JP2011086753A - Heat transferring device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat transferring device that is easily manufactured by suppressing the manufacturing cost, thereby decreasing the number of components; and to provide electronic equipment mounted with the same. <P>SOLUTION: The heat transferring device 100 includes a housing 1, a working fluid charged in the housing 1, and an expand metal 2 and a capillarity structure 3 which are provided in the housing 1 to form a flow passage for the working fluid. The expand metal 2 is in a shape which is wide in one plane, but has a suitable thickness in its thickness direction. The housing 1 can therefore be reinforced, especially, in the thickness direction. Further, a suitable space where the working fluid in vapor phase circulates at least in the thickness direction is formed as an opening 2a in the expand metal 2. Namely, the expand metal 2 combines both functions of a reinforcing member and a vapor-phase flow passage. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat transport device that uses capillary force as a main driving force of a working fluid and transports heat by movement of latent heat due to a phase change of the working fluid, and an electronic apparatus equipped with the heat transport device.

  Conventionally, a planar heat pipe has been widely used as a device for cooling a heat source such as a CPU (Central Processing Unit). The planar heat pipe is also used as a cooling device for a CPU mounted on a recent thin TV. In such a planar heat pipe, the working fluid is sealed inside the planar heat pipe in order to cool the heat source by utilizing the phase change of the working fluid.

  For example, Patent Document 1 discloses a heat spreader using the operation principle of a heat pipe. This heat spreader includes a capillary structure formed of a metal mesh and a plurality of columnar reinforcing members joined to the inside of the metal housing (see FIG. 3 of Patent Document 1). The reinforcing member has a function of preventing the housing from being deformed by an increase in pressure from the inside of the housing due to evaporation of the working fluid when the heat spreader absorbs heat.

  Patent Document 2 discloses a micromixer using a wick having a capillary force, although it is not a phase change heat transport device. This micromixer mixes liquid and other fluid (mainly gas) in the wick, and may be used for heat transfer (from gas to liquid) or heat exchange (Patent Document). 2 paragraph [0047]). In this micromixer, an expanded metal screen is cited as an example of a sheet made of a porous material, which is one of the members constituting the layered wick (see paragraph [0021] of Patent Document 2). .

JP 2006-140435 A JP 2009-509119 A (Pamphlet of International Publication No. 2007/035303)

  In the heat spreader of Patent Document 1, a plurality of aluminum columnar members and the like are used as reinforcing members. Therefore, a plurality of columnar members and the like are required, and the number of parts increases. Moreover, in this heat spreader, in order to use a columnar member, a step of processing a metal mesh in three dimensions according to the shape of the housing and a step of forming a hole for passing the columnar member through the metal mesh are required. Become.

  In view of the circumstances as described above, it is an object of the present invention to provide a heat transport device capable of reducing the number of parts, facilitating manufacturing, and suppressing manufacturing cost, and an electronic apparatus equipped with the heat transport device.

In order to achieve the above object, a heat transport device according to an embodiment of the present invention includes a housing, a working fluid, and an expanded metal.
The working fluid transports heat by phase change.
The expanded metal is provided in the housing, reinforces the housing, and forms a flow path for the working fluid.

  The expanded metal has an appropriate thickness in the thickness direction while having a wide shape on one plane. Therefore, the housing can be reinforced by the expanded metal particularly in the thickness direction. The opening of the expanded metal is formed as a space for the working fluid to flow at least in the thickness direction. That is, the expanded metal has both functions of a reinforcing member and a flow path. Therefore, the number of parts can be reduced as compared with the conventional case. For example, an expanded metal having an arbitrary shape can be manufactured in accordance with the shape in the housing, so that the manufacture is also facilitated. As a result, the manufacturing cost can be suppressed.

  The expanded metal may form a flow path for the working fluid in a gas phase. Since the expanded metal functions as a gas phase region, the function as a reinforcing member does not deteriorate even if the opening is formed relatively large.

  The expanded metal may form a flow path for generating a capillary force in the liquid-phase working fluid.

A heat transport device according to another aspect of the present invention includes a housing, a working fluid that transports heat by phase change, and a first expanded metal.
The first expanded metal has an opening of a first size, is provided in the housing, reinforces the housing, and forms a flow path for the working fluid in a gas phase.

  The expanded metal has an appropriate thickness in the thickness direction while having a wide shape on one plane. Therefore, the housing can be reinforced by the expanded metal particularly in the thickness direction. In addition, the opening of the expanded metal is formed as a space for flowing a gas-phase working fluid at least in the thickness direction. That is, the expanded metal has both functions of a reinforcing member and a gas phase flow path.

  The heat transport device may further include a capillary structure. The capillary structure has an opening having a second size smaller than the first size, and is provided so as to be laminated on the first expanded metal, and generates a capillary force in the liquid-phase working fluid.

  Since the capillary structure is provided so as to be laminated on the first expanded metal, the first expanded metal can reinforce the housing while being in contact with the capillary structure.

  The capillary structure may include a second expanded metal having an opening of the second size.

  Alternatively, the capillary structure may include a mesh member having the second size opening.

  The capillary structure includes a first capillary member having an opening of the second size, and a second capillary member having an opening of a third size smaller than the first size and larger than the second size. You may have. The first capillary member is any one of a mesh member, expanded metal, and other capillary members. Similarly, the second capillary member is any one of a mesh member, expanded metal, and other capillary members. The specific combination of the first capillary member and the second capillary member is arbitrary.

A heat transport device according to another aspect of the present invention includes a housing, a working fluid that transports heat by phase change, and a plurality of expanded metals.
The plurality of expanded metals each have openings of different sizes and are provided in a stacked manner to reinforce the housing and form a flow path for the working fluid.

  Among the plurality of expanded metals, the expanded metal having an opening of a size that substantially generates a capillary force in the working fluid can hold the liquid-phase working fluid by the capillary force. An expanded metal having an opening of a size that does not substantially generate a capillary force in the working fluid has a function of circulating a gas-phase working fluid. The plurality of expanded metals further have a function as a reinforcing member. Therefore, the number of parts can be reduced as compared with the prior art, and the manufacture is facilitated. As a result, the manufacturing cost can be suppressed.

  An electronic apparatus according to an embodiment of the present invention includes any one of the above heat transport devices.

  As described above, according to the present invention, the number of parts of the heat transport device can be reduced to facilitate the manufacturing, and the manufacturing cost can be suppressed.

It is a typical sectional view showing the heat transport device concerning a 1st embodiment of the present invention. It is a top view which shows a part of expanded metal of a heat transport device. It is the sectional view on the AA line shown in FIG. It is a model figure which shows the heat transport principle in the device which transports heat by movement of latent heat using capillary force as the main driving force of the working fluid. It is the graph which showed the difference in the flow-path resistance by the case where a normal mesh member is used as a member which forms a gaseous-phase flow path, and the case where an expanded metal is used. It is a graph which shows the result of having compared the maximum heat transport amount by the case where a mesh member is used as a gaseous-phase flow path, and the case where an expanded metal is used. It is sectional drawing which shows the heat transport device which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the heat transport device which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows the heat transport device which concerns on the 4th Embodiment of this invention. It is sectional drawing which shows the heat transport device which concerns on the 5th Embodiment of this invention. It is a figure for demonstrating the relationship between the direction through which a gaseous-phase working fluid flows and arrangement | positioning of openings, such as an expanded metal, in the heat transport device which concerns on the said 1st-5th embodiment. When the inventor changed the pitch of the opening of an expanded metal in the X-axis direction, it is a graph which shows the flow-path resistance of the gaseous-phase working fluid which flows through an expanded metal before and after the change. It is a graph which shows the maximum heat transport amount before and behind the change in FIG. It is a disassembled perspective view which shows another embodiment of the housing of a heat transport device. A laptop PC is shown as an electronic apparatus equipped with the heat transport device according to one of the first embodiments.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 is a cross-sectional view showing a heat transport device according to an embodiment of the present invention.

  The heat transport device 100 includes a housing 1, a working fluid (not shown) sealed in the housing 1, and an expanded metal 2 and a capillary structure 3 provided in the housing 1 and forming a flow path for the working fluid. It has. The expanded metal 2 and the capillary structure 3 are provided so as to be stacked.

  The housing 1 has, for example, an upper plate member 11 and a lower plate member 12, and these are joined to form the housing 1. Note that the “upper plate member” and the “lower plate member” are expressed as “upper and lower” for convenience of explanation, and it is not necessary to distinguish the upper and lower when using the heat transport device 100.

  The housing 1 is typically made of oxygen-free copper, tough pitch copper, or a copper alloy. However, the present invention is not limited to this, and the housing 1 may be made of a metal other than copper, or a resin may be used.

  Examples of methods for joining the upper plate member 11 and the lower plate member 12 include diffusion bonding, ultrasonic bonding, brazing, and welding.

  The housing 1 is not limited to the case where the upper plate member 11 and the lower plate member 12 are configured as described above. For example, as shown in the exploded perspective view of FIG. 14, the upper plate 121, the frame body 123, and the lower plate 122. These may be joined to form one housing.

  The shape of the housing 1 is typically substantially rectangular when viewed in plan, for example, a rectangle that is long in the Y-axis direction in FIG.

  The housing 1 is provided with an inlet (not shown) having a diameter of about 0.1 mm to 1 mm, for example, and the working fluid is injected into the housing 1 through the inlet. The working fluid is typically injected with the inside of the housing 1 being depressurized from the atmospheric pressure.

  Examples of the working fluid include pure water, alcohol such as ethanol, fluorine-based liquid such as Fluorinert FC72, or a mixture of pure water and alcohol.

  FIG. 2 is a plan view showing a part of the expanded metal 2 of the heat transport device 100, and FIG. 3 is a cross-sectional view taken along line AA shown in FIG.

  The expanded metal 2 has a substantially diamond-shaped (or parallelogram-shaped) opening 2a. The size of the opening 2a, for example, the length of one side of the rhombus is typically about 2 mm to 20 mm. The thickness of the plate material before being processed as the expanded metal 2 is typically 0.3 to 0.8 mm, for example, 0.4 mm. However, these values are appropriately determined depending on the material of the working fluid, the size of the housing 1, the material of the housing 1, the material of the expanded metal 2, or the maximum heat transport amount transported by the heat transport device 100. It can be changed.

  The “opening size” includes, for example, the meaning of the opening area, the length of one side of the opening, or the length of the diagonal line of the opening.

  In the market, expanded metal 2 having openings 2a of various thicknesses and various sizes is in circulation. In general, the expanded metal 2 is formed by forming a plurality of openings 2a in one plate material. The plurality of openings 2a are formed by a cutter having a plurality of teeth corresponding to the size of the opening 2a. After the plate material is cut by the cutter for forming the opening 2a, the plate material is stretched so that the size of the opening 2a becomes a desired size. Alternatively, the aspect ratio of the opening 2a may be determined by gradually extending the plate material by the pressing force of the cutter while the plate material is being cut by the cutter to form the opening 2a.

  As shown in FIG. 3, in the expanded metal 2, the opening surface is in an obliquely formed state, so that the expanded metal 2 has an appropriate thickness in the thickness direction while having a wide shape on one plane. .

  The expanded metal 2 is made of copper, phosphor bronze, aluminum, silver, stainless steel, molybdenum, or at least two kinds of alloys thereof, but is not limited to these materials.

  As the capillary structure 3, a mesh member 31 is used. The mesh member 31 is typically formed by cutting a mesh woven with metal wires into an arbitrary size.

  Examples of the weaving method of the mesh member 31 include, but are not limited to, plain weave and twill weave. For example, a rock crimp weave, a flat top weave, or the like may be used. The material of the mesh member 31 may be the same as that of the expanded metal 2 described above. The size of the mesh (opening) of the mesh member 31 is set to be smaller than the size of the opening 2 a of the expanded metal 2.

  The materials of the expanded metal 2 and the mesh member 31 may be the same or different.

  The expanded metal 2 forms a gas phase flow path for circulating a gas phase working fluid. Further, the capillary structure 3 forms a liquid-phase flow path through which the liquid-phase working fluid flows, and the capillary structure 3 generates a capillary force in the liquid-phase working fluid.

  FIG. 4 is a model diagram showing the heat transport principle in a device that transports heat by moving latent heat using capillary force as the main driving force of the working fluid.

  In the evaporation region E, the liquid-phase working fluid receives heat from the heat source, evaporates with a vapor pressure difference ΔPe, and becomes a gas-phase working fluid. The gas-phase working fluid moves from the evaporation region E to the condensation region C through the gas-phase flow path. At this time, the gas-phase working fluid moves to the condensation region C while receiving the pressure loss ΔPv due to the resistance of the gas-phase flow path.

  The working fluid in the gas phase that has moved to the condensation region C releases heat W and condenses, and changes in phase from the gas phase to the liquid phase. Let the vapor pressure difference at this time be ΔPc. The liquid working fluid flows through the liquid phase flow path using the capillary force ΔPcap of the capillary structure (corresponding to the capillary structure 3 shown in FIG. 1) as a pump force, and moves from the condensation region C to the evaporation region E. At this time, the liquid-phase working fluid moves to the condensation region C while receiving the resistance ΔPl of the liquid-phase flow path.

  The liquid-phase working fluid that has returned to the evaporation region E receives heat from the heat source again and evaporates. By repeating the above operation, heat from the heat source is transported.

  If the total pressure loss inside the heat transport device is less than the capillary force ΔPcap of the capillary structure, the heat transport device will operate properly. Conversely, if the total pressure loss is greater than the capillary force ΔPcap, the heat transport device will not operate and heat will not be transported. When the total pressure loss and the capillary force ΔPcap are balanced, the maximum heat transport amount Qmax of the heat transport device is obtained.

Therefore, ΔPcap which becomes the maximum heat transport amount Qmax is expressed by the following equation (1).
ΔPcap = ΔPv + ΔPl + ΔPe + ΔPc + ΔPh (1)
ΔPv: Pressure loss of gas phase working fluid ΔPl: Pressure loss of liquid phase working fluid ΔPe: Pressure difference due to evaporation ΔPc: Pressure difference due to condensation ΔPh: Pressure difference due to body force

Here, when the channel resistance per unit amount of heat is Rq, the maximum heat transport amount Qmax is expressed by the following equation (2).
Qmax = ΔPcap / Rq (2).

The maximum heat transport amount Qmax is expressed by the following equation (3), where H is the latent heat and Rtotal is the total flow resistance.
Qmax = ΔPcap × H / Rtotal (3).

  The total flow path resistance Rtotal is the sum of the resistance due to the resistance Rv of the gas phase flow path, the resistance Rl of the liquid phase flow path, the boiling resistance Re, the condensation resistance Rc, and the body force Rb. Therefore, from the equation (3), the maximum heat transport amount Qmax generally increases as the capillary force ΔPcap increases, and decreases as the resistance Rl of the liquid phase flow path increases.

  The pressure loss ΔPv of the gas-phase working fluid, the pressure loss ΔPl of the liquid-phase working fluid, the pressure difference ΔPe due to evaporation, the pressure difference ΔPc due to condensation, and the pressure difference ΔPh due to the body force Rb are respectively expressed by the following formulas (4) to (4): 8).

ΔPv = 8 × μv × Q × L / (π × ρv × rv ^ 4 × H) (4)
ΔPl = μl × Q × L / (K × Aw × ρl × H) (5)
ΔPe = (RT / 2π) ^ (1/2) × Q / [αc (H−1 / 2 × RT) × rv × le] (6)
ΔPc = (RT / 2π) ^ (1/2) × Q / [αc (H−1 / 2 × RT) × rv × lc] (7)
ΔPh = (ρl−ρv) × g × L × sinφ (8)
μv: Viscosity coefficient of the working fluid in the gas phase μl: Viscosity coefficient of the working fluid in the liquid phase ρv: Density of the working fluid in the gas phase ρl: Density of the working fluid in the liquid phase Q: Heat transport amount L: Length of the heat transport device Size in the direction le ... Size in the longitudinal direction of the evaporation region E lc ... Size in the longitudinal direction of the condensation region C Aw ... Cross-sectional area of the capillary structure rv ... Capillary radius of the gas phase channel K ... Permeation coefficient R ... Gas Constant g: Gravity acceleration φ: inclination of the heat transport device with respect to the horizontal (the volume force Rb becomes zero when the heat transport device is used horizontally).

  Focusing on formulas (4), (6), and (7) among the above formulas (4) to (8), the pressure loss ΔPv of the gas phase working fluid, the pressure difference ΔPe due to evaporation, and the pressure difference ΔPc due to condensation Is a function of the capillary radius rv of the gas phase channel. The capillary radii rv of the gas phase flow path are all arranged in the denominator in the equations (4), (6), and (7). Therefore, if the capillary radius rv of the gas phase flow path is increased, the three pressure losses ΔPv, ΔPe, ΔPc can be reduced, and the maximum heat transport amount Qmax can be increased.

Here, the capillary radius r of the flow path through which the gas-phase or liquid-phase working fluid moves will be described. When a capillary structure (for example, the mesh member 31 shown in FIG. 1) formed by braiding wires is used as the working fluid flow path, the capillary radius r is expressed by the following equation (9).
r = (W + D) / 2 (9)
W: Size of the opening of the capillary structure D: Diameter of the wire.

On the other hand, when a capillary structure or the like is not used as a working fluid channel and a rectangular cavity is a channel, such as a gas phase channel of a heat transport device, the capillary radius r is expressed by the following formula ( 10).
r = ab / (a + b) (10).

a ... Width of channel (size in short direction)
b: The depth of the channel (thickness of the channel).

  Next, the operation of the heat transport device 100 according to this embodiment will be described.

  As shown in FIG. 1, it is assumed that the heat source 10 is in contact with the lower plate member 12 of the housing 1, for example. The heat generated from the heat source 10 evaporates the liquid-phase working fluid held by the capillary force to become a gas-phase working fluid. The working fluid in the gas phase moves to and diffuses in the gas phase region where the expanded metal 2 is mainly disposed, which is a region having a smaller flow resistance compared to the liquid phase region where the capillary structure 3 is disposed. . As will be described later, the expanded metal 2 forms a gas phase flow path, whereby the housing 1 can be reinforced while maintaining the flow path resistance (ΔPv which is the gas phase flow path resistance) small.

  The gas phase working fluid releases heat to the housing 1 itself and the outside of the housing 1 in the gas phase region and condenses. The working fluid is more likely to condense as the distance from the heat source 10 increases. The gas-phase working fluid can be condensed with low condensation resistance by flowing through the opening 2 a of the expanded metal 2. The working fluid that has become a liquid phase returns to the liquid phase region by the capillary force of the capillary structure 3 again. The working fluid transports heat by moving the latent heat by repeating the above phase change. As a result, the heat source is cooled.

  The heat source only needs to be thermally connected to the housing 1. Thermal connection means, for example, a form in which the heat source and the housing 1 are in direct contact, or in a state where the heat source can efficiently conduct heat through a member such as a heat diffusion sheet. Includes connected forms. The heat source may be in contact with the upper plate member 11 of the housing 1.

  Further, for example, in the longitudinal direction of the housing 1, a heat sink (not shown) may be thermally connected to the side opposite to the side to which the heat source is connected.

