US20110265976A1

US20110265976A1 - Heat dissipation device with heat pipe

Info

Publication number: US20110265976A1
Application number: US12/790,889
Authority: US
Inventors: Wei Li; Yi-Qiang Wu
Original assignee: Fuzhun Precision Industry Shenzhen Co Ltd; Foxconn Technology Co Ltd
Current assignee: Fuzhun Precision Industry Shenzhen Co Ltd; Foxconn Technology Co Ltd
Priority date: 2010-04-28
Filing date: 2010-05-31
Publication date: 2011-11-03
Also published as: CN102238847A

Abstract

An exemplary heat dissipation device for a heat-generating component includes a heat sink, a heat pipe and a heat conductive member. The heat sink includes a plurality of stacked first fins and second fins. Each of the first fins defines an accommodating groove therein. The heat pipe includes an evaporator section, a condenser section and a connecting section interconnecting the evaporator section and the condenser section. The evaporator section thermally connects the heat-generating component. The connecting section extends obliquely from the evaporator section to the first fins. The condenser section is attached to the second fins. The connecting section is accommodated in the accommodating grooves of the first fins, and makes no thermal contact with the first fins. The heat conductive member thermally connects the first fins with the heat-generating component.

Description

BACKGROUND

1. Technical Field
The disclosure generally relates to heat dissipation, and particularly to a heat dissipation device with a heat pipe.
2. Description of Related Art
It is well known that heat is generated by electronic components, such as integrated circuit chips, during their operation. If the heat is not efficiently removed, the electronic components may suffer damage. Thus, heat dissipation devices are often used to cool the electronic components.
A typical heat dissipation device includes a fin assembly and a heat pipe attached to the fin assembly. The heat pipe is generally bent to have an oblique section with respect to the fin assembly. With this configuration, heat generated by an electronic component can be rapidly transferred to the fin assembly.
However, during assembly, it is difficult for the oblique section of the heat pipe to snugly contact the fin assembly. This may adversely affect heat transfer between the heat pipe and the fin assembly. If some fins of the fin assembly corresponding to the oblique section of the heat pipe are omitted, not only is the overall heat dissipation surface reduced, but also the oblique section of the heat pipe becomes exposed. The exposed oblique section of the heat pipe may adversely affect the aesthetic appearance of the heat dissipation device.
What is needed, therefore, is a heat dissipation device with a heat pipe which can overcome the described limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the various views.

FIG. 1 is an exploded, isometric view of a heat dissipation device in accordance with a first embodiment of the disclosure.

FIG. 2 is inverted, enlarged, isometric view of a heat pipe assembly, a heat conductive member, a fan, and a mounting rack of the heat dissipation device of FIG. 1.

FIG. 3 is an enlarged, partly assembled view of the heat dissipation device of FIG. 1, showing a heat sink disassembled from the heat pipe assembly, the heat conductive member, the fan, and the mounting rack.

FIG. 4 is an assembled view of the heat dissipation device of FIG. 3.

FIG. 5 is a plan view of a heat pipe of a heat dissipation device in accordance with a second embodiment of the disclosure.

FIG. 6 is a plan view of a heat pipe of a heat dissipation device in accordance with a third embodiment of the disclosure.

