Improving bending property of copper foil by the combination of double-rolling and cross rolling

Copper foils with excellent bending property were fabricated by double-rolling followed by cross rolling. The deformation characteristics of the two advanced rolling processes introduce high density of grain boundaries and dislocations in copper foils. Due to high densities of grain boundaries, dislocations and strong single texture, bending cracks are fine and dispersive, a 101.0% improvement of the bending fatigue life compared to copper foils fabricated by conventional rolling process. After bending fracture, concentrated dislocation and fine dispersive cracks can be observed.