Abstract: A rigid-flexible circuit board is fabricated by providing a core having a dielectric substrate and conductive layer thereon. A sub-composite comprising a polyimide and rigid dielectric substrate adjacent the conductive layer and in both the rigid and flexible segments of the board is provided. A release layer corresponding to the flexible segment of the board is provided. A rigid bonding layer is provided at rigid segments of the board but not at the flexible segments. A composite is formed by providing a second conductive layer adjacent the rigid bonding layer. The composite is laminated. Portions of the second conductive layer corresponding to the flexible segment and release layer are removed.

Abstract: A composite for providing a rigid-flexible circuit board includes at least one core that contains a dielectric substrate and at least one conductive layer thereon; at least one sub-composite that includes a polyimide and a rigid dielectric substrate; a release layer; at least one rigid bonding layer and a second conductive layer. The composite is used in the fabrication of a rigid-flexible circuit board.