  As described above, the expanded metal 2 is used in the present embodiment. Although the expanded metal 2 has a wide shape on one plane, it has an appropriate thickness in the thickness direction. Therefore, the housing 1 can be reinforced particularly in the thickness direction. That is, a columnar member as a reinforcing member is not required unlike the conventional case. In addition, an appropriate space for the vapor-phase working fluid to flow at least in the thickness direction is formed in the expanded metal 2 as the opening 2a. That is, the expanded metal 2 has both functions of a reinforcing member and a gas phase flow path. Therefore, the number of parts can be reduced as compared with the conventional case. For example, the expanded metal 2 having an arbitrary shape can be manufactured in accordance with the shape in the housing 1, so that the manufacture is facilitated. As a result, the manufacturing cost can be suppressed.

  Moreover, by using the expanded metal 2, the heat transport device 100 having high heat transport performance and high durability can be realized.

  There is an advantage that the size of the opening 2a of the expanded metal 2 can be increased as much as the mesh member 31 cannot realize. Therefore, for example, according to the size of the housing 1, the size of the opening 2a of the expanded metal 2 can be appropriately set.

  FIG. 5 is a graph showing the difference in channel resistance between the case where the normal mesh member according to the comparative example is used and the case where the expanded metal 2 is used as the member forming the gas phase channel. And shows actual measurement values.

  The size of each opening 2a of this mesh member 31 and the expanded metal 2 was made substantially the same. The material is pure copper for both the mesh member and the expanded metal, and the working fluid is water. As the expanded metal, for example, one having a length a = b = 2 mm shown in FIG. 11 described later was used. The mesh member according to the comparative example is a # 18 mesh, that is, a mesh having 18 openings per 1 inch (25.4 mm) square.

  From this experiment, it has been found that the expanded metal 2 has a smaller flow path resistance than the mesh member 31.

  FIG. 6 is a graph showing a result of comparing the maximum heat transport amount when the mesh member 31 is used and when the expanded metal 2 is used. As is clear from this experiment, it is understood that the maximum heat transport amount is larger when the expanded metal 2 is used.

[Second Embodiment]
FIG. 7 is a view showing a heat transport device according to the second embodiment of the present invention. In the following description, the same members, functions, and the like included in the heat transport device 100 according to the embodiment shown in FIG. 1 and the like will be simplified or omitted, and different points will be mainly described.

  In the housing 1 of the heat transport device 200, a mesh member 23 for circulating a gas phase and an expanded metal 22 as a capillary structure and as a reinforcing member are provided. The structure of the expanded metal 22 is substantially the same as the structure of the expanded metal 2 according to the first embodiment, and the sizes of both openings are different. That is, the expanded metal 22 has an opening having a size that generates a capillary force in the liquid-phase working fluid. The size of the opening of the mesh member 23 is larger than that of the expanded metal 22 and is set so that the flow path resistance of the gas-phase working fluid is reduced.

[Third embodiment]
FIG. 8 is a diagram showing a heat transport device according to the third embodiment of the present invention.

  In this heat transport device 300, the expanded metal 16 is used as a capillary structure in addition to the expanded metal 2 that mainly circulates the gas-phase working fluid. That is, the expanded metal 16 has an opening having a size smaller than that of the expanded metal 2. The size of the opening of the expanded metal 16 may be a size that can generate a capillary force in the liquid-phase working fluid.

  Thus, in addition to the expanded metal 2 for the gas-phase flow path, the expanded metal 16 is used as a capillary structure, so that the housing 1 can be reinforced compared to the heat transport device 100 according to the first embodiment. Function can be enhanced.

[Fourth Embodiment]
FIG. 9 is a view showing a heat transport device according to the fourth embodiment of the present invention.

  The heat transport device 400 according to this embodiment includes the expanded metal 2 that forms a gas phase channel and the capillary structure 32 that generates a capillary force as a liquid phase channel. The capillary structure 32 is composed of two layers of expanded metals 17 and 18. These expanded metals 17 and 18 have openings of different sizes. For example, the size of the opening of the expanded metal 18 is smaller than the size of the opening of the expanded metal 17. The size of the opening of the expanded metal 2 is the largest.

