US20020033249A1

US20020033249A1 - Heat dissipation apparatus

Info

Publication number: US20020033249A1
Application number: US09/917,666
Authority: US
Inventors: Chia-Chin Chuang
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-21
Filing date: 2001-07-31
Publication date: 2002-03-21

Abstract

The present invention relates to a heat dissipation apparatus for dispersing heat from a heat source. The heat dissipation apparatus has a sealed space for containing a cooling medium, and the cooling medium is provided at appropriate pressure conditions below room temperature to approach the liquid-gas phase critical state and perform rapid heat convection in the heat dissipation apparatus in the presence of local temperature differential. In addition, the present invention increases the contact area between the cooling medium and the housing of the heat dissipation apparatus by a specific internal structure, so that heat can be rapidly dissipated to the heat dissipation apparatus to achieve a better effect than that of conventional heat dissipation apparatus.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat dissipation apparatus, and more specifically, to an apparatus for dissipating heat from a heat source such as a CPU.

2. Description of the Related Art

In recent years, trends in central processing unit (CPU) technology have moved toward the combination of high speeds and compact volumes. CPU generation has evolved rapidly from 80486 CPU to Pentium IV. Core speeds (from 75 MHz to over 680 MHz) and the dissipate power (from 10 W to over 120 W) of the CPU have increased, inducing a major design problem. The compact volume combination greatly increases generated heat per volume or area for the electronic device, and subsequent CPU heat dissipation is a major task to be dealt with.

Practically, a conventional CPU heat sink is fabricated with conductive material such as aluminum in one-body formation by extrusion. The fabricated heat sink is then adhered or attached to a CPU. In the heat dissipation process, the contact surface of the heat sink absorbs heat produced by the operating CPU, and conducts the heat to another part of the heat sink; eventually, the heat is dissipated to the ambient air through the dissipating fins provided on the external surface of the heat sink. Generally, an additional fan is applied to increase convection in order to achieve the preferred heat dissipation performance.

There are various kinds of modification in the conventional heat sink. Most of these modifications emphasize increasing the area of the fins, optimum diversion design and shape design, improved fan design, and the like. Some modifications that focus on conduction improvement are based on material conductivity. None of these modifications, however, focus on the possibility of installing a structure or substance that contributes to heat transfer inside the heat sink.

In the field of thermodynamics, it is well known that fluid contained in a sealed vessel (that is in an isometric condition) may undergo significant pressure change with slight variation in temperature under the boundary condition of a liquid-gas phase critical state (a specific temperature-pressure curve), also referred to as a super-critical fluid state. Therefore, if any temperature differential exists within the sealed vessel's contents, corresponding pressure difference will cause rapid fluid motion; that is, any partial temperature differential within the fluid in the sealed vessel will reach a balance rapidly with the effect of heat convection.

SUMMARY OF THE INVENTION

In order to utilize the above-mentioned principle, a sealed space containing a cooling medium is provided in the heat dissipation apparatus of the present invention, and the cooling medium is set to an appropriate pressure condition below room temperature to obtain the above-mentioned effect.

Further, in the case of heat conduction, the time rate of heat transfer is in substantial proportion to the contact area; as a result, the present invention increases the contact area between the cooling medium and the housing of the heat dissipation apparatus with a specific internal structure in order to distribute the heat rapidly to the heat dissipation apparatus by conduction to achieve better heat dissipation in comparison to the prior art.

As mentioned above, the first embodiment of the present invention discloses a heat dissipation apparatus for dispersing heat from a heat source. The heat dissipation apparatus comprises: a heat dissipation body having a contact surface and a sealed chamber, wherein the contact surface is in contact with the heat source; a plurality of first heat conductive strips, each having a first end and a second end, the first end of each first heat conductive strip disposed on the heat dissipation body in the sealed chamber, and the second end of each first heat conductive strip extended substantially away from the contact surface; a plurality of second heat conductive strips each having a third end and a fourth end, the third end of each second heat conductive strip disposed on the heat dissipation body in the sealed chamber, and the fourth end of each second heat conductive strip extended substantially toward the contact surface, wherein certain spaces are respectively formed between the first heat conductive strips and the second heat conductive strips; and a cooling substance contained in the sealed chamber.

The first embodiment of the present invention may further comprise a plurality of heat dissipation fins respectively disposed on the periphery of the heat dissipation body. Further, in the first embodiment of the present invention, the heat dissipation body, the heat dissipation fins, the first heat conductive strips, and the second heat conductive strips may be respectively made of heat conductive materials. Further, the cooling substance can be a cooling medium under a certain condition, the cooling medium suited to performing phase change according to a certain range of temperature change thereof, and the heat conductive materials can be selected from the group consisting of copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, and stainless steel.

