To the assembly people, just a thought.
It seems that the total flexing of BGA due to size and mismatched CTEs is a
given. WHY not try high temp balls that do not collapse as much and hence
reduced or no bridging. It may cost a bit more but I am sure it is worth
considering what you pay for reworking those BGAs. I am sure TI will be
willing to work with you guys because that may be quick fix, without doing
extensive studies on finding materials and/or narrowing process window too
much.
Steve may be you can try this at the rework level. Reball the BGAs using
high temp balls.
Just an engineer thinking.
Rush