JP2005011337A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure having high cooling performance and high reliability in structure cooling a heat generating element of an electronic device by liquid circulation. <P>SOLUTION: A water-cooling jacket 8 is thermally connected to the heat generating element 7. A radiating pipe 9 is thermally connected to a radiating board 10 installed on the back face of a display 2. A refrigerant liquid is circulated between the water cooling jacket 8 and the radiating pipe 9 by means of a liquid drive unit 11. The water-cooling jacket 8 is formed to jacket base channel integral structure by die-cast molding or water-cooling jacket piping channel integral structure by jacket base and metal pipe junction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic device including a device that cools a semiconductor element that generates heat using a circulating liquid.

Conventional techniques can be found in JP-A-6-266474, JP-A-7-142886, and the like.
In an example of Japanese Patent Laid-Open No. 6-266474, an electronic device including a main body housing that houses a wiring board on which a heating element is mounted, and a display device housing that includes a display panel and is rotatably attached to the main body housing. A structure in which a water cooling jacket attached to a heat generating element, a heat radiating pipe installed in a display device casing, and a liquid driving mechanism are connected by a flexible tube is shown.
Further, Japanese Patent Application Laid-Open No. 7-142886 discloses an example in which the casing is made of metal in the example of Japanese Patent Application Laid-Open No. 6-266474.

  In these examples, heat generated in the heat generating element is transmitted to the water cooling jacket, and the heat is transmitted from the water cooling jacket to the heat radiating pipe by driving the liquid by a liquid driving mechanism, and is radiated to the outside air.

JP-A-6-266474

JP-A-7-142886

  In an electronic device typified by a portable personal computer or the like, a heat generating element (semiconductor element) is highly heated due to improved performance. On the other hand, it is desired to reduce the size and thickness of the housing suitable for carrying.

Each of the known examples has a structure in which heat generated by the heat generating element is transported to the display side to dissipate heat in response to an increase in heat generation of the heat generating element. The heat is transferred from the heating element to the display side by driving the liquid between them. Heat transport by liquid is suitable for heat transport from a highly efficient and highly heat generating element.
However, if the heat transfer efficiency from the heat generating element to the liquid is poor, the heat generating element cannot be sufficiently cooled regardless of the efficiency of heat transport by the liquid. In addition, it is necessary to consider reduction of liquid in the system due to liquid permeation from the water cooling jacket itself or the piping system, corrosion of the water cooling jacket, and the like.

  In the above-mentioned known examples, the structure of the water cooling jacket for these has not been sufficiently considered.

  An object of the present invention is to provide an electronic apparatus having a water-cooling jacket that has high heat transfer efficiency from a heating element to a refrigerant liquid and has high reliability against corrosion, liquid permeation, and liquid leakage.

  The object is to house a heat receiving member thermally connected to the heat generating element, a heat radiating member connected to the heat receiving member, and a liquid driving means connected to the heat radiating member and the heat receiving member in a housing, In the electronic device in which the liquid coolant is circulated between the heat receiving member and the heat radiating member by the liquid driving means, the heat receiving member has a metal plate that is thermally connected to the heating element, and the metal plate includes the metal plate inside the metal plate. This is achieved by forming a flow path for the refrigerant liquid.

  Further, the object is to house a heat receiving member thermally connected to the heat generating element, a heat radiating member connected to the heat receiving member, and a liquid driving means connected to the heat radiating member and the heat receiving member in the housing. In the electronic device in which the refrigerant liquid is circulated between the heat receiving member and the heat radiating member by the liquid driving means, the flow path of the heat receiving member is formed by a part of a pipe constituting the flow path through which the refrigerant liquid circulates. Is achieved.

  Further, the object is to house a heat receiving member thermally connected to the heat generating element, a heat radiating member connected to the heat receiving member, and a liquid driving means connected to the heat radiating member and the heat receiving member in the housing. In the electronic device in which the liquid coolant is circulated between the heat receiving member and the heat radiating member by the liquid driving means, the heat receiving member has a metal base that is thermally connected to the heat generating element. This is achieved by being thermally connected to a part of the pipe through which the refrigerant liquid circulates.

  The above object is achieved by connecting the metal base and a part of the pipe through which the coolant circulates with heat conductive grease or adhesive.

  The above object is achieved by integrally molding the metal base and a part of the pipe through which the refrigerant liquid circulates.

  Further, the above object is achieved by forming a part of a pipe through which the refrigerant liquid circulates in a loop shape and thermally connecting with the metal base.

  Further, the object is to form a part of the pipe through which the refrigerant liquid circulates in a loop shape from the center to the outer periphery, and to make the center position of the loop coincide with the approximate center position of the heat generating element so that the refrigerant liquid circulates. This is achieved by moving the direction from the center of the loop to the outer periphery.

  Further, the above object is achieved by forming a part of a pipe through which the refrigerant liquid circulates in a loop shape in which the flow directions in adjacent flow paths are opposite to each other and thermally connecting to the metal base. Achieved.

  Further, the above object is achieved by arranging a plurality of the heat generating elements and thermally connecting the plurality of heat generating elements to the heat receiving member.

  Moreover, the said objective is achieved by cooling the said heat receiving member with a fan.

  ADVANTAGE OF THE INVENTION According to this invention, the heat transfer efficiency from a heat generating element to a refrigerant | coolant liquid is good, and the electronic apparatus provided with the reliable water cooling jacket with respect to corrosion, liquid permeation | transmission, and a liquid leakage can be provided.

  2. Description of the Related Art Electronic device apparatuses, so-called personal computers (hereinafter referred to as personal computers) include portable laptop computers and desktop computers that are mainly used on desks. Each of these personal computers has a high demand for high-speed processing and large capacity year by year, and as a result of satisfying these demands, the heat generation temperature of a CPU (hereinafter referred to as CPU), which is a semiconductor element, has increased. This trend is expected to continue in the future.

On the other hand, these current personal computers are generally air-cooled by a fan or the like. This air-cooled type has a limit in heat dissipation capability and may not be able to follow the heat dissipation of a CPU that tends to generate heat as described above. However, this can be dealt with by rotating the fan at a high speed or by increasing the size of the fan, but this is not practical because it goes against the reduction in noise and weight of the personal computer.
On the other hand, conventionally, there is a device that cools a CPU by circulating a cooling medium such as water as heat radiation instead of air-cooled heat radiation.
This cooling device is mainly used for cooling large computers used in companies or banks, and is a large-scale device in which cooling water is forcibly circulated by a pump and cooled by a dedicated refrigerator.

  Therefore, for a notebook computer that is frequently moved and a desktop computer that may be moved due to rearrangement in the office, the above-mentioned water cooling device is not used. Even if it is downsized, it cannot be mounted.

  Thus, various water cooling devices that can be mounted on a small personal computer have been studied as in the above-mentioned conventional technology. At the time of filing of this conventional technology, the heat generation temperature of the semiconductor element was not as high as in recent years. Even so, personal computers equipped with water cooling devices have not yet been commercialized.

  On the other hand, the present invention makes it possible to significantly reduce the size of the water-cooling device by using an aluminum alloy or a magnesium alloy with good heat dissipation as the casing that forms the outer shell of the computer main body. It has become possible.

By the way, in order to cool a semiconductor element in a limited space inside a personal computer, it must be cooled with a limited amount of liquid medium. Therefore, how to transfer the heat of the semiconductor element from the water cooling jacket to the liquid medium without waste is an important issue for this water cooling apparatus.
If the heat of the semiconductor element is not sufficiently transferred to the liquid medium, the semiconductor element cannot be sufficiently cooled, and in some cases, there is a risk of thermal runaway.

  In view of this, the present invention has obtained a water cooling jacket described below as a result of examining a water cooling jacket having high heat transfer efficiency.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of the electronic device of this embodiment.
In FIG. 1, the electronic device includes a main body case 1 and a display case 2 provided with a display. These cases 1 and 2 are rotatable via hinges. A keyboard 3 installed in the main body case 1, a wiring board 4 equipped with a plurality of elements, a hard disk drive 5, an auxiliary storage device (for example, floppy disk drive, CD drive, etc.) 6, a battery 13, and the like are installed.
On the wiring board 4, a semiconductor element (hereinafter referred to as “CPU”) having a particularly large calorific value such as a CPU (Central Processing Unit) 7 is mounted. A water cooling jacket 8 is attached to the CPU 7. The CPU 7 and the water-cooled jacket 8 are connected via a flexible heat conductive member (for example, Si rubber mixed with a heat conductive filler such as aluminum oxide).

