Pete: A few things to consider. 1. Even though you say the nickel is not passivated how do you know for sure that it is not? Whether you are running an automated or manual line there could be delays in transfer time between nickel activation - rinse - copper plate that could occasionally lead to passivatioin of the surface of the nickel. See if there are certain cycles or timing issues that could cause this. 2. What are you using for nickel activation chemistry? Is the time, temp, chemical concentration and bath life correct and being properly maintained? You could be on the edge of the window on one or a combination of these that causes the problem to intermittently show up. 3. Are your rinse water temps too hot causing premature drying of the part during transfer? Are they too cold causing insufficient rinsing of the previous chemistry resulting in contamination of down stream baths and on the surface of the part? 4. Is the electrolytic copper rectification working properly? Delays in applying current or insufficient or excessive current can cause adhesion problems. In the same vein high or low current density areas can result in the same type of problem. 5. Check your copper bath for excessive organics. Michael Barmuta Staff Engineer Fluke Corp. Everett WA 425-446-6076 -----Original Message----- From: Peter Nemcik [mailto:[log in to unmask]] Sent: Thursday, February 28, 2002 7:25 AM To: [log in to unmask] Subject: Re: [TN] Electroless nickel to electroplated copper separation Hi Rudy, it's the other way around: elecrolytic copper on EN, which is plated onto aluminum. Regards Pete _____ Do You Yahoo!? Yahoo! <http://greetings.yahoo.com> Greetings - Send FREE e-cards for every occasion! --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------