Environmentally friendly copper electroplating process development

Ülgüdür, Nilüfer
Electroplating is the deposition of a metal by applying electrical current in the presence of an electrolyte. Electroplating industry creates wastes that are heavy metal containing, highly conductive, strongly acidic/alkaline in composition. Many industries are now enforced to prevent their wastes from being formed via pollution prevention guidelines. It is both economically and environmentally more advantageous to consider pollution prevention before establishment of a process. In this study, waste minimization in copper strike plating over aluminium metal using copper cyanide bath was targetted in a laboratory scale production process. In this framework, preliminary setups were conducted to compare several strike baths for copper deposition including copper cyanide and copper pyrophosphate baths. Visual inspection, roughness measurements, SEM imaging and reflectivity measurements were conducted on the products after deposition. Percent deviation in integrating sphere reflectivity measurements ranged between 1-2% and 7-29% for copper pyrophosphate bath and copper cyanide baths, respectively. Similarly, SEM and roughness indicators were more favorable for copper pyrophosphate bath products. Secondary setups were performed in order to compare life time of baths by tracking changes in critical parameters in long run plating processes for two selected baths. The concentrations of copper and cyanide increased by 17.5 % and 11.5%, respectively, after four hours of plating whereas copper and pyrophosphate concentrations fluctuated over time during plating without a significant change. The results have shown that for the field of application of the product, cyanide bath can be replaced by a non-cyanide alternative that is a pyrophosphate strike.


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Citation Formats
N. Ülgüdür, “Environmentally friendly copper electroplating process development,” M.S. - Master of Science, Middle East Technical University, 2013.