There are more types of aluminum electrolytic capacitors construction and termination styles:
The most common styles are wound foil capacitors packaged in aluminum can as leaded or SMD termination styles.
Electrolyte can be wet, gel (TCNQ salt), solid (conductive polymer) or hybrid (combining wet and conductive polymer) based:
Wet Liquid Types
Solid Conductive Polymer
Hybrid Wet + Polymer
The production process starts with mother rolls. First, the etched, roughened and pre-formed anode foil on the mother roll as well as the spacer paper and the cathode foil are cut to the required width.
The foils are fed to an automatic winder, which makes a wound section in a consecutive operation involving three sequential steps: terminal welding, winding, and length cutting. In the next production step the wound section fixed at the lead out terminals is soaked with electrolyte under vacuum impregnation.
The impregnated winding is then built into an aluminum case, provided with a rubber sealing disc, and mechanically tightly sealed by curling. Thereafter, the capacitor is provided with an insulating shrink sleeve film. This optically ready capacitor is then contacted at rated voltage in a high temperature post-forming device for healing all the dielectric defects resulting from the cutting and winding procedure.
After post-forming, a 100% final measurement of capacitance, leakage current, and impedance takes place. Taping closes the manufacturing process; the capacitors are ready for delivery.