JP7371054B2 - vapor chamber - Google Patents

Description

The present invention relates to a vapor chamber that exhibits excellent heat transport characteristics due to its excellent resistance to pressure from the external environment and excellent thermal connectivity with the object to be cooled.

BACKGROUND ART Electronic components such as semiconductor elements installed in electrical and electronic equipment are increasing in heat generation due to higher functionality and higher density mounting, and cooling them has become more important in recent years. Furthermore, heating elements such as electronic components are sometimes placed in narrow spaces due to miniaturization of electronic devices. 2. Description of the Related Art A vapor chamber (flat heat pipe) equipped with a flat container is sometimes used as a method for cooling a heat generating element such as an electronic component placed in a narrow space.

Further, from the viewpoint of reducing the size and weight of the vapor chamber, it is required that the wall thickness of the vapor chamber container be reduced. Since the inside of the container is subjected to reduced pressure treatment, as the wall thickness of the container becomes thinner, there is a risk that the container may be deformed due to atmospheric pressure or load. If the container is deformed, the flow characteristics of the working fluid may deteriorate, and the heat dissipation characteristics of the vapor chamber may deteriorate. Therefore, a support part is sometimes provided inside the container of the vapor chamber in order to maintain the internal space of the container.

In order to maintain the internal space of the container, a vapor chamber provided with a support inside the container is arranged in a space sealed by an upper plate, a lower plate, and a plurality of side walls, and the upper plate and the lower plate a wick body having a plurality of first wick parts that are in contact with the plurality of first wick parts, and a pillar that is arranged in the space and is in contact with the upper plate and the lower plate; A vapor chamber has been proposed that is arranged between the straight parts of two adjacent first wick parts with a space between them with respect to the straight parts (Patent Document 1). Patent Document 1 discloses a vapor chamber that includes a wick body in contact with an upper plate and a lower plate, and a pillar in contact with an upper plate and a lower plate, thereby ensuring a vapor flow path even if the thickness of the container is reduced.

On the other hand, when a vapor chamber cools a heat generating element such as an electronic component arranged in a narrow space, a plurality of heat generating elements may be cooled in one vapor chamber. The plurality of heating elements do not necessarily have the same shape and size, and for example, it may be required to cool a plurality of heating elements having different heights in one vapor chamber.

FIG. 5 is a side view illustrating an example of how to use a conventional vapor chamber. As shown in FIG. 5, a plurality of heating elements 100 of different heights are mounted on a substrate 110 in a conventional vapor chamber 200 such as Patent Document 1 (for convenience of explanation, four heating elements of different heights are mounted on a substrate 110 in FIG. 5). When attempting to thermally connect the heating elements 100-1, 100-2, 100-3, 100-4), the most Excellent thermal connectivity can be obtained for the high heating element 100-1. However, in the vapor chamber 200, the three heating elements 100-2, 100-3, and 100-4, which are lower in height than the heating element 100-1, are A gap is created between the heating elements 100-2, 100-3, and 100-4, making it impossible to obtain excellent thermal connectivity.

Therefore, by inserting thermally conductive resin or thermally conductive grease into the gaps created between the vapor chamber 200 and the heating elements 100-2, 100-3, and 100-4, the vapor chamber 200 and the heating elements 100- 2, 100-3, and 100-4 may be ensured. Moreover, by arranging a metal block in the gap created between the vapor chamber 200 and the heating elements 100-2, 100-3, 100-4, the vapor chamber 200 and the heating elements 100-2, 100-3, 100-4 can be -4 may be ensured for thermal connectivity. However, even if the gap between the vapor chamber 200 and the heating element 100 is filled using another member such as thermally conductive resin, thermally conductive grease, or a metal block, the heat between the vapor chamber 200 and the heating element 100 is There was a problem that sufficient connectivity could not be ensured.

Another method of using the vapor chamber is to thermally connect the vapor chamber to the back side of the substrate to cool the heating element, which is the heating element to be cooled, which is thermally connected to the front surface of the substrate. can be mentioned.

FIG. 6 is a side view illustrating another example of how to use the conventional vapor chamber. As shown in FIG. 6, by forming a through hole 111 in the thickness direction in the substrate 110 and inserting a metal coin 120 such as a copper coin into the through hole 111, heat is generated between the front surface 112 and the back surface 113 of the substrate 110. Make it conductive. Heat from the heating element 100 thermally connected to the front surface 112 of the substrate 110 is transferred from the front surface 112 to the back surface 113 of the substrate 110 via the metal coin 120. The heat transferred to the backside 113 of the substrate 110 is spread throughout the vapor chamber 200 due to the heat transport properties of the conventional vapor chamber 200 thermally connected to the backside 113 of the substrate 110 . The heat is emitted to the outside environment by the heat exchange action of the heat dissipating fins 210.

However, the metal coin 120 may be inserted into the through hole 111 in an inclined state. If the metal coin 120 is tilted within the through hole 111, only the tilted part of the metal coin 120 will protrude from the back surface 113 and come into contact with the vapor chamber 200. From the above, in order to prevent only the tilted part of the metal coin 120 from coming into contact with the vapor chamber 200, the metal coin 120 is placed in advance so that the metal coin 120 is recessed than the back surface 113 of the substrate 110. The thickness of the substrate 110 may be designed to be thinner than the thickness of the substrate 110.

However, as shown in FIG. 6, when the metal coin 120 is depressed below the back surface 113 of the substrate 110, a gap 121 is created between the metal coin 120 and the vapor chamber 200. 120, it is not possible to obtain excellent thermal connectivity between the two.

Therefore, thermal connectivity between the vapor chamber 200 and the metal coin 120 may be ensured by inserting thermally conductive grease or thermally conductive resin into the gap 121 between the metal coin 120 and the vapor chamber 200. However, even if the gap 121 between the vapor chamber 200 and the metal coin 120 is filled using a separate member such as thermally conductive grease, thermal connectivity between the vapor chamber 200 and the metal coin 120 is not sufficiently ensured. The problem was that it couldn't be done.

International Publication No. 2017/104819

In view of the above circumstances, an object of the present invention is to provide a vapor chamber that exhibits excellent heat transport characteristics by having excellent thermal connectivity with the object to be cooled while having resistance to pressure from the external environment. do.

The gist of the configuration of the present invention is as follows.
[1] A container having a first surface and a second surface opposite to the first surface, in which a cavity is formed, a wick structure provided in the cavity, and a container in the cavity. comprising an encapsulated working fluid and a vapor flow path provided in the cavity through which the working fluid in a vapor phase flows;
The first surface has a flat part and a convex part protruding outward from the flat part, so that the container has a flat part and a convex part protruding outward from the flat part,
The inner space of the convex part of the container is in communication with the inner space of the flat part, so that the hollow part is formed,
A vapor chamber in which the wick structure is erected from a portion of the second surface facing the convex portion toward the convex portion, and the wick structure is in contact with the second surface and the convex portion. .
[2] The vapor chamber according to [1], wherein the container has a plurality of the protrusions.
[3] The vapor chamber according to [1] or [2], wherein the wick structure is a member whose dimension in the upright direction decreases in response to stress in the upright direction.
[4] The wick structure is at least one selected from the group consisting of a sintered body of powder containing metal powder, a mesh made of fine metal wire, a metal braid, a metal wire, and a nonwoven fabric [1] The vapor chamber according to any one of [3].
[5] The vapor chamber according to any one of [1] to [4], wherein the first surface is a metal material having a tensile strength of 200 N/mm ² or less.
[6] The vapor chamber according to any one of [1] to [5], wherein the wick structure is a support part that maintains the internal space of the container.
[7] The container is formed of one plate-shaped body and another plate-shaped body facing the one plate-shaped body, and the one plate-shaped body has the convex portion projecting outward. The vapor chamber according to any one of [1] to [6].
[8] The vapor chamber according to any one of [1] to [7], wherein the convex portion and the flat portion include a heat receiving portion to which an object to be cooled is thermally connected.

According to an aspect of the vapor chamber of the present invention, the first surface has a flat portion and a convex portion protruding outward from the flat portion, so that the container has a flat portion and a convex portion protruding outward from the flat portion. a wick structure is erected from a portion of a second surface facing the convex portion toward the convex portion, and the wick structure is in contact with the second surface and the convex portion. As a result, the wick structure located at the convex portion can be thermally connected to the object to be cooled, such as a low-height heating element, at the convex portion while maintaining the internal space of the container.

Therefore, the vapor chamber of the present invention can exhibit excellent heat transport characteristics by providing excellent thermal connectivity with the object to be cooled while imparting resistance to pressure from the external environment to the container.

According to the aspect of the vapor chamber of the present invention, since the container has a plurality of the convex portions, it is possible to obtain excellent thermal connectivity even for two or more cooling objects having different heights. , it can exhibit excellent heat transport properties even when cooling two or more objects of different heights.

According to an aspect of the vapor chamber of the present invention, the wick structure is at least one selected from the group consisting of a sintered body of powder containing metal powder, a mesh made of metal wire, a metal braided body, a metal wire, and a nonwoven fabric. By being of one type, the height of the wick structure can be easily adjusted by stress in the thickness direction of the container. Therefore, in the vapor chamber of the present invention, the accuracy of the amount of outward protrusion of the convex portion is improved while maintaining the internal space of the container, thereby reliably improving thermal connectivity with the object to be cooled.

According to an aspect of the vapor chamber of the present invention, since the first surface is made of a metal material having a tensile strength of 200 N/mm ² or less, the convex portion of the container is easily deformed plastically, and as a result, the convex portion of the container is easily deformed in the thickness direction of the container. It is also facilitated to adjust the height of the wick structure in accordance with the amount of plastic deformation of the convex portion. Therefore, in the vapor chamber of the present invention, since the accuracy of the amount of outward protrusion of the convex portion is improved, the thermal connectivity with the object to be cooled is reliably improved.

According to the aspect of the vapor chamber of the present invention, since the wick structure is a support part that maintains the internal space of the container, there is no need to separately provide a support member for maintaining the internal space of the container. , a sufficient steam flow path can be secured, and the flow characteristics of the gas-phase working fluid are further improved.

