Hi Ricky, copper has a chemical affinity to form a bond with the free electron pair of nitrogen in nitrogen-containing compounds like ammonia ( by forming this: [Cu(NH3)4]2+) or its derivative TMAH. Im not sure if sterically possible for TMAH to form a fourfold tetramethyl ammonium complex with copper or if its only a twofold. There is always a slight oxidation of copper under the presence of oxygen. If there is also such a nitrogen-compound, you will have a reaction as described above. Best regars/Mit freundlichem Gruß André Bödecker Institut für Mikrosensoren, -aktoren und -systeme Universität Bremen Fachbereich 1 Otto-Hahn-Allee1 28359 Bremen Tel: 0421 218 62596 _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk