The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2020-146410, filed on Aug. 31, 2020, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a heat conductor.
Conventionally, a vapor chamber is used as a heat conductor for dissipating heat of a heat generator. Additionally, there has been proposed a thinned vapor chamber with reduced thickness. The space in the vapor chamber is provided with a capillary member formed at the bottom and an evaporation space between the capillary member and a lid. The vapor chamber has multiple supports that are in contact with the capillary member and the lid.
When the vapor chamber is bent according to an installation place or the like, the thickness of the vapor chamber is reduced, and there has been a problem that a space for returning the working fluid cannot be secured inside. As a result, it has not been easy to bend the vapor chamber into a desired three-dimensional shape.
An example embodiment of a heat conductor of the present disclosure includes a housing including a space therein and a working medium in the space. The housing includes an upper plate located on an upper side of the housing in a thickness direction and covering an upper side of the space, a lower plate located on a lower side of the space and opposing the upper plate in the thickness direction, and pillars between the upper plate and the lower plate. The housing further includes a bent portion in which both the upper plate and the lower plate are bent in a same direction in the thickness direction. At least a portion of the pillars is located on the bent portion.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
Example embodiments of the present disclosure will be described below with reference to the drawings. Note that the scope of the present disclosure is not limited to the example embodiments described below, but includes any modification thereof within the scope of the technical idea of the present disclosure.
In the drawings, an XYZ coordinate system is appropriately illustrated as a three-dimensional orthogonal coordinate system. The X direction, the Y direction, and the Z direction are orthogonal to one another. In the present specification, a normal direction of one surface of a heat conductor 1 facing a heat generator H to be described later is referred to as a “vertical direction” (Z direction), and a direction orthogonal to the vertical direction is referred to as a “horizontal direction” (X direction and Y direction). In a heated portion 11 of the heat conductor 1 facing the heat generator H, the vertical direction (Z direction) coincides with a “thickness direction” of a housing 2. A side on which the heat conductor 1 is located with respect to the heat generator H is referred to as an “upper side”, and a side on which the heat generator H is located with respect to the heat conductor 1 is referred to as a “lower side”. The shape and positional relationship among parts of the heat conductor will be described on the basis of these directions. Note that the definitions of these directions do not limit the orientation and positional relationship of the heat conductor at the time of use.
Additionally, in the present specification, a cross section parallel to the vertical direction is referred to as a “longitudinal section”, and a cross section parallel to the horizontal direction orthogonal to the vertical direction is referred to as a “transverse section”. Additionally, the expressions “parallel” and “orthogonal” do not refer only to mathematically strictly parallel and orthogonal, but also include parallel and orthogonal to the degree to which the effect of the present disclosure is exhibited, for example.
The heat conductor 1 has the heated portion 11 and a heat dissipating portion 12. The heated portion 11 is located adjacent to the heat generator H, for example, and is heated by heat generated by the heat generator H. The heat dissipating portion 12 dissipates the heat received from the heat generator H in the heated portion 11 to the outside. Furthermore, in the present example embodiment, the heat conductor 1 has a housing 2, a wick structure 3, and a working medium 4.
The housing 2 is formed of metal such as copper, for example, and is a box that has a space 2S therein and is rectangular when viewed in the vertical direction. A part of the housing 2 is included in the heated portion 11. Another part of the housing 2 is included in the heat dissipating portion 12. The space 2S is a sealed space, and is maintained in a depressurized state where the atmospheric pressure is lower than the barometric pressure, for example. Since the space 2S is in the depressurized state, the working medium 4 accommodated in the space 2S is easily evaporated.
The wick structure 3 is disposed in the space 2S of the housing 2. The wick structure 3 extends continuously from a region included in the heated portion 11 to a region included in the heat dissipating portion 12 in the space 2S. The wick structure 3 is formed of a metal net-like member (metal mesh), for example, and transports the working medium 4 by capillary action.
Note that the wick structure 3 is not limited to a metal net-like member (metal mesh), as long as it has a structure capable of transporting the working medium 4 in the space 2S. The wick structure 3 may be, for example, a sintered wick formed of a porous copper sintered body, a groove wick having a groove structure, or the like.
