Method and apparatus for immersion cooling or an electronic board
First Claim
1. Liquid heat sink apparatus for cooling electronic components mounted on a printed circuit board, comprising:
- (a) a cold plate mounted opposite said electronic components and substantially parallel to said printed circuit board;
(b) means for containing a liquid coolant between said printed circuit board and said cold plate;
(c) said liquid coolant contained between said printed circuit board and said cold plate and in thermal contact with said printed circuit board said electronic components mounted thereon, and said cold plate,wherein said cold plate is maintained a distance d from said electronic components sufficient to provide a Rayleigh number of at least 1700 in the equation ##EQU4## where g is the acceleration of gravity, β
is the volumetric coefficient of expansion of said liquid coolant, T1 is the temperature of said cold plate, T2 is the temperature of the component to be cooled, ν
is the kinematic viscosity of said liquid coolant, and α
is the thermal diffusivity of said liquid coolant;
(d) means for maintaining said cold plate said distance d from said printed circuit board, comprising a sealed housing supporting said cold plate and surrounding said printed circuit board and attached thereto to thereby provide a sealed space for maintaining said liquid coolant herein; and
(e) said sealed housing including means for accommodating expansion of said liquid coolant during thermal cycling.
1 Assignment
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Accused Products
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, β is the volumetric coefficient of expansion of the liquid coolant, T1 is the temperature of the cold plate, T2 is the temperature of the component to be cooled, ν is the kinematic viscosity of the liquid coolant, and α 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.
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Citations
7 Claims
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1. Liquid heat sink apparatus for cooling electronic components mounted on a printed circuit board, comprising:
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(a) a cold plate mounted opposite said electronic components and substantially parallel to said printed circuit board; (b) means for containing a liquid coolant between said printed circuit board and said cold plate; (c) said liquid coolant contained between said printed circuit board and said cold plate and in thermal contact with said printed circuit board said electronic components mounted thereon, and said cold plate, wherein said cold plate is maintained a distance d from said electronic components sufficient to provide a Rayleigh number of at least 1700 in the equation ##EQU4## where g is the acceleration of gravity, β
is the volumetric coefficient of expansion of said liquid coolant, T1 is the temperature of said cold plate, T2 is the temperature of the component to be cooled, ν
is the kinematic viscosity of said liquid coolant, and α
is the thermal diffusivity of said liquid coolant;(d) means for maintaining said cold plate said distance d from said printed circuit board, comprising a sealed housing supporting said cold plate and surrounding said printed circuit board and attached thereto to thereby provide a sealed space for maintaining said liquid coolant herein; and (e) said sealed housing including means for accommodating expansion of said liquid coolant during thermal cycling. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification