JP2022027308A - Heat transfer member and manufacturing method of heat transfer member - Google Patents

Abstract

To provide a heat transfer member which lets a gasified working medium flow smoothly, whereby it is possible to enhance the heat conduction efficiency of the working medium.SOLUTION: A heat transfer member 100 includes a housing 101 with a working medium sealed inside thereof. The housing includes a first plate portion 1, a second plate portion 2 stacked above the first plate portion, and a plurality of pillar portions 3 extending downward from the second metal portion. Each pillar portion has a base portion 31 connected to the second plate portion and narrowing downward, and a stick-shaped portion 32 extending downward from an end portion 30 at a lower part of the base portion. At least the stick-shaped portion has an oval cross-sectional shape in a cross section taken orthogonal to a vertical direction.SELECTED DRAWING: Figure 3

Description

The present invention relates to a heat conductive member and a method for manufacturing the heat conductive member.

Conventionally, a method using a vapor chamber is known as a method for cooling a heating element. The vapor chamber has a container in which a cavity is formed by one plate-shaped body and the other plate-shaped body facing the one plate-shaped body. Then, the working fluid and the wick structure are housed inside the container. The vapor chamber has a support column portion on the inner surface of the other plate-like body having a function of maintaining the internal space of the hollow portion under reduced pressure (see, for example, Japanese Patent Application Laid-Open No. 2019-82264).

Japanese Unexamined Patent Publication No. 2019-82264

In the conventional vapor chamber, the strut portion has the purpose of maintaining the internal space of the cavity portion. Therefore, it is necessary to occupy a certain range of the internal space of the cavity, and the space for the working fluid changed to the gas phase due to heating to flow is narrowed, which may hinder the flow. Further, the support column portion may become a resistance to the flow of the working fluid in the gas phase due to its shape.

Therefore, an object of the present invention is to provide a heat conductive member capable of increasing the heat conduction efficiency by the working medium by smoothly flowing the vaporized working medium.

The exemplary heat conductive member of the present invention has a housing in which a working medium is enclosed. The housing has a first plate portion, a second plate portion overlapped on the upper portion of the first plate portion, and a plurality of pillar portions extending downward from the second plate portion. Each pillar portion has a pedestal portion that is connected to the second plate portion and becomes thinner toward the bottom, and a rod-shaped portion that extends downward from the lower end portion of the pedestal portion, and at least the rod-shaped portion has a rod-shaped portion. , The cross-sectional shape of the cut surface orthogonal to the vertical direction is a flat circular shape.

An exemplary method for manufacturing a heat conductive member of the present invention includes an etching step of forming a recess recessed upward from the lower surface of the second plate portion and a plurality of protrusions arranged inside the recess and extending in the vertical direction by etching. The present invention includes a pressing step of applying a jig to the lower end portions of the plurality of the protrusions in the vertical direction and compressing the protrusions with the jig to form a pillar portion.

According to the exemplary heat conduction member of the present invention, the heat conduction efficiency of the working medium can be increased by smoothly flowing the vaporized working medium.

FIG. 1 is a perspective view of a heat conductive member according to the present invention. FIG. 3 is a bottom view of the heat conductive member shown in FIG. FIG. 2 is a cross-sectional view of the heat conductive member shown in FIG. FIG. 4 is a bottom view of the pillar portion. FIG. 5 is a cross-sectional view of a cut surface of the pillar portion shown in FIG. 4 along the VV line. FIG. 6 is a cross-sectional view of a cut surface of the pillar portion shown in FIG. 4 along the VI-VI line. FIG. 7 is an enlarged bottom view of the second plate portion. FIG. 8 is a cross-sectional view of a plate portion forming plate material in which recesses and protrusions are formed by etching treatment. FIG. 9 is a cross-sectional view of the second plate portion formed by press working. FIG. 10 is a cross-sectional view showing a joining process in which the second plate portion is overlapped with the first plate portion. FIG. 11 is a bottom view of the pillar portion of the first modification. FIG. 12 is a bottom view of the second plate portion of the second modification. FIG. 13 is a bottom view of the second plate portion of the third modification.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In the present specification, the heat conductive member 100 has a rectangular shape in a plan view, and the first plate portion 1 and the second plate portion 2 overlap each other in the direction of gravity. Therefore, the direction in which the first plate portion 1 and the second plate portion 2 overlap, that is, the vertical direction is defined as the Z direction. Further, when the heat conductive member 100 is viewed from the Z direction, the lateral direction of the heat conductive member 100 is the X direction, and the longitudinal direction is the Y direction. The size relationship between the dimensions, shape, and components in the figure is an example, and is not necessarily the same as the actual size, shape, and size relationship between the components.

<Heat conduction member 100>
FIG. 1 is a perspective view of the heat conductive member 100 according to the present invention. FIG. 2 is a bottom view of the heat conductive member 100. FIG. 3 is a cross-sectional view of the heat conductive member 100 shown in FIG. 2 cut along a plane parallel to the ZY plane.

As shown in FIGS. 1 to 3, the heat conductive member 100 has a housing 101. As shown in FIGS. 2 and 3, the housing 101 has a space 102 inside. A pillar portion 3 and a wick structure 4 are arranged inside the space 102. The space 102 is hermetically sealed, and the working medium Md is enclosed inside the space 102. That is, the heat conductive member 100 has a housing 101 in which the working medium Md is enclosed.

The heat conductive member 100 is a so-called vapor chamber that carries heat by utilizing the state change of the enclosed working medium Md, that is, evaporation by heating and condensation by cooling.

The heat conductive member 100 comes into contact with the heating element Ht, and heat from the heating element Ht is transferred to the heat conductive member 100. As shown in FIG. 3, in the heat conductive member 100, one side of the housing 101 in the Y direction is the heated region 103, and the other side is the heat dissipation region 104. The heating element Ht comes into contact with the lower surface of the heated region 103. The heat of the heating element Ht is transferred to the heated region 103 of the heat conductive member 100.

The working medium Md of the liquid enclosed in the space 102 is heated by the heat from the heating element Ht, evaporated, and changed to the steam Vp (hereinafter, simply referred to as steam Vp) of the working medium. The steam Vp flows in the heat dissipation region 104. The heat of the steam Vp is transferred to the housing 101 in the heat dissipation region 104. As a result, the vapor Vp is condensed and returned to the liquid working medium Md. The liquid working medium Md flows through the wick structure 4 to the heated region 103. The liquid working medium Md is heated again in the heated region 103 and evaporated to change its state to vapor Vp. By repeating the above operation, the heat conductive member 100 carries the heat from the heating element Ht and lowers the temperature of the heating element Ht. That is, the heat conductive member 100 is used as a heat radiating member of the heating element Ht.

In the heat conductive member 100 of the present embodiment, water is used as the working medium Md, but the present invention is not limited to this. For example, alcohol compounds, CFC substitutes, hydrocarbon compounds, fluorinated hydrocarbon compounds, glycol compounds and the like can be mentioned. As the working medium Md, a substance that evaporates (vaporizes) with heat from the heating element Ht in the heated region 103 and is condensed (liquefied) by transferring heat to the housing 101 in the heat radiating region 104 is widely adopted. Can be done.

The heat conductive member 100 will be described in more detail. As shown in FIGS. 1 to 3, the housing 101 of the heat conductive member 100 has a first plate portion 1, a second plate portion 2, and a pillar portion 3. In the heat conductive member 100, the first plate portion 1 and the second plate portion 2 are overlapped in the Z direction, and the outer edge portions in the X direction and the Y direction are joined. The housing 101 is formed by joining the first plate portion 1 and the second plate portion 2. That is, the housing 101 has a first plate portion 1 and a second plate portion 2 stacked on the upper portion of the first plate portion 1.

<First plate part 1>
In the present embodiment, the first plate portion 1 is formed of, for example, a material containing a copper alloy. The material constituting the first plate portion 1 is not limited to the copper alloy, and a material such as a metal having a certain strength (elastic modulus) or more and a certain thermal conductivity or more can be adopted.

For example, the surface of a metal material such as stainless steel, titanium, or a titanium alloy may be formed of a material that has been subjected to a treatment for forming a metal film such as copper plating. Even materials that are difficult to join with a brazing material can be joined with a brazing material for joining copper or a copper alloy by forming copper plating. Therefore, it is easy to select the brazing material.

As described above, the first plate portion 1 is a plate material, and when viewed from the Z direction, the first plate portion 1 has a rectangular shape in the longitudinal direction in the Y direction. When viewed from the Z direction, the outer edge portion is the jointed portion 11 to be joined to the jointed portion 22 described later.

In the present embodiment, by using the first plate portion 1 whose upper surface is flush with each other, the step of forming the recess can be omitted, but the present invention is not limited to this. For example, the first plate portion 1 may have a recess that constitutes the space 102. By doing so, the space 102 can be increased.

<Second plate part 2>
In the present embodiment, the second plate portion 2 is formed of, for example, a material containing a copper alloy. The material constituting the second plate portion 2 is not limited to the copper alloy, and a material such as a metal having a certain strength (elastic modulus) or more and a certain thermal conductivity or more can be adopted.

For example, the surface of a metal material such as stainless steel, titanium, or a titanium alloy may be formed of a material that has been subjected to a treatment for forming a metal film such as copper plating. Even materials that are difficult to join with a brazing material can be joined with a brazing material for joining copper or a copper alloy by forming copper plating. Therefore, it is easy to select the brazing material.

As shown in FIG. 2, the second plate portion 2 has a flat plate portion 21 and a joint portion 22. The flat plate portion 21 has a rectangular shape when viewed from the Z direction. The joint portion 22 extends downward in the Z direction from the outer edge of the lower surface of the flat plate portion 21. When viewed from the Z direction, the joint portion 22 is formed in a closed annular shape. The second plate portion 2 has a recess 20 formed by the flat plate portion 21 and the joint portion 22. The recess 20 is recessed upward in the Z direction from the lower surface of the second plate portion 2. That is, the second plate portion 2 has a recess 20 recessed from the surface facing the first plate portion 1. When the first plate portion 1 and the second plate portion 2 are joined, the recess 20 forms a space 102.