1 is a side sectional view illustrating an outline of the internal structure of a vapor chamber according to a first embodiment of the present invention; FIG. FIG. 7 is a side sectional view illustrating an outline of the internal structure of a vapor chamber according to a second embodiment of the present invention. FIG. 7 is a side sectional view illustrating an outline of the internal structure of a vapor chamber according to a third embodiment of the present invention. FIG. 7 is a side sectional view illustrating another example of how to use the vapor chamber of the present invention. FIG. 2 is a side view illustrating an example of how to use a conventional vapor chamber. FIG. 3 is a side view illustrating another example of how to use a conventional vapor chamber.

A vapor chamber according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view illustrating the outline of the internal structure of a vapor chamber according to a first embodiment of the present invention.

As shown in FIG. 1, the vapor chamber 1 according to the first embodiment of the present invention includes two opposing plate bodies, that is, one plate body 11 and the other plate body 11 facing the one plate body 11. A container 10 in which a cavity 13 is formed by stacking plate-like bodies 12, a working fluid (not shown) sealed in the cavity 13, and a cavity through which a gas-phase working fluid flows. 13 and a steam flow path 15 provided therein.

The container 10 is a thin plate-shaped container, that is, a flat container, in which one plate-shaped body 11 has a first surface 21 that is a first main surface, and the other plate-shaped body 12 has a second surface 21. It has a second surface 22 which is the main surface of. Therefore, the container 10 has a first surface 21 that is a first main surface and a second surface 22 that is a second main surface that is opposite to the first surface 21.

The first surface 21 has a flat planar portion 32 and a convex portion 31 projecting outward from the planar portion 32. In the vapor chamber 1 , a plurality of convex portions 31 are provided on the first surface 21 . In the vapor chamber 1 of FIG. 1, three convex portions 31-1, 31-2, and 31-3 are provided for convenience of explanation. Further, the side surface of the convex portion 31 protrudes from the flat portion 32 in the vertical direction. On the other hand, the second surface 22 does not have any convex portions, and the entire second surface 22 is a flat planar portion. Since the first surface 21 has the flat portion 32 and the convex portion 31 that protrudes outward from the flat portion 32, the container 10 has the flat portion 17 and the convex portion 16 that protrudes outward from the flat portion 17. have. From the above, one plate-like body 11 has a convex portion 16 that projects outward. Therefore, the container 10 is provided with a plurality of convex portions 16 (in the vapor chamber 1 of FIG. 1, for convenience of explanation, three convex portions 16-1, 16-2, and 16-3) on the first surface 21. Therefore, no convex portion is provided on the second surface 22. From the above, the flat portion 17 and the convex portion 16 of the container 10 are integrally molded. Further, the side surface of the convex portion 16 projects from the flat portion 17 in the vertical direction.

Furthermore, a side wall 25 is provided upright on the other plate-shaped body 12 along the periphery of the second surface 22 . The cavity 13, which is the internal space of the container 10, is formed by arranging and abutting the tip of the side wall 25 of the other plate-shaped body 12 against the periphery of the inner surface 23 of the first surface 21. Therefore, the side wall 25 forms the side surface of the container 10. The cavity 13 is a closed space, and the pressure is reduced by degassing. The internal space of the convex part 16 of the container 10 communicates with the internal space of the flat part 17, and the hollow part 13 of the container 10 is formed from the internal space of the convex part 16 and the internal space of the flat part 17. . Therefore, the working fluid can flow between the internal space of the convex portion 16 and the internal space of the flat portion 17.

The shape of the container 10 is not particularly limited, but in the vapor chamber 1, for example, in a plan view (viewed from a direction perpendicular to the flat part 17 of the container 10), a polygonal shape such as a rectangular shape, a circular shape, Examples include an elliptical shape, a shape having a straight portion and a curved portion, and the like.

As shown in FIG. 1, in the vapor chamber 1, a wick structure 40 is provided in the cavity 13. The wick structure 40 is a member having capillary force, and extends along the main surface of the container 10 from one end of the container 10 to the other end. Further, the wick structure 40 is a columnar member extending along the thickness direction of the container 10 in a side view. From the above, the wick structure 40 is a columnar member in side view extending from the inner surface 24 of the second surface 22 toward the inner surface 23 of the first surface 21 . One end of the wick structure 40 is in contact with the inner surface 23 of the first surface 21 , and the other end of the wick structure 40 is in contact with the inner surface 24 of the second surface 22 .

The wick structure 40 is made up of a plurality of members that are columnar in side view. The wick structure 40 has a structure in which a plurality of columnar members in side view are arranged in parallel at predetermined intervals along the main surface of the container 10. Specifically, the wick structure 40 includes a first wick portion 41 that is a columnar member when viewed from the side, and a second wick portion 42 that is a columnar member when viewed from the side. The first wick part 41 is erected on the convex part 16 of the container 10 , and the second wick part 42 is erected on the flat part 17 of the container 10 .

The first wick portion 41 of the wick structure 40 is erected from a portion of the second surface 22 facing the convex portion 31 toward the convex portion 31 . A plurality of first wick parts 41 are provided at predetermined intervals. Further, the first wick portion 41 of the wick structure 40 is in contact with the second surface 22 and the convex portion 31. Therefore, one end of the first wick portion 41 is in contact with the convex portion 31 of the inner surface 23 of the first surface 21, and the other end of the first wick portion 41 is in contact with the inner surface 24 of the second surface 22. Of these, the portion facing the convex portion 31 is in contact with the portion. The dimension from one end of the first wick part 41 to the other end is the height of the first wick part 41. Further, the first wick portion 41 is made of the same material from one end to the other end.

