HI, Dan or Daan I'm really not sure of your name 
Any way Hi,

First you need to verify your Magnification,
 Note page vi of your 610 
 Second Please understand that all solder balls are a defect but under acceptable conditions you may approve the parts. With the 
understanding that you will need to do a process check
Question:
1. Are the solder balls able to create a short / bridge between the smallest electrical clearance on the PCB
2. Do you have any type on conformal coating for entrapment

If you can give more details maybe I can help.
But you really do need to check your process and understand why there are solder balls.

Your problem could be as easy as over fluxing or removal of parts from the solder pallets creating a splash / solder balls onto other boards.
 Jack Crawford is great you can get him at [log in to unmask]

Or if needed reply back 
[log in to unmask]
Nancy

 

>>> "." <[log in to unmask]> 08/31/99 12:30PM >>>
Hello Technet,

With X-ray inspection we have seen some solder balling underneath microBGA's. According to the IPC 610B spec these solder balls are a nonconforming defect, since there is a risk that they become dislodged and make a short-circuit elsewhere on the board. 
On a normal SMT board we would definitely remove them, but on a BGA-board it would be necessary to replace the BGA. Considering the very slight risk that these solderballs really result in short-circuits, I would like to consider this situation as a process indicator and not as a defect. Our inspection people do not agree with me (they are paid to inspect according to the specs, so who am I to blame them ?) 
I'm interested to hear some opinions on how to deal with such a situation. How would this be influenced by  the quality class or product type ? 

Daan Terstegge

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