US20090101316A1

US20090101316A1 - Heat dissipating assembly with reduced thermal gradient

Info

Publication number: US20090101316A1
Application number: US11/874,655
Authority: US
Inventors: Tai-Sheng (Andrew) Han
Original assignee: EVGA Corp USA
Current assignee: EVGA Corp USA
Priority date: 2007-10-18
Filing date: 2007-10-18
Publication date: 2009-04-23
Also published as: WO2009052515A1

Abstract

A device to dissipate thermal energy generated by a heat generating component. The device includes a base plate and a housing secured to and disposed on the base plate to form an enclosed space surrounded thereby. The device also includes a plurality of fins secured to the base plate and disposed in the space; an inlet pipe for introducing cooling fluid into the space and an outlet pipe for exhausting the cooling fluid from the space. The inlet pipe has a flow exit positioned over the fins so that the cooling fluid flows from the top portions of the fins toward the base plate.

Description

BACKGROUND OF THE INVENTION

The present invention generally relates to devices for cooling electrical components and, more particularly, to liquid cooled waterblocks for dissipating heat energy.
With the advance of main unit's operation speed, the thermal energy generated by active components of a computer, such as processor and memory chip, often becomes significant. For instance, in order to enable desktop and other computers to rapidly process graphics and game technology, add-on units generally referred to as “graphics cards” or “VGA” cards” are often installed in computer devices. Such cards include a separate processor, called a GPU, one or more memory chips, and other required circuitry, all mounted to a circuit board including an edge connector that is adapted to plug into an available slot in the associated computer device. Typically, GPU and/or memory chips generates substantial heat that if not dissipated will adversely affect operation of the graphics card.
Heretofore, various approaches have been tried to dissipate or otherwise remove heat from the thermal energy generating components. FIG. 1 shows a conventional liquid cooled waterblock 100 for dissipating heat energy generated by an active component. As depicted, the waterblock 100 includes a top cover 102 and a body 104 sealingly secured to the top cover by a plurality of fasteners (not shown in FIG. 1) passing through the holes 106. The body 104 includes a channel 110 that forms a passageway for cooling liquid with the bottom surface of the top cover 102. The waterblock 100 may be disposed on and in contact with a heat generating component so that the heat energy generated by the component is conducted to the radiator 108 included in the body 104. The cooling fluid flows into the channel 110 via an inlet pipe 112, dissipate heat energy from the radiator 108 and body 104, and exits the waterblock via the outlet pipe 114.
As the cooling liquid flows through the channel 110 in one direction, a thermal gradient may be established in the radiator 108 along the flow direction, which may induce a similar thermal gradient in the heat generating component disposed under the radiator 108. The thermal gradient in the heat generating component may reduce the operational performance thereof and possibly shorten the life expectancy due to the heat damage on the lee side thereof. Furthermore, as the cooling liquid flows through the channel 110, the cooling liquid may be pre-warmed before reaching the radiator 108, reducing the efficiency in cooling the radiator 108. Thus, there is a need for an improved heat extraction or dissipation mechanism that can reduce the pre-warming of the cooling liquid and the thermal gradient of the heat generating component thereby to enhance the performance thereof.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a device for cooling a component includes: a base plate; a housing secured to and disposed on the base plate to form an enclosed space surrounded thereby; a plurality of fins secured to the base plate and disposed in the space; an inlet pipe for introducing cooling fluid into the space, the inlet pipe having a flow exit positioned over the fins; and an outlet pipe for exhausting the cooling fluid from the space.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded perspective view of a conventional liquid cooled waterblock;

FIG. 2 shows a schematic perspective view of a liquid cooled waterblock in accordance with one embodiment of the present invention;

FIG. 3 shows a schematic cross sectional view of the waterblock in FIG. 2, taken along the line III-III;

FIG. 4 shows a schematic cross sectional view of the waterblock in FIG. 2, taken along the line IV-IV; and

