JPH0310705Y2 - - Google Patents

Description

[Detailed description of the invention] [Summary] A metal member having a pinhole is fixed to the tip of the bellows via a heat sink head, and the metal member has a low melting point that is melted by the heat generated by the electronic component. By impregnating it with metal, it is formed to ensure adhesion between the surface of the electronic component and the heat sink head during cooling, and to improve thermal conductivity.

[Industrial application field]

The present invention relates to a cooling structure for cooling electronic components such as LSI elements mounted on a printed circuit board, and in particular,
The present invention relates to a cooling structure configured to perform cooling by a cooling plate through which a refrigerant is circulated.

In recent years, electronic components such as LSI elements that are widely used in electronic devices have become increasingly densely packaged and processed at high speeds. A major challenge is how to efficiently cool such electronic components.

Such cooling is economical, and the cooling structure shown in FIG. 3 using a refrigerant that provides a high cooling effect is generally known.

FIG. 3 is a perspective view showing an outline of the cooling structure.
A cooling plate 3 is provided to overlap the printed circuit board 1 on which a plurality of electronic components 2 are mounted as shown by an arrow F, and a bellows 5 is fitted to the surface of the electronic component 2 at a predetermined location on the cooling plate 3. It is set up so that

Therefore, the tip of the bellows 5 is connected to the electronic component 2.
One opening 1 of the cooling plate 3 is pressed against the surface of the cooling plate 3.
The refrigerant 4 is supplied from the refrigerant 4 in the direction of the arrow A and discharged from the other port 10 in the direction of the arrow B, so that the coolant 4 is circulated and the heat generated by each electronic component 2 is cooled.

In such a cooling structure, in order to improve the cooling efficiency of the electronic components 2, it is necessary to determine how uniformly the surface of each electronic component 2 is on a predetermined surface of the cooling plate 3.
Moreover, it is important that they are tightly attached to each other so that good heat transfer can be achieved.

[Conventional technology]

Conventionally, the structure was as shown in the conventional cross-sectional view of FIG. 4.

As shown in FIG. 4, a bellows 5 with a heat transfer member 14 fixed to one end is fixed by attaching a flange 11 to a predetermined location of the cooling plate 3 using an O-ring 13, and further, the heat transfer member 14 By attaching a heat transfer sheet 12 to the device, the heat transfer sheet 12 was configured to be pressed against the surface of the electronic component 2 mounted on the printed circuit board 1.

Therefore, the refrigerant 4 indicated by the arrow A1 that has flown through the one circulation path 3A of the cooling plate 3 is ejected from the nozzle 3B in the direction of the arrow A2, and further flows through the other circulation path 3A.
The heat transfer member 14 and the heat transfer sheet 12 cool the electronic component 2 through the heat transfer member 14 and the heat transfer sheet 12.

Such a bellows 5 is designed to provide a uniform contact pressure to the surface of the electronic component 2 without adversely affecting the electronic component 2,
It is made of a material such as copper or stainless steel that is as thin as possible, and is shaped like a bellows to have spring properties.

Further, the heat transfer sheet 12 is made of a soft resin material mixed with metal powder, which is a good thermal conductive material, so as to absorb the difference in parallelism between the heat transfer member 14 and the surface of the electronic component 2 and bring them into close contact with each other. It is formed.

[Problem that the invention attempts to solve]

However, in such a configuration, the heat transfer sheet 12
Since the base material is a resin material to provide flexibility, the thermal conductivity decreases.

Therefore, there was a problem in that the heat absorption of the circulating refrigerant 4 was reduced, and the cooling capacity was reduced.

It is conceivable to apply a jelly-like heat transfer paste to the surface of the electronic component 2 without using such a heat transfer sheet 12, but applying it to the surface of each electronic component 2 requires a huge amount of man-hours. In addition, when it becomes necessary to remove the printed circuit board 1 due to a failure or maintenance inspection, the applied heat transfer paste must be removed, and this removal also requires a huge amount of man-hours just like the application. was.

[Means for solving problems]

FIG. 1 is a sectional view of the principle of the present invention.

