JPH07111392A - Electronic device cooling structure - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a cooling structure for an electronic device, which efficiently cools a planar mounting part on which a large number of chips with high heat generation are mounted, and at the same time, can also cool a bookshelf part. The purpose is to do. According to the present invention, in an electronic device for forcibly air-cooling together a bookshelf mounting shelf 2 and a planar mounting shelf 5 that are mixedly mounted on a rack 9 and mounted in the planar mounting shelf 5. The air guide 1 (17) is provided on the side surface parallel to the direction in which the cooling air flows through the multi-chip modules 3A and 3B on the planar mounting substrate 4 on which the multi-chip modules 3A and 3B are mounted.
Further, an air guide 2 (18) is provided close to the upper surfaces of the multi-chip modules 3A and 3B, and the air guide 2 (18) has a wider front side with respect to the flow of cooling air. It is characterized by having done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for an electronic device capable of cooling a device that generates a large amount of heat with a high capacity by increasing the speed and density of the electronic device system.

[0002]

2. Description of the Related Art FIG. 7 is a plan view of a bookshelf mounting shelf in which a plurality of electronic circuit packages each having a plurality of chips are mounted in a rack-like shelf, and at least one multichip module is mounted. FIG. 3 is a diagram showing a conventional mounting structure in which one or more mounting shelves are mixed and mounted on a rack (cabinet), and are collectively cooled by a cooling fan. Here, 1 is an electronic circuit package on which a large number of chips are mounted, 2 is a bookshelf mounting shelf for mounting a plurality of electronic circuit packages 1 in a rack shape, 3 is a multi-chip module, 4
Is a planar mounting board for mounting at least one multi-chip module 3, 5 is a planar mounting shelf for accommodating the planar mounting board (here, it has the same external dimensions as the bookshelf mounting shelf), 6 Is an electronic circuit package insertion / extraction lever for inserting or removing the electronic circuit package 1 into / from the shelf 2, 7 is an alarm lamp provided in the electronic circuit package 1, and 8 is at least one or more mounted on the top and bottom of the rack 9. A fan unit composed of a fan, a rack 9 forming an electronic device, and a rack lamp 10 are shown.

FIG. 8 is a perspective view showing the range B shown in FIG. 7, in which 11 is an interface board mounted on the back side of the planar mounting board 4 in a bookshelf shape, and 12 is the interface board 11. , 13 is a heat sink provided on the back surface of the multi-chip module 3, 14 is a fan mounted on the fan unit 8, and 15A, 15B, and 15C are cooling air flow directions.

[0004]

In the structure shown in FIGS. 7 and 8, the cooling air passing through the bookshelf mounting shelf 2 is used to mount a high-temperature multi-chip mounted on the planar mounting shelf 5. It has a structure for cooling the module 3. As is clear from FIG. 8, since a sufficient space is provided above the high heat-generating multi-chip module 3 mounted on the planar mounting shelf 5, the cooling air is blown to the high-heat-generating multi-chip module 3. If they flow in a concentrated manner, sufficient cooling is possible. However, since the multi-chip module 3 has a high heat generation, the heat sink 13 is generally mounted, and as a result, the heat sink 1
The fluid resistance of No. 3 is significantly increased. Therefore, since the space above the multi-chip module 3 that generates a high amount of heat has a small fluid resistance, the cooling air flows through the space above the multi-chip module 3 where the fluid resistance is low, resulting in difficulty in cooling the multi-chip module 3. There was a problem that became.

On the other hand, when the heat sink 13 is not provided in the multi-chip module 3, it is possible to effectively flow the cooling air over the multi-chip module 3, but generally the thermal resistance is 1 / (average heat transfer coefficient). As is clear from the definition of) / (heat radiation area), the heat radiation area is remarkably reduced due to the absence of the heat sink 13, and as a result, the thermal resistance is increased. Therefore, there is a problem that the high heat generation multi-chip module 3 cannot be cooled.

Further, when the bookshelf mounting shelf 2 is mounted on the flat mounting shelf 5 and is air-cooled collectively, the multi-chip module 3 having a high heat generation is used.
Since it can only be cooled with a small amount of cooling air, the air temperature after cooling the multi-chip module 3 becomes extremely high, and this is guided to the upper bookshelf mounting section, so that the upper bookshelf mounting shelf 2
In addition, since extremely high temperature cooling air flows through the electronic circuit package 1 mounted on the upper position where the multichip module 3 is mounted, there is a problem that the allowable power consumption thereof is significantly reduced. In other words, there is a problem that the mixed mounting condition with the planar mounting shelf is considerably limited.

