| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer substrate and a flexible printed wiring board which generate little dust from an etching edge face of a through-hole or an outer peripheral end.SOLUTION: A multilayer substrate comprises: an insulating substrate containing polyimide resin; a bonding layer formed at least on one of the faces of the insulating substrate and containing thermoplastic polyimide resin; and a through-hole formed by etching and penetrating the insulating substrate and the bonding layer in the thickness direction. In a cross section of the through-hole, an end of a lower face of the bonding layer brought into contact with the insulating substrate is present on the insulating substrate. If a perpendicular line is assumed which passes through the end of the lower face of the bonding layer and is perpendicular to an interface between the insulating substrate and the bonding layer, the entire bonding layer does not protrude in a direction toward the center of the through-hole beyond the perpendicular line. |
