JP2012160533A - Cooling mechanism and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cooling mechanism which enables noise reduction and power saving of an electronic apparatus.SOLUTION: In a cooling mechanism, components 11 to 13 including a high heat generating component 5, which compose an electronic apparatus, are mounted on a circuit board 9, and the circuit board 9 is fixed at a substantially central part of a case in the height direction by using a substrate fixing component 10. Passages 14, 15 are respectively formed on the component mounting surface of the circuit board 9 and the opposite side of the component mounting surface of the circuit board for flowing cooling air generated by cooling fans. The cooling mechanism further includes: a heat receiving part 6 contacting with the high heat generating component 5, heat transfer parts 7 connecting with the heat receiving part 6 and transferring heat to the opposite side of the component mounting surface of the circuit board, and a heat radiation part 8 connecting with the heat transfer part 7 and provided in the passage 15 on the opposite side of the component mounting surface of the circuit board.

Description

  The present invention relates to a cooling mechanism and an electronic apparatus, and more particularly to a cooling mechanism suitable for use in an electronic apparatus including an information processing apparatus and an electronic apparatus using the cooling mechanism.

  2. Description of the Related Art In recent years, semiconductors used in electronic devices, particularly semiconductor components represented by a CPU of an information processing apparatus, have been rapidly evolving, and are becoming higher in density and higher in heat generation. Along with this, electronic devices such as information processing devices using semiconductor components have increased the number of mounted cooling fans or the number of rotations for cooling electronic components including those semiconductor components. Noise and power consumption tend to increase.

  In general, electronic devices including an information processing apparatus as described above are often installed in offices and the like, and thus there is a strong demand for low noise by users. There is a strong demand for power saving from the viewpoint. In order to meet the demands of these users, development of high-efficiency cooling technology is required, and development of high-efficiency fans and high-performance heat sinks have been performed.

  FIG. 4 is a side view showing a configuration example of an electronic device having a cooling mechanism according to the prior art that performs main heat dissipation of the heat generating element in a flow path including a circuit board surface on which a heat generating element such as a semiconductor is installed, and FIG. 4 is a top view showing a configuration example of the top surface of the electronic device shown in FIG. 4, and FIG. 6 is a bottom view showing the bottom surface of the electronic device shown in FIG. 4. Hereinafter, referring to FIGS. Next, the cooling of the electronic device will be described.

  As shown in FIG. 4, an electronic device having a cooling mechanism according to the prior art has a semiconductor component part (hereinafter simply referred to as a heating element 5) such as a CPU on a circuit board 9, and the heat generation amount is as high as the CPU. The component 11, the component 12, and the component 13, which are not many, are arranged and sequentially mounted from one side of the circuit board 9, and the circuit board 9 on which these are mounted is housed in a case 29. A heat sink 16 is attached to the top of the heating element 5, and cooling air is supplied from the outside of the case 29 to the outside of the circuit board 9 on the side where the heating element 5 of the circuit board 9 is mounted. A cooling fan 4 is provided.

  In the example of the electronic apparatus having the cooling mechanism according to the prior art shown in FIGS. 4 to 6, two sets of the heating element 5 and the parts 11 to 13 are mounted on the same circuit board 9 as shown in FIG. In the illustrated example, two cooling fans 4 are also provided for each set described above. Further, in this prior art, since all the parts constituting the electronic device are mounted on the upper surface of the circuit board 9, nothing is provided on the lower surface as shown in FIG. There is only a slight gap between the substrate 9 and the bottom surface of the case 29.

  4 to 6, the heating device 5, the component 11, the component 12, and the component 13 are sequentially arranged and mounted on the circuit board 9, and the side of the circuit board 9 on which the heating element 5 is mounted. Since the cooling fan 4 for taking in cooling air is provided outside the circuit board 9, the cooling air flow path 17 including the board surface of the circuit board 9 with the heating element 5 as the most upstream is formed. become. For this reason, heat from the heating element 5 through the heat sink 16 is radiated into the flow path 17. As a result, the temperature in the flow path 17 rises, and the ambient temperature of the parts 11, 12 and 13 downstream of the heating element 5 and the temperature of the exhaust 18 also rise. Thereby, even when there is no problem in cooling of the heating element 5, it may be difficult to cool the part 11, the part 12, and the part 13, and cooling of the part 11, the part 12, and the part 13 downstream of the heating element 5 may be difficult. It will be a concern. In order to eliminate the concern about the cooling of the parts 11, 12 and 13 downstream of the heating element 5, the rotation speed of the cooling fan 4 may be increased. Electric power will increase.

