Electroless nickel plating bath - containing nickel salt, reducing agent, complexing agent and a compound with sulphur to sulphur bond

摘要

An electroless nickel plating bath comprising (a) a water-soluble Nickel salt, (b) a reducing agent, (c) a complex former and (d) a compound with a sulphur-to-sulphur bond. A primer coating of Ni may be deposited by immersing the substrate in an electroless Ni plating bath containing no component (d), and then immersing the substrate in a second electroless Ni plating bath containing components (a), (b), (c) and (d). Component (d) is chosen eg from a thiosulphate, dithionate, polythionate, or dithionite.