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 of FIG. 1;
FIG. 3 is a view similar to FIG. 2 with heat pipes being mounted on a lower plate of the heat sink; and
FIG. 4 is an inverted view of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, a heat sink 10 in accordance with a preferred embodiment of the present invention is for being mounted on an electronic component (not shown) to dissipate heat therefrom. The heat sink 10 comprises a lower plate 20, an upper plate 30, a plurality of heat pipes 60 sandwiched between the lower plate 20 and the upper plate 30, and an upper fin set 40 and a lower fin set 50 attached on the upper plate 30 and the lower plate 20, respectively.
Also referring to FIG. 4, the lower plate 20 is made by bending a metal plate, it comprises a rectangular and planar panel 22, a pair of sidewalls 24 extending upwardly and perpendicularly from two opposite lateral sides of the panel 22, and a pair of flanges 26 formed horizontally and oppositely from tops of the pair of sidewalls 24, respectively. A square area of the panel 22 is stamped downwardly to form a protrusion 220 (shown in FIG. 4) projecting beyond a bottom face the panel 22, and a cavity 222 located corresponding to the protrusion 220 and beneath a top face of the panel 22. The protrusion 220 is adapted for contacting the electronic component to absorb heat therefrom. In the preferred embodiment of the present invention, the protrusion 220 is located at a front part of the panel 22; nevertheless, a location of the protrusion 220 on the panel 22 can be varied according to positions of the electronic component. A plurality of bumps 200 are formed on the panel 22 by stamping corresponding points of the panel 22 upwardly. The bumps 200 are arranged according to profiles of the heat pipes 60 so as to suitably sandwich the heat pipes 60 therebetween, wherein two of the bumps 200 are located in the cavity 222, and other bumps 200 are located outside the cavity 222. Corresponding portions of the sidewalls 24 and the flanges 26 are bent outwardly and oppositely to form a pair of horizontal wings (not labeled) at two lateral sides of the lower plate 20, respectively. A pair of rectangular securing members 70 are disposed on the two wings of the lower plate 20 and inserted into the flanges 26 and the sidewalls 24, with an outer side thereof being coincidental with an outer edge of a corresponding wing. Each of the securing members 70 has a height larger than that of the sidewalls 24, whereby a top of the each securing member 70 extends beyond the flanges 26 for contacting the upper plate 30. A hole 700 is defined through each securing member 70 and each wing to provide a passage for a fastener (not shown).
The upper plate 30 is soldered on the two flanges 26 of the lower plate 20. The upper plate 30 has a periphery coincidental with a periphery of the lower plate 20. A pair of cutouts 32 are defined at each lateral side of the upper plate 30 corresponding to one of the wings, while a part of the upper plate 30 located between the pair of cutouts 32 forms a rectangular tab 34, which is for resiliently abutting against a corresponding securing member 70. Total areas of the two cutouts 32 and the tab 34 are identical to an area of the securing member 70 (illustrated in FIG. 1). A circular hole 340 is defined in each tab 34 corresponding to the hole 700 in the lower plate 20 and the securing member 70. The fastener extends through the circular hole 340 of the upper plate 30 and a corresponding hole 700 of the lower plate 20 and the securing member 70 to attach them on a printed circuit board (not shown) where the electronic component is mounted.
The upper fin set 40 and the lower fin set 50 are fixed on the upper plate 30 and the lower plate 20 by soldering, respectively. Each of the upper fin set 40 and the lower fin set 50 comprises a plurality of parallel fins 42, 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. The lower fin set 50 is secured on a rear part of the bottom face of the panel 22 and near the protrusion 220 (viewed from FIG. 4), by soldering upper pieces of the fins 52 on the panel 22; the upper fin set 40 is secured on a whole top face of the upper plate 30, by soldering lower pieces of the fins 42 on the upper plate 30, wherein every two adjacent fins 42, 52 form a passage therebetween for allowing an airflow therethrough. The lower fin set 50 has a width similar to that of the panel 22, and the upper fin set 40 has a profile similar to that of the upper plate 30 and a width larger than that of the lower fin set 50 (shown in FIG. 4).
