Ultrasonic agitation in barrel electroplating: field trial results

Barrel electroplating is an extremely useful method to coat a large number of components. Despite its successful use for many years it does have drawbacks, often stemming from poor electrolyte movement within the barrel. This can result in issues associated with mass transport, i.e. low limiting current, slow electroplating rates and, in the case of alloy electroplating, inconsistent alloy composition. Field trials carried out at an industrial facility, using ultrasonic agitation during the barrel electroplating of a Sn–Pb alloy, are reported. It was found that if electroplating was performed in a low frequency ultrasonic field then the limiting current could be increased, resulting in higher electroplating rates; the incidence of ‘burning’ was also reduced. In addition, the proportion of components having an alloy coating composition within the customer specification was higher, lowering the defect rate and increasing production capacity.