We've seen the same phenomenon as Susan. If I recall, an average thermal stress can remove up to a ten of a mil of copper from the knee sitting in the solder pot. We did a lot of work on this when looking into rework of a multiple segment edge connector. I know of nothing that would explain significant loss at the top side knee. Regards, Paul Terranova Analytical and Environmental Test Services Lab Digital Equipment Corporation 200 Forest Street Mail Stop: MRO3-1/D2 Marlboro, MA 01752-3085 ' Phone: (508)467-3109 * Fax: (508)467-6796 * Email: [log in to unmask] WebSite: http://www.digital.com/lab-services -----Original Message----- From: Robisan1 [mailto:[log in to unmask]] Sent: Sunday, April 26, 1998 10:48 AM To: [log in to unmask] Subject: Re: [TN] Dissolution of plated copper Scott I have seen this dissolution when performing multiple thermal stress tests. In fact eventually knees will disappear completely if you expose them enough One thing that can effect this is type of plating A totally electroless deposit will go into solution much faster than the electrolytic deposits. I have done nothing that would compare one to the other, but I do know it happens Susan Mansilla Technical Director Robisan Lab ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################