JP7495310B2 - Vapor Chamber - Google Patents

Description

This disclosure relates to a vapor chamber.

The amount of heat generated by electronic components such as semiconductor elements mounted in electrical and electronic devices such as laptops, digital cameras, and mobile phones tends to increase due to factors such as high density mounting that accompanies high functionality. For this reason, there is a demand for electronic components to be configured to be cooled efficiently. In recent years, configurations that use vapor chambers to cool electronic components have been adopted.

For example, Patent Document 1 describes a vapor chamber in which a wick is provided inside a sealed container, and the wick on the evaporator side has a larger capillary pressure than the wick on the condenser side, and the wick on the condenser side has a smaller flow resistance of the working fluid than the wick on the evaporator side. Patent Document 1 also describes that the wick on the condenser side and the wick on the evaporator side are made of a porous sintered body.

Patent No. 4354270

However, in the vapor chamber of Patent Document 1, the wick, which affects the heat transport properties of the vapor chamber, is made of a sintered body, so the mechanical strength of the wick tends to be weak, and the wick may be destroyed by impact such as vibration. When assembling an airtight container after installing a sintered body with a thickness greater than the thickness of the internal space of the vapor chamber, the sintered body may collide with the container and be destroyed during assembly of the airtight container. When the wick, which is a sintered body, is destroyed, a gap is generated between the wick and the airtight container, and the heat transport properties of the vapor chamber are reduced. In addition, when a vapor chamber including a precursor of the sintered body is heat-treated after installing a precursor of the sintered body in a closed container, the sintered body formed by the heat treatment becomes smaller than the precursor, and a gap may be generated between the sintered body and the airtight container. In this case as well, the heat transport properties of the vapor chamber are reduced. In this way, the wick is easily destroyed, and further, since it is difficult to adjust the size between the wick and the internal space of the vapor chamber during manufacturing the vapor chamber, the heat transport properties of the vapor chamber are easily reduced.

The objective of this disclosure is to provide a vapor chamber that has a wick structure that is resistant to destruction, has excellent heat transport properties, and is easy to manufacture.

[1] A vapor chamber having a working fluid in an internal space formed between a first metal plate and a second metal plate, characterized in that the vapor chamber further comprises a wick structure that is disposed in the internal space, is in contact with the first metal plate and the second metal plate, and expands and displaces in a direction in which the first metal plate and the second metal plate move away from each other in response to a compressive displacement in a direction in which the first metal plate and the second metal plate move closer to each other.
[2] The vapor chamber described in [1] above, wherein the wick structure is composed of at least one material selected from the group consisting of braided wire, twisted wire, and metal sponge.
[3] The vapor chamber according to [1] or [2] above, wherein the wick structure is made of a circular braided wire of a copper-based material.
[4] The vapor chamber described in [1] above, wherein the wick structure has a plurality of first wick structure parts overlapping along the thickness direction of the vapor chamber, and the first wick structure parts expand and displace in a direction in which the first metal plate and the second metal plate move away from each other in response to a compressive displacement in a direction in which the first metal plate and the second metal plate move closer to each other.
[5] The vapor chamber described in [1] above, wherein the wick structure has one or more first wick structure parts and one or more second wick structure parts that overlap along the thickness direction of the vapor chamber, and the first wick structure parts expand and displace in a direction in which the first metal plate and the second metal plate move away from each other in response to a compressive displacement in a direction in which the first metal plate and the second metal plate move closer to each other.
[6] The vapor chamber described in [5] above, wherein the second wick structure portion is composed of at least one selected from the group consisting of a sintered body, a mesh sheet, and a fiber sheet.
[7] The vapor chamber according to any one of [4] to [6] above, wherein the first wick structure is composed of at least one material selected from the group consisting of braided wire, twisted wire, and metal sponge.
[8] The vapor chamber according to any one of [4] to [7] above, wherein the first wick structure is made of a circular braided wire made of a copper-based material.
[9] The vapor chamber according to any one of [1] to [8] above, wherein the first metal plate and the second metal plate are made of any one selected from the group consisting of aluminum, an aluminum alloy, copper, a copper alloy, and stainless steel.
[10] The vapor chamber according to any one of [1] to [9] above, wherein the working fluid is cis-1-chloro-3,3,3-trifluoropropene.