A metal heat radiating plate 10 to which a heat radiating pipe 9 (made of metal such as copper or stainless steel) is connected is installed on the back surface (inner case) of the display case 2. A tank 14 connected to the heat radiating pipe 9 is installed at the upper back of the display case 2, and the tank 14 is provided in the middle of the flow path. The tank 14 has a volume sufficient to secure an amount necessary for cooling in the circulation flow path even if the liquid is reduced by liquid permeation or the like.
The metal heat sink 10 may be omitted by making the display case 2 itself made of metal (for example, aluminum alloy or magnesium alloy), and the heat radiating pipe 9 may be directly connected to the display case 2. In addition, a pump 11 that is a liquid driving means is installed in the main body case 1.
The water cooling jacket 8, the heat radiating pipe 9, and the pump 11 are connected by a flexible tube 12, and the refrigerant liquid enclosed inside by the pump 11 circulates. The flexible tube 12 may be used only for at least the hinge portion 15.

That is, a metal pipe is used for piping between the water cooling jacket 8 and the hinge portion 15, between the pump 11 and the hinge portion 15, and between the pump 11 and the water cooling jacket 8, and at least at the hinge portion 15, The heat radiating pipe 9 is connected by the flexible tube 12, and the ratio of the metal pipe portion that is fitted to the entire pipe is increased as much as possible.
Thereby, it can respond to opening and closing of the display part around a hinge part, and can suppress moisture permeation from piping. The piping system in this case is a water cooling jacket, flexible tube, metal pipe, hinge flexible tube, heat radiating pipe, hinge flexible tube (metal pipe, flexible tube), pump, flexible tube, (metal pipe, flexible tube) A water cooling jacket is connected and configured (elements in parentheses may be added).

  For each connecting portion, an appropriate joint and a tightening band (plate shape, coil spring shape) for preventing removal are used. Furthermore, the connecting portion may be coated with a resin to prevent water leakage. In addition, the material of the flexible tube 12 is butyl rubber or the like with little moisture permeation.

FIG. 2 is a front view and a partial sectional view showing details of the water cooling jacket.
In FIG. 2, a flow path 21 is formed in a base 22 made of a metal block and sealed with a lid 24 via an O-ring 23. The base 22 is made of, for example, (pure) aluminum having excellent thermal conductivity and formability, and is subjected to corrosion resistance treatment such as alumite treatment after molding.
The water cooling jacket and the heating element 7 are connected via a flexible heat conducting member 16. The outer size of the water-cooling jacket is larger than that of the heat generating element 7, and it is desirable to make the flow path area 21a forming the flow path inside the O-ring groove as large as possible. In the base 22, for example, a flow path, an O-ring groove and a water inlet / outlet port 31, 32 are integrally formed in the base by die casting.
According to die casting, the width of the flow path 21 can be reduced to the limit of die casting, and the flow path surface area can be increased. Therefore, the heat transfer performance to the liquid flowing in the flow channel 21 can be improved. In addition, by reducing the width of the flow path 21, the flow path 21 having a necessary and sufficient surface area in the same area as the heat generation element 7 can be formed in the base 22, and the heat generation element can be connected to the flow path formation area. The thermal resistance associated with the area expansion can be reduced. At the same time, the water cooling jacket can be downsized.

FIGS. 3A and 3B are a front view and a partial cross-sectional view showing another embodiment of the water cooling jacket.
In FIG. 3, the water-cooled jacket forms a flow path by meandering a metal pipe 26, and soldering or silver brazing as shown by a joint 27 in a metal (aluminum, copper, etc.) base 25. It has a structure.
The heat of the heat generating element is thermally conducted to the base 25, then diffuses in the base 25, is conducted to the metal pipe 26, and is transferred to the liquid from the inner wall surface of the metal pipe 26. At this time, heat conduction in the circumferential direction in the wall of the metal pipe 26 also contributes.

