US20090159252A1 - Heat sink having bumps for positioning heat pipes therein - Google Patents

Abstract

A heat sink adapter for cooling an electronic component includes a lower plate, an upper plate, an upper fin set and a lower fin set respectively fixed on the upper plate and the lower plate, and a plurality of heat pipes sandwiched between the upper plate and the lower plate. The lower plate forms a plurality of bumps projecting upwardly therefrom, which sandwich the heat pipes therebetween to position the heat pipes on the lower plate, wherein some of the heat pipes are bent and sandwiched between two bumps at each bended position, and some of the heat pipes are straight and located near one bump at each end portion thereof.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a heat sink, and more particularly to a heat sink having bumps for positioning heat pipes therein.
• 2. Description of Related Art
• The central processing unit (CPU) mounted on the motherboard in a computer is the center of operations of the computer. During the operations of the computer, the CPU produces heat. The heat must be quickly carried away from the CPU during the operations of the computer. Accordingly, a heat sink is used to remove the heat from the CPU.
• Conventionally, a heat sink includes a metal base contacting the CPU and a plurality of fins extending from the metal base for dissipating heat absorbed by the metal base from the CPU to an ambient. Heat pipes are often mounted to the metal base for enhancing a heat dissipating efficiency of the heat sink.
• In order to position the heat pipes in the heat sink, the metal base usually defines a plurality of grooves for receiving the heat pipes therein. Nevertheless, for receiving the heat pipes therein substantially, the metal base should be made to have a thickness larger than diameters of the grooves, whereby a material cost of the metal base is increased.
• Another method to position the heat pipes in the heat sink is to use positioning clamps. The positioning clamps are disposed on the metal base at first, and then the heat pipes are brought to fit into gaps between the positioning clamps, thereby realizing the positioning of the heat pipes on the metal base. However, if a size of the heat sink is small, there will have not enough area of the metal base for disposing the positioning clamps thereon; therefore, the positioning of the heat pipes becomes difficult.
• What is needed, therefore, is a heat dissipating device which can overcome the above-mentioned disadvantages.
SUMMARY OF THE INVENTION
• A heat sink adapter for cooling an electronic component includes a lower plate, an upper plate, an upper fin set and a lower fin set respectively fixed on the upper plate and the lower plate, and a plurality of heat pipes sandwiched between the upper plate and the lower plate. The lower plate forms a plurality of bumps projecting upwardly therefrom, which sandwich the heat pipes therebetween to position the heat pipes on the lower plate, wherein some of the heat pipes are bent and sandwiched between two bumps at the bended positions. Compared with the conventional heat sink that forms grooves on a base to position heat pipes therein and the conventional heat sink that use positioning clamps to position heat pipes on the base, the heat sink of the present invention just forms the plurality of bumps on the lower plate, which do not need the lower plate being thick and are able to provide a convenient positioning for the heat pipes.
• 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, in which:
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 sink in accordance with a preferred embodiment of the present invention;
• FIG. 2 is an exploded view ofFIG. 1;
• FIG. 3 is a view similar toFIG. 2 with heat pipes being mounted on a lower plate of the heat sink; and
• FIG. 4 is an inverted view ofFIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
• Referring toFIGS. 1 and 2, aheat sink10 in accordance with a preferred embodiment of the present invention is for being mounted on an electronic component (not shown) to dissipate heat therefrom. Theheat sink10 comprises alower plate20, anupper plate30, a plurality ofheat pipes60 sandwiched between thelower plate20 and theupper plate30, and an upper fin set40 and alower fin set50 attached on theupper plate30 and thelower plate20, respectively.
