Questing regarding zones


#1

I understand this might not be a kicad specific question but I don’t know really where to go to ask this. If i specify that my top layer is a ground zone, can I connect things that go to ground to my layer? of course I have to connect that layer to my battery ground.

If that is possible then I have 2 questions, what do I have to do to connect my battery ground that comes in into my layer and also how do I connect let say a pin from a micro-controller to that said ground layer?


#2

If your copper zone is a ground, then when it overlaps with any pin that is also a ground - it will get connected - as long as it covers the area with battery and your micro.

Alternatively, if the battery and micro are on the bottom layers - you will need a via. that’s all.


#3

How do I make a pin overlaps with a zone?


#4

Draw the zone so that the pin is inside of it…


#5

Sorry for being ignorant, but my zone already overlaps everything in my circuit, i just outlined my zone on the edge board. So you are saying everything within my zone already touches the the zone unless I do something about it?


#6

Everything inside the zone on its layer which has the same net name as the zone gets connected to the zone. Everything else has some separation, which is determined by the trace clearance rules.


#7

I see, so let say I have a micro-controller I don’t use all the pins on it, if I don’t connect anything to them they are going to be automatically connected to ground?

If that is the case, whenever I have a ground just don’t connect a trace to it and it will be grounded?


#8

yes, if they are on the same side of the pcb as the zone, they get connected (if they belong to the same net). And if the zone can reach the pads by the rules given in that zone properties window (minimum width, etc.)

When your GND zone is on the bottom of the PCB you need a via to get to there from the top, but that’s all that is needed.

…see screenshot from canvas mode (openGL looks different).
That’s the menu you should be seeing once the zone tool starts.
You have to select the layer and the net the zone is on - for you this should be F.Cu and GND as per your fist post.
Selectors to the right are just for complex circuitry to find the nets you need.
All options below are mostly self-explanatory.
If you want to define several zones in the same layer (top, bottom, etc) and they belong to different nets you have to tell KiCAD which outline has the highest priority. The ones with prio ‘0’ are being created last and depnd on all that have been done before

If you want to stitch ground planes for top and bottom you need to search a thread on this very forum for some help how to do this, as KiCAD does allow you to start free-floating tracks/vias on a ground plane with the correct net applied. But reloading that board will make this net-connection disappear. You need some workaround that involves special via footprints.
see here: Protip: nicer via stitching


#9

ah I see it now, I made a mistake by applying the zone before I put my circuit down so the zone was going into weird places when I removed it and reapplied it I can see that the zone went over my pins that were assigned to ground only.

Man this make stuff SOOOO much easier the ground was taking so much of my circuit that removing all those extra lines allows me to fit more stuff in there!


#10

NO, of course not, unless you explicitly connect the unused pins to ground in your schematic.

Right – say you put a part on the top layer, and some of its pins are connected to the GND net on the schematic. If you pour a zone on the top layer, and you assign that pour to net GND, then all of the GND pins are automatically connected to the pour. You don’t need to draw a trace between the pins and the pour.

Now if the pour is on a different layer than the part, of course you must draw a trace from the part and drop a via from that trace so the trace connects to the pour on the other layer.