On the left is the library footprint, for a normal 16 pin USB socket. But for some reason the footprint being displayed on the right in the PCB editor has additional small circular exclusion zones that just appeared - I didn’t make them and they don’t show up in the footprint editor.
They effectively block half the pads from routing out the back, and block other tracks on the PCB. If I flip the footprint to the front, the little zones disappear, but they’re still there, just only show up when a track is being actively routed from the footprint. If I delete the footprint and reload it, or just completely redo the schematic, the problem remains.
Any ideas as to what I’m doing wrong to cause this behaviour?
It was a custom footprint created myself. So I have in principle solved the issue by using a library footprint instead, but since I’m often making custom footprints, I’d like to know if there was something I did incorrectly with this one that caused this problem. I think I may have used Kicad 6 to create it.
Upload the footprint file or a archived project (with footprint placed on the pcb) and we may be able to look into this.
Just from looking at the pictures I have no idea.
This must have been the problem, I think there are lots of zero area pads in the front layer for some reason. Is there a way to see a full list of all pads? I couldn’t replicate it though, it throws up an error message if I try to set a pad’s dimensions to zero.
I think there was some error in old versions that created or allowed zero sized pads. In the worst case, you could open the file with a text editor and remove all dubios pads.
From the pictures it does indeed like very small pads with a clearance around them. As this is a self made footprint, Is your best guess you did it yourself accidentally, or do you suspect it may be a bug in KiCad? If you suspect a bug, then saving the faulty footprint, uploading it here and (attempting to) recreate it is a logical next step in the process. If you did it yourself, then just fixing it is enough.
One way that probably works is to: Footprint Editor / View / Drawing Mode / Sketch Pads, then zoom in, an select the offending items by dragging a box around them (Dragging from left to right only selects fully enclosed objects, while dragging from right to left also includes partially enclosed objects.
The USB socket has two plastic alignment nubs on the underside, so the footprint required matching drill holes. I guess that in the process of trying to create holes without copper/mask features in the footprint editor, I ended up creating these tiny pads - although why they got distributed all over the footprint I don’t know. Looking at the current drill holes, I can see that they are also 0.001mm diameter pads, but with a hole diameter of 0.8mm so that they’re drilled out without effecting the copper/mask layers.
I couldn’t even see the little red dots in my own screenshot without putting on stronger reading glasses, so thank you all for your help! User error, not a Kicad bug.
