JPH0595064A - Semiconductor cooling device - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to prevent the pressure rise of the cooling container due to the volume expansion of the refrigerant liquid that has received the heat of the semiconductor chip. A cooling container 7 is formed by a substrate 1 on which a large number of semiconductor chips 2 are mounted and a chamber 5, and a cooling liquid 7 is sealed in the cooling container 7 to cool the semiconductor chips 2 that generate heat.
A pressure absorbing mechanism 23 is attached to prevent the pressure inside the cooling container 7 from rising due to the volume expansion of the refrigerant liquid. [Effect] By preventing the pressure increase, the reliability of the cooling container formed by the substrate and the chamber can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip cooling device, and more particularly to a semiconductor cooling device for directly cooling a semiconductor chip, which is a heating element, by enclosing a coolant liquid in the cooling device.

[0002]

2. Description of the Related Art In a conventional semiconductor cooling device, an LS is disclosed in Japanese Patent Application No. 63-23246.
There is a device in which a coolant liquid is sealed between a substrate on which an I chip is mounted and a chamber, and the coolant liquid is flown to each LSI chip. This does not cause the coolant liquid to boil, but improves the cooling performance by causing the coolant liquid to flow through the LSI chip at a certain speed.

Further, as a proposed technique, an LSI chip and a mounting substrate which form a computer are inserted into a chamber, and the LSI chip which generates heat is cooled by boiling of a refrigerant liquid sealed in the chamber. Multiple L's on the mounting board
The SI chip is mounted, and the refrigerant liquid is a liquid having a low boiling point, such as parafluorocarbon liquid, and excellent electrical insulation. When the computer operates, the LSI chip generates heat, the refrigerant liquid boils and receives the heat of the LSI chip, and the bubbles of the generated refrigerant liquid rise upward. The refrigerant liquid in the chamber is sealed to the extent that the LSI chip is immersed, and a condenser is installed in the upper part of the chamber, and the bubbles of the refrigerant liquid rising due to the flow of cold water inside the condenser touch the condenser. As a result, it liquefies and returns downward. At this time, a constant pressure device composed of a bellows or the like is attached to the chamber. This serves to fill and extract the refrigerant liquid, and at the same time, to keep the pressure inside the chamber constant.

In the above two examples, the refrigerant liquid is directly immersed in the LSI chip.

[0005]

In a semiconductor device for electric power, noise is reduced, or in an LSI chip (semiconductor chip) such as a computer, an electric input to the semiconductor device is increased in order to improve an operation speed. And the amount of heat generated increases. As a countermeasure, it is necessary to improve the cooling efficiency of the semiconductor cooling device.

Generally, a plurality of LSI chips are mounted on a substrate. Therefore, when the coolant liquid is sealed in the chamber, both the LSI chip and the substrate can be inserted into the chamber, but the structure of the portion for taking out a large number of signal lines communicating with the substrate to the outside of the chamber becomes complicated. In other words, there must be a structure in which the refrigerant liquid or the refrigerant gas does not leak out of the chamber, and there is a structure in which signal lines are taken out by using a hermetic seal or the like, but the structure is complicated to take out many signal lines. However, the area for that is also required, and there is a problem that the size of the chamber becomes large. Further, there is a problem that reliability in actual use is lowered.

Therefore, the substrate and the chamber form a cooling container for enclosing the cooling medium. With this configuration, it is possible to output a signal from the substrate surface side opposite to the surface on which the LSI chip is mounted, and it becomes relatively easy to take out the signal line from the cooling container. By the way, in the case of this configuration, the refrigerant liquid is sealed in the cooling container, but generally the refrigerant liquid expands when the temperature rises. Therefore, when the cooling container is composed of the substrate and the chamber, for example, the coolant liquid is sealed at a general temperature (about 20 ° C.), and 50 to 10 is supplied during operation.
When the temperature rises to 0 ° C., the liquid expands and damages the cooling container.