The present invention has been made in view of the above circumstances, and one of the advanced mounting techniques such as multi-chip module mounting and planar mounting, which is associated with an increase in the exchange processing amount, such as a switch unit used in a communication device. In the electronic device that is adopted as a part of the electronic device and mixed with the conventional bookshelf mounting, the electronic device that efficiently cools the planar mounting part on which many chips with high heat generation are mounted and also enables cooling of the bookshelf part at the same time. It is intended to provide a cooling structure of.

[0008]

In order to achieve the above object, a cooling structure for an electronic device according to the present invention has a plurality of electronic circuit packages each having a plurality of chips mounted on a rack-shaped shelf. One or more shelves for mounting bookshelves and one or more plane mounting shelves on which at least one or more multi-chip modules are mounted are mixed and mounted on a rack (cabinet), and at least one rack is mounted on the rack. In a fan unit configured using a cooling fan, in the electronic device for forcibly air cooling the bookshelf mounting shelf and the planar mounting shelf together, the multi-chip mounted in the planar mounting shelf Place the module on a flat mounting board in the direction in which cooling air flows through the multi-chip module. The air guide 1 is provided on the side surface of the multi-chip module, and the air guide 2 is provided close to the upper surface of the multi-chip module, and the air guide 2 has a wider front side with respect to the flow of cooling air. West,
Further, the greatest feature is that the air guide 3 is provided close to the upper surface side of the multi-chip module.

As a result, the flow of the cooling air can be forcibly guided to the heat sink provided on the back surface of the multi-chip module having a high fluid resistance, so that the cooling air can effectively flow to the multi-chip module. . As a result, as shown in the section of the prior art, it is possible to improve the heat transfer coefficient because the wind speed can be improved, and it is possible to significantly reduce the thermal resistance because the heat dissipation area can be sufficiently taken. It is significantly different from the prior art in that it can be increased.

Further, since the air guide 2 has a wider front side with respect to the flow of the cooling air, it is possible to introduce cool cooling air to the multi-chip module mounted on the downstream side. Becomes Generally, the junction temperature T of the chip mounted on the multi-chip module
j is represented by Tj = Ta + Rj−a × P. Here, Ta is the air temperature, Rj-a is the thermal resistance from the air to the junction, and P is the power consumption of the chip.

As described above, guiding cold air is equivalent to lowering Ta, while Tj has a constant temperature, so that the power consumption of the chip can be increased, and thus the multichip module 3 can be used. The difference from the prior art is that the permissible power consumption can be increased.

As another feature of the present invention, for the multi-chip module mounted on the downstream side,
This is because the air guides 4 and 5 are provided so that the frontage becomes wider toward the downstream side with respect to the flow of the cooling air.

For this reason, when the bookshelf mounting shelf is mixedly mounted on the upper surface of the planar mounting shelf on which the multichip module is mounted, a uniform flow rate is applied to each electronic circuit package mounted on the bookshelf mounting shelf, and The point that the cooling air having a uniform temperature can be sent is significantly different from the conventional technology.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a bookshelf mounting shelf 2 in which a plurality of electronic circuit packages 1 each having a plurality of chips mounted therein are mounted in a rack-like shelf, and at least one shelf.
According to the present invention, one or more shelves for planar mounting, each of which has one or more multi-chip modules 3A and 3B, are mixed and mounted on a rack (cabinet) 9 and are collectively cooled by a fan unit 8. FIG. 2 is a mounting structure diagram showing a first embodiment, and FIG. 2 is a sectional view taken along the line AA of FIG. 1. Here, 1 is an electronic circuit package on which a large number of chips are mounted, 2 is a bookshelf mounting shelf for mounting a plurality of electronic circuit packages 1 in a rack shape, 3
A and 3B are multi-chip modules, 4 is a plane mounting board for mounting the multi-chip modules 3A and 3B,
Reference numeral 5 is a plane mounting shelf for accommodating a plane mounting board (here, it has the same external dimensions as the bookshelf mounting shelf), 6 is an electronic circuit package 1 and a shelf 2
Lever for inserting / removing an electronic circuit package for inserting / removing into / from the unit, 7 an alarm lamp provided in the electronic circuit package 1, 8 a fan unit mounted on the top and bottom of a rack 9 and composed of at least one fan, Reference numeral 9 is a rack constituting an electronic device, 10 is a rack lamp, 16A, 16B, and 1
6C is the flow direction of the cooling air, 17 is the air guides 1, 18
Indicates an air guide 2 and 19 indicates an air guide 3, respectively.

FIG. 3 is a perspective view of the illustrated range B shown in FIG. 1. 11 is an interface board mounted on the back side of the planar mounting board 4 in a bookshelf shape, and 12 is the interface board 11. Electronic components mounted on the fan unit, 14 is a fan mounted on the fan unit 8, 15
A and 15C respectively represent the flow directions of the cooling air.

