Guenter

Unfortunately, or rather fortunately, attachments get deleted on the net list (pity they don't eliminate HTML, at the same time!). You can either post them on a web site and give the URL so that everyone
can see them or send them in individual e-mails to those requesting them, such as myself now. From your description, I have an idea, but I prefer to see the photos before pronouncing.

Best regards

Brian

PS Did you get the e-mail I sent you a coupla weeks ago?

Guenter Grossmann wrote:

> Hi all
>
> I have a case here where I am not sure what I see.
> - There are dark spots visible below the solder mask on the surface of the traces on a PCB. I attached 2 Pictures in JPEG that show a view onto the surface of the traces with 10x and 40x magnification.
> - In microsections we see clearly a cavity between the traces and the soldermask.
> - EDX is hopeless, since the dark layer is so thin that the background covers all but the copper peak.
>
> Before I start to work with TOF SIMS, Spectroscopy and other expensive analysis methods I'd like to ask whether one of you knows what the dark spots are.
>
> Thanks in advance. Have a great day.
>
> Guenter
>
> Guenter Grossmann
> Swiss Federal Institute for Materials Testing and Research EMPA
> Centre for Reliability
> 8600 Duebendorf
> Switzerland
>
> Phone: xx41 1 823 4279
> Fax :      xx41 1823 4054
> mail:     [log in to unmask]
>
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