Wei, I wouldn't worry about the Au not going completely into solution with the hand soldering of the 0402 caps... You will probably have more reliability issues with the thermal damage to the caps, than the Sn-Au and Sn-Ni interfaces... Paul Paul Edwards Process Engineering [log in to unmask] Tel: 408-433-4700 FAX: 408-433-9988 Surface Art Engineering 81Bonaventura Dr. San Jose, CA 95134 DUNS: 944740570 CAGE/NCAGE: 1XZ48 -----Original Message----- From: Wei-Shun Wang [mailto:[log in to unmask]] Sent: Monday, September 13, 2004 3:38 PM To: [log in to unmask] Subject: [TN] Soldering to hard gold Hi, Is there a good method to hand solder 0402 cap to hard gold plated pads (30-50 micro inches) and maintain reliability? It is a design issue. Customer needs to install a BGA socket on top side. So they specify hard gold plate on BGA area. But there are lots of caps on bottom side of the BGA and those pads are plated with hard gold too. No one wants to scrap those fabs due to hot schedule and high cost. Please advise. Thanks, Wei Wang Process Engineer Sanmina-SCI --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 847-509-9700 ext.5315 -----------------------------------------------------