Phantom GND trace in the middle of GND pour

Making PCB Layouts, Manual routing, Auto-routing, Copper pouring, Updating from Schematic, Manufacturing Output
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Zhenek
Posts: 7
Joined: 14 Nov 2018, 07:48

Phantom GND trace in the middle of GND pour

#1 Post by Zhenek » 18 Nov 2019, 12:24

I've encountered this weird bug (at least I think it's a bug). Programs thinks, there's a GND trance connecting pins all over the board, despite copper pour which is also connected to ground.
DTBUG.png
Because of that one trace is cut by a couple of vias, in order not to cross this GND trace. If i bring this trace to bottom level and re-apply copper pouring, program draws this GND trace on top of this trace, and of course DRC check is failed.
I finally unrouted this particular segment, and it worked.
DTBUG2.png
But I wonder why does autorouter keeps these phantom traces? This problem also makes extra connections of pads to GND copper. I make a setting "4 spoke 45", but extra and thick ones are added, see below
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Tomg
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Joined: 20 Jun 2015, 14:39

Re: Phantom GND trace in the middle of GND pour

#2 Post by Tomg » 18 Nov 2019, 16:43

Did you route the GND net before assigning the pour to the GND net?
Tom

Zhenek
Posts: 7
Joined: 14 Nov 2018, 07:48

Re: Phantom GND trace in the middle of GND pour

#3 Post by Zhenek » 19 Nov 2019, 00:26

TomG, this GND trace has been created by autorouter.

Tomg
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Joined: 20 Jun 2015, 14:39

Re: Phantom GND trace in the middle of GND pour

#4 Post by Tomg » 19 Nov 2019, 09:36

The only thing that comes to mind is that the autorouter was run before the copper pour was assigned to the GND net and updated. Try this to see if it clears up the unnecessary GND traces...
1) In the Main Menu click on Edit and choose Edit Selection... in the drop-menu to bring up the Edit Selection dialog window.
2) In the Edit Selection dialog window choose New Selection in the Action: drop-list, only enable [x]Vias, select All in the Vias drop-list and click on OK.
3) Right-click on one of the selected vias and choose Lock Selected in the pop-up menu. This should preserve all of the vias when the next step is performed.
4) Now right-click on one of the unnecessary GND net traces and choose Unroute Net in the pop-up menu.
5) Run the Update All Copper Pours tool. (If you don't have a hotkey assigned for this, you can find the command in the Main Menu under Objects.)
6) In the Main Menu click on Edit and choose Edit Selection... in the drop-menu to bring up the Edit Selection dialog window again.
7) In the Edit Selection dialog window choose New Selection in the Action: drop-list, only enable [x]Vias, select All in the Vias drop-list and click on OK.
8) Right-click on one of the selected vias and choose Unlock Selected in the pop-up menu. This will free up all of the vias for possible future changes.
9) Run the Check Net Connectivity verification tool to check for possible problems.
Tom

Zhenek
Posts: 7
Joined: 14 Nov 2018, 07:48

Re: Phantom GND trace in the middle of GND pour

#5 Post by Zhenek » 19 Nov 2019, 12:19

Tomg, thanks, it worked!
You mentioned, that the reason is that I've run autorouter before adding copper pour. I really did that, should these actions be reversed? First add pour (it will obviously cover all board), and then start autorouter?

Tomg
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Posts: 1403
Joined: 20 Jun 2015, 14:39

Re: Phantom GND trace in the middle of GND pour

#6 Post by Tomg » 19 Nov 2019, 12:39

Zhenek wrote:
19 Nov 2019, 12:19
You mentioned, that the reason is that I've run autorouter before adding copper pour. I really did that, should these actions be reversed? First add pour (it will obviously cover all board), and then start autorouter?
That is what I would recommend. After adding the copper pour, but before running the autorouter, assign the pour to the GND net and run the Update All Copper Pours tool. After running the autorouter, run the Update All Copper Pours tool, again. This is where it is beneficial to have hotkeys assigned to update/unpour copper pours.

p.s. If you find that the autorouter is unable to find its way through the copper pour, temporarily unpour the copper pour (don't delete it), run the autorouter and then repour/update the copper pour.
Tom

Zhenek
Posts: 7
Joined: 14 Nov 2018, 07:48

Re: Phantom GND trace in the middle of GND pour

#7 Post by Zhenek » 19 Nov 2019, 15:01

Thanks, Tomg!

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