Electronic – How to make untented vias in KiCad

I have done it two ways.

1. Don't change the footprint file but draw a zone on the top solder mask the size you want the metal to be. Then draw a zone on the copper layer that is connected to the same net as the SMD pad. It is especially convenient if that pad connects to ground. Change the zone properties to Pad connection: Solid so that it will fill completely. Now you can add vias to this area, if you are connecting between the top and ground that will give you more metal to dissipate heat. You might want to remove the preference Delete unconnected tracks, and any others that deal with deleting redundant tracks.

   

2. Do it from the footprint. Just add more pins (through hole) with the same pin number as the smd pad number. These will act as your thermal vias so size them appropriately.

   

The simple solution is as follows.

1. Set you Mask Limit and run DRC to apply it.
2. Group everything on the board, then select Stop->On from the Change tool (button looks like a Spanner/Wrench).
3. Apply that to the whole group (right-click in an empty space on the board somewhere and select Group:Change). This will ensure that every via on the board has a stop mask aperture applied.*
4. Now select Stop->Off from the Change tool
5. Click on each via individually that you want to be tented. This will remove the aperture in the stop mask for that via individually.

*Note: Applying to the whole group with Stop->On shouldn't cause you an issue. The attribute won't affect components (and crucially pads within them), so any stop mask settings within a component will remain as they were. The only thing as far as I know that responds to the Stop attribute is vias, and only those which are not excluded by the Mask Limit in the DRC.