HI Vlad - we can't open Dropbox here due to firewall restrictions so can
you have Steve G. post the pictures?

Dave Hillman
Rockwell Collins
[log in to unmask]

On Wed, Dec 9, 2015 at 4:59 PM, Vladimir Igoshev <[log in to unmask]
> wrote:

> HI everyone,
>
> I'm attaching a link to a file showing something I'd appreciate your
> thoughts on. It's a cross-section of a QFN on an IAg board;
> Pb-free/no-clean process. As you can see from the EDS spectrum, that
> greyish stuff between pins has pretty much only Sn and O in its elemental
> composition.
>
> I know there is burn flux residue around solder joints but that stuff
> doesn't have any C in it. The question I have is what is it.
>
> I spoke to Bev and both of us are still puzzled.
>
> Here is the link:
> https://www.dropbox.com/s/3wbj62vqjyhvj2y/What%20else%20it%20can%20be.pdf?dl=0
>
> Thank you very much in advance.
>
> Regards,
>
> Vladimir
>
> SENTEC
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________