Per-Erik,
I appreciate that information. I am in the middle of attempting to
understand IBM's research and findings concerning hard balls. They seem, so
far, to be saying exactly what you state.
The delimma simply is, I would prefer plastic over ceramic no matter the
findings. This is for reasons obvious as "easy" to profile and assemble with
very high quality and reliability solder joints not having such as high CTE
to board/pad ratio as ceramic.
We've all been down this path with LCCC's in military applications. Having
said that, the most reliable conditions were met using constraining or
tailoring cores in MLB's. As our application certainly must be reliable, it
cannot compete under such conditions in a commercial market. My biggest
concern in all this is knowing no matter how good our design rules, taken
from TI and other industry leaders, MLB's, and assembly processes, in
qualified manufacturing capabilities, it may be likely we will experience
failures down the road due, in part, to the huge CTE differential on
"normal" boards. This concern is compounded by normal thermal and mechanical
stresses endured under "normal" operating conditions.
I am looking into TI's "new" super BGA packaging in which 4 DSP's are
attached inside one of these packages offering, hopefully, better pricing
along with no fuss assembly. While on this subject, has anyone had
experience using these components?
I would appreciate knowing how I might receive your findings either in
papers, articles, or books. Could you let me know.
I certainly appreciate your very valuable input. Could you tell me a bit
more about yourself.
Enjoy,
Earl
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