US20100206538A1

US20100206538A1 - Thermal module having enhanced heat-dissipating efficiency and heat dissipating system thereof

Info

Publication number: US20100206538A1
Application number: US12/703,785
Authority: US
Inventors: Jia-Shao Chen
Original assignee: ZEX TECHNOLOGIES Inc
Current assignee: ZEX TECHNOLOGIES Inc
Priority date: 2009-02-16
Filing date: 2010-02-11
Publication date: 2010-08-19
Also published as: TW201031881A

Abstract

A thermal module includes a conductive base disposed on a heat source for conducting heat generated by the heat source, and a plurality of thermal fins disposed substantially on the conductive base in parallel. A plurality of protruding portions is formed on each thermal fin in a direction whereto the thermal fins are stretched from the conductive base, and the protruding portions of adjacent thermal fins are arranged alternately in the direction whereto the thermal fins are stretched from the conductive base so as to dissipate the heat conducted to the conductive base from the heat source.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a thermal module and a heat dissipating system thereof, and more particularly, to a thermal module having enhanced heat dissipating efficiency and a heat dissipating system thereof.
2. Description of the Prior Art
With the advanced technology, heat dissipating efficiency becomes an important issue in an application of a heat dissipating system. However, the conventional heat dissipating methods are unable to effectively dissipate huge heat generated by a heat source with high power, and various advanced heat dissipating methods are designed to dissipate the heat so as to keep an electronic device in a normal working temperature. Conventional air cooling systems with a fan still have problems, so improving heat dissipating efficiency of the heat dissipating component with the conventional fan is an important issue for increasing the heat dissipating efficiency of the conventional heat dissipating system.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a diagram of a thermal device 20 in the prior art. FIG. 2 is a sectional view of the thermal device 20 in the prior art. The thermal device 20 includes a conductive base 22 disposed on a heat source 24 for conducting heat generated by the heat source 24, and a plurality of thermal fins 26 substantially disposed on the conductive base 22 in parallel. A plurality of tunnels 261 is formed between adjacent thermal fins 26 so that airflow can flow through the thermal device 20 via the tunnels 261. Surfaces of the thermal fins 26 stretching from the conductive base 22 (X direction) are smooth so as to dissipate the heat conducted to the conductive base 22 from the heat source 24. As shown in FIG. 1, the conductive base 22 can be made of metal material having greater heat conductive coefficient, such as aluminum and copper material. The conductive base 22 is disposed on a side of the heat source 24 for contacting the heat source 24 directly, so that the heat generated by the heat source 24 is transmitted to the conductive base 22 by heat conduction manner. The plurality of thermal fins 26 can be made of metal material having greater heat conductive coefficient, such as the aluminum and the copper material. The heat conducted from the heat source 24 to the conductive base 22 is continuously conducted to the plurality of thermal fins 26. The plurality of thermal fins 26 is substantially disposed on the conductive base 22 in parallel for increasing contacting area between the thermal device 20 and the air, which means the contacting area is increased to surface areas of two sides of the plurality of thermal fins 26. Therefore, the heat generated by the heat source 24 can be dissipated by the thermal fins 26 effectively. Air resistance inside the tunnels 261 is consistent due to a constant width W1 between adjacent tunnels 261. The convection without external forces is natural convection. Although the thermal device has low air resistance, the contacting area of the thermal device 20 is too small to dissipate the heat effectively. Therefore, the thermal device 20 can further include a fan 28 for enhancing the air convection, which is forced convection. The fan 28 is disposed on a lateral side or an upper side of the plurality of thermal fins 26 for inhaling or exhaling the air through the tunnels 261 so as to dissipate the heat generated by the heat source 24 effectively.
Please refer to FIG. 3 and FIG. 4. FIG. 3 is a diagram of a thermal device 40 in the prior art. FIG. 4 is a sectional view of the thermal device 40 in the prior art. The thermal device 40 includes a conductive base 42 disposed on a heat source 44 for conducting heat generated by the heat source 44, and a plurality of thermal fins 46 substantially disposed on the conductive base 42 in parallel. A plurality of tunnels 461 is formed between adjacent thermal fins 46 so that the airflow can flow through the thermal device 40 via the tunnels 461. A plurality of protruding parts 463 is formed on surfaces of the thermal fins 46 stretching from the conductive base 42 (X direction), and the plurality of protruding parts 463 is disposed on adjacent thermal fins 46 symmetrically for dissipating the heat conducted to the conductive base 42 from the heat source 44. Functions and arrangements of the conductive base 42, the heat source 44, and the thermal fins 46 are the same as ones of the above-mentioned device, and detailed description is omitted herein for simplicity. The plurality of protruding parts 463 formed on the plurality of thermal fins 46 increases contacting area between the thermal device 40 and the air. A width W20 is formed between the protruding parts 463 on adjacent thermal fins 46, a width W22 is formed between the smooth surfaces on adjacent thermal fins 46, and the width W22 is larger than the width W20.
Comparing to the thermal device 20, the thermal device 40 has larger contacting area so as to dissipate the heat generated by the heat source 44 quickly in an air cooling manner, so that the heat dissipating efficiency of the thermal device 40 is better than the heat dissipating efficiency of the thermal device 20. Due to difference of the width W20 and the width W22, the air resistance and the flow pressure are not consistent in the plurality of tunnels 461, so as to affect the natural convection inside the plurality of tunnels 461. Therefore, the thermal device 40 can further include a fan 48 for enhancing the air convection. As shown in FIG. 3, as the fan 48 is disposed on a lateral side of the plurality of tunnels 46 for inhaling or exhaling the air, width difference between adjacent protruding parts 463 unbalances the air resistance inside the tunnels 461, which means the flow pressure inside the plurality of tunnels 461 is unstable so that the heat dissipating efficiency of the forced convection is decreased. As the fan 48 is disposed on an upper side of the plurality of thermal fins 46 for inhaling or exhaling the airflow through the plurality of tunnels 461, the width difference due to symmetrical protruding parts 463 increase the air resistance of the thermal module 40 than the air resistance of the thermal module 20, so that the heat dissipating efficiency of the forced convection inside the plurality of tunnels 461 is decreased. Therefore, disposition of the plurality of protruding parts 463 of the thermal device 40 has drawbacks that the thermal device 40 is unable to dissipate the heat effectively. Thus, design of a thermal device not only has large contacting area but also is applied for preferable functions of the natural convection and the forced convection both is an important issue in the mechanical industry.

