JP2001196777A - Forced air cooling for electronic circuits - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To perform forced air cooling of a device provided with a motherboard mounted with sub-modules in a frame and collectively air-cooled with an intake fan or an exhaust fan provided in the frame, the occurrence of uneven cooling and high efficiency. Cannot cool. SOLUTION: Sub-modules 11A to 11D mounted on a motherboard 12 are forcibly air-cooled individually by ducts covering outer peripheral portions of heat sinks and intake fans and exhaust fans at both ends thereof. The common exhaust duct 14
The air introduced from the exhaust port of the submodule is directly
3 Exhaust to the outside. A plurality of fans 15 </ b> A to 15 </ b> D are provided inside the common exhaust duct, and the air flow increases stepwise from the upstream to the downstream of the common exhaust duct by these fans.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced air cooling system in a frame provided with a mother board on which a plurality of electronic circuit sub-modules having a relatively large heat generation are mounted, and to the use of a relatively small-sized forced air cooling fan. To suppress the temperature rise in the frame,
The present invention relates to a forced air cooling device for an electronic circuit for efficiently cooling each sub-module individually in a frame.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional forced air cooling device in a frame. As a forced air cooling means for a frame 3 incorporating a motherboard 2 on which a plurality of sub-modules 1A to 1D are mounted, an intake fan 4 is provided on one side (or bottom) of the frame 3 and an exhaust fan is provided on the other side (or top). A fan 5 is provided. The sub-modules 1A to 1D are air-cooled by the intake air taken into the rack 3 by the intake fan 4, and the air whose temperature has increased by this cooling is exhausted to the outside by the exhaust fan 5.

[0003] Among the electronic circuit components mounted on each submodule, an electronic circuit component (LSI) that generates a relatively large amount of heat is used.
And power transistors, etc.) to enhance the heat dissipation effect by attaching a heat sink with heat dissipation fins.

[0004]

In the conventional forced air cooling system, in order to reliably discharge the heat generated in each sub-module by forced air cooling, it is necessary to secure a flow of air throughout the entire frame. For this reason, an intake fan and an exhaust fan having relatively large blowing capacity are required. Also,
The need to ensure airflow can limit the implementation of sub-modules and other modules.

In addition, in the case of forced air cooling in the whole frame, since the downstream side of the air flow path is affected by the air heated by the sub-modules on the upstream side, all the sub-modules mounted in the frame are uniformly distributed. Cooling requires a fan with a greater blowing capacity.

When the number of sub-modules mounted on the motherboard is large, the capacity of the intake and exhaust fans in the rack tends to be insufficient, and air stagnation occurs around the sub-modules in the rack. In some cases, the temperature of the intake air for cooling the submodule rises, and a sufficient cooling effect cannot be obtained.

An object of the present invention is to provide a rack containing a motherboard on which a plurality of sub-modules are mounted.
It is an object of the present invention to provide a forced air cooling device for an electronic circuit that can suppress a rise in temperature in a frame by using a relatively small-sized forced air cooling fan and efficiently cool each sub-module individually in the frame.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method in which sub-modules are forcibly air-cooled individually and heat generated by air-cooling of the sub-modules is directly exhausted to the outside of the frame. Equipped with exhaust duct. In addition, a plurality of small fans are provided in the common exhaust duct, and the air volume of each fan is increased stepwise from upstream to downstream so that smooth exhaust can be performed even when a large number of submodules are mounted. .

As described above, according to the present invention, even when the number of mounted sub-modules is large, the large-sized frame can be directly exhausted to the outside of the frame using the common exhaust duct, by using the common exhaust duct. A temperature rise of the intake air to the heat sink for cooling the sub-module can be avoided without the internal intake and exhaust fans, and an efficient forced air cooling device is provided.

[0010] A forced air cooling device for electronic circuits, in which a plurality of electronic circuit sub-modules are mounted on a motherboard and forcibly air-cooled in a frame accommodating the motherboard, is provided on an outer peripheral portion of each of the submodules. It has a plurality of forced air cooling means for individually forcibly cooling the sub-modules, and a plurality of intake ports connected to the exhaust ports of the respective forced air cooling means, and directly introduces air introduced from each intake port to a common exhaust duct. And a common exhaust duct means for exhausting to the outside of the frame.

The forced air cooling means includes a duct for guiding an air flow covering a heat sink for radiating heat generated from the sub-module, and an air intake for sucking the air for cooling the heat sink into the duct. A fan and an exhaust fan for exhausting the air after cooling the heat sink to the common exhaust duct are provided.

Further, the common exhaust duct means is provided with a plurality of fans inside the common exhaust duct, and each of these fans has a configuration in which the air volume increases stepwise from upstream to downstream of the common exhaust duct. It is characterized by.

[0013]

FIG. 1 is a block diagram of a forced air cooling apparatus showing an embodiment of the present invention, in which four electronic circuit sub-modules 1A to 1D are mounted on a motherboard 12 in a parallel arrangement. This is a case where the present invention is applied to an electronic circuit application device housed in the electronic device.

As shown in the enlarged view of FIG. 2, the submodules 11A to 11D have electronic circuit components mounted on a printed circuit board 21 and a heat sink for heat radiation above the electronic circuit components when forced air cooling is required. 22 are provided.

The outer periphery of the sub-module having such a configuration is covered with a cylindrical duct (not shown) for forming an air flow path along the direction of the radiation fins of the heat sink 22. At one end of the duct, an intake fan 23 for feeding cooling air to the heat sink 22 is provided. Also,
The other end of the duct is provided with an exhaust fan 24 for exhausting the air heated by the heat radiation of the heat sink. An exhaust outlet duct 25 is provided at the exhaust outlet of the exhaust fan 24.

Therefore, each sub-module is provided with a duct, an intake fan 23, an exhaust fan 24, and an exhaust port duct 25, so that each sub-module can be individually forcibly cooled. The rack 13 is provided with air inlets 13A to 13D at appropriate locations in order to obtain intake air from each of the sub-modules from the outside and to cool the entire rack naturally.

Returning to FIG. 1, the motherboard 12 is provided with a common exhaust duct 14 for exhausting air used for cooling each sub-module directly to the outside of the frame. The common exhaust duct 14 is provided with four intake ports 14A to 14D which are respectively connected to the exhaust port ducts 25 provided in the sub-modules 11A to 11D. In addition, common exhaust duct 1
The fourth common exhaust port 14E faces the outside of the frame 13.

Further, the common exhaust duct 14 is provided with four exhaust duct fans 15A to 15D in a common exhaust passage from each intake port 14A to 14D to the common exhaust port 14E.
The exhaust duct fans 15A to 15D are for equally exhausting the air used for cooling the sub-modules 11A to 11D to the outside of the frame. These fans 15A
The air blowing capacity of ~ 15D is determined according to the calorific value of the sub-module, but is relatively small because of individual air cooling.

The common exhaust duct 14 may be attached to the rack 13 instead of the motherboard. In this case, it is preferable in terms of assembling the apparatus that the exhaust port duct 25 of each sub-module can be attached to the intake port of the common exhaust duct 14 with one touch.

According to the above configuration, the air used for individual cooling of the four sub-modules 11A to 11D can be directly exhausted to the outside of the frame through one common exhaust duct 14, and is heated by the sub-modules. The air does not stay in the rack to increase the temperature of other electronic circuits and the like in the rack.

Here, the air blowing capacity of the fans 15A to 15D inside the common exhaust duct 14 will be described on the assumption that the heat generation amounts of the respective sub-modules are equal. The air volume of the first exhaust duct fan 15A located on the most upstream side of the common exhaust channel has the same air volume as the cooling fans 23 and 24. The second exhaust duct fan 15B on the downstream side is twice as large as the fan for cooling each sub-module, and the third exhaust duct fan 15C on the downstream side is three fans of the sub-module. The air volume is doubled, and the fourth exhaust duct fan 15D located at the most downstream has an air volume that is four times that of each submodule cooling fan.

