Abstract: A printed circuit board (PCB) has multiple layers, where select portions of one or more conductive layers, referred to as core circuitry, form a semi-flexible PCB portion that is protected by an exposed prepreg layer. The semi-flexible PCB portion having an exposed prepreg layer is formed using a dummy core process that leaves the exposed prepreg layer smooth and undamaged. The core circuitry is part of a core structure. The semi-flexible PCB portion is an extension of the remaining adjacent multiple layer PCB. The remaining portion of the multiple layer PCB is rigid. The core structure is common to both the semi-flexible PCB portion and the remaining rigid PCB portion.

Abstract: A printed circuit board (PCB) has multiple layers, where select portions of inner layer circuitry, referred to as inner core circuitry, are exposed from the remaining layers. The PCB having an exposed inner core circuitry is formed using a dummy core plus plating resist process. The select inner core circuitry is part of an inner core. The inner core corresponding to the exposed inner core circuitry forms a semi-flexible PCB portion. The semi-flexible PCB portion is an extension of the remaining adjacent multiple layer PCB. The remaining portion of the multiple layer PCB is rigid. The inner core is common to both the semi-flexible PCB portion and the remaining rigid PCB portion.

Abstract: An embedded component is formed in a PCB stack by applying an adhesive layer across an entire surface of a copper layer and selectively positioning the component on a portion of the adhesive layer. A B stage pre-preg layer having a component cut-out is added onto the adhesive layer such that the component adhered to the adhesive layer fits within the component cut-out of the B stage pre-preg layer. Another copper layer is added onto the B stage pre-preg layer and the PCB stack is laminated. Since B stage pre-preg is not fully cured, a gap between the component and a side wall of the component cut-out is filled by flow of the surrounding B stage pre-preg during the lamination step. One or more additional pre-preg and copper layers are added to the PCB stack with corresponding interconnects formed and coupled to the contact pads on the component.