Therefore, the base 25 and the metal pipe 26 in the flow path are joined metallically, and further, the material of the metal pipe 26 is made of copper having excellent heat conduction and the thickness is increased, thereby increasing the thickness from the heating element. The thermal resistance to the liquid inside can be reduced.
When the meandering flow path is formed by the metal pipe 26, it is necessary to bend at a minimum bending radius that does not bend the pipe. Therefore, in order to make the flow path length as long as possible in the base 25 (increase the number of turns), as shown in FIG. You may shape | mold so that it may contact | connect.

  In this embodiment, since there is no seal portion as compared with the structure shown in FIG. 2, there is no decrease in liquid due to leakage at the seal portion and permeation of moisture. Furthermore, if a corrosion-resistant material is used for the metal pipe 26 as in the case of the heat radiating pipe 9 or the like, it is not necessary to consider corrosion on the base 25. Further, by extending the metal pipe 26 that constitutes the flow path of the water cooling jacket and also serving as piping for the entire system, a system with less leakage and moisture permeation can be achieved. This embodiment is shown in FIG.

FIG. 4 is a perspective view of an electronic device showing an embodiment in which the flexible tube is only the hinge portion of both cases.
In FIG. 4, the metal pipe 26 of the flow path used for the water cooling jacket 8 is extended to constitute a part of the piping of the entire cooling system. That is, the metal pipe 26 which comprises the flow path of a water cooling jacket is used for piping between the pump 11 and the water cooling jacket 8, and between the water cooling jacket 8 and a hinge part. In the hinge portion, the metal pipe 26 and the heat radiating pipe 9, and the pump 11 and the heat radiating pipe 9 are connected by the flexible tube 12. Appropriate joints and fastening bands 35a to 35d for preventing disconnection are provided at the connection portion.
According to the present embodiment, it is possible to increase the proportion of the metal piping portion that is included in the entire piping, so that a piping system with little leakage and moisture permeation can be configured.

FIGS. 5A, 5B and 6 are cross-sectional views showing another embodiment of a water cooling jacket similar to the embodiment shown in FIG.
5 (a), 5 (b) and FIG. 6, the groove 28 is formed in the base 25 made of metal (aluminum, copper, etc.) along the bent shape of the metal pipe 26 (by die casting or the like). ), A metal pipe 26 is fitted in the groove 28. A contact portion between the metal pipe 26 and the groove 28 of the base 25 is filled with grease or adhesive having high thermal conductivity.
5 (b) and FIG. 6 are examples in which the contact area is enlarged in order to increase the heat conduction efficiency between the base 25 and the metal pipe 26 from FIG. 5 (a). The groove 28 is deepened and filled with highly heat conductive grease or adhesive. FIG. 6 shows a structure in which a base 25 provided with a groove having a depth half that of the diameter of the metal pipe 26 is sandwiched between the metal pipes 26.

  According to these embodiments, there is an advantage that the cost can be reduced as compared with the water cooling jacket (FIG. 3) in which the metal pipe 26 and the base 25 are joined metallically. However, since grease or an adhesive is used at the contact portion between the metal pipe 26 and the base 25, the heat conduction performance is inferior. In contrast, the embodiment of FIG. 7 solves this point.

  In the embodiment of FIG. 7, when a metal base 25 such as aluminum is die-cast, a metal pipe 26 bent into a predetermined shape is cast and formed at the same time. According to this method, since the metal pipe 26 and the base 25 are completely in contact with each other, high heat conduction performance can be obtained without using high thermal conductivity grease or adhesive at the contact portion.

FIG. 8 is a front view of a water cooling jacket provided with another embodiment.
The embodiment of FIG. 8 has a structure in which a metal pipe and a metal base are combined as in the embodiment shown in FIGS.
In FIG. 8, the heat transfer efficiency from the heating element 7 to the refrigerant liquid is increased by increasing the flow path length (surface area with the liquid flowing inside) as much as possible. The metal pipe 26 is formed in a loop shape and connected to the metal base 25. The connection method can be the same as that shown in FIGS.