  In the prior art as described above, the temperature of the intake air 1 to the cooling fan 4 is 35 ° C., the temperature rise of the flow path 17 by the heating element 5 and the heat sink 16 is 35 ° C., the surface of the component 11 and the ambient temperature. Considering the case where the temperature rise of the component 11 is 15 ° C. and the specification maximum temperature of the component 11 is 80 ° C., the ambient temperature of the component 11 is 35 ° C. 70 ° C., 85 ° C. obtained by adding 15 ° C. temperature rise between the component surface and ambient temperature of the component 11 becomes the temperature of the component 11 and exceeds the maximum specification temperature of 80 ° C. Therefore, in this case, it is necessary to increase the rotational speed of the cooling fan 4 to increase the flow rate of the cooling air in the flow path 17 so that the temperature of the component 11 does not exceed the maximum specification temperature of 80 ° C.

  For example, a technique described in Patent Document 1 is known as a conventional technique related to cooling of electronic equipment related to the present invention.

Japanese Unexamined Patent Publication No. 2000-277756

  Conventional electronic equipment that employs an air cooling system using a cooling fan causes an increase in cooling air temperature due to heat dissipation from a heat generating element such as a semiconductor component such as a CPU, and the same substrate surface downstream of the heat generating element. It may affect the cooling of other electronic components mounted on the top. Further, even when the amount of air that can cool the heating element is secured by the high-efficiency cooling fan and the high-performance heat sink, if the rise in the air temperature is large, it is sometimes difficult to cool the downstream components. Conventionally, in such a case, it has been possible to increase the air volume by increasing the number of rotations of the cooling fan, etc., and to cool the components on the downstream side. However, such a method increases fan noise and fan power consumption. As a result, noise reduction and power saving could not be achieved.

  An object of the present invention is to provide a cooling mechanism capable of efficiently cooling an electronic device without increasing fan noise and fan power consumption in view of the problems of the prior art as described above, and the use of the cooling mechanism. Is to provide an electronic device.

  According to the present invention, the object is to provide a cooling mechanism in an electronic device having an air-cooling cooling mechanism using a cooling fan, the component mounting surface side of a circuit board on which a component including a high heat generating component constituting the electronic device is mounted, and the circuit A flow path for flowing cooling air from the cooling fan is formed on the opposite side of the component mounting surface of the board, and a heat receiving portion that is in contact with the high heat generating component, and a component mounting surface of the circuit board that is connected to the heat receiving portion This is achieved by including a heat transport section that transports heat to the opposite surface side of the circuit board and a heat radiating section that is connected to the heat transport section and provided in the flow path on the opposite surface side of the component mounting surface of the circuit board. .

  According to the present invention, it is possible to efficiently cool an electronic device without increasing fan noise and fan power consumption.

It is a side view which shows the structural example of the electronic device with a cooling mechanism by one Embodiment of this invention. It is a top view which shows the structural example of the upper surface of the electronic device shown in FIG. It is a bottom view which shows the lower surface of the electronic device shown in FIG. It is a side view which shows the structural example of the electronic device with the cooling mechanism by the prior art which performs the main heat dissipation of a heat generating body in the flow path containing the circuit board surface in which the heat generating body of components, such as a semiconductor, was installed. FIG. 5 is a top view illustrating a configuration example of a top surface of the electronic device illustrated in FIG. 4. It is a bottom view which shows the lower surface of the electronic device shown in FIG. It is the side view explaining the detailed structure of the thermal junction part which connects the heat receiving part and heat transport part in embodiment of this invention, and the enlarged view of a thermal junction part. It is the front view and side view which show the structural example of the blade server when the electronic device with the cooling mechanism by embodiment of this invention is assumed to be a blade module.

  Hereinafter, embodiments of a cooling mechanism and an electronic device according to the present invention will be described in detail with reference to the drawings. The embodiment of the present invention described here uses a cooling part having a heat receiving part, a heat transport part, and a heat radiating part. The heat receiving part is brought into contact with a heating element such as a semiconductor part having a large heat generation amount and connected to the heat receiving part. The heat transport part transports heat to the opposite side of the circuit board on which the heating element is installed, and the heat dissipation part connected to the heat transport part in the cooling air flow path formed on the opposite side of the circuit board dissipates heat. In this way, main heat dissipation of the heating element is performed on the side opposite to the circuit board surface on which the heating element is installed.

  1 is a side view showing a configuration example of an electronic device having a cooling mechanism according to an embodiment of the present invention, FIG. 2 is a top view showing a configuration example of an upper surface of the electronic device shown in FIG. 1, and FIG. 3 is shown in FIG. It is a bottom view which shows the lower surface of an electronic device.

