High pressure pump for cooling electronics
A pump includes a shaft, a first electric motor associated with first portion of the shaft, a second electric motor associated with a second portion of the shaft, and a position sensor associated with a third portion of the shaft. A controller commutates the first electric motor and the second electric motor to rotate the shaft and maintain a substantially equal distance between the sensor and the shaft.
Bare electronic chips typically need to be packaged in a package that provides an electric circuit between each electrical connection of the chip and an external connector such as a pin or a ball extending from the package to external circuitry such as a printed-circuit board. The circuit side of the chip typically provides pads that are connected to the chip's packaging using, for example, solder-ball connections, which provide connections for electrical power and for input-output signals. A package typically has a non-conductive substrate (such as a plastic film or layer, or a ceramic layer) with conductive traces (wires) on or in a surface of the substrate. Either solder-ball connections or wirebond connects a chip to the package. Some packages include multiple chips, such as one or more logic or processor chips, one or more communications chips (such as for a cell phone or wireless local-area network (LAN)), and/or one or more memory chips, such as a FLASH-type reprogrammable non-volatile memory. Optionally, a cover or encapsulant is used to enclose parts or all of the chip or chips.
The circuitry on the chip, particularly a very fast chip such as a microprocessor, generates a considerable amount of heat. The heat generated must be removed or the chip can be damaged or ruined. Typically, the circuitry and electrical connections for a chip are provided on one face of the chip. A heat sink or other heat-removing device is attached to the opposite or back side of the chip. In some instances, the heat produced by a chip is removed by a passive cooling system. A passive cooling system uses air to cool or remove heat from the chip. Ambient air can be used. In other instances, a fan is used to move air through or past the heat sink to remove heat from the heat sink, and the chip.
Passive cooling systems remove from the chip. Sometimes the passive cooling systems can not keep the chip below a specified temperature. A liquid cooling system can be used to cool the chip. A pump is used to move the liquid through a heat exchanger. In instances where the heat exchanger inludes closely spaced plates or small openings, the amount of power needed to move the liquid through such a heat exchanger requires very high pressure. Many pumps use ball bearings to support the rotating shaft of the pump. A pump producing high pressure translates into high radial loads on the bearings of the pump. As a result, the ball bearings have a limited life which translates into a limited life for the cooling system and a less reliable processor. If the pump uses a sleeve bearing, the life of the pump and the processor is even more limited and less reliable.
BRIER DESCRIPTION OF THE DRAWINGS
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which some embodiments of the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
The pump 600 includes rotors or impellers for moving the fluid or coolant. The pump 600 moves cool fluid through the tubing or fluid path 230 to the cold plate 101. The pump also produces a pressure which forces the fluid across the cold plate 101. The cold plate 101 includes an inlet manifold 111, and an outlet manifold 112. The coolant is heated as it moves through the cold plate 101. The heated coolant is moved through the tubing to the plurality of fins 220 attached to an external surface of the tubing 230. Ambient air can be used to cool the fluid, or coolant, at the portion of the tubing or fluid path 230 that includes the plurality of fins 220. In some example embodiments, a cooling fan 240 is positioned near the plurality of fins 220 to move a greater volume of air over the plurality of fins 220 and carry more heat away from the coolant, or cooling fluid traveling through the tubing or fluid path 230. The coolant within the fluid path or tubing 230 is cooler as it exits the plurality of fins 220 than when the coolant entered the portion of the fluid path or tubing carrying the plurality of fins 220.
The cooled coolant moves to the pump 600 where it is then pumped again to and through the cold plate and through the loop of tubing associated with the fluid path 230. It should be noted that the plurality of fins 220 can take on any type of form. The fins can be any shape that enhances the transfer of heat from the fluid in the tubing and from the tubing. A heat exchanger or the like could also be substituted for the plurality of fins 220.
A chip package 100 includes a semiconductor chip or die 99 which is attached to a substrate 212. The chip package also includes the cold plate 101. The package protects the chip or die 99 and also spaces the connectors 199 between the chip and the substrate 212 out in a grid pattern or other pattern that is less dense as depicted by connectors 98 on the substrate 212. The die or chip 99 is the component that produces heat. The die or chip 99 is in thermal contact or thermal communication with the cold plate 101 in the liquid cooling system 200. The liquid or coolant in the tubing 230 and in the cold plate 101 is separate from the die 99 and the substrate 212. The die or chip 99 generates heat during its operation. The heat produced is transferred to the liquid coolant in the tubing 230 and specifically in the cold plate 101. The cold plate 101 and the liquid coolant passing through the cold plate remove a sufficient amount of heat from the die or semiconductor 99 so as to prevent a shortened life. In other words, enough heat is removed from the semiconductor or chip 99 so that the chip or semiconductor 99 will not fail prematurely. Removal of heat from the semiconductor or chip 99 enhances the reliability of the semiconductor or chip 99 and the computing system in which the semiconductor or chip 99 is used.
