Process analysis of electroless nickel deposition baths by Raman spectroscopy

In a test experiment carried out in a small compact electroless plating facility, the concentrations of hypophosphite and phosphite in a nickel deposition bath of the Kanigen type were monitored on‐line with a dispersive Raman spectrometer. From the results, which agreed with off‐line Fourier transform (FT) IR data within ca. 10%, the molar amounts of nickel, hypophosphite and phosphite consumed and formed were calculated and compared with the stoichiometry of the nickel plating process adopted. In addition, nickel bath samples were also measured with an FT Raman spectrometer to compare the performances of both Raman techniques with a view to their application to aqueous solutions.