JPH09326578A - Cooling device of electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower air resistance and noise of air flow path and power consumption by mixing a cooling air in the down-stream side if at least one heat generating semiconductor element on the substrate at the time of cooling a plurality of heat generating semiconductor element with the cooling air flowing along the substrate. SOLUTION: Many heat generating semiconductor elements 11a to 11c such as LSI, etc., are mounted on a substrate 10. The cooling air flows as indicated by 15 into the substrate 10 and is exhausted as indicated by 16 after it flows to cool each LSI 11, etc. As a mixing mechanism for mixing the cooling air on the substrate 10, a plate 18 for squeezing the path of cooling air is installed one by one at both ends of the path the constrict the flow of air in the width direction of the substrate 10. The plate 18 for constricting the path provides higher effect when it is installed in the down-stream side rather than the center of the substrate 10. A mass of the cooling air which is heated by 11a, 11b to locally have a higher temperature distribution is forced to be squeeze the flow thereof with the plate 18 for constricting the path and is intensively mixed as an isolating flow at the rear part of the plate 18 for constricting the path.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for electronic equipment equipped with heat-generating semiconductor components.

[0002]

2. Description of the Related Art A cooling method for electronic equipment for information processing is
Generally, a method of cooling a plurality of heat-generating semiconductor components mounted on a circuit board such as a printed board or a ceramic board with air is used. In this air cooling system, a method is often used in which cooling air is circulated in parallel to the substrate to supply cooling air from the side of the heat-generating semiconductor component to sequentially cool the heat-generating semiconductor component. However, when the amount of heat generated by the heat-generating semiconductor component is large, the cooling performance of the heat-generating semiconductor component on the downstream side is poorer, and there is a problem in that the temperature exceeds the predetermined temperature range allowed for the heat-generating semiconductor component.

The deterioration of the cooling performance is roughly divided into two factors. The first factor is deterioration of cooling performance of the heat sink itself mounted on the heat-generating semiconductor component. This is mainly due to the fact that the cooling air escapes into the free space toward the downstream side on the substrate, and thus the flow velocity of the cooling air passing through the heat sink decreases. The second factor is an increase in the temperature of the cooling air. When a large amount of heat is generated by the heat-generating semiconductor component and a large number of heat-generating semiconductor components are mounted on the substrate, the influence of the second factor becomes extremely large. The wind temperature rise is
Even if the cooling air is completely mixed, the effect is large, but in reality, there are locally high air temperature parts, so the temperature may rise several times as much as the temperature of the air when fully mixed depending on the location. There is also.

Therefore, as a method for solving the deterioration of the cooling performance due to the first factor, many methods have conventionally been devised for improving the cooling performance of the heat sink mounted on the heat-generating semiconductor component. For example, "cooling structure for multi-chip module" described in Japanese Patent Laid-Open No. 6-163771.
Is mentioned. This conventional example will be described with reference to FIG. In FIG. 11, the multi-chip module 2 which is a heating element is mounted on the substrate 1. A heat sink 3 composed of a plate fin is provided on the multi-chip module 2, and cooling air 4 is supplied from the side of the heat sink 3 to cool the multi-chip module 2. The airflow control plate 5 is installed on the side surface and the upstream side of the multichip module 2, and the airflow control plate 5 is bent at an angle wider than the width of the multichip module 2 on the upstream side of the multichip module 2. By adopting this structure, the cooling air flows intensively in the heat sink, and the cooling performance of the heat sink 3 is improved.

Next, as a method for solving the deterioration of the cooling performance due to the second factor, several methods for promoting the mixing of cooling air have been conventionally devised. For example,
The "cooling structure for electronic circuit board" described in JP-A-6-196886 can be mentioned. This conventional example is shown in FIG.
It will be described based on. An LSI package 6, which is a heating element, and many IC chips 7 are mounted on the substrate 1. LS
The heat sink 3 is provided on the I package 6, and the cooling air 4 is supplied from the side of the heat sink 3,
The LSI package 6 is being cooled. A rod body 8 is installed on the most upstream side of the substrate 1. The Karman vortex generated by the rod 8 disturbs the air flow, promotes the mixing of the air flow, and improves the cooling performance.

[0006]

In the first conventional example, although the cooling performance of the heat sink itself is improved, it is not possible to equalize the local air temperature rise due to the heat-generating semiconductor components on the upstream side, and the heat-generating semiconductor is used. When the amount of heat generated by the components is large and a large number of heat-generating semiconductor components are mounted on the substrate, the cooling performance deteriorates due to the increase in air temperature.

