This Non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application Nos. 094138665 filed in Taiwan, Republic of China on Nov. 4, 2005, the entire contents of which are hereby incorporated by reference.
1. Field of Invention
The invention relates to a heat dissipation module, and in particular to a heat dissipation module having a heat pipe with high dissipation efficiency.
2. Related Art
With the continuous progress of the industrial technology, the number of the transistors on unit area of an electronic element is increasing, which result in the increase of the heat produced during working time. Also, the working frequency of the electronic element becomes higher, and the switch loss during the transistor changing status (on/off) is also increasing. Thus, heat generated by the electronic element grows. If the heat can not be dissipated adequately, it will lower the operating speed of the chip or even damage the chip. In order to enhance the heat dissipation efficiency of the electronic element, a heat sink is frequently applied to the electronic element so as to dissipate heat to external environment by direct conduct and also a fan is applied in facilitating the dissipation by proving airflow.
Because a heat pipe can transfer a lot of heat by a considerable distance with a quite small cross-sectional area and a quite small temperature difference and the heat pipe can work without external power supply, the heat pipe has become one of the most widely used heat conducting elements in the electronic heat dissipation product.
The main body 12 is an integrally formed with a sidewall portion 122 and a bottom portion 124. There are wicks 16a and 16b respectively formed on the inner wall of the main body 12 (i.e., the inner surfaces of the sidewall portion 122 and the bottom portion 124). The heat pipe 10 is filled with a working fluid “W”. When the column-like heat pipe 10 is used in practice, the bottom portion 124 directly contacts a heat source (not shown, such as a electronic element) located below the heat pipe 10 so as to dissipate the heat generated by the heat source. The bottom portion 124 of the column-like heat pipe 10 is an evaporating end, while the sidewall portion 122 and the top cover 14 are condensing ends. The working fluid “W” at the evaporating end absorbs heat and evaporates into a vaporized working fluid and naturally flows toward the condensing end under the influence of the pressure difference. Then, the vaporized working fluid releases the latent heat at the condensing end and condenses into the liquid working fluid “W”. The condensed working fluid further flows back to the evaporating end by the capillary forces of the wicks 16a and 16b, and the procedures circulate again and again to achieve the effect of heat dissipation.
However, when the wicks 16a and 16b of the column-like heat pipe 10 are formed by powder sintering, the wick 16b on the bottom portion 124 and the wick 16a on the sidewall portion 122 are commonly filled with powder and then sintered but no wick is additionally formed on the inner surface of the top cover 14 under the limitation of the sintering mold and the manufacturing factors. Thus, the working fluid “W” condensed at the top cover 14 cannot flow back, and the condensing end “B” at the top cover 14 becomes invalid, thereby decreasing the fluctuation of the mass of the working fluid “W” in the heat pipe 10 and thus decreasing the heat conducting efficiency and the whole heat resistance of the heat pipe 10.
If it is desired to form a wick on the inner surface of the top cover 14, powder has to be filled within the evaporating end and the condensing end simultaneously and then be sintered. Thus, the controls of the shape of the wick and the powder particles become difficult, so the manufacturing processes cannot be utilized to achieve this object. Consequently, if the inner surface of the top cover 14 has to be formed with the wick, a copper mesh may be inserted such that a mesh wick is formed. However, because the wick at the top cover 14 and the wick 16a on the sidewall portion 122 are not manufactured simultaneously and pertain to different kinds of wicks (one is a powder sintering wick, and the other is a mesh wick), the connection between these two different wicks is poor such that the working fluid cannot smoothly flow to the sidewall portion 122 from the top cover 14 owing to lacking enough capillary force there between. Thus, the overall heat dissipation property of the heat pipe 10 deteriorates.
Thus, it is an important subject of the invention to provide a heat pipe which has a low cost and can be manufactured easily so as to solve the above-mentioned problems.
In view of the foregoing, the invention is to provide a heat dissipation module and a heat pipe thereof with advantages of low cost and simple manufacture procedures. In addition, the invention solve the problem of poor connection between the sidewall portion and the top cover of the column-like heat pipe in the prior art. The invention also effectively enlarges heat exchanging area of the heat pipe and enhances the overall heat dissipation efficiency.
