their kinetic energy which endangers the polymer integrity. The UV-Vis spectra of the compounds were recorded to illustrate the energy absorbing behavior, and the effects of these additives on epoxy curing, glass transition temperature and dielectric properties are presented. In the study, pyrene was found to enhance the breakdown voltage of the epoxy film.