As shown in FIGS. 1 and 2, when viewed from the Z direction, the first plate portion 1 and the second plate portion 2 have a rectangular shape having the same size. At this time, the outer edge of the first plate portion 1 and the outer edge of the second plate portion 2 overlap in the Z direction. The first plate portion 1 may be larger than the second plate portion 2. In this case, when viewed from the Z direction, the outer edge of the second plate portion 2 is arranged inside the outer edge of the first plate portion 1. The first plate portion 1 and the second plate portion 2 are not limited to a rectangular shape when viewed from the Z direction. It may have a square shape in a plan view, a polygonal shape such as a triangle or a hexagon, or a circular shape. Further, the shape may be a combination of these shapes.

<Pillar 3>
The details of the pillar portion 3 will be described with reference to the drawings. FIG. 4 is a bottom view of the pillar portion. FIG. 5 is a cross-sectional view of a cut surface of the pillar portion shown in FIG. 4 along the VV line. FIG. 6 is a cross-sectional view of a cut surface of the pillar portion shown in FIG. 4 along the VI-VI line. In FIGS. 5 and 6, the boundary between the pedestal portion 31 of the pillar portion 3 and the rod-shaped portion 32 is shown, but in the actual pillar portion 3, the boundary may not be clearly discriminated.

As shown in FIG. 3, the pillar portion 3 has a pedestal portion 31 and a rod-shaped portion 32. The pillar portion 3 extends downward from the portion of the second plate portion 2 that forms the recess 20 of the flat plate portion 21. That is, the plurality of pillar portions 3 extend downward from the second plate portion. The pedestal portion 31 extends downward in the Z direction from the lower surface of the second plate portion 2. The cross-sectional shape of the cut surface of the pedestal portion 31 orthogonal to the Z direction is circular. The pedestal portion 31 becomes thinner toward the lower side in the Z direction. That is, the pedestal portion 31 is connected to the second plate portion 2 and becomes thinner toward the bottom.

As shown in FIGS. 5 and 6, the cross-sectional shape of the cross section of the pedestal portion 31 along the Z direction is trapezoidal, and the portion corresponding to the hypotenuse is curved. However, the present invention is not limited to this, and it may be a straight line or a shape in which a plurality of straight lines are connected.

The rod-shaped portion 32 extends downward from the lower end portion of the pedestal portion 31. That is, the rod-shaped portion 32 extends downward from the lower end portion of the pedestal portion 31. The rod-shaped portion 32 is a columnar body having a uniform or substantially uniform cross-sectional shape in the Z direction. As shown in FIGS. 4 to 6, the cross-sectional shape of the cut surface of the rod-shaped portion 32 of the pillar portion orthogonal to the Z direction is shorter than the long axis a1 extending in the Y direction and the long axis a1 extending in the X direction. It is a flat circular shape having a short axis a2. That is, at least the rod-shaped portion 32 is a circular shape having a flat cross-sectional shape of a cut surface orthogonal to the vertical direction. Here, the outer diameter in the intersecting direction is different from the flat circular shape, and a shape in which at least a part of the outer circumference is formed by a curved line is broadly shown.

For example, a mathematically defined ellipse and an outer peripheral shape in which two side-by-side circles are connected by a common tangent are also flat circles. Then, the long axis is the line segment connecting two points having the longest external distance on the flat circular shape, and the longest line segment in the direction orthogonal to the long axis is the short axis. The flat circle may have a shape having a major axis and a minor axis, and may not have symmetry such as point symmetry or line symmetry.

As shown in FIGS. 3 to 6 and the like, in the pillar portion 3, the pedestal portion 31 and the rod-shaped portion 32 are formed of a single member. Further, as shown in FIG. 3, the pillar portion 3 is arranged inside the recess 20 of the second plate portion 2, and is formed of the flat plate portion 21 and a single member. The pillar portion 3 extends downward in the Z direction from the lower surface of the flat plate portion 21. As shown in FIG. 3, the length L1 of the plurality of pillars 3 in the Z direction is shorter than the depth D1 of the recess 20 in the Z direction.

That is, the vertical length L1 of the pillar portion 3 is shorter than the vertical depth D1 of the recess 20, and a plurality of pillar portions 3 are arranged inside the recess 20. With this configuration, a gap is formed between the first plate portion 1 and the pillar portion 3. The wick structure 4 can be arranged in this gap. As a result, it is not necessary to form a recess in the first plate portion 1, and the manufacturing process of the housing 101 can be simplified.

Next, the arrangement of the second plate portion 2 of the pillar portion 3 in the recess 20 will be described with reference to the drawings. FIG. 7 is an enlarged bottom view of the second plate portion 2. As shown in FIGS. 2 and 7, in the recess 20 of the second plate portion 2, the plurality of pillar portions 3 are arranged at equal intervals in the X direction and the Y direction, respectively. That is, the plurality of pillar portions 3 are arranged at equal intervals in the X direction. Further, the plurality of pillar portions 3 are arranged at equal intervals in the Y direction as well.

In the second plate portion 2, the arrangement spacing in the X direction and the arrangement spacing in the Y direction of the plurality of pillar portions 3 are the same length. Therefore, the arrangement spacing in the X direction and the arrangement spacing in the Y direction of the plurality of pillars 3 are both set as the arrangement pitch P1. The spacing in the X direction and the spacing in the Y direction are the same, but the limitation is not limited to this. It may be at different intervals. Further, they may be arranged at an angle with respect to the X direction and the Y direction.

