[SI-LIST] Re: Fixing a black pad

Hello Bill,
Thanks for the response. The pad finishing was ENIG and the BGA have
SnPb solder balls. I saw the Black pad only after removing the BGA
components that was mounted more then a year ago (due to
disconnections). Is it possible that it is not a real black pad but too
low reflow temp in this components (partially could soldering) causing
to oxidation of the Ni?

Thanks,
Gil 

-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
On Behalf Of Bill Wurst
Sent: Tuesday, June 28, 2005 2:46 PM
To: si-list
Subject: [SI-LIST] Re: Fixing a black pad

Gil,

I'm wondering if the black pad is silver (Ag) oxide.  Have you recently
switched to lead (Pb) free processing?  Or worse, has your BGA vendor
begun to supply you with lead free parts without your knowledge? 
Unfortunately, I'm not very knowledgeable when it comes to silver solder
processes, but would like to hear from anyone else with more knowledge
than I in this area.  We may all need to learn about this quickly as the
electronics industry makes the lead-free transition.

     -Bill


       /************************************
      /         billw@xxxxxxxxxxx         /
     /                                   /
    / Advanced Electronic Concepts, LLC /
   /           www.aec-lab.com         /
   ************************************
=========================================================
Zilber Gil wrote:
> Hello all,
> After removing a BGA components a black pads was seen on some of the 
> pads. Is it possible to fix it? If trying to use activated flux it is 
> possible to coat the pad with solder (receive back the wetting). Does 
> the black pad phenomenon will appear again on this pad (will I 
> encounter it later on other pads?)?
> 
>  
> 
> Thanks,
> 
> Gil Zilber
> 
> Elta systems
> 
> 
> 
> 
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 The information contained in this communication is proprietary to Israel 
Aircraft Industries Ltd. 
and/or third parties, may contain confidential or privileged information, and 
is intended only for 
the use of the intended addressee thereof. If you are not the intended 
addressee, please be aware 
that any use, disclosure, distribution and/or copying of this communication is 
strictly prohibited.
If you receive this communication in error, please notify the sender 
immediately and delete it from 
your computer. Thank you. 


This message is processed by the PrivaWall Email Security Server. 



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