Cooling assembly

• US 7,545,646 B2
• Filed: 06/23/2005
• Issued: 06/09/2009
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Holmberg, Per Anders, Andretzky, Ulf Eric
• Primary Examiner(s): DATSKOVSKIY, MICHAIL V
• Application Number:
  US11/917,669
• Publication Number:
  US 20080198554A1
• Time in Patent Office: 1,447 Days
• Field of Search: 361/687, 361690-697, 361700-712, 361/715, 361/719, 165 802- 805, 165/104.21, 165/104.26, 165/104.33, 165/185, 174/15.2, 174/16.3, 174/252, 257/707, 257/714, 257/715, 257/718, 257/719, 257/727, 298/900.32, 298/900.4, 29890041-890046
• US Class Current: 361/701
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence
• CPC Class Codes: F28D 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: F28F 1/12 the means being only outside the tubular element
• CPC Class Codes: F28F 1/20 the means being attachable to the element F28F1/22 takes precedence
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• 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
• CPC Class Codes: H05K 1/0272 Adaptations for fluid transport, e.g. channels, holes
• CPC Class Codes: H05K 2201/064 Fluid cooling, e.g. by integral pipes
• CPC Class Codes: H05K 2201/066 Heatsink mounted on the surface of the printed circuit board [PCB]
• CPC Class Codes: Y10T 29/4935 Heat exchanger or boiler making

Abstract

A cooling assembly and method of cooling a heat-generating electronic component on a circuit board. A heat collector collects heat from the electronic component. A heat pipe transfers the heat to a location remote from the electronic component. A heat sink is mounted to the circuit board at the distant location. The heat sink has at least one groove formed on an underside thereof. The heat sink is mounted so that is overlies the heat pipe and the heat pipe is introduced into the groove, thereby securing the heat pipe between the heat sink and the circuit board.

Claims

1. A method of cooling at least one heat-generating electronic component mounted on a circuit board, said method comprising the steps of:

attaching a heat collector to the component;

placing at least one heat pipe in direct thermal contact with the heat collector to remove heat from the heat collector and move the heat to a location which is distant from the electronic component; and

mounting to the circuit board at the distant location, at least one heat sink having at least one groove formed on an underside thereof, wherein the at least one heat sink is mounted so that it overlies the heat pipe and the heat pipe is introduced into the groove, thereby securing the heat pipe between the heat sink and the circuit board.

2. The method as recited in claim 1, wherein the at least one groove in the at least one heat sink has a wall, and the groove is sized so that the heat pipe is in direct thermal contact with the wall when the heat pipe is secured between the heat sink and the circuit board.

3. The method as recited in claim 2, wherein the at least one groove extends for the entire length of the at least one heat sink, and the step of mounting at least one heat sink to the circuit board includes aligning and mounting multiple heat sinks to the circuit board so that the groove in each heat sink is aligned with the groove in an adjacent heat sink, wherein each heat sink overlies a different portion of the heat pipe and secures the respective portion of the heat pipe to the circuit board.

4. The method as recited in claim 2, wherein a plurality of heat pipes remove heat from the heat collector, and the step of mounting at least one heat sink to the circuit board includes mounting multiple heat sinks to the circuit board so that the groove in each heat sink is aligned with a different one of the heat pipes, wherein each heat sink overlies a different heat pipe and secures the respective heat pipe to the circuit board.

5. The method as recited in claim 2, wherein a plurality of heat pipes remove heat from the heat collector, and the heat sink has a plurality of grooves formed on an underside thereof, wherein the step of mounting at least one heat sink to the circuit board includes mounting the heat sink to the circuit board so that the plurality of grooves is aligned with a different one of the heat pipes, wherein the heat sink overlies the plurality of heat pipes and secures the heat pipes to the circuit board.

6. The method as recited in claim 5, further comprising transferring heat from a plurality of heat-generating electronic components to the at least one heat sink.

7. The method as recited in claim 2, wherein the step of mounting at least one heat sink to the circuit board also includes mounting the heat sink to the circuit board so that the heat pipe is in direct thermal contact with the circuit board.

8. The method as recited in claim 2, wherein the step of mounting at least one heat sink to the circuit board includes mounting a heat sink having grooves of different sizes to secure heat pipes of different sizes to the circuit board.

9. The method as recited in claim 2, further comprising pre-applying a thermal interface material to the groove in the heat sink prior to mounting the heat sink to the circuit board.

10. A cooling assembly for cooling at least one heat-generating electronic component mounted on a circuit board, said cooling assembly comprising:

a heat collector attached to the heat-generating electronic component;

at least one heat pipe placed in direct thermal contact with the heat collector to remove heat from the heat collector and move the heat to a location which is distant from the electronic component; and

at least one heat sink mounted to the circuit board at the distant location, said heat sink having at least one groove formed on an underside thereof, wherein the at least one heat sink is mounted so that it overlies the heat pipe and the heat pipe is introduced into the groove, thereby securing the heat pipe between the heat sink and the circuit board.

