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The 16.5 PCB SI product’s rectangular mesh scheme is used for shapes, cutouts, slots, anti-pads and voids within shapes. The mesh cell size you pre-specify is the maximum cell size ,and the system will automatically adjust/reduce the cell size if necessary. You can ignore the meshing for anti-pads and small shapes/voids through the Preferences settings.
Read on for more details …
All analysis functionality is available on the main PDN Analysis GUI:
In the mesh dialog, there is a brief description for meshing and all functions:
Selecting the Preferences button brings up the Preferences form:
The General tab sets many of the default values. The Simulation tab sets the frequency range and maximum number of points for frequency-domain analysis, duration time, and time step for time-domain analysis. The top section of the Field Solver tab contains the settings for mesh generation:
The Mesh settings are one area of settings where a tradeoff between accuracy and performance is set. The default settings are for a Regular mesh with all voids in shapes included in the mesh. If you select the Ignore option from the following drop-down list, then all anti-pads of vias/pins will be ignored during the meshing. If you select the Include option, then all anti-pads of vias/pins will be meshed exactly:
You can ignore small island shapes or small voids by specifying a value for Ignore all shapes/voids less than:
This value is a scale factor of the maximum mesh cell size you specified (fine, regular or coarse or custom size). Start the mesh by selecting the Mesh button on the Power/Ground Plane Meshing form:
Once the meshing is started, you will see a progress dialog appear and then the PDN Audit Results:
Depending on your layer settings or specific design configuration, you may not see any mesh displayed in your design:
To aid in reviewing any PDN results including mesh generation, it is recommended that you pin the Options and Visibility fold out window panes in the PCB SI canvas:
The Options panel displays the type of analysis run and allows you to cross probe to the canvas and select the layer to review. Use the Review pull-down in the Options panel to review a specific layer of interest in the design. Select the mesh in the canvas to see the net name appear in the Options panel:
Please share your experiences using this new 16.5 capability.
Jerry "GenPart" Grzenia