FIG. 7 is an exploded, isometric view of a heat conductive member and a heat sink of a heat dissipation device in accordance with a fourth embodiment of the disclosure.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a heat dissipation device in accordance with a first embodiment of the disclosure is shown. The heat dissipation device dissipates heat generated by a heat-generating electronic component (not shown), such as a central processing unit (CPU) or other component. The heat dissipation device includes a base 10, a fan 20 located on the base 20, a heat pipe assembly 30 mounted on the base 10, a heat sink 40 thermally connecting with the heat pipe assembly 30, and a plurality of electrically conductive posts 50 mounted on the heat sink 40.
The base 10 includes a bottom plate 11, and a mounting rack 13 and a heat conductive member 15 located on the bottom plate 11.
The bottom plate 11 is made of metal or metal alloy with a high heat conductivity coefficient, such as copper, copper-alloy, or other suitable material. The bottom plate 11 is generally rectangular, and is attached to the heat-generating electronic component at a bottom surface thereof. The bottom plate 11 defines a plurality of parallel and spaced receiving grooves 111 in a top surface thereof, and a plurality of fastener holes 113 at an outer periphery of the receiving grooves 111 thereof.
The mounting rack 13 is substantially rectangular, and forms a plurality of fasteners 131 thereon, for mounting the heat dissipation device on a circuit board (not shown) on which the heat-generating electronic component is disposed. The mounting rack 13 includes a top plate 132 at the center thereof. The top plate 132 is generally rectangular, and defines a plurality of parallel and spaced receiving grooves 1321 in a bottom surface thereof, corresponding to the receiving grooves 111 of the bottom plate 11. The top plate 132 further defines an opening 1322 at a center thereof, and a plurality of fixing holes 1323 at an outer periphery of the opening 1322 thereof. The fixing holes 1323 correspond to the fastener holes 113 of the bottom plate 11, respectively. The opening 1322 includes an orienting hole 1324 and a pair of fixing grooves 1325 in communication with the orienting hole 1324. The orienting hole 1324 is generally rectangular, and spans through an entire thickness of the top plate 132. The fixing grooves 1325 are defined in a bottom surface of the top plate 132, and are disposed at opposite ends of the orienting hole 1324, respectively. The mounting rack 13 defines two through holes 133, 134 at opposite sides of the top plate 132, respectively.
The heat conductive member 15 extends through the opening 1322 of the mounting rack 13. The heat conductive member 15 includes a heat conductive base 151, and a plurality of cylindrical heat transfer posts 152 extending perpendicularly up from the heat conductive base 151. The heat conductive base 151 and the heat transfer posts 152 are made of metal or metal alloy with a high heat conductivity coefficient, such as copper, copper-alloy, or other suitable material. In this embodiment, the heat transfer posts 152 are integrally formed with the heat conductive base 151 as a single monolithic piece. Alternatively, each of the heat transfer posts 152 can be a single monolithic body welded or riveted on the heat conductive base 151. The heat conductive base 151 includes a main body 1514, and a pair of tabs 1515 extending out from opposite ends of the main body 1514, respectively. The main body 1514 defines a plurality of parallel and spaced receiving grooves 1516 in a bottom surface thereof. A height of the main body 1514 is greater than a depth of the opening 1322. A height of each of the tabs 1515 is equal to a depth of each of the fixing grooves 1325 of the opening 1322. The main body 1514 extends through the orienting hole 1324 of the opening 1322. The tabs 1515 are received in the fixing grooves 1325 of the opening 1322, respectively. At this time, the receiving grooves 1516, 111, 1321 of the main body 151, the bottom plate 11 and the mounting rack 13 align with each other, and cooperatively define a plurality of cylindrical receiving grooves for receiving the heat pipe assembly 30.
The fan 20 is an axial fan directing airflow toward the heat sink 40, and is fixed on one lateral side of the mounting rack 13.
The heat pipe assembly 30 includes a first heat pipe 31, and a pair of second heat pipes 33 at opposite sides of the first heat pipe 31. The first and second heat pipes 31, 33 are cylindrical. The first heat pipe 31 is bent to a U-shape. The first heat pipe 31 includes an evaporator section 311, and two condenser sections 312 extending perpendicularly up from opposite ends of the evaporator section 311, respectively. The evaporator section 311 is horizontal and straight. Each condenser section 312 is vertical and straight, and is attached perpendicularly to the heat sink 40. Each of the second heat pipes 33 includes an evaporator section 331, two condenser sections 332, and two connecting sections 333 interconnecting the condenser sections 332 and opposite ends of the evaporator section 331, respectively. The evaporator section 331 is horizontal and straight. The connecting sections 333 extend laterally, obliquely and outwardly up from the opposite ends of the evaporator section 331 to the heat sink 40, respectively. In this embodiment, the connecting sections 333 are straight. Each condenser section 332 extends from a corresponding connecting section 333 to the heat sink 40. The condenser section 332 is vertical and straight, and is attached perpendicularly to the heat sink 40.
