Happy Monday!

Does anyone have any experience with conformal coating of
BGAs and, in particular, what performance standards are used? 
We are using a silicone coating 3-5 mils thick (sprayed), and we
are not using a BGA underfill.  We are uncertain whether the
edges should be sealed or not.  It's not bad for plastic BGAs (as
the balls collapse), but the ceramics can be near impossible.

This is a military (avionics) application.  I appreciate any advice/
experience that you may have.

Thanks,
Steve Murphy
TRW Automotive Electronics Group
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