11. The cooling assembly as recited in claim 10, wherein the at least one groove in the at least one heat sink has a wall, and the groove is sized so that the heat pipe is in direct thermal contact with the wall when the heat pipe is secured between the heat sink and the circuit board.

12. The cooling assembly as recited in claim 11, wherein the at least one groove extends for the entire length of the at least one heat sink, and the cooling assembly includes a plurality of heat sinks aligned and mounted to the circuit board so that the groove in each heat sink is aligned with the groove in an adjacent heat sink, wherein each heat sink overlies a different portion of the heat pipe and secures the respective portion of the heat pipe to the circuit board.

13. The cooling assembly as recited in claim 11, wherein a plurality of heat pipes remove heat from the heat collector, and the cooling assembly includes a plurality of heat sinks mounted to the circuit board so that the groove in each heat sink is aligned with a different one of the heat pipes, wherein each heat sink overlies a different heat pipe and secures the respective heat pipe to the circuit board.

14. The cooling assembly as recited in claim 11, wherein a plurality of heat pipes remove heat from the heat collector, and the heat sink has a plurality of grooves formed on an underside thereof, wherein the heat sink is mounted to the circuit board so that the plurality of grooves is aligned with a different one of the heat pipes, wherein the heat sink overlies the plurality of heat pipes and secures the heat pipes to the circuit board.

15. The cooling assembly as recited in claim 14, further comprising a plurality of heat collectors attached to a plurality of heat-generating electronic components, wherein the plurality of heat pipes are arranged to remove heat from the plurality of heat collectors and to transfer the heat to the at least one heat sink.

16. The cooling assembly as recited in claim 14, wherein the plurality of grooves is aligned parallel to cooling fins on a top side of the heat sink.

17. The cooling assembly as recited in claim 11, wherein the heat sink is mounted to the circuit board so that the heat pipe is in direct thermal contact with the circuit board.

18. The cooling assembly as recited in claim 11, wherein the heat sink has grooves of different sizes to secure heat pipes of different sizes to the circuit board.

19. The cooling assembly as recited in claim 11, further comprising a thermal interface material applied to the groove in the heat sink.

20. The cooling assembly as recited in claim 11, wherein the at least one heat sink includes:

an upper part having the groove formed on the underside thereof; and

a lower part that connects to the upper part through an aperture in the printed circuit board;

wherein at least a portion of the heat pipe is secured between the upper part and the lower part of the heat sink.

21. The cooling assembly as recited in claim 11, wherein the at least one heat pipe includes a curved portion.

22. The cooling assembly as recited in claim 11, wherein the cooling assembly includes a plurality of heat sinks cut into different lengths from one single profile of a metallic material.

23. A method of designing and manufacturing a cooling assembly for cooling at least one heat-generating electronic component mounted on a circuit board, said method comprising the steps of:

selecting a heat collector;

attaching the heat collector to the component;

selecting at least one heat pipe;

placing the at least one heat pipe in direct thermal contact with the heat collector to remove heat from the heat collector and move the heat to a location which is distant from the electronic component; and

designing at least one heat sink having at least one groove formed on an underside thereof; and

mounting to the circuit board at the distant location, the at least one heat sink, wherein the at least one heat sink is mounted so that it overlies the heat pipe and the heat pipe is introduced into the groove, thereby securing the heat pipe between the heat sink and the circuit board.

24. The method as recited in claim 23, wherein the step of selecting a heat collector includes the steps of:

calculating a cooling capacity required for each heat-generating electronic component; and

based on the calculated required cooling capacity for each component, designing a heat sink for each component from a standard range of heat collector sizes and designs.

25. The method as recited in claim 23, wherein the step of selecting a heat pipe includes the steps of:

calculating a cooling capacity required for each heat-generating electronic component; and

based on the calculated required cooling capacity for each component, selecting a heat pipe for each component from a standard range of heat pipe sizes and designs.

26. The method as recited in claim 23, wherein the step of designing a heat sink includes the steps of:

calculating a cooling capacity required for each heat-generating electronic component; and

based on the calculated required cooling capacity for each component, designing a heat sink having a groove formed on the underside thereof for receiving each heat pipe.

27. The method as recited in claim 23, wherein the step of designing a heat sink includes the steps of:

calculating a cooling capacity required for each heat-generating electronic component;

based on the calculated required cooling capacity for each component, selecting a heat sink from a standard range of heat sink sizes and designs; and

modifying the heat sink with a groove formed on the underside thereof for receiving each heat pipe.

28. The method as recited in claim 27, wherein the step of modifying the heat sink with a groove formed on the underside thereof includes modifying the heat sink with grooves of different sizes to receive heat pipes of different standard dimensions.

29. The method as recited in claim 27, wherein the step of modifying the heat sink with a groove formed on the underside thereof includes forming curved grooves in the heat sink to accommodate heat pipes having a curved portion and/or U-shaped heat pipes and/or S-shaped heat pipes.