JP2007250701A - Cooling device for electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device for electronic equipment that can decrease the temperature rise of a heating element such as a CPU and has a high performance and excellent in reduction of costs. <P>SOLUTION: The cooling device is comprised of a first heat exchanger for receiving heat of a heat generating body, a second heat exchanger for radiating heat that is conveyed by a liquid refrigerant and a piping member for circulating the liquid refrigerant. The heat exchanger is comprised of a frame to be sealed to distribute the liquid refrigerant and a distributing member comprised of a plurality of distributing wall pieces arranged in parallel to separate and distribute the liquid refrigerant in the frame. In the frame, a header is provided among the distributing members to separate or collect the liquid refrigerant, and the distributing wall pieces of the distributing member are arranged on the curved surfaces of the respective wall planes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid cooling apparatus suitable for cooling a heating element in various electronic devices in which a semiconductor integrated circuit element that is a heating element is mounted, as represented by, for example, a personal computer or a server.

  An electronic device typified by a personal computer or a server is provided with a semiconductor integrated circuit element typified by a CPU (Central Processing Unit), which is a heating element, inside the casing. Cooling is required to ensure the normal operation of the device. In recent years, CPUs have increased in calculation processing speed, and accordingly, the amount of heat generation has increased.

  Conventionally, cooling of the CPU has been mainly performed by an air cooling method in which a heat sink is fixed to the CPU, a fan is attached to the heat sink or an apparatus housing, and the cooling air is blown onto the heat sink. However, as the density of the device is increased, the space around the CPU is limited and the heat sink size is limited, so that the cooling capacity is naturally limited. In addition, since the fan size is also limited, it is necessary to rotate the small fan at high speed in order to obtain a high air volume, which increases noise.

  On the other hand, in the liquid cooling method disclosed in Patent Document 1 and the like, the heat exchanger can be provided at a relatively free position, so that the size is less restricted and the cooling limit is higher than that of the air cooling method. And low noise. For this reason, in recent years, a liquid cooling system has started to be used for cooling CPUs of electronic devices. When applying the liquid cooling method to electronic devices such as personal computers and servers, it is especially important to improve the performance of heat exchangers (jackets) that are connected to heat generating elements such as CPUs and transmit the heat to the liquid medium. is there. As a prior art regarding a jacket, it is disclosed by patent document 2, for example. In patent document 2, what comprised metal piping in the shape of a loop was joined on the metal base board, and the liquid flow path of the jacket was comprised. Patent Document 3 discloses an example in which a plurality of metal plates having slits are stacked and joined to form a slit portion as a flow path.

JP-A-6-266474 JP 2003-152376 A JP 2005-166855 A

  In recent years, electronic devices such as personal computers and servers have increasingly increased the amount of heat generated by heating elements such as CPUs as the processing speed increases and the performance increases. In order to operate a high-performance electronic device with high reliability for a long period of time, it is necessary to reduce the temperature rise of the heating elements such as the CPU. For this purpose, the conventional technique has the following problems.

  In improving the performance of a heat exchanger (jacket), it is desirable to increase the surface area of the liquid flow path as much as possible. For this reason, in an example in which the jacket channel is formed of a metal tube, it is necessary to increase the tube length by configuring the metal tube on the loop in order to increase the surface area of the channel. However, if the pipe length is increased, the flow path resistance increases and a pump with a large capacity is required.

  In addition, in the example in which the slit plates are laminated, in order to increase the surface area, it is necessary to form a large number of fine slits on the thin plate and to join all of the thin plates, which has a disadvantage that the manufacturing cost is very high. It was.

  Accordingly, the present invention has been made in view of the above-described problems in the prior art, and reduces an increase in temperature of a heating element such as a CPU with respect to an electronic device equipped with a CPU that generates a high heat. An object of the present invention is to provide a cooling device for electronic equipment having a jacket with excellent cost.

