Thank you Phil very much. Your studies and comments are very insightful. It seems "current" solder joint formation technology, dating back over a thousand or more years, is very reliable and forgiving under almost any condition, stress, shock, or operational environment. High or relatively low purity copper, high or low thickness intermetallic compounds, etc. all seem to have little affect on solder joints, in general. Once a "good" solder joint is formed, it seems that it should remain in tact for some time. Will this be true for our "new age" solder joints - as lead free, depending on the alloy, or not, for a particular application? Earl Moon --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------