1. A semifinished product, comprising:a sacrificial structure;
two component carriers releasably formed on opposing main surfaces of the sacrificial structure;
wherein the sacrificial structure comprises a central structure and releasing layers on or over both opposing main surfaces of the central structure;
wherein the central structure comprises a dummy core being covered on or over both main surfaces thereof with a respective one of two spatially separated sections of separate dielectric material;
wherein the dummy core comprises a central layer and two electrically conductive layers on the central layer.