As the container 10 is plastically deformed in the thickness direction due to the stress F in the thickness direction, the first wick portion 41 of the wick structure 40 is compressed in the height direction and its height decreases. do. That is, the first wick portion 41 of the wick structure 40 is compressed by the stress F in the height direction. As described above, the first wick portion 41 of the wick structure 40 is formed of a member whose dimension in the upright direction decreases in accordance with the stress F in the upright direction.

Examples of the member of the first wick portion 41 include porous members such as sintered bodies of powder containing metal powder, meshes made of fine metal wires, metal braids, nonwoven fabrics, and metal wires. These materials may be used alone or in combination of two or more. A sintered body of powder containing metal powder can be made into a porous member suitable for the first wick portion 41 by, for example, increasing the average particle diameter of the metal powder as a raw material. Examples of sintered bodies of powder containing metal powder include sintered bodies of metal powders such as copper powder and stainless steel powder, and sintered bodies of mixed powders of metal powders such as copper powder and carbon powder. I can do it. Further, the mesh made of thin metal wires and the nonwoven fabric can be made into a member suitable for the first wick portion 41 by, for example, twisting a predetermined amount or folding a predetermined amount.

In the vapor chamber 1, a porous member made of a sintered body of powder containing metal powder is used as the first wick portion 41.

The second wick portion 42 of the wick structure 40 is erected from a portion of the second surface 22 opposite to the flat portion 32 of the first surface 21 toward the flat portion 32 . A plurality of second wick parts 42 are provided at predetermined intervals. Further, the second wick portion 42 of the wick structure 40 is in contact with the second surface 22 and the planar portion 32 of the first surface 21 . Therefore, one end of the second wick portion 42 is in contact with the flat portion 32 of the inner surface 23 of the first surface 21, and the other end of the second wick portion 42 is in contact with the inner surface 24 of the second surface 22. Of these, the portion facing the flat portion 32 is in contact with the portion. The dimension from one end of the second wick part 42 to the other end is the height of the second wick part 42. Further, the second wick portion 42 is made of the same material from one end to the other end.

Examples of the member of the second wick portion 42 include a sintered body of powder containing metal powder, a mesh made of fine metal wire, a metal braid, a nonwoven fabric, and a metal wire. The members of the second wick part 42 may be the same as or different from the members of the first wick part 41. These materials may be used alone or in combination of two or more. A sintered body of powder containing metal powder may be made into a porous member by increasing the average particle diameter of the metal powder as a raw material, for example, as in the first wick portion 41. In addition, the sintered body of powder containing metal powder can be produced by, for example, making the average particle diameter of the metal powder as a raw material smaller than that of the first wick part 41, so that the height direction of the second wick part 42 is reduced. It may also be a member with improved mechanical strength that can prevent the height of the second wick portion 42 from decreasing even when subjected to compression. Examples of sintered bodies of powder containing metal powder include sintered bodies of metal powders such as copper powder and stainless steel powder, and sintered bodies of mixed powders of metal powders such as copper powder and carbon powder. I can do it. Further, the mesh made of thin metal wires and the nonwoven fabric can be twisted together in a predetermined amount or folded in a predetermined amount to form a columnar member in side view, for example.

In the vapor chamber 1, a porous member made of a sintered body of powder containing metal powder, which is the same member as the first wick part 41, is used as the second wick part 42.

Further, the wick structure 40 also functions as a support section that maintains the internal space of the container 10. The wick structure 40, which also serves as a support, has a function of maintaining the internal space of the container 10, that is, the cavity 13, which is under reduced pressure. The first wick part 41 of the wick structure 40 functions as a support part for maintaining the internal space of the container 10 at the convex part 16 of the container 10, and the second wick part 42 of the wick structure 40 functions as a support part for maintaining the internal space of the container 10. The flat portion 17 of 10 functions as a support portion that maintains the internal space of the container 10. In the vapor chamber 1, a space between the supporting parts (wick structure 40) becomes a vapor flow path 15 through which a gas-phase working fluid flows.

As for the material of the container 10, the first surface 21 of at least one plate-shaped body 11 is preferably made of a metal material having a tensile strength of 200 N/mm ² or less. Since the first surface 21 is made of a metal material with a tensile strength of 200 N/mm ² or less, when the convex portion 16 of the container 10 receives stress F in the thickness direction, the container 10 is likely to be plastically deformed in the thickness direction. . That is, the convex portion 16 of the container 10 is easily crushed by the stress F in the thickness direction. As a result, as will be described later, the height of the wick structure 40 can be easily adjusted to follow the amount of plastic deformation of the convex portion 16 in the thickness direction of the container 10. The tensile strength of the material of one plate-shaped body 11 having the first surface 21 of the container 10 is 185 N/mm ² or less, since the plastic deformation of the convex portion 16 in the thickness direction of the container 10 becomes easier. is more preferable, and 155 N/mm ² or less is particularly preferable. On the other hand, from the viewpoint of the mechanical strength of the container 10, the lower limit of the tensile strength of the material of the container 10 is preferably 50 N/mm ² for one plate-shaped body 11 and 185 N/mm ² for the other plate-shaped body 12. is preferred. Note that the tensile strength of the material of the container 10 means the strength measured according to JIS Z 2241.

