Apparatus for absorbing and dissipating excess heat generated by a system

• US 7,593,230 B2
• Filed: 07/14/2005
• Issued: 09/22/2009
• Est. Priority Date: 05/05/2005
• Status: Expired due to Fees

• Current Assignee: GLT Acquisition Corporation
• Original Assignee: Sensys Medical, Inc. (Sensys Medical Limited)
• Inventors: Abul-Haj, N. Alan, Hazen, Kevin H., Stippick, Timothy W., Abul-Haj, Roxanne E.
• Primary Examiner(s): Hyeon; Hae Moon
• Application Number:
  US11/182,309
• Publication Number:
  US 20060250776A1
• Time in Patent Office: 1,531 Days
• Field of Search: 361/697, 361/710, 361/702, 361/703, 361/705
• US Class Current: 361/710
• CPC Class Codes: F28F 13/08 by varying the cross-section of the flow channels
• CPC Class Codes: F28F 3/02 Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations F28F3/08 takes precedence
• CPC Class Codes: H01L 23/3737 Organic materials with or without a thermoconductive filler
• CPC Class Codes: H01L 23/467 by flowing gases, e.g. air H01L23/473 takes precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

The invention relates to a heatsink. More particularly, the invention relates to a heatsink having tapered geometry that improves passive cooling efficiency. A tapered geometry between heatsink heat dissipation elements, as a function of distance along a z-axis opposing gravity, decreases resistance to rarification of passively flowing cooling gas upon heating. Thus, the tapered heatsink elements result in higher velocity of gas flow and increased cooling efficiency of the heatsink. Optionally, the heatsink is made from a thermally conductive polymer allowing the heatsink to be created in complex shapes using injection molding.

Claims

1. An apparatus for heat transfer, comprising:

a heatsink comprising;

a thermal interface surface having a series of apertures disposed therein, wherein said series of apertures allows heated air to pass through the thermal interface surface; and

an array of heat exchange elements coupled to said thermal interface surface, wherein said series of apertures are intercalated within said array, wherein the cross-sectional area between elements of said array of heat exchange elements increases as a function of vertical distance along a z-axis, wherein said z-axis is aligned with gravity, wherein said array comprises at least ten heat sink elements, wherein said series of apertures comprises at least five apertures, such that an air flow is induced along the z-axis as the heated air expands with the increase in cross-sectional area, thus passively drawing heated air away from the thermal interface layer.

2. The apparatus of claim 1, wherein at least part of said heatsink comprises:

a thermally conductive polymer.

3. The apparatus of claim 2, wherein said thermally conductive polymer has a heat transfer coefficient of at least five W/m−

K, where W is heat in Watts, m is distance in meters, and K is temperature in degrees Kelvin.

4. The apparatus of claim 1, wherein at least one of said heat exchange elements comprises any of:

a fin; and

a post.

5. The apparatus of claim 4, wherein either said fin or said post comprises:

at least two axes of taper.

6. The apparatus of claim 1, wherein said array of heat exchange elements comprise integration into any of:

a vertical side of said heatsink;

an inclined plane side of said heatsink; and

a curved side of said heatsink.

7. The apparatus of claim 1, wherein said heatsink is coupled to at least a part of any of:

a heat source;

a heatpipe;

heat conducting means;

a biomedical device;

a handheld device

a flue;

an inside of said heat source;

a periphery of said heat source; and

an integrated circuit.

8. The apparatus of claim 1, where optimization of said heatsink comprises controlling any of:

geometry of said at least two heat exchange elements;

environmental temperature;

origin of airflow;

angle of tapering;

geometry of tapering;

a coating layer; and

airflow rate.

9. The apparatus of claim 1, wherein said cross-sectional area between said elements of said array of heat exchange elements is optimized using fluid dynamic software.

10. The apparatus of claim 1, wherein the increase in cross-sectional area between said elements of said array of heat exchange elements comprises a taper in the at least two heat exchange elements.

11. The apparatus of claim 10, wherein the taper comprises an angle less than twenty degrees off vertical and more than three degrees off vertical.

12. The apparatus of claim 10, wherein the taper comprises an angle greater than six degrees off vertical.

13. The apparatus of claim 1, at least a portion of the heatsink comprises a coating in continual contact with at least a portion of the heatsink.