Hi Jim - 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. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Brown resin like residue in solder bath Author: [log in to unmask] at ccmgw1 Date: 12/11/96 3:14 AM We have recently experenced a brown resin like substance in our solder bath after wave solder of a qty of paper phenolic pcbs. The boards have a solder resist and laqer finish. Can anyone tell me what this bown substance is and what is the cause. Thank you Jim Hedderick [log in to unmask] *************************************************************************** * 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] * *************************************************************************** *************************************************************************** * 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] * ***************************************************************************