DRC width check of mitered lines

activcirk

Is it possible to check the width of a mitered bend? For example a 6 um line with a mitered bend should fail DRC with a 5 um min linewidth because the miter produces a region where the distance from the inner corner to the miter is < 5 um.

This is the line that I am using that does not fail:
metal1.width(5.um, projection, angle_limit(45)).output("9-1, 9-2", "Min Met1 Width: 5 um")

The third image from the top of this page shows an example of a mitered bend: http://www.microwaves101.com/encyclopedias/mitered-bends

Thanks so much for this forum and software!

Matthias

Hi,

thanks :-)

Regarding your problem the plain width check will work:

metal.width(5.um).output(...)

The rule you sketched uses "projection" and "angle_limit" and this will disable the width check on the miter in two ways:

• First the projection constraint will only check the parts of two edges against each other, where the edges mutually project on each other. Consider two edges A and B, then B will be projected on A which selects a part of A. When A will be projected on B which selects a part of B. The width check then will be constrained to these two parts and depending on the original edges configuration, the selected parts may be too far away from each other to render a width violation.
• angle_limit(45) will basically constrain the check to parallel edges. This specification means to exclude edge pairs from the check where the edges enclose an angle of 45 and more. This leaves only parallel edges. So the 45 degree miter edge does not participate at since there is no parallel edge. To make the miter edge participate, use "angle_constraint(46)" for example.

Matthias