  In order to achieve the above-described object, the electronic apparatus cooling device of the present invention is transferred by the first heat exchanger that receives the heat generated by the heating element, the refrigerant liquid that transfers the received heat, and the refrigerant liquid. A second heat exchanger that dissipates heat; and a piping member that is arranged to circulate the refrigerant liquid between the first heat exchanger and the second heat exchanger. One or both of the first heat exchanger and the second heat exchanger includes a sealed frame for flowing the refrigerant liquid, and the frame in the frame. It is composed of a flow passage member made up of a plurality of flow wall pieces arranged in parallel for diverting and flowing the refrigerant liquid, and the side wall of the heat exchanger has an inlet into which the refrigerant liquid is introduced and the An outlet through which the refrigerant liquid flows out is provided and connected by the piping member. A flow inlet, and a header portion serving as a space for diverting or joining the refrigerant liquid between the outlet and the flow member, and the flow wall piece of the flow member are connected to the refrigerant liquid. In order to increase the contact area, each of the wall planes arranged in parallel is formed in a curved surface and arranged.

  Further, the front wall of the flow wall piece row in which the plurality of flow wall pieces arranged in parallel is arranged is larger than the width of the header portion serving as a space for diverting the refrigerant liquid provided in the frame. It was made to become.

  According to the present invention, in the electronic device cooling device, the flow-through member is formed of a flow-wall piece and a base member, and the flow-wall piece is formed by a cut-and-raft process by cutting the base member. The base member is integrated with the base member.

  By constructing as described above, a heat exchanger (jacket) with high performance and excellent cost can be obtained by reducing the temperature rise of a heating element such as a CPU with respect to an electronic device equipped with a CPU that generates high heat. It is possible to provide a cooling device for an electronic device having the electronic device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First, FIGS. 1 and 2 attached show a configuration of a jacket according to an embodiment of the present invention and an example in which a liquid cooling module using the jacket is applied to cooling an electronic device. Is.

  As shown in FIG. 1, the jacket 1 has a fin piece 4 in which a large number of parallel fins 3 are formed on a metal plate (fin base portion) 2 having excellent heat conduction, such as copper, in accordance with the height of the fin piece 4. The cover case 7 is covered with the jacket case 6 in which the indented portion 5 is formed. For example, the fin piece 4 is formed by continuously cutting the surface of the metal plate 2 from the end portion at a fine pitch, and cutting and raising the fin piece 4. This processing method is an effective method for forming a liquid flow path at a fine pitch, and the fin surface is curved in the height direction, so that the fin length in the height direction is longer than that of a normal linear fin. Since it can be taken, there is an advantage that the surface area can be increased. The jacket case 6 has liquid refrigerant inlet and outlet ports 8 and 9 formed therein. The jacket case 6 and the fin base portion 2 of the fin piece 4, and the jacket case 6 and the lid 7 are joined by brazing or the like.

  FIG. 2 shows an example in which a liquid cooling module using this jacket is applied to cooling an electronic device. In this example, for example, the case where the present invention is applied to the main body of a desktop personal computer is shown. First, as shown in the figure, the desktop personal computer has a main body 100 that includes a casing 100 formed of a metal plate in a cubic shape, for example, and includes a disk, a CD, a DVD, and the like. Various driver devices 101 for driving an information recording medium, a storage device including a hard disk device, and the like are provided. On the other hand, on the back side of the casing 100, an electronic circuit unit 102 having a liquid cooling system according to the present invention is disposed.

  Reference numeral 103 in the figure denotes a power supply unit for supplying desired power from a commercial power supply to each unit including the driver device 101 and the electronic circuit unit 102. The electronic circuit unit 102 is equipped with a heat generating element, that is, a CPU, which is a main component thereof. In this example, the CPU chip, which is the heating element, is mounted in direct contact with the lower surface side of the jacket 1, and is not shown here.

  As is apparent from the figure, the electronic circuit unit 102 includes a jacket 1 connected to the CPU and receiving heat generated by the CPU, and a radiator unit 20 radiating heat generated from the CPU to the outside of the apparatus. The circulation pump 21 and a flow path for passing a liquid refrigerant (for example, water or water in which a so-called antifreeze liquid is mixed at a predetermined ratio) such as water or propylene glycol to each part constituting the heat cycle by these. , For example, are connected by tubes (piping) 22, 23... Made of metal or an elastic body such as rubber. Further, the radiator section 20 blows air to a large number of fins that are constituent elements thereof, so that the plate-like fan 24 for forcibly radiating the heat conveyed from the jacket 1 (in this example, A plurality (for example, 3) are attached.

