Hi Inge, Yes, the intermetallics itself is strong, BUT it doesn't count, as all failures I've seen goes at the tin/intermetallics interface. The larger were the platelets, the worse it looked. Regards, Vladimir ------Original Message------ From: Inge Sender: TechNet To: [log in to unmask] ReplyTo: TechNet E-Mail Forum ReplyTo: Inge Sent: Apr 14, 2009 16:55 Subject: [TN] Gold/Tin Intermetallics, why are we afraid? These infamous IMCs are like parias or ghosts in most people's mind in our business. I shocked our production guys recently by giving the advice to let the boards go on. Large crystals and bad looking. But I always try to avoid exaggerations. If no serious temp changes are predicted, nor any severe power switching, why rework and risk introducing failures? The actual components were very hard to rework, the cost had been unacceptable. I can see many of you get the coffee wrong. I don't mean to spread quality distractions, I talk about very few boards and a unique situation. My statement was based on the fact that a gold tin intermetallic bond is extremly strong and can last long, if not exposed to what I pointed at earlier. I expect to be hammered down in the shop floor until only the nose is visible.... Inge --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca