JP7244375B2 - vapor chamber - Google Patents

Description

The present invention relates to vapor chambers.

Patent Literature 1 discloses a vapor chamber that includes a container, and a wick body and a working fluid sealed inside the container. When the container is heated by the heat source, the wick body is heated via the container, and the liquid-phase working fluid impregnated in the wick body evaporates. The vapor-phase working fluid is condensed in a portion remote from the heat source and flows again near the heat source due to the capillary force exerted by the wick body. By repeating such action, heat can be repeatedly transported and the heat source can be cooled.

JP 2015-132399 A

Such vapor chambers are required to transport heat more efficiently.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vapor chamber capable of transporting heat more efficiently.

In order to solve the above problems, a vapor chamber according to an aspect of the present invention includes a container having a lower plate portion that receives heat from a heat source, an upper plate portion that faces the lower plate portion with a gap therebetween, and a side wall portion. , a working fluid enclosed inside the container; and a wick body enclosed inside the container and formed of a porous material. A plurality of radially extending fins are provided, the plurality of fins extend upward from the lower plate portion, a gap is provided between the plurality of fins and the upper plate portion, and the wick body is in contact with the lower plate portion and the plurality of fins.

According to the above aspect, when the lower plate receives heat from the heat source, the heat is transferred to the plurality of fins extending upward from the lower plate. Next, the wick body in contact with the lower plate portion and the plurality of fins is heated to evaporate the liquid-phase working fluid impregnated in the wick body. At this time, the heat can be efficiently transferred to the liquid-phase working fluid by increasing the area of the heat-receiving portion of the wick body as compared with the case where the plurality of fins is not provided. In addition, since the plurality of fins radially extend from the center of the evaporating section, heat can be transported using heat conduction inside each fin. According to heat conduction, heat resistance can be reduced, so that heat can be efficiently transported. Furthermore, since gaps are provided between the plurality of fins and the upper plate portion, the gaps function as vapor flow paths for the gaseous-phase working fluid, and the flow of the gaseous-phase working fluid contributes to heat transport efficiency. can be improved.

Here, the inside of the container may be provided with a heat transfer section that connects the upper surface of at least one of the fins and the lower surface of the upper plate section.

Further, a plurality of pillars are provided inside the container to connect the lower surface of the upper plate portion and the upper surface of the lower plate portion. When the region where the pillars are located is defined as a first region A1 and the region outside the first region is defined as a second region A2, the density of the plurality of pillars in the first region A1 is the same as the density of the plurality of pillars in the second region. may be greater than the density of the pillars of

Further, a plurality of connecting fins extending radially from the center of the evaporating section in plan view and connecting the lower surface of the upper plate portion and the upper surface of the lower plate portion may be provided inside the container. .

In a plan view, each of the plurality of connecting fins has a length in the longitudinal direction longer than each of the plurality of fins in the longitudinal direction, and a space between the plurality of connecting fins and the side wall portion is A gap may be provided.

According to the aspect of the present invention, it is possible to provide a vapor chamber capable of transporting heat more efficiently.

It is an exploded perspective view of a vapor chamber concerning this embodiment. It is the figure which looked at the vapor chamber of FIG. 1 from the upper side. However, illustration of the top plate is omitted. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2;

The vapor chamber of this embodiment will be described below with reference to the drawings.
As shown in FIGS. 1 to 3, the vapor chamber 1 includes a container C and a wick body 30. As shown in FIGS. The container C has an upper plate portion 11, a lower plate portion 21, and side wall portions 22, and is formed in a hollow rectangular parallelepiped shape. A wick body 30 and a working fluid (not shown) are sealed inside the container C. As shown in FIG.

The wick body 30 is made of a porous material. The liquid-phase working fluid is impregnated in the pores of the wick body 30 and flows through the wick body 30 by capillary force generated by the pores. Note that the shape of the container C may be changed as appropriate as long as it is hollow.

(direction definition)
In the present embodiment, the direction in which the upper plate portion 11 and the lower plate portion 21 face each other is referred to as a vertical direction Z. As shown in FIG. In the vertical direction Z, the upper plate portion 11 side is referred to as the upper side, and the lower plate portion 21 side is referred to as the lower side. Viewing from the vertical direction Z is called planar view. A direction orthogonal to the up-down direction Z is called a front-rear direction X, and a direction orthogonal to both the up-down direction Z and the front-rear direction X is called a left-right direction Y.

