Copper Additives in Electroplating BathsI know the HPLC analysis of plating baths for electronics may not sound exciting but I found the white paper featured here on this subject to be fascinating reading. And, it led me to doing a little research. Did you know that damascene, or acid copper plating baths, have been in use since the mid 19th century on decorative items and machinery, including integrated circuits and satellites in recent times? And, that the art of inlaying different metals into one another is called damascening, from the resemblance of such items to patterns of damask silk (link & source Wikipedia)?

The reason why the plating process requires accurate and frequent monitoring is because this can result in significant savings due to reduced scrap rate, reduced bath solution losses, and improved quality. Both HPLC and ion chromatography can be used to quickly determine both trace and major constituents of a wide variety of electroplating solutions, acid etchants, conversion coatings, cleaning solutions, and the various rinses and wastewaters derived from these solutions.

White Paper 71211, Measurement and Control of Copper Additives in Electroplating Baths by High-Performance Liquid Chromatography, (downloadable PDF), outlines two methods in which additives used to control the acid-bath electroplating quality of copper are measured. One aliquot of sample is treated to neutralize the acid, which is then analyzed by both methods, providing results on both quantity and quality of one or more additives.

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This HPLC method provides a more reliable control of an operating plating bath, less produc­tion costs and improvements in product quality:

  • Results reflect the current state of the operating plating bath
  • Corrections of additive amounts based on more accurate analytical results will yield products of higher and more consistent levels of quality
  • Operational times will be increased, with less time wasted on correcting additive amount errors and unnecessary carbon treatments
  • A measure of plating bath quality can now be determined as a function of suppressor breakdown

The white paper was authored by our scientists in collaboration with a scientist from Seagate Technologies (USA); you might also be interested in the following poster, also authored by our scientists: Poster Note, Quantitation and Characterization of Copper Plating Bath Additives by Liquid Chromatography with Charged Aerosol Detection, (downloadable PDF). The poster presents HPLC methods that are precise and sensitive for the determination of all additives in plating baths and use the same sample preparation. One of our dual HPLC systems (Thermo Scientific Dionex UltiMate 3000 x2 Dual LC system) was used with two of our Charged Aerosol Detectors (Thermo Scientific Dionex Corona ultra RS detector and the Dionex Coulochem III detector).

Additional Resources

  • You might also be interested in our Chromatography Solution Online Center which features many useful and complimentary chromatography tools which can help speed up your analysis. The site is updated on a monthly basis; therefore, do check out the Archives section to see what was previously featured.

Do you have questions about the application? Do let us know using the comments box below: we look forward to hearing from you!