In some embodiments, a plurality of deep parallel grooves (microchannels) 114 are formed between thin walls 113. The microchannels 114 receive fluid from inlet manifold 111 at one of their ends (e.g., their left ends in
In some embodiments, the cold plate 101 structure is larger (in width and/or in breadth) than the die 99 to be cooled. This allows more space for the manifolds 111 and 112 without decreasing the thermal performance of the combined package 100. Once the structures have been created, the attachment of the cold plate 101 to the die 99 can be accomplished through a variety of methods, including, in some embodiments, silicon-silicon bonds (the same technique as is sometimes used for wafer-wafer bonding, which, in some embodiments involves providing a very smooth polished, oxide-free surface on both parts, then squeezing them together and heating them). In other embodiments, high-thermal-conductivity solders, gold bonding, heat-sink paste or epoxy, or other bonding methods are used. In yet other embodiments, the cold plate 101 and the chip 99 are just clamped together. In still other embodiments, a thermal interface material is provided to enhance the thermal conductivity between the die 99 and the cold plate 101.
The material thickness used for the thermal bond between the die and the cooling structure can be virtually zero (with silicon-silicon bonding) or made very thin due to the two mutually flat, smooth surfaces 94 (the top of chip 99) and 104 (the bottom of cold plate 101). CTE mismatch between the die 99 and the cooling structure 101 is not a concern, since both are made of the same material (e.g., both are silicon if the chip is silicon, in some embodiments).
The cold plate 101 of
In other embodiments, chip 99 is placed against cover 120 rather than cold-plate base 110 (e.g., on the top of cold plate 101 rather than the bottom as shown in
In other embodiments, walls 113 and microchannels 114 are formed on cover 120 in addition to or instead of being formed on substrate base 110, such that the manifolds 111 and 112 are in the substrate base 110, but the microchannels 114 are in cover 120.
In some example embodiments, the apparatus 100 includes a cold-plate 101. The cold-plate encloses an inlet plenum 111, an outlet plenum 112, and a plurality of microchannels 114 connecting the inlet plenum 111 to the outlet plenum 112, wherein the cold-plate 101 is substantially made of silicon.
In some embodiments, the cold-plate 101 includes a cold-plate base 110 having the inlet plenum 111, the outlet plenum 112, and the plurality of microchannels 114 formed therein, and a cover 120. In some such embodiments the cold-plate base 110 is made of polycrystalline silicon. In some embodiments, the cover 120 is made of polycrystalline silicon. In some embodiments, the microchannels 114 are formed by etching into the cold-plate base 110 or 510.
The pump 600 also includes a rotor 660 attached to the shaft 610 a housing 662 for the rotor 660. The housing 662 has an inlet 664 and an outlet 666. The rotor 660 rotates within the housing 662 to move a fluid from the inlet 664 to the outlet 666. The pump 600 also moves coolant or fluid along the fluid path or tubing 230 and through the cold plate 101 and the plurality of fins 220.
The pump 600 also includes a case 670. In some embodiments, the case 670 of the pump 600 also includes a first catcher 671 positioned about a fourth portion of the shaft 610, and a second catcher 676 positioned about a fifth portion of the shaft 610. The first catcher 671 and the second catcher 676 support the shaft 610 when the pump is in a non-operating mode. In some embodiments, the shaft also includes a first collar 611 positioned on the fourth portion of the shaft 610, and a second collar 616 positioned on the fifth portion of the shaft 610. The first collar 611 and the second collar 616 are adapted to interact with the first catcher 671 and the second catcher 676 when the pump 600 is in the non-operating mode. The first catcher 671 includes a set of sidewalls 672, 673 to limit motion of the first collar 611 positioned on the fourth portion of the shaft 610. Similarly, the second catcher 676 includes a set of sidewalls 677, 678 to limit motion of the second collar 616 positioned on the fifth portion of the shaft 610. The first catcher 671, the second catcher 676, the position sensor 640 and a portion of the first electric motor 620 and the second electric motor 630 are located within the casing 670. A portion of the first electric motor 620 and a portion of the second electric motor 630 are positioned outside the casing 670. In some embodiments, a stator of the first electric motor 620 and a stator of the second electric motor 630 are positioned outside the casing 670. The controller 650 associated with the pump 600 controls a portion of the first electric motor 620 and a portion of the second electric motor 630 positioned outside the casing. The external installation of the portions of the first and second electric motors and the controller allows the pump can be totally encapsulated and substantially leak free. The casing 670 is also made of a nonferrous material that will have very little, if any, effect on the magnetic fields produced by the various portions of the first electric motor 620 and th second electric motor 630.
