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Metallized films and capacitors for capacitors

Release time:

2024-09-20

Metallized film capacitors manufacturing process is a major advance in electrode metallization. Metallized electrodes so that the capacitor has a self-healing ability to improve reliability, reduce the size of the capacitor and reduce the weight, prevent the failure of the capacitor under low voltage, and is conducive to the use of capacitors in series, and reduces the difficulty of capacitor manufacturing.

Metallized films and capacitors for capacitors

Metallized film capacitors have a self-healing function, in the event of partial breakdown of the capacitor, through the self-healing of the metallized layer can quickly restore the performance of the capacitor, improving the reliability of the capacitor. Self-healing can be categorized into discharge self-healing and electrochemical self-healing.

Defects (metallization defects, semiconductor defects, poor insulation defects or air holes) are usually present in the metallized film. At a certain voltage applied to the capacitor, the Joule heat generated in the area close to the defect melts the metallization layer in that area, causing an arc to fly between the electrodes. Arc quickly evaporate and throw away the molten metal in the region, the formation of metal-free insulation isolation zone, the arc is extinguished, to realize the discharge self-healing. It should be ensured that the discharge self-healing time is very short, the self-healing energy is small, excellent isolation of defects, no damage to the medium. If you can not do these, excessive self-healing will occur, the lesser of which will cause a significant drop in capacitance, and the more serious can make the capacitor failure.

Metallized film of evaporated metal if easy to form oxide insulation layer (such as aluminum metallized film), capacitors manufactured with it at lower voltages will occur electrochemical self-healing, in the defects around the formation of the metal oxide. Electrochemical self-healing lasts for a long time, causing the capacitor to fail with excessive capacitance in advance at lower voltages.