JPH0267792A - Dip cooling module - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding an immersion cooling module that cools printed circuit board packages widely used in various electronic devices, by exchanging heat with the cooling liquid inside the container whose temperature has risen due to the heat generated by the semiconductor chip, The purpose of this system is to minimize the vapor ejection of the vaporized cooling liquid and always provide high cooling capacity, by forming a sealed container in which a printed circuit board package with a semiconductor chip mounted thereon is immersed in the cooling liquid, and the interior of the container is A cooling pipe for cooling the cooling liquid is installed in the container, a heat exchange member having elasticity that can withstand the pressure of the container is installed in at least one side wall, and a safety valve for spouting the vapor of the cooling liquid is installed in the upper part of the container. A module provided with a pressure switch that operates at a pressure lower than the operating pressure of the safety valve, a duct surrounding the heat exchange member of the module, and an external module disposed at the lower inlet of the duct and driven by the operation of the pressure switch. The cooling means is configured to control the heat exchange member, which expands due to an increase in vapor pressure of the cooling liquid, to cooling by natural convection or forced cooling by the external cooling means by actuation of the pressure switch.

[Industrial application field]

The present invention relates to an immersion cooling module for cooling printed board packages widely used in various electronic devices.

Recently, printed board packages (hereinafter referred to as printed boards) mounted on large computers, etc. have become larger and more dense, but at the same time semiconductor chips mounted on these printed boards have become even more dense. As semiconductor chips become more integrated, the amount of heat generated by them increases, and the requirements for the cooling performance of semiconductor chips are also becoming very strict.

For this reason, a highly efficient immersion liquid cooling method has been adopted in which the printed circuit board is directly immersed in an inert cooling liquid. As the pressure inside the container increases, vaporized coolant will spout out from the safety valve installed in the container, reducing the amount of coolant inside and reducing cooling capacity, so minimize the spout of vaporized coolant. There is a need for new immersion cooling modules with consistently high cooling capacity.

[Conventional technology]

The conventional immersion cooling module is LS as shown in Figure 3.
A container 3 that houses and seals the printed board 1 on which IL-1 is densely mounted, and into which a cooling liquid 2 made of, for example, fluorocarbon with a low boiling point is injected to cool the LSil-1 and the printed board 1 is immersed therein. In addition, a safety valve 5 is provided on the top plate to blow out the steam to the outside when the steam pressure of the coolant 2 generated by the heat generated by the LSil-1 exceeds a certain level. A cooling pipe 4, which pumps cooling water using a pump (not shown) and exchanges heat with the cooling liquid 2 whose temperature has risen due to heat generation in the LSil-1, is installed close to the back of the LSil-1 mounted on the printed board 1. It is configured so that the LSil-1 of the printed board 1 immersed in the cooling liquid 2 is cooled by immersion.

[Problem to be solved by the invention]

The problem with the conventional immersion cooling module described above is that when a voltage is applied to the printed circuit board, the mounted LSi heats up, bubbles of the cooling fluid are generated from the surface, and the temperature of the cooling fluid rises. When the temperature of the liquid exceeds a certain level, the coolant vapor does not liquefy, so the internal pressure of the container gradually increases due to the vapor, but when the internal pressure exceeds a certain level, the coolant vapor ejects from the safety valve installed in the container. As a result, the coolant inside the container gradually decreases and the LS
A problem has arisen in that the cooling capacity of i is reduced.

In addition, in order to prevent the cooling capacity of LSt from decreasing, it is possible to newly inject the insufficient cooling liquid inside the container, but this has the problem of requiring extra man-hours to inject new cooling liquid. be.

In view of the above-mentioned problems, the present invention has been developed by exchanging heat with the cooling liquid inside the container whose temperature has increased due to the heat generated by the LSi.
The purpose of the present invention is to provide a new immersion cooling module that minimizes the vapor ejection of vaporized cooling liquid and constantly provides high cooling capacity.

[Means to solve the problem]

As shown in FIG. 1, the present invention forms a sealed container in which a printed board 1 on which LSil-1 is mounted at high density can be immersed in a cooling liquid 2, and the heat generated by LSil-1 is attached to the side wall of the sealed container. A plurality of heat exchange members 13-1 having excellent heat conduction and elasticity are provided to cool the coolant 2 whose temperature has increased, and a cooling pipe 4 to cool the coolant 2 to below the boiling point and a safety valve 5 for blowing out steam are provided. The heat exchange member 13-1 protruding from one side wall of the sealed container is attached to the module 13 which is provided in the same way as in the past and has a pressure switch 16 on the upper plate which operates at a pressure slightly lower than the operating pressure of the safety valve 5. Turn on the pressure switch 16 at the surrounding duct 17 and the lower inlet of this duct 17.
An external cooling means 1, such as a fan 18, driven by a fan 18 is provided. Then, the heat exchange member 13-1, which has expanded due to the increase in the internal pressure of the module 13 due to the heat generated by the LSil-1, is controlled to be cooled by natural convection by the operation of the pressure switch 16, and forced air cooling by the fan 18. It is composed of

0 operation] In the present invention, when no voltage is applied to the printed board 1 of the module 13 immersed in the cooling liquid 2, the module 1
The elastic heat exchange member 13-1 disposed on the side wall of the printed circuit board 1 is contracted as shown in FIG. generates heat, bubbles of the coolant 2 are generated from its surface, and the temperature of the coolant 2 also increases. The internal pressure of the module 13 gradually increases due to these bubbles (as shown in figure bJ, the heat exchange member 13-1 expands, and the heat of the expanded heat exchange member 13-1 causes a duct) to rise inside the module 17. Natural convection occurs in this direction, and the heat exchange member 13-1 is naturally cooled.

