(19) Japan Patent Office (JP)
`
`(12) Unexamined Patent Gazette (A)
`
`(11) Japanese Unexamined Patent
`Application Publication Number
`2002–151638
`(P2002–151638A)
`(43) Publication date: May 24, 2002 (5/24/2002)
`Theme codes (reference)
`5E322
`5F036
`
`(51) Int. Cl.7
`H01L 23/473
`H05K
`7/20
`
`Identification codes
`
` FI
`H05K
`H01L
`
`7/20
`23/46
`
`N
`Z
`
`Request for examination: Not yet requested Number of claims: 1 OL (Total of 5 pages)
`
`(21) Application number
`
`(22) Filing date
`
`Japanese Patent Application 2000–
`345470 (P2000–345470)
`November 8, 2000 (11/8/2000)
`
`(71) Applicant
`
`(72) Inventor
`
`(74) Agent
`
`F-terms
`(reference)
`
`000005108
`Hitachi Ltd.
`6 Kanda Surugadai 4-chome, Chiyoda-ku,
`Tokyo-to
`SHIN, Takayuki
`c/o Hitachi Ltd. Mechanical Engineering
`Research Laboratory, 502 Kandatsu-machi,
`Tsuchiura-shi, Ibaraki-ken
`100075096
`Patent Attorney SAKUTA, Yasuo
`
`(54) [Title of the invention] Cooling device for electronic equipment
`
`(With corrections)
`(57) [Abstract]
`[Problem] A cooling structure for compactly mounting a
`liquid cooled heat sink and pump inside a case.
`[Solution] A pump 5 is installed on the top part of a liquid
`cooled heat sink 4 and made into a structure allowing the
`pump 5 and liquid cooled heat sink 4 to be handled as an
`integral structure, making it possible to implement a liquid
`cooling system of high cooling performance, low noise and
`high reliability that can be compactly installed in an
`electronic equipment case without major changes to the case
`structure of conventional air cooled electronic equipment
`
`FIG. 1
`
`Shenzhen Apaltek Co., Ltd. Ex. 1014, Page 1 of 6
`Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S
`IPR2022-01317
`
`