FIG. 5 shows a schematic cross sectional view of a waterblock in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Referring to FIG. 2 of the drawing, a waterblock in accordance with one embodiment of the present invention is illustrated at 200 and includes a base plate 204 and an upper cover or housing 202 sealingly secured to the base. FIGS. 3 and 4 show schematic cross sectional diagrams of the waterblock 200 in FIG. 2, taken along the lines III-III and IV-IV, respectively. Cooling fluid enters into the waterblock 200 through the inlet pipe 206 and exits through the outlet pipe 208. The cooling fluid is preferably water or any other suitable liquid or gas for dissipating heat from the waterblock. For brevity, a pump for circulating the cooling fluid through the inlet/outlet pipes and a cooling system for extracting heat energy from the cooling fluid are not shown in FIG. 2. However, it should be apparent to those of ordinary skill that any suitable conventional pump and cooling system may be used with the waterblock 200.
The base plate 204 may be formed of heat conducting material, such as aluminum, copper, nickel, or any other suitable metal. The base plate 204 can be mounted on a heat generating component 214 to extract heat energy therefrom. The housing 202 may be formed of plastic that can stand the temperature of the cooling fluid. In one exemplary embodiment, the housing 202 may be injection molded polyoxymethylene (POM) plastic. The inlet pipe 206 and outlet pipe 208 can be connected to a pump (not shown in FIG. 2) by use of a conventional fitting, such as “F” fitting.
The waterblock 200 includes an upper chamber 212 and a lower chamber 213 separated by a middle plate 216 having one or more openings 218 for fluid communication between the upper and lower chambers. The middle plate 216 may be formed of metal or plastic that can stand the temperature of the cooling fluid. In one exemplary embodiment, the middle plate 216 and housing 202 can be formed as an integral body.
Attached to the upper surface of the base plate 204 are a plurality of fins 210, each fin having a dome-shaped top portion and a cylinder-shaped bottom portion. The cylinder-shaped bottom portion may have various cross sectional shapes, such as hexagon, rectangle, circle, oval, or the like. The fins 210 operate as radiator, i.e., the heat generated by the heat generating component 214 is conducted to the fins 210 via the base plate 204. The fins 210 may be formed of heat conducting material, such copper, aluminum, nickel, or the like, and arranged in a two-dimensional array format, for instance. The number, size, and arrangement of the fins 210 may be determined by various design parameters, such as flow rate, pressure drop, and heat conduction rate.
The inlet pipe 206 extends through the upper chamber 212 to the lower chamber 213, thereby introducing cooling fluid directly into the lower chamber 213. The inlet pipe 206 has a flow exit positioned over the fins 210 so that the cooling fluid exiting the inlet pipe 206 flows from the top portions of the fins 210 toward the base plate 204, dissipating heat energy from the fins 210 and base plate 204. The heated cooling fluid exits the lower chamber 213 to the upper chamber 212 through the openings 218 and thence exits the upper chamber through the outlet pipe 208.
It is noted that cooling fluid flows generally in radial directions when seen from the top. Thus, the thermal gradient may be developed along the distance, D, between the inlet pipe wall and edges of the base plate 204. For a base plate having the same dimension as the radiator 108, the thermal gradient in the base plate 204 would be much smaller than that of the radiator 108 since the distance D is much smaller than the length of the radiator 108.
It is also noted that the cooling fluid contacts the fins 210 as soon as it exits the inlet pipe 206. As such, the cooling fluid is not pre-warmed before reaching the fins 210, providing an improved cooling efficiency compared to the conventional waterblock 100.
In one exemplary embodiment, the fins 210 may be secured to the base plate 204 by fasteners, such as bolts, or by suitable adhesive, such as thermal epoxy. In another exemplary embodiment, the fins 210 and base plate 204 may be formed as an integral body. The base plate 204 may be secured to the heat generating component 214 by suitable thermal epoxy. The form factors of the waterblock 200 may be determined by various parameters, such as the dimension of the heat generating component 214. It should be apparent to those of ordinary skill that the base plate 204 may have a suitable shape, such as circle, and the housing 202 may also have a suitable shape, such as circular cylinder.
FIG. 5 shows a schematic cross sectional view of a waterblock 300 in accordance with another embodiment of the present invention. The waterblock 300 may be similar to the waterblock 200, with the difference that the inlet pipe 302 has a nozzle-shaped tip. The nozzle-shaped tip may enhance flow uniformity over the top portions of the fins 306, thereby reducing the thermal gradient in the base plate 304.
Notwithstanding that the present invention has been described above in terms of several alternative embodiments, it is anticipated that still other alterations and modifications will become apparent to those of ordinary skilled in the art after having read this disclosure. It is therefore intended that such disclosure be considered illustrative and not limiting, and that the appended claims be interpreted to include all such alterations, modifications and embodiments as fall within the true spirit and scope of the invention.

Claims

1. A device for cooling a component, comprising:

a base plate;

a housing secured to and disposed on the base plate to form an enclosed space surrounded thereby;

a plurality of fins secured to the base plate and disposed in the space;

an inlet pipe for introducing cooling fluid into the space, the inlet pipe having a flow exit positioned over the fins; and

an outlet pipe for exhausting the cooling fluid from the space.

2. A device as recited in claim 1, further comprising:

a middle plate separating the space into upper and lower chambers and including one or more openings for fluid communication therebetween,

wherein the inlet pipe extends through the upper chamber to the lower chamber and the outlet pipe is operatively coupled to the upper chamber and the fins are disposed in the lower chamber.

3. A device as recited in claim 1, wherein each said fin includes a dome-shaped top portion and a cylinder-shaped bottom portion.

4. A device as recited in claim 3, wherein a cross section of the cylinder-shaped bottom portion has a shape selected from the group consisting of circle, oval, hexagon, and rectangle.

5. A device as recited in claim 1, wherein the flow exit of the inlet pipe has an expanding nozzle shape.

6. A device as recited in claim 1, wherein the base plate is formed of heat conducting material.

7. A device as recited in claim 6, wherein the heat conducting material is selected from the group consisting of aluminum, copper, and nickel.

8. A device as recited in claim 1, wherein the fins are formed of heat conducting material.

9. A device as recited in claim 8, wherein the heat conducting material is selected from the group consisting of aluminum, copper, and nickel.

10. A device as recited in claim 1, wherein the housing is formed of plastic.

11. A device as recited in claim 1, further comprising:

a pump coupled to the inlet and outlet pipes and operative to circulating the cooling fluid through the inlet and outlet pipes.

12. A device as recited in claim 1, further comprising:

a cooling system coupled to the inlet and outlet pipes and operative to extract heat energy from the cooling fluid.