  The electronic apparatus having the cooling mechanism according to the embodiment of the present invention shown in FIGS. 1 to 3 has the heating element 5 and the components 11 to 13 mounted on the same circuit board 9 as described in the prior art. Two sets of such heating elements 5 and parts 11 to 13 are mounted, and two cooling fans 4 are provided for each of the above-described sets in the illustrated example. In the embodiment of the present invention, all the parts constituting the electronic device are mounted on the upper surface of the circuit board 9, and the circuit board 9 is substantially at the center in the height direction of the case 29 using the board fixing part 10, and The cooling fan 4 is attached at a position that is the center height. The board fixing component 10 may be a plate-like member having substantially the same size as the inner dimension of the case 29, or a frame-like member having only a peripheral portion of the plate-like member.

  In addition, a cooling component having a heat receiving portion 6, a heat transport portion 7, and a heat radiating portion 8 is attached to the heating element 5. The cooling component includes a heat receiving unit 6 that is brought into contact with the heating element 5, a heat transport unit 7 that guides the heat received from the heating element 5 to the opposite side of the circuit board 9, and a circuit coupled to the heat transport unit 7. The heat radiating portion 8 is provided on the opposite surface side of the substrate 9, and the heat received from the heating element 5 by the heat receiving portion 6 is radiated from the heat radiating portion 8 provided on the opposite surface side of the circuit board 9. I have to.

  The electronic device according to the embodiment of the present invention having the above-described configuration is attached to a position where the circuit board 9 is approximately at the center in the height direction of the case and the center height of the cooling fan 4 using the board fixing component 10. Therefore, the flow path of the cooling air by the cooling fan 4 is divided by the circuit board 9 into the flow path 14 on the upper side of the board and the flow path 15 on the lower side of the board. That is, a flow path 14 including the same substrate surface on which the heating element 5 and the components 11, 12 and 13 downstream of the heating element are mounted, and the flow on the opposite surface formed through the substrate 9 and the substrate fixing component 10. A path 15 is formed. In the above-described embodiment of the present invention, the heat from the heating element 5 is radiated to the flow path 15 from the heat radiation portion 8 provided on the opposite surface side of the circuit board 9.

  Thereby, the temperature rise by the heat generating body 5 of the flow path 14 containing the heat generating body 5 and the circuit board surface in which other components were installed downstream of the heat generating body 5 can be avoided.

  In the embodiment of the present invention as described above, it is assumed that the physical property values of the heating element 5 and the component 11 and the air volume of the cooling fan 4 are the same as those of the prior art described above, and the circuit board 9 and the board fixing component 10. It is assumed that the air volume in the flow path 14 with the component 11 is reduced to one third of the air volume in the flow path 17 in the case of the prior art by dividing the flow path. The flow rate of the flow path 14 is assumed to be 1/3 instead of 1/2. The flow path 14 is resistant to the heat flow of the heating element 5 and the components 11 to 13 mounted on the circuit board 9. In contrast, the heat-dissipating member has a plate-like fin that has less resistance to airflow than the members such as the heating element 5 and the components 11 to 13 in the flow path on the back surface side of the circuit board 9. This is because the part 8 is only arranged. In this case, the ambient temperature of the component 11 is 35 ° C. due to the temperature of the intake air 1 of 35 ° C., and the temperature rise between the component surface of the component 11 and the ambient temperature is reduced to one third, and the temperature is 26 ° C. 61 ° C. added with the above becomes the temperature of the part 11, which satisfies the maximum specification temperature of 80 ° C. Therefore, in the embodiment of the present invention, it is not necessary to increase the rotational speed of the cooling fan 4, and cooling can be performed efficiently while reducing fan noise and fan power consumption.

  FIG. 7 is a side view for explaining the detailed structure of the thermal joint part connecting the heat receiving part 6 and the heat transport part 7 in the embodiment of the present invention and an enlarged view of the thermal joint part.

  As shown in FIG. 7, the joint convex portion 19 is coupled to the heat receiving portion 6. The joint projection 19 is made of a highly heat conductive material such as a heat pipe connected to the heat receiving portion 6 of the cooling component, is provided through the inside of the heat receiving portion 6, and extends downward from the side of the heat receiving portion 6. Is bent. In addition, the heat transport portion 7 described above is connected to a tubular joint concave portion 20 formed of a material having excellent thermal conductivity such as copper into which the above-described joint convex portion 19 can be inserted, and the joint concave portion 20. It is comprised by the junction recessed part 21 using high heat conductive materials, such as a heat pipe.