In this embodiment, the multichip module 3 is used.
This is an example in which two A and 3B are mounted on the planar mounting substrate 4,
Air guide 1 (17) on the side of the multi-chip module
And the air guide 2 (18) is also provided on the upper surface side of the multi-chip module.
(18) is configured as an air guide whose opening is wider toward the upstream side with respect to the flow of cooling air, and further, the air guide 3 (is provided between the air guide 2 (18) and the upper surface of the multichip module 3A. 19) is provided. Therefore, cool air from the downstream is directly introduced to the multi-chip module 3A located on the upstream side, while the air guide 2 is introduced to the multi-chip module 3B located on the downstream side.
Since the cold air passing through the gap between the air guide 3 and the air guide 3 can also be guided, the cooling air temperature can be lowered and the air wind speed can be increased. Allowable power consumption can be increased.

FIG. 4 is a characteristic diagram qualitatively showing the above-mentioned effects. The horizontal axis represents the mounting position of the multichip module, and the vertical axis represents the air temperature in the rack. The air guide 1 (1
By providing 7), a sufficient air flow can be guided, and the downstream multi-chip module 3B can guide cool cooling air and can increase the wind speed, so that it is almost close to the multi-chip module 3A. The temperature inside the rack can be obtained.

FIG. 5 is a rack mounting view showing a second embodiment according to the present invention, and FIG. 6 is a sectional view taken along the line AA of FIG.
Here, 20 indicates the air guide 4, and 21 indicates the air guide 5, respectively.

The present embodiment shows an effective means when the bookshelf mounting shelf 2 is mixedly mounted on the upper surface of the plane mounting shelf 5, and the multichip module mounted on the downstream side is shown. For 3B, the air guide 4 (20) and the air guide 5 (21) are provided in a structure in which the frontage becomes wider toward the downstream side with respect to the flow of the cooling air.

In this case, the multichip module 3A,
When the bookshelf mounting shelf 2 is mixedly mounted on the upper surface of the planar mounting shelf 5 on which 3B is mounted, each electronic circuit package 1 mounted on the bookshelf mounting shelf 2 has a uniform flow rate and a uniform temperature. Can send cooling air. Therefore, the planar mounting section and the bookshelf mounting section can be easily mixedly mounted.

In the above example, the case where the plane mounting shelf 5 in which the interface board 11 is mounted in a bookshelf mounting state is used on the back surface side of the plane mounting board 4 is used as the plane mounting section. Needless to say, it is also effective to use a plane mounting shelf consisting of the plane mounting substrate 4 only.

As described above, in the present embodiment, a bookshelf mounting shelf 2 in which a plurality of electronic circuit packages 1 each having a plurality of chips mounted therein are mounted in a rack-shaped shelf, and at least one or more are mounted. A shelf 5 for planar mounting on which the multi-chip modules 3A and 3B are mounted,
One or more shelves are mixed and mounted on the rack 9, and a fan unit 8 configured by using at least one cooling fan 14 on the rack 9 is used for the bookshelf mounting shelf 2 and the planar mounting shelf. In the electronic device for forced air cooling of 5 and 5 together, the multi-chip modules 3A and 3B are mounted on the plane-mounting board 4 on which the multi-chip modules 3A and 3B are mounted, which are mounted inside the plane-mounting shelf 5. The air guide 1 (17) is provided on the side surface parallel to the direction in which the cooling air passes through
Further, an air guide 2 (18) is provided close to the upper surfaces of the multi-chip modules 3A and 3B, and the air guide 2 (18) has a wider front side with respect to the flow of cooling air. The biggest feature is that

With this arrangement, the cooling air flows 16A to 16C can be forcibly guided to the heat sinks provided on the back surfaces of the multi-chip modules 3A and 3B having high fluid resistance. It becomes possible to flow cooling air. As a result, there is an advantage that the allowable power consumption of the multi-chip modules 3A and 3B can be significantly increased.

Further, since the air guide 2 (18) has a wider front side with respect to the flow of the cooling air, the multi-chip module 3B mounted on the downstream side is supplied with cool cooling air. It is possible to lead. Therefore, there is an advantage that the allowable power consumption of the multi-chip module 3B mounted on the downstream side can be increased.

Further, as another feature of the present invention, for the multi-chip module 3B mounted on the downstream side, the air guide 4 (20) is widened toward the downstream side with respect to the flow of cooling air. There is an advantage in providing the air guide 5 (21).