The present disclosure provides a vapor chamber that has a wick structure that is resistant to destruction, has excellent heat transport properties, and is easy to manufacture.

FIG. 1 is a perspective view showing an example of a vapor chamber of the first embodiment. FIG. 2 is a cross-sectional view of surface A of FIG. FIG. 3 is a cross-sectional view showing the configuration of the vapor chamber of FIG. 2 before it is manufactured. FIG. 4 is a perspective view showing another example of the vapor chamber of the first embodiment. FIG. 5 is a cross-sectional view of surface B of FIG. FIG. 6 is a perspective view showing an example of a vapor chamber according to the second embodiment. FIG. 7 is a cross-sectional view of surface C of FIG. FIG. 8 is a cross-sectional view showing the configuration before the vapor chamber of FIG. 7 is manufactured. FIG. 9 is a perspective view showing another example of the vapor chamber of the second embodiment.

The following provides a detailed explanation based on the embodiment.

After extensive research, the inventors focused on the configuration of the wick structure, which affects the heat transport properties of the vapor chamber, and adopted a wick structure that is compliant with deformation and less likely to break, thereby improving the heat transport properties of the vapor chamber and making it easier to manufacture.

The vapor chambers 1 and 2 of the embodiment are vapor chambers having a working fluid in an internal space S formed between a first metal plate 10 and a second metal plate 20, and are equipped with wick structures 30 and 30a that are disposed in the internal space S, are in contact with the first metal plate 10 and the second metal plate 20, and expand and displace in a direction in which the first metal plate 10 and the second metal plate 20 move away from each other in response to a compressive displacement in a direction in which the first metal plate 10 and the second metal plate 20 move closer to each other.

First Embodiment
FIG. 1 is a perspective view showing an example of a vapor chamber of the first embodiment. FIG. 2 is a cross-sectional view of surface A of FIG. 1. FIG. 3 is a cross-sectional view showing the configuration before the vapor chamber of FIG. 2 is manufactured. For convenience, FIG. 1 shows a partially transparent state so that the internal structure of the vapor chamber can be seen. In addition, the direction in which the liquid phase working fluid F (L) flows is indicated by a solid arrow, and the direction in which the gas phase working fluid F (g) flows is indicated by a hollow arrow.

As shown in Figures 1 and 2, the vapor chamber 1 of the first embodiment has a first metal plate 10 and a second metal plate 20. The first metal plate 10 and the second metal plate 20 are joined so that they face each other. The vapor chamber 1 also has a working fluid in an internal space S formed between the first metal plate 10 and the second metal plate 20. The internal space S is sealed by joining the first metal plate 10 and the second metal plate 20. The internal space S provided inside the vapor chamber 1 is filled with a working fluid.

The first metal plate 10 constituting the vapor chamber 1 has a first plate portion 11 and a first peripheral wall portion 12. The first peripheral wall portion 12 of the first metal plate 10 extends from the periphery of the first plate portion 11 toward the second metal plate 20. For example, the first peripheral wall portion 12 is provided around the entire periphery of the first plate portion 11.

The second metal plate 20 constituting the vapor chamber 1 faces the first plate portion 11 of the first metal plate 10. That is, the inner surface 20a of the second metal plate 20 and the inner surface 11a of the first plate portion 11 of the first metal plate 10 face each other. The first peripheral wall portion 12 of the first metal plate 10 is joined to the inner surface 20a of the second metal plate 20, thereby sealing the internal space S of the vapor chamber 1.

A cooled member 40 and heat dissipation fins 41 are provided on the outer surface 20b of the second metal plate 20. The cooled member 40 is a member that is cooled in the vapor chamber 1, and is, for example, a heat generating body such as an IC (integrated circuit) or an ECU (engine control unit).

The vapor chamber 1 is disposed in the internal space S and includes a wick structure 30 in contact with the first metal plate 10 and the second metal plate 20. The wick structure 30 exerts a capillary effect on the liquid phase working fluid and has a suction function for the liquid phase working fluid. The wick structure 30 is in contact with the inner surface 11a of the first plate portion 11 and is in contact with the inner surface 20a of the opposing second metal plate 20.

The wick structure 30 expands and displaces in a direction in which the first metal plate 10 and the second metal plate 20 move away from each other (hereinafter also referred to as the extension direction) following a compressive displacement in a direction in which the first metal plate 10 and the second metal plate 20 move closer to each other (hereinafter also referred to as the compression direction) in the thickness direction L of the vapor chamber 1, which is a direction that connects the first metal plate 10 and the second metal plate 20 in a straight line.

