Selective electroless plating of metals onto substrates - esp. for mfg. printed circuit boards coated with large number of sharply defined and very narrow conductor paths

摘要

The substrates are made esp. of electrically insulating materials, and are plated using at least one sensitising, and/or activation-, and/or chemical plating- and/or rinsing-bath. At least one metal cpd. (I) is used, and/or an underlayer, so that no metal plating is formed on zones which should remain unplated. Cpd.(I) pref. contains Ba, Cd, Ga, In, Pb and/or Sb, esp. as inorganic salts. When seed nuclei are formed on the substrate by photochemical methods, a cpd.(I) is pref. present and/or the seed nuclei are thickened by chemical plating of at least one underlayer of Co, Co-Cu or Ni-Cu. The process is used esp. to deposit more than 10 conductor paths per mm eidth on printed circuit boards(PCB). Used in mfg. PCB or resistor networks, sharply defined conductor paths can be obtd. without the chemical plating of metals onto substrate zones which should remain bare.