The heat sink 40 includes a plurality of stacked first fins 41, second fins 43 and third fins 45. The first fins 41 are located at the bottommost end of the heat sink 40 adjacent to the base 10. The third fins 45 are located at a topmost end of the heat sink 40 farthest away from the base 10. The second fins 43 are disposed between the first fins 41 and the third fins 45. In other words, the second fins 43 are arranged on the first fins 41, and under the third fins 45. The second and third fins 43, 45 correspond to the condenser sections 332 of each second heat pipe 33. The first fins 41 correspond to the connecting sections 333 of each second heat pipe 33. The connecting sections 333 of each second heat pipe 33 extend laterally, obliquely and outwardly from the opposite ends of the evaporator section 331 to the first fins 41, respectively.
The first, second and third fins 41, 43, 45 are substantially rectangular and parallel to each other, with a plurality of air channels (not labeled) defined therebetween. Each of the first, second and third fins 41, 43, 45 defines a plurality of joining holes 411, 431, 451, for receiving the electrically conductive posts 50 therein, respectively. Each of the first and second fins 41, 43 defines a receiving hole 412, 432 in one end thereof adjacent to the fan 20. The receiving holes 412, 432 of the first and second fins 41, 43 align with each other, and cooperatively define a receiving space for receiving the fan 20. The receiving space is higher than the fan 20. Alternatively, the receiving space can be defined only in the first fins 41 when such a receiving space is large enough to receive the fan 20.
Each of the first fins 41 defines two accommodating grooves 413, 414 at opposite ends of the group of evaporator sections 311, 331 of the heat pipe assembly 30, for accommodating the four connecting sections 333 of the two second heat pipes 33. The accommodating grooves 413, 414 align with the through holes 133, 134 of the mounting rack 13, respectively. The accommodating grooves 413 are located at one side of the first fins 41 farthest away from the fan 20, and cooperatively define an accommodating space for accommodating one of the connecting sections 333 of each second heat pipe 33. The accommodating grooves 414 are disposed between the accommodating grooves 413 and the receiving holes 412, and communicate with the receiving holes 412. The accommodating grooves 414 cooperatively define another accommodating space for accommodating another one of the connecting sections 333 of each second heat pipe 33. The accommodating grooves 413, 414 are substantially rectangular. A transverse width of each of the accommodating grooves 413, 414 corresponding to a respective pair of the connecting sections 333 of the second heat pipes 33 is greater than a distance spanned by such pair of connecting sections 333 when projected onto the first fins 41. A topmost pair of the accommodating grooves 413, 414 is not lower than topmost ends of the connecting section 333 of the second heat pipes 33.
Each first fin 41 defines a plurality of engaging holes 416 between the accommodating grooves 413, 414. The engaging holes 416 are circular, and align with the heat transfer posts 152 of the heat conductive member 15 for receiving the heat transfer posts 152 therein, respectively. The number of engaging holes 416 corresponds to the number of heat transfer posts 152. Each of the second and third fins 43, 45 defines a plurality of connecting holes 435, 455, which align with the condenser sections 312, 332 of the heat pipe assembly 30 and the accommodating grooves 413, 414 of the first fins 41, respectively.
The electrically conductive posts 50 are made of metal or metal alloy with a high heat conductivity coefficient, such as copper, copper-alloy, or other suitable material. The electrically conductive posts 50 are elongated and cylindrical. The electrically conductive posts 50 extend through and are snugly engaged in the joining holes 411, 431, 451 of the first, second and third fins 41, 43, 45, respectively. Thus, the first, second and third fins 41, 43, 45 and the electrically conductive posts 50 are electrically connected together. This reduces the electric resistance between the first, second and third fins 41, 43, 45. Therefore, the first, second and third fins 41, 43, 45 can easily attain a consistent and desired metal oxide film with a predetermined thickness all over their surfaces during the process of anodizing the heat sink 40. Each of the electrically conductive posts 50 is fixed on the mounting rack 13 of the base 10, for further fixing the heat sink 40.
