Method of producing planar electrical circuits

A method of producing a plurality of equal printed circuits on a common, planar insulating carrier of which at least one side is provided with an electrically conducting layer for producing oscillating circuits of which every one comprises an electrical circuit closed in itself and including spirally arranged conduit tracts forming at least one induction coil and including at least one capacitor, comprising the steps of:

• (a) applying by means of laser rays a plurality of reference perforations on at least one of a sheet and web-shaped composite body formed of an insulating carrier and at least on one side thereof an applied conducting layer, each individual one of said perforations being allocated to one respective oscillating circuit to be produced and the mutual distances of which depending from the dimensions of the circuits to be produced, which perforations serve as reference points for the application of apparatus for the performance of further working steps;
• (b) thereafter extricating the rough contours of the oscillating circuits and of the intended capacitor surfaces at the at least one electrically conductive covering layers;
• (c) thereafter bringing the surfaces serving for the forming of the capacitors to the final dimensions and extricating, by means of at least one of a program and computer controlled laser rays, the circuit tracts forming the oscillating circuit;
• and
• (d) to finally produce the oscillating circuits determining the actual electrical values and comparing such with the design values to carry out corresponding adjustments by an additional working by laser rays.