How is PI film coated electrolytic copper foil produced?

Electrolytic copper foilThere are four types of electrolytic copper foils based on their performance: standard electrolytic copper foil (sTD type), high ductility electrolytic copper foil (HD type), high-temperature high ductility electrolytic copper foil (HTE type), and annealed electrolytic copper foil (ANN type). There are four types of rust prevention based on surface conditions: untreated without rust prevention, untreated without rust prevention, single-sided with rust prevention, and double-sided with rust prevention. From the thickness direction, thin electrolytic copper foil is referred to as one with a thickness less than 12 μ m. To avoid measurement errors in thickness, the unit weight is expressed as 153 and 305 g/m2 for commonly used 18 and 35 μ m electrolytic copper foils, respectively. The quality standards for electrolytic copper foil products include purity, resistivity, strength, elongation, weldability, porosity, surface roughness, etc.
The production process of electrolytic copper foil is divided into three parts: preparation of electrolyte, electrolysis, and post-treatment.

Preparation of electrolyte: Copper material with a purity higher than 99.8% is degreased and placed in a copper dissolution tank. It is then cooked and stirred with sulfuric acid to dissolve into copper sulfate. When the concentration reaches the required level, it is transferred to the storage tank and connected to the electrolytic cell through pipelines and pump sets, forming a solution circulation system. After the solution circulation stabilizes, the electrolytic cell can be electrified for electrolysis. An appropriate amount of surfactant needs to be added to the electrolyte to ensure the particle size, crystal orientation, roughness, porosity, and other indicators of the copper foil.

The electrode and the cathode used in the electrolysis process are a rotatable drum called the cathode roller; Mobile headless metal strips can also be used as cathodes. After being powered on, copper begins to deposit on the cathode. Therefore, the width of the wheel and belt determines the width of the electrolytic copper foil; The speed of rotation or movement determines the thickness of the electrolytic copper foil. The copper deposited on the cathode is continuously stripped off, cleaned, dried, trimmed, coiled, and inspected. Qualified ones are sent for further processing. The anode used for electrolysis is insoluble lead or lead alloy. In addition to the operating speed of the cathode, electrolysis process parameters also include electrolyte concentration, temperature, and cathode current density during electrolysis. For example, when producing 25 μ m electrolytic copper foil, the electrolyte should contain CuSO4.? 5H20150-280g/I. And H2S04. 100-110g/I, temperature 40-60 ℃, cathode current density 1600-3000A/m2.

The cathode roller is formed by spinning titanium plate. Because titanium has high chemical stability and strength,Electrolytic copper foilEasy to peel off from the roller surface and low porosity. During the electrolysis process, titanium cathodes may also experience passivation, which requires regular cleaning, grinding, polishing, nickel plating, and chrome plating. Corrosion inhibitors such as aromatic or aliphatic compounds of nitro or nitroso groups can also be added to the electrolyte to slow down the passivation rate of titanium cathodes.