Quality testing methods of foil-based capacitors

Foil-based capacitors are widely used passive elements and therefore should be cheap and reliable. The contemporarily applied methods of their testing are time-consuming and energy-intensive. Additionally, these methods cannot select capacitors that should be very durable due to specific consumers demands (e.g. mining industry, medical equipment). Therefore, new and more efficient methods should be proposed. This manuscript presents in depth the mechanisms of capacitor failures which result from their construction and production methods. Theoretical consideration of possible capacitor failures due to an excessive electric field within the dielectric foil are enclosed. Results of correlation between the selected electrical parameters and capacitance drop due to excessive aging is presented and new methods of capacitor quality prediction are proposed and discussed in detail.