Views: 0 Author: Giselle Guo Publish Time: 2025-11-13 Origin: Site
When a capacitor fails by bulging or bursting, the immediate suspicion often falls on the dielectric film not being thick enough. However, the true culprit can lie deeper within its current-handling architecture.
The dielectric film is primarily designed for voltage endurance. ⚡ The capability to carry current, however, is fundamentally determined by the cross-sectional area of the internal current-carrying components (like the foil or tabs).
If these internal conductors are undersized for the application's current, their resistance leads to persistent Joule heating. This heat is generated from within, directly warming the dielectric and electrolyte, leading to a buildup of internal pressure. When this heat cannot be dissipated effectively, the pressure eventually compromises the casing, resulting in the visible bulge.
Key Insight: Look beyond just film thickness. Ensuring the conductor's cross-section is adequately matched to the operational current is a critical step in preventing overheating and the subsequent failure mode of bulging. ✅
