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Fiducial mark

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Jaya

#36156

Fiducial mark | 17 August, 2005

Hi There, I'm Jaya, would like to understand in details about global fiducial mark.Can anyone share with me or either give me some reading material about this..

regards Jaya

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DannyJ

#36160

Fiducial mark | 17 August, 2005

Hi Jaya,

Here's a definition, towards the bottom of the listing...

http://en.wikipedia.org/wiki/Fiducial

Mainly, a 'global' fiducial refers to the outside of the board, usually on the scrap rails. This allows the machine to locate two reference points that are programmed beforehand and uses these reference points to indicate any 'skewing' or angle that the board may be sitting. Then, the machine will calculate all the placements, including any discrepencies to rotation.

Having programmed various machines with different panels, I always like to see 'global' fiducials on the scrap, then 'board' fiducials for any boards within a panelized PCB and then 'local' fiducials, for very difficult to place parts, such as large, fine pitched QFPs.

The terminology may differ from job to job, designer to designer and program to program, but I hope this is enough for you to get started.

Dan

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#36173

Fiducial mark | 18 August, 2005

Search for this posting "Component Location Related to Fiducial Marks" from 9/06/04 by Joe O.B.

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Jaya

#36199

Fiducial mark | 20 August, 2005

HI Darby & Danny. Thank YOu. I have got the information. With your help,I u'stand and start asking my supplier to run the boards with glb fid's which also accept by Customer.

regards Jaya.

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