I'm trying to wrap up a PCB layout for a client who insists the DRC should have no errors or warnings, however irrelevant they are. All is fine except for 1 last warning and I can't find the source of it, see screenshot of dialog:



I get what the warning is telling me - I just can't find where it thinks an SMD part expects 'Through hole' pads. The part in question is the TI 74HC4067 which is in the KiCAD library with both SOIC-24 and TSSOP-24 footprints. However I'm using the VQFN-24_EP2 variant of the chip which isn't in the library. So I modified the symbol to add the 25th 'pin' for the thermal pad, changed the part # to add the RGYR (VQFN package) suffix and added the part to my project library and then assigned the TI RGYR VQFN24_EP2 footprint from the footprint library to the part. All was well til I ran the DRC and this violation pops up! I can't find anywhere any reference to through hole pads, everywhere I've looked says SMD. What am I missing? Its seriously doing my head in... and I need to get this out of the door like yesterday1

 

Should that be designated HTSSOP ?

 

Should that be designated HTSSOP ?

I don't think so. This part doesn't come in an HTSSOP package, TI very definitely call it VQFN-24

 

https://gitlab.com/kicad/libraries/kicad-footprints/-/work_items/2634

The thermal vias (they're actually pads) need to have the "Heatsink pad" Fabrication property on them.

Maybe try that if you haven't already.

 

https://gitlab.com/kicad/libraries/kicad-footprints/-/work_items/2634

Maybe try that if you haven't already.

Thanks, I'll give it a go, though I tried removing the vias earlier, sort of thinking along those lines, but it didn't change anything.