and lamination while the terminals 11 21 31 of the conductor elements 12 22 32 in the perforated sheets 10 20 as well as in the sheets 30 have been illustrated and described as formed only on one and the same edges of the respective elements it will be appreciated by those skilled in the art that those sheets may be punched to have the terminals formed instead on both edges of the elements fig1 a and 14b are fragmentary views of dies showing the cutting edge contours for removing the connecting ribs as already noted the connecting ribs 13 23 or 33 between the adjacent conductor elements 12 22 or 23 can be cut off after the temporary bonding and lamination by rectangular dies 40 or elliptical dies 40a the end connecting ribs 14 24 34 can also be trimmed off in a similar way for an enhanced cutting efficiency a plurality of such dies 40 or 40a may be arranged in a row corresponding to the space between the conductor elements so that the connecting ribs between each pair of adjacent elements can be all trimmed off by a single stroke of the die arrangement in the final stage following the pressing and forming operation as described above the surface insulating materials 27 of all conductor element assemblies are simultaneously marked with the name of the products and other necessary data and are inspected all.