The wick structure 30, which has such deformation-following ability, generates a reaction force based on a predetermined compressive displacement that occurs along the compression direction. Then, based on the reaction force, the wick structure 30 undergoes an elongation displacement in the elongation direction, following the compressive displacement. Because the wick structure 30 has deformation-following ability, the elongation displacement of the wick structure 30 after the compressive displacement occurs automatically without receiving an external force from the outside on the wick structure 30. The thickness of the wick structure 30 after the elongation displacement is greater than the thickness of the wick structure 30 at maximum compression.

The wick structure 30, which has the deformation followability along the thickness direction L of the vapor chamber 1 as described above, acts as follows in the manufacture of the vapor chamber 1.

First, as shown in FIG. 3, in the configuration before the vapor chamber 1 is manufactured, the wick structure 30 is installed in advance on the inner surface 11a of the first plate portion 11 of the first metal plate 10 and the inner surface 20a of the second metal plate 20. The first metal plate 10 and the second metal plate 20 are arranged facing each other without being joined to each other.

The thickness of the wick structure 30 along the thickness direction L in the configuration before the vapor chamber 1 is manufactured shown in FIG. 3 is greater than the length between the inner surface 11a of the first plate portion 11 and the inner surface 20a of the second metal plate 20 in the vapor chamber 1 shown in FIG. 2, i.e., the thickness of the internal space S of the vapor chamber 1. Thus, in the state shown in FIG. 3, the thickness of the wick structure 30 is greater than the length of the first peripheral wall portion 12 of the first metal plate 10.

In this manner, the wick structure 30 having a thickness greater than the thickness of the internal space S is pre-installed on the inner surface 11a of the first plate portion 11 and the inner surface 20a of the second metal plate 20. Then, while moving the first metal plate 10 and the second metal plate 20 in a direction approaching each other, the wick structure 30 is compressed along the thickness direction L to join the first metal plate 10 and the second metal plate 20.

When the first metal plate 10 and the second metal plate 20 are joined, the wick structure 30 is compressed and displaced in the direction in which the first metal plate 10 and the second metal plate 20 approach each other. When the thickness of the wick structure 30 at maximum compression becomes smaller than the thickness of the internal space S, the wick structure 30 does not come into contact with either the inner surface 11a of the first plate portion 11 of the first metal plate 10 or the inner surface 20a of the second metal plate 20. Since the wick structure 30 has deformation followability along the thickness direction L of the vapor chamber 1, even if the thickness of the wick structure 30 at maximum compression becomes smaller than the thickness of the internal space S, the wick structure 30 is elongated and displaced in the direction in which the first metal plate 10 and the second metal plate 20 move away from each other, that is, in the direction toward the first metal plate 10 and the second metal plate 20. The elongated wick structure 30 comes into contact with the inner surface 11a of the first plate portion 11 of the first metal plate 10 and the inner surface 20a of the second metal plate 20. In this way, the wick structure 30 can automatically adjust its thickness so that it matches the thickness of the internal space S.

The wick structure 30, which is in contact with the first metal plate 10 and the second metal plate 20, exerts a capillary effect on the liquid phase working fluid. Therefore, the liquid phase working fluid flowing on the inner surface 11a of the first plate portion 11 of the first metal plate 10 is sucked up by the wick structure 30 and flows toward the inner surface 20a of the second metal plate 20. The heat generated in the cooled member 40 is transferred from the outer surface 20b to the inner surface 20a via the second metal plate 20. The heat transferred from the cooled member 40 evaporates the liquid phase working fluid on the inner surface 20a of the second metal plate 20, generating a gas phase working fluid.

In this way, since the wick structure 30 is in contact with the first plate portion 11 of the first metal plate 10 and the second metal plate 20, the flow of the working fluid along the thickness direction L of the vapor chamber 1 and the transfer of heat between the cooled member 40 and the working fluid are efficient, and the transfer of heat in the internal space S of the vapor chamber 1 is excellent. A vapor chamber 1 equipped with such a wick structure 30 has excellent heat transport properties.

Furthermore, since the wick structure 30 has deformation followability, even if an impact is applied to the wick structure 30 when the first metal plate 10 and the second metal plate 20 are joined, the wick structure 30 is unlikely to be destroyed.

