Sumxp It is likely the thickness of the gold is inadequate and the underlying nickel has oxidized. I would measure the gold thickness (XRF) and compare it to the minimum specified. The silver color after erasing is most likely the nickel that is under the gold and with the oxides removed. There are many other alternatives these days to ENIG such as immersion silver. Have you evaluated into any of these? Best regards Lee J. L. Parker Ph.D. JLP Consultants LLC (804) 779 3389 Best regards Lee J. L. Parker Ph.D. JLP Consultants LLC (804) 779 3389 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of sumxp Sent: Friday, January 13, 2006 10:48 AM To: [log in to unmask] Subject: [TN] enig bad board Hi, We noticed few ENIG bga pads black in color instead of gold.It turn silver when use eraser to remove away the black color pad.What is the defect mode? Any reliability issue?Is it advisable to continue using these pcbs? Thanks...... --------------------------------------------------- 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 847-615-7100 ext.2815 ----------------------------------------------------- R --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------