Rolled copper foil (rolled copper foil)

1) Production process of rolled copper foil (rolled copper foil) : Ingredient control of semi-continuous casting/horizontal continuous casting/cold-rolled open-up surface

2)Features of rolled copper foil

Rolled copper foil size range is 0.050-0.010 mm (thickness)40-600mm (width) , coil length should not be less than 5000mm. Its state has soft state and hard state, generally for hard state. It is characterized by dense structure, uniform performance, high Surface finish and good tolerance, but the minimum thickness and width are limited.

3)Rolled copper foil

The rolled copper foil can be divided into oxygen-free copper foil, oxygen-free copper foil and copper foil for electronic tube according to its chemical composition. The copper foil is added with corrosion-resistant alloy copper foil and heat-resistant alloy copper foil with micronutrient. Pure copper foil is mainly used for Flexible electronics, printed circuit boards, electromagnetic shielding tape, composite flat cables, windings and layer electrodes of lithium batteries. Corrosion-resistant alloy copper foil and heat-resistant alloy copper foil are mostly used in radiator, gasket, brake pad, etc. . With the miniaturization of electronic components, copper and copper alloy foil will be more and more widely used. The chemical composition, properties and uses of rolled copper foil are shown in the table below.

Note: The property of low temperature softening foil refers to the property value after heating for 15 min at 177 °C.

2.Electrolytic copper foil

1)The process of electrolytic copper foil is made by using cathode roller to make copper cation precipitate on the surface of cathode roller and then remove it by surface treatment. At present, the production of electrolytic copper foil in most countries in the world adopts roll-type continuous electrolysis method, which consists of two major parts, namely, the production process of raw foil (or rough foil) and the surface treatment process, nAMELY: Melting copper-electrolysis-surface treatment (pickling, coarsening). PRODUCTION PROCESS FLOW OF ELECTROLYTIC COPPER FOIL:

Surface treatment process three steps: the first step coarsening to further improve the surface structure of wool foil, improve its adhesion; the second step electroplating brass or zinc, forming an isolation layer to prevent pollution of the substrate; the third step, zinc or nickel, tin, etc. , to form an anti-oxidation layer.

2)Main equipment for electrolytic copper foil

The equipment is composed of dissolving tank, electroforming (dissolving) tank, processor, slitting machine, coating machine, stove, shearing machine and coiler. The copper ions in the solution are electroformed and deposited on the surface of the cathode roller to form copper foil. The copper foil is washed and dried by water after the cathode roller is peeled off by the processor. Slitting machine cutting edge or slitting; coating machine is the surface treatment device, surface coating.

3)Characteristics of electrolytic copper foil

The thickness of electrolytic copper foil ranges from 0.140.009 mm to 0.018 mm and 0.035 mm. Electrolytic copper foil is pure copper foil, high copper content, good conductivity, but the density is not as calendered copper foil. Uniform chemical composition, small size and tolerance, no pinholes, wrinkles and other defects on the surface. The special property of electrolytic copper foil is that its surface is rough, it can be bonded, it has certain strength after surface treatment, and it has strong anti-stripping and anti-oxidation.

4)Application of electrolytic copper foil

Electrolytic copper foil, due to low production costs, is widely used in the printed circuit board industry. But on flexible moving lines, such as flip-top connections for mobile phones, cameras and computers, photocopiers, and moving parts for smart machines, electrolytic copper foil is deposited. The microstructure and properties are essentially different from the processed microstructure, and the bending resistance is far worse than that of the rolled copper foil. Electrolytic copper foil used to be mainly used in the construction industry, as doors, windows and walls decoration; harsh environment, as radio equipment shielding cover, coaxial cable shell. At present, most of the electrolytic copper foil produced in the world is used to manufacture printed circuit board, flexible bus bar, high frequency bus bar, heat energy collector and so on.

5. Factors affecting the quality of electrolytic copper foil

The main process that affects the thickness of electrolytic copper foil is the forming process of wool foil. The thickness of copper foil is controlled by electrolyte composition, cathode roller current density and cathode roller speed (electrolysis time) . In addition, the factors that affect the shape and uniformity of the peak and Valley of the surface are mainly the uniformity of the cathode Surface roughness and current density. The factors that affect the porosity of copper foil are whether there are pinholes on the surface of the cathode roller or the adhesion of dust particles.

The main factors affecting the mechanical and electrical properties of copper foil are electrolyte purity, temperature and crystallization rate. In the process of surface treatment, the main factors affecting the size, composition, distribution, anti-stripping strength, substrate pollution, heat resistance and anti-oxidation properties are the treatment methods and process conditions.

The effect of mechanical coarsening on the copper foil below 0.035 mm is poor, and the effect of dipping or spraying or corrosion treatment is better.

3. The difference

The difference of production process results in the difference of properties and uses of the two kinds of foil materials. In general, the quality of rolled copper foil is better than that of electrolytic copper foil.

Source: Copper Aluminum Online