Hi Ted, What you describe sure sounds like a fatigue problem stemming from a design that did not consider the effects of thermal expansion mismatches, global or local. Appendix A of IPC-D-279 is applicable if what you have is a fatigue problem (I can not be really sure without seeing more details). You should however check if the damage terms in the Appendix A analysis fit your applications and that your application does not violate any of the stated caveats. For testing procedures I would refer you to IPC-SM-785. You could make your life easier and get things done faster by hiring me. Werner Engelmaier Engelmaier Associates, Inc. Electronic Packaging, Interconnection and Reliability Consulting 23 Gunther Street Mendham, NJ 07945 USA Phone & Fax: 973-543-2747 E-mail: [log in to unmask] ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################