Hi Moon<Out-Of-The-Cave>Man,
I did not respond to your query earlier since I had thought that I had
covered the subject previously, but perhaps not.
>1) socket or not here I come
A: socketing is always, so not necessarily cheap, an answer;
>2) constraining/tailoring core materials in MLB structures
A: if you go this route, i.e. CIC, you could just as well stay with Kevlar
MLBs; problem is as soon as you CTE-tailor the MLB for ceramic components,
you mis-tailor [new word] it for your plastic ones--this of course is not a
problem if you have none of those;
>3) go to "very precise" and recommended design rules for blind micro vias
>and buried dog bones with blind interstitial vias using sequential lamination
A: I do not know how this would solve your CTE-mismatch problem;
>4) punt
A: remember, punting can lead to fumbles.
I would strongly reommend you get IPC-D-279 and follow the info in Appendix
A--in the alternative, you always hire a consultant. While we in the
'commercial/cheap environment' do not call out stuff "HI-REL," we still can
not afford any failures if we want to survive.

Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL  32174  USA
Phone: 904-437-8747, Fax: 904-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com

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