JP3739142B2 - Electronic element cooling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic element cooling structure which has a high cooling power to electronic elements and prevents other members in a package than the electronic elements from increasing temp. SOLUTION: The structure for cooling heating electronic elements 7 in a package 5 comprises a small-aperture flexible heat pipe 8 disposed so that its one end can transfer the heat with the element 7 and a heat sink 10 can transfer the heat with the other end of the pipe 8. An intake 12 is communicated with the heat sink 10 in one body and fan 11 is disposed to blow air to outside of the package.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling structure for an electronic device that prevents overheating of the electronic device by using a heat pipe that transports heat as latent heat of a working fluid.
[0002]
[Prior art]
In the field of computers, the output of electronic elements such as arithmetic processing units has increased with the increase in functionality and processing speed. On the other hand, downsizing and weight reduction of a computer are strongly desired. Therefore, naturally, a space that can be occupied by a device for cooling an arithmetic processing unit or the like in the internal space of the case is extremely limited. Therefore, conventionally, a heat pipe having excellent heat transport capability has been used as an example of a cooling device.
[0003]
FIG. 2 shows a heat pipe for a personal use computer (hereinafter referred to as a personal computer) described in a book “Practical Heat Pipe” (produced by Nikkan Kogyo Shimbun) distributed on October 25, 1985 in Japan. An example is shown. The heat pipe 1 is a so-called flat plate heat pipe, the container is formed in a rectangular cross section, the lower surface in the figure of the container is a heating unit 1a, and the upper surface is a heat radiating unit 1b. . A large number of heat dissipating fins 1c are provided outside the heat dissipating part 1b. The container is filled with a predetermined amount of condensable working fluid 3 such as water after being sucked so as to be evacuated.
[0004]
On the other hand, a central processing unit (hereinafter referred to as a CPU) 2 is attached to a predetermined portion of a circuit formed on the printed circuit board 4, and a heat pipe 1 is a heating unit on the upper surface of the CPU 2. 1a is attached in close contact.
[0005]
In the heat pipe 1, when the circuit 2 is energized and the CPU 2 generates heat, and the heating part 1a is heated by the heat, the sealed working fluid 3 is heated to boil and become steam. The vapor | steam of the working fluid 3 moves upwards and condenses in the low temperature thermal radiation part 1b. That is, the heat carried in the state of latent heat of vaporization of the working fluid 3 is dissipated from the radiation fins 1c provided outside the heat radiation part 1b.
[0006]
Thus, by using the heat pipe 1 for cooling the CPU 2, a large amount of heat can be transported in the state of latent heat of vaporization, and therefore the CPU 2 can be effectively cooled. As a result, it is possible to prevent the personal computer from becoming inoperable or deteriorating due to overheating of the CPU 2.
[0007]
[Problems to be solved by the invention]
However, since the heat pipe 1 itself is installed inside the personal computer case in the above-described conventional configuration, the heat radiation from the heat radiating fins 1c is naturally performed inside the personal computer main body 1. There was an inconvenience that heat was easily generated in the internal space.
[0008]
Therefore, conventionally, a configuration in which a personal computer case is provided with an exhaust hole and a blower fan that supplies air to the radiating fins 1c has been proposed. That is, when the blower fan is operated, the air inside the personal computer case flows through the heat radiation fins 1c and then flows so as to flow out of the personal computer case through the exhaust holes. Therefore, according to this configuration, since the heat of the CPU 2 is carried to the outside of the personal computer case together with the flowing air, the above-described problems can be reliably and easily solved.
[0009]
However, in the above-described configuration including the blower fan, the high-temperature air contacts the CPU 2 and the heat pipe 1 and flows inside the PC case toward the exhaust hole. There was a problem of inevitably increasing the temperature.
[0010]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cooling structure for an electronic element that has a high cooling capacity for the electronic element and that can prevent a temperature rise of members provided in the casing other than the electronic element. It is what.
[0011]
[Means for Solving the Problem and Action]
In order to achieve the above object, the present invention provides an electronic element cooling structure in which a heat generating electronic element is installed inside a housing, and the electronic element has one end of a small diameter and flexible heat pipe. together parts are arranged to be thermally exchanged, the other end of the heat pipe, the heat sink is thermally exchanged capable disposed further suction write unit for sucking air inside of said housing said heatsink it is characterized in that provided, and a fan for air to the outside of the front Symbol suction unit air housing has entered the heat sink from being provided.
