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