What is the production process of the capacitor?
The following example describes a typical manufacturing process flow for film capacitors.
1. Film stretching and metallization — To increase the capacitance value of the capacitor, the plastic film is drawn using a special extrusion process of bi-axial stretching in longitudinal and transverse directions, as thin as is technically possible and as allowed by the desired breakdown voltage.
2. Film slitting — Next, the rolls are slit into small strips of plastic film in the required width according to the size of the capacitors being manufactured.
3. Winding — Two films are rolled together into a cylindrical winding. The two metallized films that make up a capacitor are wound slightly offset from each other, so that by the arrangement of the electrodes one edge of the metallization on each end of the winding extends out laterally.
4. Flattening — The winding is usually flattened into an oval shape by applying mechanical pressure.(There are some models of capacitors that require this step.Such as CBB61 .fan capacitor )
5. Metal spraying —The projecting end electrodes are covered with a liquefied contact metal zinc which is sprayed with compressed air on both lateral ends of the winding.
6. Healing — The windings which are now electrically connected by the schoopage have to be "healed". This is done by applying a precisely calibrated voltage across the electrodes of the winding so that any existing defects will be "burned away"
7. Impregnation — For increased protection of the capacitor against environmental influences, especially moisture, the winding is impregnated with an insulating fluid, such as wax.
8. Welding — Solder the terminals of the capacitors with metal tin or solder on the end metal contact layer at the school.
9. Coating — After attaching the terminals, the capacitor body is potted into an external casing.
10. Machine testing — The capacitor is charged at three times the voltage for two seconds to measure stability.
11. Artificial secondary detection.
As an alternative to the traditional wound construction of film capacitors, they can also be manufactured in a “stacked” configuration.such as power capacitor which is made up of several small capacitors.