ESR Modeling for Atmospheric Corrosion Behavior of Metallized Film Capacitors

Atmospheric corrosion significantly affects the reliability of metallized film capacitors (MFCs). Oxygen and moisture will induce oxidation reactions that lead to electrode corrosion, elevating the equivalent series resistance (ESR). In this work, an ESR elevation model is proposed to study the mechanism and regularity of the corrosion, and the influence of metal composition is analyzed with the accelerated aging test. It is found that the anti-corrosion ability results from the oxide structure on electrodes, with a transition from oxide plates to a compact oxide film as Al content ascends. The end contact degradation of MFCs has a notable impact on the ESR elevation, which can be inhibited by increasing the Al content to over 50 wt.%.