Hello technetters. We have a bad wettability (SnPb process) on some copper ribbons covered by a Ni layer and Au layer. These are applied by an ENIG process. The ribbon no-wet area is located on alongside and edges of ribbons. No issue in the centrum area of the ribbon. The ribbons are 3 mm width and 0.3 mm thick. The Ni layer and Au layer have the good thickness : 4µm and 0.1 µm. But with a SEM analysis we see in the bad area a porous Au. At the degolding operation, the area becomes black, the SnPb don't wet and the SEM analysis gives a high presence of Phosporus in that area (Qualitative analysis, the P peak is half the Ni peak). At soldering operation more you try and worse it is. The manufacturer of the ribbon says the P in the Ni-P bath is 9%. Question: I think the cause is a bad control and homogeneity of the Ni-P bath. Is it correct or could be another cause as "only" 2/3 of the lot is bad? After ENIG process, how many P has to remain on the Ni layer ? Thanks for your answers. Best regards, CANTAGALLO Luigi ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- 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 -----------------------------------------------------