That sort of voiding in a reflowed BGA (ball grid array) solder joint is unavoidable, and is acceptable in IPC workmanship standards up to a percentage limit. I don’t recall the specific numbers, but these voids look normal/OK to me (recently retired process engineer in electronics manufacturing).
I agree 100% about the acceptability of the voiding seen in the x-ray images of the reflowed BGA solder joints. Perfectly normal.
That sort of voiding in a reflowed BGA (ball grid array) solder joint is unavoidable, and is acceptable in IPC workmanship standards up to a percentage limit. I don’t recall the specific numbers, but these voids look normal/OK to me (recently retired process engineer in electronics manufacturing).