As shown in FIGS. 2 and 7, when viewed from the Z direction, the long axis a1 of the cut surface of the cross section orthogonal to the Z direction of the rod-shaped portion 32 of each pillar portion 3 is along the Y direction. That is, the long axes a1 of the cross sections orthogonal to the vertical direction of the rod-shaped portions 32 of the plurality of pillar portions 3 are parallel to each other. That is, when viewed from the Z direction, the plurality of pillar portions 3 are two-dimensionally arranged with the rod-shaped portions 32 facing in the same direction.

As shown in FIG. 7, the outer peripheral surfaces of the rod-shaped portions 32 of the pillar portions 3 arranged in the X direction face each other in the X direction via the gap W1. The gap W1 is in the direction along the short axis a2 of the rod-shaped portion 32, and is longer than the short axis a2. That is, the gap W1 between the outer peripheral surfaces of the rod-shaped portions 32 of the pillar portions 3 adjacent to each other in the direction along the short axis a2 of the cross section orthogonal to the vertical direction of the rod-shaped portion 32 is longer than the length of the short axis a2.

<Wick structure 4>
The housing 101 further has a wick structure 4 arranged between the first plate portion 1 and the second plate portion 2. The wick structure 4 comes into contact with the lower end 30 of the rod-shaped portion 32 of the pillar portion 3. The wick structure 4 may be, for example, a porous body such as a wire, a mesh, a non-woven fabric, or a sintered body. The material of the wick structure 4 may be the same copper alloy as the materials of the first plate portion 1 and the second plate portion 2, but is not limited thereto. For example, copper, aluminum, nickel, iron, titanium and alloys thereof, carbon fiber and ceramics can be mentioned.

Further, the wick structure 4 is arranged on the upper surface of the first plate portion 1. The wick structure 4 and the first plate portion 1 may be formed of a single member. When the first plate portion 1 having a recess on the upper surface is used, the wick structure 4 can be arranged in the recess. This facilitates the positioning of the wick structure 4 when manufacturing the heat conductive member 100.

<Structure of heat conductive member 100>
As shown in FIG. 3, in the housing 101, the joint portion 22 of the second plate portion 2 is joined to the bonded portion 11 of the first plate portion 1, and the second plate portion 2 is joined to the first plate portion 1 in the Z direction. It is layered on.

The bonding between the bonded portion 11 and the bonded portion 22 is performed, for example, by heating or pressurizing. Specifically, the temperature of the bonded portion 11 and the bonded portion 22 is raised to a predetermined temperature. Then, the upper surface of the bonded portion 11 and the lower surface of the bonded portion 22 are brought into contact with each other, and a bonding process is performed in which the pressure on the contact surface is set to a predetermined pressure or higher. By performing the bonding process, some particles are arranged across both the bonded portion 11 and the bonded portion 22 on the contact surface between the bonded portion 11 and the bonded portion 22. As a result, the bonded portion 11 and the bonded portion 22 are joined. The details of the joining process will be described later.

In the housing 101, the joint between the joint portion 11 and the joint portion 22 has an airtightness capable of suppressing the permeation of the liquid working medium Md and the vapor Vp at the joint portion.

The method of joining the joined portion 11 and the joined portion 22 is not limited to this. For example, a brazing material may be arranged between the bonded portion 11 and the bonding portion 22 and bonded by heating and pressurizing with the brazing material, so-called brazing. When brazing, a groove may be formed on at least one of the upper surface of the bonded portion 11 and the lower surface of the bonded portion 22, and the brazing material may be arranged.

In the housing 101 of the heat conductive member 100 of the present embodiment, the upper surface 10 of the first plate portion 1 is planar. Therefore, when the second plate portion 2 is overlapped and joined on the upper portion of the first plate portion 1, the recess 20 of the second plate portion 2 is closed to the upper surface of the first plate portion 1 to form a space 102. .. In the housing 101, the height of the space 102 in the Z direction is substantially the same as the depth D1 of the recess 20. Therefore, the height of the space 102 is also indicated by D1 (see FIG. 3).

When joining the first plate portion 1 and the second plate portion 2, the wick structure 4 is arranged in a portion of the upper surface portion 10 of the first plate portion 1 surrounded by the joined portion 11. As a result, the wick structure 4 is arranged inside the space 102. As shown in FIG. 3, the length L1 of the pillar portion 3 in the Z direction is shorter than the height D1 of the space 102 in the Z direction. Therefore, a gap is formed between the lower end portion 30 of the pillar portion 3 and the upper surface 10 of the first plate portion 1. In the heat conductive member 100, the wick structure 4 is arranged in the gap between the pillar portion 3 and the first plate portion 1. More specifically, in the heat conductive member 100, the lower end portion 30 of the pillar portion 3 comes into contact with the wick structure 4. The heat conductive member 100 has the configuration shown above.

