| 摘要 |
1293356 Gold-tin alloy plating baths SEL-REX CORP 24 Nov 1969 [28 Nov 1968] 57431/69 Heading C7B An aqueous gold-tin alloy plating bath contains 1 to 30 g/l Au in the form of an alkali metal (e.g. K) gold cyanide and 0À01 to 100 g/l Sn ions, or ions of Sn and at least one other metal chosen from Groups IIb, IIIb, IVb and Vb, e.g. Sb, In, Bi, Cd, Zn, As, Ga and Pb, added as a stable compound, e.g. antimony glycerolate, arsenic citrate or lead nitrate; with at least one other metal, the bath also contains 5 to 500 g/l of at least one compound capable of complexing the ions of Sn and the or each other metal, e. g. malic, maleic, lactic, gluconic, malonic or citric acid or salt thereof such as sodium gluconate and potassium citrate. The Sn ions may be added in the form of stannous sulphate, chloride or fluorborate with the corresponding sulphuric, hydrochloride or fluorboric acid. The bath may also contain a polyalcohol e.g. glycerine or ethylene glycol. Anodes of Sn or Sn and the or each other metal are used for continuously replenishing alloying ions. The anolyte and catholyte may be separated by a diaphragm. |
