| 摘要 |
PROBLEM TO BE SOLVED: To provide a flexible wiring board superior in folding endurance, which is a plated substrate superior in folding endurance, and which enables the increase in the folding endurance of a metalized substrate arranged by sequentially forming, on at least one side of a resin film base, metal layers including a base metal layer and a copper layer through no adhesive.SOLUTION: A flexible wiring board 6 comprises: a resin film substrate 1; and wiring of a metal laminate 7 provided on a surface of the resin film substrate 1 through no adhesive, and including a base metal layer 2 of a nickel alloy, and a copper layer 5 provided on a surface of the base metal layer. In the wiring of the metal laminate, the difference "d" between a [(200)/(111)] orientation ratio, which is a crystalline orientation ratio of the copper layer, obtained before the execution of "the folding endurance test defined by JIS C-5016-1994" and that obtained after the execution is 0.03 or more. In a cross section of the wiring taken along a widthwise direction thereof, the width "B" of a bottom part of the wiring, the width "T" of a top part, and the width "M" of a center part located at a substantial center of the bottom and top parts satisfy the condition, B≥M≥T; and the width "B" of the bottom part is 50 μm or less. |