Examples of the material for the container 10 include copper, copper alloy, aluminum, and aluminum alloy.

The thickness of the vapor chamber 1 can be, for example, 0.3 mm or more and 1.0 mm or less. The thickness of one plate-shaped body 11 and the thickness of the other plate-shaped body 12 may be the same or different, and in the vapor chamber 1, the thickness of one plate-shaped body 11 and the thickness of the other plate-shaped body 12 are The thickness is approximately the same. In the vapor chamber 1, the thickness of one plate-like body 11 is substantially uniform over the entire one plate-like body 11. Further, the thickness of the other plate-like body 12 is substantially uniform over the entirety of the other plate-like body 12. The thickness of one plate-like body 11 and the other plate-like body 12 can be, for example, 0.1 mm, respectively.

Further, by joining the peripheral edge of one plate-like body 11 and the peripheral edge of the other plate-like body 12 in contact with each other over the entire circumference, the container 10 which is a closed container is formed, and the cavity 13 is sealed. will be stopped. The method for joining the peripheral portion is not particularly limited, and examples thereof include diffusion bonding, brazing, laser welding using a fiber laser or the like, ultrasonic welding, friction bonding, pressure bonding, and the like.

The working fluid sealed in the cavity 13 can be selected as appropriate depending on its compatibility with the material of the container 10, and examples thereof include water, as well as alternative fluorocarbons, fluorocarbons, and cyclopentanes. , ethylene glycol, and mixtures of these and water.

Next, an example of how to use the vapor chamber 1 according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 1, the vapor chamber 1 cools a plurality of heating elements 100 mounted on a substrate 110. In FIG. 1, for convenience of explanation, four heating elements 100-1, 100-2, 100-3, and 100-4 are mounted on the substrate 110, and the heights of the heating elements 100 are as follows: The height increases in the order of 100-2, 100-3, and heating element 100-4. Note that the heating element 100 may be, for example, a semiconductor component such as a central processing unit.

Before the vapor chamber 1 is thermally connected to the heating element 100, the heights of the plurality of protrusions 16 (in FIG. 1, the three protrusions 16-1, 16-2, and 16-3) are the same. It is high. The tallest heating element 100-1 is thermally connected to the flat part 17 of the container 10, and the shortest heating element 100-4 is thermally connected to the convex part 16-3 of the container 10. The heating elements 100-2 and 100-3, which have a height intermediate between the heating elements 100-1 and 100-4, are thermally connected to the protrusions 16-1 and 16-2 of the container 10, respectively. be done. As described above, the convex portion 16 and the flat portion 17 have a heat receiving portion to which the heating element 100 to be cooled is thermally connected.

When the container 10 is thermally connected to the four heating elements 100-1, 100-2, 100-3, and 100-4, the convex portions 16-1, 16-2, and 16-3 of the container 10, By receiving stress F in the thickness direction of the container 10 from the heating elements 100-2, 100-3, and 100-4, the convex portions 16-1, 16-2, and 16-3 move in the thickness direction of the container 10. It is compressed and deformed plastically. At that time, since the heating elements 100-2 and 100-3 are higher than the heating element 100-4, the stress F is larger in the protrusion 16-1 and the protrusion 16-2 than in the protrusion 16-3. As a result, the amount of plastic deformation becomes larger than that of the convex portion 16-3. Following the amount of plastic deformation of the convex portions 16-1, 16-2, and 16-3 in the thickness direction of the container 10, the first wick portion 41 of the wick structure 40 deforms by a predetermined amount in the thickness direction of the container 10. Compressed. Therefore, the first wick portions 41 located on the convex portions 16-1 and 16-2 have a larger compression amount than the first wick portions 41 located on the convex portions 16-3. In the vapor chamber 1, the convex portion 16 is plastically deformed by a predetermined amount depending on the height difference of the heating element 100, and the first wick portion 41 is compressed by a predetermined amount to maintain the cavity portion 13. At the same time, excellent thermal connectivity can be exhibited even with a plurality of heating elements 100 having different heights.

Next, the operation of the vapor chamber 1 according to the first embodiment of the present invention will be described. The heating element 100 is thermally connected to the outer surface of the first surface 21 of the container 10, so that the first surface 21 functions as a heat receiving surface. The part that is in contact functions as a heat receiving part. When the vapor chamber 1 receives heat from the heating element 100 at the heat receiving section, the liquid phase working fluid sealed in the cavity section 13 changes from the liquid phase to the gas phase at the heat receiving section, and the phase-changed gas phase is activated. The fluid flows through the vapor flow path 15 and diffuses throughout the cavity 13 from the heat receiving section of the vapor chamber 1 . The gaseous working fluid that has diffused throughout the cavity 13 from the heat receiving section radiates latent heat and changes its phase from the gaseous phase to the liquid phase. At this time, the released latent heat is released from the entire container 10 to the external environment of the vapor chamber 1. The working fluid whose phase has changed from the gas phase to the liquid phase is returned from the entire cavity 13 to the heat receiving section by the capillary force of the wick structure 40.

