US20090165998A1

US20090165998A1 - Heat dissipation device

Info

Publication number: US20090165998A1
Application number: US11/964,909
Authority: US
Inventors: Hong-Bo Xu
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2007-12-27
Filing date: 2007-12-27
Publication date: 2009-07-02

Abstract

A heat dissipation device includes a base, a fin group located at a top of the base, a heat pipe connecting with the base and the fin group, a fan located at a top of the fin group, and a fan holder. The fan holder includes a securing portion mounted between the base and the fin group, a mounting portion extending from the securing portion. The mounting portion of the fan holder is located at a top of and spaced from the fin group and the fan is mounted on the mounting portion.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a heat dissipating device, more particularly to a heat dissipation device for dissipating heat generated by an electronic component.
2. Description of related art
A computer central processing unit (CPU) is the core controller of electrical signals in the contemporary personal computers. Continued development of the CPUs has enabled them to perform more and more functions. Heat generated by the CPUs has thus increased enormously. Such heat can adversely affect the operational stability of the computers. Measures must be taken to efficiently remove the heat from the CPU. Typically, a dissipation device having great heat conductivity is mounted on the CPU to remove the heat therefrom.
The conventional heat dissipation device commonly comprises a heat sink thermally connecting with the CPU, a heat pipe connecting with the heat sink and the CPU and a fan mounted on a top portion of the heat sink. The heat sink comprises a base and a plurality of fins extending upwardly from the base. The fins are made of aluminum. Each fin has a body and two legs extending downwardly from opposite ends of the body. The legs of the fins abut against the base. A condensing portion of the heat pipe extends through the body of the fins and an evaporating portion of the heat pipe is sandwiched between the base and the CPU. The fan is mounted on the fins. When the heat dissipation device works a long time, the fins and the heat pipe are deformed because of vibration and pressure via the fan. Thus, heat dissipation efficiency of the heat dissipation device is affected.
Thus, it is desired to devise a heat dissipating device which having a stable configuration.

SUMMARY OF THE INVENTION

A heat dissipation device includes a base, a fin group located at a top of the base, a heat pipe connecting with the base and the fin group, a fan located at a top of the fin group, and a fan holder. The fan holder includes a securing portion mounted between the base and the fin group, a mounting portion extending from the securing portion. The mounting portion of the fan holder is located at a top of and spaced from the fin group and the fan is mounted on the mounting portion.
Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:

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 being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an exploded view of a heat dissipation device in accordance with a preferred embodiment of the present invention;

FIG. 2 is an inverted view of FIG. 1;

