The present invention comprises a processed thin film substrate (10) and a method therefore, in order to produce a flexible printed circuit card, having a plurality of microvias going or passing through the thin film substrate and electrically connected along faced-away surfaces, in order to form an electric circuit. A first a number of real nano-tracks are filled with a first material (M1), having good electric properties, for the formation of a first number of, here denominated, first vias (V10, V30, V 50), that a second number of real nano-tracks are filled with a second material (M2), having good electric properties, for the formation of a second number of, here denominated, second vias (V20, V40, V60). The first material (M1) and the second material (M2) of said first and second vias (V10 V60) are chosen having mutually different thermoelectric properties. A material surface-applied to the thin film substrate, coated on both sides (10a, 10b) of the thin film substrate (10), is distributed and/or adapted in order to allow the electrical interconnection of first vias, allocated the first material (M1), with second vias, allocated the second material (M2), and that a first via (V10) included in a series connection and a last via (V60) included in the series connection are serially co-ordinated in order to form an electric thermocouple (100) or other circuit arrangement.