JP3002611B2 - Heating element cooling device - Google Patents

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 efficiently cooling a high-density mounted semiconductor device.

[0002]

2. Description of the Related Art Since a computer is required to have a high processing speed, a method for mounting a large-scale LSI at high density has been developed in recent years. Accordingly, the amount of heat generated by the LSI itself is enormous, and the heat generation density of the semiconductor device is significantly increased due to the high-density mounting of the LSI. For this reason,
It is becoming increasingly important to efficiently cool LSIs. Conventionally, as a means for cooling a plurality of heat-generating semiconductor components mounted on a circuit board such as a printed circuit board or a ceramic substrate with a coolant such as air, fins are mounted on the heat-generating semiconductor components, respectively, and a cooling fluid is provided. In many cases, the heat is supplied from the side of the heat-generating semiconductor device and the heat-generating semiconductor device is sequentially cooled. However, in the above-described method, a problem arises in that the air temperature rises more toward the downstream side, and the cooling performance decreases. Therefore, as a method for solving this problem, a high-performance fin having a large heat-radiating surface on a heat-generating semiconductor component as described in JP-A-2-34993, JP-A-1-113355 and the like. Equipped with cooling air supplied from the blower,
A system has been proposed in which individual fins are individually blown through a chamber, a nozzle, or the like provided on the fins without air leakage.

[0003]

Of the above-mentioned conventional individual air-flow type air cooling devices, the air-cooling radiator disclosed in Japanese Patent Application Laid-Open No. 2-34993 has a heating element on a substrate (not shown) as shown in FIG. A large number of LSIs 1 are mounted, and a heat sink 3 composed of fins 2 is mounted on the LSI 1. The cooling air is supplied through a nozzle that covers the entire upper portion of the heat sink 3 and cools the LSI 1. The exhaust from the heat sink 3 is exhausted from the opening 4. In this case, even if the cooling air is uniformly supplied to the fins 2 in the heat sink 3 via the nozzles covering the entire upper part of the heat sink 3, the cooling air flows through the gaps between the fins 2 in the heat sink 3 and flows toward the opening 4. In the meantime, a velocity distribution having a different flow velocity is generated due to the flow loss of the fluid, and the velocity of the cooling air flowing near the fin root in the central part of the LSI 1 requiring particularly high cooling performance becomes the lowest. As a result, LSI1
At the center of the chip becomes the highest, and it is difficult to uniformly cool the temperature inside the chip.

Therefore, in Japanese Utility Model Laid-Open No. 1-113355,
An air cooling structure as shown in FIG. 11 has been proposed. In this case, the air outlet 5 above the heat sink 3 is not the entire area above the heat sink 3 but a narrowed air outlet 5.
However, even if the cooling air is strongly supplied to the center of the fin in the heat sink 3 by narrowing the air outlet 5 in this way, the cooling air passes through the fin gap in the heat sink 3 and the opening 6 on both sides of the heat sink 3. While flowing toward the fin, a velocity difference occurs due to fluid flow loss on the fin surface, and the semiconductor 1
It is difficult to remarkably increase the speed of the cooling air flowing near the center of the fin at the center. Generally, the point where the flow collides with the wall is called a stagnation point, where the flow stagnates. Even if the colliding flow is accelerated, the flow near the stagnation point cannot be accelerated. As a result, even in this case, the temperature at the center of the semiconductor 1 becomes highest, and there is a disadvantage that the temperature in the chip cannot be uniformly cooled.

[0005] Therefore, none of the above-mentioned prior arts takes into account the fact that the temperature distribution of the semiconductor integrated circuit element LSI is made uniform, and there is a problem in improving the cooling performance of the LSI.

An object of the present invention is to solve such a problem, and an object of the present invention is to make uniform the temperature distribution of a heating element such as a semiconductor integrated circuit device LSI which generates a large amount of heat and to make the heating element efficient. An object of the present invention is to provide a cooling device for a heating element that cools well. In particular, the present invention relates to a method in which a large number of LSI chips in a multi-chip module in which high-heat-generation LSI chips developed in recent years due to the demand for high-speed processing of a computer are mounted at a high density are mounted on air. It is an object of the present invention to provide an apparatus for uniformly cooling with a refrigerant such as the above.