The second embodiment of the present invention is a heat dissipation apparatus for dispersing heat from a CPU. The heat dissipation apparatus comprises: a heat dissipation body having a contact surface in contact with the CPU and a column-shaped sealed chamber substantially perpendicular to the contact surface, wherein the heat dissipation body in the sealed chamber is provided with corresponding first and second end surfaces, the first end surface and the second end surface being substantially parallel to the contact surface; a plurality of first heat conductive strips each having a first end and a second end, the first end of each first heat conductive strip disposed on the first end surface, and the second end of each first heat conductive strip extending substantially toward the second end surface; a plurality of second heat conductive strips each having a third end and a fourth end, the third end of each second heat conductive strip disposed on the second end surface, and the fourth end of each second heat conductive strip extended substantially toward the first end surface, wherein certain spaces are respectively formed between the first heat conductive strips and the second heat conductive strips; a cooling medium contained in the sealed chamber under a certain condition, the cooling medium suited to performing phase change according to a certain range of temperature change thereof; and a plurality of heat dissipation fins respectively disposed on the periphery of the heat dissipation body.

The heat dissipation body in the sealed chamber may also have an internal wall provided between the first end surface and the second end surface, and the internal wall may comprise a plurality of ridges respectively extending between the first end surface and the second end surface. In addition, the heat dissipation body, the heat dissipation fins, the first heat conductive strips, the second heat conductive strips, and the ridges may be respectively made of heat conductive materials. Further, the heat conductive materials may be selected from the group consisting of copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, and stainless steel, and the first heat conductive strips and the second heat conductive strips may be respective board-shaped components. The second embodiment of the present invention may further comprise a plurality of protrusions of the heat conductive materials provided on the first heat conductive strips and the second heat conductive strips. Further, each of the first heat conductive strips and the second heat conductive strips may respectively have a hollow portion forming a tube structure, and the second embodiment of the present invention may further comprise a plurality of heat conductive meshes of the heat conductive materials contained in the hollow portions.

The second embodiment of the present invention discloses a heat dissipation apparatus for dispersing heat from a CPU. The heat dissipation apparatus comprises: a heat dissipation body having a contact surface in contact with the CPU and a column-shaped sealed chamber substantially perpendicular to the contact surface, wherein the heat dissipation body in the sealed chamber is provided with corresponding first and second end surfaces, the first end surface and the second end surface being substantially parallel to the contact surface; a plurality of heat conductive strips each having a first end and a second end, the first end of each heat conductive strip disposed on the first end surface, and the second end of each heat conductive strip disposed on the second end surface, wherein certain spaces are respectively formed between the heat conductive strips; a cooling medium contained in the sealed chamber under a certain condition, the cooling medium suited to performing phase change according to a certain range of temperature change thereof; and a plurality of heat dissipation fins respectively disposed on the periphery of the heat dissipation body.