  Details of the jacket will be described below with reference to FIGS. FIG. 3 shows a cross-sectional view of the jacket configured as shown in FIG. As shown in FIG. 3, the fin piece 4 has a gap between the tip of the fin 3 and the lid 7 and the ends of the fin base 2 so that the refrigerant liquid does not bypass the portion other than between the fins 3. The dimensions are controlled so that the gap between the fin 30 and the inner surface 10 of the jacket case 6 is equal to or less than the flow path width, that is, the fin interval. The CPU 11 contacts the outer surface of the jacket case 6 via thermally conductive grease or the like. In order to efficiently transfer the heat generated by the CPU 11 to the liquid refrigerant flowing through the flow path between the fins 3, the jacket case 6 and the fin base portion 2 of the fin piece 4 are metallic and brazed by brazing or the like. It is desirable that the bonding surfaces be bonded together with complete contact.

FIG. 4 is a top sectional view of the inside of the jacket. The liquid refrigerant inlet and outlet ports 8 and 9 are formed, for example, by passing two pipes or the like through one side surface of the jacket case 6. On the upstream side and downstream side of the fin piece 4, there are space portions (header portions) 12 and 13 connected to the inlet and outlet ports 8 and 9. The header portions 12 and 13 are buffer regions formed so that the liquid refrigerant flowing from the inlet port 8 is uniformly distributed between the fins (liquid flow paths) formed in the fin pieces 4. Further, the concave portions 14 and 15 are formed on the inner side surface of the jacket case 6 so that the end portions of the fin base portion 2 enter the concave portions 14 and 15. That is, the front edge of the fin row arranged in parallel is larger than the width of the header portion 12 (width in the direction perpendicular to the longitudinal direction of the inter-fin liquid flow path and parallel to the paper surface). As long as the opening of the fin row is larger than the width of the inflow portion between the fins of the header portion on the side where the liquid refrigerant flows, a structure in which a convex portion is formed on the inner side surface of the jacket case 6 may be used.
By adopting this configuration, the liquid refrigerant can be prevented from bypassing and flowing into the gap formed between the fin 30 formed at the outermost end of the fin base portion 21 and the inner surface of the jacket case 6, and the jacket. Positioning when the fin piece 4 is joined to the case 6 is also facilitated. In the formation of fine fins by cutting and raising, the fin surface is curved, so the gap formed between the fin formed at the outermost end of the fin base portion 21 and the inner surface of the jacket case 6 must be large. . Therefore, the molding by fitting the concave portion provided on the inner surface of the jacket case 6 and the fin base 2 as described above has a particularly great effect in preventing the bypass of the liquid flow other than the flow path between the fins.

  Similarly, it is desirable that there is no gap between the fin tip and the inner surface of the lid. If there is variation in the height of each fin tip, the height of the lid will be determined by the high fin, so there is a possibility that a gap will occur in the low fin and the liquid will bypass. is there. For this reason, it is conceivable to braze the lid in a state where a load is applied so that the fin tip is pressed by the lid and all the fins are in contact with the lid. Since the fins are curved, individual fins can be easily deformed in the fin height direction. Therefore, by making the fins curved, it is easy to make the tips of all the fins come into contact with the lid, and a particularly great effect is obtained in preventing a liquid flow bypass between the fin tip and the lid. It is done.

  Further, as shown in FIG. 5, the tip 31 of the fin 3 is tilted or the curvature of the fin tip 31 is increased so that adjacent fins come into contact with each other at the fin tip. By joining the fin piece 4, the jacket case 6, and the lid 7 formed in this shape, the gap between the fin tip and the lid can be reduced. Furthermore, a brazing material can be interposed between the fin tip and the lid, and the gap can be eliminated more reliably.

  In the following, another embodiment of the jacket of the present invention will be described. However, the structure for avoiding the bypass of the liquid flow between the fin and the jacket case and between the fin and the lid as described above is described below. Can be combined.

