JPH1131767A - Deformable heat-transmitting body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a air layer from remaining between both members when mounting a heat-transmitting body between an exothermic member and a heat- receiving member of large area. SOLUTION: This heat transmitting body is an assembly of heat-radiation sheets 10, wherein being a small strip-like heat transmitting body, its thickness is constant while its width is wider at its central part, being gradually narrower toward the end part in the longitudinal direction. The heat-radiation sheet 10 is deformed when compressed, and so allocated in parallel that its larger part contacts a larger part of an adjoining heat-radiation sheet 10. On the assembly of heat-radiation sheets 10, a base film 12 is pasted on at least one surface, in advance, while peeling-off is allowed. The heat-radiation sheets 10 allocated in parallel with specified intervals on the base film 12 are flipped, pasted on a heat-receiving member, then the base film 12 is peeled off the heat-radiation sheets 10, and an exothermic member is placed on the heat-radiation sheets 10. After that, the heat-radiation sheets 19 are compressed between the exothermic member and the heat-receiving member, causing an air to be pressed out from the center part to both end parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a deformable heat transfer element,
In particular, the present invention relates to a structure of a deformable heat transfer body that eliminates air between a heat generating member and a heat receiving member, fills a space between the two with a heat transfer body, and improves heat transfer between the two.

[0002]

2. Description of the Related Art Heretofore, for cooling electronic components such as ICs mounted on a printed circuit board, it has been common practice to forcibly cool by a fan or the like. However, in the case of air cooling, there is a problem that the mounting density of components on a printed circuit board is extremely reduced.

Therefore, for example, Japanese Patent Application Laid-Open No. 58-143600
In the “Cooling Device for Printed Circuit Board-mounted Components” in the publication, a heat radiating plate is arranged for a specific electronic component such as a component that generates a large amount of heat among electronic components such as an IC mounted on the printed circuit board. There is disclosed an apparatus for cooling by interposing a gel-like heat transfer medium having good thermal conductivity between a heat transfer plate and a heat sink. More specifically, one gel heat transfer medium having a constant thickness molded slightly thicker than the space formed between the IC mounted on the printed circuit board and the heat sink is interposed between the IC and the heat sink, A cooling device is disclosed which is incorporated in a slightly compressed form by utilizing its elasticity.

In the case of a small component such as an IC, the gel heat transfer medium can be brought into close contact with the IC and the radiator plate only by compressing a slightly thicker gel heat transfer medium. The air present between them can be almost completely eliminated. Therefore, heat generated from the IC is conducted to the heat radiating plate via the gel heat transfer medium, and is radiated from the heat radiating plate. For this reason,
The heat of the high heat-generating component can be efficiently generated while keeping the mounting density high.

[0005]

However, the cooling device disclosed in Japanese Patent Application Laid-Open No.
Since the present invention relates to a cooling device for small parts such as C, one gel-like heat transfer medium as described in the above-mentioned publication is used for, for example, an inverter or a module (having a size of 6 × 6 cm or more) of an electric vehicle. The following problem arises when it is used for heat radiation of such large components.

That is, a heat-generating member and a heat-receiving member (for example, a heat sink) of a large component such as an inverter module
When one gel heat transfer medium having a constant thickness is disposed between the heat transfer member and the heat transfer member, the gel heat transfer medium is compressed, as shown in FIG. There is a high possibility that the air layer 4 remains between the heat transfer medium 1 and the heat generating member 3 and the heat receiving member 2, and the gel heat transfer medium 1 does not adhere to both members over the entire surface. This phenomenon appears remarkably for the heat generating member 3 and the heat receiving member 2 having a large surface area.

As described above, when the air layer 4 exists between the gel-like heat transfer medium 1 and the two members, the thermal resistance in the heat transfer between the air layer 4 and the heat generating member 3 and the heat receiving member 2, and The thermal resistance in the heat conduction in the air layer 4 increases, and the overall thermal resistance increases. For this reason, there has been a problem that heat radiation efficiency is reduced.

In order to prevent the air layer 4 from remaining as described above, (i) the heat generating member 3 and the heat receiving member 2 and the gel heat transfer medium 1 are simultaneously brought into close contact with each other, or (ii) the heat generating member 3 and the heat-receiving member 2 and the gel-like heat medium 1 are gradually brought into contact with each other from the center to both ends, or (iii) the heat-generating member 3 and the heat-receiver 2 and the gel-like heat medium 1 are moved from one end to the other. It is conceivable to gradually contact and adhere to the end.

