Graphics card apparatus with improved heat dissipating mechanisms

A cooling mechanism to dissipate thermal energy generated by the active electronic components of a graphics card assembly. A mechanism includes a radiator and a metal block that is thermally coupled to the active electronic components and that has a tubing therewithin. The radiator includes a pipe and baffles attached to the pipe, where one end of the pipe is connected to one end of the tubing. A pump, connected to the other ends of the tubing and pipe, circulates coolant through the pipe and tubing to transfer thermal energy from the metal block to the radiator. The mechanism also includes a heat sink that is thermally coupled to the metal block via a thermal transfer plate. A fan unit of the mechanism generates and directs an air flow toward the radiator, metal block and heat sink, where the air flow removes the thermal energy therefrom.

BACKGROUND OF THE INVENTION

The present invention generally relates to graphics card apparatus and, more particularly, to an improved graphics card assembly having a cosmetic cover plate and two heat dissipating mechanisms cooled by a fan unit.

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.

Such cards often have extremely large computing power and, as a consequence, generate 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 and normally include some type of fan for blowing air across the active components, and perhaps some type of thermal mass capable of sinking the heat generated. To date, however, the efficiency of such devices has not been optimal. Besides, the thermal energy generated by the GPU and memory chips for more sophisticated graphics and games, such as 3-D graphics, may approach the maximum capacity of the existing heat dissipation mechanisms. Thus, there is a need for an improved heat extraction or dissipation mechanism, which can be added to a standard graphics card to efficiently remove thermal energy generated thereby.

SUMMARY OF THE INVENTION

The present invention provides a graphics card assembly that has two heat dissipating mechanisms or subassemblies to dissipate thermal energy generated by active electronic components, such as GPU and memory. The first mechanism includes a heat sink that is thermally coupled to the electronic components and that has one or more radiators, where the thermal energy transferred to the heat sink is dissipated by a portion of air flow generated by a fan. The second mechanism includes a metal block that has a tubing therewithin and a radiator that has baffles and a pipe. The metal block is thermally coupled to the heat sink of the first mechanism and receives any thermal energy that is not dissipated by the first mechanism and thus remaining in the heat sink. A pump, connected to the pipe and tubing, circulates coolant therethrough so that the thermal energy conducted to the metal block is sunk to the baffles of the radiator. A portion of air flow generated by the fan is directed toward the metal block and radiator to remove heat therefrom.

In one aspect of the present invention, a graphics card apparatus with improved heat dissipation includes a radiator and a metal block that is thermally coupled to one or more active electronic components of the apparatus and that has a tubing therewithin. The radiator has a pipe and baffles thermally coupled to the pipe, where the inlet end of the pipe is connected to the exit end of the tubing. A pump, connected to the inlet end of the tubing and the exit end of the pipe, circulates coolant through the pipe and tubing to transfer thermal energy from the metal block to the radiator. The apparatus also includes a fan carrier for carrying a fan and vanes, where the air flow generated by the fan is directed toward the radiator baffles and metal block by the vanes. A flow director is positioned beneath the cover plate of the apparatus and surrounds the radiator and metal block forming an air flow passage from the fan to the metal block and thence to the radiator. Thermal energy generated by the electronic components is transferred to the metal block and thence to the radiator via the coolant and is ultimately removed from the radiator and metal block by an air flow drawn into the air passage.

In another aspect of the present invention, a graphics card assembly includes a printed circuit board with heat generating components affixed thereto and a heat dissipating mechanism attached to the printed circuit board. The heat dissipating mechanism includes a radiator and a metal block that is thermally coupled to the heat generating components and that has a tubing therewithin. The radiator has a pipe and baffles thermally coupled to the pipe, where the inlet end of the pipe is connected to the exit end of the tubing. A pump, connected to the inlet end of the tubing and the exit end of the pipe, circulates coolant through the pipe and tubing to transfer thermal energy from the metal block to the radiator. The mechanism also includes a fan carrier for carrying a fan and vanes, where the air flow generated by the fan is directed toward the radiator baffles and metal block by the vanes. A flow director is positioned beneath the cover plate of the assembly and surrounds the radiator and metal block forming an air flow passage from the fan to the metal block and thence to the radiator. Thermal energy generated by the components is transferred to the metal block and thence to the radiator via the coolant and is ultimately removed from the metal block and the radiator by an air flow drawn into the air passage.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIG. 1of the drawing, a graphics card assembly in accordance with the present invention is illustrated at10and includes a lower heat dissipating mechanism11and an upper heat dissipating mechanism13. As illustrated, the assembly also includes a printed circuit board12having edge connectors14and populated with numerous electronic components some of which are shown at16. The board is attached at the near end to an end plate18carrying various cabling connectors20,22and24used to communicate signals into and out of the assembly. The end plate18also has perforations or holes21forming the inlet of air flow generated by a fan unit, as will be explained later. Affixed to the printed circuit board12by means of vertically extending spacing legs or risers, one of which is shown at26c, is a planar, generally rectangular middle insulating plate32. The cover plate40is secured to the board12and insulating plate32by means of risers, two of which are shown at26aand38. The cover plate40may be made of a heat conducting material, while the insulating plate32may be made of Teflon or any suitable heat insulating plastic. The thermal transfer plate30has a generally rectangular shape and a side that is in contact with the insulating plate32. The foremost extremity of the cover plate40includes a laterally extending tab34conforming to a similar tab on the board12.

