I’m writing to you because I haven’t been able to find my mistake for a while now. I made two ground planes : one for the ground (GND_D) and the other for the power supply (+5V_D). However, when I click on B and check the circuit, the message ‘Missing connection between items’ appears and I can’t work out why. To help you understand, the two ground planes are on both layers (bottom and forward) and the +5V_D ground plane has a priority of 0 and the GND_D ground plane has a priority of 1. Can you tell me why these errors occur?
It’s not a GND plane if it’s not connected to GND. When you use: PCB Editor / Place / Add Filled Zone [Shift + Ctrl + Z], then you also have to specify to which net this zone must connect. In the big connector on the top, I see thermal spokes connecting to pad 2 (GND_D net), but nothing is connected to pad 1 (The +5V_D net).
In addition, all the other parts are SMT parts. These only connect to the top layer, and do not connect to the bottom at all.
The most common way is to dedicate the whole bottom to the GND zone (plane), and then connect them to the pads by adding vias to the PCB. The the smt parts on the top are then routed with tracks, including the power connections. There is no real need (nor advantage) to use a zone for the +5V_D net. It is quite common to use a GND zone (and thus connected to GND) for the top layer too.
At what layer is your +5V_D zone? It looks that no zone were connected to +5V_D connector pad. Connector pad has THT pads so they can be connected at all layers. If such pad is not connected that means there is no the same net zone around it.
I suppose that you placed one zone on another and first filled won with the second one.
They are on different layers, and there is no interaction between those two layers. I am guessing that you are missing some fundamental insights in how a PCB works and how it is represented in KiCad. Maybe it helps if you view the PCB in the 3D viewer (With [Alt + 3]) Experiment a bit with the settings of the 3D viewer, so you can also look inside the PCB (Turning off the solder mask layer and the board body for example).
Thank you, I understand. I’m indeed a beginner in Kicad. In this picture that I sent, we can see that some GND_D pads are connected to the GND_D’s plane but some for example the pins 30 and 32 are not. Can you explain why it is not connected to the plane ?
You have 2 layers at your PCB and you placed 2 zones each on two layers (so really 4 zones). We don’t know your zone shapes. Do you have separate, not overlapping shape for +5V and GND zones?
I repeat what I said:
Now I suppose that you did it on both layers (on both layers you placed two zones so 4 in total). And thanks to priority one of them (GND) wins on both layers.
It looks like you expect two zones with different voltage can lay one on another at one PCB layer. I hope you know it is not possible.
Oops, I missed that. Apparently all zones are defined across the whole PCB. That does indeed not work at all. Zone priority only yields useful results when there is only a small overlap between the zones.
Pads 23 and 25 are connected between them, but there is no real zone (only a small triangle to the left of them).
You have set thermal spoke width to 0.5mm and it looks that these pads are also 0.5mm. Pad 27 clearance line (see these very thin red lines) shows that pad 29 is too close (at least it looks so for me) to it. So if thermal spoke line have to be 0.5mm it looks that it can’t be started from pad 27 center as it will be too close to pad 29. The same problem is probably for pads 30 and 32.
