Film capacitors can be divided into three basic construction types: film/foil capacitors, metallized filmcapacitors, and mixed technology capacitors. Film/foil capacitors consist of two metal foil electrodes made of aluminum foil separated by a piece ofplastic film. The plastic film can be polyester, polypropylene or polycarbonate. There are other types ofplastic films but these films are used in specialized applications. The thickness of the plastic film typically ranges from 2 µm to 20 µm, while the aluminum foil thicknesses range from 5 µm to 9 µm. A film/foil capacitor is made by alternating two pieces of aluminum foil with two layers of plastic film. These interleaved layers are wound around a spindle in a manner that prevents the metal layers fromtouching. Film/foil capacitors can be wound in two different ways inductive (insert tab) and non-inductive(extended foil).