Analysis of failure Mechanism of Capacitor at High temperature and High pressure(II)

2. Effect of plate (aluminum foil) on breakdown of capacitors:

Aluminum foil in the cutting, because the hob is not sharp, after cutting aluminum foil plate will appear sawtooth, burr and so on. This kind of disk material is easy to stab the dielectric film in the winding, reduce the voltage resistance, the serious burr will also cause the capacitor to pressurize and break down.

3. The effect of lead spot welding on capacitor breakdown:

In the winding process of capacitors, the lead wire is directly spot welded on aluminum foil. Therefore, improper adjustment of the pressure of the two electrodes, the size of spot welding current and the flatness of the spot welding platform during spot welding will result in burrs between the lead wire and aluminum foil welding. Stabs the dielectric film, reduces the voltage resistance, the serious burr will cause the capacitor to pressurize after breakdown,

4. The effect of heat seal on the breakdown of capacitors:

The wrapped film of the core group of capacitors is sealed by the heat of the heat seal. If the heat control of the heat seal is not proper, or the contact time between the heat seal and the core group is too long, it is easy to burn the outer film, which affects the voltage resistance of the capacitor. It will cause the capacitor to break down after pressurization.