How to pay attention to the loss of film capacitance during the production process

The loss of the film capacitor in the high frequency state is mainly metal loss, mainly including capacitor lead line loss, capacitor plate loss and contact loss. Nowadays, the lead wires used in film capacitors are tinned copper clad steel wires or tinned copper wires, and their own losses are extremely small and negligible. Therefore, the loss of the film capacitor under high frequency conditions is mainly the plate loss and the contact loss. In the production process of film capacitors, attention should be paid to the following aspects:

(1) The electrode material used for the foil film capacitor is an aluminum foil, which is required to have a uniform thickness, good electrical conductivity, and no corrosion. The end face of the aluminum foil is not bumped.

(2) The material used for the metallized film capacitor is a metallized film, which deposits metal aluminum (or other metal) on the surface of the medium by vacuum evaporation, which can reduce the volume of the capacitor, improve the self-healing of the capacitor, and reduce the capacitor. the cost of. However, since the film is easily scratched during the vacuum evaporation process or during the slitting process of the metallized film and during the winding of the capacitor core, the metallized film capacitor is fatal.

It is necessary to strengthen the sampling inspection of the metallized film entering the factory. In addition to the electrical properties, thickness, width, appearance, and squareness test of the metallized film, it is also necessary to check the adhesion of the metal layer on the film and whether there is any metal layer. Whether there are scratches on the defects and on the metal layer. Secondly, it is necessary to strengthen the inspection and inspection during the production process of the winding process. After the inspection of the capacitor core, it can be mass-produced after passing the test. In the mass production process, the inspection of the capacitor core is strengthened, and the problem is solved in time to ensure the winding. The product quality of the process. For the film capacitors with the final frequency loss, the process checks the loss, and during the sampling process, the abnormality is found. The batch of products should be tested in time, and the test is qualified to be transferred. If the test fails, the batch of products should be downgraded or scrapped. deal with.