A method of producing a multilayer printed circuit board comprising a metallic conductor structure, comprising:
- a. providing a base substrate comprising a film or plate and having a first substrate side and a second substrate side, which base substrate at least partly consists of an electrically non-conductive organic polymer material and wherein the first substrate side is covered with a cover metal layer, the cover metal layer is formed directly on the substrate by vapor deposition, sputtering or a wet-chemical coating process,
- b. partially removing the cover metal layer while subdividing the first substrate side into at least one first partial area, in which the first substrate side is free of the cover metal layer, and into at least one second partial area, in which the first substrate side is covered with the cover metal layer,
- c. causing a plasma to act on the first substrate side with the aid of which plasma the polymer material is removed in the at least one first partial area while forming at least one trench, wherein the plasma is an inductively coupled plasma (ICP plasma) generated by an ICP generator with a DC bias,
- d. filling the at least one trench with a filling metal, and
- e. completely removing the cover metal layer in the at least one second partial area while forming a first conductor structure or a part of a first conductor structure,
- f. planarizing the first substrate side with the at least one trench that has been filled, wherein the planarizing of the first substrate side at least comprises removing the cover metal layer in the at least one second partial area by an etching step or removing the cover metal layer in the at least one second partial area by mechanical processing of the first substrate side,
- g. covering the first conductor structure with an insulation layer, which in a composite assembly with the base substrate has an underside directly in contact with the first conductor structure and a top side facing away from the first conductor structure and which at least partly consists of an electrically non-conductive organic polymer material,
- h. if not yet present, forming a cover metal layer on the top side of the insulation layer,
- i. partially removing the cover metal layer while subdividing the top side into at least one first partial area, in which the top side is free of the cover metal layer, and into at least one second partial area, in which the top side is covered with the cover metal layer,
- j. causing a plasma to act on the top side, with the aid of which plasma the polymer material is removed in the at least one first partial area while forming at least one trench,
- k. filling the at least one trench with a filling metal, and
- l. completely removing the cover metal layer in the at least one second partial area while forming a second conductor structure or a part of a second conductor structure.