The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 1994
Filed:
Dec. 16, 1992
Rolf Andresen, Tucson, AZ (US);
Robert J Bellar, Tucson, AZ (US);
Sung J Kim, Tucson, AZ (US);
Alan L Murphy, Tucson, AZ (US);
IBM Corporation, Armonk, NY (US);
Abstract
A liquid heat sink is provided that employs natural convection of a liquid coolant (18') to cool a printed circuit board (14) on which are mounted a plurality of heat-generating components (12). In particular, the spacing d between the heat-generating components and a cold plate (20) used to cool the liquid must be such as to provide a Rayleigh number of at least about 1700 in the Rayleigh equation: ##EQU1## In the above equation, g is the acceleration of gravity, .beta. is the volumetric coefficient of expansion of the liquid coolant, T.sub.1 is the temperature of the cold plate, T.sub.2 is the temperature of the component to be cooled, .nu. is the kinematic viscosity of the liquid coolant, and .alpha. is the thermal diffusivity of the liquid coolant. The novel heat sink of the present invention allows complete immersion of the component in the liquid to provide maximum heat transfer, while at the same time providing a mounting/packaging scheme that allows full utilization of the desired heat transfer properties.