Influence of polarization curve slope on the accuracy of local copper electrodeposition from sulphate electrolyte

Local electrochemical deposition is an emerging technique, used in the field of additive manufacturing. The advantage of electrochemical additive manufacturing lies in the utilization of room temperature electrolyte and permits to manufacture microscale objects with high precision. The increase in deposition current increases the deposition area, so measures are to be taken to focus the electric field. This work describes the influence of polarization curve slope on the accuracy of local deposition, both experimentally and by computer modelling. The copper was deposited using rotating anode on the surface of stainless steel from sulphate electrolyte. The influence of electrolyte composition on the accuracy of deposition was investigated. The profile of deposited parts was analyzed by profilometry and microscopy. The increased amount of sulfuric acid and presence of the additive in the electrolyte was shown to increase the accuracy of deposition by changing the slope of cathodic polarization curve from 320 to 1100 mA V–1cm–2).