Further, when the liquid refrigerant is sealed in the cooling container in the factory, the cooling container must be transported to the site, and a structure for sealing the refrigerant liquid in the state of the cooling container is required.

Further, when a cooling container is installed on-site, it must be installed in the piping system without leaking the refrigerant liquid.

It is an object of the present invention to provide a semiconductor cooling device capable of preventing a pressure rise in a cooling container even when a semiconductor chip is cooled and a liquid refrigerant expands in volume.

[0011]

In order to solve the above-mentioned problems, a semiconductor cooling device according to the present invention cools a plurality of semiconductor chips mounted on a substrate with a coolant liquid to form a cooling container with the substrate and a chamber. In a semiconductor cooling device comprising a refrigerant inflow pipe and a refrigerant outflow pipe for a refrigerant liquid in a cooling container, a pressure container is provided with a pressure absorbing mechanism for preventing a pressure rise due to volume expansion of the refrigerant liquid. And

The cooling container has a one-touch connector on each of the refrigerant inflow pipe and the refrigerant outflow pipe.

Further, the cooling container is constructed such that at least one of the refrigerant inflow pipe and the refrigerant outflow pipe is provided with a pressure absorbing mechanism made of a bellows.

Further, the cooling container may have a structure in which the chamber is formed by a pressure absorbing mechanism composed of a bellows.

The cooling container may have a structure in which the chamber is formed by a pressure absorbing mechanism having a thin structure.

The cooling container may have a structure in which a pressure absorbing mechanism made of a bellows is attached to the chamber.

Further, the cooling container may have a space above the liquid surface of the refrigerant liquid filled in the chamber, and the space may serve as a pressure absorbing mechanism.

Further, a plurality of cooling containers containing a substrate on which a plurality of semiconductor chips are mounted together with a refrigerant liquid are provided, a space is formed above the liquid surface of the refrigerant liquid, and the liquid surfaces are maintained at substantially the same height. Cooling containers were arranged side by side, and a liquid cooler having a space and arranged at approximately the same height as the liquid level was connected to the liquid coolers and the respective cooling containers, and provided in contact with the liquid level. The configuration may include a refrigerant outflow pipe, a refrigerant inflow pipe connecting the liquid cooler and each cooling container, and a refrigerant liquid circulation means.

Further, the liquid cooler is provided with a liquid level control plate for maintaining the liquid level of the refrigerant liquid substantially constant.

Further, a plurality of cooling containers, each of which accommodates a substrate on which a plurality of semiconductor chips are mounted together with a refrigerant liquid, and is arranged in parallel,
A liquid cooler connected to each cooling container through a refrigerant inflow pipe, a refrigerant outflow pipe, and a refrigerant liquid circulation means, and a bellows provided in at least one of the liquid cooler and each cooling container. It may be configured.

[0021]

[Function] The volumetric expansion of the refrigerant liquid is about 3 to 5% in consideration of the room temperature at the time of encapsulation and about 100 ° C at the time of operation.
However, it is necessary to absorb this volume expansion. When the refrigerant liquid is filled, the bellows is in a contracted state due to the spring force of the flexible bellows attached to the cooling container. For example, when a parafluorocarbon liquid is used as the refrigerant liquid, the room temperature (for example, 20
(° C), the inside of the cooling container is pulled down by a vacuum pump to reduce the pressure and the refrigerant liquid is enclosed.
In this state, the outside of the cooling container is at atmospheric pressure, whereas the inside of the cooling container is in a negative pressure state where the pressure is lower than atmospheric pressure. At this point, the flexible bellows is in a fully contracted state. When the semiconductor element is activated, the LSI chip (semiconductor chip) generates heat. LSI
The temperature of the chip approaches 100 ° C., and the coolant liquid receives the heat of the LSI chip from the surface of the LSI chip. At this time, the refrigerant liquid expands in volume at a rate at which the temperature of the refrigerant liquid rises. At this point, the flexible bellows expands. If the outside of the cooling container is at atmospheric pressure and the bellows is excellent in flexibility, the internal pressure of the cooling container can be maintained at a value slightly higher than atmospheric pressure.

