ROLLED COPPER FOIL FOR FLEXIBLE PRINTED CIRCUIT BOARD

摘要

PROBLEM TO BE SOLVED: To provide a rolled copper foil excellent in vibration resistance in addition to flex resistance.SOLUTION: A rolled copper foil has an average crystal grain diameter in a cross section parallel to a rolling direction of 100 μm or more when being subjected to heating at 400°C for an hour. A predetermined element is added to a tough pitch copper (TPC) or oxygen-free copper (OFC) to form an ingot by melt casting. The ingot is subjected to hot rolling, and then subjected to a cycle of annealing and cold rolling repeatedly with a final cold rolling under a predetermined drawing rate, and in a final step, subjected to annealing in an Ar atmosphere to obtain the copper foil.