topic Re: Stub detection and how to remove a stub below a fatter trace on same layer in Fusion Electronics Forum

Stub detection and how to remove a stub below a fatter trace on same layer

mjstn2011 — Fri, 29 Aug 2025 05:33:38 GMT

For some reason the normal detection that runs all the time for 2D pcb catches most things but it seems that I have to specifically run a DRC check from the menu for it to then all at once detect what may be a great many little stubs. Why does it not seem to check for stubs in the normal run-all-the-time DRC check? This may be a feature to prevent loading or something?

Part 2: I am removing part 2 because I found right click then use 'Select' allows finding other traces such as a tiny trace that I was having trouble removing this tiny stub that was smaller than another same layer trace.

As always, thank you for your assist on this forum.

Re: Stub detection and how to remove a stub below a fatter trace on same layer

jorge_garcia — Fri, 29 Aug 2025 20:20:38 GMT

Hi @mjstn2011 ,

I hope you're doing well. This is unexpected, the live DRC should be catching the stubs. Have you adjusted the stub rule at all? If you can post a picture with an example that would help.

Let me know if there's anything else I can do for you.

Best Regards,

Re: Stub detection and how to remove a stub below a fatter trace on same layer

mjstn2011 — Mon, 08 Sep 2025 06:25:09 GMT

@jorge_garcia I keep hitting the issue where unless I manually run the DRC I miss several stubs that are usually due to adding fatter traces and the little left over stubs are still present but not detected as Wire stubs till I do a manual DRC check which is not as freqent so they pile up.

I attach one specific Wire Stub. If I remove the cross-hatched stub the DRC fault goes away but these are clearly missed in ongoing active DRC checks.

I hope this helps your team. I know to run manual DRC to catch these but you mentioned it should be caught in the automatic background DRC.

I show a few views highlighting different traces. Yes I know this is a bit messy but it has shown this 'minor' issue that needs attention for background DRC checks.

Thanks, Mark

Re: Stub detection and how to remove a stub below a fatter trace on same layer

mjstn2011 — Mon, 08 Sep 2025 06:29:32 GMT

I meant to show one other involved trace so I re-post same picture but right hand of the 3 is updated now. May help.

Re: Stub detection and how to remove a stub below a fatter trace on same layer

jorge_garcia — Mon, 08 Sep 2025 19:25:22 GMT

Hello @mjstn2011 ,

I think the difference here is the fact that wire-stubs raise warnings and not errors. Warnings don't necessarily need to be corrected, they are things that are not what Fusion expects but can be OK. That's why the live DRC doesn't flag them.

I'm going to reach out to our developers on if we always treat stubs as warnings, I feel like i've seen them reported as errors before but I could be wrong on that. Stubs can lead to noise issues if they go nowhere (they behave like an antenna) but in this case they are all overlapping each other on the finished PCB the copper shape will be the filled contour of all these shapes.

For the examples you've given, they would not affect the function or performance of the PCB so you could leave them be if you are so inclined.

Let me know if there's anything else I can do for you.

Best Regards,