Application area

As one of the basic materials of electronic industry, electrolytic copper foil is mainly used to manufacture printed circuit board (PCB), copper clad laminate (CCL), etc. it is widely used in household appliances, communication, computing (3C) industry, etc. In recent years, due to the rapid development of electronic industry, as well as its dense, light, thin, short and small development characteristics, there are higher and newer requirements for copper foil, which are mainly manifested in: low (low coarsening), thin (developing to less than 12 microns), high (high physical performance, reliability), no (no surface appearance defects), electrolytic copper foil belongs to copper processing products with higher technical level.

Brief introduction of production process

Although the specifications and properties of electrolytic copper foil have their own characteristics due to different copper foil manufacturers, the manufacturing process is basically the same. That is to say, using electrolytic copper or waste copper with the same purity as electrolytic copper as the raw material, dissolving it in sulfuric acid to make an aqueous solution of copper sulfate. Taking the metal roller as the cathode, the copper is electrodeposited on the surface of the cathode roller continuously through electrolytic reaction, and is peeled from the cathode roller continuously at the same time. This process is called the foil electrolysis process. Finally, the stripped side (smooth side) from the cathode is the one seen on the surface of the laminate or printed circuit board, and the reverse side (commonly known as the rough side) is the one that needs a series of surface treatment and is bonded with resin in the printed circuit board.

Electrolysis principle

During electrolysis, the cations in the electrolyte migrate to the cathode, and the electrons on the anode are reduced. The anions run to the anode and lose electrons and are oxidized. Connect two electrodes in copper sulfate solution and apply direct current. At this time, it will be found that copper and hydrogen are separated on the electrode plate connected to the cathode of the power supply. If it is copper anode, the dissolution of copper and the precipitation of oxygen occur simultaneously. The reaction is as follows: cathode: Cu2 + + 2e → 2cu2h + + 2e → H2 ↑ anode: 4OH - + 4E → 2H2O + O2 ↑ 2s042 - + 2h2o-4e → 2h2s04 + O2 ↑ copper dissolved from the anode, supplementing the consumption of copper ion in the electrolyte. After a certain treatment of the cathode surface, the copper layer deposited on the cathode can be peeled off, and a certain thickness of copper skin can be obtained. Copper skin with certain functions is called copper foil.

Electrolytic copper foil