Influence of 3-Mercapto Propionic Acid additive on the plating and bath characteristics of autocatalytic copper nano film coating

This article focusses at studying the influence of the azole additive 3-Mercapto Propionic Acid (3-MPA) on the rate of autocatalytic copper nano film coating on epoxy sheet surface. The effect of 3-MPA on the characteristics of both the electroless deposition bath and electroless copper plating is also analyzed. Dimethylamine borane (DMAB) is employed as the reducing agent and xylitol as complexing agent in the copper methanesulphonate bath. Potassium hydroxide acts as the apt pH regulator to modify the properties of nano copper deposits. 3-MPA is added in this eco-friendly bath and optimized at a pH of 11.25 ± 0.25 at a
temperature of 28±2 °C. The results obtained from various studies imply that 3-MPA had an inhibiting effect on copper deposition rate. The physical properties like deposition rate, thickness and activation energy are calculated to support the stabilizing effects of 3-MPA. Surface morphology of the copper deposits is characterized by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) techniques. Structural properties such as crystallite size and specific surface area of plain bath and 3-MPA loaded bath are investigated using X-ray diffraction studies.