When the internal pressure of the module 13 further increases, the pressure switch 16 is activated to turn on the circuit as shown in Figure fC1, and the fan 18 rotates in the direction of the arrow and flows into the duct 17. Since the cooling air in the direction is force-fed, the heat exchange member 13-1 is forcedly air-cooled. Module 1 is cooled by natural air cooling or forced air cooling from the outside and water cooling by cooling pipe 4.
Since the cooling liquid 2 in the module 13 is cooled, the steam generated in the module 13 is liquefied by the cooling liquid 2, thereby making it possible to minimize the steam spewing out from the safety valve 5.

〔Example〕

The present invention will be described in detail below with reference to FIGS. 1 and 2.

FIG. 1 is a schematic diagram showing the immersion cooling module according to the present embodiment, and FIG. 2 is a side sectional view illustrating the function of the immersion cooling module according to the present embodiment. The other 13, which has the same symbol, is a module that cools the LSil-1 mounted by immersing the printed board 1 in the cooling liquid 2.

17 is a duct for cooling the heat exchange member disposed on the side wall of the module, and 18 is an air cooling fan.

As shown in FIG. 1, the module 13 is large enough to accommodate a printed board 1 on which LSills are mounted at high density, and the LSil-1 is immersed in a cooling liquid 2 made of fluorocarbon with a low boiling point injected into the module. A heat exchange member 9 having excellent heat conduction and elasticity for cooling the internal cooling liquid 2 from the outside is provided on the side wall facing the LSil-1, and a bellows 13-1 made of a copper alloy, for example, is provided. , forming a sealed container planted in a staggered manner at a constant pitch. As in the past, a cooling pipe 4 for cooling the internal coolant 2 below the boiling point and a safety valve 5 for blowing out steam are provided, and the circuit is turned on and off at a constant pressure slightly lower than the operating pressure of the safety valve 5.
A pressure switch 16 is disposed on the upper plate.

The duct 17 is a thin metal plate bent into a U-shape and has a width and height approximately equal to the side wall of the sealed container so as to surround the bellows 13-1 protruding from the side wall of the sealed container.

The fan 18 is a general-purpose axial cooling fan 18 that is driven when the pressure switch 16 is turned on.

The immersion cooling module using the above-mentioned members has a duct 17 arranged so as to surround the bellows 13-1 protruding from the side wall of the module 13, a fan 18 provided at the lower entrance of the duct 17, and a fan 18 and the module 13. It is connected to a pressure switch 16 disposed on the upper plate, and the pressure switch 16 is activated by the rise in internal pressure of the module 13, and the extended bellows 13-1 is forcedly air-cooled to cool the internal cooling liquid 2. It is configured as follows.

As a result, when voltage is applied to print vii, LSil
-1 generates heat and bubbles of the coolant 2 are generated from its surface, and the temperature of the coolant 2 also rises, causing the internal pressure of the module 13 to gradually rise, causing the bellows 13 to rise as shown in FIG. 2(b). -1 expands and enters duct 17 due to its heat? directional convection occurs and natural air cooling occurs. When the internal pressure of the module 13 further increases, the pressure switch 16 is activated as shown in Figure CC1, the circuit is turned on, the fan 18 rotates, and the cooling air flows into the duct 17. Since the bellows 13-1 is forcedly fed in the direction, the bellows 13-1 is forcedly air-cooled.

The cooling liquid 2 inside the module 13 is cooled by this natural air cooling or forced air cooling from the outside and water cooling by the cooling pipe 4, and the steam inside the module 13 is liquefied at the temperature of the cooling liquid 2, so that the steam inside the module 13 is liquefied at the temperature of the cooling liquid 2. can minimize steam eruptions.

The above description has been made based on the illustrated embodiment, but the present invention is not limited to the embodiments described above. For example, cooling water may be sent into the duct 17 by a pump (not shown) by the operation of the pressure switch 16. The bellows 13-1 may be water-cooled, and is not limited to forced air cooling using the fan 18.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the cooling medium can be cooled from the outside with an extremely simple configuration, suppressing the spout of the vaporized cooling medium, and providing high cooling capacity. In order to suppress the spout of vaporized cooling medium as much as possible, we have developed an immersion cooling module that has the advantage of requiring almost no man-hours to newly inject cooling medium into the container, and can be expected to have significant economic and reliability effects. can be provided.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an immersion cooling module according to an embodiment of the present invention, Fig. 2 is a side sectional view explaining the operation of the immersion cooling module of this embodiment, and Fig. 3 shows a conventional immersion cooling module. Schematic % formula % 1 is printed board, 1-1 is LSi, 2 is coolant,
4 is a cooling pipe, 5 is a safety valve, 13 is a module, 13-1 is a bellows, 16 is a pressure switch, 17 is a duct, and 18 is a fan. f(1) <b), iJθノJ-fnf)go/-jj yt4nEFmoji'5-IL@*zu:, 7! ,&2t2go Figure 1

Claims (1)

[Claims] A sealed container is formed in which a printed circuit board package (1) on which a semiconductor chip (1-1) is mounted is housed and immersed in a cooling liquid (2), and the cooling liquid (2) is placed inside the container. A cooling pipe (4) for cooling the liquid is installed, a heat exchange member (13-1) having elasticity that can withstand the pressure of the container is installed in at least one side wall, and the vapor of the cooling liquid (2) is installed in the upper part. Safety valve for ejection (
5) and a module (13) provided with a pressure switch (16) that operates at a pressure lower than the operating pressure of the safety valve (5).
), a duct (17) surrounding the heat exchange member (13-1) of the module (13), and a pressure switch (
and an external cooling means (18) driven by the operation of the pressure switch (16). Cooling by natural convection and the external cooling means (1)
8) An immersion cooling module characterized in that it is configured to control forced cooling according to 8).