SUMMARY OF THE INVENTION

The present invention provides a thermal module having enhanced heat-dissipating efficiency and a heat dissipating system thereof for solving above drawbacks.
According to the claimed invention, a thermal module includes a conductive base disposed on a heat source for conducting heat generated by the heat source, and a plurality of thermal fins substantially disposed on the conductive base in parallel, a plurality of protruding portions being formed on each thermal fin in a direction whereto the thermal fins are stretched from the conductive base, and the plurality of protruding portions on adjacent thermal fins being arranged alternately in the direction whereto the thermal fins are stretched from the conductive base so as to dissipate the heat conducted to the conductive base from the heat source.
According to the claimed invention, a heat dissipating system includes a circuit board, a heat source installed on the circuit board, and a thermal module. The thermal module includes a conductive base disposed on the heat source for conducting heat generated by the heat source, and a plurality of thermal fins substantially disposed on the conductive base in parallel, a plurality of protruding portions being formed on each thermal fin in a direction whereto the thermal fins are stretched from the conductive base, and the plurality of protruding portions on adjacent thermal fins being arranged alternately in the direction whereto the thermal fins are stretched from the conductive base so as to dissipate the heat conducted to the conductive base from the heat source.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a thermal device in the prior art.

FIG. 2 is a sectional view of the thermal device in the prior art.

FIG. 3 is a diagram of another thermal device in the prior art.

FIG. 4 is a sectional view of the thermal device in the prior art.

FIG. 5 is a diagram of a thermal module having enhanced heat dissipating efficiency according to a first embodiment of the present invention.

FIG. 6 is a sectional view of the thermal module according to the first embodiment of the present invention.

FIG. 7 is a diagram of a thermal module having a plurality of triangle-shaped protruding portions according to a second embodiment of the present invention.

FIG. 8 is a diagram of a thermal module having a plurality of sawtooth-shaped protruding portions according to a third embodiment of the present invention.

FIG. 9 is a diagram of a thermal module having a plurality of wave-shaped protruding portions according to a fourth embodiment of the present invention.

FIG. 10 is a diagram of a thermal module having a plurality of sawtooth-shaped protruding portions with a plurality of protruding portions and corresponding sunken parts arranged alternately according to a fifth embodiment of the present invention.