The front edge of the cover plate40is captured beneath a turned back lip48forming a side of the cover plate40. Disposed between the plate40and plates30and32is the upper heat dissipating subassembly13including an upper heat sink or radiator, a metal block and a portion of a flow director42, which will be elucidated below. Note that the cover plate40is flat and ideally suited for decorative graphics, manufacturer's or marketer's trademarks, etc. A lower heat sink36is affixed to the board12by means of vertically extending risers (not shown inFIG. 1).

In use, the graphics card assembly is oriented so as to have the near right edge of the assembly, as depicted, facing a slot on a computer motherboard and mounted thereto by slipping the edge connectors14into the slot so that the assembly communicates with devices on the motherboard via the edge connector14. As described in more detail below, most of the thermal energy generated by the electronic components of the assembly is sunk to the lower heat sink36and upper radiator (not shown inFIG. 1), wherein the lower heat sink36and upper radiator are cooled by the air flow created by a fan unit29(not show inFIG. 1).

InFIG. 2, the lower heat dissipating mechanism11, fan unit29carried by a fan carrier35, middle plates30and32, risers26a-26c, and flow director42are shown exploded away from the populated graphics card12. The lower heat dissipating mechanism11(FIG. 1) includes: the lower heat sink36that has a Zalman tube86and heat sinks or radiators37and39; additional heat sink ribs or radiator88; and thermal transfer block56. The lower heat dissipating mechanism11also includes copper plates50,52and54that are shown below the lower heat sink36and radiator88. The plates50,52and54may be formed of any suitable material that has good heat conducting characteristics. These copper plates50,52and54respectively engage the top surfaces of and transfer heat from GPU, memory and power IC that are not shown but will be positioned at60,62and64on the board12. Each of the copper plates50,52and54may be soldered or brazed to, or molded into the bottom of the lower heat sink36or radiator88. The thermal transfer block56engages the top surface of a heat generating, active electronic component that is not shown but will be positioned at58, and transfer heat to the middle thermal transfer plate30.

The fan carrier35includes a top plate63, a bottom plate67, a side wall43and a flow barrier65, and encloses the lower fan unit29. The bottom plate67carries the fan unit29and vanes87for directing the air flow generated by the fan toward the lower heat sink36. The bottom plate67also includes a circular hole (not shown inFIG. 1) for accommodating the fan unit29. The top plate63has a circular aperture or hole31through which the fan unit29draws air. The holes21in the end plate18provide fluid communication between the atmosphere and circular aperture31. The lower heat sink36includes a generally flat bottom plate and radiators37and39formed on the bottom plate, wherein the bottom plate and radiators are made of materials having good heat conducting characteristics.

Thermal energy generated by electronic components, such as GPU and memory, is transferred to the lower heat sink36via the plates50and52. A portion of the air flow, which is generated by the fan unit29and passes through the radiators37and39, tends to remove the thermal energy as it propagates through the copper blocks50and52to the top of the radiators37and39. The thermal energy remaining in the radiators37and39is transferred to the thermal transfer plate30that is soldered or brazed to the top of the radiators37and39.

The fan carrier35is attached to the flow director42. Alternatively, the flow director42and the fan carrier35are formed in one body. The middle thermal transfer plate30, preferably made of copper, is attached to the top edges of the radiators37and39. As pointed out above, the copper plates50and52affixed to the bottom surface of the lower heat sink36engage the top of the GPU and memory to be mounted at60and62, respectively, in order to transfer heat therefrom to the lower heat sink36. As will be explained in more detail, any thermal energy remaining in the radiators37and39is conducted to the metal block of the upper heat dissipating assembly13via the thermal transfer plate30.

