JPH02210898A - Cooling system for electronic apparatus - Google Patents

Abstract

PURPOSE:To improve overall cooling efficiency by selectively applying one of air flows, produced through dividing a cooled air flow into a predetermined number of air flows beforehand, to each of element groups or printed board groups, and removing the divided flows once used for cooling from the cooling region. CONSTITUTION:A cooling air flow 6 introduced into the space for a printed board 4 is divided at the position A into two layers, i.e., upper and lower layers, to from divided flows 6a, 6b. The divided flow 6a passes through the lower side path and directly led by an element group 5a to cool the same, and then led to the upper side path before entering the region of an element group 5b and bypasses the same. On the other hand, the divided flow 6b passes through the upper side path and does not come into contact with the element group 5a in the first stage, and is led to the lower path at the position of the element group 5b to be in contact with the same. When it has passed the element group 5b, both divided flows 6a, 6b join together and are discharged outside the system. Thus, preferable cooling effect can be obtained.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a system for forcibly cooling the heat generated from the elements during operation in an electronic device equipped with printed circuit boards mounted with a large number of semiconductor integrated circuit elements in parallel. The aim is to provide a simple system that has a reasonable cooling capacity according to the amount of heat generated by the elements of the entire device and can cool the elements evenly regardless of their placement position. A fan unit is provided at the top and/or the bottom of an electronic device configured with a plurality of mounted printed circuit boards arranged in parallel within a shelf, and the fan unit is provided at the top and/or the bottom of the electronic device, and the fan unit is directed inside the electronic device from the bottom to the top through the space between the adjacent printed circuit boards. The cooling airflow supplied to the space between the printed circuit boards is divided into a plurality of divided streams, and a specific divided stream is brought into contact only with a specific element group or printed circuit board, and other A split flow exchange section is provided so as not to come into contact with the element group or the printed circuit board.

[Industrial application field]

TECHNICAL FIELD The present invention relates to a system for forcibly cooling the heat generated from the elements during operation in an electronic device equipped with printed circuit boards on which a large number of semiconductor integrated circuit elements are mounted in parallel.

[Conventional technology]

BACKGROUND OF THE INVENTION Electronic devices such as computers and communication devices are becoming increasingly denser in order to meet demands for high-speed processing and to increase economic efficiency. As a means to achieve this, semiconductor integrated circuit elements are used as main components in electronic devices.
A design has been made in which a large number of elements are arranged and mounted on a printed circuit board, and these elements are arranged in parallel within a narrow space within a shelf.

These semiconductor integrated circuit elements generate heat as they operate, and when that heat accumulates inside, the temperature of the element rises.
Its structure and function are destroyed. In particular, as the degree of integration increases, the amount of heat generated per unit volume increases, and this tendency is exacerbated. Therefore, efficient cooling of the interior of electronic equipment is an urgent need at present.

[Conventional technology]

As shown in FIGS. 16(a) and 16(b), conventional cooling systems include
Alternatively, a fan unit 2 is provided at the bottom, and cool air is forced to flow from the bottom to the top through the gaps between the printed circuit boards 4 that are housed in parallel in the shelf 3. A method of cooling the element 5 is common.

[Problem to be solved by the invention]

According to this method, when elements are arranged on a printed circuit board in series with the direction of the cooling air flow, the elements placed on the leeward side are Since the heated airflow acts as a cooling agent, the cooling efficiency tends to decrease. Furthermore, since elements located upwind obstruct ventilation, this tendency is further exacerbated. The same thing can be said at the level of printed circuit boards within each shelf when shelves are stacked in multiple stages.

Therefore, when designing a cooling system for electronic equipment, it is necessary to always pay attention to the cooling of the elements or printed circuit boards located furthest downwind, and the system must have enough cooling capacity to cool downwind elements to the desired temperature. Applicable. For this reason, elements located upwind will inevitably be excessively cooled, resulting in wasted energy consumption. In other words, the current situation is that excessive cooling equipment is provided due to the poor cooling performance of elements on the leeward side.

In view of the problems of the prior art, the present invention has an appropriate cooling capacity according to the heat generation amount of the elements of the entire electronic device,
It is an object of the present invention to provide a simple system capable of uniformly cooling an element or a printed circuit board regardless of its placement position.

[Means to solve the problem]

This purpose is to provide a fan unit at the top and/or bottom of an electronic device that is configured with a plurality of printed circuit boards with a large number of elements mounted in series on their surfaces arranged in parallel inside a shelf.
Generating a cooling airflow that penetrates the electronic device from below to above through the space between the adjacent printed circuit boards,
The cooling airflow supplied to the space between the printed circuit boards is divided into a plurality of divided streams, and a specific divided stream is brought into contact only with a specific element group or printed circuit board, and with respect to other element groups or printed circuit boards. This is achieved by a cooling system for electronic equipment characterized by providing a switching section for the divided flows so as not to cause contact.