<Operation of heat conductive member 100>
The details of the operation of the heat conductive member 100 will be described. As shown in FIG. 3, when the heat from the heating element Ht is transferred to the heated region 103 of the housing 101, the liquid working medium Md is heated and evaporated (vaporized). The steam Vp generated by the evaporation of the working medium Md moves in the space 102 toward the heat dissipation region 104. That is, heat is carried. Then, in the heat dissipation region 104, the latent heat of the steam Vp is transmitted to the housing 101. As a result, the vapor Vp is cooled, condensed (liquefied), and returned to the liquid working medium Md. The heat transferred from the steam Vp to the housing 101 is dissipated to the outside at a lower temperature than the housing 101.

The working medium Md is adsorbed on the wick structure 4. The working medium Md adsorbed on the wick structure 4 is refluxed to the heated region 103 in the space 102 by the capillary phenomenon. Then, the working medium Md evaporates again in the heated region 103. By repeating the above operation, the heat conductive member 100 transfers heat from the heated region 103 to the heat radiating region 104. In the heat conductive member 100, by making the heat dissipation region 104 of the housing 101 larger than the heated region 103, more heat can be carried. Thereby, the heat from the heating element Ht can be efficiently removed.

By having the wick structure in the heat conductive member 100, the working medium Md condensed in the heat radiation region 104 can be quickly flowed to the heated region 103 by utilizing the capillary phenomenon. This makes it possible to increase the heat conduction efficiency of the heat conduction member 100. The wick structure 4 is omitted if the structure allows the liquid working medium to flow by forming a gradient from the heat dissipation region 104 toward the heated region 103 on the upper surface 10 of the first plate portion 1. You may. In this case, the pillar portion 3 comes into contact with the upper surface 10 of the first plate portion 1.

As described above, the heat conductive member 100 carries the heat generated by the heating element Ht and dissipates the heat of the heating element Ht. Examples of the heating element Ht include integrated circuits such as CPUs, MPUs, and memories, devices having rotating bodies such as hard disks and optical disks, batteries, liquid crystal panels, and other devices used in electronic devices such as smartphones, tablet PCs, and personal computers. It can be mentioned, but it is not limited to this. The heat conductive member 100 can be widely used for heat dissipation of equipment that generates heat during operation.
Ru

Inside the space 102, the working medium Md is evaporated by the heat of the heating element Ht. In order to facilitate evaporation of the working medium Md, the pressure inside the space 102 is often lower than the pressure outside. Therefore, a force due to the pressure difference between the inside and the outside is applied to the housing 101. For example, the flat plate portion 21 is likely to be dented due to the pressure difference between the inside and outside of the housing 101.

By supporting the flat plate portion 21 by the plurality of pillar portions 3, deformation due to the pressure difference between the inside and outside of the space 102 of the housing 101 is suppressed. Further, the strength of the connecting portion of the pillar portion 3 is increased by forming the connecting portion of the pillar portion 3 with the second plate portion 2 so as to expand from the boundary portion with the rod-shaped portion 32 toward the second plate portion 2. Can be enhanced. For example, even when an external force in the direction of falling is applied to the pillar portion 3, it is possible to suppress the deformation of the pillar portion 3 in the direction of falling. Therefore, the deformation of the pillar portion 3 is suppressed, and the deformation of the space 102 can be suppressed. Then, by suppressing the deformation of the space 102, the movement of the steam Vp in the space 102 is less likely to be hindered.

The first plate portion 1 may also be deformed due to the pressure difference between the inside and outside. If the first plate portion 1 is recessed, the heating element Ht and the first plate portion 1 may be separated from each other. Further, the concave portion of the first plate portion 1 may make it difficult for the actuating medium Md to move. The plurality of pillar portions 3 and the wick structure 4 can also suppress deformation of the first plate portion 1. As a result, the heating element Ht and the first plate portion 1 can be brought into contact with each other, and heat can be stably transferred from the heating element Ht to the first plate portion 1. Further, by suppressing the deformation of the first plate portion 1, the movement of the working medium Md in the space 102 is less likely to be hindered. From the above, in the heat conductive member 100 of the present embodiment, it is possible to suppress a decrease in heat dissipation efficiency from the heating element Ht.

In the heat conductive member 100, the pillar portion 3 has a shape in which the pedestal portion 31 connected to the flat plate portion 21 of the second plate portion 2 expands upward. Therefore, the strength of the portion of the pillar portion 3 connected to the flat plate portion 21 can be increased. Therefore, the ratio of the pillar portion 3 to the space 102 can be reduced, and the region where the steam Vp flows can be widened. As a result, the heat conduction efficiency of the working medium can be improved by smoothly flowing the steam of the working medium.

In the heat conductive member 100, the heated region 103 and the heat radiating region 104 are arranged side by side in the Y direction. The steam Vp heated and evaporated in the heated region 103 moves in the Y direction. The steam Vp moves in the Y direction in the gap between the pillars 3 adjacent to each other in the X direction. Seen from the Z direction, the plurality of pillar portions 3 are two-dimensionally arranged in the X direction and the Y direction with the rod-shaped portions 32 facing the same direction. As a result, the flow direction of the steam Vp is made uniform in the Y direction. Further, in the heat conductive member 100, the gap W1 between the pillars 3 adjacent to each other in the X direction is wider than the short axis a2 which is the width of the rod-shaped portion 32 of the pillar 3 in the X direction (see FIG. 7). Therefore, the steam Vp tends to flow.