Furthermore, the wick structure 30 installed on the first metal plate 10 and the second metal plate 20 before the vapor chamber 1 is manufactured is deformed along the thickness direction L without being destroyed when the first metal plate 10 and the second metal plate 20 are joined. Therefore, it is not necessary to adjust the size of the thickness of the wick structure 30 and the thickness of the internal space S of the vapor chamber 1 before manufacturing the vapor chamber 1. Furthermore, since the wick structure 30 can be automatically adjusted to the thickness of the internal space S of the vapor chamber 1 during the manufacturing of the vapor chamber 1, it becomes easy to adjust the size of the thickness of the wick structure 30 and the thickness of the internal space S of the vapor chamber 1, and it becomes easy to install the wick structure 30 in the internal space S. As a result, the vapor chamber 1 can be easily manufactured.

The vapor chamber 1 equipped with such a wick structure 30 cools the cooled member 40 mainly through the following cooling path.

The liquid phase working fluid flowing through the inner surface 11a of the first plate portion 11 flows toward the second metal plate 20 as shown by the arrow F (L) by the wick structure 30 in contact with the inner surface 11a of the first plate portion 11 and the inner surface 20a of the second metal plate 20. The evaporation section 50 evaporates the liquid phase working fluid flowing through the second metal plate 20 by the heat transferred from the cooled member 40 to the second metal plate 20, and changes the phase to a gas phase working fluid. The heated gas phase working fluid flows to the condensation section 51 located away from the evaporation section 50 as shown by the arrow F (G). In the process of the gas phase working fluid flowing toward the condensation section 51, the temperature of the working fluid decreases. In the condensation section 51, the gas phase working fluid with the reduced temperature is condensed and changes the phase to a liquid phase working fluid. The latent heat generated by the phase change is transferred to the heat dissipation fin 41 via the second metal plate 20 and is released to the outside of the vapor chamber 1. The condensed liquid phase working fluid flows smoothly along the inner surface 11a of the first plate portion 11. The liquid phase working fluid on the inner surface 11a flows again to the second metal plate 20 by the wick structure 30. This smooth circulation of the liquid and gas phase working fluids allows the vapor chamber 1 to efficiently cool the cooled member 40.

If the wick structure 30 does not have the above-mentioned deformation followability, the wick structure 30 that is compressed and displaced when the first metal plate 10 and the second metal plate 20 are joined will remain compressed and displaced without being elongated. Therefore, the wick structure 30 may not contact the first metal plate 10 and the second metal plate 20, and a gap may be generated between the wick structure 30 and the inner surface 11a of the first plate portion 11 or between the wick structure 30 and the inner surface 20a of the second metal plate 20. This gap impedes the flow of the liquid phase working fluid along the thickness direction L of the vapor chamber 1, reducing the efficiency of heat transfer between the working fluid and the cooled member 40. Therefore, the heat transport characteristics of the vapor chamber 1 are reduced. Furthermore, the wick structure 30 is easily destroyed by the impact when the first metal plate 10 and the second metal plate 20 are joined. Furthermore, the thickness of the wick structure 30 and the thickness of the internal space S are adjusted during the manufacture of the vapor chamber 1, so that the manufacture of the vapor chamber 1 is not easy.

In view of the above-mentioned deformation followability and breakage resistance of the wick structure 30, and the improvement of the heat transport properties of the vapor chamber 1, it is preferable that the wick structure 30 is composed of at least one selected from the group consisting of braided wire, twisted wire, and metal sponge. The braided wire is made by braiding multiple metal wires. The twisted wire is made by twisting multiple metal wires together. From the above-mentioned viewpoint, the metal is preferably a copper-based material including copper and copper alloy, and copper is more preferable. For these reasons, the wick structure 30 is preferably composed of a braided wire of a copper-based material, and more preferably composed of a round braided wire of a copper-based material. The preferred braided wire configuration is a bundle of 10 to 50 copper wires with a wire diameter of 1 mm, braided into 10 to 20 bundles.

The wick structure 30 is not made of a material that does not have deformation followability, such as a sintered body. In particular, when the wick structure 30, which is made of at least one material selected from the group consisting of braided wire, twisted wire, and metal sponge, has a hollow portion inside along the extension direction, the gas phase working fluid flows easily inside the hollow portion, further improving the heat transport properties of the vapor chamber 1. Since such a hollow portion is larger than the pores of the sintered body, the gas phase working fluid flows more easily inside the hollow portion of the wick structure than in a sintered body.

