The initial intention in the semi-finished product of the invention is to provide a functional separation between the requirement for mechanical strength and the previously concomitant requirement, for completing a circuit, in order to bring the pure circuit connection, especially for signals, "closer" to the electrical and technical properties of chips. To do this, the layout miniaturisation is optimised without regard for the mechanical strength of the substrate. Instead of a printed circuit board (MCM), a semi-finished product which can be developed into a printed circuit board is made. The semi-finished product of the invention consists of an extremely thin film (8) with a plurality of extremely small holes (14) made simultaneously by an etching process. The hole diameters can be reduced by almost an order of magnitude (down to 20 mu m), facilitating, for instance, definite sub-100 mu m technology. Such a semi-finished product (19) does not act as a mechanical support but is designed only for signal conduction. The semi-finished product (19) which carries the densely packed wiring pattern, is bonded to a not densely packed power supply plane (22) acting as the service plane and the printed circuit board thus made is finally secured to a mechanical support (20).