How do I prevent soldermask openings of adjacent parts from connecting?

Layout
1

For example,

How do I guarantee that the solder-mask sliver between the pads of adjacent components will be above a certain minimum?

Thank you.

Version 4.0.2

2

Globally with Dimensions->Pad Mask Clearance or can be set per pad.

You might also consider allowing more space between components…

3

But this doesn’t show an error when the soldermask overlaps, it only controls the size.

4

There’s also a “Solder mask min width” under “Dimensions->Pad Mask Clearance”

This option joins solder mask openings if they are spaced by less than the desired number. To meet minimum mask width of the PCB manufacturer.

5

I want the opposite–I don’t want to combine soldermask openings.

Basically, I’m looking for DRC for soldermask-to-soldermask and/or footprint-footprint, neither of which seems to exist.

6

I don’t think this exists, as the system usually works the other way around, that means - the soldermask for a device/pad/fabricator is the master and what it looks like with other pads around is a function of that.
If you were to be able to define minimum soldermask bridge thicknesses no matter what, you will wind up with pads that are not to spec for having adequate pad size for the housing that goes onto it (mechanical, electrical, etc…).

Does any package allow such behavior?

That’s also why footprints should have visible Courtyard layers during layout, so you cant put them too close together by accident - there is no DRC for courtyard yet in KiCAD, that task is up to you.

The solder shouldn’t bridge the gap between pads either way (handsoldering or reflow) even without soldermasks on the pcb unless you do something wrong - my experience.

PS: forgot to add, the courtyard also takes into account placements by automats, which also have a minimum spacing between components they can’t fall below, otherwise the board can’t be populated by a machine… dunno if that’s important for your desings though. But I found that going as close as the standard courtyard allows is already tricky enough for handsoldering as well (with microscope and sharp solder iron tip).

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