Bingo! There is the crux of it. I am not talking about joints already made, I am talking about TRYING to MAKE joints. I hope I don't get in trouble for this. My original, vague question was because of - head in pillow. Inge guessed correctly. I don't mean to be rude, but we already have a very extensive fishbone for this, so please don't come back with the usual reasons. They are being addressed, trust me. What I am exploring is whether unusual amounts of gold tin intermetallics on the surface of the solder balls pried off of boards that show head in pillow did not solder because of these materials. Bev RIM -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier /* Sent: Thursday, January 17, 2008 10:36 AM To: [log in to unmask] Subject: Re: [TN] SV: [TN] SV: [TN] Solderability of Tin-Gold Intermetallic Hi All, We know that Cu6Sn5 is non-solderable after oxidation. However, I do not know whether we really KNOW that it is solderable prior to that, and we know even less about the solderability of AuSn4, Ag3Sn, or for that matter Sn3Ni4. Werner ************** Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489 --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. --------------------------------------------------- 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 -----------------------------------------------------