Well said Werner,

However, I am more concerned about surviing operational performance than
simple assembly processes if I am a user of that product.

I?ve never disagreed with the fact we must survive assembly. The old 55110,
and the new one?s, specified that test coupon B, derived from specified
quality conformance test circuitry must be subjected to an extensive
preconditioning period prior to being subjected to a solder ?float? of 550
F. for 10 seconds to ensure the most extreme soldering conditions, during
assembly, would ensure acceptable product. Also, thermal shock conditions
were to be imposed as ?55 C to 125 C in an elevator ride between low and
high temperature chambers simulating PERFORMANCE conditions. Therefore, if
the tests yielded acceptable results, no delamination, in the laminate
evaluation zone, or hole cracking, in the thermal evaluation zone, in
accordance with all that specification?s requirements, it would pass all
assembly processes. In other words, both assembly and performance conditions
would be satisfied and product would be acceptable.

 All this meant if I?m a pilot sitting in my F-16 at 40,000 feet and
counting on going from ground level to that altitude, I certainly would feel
a bit more comfortable if my flight control system assembly was capable of
surviving the thermal transition both as stress and shock. To say the
assembly process is more important and it correlates directly to Tg, is
inadequate. Simply, it is but the first step and if failures exist at the
assembly level, they certainly will during performance ? at altitude as but
one example. AS LONG AS IT WORKS WELL having survived some nearly bad
fabrication/plating processes, I don't care the Tg. After all, we've
successfully used unmodified epoxy resin systems for years even though they
keep getting better.

MoonMan

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