In the second conventional example, since the rod for mixing the cooling air is installed in the most upstream part of the substrate, the turbulence of the cooling air does not continue to the downstream side of the substrate. for that reason,
Mixing of cooling air is not realized in the downstream part of the board, which is most affected by the increase in air temperature and deteriorates performance.
In the downstream part of the substrate, the local increase in air temperature cannot be made uniform.

Further, if the air volume of the cooling air is increased in order to compensate for the deterioration of the cooling performance due to the increase in the air temperature, ventilation resistance and noise will increase, and power consumption will increase. Furthermore, if the operating temperature of the semiconductor component rises due to the rise in air temperature, the calculation speed and reliability will decrease.

An object of the present invention is to reduce ventilation resistance, noise and power consumption of a flow path when a large amount of heat is generated from a heat-generating semiconductor component and a large number of heat-generating semiconductor components are mounted on a substrate. , To improve the operation speed of semiconductor components.

[0010]

In order to achieve the above-mentioned object, the present invention provides a cooling device for electronic equipment, in which a plurality of heat-generating semiconductor components mounted on a substrate are cooled by cooling air flowing along the substrate, A mixing mechanism for mixing the cooling air was installed downstream of at least one heat-generating semiconductor component on the substrate.

Further, a mixing mechanism for mixing the cooling air is installed at a position downstream of the center of the substrate.

Further, the mixing mechanism is composed of a plate or an orifice for narrowing the flow path of the cooling air.

Further, the mixing mechanism is composed of a turbulent vortex generator such as one or a plurality of cylinders, prisms, rectangular plates and triangular blades.

Further, the mixing mechanism is composed of a grid structure having a plurality of guide plates crossing each other.

The mixing mechanism is composed of one or a plurality of blowers.

Further, the mixing mechanism is attached to a cover member that covers a part or the whole of the substrate, or is configured in the cover member itself.

Further, the mixing mechanism is attached to the reinforcing frame member installed on the substrate.

Further, the mixing mechanism is attached to the back side of another substrate which is installed adjacently.

In the electronic device of the present invention, since the mixing mechanism for mixing the cooling air is installed, the local heat-generating semiconductor components on the upstream side of the substrate, which occur when a large number of high-heat-generating semiconductor components are mounted on the substrate, are provided. Of uneven wind temperature rise
The mixing mechanism provided on the downstream side of the substrate can mix the cooling air to make the air temperature uniform, thereby improving the cooling performance. Further, it becomes possible to reduce the ventilation resistance, noise, and power consumption of the flow path, and improve the operation speed and reliability of the semiconductor component.

By attaching the mixing mechanism to the cover member that covers the substrate and the reinforcing frame member installed on the substrate, a special jig for the mixing mechanism is not required, and the mixing mechanism can be constructed at low cost. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a cooling device for electronic equipment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view of this embodiment. On a substrate 10 such as a printed wiring board or a ceramic substrate, a large number of heat-generating semiconductor components 11a to 11c represented by LSIs, multi-chip modules, etc. having different shapes and heat generation amounts are mounted in a mixed manner. A heat sink 12 for effectively transmitting the generated heat to the cooling air is attached to the LSI 11a which generates a relatively large amount of heat among the heat generating semiconductor components 11. The heat sink 12 is, for example, a flat plate fin type heat sink in which a large number of flat plates are arranged side by side. Here, the material of the heat sink may be a material having good thermal conductivity such as copper, aluminum, or high thermal conductive ceramics. The shape of the heat sink is not limited to the flat plate fin shape, but may be, for example, a pin fin shape or a slit fin used in a heat exchanger or the like. In addition, the LSI 11b that generates a relatively small amount of heat (for example, SRAM or D
A memory system LSI such as a RAM) radiates heat directly from the LSI surface without attaching a heat sink. A large number of memory cards 13 are mounted on the right end of the substrate 10 in a laminated form. A memory LSI 14 (for example, DRAM or the like) is mounted on both surfaces of 13. The cooling air flows in on the substrate 10 as indicated by 15, flows while cooling each LSI 11, and is discharged as by 16. Although not shown in the figure, there is a blower upstream or downstream of the substrate for supplying cooling air under pressure or pressure. 17 is the substrate 10
It is a cover that covers the whole. The cover 17 forms a duct-shaped flow path for preventing the cooling air from the blower from escaping into the free space above the substrate. Further, if the cover 17 is made of metal, it also serves as an electromagnetic shield for each substrate.