`

`(2)
`
`Japanese Unexamined Patent Application Publication 2002–151638
`
`[Scope of patent claims]
`[Claim 1] A cooling device for electronic equipment
`comprising a wiring board, a heat generating element
`including an electronic circuit component such as an LSI
`chip installed on said wiring board, a liquid cooled heat sink
`installed on said heat generating element in thermal contact
`therewith, and a pump which pressurizes and circulates a
`liquid coolant, characterized in that said pump is installed on
`the top part of said liquid cooled heat sink.
`[Detailed description of the invention]
`[0001]
`[Technical field of the invention] The present invention
`pertains to a cooling structure for liquid cooling of heat
`generating electronic circuit components such as LSI chips
`installed on a wiring board, relating in particular to a cooling
`structure for compactly mounting a liquid cooled heat sink
`and pump.
`[0002]
`[Prior art] In recent years, the amount of heat generated by
`electronic equipment, as
`represented by computers,
`communication equipment, multimedia equipment, etc., has
`tended to increase markedly. In particular, the cooling of
`CPUs, which perform centralized computation processing,
`image processing LSI chips, power amplifiers and the like,
`has become a very important problem.
`[0003] Furthermore, as the cooling scheme, conventionally,
`an air cooling scheme combining air cooling fins with a fan
`has been frequently used. However, air cooling schemes
`have a low cooling limit compared to liquid cooling schemes,
`so recently, schemes have been considered for liquid cooling
`of high heat output LSI chips such as CPUs alone using a
`liquid coolant such as water.
`[0004] For example,
`Japanese Unexamined Patent
`Application Publication H8–32262 discloses a liquid cooling
`scheme as illustrated in FIG. 4. LSI chips 51, which do not
`have a high heat output and can be air-cooled, and LSI chips
`which are cooled by a water cooled heat sink 40 due to their
`high heat output, are installed on the same wiring board 50.
`The air-coolable LSI chips 51 are air-cooled by means of
`two fans 47. Cooling air is supplied from outside, as shown
`by 48, and is exhausted as shown by 49. The water cooled
`heat sink 40 installed on LSI chips of high heat output is
`connected via a hose 41 to an outlet pipe 42, and the cooling
`water warmed at 40 is cooled in heat exchanger 43 by the air
`of the fans 47. The cooled cooling water flows through
`coolant pipe 44 to pump 45 and is pressurized and then
`passes through inlet pipe 46 and is supplied again to the
`water cooled heat sink 40.
`[0005]
`[Problem to be solved by the invention] In the cooling
`structure disclosed
`in
`Japanese Unexamined Patent
`Application Publication H8–32262, the pump 45 is installed
`away from the wiring board 50 and water cooled heat sink
`40, so space for mounting the pump 45 is required inside the
`case separately from the space for the pipes which are
`connected to the pump 45, and so there is the problem that
`the electronic equipment case cannot be made compact.
`[0006] It is an object of the present invention to provide a
`cooling structure for electronic devices which is compact,
`has low noise, superior cooling performance and high
`reliability.
`[0007]
`
`[Means for solving the problem] To achieve the aforesaid
`object, the present invention, assuming a cooling device for
`electronic equipment comprising a wiring board, a heat
`generating
`element
`including
`an
`electronic
`circuit
`component such as an LSI chip installed on the wiring board,
`a liquid cooled heat sink installed on the heat generating
`element in thermal contact therewith, and a pump which
`pressurizes and circulates a liquid coolant, adopts a structure
`wherein the pump is installed on the top part of the liquid
`cooled heat sink.
`[0008] Furthermore, the pump is secured to the top part of
`the liquid cooled heat sink, forming a structure that allows
`the pump and liquid cooled heat sink to be handled as an
`integral structure.
`[0009] Furthermore, a structure is formed wherein the liquid
`coolant discharge section of the pump is directly connected
`to the liquid cooled heat sink by means of a pipe, etc.
`[0010] Furthermore, an arrangement is adopted whereby the
`pump operates from a direct current power supply.
`[0011] Moreover, a structure is formed whereby the pump is
`secured to the liquid cooled heat sink across a vibration
`absorption member or the like.
`[0012]
`invention] A first embodiment
`the
`[Embodiments of
`example of the present invention will be described using FIG.
`1. The heat generating element 1, which includes an
`electronic circuit component such as an LSI chip, is installed
`on a wiring board 2 in electrical contact via wiring pins 3,
`solder balls or the like. The heat generating element 1 is, for
`example, a computer CPU, image processing LSI chip, FET
`power amplifier, etc. On the heat generating element 1, a
`liquid cooled heat sink 4 for liquid cooling of the heat
`generating element 1 is installed in thermal contact therewith
`across a thermally conductive compound 21, thermally
`conductive grease, thermally conductive sheet, or the like.
`Furthermore, a pump 5 which pressurizes and circulates
`liquid coolant is installed on the top part of the liquid cooled
`heat sink 4.
`[0013] In the present embodiment example, a structure is
`employed whereby the pump 5 is secured to the liquid
`cooled heat sink 4 across a vibration absorbing member 19.
`Thus, a structure is formed whereby the vibration of the
`pump 5 does not readily have a direct effect on the CPU or
`other electronic component. The pump 5 is connected to the
`liquid cooled heat sink 4 by a flexible hose 6. The hose 6 is
`connected at one end to a coolant discharge section coupler
`7 of the pump 5 and is connected at the other end to a water
`supply coupler 9 of the liquid cooled heat sink 4, and
`pressurized coolant flows as shown by 8 and then flows
`directly into the liquid cooled heat sink 4 as shown by 10.
`The liquid coolant, after flowing into the liquid cooled heat
`sink 4, is split into a plurality of channels formed inside the
`heat sink and flows in snaking fashion, absorbing the heat of
`the heat generating element 1. The heated liquid coolant
`flows through drainage coupler 17 and hose 16 into a heat
`exchange section (not illustrated) which cools the liquid
`coolant, as shown by 18. Liquid coolant which has been
`cooled in the heat exchange section returns, as shown by 15,
`and is sucked into pump 5 via hose 13 and coolant intake
`section coupler 14, and is again pressurized and supplied to
`the liquid cooled heat sink 4.
`[0014] It will be noted that the aforementioned couplers 7, 9,
`
`
`
`Shenzhen Apaltek Co., Ltd. Ex. 1014, Page 2 of 6
`Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S
`IPR2022-01317
`
`

