JPH05291447A - Cooling structure for semiconductor device - Google Patents

Abstract

PURPOSE:To construct an effective air discharge passage when a semiconductor is cooled by blowing upon generation of heat and to improve a cooling effect. CONSTITUTION:The cooling structure for a semiconductor device comprises the device 52 which generates heat, a radiator 53 in contact with the device, an exhaust guide 60 of cooling air extended from a bottom toward an opening around the radiator, and an outlet 56 for cooling air opposed to an opening surface of the radiator. The cooling air to be discharged from the outlet 56 is discharged in a circumferential direction of the outlet 56 by the guide 60 around the radiator through the radiator 53.

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 a semiconductor device, which forms an effective exhaust path for an exhaust flow accompanied by cooling by blowing air to the semiconductor device which generates heat.

In electronic / communication devices and the like, the miniaturization and high density of semiconductor devices have led to the progress of integration of semiconductor devices, and the heat generation due to the power consumption thereof increases. Therefore, it is extremely effective to dissipate and cool the heat generation. It has become important.

A conventional telecommunication device used for analog communication, digital communication, etc. has a form called "bookshelf type mounting" as shown in FIG. 6 in which maintainability and mounting efficiency are prioritized. .. That is, the shelve frames 2 are stacked in multiple stages inside the device 1, and a large number of printed boards 3 are inserted and mounted in parallel in the vertical direction.

FIG. 7 shows a partial perspective view of the shelving frame as seen from the back side. A mother board 4 made of a printed board is attached to the back surface of the shelve frame 2, and a connector 5 is provided on the front surface side. The printed board connector 6 of the printed board 3 is inserted and connected to the connector 5. Reference numeral 7 is a terminal pin of the connector 5.

In the above conventional structure, since the signal speed for transmission processing between the IC and the LSI is slow, the length of the electrical connection does not matter so much, and the size is small enough not to lower the manufacturing efficiency. It was Since the heat generation amount of ICs, LSIs, etc. is small, it was possible to cope with it by a natural air cooling method using natural convection in the apparatus or forced air cooling by a small blower.

[0006] According to the device 1 of the above-mentioned conventional Book-Chierf type mounting structure, the connector 5 for connecting the printed board 3 to the mother board 4 is provided, but the terminal pins 7 of this connector 5 are many. Since it protrudes to the back surface of the board, even if an attempt is made to mount a circuit component on the mother board 4, there is no space. That is, the mother board 4 has only a wiring connection function between the printed boards 3.

What is required for future telecommunications is that the telecommunications equipment for high-speed digital signal processing is
If the wiring length for electrical connection to C, LSI, etc. becomes longer,
The occurrence of such a situation is suppressed because a signal transmission delay is caused or a high-speed digital signal passes through a large number of connectors, which is affected by the deterioration of electric signals and noise, and causes deterioration of communication quality. Is required. So I
In order to minimize the wiring length between C, LSI, etc., it is necessary to realize high-density packaging by shortening these components as much as possible.

As described above, the signal from one printed board passes through the wiring inside the printed board and is connected to the motherboard through the connector, passes through the wiring inside the motherboard, and again through another connector. Since it is connected to the elements in one printed board, it is inevitable that the wiring distance between the elements becomes long.

On the other hand, in the conventional mounting structure described above, ICs and LSIs are used.
When the amount of heat generated by parts such as is relatively small, the forced cooling system with a small blower was sufficient, but in order to perform high-speed digital signal processing, the gate size of the LSI is 10 times or more than the conventional scale. Therefore, a large number of large-scale LSIs that locally generate high heat are used. Therefore, the conventional cooling method using a small blower cannot provide sufficient cooling.

From the above, the communication device 10 shown in FIG. 8 has been devised. FIG. 8 (a) is a front view,
(B) The figure is a rear view. In the front view of FIG. 6A, the printed circuit board 1 is attached to the shelving frame 11 which is stacked in multiple layers as in FIG.
A state in which a large number of 2 are inserted and mounted in parallel in the vertical direction is shown. Then, blowers 13 and 14 for exhaust and cooling are provided above and below the device casing to cool the heat-generating components of the printed board 12.

