Abstract
Effects of stabilizers such as lead nitrate, thiourea and thiodiglycolic acid on nickel-boron electroless plating were studied in a bath containing sodium borohydride as a reductant and tartrate salt and glycine as ligands. Lead nitrate remarkably stabilized the plating bath and gave significant deposition rates with sodium fluoride as an accelerator. Effect of the concentration of each component on the deposition rate of the film was investigated and it was found that a bath containing 0.04mol dm-3 of nickel chloride, 0.05mol dm-3 of sodium borohydride, 0.1mol dm-3 of potassium sodium tartrate, 0.1mol dm-3 of glycine, 1.2×10-4mol dm-3 of lead nitrate and 7.1×10-2mol dm-3 of sodium fluoride gave 0.54g dm-2h-1 of deposition rate comparable to ca. 1/4 of that in Nibodur bath. Spectrophotometric measurement suggested the plating rate and appearance of plating film did not depend on alteration of nickel-complex caused by concentration changes of ligands.