`

`14 and 17 make it easy to connect and disconnect the hoses
`6, 13 and 16, thus implementing a structure with good
`assembly characteristics and maintenance characteristics.
`[0015] Forming a structure in which the pump 5 is installed
`on the top part of the liquid cooled heat sink 4, as described
`above, eliminates the need for providing space inside the
`electronic equipment case for separately installing the pump
`5 and makes it possible to shorten the hose going from the
`pump to the liquid cooled heat sink 4, thus making it
`possible to compactly install the liquid cooling system inside
`the electronic equipment case. Thus, it becomes possible to
`install a
`liquid cooling system with high cooling
`performance and low noise without making major changes
`to the structure of conventional air cooled electronic
`equipment cases.
`[0016] Furthermore, securing the pump 5 to the top part of
`the liquid cooled heat sink 4 and making it possible to
`handle the pump and liquid cooled heat sink as an integral
`structure reduces the number of components at the time of
`assembly and makes it possible to install an integral
`component kit comprising this pump and liquid cooled heat
`sink instead of an air cooled heat sink with fan as commonly
`used in conventional personal computers, etc., thus allowing
`a liquid cooling system to be adopted without difficulty.
`[0017] Furthermore, a structure is created wherein the
`coolant discharge section 7 of the pump 5 is directly
`connected by means of a pipe, etc. to the water supply
`coupler 9 of the liquid cooled heat sink 4. Thus, the hose
`from the pump 5 to the liquid cooled heat sink 4 can be
`made very short, allowing flow loss of liquid coolant in the
`hose to be reduced and as a result making it possible to
`reduce the lift capacity of the pump 5 and ultimately reduce
`motor power and make the pump more compact.
`[0018] The pump 5 comprises an impeller case 11 and motor
`12.
`In the present embodiment example, the pump 5
`illustrates an example of a centrifugal type pump which
`pressurizes liquid coolant by rotating an impeller arranged
`inside the impeller case 11, but a volumetric type pump
`which pressurizes the liquid coolant through mechanical
`volume change using a diaphragm, etc. may be used as well.
`Furthermore, in the present embodiment example, the shaft
`of the motor and impeller are installed so as to be
`perpendicular to the top surface of the liquid cooled heat
`sink 4, so the bottom surface of the motor is joined to the top
`surface of the liquid cooled heat sink 4 across the vibration
`absorption member 19, thus making it possible to implement
`a structure with good seating of the motor.
`[0019] The motor 12 is a DC motor driven by a direct
`current power supply. Using a DC motor allows the motor
`speed to be easily changed by changing the DC voltage, thus
`enabling control of cooling power. Moreover, making the
`motor into a DC brushless motor makes it possible to
`implement a pump of low noise and long service life.
`[0020] If the flow rate of liquid coolant is relatively low, on
`the order of 0.1 (liters/minute), making the drive voltage
`such that it can be driven by dry cells of, for example, about
`1 to 1.5 (V), allows for battery driving of the pump, making
`it possible to create a liquid cooling system of high
`reliability. Furthermore, if the flow rate of liquid coolant is
`relatively high, on the order of 1 (liter/minute), making the
`drive voltage into a voltage of about 2 to 12 (V), which can
`be supplied by the DC power supply of electronic equipment,
`
`(3)
`
`Japanese Unexamined Patent Application Publication 2002–151638
`
`makes it possible to create a compact and inexpensive liquid
`cooling system, because there is no need to provide a
`dedicated power supply for the pump. However, the present
`invention does not necessarily limit the motor 12 to a DC
`motor, and an AC motor driven by alternating current of, for
`example, 100 (V) or 200 (V) may be used as well.
`[0021] For the liquid coolant, water, which is easy to obtain,
`is suitable, and especially with pure water, the thermal
`capacity is high, so the cooling performance can be
`increased, the resistance against corrosion is better, and
`impurities do not tend to become deposited in the channels,
`thus making it possible to implement a high performance
`liquid cooling system. Furthermore, if a non-freezing liquid
`obtained by adding ethylene glycol or the like to water is
`used as the liquid coolant, damage to the channels due to
`freezing of the liquid coolant during cold can be prevented.
`Furthermore,
`if a nonconductive coolant
`such as
`perfluorocarbon is used for the liquid coolant, accidents such
`as shorting of electronic circuits can be prevented in the
`event of liquid leakage.
`[0022] A second embodiment example of the present
`invention will be described using FIG. 2. In the present
`embodiment example, the shaft of the motor 5 and impeller
`is installed so as to be substantially parallel to the top surface
`of the liquid cooled heat sink 4. As a result, even high output
`pumps with a high motor output and thus a long length of
`the motor in the axial direction can be compactly installed
`on the liquid cooled heat sink 4. In the present embodiment
`example, the pump 5 is secured to a bracket 20 on the liquid
`cooled heat sink 4. By making the bracket 20 into a vibration
`absorbing member or by using a vibration absorbing
`member for a portion thereof, a structure can be created
`whereby vibration of the pump 5 does not readily have a
`direct affect on the electronic component such as a CPU.
`Except for the above, the second embodiment example is the
`same as the first embodiment example.
`[0023] A third embodiment example of the present invention
`will be described using FIG. 3. The present embodiment
`example illustrates an example in which the liquid cooling
`system with integral pump and liquid cooled heat sink
`presented in the first embodiment example has been installed
`inside an actual electronic equipment case.
`[0024] The heat generating element 1, such as an LSI chip,
`is installed on a wiring board 2, which is a motherboard. A
`liquid cooled heat sink 4 for cooling the heat generating
`element 1 is installed on the heat generating element 1.
`Furthermore, a pump 5 is installed on the top part of the
`liquid cooled heat sink 4. Besides the heat generating
`element 1, heat generating elements 22a, 22b, 22c, such as
`memory LSI and driver LSI chips, which can be cooled by
`air cooling, as well as an IO card, memory card, hard disk or
`other card mounting board 23 are also installed on the wiring
`board 2. The wiring board 2 is housed inside case 24, which
`is an electronic equipment case. An air cooling fan 34 is
`installed in the case 24, and the aforementioned multiple air
`cooled components are air-cooled by cooling air 25.
`[0025] Liquid coolant which has been heated in the liquid
`cooled heat sink 4 flows through hose 16, as shown by 18,
`which is connected via a connecting coupler 26 to a heat
`exchanger 27 installed on a side panel 32 of the case. In the
`present embodiment example,
`the pipes of
`the heat
`exchanger 27 are installed in thermal contact with the side
`
`
`
`Shenzhen Apaltek Co., Ltd. Ex. 1014, Page 3 of 6
`Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S
`IPR2022-01317
`
`

