Printed wiring board having a cover lay laminated on a polyimide resin base film containing conductive circuits

摘要

Conductive circuits (copper foil) are provided on both surfaces of a basefilm. A first prepreg is laminated onto both surfaces of the basefilm. A cover lay is provided at an opening portion of the basefilm. The cover lay may extend to a through-hole. The semirigid cover lay, made from polyimide-containing resin material, is placed to cover the opening portion, thermocompressed, and bonded to be laminated onto the surface of the basefilm. A second prepreg having an opening portion whose shape is substantially similar to the opening portion of the first prepreg, is laminated on the first prepreg.