On the other hand, by taking out the pipe from which the refrigerant flows out of the cooling container from a predetermined location in the cooling container, the refrigerant liquid does not flow into the portion at a position higher than the outflow pipe in the cooling container. By increasing the diameter of the outlet pipe to some extent, that is, if it is too small and the flow pressure loss in this part is large, the refrigerant liquid level in the cooling container rises, and the cooling liquid is filled in the cooling container. There is no end.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an external perspective view, and FIG. 2 is a sectional view thereof. A plurality of LSI chips (semiconductor chips) 2 are mounted on the substrate 1. A large number of signal pins 3 are provided on the opposite surface of the substrate 1. A large number of solder balls 4 for connecting signals are installed between the substrate 1 and the LSI chip 2. Although this is an example of a computer, when the computer is operating, the semiconductor elements in the LSI chip 2 exchange signals to perform arithmetic operations.
The chip 2 generates heat. It must be cooled in order to maintain this temperature at the desired temperature. Next, the cooling system will be described. The cooling liquid 6 is enclosed by the substrate 1 and the chamber 5 to form a cooling container 7. The chamber 5 includes an inflow part 8 into which the coolant liquid 6 flows, a cooling part 9 in which the coolant liquid 6 cools the LSI chip 2, and an outflow part 10 in which the coolant flows out. A refrigerant inflow pipe 11 and a refrigerant outflow pipe 12 are attached to the chamber 5. Inflow part 8 and cooling part 9 of the refrigerant liquid 6
Nozzles 14 are attached to the partition plate 13 for partitioning the and, in a direction from the partition plate 13 side to the LSI chip 2 side, corresponding to each LSI chip 2. The cooling part 9 and the outflow part 10 are partitioned by the second partition plate 15 as necessary. The nozzle 14 is provided on the second partition plate 15 as the LSI chip 2
An opening 16 is provided corresponding to each nozzle 14 so as to project to the side. Therefore, the size of the opening 16 is larger than the outer diameter of the nozzle 14. The refrigerant inflow pipe 11 is attached to the inflow portion 8, and the refrigerant outflow pipe 12 is attached to the outflow portion 10. The chamber 5 is composed of an outer chamber 17 forming an inflow portion 8 and an inner chamber 18 forming a cooling portion 9 and an outflow portion 10. The substrate 1 and the inner chamber 18 are sealed by a seal member 19, and the outer chamber 17 and the inner chamber 18 are sealed by a seal member 20. One-touch connector 21 is attached to the refrigerant inflow pipe 11,
A one-touch connector 22 is attached to the refrigerant outflow pipe 12, and a flexible bellows 23 is attached to one end of the refrigerant inflow pipe 11 that communicates with the inflow portion 8 and the one-touch connector 22. In the example of FIG. 2, the flexible bellows (pressure absorbing mechanism) 23 is attached to the refrigerant inflow pipe 11 side, but the flexible bellows 23 is provided between the one-touch connector 21 and the outflow portion 10 on the refrigerant outflow pipe 12 side. May be attached.

Next, the operation of this embodiment will be described. The one-touch connectors 21 and 22 have a sealing property when they are removed from the piping system, and have a function of passing a flow when they are attached to the piping system, and are already commercially available. Therefore, for example, in the case where the cooling medium 7 is sealed in the cooling container 7 in the manufacturing factory, if the cooling medium 6 is filled so as to be filled up, the one-touch connectors 21, 2
Sealed by 2. When the cooling container 7 in which the refrigerant liquid 6 is sealed in this way is assembled on-site, the piping system is configured via the one-touch connectors 21 and 22.

