Abstract:
Non-adherent copper metal particles ("fines") formed in a plating bath during the course of autocatalytic electroless copper deposition onto activated substrate surfaces are oxidized and redissolved in the bath by brief application of current between an anode element and a cathode element immersed in the bath, the anode element being comprised of an anode surface substantially parallel and proximate to the bottom surface of the vessel containing the bath.
Abstract:
The adhesion between surfaces of polyimide, particularly the through hole surfaces of polyimide-based multilayer laminates used in the fabrication of multilayer printed circuits, is improved by pretreatment of the surfaces with an essentially non-alkaline aqueous permanganate solution.
Abstract:
A process for preparing a non-conductive substrate for electroplating is proposed. The proposed process comprises contacting the substrate, after desmear, with a combined neutralization/sacrificial coating solution followed by treatment with a carbon dispersion solution. The combined neutralization/sacrificial coating solution neutralizes permanganate residues from the desmear step and applies a sacrificial coating to metallic surfaces on the substrate. The sacrificial coating allows for easy and reliable removal of unwanted carbon residues from the metallic surfaces prior to electroplating.
Abstract:
A process for preparing a non-conductive substrate for electroplating is proposed. The proposed process comprises contacting the substrate, after desmear, with a combined neutralization/sacrificial coating solution followed by treatment with a carbon dispersion solution. The combined neutralization/sacrificial coating solution neutralizes permanganate residues from the desmear step and applies a sacrificial coating to metallic surfaces on the substrate. The sacrificial coating allows for easy and reliable removal of unwanted carbon residues from the metallic surfaces prior to electroplating.