However, in the case of (i), it is extremely difficult in the process of construction, and in (ii) and (iii), the gel heat transfer medium 1 is applied to one surface of the heat generating member 3 or the heat receiving member 2. Even if possible when constructing,
It is impossible to further apply the gel heat transfer medium 1 to the other surface in the same manner.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to leave an air layer between a heat-generating member and a heat-receiving member having a large area when both members are compressed. Instead, to provide a deformable heat transfer member that is in close contact with both members.

[0011]

Means for Solving the Problems In order to solve the above problems, a deformable heat transfer body according to the present invention has the following features.

(1) The heat generating member and the heat receiving member are disposed in a space between the heat generating member and the heat receiving member, conduct heat between the heat generating member and the heat receiving member, and are compressed and sandwiched by the heat generating member and the heat receiving member. At this time, it has a shape that can be deformed so as to push out the air in the space from the center to the end.

Therefore, no air layer remains between the heat generating member and the heat receiving member and the heat transfer member. Therefore, the heat radiation efficiency is improved.

(2) In the deformable heat transfer body according to the above (1), the width of the heat transfer body is expanded at a central portion, and
It is an aggregate of substantially rectangular small heat transfer bodies whose width becomes narrower toward the longitudinal end, wherein the small heat transfer body is deformed when compressed, and the bulge can contact the bulge of an adjacent small heat transfer body. Are arranged in parallel.

At the time of compression, the plurality of small heat transfer bodies first deform at their central bulges and come into contact with each other. This allows
The air existing in the central portion of the space between the heat generating member and the heat receiving member is pushed away and escapes into a gap extending from the central portion formed between the small heat transfer members to both ends. Further, by applying a load to and deforming the small heat transfer body, the gap gradually narrows from the center. Therefore, the air existing in the gap is also pushed out to the end. When a load is further applied, the gap disappears, and the heat generating member and the heat receiving member and the heat transfer member are in close contact with each other over the entire surface, and no air layer remains between the heat generating member and the heat receiving member and the heat transfer member. . Therefore, the heat radiation efficiency is improved.

(3) In the deformable heat transfer element according to the above (1), the heat transfer element is a small heat transfer element in which substantially rectangular small heat transfer elements formed in a vertically convex shape are arranged in parallel. A collection of bodies.

Accordingly, when a load is applied, air is gradually pushed out from the convex portion toward the thin portion,
Eventually, the small heat transfer body is deformed and the thickness becomes uniform, the gap disappears, the heat generating member and the heat receiving member and the heat transfer body are in close contact with each other, and the heat generating member and the heat receiving member and the heat transfer body There is no air layer remaining on the floor. Therefore, the heat radiation efficiency is improved.

(4) In the deformable heat transfer material according to the above (2) or (3), a base film is preliminarily attached to at least one surface of the heat transfer material or the small heat transfer material in a releasable manner. Have been.

Therefore, after attaching and disposing the surface of the heat transfer member opposite to the base film attached to one member, the base film can be peeled off and the other surface of the heat transfer member can be attached to the other member. For this reason, the easily deformable heat transfer body can be easily arranged at a predetermined position, handling is facilitated, and workability is improved.

(5) In the deformable heat transfer material according to any one of (1) to (4), the heat transfer material or the aggregate of small heat transfer materials is a rubber containing a filler having high heat conductivity. Or made of gel, with at least 10% deformation under load
That is all.

Since the above-mentioned gel or rubber contains a filler having high thermal conductivity, it has a high thermal conductivity and the amount of deformation due to a load is 10% or more. Therefore, the gel or rubber is compressed by the heat generating member and the heat receiving member. In this case, there is no possibility that an air layer remains between the two members. Therefore, the heat radiation efficiency is improved.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described.

Embodiment 1 With reference to FIGS. 1 to 3 and FIGS. 5 to 7, a deformable heat transfer body of the present embodiment will be described.

As shown in FIG. 1, the deformable transmission body of the present embodiment has a constant thickness, a width swelling at a central portion,
The heat dissipation sheet 10 is an aggregate of heat dissipation sheets 10 each of which is a substantially strip-shaped small heat conductor whose width becomes narrower toward the end in the longitudinal direction. The heat radiating sheets 10 are arranged in parallel so as to be deformed during compression so that the bulges and the bulges of the adjacent heat radiating sheets 10 can come into contact with each other.

Also, as shown in FIG.
Of the base film 1 in advance on at least one side.
2 is releasably attached. By using the base film 12, a plurality of heat radiation sheets 10 can be attached to one member at a time and arranged at a constant interval. Furthermore, the base film 12 can be peeled off, and the other surface of the heat dissipation sheet 10 can be attached to the other member. Therefore, the heat dissipating sheet that is easily deformed can be easily arranged at a predetermined position, and the handling becomes easy, and the workability is improved.

