JP2747156B2 - Immersion jet cooling heat sink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink for immersion jet cooling of an integrated circuit chip used for electronic equipment using liquid cooling, and more particularly, to immersing the integrated circuit chip in an insulating refrigerant so that it can be immersed in a nozzle. The present invention relates to a submerged jet cooling heat sink used for cooling by a jet.

[0002]

2. Description of the Related Art In recent years, with the increase in the amount of heat generated in electronic devices such as electronic computers, the importance of cooling technology has been increasing. In addition, as the speed and power consumption of integrated circuits have increased, air cooling has shifted to liquid cooling using water.In recent years, in order to further increase cooling efficiency, integrated circuit chips have been made of insulating materials such as fluorine carbide. The technique of immersion cooling directly immersed in a liquid or immersion jet cooling in which cooling by a jet from a nozzle is added has become important.

FIG. 4 is a perspective view showing a first example of a conventional heat sink for convection type air cooling. FIG. 5 is a sectional view showing an example of a longitudinal section of the heat sink of FIG. 4 used for immersion jet cooling. FIG. 6 is a perspective view showing a second example of the conventional heat sink. As shown in FIGS. 4 and 6, the conventional heat sink is mounted such that fins 23, 33 having a constant pitch are perpendicular or parallel to the surfaces of the integrated circuit chips 21, 31.
The surface of No. 3 has a smooth finished structure.

[0004]

When a conventional heat sink is used for cooling the immersion jet, as shown in FIG. 5, at the center of the heat sink, the refrigerant jetted from the nozzle 26 is exposed on the surface of the fin 23. A high impingement cooling efficiency can be obtained in order to sufficiently reach the fin bottom portion 27 at the center of the heat sink while removing bubbles due to boiling. However, in the peripheral portion of the heat sink, the fin 23 at the central portion of the heat sink acts as an obstacle, so that the refrigerant ejected from the nozzle 26 does not sufficiently reach the fin bottom portion 28 at the peripheral portion of the heat sink. Therefore, the cooling efficiency cannot be increased so much in the peripheral portion of the heat sink. Therefore, in the integrated circuit chip 21, the temperature distribution through the solder or the thermally conductive adhesive 22 becomes non-uniform, so that there is a problem that effective cooling cannot be performed.

[0005]

According to a first aspect of the present invention, there is provided a heat sink for immersion jet cooling, wherein a flat plate having good heat conductivity is bonded on an integrated circuit chip, and a cylindrical fin is formed on the flat plate having good heat conductivity. Then, a plurality of small-diameter holes penetrating the front and back sides are formed in the side surface of the cylindrical fin.

A immersion jet cooling heat sink according to a second aspect of the present invention is a radial fin having a heat conductive plate adhered on an integrated circuit chip and having a hole at the center of the heat conductive plate. Is formed, and a plurality of small-diameter holes penetrating the front and back sides are formed in the side surface of the radial fin.

[0007]

The immersion jet cooling heat sink of the present invention has a cylindrical or radial fin, so that the jet from the nozzle can sufficiently reach the entire fin including the fin bottom. In addition, the small-diameter holes formed in the fin side surfaces have the effect of suppressing the growth of bubbles and removing the bubbles by a jet during the minute period of the beginning of boiling.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a first embodiment of a heat sink for cooling a submerged jet according to the present invention. As shown in FIG. 1, in this embodiment, the chip heat dissipation surface of the face-down integrated circuit chip 1 is bonded to a flat plate 4 having good heat conductivity via solder or a heat conductive adhesive 2. Also,
A flat plate 4 having good thermal conductivity is provided with a cylindrical fin 3, and a small-diameter hole 5 penetrating from the front to the back is formed on the side surface of the cylindrical portion of the cylindrical fin 3.

FIG. 2 is a sectional view showing an example of a longitudinal section of the heat sink for cooling a submerged jet shown in FIG. As shown in FIG. 2, an insulating refrigerant such as fluorocarbon advances in the direction of the arrow in the figure, passes through the nozzle 6, and is not disturbed by the cylindrical fin 3, and has a good heat conductivity. Collision 4 The refrigerant collides with the flat plate 4 having good heat conductivity, thereby removing the heat of the integrated circuit chip 1 and then flowing out of the small-diameter hole 5 formed in the side surface of the cylindrical fin 3.