The vapor chamber 1 is a heat transport element for transporting and diffusing heat using the latent heat of the working fluid to cool the heat source H (for example, CPU). In the examples of FIGS. 1 to 3, the heat source H is arranged in the central portion of the lower surface of the lower plate portion 21. As shown in FIG. The working fluid is a well-known heat transport medium capable of phase change, and changes phases within the container C between a liquid phase and a gas phase. For example, water (pure water), alcohol, ammonia, or the like can be used as the working fluid. Although the material of the container C is not particularly limited, for example, copper with low thermal resistance (high thermal conductivity) can be preferably used.

A portion of the vapor chamber 1 close to the heat source H functions as a working fluid evaporating portion, and a portion far from the heat source H functions as a working fluid condensing portion. The evaporator receives heat from the heat source H to evaporate the liquid-phase working fluid. The evaporated working fluid flows through the gap between the surface of the wick body 30 and the inner surface of the container C (hereinafter referred to as vapor flow path S) so as to diffuse from the evaporator. The vapor-phase working fluid that has diffused is condensed in a portion (condensing portion) away from the heat source H by being deprived of heat by the outside air or the like via the container C. As shown in FIG.

The condensed working fluid flows toward the evaporator due to capillary force generated by the pores of the wick body 30 . In the evaporator, the liquid-phase working fluid receives heat again and evaporates. By repeating such action, the vapor chamber 1 can continuously transport and dissipate the heat of the heat source H.

The wick body 30 is made of a porous material and has a large number of pores that exert a capillary force on the liquid-phase working fluid. As the porous material, for example, a material obtained by sintering a powder material containing metal can be used. Alternatively, a mesh material in which a plurality of thin wires are woven in a lattice may be used as the porous material. Also, a sintered powder material or a porous material other than a mesh material may be employed.

The wick body 30 is arranged so as to be in contact with the upper surface of the lower plate portion 21 . The thickness of the wick body 30 in the vertical direction Z is smaller than the distance between the lower plate portion 21 and the upper plate portion 11 . Therefore, a gap in the vertical direction Z is provided between the wick body 30 and the upper plate portion 11 . In this embodiment, this gap is called a steam flow path S (see FIG. 3). The vapor channel S is a channel through which the vapor-phase working fluid flows.

The container C is formed by joining a top plate 10 and a bottom plate 20 to each other. The bottom plate 20 has a lower plate portion 21 and side wall portions 22 . The lower plate portion 21 extends on a plane perpendicular to the vertical direction Z. As shown in FIG. The lower plate portion 21 is formed in a rectangular shape that is longer in the horizontal direction Y than in the front-rear direction X in plan view. The side wall portion 22 extends upward from the outer peripheral edge of the lower plate portion 21 .

The top plate 10 has an upper plate portion 11 . The upper plate portion 11 extends in a plane orthogonal to the vertical direction Z. As shown in FIG. The upper plate portion 11 is formed in a rectangular shape that is longer in the left-right direction Y than in the front-rear direction X in plan view. Note that the top plate 10 of the present embodiment has only the upper plate portion 11 and does not have side wall portions. However, the top plate 10 may have a side wall portion extending downward from the outer peripheral edge of the upper plate portion 11 and connected to the side wall portion 22 of the bottom plate 20 . In this case, the side walls of the container C may be formed by the side walls 22 of the bottom plate 20 and the side walls of the top plate 10 .

The upper plate portion 11 and the lower plate portion 21 are opposed to each other in the vertical direction Z with a gap therebetween. As shown in FIG. 3, the upper plate portion 11 and the side wall portion 22 are joined together. As a bonding method, brazing, diffusion bonding with silver, laser welding, or the like can be used.

As shown in FIGS. 2 and 3, inside the container C, a plurality of pillars 23, a plurality of fins 24, and a plurality of connection fins 25 are provided. A plurality of pillars 23 , a plurality of fins 24 and a plurality of connecting fins 25 contact the wick body 30 .