Next, the operation at the time of operation when the piping system is configured will be described. The refrigerant liquid 6 that has flowed in from the refrigerant inflow pipe 11 is first guided to the inflow portion 8 and then branched into each nozzle 14 and supplied to each LSI chip 2. Each L
The SI chip 2 is generating heat, and the supplied refrigerant liquid 6 is heated, so that the temperature may rise or may boil. The refrigerant that has received the heat passes through the opening 16 and flows out from the outflow portion 10
And is discharged from the refrigerant outflow pipe 12.

FIG. 3 shows another embodiment of the present invention. Corresponding to each LSI chip 2, a flow path branching plate 24 is provided on the second partition plate 15 so as to project to the cooling unit 9 side. FIG. 4 shows the relative positions of the flow path branching plate 24 and the LSI chip 2, and is a cross-sectional view taken along the line AA shown in FIG. A lattice-shaped flow path branching plate 24 is arranged in each gap between the plurality of arranged LSI chips 2. In this configuration, the coolant that has cooled the LSI chip 2 is caused to flow into the flow channel branching plate 24 corresponding to the LSI chip 2 so that the coolant is guided to the outflow portion 10.

FIG. 5 shows another embodiment. Outer chamber 17
A flexible bellows structure 26 is provided on the entire outer wall 25 of the above.

FIG. 6 shows another embodiment. Outer chamber 17
The outer wall 25 as a whole has a thin-walled structure (pressure absorbing mechanism) 27 so as to function similarly to a flexible bellows.

FIG. 7 shows another embodiment. Outer chamber 17
A flexible bellows tube 28 is attached to the outer wall 25 of the above.

FIG. 8 shows another embodiment. Refrigerant inflow pipe 1
1 is a flexible bellows structure 29.
Of course, a part of the refrigerant outflow pipe 12 may have a flexible bellows structure.

9 and 10 show another embodiment. Figure 9
Is an external perspective view, and FIG. 10 is a sectional view thereof. Cooling container 7
Is arranged vertically, the takeout portion of the refrigerant outflow pipe 12 is provided above the side surface and in contact with the liquid surface of the refrigerant. In this case, the flexible bellows need not be attached. In a production plant, the cooling liquid is sealed in the cooling container 7 by keeping a space by the volume of liquid expansion (volume expansion) expected at the time of operation, so that the temperature of the cooling container 7 fluctuates during transportation. Even if the liquid expands, the liquid only expands into the space, and the pressure in the cooling container 7 does not rise. Further, during the operation, the space 30 between the mounting position of the refrigerant outflow pipe 12 and the internal structure of the inner chamber 18 is filled with the refrigerant gas without accumulating the refrigerant liquid. Even if the temperature of the refrigerant liquid rises and the liquid expands,
The pressure in the cooling container 7 does not rise due to the absorption of the space in this portion. Therefore, the installation position of the refrigerant outflow pipe 12 must be such that the space between this position and the uppermost stage of the internal structure of the inner chamber 18 is always kept larger than the expected volume expansion amount of the refrigerant liquid. .. Further, in order to reduce the flow pressure loss, it is necessary to increase the diameter of the refrigerant outflow pipe to some extent.

