JPH0263147A - Cooling apparatus - Google Patents

Abstract

PURPOSE:To efficiently remove a coolant vapor air bubble inside a coolant flow route and to prevent a drop in a cooling capacity in a downstream part of the coolant flow route by a method wherein a plurality of pins, for air-bubble suction use, used to suck an air bubble which is generated from the surface of a semiconductor element and which is contained in a coolant liquid are installed in a downstream position of the semiconductor element inside the coolant flow route. CONSTITUTION:A coolant flow route 101 is connected to a heat exchanger via a circulating pump; a coolant liquid 103 is circulated inside the coolant flow route 101 by this system. In addition, also coolant vapor air bubbles 105 which have been sucked by pins 106 for air- bubble suction use are liquefied; after that, the air bubbles are again fed into the coolant flow route 101 by using the circulating pump. The pins 106, for air-bubble suction use, of, e.g., three pieces per semiconductor element chip are installed in a downstream position of a semiconductor element 102 inside the coolant flow route 101. Thereby, since the air bubbles 105 generated by heat of the semiconductor element 102 are sucked on the downstream side of the semiconductor element 102; the air bubbles 105 existing inside the coolant flow route 101 are small, and a cooling capacity in the downstream part of the coolant flow route 101 is not caused. Accordingly, the semiconductor element 102 which generates high heat can be cooled.

Description

[Detailed Description of the Invention] [Summary] Regarding a forced convection boiling cooling device for efficiently cooling semiconductor elements that generate a large amount of heat, cooling is achieved downstream of the refrigerant flow path by efficiently removing refrigerant vapor bubbles within the refrigerant flow path. To prevent a decline in performance and to cool a semiconductor element that generates a high amount of heat. The purpose is to also be able to cool a larger number of semiconductor devices at once.

In a cooling device that radiates heat from a plurality of semiconductor elements directly immersed in a refrigerant flow path by forced convection and boiling of refrigerant liquid, heat generated from the surface of the semiconductor element at a downstream position of the semiconductor element in the refrigerant flow path, It is configured to include a plurality of bubble suction pins for sucking bubbles contained in the refrigerant liquid.

(Industrial Application Field) The present invention relates to a cooling device, and particularly to a forced convection boiling cooling device for efficiently cooling a semiconductor element that generates a large amount of heat.

BACKGROUND ART In recent years, in electronic devices such as high-speed computers that use semiconductor elements, the amount of heat generated by the semiconductor elements has increased, and nine different cooling methods have been proposed to dissipate this heat to the outside.

In high-speed computers, the amount of heat generated per unit volume is increasing dramatically due to the high integration and high-density packaging of semiconductor elements. Therefore, it is necessary to establish even more efficient cooling technology.

[Conventional technology]

Conventionally, methods for cooling semiconductor devices such as LSIs include attaching heat dissipation fins to the semiconductor devices, using an air-cooling method in which the semiconductor devices are forced to cool with air using a fan, and cooling methods in which the semiconductor devices are directly immersed in a coolant. There is.

FIG. 3 is a diagram showing a pool boiling type cooling device belonging to the latter category.

In FIG. 3, 201 is a semiconductor element, 202 is a mounting board, 203 is a container, and 204 is a refrigerant liquid.

205 is a bubble, 206 is an upper space, and 207 is a heat exchange pipe.

Hereinafter, a conventional pool boiling type cooling device will be explained using FIG.

A mounting board 202 on which a plurality of semiconductor elements 201 are mounted is immersed in a refrigerant liquid 204 filled in a container 203.

A part of the heat generated by the semiconductor element 201 is transferred to the coolant and body 2.
It is absorbed as latent heat of boiling and vaporization of 04. At this time, bubbles 205 are generated in the refrigerant liquid 204.

The air bubbles 205 are liquefied by a heat exchange pipe 207 provided in the upper space 206 of the container 203.

The pool boiling type cooling device has been described above, but since the refrigerant liquid 204 is confined within the container 203 in this type of cooling device, there is a limit to the amount of heat radiation. Therefore, in order to obtain a larger amount of heat dissipation, a forced convection boiling cooling device has been proposed in which the refrigerant liquid is forced to undergo convection.

A forced convection boiling cooling device is a pool boiling type cooling device shown in FIG. 3, in which a heat exchanger is provided outside the container 203, and a refrigerant liquid is circulated between the container 203 and the heat exchanger using a circulation pump. This increases the amount of heat dissipation.

[Problem to be solved by the invention]

Although conventional forced convection boiling cooling equipment has high heat transfer efficiency, it does not produce vapor bubbles of the refrigerant caused by boiling.

Since it mixes with the circulating refrigerant liquid and becomes a gas-liquid two-phase flow, the heat exchange efficiency decreases as the amount of vapor bubbles relative to the refrigerant liquid increases. There was a problem.

Furthermore, when the amount of vapor bubbles increases, the pressure balance of the refrigerant liquid that is being pressurized and circulated by the circulation pump is disrupted, and a pulsating flow occurs that prevents stable cooling. There was also the problem.

Furthermore, the amount of heat generated by semiconductor elements increases.

Because the refrigerant boils violently, the amount of bubbles generated by boiling increases downstream of the refrigerant flow path in systems that cool multiple semiconductor devices at once.

The cooling efficiency decreases, the refrigerant reaches film boiling on the surface of the semiconductor element, and the temperature rises rapidly, resulting in destruction of the semiconductor element. There was also the problem.

When applying forced convection boiling cooling, which has higher cooling efficiency than forced air cooling or conduction water cooling, to semiconductor devices with high heat generation density, the biggest obstacle is the gas and liquid generated in the flow path.
It is a phase flow process.