The height of the thermal transfer block56is such as to substantially span the distance between the top of a corresponding active component mounted to board12and the bottom surface of the thermal transfer plate30. Any gap remaining is closed by an appropriate thermally conductive compound. Likewise, any gap between the bottom surface of the metal plates50and52and the top of active electronic components is closed by an appropriate thermally conductive compound. The lower heat sink36is secured to the board12by a force fit of the upper ends of four risers26bto openings69in the heat sink36. The lower ends of the risers26bare secured to the board12by means of appropriate mounting screws68or other suitable fasteners. Alternatively, the lower heat sink36and the bottom plate67may be formed in one body.

As will be illustrated later, the middle insulating plate32prevents the air flow passed through the lower heat sink36from heating an upper radiator (not shown inFIG. 2) positioned over the plate32. The plate32is secured to the board12by a force fit of the upper ends of three risers26cto openings80in the plate32. The lower ends of the risers26care secured to the board12by mounting screws78or other suitable fasteners. As will be explained inFIG. 3, the cover plate40is secured to the board12by the same way as the plate32using the two risers26aand the screws74.

As the GPU and memory of the recent graphics cards may generate thermal energy exceeding the maximum capacity of the lower heat dissipating mechanism11depicted inFIG. 2, an additional cooling mechanism may become necessary.FIG. 3shows an exploded view of the additional cooling mechanism, referred to as upper heat dissipating mechanism13(FIG. 1), middle plates30and32, risers38, flow director42, fan carrier35and cover plate40. The upper heat dissipating mechanism13includes: an upper heat sink or radiator94including a pipe92and baffles thermally coupled to the pipe; a metal block96; and a pump102. The pump102, such as a Ceramic pump, circulates coolant through the pipe92and a tubing98formed in the metal block96to transfer thermal energy in the metal block96to the radiator94. The thermal transfer plate30transfers any thermal energy remaining in the lower heat sink36(FIG. 2) to the metal block96. The metal block96, preferably made of copper, includes a hollow tubing or tortuous flow passage98for circulating coolant therethrough, and secured to the flow director42by four screws126passed through openings100on the flow director42and threaded into threaded bores tapped into the sides of the metal block96.

The upper radiator94, including baffles and the pipe92attached to the baffles, is secured to the flow director42by four screws124passed through the openings125in the flow director42and threaded through threaded bores (not shown inFIG. 3) tapped into sides of the upper radiator94. The upper radiator94has a structure similar to the radiator88, i.e., it has a bottom plate and baffles formed on the bottom plate. Alternatively, the upper radiator94may be molded onto the flow director42. Further alternatively, the upper radiator94may include a portion of the pipe92and baffles only. The pipe92is connected to the tubing98and the pump102forming a closed passage of coolant circulated by a pump102, and thereby the thermal energy in the metal block96is transferred to the radiator94via the coolant.

The height of the flow barrier65is such as to maintain a predetermined distance between the top plate63of the fan carrier35and cover plate40, where the predetermined distance is at least 5 mm in the preferred embodiment. As mentioned, the fan carrier35is molded onto the flow director42or attached to the flow director42by a suitable method, such as soldering. The flow director42having a generally elongated strip shape is secured to the cover plate40by four screws114passed through openings116and threaded into threaded bores118tapped into the flow director42. The flow director42and cover plate40form an enclosure providing an air passage therebetween so that a portion of the air flow generated by the fan unit29passes over the metal block96and through the upper radiator94dissipating heat in the metal block96, pipe92and radiator94. The insulating plate32prevents heat transfer between the upper radiator94and the air flow passed through the lower heat sink36(FIG. 2).

As the air flow removes thermal energy from the metal block96and upper radiator94as it passes through the air passage, the air temperature is highest at the downstream end of the passage, i.e., at near the right hand side edge of the upper radiator94. Thus, the efficacy of the upper heat dissipating mechanism13may be maximized by positioning the hottest portion of the pipe at the downstream end of the passage. As depicted inFIG. 3, the coolant exiting from the exit port of the pump102enters into the inlet end of the tubing98and removes thermal energy from the metal block96. The temperature of the coolant reaches the highest point when the coolant exits from the outlet end of the tubing. Subsequently, the heated coolant is directed toward the downstream end of the air passage through the pipe92and cooled down as it passes through the upper radiator94and returns to the pump102.

The insulating plate32is secured to the cover plate40by a force fit of the lower ends of three risers38to openings80in the insulating plate32. The upper ends of the risers38are secured to the cover plate40by mounting screws106(or other suitable fasteners) that pass through the holes110in the cover plate40. The cover plate40is secured to the board12by risers26a, where the top ends of risers26aare secured to the cover plate40by a force fit and the bottom ends of risers26aare secured to the board12by mounting screws74(FIG. 2)

InFIGS. 2 and 3, only two radiators37and39and one heat transfer block56are shown to transfer heat to the upper heat dissipating mechanism13via the thermal transfer plate30. However, it should be apparent to those of ordinary skill that more or less radiators or heat transfer blocks may be used without departing from the essence of the present invention.