In the vapor chamber 1, the first surface 21 has the flat portion 32 and the convex portion 31 protruding outward from the flat portion 32, so that the container 10 has the flat portion 17 and the convex portion protruding outward from the flat portion 17. 16, the first wick part 41 of the wick structure 40 is erected from the second surface 22 facing the convex part 31 toward the convex part 31, and the first wick part 41 of the wick structure 40 is Since the portion 41 is in contact with the second surface 22 and the convex portion 31, the wick structure 40 located on the convex portion 16 maintains the internal space of the container 10, while maintaining the inner space of the container 10. Thermal connection can be made at the convex portion 16. Therefore, the vapor chamber 1 can exhibit excellent heat transport characteristics by providing excellent thermal connectivity with the heating element 100 while imparting resistance to pressure from the external environment to the container 10.

In addition, in the vapor chamber 1, in particular, since the container 10 has a plurality of convex portions 16, excellent thermal connectivity can be obtained even for a plurality of heating elements 100 of different heights. Excellent heat transport characteristics can be exhibited even for a plurality of heating elements 100 having different temperatures.

Furthermore, in the vapor chamber 1, the wick structure 40 is made of at least one kind selected from the group consisting of a sintered body of powder containing metal powder, a mesh made of metal wire, a metal braided body, a metal wire, and a nonwoven fabric. As a result, the stress F in the thickness direction of the container 10 facilitates the height adjustment by compression of the wick structure 40, so that the convex portion 16 protrudes outward while maintaining the hollow portion 13. The accuracy of the amount is improved, and the thermal connectivity with the heating element 100 is reliably improved.

Moreover, in the vapor chamber 1, the first surface 21 of the container 10 is formed of a metal material having a tensile strength of 200 N/mm ² or less, so that the stress F in the thickness direction of the container 10 causes the convexity of the container 10. The portion 16 is more likely to be plastically deformed. Further, the height of the first wick portion 41 can be easily adjusted in accordance with the amount of plastic deformation of the convex portion 16 in the thickness direction of the container 10. Therefore, in the vapor chamber 1, the accuracy of the amount of outward protrusion of the convex portion 16 is improved, and the thermal connectivity with the heating element 100 is reliably improved.

Further, in the vapor chamber 1, since the wick structure 40 also functions as a support member for maintaining the internal space of the container 10, there is no need to separately provide a support member for maintaining the internal space of the container 10. Therefore, the steam flow path 15 can be sufficiently secured, and the flow characteristics of the gas-phase working fluid are further improved.

Next, details of a vapor chamber according to a second embodiment of the present invention will be described. FIG. 2 is a side sectional view illustrating an outline of the internal structure of a vapor chamber according to a second embodiment of the present invention. The vapor chamber according to the second embodiment has the same main components as the vapor chamber according to the first embodiment, so the same components as the vapor chamber according to the first embodiment are the same. This will be explained using symbols.

In the vapor chamber 1 according to the first embodiment, the plurality of first wick parts 41, 41, 41... were all made of the same material from one end to the other end. In the vapor chamber 2 according to the second embodiment, at least some of the first wick parts 41 among the plurality of first wick parts 41, 41, 41, . . . are made of different materials on one end side and the other end side. It becomes. In the vapor chamber 2, one end of the first wick section 41 is formed of a first member 41-1, and the other end of the first wick section 41 is formed of a second member 41-2.

Examples of the first member 41-1 include a porous member formed of a sintered body of powder containing metal powder having a large average particle size, a mesh made of thin metal wires, a metal braid, a nonwoven fabric, and the like. Further, as the second member 41-2, the first member 41-1 is formed of a sintered body of powder containing metal powder with a small average particle diameter, a mesh made of thin metal wires, a metal braided body, a nonwoven fabric, etc. Examples include members that are less porous. Since the first member 41-1 is a porous member, the first member 41-1 is compressed by a predetermined amount in the thickness direction of the container 10 in accordance with the amount of plastic deformation of the convex portion 16, and as a result, The first wick portion 41 is compressed by a predetermined amount in the thickness direction of the container 10.

The height ratio of the first member 41-1 and the second member 41-2 is not particularly limited, but for example, the height of the first member 41-1 may be approximately the same as the height of the convex portion 16. The height of the second member 41-2 may be approximately the same as the height of the second wick portion 42.

In the vapor chamber 2 as well, the wick structure 40 located in the convex part 16 can maintain the internal space of the container 10 and can be thermally connected to the low-height heating element 100 at the convex part 16. Therefore, the vapor chamber 2 can also exhibit excellent heat transport characteristics by providing excellent thermal connectivity with the heating element 100 while imparting resistance to pressure from the external environment to the container 10.

Next, details of a vapor chamber according to a third embodiment of the present invention will be described. FIG. 3 is a side sectional view illustrating an outline of the internal structure of a vapor chamber according to a third embodiment of the present invention. The vapor chamber according to the third embodiment has the same main components as the vapor chambers according to the first and second embodiments, so it is different from the vapor chambers according to the first and second embodiments. The same components will be explained using the same reference numerals.

