I have been experiencing bridges on some 1.27mm pitch BGAs.
The bridges always happen in the corners, and my suspicion
is that the BGAs (yes, the components) are warping downward
to the point of creating the bridges on the corners, where the
distance from the BGA to the pwb is shortest.
I have seen this phenomena while reworking the BGAs, but I am
a little surprise to see it during the oven reflow.
Any ideas what is causing the bridges?
Thanks!

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