In a message dated 3/20/2007 12:33:06 P.M. Eastern Daylight Time, [log in to unmask] writes: I have noticed a trend with our ENIG PCBs where Nickel is growing beyond the Copper and onto the FR4 and Soldermask. I would like to know: * Is it a cause for concern with our assembly process? If the growth causes solder bridges, yes, it will affect assembly * Is it a cause for concern for the end user? Again, if the growth violates minimum spacing requirements. Also, if the extraneous nickel does not have good adhesion, it could fracture off the board and cause shorts at another location. * How is it caused? Sounds to me like the activation process for nickel to plate on the copper pads is out of control. It is activiting insulators - laminate and mask to now plate with electroless nickel. * How could it be prevented? Proper operation of the preplate chemistry before the electroless nickel bath should only activate the copper pads. Denny Fritz MacDermid ************************************** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. --------------------------------------------------- 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 -----------------------------------------------------