Question

Is there a function within OrCAD Layout that I can use to find double hit via’s or overlapping via’s?

 

Solution

The via/pin spacing rules change depending on the relative position of the pads. When the via/pin is close to or slightly overlapping the pad, then the Same Net Spacing - Via to Pin constraint is used. As soon as the via/pin is moved close enough that the connect point of the via/pin is within the boundary of the pad shape then the Same Net Spacing constraints do _not_ apply and the physical Pad-Pad Connect constraint is used.

 The image that follows show the overlapping pads to the right that are constrained by the Physical constraint Pad to Pad Connect. The overlapping pins to the right with the DRC marker are constrained by the Same Net Spacing constraint via to via.

 

 

 

If the vias are in the exact same location then the system can detect these as redundant vias. 

  1. Select Check > Database Check.
  2. Select the desired check boxes on the form then click the Check button.
    Redundant vias are removed and reported in the log file. Note: if the vias are very close they are not considered redundant.

If you do not want to allow vias to overlap then you can set the physical constraint for pad to pad direct connect. With this constraint set and enabled you will see a DRC marker on vias that are very close but not exactly on top of each other.

This setting is available in Constraint Manager under the physical domain which is located on the right side of the worksheet under Allow Pad-Pad Connect.