Via eyeballs

No. This isn't a closeup of an owl face.

There is still some debate on how best to create a land pattern for a 0.4mm pitch BGA. We recommend soldermask defined pads at that pitch. But that's not really what this post is about. Although this land pattern uses non-soldermask defined pads which can encourage bridges. If you need to cross a river, encouraging bridges is good. If you're trying to make a board work, they are not.

In the case of the two BGA pads shown, I really doubt you would have to worry about bridging. That's because the solder ball would most likely be sucked off the BGA due to the capillary action of the via in the middle of the pad. You most likely wouldn't get bridging. You most likely wouldn't get any contact of any kind at all. This will not work.

Duane Benson

Hoot. Hoot.