When I run the plot command all my thermal reliefs disappear. Refilling does not bring them back. I have to quit the program without saving to get them back. What am I missing? Thanks!!
What version of Kicad and what OS?
I have several independent ground planes on the front copper. Each ground plane uses thermal reliefs on each ground connection. The thermal spokes disappear when I plot gerbers, and they also disappear when I do certain other things, but I don’t know what those things are yet. How is it that all thermal spokes can disappear at the same time?
It happened again when I hit “B” (fill all zones). This was just after I deleted some NPT holes. When I hit “B”, the clearance holes in the pour disappeared, but so did all the thermal spokes in the layout.
What does the zone properties “Pad Connections” box say?
Can you share the affected design files?
- What does DRC say? (any errors? is anything reported as unconnected?)
- do you have multiple zones overlapping on the same layer?
- if yes: Have all of them a net? Are they set to different priorities?
- does the view of kicad pcb_new differ from the output or do they agree? (If yes check the zone properties, footprint and pad properties of what is affected. Make sure the zone is set to “thermal” and footprint and pad are set to “by parrent”.
- can you at least share a screenshot of one of the affected areas? (plus screenshot of the zone properties, pad and footprint properties of what is affected.)
Pad Connections box is marked Thermal.
Is correct net associated with the zone?
There is no net listed in the Zone Properties window. I should explain that I 'm not a skilled board designer. I’m trying to finish a layout begun by my tech, who recently succumbed to lung cancer. So far, I haven’t been able to find anyone in the San Jose area with KiCad skills to finish the board!? Surprising, considering all the designers here.
That is at least one reason why there are no thermal reliefs on the Front layer.
Each filled zone, and they can overlap, needs to be assigned the net of the copper the design requires to have thermal reliefs on.
I know we like to be able to work with local people when possible but if the schematic is finished do you really need someone local?
This board did not originate from a KiCad schematic file. The footprints were laid in one by one from the library.
The board was not quite finished. It also needs some cleanup work. I can do some, but am struggling with others.
DRC reports no unconnected errors, but there are other errors such as:
- Board outline does not form a closed polygon
- Pad too close to pad
- Drilled holes too close together
- Track too close to pad
- Courtyards overlap
No nets, no ratsnest. The footprints were laid in manually. The designer worked from my LTspice schematic. There is no KiCad schematic file.
Zone priorities are all set to 0.
The view menu of a PCB_New file shows a green checkmark as the ratsnest icon. In my pcb file the ratsnest icon is a group of crossed over lines.
Here are the Pad Properties:
I can’t find the footprint properties.
Correct, this is the cause of the zone fill not connecting. Is this another attempt to use Pcbnew without a schematic?
The board was designed without a KiCad schematic, and has been fabricated without any problems. At least, until now. The board was originally designed in 2017 using a much older version of KiCad.
Thanks, everyone, for the guidance. Evidently the thermal spokes disappear when I hit “B” because there is no net assigned to the ground planes. Now can someone please explain how to assign a net to my ground planes?
Something is fishy here.
First, I can’t fathom someone would create a pcb of such non-trivial complexity without creating a schematic first, just by plopping down footprints.
Second net information was obviously there at some point because zones have spokes to some pads and not others.
Maybe this board is back imported from gerbers? That’s one way it would loose net information.
To answer your question: you can’t create nets in pcbnew, at least not with GUI.
I would suggest you get original files, including schematic and continue from there. If you can’t get your hands on that it would be more efficient to start from scratch (and possibly use this file as a guide to place footprints in your new project, that will save some time).
All I can tell you is that my board designer was very much old-school. That’s the way he’s always done it, and that’s the way he approached using KiCad. Not by the book, but it worked. We made a run of 25 boards without a squawk from the fab house.
I’m sure he didn’t back import gerbers, because he designed the board from scratch in KiCad. I’m guessing that he did not refill zones, ever. If I plot gerbers, the thermal spokes show up on the front copper so long as I use the “plot without refilling zones” option. Could this be how he did it? If so, what are the implications? Anyone?