I was making a modification to an existing PCB taking it from Rev D to Rev E. I had to change the connections on two resistors. I accidentally switched the pads on the resistors in the schematic when I rotated the resistor on the schematic. Then I updated the PCB with the schematic changes. The signals were connected to wrong side of the resistor in the PCB but looked correct since a resistor is a non-polarized part. The DRC indicated there was a problem with a clearance violation and I traced it to this problem. I went back to the schematic and rotated the resistor twice to switch the pad connections, saved it, updated the PCB and the DRC violation went away. There didn’t seem to be any reference to this root cause of the clearance violation so I thought I would post it.
Of course, when you switch around the connections in the schematic, and update the pcb now the tracks that are connected to the part have the wrong signals on them, making the drc trigger a violation, a clearance violation in that case, as a pad with signal “A” now is directly on top of a track with signal “B”. Completely normal and expected behavior.
Post was purely informational to list another possible root cause for a clearance violation error. I just thought the error was misleading because it was a connection error and not a clearance error. Thanks for the tip on using the “ratsnest display”. I’ll give that a try next time.
DRC is not smart enough to know that you caused the situation by reversing the footprint. As far as it’s concerned, the track is too close to something it shouldn’t be connected to.