Abstract: A composition and method for cleaning and conditioning a non-conductive surface defined by a through hole in a printed circuit board (PCB) is disclosed. The through hole surface is contacted with the composition of the invention to provide a cleaned and conditioned surface. The clean and conditioned surface is coated with conductive carbon particles (usually graphite) to provide a carbon-coated surface. The carbon-coated surface is electro plated and then soldered using hot solder. Those surfaces that have been soldered and also treated with the composition of the invention exhibit fewer blow hole problems. The composition of the invention comprises carbonates, binders, and resins, and combinations thereof, that improve the adhesion and coverage of a coating containing graphite to a surface defined by a through hole bore or other substrate. (“Through holes” as used herein refers both to through holes and to vias.

Abstract: A composition and method for cleaning and conditioning a non-conductive surface defined by a through hole in a printed circuit board (PCB) is disclosed. The through hole surface is contacted with the composition of the invention to provide a cleaned and conditioned surface. The clean and conditioned surface is coated with conductive carbon particles (usually graphite) to provide a carbon-coated surface. The carbon-coated surface is electro plated and then soldered using hot solder. Those surfaces that have been soldered and also treated with the composition of the invention exhibit fewer blow hole problems. The composition of the invention comprises carbonates, binders, and resins, and combinations thereof, that improve the adhesion and coverage of a coating containing graphite to a surface defined by a through hole bore or other substrate. (“Through holes” as used herein refers both to through holes and to vias.

Abstract: A composition and method for applying an electrically conductive coating to an initially electrically nonconductive surface, such as a printed wiring board having through holes is disclosed. The method is carried out by applying a composition of electrically conductive carbon particles, a second conductive material, a water dispersible binding agent, and an aqueous dispersing medium to a nonconductive substrate to form a substantially continuous, electrically conductive coating. Enough of the carbon particles are present to provide an electrically conductive coating when the composition is applied to the substrate. Enough of the second conductive material is present to provide an improved electrically conductive coating when the composition is applied to the substrate. The resulting coating carbon coating has an improved conductivity over prior through hole coating compositions and processes and is capable of being exposed to molten solder without resulting in the formation of blowholes.

Abstract: A composition and method for cleaning and conditioning a non-conductive surface defined by a through hole in a printed circuit board (PCB) is disclosed. The through hole surface is contacted with the composition of the invention to provide a cleaned and conditioned surface. The clean and conditioned surface is coated with conductive carbon particles (usually graphite) to provide a carbon-coated surface. The carbon-coated surface is electro plated and then soldered using hot solder. Those surfaces that have been soldered and also treated with the composition of the invention exhibit fewer blow hole problems. The composition of the invention comprises a cationic conditioning agent and one of a binder or an anionic dispersant that improve the adhesion and coverage of a coating containing graphite to a surface defined by a through hole bore or other substrate. (“Through holes” as used herein refers both to through holes and to vias.

Abstract: An improved desmear process for removing resin smeared on an interior wall of a through hole drilled in a resinous substrate, especially resinous substrates made from epoxy, polyimide, cyanate ester resins and bis-maleimide triazine epoxy resins. The process involves contacting the resin smear with a solvent solution to soften the resin smear, followed by treatment with an alkaline permanganate solution to remove the softened resin, and treatment with a neutralizer to neutralize and remove the permanganate residues. The solvent solution comprises a mixture of at least two solvent components, with at least one solvent component being selected from the group consisting of gamma-butyrolactone, ethyl-3-ethoxypropionate, N-ethyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-(2-hydroxyethyl)-2-pyrrolidone, and N-octyl-2-pyrrolidone. The solvent solution is selective for the softening and removal of epoxy, polyimide, cyanate ester resins and bis-maleimide triazine epoxy resins.

Abstract: The present invention is directed to an improved method for treating an oxidized surface of a copper film for bonding to a resinous layer such as in the formation of a single-sided, double-sided, or multi-layered circuit board and to a layered product produced by the method. In particular, the method of the present invention comprises the steps of: contacting the oxidized surface of a copper film, having cupric oxide whiskers protruding therefrom, with an acidic reducing solution having a pH of 1 to 6.5 and having an effective amount of a water soluble thiosulfate reducing agent dissolved therein to provide a reduced copper surface; and rinsing the reduced copper surface with an acidic solution to produce a rinsed and reduced copper surface having reduced whiskers protruding therefrom, said reduced whiskers each being a mix of cuprous oxide and metallic copper. Preferably, the reduced surface is treated with a passivating agent to minimize any reoxidation prior to laminate formation.