Aluminum foil is the main material of aluminum electrolytic capacitors. The aluminum foil is set as the anode. After electricity is applied in the electrolyte, an oxide film (Al2O3) will be formed on the surface of the aluminum foil. This oxygen film functions as a dielectric, and the role of etching is to enlarge the surface area of the aluminum foil. Etching is an electrochemical process in which alternating or direct current is applied to a chloride solution.

Into

Formation is the process of forming a dielectric layer (Al2O3) on the surface of the anode aluminum foil. Generally, the formed aluminum foil is used as an anode.

In order to expand the surface area, the aluminum foil material is placed in an aqueous chloride solution for electrochemical etching. Then, after applying a voltage higher than the rated voltage in the ammonium borate solution, a dielectric oxide layer (Al2O3) is formed on the surface of the aluminum foil. This dielectric layer is a very thin and dense oxide film, about 1~1.5nm/vot, insulation resistance It is approximately 108 to 109Ω/m. In order to increase the efficiency of expanding the surface area, the etching shape is different according to the rated voltage.

Crop

Cut the aluminum foil (cathode foil and anode foil) and electrolytic paper to the required size according to the size requirements of different products.

Winding

The electrolytic paper is inserted between the cathode foil and the anode foil, and then wound into a cylindrical shape. In the winding process, the cathode foil and the anode foil are connected to terminals. Electrolytic paper mainly plays a role in balancing the distribution of electrolyte and keeping the gap between cathode foil and anode foil.

Impregnated

Impregnation is the process of immersing the element into the electrolyte. The electrolyte can further repair the dielectric layer. The electrolyte is a liquid that conducts electricity by ions. It is a cathode in the true sense and serves as a dielectric layer connecting the surface of the anode aluminum foil. The cathode aluminum foil acts like a collector to connect the real cathode to the internal circuit. Electrolyte is the key material that determines capacitor characteristics (temperature characteristics, frequency characteristics, service life, etc.).

Seal

Sealing is the process of packing the element into the aluminum shell and then sealing it with a sealing material (rubber, rubber cover, etc.). The main function of the aluminum shell and the sealing material made of rubber is to keep the capacitor airtight.

Ageing

Aging is the process of applying voltage to the sealed capacitor at a high temperature. This process can repair some damage to the dielectric layer during the cutting and winding process.

Full inspection, packaging

After aging, all products will be checked for electrical characteristics. And for terminal processing. Finally, packaging.