This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 097134173 filed in Taiwan, Republic of China on Sep. 5, 2008, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The invention relates to a cooling fin, a thermal module including the cooling fin, and a method for assembling the thermal module.
2. Description of the Related Art
In past, only a central processing unit needs a thermal module to keep an operating temperature and stability of the central processing unit. With improvement of operating performance of other electronic elements, such as a graphic chip, a north bridge chip, a south bridge chip, a light-emitting diode and so on, the thermal module becomes more and more important for preserving stability of the electronic elements and the electronic devices having the electronic elements.
For manufacturing light, slim, and powerful electronic device, a plurality of electronic elements is assembled on a circuit board with a limited area, which results in a high heat flux of heat dissipation. Therefore, the thermal module becomes more and more important.
A conventional thermal module generally includes a plurality of fins and one or more heat pipes passing through the fins.
However, the heat pipe 72 may squeeze the solder paste 74 out when inserting the heat pipe 72 into the through holes 700. Thus, the solder paste 74 overflows onto other positions of the fins 70 around the through holes 700. Therefore, the overflowed solder paste 74 needs to be cleaned manually. Thus, additional labor is needed, and the solder paste 74 is wasted. Further, the distribution of the solder paste 74 is non-uniform, deteriorating the heat dissipation.
Therefore, a patent No. 568261 in Republic of China provides a novel thermal module.
When the thermal module 9 is made, the heat pipe 92 first passes through the through holes 900 of the fins 90 one by one. Then, solder paste 94 is injected into the solder paste feeding holes 902. Next, the solder paste 94 is heated to be melted, such that the solder paste 94 flows and fills a clearance between the heat pipe 92 and the through holes 900 via capillary action. Afterwards, the solder paste 94 is cooled and solidified to finish making the thermal module 9.
However, practical applications show that the clearance between the heat pipe 92 and the through hole 900 cannot be fully filled by the patent No. 568261 in Republic of China.
One objective of this invention is to provide a cooling fin and a method for assembling the thermal module. Particularly, the invention can uniformly spread the solder material to the clearance between the heat pipe and the fins of the thermal module. The soldering quality and the heat transfer performance can be well improved, thus to improve the prior art.
According to a first embodiment of the invention, the cooling fin can be combined with a heat pipe and a joint material. The cooling fin includes a main body. The main body has a through hole and a feeding hole. The heat pipe passes through the through hole. The feeding hole communicates with the through hole. The joint material is injected into the feeding hole to fill the clearance between the heat pipe and the inner wall of the through hole.
According to a second embodiment of the invention, the thermal module includes a heat pipe, a joint material, and a plurality of fins. As mentioned above, each fin includes a main body having a through hole and an feeding hole. The heat pipe passes through the through hole. The feeding hole communicates with the through hole. The joint material is injected into the feeding hole to fill the clearance between the heat pipe and the inner wall of the through hole.
Particularly, when assembling the thermal module, the feeding hole is located above the through hole, the joint material flows downward along the clearance, and the clearance gradually narrows along a flowing direction of the joint material.
According to a third embodiment of the invention, a method for assembling the thermal module is provided to combine a cooling fin with a heat pipe and a joint material. The method includes the following steps. A plurality of fins is made. As mentioned above, each fin has a through hole and a feeding hole communicating with each other.
Then, the heat pipe is made to pass through the through holes of the fins, and the feeding hole is made to be above the through hole. A clearance between the heat pipe and the inner wall of the through hole gradually narrows downward. Finally, the joint material is injected into the feeding hole to fill the clearance between the heat pipe and the inner wall of the through hole, thus to allow the joint material to flow downward along the clearance.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings.
This invention provides a cooling fin, a thermal module including the cooling fin, and a method for assembling the thermal module.
According to one embodiment of the invention, the cooling fin can be combined with a heat pipe and a joint material, thus to form the thermal module.
In
In
In
In
In addition, in one practical application, the shape of the feeding hole 104 can be adjusted according to needs, and it is not limited thereto. For example, the shape of the feeding hole 104 may be adjusted according to a used joint material, a needed moving speed of the joint material, needed capillary force and so on.
In one practical application, the main body 100 can further include a structure for helping heat dissipation or fastening, such as a bend, a protrusion, a recess, a fastening hole and so on. In addition, the appearance of the main body 100 can be changed and adjusted according to situations, and it is not limited to
In step S50, a heat pipe 12 and a cooling fin 10 as shown in
In this embodiment, the feeding hole 104 of the made fin 10 is the same as that in
In step S52, the cooling fin 10 is sleeved on the heat pipe 12 via the through hole 102 as shown in
In step S54, the joint material 14 is injected into the feeding hole 104 (as shown in
In step S56, the cooling fin 10 is disposed to keep the feeding hole 104 above the through hole 102 (as shown in
Finally, in step S58, the joint material 14 is made to flow downward along the clearance to tightly combine the cooling fin 10 and the heat pipe 12.
In one practical application, when the joint material is solder paste, step S58 can further include the following steps. The solder paste is heated to be melted. Further, after the solder paste flows downward along the clearance and reaches the bottom of the through hole, the solder paste is cooled to tightly combine the cooling fin and the heat pipe.
In the method according to the embodiment of the invention, the joint material flows downward and is uniformly distributed to the clearance between the heat pipe and the through hole via capillarity and gravity. In addition, the cooling fin is disposed to keep the feeding hole above the through hole. When the joint material flows from the first end portion of the through hole to the second end portion of the through hole along the clearance between the heat pipe and the through hole, the clearance between the heat pipe and a wall of the second end portion gradually narrows. Therefore, the capillary force can exist all the time, which is help for the joint material to fully fill the clearance between the heat pipe and the through hole.
To further describe the relation between gradually narrowing of the clearance and the capillary force, please refer to
In
According to the following formula, in
ΔP=2σ cos θ/R.
Further, as the clearance between the two walls 30, 32 gradually narrows, the following relation can be achieved according to α, θ, and H.
In other words, the curvature radius R is directly proportional to the distance H. When the distance between the walls 30, 32 becomes smaller, the H becomes smaller, and the R also becomes smaller. Therefore, the ΔP becomes greater. As the clearance between the heat pipe and the through hole gradually narrows, the capillary force exists all the time, thus to allow the joint material to be capable of successfully filling the clearance between the heat pipe and the through hole.
In
In one practical application, the fixture base 16 is made of a material with a better heat dissipation effect (such as copper, alumina, alloy, or other suitable materials). The fixture base 16 can be fixed around a heating element (not shown) to allow the heat pipe 12 to approach the heating element, thus to quickly dissipate the heat generated by the heating element.
In
In one practical application, the thermal module can be applied to an electronic device such as a computer, a display, a light and so on for dissipating heat of a heating element in the electronic device such as a processor, a display chip, a graphic chip, a light-emitting diode and so on. In addition, the thermal module can include a plurality of heat pipes, or it can be combined with a fan, a heat dissipation plaster, a cooling fin, or other suitable elements for improving the heat dissipation effect.
To sum up, the joint material can be uniformly distributed to the clearance between the edge of the through hole and the heat pipe via the feeding hole and disposing the cooling fin to keep the feeding hole above the through hole during manufacture, thereby tightly combining the cooling fin and the heat pipe and improving the heat dissipation effect. In addition, according to the method provided by the embodiment of the invention, the situation that the joint material deposits or overflows in the prior art can be avoided.
Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope of the invention. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope and spirit of the invention. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above.
Number | Date | Country | Kind |
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097134173 | Sep 2008 | TW | national |