| abstract |
PCT No. PCT/EP90/01326 Sec. 371 Date Feb. 28, 1992 Sec. 102(e) Date Feb. 28, 1992 PCT Filed Aug. 11, 1990 PCT Pub. No. WO91/03920 PCT Pub. Date Mar. 21, 1991.A process is described for manufacturing through-hole plated single-layer or multi-layer printed circuit boards based on a polymeric substrate material or on a ceramic material provided optionally on both sides with at least one photoresist layer temporarily exposing the electroconductive circuit pattern by electroplating or electroless plating with a metal layer also on those surfaces which have not been coated with a conductive metal layer, characterized in that a) the surfaces of the substrate, after hole-drilling and a subsequent mechanical surface-treatment, are laminated with a suitable photoresist, exposed to light and developed so that the circuit pattern image is exposed, b) the surfaces of the substrate are pre-treated in a solution having oxidizing activity, c) after removal of the residual solution by rinsing, the substrate is introduced into a solution which contains at least one heterocyclic monomer, and more specifically pyrrole, thiophene, furane or derivative(s) thereof, which in a polymeric form is electrically conductive, d) the substrate is then transferred into an acidic solution whereby an electrically conductive polymeric layer is formed, whereupon, if desired or required, any residual solution is removed by rinsing, and the through-holes and the circuit pattern image are metallized in one step by galvanic or, preferably, electroless metallization. |