Abstract: A flexible circuit board having an improved protective coverlay is provided. The product flexible circuit board comprises a flexible, dielectric substrate, one or more electrical conductors carried on the surface thereof, one or more electrical contact bumps in electrical communication with the conductors, and an improved protective coverlay electrically insulating the electrical conductors. The coverlay, which is a solid, tack-free film bonded to the surface of the dielectric substrate, is formed in situ from one or more layers of flexible, dielectric, polymeric adhesives and avoids the use of a pre-formed, self-supporting film.