[0012]
Therefore, according to the present invention, when the electronic element generates heat, first, the heat is transmitted to one end of the heat pipe. Then, the liquid-phase working fluid is heated and evaporated, and the working fluid vapor flows toward the end of the heat pipe container that is disposed in the heat sink having a low internal pressure, and the heat sink takes heat away. Condensate.
[0013]
When the fan is operated, air flows so as to pass through the heat sink, and the air further flows out of the housing. In that case, the heat of the electronic element held by the heat sink is carried to the outside of the housing together with the flowing air. Therefore, heat is not applied to the internal space of the housing, and the electronic element is cooled well.
[0014]
In this way, the heat of the electronic element, which is a heat generation source, is once collected in the heat sink via the heat pipe having a high heat transport capability, and then directly discharged from the housing to the outside. Not only is the capability high, but there is no risk of unnecessarily raising the temperature of other members provided in the housing.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Specific examples of the present invention will be described below with reference to the drawings. The example shown here is an example applied to cooling a CPU mounted on a notebook personal computer (hereinafter referred to as a personal computer). A personal computer case 5 corresponding to the housing of the present invention is a hollow container formed of a metal panel such as a plastic panel or a magnesium alloy. A top surface of the personal computer case 5 in FIG. 1 is provided with a display 6 that can be freely opened and closed within a predetermined range centered on a rotation shaft (not shown).
[0016]
A printed circuit board (not shown) is provided substantially horizontally near the bottom inside the personal computer case 5. A CPU 7 corresponding to the electronic device of the present invention is attached to the upper surface of the printed board in FIG. One end of the heat pipe 8 and the heat transfer block 9 are attached to the upper surface of the CPU 7. More specifically, as an example, a heat pipe 8 in which pure water is sealed as a working fluid inside a narrow hollow flat copper container is employed. In addition, this heat pipe 8 has flexibility and can bend the middle part of a container freely.
[0017]
On the other hand, the heat transfer block 9 is provided as necessary to promote heat transfer between the CPU 7 and the heat pipe 8, and is a plate-like body formed of copper or aluminum alloy as an example. Therefore, a concave portion that follows the container shape of the heat pipe 8 is formed on the lower surface in FIG. The heat transfer block 9 is fixed in close contact with the upper surface of the CPU 7 by an appropriate means (not shown) in a state where the heat pipe 8 is closely fitted in the recess. Therefore, the CPU 7 and the heat pipe 8 can transfer heat to each other.
[0018]
On the other hand, on the bottom of the personal computer case 5, as an example, a heat sink 10 having a structure in which a large number of flat plates (fins) are provided in parallel at a narrow interval is laid on the inner surface of an aluminum pipe having a rectangular cross section. And the other end part of the heat pipe 8 is attached to the upper surface part of this heat sink 10 along the lower surface of the container. The intermediate portion of the heat pipe 8 is appropriately bent so as to pass through a gap between parts (not shown) provided inside the personal computer case 5, so-called dead space. Further, the height of the heat sink 10 in the installed state is set to be larger than the height of the CPU 7, and therefore, the heat pipe 8 has an end portion provided on the CPU 7 at an end portion provided on the heat sink 10. Is located above.
[0019]
In addition, you may carry out heat insulation coating of the outer peripheral part of the intermediate location which does not contact CPU7 and the heat sink 10 among the heat pipes 8 as needed. If comprised in this way, the heat discharge | released to the internal space of the personal computer case 5 from a container during heat pipe operation | movement can be reduced.
[0020]
A small fan 11 is integrally attached to the opening end of the heat sink 10 on the side away from the CPU 7. More specifically, the fan 11 is, for example, a lower horizontal discharge type radial flow fan, and an opening portion on the suction portion 12 side is attached to an opening end of the heat sink 10 in an airtight state. On the other hand, the opening part of the discharge part 13 of the fan 11 is arrange | positioned in the vicinity of the exhaust hole (not shown) provided in the personal computer case 5. FIG. That is, when the fan 11 is operated, the air inside the PC case 5 enters the inside from the opening end of the heat sink 10 on the side close to the CPU 7 and faces the discharge portion 13 of the fan 11. Then, it is sent out through the exhaust hole.
[0021]
Next, the operation of the cooling structure for the electronic device configured as described above will be described. First, the fan 11 is operated. Then, the air in the personal computer case 5 passes through the inside of the heat sink 10 in the direction of the arrow, and flows out to the outside of the personal computer case 5 via the exhaust hole as it is. Such a flow of air naturally occurs until the fan 11 stops.
