Film capacitors are versatile components that can be designed into power electronics for industries ranging from consumer and renewables to automotive, aerospace and military. These capacitors come with very specific advantages including non-polarity, a high insulation resistance, low dielectric losses and self-healing capability.
Vishay film capacitors uses the following film materials in their production: Polyester film offers a high dielectric constant, and a high dielectric strength. It has further excellent self-healing properties and good temperature stability. The temperature coefficient of the material is positive.
Like all capacitors, metallized film capacitors incorporate metal plates separated by a dielectric. Film capacitors are also known as plastic film, polymer film, or film dielectric capacitors. Film capacitors are inexpensive and come with a nearly limitless shelf life.
These capacitors come with very specific advantages including non-polarity, a high insulation resistance, low dielectric losses and self-healing capability. Film capacitors can be optimized through diferent materials and manufacturing methods.
Polyester film capacitors are film capacitors using a dielectric made of the thermoplastic polar polymer material polyethylene terephthalate (PET), trade names Hostaphan or Mylar, from the polyester family. They are manufactured both as metallized wound and stacked versions, as well as film/foil types.
Especially for applications with high current pulse loads or high AC loads in electrical systems, heavy-duty film capacitors, here called "power capacitors", are available with dielectric ratings of several kilovolts. But the manufacture of film capacitors does have a critical dependency on the materials supply chain.
OverviewCharacteristics of film materials for film capacitorsOverview of construction and featuresInternal structureStyles of film capacitorsHistorical developmentDielectric materials and their market shareStandardization of film capacitors
The electrical characteristics, and the temperature and frequency behavior of film capacitors are essentially determined by the type of material that forms the dielectric of the capacitor. The following table lists the most important characteristics of the principal plastic film materials in use today. Characteristics of mixed film materials are not listed here.