High temperature studies of perfluoroalkoxy (PFA) film (for HV capacitors)

Teflon perfluoroalkoxy (PFA) film was characterized electrically to explore the possibility of its use for high-temperature high-voltage capacitors for space applications. The properties measured at temperatures up to 250 degrees C included the AC breakdown voltage and the dielectric constant and dissipation factor at frequencies up to 100 kHz. To understand the breakdown mechanism taking place at these higher temperatures, the prebreakdown conduction currents were also monitored. The results show a drastic reduction in the dielectric strength, as well as an increase in dissipation factor and conduction current with increasing temperature. The results are explained in light of the breakdown models available.<>