`

`panel 32, and the liquid coolant flows upward while snaking
`through the inside of the heat exchanger as shown by 28 and
`29. The heat of the liquid coolant spreads through thermal
`conduction to the entirety of the side panel 32 and is then
`released with the aid of the cooling air 25 provided by the
`fan 34 and air flow 33 provided by natural convection
`around the electronic equipment case.
`[0026] The cooled liquid coolant flows as shown by 30, and
`is connected to the return side hose 13 via connecting
`coupler 31 and returns to the pump 5 as shown by 15, and is
`again pressurized and supplied to the liquid cooled heat sink
`4.
`[0027] As an example of the method of constructing the side
`panel 32 and heat exchanger 27, there is the method whereby
`the side panel 32 is fashioned from a metal material such as
`aluminum, magnesium or steel, the pipes of the heat
`exchanger are also fashioned from metal material, and the
`two are connected through metal joining, such as brazing or
`soldering, or by using a thermally conductive adhesive, or
`the like. In this case, the thermal conductivity can be
`improved, making it possible to improve the cooling
`performance of the liquid cooling system. Furthermore, by
`using a fabrication method such as roll bonding, in which
`two metal plates are joined in a state with snaking channels
`of a heat exchanger being formed, and the side panel and
`heat exchanger are integrally molded, the heat exchanger can
`be produced more inexpensively. However, the effect of the
`present invention can be achieved even if the side panel 32 is
`made of a non-metal material such as resin and the pipes of
`the heat exchanger 27 are a non-metal material.
`[0028] Based on the foregoing, employing the configuration
`of the present embodiment example eliminates the need to
`provide space inside the electronic equipment case for
`separately installing a pump 5 and allows the hose from the
`pump to the liquid cooled heat sink 4 to be shortened, thus
`making it possible to compactly install the liquid cooling
`system in an electronic equipment case.
`[0029] Furthermore, it becomes possible to implement a
`liquid cooling system of high cooling performance and low
`noise simply by adding a side panel 32 equipped with a heat
`exchanger 27, a liquid cooled heat sink with integral pump,
`and two connecting hoses 13 and 16, without making major
`changes to the structure of conventional air cooled electronic
`equipment cases.
`[0030] Furthermore, an integral component kit comprising
`this pump and liquid cooled heat sink can be installed
`instead of an air cooled heat sink with fan as frequently used
`in conventional personal computers and the like, making it
`possible to adopt a liquid cooling system into electronic
`devices without difficulty. If the power supply of the pump
`is compatible with the fan power supply for an air cooled
`heat sink with fan, the adoption of course becomes even
`easier.
`
`(4)
`
`Japanese Unexamined Patent Application Publication 2002–151638
`
`[0031]
`[Effect of the invention] According to the present invention,
`as described above, first, a liquid cooling system can be
`compactly installed inside an electronic equipment case.