• Also referring toFIG. 4, thelower plate20 is made by bending a metal plate, it comprises a rectangular andplanar panel22, a pair ofsidewalls24 extending upwardly and perpendicularly from two opposite lateral sides of thepanel22, and a pair offlanges26 formed horizontally and oppositely from tops of the pair ofsidewalls24, respectively. A square area of thepanel22 is stamped downwardly to form a protrusion220 (shown inFIG. 4) projecting beyond a bottom face thepanel22, and acavity222 located corresponding to theprotrusion220 and beneath a top face of thepanel22. Theprotrusion220 is adapted for contacting the electronic component to absorb heat therefrom. In the preferred embodiment of the present invention, theprotrusion220 is located at a front part of thepanel22; nevertheless, a location of theprotrusion220 on thepanel22 can be varied according to positions of the electronic component. A plurality ofbumps200 are formed on thepanel22 by stamping corresponding points of thepanel22 upwardly. Thebumps200 are arranged according to profiles of theheat pipes60 so as to suitably sandwich theheat pipes60 therebetween, wherein two of thebumps200 are located in thecavity222, andother bumps200 are located outside thecavity222. Corresponding portions of thesidewalls24 and theflanges26 are bent outwardly and oppositely to form a pair of horizontal wings (not labeled) at two lateral sides of thelower plate20, respectively. A pair of rectangular securingmembers70 are disposed on the two wings of thelower plate20 and inserted into theflanges26 and thesidewalls24, with an outer side thereof being coincidental with an outer edge of a corresponding wing. Each of thesecuring members70 has a height larger than that of thesidewalls24, whereby a top of the eachsecuring member70 extends beyond theflanges26 for contacting theupper plate30. Ahole700 is defined through each securingmember70 and each wing to provide a passage for a fastener (not shown).
• Theupper plate30 is soldered on the twoflanges26 of thelower plate20. Theupper plate30 has a periphery coincidental with a periphery of thelower plate20. A pair ofcutouts32 are defined at each lateral side of theupper plate30 corresponding to one of the wings, while a part of theupper plate30 located between the pair ofcutouts32 forms arectangular tab34, which is for resiliently abutting against acorresponding securing member70. Total areas of the twocutouts32 and thetab34 are identical to an area of the securing member70 (illustrated inFIG. 1). Acircular hole340 is defined in eachtab34 corresponding to thehole700 in thelower plate20 and thesecuring member70. The fastener extends through thecircular hole340 of theupper plate30 and acorresponding hole700 of thelower plate20 and the securingmember70 to attach them on a printed circuit board (not shown) where the electronic component is mounted.
• The upper fin set40 and thelower fin set50 are fixed on theupper plate30 and thelower plate20 by soldering, respectively. Each of the upper fin set40 and thelower fin set50 comprises a plurality ofparallel fins42,52, each of which consists of an upright sheet (now labeled) and a pair of pieces (not labeled) bent horizontally from a top and a bottom of the sheet, respectively. Thelower fin set50 is secured on a rear part of the bottom face of thepanel22 and near the protrusion220 (viewed fromFIG. 4), by soldering upper pieces of thefins52 on thepanel22; theupper fin set40 is secured on a whole top face of theupper plate30, by soldering lower pieces of thefins42 on theupper plate30, wherein every two adjacent fins42,52 form a passage therebetween for allowing an airflow therethrough. Thelower fin set50 has a width similar to that of thepanel22, and theupper fin set40 has a profile similar to that of theupper plate30 and a width larger than that of the lower fin set50 (shown inFIG. 4).
