Electroless deposition of copper from methane sulphonate complexed bath

Abstract Electroless copper deposition is widely used for printed circuit applications. A new bath based on copper methane sulphonate replacing copper sulphate, EDTA and paraformaldehyde has been developed, which is very useful for plating on non-conductors and through hole plating in printed circuit manufacturing processes. The new bath has a higher rate of deposition of 3·3 μm h−1 than the conventional sulphate bath (with a rate of 1·5 μm h−1) and the bath stability and the quality of the deposits are very good. Scanning electron microscopy, X-ray diffraction and atomic force microscopy studies have been carried out and the crystallite size of the copper is measured to be 134 nm with a preferred orientation of 200 planes. The deposit obtained is pure copper and the surface roughness is of the order of 10 nm.