Referring to FIGS. 3 and 4, during assembly of the heat dissipation device, the evaporator sections 311, 331 of the heat pipe assembly 30 are received in the cylindrical receiving grooves cooperatively defined by the receiving grooves 1516, 111, 1321 of the heat conductive member 15, the bottom plate 11 and the mounting rack 13, respectively. The condenser sections 312, 332 of the heat pipe assembly 30 extend through the through holes 133, 134 of the mounting rack 13, respectively. The heat conductive member 15 is disposed between the condenser sections 312, 332 of the heat pipe assembly 30. A plurality of screws 137 (shown in FIG. 1) extend through the fixing holes 1323 of the top plate 132 of the mounting rack 13 and are screwed in the fastener holes 114 of the bottom plate 11, respectively, thereby snugly engaging the evaporator sections 311, 331 of the heat pipe assembly 30 with the bottom base 11, the mounting rack 13 and the heat conductive member 15.
The heat sink 40 is secured on the base 10. At this time, the fan 20 is received in the receiving holes 412, 432 of the first and second fins 41, 43 and aligns with the air channels between the fins 41, 43. The condenser sections 332 of the second heat pipes 33 extend through the accommodating grooves 413, 414 of the first fins 41, and are received and engaged in the connecting holes 435, 455 of the second and third fins 43, 45 via welding, respectively. The connecting sections 333 of the second heat pipe 33 are received in the accommodating grooves 413, 414 of the first fins 41, respectively, and have no thermal contact with the first fins 41. Top portions of the condenser sections 312 of the first heat pipe 31 are received and engaged in the connecting holes 435, 455 of the second and third fins 43, 45 via welding, and bottom portions of the condenser sections 312 of the first heat pipe 31 are received in the accommodating grooves 413, 414 of the first fins 41, respectively. The heat transfer posts 152 of the heat conductive member 15 are received and engaged in the engaging holes 416 of the first fins 416 via welding, respectively.
During operation of the heat dissipation device, the bottom plate 11 absorbs heat from the heat generating electronic component. A portion of the heat absorbed by the bottom plate 11 is transferred to the second and third fins 43, 45 of the heat sink 40 via the heat pipe assembly 30, and another portion of the heat absorbed by the bottom plate 11 is transferred to the first fins 41 of the heat sink 40 via the heat conductive member 15. The fan 20 produces airflow toward the heat sink 40, and thereby dissipates heat from the heat sink 40 into the ambient air.
In the heat dissipation device, the first fins 41 of the heat sink 40 define the accommodating grooves 413, 414 for receiving the oblique connecting sections 333 of the second heat pipes 33, respectively, and the heat conductive member 15 thermally connects the first fins 41 with the heat-generating electronic component. Therefore, the heat generated by the heat-generating electronic component can be transferred to the first fins 41 via the heat conductive member 15. Thus, the first fins 41 corresponding to the oblique connecting sections 333 of the second heat pipes 33 are full utilized for heat dissipation, whereby the overall heat dissipation surface area of the heat dissipation device is increased. In addition, the oblique connecting sections 333 of the second heat pipes 33 are not exposed. Thereby, the aesthetic appearance of the heat dissipation device is improved.
Referring to FIG. 5, a second heat pipe 33 a of a heat dissipation device in accordance with a second embodiment of the disclosure is shown. The second heat pipe 33 a differs from the second heat pipe 33 of the first embodiment only in that connecting sections 333 a of the second heat pipe 33 a are arcuate, and extend longitudinally, obliquely and outwardly up from the opposite ends of the evaporator section 331 to the heat sink 40, respectively.
Referring to FIG. 6, a second heat pipe 33 b of a heat dissipation device in accordance with a third embodiment of the disclosure is shown. The second heat pipe 33 b differs from the second heat pipe 33 a in the second embodiment only in that the second heat pipe 33 b only includes one condenser section 332 b and one connecting section 333 b formed at one end of the evaporator section 331.
The quantity and the locations of the accommodating grooves 413, 414 and the connecting holes 435, 455 of the heat sink 40 can be varied according to the second heat pipes 33 a, 33 b of the second and third embodiments.
Referring to FIG. 7, a heat sink 40 c and a heat conductive member 15 c of a heat dissipation device in accordance with a fourth embodiment of the disclosure is shown. The heat sink 40 c differs from the heat sink 40 of the first embodiment only in that each of second and third fins 43 c, 45 c further defines an engaging hole 436 c, 456 c aligning with the engaging hole 416 of each first fin 41. The heat conductive member 15 c differs from the heat conductive member 15 of the first embodiment in that heat transfer posts 152 c of the heat conductive member 15 c further extend into the second and third fins 43 c, 45 c, and are snugly received in the engaging holes 416, 436 c, 456 c of the first, second and third fins 41, 43 c, 45 c, respectively. Thus, the heat generated by the electronic component can be further transferred to the second and third fins 43 c, 45 c via the heat conductive member 15 c. Alternatively, the heat transfer posts 152 c can be only received in the engaging holes 416, 436 c of the first and second fins 41, 43 c, respectively.
It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

1. A heat dissipation device for a heat-generating component, the heat dissipation device comprising:

a heat sink comprising a plurality of stacked first fins and second fins, each of the first fins defining an accommodating groove therein;

a heat pipe attached to the heat sink, the heat pipe comprising an evaporator section, a condenser section and a connecting section interconnecting the evaporator section and the condenser section, the evaporator section configured for thermally connecting with the heat-generating component, the connecting section extending obliquely from the evaporator section to the first fins, the condenser section attached to the second fins, the connecting section accommodated in the accommodating grooves of the first fins and not contacting the first fins; and

a heat conductive member connecting with the first fins, and configured for thermally connecting with the heat-generating component.

2. The heat dissipation device of claim 1, wherein each first fin defines a joining hole therein, the heat conductive member comprises a heat conductive base and a heat transfer post on the heat conductive base, the heat conductive base is configured for thermally connecting with the heat-generating component, and the heat transfer post is received in the joining holes of the first fins.

3. The heat dissipation device of claim 2, further comprising a top plate, the top plate defining an opening therethrough, the heat conductive base extending through the opening.

4. The heat dissipation device of claim 3, wherein the top plate and the heat conductive base both define a receiving groove therein, and the receiving grooves receives the evaporator section of the heat pipe.

5. The heat dissipation device of claim 3, wherein the opening comprises an orienting hole and a pair of fixing grooves in communication with the orienting hole, the orienting hole spans through an entire thickness of the top plate, the fixing grooves are disposed at opposite ends of the orienting hole, respectively, the heat conductive base comprises a main body and a pair of tabs extending out from opposite ends of the main body, respectively, the main body extends through the orienting hole of the opening, and the tabs are oriented in the fixing grooves of the opening, respectively.

6. The heat dissipation device of claim 2, wherein each of the second fins defines a joining hole therein, and the heat transfer post further extends to the second fins and is received in the joining holes of the second fins.

7. The heat dissipation device of claim 1, wherein the connecting section of the heat pipe extends laterally and obliquely from the evaporator section, or longitudinally and obliquely from the evaporator section.

8. The heat dissipation device of claim 1, wherein a width of the accommodating groove is greater than a distance spanned by the connecting section when projected onto the first fins.

9. The heat dissipation device of claim 1, wherein the connecting section of the heat pipe is one of arcuate and straight.

10. The heat dissipation device of claim 1, further comprising an electrically conductive post extending through at least one of the plurality of first fins and the combined plurality of first and second fins.

11. The heat dissipation device of claim 1, wherein each of the second fins defines a connecting hole aligning with the accommodating grooves of the first fins, and the condenser section of the heat pipe is received in the connecting holes of the second fins.

12. The heat dissipation device of claim 1, further comprising a fan positioned for directing airflow to the heat sink, one of the plurality of first fins and the combined plurality of first and second fins defining a receiving space receiving the fan therein, the receiving space communicating with the accommodating grooves of the first fins.

13. A heat dissipation device for a heat-generating component, the heat dissipation device comprising:

a heat sink defining an accommodating space therein;

a heat pipe comprising an evaporator section, a condenser section and a connecting section interconnecting the evaporator section and the condenser section, the evaporator section configured for thermally connecting with the heat-generating component, the connecting section extending obliquely from the evaporator section to the heat sink, the condenser section attached to the heat sink, the connecting section accommodated in the accommodating space of the heat sink and not contacting the heat sink; and

14. The heat dissipation device of claim 13, wherein the heat sink defines a joining hole therein, the heat conductive member comprises a heat conductive base and a heat transfer post on the heat conductive base, the heat conductive base is configured for thermally connecting with the heat-generating component, and the heat transfer post is received in the joining hole of the heat sink.

15. The heat dissipation device of claim 14, further comprising a top plate, the top plate defining an opening therethrough, the opening comprising an orienting hole and a pair of fixing grooves in communication with the orienting hole, the orienting hole extending through the top plate, the fixing grooves disposed at opposite ends of the orienting hole, respectively, the heat conductive base comprising a main body and a pair of tabs extending out from opposite ends of the main body, respectively, the main body extending through the orienting hole of the opening, the tabs oriented in the fixing grooves of the opening, respectively.

16. The heat dissipation device of claim 13, wherein the connecting section of the heat pipe extends laterally and obliquely from the evaporator section, or longitudinally and obliquely from the evaporator section.

17. The heat dissipation device of claim 13, wherein a width of the accommodating space is greater than a distance spanned by the connecting section when projected onto the heat sink.

18. A heat dissipation device for a heat-generating component, the heat dissipation device comprising:

a heat sink comprising a plurality of stacked first fins and second fins, internal portions of the first fins cooperatively defining an accommodating space of the first fins;

a heat pipe attached to the heat sink, the heat pipe comprising an evaporator section, a condenser section and a connecting section interconnecting the evaporator section and the condenser section, the evaporator section configured for thermally connecting with the heat-generating component, the connecting section extending obliquely from the evaporator section to the first fins, the condenser section attached to the second fins, and the connecting section accommodated in the accommodating space of the first fins without contacting any of the first fins; and

19. The heat dissipation device of claim 18, wherein each first fin defines a joining hole therein, the heat conductive member comprises a heat conductive base and a heat transfer post on the heat conductive base, the heat conductive base is configured for thermally connecting the heat-generating component, and the heat transfer post is received in the joining holes of the first fins.

20. The heat dissipation device of claim 18, wherein the connecting section of the heat pipe extends laterally and obliquely from the evaporator section, or longitudinally and obliquely from the evaporator section.