Output from the position sensor 640 is fed back to the controller 650 for use in commutating the first electric motor 620 and the second electric motor 630 to rotate the shaft 610 and maintain a substantially equal distance between the sensor 640 and the shaft 610. In some example embodiments, the controller 650 commutates the first electric motor 620 and the second electric motor 630 synchronously.
The first electric motor 620 includes a stator 622 which is located on the exterior surface of the casing 670. The first electric motor 620 also includes laminations on the shaft 610. The laminations form a permanent magnet 624 that has a fixed magnetic field. The controller 650 is used to switch the magnetic field in the stator 622. As a result, the rotor or permanent magnet 624 attached to the shaft 610 follows the magnetic field as it is changed in the stator 622 to produce rotation. The second electric motor 630 also includes a stator 632 and laminations on the shaft 610 that form a permanent magnet having a fixed magnetic field. The controller 650 is used to change the magnetic field in the stator 632 to cause the rotor or laminations 634 on the shaft 610 to follow the changing magnetic field in the stator 632.
In operation the two electric motors 620, 630 simultaneously provide torque and a magnetic bearing type support. The controller 650 commutates both the first electric motor 620 and the second electric motor 630 to maintain the shaft 610 of the pump 600 in suspension or levitation due to the forces generated by the magnetic field of the stator 622 and 632, respectively. In one example embodiment, the first motor 620 and the second motor 630 are connected in series, and will always be synchronus. The position of the shaft 610 is continuously monitored by the position sensor 640. The position sensor is capable of monitoring the distance between the shaft 610 and the sensor 640 in the X, Y, and Z directions. Output from the position sensor 640 is fed back to the controller 650. The controller 650 commutates the first electric motor 620 and the second electric motor 630 in order to maintain an optimal distance between the sensor 640 and the shaft 610 of the pump 600. During operation, the shaft 610 does not touch the casing 670. The shaft 610 is levitated within the casing 670. The electric motors 620, 630 act as a magnetic bearing to provide a substantially friction-free coupling between the shaft 610 and the casing 670. The first electric motor 620 and the second electric motor 630 also provide the torque that rotates the shaft 610 and the attached rotor or impeller 660.
The catchers 671 and 676 include sidewalls, such as sidewall 672 and 673 for the first catcher 671, and sidewalls 677 and 678 for the second catcher 676. The sidewalls limit lateral motion of the shaft 610 in direction co-axial with the casing 670. The first catcher 671 and the second catcher 677 limit motion during the operation or while the pump 600 is an operating mode and also limit the motion of the shaft 610 when in a non-operating mode. When the electric motors 620 and 630 are not commutated, the impeller or rotor 660 does not continue to turn and the pump 600 is in a non-operating state. The first collar 611 and the second collar 616 attached to the shaft 610 of the pump 600, rest within the first catcher 671 and the second catcher 676. The first collar 611, interacting with the first catcher 671 and the second collar 616 interacting with a second catcher 676, prevents the shaft 610 from resting along its length, on the interior surface of the casing 670. Thus the catchers 671, 676 prevent or minimize the amount of contact between the shaft 610 and the casing 670, when the pump 600 is in a non-operating mode. The limited contact between the catchers 671, 676 and the collars 611, 616 lessen the amount of force necessary to start the pump 600.
