Title :
Electrochemical migration of copper in pure water used in printed circuit boards
Author :
Medgyes, Balint ; Illes, Balazs ; Rigler, Daniel ; Ruszinko, Miklos ; Gal, Laszlo
Author_Institution :
Dept. of Electron. Technol., Budapest Univ. of Technol. & Econ., Budapest, Hungary
Abstract :
Electrochemical migration (ECM) behaviour investigations were carried out on “oxide-free” and highly oxidized copper surfaces in pure water. It was shown in our previous paper that the oxidation number of copper ion mainly depends on the oxide layer thickness of the copper surface; in the case of “oxide-free” copper surface the Cu1+ ions dominated, while Cu2+ ions were mainly formed in the case of highly oxidized copper surface, which modify the standard electrode potential and also the solubility product constant of copper-hydroxides, thus can effect on the mean time to failure (MTTF) caused by ECM. In order to verify the effect of different copper ions (Cu1+ vs. Cu2+) on MTTF, water drop (WD) tests were carried out on both copper surfaces. The results showed that in the case of “oxide-free” copper the MTTF value was lower than in the case of highly oxidized copper.
Keywords :
copper; electrodes; electromigration; printed circuit interconnections; water; Cu; MTTF; electrochemical migration; electrode potential; oxide layer thickness; oxide-free copper surface; printed circuit boards; pure water; solubility product constant; water drop tests; Copper; Electrodes; Electronic countermeasures; Ions; Standards; Surface cleaning; electrochemical migration; lead-free low Ag micro-alloyed solder alloy; water drop test;
Conference_Titel :
Design and Technology in Electronic Packaging (SIITME), 2013 IEEE 19th International Symposium for
Conference_Location :
Galati
DOI :
10.1109/SIITME.2013.6743688
