GB1304100A - - Google Patents

Abstract

1304100 Electroless Cu solutions SHIPLEY CO Inc 31 July 1970 37087/70 Heading C7F An aqueous electroless Cu-plating solution comprises a source of copper ions, a reducing agent therefor, a complexing agent therefor, a pH adjuster, and, as stabilizing agent mercury ions and another, different, stabilizer. The reducing agent may be formaldehyde, a precursor thereof, or an amino-borane. Mercury ions may be provided in amounts of 1-100 ppm, by mercuric acetate, benzoate, bromate, carbonate, chloride, chlorate, iodate, nitrate, sulphate, or mercuric ammonium chloride. The other stabilizer may be a divalent sulphur compound, e.g. Na 2 S, K 2 S, Na or K polysulphide, NaCNS, KCNS, K 2 S 2 O 6 , Na 2 S 2 O 3 , K 2 S 2 O 3 , thiourea, 2-mercaptobenzothiazole, 1, 2-ethane dithiol, 1, 2-benzoisothiazane, methionine, 2, 2'-thiodiethanol, dithioglycol or thioglycollic acid; a water soluble cyanide, e.g. NaCN, KCN, an α-hydroxynitrile, iminodiacetonitrile, or 3, 3' imino dipropionitrile, (all trace to 300 ppm) or R-C # CH or R' -C# C-R", R, R' and R" being lower monovalent hydroxyalkyl, cyclohydroxyalkyl, or hydroxyalkylether, or alkyl or aryl substituted with a water-solubilizing group such as -OH or - COOH. The Hg is incorporated into the eventual Cu coating. Typically, plastics or cotton cloth is cleaned, sensitized with SnCl 2 /PdCl 2 or with a precious metal/stannic acid colloid and electroless plated in the solution.