HEAT DISSIPATION DEVICE

Abstract

A heat dissipation device includes a plurality of fins stacked together, a plurality of heat pipes extending through the fins, and solder filled in gaps between the fins and the heat pipes. Each fin includes a plate defining a plurality of holes therein for extension of the heat pipes therethrough, respectively. A collar extends from a periphery of each of the holes. The collar includes a columned portion attached to an outer surface of each of the heat pipes, and a taper portion interconnecting the plate and the columned portion. The solder fills in a gap between the columned portion and a corresponding heat pipe and a space between the taper portion and the corresponding heat pipe. The collar has a height slightly smaller than a distance between two adjacent fins.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat dissipation device incorporating heat pipes and fins, and more particularly to a combination structure of the fins which is used for combining the fins and the heat pipes together.

2. Description of Related Art

Computer electronic components, such as central processing units (CPUs), generate large amounts of heat during normal operation. If the heat is not properly dissipated, it can adversely affect operational stability of the electronic components and damage associated electronic devices. A heat dissipation device is often attached to a top surface of a CPU to dissipate heat therefrom.

Conventionally, a heat dissipation device as shown in FIG. 3 includes a plurality of fins 90 stacked together. A plurality of holes 91 and collars 92 extending from edges of the holes 91 are formed by punching (or other means) of the fins 90. Heat pipes (not shown) extend through the holes 91, with a part of outer surfaces of the heat pipes attached to the collars 92. Solder (not shown) is filled in gaps existed between the collars 92 and the heat pipes to secure the heat pipes in the holes 91 and increase heat transfer efficiency from the heat pipes to the fins 90. A distance, which is indicated by P1, is defined between every two adjacent fins 90, functioning as a channel for air flowing therethrough.

Due to a limited ductility of the fins 90 which are made of metallic material, a height of the collars 92, which is indicated by H1 in FIG. 3, cannot be as high as the distance P1, since such a large height may result in a break of the collars 92. Therefore, a bottom of each collar 92 is spaced from an adjacent fin 90. The collars 92 such configured cannot retain enough solder therein, which causes the solder to flow from bottoms of the collars 92 onto an adjacent fin during the solder being filled in the gaps between the collars 92 and the heat pipes. The overflowed solder is not only a waste of material, but also a negative impact to an aesthetic appearance of the heat dissipation device.

What is needed, therefore, is an improved heat dissipation device which can overcome the described limitations.

SUMMARY OF THE INVENTION

A heat dissipation device includes a plurality of fins stacked together, a plurality of heat pipes extending through the fins, and solder filled in gaps between the fins and the heat pipes. Each fin includes a horizontal, flat plate defining a plurality of holes therein for extension of the heat pipes therethrough, respectively. A collar extends from a periphery of each of the holes. The collar includes a columned portion attached to an outer surface of the heat pipe, and a taper portion interconnecting the plate and the columned portion. A height of the collar approaches to a distance between two adjacent fins. The taper portion has an inner surface facing towards the heat pipe. A portion of the solder is retained in a space between the inner surface of the taper portion of the collar and the heat pipe to prevent the portion of the solder from overflowing to the horizontal, flat plate of the fin.

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.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an assembled, isometric view of a heat dissipation device in accordance with a preferred embodiment of the disclosure.

FIG. 2 is a cross-sectional view of the heat dissipation device of FIG. 1, taken along line II-II thereof.

FIG. 3 is a side elevation view of a related heat dissipation device, with heat pipes thereof being removed.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-2, a heat dissipation device in accordance with a preferred embodiment of the disclosure comprises a plurality of fins 10 stacked together, and a plurality of heat pipes 20 extending through the fins 10. Bottom ends of the heat pipes 20 are used to connect with a base (not shown) which is attached to a heat generating component (not shown), such as a CPU. Heat generated by the heat generating component is transferred by the heat pipes 20 to the fins 10 and dissipated by the fins 10 to ambient air.

