Hi, Shahed,
If your BGA's are on a reasonably large board (over 6 inches, say), and
located somewhere well away from the corner fiducial marks, then Yes, local
fiducial marks are a very good idea to ensure proper registration of balls
to lands. You can get away with one additional fiducial mark close to the
BGA location, if a second fiducial mark is nearby, but if not, I recommend
two. As with the board fiducials, the local fiducials should be sited at
opposite corners, but of the component footprint.
Pete Duncan
"Safavi-Bayat
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Sent by: Subject: [TN] Fiducials
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05/09/01
10:58 PM
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Hi everyone
My question is for BGAs how many fiducials we need to use?
Is it one fiducial enough ? Or do wee need fiducial at all?
Any feed back appreciated
Shahed
--
Shahed Safavi-Bayat
PCB Designer, C.I.D.
Harris, Microwave Communication Division
3 Hotel de Ville, Dollard-Des-Ormeaux, QUE, H9B 3G4 Canada
Phone: (514)822-2121/Fax: (514)421-4222
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