• As viewed fromFIGS. 2-3, theheat pipes60 are sandwiched between theupper plate30 and thelower plate20. In the preferred embodiment of the present invention there are fourheat pipes60; however, the number of theheat pipes60 is adjustable according to the amount of heat that the electronic component generates. Twomiddle ones62 of the fourheat pipes60 are straight and planar and parallel to each other; twolateral ones64 of the fourheat pipes60 are planar and each have astraight section640 parallel to the twomiddle heat pipes62, twobended sections642 extended slantwise and outwardly from two opposite ends of thestraight section640, and anextremity end644 extending backwardly from a rearbended section642, wherein eachbended section642 defines an angle approximate to 135 degrees with thestraight section640. The fourheat pipes60 are so arranged that the twomiddle heat pipes62 abut side-by-side against each other along a lengthwise direction of thelower plate20, and the twolateral heat pipes64 are juxtaposed with the twomiddle heat pipes62 in a manner that thestraight sections640 thereof directly contact the twomiddle heat pipes62, thebended sections642 are inclinedly spaced from the twomiddle heat pipes62, and theextremity ends644 are gapped from and parallel to the twomiddle heat pipes62. A distance from an outmost portion of a front bendedsection642 to an outmost portion of theextremity end644 of eachlateral heat pipe64 is identical to a length of themiddle heat pipe62. A distance between two extremity ends644 of the twolateral heat pipes64 is less than that between twosidewalls24 of thelower plate20, whereby when the fourheat pipes60 are fixed on thelower plate20, theextremity ends644 would be spaced from thesidewalls24 to define gaps (not labeled) therebetween (illustrated inFIG. 5), which allow the airflow therethrough to increase heat dissipation of theheat sink10. The fourheat pipes60 are positioned on thepanel22 by thebumps200 in a manner such that the twomiddle heat pipes62 are sandwiched between twobumps200 near each end thereof; each junction (not labeled) of the twolateral heat pipes64 between thebended sections642 and thestraight sections640 is sandwiched by twobumps200, each of joints of thebended sections642 and theextremity ends644 is sandwiched by twobumps200, each front bendedsection642 is located between twobumps200, and each extremity end644 abuts against onebump200. In other words, twobumps200 sandwich the twolateral heat pipes64 at each bended position thereof. Eachheat pipe60 has a part projecting downwardly from a bottom face thereof to form arectangular chassis646, which has a length less than that of thecavity222 of thelower plate20, and a thickness approximate to a depth of thecavity222 of thelower plate20. Fourchassises646 are located just above thecavity222 and for being substantially accommodated into thecavity222 and directly contacting a top face of theprotrusion220 to absorb heat therefrom.
• In assembly, theheat pipes60 are brought to be disposed downwardly on thepanel22 between thebumps200 and soldered to thepanel20; then theupper plate30 is put and soldered on theflanges26 of thelower plate20; finally, the lower fin set50 and theupper fin set40 are soldered on thelower plate20 and theupper plate30, respectively.
• In use, theheat sink10 is disposed on the printed circuit board with itsprotrusion220 contacting with the electronic component, wherein the upper fin set40 is located above the printed circuit board, and the lower fin set50 extends downwardly beyond the printed circuit board and has a part located lower than the printed circuit board. Heat generated by the electronic component is absorbed by theprotrusion220, and then is transferred to other portions of theheat pipes60 via thechassises646. Theheat pipes60 distribute the heat over theupper plate30 and thelower plate20, which disperses the heat to the ambient via the lower fin set50 and the upper fin set40.
• On contrary to the conventional heat sink which needs forming grooves in a base to position heat pipes therein, and the conventional heat sink which needs positioning clamps disposed on a base to position heat pipes thereon, thelower plate20 of the present invention only forms thebumps200 thereon, which do not need thelower plate20 having a large thickness to form them, and also do not occupy so much areas of thepanel22; therefore, a thickness of thelower plate20 is capable of being controlled in a small range and a material cost is reduced accordingly, and a convenient positioning between theheat pipes60 and thelower plate20 is achieved which is not sensitive relative to a size of thelower plate20.
• 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 (20)

