l'oeil est fraudé ? Peut-être. I believe something is bleeding out from the
adjacent components. Check if there are any more sites with exactly the same
parts, but with no discoloration. If the answer is negative, I think even
stronger, that the issue is connected with the two packages.

seulement une proposition

Inge




On 21 October 2011 22:26, Ioan Tempea <[log in to unmask]> wrote:

> Dear Technos and Smarts,
>
>
>
> I got this issue, see http://ipc-technet.groupsite.com/gallery/21662
>
>
>
> So 6 layer, 2oz Cu per layer PCB, epoxy filled vias and plated over. After
> assembly we see 4-5 vias having reddish stains, on most boards. Had it
> analyzed, no trouble with via integrity, no cracks in cover plating, no
> migration of fluids from inside out. FTIR does not detect any surface
> contamination.
>
>
>
> Au plating thickness stands at 2.09 micro inches.
>
>
>
> Nothing special detected in the stains, so the lab concluded what we see is
> an optical effect due to a certain roughness of the Cu. The logical
> conclusion is no issue, cosmetic defect.
>
>
>
> However, our end customer, high reliability, want to know what the stains
> are and want absolute confirmation that long term reliability is not
> affected. Also, we've been warned that no such issues will be tolerated on
> future lots.
>
>
>
> My questions to your infinite knowledge is: have you seen this before? How
> can I convince the customer everything is OK? What is the root cause and how
> can I get rid of the issue?
>
>
>
> Many thanks,
>
>
>
> Ioan Tempea, ing.
> Ingénieur Principal de Fabrication / Senior Manufacturing Engineer
> T | 450.967.7100 ext.244
> E | [log in to unmask] <mailto:[log in to unmask]>
> W | www.digico.cc <http://www.digico.cc/>
>
>
>  N'imprimer que si nécessaire - Print only if you must
>
>
>
>
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