[0022]
On the other hand, when the CPU 7 generates heat due to energization associated with the use of the personal computer, the heat is transmitted to one end of the heat pipe 8 and the heat transfer block 9. In that case, since the outer periphery of the heat pipe 8 is covered with the heat transfer block 9, the heat of the CPU 7 is transmitted to the heat pipe 8 without waste, and the working fluid accumulated at the bottom of the container is heated. Evaporate. Therefore, the inner surface of the end portion attached to the heat transfer block 9 in the heat pipe 8 becomes the evaporation portion.
[0023]
The working fluid that has become vapor flows toward the end portion disposed in the heat sink 10 where both the internal pressure and temperature are low, and the heat sink 10 is deprived of heat and condenses. Therefore, the inner surface of this end portion of the heat pipe 8 becomes a condensing portion. As described above, since the heat pipe 8 is disposed in a state having a gradient, the operation mode thereof is the bottom heat mode, and the evaporation / condensation cycle of the working fluid is smoothly performed. As a result, the heat transport is performed. Ability increases. The working fluid that has been condensed and returned to the liquid phase travels through the inner surface of the container middle portion to the evaporating portion, where it is heated and evaporated again.
[0024]
On the other hand, the heat of the CPU 7 transmitted from the heat pipe 8 to the upper surface portion of the heat sink 10 is conducted to almost the entire area of the heat sink 10. As described above, air flows inside the heat sink 10 by the fan, and the heat of the CPU 7 held by the heat sink 10 is carried to the outside of the personal computer case 5 through the exhaust hole. That is, the heat of the CPU 7 is discharged to the outside of the personal computer case 5 together with air. Therefore, since heat does not go inside the personal computer case 5, overheating of the CPU 7 during use of the personal computer is prevented.
[0025]
As described above, since the heat of the CPU 7 is once collected in the heat sink 10 by the heat pipe 8 and directly discharged to the outside of the personal computer case 5, heat is not applied to the internal space of the personal computer case 5, and the conventional cooling structure In addition, the cooling capacity is further improved, and there is an advantage that excessive temperature rise of existing parts other than the CPU 7 is prevented.
[0026]
Further, in the cooling structure of this specific example, since heat transfer from the CPU 7 to the fan 11 is performed using the heat pipe 8, the CPU 7 is usually adjacent to the fan 11 which must be installed near the wall surface of the personal computer case 5. This is not necessary, and therefore the degree of freedom of layout of the CPU 7 inside the personal computer case 5 is improved. Further, since the heat pipe 8 is disposed in the dead space, the personal computer case 5 itself can be made smaller than the conventional cooling structure.
[0027]
In the above specific example, the cooling of the CPU of the notebook personal computer has been exemplified. However, the present invention is not limited to the above specific example, and is applied to, for example, an electronic device mounted on a desktop personal computer or a server. You can also. In addition, a flat container heat pipe was adopted, but instead of using a general circular cross-section container-shaped heat pipe, a U-shaped cross-section mounting groove is formed on the upper surface of the heat sink, You may comprise so that it may fit closely in the state which put the heat pipe along there.
[0028]
Furthermore, in the above specific example, instead of the lower horizontal discharge type radial flow fan, for example, an axial flow fan having a conventionally known configuration may be employed. Further, the heat sink and the fan need only be configured to communicate integrally with each other as a function thereof, and therefore, for example, a suction duct can be provided between them.
[0029]
【The invention's effect】
As is apparent from the above description, according to the present invention, one end of the heat pipe is disposed so as to be able to transfer heat to the electronic element, and a heat sink is disposed so as to be able to transfer heat to the other end of the heat pipe. In addition, since the fan is provided so that the suction portion is integrally communicated with the heat sink and air is supplied toward the outside of the housing, the cooling capability for the electronic element can be improved compared to the conventional case. Further, it is possible to prevent the temperature rise of components provided in the casing other than the electronic element.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a specific example of the present invention.
FIG. 2 is a schematic view showing a conventional heat pipe for cooling a personal computer.
[Explanation of symbols]
5 ... PC case, 7 ... CPU, 8 ... Heat pipe, 9 ... Heat transfer block, 10 ... Heat sink, 11 ... Fan, 12 ... Suction part.

Claims (1)

In the cooling structure of an electronic element in which an electronic element that generates heat is installed inside the housing,
To the electronic device, one end portion of the heat pipe is thermally exchanged direction end, the other end of the heat pipe, the heat sink is thermally exchanged capable disposed, further, the internal air of the housing electronic device suction write unit for inhalation, characterized in that fan the provided heat sink, and to the air toward the entering air before Symbol suction unit into the heat sink outside the housing is provided Cooling structure.

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