It is another object of the present invention to provide a clamp device which reliably attaches a high-performance heat sink to a heating element such as a multi-chip module and reduces leakage of cooling fluid from the heat sink.

Still another object of the present invention is to provide a nozzle for supplying a cooling fluid to a heat sink without burdening an electric circuit connecting portion of a heating element such as a multi-chip module and reducing leakage of the cooling fluid. It is to provide a connection structure.

[0009]

In order to achieve the above object, a cooling device for a heating element according to the present invention is provided with a through slit extending from the upper surface of the heat sink to the base of the fin at the center of the heat sink for cooling the heating element. A mechanism in which a cooling fluid ejected from the upper surface of the heat sink directly reaches the upper portion of the center of the heating element without lowering the fluid velocity through the through slit and without increasing the temperature of the cooling fluid. It is.

Another feature of the cooling device of the present invention is that a guide for guiding the cooling fluid ejected from the upper surface of the heat sink to the center of the heat sink at a high speed is provided inside the heat sink.

Another feature of the present invention is that an L-shape having a bottom surface of a heating element such as a multi-chip module is provided with a leaf spring capable of adjusting a tightening force in a through slit provided in a heat sink. By providing mold clamps on both sides of the heat sink and combining with the above-mentioned leaf springs, it is possible to attach a high-performance heat sink to a heating element such as a multi-chip module with high reliability and space efficiency. The L-shaped clamp has a clamp device inside the heat sink for reducing leakage of the cooling fluid from the through slit.

Still another feature of the present invention is that a nozzle for supplying a cooling fluid to the heat sink and the heat sink are not integrally connected, but a soft buffer member is attached to the tip of the nozzle and inserted into a nozzle connection port provided on the heat sink. Therefore, a structure is provided in which a nozzle for supplying a cooling fluid with a reduced leakage of the cooling fluid is connected to a heat sink without placing a burden on an electric circuit connecting portion of a heating element such as a multi-chip module. is there.

[0013]

According to the present invention, since a through slit is provided in the center of the heat sink for cooling the heat generating element and extends from the upper surface of the heat sink to the root of the fin and traverses the fin, the fuel is injected from the upper surface of the heat sink. The cooling fluid passing through the through slit has a smaller pressure loss in the passage flow path than the cooling fluid passing between the fins constituting the heat sink. It can reach the root of the upper fin directly. Furthermore,
Since the cooling fluid passing through the through slit does not pass between the fins, the cooling fluid temperature can hardly increase and can directly reach the fin root at the upper center of the heating element with a low intake temperature. For this reason, the cooling performance of the central part of the heating element can be improved. As a result, it is possible to uniformly cool the temperature distribution of a heating element such as a semiconductor integrated circuit element LSI that generates high heat and efficiently cool the heating element. Especially in recent years,
A large number of LSI chips in a multi-chip module that collectively mount high heat-generating LSI chips developed from the demand for high processing speed of computers without using a special cooling fluid such as water. Cooling can be performed uniformly with a cooling fluid such as familiar air.

According to the present invention, at least one or more sets of flow guides for guiding the cooling fluid injected from the upper surface of the heat sink to the central portion of the heat sink at a high speed are provided inside the heat sink. The vicinity of the fin root in the upper center of the heating element can be concentrated and cooled. In addition, if the flow guide is provided in a location where the heat generation distribution is large, the temperature distribution of the heat generating element generating high heat can be made more uniform and the heat generating element can be efficiently cooled.

Further, according to the present invention, a plate spring inserted into the through slit and an L-shaped clamp fitting having a bottom surface of a heating element such as a multi-chip module as a support surface are combined to form a heat sink. By attaching to a heating element such as a multi-chip module, the cooling performance of a high-performance heat sink provided with a through slit can be reliably attached to a heating element such as a multi-chip module without lowering the cooling performance. The L-shaped clamp can reduce the leakage of the cooling fluid from the through slit and prevent the cooling performance from lowering.

