| 摘要 |
PROBLEM TO BE SOLVED: To provide a flexible printed wiring board exhibiting excellent quality of appearance and excellent high temperature bonding strength between a polyimide film and a conductor in which curl is eliminated and no flaw, e.g. scratch or irregularities, occurs on the surface of the conductor. SOLUTION: A flexible sheet-like substrate produced by coating the roughened surface of a conductor directly with polyimide based precursor resin solution and then drying it, a sheet-like material having mean surface roughness Ra of 0.5μm or above, and a sheet-like protective material having smooth surface are passed through respective guide rolls. On a rotary roll, three layers are laid in layer in such an order as the sheet-like material is located on the flexible sheet-like substrate side and the sheet-like protective material is located on the conductor side. The three layers are wound around the outer surface of a tubular body being rotated forcibly to produce a multilayer tubular body which is then placed in a thermosetting furnace and the polyimide based precursor resin layer is thermoset thus producing a flexible printed wiring board. COPYRIGHT: (C)2005,JPO&NCIPI
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