George,

You can feel my pain. Thanks to the forum I have a better understanding of probable causes and what the approach towards better analyses should have been.

I think I am ready to turn the knobs that will lead me towards the root cause.

BTW, we are assembling a lot of ENIG and it was pretty good for us. But now I can see why Werner said he would not recommend this finish to his high-rel customers; there's more to it than black pad.

Best regards,

Ioan Tempea, ing.
Ingénieur Principal de Fabrication / Senior Manufacturing Engineer
T | 450.967.7100 ext.244
E | [log in to unmask] 
W | www.digico.cc

N'imprimer que si nécessaire - Print only if you must


-----Message d'origine-----
De : Wenger, George M. [mailto:[log in to unmask]] 
Envoyé : October-26-11 2:34 PM
À : TechNet E-Mail Forum; Ioan Tempea
Objet : RE: [TN] Discoloration on plated over vias

Ioan,

It sounds like you've already put a lot of effort into determining what it is and still don't have a definitive answer and you probably need to spend more time determining what it is and then determining how to prevent it from happening in the future.  Once you do all that what happens when some time down the road you again see the same stains again , which is a likely possibility unless you really find the real root cause and put in place real corrective actions.  From your original email it sound like the customer  "want absolute confirmation that long term reliability is not affected".  That sounds to me like you might want to consider doing reliability testing comparing assembles with and without stains so you can confirm long term reliability.

Regards,
George
George M. Wenger
Senior Principal Reliability / FMA Engineer
Andrew Corporation - Wireless Network Solutions
40 Technology Drive, Warren, NJ 07059
(908) 546-4531 Office (732) 309-8964 Mobile
E-mail: [log in to unmask]

______________________________________________________________________
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 16.0
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
For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------