If you are building the boards to either IPC-6013 or MIL-50884, you must pass the thermal stress test to certify them as compliant. Rigid, Flex and Rigid/Flex boards can and do regularly pass this test. You might want to make certain the test lab has baked the samples prior to thermal stress. There is a 6 hour minimum bake. Of course you could have a third party repeat the testing, if you think it was done improperly. However to certify boards to those specifications, you must pass the test Susan Mansilla Robisan Laboratory ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################