Scheel, W.W.ScheelHannemann, M.M.HannemannSchmidt, R.R.SchmidtMueller, J.J.MuellerMeyer, H.H.MeyerRehak, W.W.Rehak2022-03-082022-03-082001https://publica.fraunhofer.de/handle/publica/304911NOVELTY - A solution for current-less gold plating contains, as gold(I) compound, complex(es) of Au(I) ions with amino-acids showing a complex-forming constant for Au(I) ions of at least 1010 or with salts of such acids, or the amino-acid (and/or salt) is an additional component in a solution containing Au(I) compound, reducing agent and solvent. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a current-less gold-plating process comprising: (1) coating the workpiece with a catalytic layer for current- less metal plating; and (2) treating the workpiece with the above solution. USE - For gold-plating printed circuit boards and semi- conductor circuits (claimed). ADVANTAGE - Enables the deposition of gold (or palladium etc.) from acid bath solutions at low temperature (e.g. room temperature) at a rate of more than 1 micron/hour. These solutions also show a stability (towards self-decomposition) which is not less than that of known systems.de608621patent1997-19745601