As shown in FIG. 1, it is formed of a heat sink head 6 fixed to the tip of the bellows 5 and a good heat conductive material having pinholes, one side is fixed to the heat sink head 6 and the other side is an electronic A metal member 7 is provided which is pressed into contact with the electronic component 2, and the metal member 7 is impregnated with a low melting point metal 8 that is melted by heat generated by the electronic component 2.

With this configuration, the above-mentioned problems are solved.

[Effect]

That is, by providing a metal member impregnated with a low-melting point metal using a heat sink head fixed to the tip of the bellows, and pressing the metal member against the electronic component, the heat generated by the electronic component cools the metal member. The metal is melted and the heat sink head is tightly attached to the surface of the electronic component, and when not being cooled, the low melting point metal is impregnated into the pinholes of the metal component and solidified. .

Therefore, when cooling, we aim to improve cooling efficiency.
When cooling is not performed, it is possible to easily attach and detach the printed circuit board.

〔Example〕

The present invention will be explained in detail below with reference to FIG.
FIG. 2 is a sectional view of an embodiment of the present invention.
The same reference numerals indicate the same objects throughout the figures.

As shown in FIG.
It is secured to the cooling plate 3 by being fixed using a ring 13, and the heat sink head 6 is further provided with a metal member 7 impregnated with a low melting point metal 8.

This low melting point metal 8 is solid at low temperatures without cooling, and becomes a medium at high temperatures when cooling is performed.
For example, 40℃~120℃ made of alloys such as gallium (Ga), indium (In), and tin (Sn).
It melts in the range of ℃.

Further, the metal member 7 has a small diameter pinhole by compression molding foamed metal, mesh, or the like.

Therefore, the pinhole of the metal member 7 is formed so as to be impregnated with the low melting point metal 8 by melting it.

Therefore, the metal member 7 fixed to the heat sink head 6 is pressed against the surface of the electronic component 2 by the spring force of the bellows 5, and when the electronic component 2 generates heat, the impregnated low melting point metal 8 pushes the electronic component 2 and the metal member 7 are in close contact with each other, and good heat transfer is achieved.

In this case, the liquefied low melting point metal 8 is not flowed out due to surface tension.

In addition, the refrigerant 4 is circulated from one circulation path 3A of the cooling plate 3 to the nozzle 3B as shown by the arrow A11, as described above, and from the nozzle 3B to the nozzle 3B as shown by the arrow A1.
2, and the injected refrigerant 4 is further flowed out from the other circulation path 3A in the direction of arrow A 13.

Since this low melting point metal 8 is solid when it is not cooled, when the printed circuit board 1 is removed, the low melting point metal 8 is impregnated with the metal member 7 and can be easily removed.

[Effects of the invention] As explained above, according to the invention, by providing the metal member with a low melting point metal that becomes liquid when cooled and becomes solid when not cooled,
During cooling, it is possible to improve the adhesion between the heat sink head and electronic components, and when cooling is not performed, it is possible to easily attach and detach the printed circuit board.

Therefore, stable cooling can be performed, the cooling capacity can be improved, and the work of attaching and detaching the printed circuit board due to obstacles etc. is facilitated, which has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the principle of the present invention, FIG. 2 is a sectional view of an embodiment of the invention, FIG. 3 is a perspective view showing an outline of the cooling structure, and FIG. 4 is a sectional view of a conventional cooling structure. In the figure, 1 is a printed circuit board, 2 is an electronic component, 3 is a cooling plate, 4 is a refrigerant, 5 is a bellows, 6 is a heat sink head, 7 is a metal member, and 8
indicates a low melting point metal.

Claims (1)

[Claims for Utility Model Registration] A cooling plate 3 through which a refrigerant 4 is circulated, a flexible bellows 5 secured to a predetermined position of the cooling plate 3, and an electronic component 2 mounted on a printed circuit board 1. A cooling structure in which the tip of the bellows 5 and the surface of the electronic component 2 are pressed together, and a heat sink head 6 fixed to the tip.
and is formed of a good heat conductive material having pinholes, and one side is fixed to the heat sink head 6,
A metal member 7 whose other surface is pressed against the electronic component 2 is provided, and the metal member 7 is impregnated with a low melting point metal 8 that is melted by the heat generated by the electronic component 2. cooling structure.