In the vapor chamber 1 according to the first embodiment, the plurality of first wick parts 41, 41, 41... and the plurality of second wick parts 42, 42, 42... are all connected from one end to the other. The material was the same all the way to the ends. Instead, in the vapor chamber 3 according to the third embodiment, at least some of the first wick parts 41 among the plurality of first wick parts 41, 41, 41... The other end is made of a different material.

In the vapor chamber 3, one end of the first wick portion 41 is an elastic member 43. In the vapor chamber 3 , one end of the first wick portion 41 that is in contact with the first surface 21 is an elastic member 43 . The other end of the first wick portion 41 that is in contact with the second surface 22 is a wick member, similar to the vapor chambers 1 and 2. As the elastic member 43, for example, a member formed of a metal wire material in a spiral shape can be mentioned. The elastic member 43 is connected to the material of the wick structure 40, such as a sintered body of powder containing metal powder, a mesh made of metal wire, a metal braid, a metal wire, and a nonwoven fabric.

In the vapor chamber 3, when the convex part 16 of the container 10 receives stress in the thickness direction of the container 10 from the heating element 100, the convex part 16 is compressed in the thickness direction of the container 10 and plastically deforms. Following the amount of plastic deformation of the convex portion 16, the elastic member 43 is compressed by a predetermined amount. By compressing the elastic member 43 by a predetermined amount, the first wick portion 41 of the wick structure 40 is compressed by a predetermined amount in the thickness direction of the container 10, which is excellent even for a plurality of heating elements 100 of different heights. It can exhibit excellent thermal connectivity.

In the vapor chamber 3 as well, the wick structure 40 located in the convex part 16 can maintain the internal space of the container 10 and can be thermally connected to the low-height heating element 100 at the convex part 16. Therefore, the vapor chamber 3 can also exhibit excellent heat transport characteristics by providing excellent thermal connectivity with the heating element 100 while imparting resistance to pressure from the external environment to the container 10.

Next, another example of how to use the vapor chamber of the present invention will be explained. Here, another example of how to use the vapor chamber 1 according to the first embodiment will be described. FIG. 4 is a side sectional view illustrating another example of how to use the vapor chamber of the present invention.

As shown in FIG. 4, as another example of how to use the vapor chamber 1, the vapor chamber 1 is placed on the back surface 113 of the substrate 110 with respect to the heating element 100 which is the object to be cooled and which is thermally connected to the front surface 112 of the substrate 110. An example of a usage method is to cool the heating element 100 by thermally connecting it. Note that the heating element 100 in other usage examples includes a power semiconductor such as a transistor (for example, a metal oxide semiconductor field effect transistor).

In another usage example, the substrate 110 has a through hole 111 in the thickness direction, and a metal coin 120 such as a copper coin, which is a thermally conductive member, is inserted into the through hole 111. Heat can be conducted between the front surface 112 and the back surface 113 of. A plurality of metal coins 120 are provided, and in FIG. 4, the substrate 110 has a metal coin 120-1 which is the most recessed with respect to the back surface 113 of the substrate 110, and which is substantially on the same plane with respect to the back surface 113 of the substrate 110. It has a metal coin 120-2 and a metal coin 120-3 slightly set back with respect to the back surface 113 of the substrate 110.

The metal coin 120-1 that is the most retracted with respect to the back surface 113 of the substrate 110 is thermally connected to the convex portion 16-1 of the container 10, and the metal coin 120-1 that is on substantially the same plane as the back surface 113 of the substrate 110 is -2 is thermally connected to the convex part 16-2 of the container 10, and the metal coin 120-3, which is slightly retracted from the back surface 113 of the substrate 110, is thermally connected to the convex part 16-3 of the container 10. be done. As described above, the convex portion 16 has a heat receiving portion to which the metal coin 120 to be cooled is thermally connected.

When the container 10 is thermally connected to the three metal coins 120-1, 120-2, and 120-3, the convex portions 16-1, 16-2, and 16-3 of the container 10 are connected to the metal coins, respectively. By receiving the stress F in the thickness direction of the container 10 from 120-1, 120-2, and 120-3, the convex parts 16-1, 16-2, and 16-3 are compressed in the thickness direction of the container 10. Plastically deforms. At this time, since the metal coin 120-2 is on substantially the same plane as the back surface 113 of the substrate 110, the stress F is greater in the protrusion 16-2 than in the protrusion 16-1 and the protrusion 16-3. As a result, the amount of plastic deformation becomes larger than that of the convex portions 16-1 and 16-3. Furthermore, since the metal coin 120-3 is slightly recessed with respect to the back surface 113 of the substrate 110, the stress F on the protrusion 16-3 becomes larger than that on the protrusion 16-1, and as a result, the protrusion 16-3 The amount of plastic deformation becomes larger than that. Following the amount of plastic deformation of the convex portions 16-1, 16-2, and 16-3 in the thickness direction of the container 10, the first wick portion 41 of the wick structure 40 deforms by a predetermined amount in the thickness direction of the container 10. Compressed. Therefore, the first wick portion 41 located on the convex portion 16-2 has a larger compression amount than the first wick portion 41 located on the convex portions 16-1 and 16-3. Furthermore, the amount of compression of the first wick portion 41 located on the convex portion 16-3 is greater than that of the first wick portion 41 located on the convex portion 16-1.

