Copper Surface Preparation Process for Electroless Plating
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2005-Feb-15
A process using baths 1-2 on copper pads of printed circuit boards made of epoxy-glass laminate will reproducibly remove surface contaminants including heavy oxidation, organics, and other impurities and prepare the surface adequately for electroless metal deposition processes (e.g., nickel and palladium). This invention is an improvement over the presently used 10-20% HC1 baths because (1) it reproducibly cleans a wider range of copper surfaces including heavily oxidized ones while the latter does not, (2) it avoids the problem of rapid reoxidation of the copper surface prior to introduction of parts into the plating bath, and (3) it eliminates auxiliary activation steps, such as using steel (dummy) parts, to initiate the chemical reaction. Electroless plating of metals (nickel, palladium, gold, etc.