US20070051498A1

US20070051498A1 - Heat dissipation device with a heat pipe

Info

Publication number: US20070051498A1
Application number: US11/308,392
Authority: US
Inventors: Wan-Lin Xia; Tao Li; Jun Long; Yong Zhong
Original assignee: Individual
Current assignee: Foxconn Technology Co Ltd
Priority date: 2005-09-02
Filing date: 2006-03-21
Publication date: 2007-03-08
Also published as: CN1925143A; CN100444364C

Abstract

A heat dissipation device includes a seat and a base having a first face and a second face opposite to the first face and thermally contacting the seat. A plurality of fins extends from the first face of the base. Two heat pipes are thermally arranged on the second face of the base. Each of the two heat pipes is bent and has a section sandwiched between the base and the seat, and another section thereof stretching along the base from said section to a portion of the base in no attachment with the seat.

Description

FIELD OF THE INVENTION

The present invention relates to heat dissipation devices for use in removing heat from electronic devices, and more particularly to a heat dissipation device incorporating a heat pipe for improving heat dissipation efficiency of the heat dissipation device.

DESCRIPTION OF RELATED ART

During operation of an electronic device such as a computer central processing unit (CPU), a large amount of heat is often produced. The heat must be quickly removed from the electronic device to prevent it from becoming unstable or being damaged. Typically, a heat dissipation device is attached to an outer surface of the electronic device to absorb heat from the electronic device. The heat absorbed by the heat dissipation device is then dissipated to ambient air.
Conventionally, a heat dissipation device comprises a solid metal base attached on the electronic device, and a plurality of fins arranged on the base. The base is intimately attached on the electronic device thereby absorbing the heat generated by the electronic device. Most of the heat accumulated at the base is transferred to the fins and is then dissipated from the fins. However, electronics technology continues to advance, and increasing amounts of heat are being generated by powerful state-of-the-art electronic devices. Many conventional heat dissipation devices are no longer able to efficiently remove heat from these electronic devices.
In order to overcome the disadvantages of the heat dissipation device set out above, one type of heat dissipation device used for the electronic device includes a heat pipe for transferring heat from a position to another position of the heat dissipation device. The heat pipe is a vacuum-sealed pipe that is filled with a phase changeable fluid, usually being a liquid, such as water, alcohol, acetone and so on, and has an inner wall thereof covered with a capillary configuration. As the electronic device heats up, a hot section which is usually called the evaporating section of the heat pipe and is located close to the electronic device also heats up. The liquid in the evaporating section of the heat pipe evaporates and the resultant vapor reaches a cool section usually called condensing section of the heat pipe and condenses therein. Then the condensed liquid flows to the evaporating section along the capillary configuration of the heat pipe. This evaporating/condensing cycle repeats and since the heat pipe transfers heat so efficiently, the evaporating section is kept at or near the same temperature as the condensing section of the heat pipe. Correspondingly, the heat-transfer capability of the heat dissipation device including the heat pipe is improved greatly.
Typically, a heat dissipation device illustrated as follows is used. The heat dissipation device comprises a base for absorbing heat from a heat generating electronic device, a heat pipe thermally connected to the base, and a plurality of fins arranged on the base. Generally, the heat pipe is I-shaped. The base defines a groove substantially in the center thereof receiving the heat pipe therein. In use, the base is in contact with the electronic device and absorbs heat from the electronic device. The heat in the base is absorbed by the heat pipe, and the heat pipe transfers the heat from the center to other parts of the base. The heat in the base spreads to the fins to be dissipated to ambient air. However, the heat pipe is straight, which results in the thermally contacting area between the base and the heat pipe being relatively small. Consequently, the heat in the center of the base can not be transmitted to other parts of the base rapidly and evenly. The heat generated by the electronic device accumulates in the center of the base and the electronic device. Normal functions and abilities of the electronic device are adversely affected. Therefore, the heat dissipation device needs to be improved.
What is needed, therefore, is a heat dissipation device which achieves a greater heat-transfer capability and a greater heat dissipation capability.

