Franklin Just one additional comment to add to Doug's IPC-TM-650, Method 2.6.3 is titled Moisture and Insulation Resistance, Printed Boards This method has be used - originally as part of DOD-200 test methods - for a very long time 30+ years to test printed wiring boards. It is the cycling of temperature while keeping the humidity very high. It was proposed in order to force moisture through conformal coating, solder mask and further into a multilayer board to evaluate the "cleanliness" of internal layers as well as the surface. Susan Mansilla --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------