  FIG. 6 shows another embodiment of the jacket of the present invention. In the embodiment of the jacket shown in FIG. 1, in order to efficiently transfer the heat of a heating element such as a CPU to the refrigerant liquid flowing between the fins, the bottom surface of the jacket case and the fin base portion of the fin piece are joined together. It must be brazed so that the surface is in perfect contact. However, as the area of the joint surface increases, an unjoined portion is likely to be generated, and the thermal resistance is increased. In view of this point, an example in which the CPU and the fin base portion are in direct contact is shown in FIG. The jacket of the present embodiment has a fin piece 4 having a curved fin 3 formed by cutting and raising the fin base 2 while leaving a flange portion 16 that does not form fins in the periphery, and ports 8 and 9 for inflow and outflow of liquid. And a lid 18 having a recess 17 formed in the center in accordance with the height of the fin 3, and the flange portion 16 of the fin piece 4 and the lid 18 are joined by brazing or the like. As a method of forming the flange portion 16, the fin 3 is formed on the entire surface of the fin base 2, and the periphery is deleted. The fin base 2 having a convex portion is prepared in advance at the central portion where the fin 3 is formed, and the convex portion is cut. There is a method of forming a curved fin 3 by performing a raising process. As shown in the cross-sectional view of FIG. 7, the periphery of the lid 18 and the flange portion 16 of the fin piece are joined together to form a liquid flow path between the curved fin 3 and the concave portion 17 of the lid 18. In this embodiment, it suffices that the joint between the lid 18 and the flange portion 16 of the fin piece 4 is kept airtight, and the thermal connection from the CPU to the fin base 2 can be performed reliably and with a small thermal resistance. Since the lid 18 and the flange portion 16 of the fin piece only need to be able to be airtightly joined, a seal structure using an O-ring or the like may be used in addition to a method such as brazing.

  As a similar method, the configuration shown in FIGS. In the present embodiment, similar to the previous embodiment shown in FIGS. 6 and 7, the flange portion is not formed on the fin piece, and the same effect is obtained. As shown in FIG. 8, the frame 31 has substantially the same configuration as that of the previous embodiment (FIGS. 6 and 7), but a frame 31 having an opening larger than the outer shape of the CPU 11 is prepared. It has the same function as (FIGS. 6 and 7). As shown in the sectional view of FIG. 9, the fin 31 in the previous embodiment (FIGS. 6 and 7) is formed by simultaneously and airtightly bonding the periphery of the lid 18 and the fin base 2 (the surface on which the fins 3 are not formed) by the frame 31. A function similar to that of the flange portion 16 is made to function by the frame body 31, and the thermal connection from the CPU 11 to the fin base 2 is reliably performed with a small thermal resistance without providing the fin portion 4 with the flange portion. The fin piece 4 may be the same as the embodiment shown in FIG. In the case of the method of removing the surrounding fins after forming the fins on the entire surface of the fin base as in the previous embodiment (FIGS. 6 and 7), the gap between the fins may be caused by burrs or burr during the fin cutting process. It is necessary to prevent it from being blocked. On the other hand, in this embodiment, since the fin post-cutting process is not included, it is not necessary to consider that the gap between the fins is blocked. can do.

  FIG. 10 shows another embodiment of the flow path configuration. A plurality of fin pieces (for example, two pieces in FIG. 10) in which curved fins are formed by cutting and raising are prepared, and partially formed in the jacket case 60 according to the height of the fin pieces 41 and 42. Fin pieces 41 and 42 are arranged in the hollow portion 50 so that the flow paths formed by the fin pieces are in series (the flow direction of the liquid refrigerant is indicated by an arrow) and joined. In this embodiment, the flow rate between the fins is increased compared to the case where one fin piece as in the previous embodiment is used in the same number of fins, fin area, and overall liquid flow rate. The cooling effect can be further enhanced by, for example, reducing variation in the flow rate at the bottom.

  11 and 12 show another embodiment. This embodiment is a structure having a partition plate that divides the inside of the jacket in the thickness direction in the previous embodiment (for example, FIG. 1), and includes a jacket case 6 that accommodates the fin pieces 4 and a lid 35 having a hollow portion. And a partition plate 31 having an opening 34 and provided between them. As shown in the sectional view of FIG. 12, the partition plate 31 divides the inside of the jacket into a region 32 in which the fin pieces 4 are provided and a region 33 in which liquid is stored, and both regions are separated by openings 34 provided in the partition plate 31. Communicate. The liquid storage area 33 is formed by a recess 36 provided in the lid 35. In each region, a liquid inflow port 8 and a liquid outflow port 9 are attached to the jacket case 6 and the lid 35, respectively. The internal volume of the liquid storage area 33 is, for example, a size corresponding to an amount that can compensate for a decrease due to liquid permeation or the like over a long period of product life, and has the same function as a so-called reserve tank. That is, the jacket and the reserve tank are integrated.

