| 摘要 |
An electronic package is mounted by its leads in an inner hermetically sealed package in an atmosphere of dry nitrogen gas at about 50 torr gas pressure. Leads extend through hermetically sealed electric feedthroughs into an outer enclosure which is maintained at a vacuum of at least 1x10-4 torr. Electrical leads which extend substantially the entire length of the interior space of the outer enclosure pass out of the outer enclosure at first ends of the leads through hermetically sealed electrical feed-throughs and at second ends electrically communicate with and structurally support the leads from the inner enclosure so that the inner enclosure is disposed between the first and second ends. The surfaces of the inner enclosure and the interior surface of the outer enclosure are electropolished. The electronic package consists of a central core sandwiched between beryllium oxide heat spreaders on which are mounted heaters in the form of power transistors. This structure is in turn sandwiched between ceramic substrates. The most heat sensitive circuit elements are mounted in the central core, while additional circuitry including controls for the power transistors is mounted on the substrates. A support bridge designed to provide shock and vibration support for the inner enclosure while at the same time affording minimum heat transfer therefrom is disposed at the second ends.
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