In the second embodiment of the present invention, the heat dissipation body in the sealed chamber may also have an internal wall provided between the first end surface and the second end surface, and the internal wall may comprise a plurality of ridges respectively extending between the first end surface and the second end surface. In addition, the heat dissipation body, the heat dissipation fins, the heat conductive strips, and the ridges may be respectively made of heat conductive materials. Further, the heat conductive materials may be selected from the group consisting of copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, and stainless steel, and the heat conductive strips may be, respectively, board-shaped components. The third embodiment of the present invention may further comprise a plurality of protrusions of the heat conductive materials provided on the heat conductive strips. Further, each of the heat conductive strips may respectively have a hollow portion forming a tube structure, and the third embodiment of the present invention may further comprise a plurality of heat conductive meshes of the heat conductive materials contained in the hollow portions.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein: [0016]
FIG. 1 is a perspective view according to the first embodiment of the present invention; [0017]
FIG. 2 is a perspective cross-sectional view of FIG. 1; [0018]
FIG. 3 is a perspective cross-sectional exploded view of FIG. 1; [0019]
FIGS. 4[0020] a and 4 b are top cross-sectional views of FIG. 1;
FIG. 5 is a perspective view according to the second embodiment of the present invention; [0021]
FIG. 6 is a perspective cross-sectional view of FIG. 5; [0022]
FIG. 7 is a perspective cross-sectional exploded view of FIG. 5; and [0023]
FIGS. 8[0024] a and 8 b are top cross-sectional views of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will be hereinafter described with two embodiments. [0025]
First Embodiment [0026]
FIG. 1 to FIG. 4 shows the first embodiment of the present invention. A [0027] heat dissipation apparatus 100 for a computer CPU is shown in the figures, and a heat dissipation body 10 (as shown in FIG. 2) having a contact surface 12 in contact with the CPU is provided in the apparatus 100. The internal structure of the apparatus 100 can be seen in FIG. 2 and FIG. 3. In the heat dissipation body 10, a column-shaped sealed chamber 11 that is substantially perpendicular to the contact surface 12 is provided, and the portion of the heat dissipation body 10 in the sealed chamber 11 is provided with corresponding first end surface 111 and second end surface 112, as shown in FIG. 3. The first end surface 111 and the second end surface 112 are substantially parallel to the contact surface 12. In addition, heat dissipation fins 30 are respectively disposed on the periphery of the heat dissipation body 10 in order to increase the peripheral area of the heat dissipation apparatus 100 so that heat transfer through the surrounding air convection may be improved.
In practical manufacture, it is preferred that the [0028] heat dissipation apparatus 100 to be fabricated in three components 101, 102 and 103, as shown in FIG. 3, and composed together with, for example, a welding process.
The [0029] component 101 in this embodiment forms the first end surface 111, and has a plurality of first heat conductive strips 113 (three strips in this embodiment). The component 102 in this embodiment forms the second end surface 112, and has a plurality of second heat conductive strips 114 (also three strips in this embodiment). Each of the first heat conductive strips 113 has a first end 113 a provided on the first end surface 111 and a second end 113 b extended substantially toward the second end surface 112 while the components are in combination; and each of the second heat conductive strips 114 has a third end 114 a provided on the second end surface 112 and a fourth end 114 b extended substantially toward the first end surface 112 while the components are in combination.
Specifically, the sealed [0030] chamber 11 in this embodiment is filled with a cooling medium 20 as shown in FIG. 4a. The cooling medium 20 dissipates heat in the apparatus 100 mainly by heat convection. In order to perform the desired effect, it is preferred to have the cooling medium 20 sealed in the sealed chamber 11 under a condition approaching liquid-gas phase critical pressure (in which the temperature is below room temperature). To achieve this, for example, the system may be composed in a closed space at the specific pressure.
The size and quantity of the first and second heat [0031] conductive strips 113, 114 and the space between the strips 113, 114 will determine heat conductive conditions between the heat dissipation body 10 and the cooling medium 20. For example, in FIG. 4a, if the total area of the sectional areas (the circle areas shown with slant lines) of the first heat conductive strips 113 (and the second heat conductive strips 114) is constant, the overall surface area of the first and second heat conductive strips 113, 114 will be increased when the quantity of strips increases, and thus, better heat conduction is achieved. That is, the first and second heat conductive strips 113 and 114 can be made thinner to achieve better effect.
Further, experiments with heat transfer have proven that the space between the [0032] strips 113 and 114 can be made smaller to achieve better heat transfer effects. If the space is small enough that the cooling medium 20 therein approaches a film state, the local temperature change may cause the system to produce a heat pulse effect, producing an enormous heat transfer effect.
In addition, it is preferred to provide [0033] ridges 115 a on the internal wall 115 of the sealed chamber 11, as shown in FIG. 3 and FIG. 4a, in order to further increase the contact area between the heat dissipation body 10 and the cooling medium 20. The ridges 115 a can be extended between the first end surface 111 and the second end surface 112.
In addition, the [0034] heat dissipation body 10, the heat dissipation fins 30, the first heat conductive strips 113, the second heat conductive strips 114 and the ridges 115 a can be respectively made of heat conductive materials, such as copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, or stainless steel.