Each fin 10 has a rectangular thin plate 11 and two flanges 12 bent downwardly from two long sides of the plate 11. The thin plate 11 is horizontal and flat. A channel 13 is defined between every two adjacent fins 10 by the flanges 12. The channel 13 has a height which is indicated by P in FIG. 2. A plurality of round holes 19 (six in this embodiment) is defined in each plate 11. A collar 16 extends from a periphery of each hole 19. The collar 16 has a funnel-like shape. The collar 16 comprises a columned portion 14 and a taper portion 15 interconnecting the plate 11 and the columned portion 14. The columned portion 14 is cylindrical. The taper portion 15 is substantially a truncated cone with a small bottom thereof connecting a top of the columned portion 14, and a big top thereof connecting the plate 11. The collar 16 has a height in an axial direction of the hole 19 (i.e., an axial direction of the heat pipes 20) which is indicated by H. The height H of the collar 16 approaches to the height P of the channel 13. That is, a distance between a bottom of the columned portion 14 and an adjacent underlying fin 10 along the axial direction of the hole 19 is very small. A height of the columned portion 14 is substantially equal to that of the taper portion 15.

Each heat pipe 20 has a round cross section. The heat pipe 20 has wick structures (not shown) formed in an inner surface thereof and working fluid (not shown) contained therein.

In assembly, the fins 10 are stacked together. The flanges 12 of each fin 10 abut against a lower, adjacent fin 10. Solder 30 is spread on inner surfaces of the columned portions 14 of the collars 16 of the fins 10. The heat pipes 20 are then inserted into the holes 19 of the fins 10. By the provision of the taper portions 15 which are located very close to the bottoms of the columned portions 14 of the corresponding upper collars 16, excessive solder 30 which is pushed out of the columned portions 14 is immediately received in the taper portions 15, thereby eliminating the possibility that the excessive solder 30 will drop on the flat plates 11. Then, the fins 10 together with the heat pipes 20 are put into an oven to be heated. The solder 30 on the heat pipes 20 and located corresponding to the columned portions 14 of the collars 16 is heated to flow. The flowed solder 30 evenly fills in gaps between the inner surfaces of the columned portions 14 of the collars 16 and the heat pipes 20. After cooled, the solidified solder 30 thermally and mechanically connects the heat pipes 20 and the columned portions 14 of the collars 16 together. The solder 30 on the heat pipes 20 and located between the columned portions 14 is heated to flow downwardly into spaces between inner surfaces of the taper portions 15 of the collars 16 and the heat pipes 20 as shown in FIG. 2. After cooled, the solidified solder 30 thermally and mechanically connects the taper portions 15 of the collars 16 and the heat pipes 20 together whereby the thermal and mechanical connections between the fins 10 and the heat pipes 20 are reinforced. In the present invention, by the provision of the taper portions 15 and the design that the bottom of the columned portion 14 is very close to a corresponding lower taper portion 15, the solder 30 will not drop or flow to the horizontal, flat plate 11 to unfavorably affect an aesthetic appearance of the heat dissipation device.

The formation of the taper portions 15 results in an increasing of a total height H of the collars 16 along the axial direction of the heat pipes 20. That is, the distance between bottoms of the columned portions 14 and the adjacent underlying fin 10 is decreased, which could prevent the solder 30 from spraying onto the horizontal, flat plate 11 of the adjacent underlying fin 10. Furthermore, the taper portions 15 connect to the outer surfaces of the heat pipes 20 by the solder 30 retained in the spaces therebetween. Therefore, a contact surface between the fins 10 and the heat pipes 20 is increased, which is an advantage of enhancing the heat dissipation efficiency of the heat dissipation device.