To achieve the above, a heat pipe of the invention includes a main body, a base, a first wick, a second wick and a working fluid. The main body has a top portion and a sidewall portion disposed around the top portion. When the base and the main body are assembled, the base and the main body are combined to form a closed chamber, and the base is disposed corresponding to the top portion. The working fluid is filled within the closed chamber. The base has an uneven surface facing the top portion, and the first wick is disposed on the sidewall portion and the top portion of the main body. The second wick is disposed on the uneven surface of the base and connected to the first wick.
As mentioned above, the sidewall portion and the top portion may be integrally formed as a single piece. Alternatively, the sidewall portion and the top portion are two separate components and are combined together to form the main body. The uneven surface of the base is formed with at least one protrusion, and the cross section of the protrusion on the base has a rectangular, semi-circular semi-spherical, arc, triangular, quadrangular or trapezoidal shape. The protrusions on the uneven surface of the base constitute a checkerboard pattern, an array pattern, a symmetrical pattern or an asymmetrical pattern.
The second wick is disposed on the uneven surface of the base such that the second wick faces the top portion and forms a plane. The second wick has a first thickness H1 and a second thickness H2, which is relatively smaller than the first thickness H1, in a direction perpendicular to the base. Or, the second wick is disposed along an uneven surface profile of the base and the thickness of the second wick has a uniform or varied thickness. Moreover, the inner surface of the sidewall portion may have even or uneven profiles. The inner surface of the sidewall portion is formed with at least one protrusion. The cross section of the protrusion on the sidewall portion constitutes a sawtooth ring pattern, a continuous semi-circular pattern or any other patterns constituted by the equivalent structure.
The sidewall portion of the main body has a shape like a hollow tube. The main body and the base are made of a material with high thermal conductivity, such as copper, silver, aluminum or alloy thereof. The material of the first wick and the second wick may be a plastic material, a metallic material, an alloy or a porous non-metallic material, and be formed by way of sintering, adhering, filing and depositing or any combinations thereof. The working fluid W may be an inorganic compound, pure water, alcohol, ketone, liquid metal, refrigerant, an organic compound or any mixtures thereof.
The invention also provides a heat dissipation module including a heat pipe and a plurality of fins, which are connected to and disposed around the heat pipe. The heat pipe includes a main body, a base, a first wick, a second wick and a working fluid. The main body has a top portion and a sidewall portion disposed around the top portion. When the base and the main body are assembled, the base and the main body are combined to form a closed chamber, and the base is disposed corresponding to the top portion. The base has an uneven surface, which faces the top portion, and the first wick is disposed on the sidewall portion and the top portion of the main body. The second wick is disposed on the uneven surface of the base and connected to the first wick. The working fluid is filled within the closed chamber.
The fins are manufactured by way of aluminum extrusion, pressing or other methods. The fins may be disposed in a horizontal interval distribution, a vertically interval distribution, a slantingly interval distribution, a radial distribution, or other distributions. The fins are disposed around the heat pipe and connected to the heat pipe. The fins are connected to the heat pipe by a way selected from welding, embedding, engaging or adhering. The heat pipe is embedded in and/or engaged with the fins by way of hot mounting. Alternatively, a soldering paste, a grease or a material capable of serving as a thermal conductive interface may be coated between the fins and the heat pipe.
In the heat dispassion module, the heat pipe may contact the heat source directly or indirectly through an external carrier to the fins. The carrier is a solid metal block, and the heat source is an electronic element, such as a CPU (Central Processing Unit), a transistor, a server, an advanced graphics card, a hard disk, a power supply, a mobile control system, a multimedia electronic mechanism, a wireless communication transceiver station or an advanced game machine, which generates the heat. In addition, a fan may be applied to the heat dissipation module, which facilitate heat dissipation more quickly.