FIG. 4is a side elevation of the graphics device assembly10taken along the direction4-4inFIG. 1, illustrating air flows through the lower and upper heat dissipating mechanisms11and13. The fan unit29draws air through the opening21in the end plate18and thence through the circular aperture or hole31in the top plate63of the fan carrier35. The air flow97agenerated by the fan unit29is split into upper and lower air flows97cand97b. The upper air flow97cpasses through the air passage formed by the cover plate40and flow director42dissipating heat from the heat block96and upper radiator94(FIG. 3), and exits the upper heat dissipating mechanism13. The lower air flow97bpasses through the lower heat sink36, radiator88and thermal transfer block56(FIG. 2), and is discharged to open space around the electrical components16. The insulating plate32prevents the lower air flow97bpassed through the lower heat sink36from heating the upper radiator94(FIG. 3).

InFIG. 5, an assembled card apparatus10is shown from the top with the cover plate40and middle plates30and32partially broken away to reveal the fan carrier35having vanes87, lower heat sink36and thermal transfer block56. As pointed out above, thermal energy generated by GPU and memory (not shown inFIG. 5but will be mounted to the board12) is conducted into the bottom of the lower heat sink36and thence to the radiators37and39which in turn transfer heat to the plate30(FIG. 3). The lower air flow97bgenerated by the fan unit29is directed through the radiators37and39, drawing with it the heat transferred from the bottom plate of the lower heat sink36, the radiators37and39, and the bottom surface of the thermal transfer plate30, and thence discharged to the space around the radiator88, thermal transfer block56and other electronic components16.

Alternatively, the fan unit29could be reversed to draw air in from the open sides of the lower heat dissipating mechanism11through the radiators37and39and to discharge the heated air through the holes21(FIG. 2) in the end plate18. Flow in this direction would be preferable for some applications where the thermal energy generated by the thermal transfer block56and radiator88is substantially less than the thermal energy generated by the GPU and memory.

InFIG. 6, an assembled card apparatus10is shown from the top with the cover plate40partially broken away to reveal the fan unit29, vanes87, upper radiator94, metal block96, flow director42, cooling pipe92, pump102and middle plates30and32. The upper air flow97cgenerated by the fan unit29is directed through the air passage formed by the cover plate40and flow director42; it passes over the metal block96and through the baffles of the upper radiator94, drawing with it the heat transferred to the metal block96, pipe92and upper radiator94before it is discharged to the open space on the right hand side of the assembly10. Suitable coolant is circulated through the pipe92and tubing98by the pump102so that the heat transferred to the metal block96is transferred to the upper radiator94. Alternatively, the fan unit29could be reversed in some applications where the temperature of the upper radiator94is substantially lower than the temperature of the metal block96. Further alternatively, an additional thermal transfer plate (similar to the plate30) may be positioned between the upper radiator94and the cover plate40made of a heat conducting material, where the additional thermal transfer plate transfers heat from the upper radiator94to the cover plate40.

FIG. 7is an exemplary form of a simple thermal transfer block that may be uses as the thermal transfer block56inFIG. 2. The block may be formed of, preferably, copper metal. However, any material having good thermal conductivity may be used. The illustrated block has four elongated openings82for receiving air flow induced by the fan unit29(FIG. 6). The bottom surface86is planar and intended to physically engage the top surface of an active electronic component mounted on the board12and transfer thermal energy therefrom. Similarly, the top surface84is planar and intended to engage the bottom surface of the thermal transfer plate30either directly or via an appropriate heat transferring compound deposited therebetween. Air flowing through the openings or passageways82, as well as around the sides of the block, tends to remove thermal energy as it propagates through the block from bottom to top to be sunk to the thermal transfer plate30.

Although the present invention has been described above in terms of particular embodiments illustrated in the several figures of the drawing, it will be appreciated that other configurations of fan carrier, flow directing vanes, thermal transfer blocks, heat sink ribs and cover plates may be utilized without deviating from the essence of the present invention. For example, ribs, vanes, or simple grooves or corrugations may be provided in the cover plate40in order to increase the surface area thereof. More details of the cover plate can be found in U.S. Pat. No. 6,671,177, entitled “Graphics card apparatus with improved heat dissipation,” which is incorporated herein in its entirety. Also, more than one thermal transfer block may be used to transfer thermal energy from electronic components to the thermal transfer plate30.

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.