The rear view of FIG. 2B is a cross-sectional view with the upper part cut away, but it can be seen that the radiators 15 provided in a large-scale LSI are arrayed and mounted on the horizontal and vertical planes. Blower 1 for blowing cooling air to this radiator 15 to cool it
6 is provided below the device casing, and a blower 17 is provided above for the exhaust of the cooled air.

As shown in the partially enlarged view of FIG. 9, the radiator 15 has a large number of vertical radiating fins 18 arranged side by side in parallel. As shown by the arrow, the cooling air blown from below is supplied. The flow comes into contact with the radiating fins 18 to take heat and is effectively discharged by the blower 17 above.

In order to have such a structure, the mother board 4 shown in FIG. 7 is formed as a multi-layer and connector pins are implanted on the front surface side to form a connector, and the connector pins do not project to the rear surface side. The wiring is connected between the printed boards by inserting it up to the middle. Then, another connector pin is planted on the back side so as to form a connector for wiring connection between the LSIs, and the LSI is mounted on this connector. Therefore, the front side and the rear side of the mother board have independent wiring configurations, but the front and rear wirings are connected at necessary portions.

In this way, by forming electrically and structurally independent connectors on both sides of the mother board, it is possible to have a function similar to that of a plurality of mother boards and to wire necessary parts. By connecting, it becomes possible to connect each function in the shortest distance instead of the conventional connection. Therefore, it is possible to effectively use the depth space in the device, and high-density mounting can be performed.

An optimal cooling system can be constructed by dividing the heat generating portion in the apparatus into a low heat generating portion and a high heat generating portion, and adopting a cooling method according to each heat generation amount. The bookshelf type mounting part on the front side is a cooling method using a small blower, and the LSI generates high heat locally.
It became possible to mount it on the back side in a plane and let a large amount of high-speed cooling air flow, and apply the optimal cooling method to each to avoid the problem of excess or insufficient cooling capacity.

[0016]

2. Description of the Related Art Due to the above-mentioned improved construction, a great cooling method and mounting improvement have been made.
The cooling surface still has the following problems, and it was necessary to solve this problem.

That is, in the cooling method as shown in FIG. 9, as is apparent from FIG. 8, due to the arrangement of a large number of LSIs and their radiators 15, as the cooling air from below rises in sequence, the cooling air from above is raised one after another. As it touches the radiator 15,
The temperature of the air rises, and it becomes impossible to appropriately cool the radiator 15 above.

Therefore, in order to solve such a problem, a cooling method as shown in FIGS. 10 and 11 was devised. This does not merely send the cooling air from below to the whole, but rather sends the cooling air blown from the blower 16 below to the radiator 1
5, air ducts 19 are provided over the entire area, and the air outlets 20 facing the radiator 15 are directed from the air ducts.

FIG. 12 shows a perspective view (a) of one shelf 11 as seen from the back side, and FIG. The multi-chip module 21 is cooled by one radiator 22. Radiator fin groups 23 are formed at four locations in this radiator, and a delivery port 20 from the air duct 19 faces the radiator fin groups 23.

As described above, it is possible to constantly apply the same cooling air to all radiators, and it is possible to prevent temperature changes from occurring in the upper and lower radiators. Further, by changing the opening diameter of the outlet 20, it is possible to adjust the amount of air blow according to the amount of heat generation.

[0021]

According to the above-mentioned conventional structure, the cooling air from the air duct is centrally supplied to the radiators through the outlets to cool the radiators.
Although it became possible to cool effectively, it turned out that there were further problems. The airflow emitted from the outlet hits the opposing radiator and is dispersed into the airflow in the reflection direction and the airflow to the side and discharged upward, but this airflow induces the air outside the surrounding ducts. It becomes a mixed jet air flow.

This ambient air is, in other words, the exhaust flow of the cooling air below. As a result, the temperature of the cooling airflow is so high that an effective cooling effect cannot be obtained. This tendency becomes higher as it goes up.

Further, since the blower for exhausting air to the outside of the apparatus casing is located in the direction directly above the radiator side, the exhaust flow from below flows near the radiator, which also causes the exhaust temperature to rise. It is not preferable because it is transmitted to the radiator above.

An object of the present invention is to solve the above-mentioned various conventional problems.