[Fifth Embodiment]
FIG. 10 is a view showing a heat transport device according to the fifth embodiment of the present invention.

  The heat transport device 500 according to this embodiment includes the expanded metal 2 and the capillary structure 42. The capillary structure 42 is composed of the expanded metal 19 and the mesh member 33. The opening size of the mesh member 33 is smaller than the opening size of the expanded metal 19.

  Instead of the capillary structure 42 of the heat transport device 500, at least two mesh members each having openings of different sizes may be used.

  FIG. 11 is a diagram for explaining the relationship between the direction in which the gas-phase working fluid flows and the arrangement of the openings of the expanded metal 2 and the like in the heat transport device 100 and the like according to the first to fifth embodiments. . Of the two diagonal lines a and b of the diamond-shaped opening 2a of the expanded metal 2, the expanded diagonal line b (the X-axis direction in FIG. 11) extends along the direction in which the gas-phase working fluid flows. It is effective when the metal 2 is arranged. Typically, when heat is transported in the longitudinal direction of the housing 1, the expanded metal 2 is disposed in the housing 1 so that the X axis substantially coincides with the longitudinal direction.

  When the expanded metal 2 is manufactured, since the expanded metal 2 is stretched, the size of the opening 2a is easily changed, so that the heat transport device 100 and the like can be easily manufactured. On the other hand, the aspect ratio of the opening of the mesh member 31 is fixed to a value that is substantially the same.

  FIGS. 12 and 13 show the case where the inventor changed the length of the diagonal line b in FIG. 11 (pitch in the X-axis direction of the opening 2a) of the gas phase flowing through the expanded metal 2 before and after the change. The flow path resistance of the working fluid and the maximum heat transport amount at that time are shown. In the experiment, the length of the diagonal line b after the change was set to be longer than that before the change. From these figures, it was found that a larger pitch is more effective. The expanded metal before the change is a = b = 2 mm, and the expanded metal after the change is a = 1.4 mm, b = 2.4 mm.

  FIG. 15 shows a laptop personal computer (PC) as an electronic apparatus equipped with the heat transport device according to one of the above embodiments.

  The PC 150 includes a first casing 111, a second casing 112, and a hinge portion 113 that rotatably supports the first casing 111 and the second casing 112.

  The first housing 111 includes a display unit 101 and an edge light type backlight 102 that irradiates the display unit 101 with light. The backlights 102 are respectively arranged in the vertical direction of the first casing 111 inside the first casing 111. The backlight 102 is formed, for example, by arranging a plurality of white LEDs (Light Emitting Diodes) on a copper plate.

  The second housing 112 has a plurality of input keys 103 and a touch pad 104. The second housing 112 has a control circuit board (not shown) on which electronic circuit components such as the CPU 105 are mounted.

  The heat transport device 10 is disposed inside the second housing 112 so as to be in contact with the CPU 105. In FIG. 15, the heat transport device 10 is shown to be smaller than the planar outer shape of the second housing 112, but the heat transport device 10 has a size equivalent to the planar outer shape of the second housing 112. Also good.

  Alternatively, the heat transport device 10 may be disposed inside the first housing 111 so as to be in contact with the copper plate forming the backlight 102. In this case, a plurality of heat transport devices 10 are arranged in the first housing 111.

  As described above, since the heat transport device 10 has high heat transport performance, the heat generated by the CPU 105, the backlight 102, and the like can be transported quickly. Thereby, heat can be quickly released to the outside of the PC 150. Moreover, since the temperature inside the first housing 111 or the second housing 112 can be made uniform by the heat transport device 10, low temperature burns can be prevented.

  Furthermore, since the heat transport device 10 has a high heat transport performance and is thin, the PC 150 can be thinned.