An inlet 811 is provided in a casing 870, near the area where the pump gear rotor, or driver gear 810 engages the pump gear rotor driven gear 820. Fluid or coolant is placed or input into the inlet 811. An outlet 812 is also placed near the area of the casing where the pump gear rotor driver 810 engages the pump gear rotor driven gear 820. The inlet 811 and the outlet 812 are spaced from one another. As the driver gear 810 and the driven gear 820 engage with one another they also, in turn, pump the fluid from the inlet 811 to the outlet 812 along the fluid path, such as tubing 230 (shown in
A thermal solution system includes a cold plate 101, a coolant in fluid communication with the cold plate 101, and a pump 600, 800 for moving the coolant through the cold plate 101. The pump 600, 800 also includes a shaft 610, a first electric motor 620 associated with first portion of the shaft 610, a second electric motor 630 associated with a second portion of the shaft 610, and a position sensor 640 associated with a third portion of the shaft 610. The system also includes a controller 650 for commutating the first electric motor 620 and the second electric motor 630 to rotate the shaft and maintain a substantially equal distance between the sensor 640 and the shaft 610. In one example embodiment, the system further includes a semiconductor device 99. The cold plate 101 is in thermal communication with the semiconductor 99. In another example embodiment, the cold plate 101 includes a plurality of channels or microchannels. In some embodiments, the microchannels include a plurality of parallel high-aspect-ratio grooves etched into a cold-plate base 101, wherein the cooling base is covered with a cover. The high-aspect-ratio grooves have an aspect ratio in the range of 12 to 20. In still another example embodiment, the cold plate 101 includes a plurality of openings having a dimension in the range of 2 mm to 8 mm.
In yet another embodiment, the thermal solution system includes a passageway 230 for the coolant. The passageway 230 includes a loop. The pump 600, 800 and the cold plate 101 are in the loop. In some embodiments, a plurality of fins 220 attached to at least one portion of the loop of the passageway 230. The fins 220 are for cooling the coolant within the loop. Some example embodiments also include a fan 240 positioned to direct a flow of air past the plurality of fins 220 to further enhance cooling of the coolant within the loop. The semiconductor device 99 can be a microprocessor. The pump 600, 800 associated with the system can include a rotor 660 attached to the shaft, and a housing 662 for the rotor 660. The housing 662 has an inlet 664 and an outlet 666. The rotor 660 rotates within the housing 662 to move a fluid from the inlet 664 to the outlet 666. The pump 600, 800 also includes a first catcher 671 positioned about a fourth portion of the shaft 610, and a second catcher 676 positioned about a fifth portion of the shaft 610. The first catcher 671 and the second catcher 676 support the shaft 610 when the pump 600, 800 is in a non-operating mode. The shaft 610 of the pump 600 includes a first collar 611 positioned on the fourth portion of the shaft 610, and a second collar 616 positioned on the fifth portion of the shaft. The first collar 611 and the second collar 616 are adapted to interact with the first catcher 671 and the second catcher 676 when the pump 600, 800 is in the non-operating mode. In some example embodiments the pump 800 associated with the system also includes a gear driver rotor 810 attached to the shaft 610, and a gear driven rotor 820 engaged with the gear driver rotor 810. The gear driven rotor 820 and the gear driver rotor 810 are positioned within a housing 870.
It should be noted that the information handling system or computer system 2000 described above is one example embodiment of a computer system. Other computer systems can include multiple central processing units and multiple memory units. The computer system or information handling system 2000 can include a thermal solution for semiconductor devices the employ the pump 600, 800 to cool the semiconductor device. In some embodiments, the central processing unit 2004, or a random access memory 2032, or a read only memory 2034, or even a peripheral device can use a thermal solution that includes the pump 600, 800.
It is understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should be, therefore, determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
Claims
1. A pump comprising:
- a shaft;
- a first electric motor associated with first portion of the shaft;
- a second electric motor associated with a second portion of the shaft;
- a position sensor associated with a third portion of the shaft; and
- a controller for commutating the first electric motor and the second electric motor to rotate the shaft and maintain a distance between the sensor and the shaft substantially within a selected range.
2. The pump of claim 1, further comprising rotor attached to the shaft.
3. The pump of claim 1, further comprising:
- rotor attached to the shaft;
- a housing for the rotor, the housing having an inlet and an outlet, the rotor rotating within the housing to move a fluid from the inlet to the outlet.
4. The pump of claim 1, further comprising:
- a first catcher positioned about a fourth portion of the shaft; and
- a second catcher positioned about a fifth portion of the shaft, the first catcher and the second catcher supporting the shaft when the pump is in a non-operating mode.
5. The pump of claim 4, wherein the shaft includes:
- a first collar positioned on the fourth portion of the shaft; and
- a second collar positioned on the fifth portion of the shaft, the first collar and the second collar adapted to interact with the first catcher and the second catcher when the pump is in the non-operating mode.
6. The pump of claim 5, wherein the first catcher includes a set of sidewalls to limit motion of the first collar positioned on the fourth portion of the shaft.
7. The pump of claim 4, further comprising a casing for housing the shaft, the first catcher, the second catcher, the position sensor and a portion of the first electric motor and the second electric motor.
8. The pump of claim 7 wherein a stator of the first electric motor and a stator of the second electric motor are positioned outside the casing.
