Dan, A few more details please. What kind of mask (e.g. dry film , wet screen, LPI)? Is is over a melting metal? What wave temperatures? Were the boards acceptable before, i.e. was there some change in materials and processes which precipitated the problem? 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] * ***************************************************************************