SUMMARY OF INVENTION

A heat dissipation device in accordance with a preferred embodiment of the present invention comprises a seat for absorbing heat from a heat generating electronic device, and a base having a first face and a second face opposite to the first face and thermally contacting the seat. A plurality of fins integrally extends from the first face of the base. Two heat pipes are thermally arranged on the second face of the base. Each of the two heat pipes is bent and has a section sandwiched between the second face of base and the seat, and another section thereof stretching along the second surface of the base from said section to a portion of the base in no attachment with the seat.
Other advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded, isometric view of a heat dissipation device in accordance with a first embodiment of the present invention;
FIG. 2 is an inverted view of FIG. 1 but without a base;
FIG. 3 is an inverted and assembled view of FIG. 1;
FIG. 4 is an inverted and partially assembled view of a heat dissipation device in accordance with a second embodiment of the present invention;
FIG. 5 is an inverted and partially assembled view of a heat dissipation device in accordance with a third embodiment of the present invention; and
FIG. 6 is an inverted and partially assembled view of a heat dissipation device in accordance with a fourth embodiment of the present invention.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a heat dissipation device according to a first embodiment of the present invention for dissipating heat generated by an electronic device (not shown) located on a printed circuit board (not shown) is shown. The heat dissipation device comprises a seat 10, a heat sink 30 on the seat 10, and two heat pipes 50 thermally contacting the seat 10 and the heat sink 30.
The seat 10 is a substantially rectangular metal plate having great thermal conductivity, and has a bottom face (not labeled) for contacting with the electronic device (not shown) and a top face (not labeled) opposite the bottom face. Two parallel grooves 110 each with semicircular cross section are defined in the top face of the seat 10 for receiving the heat pipes 50 therein.
The heat sink 30 comprises a base 31 and a plurality of fins 33 on the base 31. The base 31 is a substantially rectangular plate and comprises a top face having the fins 33 integrally extending therefrom and a bottom face having a protrusion 34 extending downwardly from a center portion thereof. The protrusion 34 has a bottom face thereof defining two substantially U-shaped grooves 310 therein. The two grooves 310 are juxtaposed in the bottom face of the base 31 but oriented oppositely to each other. Each groove 310 comprises a first section 311 and two parallel second sections 313 substantially perpendicularly extending from two ends of the first section 311, respectively. The first sections 311 of the grooves 310 are located adjacent a center of the protrusion 34. The second sections 313 of the grooves 310 are located adjacent two opposite lateral sides of the bottom face of the base 31. The two first sections 311 of the two grooves 310 are parallel to each other. The corresponding second sections 313 of the two grooves 310 extend oppositely in the bottom face of the base 31. A round corner is formed at each joint of the first section 311 and second sections 313 of each groove 310.
Each of the two heat pipes 50 is substantially U-shaped and is identical to the groove 310 of the base 31 in profile. Each heat pipe 50 comprises a first transferring section 510 and two substantially parallel second transferring sections 530 extending from two ends of the first transferring section 510. A round corner is formed at each joint of the first and second transferring sections 510, 530 of each heat pipe 50.
Referring to FIG. 3, the top face of the seat 10 is thermally combined to the bottom face of the protrusion 34 of the heat sink 30. Therefore, the grooves 110 of the seat 10 and the first sections 311 of the grooves 310 of the base 31 of the heat sink 30 corporately define two parallel channels (not labeled). The two heat pipes are juxtaposed in the base 31 of the heat sink 30. The first transferring sections 510 of the two heat pipes 50 are accommodated in the two channels, respectively. The second transferring sections 530 of the two heat pipes 50 extend beyond the seat 10 and are received in the second sections 313 of the grooves 310 of the heat sink 30, respectively. Therefore, the two heat pipes 50 are thermally combined to the heat sink 30 side by side but oppositely. The first transferring sections 510 of the two heat pipes 50 are positioned adjacent the center of the bottom face of the base 31 of the heat sink 30. The corresponding second transferring sections 530 of the two heat pipes 50 extend oppositely and are positioned near the two opposite lateral sides of the base 31 of the heat sink 30.
In use, the bottom face of the seat 10 contacts the electronic device to absorb heat from the electronic device. The heat in the seat 10 is absorbed by the first transferring sections 510 of the heat pipes 50 and the protrusion 34 of the heat sink 30. And then, part of the heat in the heat pipes 50 and the protrusion 34 directly spreads upward to the fins 33, and part of the heat is transferred outwardly to lateral portion of the base 31 of the heat sink 30 via the second transferring sections 530 of the heat pipes 50. Subsequently, the heat in the fins 33 is dissipated to ambient air.
According to the first embodiment of the present invention, the heat pipes 50 combined to the bottom of the base 31 of the heat sink 30 are curved to form a U-shape; therefore, the heat pipes 50 and the base 30 have a larger thermal contacting area therebetween; the heat in the center of the base 31 can be transferred to lateral portions of the base 31 rapidly via the second transferring sections of the heat pipes 50 in comparison with the conventional heat dissipation device; therefore, the heat generated by the electronic device is evenly distributed to the base 31, to thereby be dissipated by the fins 33 rapidly. Thus, the heat-dissipating capability of the present invention is improved greatly.
Referring to FIG. 4, a heat dissipation device in accordance with a second embodiment of the present invention is shown. The heat dissipation device is similar to the heat dissipation device of the first embodiment, but the main difference is that each of two heat pipes 50 a has one of two second transferring sections 530 a thereof located adjacent to a center of a bottom face of a base 31 a of the heat sink 30, the other of the two second transferring sections 530 a located adjacent to lateral sides of the base 31 a of the heat sink 30. Two first transferring sections 510 a of the two heat pipes 50 are substantially parallel to each other and are located adjacent to two opposite lateral sides of the base 31 a. The second transferring sections 530 a of the two heat pipes 50 a are parallel to each other. The base 31 a of the heat sink 30 defines grooves 310 a accommodating the heat pipes 50 a therein.
Referring to FIG. 5, a heat dissipation device in accordance with a third embodiment of the present invention is shown. The heat dissipation device is similar to the heat dissipation device of the second embodiment, but the main difference is that one of two heat pipes 50 b of the heat dissipation device has one second transferring section 530 b located between two second transferring sections 530 b of the other heat pipe 50 b. A base 31 b of the heat sink 30 defines grooves 310 b accommodating the heat pipes 50 b therein.
Referring to FIG. 6, a heat dissipation device in accordance with a forth embodiment of the present invention is shown. The heat dissipation device is similar to the heat dissipation device of the third embodiment, but the main difference is that two heat pipes 50 c of the heat dissipation device are substantially rectangular without being closed up. Each heat pipe 50 c comprises four transferring sections 510 c. Each heat pipe 50 c has one transferring section 510 c positioned adjacent a center of a base 31 c, and other three transferring sections 510 c positioned adjacent three lateral sides of the base 31 c of the heat sink 30. The transferring section 510 c adjacent the center of the base 31 c of one heat pipe 50 c is disposed among the four transferring sections 510 c of the other heat pipe 50 c. Therefore, the two heat pipes 50 c are located in the base 31 c taking the format crossing loops.
It is believed that the present invention and its 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 comprising:

