抄録
The authors could not prepare an electroless plating bath containing sodium hypophosphite as a reducing agent for depositing iron, but they prepared and classified some kinds of electroless plating baths containing that agent for depositing Ni-Fe-P alloys.
The relation between conditions of baths or the rates of deposition and the compositions of alloys was studied in detail on two kinds of baths, ammoniacal alkaline citrate bath (A-C) and caustic alkaline citrate bath (C-C).
As the results, the conditions optimum for stable and practical baths were obtained as follows:
Ammoniacal alkaline citrate bath (A-C) Caustic alkaline citrate bath (C-C)
FeSO4+NiSO4 0.1mol/l 0.1mol/l
NaH2PO2 0.2mol/l 0.2mol/l
Na-citrate 0.15mol/l 0.25mol/l
(NH4)2SO4 0.50mol/l -
H3BO3 - 0.50mol/l
pH 10 (NaOH) 9 (NaOH)
Operating temperature 90±1°C 90±1°C
The plating rate in A-C Bath was usually high and the both contents of iron and phosphorus in the deposited film were low.
On the other hand, the plating rate in C-C Bath was relatively low and the both contents of iron and phosphorus in the deposited film were high-The composition of the deposit was easily controlled by the ratios among metallic salts in the bath.