The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Referring to
The base 28 has an uneven surface 281, which is formed with at least one protrusion 282, and the cross section of the protrusion 282 on the uneven surface 281 of the base has a rectangular, semi-circular semi-spherical, arc, triangular, quadrangular or trapezoidal shape. Herein, it is to be noted that the pattern and the number of the protrusion(s) 282 formed on the uneven surface 281 of the base 28 are not particularly limited. As shown in
The first wick 26a is disposed on the sidewall portion 222 and top portion 224, and the second wick 26b is disposed on the uneven surface 281 of the base 28 and connected to the first wick 26a. Referring to
In
When the heat pipe 20 is actually used, the base 28 directly contacts a heat source (not shown) located below the heat pipe 20 so as to conduct the heat, which is generated by the heat source, away from the heat source. Alternatively, the heat pipe 20 may contact the heat source through an external carrier (not shown) located below the heat pipe 20 and above the heat source. When the heat pipe 20 is disposed above the heat source, the working fluid at the second wick 26b (i.e., the evaporating end) near the heat source absorbs the heat generated by the heat source and becomes a vaporized working fluid. The vaporized working fluid flows to the condensing end naturally under the action of the pressure difference, and then releases the latent heat at the first wick 26a (i.e., the condensing end B) of the end away from the heat source and becomes the liquid working fluid. The liquid working fluid W flows back to the evaporating end by the capillary force provided by the second wick 26b. The circulation repeats to continuously dissipate heat of the heat source.
Because the main body 20 and the bases 28 are two separate components, the uneven surface 281 of the base 28 can be manufactured to form an uneven surface easily, so that the contact area between the base 28 and the second wick 26b is increased to enhance the evaporating efficiency of heat pipe 20. Moreover, the first wick 26a disposed on the sidewall portion of the main body 22 and the second wick 26b disposed on the uneven surface 281 of the base 28 are disposed separately so as to enlarge the exposed surface area of the wick and to enhance the evaporating efficiency of the working fluid W and thus to enhance the heat dissipation performance of the heat pipe 20 at the evaporating end.
The main body 22 and the base 28 are made of a material with high thermal conductivity, such as Copper, silver, aluminum or alloy thereof. The first wick 26a and the second wick 26b may be made by plastic material, a metallic material, an alloy and a porous non-metallic material, and formed by way of sintering, adhering, filling and depositing or any combinations thereof. The working fluid W may be an inorganic compound, pure water, alcohol, ketone, liquid metal, refrigerant, an organic compound or any mixtures thereof.
The sidewall portion 222 and the top portion 224 may be integrally formed as a single piece and combined together to form the main body 22. Alternatively, the sidewall portion 222 has a shape of hollow tube, the sidewall portion 222 and the top portion 224 may be two separate components and be further combined together to form the main body 22. Refer to
The main body 42 has a top portion 424 and a sidewall portion 422 disposed around the top portion 424. Different from the previously mentioned heat pipe 20 of
In addition to the configuration of the uneven surface of the base 28, 48, it is feasible to configure the inner surface of the top portion or the inner surface of the sidewall portion of the main body 22 into uneven surfaces so as to enlarge the exposed surface area of the second wick 26b. That is, the inner surface of the top portion 224 and/or 424 or the inner surface of the sidewall portion 222 and/or 422 may have even or uneven profiles.
As shown in
Referring to
Similar to the disposed way of the first wick 26a and the second wick 26b of
Referring to
In
Multiple fins 52a are disposed around the heat pipe 20 in radial distribution and connected to the heat pipe 20. The heat pipe 20 is embedded in and/or engaged with the fins 52a, such as the heat pipe 20 is passed through by the fins 52a. Alternatively, as shown in
In the heat dissipation module and the heat pipe thereof according to the embodiments, the heat dissipation module and the heat pipe thereof have advantages of low cost and simple manufacture procedures. Besides, the sidewall portion and the top portion of the main body are integrally formed or may be tightly fit with each other, and then the second wicks are simultaneously disposed on the inner surfaces of the sidewall portion and the top portion. Because the wicks on the sidewall portion and the top portion are continuous, the working fluid condensed at the wick on the top portion can flow to the wick on the sidewall portion smoothly. Thus, the invention not only solves the problems of poor connection between the sidewall portion and the top cover of the conventional column-like heat pipe in the prior art, but also effectively enlarges the heat exchanging area of the column-like heat pipe and thus enhances the overall heat dissipation efficiency.
Moreover, the main body and the bases are two separate components, and the uneven surface of the base can be manufactured to form an uneven surface easily, so that the contact area between the base and the second wick is enlarged to enhance the evaporating efficiency of heat pipe. In addition, the first wick disposed on the sidewall portion of the main body and the second wick disposed on the uneven surface of the base are disposed separately, so it is easy to form a wick with uniform or varied thickness to enlarge the surface area of the wick and to enhance the evaporating efficiency of the working fluid and thus to enhance the heat dissipation performance of the heat pipe at the evaporating end.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
Number | Date | Country | Kind |
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094138665 | Nov 2005 | TW | national |