What kind of PCBA wave soldering is the standard process
Level 1: Applicable to general consumer electronics. BGA bubble requirements must not be greater than 60% (diameter) or 36% (area).
Level 2: Suitable for commercial/industrial electronic products. The bubble requirement of the BGA should not be greater than 42% (diameter) or 20.25% (area).
Level 3: Suitable for military/medical electronic products. BGA bubble requirements must not be greater than 30% (diameter) or 9% (area).
2012-Jul-01 update: According to the IPC-7095B 220.127.116.11 specification update, the uniformity of bubbles in the BGA solder ball should not exceed 25% (diameter) or 6.25% (area).