For example, the wick structure 30 may be composed of three wick parts 31 composed of braided wire, or may be composed of one wick part 31 composed of braided wire, one wick part 31 composed of twisted wire, and one wick part 31 composed of metal sponge. The arrangement of the wick parts 31, such as the constituent materials of the wick parts 31 and the number of wick parts 31, is appropriately selected depending on the application of the vapor chamber 1.

Furthermore, as shown in Figures 4 and 5, it is preferable that the vapor chamber 1 has one or more first protrusions 13 provided on the inner surface 11a of the first plate portion 11.

The first protrusion 13 protrudes from the inner surface 11a of the first plate portion 11 toward the inner surface 20a of the second metal plate 20 and abuts against the inner surface 20a of the second metal plate 20. Since the first protrusion 13 abuts against the opposing second metal plate 20, the pressure resistance of the vapor chamber 1 is improved. In addition, the wick structure 30 can be arranged in any shape between the first protrusions 13. In addition, the first protrusions 13 can suppress the movement of the wick structure 30 installed in the vapor chamber 1. The arrangement configuration, such as the shape, number, and position of the first protrusions 13, is appropriately selected depending on the application of the vapor chamber 1.

Although FIGS. 4 and 5 show the vapor chamber 1 having the first protrusion 13, the vapor chamber 1 may have one or more second protrusions (not shown) provided on the inner surface 20a of the second metal plate 20. When the vapor chamber 1 has a second protrusion, the vapor chamber 1 may or may not have the first protrusion 13.

The second protrusion protrudes from the inner surface 20a of the second metal plate 20 toward the inner surface 11a of the first plate portion 11 and abuts against the inner surface 11a of the first plate portion 11. Since the second protrusion abuts against the opposing first plate portion 11, the pressure resistance of the vapor chamber 1 is improved. As with the first protrusion 13, the wick structure 30 can be arranged in any shape between the second protrusions. In addition, the second protrusion can suppress the movement of the wick structure 30 installed in the vapor chamber 1. The arrangement configuration, such as the shape, number, and position of the second protrusions, is appropriately selected depending on the application of the vapor chamber 1. In addition, the installation ratio of the first protrusion 13 and the second protrusions is also appropriately selected depending on the application of the vapor chamber 1.

In addition, from the viewpoint of improving the heat transport properties of the vapor chamber 1, the first metal plate 10 and the second metal plate 20 are preferably made of any one selected from the group consisting of aluminum, aluminum alloy, copper, copper alloy, and stainless steel. Among them, in order to reduce the weight of the vapor chamber 1, it is more preferable that the first metal plate 10 and the second metal plate 20 are both made of aluminum. In addition, in order to increase the pressure resistance of the vapor chamber 1, it is more preferable that the first metal plate 10 and the second metal plate 20 are both made of stainless steel. In addition, in order to increase the heat transport properties of the vapor chamber 1, it is more preferable that the first metal plate 10 and the second metal plate 20 are both made of copper. In addition, tin, tin alloy, titanium, titanium alloy, nickel, nickel alloy, etc. may be used for the first metal plate 10 and the second metal plate 20 depending on the usage environment.

From the viewpoint of the cooling performance of the vapor chamber 1, the working fluid sealed in the internal space S of the vapor chamber 1 is preferably pure water, ethanol, methanol, acetone, fluorine-based solvents, etc. Among these, from the viewpoint of improving the heat transport properties of the vapor chamber 1 and reducing the environmental load, the working fluid is more preferably a fluorine-based solvent, and even more preferably cis-1-chloro-3,3,3-trifluoropropene (1233zdZ). Furthermore, when the working fluid is an aqueous solvent, the wick structure is subjected to an oxidation-reduction treatment to remove contamination such as oil components adhering to the wick structure, but when the working fluid is a fluorine-based solvent, the above treatment for the wick structure is unnecessary.

According to the first embodiment described above, by installing a wick structure that has deformation-following properties along the thickness direction of the vapor chamber inside the vapor chamber, the wick structure is less likely to be destroyed, the heat transport properties of the vapor chamber are improved, and the vapor chamber can be easily manufactured.