Further, the first heat [0035] conductive strips 113 and the second heat conductive strips 114 can be, respectively, board-shaped components (not shown); it is also acceptable for the strips 113 and 114 to respectively have a plurality of protrusions thereon; or, the strips 113 and 114 may have hollow portions 113 c, 114 c to respectively form a tube structure as shown in FIG. 4b. If the first heat conductive strips 113 and the second heat conductive strips 114 have hollow portions 113 c, 114 c, it is also acceptable to contain a plurality of conduction meshes 113 d, 114 d in the hollow portions 113 c, 114 c, so that the total area of heat conduction will be increased.
Second Embodiment [0036]
FIG. 5 to FIG. 8 shows the second embodiment of the present invention. A [0037] heat dissipation apparatus 400 for a computer CPU is shown in the figures, and a heat dissipation body 40 (as shown in FIG. 6) having a contact surface 42 in contact with the CPU is provided in the apparatus 400. The internal structure of the apparatus 400 can be seen in FIG. 6 and FIG. 7. In the heat dissipation body 40, a column-shaped sealed chamber 41 that is substantially perpendicular to the contact surface 42 is provided, and the portion of the heat dissipation body 40 in the sealed chamber 41 is provided with corresponding first end surface 411 and second end surface 412, as shown in FIG. 7. The first end surface 411 and the second end surface 412 are substantially parallel to the contact surface 42. In addition, heat dissipation fins 60 are respectively disposed on the periphery of the heat dissipation body 40 in order to increase the peripheral area of the heat dissipation apparatus 100 so that heat transfer through the surrounding air convection may be improved.
In practical manufacture, it is preferred that the [0038] heat dissipation apparatus 400 to be fabricated in three components 401, 402 and 403, as shown in FIG. 7, and composed together with, for example, a welding process.
The [0039] component 401 in this embodiment forms the first end surface 411, and has a plurality of heat conductive strips 413 (six strips in this embodiment). Each of the first heat conductive strips 413 has a first end 413 a provided on the first end surface 411 and a second end 413 b. The component 402 in this embodiment forms the second end surface 412 which is in connection to the second ends 413 b while the components are in combination.
Specifically, the sealed [0040] chamber 41 in this embodiment is filled with a cooling medium 50 as shown in FIG. 8a. The cooling medium 50 dissipates heat in the apparatus 400 mainly with through heat convection. In order to perform the desired heat convection, it is preferred to have the cooling medium 50 sealed in the sealed chamber 41 under a condition approaching liquid-gas phase critical pressure (in which the temperature is below room temperature). To achieve this, for example, the system may be composed in a closed space at the specific pressure.
The size and quantity of the heat [0041] conductive strips 413 and the space between the strips 413 will determine heat conductive conditions between the heat dissipation body 40 and the cooling medium 50. For example, in FIG. 8a, if the total area of the sectional areas (the circle areas shown with slant lines) of the heat conductive strips 413 is constant, the overall surface area of the heat conductive strips 413 will be increased when the quantity of strips increases, thus better heat conduction is achieved. That is, the heat conductive strips 413 can be made thinner to achieve better effect.
Further, experiments with heat transfer have proven that the space between the [0042] strips 413 can be made smaller to achieve better heat transfer. If the space is so small that the cooling medium 50 therein approaches a film state, the local temperature change may cause the system to produce a heat pulse effect, producing enormous heat transfer effects.
In addition, it is preferred to provide [0043] ridges 415 a on the internal wall 415 of the sealed chamber 41, as shown in FIG. 7 and FIG. 8a, in order to further increase the contact area between the heat dissipation body 40 and the cooling medium 50. The ridges 415 a can be extended between the first end surface 411 and the second end surface 412.
In addition, the [0044] heat dissipation body 40, the heat dissipation fins 60, the heat conductive strips 413 and the ridges 415 a can be respectively made of heat conductive materials, such as copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, or stainless steel.
Further, the heat [0045] conductive strips 413 can be board-shaped components (not shown); it is also acceptable to have the strips 413 respectively having a plurality of protrusions thereon; or, the strips 413 may have hollow portions 413 c in order to respectively form a tube structure as shown in FIG. 8b. If the heat conductive strips 413 have hollow portions 413 c, it is also acceptable to contain a plurality of conduction meshes 413 d in the hollow portions 413 c, so that the total area of heat conduction will be increased.
The heat dissipation apparatus has a system inside for continuously producing convection with temperature difference. Thus, heat will be brought from the [0046] contact surface 12 and 42 to the outer surface than in the prior art. That is, the heat dissipation apparatus in the present invention has better performance than the conventional heat dissipation apparatus.
In the above-mentioned embodiments, the heat dissipation apparatus is used with CPU heat dissipation. However, it should be noted that the present invention is not limited to the described embodiments; that is, the present invention can be applied in the case of dispersing heat from any other heat source. [0047]
While the present invention has been described with reference to the preferred embodiments thereof, it is to be understood that the invention is not limited to the described embodiments or constructions. On the contrary, the invention is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. [0048]