As described above, when the high heat generating semiconductor components having various sizes and heat generation values are densely mounted in a mixed manner without having a simple regularity, the following problems occur. Occurs. The problem is that the cooling air warmed by the heat generating semiconductor components 11a, 11b arranged on the upstream side in the substrate 10 flows into the heat generating semiconductor component 11c arranged on the downstream side in the substrate 10 to cool the 11c. Therefore, the cooling performance of 11c is deteriorated. In particular, in the case where high-heat-generating semiconductor components having various sizes and heat generation values are mixedly mounted on the upstream side of the board, the cooling air flowing into 11c located on the downstream side of the board has a cross section perpendicular to the flow direction. The air temperature distribution in the area becomes extremely uneven. Therefore, some of the heat-generating semiconductor components of 11c are exposed to the cooling air having a very high temperature, which exceeds the predetermined temperature range allowed for the heat-generating semiconductor components, which lowers the calculation speed and reliability. Will be invited. Further, when the air volume of the cooling air is increased to compensate for the deterioration of the cooling performance due to the increase in the air temperature, ventilation resistance and noise increase, and power consumption increases.

There are two main causes of non-uniform wind temperature distribution. The first cause is the arrangement of heat-generating semiconductor components. This is because when a large number of heat-generating semiconductor components that generate a large amount of heat are arranged in the flow direction, the temperature of the cooling air passing therethrough is higher than that of the other parts. The second cause is non-uniform wind speed. If a large number of heat-generating semiconductor components with heat sinks are lined up in the flow direction,
This is because the flow velocity of the cooling air passing therethrough gradually decreases, and the wind speed becomes smaller than that of the portion with less heat sink. When the wind speed decreases, the air temperature rise increases naturally.

In order to solve this problem, in this embodiment, as a mixing mechanism for mixing the cooling air on the substrate 10, plates 18 for narrowing the cooling air flow passage are installed one at each end of the flow passage, The structure is such that the flow is restricted in the width direction of the substrate 10. When the plate 18 is installed with a certain inclination angle in the flow direction (for example, about 45 ° with respect to the flow), the ventilation resistance does not increase relatively. Heat-generating semiconductor component 1 on the downstream side of the substrate 10
Since 1c is most affected by the deterioration of the cooling performance due to the locally high temperature cooling air, installing 18 in front of 11c is most effective. That is, 18 is highly effective when installed on the downstream side of the central portion of the substrate 10. 11a, 11b
The cooling air mass that is heated by and has a locally high temperature distribution is forcibly restricted in flow by 18 and becomes a separated flow behind 18 and is strongly mixed. As a result, the cooling air that has passed through 18 has a relatively uniform temperature distribution and reaches 11c, so that the cooling performance of 11c can be improved.

FIG. 2 is a perspective view of the second embodiment. Second
In the embodiment of the first embodiment, a plate for narrowing the flow path of the cooling air is installed in the upper part of the flow path so as to cause downflow to the substrate 10, as shown in 19, It has a structure that mixes cooling air. In this embodiment, the flow is restricted in the direction perpendicular to the substrate 10.
With the configuration of this embodiment, the downflow generated in 19 is concentrated near the LSI of 11c, so that the cooling air is less likely to escape above the heat sink, and since it becomes jet-like cooling air, the cooling performance of 11c is Further improve.

FIG. 3 is a perspective view of the third embodiment. Third
In contrast to the first embodiment, this embodiment has a structure in which the plate for narrowing the flow path of the cooling air is a perforated plate having a large number of holes as shown in 20. In this embodiment, the perforated plate 20 is installed in the direction perpendicular to the flow of the cooling air, and the perforated plate 20 is forced to pass through a large number of holes. With the configuration of the present embodiment, the cooling air is jetted out from each of the holes in a jet shape and is mixed strongly, so that the temperature distribution of the cooling air can be improved very uniformly.

FIG. 4 is a perspective view of the fourth embodiment. 4th
Compared with the first embodiment, this embodiment has a structure in which a plate for narrowing the flow path of the cooling air is smoothly curved in a wave shape as shown by 21. 21 is installed above the flow path,
It has a structure protruding toward the substrate surface. In this embodiment, since the cross section of the flow passage changes smoothly, it is possible to mix the cooling air without significantly increasing the ventilation resistance.
Further, 21 is the cover 17 shown in the first embodiment of FIG.
It can be easily attached to. Further, the cover 17 itself can be easily configured by being curved by boss processing, press processing, sheet metal processing, or the like.

