Shahed - I'm not trying to be vague, but how many fiducials you need depends on the placement equipment, and whether you are using standard 50-mil pitch, micro BGA's, or whatever. For most equipment you need two or three board fiducials. Now, whether or not you also need component fiducials depends again on the lead (ball) pitch of the BGA's in question, the board size, and your placement equipment. One fiducial is not enough, and yes you should have fiducials.

My best suggestion is for you to talk with the Manufacturing/Process Engineer for the placement equipment that will be used to assemble your boards and follow his/her recommendations.

Ed Valentine
Electronics Manufacturing Solutions
8612 Mourning Dove Road, Raleigh, NC 27615
Phone: (919) 270-5145, Fax: (919) 847-9971
Email: [log in to unmask]
Website: http://www.ems-consulting.com

----- Original Message -----

From: [log in to unmask] href="mailto:[log in to unmask]">Safavi-Bayat,Shahed

To: [log in to unmask] href="mailto:[log in to unmask]">[log in to unmask]

Sent: Wednesday, May 09, 2001 10:58 AM

Subject: [TN] Fiducials

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
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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