The plurality of pillars 23 connect the upper surface of the lower plate portion 21 and the lower surface of the upper plate portion 11 to improve the strength of the container C in the vertical direction Z. As shown in FIG. In this embodiment, the pillars 23 are formed on the bottom plate 20 . That is, the lower plate portion 21 and the plurality of pillars 23 are integrally formed, and the upper surface of each pillar 23 is in contact with the upper plate portion 11 . Note that the plurality of pillars 23 may be formed integrally with the upper plate portion 11 . The plurality of pillars 23 are arranged at intervals in the left-right direction Y and the front-rear direction X. As shown in FIG.

The plurality of fins 24 radially extend from the center of the heat source H (that is, the center of the evaporator) in plan view. Although six fins 24 are provided in the example of FIG. 2, the number of fins 24 may be changed as appropriate. In plan view, each fin 24 extends so as to straddle the contour line (double-dot chain line) of the region where the heat source H is provided. However, each fin 24 may be located inside the contour line without straddling the contour line.

As shown in FIG. 3 , each fin 24 is formed integrally with the lower plate portion 21 and extends upward from the lower plate portion 21 . That is, each fin 24 is formed on the bottom plate 20 . A gap in the vertical direction Z is provided between the upper surface 24 a of each fin 24 and the lower surface of the upper plate portion 11 . This gap is also included in the steam flow path S described above.

The upper surface 24a of each fin 24 is formed with a heat transfer portion 24b extending upward and in contact with the lower surface of the upper plate portion 11 . In the example of FIG. 2, some of the fins 24 are formed with one heat transfer portion 24b, and the other fins 24 are formed with two heat transfer portions 24b. Each heat transfer portion 24b is formed in a columnar shape extending in the up-down direction Z. As shown in FIG. Note that the shape of the heat transfer portion 24b can be changed as appropriate, and may be, for example, a prism shape.

As shown in FIG. 2, in the present specification, a region of the interior space of the container C where the plurality of fins 24 are located is referred to as a first region A1 in plan view. A region outside the first region A1 is referred to as a second region A2. The first area A1 at least partially overlaps the area where the heat source H is provided in a plan view. In this embodiment, the density of the pillars 23 in the first area A1 is higher than the density of the pillars 23 in the second area A2. Note that the “pillar density” is a value obtained by dividing the number of pillars provided in the region by the area of the region.

As shown in FIG. 2, the plurality of connection fins 25 radially extend from the center of the heat source H (that is, the center of the evaporator) in plan view. In the example of FIG. 2, six connection fins 25 are provided. Each connecting fin 25 is arranged between adjacent fins 24 . Note that the number and arrangement of the connection fins 25 may be changed as appropriate. In plan view, each connection fin 25 extends across the contour of the area where the heat source H is provided. In plan view, the length in the longitudinal direction of each of the plurality of connecting fins 25 is longer than the length in the longitudinal direction of each of the plurality of fins 24 . The plurality of connection fins 25 are not in contact with the side wall portion 22 of the container C, and a gap is provided between each connection fin 25 and the side wall portion 22 .

As shown in FIG. 3, the plurality of connection fins 25 connect the upper surface of the lower plate portion 21 and the lower surface of the upper plate portion 11 to improve the strength of the container C. As shown in FIG. In this embodiment, each connection fin 25 is formed integrally with the lower plate portion 21 , and the upper surface of each connection fin 25 is in contact with the upper plate portion 11 . That is, each connection fin 25 is formed on the bottom plate 20 . However, each connection fin 25 may be formed separately from the lower plate portion 21 and these may be joined to the lower plate portion 21 . Alternatively, each connection fin 25 may be formed integrally with the upper plate portion 11 so that the lower surface of each connection fin 25 is in contact with the lower plate portion 21 .

As shown in FIG. 3, the dimension of each fin 24 in the vertical direction Z is substantially the same as the thickness of the wick body 30 in the vertical direction Z. As shown in FIG. Therefore, substantially the entirety of each fin 24 is buried inside the wick body 30 . The dimension of each fin 24 in the vertical direction Z may be smaller than the thickness of the wick body 30 in the vertical direction Z, and each fin 24 may be entirely covered with the wick body 30 . Alternatively, the dimension of each fin 24 in the vertical direction Z may be larger than the thickness of the wick body 30 in the vertical direction Z, and a part of each fin 24 may protrude upward from the wick body 30 .