  The thermal joint shown in FIG. 7 is configured to mechanically and thermally join the above-described joint convex portion 19 and the tubular joint concave portion 20. The joint recess 21 using a high thermal conductivity material such as a heat pipe connected to the joint recess 20 is opposite to the circuit board surface on which the heating element 5 is mounted via the circuit board 9 and the board fixing component 10. Are connected to the heat dissipating section 8. In order to achieve both thermal conductivity and easy attachment / detachment, such a thermal bonding portion has a bonding convex portion 19 in a state where a thermal conductive material such as silicon grease is applied to the bonding convex portion 19 or the tubular bonding concave portion 20. And the tubular joint recess 20 are joined, and the heating element 5 and the heat receiving part 6 are fixed in thermal contact with each other.

  FIG. 8 is a front view and a side view showing a configuration example of a blade server when an electronic apparatus having a cooling mechanism according to an embodiment of the present invention is a blade module.

  As shown in FIG. 8A, the blade server shown in FIG. 8 is configured by mounting a plurality of blade modules, four blade modules 22 to 25 in the illustrated example, on the blade server housing 28 from the upper stage. As shown in FIG. 8B, a backplane 27 and a fan unit 26 are provided on the back side of the blade modules 22-25. The inside of each of the blade modules 22 to 25 is similar to the case shown in FIG. 1 and uses the circuit board 9 and the board fixing component 10 so that the cooling air flow path is the upper surface side flow path and the lower surface of the circuit board 9. It is divided into side channels. That is, the inside of each blade module 22-25 is the opposite surface side formed through the flow path 14 including the substrate surface on which the heating element 5 and the components 11-13 are mounted, and the circuit board 9 and the substrate fixing component 10. The flow path 15 in which the heat radiating portion 8 is disposed is formed. The cooling air is taken in from the front side of the blade server housing 28 as the intake air 1, is sucked into the fan unit 26 through the backplane 27 as the exhaust 2 and exhaust 3 through the flow paths 14 and 15, and the blade server It is discharged outside the housing 28. Thereby, the temperature rise of the flow path 14 by the heat generating body 5 can be avoided.

  According to the embodiment of the present invention described above, without providing a new space outside the electronic device casing, using a cooling fan having the same capability as in the case of the prior art, without increasing the rotation speed of the electronic device. Efficient cooling can be performed while achieving low noise and power saving.

DESCRIPTION OF SYMBOLS 1 Intake 2 Exhaust 3, 18 Exhaust 4 Cooling fan 5 Heat generating body 6 Heat receiving part 7 Heat transport part 8 Heat radiating part 9 Circuit board 10 Board | substrate fixing | fixed part 11-13 Parts 14, 15, 17 Flow path 16 Heat sink 19 Joint convex part 20 Tubular joint recess 21 Joint recess 22-25 Blade module 26 Fan unit 27 Backplane 28 Blade server housing 29 Case

Claims (4)

In a cooling mechanism in an electronic device having an air cooling mechanism by a cooling fan,
Forming a flow path for flowing cooling air from the cooling fan on the component mounting surface side of the circuit board on which the component including the high heat generating component constituting the electronic device is mounted, and on the side opposite to the component mounting surface of the circuit board;
A heat receiving part brought into contact with the high heat generating component, a heat transporting part connected to the heat receiving part and transporting heat to the opposite side of the component mounting surface of the circuit board, and connected to the heat transporting part of the circuit board A cooling mechanism comprising: a heat dissipating part provided in a flow path on the opposite side of the component mounting surface.   The cooling mechanism according to claim 1, wherein a detachable thermal joint is provided in a path of a heat transport unit that connects the heat receiving unit and the heat radiating unit. In an electronic device having an air-cooling cooling mechanism with a cooling fan,
The cooling mechanism causes cooling air to flow from the cooling fan to a component mounting surface side of a circuit board on which a component including a highly heat-generating component constituting the electronic device is mounted, and to a surface opposite to the component mounting surface of the circuit board. A flow path is formed,
A heat receiving part brought into contact with the high heat generating component, a heat transporting part connected to the heat receiving part and transporting heat to the opposite side of the component mounting surface of the circuit board, and connected to the heat transporting part of the circuit board An electronic device comprising: a heat dissipating part provided in a flow path on the side opposite to the component mounting surface.   The electronic device according to claim 3, wherein a detachable thermal joint is provided in a path of a heat transport unit that connects the heat receiving unit and the heat radiating unit.