All fluxes, by definition, must have some form of corrosive ion for it to be able to reduce metal oxides. Even pure rosin isomers have a carboxylic acid group. From your description, it seems probable that you have what is effectively a short-circuited battery with gold and copper as your electrodes with bare copper where the fingers are cut or the gold plating is too thin/porous/worn through. Any condensation would provide you with an electrolyte, exacerbated by tthe presence of any ionogenic and/or hygroscopic contaminant (not necessarily from your flux, which you don't want on gold-plated fingers, anyway). Brian On 29/02/2012 16:53, Victor Hernandez wrote: > Fellow TechNetters; > > Do No Clean LF fluxes, Rosin Core/molten solder, have a corrosive ion? Every so often when conducting analysis on Field Return Product I notice small amount of corrosion product on gold plated contact on DIMM and PCI Slot connector. Sometimes on other gold plated connector leads. So I am trying to understand which component had a corrosive ion waiting for the right conditions to flourish. Small amount of greenish/bluish residue. It can be seen on wipe zone and/or stamp edge of contact. Where is this active corrosive ion coming from? > > Can someone provide the link to Stevezea home page for posting pictures? > > Victor, > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________