9. The pump of claim 8 wherein the controller controls the a portion of the first electric motor and a portion of the second electric motor are positioned outside the casing.
10. The pump of claim 1, further comprising:
- a gear driver rotor attached to the shaft;
- a gear driven rotor engaged with the gear driver rotor, the gear driven rotor and gear driver rotor positioned within a housing.
11. The pump of claim 1 wherein output from the position sensor is fed back to the controller for use in commutating the first electric motor and the second electric motor to rotate the shaft and maintain a substantially equal distance between the sensor and the shaft.
12. A thermal solution system comprising:
- a cold plate;
- a coolant in fluid communication with the cold plate; and
- a pump for moving the coolant through the cold plate, the pump further comprising: a shaft; a first electric motor associated with first portion of the shaft; a second electric motor associated with a second portion of the shaft; a position sensor associated with a third portion of the shaft; and a controller for commutating the first electric motor and the second electric motor to rotate the shaft and maintain a substantially equal distance between the sensor and the shaft.
13. The thermal solution system of claim 12, further comprising a semiconductor device, wherein the cold plate is in thermal communication with the semiconductor.
14. The thermal solution system of claim 12, wherein the cold plate includes a plurality of channels.
15. The thermal solution system of claim 12, wherein the cold plate includes a plurality of openings having a dimension in the range of 2 mm to 8 mm.
16. The thermal solution system of claim 12, further comprising:
- a semiconductor device, wherein the cold plate is in thermal communication with the semiconductor; and
- a passageway for the coolant, the passageway including a loop wherein the pump and the cold plate are in the loop.
17. The thermal solution system of claim 16, further comprising a plurality of fins attached to at least one portion of the loop, the fins for cooling the coolant within the loop.
18. The thermal solution system of claim 17, further comprising a fan positioned to direct a flow of air past the plurality of fins.
19. The thermal solution system of claim 16, wherein the semiconductor device is a microprocessor.
20. The thermal solution system of claim 12 wherein the pump further comprises:
- rotor attached to the shaft;
- a housing for the rotor, the housing having an inlet and an outlet, the rotor rotating within the housing to move a fluid from the inlet to the outlet.
21. The thermal solution system of claim 12, wherein the pump further comprises:
- a first catcher positioned about a fourth portion of the shaft; and
- a second catcher positioned about a fifth portion of the shaft, the first catcher and the second catcher supporting the shaft when the pump is in a non-operating mode.
22. The thermal solution system of claim 21, wherein the shaft of the pump includes:
- a first collar positioned on the fourth portion of the shaft; and
- a second collar positioned on the fifth portion of the shaft, the first collar and the second collar adapted to interact with the first catcher and the second catcher when the pump is in the non-operating mode.
23. The system of claim 12, wherein the pump further comprises:
- a gear driver rotor attached to the shaft;
- a gear driven rotor engaged with the gear driver rotor, the gear driven rotor and gear driver rotor positioned within a housing.
24. A method for pumping a fluid comprising:
- commutating a first motor attached to a shaft; and
- commutating a second motor attached to the same shaft as the first, wherein the commutation of the first motor and the second motor rotates and levitates the shaft.
25. The method of claim 24 further comprising limiting the motion of the shaft when in a non-operational mode.
26. The method of claim 24 further comprising limiting the motion of the shaft when in an operational mode.
27. The method of claim 24 further comprising:
- sensing the position of the shaft as the shaft rotates; and
- feeding back position information to control the commutation of the first motor and the second motor.
28. A system comprising:
- a central processing unit;
- a thermal solution in thermal communication with the central processing unit, the thermal solution including a pump further comprising: a shaft; a first electric motor associated with first portion of the shaft; a second electric motor associated with a second portion of the shaft; a position sensor associated with a third portion of the shaft; and a controller for commutating the first electric motor and the second electric motor to rotate the shaft and maintain a substantially equal distance between the sensor and the shaft; and
- a display in electrical communication with the central processing unit, the display receiving input from the central processing unit.
29. The system of claim 28 wherein the thermal solution further comprises:
- a cold plate attached to the central processing unit; and
- a coolant in fluid communication with the cold plate, wherein the pump moves the coolant through the cold plate.
30. The thermal solution system of claim 29, wherein the cold plate includes a plurality of channels.
Type: Application
Filed: Jun 29, 2005
Publication Date: Jan 25, 2007
Inventors: Ioan Sauciuc (Phoenix, AZ), Ravi Prasher (Phoenix, AZ)
Application Number: 11/169,519
International Classification: F04B 49/00 (20060101);