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Date: | Thu, 31 Oct 1996 11:54:09 -0500 |
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Greg,
Here is one problem I was aware of..
Layer 1 and layer 2 both have seperate, and sometimes different aperture
lists in X-Gerber (RS-274X).
Layer 1 defines D16 as a .010 round.
Layer 2 defines D16 as a .015 round.
The boards shop reads Layer 1 into CAM, then reads Layer 2 into CAM.
Issue: What is D16 defined as?
In my experience, if you printed Layer 1 as it is in CAM right now, the
D16 traces would all be plotted as .015 lines, not .010 lines.
Some / most CAM tools flag this problem, but still require the operator
to make a choice.
Some time you should see a ground plane "filled" with a "80-60-15-4"
thermal instead of a .005" round.
There are draw backs to both standard and X-gerber. I prefer the
X-Gerber, but still include the aperature.txt file, (or files) as if it
were not X-Gerber.
--
George Franck Jr
Raytheon E-Systems
Product Assurance Engineer
Falls Church Va
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