Packaging system for thermally controlling the temperature of electronic equipment

TLDR: In this paper, a passive method and packaging system for thermally controlling the temperature of electronic equipment within a housing is described, where 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.

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. The second passive cooling means allows for cooling of the housing above the predetermined temperature as well as heating of the housing below the predetermined temperature by preserving heat generated by the equipment. The two cooling steps in combination, co-operate to limit both maximum and minimum temperatures within the housing and of components. The combination of cooling steps also allows control over the temperature delta between the maximum and minimum temperatures during internal temperature swings.