Polypropylene capacitors are metal foil as the electrode, after its overlapping and polypropylene film from both ends, the capacitor winding into the structure of the cylinder. Nonpolar, high insulation resistance, excellent frequency characteristic (broad frequency response), and the dielectric loss is very small. Based on the above advantages, so the film capacitor is widely used in analog circuit. The capacitor built-in high reliability explosion-proof device, the use of safe and reliable, the product has good self-healing performance, long service life, widely used in air conditioners, refrigerators, electrical and lighting lamps and lanterns, etc.