Method for producing multi-layer circuits

Abstract

The invention relates to a method for producing sequentially built-up printed circuit boards having a disparate number of conduction planes on both sides of the laminate core, which method comprises the following method steps: (A) coating both sides of a printed circuit board having conductor structures on only one side with a dielectric comprising a photopolymer or a thermally curable polymer; (B) structuring the plating holes (vias) on the side having the conductor structures by exposing the dielectric comprising a photopolymer to light and then developing with a solvent or by laser-drilling the plating holes (vias) into the dielectric comprising a thermally cured polymer; (C) depositing a copper layer on both sides of the board so obtained; (D) forming conductor structures on the front and completely etching away on the rear, if further asymmetric build-up is to be carried out, or on both sides of the printed circuit board if there is to be no further build-up or if further build-up is to be carried out symmetrically, by means of selective etching with the aid of resists; (E) repetition of process steps (A) to (D) if further asymmetric build-up is to be carried out or (A) and subsequent structuring (F) of the dielectric layer on both sides followed by (C) and (D) if further build-up is to be carried out symmetrically.

Dependencies are inferred from the claim text.