| 摘要 |
Production of a flexible (or rigid flexible) printed wiring board, in which in the bonding of a cover lay to a flexible circuit member, the mold release property and moldability at press operation having been unsatisfactory with the use of conventional mold release film are improved while maintaining excellent performance with respect to contour tracking property, uniform moldability, platability and FPC finishing appearance winkling. In particular, there is provided a mold release film comprising a mold release layer containing a thermoplastic resin of 50 to 250 MPa viscoelasticity at 180°C. A polybutylene terephthalate resin is preferably used as the thermoplastic resin. It is preferred that this mold release film have, disposed on one side of the mold release layer, a cushion layer comprised of a thermoplastic resin different from that of the mold release layer. The mold release layer is preferably subjected to given-roughness embossing. There is further provided a process for producing a flexible or rigid flexible printed wiring board with the use of the above mold release film. |
