Hi Edward, I have to agree with Gunter; I have seen little in terms of reliability data for lead-free solders. And what I have seen does not give me much confidence, since the cyclic tests were designed—for expedience's sake— without adequate dwell times at the temperature extremes and therefore, by design, totally neglect the most crucial reliability property of soft solders—creep—which increases the cyclic fatigue damage and shortens fatigue life. Soft solders, in order to be practical, will all have homologeous temperatures that are very similar; thus, their fatigue behaviour should not be dramatically different. Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 904-437-8747, Fax: 904-437-8737 E-mail: [log in to unmask] ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################