Ive seen yellow staining on immersion silver boards in the presence of rinse water with high content of chlorides or sulfides. If the rinses are not DI water this can occur very easily, you might want to check your chloride levels in the water, this might be the easier test to perform. If you dont have a chloride probe, you could just drop some silver into the rinse water in a beaker and see if it percipitates out, this is a quick and dirty test. Hope this helps. Lisa Angle Ken Mc Gowan <[log in to unmask]>@IPC.ORG> on 04/09/2001 01:49:18 PM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to Ken Mc Gowan <[log in to unmask]> Sent by: TechNet <[log in to unmask]> To: [log in to unmask] cc: Subject: Re: [TN] Immersion silver boards tarnish Hi David, Normal mechanisms of Ag tarnishing are: Diffusion of copper (do you have a brrier layer of Ni/Pd??) Presence of sulphides in the atmosphere. Organic stuff in packaging materials. Best Regards, Ken McGowan. ----- Original Message ----- From: David To: [log in to unmask] Sent: Monday, April 09, 2001 1:53 AM Subject: [TN] Immersion silver boards tarnish Has anyone ever exeprienced immersion silver MSP boards tarnishing, turned yellow after stored in ambient condition? --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------