BGA reflow soldering defects

Thread Starter

Isabel

Joined Jul 1, 2014
1
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'
 

mcgyvr

Joined Oct 15, 2009
5,394
Where is the location of the defect.. center or edge? random?
plastic BGA?
excessive solder paste?

do you have x-rays to share? that would really help
 

ErnieM

Joined Apr 24, 2011
8,377
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."
 
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