It sounds like the same story over again begining for me in the 60's (Jesus Christ - that long
ago). Nothing ever changes concerning TCE mis-matches. The epoxy expands way out of proportion
to ceramic, at least it used to. Obviously, this is done during reflow and other thermal
cycling with no fault pointed at the cleaning process.

We, then and much later, went to glass to metal seals. Then, they were Kovar glass to metal
seals with nearly matching thermal characteristics providing high degrees of hermetic sealing.
Later was in the 70's and 80's. Don't know what "modern" hybrid folks are doing now but,
again, the problems are the same.

Earl Moon

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