FIG. 11 is a diagram of a thermal module including the plurality of protruding portions arranged alternately and smooth surfaces according to a sixth embodiment of the present invention.

FIG. 12 is a diagram of a thermal module including a plurality of protruding portions arranged alternately and a plurality of protruding portions arranged symmetrically according to a seventh embodiment of the present invention.

FIG. 13 is a diagram of thermal fins with the pillar structure according to an eighth embodiment of the present invention.

FIG. 14 is a diagram of thermal fins with the slice structure according to a ninth embodiment of the present invention.

DETAILED DESCRIPTION

Please refer to FIG. 5 and FIG. 6. FIG. 5 is a diagram of a thermal module 60 having enhanced heat dissipating efficiency according to a first embodiment of the present invention. FIG. 6 is a sectional view of the thermal module 60 according to the first embodiment of the present invention. The thermal module 60 includes a conductive base 62 disposed on a heat source 64 for conducting heat generated by the heat source 64, and a plurality of thermal fins 66 substantially disposed on the conductive base 62 in parallel. A plurality of tunnels 661 is formed between adjacent thermal fins 66 so that airflow can flow through the thermal module 60 via the tunnels 661. A plurality of protruding portions 663 is formed on the thermal fins 66 in a direction (X direction) whereto the thermal fins 66 are stretched from the conductive base 62, and the plurality of protruding portions 663 is arranged on adjacent thermal fins 66 alternately in the direction (X direction) whereto the thermal fins 66 are stretched from the conductive base 62 for dissipating the heat conducted to the conductive base 62 from the heat source 64. Corresponding sunken portions 664 are formed between adjacent protruding portions 663, which means a plurality of sunken portions 664 and the plurality of protruding portions 663 are arranged alternately. That is to say, the plurality of protruding portions 663 and the plurality of corresponding sunken portions 664 are formed on two sides of each tunnel 661 between adjacent thermal fins 66 along X direction, and the protruding portions 663 on a side of the tunnel 661 face to the sunken portions 664 on the other side of the tunnel 661, so that width of the plurality of tunnels 661 are consistent along X direction. The heat source 64 can be disposed on a circuit board 63 selectively. For example, the heat source 64 can be a central processing unit or a chip installed on the circuit board 63. The heat is generated due to high speed operation of the heat source 64. The heat source 64 can further be a metal board for conducting heat generated from a heating component to the thermal module 60, and the heat source 64 is not disposed on the circuit board 63. The conductive base 62 and the plurality of thermal fins 66 can be made of metal material, such as copper and aluminum material. The conductive base 62 is disposed on a side of the heat source 64 for conducting the heat from the heat source 64 directly. Therefore, the heat conducted to the conductive base 62 from the heat source 64 can be conducted to the plurality of thermal fins 66. The plurality of thermal fins 66 is substantially disposed on the conductive base 62 in parallel for increasing contacting surface of the thermal module 60.
As shown in FIG. 5 and FIG. 6, the plurality of protruding portions 663 is formed on the thermal fins 66 in the direction whereto the thermal fins 66 are stretched from the conductive base 62. Each protruding portion 663 can be a long strip structure, and directions of the plurality of protruding portions 663 can be parallel to the conductive base 62 substantially. The plurality of protruding portions 663 can increase the contacting surface of the plurality of thermal fins 66 for increasing the heat dissipating efficiency. Due to alternate arrangement of the plurality of protruding portions 663 and the plurality of sunken portions 664, a width W3 between adjacent thermal fins 66 is consistent inside the plurality of tunnels 661 along X direction, so that air resistance and flow pressure are stable inside the plurality of tunnels 661. As the airflow flows into the thermal module 60 from a lateral side of the plurality of thermal fins 66, the alternate arrangement of the protruding portions 663 and the sunken portions 664 keeps the flow resistance stable inside the plurality of tunnels 661 and increases the heat dissipating efficiency of the thermal module 60. As the airflow flows into the thermal module 60 from an upper side of the plurality of thermal fins 66, the flow resistance inside the plurality of tunnels 661 is small due to the alternate arrangement of the protruding portions 663 and the sunken portions 664 on the thermal fins 66, so as to enhance the heat dissipating efficiency of the thermal module 60. Thus, natural convection of the plurality of thermal fins 66 is preferred as the airflow flows into the tunnels 661 from the lateral side and the upper side of the plurality of thermal fins 66.
The thermal module 60 can further include a fan 68 disposed on the lateral side or the upper side of the plurality of thermal fins 66 for dissipating the heat from the plurality of thermal fins 66. As the fan 68 is disposed on the lateral side of the plurality of thermal fins 66, the air resistance and the flow pressure keep consistent at entries and positions inside the plurality of tunnels 661 for promoting stability of the air convection inside the plurality of tunnels 661, so that the heat dissipating efficiency of the thermal module 60 is preferable. As the fan 68 is disposed on the upper side of the plurality of thermal fins 66, the heat dissipating efficiency of the airflow inside the tunnels 661 is preferable because of the smaller air resistance and the smaller flow pressure, so that a perfect convection cycle can be established at the entries and the positions inside the plurality of tunnels 661 for exchanging hot air inside the plurality of tunnels 661 with cold air outside the plurality of tunnels 661 stably and uniformly. Therefore, the forced convection function is good at the lateral side and the upper side of the plurality of tunnels 661. The plurality of fins 66 can be glued or weld on the conductive base 62. The plurality of fins 66 can further be fixed on the conductive base 62 by cutting, molding, or stamping.
