Hi Ed - I suggest you run a FTIR scan (Fourier Transform Infrared) on your unknown film. The FTIR test results should give you the chemical clues to determine the source of the film. I suggest you also talk to Doug Pauls ([log in to unmask]) - he could suggest several other techniques that may be beneficial. Without knowing what type of flux materials and cleaning systems you are using a guess on what the film could be might be totally skewed. Can you provide more process type details? Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: SMT Solder Joint Film Author: [log in to unmask] at ccmgw1 Date: 10/15/96 2:17 PM We are noticing a film on our SMT solder joints. It doesn't seem to affect ionic cleanliness or conformal coating adherence, but can only be removed mechanically with a brush or Q-tip. It has a slightly yellowish color in most cases and appears powdery. Is this contamination from the PWB pads or part leads floating to the top, or a compound derived from the solder paste (63/37 RMA)? Any insight into what this contamination is would be appreciated. Thanks. Ed Knowles Lockheed Martin Astronautics *************************************************************************** * 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. * *************************************************************************** *************************************************************************** * 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. * ***************************************************************************