Second Embodiment
Fig. 6 is a perspective view showing an example of a vapor chamber of the second embodiment. Fig. 7 is a cross-sectional view of surface C of Fig. 6. Fig. 8 is a cross-sectional view showing a configuration before the vapor chamber of Fig. 7 is manufactured.

In the following embodiment, the same components as those in the vapor chamber of the first embodiment are given the same reference numerals, and duplicate descriptions are omitted or simplified.

The vapor chamber 2 of the second embodiment is basically the same as the vapor chamber 1 of the first embodiment, except for the difference in the configuration of the wick structure 30a. Therefore, the different configuration will be mainly described here.

As shown in Figures 6 and 7, in the vapor chamber 2, the wick structure 30a has multiple first wick structure parts 35 that overlap along the thickness direction L of the vapor chamber 2, and the first wick structure parts 35 expand and displace in a direction in which the first metal plate 10 and the second metal plate 20 move apart in response to a compressive displacement in a direction in which the first metal plate 10 and the second metal plate 20 move closer to each other. For example, as shown in the figures, the wick structure 30a has two first wick structure parts 35 of the same shape that overlap each other, and the two first wick structure parts 35 are arranged rotated 90 degrees relative to each other.

The first wick structure 35, which has the ability to follow deformation along the thickness direction L, corresponds to the wick structure 30 installed in the vapor chamber 1 of the first embodiment. That is, the vapor chamber 2 of the second embodiment has multiple first wick structure parts 35 arranged along the thickness direction L, while the vapor chamber 1 of the first embodiment has one wick structure 30.

From the same viewpoint as the wick structure 30, the first wick structure 35 constituting the wick structure 30a is preferably composed of at least one selected from the group consisting of braided wire, twisted wire, and metal sponge. From the above viewpoint, the metal is preferably a copper-based material including copper and copper alloy, and copper is more preferable. For these reasons, the first wick structure 35 is preferably composed of a braided wire of a copper-based material, and more preferably composed of a round braided wire of a copper-based material.

Furthermore, like the wick structure 30, the first wick structure 35 is not made of a material that does not have deformation followability, such as a sintered body. In particular, when the first wick structure 35, which is made of at least one selected from the group consisting of braided wire, twisted wire, and metal sponge, has a hollow portion inside along the extension direction, the gas-phase working fluid flows easily inside the hollow portion, further improving the heat transport properties of the vapor chamber 1.

The first wick structure 35 constituting the wick structure 30a has deformation followability along the thickness direction L, similar to the wick structure 30 of the first embodiment. Therefore, the first wick structure 35 generates a reaction force based on a predetermined compressive displacement generated along the compression direction, and elongates and displaces in the elongation direction following the compressive displacement. The elongation displacement of the first wick structure 35 is performed automatically without receiving an external force from the outside. The thickness of the first wick structure 35 after the elongation displacement is greater than the thickness of the first wick structure 35 at maximum compression.

The wick structure 30a, which has multiple first wick structure parts 35 with the above-mentioned deformation followability, acts as follows in the manufacture of the vapor chamber 2.

As shown in FIG. 8, the total thickness of the multiple first wick structure parts 35 in the configuration before the vapor chamber 2 is manufactured is greater than the thickness of the internal space S of the vapor chamber 2 shown in FIG. 7.

When the first metal plate 10 and the second metal plate 20 are joined, the first wick structure parts 35 arranged perpendicular to each other are compressed and displaced in the direction in which the first metal plate 10 and the second metal plate 20 approach each other. When the total thickness of the first wick structure parts 35 at maximum compression becomes smaller than the thickness of the internal space S, the inner surface 11a of the first plate part 11 of the first metal plate 10 is not connected to the inner surface 20a of the second metal plate 20 via the wick structure 30a. Since the first wick structure parts 35 have deformation followability along the thickness direction L of the vapor chamber 2, even if the total thickness of the first wick structure parts 35 at maximum compression becomes smaller than the thickness of the internal space S, the first wick structure parts 35 are expanded and displaced in the direction in which the first metal plate 10 and the second metal plate 20 move apart. The multiple first wick structure parts 35 that have been stretched and displaced contact each other and the inner surface 11a of the first plate part 11 of the first metal plate 10 and the inner surface 20a of the second metal plate 20. In this way, the wick structure 30 having multiple first wick structure parts 35 can automatically adjust its thickness so that the thickness of the wick structure 30a matches the thickness of the internal space S.

