Board Setup - What do the 'Signal', 'Mixed', 'Powerplane' and 'Jumper' options entail?


Chemistry student here and new to Kicad.

I have tried to route a 2 layer board that was seemingly to dense, therefore I have decided to go down the 4-layer route.

Could someone please explain or provide some information/documentation on the ramifications of choosing these ‘Signal’, ‘Mixed’, ‘Powerplane’ and ‘Jumper’ options?

My thoughts that signal entails digital/logic signals tracks/traces only. ‘Mixed’ probably means both digital signals, power, and ground signals. Powerplane is for power pour layer, but probably also ground pour layer. No thoughts on what jumper could mean, maybe some smart routing option.

Any help would be greatly appreciated!

Welcome SGB,

Help/PCBnew manual/5.3 Layer description/5.3.1 Copper layers.

As the notes say “useful for freerouter” , but use them for whatever you wish.
I don’t recommend trying to place components on the middle layers :grinning:



Yea I read this as well, I would like to use the Freerouter to establish some of the traces (I have a 1000 connections) after manually failing twice on two layers. Would just like to be sure of the implications of the choices.

Haha yea, I’ll “try” not to place components on the middle layers :wink:

Totally oftopic, but as you brought it up and curiosity got the better part of me…
How come a chemistry student is routing such a board? :slight_smile:
When I went to Uni we had chemistry students in the experimental physics lectures at the start, but not in the electronics courses later on.

Pure interest… and having no sense of what I was getting myself into :upside_down_face:

You do not have to worry about placing footprints on internal layers in KiCad for the moment. KiCad does not support this. There have been several requests for making this possible though, and those requests are completely valid, so it is likely that some future version of KiCad will allow you to place footprints on internal layers. An example for this is a combined Flex / Ridgid PCB where the layers do not all have the same size and the PCB also does not have a uniform thickness.

As to the original question…

To the best of my knowledge KiCad does not do anything with this information itself. It may be a hint to external software such as Freerouter, but that is not a part of KiCad itself, and therefore not supported by KiCad People.

I also did a search through the official documentation on:
(You also have a copy of these files on your PC if you installed documentation).

It may have been that it is part of some partially implemented feature. Maybe this part was implemented, and then design of KiCad took another direction and nobody bothered to remove those comboboxes. Maybe it is part of some feature that is planned to be implemented but development is “temporarily diverted” to other more pressing parts, such as getting KiCad V6 ready for release.

With the knowledge of KiCad I currently have I can not find a valid use for setting those boxes. I am not aware of any change in the behavior of KiCad for changing those layer settings.

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I haven’t experimented with this yet myself, but are these layer function descriptions used in the gerber job file output?

If you go to: Pcbnew / File / Board Setup / Layers there is a drop-down box for each copper layer with these settings:

[Oops], I may have misinterpreted this. I assumed the question was were these settings come from, while it may have been if these settings end up in the Gerber Job file after you set them in Board Setup…

[Edit] I just generated a quick set of gerbers, opened the Blabla-job.gbrjob file generated by KiCad-nightly V5.99 in a text editor and it could not find any of those magic words.
Same for the Blabla-F_Cu.gbr file. So it’s still a mystery to me.

Or, a bit more elaborate (and quicker too)
In short: No output from “grep” means it did not find anything worth mentioning in the files searched.

paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599/gerber$ ls -hl
total 216K
-rw-rw-r-- 1 paul paul 1,5K Mar 11 20:14 LED_PT4115-B_Cu.gbr
-rw-rw-r-- 1 paul paul  923 Mar 11 20:14 LED_PT4115-B_Mask.gbr
-rw-rw-r-- 1 paul paul  529 Mar 11 20:14 LED_PT4115-B_Paste.gbr
-rw-rw-r-- 1 paul paul  530 Mar 11 20:14 LED_PT4115-B_Silkscreen.gbr
-rw-rw-r-- 1 paul paul  763 Mar 11 20:14 LED_PT4115-Edge_Cuts.gbr
-rw-rw-r-- 1 paul paul  55K Mar 11 20:14 LED_PT4115-F_Cu.gbr
-rw-rw-r-- 1 paul paul 2,5K Mar 11 20:14 LED_PT4115-F_Mask.gbr
-rw-rw-r-- 1 paul paul 2,1K Mar 11 20:14 LED_PT4115-F_Paste.gbr
-rw-rw-r-- 1 paul paul  36K Mar 11 20:14 LED_PT4115-F_Silkscreen.gbr
-rw-rw-r-- 1 paul paul 2,8K Mar 11 20:14 LED_PT4115-job.gbrjob
-rw-rw-r-- 1 paul paul  92K Dec  2 15:07 LED_PT4115-User_Drawings.dxf```

paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599/gerber$ grep -in "signal" *
paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599/gerber$ grep -in "power" *
paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599/gerber$ grep -in "plane" *
paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599/gerber$ grep -in "mixed" *
paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599/gerber$ grep -in "jumper" *

More, one directory higher:
Added a “r” for recursive. “signal” is the only one that returns something, and it just mentiones this setting is saved in the .kicad_pcb file.

paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599$ ls -hl
total 212K
drwxrwxr-x 2 paul paul 4,0K Nov 23 10:54 asdf_new_Library_experiment.pretty
-rw------- 1 paul paul  341 Mar 11 20:23 fp-info-cache
-rw-rw-r-- 1 paul paul  173 Nov 22 15:21 fp-lib-table
drwxrwxr-x 2 paul paul 4,0K Mar 11 20:14 gerber
drwxrwxr-x 2 paul paul 4,0K Mar 11 20:23 LED_PT4115-backups
-rw-rw-r-- 1 paul paul  182 Dec  2 18:22 LED_PT4115.kicad_dru
-rw-rw-r-- 1 paul paul 127K Dec  2 18:35 LED_PT4115.kicad_pcb
-rw-rw-r-- 1 paul paul 1,1K Mar 11 20:23 LED_PT4115.kicad_prl
-rw-rw-r-- 1 paul paul 8,9K Mar 11 20:23 LED_PT4115.kicad_pro
-rw-rw-r-- 1 paul paul  33K Dec  2 18:35 LED_PT4115.kicad_sch
-rw-rw-r-- 1 paul paul  428 Oct 28 16:45 pt4115.lib
-rw-rw-r-- 1 paul paul  341 Nov 19 12:31 sym-lib-table

paul@medion:/home/3TB_WD_Blue/projects/kicad/LED_PT4115_599$ grep -inr "signal" *
LED_PT4115.kicad_pcb:9:    (0 "F.Cu" signal)
LED_PT4115.kicad_pcb:10:    (31 "B.Cu" signal)

Yeah, that’s what I meant. Thanx for putting the time into that, and we all learned something today. :smiley:

Do you happen to remember how to install documentation ? I had no idea that was possible until now.

I do have documentation installed, but can’t remember if I did it manually or it was just part of the stuff that KiCad installed along with itself.
If you have these installed, then the HTML version probably gets started in a web browser if you press [F1] or [Any_KiCad_Program] / Help / [Any_KiCad_Program] Manual

The help files are written in Asciidoc, and then compiled into both Html, .epub and .pdf so you can read what is most comfortable to you.

paul@medion:~$ apt search kicad
i   kicad                           - Electronic schematic and PCB design softwa
p   kicad-common                    - Old common files used by kicad - Transitio
p   kicad-dbg                       - Debug symbols for kicad                   
i   kicad-demos                     - Common files used by kicad                
p   kicad-doc-ca                    - Kicad help files (Catalan)                
p   kicad-doc-de                    - Kicad help files (German)                 
i   kicad-doc-en                    - Kicad help files (English)                
p   kicad-doc-es                    - Kicad help files (Spanish)                
p   kicad-doc-fr                    - Kicad help files (French)                 
p   kicad-doc-id                    - Kicad help files (Indonesian)             
p   kicad-doc-it                    - Kicad help files (Italian)                
p   kicad-doc-ja                    - Kicad help files (Japanese)               
p   kicad-doc-pl                    - Kicad help files (Polish)                 
p   kicad-doc-ru                    - Kicad help files (Russian)                
p   kicad-doc-zh                    - Kicad help files (Chinese)                
i A kicad-footprints                - Kicad footprints (modules)                
p   kicad-its-files                 - Its file used to build KiCad on old distro
i A kicad-libraries                 - meta-package for dep to all KiCad librarie
p   kicad-locale-bg                 - Bulgarian locale for KiCad                
p   kicad-locale-ca      

paul@medion:~$ sudo apt install kicad-doc-en
[sudo] password for paul:     
Reading package lists... Done
Building dependency tree       
Reading state information... Done
kicad-doc-en is already the newest version (5.1.9-202012230803+1687~27~ubuntu20.04.1).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

paul@medion:~$ cd /usr/share/doc/kicad/help/en
paul@medion:/usr/share/doc/kicad/help/en$ ls
cvpcb.epub       getting_started_in_kicad.epub    images                 pcbnew.pdf.gz
cvpcb.html       getting_started_in_kicad.html    kicad.epub             pl_editor.epub
cvpcb.pdf.gz     getting_started_in_kicad.pdf.gz  kicad.html             pl_editor.html
eeschema.epub    gui_translation_howto.epub       kicad.pdf.gz           pl_editor.pdf.gz
eeschema.html    gui_translation_howto.html       pcb_calculator.epub    plugins.epub
eeschema.pdf.gz  gui_translation_howto.pdf.gz     pcb_calculator.html    plugins.html
gerbview.epub    idf_exporter.epub                pcb_calculator.pdf.gz  plugins.pdf.gz
gerbview.html    idf_exporter.html                pcbnew.epub
gerbview.pdf.gz  idf_exporter.pdf.gz              pcbnew.html

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Thank you, Paul, that worked splendidly to install 28 MB of documentation at /usr/share/doc/kicad under /help/en

The F1 key pops up the html from main kicad just as you explained.
eeschema and pcbnew also pop up the html in the manner you described.

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