[0025]

The constituent means of the present invention for solving the above-mentioned problems of the prior art is a semiconductor device which generates heat, a radiator in contact with the semiconductor device, and a bottom surface surrounding the radiator. An exhaust guide for the cooling airflow that expands in the opening direction,
A cooling air outlet facing the opening surface of the radiator, the cooling air sent out from the outlet passing through the radiator and surrounding the radiator in the peripheral direction of the outlet by an exhaust guide. It is a cooling structure of a semiconductor device that is discharged.

Then, the exhaust guide is shaped like a bowl. Further, a plurality of the above semiconductor devices are arranged, and a blower for exhaust is provided so that an exhaust path of the exhaust airflow of the cooling airflow is directed to the outlet side of the cooling airflow.

[0027]

According to the above-described means of the present invention, since the exhaust guide surrounds each radiator, only the amount of the exhaust itself exists inside the radiator, so that the influence of the exhaust temperature of other parts is exerted. Never receive. Moreover, the exhaust air inside is constantly replaced by fresh cooling air being jetted and supplied from the outlet for cooling air. In this way, all radiators have the same conditions.

Since the exhaust guide is constructed so that the opening side is wide, the delivery flow and the exhaust flow are separated without confusion and flow smoothly. By making the shape of the exhaust guide into a bowl shape, the exhaust flow is further discharged along the streamline, the flow of the exhaust flow is further improved, and most of the exhaust is discharged in the circumferential direction of the cooling air outlet. Will be.

By arranging the position of the blower for exhaust toward the outlet side of the cooling air, the exhaust flow flows through the outlet side having a smaller diameter than the exhaust guide, so that the resistance of the exhaust flow is small and the exhaust flow is small. The temperature will have less influence on the heat generation side.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings on the basis of the above-mentioned invention in concrete embodiments.

FIG. 1 is a side sectional view of an embodiment of the present invention. FIG. 1 omits illustrations of the apparatus housing, the blower, the overall shape of the air duct, and the like, and shows only essential parts. Reference numeral 51 in the figure
Is a motherboard made of printed boards arranged in a vertical plane, 52 is a large number of large-scale LSIs (only two are shown in the figure) mounted on the motherboard 51, and 53 is this LSI
52 is a radiator attached in contact with each.

The radiator 53 is a metal such as copper or aluminum which is a good conductor of heat and is composed of a large number of rod-shaped bodies. The surface of the radiator 53 is rough and is finished in black.
The heat dissipation is in good condition.

A cooling air outlet 56, which is an outlet for cooling air from an air duct 55, is opened to face each of the radiators 53. Then, the blower 58 for exhaust provided above the housing of the apparatus is arranged near the air duct 55 side.

The outlet 56 is constructed to have an appropriate length so that the branched flow from the air duct 55 becomes a proper laminar flow from the turbulent flow. Moreover, the opening is approximately the same size as the area of the radiator 53.

The exhaust guide 60 provided so as to surround the radiator 53 extends toward the opening 61 side with the LSI 52 side as the bottom surface, as best shown in FIG. The shape is then preferably bowl-shaped.

The operation of the above structure will be described. In the enlarged cross-sectional view of FIG. 3, the cooling blast A ejected from the outlet goes straight in the direction of the arrow and enters the radiator 53 to enter the LSI 52. This radiator 53, which has a high temperature due to the heat transferred from the radiator, is cooled. As a result, the cooling air A is heated and becomes an exhaust flow B indicated by an arrow, which is sent out toward the side surface of the radiator 53.

This is because the blast air A is sent in, so that a large number of rod-shaped radiators 53 become a kind of barrier and are pushed out in the side direction without returning to the reflection direction. Thus, the exhaust flow discharged to the side surface is not exhausted rapidly due to the decrease in the pressure, and the velocity is slow.

For this reason, the opening 61 of the exhaust guide 60 is also provided.
The portion is expanded to form a shape with less fluid loss, and is exhausted toward the outer periphery of the outlet 56 without resistance. The exhaust guide 60 may be formed in the shape of a truncated cone or a truncated pyramid, but it is most preferably formed in the shape of a bowl as shown. The reason for this is that the streamline shape is formed by a curved surface such as a paraboloid, so that the flow of the exhaust flow is smooth and the exhaust effect is excellent. For this reason, the regions of the blast airflow and the exhaust airflow are very clearly separated and mixed with each other.