  In each of the above embodiments, the case where the curved fine fin formed by the cutting and raising process is applied to the jacket that receives the heat generated by the CPU has been shown. Further, heat is radiated from the received liquid refrigerant to the outside air. You may apply to the liquid flow path part by the side of a thermal radiation part (radiator) to do. That is, for example, a liquid flow path part on the heat radiating part side is formed with the same configuration as the jacket shown in FIG. 1 and the like, and fins for heat exchange with air are further provided on the outer surface of the lid.

It is an expansion perspective view of the jacket which constitutes the cooling device for electronic equipment which becomes one embodiment of the present invention. It is a perspective view showing the whole structure which applied the said cooling device for electronic devices to cooling of the electronic device. It is a sectional side view of the jacket which comprises the said cooling device. It is upper surface sectional drawing of the said jacket. It is a sectional side view of the fin piece which comprises the said jacket. It is an expansion | deployment perspective view of the jacket which comprises the cooling device for electronic devices which becomes other embodiment of this invention. It is side sectional drawing of the said jacket. It is an expansion | deployment perspective view of the jacket which comprises the cooling device for electronic devices which becomes other embodiment of this invention. It is side sectional drawing of the said jacket. It is upper surface sectional drawing of the jacket which comprises the cooling device for electronic devices which becomes other embodiment of this invention. It is an expansion | deployment perspective view of the jacket which comprises the cooling device for electronic devices which becomes other embodiment of this invention. It is side sectional drawing of the said jacket.

Explanation of symbols

1 ... jacket, 2 ... fin base, 3 ... fin, 4 ... fin piece,
6 ... jacket case, 7 ... lid, 11 ... CPU

Claims (4)

In a liquid-cooled cooling device that transfers and dissipates heat generated by a heating element used in electronic equipment,
A first heat exchanger that receives heat generated by the heating element;
A refrigerant liquid for transferring the received heat;
A second heat exchanger that dissipates heat transferred by the refrigerant liquid;
A piping member disposed to circulate the refrigerant liquid between the first heat exchanger and the second heat exchanger;
Either or both of the first heat exchanger and the second heat exchanger include a sealed case body for allowing the refrigerant liquid to flow, a lid, and the case It is composed of a flow-through member made up of a plurality of flow-wall pieces arranged in parallel to be placed in the body and to divide and flow the refrigerant liquid,
The side wall of the heat exchanger is provided with an inlet through which the refrigerant liquid flows in and an outlet through which the refrigerant liquid flows out, and is connected by the piping member. Provide a header portion that becomes a space for dividing or joining the refrigerant liquid between the outlet and the flow member;
The electronic device is characterized in that the flow wall piece of the flow member is formed in a curved surface with each of wall planes arranged in parallel in order to increase the contact area with the refrigerant liquid. Cooling device. In a liquid-cooled cooling device that transfers and dissipates heat generated by a heating element used in electronic equipment,
A first heat exchanger that receives heat generated by the heating element;
A refrigerant liquid for transferring the received heat;
A second heat exchanger that dissipates heat transferred by the refrigerant liquid;
A piping member disposed to circulate the refrigerant liquid between the first heat exchanger and the second heat exchanger;
Either or both of the first heat exchanger and the second heat exchanger include a sealed case body for allowing the refrigerant liquid to flow, a lid, and the case It is composed of a flow-through member made up of a plurality of flow-wall pieces arranged in parallel to be placed in the body and to divide and flow the refrigerant liquid,
The flow member comprises the flow wall piece and a base member,
The electronic apparatus cooling device according to claim 1, wherein the flow-through wall piece is formed by a cut-and-raft process in which a base member is cut and has an integrated structure with the base member. In the cooling device for electronic devices according to claim 1 and claim 2,
The height of the base of the flow member and the flow wall piece is defined by the depth of the recess for housing and mounting the flow member of the case body of the heat exchanger and the space height formed by covering with the lid. A cooling device for electronic equipment, which is configured to be larger than a size and presses and holds a flow wall piece of the flow member when assembled as the heat exchanger. In the cooling device for electronic devices of Claim 1 thru | or 3,
The case body has a header part space for diverting the refrigerant liquid and a space for placing the flow member, and the width dimension of the space for placing the flow member is: A length dimension in the arrangement direction in which a plurality of flow wall pieces of the flow passage member are arranged in parallel is formed to be larger than the width of the space of the header portion. A cooling device for electronic equipment, characterized in that it is configured to have a dimension substantially equal to the width dimension, and is housed and assembled in a space in which the flow passage member is placed.

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