Heatsink method and apparatus

• US 7,751,192 B2
• Filed: 08/09/2007
• Issued: 07/06/2010
• 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, Stippick, Timothy W., Abul-Haj, Roxanne E., Hazen, Kevin H.
• Primary Examiner(s): CHERVINSKY, BORIS LEO
• Application Number:
  US11/836,755
• Publication Number:
  US 20070272400A1
• Time in Patent Office: 1,062 Days
• Field of Search: None
• US Class Current: 361/703
• 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

A heatsink having tapered geometry that improves passive cooling efficiency is discussed. 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 connecting member; and

at least two heat exchange elements;

wherein said at least two heat exchange elements are either, integrated into said connecting member or attached to said connecting member;

wherein said at least two heat exchange elements form a trough between them, said trough having a bottom opening and a top opening, wherein at least a portion of said top opening is vertically aligned with at least a portion of said bottom opening; and

wherein cross-sectional area between said heat exchange elements increases as a function of vertical distance along a z-axis, wherein said z-axis aligns with gravity.

2. The apparatus of claim 1, wherein said apparatus further comprises:

a coating covering substantially all of a at least a portion of any of;

said connecting member; and

said heat exchange elements.

3. The apparatus of claim 2, wherein said coating comprises a rough surface, wherein said rough surface enhances turbulence of air flowing across said rough surface.

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

an injection molded material; and

a thermally conductive plastic.

5. The apparatus of claim 1, wherein said thermally conductive plastic comprises:

a material having a heat transfer coefficient of at least ten W/m-K, where W is heat in Watts, m is distance in meters, and K is temperature in degrees Kelvin.

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

a fin; and

a post.

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

a taper on at least two sides.

8. A method for heat transfer from a heat source, comprising the steps of:

providing a heatsink connected to said heat source;

providing at least two heat exchange elements;

wherein said at least two heat exchange elements are either integrated into said heatsink or attached to said heatsink;

forming a trough between said at least two heat exchange elements, said trough having a bottom opening and a top opening;

vertically aligning at least a portion of said top opening with at least a portion of said bottom opening;

wherein cross-sectional area between said heat exchange elements increases as a function of vertical distance along a z-axis, wherein said z-axis aligns with gravity; and

dissipating heat from a heat source using said heatsink.

9. The method of claim 8, further comprising the step of:

either directly or indirectly coupling said heatsink to said heat source.

10. The method of claim 8, wherein said heatsink passively increases airflow.