Changzhou Preferred Electronic Copper Foil Processing
Copper foil is divided into calendered copper foil and electrolytic copper foil according to the preparation process, which accounts for the vast majority of the market. According to the Copper Foil Branch of China Electricity Association (CCFA), at present, domestic manufacturers mainly focus on the production of electrolytic copper foil. In 19 years, the domestic production capacity of electrolytic copper foil is expected to be close to 600000 tons, while that of rolled copper foil is only about 10000 tons.
Changzhou Preferred Electronic Copper Foil Processing
In order to improve the bonding strength of copper foil to the substrate, oxidation is usually used (that is, after oxidation treatment, a layer of copper oxide or cuprous oxide is formed on the surface, which improves the bonding strength of copper foil and substrate due to the polarity) Or roughen the copper foil (a roughened layer is generated on the surface of the copper foil by electrochemical method, which increases the surface area of the copper foil and improves the bonding strength between the copper foil and the substrate due to the anchoring effect of the roughened layer on the substrate).
Changzhou Preferred Electronic Copper Foil Processing
The calendered copper foil is made by repeated rolling annealing process of copper ingot based on the principle of plastic processing. Its internal structure is lamellar crystal structure, and the product has good ductility. At present, it is mainly used in the production of rigid circuit boards, while the rolled copper foil is mainly used in flexible and high-frequency circuit boards.
Changzhou Preferred Electronic Copper Foil Processing
In order to avoid the copper oxide powder falling off and moving to the substrate, the surface treatment method has also been constantly improved. For example, TW copper foil is coated with a thin layer of zinc on the roughened surface of the copper foil, and the surface is gray; TC type copper foil is coated with a thin layer of copper zinc alloy on the roughened surface of the copper foil. At this time, the surface of the copper foil is golden yellow. After special treatment, the thermal discoloration resistance, oxidation resistance and cyanide resistance of copper foil in PCB manufacturing are improved accordingly.
