Hi Kenneth, By definition, 'Burn-In' is a functional test typically at worst-case operating conditions. No significant deterioration of the good solder joints need to be expected. In contrast, 'Screening Procedures" [ESS] are designed to produce failures in latent defects in-house, so they do not occur at your customer. While some loss of life of the solder joints can be expected depending on the procedure used, it still should be no more than about 10%. I have never heard of "leaching of solder joints" under any test condition. It would be useful to provide details as to what you are doing in your "burn-in" and what it is you are observing. Regards, Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 386-437-8747, Cell: 386-316-5904 E-mail: [log in to unmask], Website: www.engelmaier.com ************************************** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------