In addition, the protruding portion 663 is not limited to an arc-shaped structure shown in FIG. 5 and FIG. 6, and can further be a triangle-shaped structure, a sawtooth-shaped structure, a wave-shaped structure, and so on. Please refer to FIG. 7, FIG. 8, FIG. 9, and FIG. 10. FIG. 7 is a diagram of a thermal module 70 having a plurality of triangle-shaped protruding portions 72 according to a second embodiment of the present invention. FIG. 8 is a diagram of a thermal module 80 having a plurality of sawtooth-shaped protruding portions 82 according to a third embodiment of the present invention. FIG. 9 is a diagram of a thermal module 90 having a plurality of wave-shaped protruding portions 92 according to a fourth embodiment of the present invention. FIG. 10 is a diagram of a thermal module 100 having a plurality of sawtooth-shaped protruding portions 102 including a plurality of protruding portions 104 and corresponding sunken parts 106 arranged alternately according to a fifth embodiment of the present invention. Dispositions and functions of components of the thermal module 70, the thermal module 80, the thermal module 90, and the thermal module 100 are the same as the components in the first embodiment, and the detailed description is omitted herein for simplicity. The plurality of thermal fins on the above-mentioned thermal modules can increase the contacting surface of the thermal modules with the air for increasing the heat dissipating efficiency. Distances between adjacent thermal fins keep consistent at any positions inside the tunnels along X direction, so that the air resistance and the flow pressure are stable inside the tunnels. Functions of the triangle-shaped protruding portions 72, the sawtooth-shaped protruding portions 82, the wave-shaped protruding portions 92, and the wave-shaped protruding portions 102 including the plurality of protruding portions 104 and sunken portions 106 are the same as the protruding portions 663 in the first embodiment.
Furthermore, the thermal fins of the present invention are not limited to the dispositions of the above-mentioned embodiment, and the thermal module can include a combination of conventional thermal fins and the thermal fins of the present invention. Please refer to FIG. 11 and FIG. 12. FIG. 11 is a diagram of a thermal module 110 including the plurality of protruding portions 1104 arranged alternately and smooth surfaces 1106 according to a sixth embodiment of the present invention. FIG. 12 is a diagram of a thermal module 120 including a plurality of protruding portions 1204 arranged alternately and a plurality of protruding portions 1206 arranged symmetrically according to a seventh embodiment of the present invention. As temperature at the center of the plurality of thermal fins 1102 of the thermal module 110 (or the center of the plurality of thermal fins 1202 of the thermal module 120) is greater than temperature at two sides of the thermal fins 1102 (or the thermal fins 1202), only the center of the thermal module 110 (or the thermal module 120) needs enhanced natural convection and forced convection for increasing the heat dissipating efficiency of the thermal module 110 (or the thermal module 120). The thermal fins 1102 (or the thermal fins 1202) can be disposed on the center of the thermal module 110 (or the thermal module 120), and the conventional thermal fins can be disposed on the two sides of the thermal module 110 (or the thermal module 120). Functions and dispositions of the thermal fins of the thermal module 110 (or the thermal module 120) are the same as the ones of the above-mentioned embodiment, and detailed description is omitted herein for simplicity.
The plurality of thermal fins 66 is not limited to the long strip structure of the above-mentioned embodiment, and can further be a pillar structure or a slice structure so as to increase the contacting area of the thermal module 60 and to promote functions of the natural convection and the forced convection simultaneously. Please refer to FIG. 13 and FIG. 14. FIG. 13 is a diagram of thermal fins 1306 with the pillar structure according to an eighth embodiment of the present invention. FIG. 14 is a diagram of thermal fins 1406 with the slice structure according to a ninth embodiment of the present invention. Functions of the thermal fins 1306 and the thermal fins 1406 are the same as the ones of the above-mentioned embodiment, and detailed description is omitted herein for simplicity.
Comparing to the prior art, the thermal module having enhanced heat dissipating efficiency of the present invention can improve drawbacks that the conventional thermal module focuses on dimension of the contacting surface of the thermal fins regardless of the inconsistent air resistance and the unstable flow pressure. The plurality of protruding portions of the present invention is disposed on the thermal fins alternately, so that the air resistance keeps consistent at any positions inside the thermal fins and the flow pressure is stable for preferable convection. Therefore, the present invention not only can increase the contacting area for improving the heat dissipating efficiency, but also can promote functions of the natural convection and the forced convection for further increasing the heat dissipating efficiency of the thermal module.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.

