We are facing deformed balls on BGA that sometime create bridges. Process looks OK. It looks like there was a strong blow from the side that was deforming the ball but all other balls are looking fine. Does anyone have a hint? Thanks'
Sorry to hear about your balls. What is the nature of the deformity? Is it excess solder (non-uniform size balls) or as they just "smeared?"
If just smeared you may be able to reform them in place by putting them balls up and running thru a reflow oven. The balls should then refreeze as perfect uniform spheres. You may need to add flux for the final reflow.
This is a condition that can be visually inspected and rejected. If a vendor problem kick it back on them. If you have a handling problem kick the handlers till they learn the word "gentle."