Grouping Vias in ECAD Xplorer

On-chip geometries are commonly fabricated using numerous small vias between signal layers which can result in highly complex geometries. Geometries can be simplified through the via grouping tool. This tool allows you to replace via regions with an equivalent wrapping polygon that has material properties representative of the grouped primitives. A demonstration of this tool is available in video and explained in the following section.

The Group Vias tool detects clusters of rectangular primitives and creates via groups accordingly. Via groups can then be combined or dissolved depending on which option is selected.

Vias can be grouped using two methods: Group by Range and Group by Proximity. Group by Range expands the new group based only on whether a potential member is separated by no more than the Tolerance from an existing member. In contrast, Group by Proximity groups vias that are a spaced similarly. Vias are not grouped if the distance between them exceeds the Tolerance.

This tool also has the Check Containment option which checks for electrical shorts by analyzing the placement of via primitives. When a short is found, this option splits the group to prevent a short.

To group vias within a design:

1. From the Simplify area of the Layout tab, click Settings to open the Geometry Simplification Settings window.

     

   1. From the Via Grouping section, select a Grouping Method:

      • Group by Proximity - groups vias by considering their spacing.
      • Group by Range - groups vias in the maximum Tolerance.
   2. Enter a Tolerance, including the units.
   3. To detect and prevent electrical shorts, enable Check Containment.
   4. Click Apply and Close.
2. Select a group of via primitives.
Note:

Via primitives can be rectangles, polygons, or lines. Only rectangular via primitives can have more than one primitive in a via group. If you want to make a via group out of polygons or lines, the group can have only one line primitive or one polygon primitive in it.

3. Choose Group Vias > option. This option is also available on the shortcut menu.
   • Persistent creates a via group and keeps the original primitives of a via group in the layout.
   • Non-Persistent creates a via group and deletes the grouped primitives.
   • Combine merges selected via groups and/or via primitives into a new via group.
   • Dissolve restores the selected via group into the primitives that comprise it.

To group vias on a specific layer, open the Layers window, right-click the layer, and select Group Vias. Choose the option you want. Only Persistent and Non-Persistent are available here.

Via groups can be assigned or reassigned to a net. Select the via group and in the Properties window, edit the net for the entire selection.