FIG. 11 shows another embodiment. A plurality of cooling containers 7 are arranged side by side. FIG. 11 shows the case of three pieces, which are arranged horizontally with the same height. By arranging them horizontally, the liquid level height 31 of the refrigerant liquid in each cooling container 7 is maintained at the same height. The present embodiment includes not only the structure of the cooling container 7 but also the circulation system for the refrigerant liquid. The heated refrigerant discharged from each cooling container 7 is connected to each other and returns from the return pipe 32 to the liquid cooler 33 (arrow 36). In the liquid cooler 33,
Cold water 35 flows from a chiller 34 that produces cold water to cool the heated refrigerant. The cooled refrigerant liquid is pressurized by the pump (refrigerant liquid circulation means) 37 and guided to each cooling container 7 through the inflow pipe 38 (arrow 39). The position of the liquid cooler 33 in the height direction is such that the liquid level height 31 of the refrigerant liquid in each cooling container 7 and the liquid level height 40 in the liquid cooler 33 are kept equal as shown in FIG. And the relative position. A refrigerant purity management device 42 for increasing the purity of the refrigerant liquid is attached at a position connecting the inflow pipe 38 and the return pipe 32 in the outlet direction of the pump 37. Examples of refrigerant purity control include water removal and dissolved oxygen removal. By maintaining the liquid level height 40 of the refrigerant liquid in the liquid cooler 33, the liquid level heights 31 of the plurality of cooling containers 7 can be more stably maintained.
Can be maintained at the same level, and the pressure in each cooling container 7 can be prevented from rising even if the refrigerant liquid expands. Further, a flexible bellows 41 may be commonly provided on the upper part of the liquid cooler 33, and one flexible bellows 41 can more completely prevent the pressure increase of the plurality of cooling containers 7.

FIG. 12 shows another embodiment. Liquid cooler 33
A liquid level control plate 43 is provided inside. The refrigerant returned from each cooling container 7 is put into the liquid cooler 33, the liquid level control plate 43 overflows, and the refrigerant liquid is guided to the inflow pipe 38. In such a structure, the space inside the liquid cooler 33 above the tip of the liquid level control plate 43 is always filled with the refrigerant gas. In this way, it is possible to always install a space for absorbing the liquid expansion in the liquid cooler 33 without providing a mechanism for absorbing the liquid expansion in each cooling container 7. A flexible bellows 41 may be provided above the liquid cooler 33, and the same effect as described above can be obtained.

According to the present invention, since the cooling container is formed by the substrate and the chamber, the signal wire take-out structure for taking out an electric signal from the signal pin mounted on the substrate to the outside of the cooling container is simplified, and the cooling is performed. By providing a space for absorbing the volume expansion of the refrigerant liquid in the container, it is possible to prevent a pressure increase in the cooling container. Further, by providing the one-touch connectors on the refrigerant inflow pipe and the refrigerant outflow pipe, it becomes possible to seal the refrigerant liquid in the cooling container in a production factory or the like.

Further, by providing the pressure expansion absorbing mechanism, it is possible to prevent the pressure increase in the cooling container due to the volume expansion of the refrigerant liquid when the cooling container is transported.

The position of the liquid cooler is set so that the liquid level of the refrigerant liquid in the liquid cooler is kept at the same level as the liquid level of the plurality of cooling containers. A space for the refrigerant gas can be provided in the space, and the pressure increase due to the volume expansion of the refrigerant liquid can be stably prevented.

Further, by providing the liquid level control plate in the liquid cooler, the liquid level height of the liquid cooler can be kept stable regardless of the position of the liquid cooler, and the pressure due to the volume expansion of the refrigerant liquid can be maintained. You can prevent the rise.

[0038]

According to the present invention, since the pressure absorbing mechanism is attached to the cooling container, the volume expansion of the refrigerant liquid is absorbed and the pressure rise is prevented, and a plurality of cooling containers are arranged side by side with the liquid cooler. It is possible to provide a semiconductor cooling / heating device including a pressure absorbing mechanism and stabilizing the pressure.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of FIG.

FIG. 3 is a sectional view showing another embodiment of the present invention.

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

FIG. 5 is a sectional view showing another embodiment of the present invention.

FIG. 6 is a sectional view showing another embodiment of the present invention.

FIG. 7 is a sectional view showing another embodiment of the present invention.

FIG. 8 is a sectional view showing another embodiment of the present invention.

FIG. 9 is an external perspective view showing another embodiment of the present invention.

10 is a cross-sectional view of FIG.

FIG. 11 is an external perspective view showing another embodiment of the present invention.

