As I know ENIG in plated through hole come from electroless copper plating. In Electroless copper process it has one step that we call activator normally will contain Palladium. Sometime after electroless it still remain some palladium in hole. So when they come through ENIG , as you know this process also used palladium before plated Nickel. What happen is everywhere that has palladium nickel will plated and then Gold. Somtawin Pornpottanamas Material Engineer Kimball Electronics (Thailand) Tel. 038-401566 ext. 211 Fax. 038-495029 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of d. terstegge Sent: Thursday, February 05, 2004 10:13 PM To: [log in to unmask] Subject: [TN] Goldresidues in non-plated holes Hi Technet, I looked at an ENIG board today and noticed it had some gold-residues in the nonplated holes. I always thought that a non-plated hole should not have any plating at all, but seeing this condition for the second time (the first time was on a board from another manufacturer and another designer) I almost begin to think this is a normal condition. What do you think, is this normal, is it acceptable (I don't think so), any idea what causes it ? For those who like to see a photograph of this, see: http://www.smtinfo.net/forum/index.php?showtopic=40 Daan Terstegge Thales Communications Unclassified mail Personal Website: http://www.smtinfo.net --------------------------------------------------- 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 -----------------------------------------------------