Further, according to the present invention, by attaching a soft buffer member to the tip of the nozzle and inserting it into the nozzle connection port provided on the upper part of the heat sink, the electric power of the heating element such as a multi-chip module can be improved while improving the assemblability. The nozzle for supplying the cooling fluid can be connected to the high-performance heat sink without imposing a burden on the circuit connecting portion and reducing the leakage of the cooling fluid.

[0017]

FIG. 1 shows a first embodiment of the present invention.
This will be described in detail with reference to FIG. FIG. 1 is a perspective view of a partial cross section of a cooling device for a heating element to which the present invention is applied. FIG.
FIG. 1 is a cross-sectional view of FIG. 1 and shows a flow of a cooling fluid in a cooling device for a heating element. In these figures, as an example of a heating element, an example of a multi-chip module in which a large number of semiconductor devices generating high heat are hermetically sealed together is shown.

The multi-chip module 1 is manufactured by mounting a large number of semiconductor devices 3 each having a built-in LSI chip as a heating element on a ceramic wiring board 2 and sealing them with a housing 4. The heat generated in the semiconductor device 3 is transmitted to the housing 4 via the heat conductive contact 5 that contacts the semiconductor device 3. On the housing 4 of the multi-chip module 1, a heat sink 6 for effectively transmitting the heat to a cooling fluid such as cooling air is provided.
Is installed. The heat sink 6 is made of a material having good thermal conductivity such as aluminum, copper, or high thermal conductivity ceramic, and is composed of a large number of flat fins 7 and fin bases 8. In the center of the heat sink, there is provided a through slit 9 extending from the upper surface of the heat sink 6 to the base of the large number of flat fins 7 and vertically cutting the large number of flat fins 7.
The width of the through slit 9 is wider than the arrangement pitch of the plate fins 7. An air flow from a blower (not shown) such as a blower is applied to the upper surface of the heat sink 6.
A cooling fluid injection nozzle 11 leading to the inside is inserted into a cooling air inlet 12 between the heat sink holding plates 10.

The nozzle 11 or the heat sink 6
A soft cushioning member 13 is attached to one of the cooling air inlets 12. Furthermore, a multi-chip module
The heat sink 6 and the heat sink 6 are in thermal contact with each other by, for example, a thermally conductive grease, a thermally conductive sheet, a thermally conductive adhesive, or a bolt. Also,
The heat sink holding plate 10 is adhered or joined to the tips of a number of flat fins 7.

According to the present embodiment, as shown in FIG. 2, the air flow (arrow 20) injected into the heat sink 6 through the nozzle 11 is guided between the large number of flat fins 7 and into the through slit 9. However, since the width of the through slit 9 is wider than the arrangement pitch of the plate fins 7, the air flow entering the through slit 9 (arrow 21) has a small flow loss of the fluid, and the air flow between the many plate fins 7 is small. The flow velocity is larger than (arrow 22). As a result, the cooling air (arrow 21) passing through the through-slit 9 can reach the fin base 8 and the fin root at the upper center of the multi-chip module 1, which is the heating element, with almost no reduction in speed. I can do it. Furthermore, cooling air passing through the through slit 9 (air flow indicated by arrow 21)
Does not pass between the fins, so that the cooling fluid temperature hardly rises and can directly reach the fin root at the upper center of the multi-chip module 1 with a low air inlet temperature while maintaining a low inlet temperature. Therefore, the cooling performance of the central portion of the multi-chip module 1 which generally has a large temperature rise is improved, and the multi-chip module having a large number of built-in semiconductor devices 3 is improved.
The temperature distribution of the semiconductor device 3 which generates a large amount of heat can be uniform even with the heater 1 and the heating element can be efficiently cooled.

If the width of the through slit 9 is too large to increase the flow rate of the cooling air passing through the through slit 9, the area of the plate fin 7 is reduced, and the heat sink of the heat sink above the center of the multi-chip module 1 is reduced. Cooling performance will be reduced. Therefore, there is an optimum value for the width of the through slit 9.

