SUPPLYING METHOD FOR PALLADIUM TO PALLADIUM-NICKEL ALLOY PLATING SOLUTION

摘要

PURPOSE:To supply Pd to an aqueous ammonia soln. contg. a prescribed amount each of Pd and Ni as a plating soln. without interruption of the plating by directly addting crystalline Pd(NH3)4Cl2 to the soln. and carrying out the electroplating of a Pd-Ni alloy. CONSTITUTION:Crystalline Pd(NH3)4Cl2 or Pd(NH3)4Cl2.H2 Ois added to a relating soln, plating soln. consist of an aqueous ammonia soln. contg. 5-30g/l Ni and the electroplating of a Pd-Ni alloy is carried out. The crystalline Pd salt is easily soluble in the plating soln. itself as well as in water and an aqueous ammonia soln. Accordingly, it is directly added even to a plating soln. with low ammonia concn., whereby the soln. can be reproduced without interrupting plating and increasing the amount of the soln. For example, where 5g Pd(NH3)4Cl2.H2O (2g as Pd) is charged into 1l plating soln. and agitated, it is throughly dissolved in 0.5-1min.