I thank you all so far for your input including those emailing me personally and those on this forum. This is a fast moving thing and should be wrapped up early next week depending on DOE implementation and results. Right now, I'm leaning heavily toward thermally induced failure causing "melt down" and subsequent, and very fast, catostrophic electrical failures. 1) Using acoustic microscopy, in accordance with MIL-STD-883 test method 2030, I have seen die attach eutectic (AuSn) bonding material voiding in exceeding minimum requirements in as received parts. This equates to poor thermal transfer, for one thing, and that the supplier missed the boat on this testing. 2) We are not using thermal compound between the device base and the heat sink thus not allowing adequate thermal dissipation/transfer. Also, we are using preliminary/prototype castings with inconsistent voiding. Again, thermal transfer is compromised. 3) As so many other tests, including liquid crystal analysis for ESD damage detection, particle impact noise detection, leak detection, RGA, various contamination/surface analysis testing, and others, have turned up negative, the thermal theory is highest on my list. 4) Other random possibilities exist, though not yet verified, as solder balls, mis-handling events, and the normal/abnormal assembly "techniques" but seem unlikely to cause such failures as found. I'll keep you all posted when all the raw data is converted to useful information. 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 ---------------------------------------------------------------------------------