How to measure width or spacing of 45 degree edges with more tolerance than orthogonal edges.

Document created by chris_balcom on Jun 26, 2012
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Sometimes 45 degree edges fail width and spacing checks while orthogonal edges pass as expected even though spacing or width seems to be the same in both cases.


It can be more difficult to make precise measurements on 45 degree angle polygon edges because of natural rounding errors. One way to take this into consideration during DRC checking is to add a DRC TOLERANCE FACTOR statement to the rule file.


DRC TOLERANCE FACTOR checks only those relationships that involve non-orthogonal edges. In other words, for any two edges being measured, where either one is skew or 45 degree with respect to the coordinate axes, the measurement constraint value is decreased by the given tolerance prior to the actual measurement. For example:





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