Jim Yanik wrote:

I would be VERY leery of a BGA "re-used";
I don't believe one can get the inner pads to solder reliably.


It's done all the time, but you have to 'reball' the chip first.
Then it's exactly like using a new part. Military & medical have to
have the lead free crap repalced with real solder balls. You can buy
the balls and simple tooling on Ebay for very little money to reball
them yourself.