Hi Jim, You write: "Propagation of the fracture is usually through the IMC at the lead surface." I respectfully disagree; if you look closely, you see that the propagation of the fracture is usually just outside the IMC at the lead surface, in the region of the SJ where Sn has been somewhat depleted to form the Sn/Cu IMCs. Lets not give IMCs a bum-rap where they do not deserve it. A truly interfacial separation shows essentially only base metal on one fracture surface and solder (rarely IMC because in most of these cases no metallurgical bonding (wetting=formation of IMCs) has taken place) on the other. Re covering the lead ends with solder am in full agreement with you. Werner Engelmaier --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------