Claims

What is claimed is:

1. A heat dissipation apparatus for dispersing heat from a heat source, the heat dissipation apparatus comprising:

a heat dissipation body having a contact surface and a sealed chamber, wherein the contact surface is in contact with the heat source;

a plurality of first heat conductive strips each having a first end and a second end, the first end of each first heat conductive strip disposed on the heat dissipation body in the sealed chamber, and the second end of each first heat conductive strip extended substantially away from the contact surface;

a plurality of second heat conductive strips each having a third end and a fourth end, the third end of each second heat conductive strip disposed on the heat dissipation body in the sealed chamber, and the fourth end of each second heat conductive strip extended substantially toward the contact surface, wherein certain spaces are respectively formed between the first heat conductive strips and the second heat conductive strips; and

a cooling substance contained in the sealed chamber.

2. The heat dissipation apparatus according to claim 1, further comprising a plurality of heat dissipation fins respectively disposed on the periphery of the heat dissipation body.

3. The heat dissipation apparatus according to claim 2, wherein the heat dissipation body, the heat dissipation fins, the first heat conductive strips, and the second heat conductive strips are respectively made of heat conductive materials.

4. The heat dissipation apparatus according to claim 3, wherein the cooling substance is a cooling medium under a certain condition, the cooling medium suited to performing phase change according to a certain range of temperature change thereof, and the heat conductive materials are selected from the group consisting of copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, and stainless steel.

5. A heat dissipation apparatus for dispersing heat from a CPU, the heat dissipation apparatus comprising:

a heat dissipation body having a contact surface being in contact with the CPU and a column-shaped sealed chamber being substantially perpendicular to the contact surface, wherein the heat dissipation body in the sealed chamber is provided with corresponding first end surface and second end surface, the first end surface and the second end surface being substantially parallel to the contact surface;

a plurality of first heat conductive strips each having a first end and a second end, the first end of each first heat conductive strip disposed on the first end surface, and the second end of each first heat conductive strip extended substantially toward the second end surface;

a plurality of second heat conductive strips each having a third end and a fourth end, the third end of each second heat conductive strip disposed on the second end surface, and the fourth end of each second heat conductive strip extended substantially toward the first end surface, wherein certain spaces are respectively formed between the first heat conductive strips and the second heat conductive strips;

a cooling medium contained in the sealed chamber under a certain condition, the cooling medium suited to performing phase change according to a certain range of temperature change thereof; and

a plurality of heat dissipation fins respectively disposed on the periphery of the heat dissipation body.

6. The heat dissipation apparatus according to claim 5, wherein the heat dissipation body in the sealed chamber has a internal wall provided between the first end surface and the second end surface, and the internal wall comprises a plurality of ridges respectively extended between the first end surface and the second end surface.

7. The heat dissipation apparatus according to claim 6, wherein the heat dissipation body, the heat dissipation fins, the first heat conductive strips, the second heat conductive strips, and the ridges are respectively made of heat conductive materials.

8. The heat dissipation apparatus according to claim 7, wherein the heat conductive materials are selected from the group consisting of copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, and stainless steel.

9. The heat dissipation apparatus according to claim 8, wherein the first heat conductive strips and the second heat conductive strips are respective board-shaped components.

10. The heat dissipation apparatus according to claim 8, further comprising a plurality of protrusions of the heat conductive materials provided on the first heat conductive strips and the second heat conductive strips.

11. The heat dissipation apparatus according to claim 8, wherein each of the first heat conductive strips and the second heat conductive strips respectively has a hollow portion forming a tube structure.

12. The heat dissipation apparatus according to claim 11, further comprising a plurality of heat conductive meshes of the heat conductive materials contained in the hollow portions.

13. A heat dissipation apparatus for dispersing heat from a CPU, the heat dissipation apparatus comprising:

a plurality of heat conductive strips each having a first end and a second end, the first end of each heat conductive strip disposed on the first end surface, and the second end of each heat conductive strip disposed on the second end surface, wherein certain spaces are respectively formed between the heat conductive strips;

14. The heat dissipation apparatus according to claim 13, wherein the heat dissipation body in the sealed chamber has a internal wall provided between the first end surface and the second end surface, and the internal wall comprises a plurality of ridges respectively extending between the first end surface and the second end surface.

15. The heat dissipation apparatus according to claim 14, wherein the heat dissipation body, the heat dissipation fins, the heat conductive strips, and the ridges are respectively made of heat conductive materials.

16. The heat dissipation apparatus according to claim 15, wherein the heat conductive materials is selected from the group consisting of copper, aluminum, titanium, copper alloy, aluminum alloy, titanium alloy, and stainless steel.

17. The heat dissipation apparatus according to claim 16, wherein the heat conductive strips are, respectively, board-shaped components.

18. The heat dissipation apparatus according to claim 16, further comprising a plurality of protrusions of the heat conductive materials provided on the heat conductive strips.

19. The heat dissipation apparatus according to claim 16, wherein each of the heat conductive strips respectively has a hollow portion forming a tube structure.

20. The heat dissipation apparatus according to claim 19, further comprising a plurality of heat conductive meshes of the heat conductive materials contained in the hollow portions.