FIG. 12 is a front view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Substrate 2 LSI Chip (Semiconductor Chip) 3 Signal Pin 5 Chamber 6 Refrigerant Liquid 7 Cooling Container 11 Refrigerant Inflow Pipe 12 Refrigerant Outflow Pipe 13 Partition Plate 14 Nozzle 21, 22 One-touch Connector 23 Flexible Bellows (Pressure Absorption Mechanism) 30 Space 33 Liquid cooler 43 Liquid level control plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Oguro 502 Jinritsucho, Tsuchiura-shi, Ibaraki Hiritsu Manufacturing Co., Ltd.Mechanical Research Laboratory (72) Inventor Toshio Hatta 502 Jinritsucho, Tsuchiura-shi, Ibaraki Hiritsu Manufacturing Co., Ltd. Mechanical Research Laboratory (72) Inventor Toshio Hatada 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Hiritsu Seisakusho Co., Ltd. (72) Inventor Kenji Takahashi 502 Jinmachi-cho, Tsuchiura-shi, Ibaraki Hiritsuteki Co., Ltd. 72) Inventor Akira Inoue 502 Kintatecho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Seisakusho Co., Ltd. (72) Kenichi Kasai 1 Horiyamashita, Hadano, Kanagawa Prefecture Hitate Works Kanagawa Plant Co., Ltd.

Claims (10)

[Claims] 1. A plurality of semiconductor chips mounted on a substrate are cooled with a refrigerant liquid, a cooling container is formed by the substrate and a chamber, and the cooling container is provided with a refrigerant inflow pipe and a refrigerant outflow pipe for the refrigerant liquid. In the semiconductor cooling device according to the present invention, the pressure container is provided with a pressure absorbing mechanism for preventing a pressure increase due to the volume expansion of the refrigerant liquid. 2. The semiconductor cooling device according to claim 1, wherein the cooling container is provided with a one-touch connector in each of the refrigerant inflow pipe and the refrigerant outflow pipe. 3. The semiconductor cooling device according to claim 1, wherein the cooling container is provided with a pressure absorbing mechanism made of a bellows in at least one of the refrigerant inflow pipe and the refrigerant outflow pipe. 4. The semiconductor cooling device according to claim 1, wherein the cooling container has a chamber formed by a pressure absorbing mechanism including a bellows. 5. The semiconductor cooling device according to claim 1, wherein the cooling container has a chamber formed by a pressure absorbing mechanism having a thin structure. 6. The semiconductor cooling device according to claim 1, wherein the cooling container has a pressure absorbing mechanism made of a bellows attached to the chamber. 7. The semiconductor cooling device according to claim 1, wherein the cooling container is provided with a space above the liquid surface of the refrigerant liquid filled in the chamber, and the space serves as a pressure absorbing mechanism. 8. A plurality of cooling containers containing a substrate on which a plurality of semiconductor chips are mounted together with a refrigerant liquid are provided, a space is formed above the liquid surface of the refrigerant liquid, and the liquid surfaces are maintained at substantially the same height. And each of the cooling containers are arranged in parallel, and the liquid cooler having the space and arranged at substantially the same height as the liquid surface,
A refrigerant outflow pipe that connects between the liquid cooler and each cooling container and is provided in contact with the liquid surface, and a refrigerant inflow pipe and a refrigerant that connects between the liquid cooler and each cooling container. A semiconductor cooling device comprising a liquid circulating means. 9. The semiconductor cooling device according to claim 8, wherein the liquid cooler is provided with a liquid level control plate for maintaining the liquid level of the refrigerant liquid substantially constant. 10. A plurality of cooling containers, in which substrates having a plurality of semiconductor chips are mounted together with a refrigerant liquid, arranged in parallel, and connected to the respective cooling containers via a refrigerant inflow pipe, a refrigerant outflow pipe and a refrigerant liquid circulation means. And a bellows provided on at least one of the liquid cooler and the respective cooling containers.