Issue link: https://resources.pcb.cadence.com/i/1532922
We can now use this Spacing Constraint Set to apply it to our Net Class-to-Class spacing, CLS1_DIFF to CLS1_DIFF. Navigate back to the Net Class-Class > All Layers worksheet. Then choose our newly created SCS2_DIFFDIFF constraint set and apply it as shown below. Now our differential pairs can get as close as 20 mils to other differential pairs within the same class (ruled by SCS2_ DIFFDIFF), while all other objects that are not within that differential pair Net Class will have to be at least 60 mils away from any differential pair (ruled by SCS_DIFF). Then of course if we need to tighten or loosen the constraint (say 10 mil spacing instead of 20, we can do that in one location instead of many). Constraint Region For our constraint region, we created a BGA_SPACE spacing constraint for BGA areas. Then we applied that constraint to the BGA region. 63 www.cadence.com OrCAD X Constraint Management Guide