Claims

1. A thermal module comprising:

a conductive base disposed on a heat source for conducting heat generated by the heat source; and

a plurality of thermal fins substantially disposed on the conductive base in parallel, a plurality of protruding portions being formed on each thermal fin in a direction whereto the thermal fins are stretched from the conductive base, and the plurality of protruding portions on adjacent thermal fins being arranged alternately in the direction whereto the thermal fins are stretched from the conductive base so as to dissipate the heat conducted to the conductive base from the heat source.

2. The thermal module of claim 1, wherein the plurality of thermal fins is made of metal material.

3. The thermal module of claim 2, wherein the plurality of thermal fins is made of copper material or aluminum material.

4. The thermal module of claim 1, wherein each thermal fin is a slice-shaped structure or a pillar-shaped structure.

5. The thermal module of claim 1, wherein distances between surfaces of adjacent thermal fins are the same.

6. The thermal module of claim 1, wherein each protruding portion is an arc-shaped structure, a triangle-shaped structure, or a sawtooth-shaped structure.

7. The thermal module of claim 1, wherein each protruding portion is a long strip structure, and directions of the plurality of protruding portions are substantially parallel to the conductive base.

8. The thermal module of claim 1 further comprising:

a fan disposed on a side of the plurality of thermal fins so as to dissipate the heat from the plurality of thermal fins.

9. The thermal module of claim 1, wherein the plurality of thermal fins is glued or welded on the conductive base.

10. The thermal module of claim 1, wherein the plurality of thermal fins is formed on the conductive base by cutting, molding, or stamping.

11. A heat dissipating system comprising:

a circuit board;

a heat source installed on the circuit board; and

a thermal module comprising:

a conductive base disposed on the heat source for conducting heat generated by the heat source; and

12. The heat dissipating system of claim 11, wherein the heat source is a central processing unit or a chip.

13. The heat dissipating system of claim 11, wherein the plurality of thermal fins is made of metal material.

14. The heat dissipating system of claim 11, wherein each thermal fin is a slice-shaped structure or a pillar-shaped structure.

15. The heat dissipating system of claim 11, wherein distances between surfaces of adjacent thermal fins are the same.

16. The heat dissipating system of claim 11, wherein each protruding portion is an arc-shaped structure, a triangle-shaped structure, or a sawtooth-shaped structure.

17. The heat dissipating system of claim 11, wherein each protruding portion is a long strip structure, and directions of the plurality of protruding portions are substantially parallel to the conductive base.

18. The heat dissipating system of claim 11, wherein the thermal module further comprises a fan disposed on a side of the plurality of thermal fins so as to dissipate the heat from the plurality of thermal fins.

19. The heat dissipating system of claim 11, wherein the plurality of thermal fins is glued or welded on the conductive base.

20. The heat dissipating system of claim 11, wherein the plurality of thermal fins is formed on the conductive base by cutting, molding, or stamping.