Further, as shown in FIGS. 2, 7, and the like, the long axis a1 of the cross section orthogonal to the vertical direction of the rod-shaped portions 32 of the plurality of pillar portions 3 extends in the direction along the moving direction of the vaporized steam Vp. Therefore, the resistance of the steam Vp flowing around the rod-shaped portion 32 is smaller than that in the case where the cross-sectional shape of the rod-shaped portion 32 is circular. From the above, by arranging the plurality of pillar portions 3 with the long axis a1 of the rod-shaped portion 32 aligned in the Y direction, steam Vp can be smoothly flowed from the heated region 103 to the heat dissipation region 104. As described above, by making the flow of steam Vp uniform and allowing the steam Vp to flow smoothly, it is possible to improve the heat conduction efficiency of the heat conduction member 100.

<Manufacturing process of housing 101>
The manufacturing process of the housing 101 will be described with reference to the drawings. FIG. 8 is a cross-sectional view of a plate portion forming plate material 2P in which a concave portion 20P and a protruding portion 3P are formed by an etching process. FIG. 9 is a cross-sectional view of the second plate portion 2 formed by press working. FIG. 10 is a cross-sectional view showing a joining process in which the second plate portion 2 is superposed on the first plate portion 1.

The second plate portion 2 of the housing 101 is formed by subjecting the bottom surface of the plate portion forming plate material 2P to an etching process. The plate portion forming plate material 2P is a plate material having the same thickness as the second plate portion 2 and having the same shape as the second plate portion 2 when viewed from the Z direction.

As shown in FIG. 8, by etching the bottom surface of the plate portion forming plate material 2P, the concave portion 20P and the protruding portion 3P which is arranged inside the concave portion 20P and protrudes downward in the Z direction are formed on the lower surface of the plate portion forming plate material 2P. It is formed. At this time, the recess 20P has a depth D1 and the length of the protrusion 3P is also D1.

As shown in FIG. 8, the protruding portion 3P protrudes downward from the lower end of the first portion 31P that narrows downward and the lower end of the first portion 31P, and the shape of the cross section orthogonal to the Z direction is uniform or substantially uniform in the axial direction. The second portion 32P and the like. When the etching process is completed, the cross-sectional shape of the cut surface orthogonal to the Z direction of the first portion 31P and the second portion 32P is circular.

As shown in FIG. 9, the jig Jg is applied to the lower end 30P of all the protruding portions 3P from the lower side of the plate portion forming plate material 2P in which the concave portion 20P and the protruding portion 3P are formed. Then, the jig Jg is urged upward to perform a pressing process for compressing the protruding portion 3P. As a result, the pillar portion 3 is formed by compressing until the length of the protruding portion 3P becomes L1. When compressed, the second portion 32P, that is, the rod-shaped portion 32, which has a small cross-sectional area, is more easily deformed than the first portion 31P, that is, the pedestal portion 31.

The cross-sectional shape of the cut surface of the rod-shaped portion 32 of the pillar portion 3 extends in the rolling direction of the plate portion forming plate material 2P by compression, and is deformed from a circular shape to a flat circular shape. For example, by setting the rolling direction of the plate portion forming plate material 2P to the direction in which the steam Vp flows, the pillar portion 3 having the major axis a1 in the flow direction of the steam Vp can be formed.

Then, as shown in FIG. 10, the wick structure 4 is arranged in the region surrounded by the joined portion 11 of the upper surface 10 of the first plate portion 1 manufactured separately, and the second plate portion 2 is first from above. Overlay on the plate part 1. At this time, the joint portion 22 of the second plate portion 2 is brought into contact with the joint portion 11 of the first plate portion 1. Then, after heating the first plate portion 1 and the second plate portion 2 to raise the temperature to a predetermined temperature, a joining process is performed in which the second plate portion 2 is pressed against the first plate portion 1.

At this time, the pressure on the contact surface between the bonded portion 11 and the bonded portion 22 becomes equal to or higher than a predetermined pressure. As a result, the bonded portion 11 and the bonded portion 22 are joined. In addition, at the time of heating at the time of performing a joining process, the whole of the 1st plate part 1 and the 2nd plate part 2 may be heated, or the joint part 11 and the joint part 22 may be partially heated. good.

After forming the housing 101, the inside of the space 102 is depressurized, and the working medium is accommodated to seal the space 102. The heat conductive member 100 is formed by the above manufacturing method. The above-mentioned manufacturing method is an example, and is not limited to this manufacturing method. For example, when the bottom surface of the plate portion forming plate 2P is subjected to the etching treatment, the circular pillar portion 3 having a flat cross section may be formed by the etching treatment.

The method for manufacturing the second plate portion 2 is not limited to etching, and the plate is scraped or melted by a chemical or physical method to form a recess on the lower surface of the second plate portion 2. A method in which the pillar portion 3 can be formed as a single member with the second plate portion 2 can be widely adopted. Further, even when the first plate portion 1 has a concave portion, the concave portion may be manufactured by an etching process, or may be formed by a chemical or physical method.

Further, in the housing 101 shown above, the second plate portion 2 and the pillar portion 3 are formed of a single member, but the present invention is not limited to this. For example, the second plate portion 2 and the pillar portion 3 of a separate member may be fixed to the portion forming the recess 20 of the flat plate portion 21 of the second plate portion 2.

