Copper Layer Order

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DipWhitt
Posts: 53
Joined: 20 Mar 2018, 13:27

Copper Layer Order

#1 Post by DipWhitt » 26 Feb 2021, 17:14

I have a board with 4 copper layers that I want to have in the following order:

Signal 1
GND
+3.3V
Signal 2

I looked and found 3 places to try to set my order but none worked for me.
The water fall up and down arrows took me for a loop. I could not manage to do much with it.

I appreciate any help. It has been a long time since I used Dip trace.

PCB attached.
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Tomg
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Posts: 1737
Joined: 20 Jun 2015, 14:39

Re: Copper Layer Order

#2 Post by Tomg » 26 Feb 2021, 23:37

1) Make the "Signal 1" layer the working layer, select/highlight all of its traces, right-click on one of those selected/highlighted traces, choose "Trace Layer" in the context menu and then choose "GND" in the flyout menu. This will move those traces up to the "GND" layer.

2) Make the "GND" layer the working layer, right-click on the edge/border of its copper pour, choose "Change Layer" in the context menu, choose "Signal 1" in the fly-out menu and update all copper pours. This will move the "GND" copper pour to the "Signal 1" layer.

3) Under the [Signal/Plane] tab of the Layers dialog window (main menu: Route > Layer Setup...), swap the names of the "Signal 1" and "GND" layers by renaming them in the Name: entry box and, finally, click on the [Close] button.

By the way, you still have custom thermal settings for your mounting pads which forces them to connect to all copper pours. This can lead to trouble. If you add a power supply pour in another layer it will result in that power supply net being shorted to the GND net, making your brand new board useless.
Tom

DipWhitt
Posts: 53
Joined: 20 Mar 2018, 13:27

Re: Copper Layer Order

#3 Post by DipWhitt » 27 Feb 2021, 11:26

Yeah, I see that but so far I haven't found a way to have the GND connected to just the ground plane and the +3.3V just connected to the +3.3V plane.

Tomg
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Posts: 1737
Joined: 20 Jun 2015, 14:39

Re: Copper Layer Order

#4 Post by Tomg » 27 Feb 2021, 12:48

cpc.png
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Tom

DipWhitt
Posts: 53
Joined: 20 Mar 2018, 13:27

Re: Copper Layer Order

#5 Post by DipWhitt » 28 Feb 2021, 10:53

Tomg
I think all of the pours are good now but the auto router can't even come close to routing it.
Obviously, I am missing something.

Tomg
Expert
Posts: 1737
Joined: 20 Jun 2015, 14:39

Re: Copper Layer Order

#6 Post by Tomg » 28 Feb 2021, 14:16

The Top layer's type is "Plane". This prevents the autorouter from doing anything there.
Under the [Signal/Plane] tab of the Layers dialog window (main menu: Route > Layer Setup...), change the "Signal 1" Layer Type: to "Signal", the "GND" Layer Type: to "Plane" and click on the [Close] button. This should allow the autorouter to route on the "Signal 1" layer. Don't forget to update all copper pours after the autorouter has finished.
Tom

DipWhitt
Posts: 53
Joined: 20 Mar 2018, 13:27

Re: Copper Layer Order

#7 Post by DipWhitt » 01 Mar 2021, 09:16

Thanks! I'll go put my Dunce Cap on now.

DipWhitt
Posts: 53
Joined: 20 Mar 2018, 13:27

Re: Copper Layer Order

#8 Post by DipWhitt » 01 Mar 2021, 13:57

Tom it looks like everything is fine, but I did Verifying\Check Net Connectivity with traces, nets, and pours checked. It said +3.3V and ground are merged and to run DRC for details. So I ran DRC Design Rules and it finds no errors. So if there is truly an error, how do I find it.

Tomg
Expert
Posts: 1737
Joined: 20 Jun 2015, 14:39

Re: Copper Layer Order

#9 Post by Tomg » 01 Mar 2021, 22:27

1) Set Layer Display Mode to "Current Only" (main menu: View > Layer Display > Current Only).
2) Update all copper pours.
3) Run the DRC verification test.
4) Cycle through each layer individually using keys 1, 2, 3 and 4 while looking for any tell-tale red circles showing the location of errors.

Let me know if you find anything. For example, you might see some DRC errors like this one...
le.png
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Tom

DipWhitt
Posts: 53
Joined: 20 Mar 2018, 13:27

Re: Copper Layer Order

#10 Post by DipWhitt » 02 Mar 2021, 11:54

Tom,
There are four traces which are locked on the top side of the board. These traces have the same exact same length
and will be adjusted to maintain 100 ohm characteristic impedance (which I wonder if Dip trace supports?)

So starting from un poured planes and the four locked traces, here are my steps:

1. Route - Run Auto-router
2. Perform copper pour
3.Type keys 1,2,3,4
4. Looks good to my untrained eyes. No Red Circles.
5. I see the word Verification on the top of the screen.
6. I click it and compare to schematic and found no errors.
7. I click verification again and then net connectivity - check only copper pours.
I get a boat load of broken nets (no circles).
8. I click verification - check design rules and get nothing.

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