摘要 |
<p>Improved activation composition for preparing substrates for metallization in an electroless plating bath and improved process for activating substrates prior to metallization and an improved process for metallizing employing the improved activating process. Electroless deposition, which involves chemically reducing ions of the metal to be plated from a plating bath and onto an activated substrate surface, is improved by employing an organic acid in the activating bath which activates the substrate surface. Preferred activating baths contain palladium halide ions to provide a catalytic surface on the substrate, stannous halide ions to provide a protective sol, a source of additional halide ions, and an organic acid such as citric or tartaric acids. The composition and process enable the elimination of a typically-required acceleration step, but yet provide consistently high quality results especially with substrates having through holes requiring coating, such as printed circuit boards requiring a plating of copper.</p> |