Abstract

The invention relates to a passive liquid immersion cooling apparatus for electronic systems operating in thermally uncontrolled environments. The apparatus comprises an external shell, defining a chamber with a plurality of heat dissipating components disposed within the chamber and surrounded by the shell. The components are immersed into a low boiling point dielectric liquid partially filling the chamber. The shell has two portions, an upper portion of the shell adjacent the area above the liquid level which forms a vapor space, and a lower portion of the shell adjacent the liquid. The shell has an external heat transfer structure providing more efficient heat transfer from the upper part of the shell, for example, in the form of external fins extending outward from the shell, and an internal heat transfer structure in the form of internal fins extending inward from the shell and into the chamber. Preferably, the external fins extend along the upper portion of the shell only. The external heat transfer structure provides effective thermal management of the electronic components within the apparatus over a wide outdoor temperature range. Additionally, a cylindrical design of the apparatus provides more reliable sealing and better pressure containment of the apparatus and may include a solar shield. An assembly of cooling apparatus employing the liquid immersion cooling apparatus and additionally comprising a conduction cooling apparatus, a forced convection cooling apparatus, and a solar shield is also disclosed.

Other References

• "Chips Immersion Cooled Inside Device Package", Howard W. Markstein, Electronic Packaging and Production, Jan. 1993, p. 3