Usually, when the boiling is in the nucleate boiling region, the cylindrical fin 3 has a high cooling efficiency because the heat of vaporization of the boiling is deprived by the refrigerant in contact therewith, but the temperature of the cylindrical fin 3 increases. Then, when the film reaches the film boiling region, a vapor film is formed between the cylindrical fin 3 and the refrigerant, and large bubbles are generated as compared with those in the nucleate boiling region. Also, the amount of heat the refrigerant takes from the cylindrical fin 3 due to the presence of the vapor film is
It decreases rapidly. Therefore, in order to quickly remove the vapor film existing between the cylindrical fin 3 and the refrigerant, and to prevent regeneration, bubbles are removed from the heat transfer surface of the cylindrical fin 3 while the bubbles are very small in the initial stage of boiling. It is necessary to prevent boiling from transitioning to film boiling.

On the other hand, when the fin surface is a smooth surface, the number of points at which bubbles are generated is reduced, and the effect of cooling utilizing the effect of removing the heat of vaporization of steam by boiling is small. However, by forming a plurality of small-diameter holes 5 on the fin surface, it is possible to provide a stable generation point of many bubbles therein.

In the immersion jet cooling heat sink of the present embodiment, the refrigerant jetted from the nozzle 6 can contact the entire heat transfer surface of the cylindrical fin 3 and has a small diameter opened on the side surface of the upper cylindrical fin 3. Since the refrigerant flows out through the holes 5, bubbles generated by boiling can be eliminated. As a result, the cooling efficiency of the integrated circuit chip 1 can be increased in order to suppress the growth of bubbles and prevent the transition to film boiling.

FIG. 3 is a perspective view showing a second embodiment of a heat sink for cooling a submerged jet according to the present invention. As shown in FIG. 3, the present embodiment is a heat sink having the radial fins 13. The flat plate 14 having good heat conductivity is connected to the integrated circuit chip 1 via the solder or the heat conductive adhesive 12.
1 is bonded to the heat dissipation surface. The flat plate 14 having good heat conductivity is in contact with the radial fin 13 perpendicular to the flat plate surface and radially extending toward the center of the flat plate. A hole is provided at the center of the radial fin 13 so that the jet flow from the nozzle can collide with the flat plate 4 having good heat conductivity without being disturbed by the radial fin 3. Further, each radial fin 13 has a large number of small-diameter holes 15 penetrating the front and back.

The refrigerant ejected from the nozzle collides with the flat plate 14 having good thermal conductivity, deprives the integrated circuit chip 11 of heat, and then flows out radially along the heat transfer surface of the radial fin 13. At this time, fine bubbles generated by boiling on the side surface of the radial fin 13 can be wiped out. As a result, the cooling efficiency of the integrated circuit chip 11 can be improved.

[0016]

As described above, in the immersion jet cooling heat sink of the present invention, during immersion jet cooling, the flow of the refrigerant due to the jet is not hindered by the fins of the heat sink, and bubbles are generated by boiling. Has the effect of increasing the cooling efficiency of the integrated circuit.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a heat sink for cooling a submerged jet according to the present invention.

FIG. 2 is a sectional view showing an example of a longitudinal section of the heat sink for immersion jet cooling of FIG.

FIG. 3 is a perspective view showing a second embodiment of a heat sink for cooling a submerged jet according to the present invention.

FIG. 4 is a perspective view showing a first example of a conventional heat sink.

FIG. 5 is a sectional view showing an example of a longitudinal section of the heat sink of FIG. 4;

FIG. 6 is a perspective view showing a second example of a conventional heat sink.

[Explanation of symbols]

 1,11,21,31 Integrated circuit chip 2,12,22,32 Solder or thermally conductive adhesive 3 Cylindrical fin 13 Radial fin 23,33 Fin 4,14 Flat plate with good heat conductivity 5,15 Small hole 6, 26 Nozzle 27 Fin bottom at center of heat sink 28 Fin bottom at periphery of heat sink

Claims (2)

(57) [Claims] 1. A flat plate having good heat conductivity is adhered on an integrated circuit chip, a cylindrical fin is formed on the flat plate having good heat conductivity, and a small-diameter hole penetrating the side of the cylindrical fin. A heat sink for immersion jet cooling, characterized in that a plurality of heat sinks are opened. 2. A flat plate having good thermal conductivity is adhered on the integrated circuit chip, a radial fin having a hole is formed in a central portion on the flat plate having good thermal conductivity, and a front and back side is penetrated into a side surface of the radial fin. A heat sink for immersion jet cooling, characterized in that a plurality of small-diameter holes are formed.