Corrosion Analysis of the Electrode Coating in Film Capacitors for Power Electronics Applications

The reliability and longevity of electronic components, particularly film capacitors, are crucial in power electronics systems due to their roles in energy storage, filtering, and voltage stabilization. However, corrosion phenomena affecting electrode coatings can compromise their performance. This study investigates the corrosion mechanisms of electrode coatings in film capacitors designed for power electronics applications. To achieve this, metallographic cross-sections were prepared and analyzed using Scanning Electron Microscopy (SEM) for high-resolution examination of the coatings' microstructural features. The research employed accelerated tests to simulate real-world operating conditions, incorporating humidity, elevated temperatures, and electrical stress. A tailored preparation methodology for the metallographic cross-sections was developed to optimize surface quality, ensuring reliable SEM results. The process involved precise cutting and polishing techniques that minimized damage to the coatings. The accelerated corrosion tests revealed significant insights into corrosion mechanisms, showing that moisture facilitated the formation of corrosion products, leading to localized degradation. The interaction between moisture and electrical stress exacerbated these effects, resulting in accelerated deterioration of the coatings. These findings highlight the importance of environmental factors in assessing film capacitor reliability. By correlating microstructural changes with test conditions, the research provides a comprehensive understanding of material behavior, emphasizing the need for improved coating materials and protective strategies as well as adapted accelerated test routines.