Hacker News Reader

This is true for most surface mount packages, the surface tension of the solder will usually center the parts in their pads during reflow.

View on HN

This. In my experience QFN-like packages self center better than comparable BGAs, it’s just that BGAs in general are big so they are easy to line up.

Small BGAs can be hell to hand solder.

I find SOICs to be by far the most forgiving; off by anything less than half the pitch and it tends to jump into place.

In fact, the force of self centering is more a problem for small 0402 parts!!!!

The force is so strong, it can 'Tombstone' the piece during reflow. This is partially why 0402 is used rather than the more electrically convenient 0204. It's easier to tombstone on the long edge.

-------

Also, if you don't care about tombstoning but need the better parasitics of a 0204 capacitor or the better heat capacities of a 0204 resistor, try them out!!

Reply on news.ycombinator.com