METHOD FOR REMOVING AN ORGANIC RESIN FROM A SURFACE OF A SUBSTRATE

The present invention relates to a method for removing an organic resin from a copper surface onto a dielectric substrate comprising conductive through holes (THs) and/or conductive blind micro vias (BMVs), the method comprising the following steps: (i) applying an organic paste to the dielectric substrate, in order to fill up the through holes (THs) and/or blind micro vias (BMVs) with the organic paste, wherein after step (i) at least a part of the surface of the dielectric substrate is covered by the organic paste; (ii) curing the organic paste to transfer the organic paste into solidified or- ganic resin, wherein after step (ii) at least a part of the surface of the die- lectric substrate is covered by the organic resin; (iii) chemical treating the dielectric substrate with a non-aqueous composi- tion to remove the organic resin from the surface of the substrate, in or- der to obtain a chemical treated surface of the substrate, the non-aque- ous composition comprising: a) at least one high-boiling solvent at a concentration from 80 % by weight to 95 % by weight wherein the high-boiling solvent has a boiling point of at least 100 °C, b) at least one carboxylic acid at a concentration from 5 % by weight to less than 20 % by weight, c) at least one anionic aromatic surfactant at a concentration from 0.25 % by weight to less than 1.5 % by weight, and d) at least one non-ionic acetylenic diol - based surfactant at a concentra- tion from 0.25 % by weight to less than 1.5 % by weight; (iv-1) mechanically treating the chemical treated surface of the substrate ob- tained after step (iii) with an abrasion tool to remove remaining organic P21/017/WO HS resin from the chemical treated surface of the substrate, in order to ob- tain a mechanically treated surface of the substrate; and/or (iv-2) wet-chemical treating the chemical treated surface of the substrate ob- tained after step (iii) with an oxidizing solution comprising an oxidizing agent to remove remaining organic resin from the chemical treated sur- face of the substrate to obtain a wet-chemical treated surface of the sub- strate; (v) optionally deposition of a conductive material, preferably electroless dep- osition of a coating metal, on the mechanically treated surface obtained after step (iv-1) or the wet-chemical treated surface of the substrate ob- tained after step (iv-2), to obtain a conductive surface of the substrate; and (vi) optionally electrolytic deposition of an additional coating metal on the