Adding Backdrills

Unused portions of vias (known as "stubs") can create significant signal integrity disturbances. Backdrilling is a technique that removes these stubs.

To add a backdrill in SI Xplorer:

1. Insert a via configuration.
2. From the Via Wizard, click a port or padstack in the diagram to select it.
3. Click Edit PS Instance.

   The Padstack Usage and Definition window appears.

   

4. Use the options in the Backdrill area to define a backdrill:
   • Top – use the drop-down menu to select the depth of the backdrill from the top layer.
   • Bottom – use the drop-down menu to select the depth of the backdrill from the bottom layer.
   • Diameter – for either top or bottom, specify the backdrill's diameter.

   The Cross Section View and Top View areas update to display the backdrill.

   

5. Click OK.