Hi Technetters, I am facing a problem with a tin/lead plating board. I am facing a problem with boards that are of Roger material and was tin/lead plated. The traces are not being masked, hence exposed. We subject the boards to reflow, and those area where no solder joint turned tarnish. This is the first time we handle such kind of board. We have no experience on this. I wander if tarnish is a defect. Can someone advise me how to remove this tarnish as I try using IPA to rub it off, it seems nothing happened. I could not find this in the IPC. Please advise me. Thanks. KH Poh --------------------------------------------------- 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 -----------------------------------------------------