Next, a partially modified example of the embodiment of FIG. 2 will be described with reference to FIG. In this embodiment, the same components as those shown in FIG.

As shown in the figure, the through-slit 9a provided at the center of the heat sink has a wide cooling air inlet side and narrows toward the fin root. For this reason, the inflow pressure loss of the through slit 9a can be reduced, the cooling air passing through the through slit 9a increases, and the cooling performance of the central part of the multi chip module where the temperature rise is large is improved. The semiconductor device built in the device can be cooled more efficiently.

Next, a partially modified example of the embodiment of FIG. 2 will be described with reference to FIG. In this embodiment, the same components as those shown in FIG.

In this embodiment, the through-slit 9b provided at the center of the heat sink is not provided to the base of the fin, and a flat fin 7b is provided on the fin base 8 at the bottom of the through-slit 9b.
But some are left. For this reason, even if the width of the through slit 9b is increased, the cooling performance at the center of the multi-chip module does not decrease.

In each of the above embodiments, the cooling fluid jet nozzle 11 for guiding the air flow into the heat sink 6
However, the width of the nozzle 11 may be the same as the width of the heat sink 6.

Next, a partially modified example of the embodiment shown in FIGS. 1 and 2 will be described with reference to FIG. In this embodiment, the same components as those shown in FIG.

In this embodiment, the heat sink holding plate 10a on the upper surface of the heat sink 6c has an L-shape, and the L-shaped bent end portion of the heat sink presses the cooling fluid jetted from the upper surface of the heat sink to the heat sink central portion at high speed. The guide 101 guides into the flat fin 7b. Therefore, a strong cooling flow (arrow 23) is guided by the flow guiding guide 101 by the through slit 9 provided at the center of the heat sink, and directly reaches the fin root at the upper center of the multi-chip module. Therefore, the cooling performance of the central portion of the multi-chip module where the temperature rise is large can be improved, and the semiconductor device built in the multi-chip module can be cooled more efficiently.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, the same components as those shown in FIG.

In this embodiment, a flow guide 102 for controlling the cooling flow between the flat fins 7c constituting the heat sink 6d is provided between the flat fins 7c, and extends from the upper surface of the heat sink toward the root of the fin. ing. The length of the flow guide 102 is shorter than the height of the flat plate fin 7c, and gradually decreases from the center of the heat sink toward the edge.

According to the present embodiment, the cooling fluid injected from the upper portion of the heat sink 6d to the heat sink 6d flows between the flat fins 7c according to the flow guiding guide 102, but the length of the flow guiding guide 102 is reduced. Since it is the longest at the center of the heat sink, it can directly reach the root of the fin even at the center of the heat sink. Furthermore, the flow guide 1
Since the length of the cooling fluid flowing out from the flow guiding guide in the central portion of the heat sink is smaller than that of the cooling fluid flowing out from the adjacent flow guiding guide since the length of the cooling fluid is gradually reduced from the central portion to the edge. It is pushed to the fin root by the flow, and the flow velocity increases. As a result, the cooling performance of the root of the fin having the highest temperature can be improved, and the cooling performance of the central portion where the temperature rise is large can be further improved.

FIG. 7 illustrates an embodiment in which a part of the above embodiment shown in FIG. 6 is modified. In this embodiment, the same components as those in FIG.

The present embodiment is different from the above-described embodiment shown in FIG. 6 in that the mounting pitch of the flow guiding guide 102a becomes narrower from the center of the heat sink toward the end. Since the space between the flow guides at the center of the heat sink is the widest, the flow can be guided more quickly.

Next, another embodiment of the present invention will be described with reference to FIGS. In this embodiment, the same components as those in FIG.

In this embodiment, a leaf spring 31 whose tightening force can be adjusted by a bolt 30 is inserted into the through slit 9 provided in the heat sink 6, and the bottom surface of the multi-chip module 1, which is a heating element, is used as a support surface. L-shaped clamps 32 are provided on both side surfaces of the heat sink.
1, the heat sink 6 is attached to the multi-chip module 1. Since the L-shaped clamp 32 can close the side surface of the through slit 9, leakage of the cooling fluid from the through slit 9 is reduced.