The working medium 4 is accommodated in the space 2S of the housing 2. The working medium 4 is water, for example, but may be another liquid such as alcohol. The working medium 4 transports heat by moving in the space 2S including the inside of the wick structure 3.
As described above, the heat conductor 1 of the present example embodiment includes the housing 2 having the space 2S therein and the working medium 4 disposed in the space 2S.
The housing 2 includes a lower plate 21 and an upper plate 22. Furthermore, the housing 2 has multiple pillars 22P.
The lower plate 21 is located in a lower part of the housing 2. The lower plate 21 faces the upper plate 22 in the thickness direction of the housing 2 and is located below the space 2S. The lower plate 21 is a metal plate, and is a copper plate, for example. The lower plate 21 may be formed by applying copper plating to a surface of a metal plate other than copper, such as stainless steel.
The lower plate 21 has a recess 21D. The recess 21D is formed in a recessed shape in which the inside is recessed downward from an outer edge portion of the lower plate 21 in the horizontal direction. The wick structure 3 is disposed in the recess 21D. That is, the lower plate 21 supports the wick structure 3 from below.
The upper plate 22 is located in an upper part of the housing 2. The upper plate 22 is made of the same metal plate as the lower plate 21. That is, the upper plate 22 is a copper plate, for example. The upper plate 22 may be formed by applying copper plating to a surface of a metal plate other than copper, such as stainless steel. Note that the upper plate 22 and the lower plate 21 may be made of different metals.
The upper plate 22 is located above the lower plate 21 and faces the lower plate 21 in the thickness direction of the housing 2. The upper plate 22 is located on the upper side in the thickness direction of the housing 2 and covers the upper side of the space 2S. That is, the upper plate 22 covers the upper side of the wick structure 3 in the space 2S.
The upper plate 22 is formed integrally with the multiple pillars 22P. The multiple pillars 22P extend downward from a lower surface of the upper plate 22 and come into contact with the wick structure 3. That is, the multiple pillars 22P are located between the upper plate 22 and the lower plate 21. The pillars 22P may be formed of the same member as the upper plate 22, or may be formed of a member different from upper plate 22. The pillar 22P is a support for holding the wick structure 3 at a lower portion in the space 2S, and can also make the thickness of the housing 2 constant.
Note that the pillars may be formed in the lower plate 21. In this case, the pillar extends upward from a bottom surface in the recess 21D of the lower plate 21. That is, the wick structure 3 is disposed on the upper side in the space 2S.
The housing 2 further has a joint portion 2B. The joint portion 2B is a joint structure in which the lower plate 21 and the upper plate 22 are joined to each other at outer edges thereof. The joint portion 2B is located around the space 2S when viewed in the vertical direction, and joins the lower plate 21 and the upper plate 22. The method for joining the lower plate 21 and the upper plate 22 is not particularly limited. Various joining methods such as a method of joining by applying heat and pressure, a method of joining using a brazing material, and the like may be used for the joint portion 2B.
The joint portion 2B may include a sealed portion. The sealed portion is, for example, a part where an injection port for injecting the working medium 4 into the housing 2 is sealed by welding in the manufacturing process of the heat conductor 1.
The housing 2 has a heat generator mounting portion 2M on a lower surface thereof. The heat generator mounting portion 2M is located in the heated portion 11. One heat generator mounting portion 2M is provided, for example, so as to match the number of the heat generator H. The heat generator mounting portion 2M overlaps the wick structure 3 when viewed in the vertical direction.
In
The heat of the heat generator H is transmitted to the wick structure 3 through the lower plate 21 in the heated portion 11. When the temperature of the wick structure 3 rises, the liquid working medium 4 contained in the wick structure 3 is vaporized, and steam is generated. The steam of the working medium 4 moves toward the heat dissipating portion 12 in the space 2S. The steam of the working medium 4 is cooled and liquefied by heat dissipation in the heat dissipating portion 12.
The liquefied working medium 4 flows along an inner surface of the housing 2 and moves in the wick structure 3 by capillary action, thereby flowing toward the heated portion 11. As the working medium 4 moves while changing its state in this manner, heat is continuously transported from the heated portion side to the heat dissipating portion 12 side in the heat conductor 1. As a result, the heat generator H in contact with the heated portion 11 is cooled by the heat conductor 1.
The housing 2 further has a bent portion 23. In the present example embodiment, the bent portion 23 includes a first bent portion 231 and a second bent portion 232. The first bent portion 231 and the second bent portion 232 are juxtaposed in parallel from an end portion of the heat conductor 1 on the heated portion 11 side toward an end portion thereof on the heat dissipating portion 12 side.
In the present example embodiment, the first bent portion 231 and the second bent portion 232 extend along the horizontal direction (Y direction in
Note that the bent portion 23 is not limited to the form bent so as to be curved in an arc shape when viewed from the Y direction, as illustrated in
The housing 2 further has a first horizontal portion 24, a second horizontal portion 25, and an inclined portion 26. The first horizontal portion 24, the second horizontal portion 25, and the inclined portion 26 are separated by the first bent portion 231 and the second bent portion 232. In the heat conductor 1, the first horizontal portion 24, the inclined portion 26, and the second horizontal portion 25 are continuous in this order from the end portion on the heated portion 11 side toward the end portion on the heat dissipating portion 12 side. The heated portion 11 is disposed in the first horizontal portion 24. Each of the first horizontal portion 24, the second horizontal portion 25, and the inclined portion 26 includes a part of the lower plate 21 and a part of the upper plate 22.
The first horizontal portion 24 and the second horizontal portion 25 extend in the horizontal direction (X direction and Y direction in
The inclined portion 26 is inclined upward in the vertical direction (Z direction in
As a result, the second horizontal portion 25 is located above the first horizontal portion 24 in the vertical direction (Z direction in
As illustrated in
First, the lower plate 21 in which the recess 21D recessed downward is formed on the inner side in the horizontal direction, the upper plate 22 in which the multiple pillars 22P extending downward is formed on the inner side in the horizontal direction, and the wick structure 3 are produced. Next, the lower plate 21 in which the wick structure 3 is disposed in the recess 21D and the upper plate 22 are joined together at the joint portion 2B to form the housing 2 (see
Next, as illustrated in
Next, as illustrated in
Note that while one and the other end sides of the housing 2 in the horizontal direction (X direction) are switched and are separately sandwiched by the jig 101 in
The pillar 22P is located on the bent portion 23. In other words, the pillar 22P is located in a region of the bent portion 23 bent so as to be curved in an arc shape when viewed in the Y direction. Specifically, as illustrated in
Although the space 2S may be narrowed by forming the bent portion 23, according to the above configuration, the space 2S can be secured in the bent portion 23 by locating the pillar 22P on the bent portion 23. That is, it is possible to provide the heat conductor 1 capable of securing the space 2S therein even when the heat conductor 1 is bent. As a result, it becomes easy to bend the flat plate-shaped heat conductor 1 into a desired three-dimensional shape. Accordingly, even if the position of the heated portion 11 and the position of the heat dissipating portion 12 are shifted in the Z direction as illustrated in
As described above, the heat conductor 1 has multiple bent portions including the first bent portion 231 and the second bent portion 232. As illustrated in
According to the above configuration, the present example embodiment can make the inclined portion 26 less prone to deformation by an external force, for example. Additionally, although the space 2S may be narrowed in the thickness direction of the housing 2 in the inclined portion 26 by forming the bent portion 23, the space 2S can be secured by the above-described configuration by locating the pillar 22P in the inclined portion 26.
As illustrated in
In other words, the multiple pillars 22P are arranged at predetermined intervals over the entire region from one end portion of the outer edge of the housing 2 to the other end portion opposite to the one end portion. Specifically, the multiple pillars 22P are arranged at predetermined intervals over the entire region from a left end portion in the X direction of
Note that in the present example embodiment, the multiple pillars 22P are arranged in a triangular lattice shape. The multiple pillars 22P may be arranged in, for example, a square lattice shape, a rectangular lattice shape, or an orthorhombic lattice shape.