Therefore, the multi-chip modules 3A, 3
When the bookshelf mounting shelf 2 is mixedly mounted on the upper surface of the planar mounting shelf 5 in which B is mounted, each electronic circuit package 1 mounted on the bookshelf mounting shelf 2 is cooled at a uniform flow rate and at a uniform temperature. It has the advantage of sending in air. Therefore, there is an advantage that the plane mounting section and the bookshelf mounting section can be easily mixedly mounted.

[0028]

As described above, according to the present invention, some advanced mounting techniques such as multi-chip module mounting and flat mounting are applied in accordance with an increase in the amount of exchange processing such as a switch unit used in communication equipment. In an electronic device that has been adopted for the mixed use with the conventional bookshelf mounting, the electronic device that efficiently cools the flat mounting part on which many chips with high heat generation are mounted and also enables cooling of the bookshelf part at the same time. A cooling structure can be provided.

[Brief description of drawings]

FIG. 1 is a front view showing a rack mounting of a high heat generating device in which bookshelf mounting and planar mounting are mixedly mounted according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3 is a perspective view showing a range B shown in FIG. 1. FIG.

FIG. 4 is a characteristic diagram showing an effect of the first embodiment according to the present invention.

FIG. 5 is a front view showing the rack mounting of the high heat generating device in which the bookshelf mounting and the planar mounting according to the second embodiment of the present invention are mounted together.

6 is a cross-sectional view taken along the line AA of FIG.

FIG. 7 is a front view showing the rack mounting of the conventional high heat generation device in which the bookshelf mounting and the planar mounting are mounted together.

8 is a perspective view showing in detail a range B shown in FIG. 7. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic circuit package, 2 ... Bookshelf mounting shelf, 3 ... Multichip module, 3A ... Multichip module, 3B ... Multichip module, 4 ... Planar mounting board, 5 ... Planar mounting shelf, 6 ... Electronic circuit package Insertion / extraction lever, 7 ... Alarm lamp, 8 ... Fan unit, 9 ... Rack, 10 ... Rack lamp, 11 ... Interface board, 12 ... Interface board mounted parts, 13 ... Heat sink, 14 ... Fan, 15A ... Cooling air flow Direction, 15B ... Cooling air flow direction, 15C ... Cooling air flow direction, 16A ... Cooling air flow direction, 16B ... Cooling air flow direction, 16C ... Cooling air flow direction, 17 ... Air guide 1, 18 ... Air guide 2, 19 ... Air guide 3, 20 ... Air guide 4, 21 ... Air guide 5.

Claims (4)

[Claims] 1. A bookshelf mounting shelf in which a plurality of electronic circuit packages each having a large number of chips are mounted in a rack-shaped shelf, and a planar mounting shelf in which at least one or more multichip modules are mounted. Are mixed on one rack or more and mounted on a rack, and at least one cooling fan is used for the rack,
In an electronic device for forcibly air-cooling the bookshelf mounting shelf and the planar mounting shelf together, in the planar mounting shelf, the multi-chip module is mounted on a planar mounting board on which the multi-chip module is mounted. An air guide 1 is provided on the side surface parallel to the direction in which the cooling air flows passing through the chip module, and further, an air guide 2 is provided close to the upper surface side of the multi-chip module, and the air guide 2 is the cooling air. The cooling structure of the electronic device is characterized in that the frontage becomes wider toward the upstream side with respect to the flow of. 2. An air guide 1 is provided on a side surface parallel to a direction in which cooling air flows through the multi-chip module, and an air guide 2 is provided on an upper surface side of the multi-chip module, and the air guide 2 comprises: The air guide 3 is provided so as to be wider toward the upstream side with respect to the flow of the cooling air, and the air guide 3 is provided between the air guide 2 and the upper surface side of the upper surface side multi-chip module. Electronic device cooling structure. 3. An air guide 1 is provided on a side surface of the plane mounting board on which the multi-chip module is mounted, the side surface being parallel to a direction in which cooling air flows through the multi-chip module, and the top surface side of the multi-chip module. The air guide 5 is provided on the upstream side of the multi-chip module mounted on the upstream side, and the air guide 5 is mounted on the downstream side with respect to the flow of cooling air. 2. The cooling structure for an electronic device according to claim 1, wherein the formed multi-chip module has a wider front side toward the downstream side with respect to the flow of cooling air. 4. An air guide 4 is provided on a side surface of the plane mounting board on which the multi-chip module is mounted, the side surface being parallel to a direction in which cooling air flows through the multi-chip module, and the air guide is upstream. For the multi-chip module mounted on the side, the front side is made wider toward the flow of the cooling air, and for the multi-chip module mounted on the downstream side, the flow of the cooling air is changed. On the other hand, the cooling structure for an electronic device according to claim 3, wherein the front side is wider toward the downstream side.