The electrodeposition of lead containing alloys have found many industrial applications including electronics and other applications. However, lead is very harmful to health and the environment and the Restriction of Hazardous Substances Directive (RoHS) has been in force in Europe since 2003 restricting the use of certain hazardous substances (e.g. lead, cadmium, mercury etc.) in electrical and electronic equipment and this is likely to be extended to other industrial sectors. For this reason there is intensive research to find alternatives to lead alloys and one favourable candidate is Sn-Cu.

This paper will describe a study carried out to obtain a deeper understanding of some of the factors affecting Sn-Cu electroplating. Experimental work, by means of Hull Cell tests, ultrasonic agitation and pulse plating, has been undertaken to understand the effect of these factors on the properties of the Sn-Cu coatings. A number of advanced analytical techniques, including scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDS) and white light scanning interferometry (WLS), have been used to evaluate the characteristics of the Sn-Cu coatings, in terms of their surface morphology, chemical composition and microstructure.

Our experimental results showed that pulse plating techniques combined with high speed magnetic stirring during deposition had a strong effect on the characteristics of the Sn-Cu electrodeposits and aslo Sn whiskers developing from the deposit.