Further, the heat sink 6 and the multi-chip module 1 are provided in consideration of the assemblability of the multi-chip module 1.
It is preferable to separate them from each other. Therefore, the multi-chip module 1 and the heat sink 6 have a structure in which they are in thermal contact with each other by, for example, a thermally conductive grease, a thermally conductive sheet or a thermally conductive adhesive, or bolting. However, since the temperature distribution of the multi-chip module 1 and the heat sink 6 are different from each other, the amounts of thermal deformation due to the temperature distribution are also different from each other. Therefore, the heat sink 6
If the thermal resistance of the multi-chip module 1 does not always follow the thermal deformation of the multi-chip module 1, the thermal resistance between the multi-chip module 1 and the heat sink 6 fluctuates. Therefore, in the clamp device of the present embodiment, a load is applied to the center of the heat sink 6 by the leaf spring 31 and the L-shaped clamp 32 having the bottom surface of the multi-chip module 1 as a support surface, and the load force is applied by the bolt 30. The adjustment allows the heat sink 6 to always follow the multi-chip module 1. As a result,
The thermal resistance between the multi-chip module 1 and the heat sink 6 can be stabilized, and the space efficiency can be improved and the cooling fluid can be prevented from leaking.

[0037]

According to the present invention, a head for cooling a heating element is provided.
By providing a through slit in the center of the sink that extends vertically from the top of the heat sink to the root of the fin,
The cooling fluid passing through the through slit can directly reach the fin root at the upper center of the heating element without reducing the speed of the cooling fluid. Further, the cooling fluid passing through the through slit can directly reach the fin root at the upper center of the heating element while the cooling fluid temperature hardly rises and remains at a low intake temperature. For this reason, the cooling performance of the central part of the heating element can be improved. As a result, the semiconductor integrated circuit device LSI
For example, it is possible to uniformly cool the temperature distribution of the heating element that generates high heat and efficiently cool the heating element. Particularly, in recent years, a high heat generation LS developed from a demand for a high processing speed of a computer.
A large number of LSI chips in a multi-chip module that collectively mounts I chips and the like at high density can be cooled uniformly with a cooling fluid such as air, without using a special cooling fluid such as water. it can.

According to the present invention, at least one set of flow guides for guiding the cooling fluid injected from the upper surface of the heat sink to the central portion of the heat sink at a high speed is provided inside the heat sink. The vicinity of the fin root in the upper center of the heating element can be concentrated and cooled. In addition, if the flow guide is provided in a location where the heat generation distribution is large, the temperature distribution of the heat generating element generating high heat can be made more uniform and the heat generating element can be efficiently cooled.

Further, according to the present invention, the heat sink is formed by combining a leaf spring inserted into the through slit with an L-shaped clamp fitting having a bottom surface of a heating element such as a multi-chip module as a support surface. By attaching to a heating element such as a multi-chip module, it can be mounted on a heating element such as a multi-chip module with good reliability and space efficiency without deteriorating the cooling performance of a high-performance heat sink provided with through slits. Therefore, the L-shaped clamp can reduce leakage of the cooling fluid from the through slit.

Further, according to the present invention, a soft cushioning member is attached to the tip of the nozzle and inserted into the nozzle connection port provided on the upper part of the heat sink, so that the electric circuit connection part of the heating element such as a multi-chip module is burdened. The nozzle for supplying the cooling fluid without reducing the leakage of the cooling fluid can be connected to the high-performance heat sink.

[0041]

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view illustrating an embodiment of a heating device cooling device to which the present invention is applied.

FIG. 2 is a cross-sectional view of a main part of FIG. 1 showing a flow of a cooling fluid in a cooling device for a heating element.

FIG. 3 is a sectional view of an essential part for explaining a partially modified example of a cooling device for a heating element of the present invention.

FIG. 4 is a cross-sectional view of a main part for explaining a partially modified example of a cooling device for a heating element of the present invention.

FIG. 5 is a sectional view of an essential part for explaining a partially modified example of a cooling device for a heating element according to the present invention.