In this embodiment, it is sufficient that the loop radius at the center of the loop is equal to or larger than the minimum curvature radius with respect to the bending. Therefore, the pipe can be efficiently arranged in the plane of the base 25 and the flow path length can be increased. When the center position of the loop is arranged so as to be substantially coincident with the center position of the heating element 7 and the direction of the liquid flow is from 32 to 31 of the pipe, first, the center of the heating element 7 having the highest temperature is obtained. The liquid is supplied to the part, and it can be cooled efficiently.
On the other hand, the pipe 32 on the inflow side crosses the loop portion of the pipe. Therefore, the height of the flow path portion of the water cooling jacket needs to be twice the pipe diameter. In contrast, in the embodiment shown in FIG. 9, the pipe is formed in a loop shape so that the inflow side and the outflow side of the flow path have the same height.

FIG. 9 is a front view of a water cooling jacket provided with another embodiment.
According to FIG. 9, unlike the embodiment shown in FIG. 8, the pipe 26 is arranged in an elliptical shape in the base 25, the flow path can be made long, and the flow directions in the adjacent pipes are opposite to each other. It has become.
Therefore, a high cooling effect can be obtained. Further, since the pipe can be arranged so that the inflow side and the outflow side of the flow path have the same height, the thickness of the water cooling jacket can be reduced.

  In addition, as shown in FIG. 10, the molded pipe 26 may be pressed into a substantially square shape with the upper and lower surfaces of the pipe flattened and directly connected to the base 25 on the flat plate. In FIG. 10, a plate 25a is further provided at the top, and the pipe 26 is sandwiched and fixed between the base 25 and the plate 25a.

FIG. 11 is a front view showing another embodiment similar to the embodiment shown in FIG.
In FIG. 11, a pipe 26 constituting a water cooling jacket (similar to the embodiment of FIG. 9) for cooling the heat generating element 7 is extended to connect the second base plate 33. The second base plate 33 is in contact with the second heat generating element 34 and has the same configuration and structure as the cooling of the heat generating element 7 (which may be any structure of the above embodiment). Cooling. It should be noted that the base plate 25 and the second base plate 33 may be integrated and brought into contact with the plurality of heating elements 7 and 34. With this configuration, a plurality of heat generating elements can be cooled by the integrated flow path.

FIG. 12 is a front view showing another embodiment of the water cooling jacket.
In FIG. 12, a water cooling jacket for cooling the heat generating element 7 is combined with a forced air cooling structure using a fan 37. A fin 36 is attached to the base plate 25 that contacts the heat generating element 7, and a fan 37 is installed. For example, the fan 37 sucks air from the upper surface (a direction perpendicular to the paper surface) and exhausts air from the side surface of the fan 37 toward the fins 36. Further, for example, the fins 36 may be formed in a plate 25a that sandwiches the pipe 26 as shown in FIG. 10, and the pipe 26 may be directly forced-air cooled.
In the present embodiment, the case where the plurality of heat generating elements 7 and 34 are cooled using the individual base plates 25 and 33 as in the embodiment shown in FIG. 11 is described, but the second base plate 33 is not provided. A structure in which the base plate 25 and the second base plate 33 are integrated to cool the plurality of heating elements 7 and 34 and cooling by the fan 37 may be combined.

  According to the present embodiment, since the heat of the heating element is transported by the circulation of the refrigerant liquid and cooled by the heat radiating plate, the forced air cooling by the fan is added, so that high cooling performance can be obtained.

  Incidentally, although the embodiments shown in FIGS. 1 to 12 are applied to a notebook personal computer, they can be applied to computers of other forms and other electronic devices.

As described above, the heat generated from the heating element is transmitted to the refrigerant liquid flowing in the water cooling jacket, and is radiated to the outside air from the heat radiating plate installed on the back of the display through the display case surface while passing through the heat radiating pipe. .
Thus, the refrigerant liquid whose temperature has been lowered is sent out again to the water cooling jacket by the liquid driving device. The heat transfer path from the heating element to the liquid consists of heat conduction from the heating element to the water-cooled jacket base, heat diffusion to the flow path formation area in the base, and heat transfer from the flow path formation area to the liquid flowing in the flow path. is there.
By die-casting the flow path in the water-cooled jacket, a flow path with a sufficient surface area in the same area as the heating element can be formed in the base, and the area expanded to the flow path formation area in the jacket base The thermal resistance associated with can be reduced. Further, by joining the jacket base and the metal pipe constituting the pipe flow path and forming the flow path in the water-cooling jacket with the metal pipe, a structure without a seal portion, that is, no liquid permeation can be achieved. In the case of this structure, if a pipe made of a corrosion-resistant metal material is used for the pipe flow path, corrosion at the water-cooled jacket portion can also be suppressed.