FIG. 3 is a partial assembly view of the heat dissipation device of FIG. 1; and

FIG. 4 is an assembly view of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-2 illustrate a heat dissipation device for dissipating heat generated by an electronic component (not shown) mounted on a printed circuit board (not shown). The heat dissipation device comprises a base 20, a fin group 50 mounted on a top of the base 20, a pair of heat pipes 40 connecting with the base 20 and the fin group 50, a fan holder 30 mounted between the base 20 and the fin group 50, a fan 60 mounted on a top of the fin group 50 via the fan holder 30, two locking members 10 mounted on a bottom portion of the base 20 and a clip 70 spanning across the base 20 to secure the base 20 on the printed circuit board.
Each heat pipe 40 has a U-shaped configuration and comprises an evaporating portion 41, a condensing portion 43 and a connecting portion 45 interconnecting with the evaporating portion 41 and the condensing portion 43.
The fin group 50 consists of a plurality of vertical fins 51. The fins 51 are parallel to each other and spaced from each other with predetermined distance, thus a plurality of vertical airflow channels is defined between the fins 11. Bottom terminations of the fins 11 cooperatively define a bottom surface 511 which is slightly vaulted toward a centre of the second fin group 50. Top terminations of the fins 11 cooperatively define a top surface 513 which is slightly concave toward a centre of the second fin group 50. A width of each fin 11 is decreased from a top portion to a bottom portion. Each fin 11 defines two through holes 515 at opposite sides thereof. The condensing portions 43 of the heat pipes 40 extend through the through holes 515 and are soldered with the fins 11, thus, the fin group 50 and the heat pipes 40 are assembled together.
The base 20 is located at a bottom of the fin group 50 and spaced from the fin group 50. The base 20 is substantially rectangular and made of high degree of heat conductivity metal such as copper or aluminum. A protrusion 21 protrudes downwardly from a central portion of a bottom surface of the base 20 for contacting with the electronic component such that two undercuts 23 are defined at two opposite sides of the protrusion 21. Two locking portions 25 are formed at the undercuts 23, for engaging with the locking members 10. The central portion of a top surface of the base 20 defines two spaced receiving grooves 27 along a transverse direction to receive the evaporating portions 41 of the heat pipes 40. Two grooves 28 are defined between the receiving grooves 27. Two mounting holes 29 are defined between opposite ends of the base 20 along the transverse direction corresponding to the fan holder 30.
The fan holder 30 is a bent metal sheet and surrounds the fin group 50 therein. The fan holder 30 comprises a securing portion 31, two supporting portions 33 extending slantwise and upwardly from opposite sides of the securing portion 31 and two mounting portions 35 extending from the supporting portions 33. The securing portion 31 contacts with the base 20 and is spaced from the fin group 50 by the clip 70. The securing portion 31 is a rectangular plate and defines an elongated cutout (not labeled) at a centre thereof corresponding to the grooves 28 of the base 20. The securing portion 31 forms two bulges 37 extending downwardly at centre of opposite ends thereof. Each bulge 37 defines a through hole 371 therein. Screws (not labeled) extend through the through holes 371 and are engaged in the mounting holes 29 of the base 20 to mount the fan holder 30 on the base 20. The supporting portions 33 are located at an outside of the fin group 50. Each supporting portion 33 is a bent plate and defines a rectangular cutout 331 at a centre thereof. The cutout 331 is used to enhance the elasticity of the supporting portion 33 and guiding airflow to dissipate heat therethrough. The mounting portions 35 are spaced from the fin group 50 and located at the top of the fin group 50. Each mounting portion 35 comprises two bent connecting plates 351 extending from opposite ends of the supporting portion 33, and two mounting legs 353 extending from the connecting plates 351. The mounting legs 353 extend from two opposite directions and located above two opposite sides of the top surface 513 of the fin group 50. The mounting legs 353 are spaced from the top surface 513. Due to a configuration of the top surface 513 which is concaved, the mounting legs 353 cannot contact with the top surface 513 even if the fan 60 is mounted on the mounting legs 353; thus a distortion of the fin group 50 and the heat pipes 40 due to a pressure of the fan 60 can be effectively prevented. A through hole 3531 is defined at a free end of each leg 353 corresponding to the fan 60.
The fan 60 has a rectangular configuration and comprises a top flange 61 and a bottom flange 63. The bottom flange 63 has four corners. Each corner of the bottom flange 63 defines a mounting hole 631 aligned with the through hole 3531 of the mounting portion 35. Four screws (not labeled) extend through the mounting holes 631 and the through holes 3531 to mount the fan 60 on the fan holder 30.
The clip 70 spans across the base 20 and the securing portion 31 of the fan holder 31 and cooperates with the printed circuit board to mount the base 20 on the printed circuit board. The clip 70 comprises an elongated body 71, a first hook plate 73, a second hook plate 75, and an actuating member 77 pivotally engaged with the second hook plate 75. The elongated body 71 consists of two bent plates (not labeled). Bottom portions of the bent plates of the elongated body 71 extend trough the cutout of the securing portion 31 of fan holder 30 and are received in the grooves 28 of the base 20. The first and second hook plate 73, 75 engage with a retainer member (not shown) on the printed circuit board, when the actuating member 77 is driven to be rotated downwardly; thus, the second base 20 is secured on the printed circuit board.
Each locking member 10 comprises a locking lever 11 engaging with the corresponding locking portion 25 of the base 20 and two legs 13 extending outwardly from opposite ends of the locking lever 11 and angled with the locking lever 11. Screws (not labeled) extend through the locking lever 11 and the locking portions 25 of the base 20 to secure the locking members 10 to the bottom of the locking portions 25.
Four fasteners 15 extend through the legs 13 of the locking member 10 to be engaged in corresponding locking holes (not shown) under the printed circuit board to thereby mount the heat dissipation device to the printed circuit board.
Referring to FIGS. 3-4, in assembly, the condensing portions 43 of the heat pipes 40 extend through the through holes 51 5 of the fin group 50 and the evaporating portions 41 of the heat pipes 40 are received in the receiving grooves 27 of the base 20. In this state, the fin group 50 is located at the top of and spaced from the base 20. The fin group 50 is supported by the condensing portions 43 of the heat pipes 40. The screws extend through the through holes 371 of the bulges 37 of the fan holder 30 and are engaged in the mounting holes 29 of the base 30 to mount the fan holder 30 on the base 20. In this state, the supporting portions 33 are located at the outsides of the fin group 50 and the mounting portions 35 are located at the top of the fin group 50. The screws extend through the mounting holes 631 and the through holes 3531 of the fan holder 30 to mount the fan 60 on the fan holder 30. The clip 70 and the locking members 10 are mounted on the printed circuit board. The clip 70 is located at a bottom of the bottom surface 511 of the fin group 50.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.