1. A heat sink adapted for an electronic component, comprising:

a lower plate; and

heat pipes fixed on the lower plate, wherein the lower plate forms a plurality of bumps according to peripheries of the heat pipes to position the heat pipes relative to the lower plate.

2. The heat sink as claimed inclaim 1, wherein the heat pipes comprises bended heat pipes, each of the bended heat pipes being sandwiched between two bumps at each bended position.

3. The heat sink as claimed inclaim 2, wherein the heat pipes comprises straight heat pipes sandwiched between the bended heat pipes, the straight heat pipes being juxtaposed and contacting with each other.

4. The heat sink as claimed inclaim 3, wherein each bended heat pipe comprises a straight section, a pair of bended sections extending slantwise and outwardly from the straight section, and an extremity end extending from one of the pair of bended sections, the straight sections of the bended heat pipes abutting side-by-side against the straight heat pipes.

5. The heat sink as claimed inclaim 4, wherein each of junctions of the straight sections and the bended sections of the bended heat pipes is sandwiched between and positioned by two bumps.

6. The heat sink as claimed inclaim 4, wherein at least one of the bended sections is located between two bumps, and at least one of the extremity ends of the bended sections is located adjacent to one bump.

7. The heat sink as claimed inclaim 1, wherein the lower plate forms a protrusion projecting downwardly therefrom and a trough defined in the protrusion and opened upwardly, the protrusion being adapted for contacting the electronic component.

8. The heat sink as claimed inclaim 7, wherein the heat pipes have a plurality of bulges projecting downwardly therefrom, the plurality of bulges being received in the cavity and abutting against the protrusion of the lower plate.

9. The heat sink as claimed inclaim 1, wherein the lower plate comprises a planar board, a pair of sidewalls extending upwardly from two opposite sides of the board, and a pair of flanges formed vertically from tops of the pair of sidewalls, the bumps being formed on the board.

10. The heat sink as claimed inclaim 9 further comprising an upper plate fixed on the flanges of the lower plate, wherein the heat pipes are sandwiched between and directly contact the board and the upper plate, and spaced from the sidewalls of the lower plate.

11. The heat sink as claimed inclaim 10 further comprising an upper fin arrangement fixed on the upper plate and a lower fin arrangement fixed on the board, wherein the upper fin arrangement occupies a total area of a top face of the upper plate and the lower fin arrangement occupies a half area of a bottom face of the board.

12. A heat sink adapted for dissipating heat from an electronic component, comprising:

a lower plate;

an upper plate fixed on the lower plate; and

a plurality of heat pipes sandwiched between the lower plate and the upper plate, wherein the lower plate has a plurality of embosses formed upwardly corresponding to shapes of the plurality of heat pipes, and wherein the plurality of heat pipes are sandwiched between the plurality of embosses to be positioned on the lower plate.

13. The heat sink as claimed inclaim 12, wherein the plurality of heat pipes comprises at least a bended heat pipe and at least a straight heat pipe, the at least a bended heat pipe being sandwiched between two embosses at each bended position, and the at least a straight heat pipe being located near one emboss at each end thereof.

14. The heat sink as claimed inclaim 13, wherein the at least a bended heat pipe comprises a straight portion parallel to and contacting the at least a straight heat pipe, a pair of bended portions extending slantwise from two ends of the straight portion, and an extremity end extending from one of the bended portions and parallel to the straight portion.

15. The heat sink as claimed inclaim 14, wherein one emboss is located adjacent to the end of the at least a straight heat pipe and sandwiches an junction of the straight portion and one of the pair of bended portions of the at least a bended heat pipe with another emboss.

16. The heat sink as claimed inclaim 12 further comprising an upper fin arrangement fixed on the upper plate and a lower fin arrangement fixed on the lower plate, wherein each of the upper fin arrangement and the lower fin arrangement comprises a plurality of fins parallel to each other.

17. The heat sink as claimed inclaim 12, wherein a protrusion projects downwardly from a part of the lower plate and a trough is defined in the protrusion and opened upwardly, the heat pipes having at least a part received in the trough and contacting the protrusion.

18. A heat sink for cooling an electronic component comprising:

a lower plate;

a lower fin set fixed on the lower plate;

an upper plate;

an upper fin set fixed on the upper plate; and

a plurality of heat pipes sandwiched between the lower plate and the upper plate comprising straight heat pipes and bended heat pipes, wherein a plurality of bumps projecting upwardly from the lower plate and sandwich the heat pipes therebetween to position the heat pipes on the lower plate, and wherein some of the bumps are located adjacent to ends of the straight heat pipes and other some of the bumps are located adjacent to the bended heat pipes at bended positions and still other some of the bumps are located adjacent to ends of the bended heat pipes.

19. The heat sink as claimed inclaim 18, wherein the upper fin set occupies a whole area of a top face of the upper plate and the lower fin set occupies a half area of a bottom face of the lower plate.

20. The heat sink as claimed inclaim 18, wherein the lower plate forms a protrusion projecting downwardly therefrom and adjacent to the lower fin set, and a trough defined in the protrusion and opened upwardly, the heat pipes having portions being received in the trough and contacting with the protrusion.

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