China Nonferrous Metallurgy

Electrolytic copper foils serve as crucial raw materials of CCL, PCB and lithium ion batteries, and ultra-thin copper foils will become the leading product in the market. By adjusting process parameters of electrolytic copper foil and controlling the proportion of additives, high purity and double shiny ultra-thin copper foils with uniform structure, great performance and a thickness of 4.5μm are produced, and its structure, appearance and performance are analyzed by using XRD, SEM, roughness meter and universal testing machine. Results show that ultra-thin copper foils are of high purity (99.98% Cu) and have an extremely low content of impurities (＜0.001%). They have uniform surface density and thickness with a fluctuation within 1%. The (111) texture that affects their tensile strength is preferred orientation and the coefficient is 58.8; the (220) texture coefficient that affects their elongation is relatively low. The matte surface of double shiny ultra-thin copper foil is evenly distributed by small particles of hilly structure, and the horizontal and vertical roughness fluctuates within a reasonable range. Ultra-thin copper foils boast excellent mechanical properties, with tensile strength of 671.54±20MPa and elongation at break of 5.81%±3.2%, which are remarkably better than those of 6μm and 8μm copper foils in the market. Besides, ultra-thin copper foils can acquire high-temperature oxidation resistance after passivation.