A plastic film capacitor uses a plastic film as the dielectric material. The electrodes are either made of a metal film or by metallizing. One capacitor can have one or more layers. The plastic film capacitor has a low electrode resistance. The most used plastic films are polyester, polycarbonate, polypropylene, polystyrene and polyenylenesulphide

The polyester film is cheap and easy to metallize, but has low stability. Used in circuits where stability is not critical

The polycarbonate film is relatively easy to metallize and better stability than polyester. It has lower dielectric constant than polyester makes a polycarbonate capacitor larger and more expensive. This capacitor is used in applications where the high stability is needed.

Polypropylene is hard to metallize and to make thin, but is stable, has a low loss factor and has a low dielectric absorption (A low dielectric absorption means that the capacitor won't 'self recharge'). The low absorption makes this capacitor ideal in sample and hold circuits and audio equipment.

Polystyrene is hard to metallize and has a low voltage tolerance but has high stability and low dielectric absorption. This capacitor is most used in filters.

The polyenylene sulphide has high temperature tolerance, good stability and a very low voltage loss, but it has a low voltage tolerance.

Plastic film capacitors are available with values from about 12pF up to 100uF.

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