a base having a first face and a second face opposite to the first face;

a seat attached to the second face of the base and adapted for absorbing heat from an electronic device;

a plurality of fins arranged on the first face of the base; and

a bent heat pipe comprising a section sandwiched between the seat and the second face of the base, and another section stretching on the second surface of the base from said section to a portion of the base in no attachment with the seat.

2. The heat dissipation device of claim 1 further comprising a heat pipe having a section sandwiched between the seat and the second face of the base, and another section stretching on the second surface of the base from said section to a portion of the base in no attachment with the seat.

3. The heat dissipation device of claim 2, wherein each of the heat pipes is generally U-shaped and comprises a first section and two second sections extending from two ends of the first section.

4. The heat dissipation device of claim 3, wherein the first sections of the two heat pipes are parallel to each other and sandwiched between the second face of the base and the seat.

5. The heat dissipation device of claim 4, wherein the second sections of the two heat pipes extend oppositely beyond the seat and located adjacent two opposite lateral sides of the second face of the base.

6. The heat dissipation device of claim 3, wherein each of the two heat pipes has one of the two second sections sandwiched between the second face of the base and the seat, the other second section thereof located adjacent two opposite lateral sides of the second face of the base.

7. The heat dissipation device of claim 6, wherein the two heat pipes have the first sections thereof extending beyond the seat and located adjacent another two opposite lateral sides of the second face of the base.

8. The heat dissipation device of claim 7, wherein the second sections of the two heat pipes are parallel to each other.

9. The heat dissipation device of claim 8, wherein one of the second sections of one of the heat pipes is positioned between the two second sections of the other one of the heat pipes.

10. The heat dissipation device of claim 2, wherein each of the two heat pipes is generally rectangular without being closed up and comprises four sections.

11. The heat dissipation device of claim 10, wherein the two heat pipes are positioned in the second face of the base taking the format crossing loops, one of the four sections of one of the heat pipes being positioned among the four sections of the other heat pipe.

12. The heat dissipation device of claim 1, wherein the seat is located at a central portion of the second face of the base.

13. A heat dissipation device comprising:

a seat adapted for absorbing heat from an electronic device;

a base having a first face and a second face opposite to the first face thermally contacting the seat;

a plurality of fins extending from the first face of the base; and

two heat pipes being thermally arranged on the second face of the base, at least one of the two heat pipes being bent and having a section located adjacent to a center of the second face of the base and engaged with the seat, and another section thereof located adjacent to a lateral side of the second face of the base and in no engagement with the seat.

14. The heat dissipation device of claim 13, wherein both of the two heat pipes have a section located adjacent to the center of the second face of the base and engaging with the seat, and another section located adjacent to a lateral side of the second face of the base.

15. The heat dissipation device of claim 14, wherein each of the two heat pipes is generally U-shaped, and comprises a first section and two second sections extending from two ends of the first section.

16. The heat dissipation device of claim 14, wherein each of the two heat pipes is generally rectangular, and comprises interconnecting four sections.