Hi Sherif! As Mike F. mentioned, silver oxide is as nearly as conductive as metallic silver. However. silver finishes will for silver sulfide films when exposed to sulfur sources which significantly increases their contact resistance. You may be able to penetrate the sulfide film with increased pressures or different probe tip geometries. I would recommend you also investigate what potential sulfur sources the pwas were exposed too - I have documented the formation of silver sulfide films on immersion silver pwbs in our manufacturing operations (using SERA testing) but not within a two week timeframe. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Sherif Refaat <[log in to unmask]>@ipc.org> on 01/08/2003 09:35:21 AM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to Sherif Refaat <[log in to unmask]> Sent by: TechNet <[log in to unmask]> To: [log in to unmask] cc: Subject: [TN] Immersion Silver oxidation Hi Technetters, I've got a situation here where boards coated with Immersion Silver were partly assembled before the Holidays and the assembly was completed this week. So, the boards were left in the factory, uncontrolled environment, for over two weeks. The circuitry on the side that was assembled first exhibits oxidation. The oxidations does not allow the In-Circuit test probes to have good contact with the test pads, hence causing lots of false opens. Any recommendations regarding how to remove Immersion Silver oxidation from assembled boards? The Immersion Silver Chemistry supplier is located overseas and because of the time difference I can not get an immediate answer. I heard about a more pointy test probes that may be able to penetrate the oxidation but the factory does not accept this solution. Can any one help? Thanks in advance. Sherif, --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------