As viewed from FIGS. 2-3, the heat pipes 60 are sandwiched between the upper plate 30 and the lower plate 20. In the preferred embodiment of the present invention there are four heat pipes 60; however, the number of the heat pipes 60 is adjustable according to the amount of heat that the electronic component generates. Two middle ones 62 of the four heat pipes 60 are straight and planar and parallel to each other; two lateral ones 64 of the four heat pipes 60 are planar and each have a straight section 640 parallel to the two middle heat pipes 62, two bended sections 642 extended slantwise and outwardly from two opposite ends of the straight section 640, and an extremity end 644 extending backwardly from a rear bended section 642, wherein each bended section 642 defines an angle approximate to 135 degrees with the straight section 640. The four heat pipes 60 are so arranged that the two middle heat pipes 62 abut side-by-side against each other along a lengthwise direction of the lower plate 20, and the two lateral heat pipes 64 are juxtaposed with the two middle heat pipes 62 in a manner that the straight sections 640 thereof directly contact the two middle heat pipes 62, the bended sections 642 are inclinedly spaced from the two middle heat pipes 62, and the extremity ends 644 are gapped from and parallel to the two middle heat pipes 62. A distance from an outmost portion of a front bended section 642 to an outmost portion of the extremity end 644 of each lateral heat pipe 64 is identical to a length of the middle heat pipe 62. A distance between two extremity ends 644 of the two lateral heat pipes 64 is less than that between two sidewalls 24 of the lower plate 20, whereby when the four heat pipes 60 are fixed on the lower plate 20, the extremity ends 644 would be spaced from the sidewalls 24 to define gaps (not labeled) therebetween (illustrated in FIG. 5), which allow the airflow therethrough to increase heat dissipation of the heat sink 10. The four heat pipes 60 are positioned on the panel 22 by the bumps 200 in a manner such that the two middle heat pipes 62 are sandwiched between two bumps 200 near each end thereof; each junction (not labeled) of the two lateral heat pipes 64 between the bended sections 642 and the straight sections 640 is sandwiched by two bumps 200, each of joints of the bended sections 642 and the extremity ends 644 is sandwiched by two bumps 200, each front bended section 642 is located between two bumps 200, and each extremity end 644 abuts against one bump 200. In other words, two bumps 200 sandwich the two lateral heat pipes 64 at each bended position thereof. Each heat pipe 60 has a part projecting downwardly from a bottom face thereof to form a rectangular chassis 646, which has a length less than that of the cavity 222 of the lower plate 20, and a thickness approximate to a depth of the cavity 222 of the lower plate 20. Four chassises 646 are located just above the cavity 222 and for being substantially accommodated into the cavity 222 and directly contacting a top face of the protrusion 220 to absorb heat therefrom.
In assembly, the heat pipes 60 are brought to be disposed downwardly on the panel 22 between the bumps 200 and soldered to the panel 20; then the upper plate 30 is put and soldered on the flanges 26 of the lower plate 20; finally, the lower fin set 50 and the upper fin set 40 are soldered on the lower plate 20 and the upper plate 30, respectively.
In use, the heat sink 10 is disposed on the printed circuit board with its protrusion 220 contacting with the electronic component, wherein the upper fin set 40 is located above the printed circuit board, and the lower fin set 50 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 the protrusion 220, and then is transferred to other portions of the heat pipes 60 via the chassises 646. The heat pipes 60 distribute the heat over the upper plate 30 and the lower plate 20, which disperses the heat to the ambient via the lower fin set 50 and the upper fin set 40.
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, the lower plate 20 of the present invention only forms the bumps 200 thereon, which do not need the lower plate 20 having a large thickness to form them, and also do not occupy so much areas of the panel 22; therefore, a thickness of the lower plate 20 is capable of being controlled in a small range and a material cost is reduced accordingly, and a convenient positioning between the heat pipes 60 and the lower plate 20 is achieved which is not sensitive relative to a size of the lower plate 20.
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.
Patent Application
20090159252
