Galvanostatic oxidation of high TOC plating baths

Sequeira, CAC; Chen, Y; Anastassakis, G

dc.contributor.author	Sequeira, CAC	en
dc.contributor.author	Chen, Y	en
dc.contributor.author	Anastassakis, G	en
dc.date.accessioned	2014-03-01T02:50:05Z
dc.date.available	2014-03-01T02:50:05Z
dc.date.issued	2005	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/34894
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-32044454455&partnerID=40&md5=59ddec8863f32e9f8dd2670dc84d034a	en
dc.subject.other	Additives	en
dc.subject.other	Cell membranes	en
dc.subject.other	Current density	en
dc.subject.other	Impurities	en
dc.subject.other	Oxidation	en
dc.subject.other	Printed circuit boards	en
dc.subject.other	Copper sulphate baths	en
dc.subject.other	Galvanostatic oxidation	en
dc.subject.other	Photo resist	en
dc.subject.other	Target compounds	en
dc.subject.other	Copper compounds	en
dc.title	Galvanostatic oxidation of high TOC plating baths	en
heal.type	conferenceItem	en
heal.publicationDate	2005	en
heal.abstract	Printed circuit board copper lines are built-up by electroplating from copper sulphate baths. Organic additives are continuously added to improve quality and speed of plating. Decomposed additives and organic compounds leached from the printed circuit boards and their photo resist, built-up in the plating bath. Eventually high contamination levels, as measured by total organic carbon (TOC), cause poor plating quality. Several methods have been considered to maintain the plating bath quality within narrower limits, but they all have raised concerns. Here we describe an electrochemical route, using a two-compartment cell submitted to galvanostatic testing, that seems to be competitive. The solutions being oxidised were synthetic copper sulphate baths with 200g/L H2SO4, 15-25 g/L copper, and 1500-2500 ppm TOC. The effects of anode materials, cell membranes, and current densities on the processing efficiency for the oxidation of the target compounds without changing other properties of the plating bath chemistry, were studied. Among the anode materials (Au, Pt, PbO2, IrO2, SnO2) investigated, doped tin dioxide electrodes showed good stability and efficiency for TOC destruction. The results of the various tin dioxide current density tests showed that there is a large increase in efficiency with decreasing current density (from 250 mA/cm2 to 1.0 mA/cm2). Concerning the cell membrane our work focused on evaluating cation exchange membranes for their ability to block the passage of copper ions, the best results being obtained using monovalent cation selective membranes and Nafion membranes. Although this initial work needs to be refined, it definitely shows that the present electrochemical approach can succeed in the destruction of organics in printed circuit board plating baths.	en
heal.journalName	REWAS'04 - Global Symposium on Recycling, Waste Treatment and Clean Technology	en
dc.identifier.spage	1117	en
dc.identifier.epage	1124	en