AnsweredAssumed Answered

CAM Clearance errors

Question asked by volain on May 21, 2014
Latest reply on Jun 4, 2014 by jduquette

I'm seeing a problem with clearances in my CAM output.  I'm using PADS Layout 9.2. 

 

This is a tight board, and I've got my clearances set to 5mil.  In a number of areas of copper pour and plane (on a split/mixed layer), I get less than my required 5mil clearance in my Gerber files (in the range of 4.7 to 4.9).  When I measure the distances in layout it's right on 5mils, but my PCB manufacturer flagged the error and when I brought the Gerbers into GCPrevue (Gerber viewer) I could see the errors.  It appears ONLY around drilled pads;  surface mount pads don't seem to have any issues. 

 

I noticed that in areas where there were rounded corners in the copper the copper actually bulged a little bit.  I changed my smoothing radius for copper pour from 0.1 to 0.3 and the clearance errors went away (although there still might be a bulge).  One of the strange things is that I don't see this on all pads, just SOME of the pads.  I've got my photo plotter setup in CAM set for RS-274X, leading 2, trailing 4 and absolute coordinates.

 

Other than going in and manually tweaking the copper in the problem areas, what can I do to resolve this?

 

Thanks,

Barry

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