A lot will depend on your Pick and Place equipment.
Most seem to work well with 1mm diameter copper with 3mm square soldermask
relief.
Remember to make sure there are no features beneath the fudicial area
(unobstructed light needs to get through).
Talk to your assembly people (it helps).
Hope it helps
FNK

Frank N Kimmey, C.I.D.
EM Designer
C&K Systems, Inc.
916-353-5366
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> ----------
> From:
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> Reply To:     TechNet E-Mail Forum.;[log in to unmask]
> Sent:         Thursday, July 01, 1999 5:20 AM
> To:   [log in to unmask]
> Subject:      [TN] FIDUCIAL SURVEY
>
> To all,
>
> What is the recommended size and shape of a fiducial?
> I believe I.P.C. recommends 0.040" round.
>
> What are your thoughts?
>
> Frustrated
>