FIG. 6 is a sectional view of an essential part for explaining another embodiment of the cooling device for the heating element of the present invention.

FIG. 7 is a cross-sectional view of a main part illustrating a partially modified example of another embodiment of the cooling device for the heating element of the present invention.

FIG. 8 is a front view illustrating another embodiment of the heating element cooling device of the present invention.

FIG. 9 is a sectional view of FIG. 8;

FIG. 10 is a perspective view and a main part sectional view illustrating a conventional heating element cooling device.

FIG. 11 is a perspective view and a main part cross-sectional view illustrating a conventional heating device cooling device.

[Description of Signs] 1 ... multi-chip module, 2 ... ceramic multilayer wiring board, 3 ... semiconductor device, 4 ... housing, 5
... Heat conduction contacts, 6, 6a, 6b, 6c, 6d, 6e
..Heat sinks, 7, 7a, 7b, 7c: plate fins, 8: fin base, 9, 9a, 9b: through slits, 10, 10a: heat sink holding plate, 11,11
a: nozzle, 12: cooling air inlet, 13: buffer member, 20, 21, 22, ... air flow arrow, 30: bolt,
31 ... leaf spring, 32 ... L-shaped clamp fitting, 101,
102, 102a ... flow guide

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Fumiko Kobayashi 1 Horiyamashita, Hadano-shi, Kanagawa Prefecture Inside the Hitachi Works Kanagawa Plant (72) Inventor Tamotsu Tsukaguchi 1st Horiyamashita, Hadano-shi, Kanagawa Japan (72) Inventor Toshio Hatada 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref.Hitachi Seisakusho R & D Laboratories Ltd. (72) Inventor Yoshito Hayashi 1 Horiyamashita, Hadano City, Kanagawa Prefecture Inside the Kanagawa Plant, Hitachi, Ltd. (56) References JP-A-64-71154 (JP, A) JP-A-1-167094 (JP, U.S.A.) ) Hikaru 1-113355 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 7/20 H01L 23/473 H01L 23/36

Claims (4)

(57) [Claims] 1. A heat sink comprising a plurality of plate-shaped fins on a fin base, wherein a first fin group in which the fins and the fins are arranged in parallel with a constant interval between the plate surfaces. And a second fin group in which the fins and the plate surfaces of the fins are arranged in parallel at a constant interval, wherein the first fin group and the second fin group are are arranged with a predetermined interval in a direction perpendicular to the array direction of the plurality of fins, the spacing is wide rather configured than the fin spacing in each group of fins, the cooling fluid is supplied from the heat sink top surface To
The heating element attached to the lower surface of the fin base is cooled.
Heat sink, characterized in that the retirement. 2. A heat sink comprising a plurality of plate-like fins on a fin base, wherein the fins and the fins are arranged in parallel with a constant interval reaching the fin base between the respective plate surfaces. A first fin group, and a second fin group arranged in parallel with a constant interval reaching the fin base between the plate surfaces of the fins and the fins. the group of fins and the second fin group is arranged with a predetermined interval in a direction perpendicular to the array direction of the plurality of fins, the spacing is wide rather configured than the fin spacing in each group of fins The cooling fluid is supplied from the upper surface of the heat sink.
The heating element attached to the lower surface of the fin base is cooled.
Heat sink, characterized in that the retirement. 3. A heat sink comprising a plurality of plate-like fins on a fin base, wherein the fins and the fins are arranged in parallel with a constant interval reaching the fin base between the respective plate surfaces. A first fin group, and a second fin group arranged in parallel with a constant interval reaching the fin base between the plate surfaces of the fins and the fins. The fin group and the second fin group are arranged at regular intervals in a direction orthogonal to the arrangement direction of the plurality of fins, so that the first fin group and the second fin group slits are formed to penetrate the array direction of arrival to and fins to the fin base between the spacing of the slits widely configuration than the fin spacing in each group of fins
It is, that the cooling fluid is supplied from the heat sink top surface
The heating element attached to the lower surface of the fin base is cooled.
Heat sink, characterized in that the retirement. 4. The heat sink according to claim 1, wherein the plurality of fins are flat fins.