As shown in FIG. 3, when the pillars 23, the fins 24, and the connecting fins 25 are formed on the bottom plate 20, it is preferable to use a sintered powder material as the porous material of the wick body 30. can be done. The reason for this is that, when manufacturing the vapor chamber 1, the inside of the bottom plate 20 is filled with a powder material, and the powder material is sintered so that the contours of the pillars 23, the fins 24, and the connecting fins 25 are formed. This is because the wick body 30 having a complicated shape can be easily formed.

Moreover, according to the manufacturing method as described above, it is possible to bring the pillar 23, the fins 24, and the connecting fins 25 into contact with the wick body 30 stably. Therefore, heat can be efficiently transferred from the pillars 23 , the fins 24 , and the connecting fins 25 to the liquid-phase working fluid in the wick body 30 .

As described above, according to the vapor chamber 1 of the present embodiment, a plurality of fins 24 radially extending from the center of the evaporating section in plan view are provided inside the container C. As shown in FIG. A plurality of fins 24 extend upward from the lower plate portion 21 , and a gap is formed between the plurality of fins 24 and the upper plate portion 11 . The wick body 30 is in contact with the lower plate portion 21 and the plurality of fins 24 .

According to this configuration, when the lower plate portion 21 receives heat from the heat source H, the heat is transferred to the plurality of fins 24 extending upward from the lower plate portion 21 . Next, the wick body 30 in contact with the lower plate portion 21 and the plurality of fins 24 is heated, and the liquid-phase working fluid impregnated in the wick body 30 evaporates. At this time, compared to the case where the plurality of fins 24 are not provided, the area of the portion of the wick body 30 that receives heat can be increased, and the heat can be efficiently transferred to the liquid-phase working fluid.

Moreover, since the plurality of fins 24 radially extend from the center of the evaporating section, heat can also be transported by heat conduction inside the fins 24 . According to heat conduction, heat resistance can be reduced, so that heat can be efficiently transported. Further, a gap that becomes the steam flow path S is formed between the plurality of fins 24 and the upper plate portion 11 . Thereby, the heat transport efficiency can be improved by the flow of the vapor-phase working fluid.

Further, inside the container C, a heat transfer portion 24 b is provided that connects the upper surface 24 a of at least one fin 24 and the lower surface of the upper plate portion 11 . With this configuration, heat can be transferred from the fins 24 to the upper plate portion 11 by heat conduction inside the heat transfer portion 24b. In this manner, by using not only the phase change of the working fluid but also heat conduction, heat can be transported to the upper plate portion 11 more efficiently. Furthermore, even when a plurality of heat transfer portions 24b are provided in one fin 24, by providing gaps between the heat transfer portions 24b, the gaps serve as steam flow paths S, which facilitate the flow of the vapor-phase working fluid. You can avoid getting in the way.

A plurality of pillars 23 are provided inside the container C, and the density of the pillars 23 in the first area A1 is higher than the density of the pillars 23 in the second area A2. By increasing the number of pillars 23 in the first region A1 in this manner, heat can be efficiently transported from the heat source H to the upper plate portion 11 by heat conduction inside the pillars 23 . On the other hand, by reducing the number of pillars 23 in the second region A2, it is possible to facilitate the flow of the vapor-phase working fluid and to reduce the weight of the vapor chamber 1 .

Further, inside the container C, a plurality of connection fins 25 are provided that radially extend from the center of the evaporator in plan view and connect the lower surface of the upper plate portion 11 and the upper surface of the lower plate portion 21 . With this configuration, heat can be transferred from the lower plate portion 21 to the upper plate portion 11 by heat conduction inside the connection fins 25 . By using heat conduction in this manner, heat can be transported to the upper plate portion 11 more efficiently.

In addition, since the working fluid evaporates in the evaporating section as a whole, the amount of gas-phase working fluid increases as the distance from the center of the evaporating section increases. If the width of the vapor flow path S is insufficient for the amount of the gas-phase working fluid, the flow velocity of the gas-phase working fluid may become excessively high, resulting in a decrease in pressure loss. Therefore, in this embodiment, the connecting fins 25 radially extend from the center of the evaporating section, and the width of the steam flow path S formed between the connecting fins 25 becomes wider as the distance from the center of the evaporating section increases. .