In this manner, in the vapor chamber 1, the convex portion 16 is plastically deformed by a predetermined amount depending on the difference in the amount of retreat of the metal coin 120 from the back surface 113 of the substrate 110 and the difference in the amount of protrusion of the metal coin 120 from the back surface 113 of the substrate 110. Furthermore, by compressing the first wick portion 41 by a predetermined amount, excellent thermal connectivity can be exhibited even for a plurality of metal coins 120 at different positions from the back surface 113 of the substrate 110.

In another example of how the vapor chamber 1 is used, the heat of the heating element 100 thermally connected to the front surface 112 of the substrate 110 is transferred from the front surface 112 to the back surface 113 of the substrate 110 via the metal coin 120 . The heat transferred to the back surface 113 of the substrate 110 is transferred from the back surface 113 of the substrate 110 to the heat receiving part of the vapor chamber 1, and due to the heat transport characteristics of the vapor chamber 1, it is diffused from the heat receiving part to the entire vapor chamber 1, and becomes vapor. is released into the environment outside chamber 1.

In another example of how to use the vapor chamber 1, the wick structure 40 located on the convex portion 16 maintains the internal space of the container 10, while maintaining the internal space of the container 10, while maintaining the space between the metal coins 120 at different positions from the back surface 113 of the substrate 110. Thermal connection can be made at the convex portion 16. Therefore, even in other usage examples of the vapor chamber 1, it is possible to provide the container 10 with resistance to pressure from the external environment while also providing excellent thermal connectivity with the heating element 100 via the metal coin 120. Can exhibit transport characteristics.

Next, other embodiments of the vapor chamber of the present invention will be described. In each of the embodiments described above, a second wick structure may be further provided on the inner surface of the first surface along the extending direction of the inner surface of the first surface. By providing the second wick structure on the inner surface of the first surface, the return characteristics of the liquid phase working fluid from the entire cavity to the heat receiving section are further improved. Furthermore, in each of the embodiments described above, a third wick structure may be further provided on the inner surface of the second surface along the extending direction of the inner surface of the second surface. By providing the third wick structure on the inner surface of the second surface, the return characteristics of the liquid phase working fluid from the entire cavity to the heat receiving section are further improved. As the second wick structure and the third wick structure, for example, a sintered body of powder containing metal powder, a mesh made of thin metal wires, a metal braided body, a plurality of grooves, a nonwoven fabric, etc. can be mentioned.

Further, in each of the above embodiments, the container has a plurality of convex portions, but the number of convex portions can be selected as appropriate depending on the number of objects to be cooled, and may be one convex portion. Further, in each of the above embodiments, the convex part and the flat part of the container had a heat receiving part to which the object to be cooled was thermally connected. may have a heat receiving part to which it is thermally connected.

Further, in the vapor chamber of the third embodiment, one end of the first wick part was an elastic member, but instead of this, one end of the first wick part and one end of the second wick part were made of an elastic member. The end may be an elastic member. Further, in the vapor chamber of the third embodiment, one end of the first wick part that is in contact with the first surface is an elastic member, but instead of this, the second wick part of the first wick part is made of an elastic member. The other end in contact with the surface may be an elastic member.

The vapor chamber of the present invention exhibits excellent heat transport properties by having excellent thermal connectivity with the object to be cooled while having resistance to pressure from the external environment. It has high utility value in the field of cooling heating elements of different shapes.

1, 2, 3 Vapor chamber 10 Container 13 Cavity 15 Steam flow path 16 Convex portion 17 Plane portion 21 First surface 22 Second surface 40 Wick structure

Claims (7)

a container having a first surface and a second surface opposite to the first surface with a cavity formed therein; a wick structure provided in the cavity; and a wick structure sealed in the cavity. comprising a working fluid and a vapor flow path provided in the cavity through which the working fluid in a gas phase flows;
The first surface has a flat part and a convex part protruding outward from the flat part, so that the container has a flat part and a convex part protruding outward from the flat part,
The inner space of the convex part of the container is in communication with the inner space of the flat part, so that the hollow part is formed,
The wick structure is erected from a portion of the second surface facing the convex portion toward the convex portion, and the wick structure is in contact with the second surface and the convex portion ,
A vapor chamber in which the first surface is made of a metal material having a tensile strength of 200 N/mm ² or less. The vapor chamber according to claim 1, wherein the container has a plurality of the protrusions. The vapor chamber according to claim 1 or 2, wherein the wick structure is a member whose dimension in the upright direction decreases in response to stress in the upright direction. Any one of claims 1 to 3, wherein the wick structure is at least one selected from the group consisting of a sintered body of powder containing metal powder, a mesh made of fine metal wire, a metal braided body, a metal wire, and a nonwoven fabric. The vapor chamber according to item 1. The vapor chamber according to any one of claims 1 to 4 , wherein the wick structure is a support part that maintains an internal space of the container. Claim 1, wherein the container is formed of one plate-shaped body and another plate-shaped body facing the one plate-shaped body, and the one plate-shaped body has the convex portion projecting outward. 6. The vapor chamber according to any one of items 5 to 5 . The vapor chamber according to any one of claims 1 to 6 , wherein the convex portion and the flat portion have a heat receiving portion to which an object to be cooled is thermally connected.

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