More specifically, as shown in FIG. 2, the heat radiating sheet 10 is arranged on the base film 12 with a gap so that the distance between the two ends increases. Further, the heat radiating sheets 10 are arranged at a predetermined distance d such that the bulging portions come into contact with each other at the time of load, but do not touch each other before the load.

In the present embodiment, the material of the heat radiation sheet 10 has a high thermal conductivity and a deformation amount under load of at least one.
There is no particular limitation as long as it is 0% or more, but for example, a gel or rubber containing at least 10% or more deformation under load and containing a filler having high thermal conductivity is preferable. Further, the gel hardness of the gel is 0.0001 to 0.5.
It is preferably 003 kg / mm ² . Examples of the filler include ZnO, Al ₂ O ₃ , and AlN. As the above gel, for example, silicone gel is preferable, and as the above rubber, for example, nitrile rubber, styrene butadiene rubber, and silicone rubber are preferable. The heat radiation sheet 10 may be formed by cutting gel or rubber into a predetermined shape, or may be formed by pouring gel or rubber into a predetermined mold and compression molding.

The material of the base film 12 of the present embodiment is not particularly limited, but polyethylene terephthalate (PET) is preferable.

Next, the mounting process of the heat transfer body of this embodiment will be described with reference to FIGS.

First, as shown in FIG. 5, the heat radiating sheets 10 arranged in parallel on the base film 12 at predetermined intervals are inverted (in the direction of the arrow), and the heat sink 2 as a heat receiving member is turned over.
The heat radiating sheet 10 is attached on the top of the heat sink. Next, as shown in FIG. 6, the base film 12 is peeled off from the heat dissipation sheet 10 (in the direction of the arrow). Next, as shown in FIG. 7, the module 30 which is a heat generating member is placed on the heat radiation sheet 10. After that, the holes 22 at the four corners of the heat sink 20 and the holes 32 of the module 30 are combined, and a bolt 40 is passed through the holes 22 and 32, and the bolts 40 are tightened.

As a result, the heat radiating sheet 10 sandwiched between the module 30 and the heat sink 20 is compressed as shown in FIG. Contact. As a result, the air existing in the center of the space between the module 30 and the heat sink 20 is pushed away, and the heat radiation sheet 10 is released.
It escapes into the gap formed between the central portion and both ends formed between them. Further, by applying a load to the heat radiating sheet 10 and deforming it, the gap gradually narrows from the center.
As a result, the air existing in the gap is also pushed out to the end. When a load is further applied, the gap disappears, and the module 30 and the heat sink 20 and the heat radiating sheet 10 come into close contact with each other over the entire surface, thereby preventing the air layer from remaining. Therefore, the heat radiation efficiency is improved.

Embodiment 2 FIG. With reference to FIG. 4, a deformable heat transfer body of the present embodiment will be described.

In the first embodiment, the heat radiating sheet 10 is formed in a substantially rectangular shape whose thickness is constant, its width swells at the center, and becomes narrower toward the end in the longitudinal direction. The heat radiating sheet 10a in the form is an aggregate of small heat conductors in which substantially rectangular small heat conductors formed in a convex shape in the vertical direction are arranged in parallel.

Therefore, when a load is applied, air is gradually pushed out from the convex portion toward the thin portion,
Finally, the heat radiation sheet 10a is deformed to have a uniform thickness, and the gap disappears. Thereby, the heat generating member and the heat receiving member are closely adhered to the heat radiating sheet heat transfer member over the entire surface, and the air layer does not remain between the heat generating member and the heat receiving member and the heat radiating sheet 10a. Therefore, the heat radiation efficiency is improved.

Embodiment 3 FIG. In the first embodiment, the heat radiating sheet has a substantially rectangular shape. However, in the present embodiment, the heat radiating sheet is particularly limited as long as its width swells at the center and becomes narrower toward the longitudinal end. Fig. 8
The heat radiation sheet 10b may be an elliptical heat radiation sheet 10b shown in FIG. 8A or a diamond-shaped heat radiation sheet 10c shown in FIG. 8B.

In each of the above embodiments,
Although the base film 12 is used, the present invention is not limited to this. When the base film is not used, the same effect can be obtained by placing the heat radiation sheets 10 one by one at predetermined positions.

Further, as in the above-described embodiment, the heat transfer body is preferably formed by arranging a plurality of small heat transfer sheets in parallel with each other. However, the present invention is not limited to this. It may be a single heat transfer body having slits at both ends, or a single heat transfer body formed in an uneven shape.

[0038]

As described above, in the deformable heat conductor according to the present invention, the heat transfer member is disposed in the space between the heat generating member and the heat receiving member, and is compressed and sandwiched by the heat generating member and the heat receiving member. In addition, since the space inside the space has a shape that can be deformed so as to push air from the center to the end, an air layer does not remain between the heat generating member and the heat receiving member and the heat transfer body. Therefore, the heat radiation efficiency is improved.

