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Date: | Mon, 14 Oct 96 15:20:00 CDT |
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John,
Two fiducials are required for correcting both the X-Y position and the
Theta position in the auto-placement machine. However, most theta error can
be corrected by the global fiducials. Thus, you only need single fiducial
to correct the X-Y position for your fine pitch devices.
Hope This Helps
Michael Yuen
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From: TechNet-request
To: technet
Subject: ASSY: Fiducials
Date: Monday, October 14, 1996 9:11AM
Address,
From past design reviews we have always used 2 fiducials per 15mil and
20mil SMT devices (my opinion, standard). Recently our designers are
placing 1 fiducial in the center of the device location. I'm not an
agreement with this change due to possible lead skew on pads and
similar problems. Has visual P&P equipment changed such, that 2
fiducials are no longer required or none at all. Please advise.
John Gulley
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