Copper foil, generally refers to copper or copper alloy, which is processed by calendering, electrolysis and other processes, with a thickness of 200 μ Copper strip (piece) below m. Copper foil can be classified in many ways according to its production process, application field, thickness, surface roughness, etc. According to the production process, it can be divided into Electrolytic copper foil and Calendered copper foil Two categories.

Electrolytic copper foil is the copper foil produced by electrolysis. It is the original foil made by dissolving the copper material into copper sulfate solution, depositing the solution through DC electrodeposition in professional electrolysis equipment, and then roughening, curing, heat resistant layer, corrosion resistant layer, oxidation resistant layer and other surface treatment. Finally, it is sold as processed foil after cutting and testing; The calendered copper foil is the copper foil produced by the calendering method. It is the original foil made from the copper plate through repeated rolling, and then the surface treatment such as degreasing, roughening, heat-resistant layer treatment and anti oxidation treatment is carried out according to the requirements to treat the foil form for sale, or it is sold in the form of light foil without treatment.

The properties of calendered copper foil are better than electrolytic copper foil, but the requirements for equipment and process are also higher. The original foil produced by physical forging of calendered copper foil usually has better physical properties, and is superior to electrolytic copper foil in copper purity, strength, toughness, ductility and other indicators. However, the thickness and width of calendered copper foil will be limited by the size of the roll, which has high requirements for equipment, complex process, high production costs, and the related process patents are monopolized by a few Japanese and American enterprises.

Electrolysis has become the mainstream process of copper foil production at home and abroad due to its cost, process and other advantages, and most domestic copper foil production enterprises also use electrolysis.