George,

I do not know if this will apply to your situation but we have found
that if a fiducial is in a very isolated location on a board that it will
naturally pick up excessive plating during electroplating.  The
increased profile combined with the small surface area of the
feature will make it susceptible to being knocked of the board
during processing.  The solution is to add a  non-functional copper
to the area to balance the electroplated copper distribution.

Regards
John Parsons
Circuit Graphics Ltd.


> Hello, Everyone,
>
> Now we have met one problem in process that we found there are fiducially mark missing in final QC. while we didn't find undercut by microsection. Some guy have advised there maybe caused by rework in HASL, is it reasonable and why? can anybody help me?
>
> George Chu
> Quality Dept.
> Phone: ++86 512 5651961 ext.6201
> Fax:   ++86 512 5613446
> Email: [log in to unmask]
>

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