FIG. 5 is a perspective view of the fifth embodiment. Fifth
Similar to the first embodiment, this embodiment has a structure in which the plates 22 for narrowing the flow path of the cooling air are installed one at each end of the flow path to narrow the flow in the width direction of the substrate 10. The difference from the first embodiment is that 22 has a structure that is smoothly wavy. In this embodiment, since the flow passage cross section changes smoothly, it is possible to mix the cooling air without increasing the ventilation resistance so much as in the fourth embodiment.
Further, 22 can be easily attached to the cover as in the case of the fourth embodiment, and the cover itself can be easily configured by curving by boss processing, press processing, sheet metal processing or the like.

FIG. 6 is a perspective view of the sixth embodiment. Sixth
Unlike the above-described embodiment, the mixing mechanism for mixing the cooling air is a turbulent vortex generator composed of a plurality of cylinder groups extending in the direction perpendicular to the substrate, as shown in 23. Is characterized by. The cooling air that has passed between the cylinder groups is mixed while vibrating periodically due to the Karman vortex generated behind the cylinders, so that the cooling air can be mixed without relatively increasing the ventilation resistance. Of course, the present embodiment is not limited to a cylindrical shape, and the same effect can be expected with a turbulent vortex generator such as a prism, rectangular plate, or triangular blade.

FIG. 7 is a perspective view of the seventh embodiment. Seventh
In the embodiment, the mixing mechanism for mixing the cooling air is 24,
As shown in 25, it is a grid structure formed by intersecting a plurality of guide plates with each other. The grid structure crosses the flow in a plane parallel to the substrate,
The guide plates 24 and 25 having different guide directions are stacked in the height direction. The cooling air that has passed through the grid structure has a uniform temperature distribution due to the mixing of the flows in the two directions. In this embodiment, since the mixing can be performed relatively well by slightly changing the flow directions, the increase in ventilation resistance can be minimized.

FIG. 8 is a perspective view of the eighth embodiment. 8th
The embodiment is characterized by having a grid structure as in the seventh embodiment. The difference from the eighth embodiment is that the grid structure intersects the flow in a plane perpendicular to the substrate and parallel to the flow direction.
In the present grid structure, the guide plates 26 and 27 are stacked in the substrate width direction so as to have an angle facing upward and downward with respect to the substrate surface. Also in this embodiment, the same effect as that of the seventh embodiment can be realized.

FIG. 9 is a perspective view of the ninth embodiment. Ninth
The embodiment is characterized in that the mixing mechanism for mixing the cooling air is constituted by one or a plurality of blowers. As shown in the figure, a small axial fan 28 is mounted on the substrate.
Are installed so that the flows face each other near the center of the substrate. The cooling air accelerated by the axial fan 28 becomes a swirling flow and merges violently, and the cooling air having an uneven temperature distribution is mixed well. In this embodiment, the intensity of mixing can be controlled by controlling the rotation speed of the axial fan 28.

FIG. 10 is a perspective view of the tenth embodiment.
Similar to the first embodiment, the tenth embodiment has a structure in which the plates 29 for narrowing the passage of the cooling air are installed at both ends of the passage so that the flow is narrowed in the width direction of the substrate 10. However, the difference from the first embodiment is that 22 is installed immediately before the heat-generating semiconductor component 11c whose cooling performance is to be improved. In the present embodiment, the heat generating semiconductor component 1 which not only mixes the cooling air having a non-uniform temperature distribution but also needs to improve the cooling performance.
Since the cooling air can be directly guided to the 1c, the cooling performance itself of the heat sink of 11c can be greatly improved.

When the cooling air mixing mechanism is actually applied to an electronic device, its mounting method is important.
Attaching the mixing mechanism to the substrate itself is not a good method considering the reliability of the substrate. One of the practical attachment methods is to attach it to a cover that covers the substrate. The cover is used to prevent the cooling air from the blower from escaping into the free space above the substrate, and forms a duct-shaped flow path above the substrate. In some cases, the cover is made of metal and serves as an electromagnetic shield for each substrate. As another attachment method, there is a method of attaching it to the reinforcing frame member attached to the substrate. When the size of the substrate is increased, reliability is reduced only by the strength of the substrate itself. Therefore, a reinforcing member for maintaining the strength of the substrate is attached. If it is attached to the reinforcing frame material, the mixing mechanism can be easily realized. Further, in the case of an electronic device in which a large number of substrates are mounted side by side in parallel, the back surface of the adjacent substrate exists above one substrate. Therefore, if the mixing mechanism is attached to the back surface of the adjacent substrate, the mixing mechanism can be realized even when there is no cover or frame material.