<First modification>
The pillar portion 3a of the first modification will be described with reference to the drawings. FIG. 11 is a bottom view of the pillar portion 3a of the first modification. The shape of the pedestal portion 31a of the pillar portion 3a shown in FIG. 11 is different from that of the pedestal portion 31 of the pillar portion 3. Other than this, the configuration of the pillar portion 3a is the same as that of the pillar portion 3. Therefore, in the pillar portion 3a, substantially the same parts as those of the pillar portion 3 shown in FIG. 4 and the like are designated by the same reference numerals, and detailed description of the same portions will be omitted.

The pedestal portion 31a of the pillar portion 3a shown in FIG. 11 is a circular shape having a flat cross-sectional shape of a cut surface orthogonal to the Z direction. That is, the cross-sectional shape of the cut surface orthogonal to the vertical direction of the pedestal portion 31a is a flat circular shape. Like the pedestal portion 31, the pedestal portion 31a has a shape that narrows downward. Then, the pedestal portion 31a is connected to the flat plate portion 21 of the second plate portion 2. The portion of the pedestal portion 31a connected to the flat plate portion 21 is a flat circular portion of the long axis b1 and the short axis b2. The flatness of the cross-sectional shape of the cut surface orthogonal to the Z direction of the pedestal portion 31a is smaller than the flatness of the cross-sectional shape of the cut surface orthogonal to the Z direction of the rod-shaped portion 32.

Further, when the pillar portion 3a is formed by the pressing process, the cross-sectional shape of the cut surface orthogonal to the Z direction of the rod-shaped portion 32 may change slightly in the Z direction. Therefore, in reality, the maximum value of the flatness of the cross-sectional shape of the cut surface orthogonal to the Z direction of the pedestal portion 31a is larger than the minimum value of the flatness of the cross-sectional shape of the cut surface orthogonal to the vertical direction of the rod-shaped portion 32. small.

With such a configuration, the volume of the pedestal portion 31a can be made smaller than that of the pedestal portion 31 having a circular cross section. As a result, the ratio of the pedestal portion 31a to the space 102 can be reduced, and the region where the steam Vp flows can be expanded. Therefore, the flow of steam Vp can be smoothed, and the heat conduction efficiency by the working medium can be further improved. As shown in FIG. 11, by aligning the long axis b1 with the flow direction of the steam Vp, the resistance of the steam Vp flowing around the pedestal portion 31a can be further reduced.

In the present embodiment, the long axis b1 of the pedestal portion 31a is in the same direction as the long axis a1 of the cross section of the rod-shaped portion 32, but the direction is not limited to this, and the long axis b1 may be tilted.

<Second modification>
The second plate portion 2b of the second modification will be described with reference to the drawings. FIG. 12 is a bottom view of the second plate portion 2b of the second modification. In the second plate portion 2b shown in FIG. 12, the direction of the long axis a1 of the rod-shaped portion 32 of the pillar portion 3 is different from that of the second plate portion 2. Other than this, the configuration of the second plate portion 2b is the same as that of the second plate portion 2. Therefore, in the second plate portion 2b, substantially the same parts as those of the second plate part 2 shown in FIG. 2 and the like are designated by the same reference numerals, and detailed description of the same parts will be omitted.

As shown in FIG. 12, the direction in which the long axis a1 of the cross section orthogonal to the vertical direction of the rod-shaped portions 32 of the plurality of pillar portions 3 of the second plate portion 2b extends is non-uniform. With this configuration, even if the direction of action on the pillar portion 3 is not uniform, the pillar portion 3 having the rod-shaped portion 32 in the same direction as the direction in which the long axis a1 acts or substantially the same direction exist. By using the second plate portion 2b, it is possible to suppress the deformation of the space 102 regardless of the direction of the force acting on the housing 101, smooth the flow of the working medium, and increase the heat conduction efficiency by the working medium. ..

<Third modification example>
The second plate portion 2c of the third modification will be described with reference to the drawings. FIG. 13 is a bottom view of the second plate portion 2c of the third modification. The second plate portion 2c shown in FIG. 13 has a square shape when viewed from the Z direction, and the direction of the long axis a1 of the rod-shaped portion 32 of the pillar portion 3 is different from that of the second plate portion 2. Other than this, the configuration of the second plate portion 2c is the same as that of the second plate portion 2. Therefore, in the second plate portion 2c, substantially the same parts as those of the second plate part 2 shown in FIG. 2 and the like are designated by the same reference numerals, and detailed description of the same parts will be omitted.

The second plate portion 2c has a square flat plate portion 21c when viewed from the Z direction, and a joint portion 22c extending downward from the outer edge portion of the flat plate portion 21c. The second plate portion 2c has a recess 20c surrounded by the joint portion 22c, and the plurality of pillar portions 3 have the long axis a1 of the rod-shaped portion 32 radially from the center point Sp seen from the Z direction of the recess 20c. It extends in the direction of spreading. That is, the long axis of the cross section orthogonal to the vertical direction of the rod-shaped portion 32 of the plurality of pillar portions 3 extends in the direction extending radially from the predetermined position Sp.

