How to use metallized capacitors

What is a metallized film capacitor?

Metallized film capacitors generally use polypropylene as the dielectric film, and use the metallized layer evaporated on the dielectric film as the electrode, which are the important power devices.

How do metallized capacitors work?

The metallized layers in these capacitors are <100 nm thick. The two films are wound around a hollow mandrel. On each end of the winding is a sprayed-on metal schoopage. The schoopage connects the metallizations of the film to the terminals of the package. Each film has one clear edge.

Are metallized film capacitors self-healing?

However, the thick metal foils prevent these capacitors from exhibiting the self-healing phenomena observed in metallized film capacitors . Metallized film capacitors are non-polar. They consist of two polymer films on which thin coatings of metal have been deposited. The films are wound and packaged into a capacitor as shown in Fig. 1.

Do metallized film capacitors need to be tested?

In the case of metallized film capacitors, the tests must be able to precipitate and accelerate the effects of self-healing on the capacitor, corrosion of the metallized film, and any mechanisms associated with the schoopage connection.

Do metallized film capacitors fail?

This paper presents a comprehensive review of metallized film capacitors used for EMI filtering and their failure modes and mechanisms. One of the major failure mechanisms discussed is the corrosion of the metallized film due to moisture ingress into the package.

Are metallized film capacitors used for EMI filtering?

Metallized film capacitors are used to reduce electromagnetic interference (EMI) in electric power mains due to their high voltage capability and their open circuit failure mode, which aids in safe operation. This paper presents a comprehensive review of metallized film capacitors used for EMI filtering and their failure modes and mechanisms.