  In FIG. 15, the PC is described as an example of the electronic device, but the electronic device is not limited to this. Other examples of the electronic device include an audio / visual device, a display device, a projector, a game device, a car navigation device, a robot device, a PDA (Personal Digital Assistance), an electronic dictionary, a camera, a mobile phone, and other electrical appliances. .

  Embodiments according to the present invention are not limited to the embodiments described above, and there are various other embodiments.

  For example, in the heat transport device 400 shown in FIG. 9, the arrangement of the expanded metals 17 and 18 may be reversed. That is, the expanded metal 18 having the smallest size opening is not necessarily disposed on the side closer to the lower surface side of the housing 1.

  Four or more expanded metals 2 may be laminated and disposed in the housing 1. Each expanded metal in that case may be arranged in any order. For example, in the thickness direction in the housing 1, an expanded metal that forms a gas phase flow path may be disposed in the center, and an expanded metal that forms a capillary structure may be disposed so as to sandwich the expanded metal.

  In the embodiment shown in FIG. 10, the expanded metal 19 and the mesh member 33 are provided as the capillary structure 42. However, the capillary structure 42 may be a combination of at least two of an expanded metal, a mesh member, and other capillary members. Examples of the capillary member other than the expanded metal and the mesh member include porous sintered bodies such as metals and ceramics.

  The size of each opening of the at least two members of the capillary structure having a combination of at least two of the expanded metal, the mesh member, and other capillary members may be the same.

  The shape of the housing 1 of the heat transport device is not limited to a rectangular shape, and may be any shape such as an L shape, a U shape, a circular shape, an elliptical shape, a polygonal shape, and a ring shape when seen in a plan view.

100, 200, 300, 400, 500 ... heat transport device 2, 16-19, 22 ... expanded metal 23, 31, 33 ... mesh member 31 ... mesh member 3, 32, 42 ... capillary structure 150 ... PC

Claims (12)

A housing;
A working fluid that transports heat by phase change;
An expanded metal provided in the housing and reinforcing the housing and forming a flow path for the working fluid. The heat transport device according to claim 1,
The expanded metal is a heat transport device that forms a flow path for the working fluid in a gas phase. The heat transport device according to claim 1,
The expanded metal is a heat transport device that forms a flow path for generating a capillary force in the liquid working fluid. A housing;
A working fluid that transports heat by phase change;
A heat transport device comprising: a first expanded metal having an opening of a first size, provided in the housing, reinforcing the housing, and forming a flow path for the working fluid in a gas phase. A heat transport device according to claim 4,
A heat further comprising a capillary structure having an opening of a second size smaller than the first size, provided so as to be laminated on the first expanded metal, and generating a capillary force in the liquid working fluid. Transport device. The heat transport device according to claim 5,
The capillary structure includes a second expanded metal having an opening of the second size. The heat transport device according to claim 5,
The capillary structure includes a mesh member having an opening of the second size. The heat transport device according to claim 5,
The capillary structure is
A first capillary member having an opening of the second size;
And a second capillary member having a third size opening smaller than the first size and larger than the second size. A housing;
A working fluid that transports heat by phase change;
A heat transport device comprising a plurality of expanded metals each having an opening of a different size and provided in a stacked manner, reinforcing the housing and forming a flow path for the working fluid. A heat source,
A housing provided in contact with the heat source; a working fluid that transports heat by phase change; and an expanded metal that is provided in the housing and reinforces the housing and forms a flow path of the working fluid. An electronic apparatus comprising the heat transport device. A heat source,
A housing provided in contact with the heat source; a working fluid for transporting heat by phase change; and a first size opening, provided in the housing, for reinforcing the housing, An electronic apparatus comprising: a heat transport device having a first expanded metal that forms a flow path of the working fluid. A heat source,
A housing provided in contact with the heat source, a working fluid that transports heat by phase change, and openings of different sizes are provided in a stacked manner to reinforce the housing and to flow the working fluid. An electronic apparatus comprising: a heat transport device having a plurality of expanded metals forming a path.

Images