PROCESS ANALYSIS OF ELECTROLESS NICKEL DEPOSITION BATHS BY RAMAN-SPECTROSCOPY

In a test experiment carried out in a small compact electroless platin g facility, the concentrations of hypophosphite and phosphite in a nic kel 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 calcu lated and compared with the stoichiometry of the nickel plating proces s adopted. In addition, nickel bath samples were also measured with an FT Raman spectrometer to compare the performances of both Raman techn iques with a view to their application to aqueous solutions.