| 摘要 |
PROBLEM TO BE SOLVED: To provide surface roughening-treated copper foil for a circuited board, particularly, for a flexible printed wiring board whose adhesive properties on adhesion with an insulating film is excellent, and also, having excellent flexibility after adhesion at high temperature with an insulating film, and a circuit board such as a flexible printed wiring board (FPC) having excellent flexibility.SOLUTION: Surface roughening-treated copper foil is obtained by applying a surface roughening treatment layer to at least one side of untreated copper foil, and, in which the endurable number of cycles on bent tests by IPC bent tests after heating at 300°C for 1 hr (IPC standards TM-650) is ≥11,000 times, the average crystal grain size in the cross-section is ≥0.5 μm, and a surface area ratio (the surface after the roughening treatment/the surface before the roughening treatment) is 1.1 to 5.0. The 0.2% proof stress of the surface roughening-treated copper foil after heating at 300°C for 1 hr is ≤160 N/mm. |
