ROLLED COPPER FOIL, AND METHOD FOR PRODUCING THE SAME

PROBLEM TO BE SOLVED: To provide a rolled copper foil suitable as a conductor in an FPC for electronic equipment, excellent in handling properties and flexibility, and having such a small tensile strength that the tensile strength after recrystallization annealing is far below 200 MPa.SOLUTION: In a method for producing the rolled copper foil, a copper ingot is subjected to hot rolling to have a predetermined thickness, and then cold rolling and intermediate annealing are repeated to obtain a base material for final cold rolling with a thickness of 0.27 mm or more and 2.0 mm or less. A rolled copper foil with a thickness of 5 μm or more and 50 μm or less and a tensile strength of 400 MPa or more and 550 MPa or less is obtained while a rate of rolling is maintained at 94.0% or more and 99.3% or less in performing final cold rolling using the base material. Further, recrystallization annealing of the obtained rolled copper foil is performed by subjecting the rolled copper foil to heat treatment at a temperature of 180°C or more and 300°C or less for 10 minutes or more and 60 minutes or less so that the rolled copper foil after the recrystallization annealing has a tensile strength of 80 MPa or more and 160 MPa or less.