The heat transfer body of the present invention comprises a plurality of substantially rectangular small heat transfer bodies, the width of which expands at the center and narrows toward the end in the longitudinal direction. And the bulge of the adjacent small heat transfer member are arranged in parallel so that they can contact with each other. Therefore, when the plurality of small heat transfer elements are compressed, the central bulge first deforms and comes into contact with each other,
The air existing in the central portion between the heat generating member and the heat receiving member is pushed and escaped to the gap extending from the central portion between the small heat transfer elements to both ends. Further, by applying a load to the heat transfer body and deforming the gap, the gap gradually narrows from the center, and the air existing in the gap is also pushed out to the end. Disappears, and the heat generating member, the heat receiving member, and the heat transfer member are in close contact with each other on the entire surface, and the air layer can be prevented from remaining between the heat generating member, the heat receiving member, and the heat transfer member.

In another heat transfer element of the present invention, a plurality of substantially rectangular small heat transfer elements formed in a convex shape in the vertical direction are arranged in parallel. Air is gradually extruded from the part toward the thin part, and finally the small heat transfer body is deformed and the thickness becomes uniform, the gap disappears, and the heat generating member and the heat receiving member and the heat transfer body And the air layer can be prevented from remaining between the heat generating member and the heat receiving member and the heat transfer member.

In addition, since the base film is preliminarily attached to at least one side of the heat transfer body or the aggregate of the small heat transfer bodies according to the present invention, the base film of the heat transfer body is attached to one of the members. After attaching and disposing the opposite surface, the base film can be peeled off, and the other surface of the heat transfer body can be attached to the other member. For this reason, the easily deformable heat transfer body can be easily arranged at a predetermined position, handling is facilitated, and workability is improved.

Further, since the heat transfer body of the present invention or the aggregate of the above-mentioned small heat transfer bodies is made of rubber or gel containing a filler having high heat conductivity, it has high heat conductivity and has at least a deformation amount under load. Since it is 10% or more, when compressed by the heat generating member and the heat receiving member, there is no possibility that an air layer remains between the two members.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a structure of a deformable heat transfer body according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement state before a load of a deformable heat transfer body according to the first embodiment of the present invention.

FIG. 3 is a plan view showing a state after a load of a deformable heat transfer body according to the first embodiment of the present invention.

FIG. 4 is a side view showing an example of a structure of a deformable heat transfer body according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a state in which the deformable heat transfer body according to the first embodiment of the present invention is mounted on a heat sink.

FIG. 6 is a diagram illustrating a state in which the base film is peeled off from the deformable heat conductor according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating a state in which the deformable heat transfer body according to the first embodiment of the present invention is compression-deformed and brought into close contact with a heat sink and a module.

FIG. 8 is a perspective view illustrating an example of a structure of a deformable heat transfer body according to a third embodiment of the present invention.

FIG. 9 is a view showing a state in which one conventional gel-like heat transfer medium is compressed and sandwiched between a large-sized heat-generating member and a heat-receiving member.

[Explanation of symbols]

10, 10a, 10b, 10c heat dissipation sheet, 12 base film, 20 heat sinks, 22 holes, 30 modules, 32 holes, 40 volts.

Claims (5)

[Claims] 1. A heat-dissipating member disposed in a space between a heat-generating member and a heat-receiving member to conduct heat between the heat-generating member and the heat-receiving member, and to be compressed and sandwiched by the heat-generating member and the heat-receiving member. A deformable heat transfer body having a shape deformable so as to push air in the space from a central portion to an end portion. 2. The deformable heat transfer body according to claim 1, wherein the heat transfer body has a substantially strip-shaped small heat transfer having a width swelling at a central portion and becoming narrower toward an end in a longitudinal direction. A deformable heat transfer device, wherein the small heat transfer member is arranged in parallel so that the small heat transfer member is deformed at the time of compression so that the bulge can contact the bulge of the adjacent small heat transfer member. body. 3. The deformable heat transfer body according to claim 1, wherein the heat transfer body is a small heat transfer body in which substantially rectangular small heat transfer bodies formed in a vertically convex shape are arranged in parallel. A deformable heat transfer body, which is an aggregate. 4. The deformable heat transfer body according to claim 2, wherein a base film is preliminarily attached to at least one surface of the heat transfer body or the small heat transfer body in a detachable manner. A deformable heat transfer body. 5. The deformable heat transfer body according to claim 1, wherein the heat transfer body or the aggregate of the small heat transfer bodies includes a gel or a rubber containing a filler having high heat conductivity. A deformable heat transfer body, comprising: a deformation amount under load of at least 10% or more.