In a message dated 96-12-11 19:49:54 EST, you write: << I haven't the foggiest idea what your brown residue is but you could conduct a Fourier Transform Infrared (FTIR) analysis to pinpoint its identity. FTIR analysis is the organic material analysis counterpart to Scanning Electron Microscopy (SEM) analysis for elements. With the FTIR analysis you can compare the residue scan with a phenolic scan, a solder mask scan, and a lacquer scan to see if any match. Good Luck. >> A good start Dave, but I don't think that FTIR will show much in this case. Since the residue is in the solder bath, I don't know of many organic materials that would survive prolonged exposure to molten solder temperatures. The SEM would be a good choice. He might also try inductively coupled plasma (ICP), which is often used on plating bath residues. Another possibility would be mass spectroscopy, although somewhat expensive. Doug Pauls CSL *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************