As described above, by increasing the air blowing capacity of the fan in the common exhaust duct in a stepwise manner in accordance with the calorific value of the submodule, only one common exhaust duct can exhaust all the submodules under the same condition. This allows smooth exhaust while appropriately forcibly cooling each sub-module.

FIG. 2 shows another embodiment of the present invention. In this case, eight sub-modules 1
1A to 11H are mounted in tandem and the two sub-modules divided into two groups are shared, and two common exhaust ducts 1 are used.
This is a case where exhaust is performed from 6A and 16B.

The two common exhaust ducts 16A and 16B collect the exhaust from the four sub-modules, respectively.
As in the case of the above-described embodiment, by disposing fans 17A to 17H having a blowing capacity according to the amount of heat generated by the sub-modules in the common exhaust duct, the air used for forced air cooling of each sub-module can be smoothly discharged. It can be exhausted outside the frame.

[0025]

As described above, according to the present invention,
In a rack that houses a motherboard with a large number of sub-modules, heat generated in each sub-module is directly exhausted to the outside of the rack without being discharged to the inside of the rack. This eliminates the uneven distribution of temperature, such as high temperatures in the downstream area, and allows all modules to use the same temperature air for cooling the heat sink, realizing an ideal air cooling system even when the number of mounted modules is large. it can.

In addition, since the common exhaust duct is provided with a fan whose air volume increases stepwise as going from upstream to downstream, the exhaust air of the plurality of sub-modules is exhausted outside the common exhaust duct. Compared to the case where the entire inside of the frame is forcibly air-cooled with a large fan,
Cooling can be efficiently performed with a small fan, and a compact forced air cooling system can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a forced air cooling device for an electronic circuit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of forced air cooling means of a submodule in the embodiment.

FIG. 3 is a configuration diagram of a forced air cooling device of a device in which eight submodules are mounted.

FIG. 4 is a configuration diagram of a conventional forced air cooling device for an electronic circuit.

[Explanation of symbols]

 11A-11H, 21 Submodule 12 Motherboard 13 Frame 14 Common exhaust duct 15A-15D, 17A-17H Exhaust duct fan 22 Heat sink 23 Intake fan 24 Exhaust fan 25 Exhaust port

Continuation of front page (72) Inventor Naoaki Yamanaka 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation F-term (reference) 3L044 AA04 BA06 CA14 DA01 FA03 KA03 KA04 5E322 AA01 BA01 BA03 BA04 BB03 EA05

Claims (3)

[Claims] 1. A forced air cooling device for electronic circuits, wherein a plurality of electronic circuit sub-modules are mounted on a motherboard, and forcibly air-cooled in a frame accommodating the motherboard, provided on an outer peripheral portion of each of the submodules. A plurality of forced air cooling means for individually forcibly cooling each sub-module, and a plurality of air intake ports connected to the exhaust port of each of the forced air cooling means, and air introduced from each air inlet to a common exhaust duct. A forced air cooling device for an electronic circuit, comprising: common exhaust duct means for exhausting air directly to the outside of the frame. 2. The forced air cooling means includes a duct for guiding an air flow covering a heat sink for radiating heat generated from the sub-module, and an intake for sucking the air for cooling the heat sink into the duct. 2. The forced air cooling device for an electronic circuit according to claim 1, further comprising: a fan; and an exhaust fan configured to exhaust air after cooling the heat sink to the common exhaust duct. 3. 3. The common exhaust duct means includes a plurality of fans provided inside the common exhaust duct, and each of the fans has a configuration in which the air volume increases stepwise from upstream to downstream of the common exhaust duct. The forced air cooling device for an electronic circuit according to claim 1 or 2, wherein: