Graham, Back in the day, we would have approached as much as we could with hybrid technology. Eutectic die attach on ceramic [High temp co-fired ceramic, alumina substrate within metal package, or Low Temp Co-fired ceramic], etc. Way back, there was even eutectic attach for passives - if properly metallized... Being in a hermetic package, no conformal coatings... Being a potentially highly corrosive environment the package is truly put to the test. Drawing upon implantable medical technologies [also a corrosive environment, believe it or not], there are multiple packaging options available including stainless & titanium. Just a different persective... Steve Creswick Sr Associate - Balanced Enterprise Solutions http://www.linkedin.com/in/stevencreswick 616 834 1883 ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________