The present invention efficiently removes refrigerant vapor bubbles in a refrigerant flow path, prevents a decrease in cooling capacity downstream of the refrigerant flow path, and makes it possible to cool semiconductor elements that generate high heat. Another object of the present invention is to provide a forced convection boiling cooling device that can cool a larger number of semiconductor devices at once.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a cooling device that radiates heat from a plurality of semiconductor elements directly immersed in a refrigerant flow path by forced convection and boiling of refrigerant liquid. A plurality of bubble suction pins for sucking bubbles generated from the surface of the semiconductor element and contained in the refrigerant liquid are provided downstream of the semiconductor element.

(Function) The cooling device of the present invention, particularly the forced convection boiling cooling device, has air bubbles generated from the surface of the semiconductor device at a position downstream of the semiconductor device in the coolant flow path and for sucking bubbles contained in the coolant liquid. Since multiple suction pins are provided, the air bubbles generated by the semiconductor element due to heat generation are sucked downstream of the semiconductor element, so there are fewer air bubbles in the refrigerant flow path and the cooling capacity downstream of the refrigerant flow path is increased. Therefore, no decrease in .

Can cool semiconductor elements that generate high heat. At the same time, it becomes possible to cool a larger number of semiconductor elements at once.

〔Example〕

Figure 1 is a sectional view of the forced convection evaporative cooling device of the present invention, Figure 2
The figure is a perspective view of the forced convection evaporative cooling device of the present invention.

In FIG. 1 and FIG. 2, lot is a refrigerant flow path, 10
2 is a semiconductor element, 103 is a refrigerant liquid, 104 is a flow of the refrigerant liquid, 10 is a bubble, and 106 is a bubble suction pin.

Hereinafter, two embodiments of the present invention will be described using FIG. 1 and FIG. 2.

A plurality of refrigerant channels 101 are provided in the forced convection evaporative cooling device of the present invention. A plurality of semiconductor elements 102 are placed inside each refrigerant flow path lO1 from upstream to downstream. Furthermore, inside the refrigerant flow path lot, as shown as a refrigerant liquid flow 104, fluorocarbon (C
Refrigerant liquid 103 such as bF+a) has a flow rate of 0.5 to 1.
It is flowing at 2m/s. The temperature of the refrigerant liquid 103 is 20
~40°C.

The refrigerant flow path 101 is connected to a heat exchanger (not shown) via a circulation pump (not shown).

This system allows the refrigerant liquid 103 to circulate within the refrigerant channel 101. Moreover, after the refrigerant vapor bubbles 105 sucked by the bubble suction pin 106 are also liquefied, they are sent into the refrigerant flow path 101 again by the circulation pump.

Next, the bubble suction pin 106, which is a feature of the present invention, will be explained.

The bubble suction pin 106 is located at a downstream position 1 of the semiconductor element 102 in the refrigerant flow path 101, for example, 1 from the end of the semiconductor element knob.
For example, 3 pieces per semiconductor element chip are attached at the crane positions. The suction amount of bubbles per bubble suction pin is 1, for example, 31/s.

In the above description, an example has been shown in which the bubble inducing pin 106 forcibly suctions and removes the refrigerant vapor bubbles generated on the surface of the semiconductor element 102 . However, even if no bubble suction force is applied to the five bubble suction pins 106, the amount of refrigerant vapor bubbles generated can be reduced and the cooling capacity can be improved by simply providing the bubble suction pins 106.

Table 1 shows an example of measuring the amount of bubbles generated, and Table 2 shows an example of measuring the cooling capacity.

(Leaving space below) Star table Amount of bubbles generated (volume %) *The chip number represents the order of the semiconductor elements in the refrigerant flow path 101, starting from the upstream: 1.2.・・・・・・、
It is 12.

**Condition A is when there is no bubble suction pin 106.

Condition B is when the bubble suction pin 106 is provided; Condition C is when the bubble suction pin 106 is provided.

This shows the case where suction is performed.

(Margin below) Table 11 Cooling capacity (W/csl) can be cooled down to -degrees.

In addition, simply attaching the bubble suction pin has the effect of creating turbulence in the flow of the refrigerant liquid, so it is possible to cool semiconductor elements that generate more heat than before.

Therefore, according to the present invention, it is possible to mount semiconductor elements at a high density, so that the calculation speed of a computer can be increased, which greatly contributes to improving performance.

*Condition A is when the bubble suction pin 106 is not provided, and Condition B is when the bubble suction pin 106 is provided.

Condition C shows the case where the bubble suction pin 106 is provided and suction is performed.

〔Effect of the invention〕

According to the present invention, it is possible to efficiently remove refrigerant vapor bubbles in a refrigerant flow path, prevent a decrease in cooling capacity downstream of the refrigerant flow path, and cool a semiconductor element that generates a high amount of heat. With the increase in the number of semiconductor devices

[Brief explanation of the drawing]

FIG. 1 is a sectional view 5 of the forced convection evaporative cooling device of the present invention. FIG. 2 is a perspective view of the forced convection evaporative cooling device of the present invention. Figure 3 is a diagram showing an example of a conventional pool boiling type cooling device. It is. In Figures 1 and 2 lOl: Refrigerant flow path 102: 103 = 104: l05: 106: semiconductor element refrigerant liquid refrigerant liquid flow bubbles Air bubble suction pin

Claims (1)

[Scope of Claims] A cooling device that radiates heat from a plurality of semiconductor elements (102) directly immersed in a refrigerant flow path (101) by forced convection and boiling of a refrigerant liquid (103), comprising: ) is provided with a bubble suction pin (106) downstream of the semiconductor element (102) for sucking air bubbles (105) generated from the surface of the semiconductor element (102) and contained in the refrigerant liquid (103). A cooling device characterized by having a plurality of cooling devices.