The global copper foil market is growing rapidly, valued at $12.4 billion in 2019 and projected to grow over 7% from 2020 to 2027*. Magneto has been working in close partnership with clients in this industry for over 20 years to deliver industry-leading anode solutions which are central to the manufacturing process.
One of the main factors driving the market is the use of copper foil as a printed circuit board (PCB) material and the electronics industry is booming. Applications include phones, PCs and tablets. Today, very low profile (VLP) copper foil for 5G, and ultra-thin copper foil for lithium and lithium-ion batteries dominate the new development direction of copper foil technology.
The manufacturing of copper foil is a high-end industry in which copper is electrodeposited from an electrolyte onto a rotating drum. The electric loop is closed again by positioning MMO anodes on opposite sides of the drum. During the process, the copper foil grows on the drum.
Although the specifications and properties of electrolytic copper foil can vary with each manufacturer, the process remains essentially the same. Generally, all foil manufacturers dissolve electrolytic copper or waste copper wire – with the same purity electrolytic copper used as the raw material – in sulfuric acid to produce an aqueous solution of copper sulfate. After that, by taking the metal roller as the cathode, the metallic copper is electrodeposited on the surface of the cathodic roller continuously through electrolytic reaction. It is peeled from the cathodic roller continuously at the same time. This process is known as the foil producing and electrolysis process.
The stripped side (smooth side) from the cathode is the one visible on the surface of the laminated board or PCB, and the reverse side (commonly known as the rough side) is the one that is subject to a series of surface treatments and is bonded with resin in the PCB. The double-sided copper foil is formed by controlling the dose of organic additives in electrolyte in the process of producing copper foil for lithium battery.
During electrolysis, the cations in the electrolyte migrate to the cathode, and are reduced after obtaining electrons on the cathode. The anions are oxidized after migrating to the anode and losing electrons. Two electrodes are connected in the copper sulphate solution with direct current. Then, it will be found that copper and hydrogen are separated on the cathode. The reaction is as follows:
Cathode:
Cu2+ +2e → Cu
2H+ +2e → H2↑
Anode:
4OH- -4e → 2H2O + O2↑
2SO42-+2H2O -4e → 2H2SO4 + O2↑
After treatment of the cathode surface, the copper layer deposited on the cathode can be peeled off, to obtain a certain thickness of copper sheet. The copper sheet with certain functions is called copper foil.
Due to the demands of decreasing foil thicknesses, the specifications in this market are demanding and the right anode partner is essential. Magneto offers its customers a trial order to enable its engineers to develop the right coating for their operation’s specific needs. The anodes can be thoroughly tested in-situ prior to launch. For product quality, stability of your operations and market-leading advice, Magneto is the partner for you.
