Art, I'll give it a try. Since this para applies only to the cleanliness test immediately prior to solder mask application, it is a little simpler than some others. If you group several different part numbers (lots) and then clean and apply solder mask to all during the same shift and if 1)these are all glass epoxy boards (material type) and 2)they all were bare copper surface conductors then you would be required to run 5 of these boards through cleanliness testing to assure that your cleaning process was adequate.. If you had one part number (lot) that required solder mask over reflowed tin lead, you would need to test 5 of these boards. If you had one part number constructed from any other laminate than glass epoxy, you would need to test 5 of these. Hope this helps Susan Mansilla Robisan Laboratory *************************************************************************** * 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. * ***************************************************************************