In this way, by widening the width of the vapor flow path S in accordance with the amount of the vapor-phase working fluid that increases as the distance from the center of the evaporating section increases, the reduction in pressure loss can be suppressed. As a result, the vapor-phase working fluid flows smoothly from the evaporator to the condenser, and dryout (liquid-phase working fluid phenomenon) can be suppressed.

Further, in plan view, the length in the longitudinal direction of each of the plurality of connecting fins 25 is longer than the length in the longitudinal direction of each of the plurality of fins 24 . By lengthening the connecting fins 25 in this way, the heat transport efficiency due to the heat conduction of the connecting fins 25 can be further enhanced. Furthermore, since a gap is provided between the connection fin 25 and the side wall portion 22 , the gap also functions as the steam flow path S. As a result, compared to the case where the connecting fins 25 are in contact with the side wall portion 22 , the gas-phase working fluid can flow smoothly.

The technical scope of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, one or two heat transfer portions 24b are formed in all the fins 24. As shown in FIG. However, the number of heat transfer portions 24b can be changed as appropriate, and the number of heat transfer portions 24b formed in each fin 24 may be the same. Also, one or more heat transfer portions 24 b may be formed only on some of the fins 24 . Alternatively, not all the fins 24 may have the heat transfer portions 24b.

Further, in the above embodiment, the density of the pillars 23 in the first area A1 was higher than that in the second area A2. However, the density of the pillars 23 may be the same between the first area A1 and the second area A2. Also, the density of the pillars 23 in the second area A2 may be higher than that in the first area A1. Alternatively, the pillars 23 may not be provided inside the container C. Even in this case, the strength of the container C can be ensured, for example, by the connecting fins 25 .

Also, in the above-described embodiment, a gap is provided between the connection fin 25 and the side wall portion 22, but the connection fin 25 and the side wall portion 22 may be in contact with each other.
Further, although the connection fins 25 were longer than the fins 24 in the above embodiment, the fins 24 may be longer than the connection fins 25 . Alternatively, the connecting fins 25 may not be provided.

Moreover, in order to more efficiently radiate heat from the upper plate portion 11 to the outside air, the upper plate portion 11 may be attached with a heat radiation member (for example, a heat dissipation fin).

In addition, it is possible to appropriately replace the components in the above-described embodiments with well-known components without departing from the scope of the present invention, and the above-described embodiments and modifications may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1... Vapor chamber 11... Upper plate part 21... Lower plate part 22... Side wall part 23... Pillar 24... Fin 24b... Heat transfer part 25... Connection fin 30... Wick body C... Container

Claims (5)

a container having a lower plate that receives heat from a heat source, an upper plate that faces the lower plate with a gap therebetween, and side walls;
a working fluid enclosed inside the container;
a wick body enclosed inside the container and formed of a porous material;
A plurality of fins extending radially from the center of the evaporating section in plan view are provided inside the container,
the plurality of fins extend upward from the lower plate portion, and a gap is provided between the plurality of fins and the upper plate portion;
The vapor chamber, wherein the wick body is in contact with the lower plate portion and the plurality of fins. 2. The vapor chamber according to claim 1, wherein a heat transfer portion connecting the upper surface of at least one fin and the lower surface of the upper plate portion is provided inside the container. A plurality of pillars connecting the lower surface of the upper plate portion and the upper surface of the lower plate portion are provided inside the container,
In a plan view, when the area in which the plurality of fins are located in the inner space of the container is defined as a first area A1, and the area outside the first area is defined as a second area A2,
3. The vapor chamber according to claim 1 or 2, wherein the density of the plurality of pillars in the first region A1 is greater than the density of the plurality of pillars in the second region. 2. A plurality of connecting fins extending radially from the center of the evaporating section in plan view and connecting the lower surface of the upper plate portion and the upper surface of the lower plate portion are provided inside the container. 4. The vapor chamber according to any one of 3. In plan view, the length in the longitudinal direction of each of the plurality of connection fins is longer than the length in the longitudinal direction of each of the plurality of fins,
5. The vapor chamber according to claim 4, wherein a gap is provided between said plurality of connection fins and said side wall.

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