This work describes as an attempt to improve the deposit properties of electroless Ni-Cu-P deposits by controlling the deposition condition and the composition of the plating solution. Tensile internal stress induced by hydrogen evolution during electroless Ni-Cu-P deposition was manipulated by controlling deposition conditions such as stirring and zincating. The stirring action releases the hydrogen-induced stress and improves adhesion of the deposit in the condition of once zincate pretreatment. It was also attempted to vary the concentration of reducing agents (NaH2PO 2·H2O), buffering agents (NH4Cl), and complexing agents (Na3C6H5O 7·2H2O) of the plating solution to improve the deposition rate, crystallinity and the composition uniformity of Ni-Cu-P deposits. The results show that a decrease in complexing agents results in steadier deposition of Ni and Cu elements and higher deposition rate. The preferable deposition solution consists of 0.057 mol/L NiSO 4·6H2O, 0.0008 mol/L CuSO 4·5H2O, 0.14 mol/L NaH2PO 2·H2O, 0.07 or 0.09 mol/L Na3C 6H5O7·2H2O, and 0.75 mol/L NH4Cl at pH 8.0, which creates amorphous and uniform Ni-Cu-P deposits.
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