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| Reply To: | TechNet E-Mail Forum. |
| Date: | Wed, 5 Sep 2001 14:01:13 -0700 |
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Wow,
Does the board shop purchase their laminate by peel strength. For fine features we use a low
profile copper, which of course has lower peel. Here you may have copper left behind from a
very large copper tooth structure. If the gold is electrolytic (amazing how often we write
about that recently) the plating will grow faster on the high current density points.
If print and etch copper, not a pattern plate job, then there may have been resist residue
that protected copper at the foot of the trace (inadequate development). If this is the case
you would see this on the traces under the mask.
Cross section will tell you the most.
Chuck Brummer
Acuson
"Busko, Wolfgang" wrote:
> Hi all,
>
> I got some new pictures on Steveīs page
> http://stevezeva.homestead.com/index.html
> <http://stevezeva.homestead.com/index.html> .
> They show an interesting phenomenom that obviously occurred during Ni/Au
> plating.
> These "pimples" and "pumples" at the base of the metallic structure right on
> the FR4 surface that surround the pads look like miserable paintwork, yanno,
> like if you paint your windowframes yourself.
> Has anybody seen something similar before and what could have caused that
> and what would you think would be the risk if we use those boards.
>
> We have to come to a quick decision and canīt afford to wait for a
> laboratory result.
>
> Thanks in advance
>
> Wolfgang
>
>
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