Mechanical properties and microstructure of rolled and electrodeposited thin copper foil

Commercial grade rolled and electrodeposited copper foils from Japan and China were selected, and their mechanical properties and microstructure were investigated. It was observed that there are notable differences in fracture strength, elongation at break and hydrophilicity between rolled and electrodeposited copper foils. The rolled copper foils have higher tensile strength, lower ductility and larger static contact angle than electrodeposited copper foils. The rolled copper foils contain a β-fiber texture, and the electrodeposited copper foils have random crystalline orientations. It was also observed that the rolled foils have packed grains, and electrodeposited foils have equiaxial grains. The uniform fine grain size and a few substructures of Japanese electrodeposited foils are major reasons for their higher elongation.