Abstract: The present invention relates to two modules containing electronic equipment, one relatively small, and one relatively large, that will be physically connected and used for extended operation in an environment where the ambient atmosphere contains moisture filled air or some other specified environmental contaminant. An absorber such as desiccant of a prescribed amount is contained within at least the relatively large module to control the absolute humidity and/or environmental contaminants within each module during extended operation in the ambient environment. Permeable wall portions are placed in the region between the relatively small module and the relative large module to allow for moisture and/or other specified environmental contaminants to pass from the relatively small module to the relatively large module. As such, the lifespan of the small module can be extended.

Abstract: A passive method and packaging system for thermally controlling the temperature of electronic equipment within a housing are disclosed. The packaging system provides for two cooling steps, each of which uses a different passive cooling technology. Cooling by changing the phase of Phase Change Material, assists in controlling internal ambient temperatures by limiting the effects of short term localized thermal phenomena which would otherwise further increase internal temperatures. Cooling is also provided for by switching on a second passive cooling means, preferably a heat pipe, as the internal temperature of the housing increases above a predetermined temperature and to switch it off as the internal temperature drops below the predetermined temperature. Turning the second passive cooling means on and off provides respectively, a low or high thermal resistance path between the interior and exterior of the housing.