BGA versions with corner markers on the copper layer? about kicad-footprint-generator HOT 5 OPEN

@poeschlr opinion?

from kicad-footprint-generator.

The balls/bumps and circular pads will self-center when the solder paste wets, so why is such an exact placement when hand-placing a BGA required? I've not used this method and had excellent results when hand-placing and hand-soldering BGAs (with hot air, of course). And I've never seen this done on any PCB from a range of factories in a few continents.

So while this one link may request these chevrons, I would want to know if this is still current for this company and if it's widespread in the industry. My experience says that this is not necessary and it consumes potentially valuable PCB real estate.

I do agree it would be relatively simple to extend the script to add these chevrons, but I question the value of doing it and also would not be in favor of adding chevron-equipped footprints to our library.

from kicad-footprint-generator.

@evanshultz I've found it hard to find data on real silkscreen tolerances and assume they may vary with cheap manufacturers. 1/3 of a 0.4pitch is 0.13mm, so the question if the tolerances can be expected below this to avoid balls landing in between pads.

I do not have prior experience soldering BGA and investigating it for a coming project, so if the experience of others shows that silkscreen reference is good enough - I'm happy to go with that =)

from kicad-footprint-generator.

Yep, silkscreen varies a lot (compared with copper), but I've not seen it to be a problem with hand-placing BGAs. You don't need the steady hands of a brain surgeon but the self-centering is very strong so if you're careful I would expect you can get good results. You will, for sure, require soldermask; don't use BGAs without mask on the board.

from kicad-footprint-generator.

Sorry for the late answer. (This is kind of the wrong repo to ask such questions to be honest.)

The term you search is fiducial. These are normally not included in other footprints but are footprints in their own right. KiCad comes with some of them so feel free to use them or add your personal ones. (They are normally used to help robots align footprints but i am sure a similar concept can be used for hand placing as well.)

from kicad-footprint-generator.