Causes of Capacity Fading of Metallized Film Capacitors

Capacity fading in metallized film capacitors can occur for a variety of reasons, depending primarily on the manufacturing process, materials, and operating conditions. Here are some common reasons that may cause capacitance fading in metallized film capacitors:

• Oxidation: The metal or dielectric layers in metallized film capacitors may become oxidized, resulting in reduced capacity. This oxidation usually occurs in high temperature or high humidity environments.
  
  
• Dielectric damage: The capacitor's dielectric layer can become damaged due to mechanical stress, excessive voltage, or other external factors, which can reduce the capacitor's capacity.
  
  
• Temperature effect: Changes in temperature may affect the performance of capacitors, especially for metallized film capacitors in high temperature environments. High temperatures can cause the performance of the dielectric layer to degrade.
  
  
• Leakage Current: Leakage current is a phenomenon that can cause capacitor capacity to decay. This phenomenon may be caused by structural or manufacturing defects in the capacitor, or by improper operating conditions of the capacitor, such as excessive operating voltage.
  
  
• Fatigue Effects: Metallized film capacitors may be subject to mechanical and electrical stress due to long-term use, which may result in degradation of capacitor performance.
  
  
• Material Quality: The quality of materials and quality control of the manufacturing process are critical to the performance of the capacitor. If the materials are defective or the manufacturing process is improper, capacity fading may result.
  
  
• Overvoltage: If a capacitor is exposed to operating conditions above its rated voltage for an extended period of time, it may cause capacity fading and performance degradation.