How is the Loss Generated in Film Capacitors

Film capacitors use metal foils as electrodes, which are overlapped with plastic films such as polyester, polypropylene, polystyrene, or polycarbonate. These components are then wound into a cylindrical capacitor structure.

Film capacitors are widely used because of their high insulation impedance, broad frequency response, and non-polarity. Therefore, film capacitors are often used in circuits such as integrated circuit boards and analog circuits. They excel particularly in signal interconnection, with low dielectric loss and a wide frequency response, ensuring that signals do not change during transmission.

The losses in film capacitors are generally divided into dielectric loss and metal loss. Dielectric loss is usually caused by dielectric leakage current and losses caused by dielectric polarization. Metal loss typically consists of the contact resistance between the electrode plate and the pin, contact electrode resistance, and pin resistance. To control the loss in film capacitors, one must control the above factors, mainly depending on the manufacturing process of film capacitors.

Another possibility is that the contact resistance between the film electrode and the sprayed metal layer is too high, affecting this contact resistance. The main factors influencing this contact resistance are ① the spraying process and the choice of spraying materials. ② The use of DC voltage during withstand voltage testing can increase this contact resistance.

This is how the loss in film capacitors is generated, so choosing a reputable manufacturer is essential. A good film capacitor manufacturer can reduce unnecessary troubles. JYH HSU Electronics offers a complete range of film capacitor models with guaranteed quality.