Hereinafter, the present invention will be explained in more detail based on preferred embodiments shown in the drawings.

[First Example] First, a first example will be described which aims to eliminate the difference in cooling efficiency due to the difference in the position of each element arranged in one printed circuit board.

First, the principle of this embodiment will be explained. For example, when elements 5a and 5b are arranged in two groups in series on a printed circuit board 4 as shown in FIG. In this embodiment, the cooling airflow 6 introduced into the space of the printed circuit board 4 is divided into upper and lower layers at position A. to form split streams 6a and 6b.

As shown by the solid line in FIG. 2, the divided flow 6a is guided directly to the element group 5a through the lower path to cool it, and then guided to the upper path before entering the region of the element group 5b. Bypass this. - On the other hand, as shown by the chain line, the split flow 6b passes through the upper path and does not come into contact with the element group 5a at the initial stage, but is guided to the lower path at the position of the element group 5b. come into contact with. When passing through the element group 5b, both the divided flows 6a and 6b merge and are discharged out of the system.

With this configuration, the divided flow 6a is in the upstream element group 5a, and the divided flow 6b is in the downstream element group 5b, in a fresh state, that is, in a state that has not been warmed by the heat generated by the other element group. A suitable cooling effect can be obtained.

In this example, we have explained the case where two layers of element groups are arranged side by side on the printed circuit board, but if the element groups are arranged in three or more layers, the height direction will be adjusted according to the number of rows. It is sufficient to set a plurality of divided streams and change the path in the height direction each time one element group is cooled so that a fresh divided stream always comes into contact with the uncooled element group.

A specific configuration for realizing the above-mentioned principle is shown in FIG.

Element groups 5a and 5b are arranged in series on the surface of the printed circuit board 4, and cooling airflow is supplied to them from below. The cooling flow is first divided into two upper and lower layers 6 by a partition plate 7 installed parallel to the printed circuit board 4 above the element group 5a.
It is divided into a and 6b.

A duct 8, which will be described later, is provided in the space between the element groups 5a and 5b.
is provided.

The lower divided flow 6a is introduced into the element group a to cool it, and the warmed air rises along the duct wall 9 and opens above the 20th partition plate 10 provided above the element group 5b. The air is blown out through multiple openings 11 in the air.

On the other hand, the upper divided flow 6b descends along the wall 12 of the duct, and the opening 13 of the duct opens below the temporary partition 10.
The air is blown out from the air to cool the element group 5b.

The duct 8, which performs the function of switching the divided flow vertically in this manner, has a shape as shown in FIG. 4. That is, a hollow rectangular parallelepiped whose large surface is surrounded by walls has openings 11 and 13 in the upper half of the front wall and the lower half of the back wall, respectively, and these units are alternately arranged in opposite directions. It is configured.

In the above example, split streams divided into two were applied to two element groups, but if the number of element groups increases, the number of split streams can be increased accordingly. for example,
FIG. 5 shows an example of how the flow paths of the eight divided streams are exchanged for eight element groups.

Further, as shown in FIG. 6, if the flow path surface of the duct 8 is formed with a curved surface, air resistance is reduced and a more efficient cooling effect can be obtained.

It is also possible to install an element that does not generate heat or an element that generates a small amount of heat in the area on the printed circuit board 4 corresponding to the installation location of the duct 8.

Furthermore, as shown in FIG. 7, the position of the duct 8 can be shifted as appropriate depending on the size of the elements to be arranged.

[Second Embodiment] Next, a second embodiment of the present invention will be described, which aims to uniformly cool the printed circuit boards in each shelf stacked in multiple stages regardless of the stacking position of the shelves.

FIG. 8 shows shelves 21°, 22.
23 is shown in an electronic device stacked in three layers. Cooling fan units 24 are housed in the upper and lower parts of the cabinet 20. Each shelf 21, 22, 23 accommodates a large number of printed boards Fi25 in parallel, each having an element 31 mounted on its surface.

In the conventional configuration, fresh cooling air comes into contact with the printed circuit boards in the lower shelf 21, so sufficient cooling is possible. As mentioned above.

In the present invention, a flow path changer 26 (described later) is installed between each shelf 21, 22° 23, and a flow divider 27 is further provided on the mounting surface side of each printed circuit board 25 housed within the shelf. It is characterized by

As shown in FIG. 10, the shunt 27 is connected to an element mounting surface 25a of a printed circuit board 25 stored in parallel in a shelf.
The space between adjacent printed circuit boards is divided into three types of ventilation sections 28, 29, and 30. Section 28 is printed circuit board 2
The sections 29 and 30 are arranged as alternating small sections behind the section 28.

Therefore, a part of the cooling air flow introduced into the interior from the lower part of the shelf 21 flows through the compartment 28 and cools the element 31 mounted on the printed circuit board 25.
will be introduced in

On the other hand, the split flow flowing through the compartments 29 and 30 passes through the shelf 21 without contacting the element 31 and rises, and is introduced into the flow path changer 26 .