Claims

1. A heat dissipation device adapted for dissipating heat generated by an electronic component mounted on a printed circuit board, comprising:

a base thermally contacting with the electronic component;

a fin group located at a top of the base;

a heat pipe connecting with the base and the fin group;

a fan located at a top of the fin group; and

a fan holder comprising a securing portion mounted between the base and the fin group, a mounting portion extending from the securing portion;

wherein the mounting portion of the fan holder is located at a top of and spaced from the fin group and the fan is mounted on the mounting portion.

2. The heat dissipation device as claimed in claim 1, wherein the fan holder comprises a pair of supporting portions extending slantwise and outwardly from two sides of the securing portion and connecting with the mounting portion and the supporting portion is located at an outside of the fin group.

3. The heat dissipation device as claimed in claim 2, wherein the supporting portion defines a cutout thereof.

4. The heat dissipation device as claimed in claim 1, wherein the mounting portion comprises two connecting plates and two mounting legs extending from the connecting plates, two through holes defined at free ends of the mounting legs to mount the fan thereon.

5. The heat dissipation device as claimed in claim 1, wherein the heat pipe comprises a condensing portion received in the base and an evaporating portion extending trough the fin group and supporting the fin group.

6. The heat dissipation device as claimed in claim 1, wherein the fin group is spaced from the base.

7. The heat dissipation device as claimed in claim 1, further comprising a clip spanning across the base.

8. The heat dissipation device as claimed in claim 7, wherein the securing portion defines an elongated cutout therein and the base defines two grooves therein corresponding to the cutout of the securing portion, and a bottom portion of the clip extends through the cutout of the securing portion and is received in the grooves of the base.

9. The heat dissipation device as claimed in claim 7, wherein the fin group comprises a plurality of fins and the fins are parallel to each other and spaced from each other with predetermined distance.

10. The heat dissipation device as claimed in claim 7, wherein the fin group has an arc-shaped top surface and an arc-shaped bottom surface, the clip is located at a bottom of the arc-shaped bottom surface.

11. A heat dissipation device, comprising:

a heat sink having a base adapted for contacting with a heat-generating electronic component and a plurality of fins mounted above the base and spaced from the base, the fins having a concaved top surface;

a fan holder having a securing portion sandwiched between the base and the fins, and a pair of supporting portions extending upwardly and slantwise from two opposite sides of the securing portion and surrounding the fins therebetween, and a pair of legs formed ends of the supporting portions and located above and spaced from the top surface of the fins; and

a fan mounted on the legs of the fan holder.

12. The heat dissipation device as claimed in claim 11, wherein a cutout is defined in each of supporting portions of the fan holder for providing passage of airflow generated by the fan.

13. The heat dissipation device as claimed in claim 12, wherein a bottom portion of the fins is arced upwardly to define a space between the securing portion of the fan holder and the bottom portion of the fins.

14. The heat dissipation device as claimed in claim 13, wherein a clip spans across the space and extends through the securing portion to be engaged in the base.

15. The heat dissipation device as claimed in claim 1, wherein a heat pipe thermally connects the base and the fins.