Development of a novel method in electroless copper plating

Abstract

The modern day electroless copper plating solution commonly consists of copper ions, chelating agents, buffers, stabilizers, accelerators and surfactants. The roles of chelating agents, stabilizers and surfactants in the plating solution were investigated with emphasis on the plating rate and surface morphology of the plated copper. Electroless plating was performed on an acrylonitrile-butadiene-styrene substrate using formaldehyde based electroless copper plating solution at 25oC.Structurally similar chelating agents of sodium potassium tartrate, trisodium citrate and potassium sodium salt of malic acid was used separately as the main chelating agent. Selected amino acids such as glycine and L-methionine were selected to replace bi-pyridine as the stabilizer in the reference plating solution and found that sulphur containing amino acid affects the plating rate and grain size considerably. Polyethylene glycol of various molecular weights was used separately to investigate the effect of surfactant on the surface morphology of the plated copper.