In this way, the wick structure 30a having the multiple first wick structure parts 35 is in contact with the first plate part 11 of the first metal plate 10 and the second metal plate 20, so the flow of the working fluid along the thickness direction L of the vapor chamber 1 is further improved. Also, as shown in the figure, when the multiple first wick structure parts 35 are arranged in different directions, the liquid phase working fluid can easily move not only in the thickness direction L of the vapor chamber 2, but also in a direction perpendicular to the thickness direction L. Therefore, the heat transport characteristics of the vapor chamber 2 are further improved. Also, the wick structure 30a having the multiple first wick structure parts 35 has further improved fracture resistance. Also, the vapor chamber 2 including the wick structure 30a having the above characteristics is further easier to manufacture. In the area where the multiple first wick structure parts 35 overlap, if the multiple first wick structure parts 35 are installed in a flat state, the above effect is efficiently exerted.

Although the above describes an example in which two first wick structures 35 of the same shape are installed in different orientations, the arrangement of the first wick structures 35, such as the number, shape, and installation orientation of the first wick structures 35, can be appropriately selected depending on the application of the vapor chamber 2.

Also, one of the first wick structures 35 may be composed of three wick parts 31 composed of braided wire, or may be composed of one wick part 31 composed of braided wire, one wick part 31 composed of twisted wire, and one wick part 31 composed of metal sponge. Similarly, the other first wick structure 35 may be composed of three wick parts 31 composed of braided wire, or may be composed of one wick part 31 composed of braided wire, one wick part 31 composed of twisted wire, and one wick part 31 composed of metal sponge. The arrangement of the wick parts 31 constituting the first wick structure 35 is appropriately selected depending on the application of the vapor chamber 2.

Also, as shown in FIG. 9, the wick structure 30a may have one or more first wick structure parts 35 and one or more second wick structure parts 36 that overlap along the thickness direction L of the vapor chamber 2. While the first wick structure part 35 has deformation followability along the thickness direction L of the vapor chamber 2 as described above, the second wick structure part 36 does not have deformation followability along the thickness direction L of the vapor chamber 2.

The vapor chamber 2 has the second wick structure 36 that does not exhibit the above-mentioned deformation tracking ability, while having the first wick structure 35 that exhibits the above-mentioned deformation tracking ability, so the wick structure 30a has deformation tracking ability along the thickness direction L of the vapor chamber 2. In addition, the thickness of the second wick structure 36 is smaller than the thickness of the internal space S of the vapor chamber 2. Therefore, compared to a wick that does not have deformation tracking ability provided in a conventional vapor chamber, the deflection of the second wick structure 36 is suppressed, and the destruction of the second wick structure 36 is suppressed. In other words, even if an existing wick that does not exhibit deformation tracking ability is applied to the second wick structure 36, since the vapor chamber 2 has the first wick structure 35 that exhibits the above-mentioned deformation tracking ability, the wick structure 30a is less likely to break than a conventional vapor chamber, and the vapor chamber 2 has excellent heat transport properties and can be easily manufactured.

The second wick structure 36 is preferably composed of at least one selected from the group consisting of a sintered body, a mesh sheet, and a fiber sheet, and in that case the porosity of the second wick structure 36 is, for example, 80% or more and 90% or less. In particular, as shown in FIG. 9, when the second wick structure 36 is a mesh sheet or a fiber sheet, the contact area between the mesh sheet or fiber sheet placed along a plane perpendicular to the thickness direction L and the inner surface 20a of the second metal plate 20 increases, improving the heat transport properties of the vapor chamber 2.

When the second wick structure 36 is composed of a sintered body, from the viewpoint of improving the heat transport properties of the vapor chamber 2, the sintered body is preferably a copper-based sintered body formed from a copper-based material, and among these, a copper-based sintered body formed from a copper-based powder having a particle size of 10 μm or more and 300 μm or less, and even more preferably a copper-based sintered body formed from a copper-based powder having a particle size of 50 μm or more and 100 μm or less. The sintered body has excellent suction performance for the liquid phase working fluid.

