Hi Rich! I recommend getting a copy of Lenora Tuscano/Don Cullen's paper given at the IPC 2003 Fall meeting titled "The Study, Measurement, and Prevention of Tarnish on Immersion Silver Board Finishes". The paper documents that the "yellow" tarnish found on immersion silver pwbs used in the study, using SERA and ESCA analytical techniques, can be silver sulfide, is in the thickness range of 200-500 angstroms, and is still quite solderable (lots of info in the paper - this is the reader's digest version). As others in our TechNet community have discussed, the yellowing can be a typical visual appearance. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Richard Kraszewski To: [log in to unmask] <[log in to unmask] cc: COM> Subject: [TN] Yellow Discoloration of Immersion Silver Boards Sent by: TechNet <[log in to unmask]> 06/16/2004 09:13 AM Please respond to "TechNet E-Mail Forum."; Please respond to Richard Kraszewski We are seeing yellow discoloration of Immersion Silver Boards right out of the package from our board house. They seem to solder fine, however this is causing some concern with our customer. I suspect that it could be a thin film of silver bromide or silver carbonate both which are yellow powders. Any one seen this before? What is it? How does the board house remedy this situation? Any associated concerns or other bits of wisdom? I would truly appreciate any input. Rich Kraszewski Advanced Manufacturing Engineer - KEDS Phone: 260.925.8919 --------------------------------------------------- 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 -----------------------------------------------------