You may want to space differential pairs in a manner that is different from the tradition via to via spacing used by Constraint Manager. PCB Editor 17.2, with hotfix S025 provides a methodology you can use to setup a spacing constraint set (SCS) for differential pairs. The screen image below shows tradition via spacing.


To setup smaller via to via spacing complete the steps that follow.

  1. Open the Spacing Domain Spacing Constraint Set/All Layers worksheet and create a new spacing constraint set. In this example, we enter the name DP_5MIL_V2V_SPACE.

  2. For the new SCS double click the Thru Via to << and change the constraint for the Thru Via To > Thru Via value. The screen image that follows, for example, shows the entry of 6 mils.

  3. Open the Physical worksheet and select the Physical Constraint Set > Net All Layers. Assign the SCSet to the differential pair in the Referenced Intra-DP Spacing CSet column.

  4. Route a differential pair using Edit > Add Connect. Select Via Pattern > Spacing from your right mouse pop-up menu.

  5. Select the Minimum radio button and then click the OK button.

    When you add your vias they will be at the spacing value set in the new spacing constraint set.