The perspective view of 1st Example of this invention Detailed view of the water cooling jacket used in the first embodiment of the present invention Top view of the second embodiment of the present invention The perspective view of 3rd Example of this invention Sectional drawing of 4th Example of this invention Sectional drawing of 5th Example of this invention Sectional drawing of 6th Example of this invention Top view of the seventh embodiment of the present invention Top view of the eighth embodiment of the present invention Sectional drawing of 9th Example of this invention Sectional view of the tenth embodiment of the present invention Sectional view of the eleventh embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Main body case, 2 ... Display case, 3 ... Keyboard, 4 ... Wiring board, 7 ... CPU, 8 ... Water cooling jacket, 9 ... Radiation pie, 10 ... Radiation metal plate, 11 ... Pump, 12 ... Flexible tube, 14 ... Tank, 21 ... channel, 22, 25 ... base, 26 ... metal pipe, 28 ... groove, 33 ... second base, 34 ... second heating element, 35 ... clamping band, 36 ... fin, 37 ... fan .

Claims (10)

  A heat receiving member thermally connected to the heat generating element, a heat radiating member connected to the heat receiving member, and a liquid driving means connected to the heat radiating member and the heat receiving member are housed in a housing, and the liquid driving means In the electronic device in which the refrigerant liquid is circulated between the heat receiving member and the heat radiating member, the heat receiving member has a metal plate that is thermally connected to the heating element, and the refrigerant liquid flows inside the metal plate. An electronic device characterized by forming a path.   A heat receiving member thermally connected to the heat generating element, a heat radiating member connected to the heat receiving member, and a liquid driving means connected to the heat radiating member and the heat receiving member are housed in a housing, and the liquid driving means In the electronic device in which the refrigerant liquid is circulated between the heat receiving member and the heat radiating member, the flow path of the heat receiving member is formed by a part of a pipe constituting the flow path through which the refrigerant liquid circulates. Electronic equipment.   A heat receiving member thermally connected to the heat generating element, a heat radiating member connected to the heat receiving member, and a liquid driving means connected to the heat radiating member and the heat receiving member are housed in a housing, and the liquid driving means In the electronic device in which the refrigerant liquid is circulated between the heat receiving member and the heat radiating member, the heat receiving member has a metal base thermally connected to the heating element, and the pipe through which the metal base and the refrigerant liquid circulate. An electronic device characterized in that it is thermally connected to a part of the electronic device.   4. The electronic apparatus according to claim 3, wherein the metal base and a part of the pipe through which the refrigerant liquid circulates are connected by heat conductive grease or adhesive.   4. The electronic device according to claim 3, wherein the metal base and a part of a pipe through which the refrigerant liquid circulates are integrally formed.   4. The electronic apparatus according to claim 3, wherein a part of a pipe through which the refrigerant liquid circulates is formed in a loop shape and thermally connected to the metal base.   A part of the pipe through which the refrigerant liquid circulates is formed in a loop shape from the center toward the outer periphery, the center position of the loop is made to coincide with the approximate center position of the heating element, and the direction in which the refrigerant liquid circulates is the center of the loop The electronic device according to claim 3, wherein the electronic device is directed from an outer periphery to an outer periphery.   4. A part of a pipe through which the refrigerant liquid circulates is formed in a loop shape in which the flow directions in adjacent flow paths are opposite to each other, and is thermally connected to the metal base. The electronic device described.   4. The electronic device according to claim 1, wherein a plurality of the heat generating elements are arranged, and the plurality of heat generating elements are thermally connected to the heat receiving member. The electronic device according to claim 1, wherein the heat receiving member is cooled by a fan.

Images