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We need to convert an extremely complex MEMs layout (DWG format) to GDSII. I can't seem to get some of the very large polygons to convert correctly.
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We need to convert an extremely complex MEMs layout (DWG format) to GDSII. I can't seem to get some of the very large polygons to convert correctly. Please advise.
Another rule when converting to GDSII, is that GDSII polygons were originally only meant to only handle 200 verticies. ACE has a limitation of 32k verticies for any polygon. Understanding that you are using many curves with a very low arc deviation means that many of your polygons will have a massive amount of vertices (probably exceeding 32k vertices for some polygons). It is generally not safe to have GDSII files with polygon counts over 8192 vertices (because many other GDSII tools used for mask making cannot handle such large polygons). You can control the maximum number of vertices ACE will allow per polygon by going the the ACE Preferences dialog (menu: Setup | Preferences), click tab "Misc." and adjust the value for "Max Polygon Points".
To fix the conversion problem, you must "Slice" some of your large polygons to result in many smaller polygons. A crude example would be to think of a circle as a polygon containing 360 vertices (one vertex for each degree); you could cut it in half to create two half-circle polygons with 180 verticies; or cut it in quarters to create 4 quarter circle polygons with only 90 vertices. This should be done to the DXF (or in Solidworks).
Note: Please keep in mind that these geometries are very intensive & complex for conversion to GDSII. GDSII built in the 70's was never envisioned to handle these types of geometries, so tweeking of your DXF is needed in order to get it into GDSII format.
I hope you find this information helpful.
Note: We offer a conversion service that can perform these difficult DWG to GDSII conversions for you for $150/drawing (one day turnaround). Simply zip files and e-mail to [email protected]
Another rule when converting to GDSII, is that GDSII polygons were originally only meant to only handle 200 verticies. ACE has a limitation of 32k verticies for any polygon. Understanding that you are using many curves with a very low arc deviation means that many of your polygons will have a massive amount of vertices (probably exceeding 32k vertices for some polygons). It is generally not safe to have GDSII files with polygon counts over 8192 vertices (because many other GDSII tools used for mask making cannot handle such large polygons). You can control the maximum number of vertices ACE will allow per polygon by going the the ACE Preferences dialog (menu: Setup | Preferences), click tab "Misc." and adjust the value for "Max Polygon Points".
To fix the conversion problem, you must "Slice" some of your large polygons to result in many smaller polygons. A crude example would be to think of a circle as a polygon containing 360 vertices (one vertex for each degree); you could cut it in half to create two half-circle polygons with 180 verticies; or cut it in quarters to create 4 quarter circle polygons with only 90 vertices. This should be done to the DXF (or in Solidworks).
Note: Please keep in mind that these geometries are very intensive & complex for conversion to GDSII. GDSII built in the 70's was never envisioned to handle these types of geometries, so tweeking of your DXF is needed in order to get it into GDSII format.
I hope you find this information helpful.
Note: We offer a conversion service that can perform these difficult DWG to GDSII conversions for you for $150/drawing (one day turnaround). Simply zip files and e-mail to [email protected]
Numerical Support Team