When the second wick structure 36 is composed of a mesh sheet, it is preferable that the mesh sheet be made of a copper-based material from the viewpoint of improving the heat transport properties of the vapor chamber 2. Furthermore, from the viewpoint of suppressing breakage due to bending of the mesh sheet, it is preferable that the mesh sheet be composed of 80 mesh or more and 230 mesh or less, and more preferably 100 mesh or more and 200 mesh or less. In addition to being difficult to break, the mesh sheet has a high degree of freedom in shape because it can be easily cut.

When the second wick structure 36 is composed of a fiber sheet, from the viewpoint of improving the heat transport properties of the vapor chamber 2, the fiber sheet is preferably made of a copper-based material or stainless steel. Also, from the viewpoint of suppressing breakage due to bending of the fiber sheet, the fiber diameter is preferably 10 μm or more and 50 μm or less, and the fiber length is preferably 0.5 mm or more and 2.0 mm or less.

According to the second embodiment described above, the design freedom of the first wick structure part and the second wick structure part that constitute the wick structure is improved, so that the internal configuration of the vapor chamber can be appropriately changed depending on the application of the vapor chamber.

In the above, as shown in Figures 6 and 7, a wick structure 30a having two first wick structure parts 35 is shown, but the wick structure 30a may have multiple first wick structure parts 35, for example, the wick structure 30a may have three first wick structure parts 35.

As shown in FIG. 9, the wick structure 30a has one first wick structure 35 and one second wick structure 36. However, the wick structure 30a may have one or more first wick structure 35 and one or more second wick structure 36. For example, the wick structure 30a may have two first wick structure 35 and two second wick structure 36. In this case, the first wick structure 35 and the second wick structure 36 may overlap each other alternately, or two consecutively overlapping first wick structure 35 and two consecutively overlapping second wick structure 36 may overlap each other.

Although the embodiments have been described above, the present invention is not limited to the above embodiments, but includes all aspects included in the concept and claims of this disclosure, and can be modified in various ways within the scope of this disclosure.

Reference Signs List 1, 2 Vapor chamber 10 First metal plate 11 First plate portion 11a Inner surface of first plate portion 12 First peripheral wall portion 13 First protrusion portion 20 Second metal plate 20a Inner surface of second metal plate 20b Outer surface of second metal plate 30, 30a Wick structure 31 Wick portion 35 First wick structural portion 36 Second wick structural portion 40 Member to be cooled 41 Heat dissipation fin 50 Evaporation portion 51 Condenser portion L Thickness direction of vapor chamber S Internal space F(L) Flow of liquid phase working fluid F(G) Flow of gas phase working fluid

Claims (10)

A vapor chamber having a working fluid in an internal space formed between a first metal plate and a second metal plate,
a wick structure that is disposed in the internal space and that contacts the first metal plate and the second metal plate with a reaction force acting in a direction in which the first metal plate and the second metal plate move away from each other based on a compressive displacement in a direction in which the first metal plate and the second metal plate approach each other ;
A vapor chamber characterized in that the wick structure is composed of a plurality of wick portions spaced apart in a direction perpendicular to the thickness direction of the vapor chamber . The vapor chamber of claim 1, wherein the wick structure is composed of at least one selected from the group consisting of braided wire, twisted wire, and metal sponge. The vapor chamber of claim 1 or 2, wherein the wick structure is made of a round braided wire of a copper-based material. The vapor chamber of claim 1 , wherein the wick structure has a plurality of first wick structure portions overlapping along a thickness direction of the vapor chamber, and the first wick structure portion is composed of the plurality of wick portions . The vapor chamber of claim 1, wherein the wick structure has one or more first wick structure parts and one or more second wick structure parts that overlap along the thickness direction of the vapor chamber, and the first wick structure part is composed of the multiple wick parts. The vapor chamber according to claim 5, wherein the second wick structure is composed of at least one material selected from the group consisting of a sintered body, a mesh sheet, and a fiber sheet. The vapor chamber according to any one of claims 4 to 6, wherein the first wick structure is composed of at least one selected from the group consisting of braided wire, twisted wire, and metal sponge. The vapor chamber according to any one of claims 4 to 7, wherein the first wick structure is made of a round braided wire made of a copper-based material. The vapor chamber according to any one of claims 1 to 8, wherein the first metal plate and the second metal plate are made of any one selected from the group consisting of aluminum, an aluminum alloy, copper, a copper alloy, and stainless steel. The vapor chamber according to any one of claims 1 to 9, wherein the working fluid is cis-1-chloro-3,3,3-trifluoropropene.

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