[0036]

According to the present invention, when a large amount of heat is generated from a heat-generating semiconductor component of an electronic device and a large number of heat-generating semiconductor components are mounted on the substrate, at least one heat-generating semiconductor component on the substrate is better than that of the heat-generating semiconductor component. Since the mixing mechanism for mixing the cooling air is installed on the downstream side, it is possible to equalize the local increase in the air temperature due to the heat-generating semiconductor components on the upstream side of the substrate, and thus to improve the cooling performance of the electronic device. . Further, it is possible to reduce ventilation resistance, noise, and power consumption of the flow path, and improve the operation speed and reliability of the semiconductor component.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a perspective view of a second embodiment of the present invention.

FIG. 3 is a perspective view of a third embodiment of the present invention.

FIG. 4 is a perspective view of a fourth embodiment of the present invention.

FIG. 5 is a perspective view of a fifth embodiment of the present invention.

FIG. 6 is a perspective view of a sixth embodiment of the present invention.

FIG. 7 is a perspective view of a seventh embodiment of the present invention.

FIG. 8 is a perspective view of an eighth embodiment of the present invention.

FIG. 9 is a perspective view of a ninth embodiment of the present invention.

FIG. 10 is a perspective view of a tenth embodiment of the present invention.

FIG. 11 is a perspective view of a conventional cooling device for electronic equipment.

FIG. 12 is a side view of a conventional cooling device for electronic equipment.

[Explanation of symbols]

10 ... Board, 11 ... Heat-generating semiconductor component, 12 ... Heat sink, 13 ... Memory card, 14 ... Memory LSI, 1
5, 16 ... Cooling air flow, 17 ... Cover, 18 ... Plates for narrowing cooling air flow path.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsuo Nishihara 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Hiritsu Manufacturing Co., Ltd.Mechanical Research Institute (72) Inventor Tadakatsu Nakajima 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Hiritsu Manufacturing Co., Ltd. Inside the Mechanical Research Laboratory (72) Inventor Takahiro Oguro 1st Horiyamashita, Hadano City, Kanagawa Prefecture

Claims (9)

[Claims] 1. A cooling device for an electronic device, wherein a heat-generating semiconductor component mounted on a substrate is cooled by cooling air flowing along the substrate, wherein a plurality of heat-generating semiconductor components are provided substantially along a flow direction of the cooling air. A mixing mechanism for arranging cooling air on the downstream side of at least one heat-generating semiconductor component on the substrate is less than the number of heat-generating semiconductor components, and at least one or more for the one substrate. A cooling device for an electronic device, characterized in that one or more pairs are installed. 2. A cooling device for an electronic device, wherein a heat-generating semiconductor component mounted on a substrate is cooled by cooling air flowing along the substrate, wherein a plurality of heat-generating semiconductor components are provided substantially along a flow direction of the cooling air. A mixing mechanism for arranging cooling air at a position downstream of the center on the substrate, the number of which is less than the number of heat-generating semiconductor components, and at least one or a pair of the substrates. A cooling device for electronic equipment, which is installed as described above. 3. The cooling device for an electronic device according to claim 1, wherein the mixing mechanism is composed of a plate or an orifice that narrows a flow path of cooling air. 4. The mixing mechanism according to claim 1, wherein the mixing mechanism is one or more cylinders, prisms, rectangular plates,
A cooling device for electronic equipment that is composed of turbulent vortex generators such as triangular blades. 5. The cooling device for an electronic device according to claim 1, wherein the mixing mechanism is a grid structure including a plurality of guide plates intersecting each other. 6. The cooling device for an electronic device according to claim 1, wherein the mixing mechanism includes one or a plurality of blowers. 7. The cooling of an electronic device according to claim 1, 2, 3, 4, 5 or 6, wherein the mixing mechanism is attached to a cover member that covers a part or all of the substrate, or is configured in the cover member itself. apparatus. 8. The cooling device for an electronic device according to claim 1, wherein the mixing mechanism is attached to a reinforcing frame member installed on a substrate. 9. The cooling device for an electronic device according to claim 1, wherein the mixing mechanism is attached to the back surface side of another substrate that is adjacently installed.