According to the above configuration, the pillars 22P can be arranged over the entire region of the housing 2 in the horizontal direction (X direction and Y direction in
Next, a modification of the heat conductor 1 will be described. Note that since the basic configuration of the modification is the same as that of the above example embodiment described with reference to
The pillars 22P located on first bent portion 231 and the second bent portion 232 have an elliptical shape when viewed in the vertical direction, for example. Specifically, in the pillar 22P located on the first bent portion 231 and the second bent portion 232, the length in the direction (X direction) intersecting the extending direction of a ridge line 23R of the bent portion 23 is longer than the length in the extending direction (Y direction) of the ridge line 23R. Note that the pillar 22P located on the bent portion 23 may have an oval shape, a rectangular shape, or the like other than the elliptical shape.
According to the above configuration, when the bent portion 23 is formed by bending the housing 2, it is possible to curb shifting of the ridge line 23R of the bent portion 23 in the direction (X direction) intersecting the extending direction of the ridge line 23R. As a result, the effect of securing the space 2S in the bent portion 23 can be enhanced.
In the present example embodiment, the pillar 22P on the bent portion 23 continuously extends from above the first bent portion 231 to above the second bent portion 232. In other words, in the direction (X direction) intersecting the extending direction of a ridge line 23R of the bent portion 23, the pillar 22P is located over the entire region of an inclined portion 26 of a housing 2. The pillar 22P on the bent portion 23 has an oblong shape when viewed in the vertical direction, for example. Note that the pillar 22P on the bent portion 23 may have an oval shape, a rectangular shape, or the like other than the oblong shape.
Note that when the housing 2 has three or more bent portions, the pillar 22P located on the bent portion continuously extends from above one bent portion to above the other bent portions. That is, when three or more bent portions are arranged in the X direction, the pillar 22P located on the bent portion may continuously extend over any one section between bent portions arranged in the X direction, or may continuously extend over all the sections, for example.
According to the above configuration, the pillar 22P on the bent portion 23 is also located between the two bent portions which are the first bent portion 231 and the second bent portion 232. As a result, the present example embodiment can make the inclined portion 26 less prone to deformation by an external force, for example. Accordingly, it is possible to enhance the effect of securing the space 2S in the bent portion 23 and between the two bent portions which are the first bent portion 231 and second bent portions 232 (inclined portion 26).
The housing 2 further has a horizontal portion 27 and a vertical portion 28. The horizontal portion 27 and the vertical portion 28 are separated by the bent portion 23. The horizontal portion 27 and the vertical portion 28 are continuous in this order from an end portion of the heat conductor 1 on a heated portion 11 side toward an end portion of the heat conductor 1 on a heat dissipating portion 12 side. The heated portion 11 is disposed in the horizontal portion 27. Each of the horizontal portion 27 and the vertical portion 28 includes a part of a lower plate 21 and a part of an upper plate 22.
The vertical portion 28 extends upward in the vertical direction (Z direction in
The pillar 22P is located on the bent portion 23. In other words, the pillar 22P is located in a region of the bent portion 23 that is bent linearly along the Y direction.
As described above, in the heat conductor 1 of the third modification, the bent portion 23 is provided in one location, and the horizontal portion 27 and the vertical portion 28 are orthogonal to each other. The pillar 22P is located on the bent portion 23. As a result, the space 2S can be secured in the bent portion 23. That is, it is possible to provide the heat conductor capable of securing the space 2S therein even when the heat conductor 1 is bent.
For example, the number of the bent portions 23 is not limited to one or two, and may be three or more. Additionally, the angle formed by the regions adjacent to each other with the bent portion 23 interposed therebetween in the housing 2 is not limited to the inclination angle and the right angle described in the above example embodiments, and may be another angle. Additionally, the bent portion 23 extends in a direction (e.g., Y direction in
Additionally, the number and arrangement of the multiple pillars 22P are not limited to the configuration illustrated in the figure, and may be other numbers and arrangements. Additionally, the pillar 22P is not limited to a column having a circular cross-sectional shape when viewed in the vertical direction, and may be a column having another cross-sectional shape such as an elliptical shape or a rectangular shape.
The present disclosure can be used for heat dissipation of a board mounted on an electronic device or an electronic component, for example.
Features of the above-described example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.
While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.
Number | Date | Country | Kind |
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2020-146410 | Aug 2020 | JP | national |