The flow path changer 26 is constructed by arranging a large number of duct units 32 as shown in FIG. 10 in parallel as shown in FIG. This is a duct assembly corresponding to all flow dividers 27.

Here, ducts 32 a, 32 b, 32 c
The inlet sides of the flow divider 27 are compartments 2B and 29.30, respectively.
is located to coincide with the exit side of the Duct 32
a is inclined so as to change the direction of the divided flow flowing through it, and at the stage of the lower shelf 21, the divided flow that has flowed through the section 28 and cooled the element 31 is transferred to the middle shelf 2.
In step 2, flow divider 270 is introduced into section 29. The duct 1-32b directs the split flow that was flowing through section 29 at the shelf 21 stage to section 28 at the shelf 22 stage, thereby cooling the element 31. The duct 32c introduces the split stream flowing through the compartment 30 at the shelf 21 stage into the compartment 30 also at the shelf 22 stage.

Through this operation, it is possible to apply a fresh divided flow that has not been used for cooling at the stage of the shelf 21 to the printed circuit board 25 in the middle shelf 2-2, and it is possible to perform effective cooling. - On the other hand, the divided flow already used for cooling at the shelf 21 stage flows through a position not involved in cooling at the shelf 22 stage.

A similar operation is performed between the middle shelf 22 and the upper shelf 23, and the split flow heated through the section 28 of the flow divider 27 at the shelf 220 stage is transferred to the shelf 22.
In step 3, it is introduced into compartment 30, while shelf 22
The unused split stream flowing through compartment 30 at stage 0 is introduced into compartment 28 at shelf 23 to effectively cool the device.

The flow conditions of each divided flow explained above are shown in Figures 13 to 15.
As shown in the figure.

The above explanation describes the cooling of electronic equipment consisting of three stacked shelves, but when the number of stacked shelves increases further, the configuration of the flow divider and flow path switcher can be changed to increase the number of split streams. A similar effect can be achieved if the device is made compatible with this.

〔Effect of the invention〕

According to the present invention, one of the divided airflows obtained by dividing the cooling airflow into a predetermined number is selectively applied to each of the element groups or printed circuit board groups arranged along the direction of the cooling airflow. Since the divided flow previously used for cooling is removed from the cooling area, it is possible to uniformly cool each element group or printed circuit board group, and the overall cooling efficiency is improved.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the state of the conventional cooling airflow to the element group, Fig. 2 is a side view showing the state of the cooling airflow of the first embodiment of the present invention, and Fig. 3 is a side view showing the state of the cooling airflow in the first embodiment of the present invention. Figure 4 is a perspective view of the duct, Figure 5 is a system diagram showing flow path replacement when split flow is applied to eight element groups, Figure 6 is a separate diagram. 7 is a plan view of an example of a change in the installation position of the duct, FIG. 8 is an exploded perspective view of an electronic device showing an outline of a cooling system according to a second embodiment of the present invention, and FIG. 9 is a side view of a duct having a shape of Figure 10 is a perspective view of the flow path shunter unit; Figure 11 is a perspective view of the flow path shunter units arranged in a row; Figure 12 is the flow path shuffler unit. Perspective view showing the whole, 13th
Fig. 15 is a side view showing the flow state of each divided flow according to the second embodiment, Fig. 16 (a) and (b) are a perspective view and a front view of an electronic device showing an outline of a conventional cooling system. It is. 1...Electronic equipment, 2...Fan unit,...Shelf,...Printed circuit board5. 5a, 5b...Element,...Cooling airflow, a, 5b...Divided flow,...Duct, 0...Cabinet, ], 22.23...Shelf, l...Element, 5... Printed circuit board, 6... Flow path exchanger, 7... Flow divider, 8.28.30... Ventilation section. Perspective view of the duct Figure 4 Figure 3 Rear view Figure 9 Perspective view of the divider No. 152 Diagram 16 of electronic equipment showing an overview of a conventional cooling system

Claims (1)

[Claims] 1. A plurality of printed circuit boards (4, 25) with a large number of elements (5, 31) mounted in series on the surface are mounted on a shelf (3, 2).
Electronic equipment (1, 22, 23) configured in parallel within
A fan unit (2) is provided at the upper and/or lower part of the electronic device (1), and cooling air flows through the electronic device (1) from below to above through the space between the adjacent printed circuit boards (4, 25). 6) and generate the printed circuit board (4, 2).
5) The cooling air flow (6) supplied to the space between is divided into a plurality of divided flows (6a, 6b), and a specific divided flow (6a or 6b
) in contact only with a specific element group (5a, 5b) or printed circuit board, and not with other element groups or printed circuit boards.
6) A cooling system for electronic equipment.