As described above, in the heat conductive member 100, the heat transferred from the heating element Ht is carried to a portion away from the heating element Ht to cool the heating element Ht. In the shape of the portion where the heating element Ht is arranged, heat may be transported radially. In such a case, the heating element Ht is arranged in the center of the heat conductive member 100 when viewed from the Z direction, and the long axis a1 of the rod-shaped portion 32 is positioned so that the heating element Ht extends radially from the center point Sp. The part 3 is arranged. As a result, the steam Vp heated and vaporized by the heat from the heating element Ht can easily move radially, the flow of the working medium can be smoothed, and the heat conduction efficiency by the working medium can be improved.

Although the configuration in which the heating element Ht is arranged in the center when viewed from the Z direction is described as an example, the present invention is not limited to this. For example, even if it deviates from the center, the center of the portion in contact with the heating element Ht is set as the center point Sp, and the pillar portion 3 is arranged at a position where the long axis a1 extends radially from the center point Sp. You may. In a device provided with a heating element Ht, the arrangement of the major axis a1 may be adjusted depending on the position of the heating element Ht and other devices. In this case, the shape of the arrangement is not limited to radial, and may be parallel or may include both.

Although the embodiments of the present invention have been described above, the present invention is not limited to this content. Further, the embodiments of the present invention can be modified in various ways as long as they do not deviate from the gist of the invention.

The heat conductive member of the present invention can be used for heat dissipation from devices that are used in thin electronic devices such as smartphones, tablet PCs, and notebook PCs and generate heat by operation. In addition to these, it can be used to dissipate heat from heat-generating equipment.

100 Heat conductive member 101 Housing 102 Space 103 Heated area 104 Heat dissipation area 1 1st plate part 10 Top surface 11 Jointed part 2 2nd plate part 20 Recessed 21 Flat plate part 22 Joint part 2b 2nd plate part 2c 2nd plate part 21c Flat plate part 22c Connection part 3 Pillar part 30 End part 31 Pedestal part 32 Rod-shaped part a1 Long axis a2 Short axis 3a Pillar part 31a Pedestal part b1 Long axis b2 Short axis 4 Wick structure 20c Recess 2P Plate part forming plate material 20P Recess Projection 30P End 31P 1st part 32P 2nd part Ht Heat generator Jg jig

Claims (10)

A heat conductive member having a housing in which a working medium is enclosed.
The housing is
The first plate part and
The second plate portion overlapped on the upper part of the first plate portion,
It has a plurality of pillars extending downward from the second plate, and has.
Each of the pillars
A pedestal portion that is connected to the second plate portion and becomes thinner toward the bottom,
It has a rod-shaped portion extending downward from the lower end portion of the pedestal portion, and has.
At least the rod-shaped portion is a heat conductive member having a flat circular cross-sectional shape of a cut surface orthogonal to the vertical direction. The cross-sectional shape of the cut surface orthogonal to the vertical direction of the pedestal portion is a flat circular shape.
In each pillar portion, the maximum value of the flatness of the cross-sectional shape of the cut surface orthogonal to the vertical direction of the pedestal portion is larger than the minimum value of the flatness of the cross-sectional shape of the cut surface orthogonal to the vertical direction of the rod-shaped portion. The small heat conductive member according to claim 1. The heat conductive member according to claim 1 or 2, wherein the long axes of the cut surfaces of the plurality of rod-shaped portions are parallel to each other. The heat conduction according to claim 3, wherein the distance between the outer peripheral surfaces of the rod-shaped portion of the pillar portion adjacent to each other along the short axis of the cross section orthogonal to the vertical direction of the rod-shaped portion is longer than the length of the short axis. Element. The heat conductive member according to claim 1 or 2, wherein the long axis of the cross section orthogonal to the vertical direction of the plurality of rod-shaped portions extends radially from a predetermined position. The heat conductive member according to any one of claims 1 to 5, wherein the long axis of the cross section orthogonal to the vertical direction of the plurality of rod-shaped portions extends in a direction along the moving direction of the vaporized working medium. The heat conductive member according to claim 1 or 2, wherein the direction in which the long axis of the cross section orthogonal to the vertical direction of the plurality of rod-shaped portions extends is non-uniform. The second plate portion has a recess recessed from a surface facing the first plate portion.
The heat conduction according to any one of claims 1 to 7, wherein the vertical length of the pillar portion is shorter than the vertical depth of the recess, and a plurality of the pillar portions are arranged inside the recess. Element. The housing further comprises a wick structure disposed between the first plate portion and the second plate portion, wherein the wick structure is a lower end portion of the rod-shaped portion of the pillar portion. The heat conductive member according to claim 8, further comprising a wick structure in contact with. It is a method of manufacturing a heat conductive member formed by enclosing a working medium inside a housing formed by superimposing a second plate portion on an upper portion of a first plate portion.
An etching step of forming a recess that is recessed upward from the lower surface of the second plate portion and a plurality of protrusions that are arranged inside the recess and extend in the vertical direction by etching.
A method for manufacturing a heat conductive member, comprising a pressing step of applying a jig to the lower end portions of a plurality of the protrusions in the vertical direction and compressing the protrusions with the jig to form a pillar portion.

Images