`[0032] Second, a liquid cooling system of high cooling
`performance, low noise, and high reliability can be installed
`without making major changes
`to
`the structure of
`conventional air cooled electronic equipment cases.
`[0033] Third, the number of components during assembly
`can be reduced, and an integral component kit comprising a
`pump and liquid cooled heat sink can be installed instead of
`an air cooled heat sink with fan, so a liquid cooling system
`can be adopted into electronic devices without difficulty.
`[0034] Fourth, the lift capacity of the pump and the power of
`the motor can be reduced, allowing for miniaturization.
`[0035] Fifth, a liquid cooling system can be created which
`allows control of cooling power by changing the rotational
`speed of the pump.
`[Detailed description of the invention]
`[FIG. 1] A perspective view of a cooling device for
`electronic equipment constituting a first embodiment
`example of the present invention.
`[FIG. 2] A perspective view of a cooling device for
`electronic equipment constituting a second embodiment
`example of the present invention.
`[FIG. 3] A perspective view of a cooling device for
`electronic equipment constituting a
`third embodiment
`example of the present invention.
`[FIG. 4] A perspective view illustrating an example of a
`conventional cooling device for electronic equipment.
`[Description of reference symbols]
`1 ∙∙∙ heat generating element; 2 ∙∙∙ wiring board; 3 ∙∙∙ wiring
`pin; 4 ∙∙∙ liquid cooled heat sink; 5 ∙∙∙ pump; 6 ∙∙∙ hose; 7 ∙∙∙
`coolant discharge section coupler; 8 ∙∙∙ liquid coolant flow; 9
`∙∙∙ water supply coupler; 10 ∙∙∙ liquid coolant flow; 11 ∙∙∙
`impeller case; 12 ∙∙∙ motor; 13 ∙∙∙ hose; 14 ∙∙∙ coolant intake
`section coupler; 15 ∙∙∙ liquid coolant flow; 16 ∙∙∙ hose; 17 ∙∙∙
`drainage coupler; 18 ∙∙∙ liquid coolant flow; 19 ∙∙∙ vibration
`absorbing member; 20 ∙∙∙ bracket; 21 ∙∙∙ thermally conductive
`compound; 22a ∙∙∙ air-coolable heat generating element; 22b
`∙∙∙ air-coolable heat generating element; 22c ∙∙∙ air-coolable
`heat generating element; 23 ∙∙∙ card mounting board; 24 ∙∙∙
`electronic equipment case; 25
`∙∙∙ cooling air; 26
`∙∙∙
`connecting coupler; 27 ∙∙∙ heat exchanger; 28 ∙∙∙ snaking
`liquid coolant flow; 29 ∙∙∙ snaking liquid coolant flow; 30 ∙∙∙
`liquid coolant flow; 31 ∙∙∙ connecting coupler; 32 ∙∙∙ side
`panel; 33 ∙∙∙ air flow; 34 ∙∙∙ fan; 40 ∙∙∙ water cooled heat sink;
`41 ∙∙∙ hose; 42 ∙∙∙ outlet pipe; 43 ∙∙∙ heat exchanger; 44 ∙∙∙
`coolant pipe; 45 ∙∙∙ pump; 46 ∙∙∙ inlet pipe; 47 ∙∙∙ fan; 48 ∙∙∙
`cooling air; 49 ∙∙∙ cooling air; 50 ∙∙∙ wiring board; 51 ∙∙∙ air-
`coolable LSI chip.
`
`
`
`Shenzhen Apaltek Co., Ltd. Ex. 1014, Page 4 of 6
`Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S
`IPR2022-01317
`
`

`

`(5)
`
`Japanese Unexamined Patent Application Publication 2002–151638
`
`[FIG. 1]
`
`FIG. 1
`
`[FIG. 2]
`
`FIG. 2
`
`[FIG. 3]
`
`FIG. 3
`
`[FIG. 4]
`
`FIG. 4
`
`Shenzhen Apaltek Co., Ltd. Ex. 1014, Page 5 of 6
`Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S
`IPR2022-01317
`
`

`

`Shenzhen Apaltek Co., Ltd. Ex. 1014, Page 6 of 6
`Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S
`IPR2022-01317
`
`