Hi Keith, Without getting the test details, concluding that "Lead-free joints are usually stronger and survive thermal fatigue better than tin-lead joints" is dangerous. Unless the testing follows the guidelines of IPC-SM-785 or IPC-9701, serious fallacious conclusions can result. Most of the fatigue results reported are from tests designed to totally ignore the creep-characteristics of solder [no dwell times at T-extremes] and also use an extreme cycle condition [-55/-40<=>+125C] that assures confounding damage mechanisms. Thus, no valid conclusions regarding product reliability are possible. To date, virtually all properly run accelerated T-cycling tests have shown inferior creep-fatigue reliability for almost all LF-solders. Werner Engelmaier --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------