I’m fairly new to PCB design and I need some clarification. I’m currently working on a project and I’m in the PCB design phase. The PCB I’m designing is single-sided, not double-sided.
I’ve run into a situation where I need to bridge a connection using a 0Ω resistor, since there’s no more room to route a trace directly. However, even after placing the 0Ω resistor, I’m still getting an “unconnected” error in the design checker.
I’ve spent a lot of time trying to figure it out, but I’m still stuck. I’ve attached an image of my PCB layout the rectangular shape in the image is the 0Ω resistor. Could you please take a look and help me understand what I’m missing?
The DRC only knows about net connectivity.
If you need to add a 0Ω jumper, you need to modify your schematic and insert a 0Ω resistor in the wire where you need it.
I do not think there is any way to carry a net through a zero ohm resistor. I think KiCad will assume that the two ends of the resistor will be on different nets. I often use 1206 resistors to bridge tracks but you could go smaller.
If this is a truly single sided board and not using plated through holes, it is wise to use larger pads and thicker tracks to reduce track lifting. There is no cost advantage for single sided these days.
Next kicad version will support internally connected pins so you will be able to have 0 ohm resistor footprints that drc considers as internally connected and you won’t have to add them to the schematic (although it’s still a good idea to do it anyway, for bom consistency if anything else).
Yes, even with 2 or more copper layers, I like to make tracks as wide as (or almost as wide as) the pads to which they are connecting. (where there is enough space.) You could even expand the track width as it gets away from the pads.
Hi, I am making 1 sided PCBs at home quite often and when I need bridges I sometimes use a second copper layer and set the resulting vias to the desired size for my wires. This way kicad can keep the netnames and the drc works fine.
So you added the 0R in the schematics. Good. Did you do a ERC there?
After that, in layout, did you update the layout from schematics? Just to be sure, I’d delete the 0R in layout and update from schematics.
I suspect you started by adding the 0R in layout.
For me, it is quite odd to have a single-sided PTH board. Why not go the old school way with single sided and mirror front side to back side? Soldering on the back, components on the front. I see no part that requires PTH.
Are you sure ? plated through to where ? if you are paying for plated through holes just get double sided and a simpler life, your time has a value too.
I guess you placed a 0 ohm resistor on the PCB so:
Place a resistor of 0 ohms in the schematic
Re-annotate the schematic.
Update the PCB from the schematic.
These actions should remove the “unconnected” error.
That’s not what I meant. Your PCB will be single sided. The second layer will NOT go into fabrication ! It only gives kicad the information about connections and is your guide where to put wires.
Maybe I misunderstood and you want to use real zero-ohm-resistors. In that case you will have to accept 2 different nets on both sides until kicad supports this natively ?
And yes you need to accept its a different net as technically it is, even if the intent is a continuation. In fact FMECA would need to consider the failure of that one resistor