The air flow exhausted as described above reaches the surface of the air duct 55, but what is important here is the position of the blower 58 for exhaust disposed in the upper part of the apparatus casing.
Since the blower 58 is on the side of the air duct 55, the exhaust flow B from the radiator 53 arranged in the vertical direction is the exhaust flow C rising along the surface of the air duct 55.

As is apparent from FIG. 1, the outer diameter of the delivery port 56 is much smaller than the outer diameter of the exhaust guide 60. Therefore, the fluid resistance to the flow of the exhaust flow C is small, and the exhaust is efficiently performed. Furthermore, this exhaust flow C
Does not flow on the motherboard 51 side,
The exhaust temperature has less influence on the LSI 52 and the like.

A more preferable shape of the delivery port 56 is shown in FIG. FIG. 4 shows the state viewed from the radiator side. As is clear from the figure, the outlet 56 is not a perfect circle but has a circular shape elongated in the longitudinal direction along the exhaust flow, or an oval shape. This also lowers the fluid resistance to the flow of the exhaust flow C.

The shape of the radiator is not limited to that in the above embodiment, but may be as shown in the front view of FIG. That is, in FIG. 5A, a large number of plate-shaped heat radiation fins 65 are formed in parallel. According to this, although the exhaust flow flows in both directions along the heat radiation fins 65, the cooling action, The effect is similar to that of the above-mentioned embodiment.

Further, as shown in FIG. 6B, the plate-like heat radiation fins 66 are radially arranged. According to this, although the exhaust flow flows in the radial direction, the cooling action and effect are shown. Is similar to the above-mentioned embodiment.

[0044]

As described in detail above, according to the cooling structure for a semiconductor device of the present invention, the cooling airflow sent from the outlet contacts the radiator of the semiconductor device, and then becomes the exhaust flow for heat dissipation. By pushing it to the side of the air duct, it changes the flow along the exhaust guide toward the outer periphery of the outlet, and this flow is guided to the upper blower for exhaust along the periphery of the outlet, so that the exhaust flow is extremely high. The practical effect that the flow is natural and a natural and smooth flow state is obtained is remarkable. It is needless to say that the present invention is not applicable only to a telecommunication device, but can be applied to the same parts in various fields.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

2 is a partially enlarged view of FIG.

FIG. 3 is a side sectional view for explaining a flow of a cooling air flow.

FIG. 4 is a front view for explaining the delivery port of FIG.

FIG. 5 is a front view of another embodiment of the radiator.

FIG. 6 is a perspective view of a conventional telecommunication device.

7 is a partial perspective view of the shelving frame of FIG.

FIG. 8: Conventional improved communication device

9 is a partially enlarged view of FIG.

10 is a partially enlarged view of FIG.

FIG. 11 is a conventional cooling structure according to the present invention.

FIG. 12 is a rear perspective view of the shelving

[Explanation of symbols]

 51 Motherboard 52 LSI 53 Heat Sink 55 Air Duct 56 Outlet 58 Blower 60 Exhaust Guide 61 Opening 65,66 Heat Dissipation Fin A Cooling Airflow B, C Exhaust Flow

Claims (3)

[Claims] 1. A semiconductor device (52) that generates heat, a radiator (53) in contact with the semiconductor device, and a cooling airflow exhaust guide (60) that surrounds the radiator and expands in the opening direction from the bottom surface.
And an outlet (56) for the cooling air that faces the opening (61) surface of the radiator, and the cooling air sent from the outlet (56) passes through the inside of the radiator (53). A cooling structure for a semiconductor device, characterized in that an exhaust guide (60) surrounding the radiator is used to discharge the heat in the peripheral direction of the outlet (56). 2. The cooling structure for a semiconductor device according to claim 1, wherein the exhaust guide (60) has a bowl shape. 3. A plurality of said semiconductor devices (52) are arranged, and a blower (58) for exhaust is formed so that an exhaust airflow of the cooling airflow is directed toward a cooling air airflow outlet (56) side. ) Is provided, The cooling structure of the semiconductor device according to claim 1 or 2 characterized by things.