The heat pipes 20 are round in this embodiment, and the collars 16 form corresponding columned portions 14 to contact with the heat pipes 20. It is to be understood that the shape of the heat pipes 20 and the collars 16 could be potentially varied, as long as the collars 16 comprise a contacting portion attached to the heat pipes 20 and an intermediate portion interconnecting with the plate 11 and the contacting portion, wherein a cross section of the intermediate portion has a size larger than that of the contacting portion. In an alternative embodiment, the solder 30 can be replaced by thermally conductive glue. When the thermally conductive glue is used, the step of heating the fins and the heat pipes in the oven can be omitted.

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 heat pipe; and

a plurality of fins stacked onto the heat pipe along an axial direction of the heat pipe, each fin comprising a plate defining a hole for extension of the heat pipe therethrough and a collar extending from a periphery of the hole, the collar comprising a columned portion attached to an outer surface of the heat pipe, and a taper portion interconnecting the plate and the columned portion, the taper portion increasing a height of the collar along the axial direction of the heat pipe.

2. The heat dissipation device as claimed in claim 1, wherein the height of the collar is slightly smaller than a distance between two adjacent fins.

3. The heat dissipation device as claimed in claim 1, wherein a height of the columned portion is similar to that of the taper portion.

4. The heat dissipation device as claimed in claim 1, wherein the taper portion has a truncated cone configuration, with a small bottom thereof connecting a top of the columned portion, and a big top thereof connecting the plate.

5. The heat dissipation device as claimed in claim 1, further comprising solder filled in gaps between the collars of the fins and the heat pipe.

6. The heat dissipation device as claimed in claim 5, wherein the taper portion has an inner surface facing towards the outer surface of the heat pipe and a portion of the solder is retained between the inner surface of the taper portion and the outer surface of the heat pipe.

7. The heat dissipation device as claimed in claim 1, further comprising thermally conductive glue filled in gaps between the collars of the fins and the heat pipe.

8. A heat dissipation device comprising:

at least one heat pipe;

a plurality of fins stacked onto the at least one heat pipe along an axial direction of the at least one heat pipe, with a channel defined between every two adjacent fins, each fin comprising a plate defining at least one hole for extension of the at least one heat pipe therethrough and a collar extending from a periphery of the at least one hole, the collar comprising a columned portion attached to an outer surface of the heat pipe, and a taper portion interconnecting the plate and the columned portion, a height of the collar being slightly smaller than a height of the channel; and

solder filled in gaps between the collars of the fins and the at least one heat pipe, the solder filling in a gap between the columned portion and the at least one heat pipe and a space between the taper portion and the at least one heat pipe.

9. The heat dissipation device as claimed in claim 8, wherein the columned portion is cylindrical, and the taper portion has a truncated cone shape, with a small bottom thereof connecting a top of the columned portion, and a big top thereof connecting the plate.

10. The heat dissipation device as claimed in claim 8, wherein a height of the columned portion is similar to that of the taper portion.

11. A heat dissipation device comprising:

at least one heat pipe;

a plurality of fins stacked onto the at least one heat pipe along an axial direction of the at least one heat pipe, each fin comprising a plate defining at least one hole for extension of the at least one heat pipe therethrough and a collar extending from a periphery of the at least one hole, the collar comprising a contacting portion attached to an outer surface of the at least one heat pipe, and an intermediate portion interconnecting the plate and the contacting portion, a cross section of the intermediate portion being larger than that of the contacting portion; and

solder filled in gaps between the collars of the fins and the at least one heat pipe, the solder filling in a gap between the contacting portion and the at least one heat pipe and a space between the intermediate portion and the at least one heat pipe.

12. The heat dissipation device as claimed in claim 11, wherein the contacting portion has a columned shape for enclosing the outer surface of the at least one heat pipe, and the intermediate portion has a taper shape with a small bottom thereof connecting a top of the contacting portion, and a big top thereof connecting the plate.

13. The heat dissipation device as claimed in claim 11, wherein a height of the collar approaches to a distance between two adjacent fins.

14. The heat dissipation device as claimed in claim 11, wherein a height of the contacting portion is similar to that of the retaining portion.