Printed circuit board for optical and/or electronic devices, comprising - a lower printed circuit board material, - a plurality of optical waveguides, which are provided on the printed circuit board material and extend substantially parallel to the plane of the printed circuit board material, the waveguides respectively having a core layer, which, seen in the vertical direction, is arranged between a bottom layer and a top layer, - an upper printed circuit board material, which is provided on the upper top layer, - a module for the optical coupling of the fibres of a fibre optic connector, which can be coupled to the module, with the waveguides of the printed circuit board that are assigned to the respective fibres, the module o having on the fibre-optic-connector side an end face aligned parallel to the printed circuit board and o having on opposite regions of its end face respectively a pin or a bore for respectively receiving a bush or a pin of a fibre optic connector, the opposite regions of the end face around the region of the pins or the bores serving as a stop surface for the fibre optic connector, o is arranged with its underside on the bottom layer or the lower printed circuit board material, o has on its end face, between the two pins or the two bores, a recess for receiving at least one single planar array of mirrors (64; 66) with mirrors (64-1 to 64-12; 66-1 to 66-12), the deflecting surfaces (64-1, 65 to 64-12, 65; 66-1, 65 to 66-12, 65) of which are arranged level with the core layer, o has a main body, which is formed integrally with the pins or bores and the at least one single planar array of mirrors (64; 66), characterized in that - an adapter for the approximate guidance and preferably releasable locking of the fibre optic connector on the printed circuit board is arranged on the upper printed circuit board material, and - the fibre optic connector and the adapter are formed by the MTP/MPO technique. - a lower printed circuit board material, - a plurality of optical waveguides, which are provided on the printed circuit board material and extend substantially parallel to the plane of the printed circuit board material, the waveguides respectively having a core layer, which, seen in the vertical direction, is arranged between a bottom layer and a top layer, - an upper printed circuit board material, which is provided on the upper top layer, - a module for the optical coupling of the fibres of a fibre optic connector, which can be coupled to the module, with the waveguides of the printed circuit board that are assigned to the respective fibres, the module o having on the fibre-optic-connector side an end face aligned parallel to the printed circuit board and o having on opposite regions of its end face respectively a pin or a bore for respectively receiving a bush or a pin of a fibre optic connector, the opposite regions of the end face around the region of the pins or the bores serving as a stop surface for the fibre optic connector, o is arranged with its underside on the bottom layer or the lower printed circuit board material, o has on its end face, between the two pins or the two bores, a recess for receiving at least one single planar array of mirrors (64; 66) with mirrors (64-1 to 64-12; 66-1 to 66-12), the deflecting surfaces (64-1, 65 to 64-12, 65; 66-1, 65 to 66-12, 65) of which are arranged level with the core layer, o has a main body, which is formed integrally with the pins or bores and the at least one single planar array of mirrors (64; 66), o having on the fibre-optic-connector side an end face aligned parallel to the printed circuit board and o having on opposite regions of its end face respectively a pin or a bore for respectively receiving a bush or a pin of a fibre optic connector, the opposite regions of the end face around the region of the pins or the bores serving as a stop surface for the fibre optic connector, o is arranged with its underside on the bottom layer or the lower printed circuit board material, o has on its end face, between the two pins or the two bores, a recess for receiving at least one single planar array of mirrors (64; 66) with mirrors (64-1 to 64-12; 66-1 to 66-12), the deflecting surfaces (64-1, 65 to 64-12, 65; 66-1, 65 to 66-12, 65) of which are arranged level with the core layer, o has a main body, which is formed integrally with the pins or bores and the at least one single planar array of mirrors (64; 66), - an adapter for the approximate guidance and preferably releasable locking of the fibre optic connector on the printed circuit board is arranged on the upper printed circuit board material, and - the fibre optic connector and the adapter are formed by the MTP/MPO technique.