JP2006275302A - Heat transportation device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide desired heat transportation capability even at any attitude. <P>SOLUTION: Even when an evaporator is arranged below a condenser and heat load is not applied to the evaporator, working fluid 19 is held by capillary tube force of a channel 14a in the condenser as shown in Fig. 6 (B) to prevent the working fluid 19 from flowing out onto an evaporator side. Consequently, only liquid phase working fluid exists in a liquid phase tube always. As a result, it is possible to prevent running-out of liquid or drying-out when the heat transportation device operates to obtain desired heat transportation capability. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat transport device that absorbs heat of a heating element and transports heat by circulating a working fluid using a capillary force as a driving force, and an electronic device equipped with the heat transport device.

  In order to cool an electronic device such as a PC (Personal Computer), a heat pipe has been conventionally used as a device for transporting heat generated from a heat generating portion of the electronic device to a heat radiating portion. In the heat pipe, the vapor-phase working fluid evaporated by the heat generated in the high-temperature heat generation part (or evaporation part) of the electronic equipment moves to the low-temperature heat dissipation part and is condensed in the heat dissipation part (or condensation part). It becomes a liquid and releases heat, whereby the heating element is cooled.

  Conventionally, for example, there is a heat pipe in which a filter is built in a pipe constituting a flow path of a working fluid (see, for example, Patent Document 1). Since the heat pipe described in Patent Document 1 is mounted on a vehicle, when the vehicle is inclined or affected by gravity or centrifugal force, the liquid refrigerant is one side in the heat pipe. I'll be close to. At this time, the filter is provided in order to prevent the refrigerant vapor on the condensing unit side from flowing back to the evaporating unit side or to quickly return the liquid refrigerant condensed in the condensing unit to the evaporating unit side.

Conventionally, there is a CPL (Capillary Pumped Loop) applying the principle of a heat pipe. The shape is not limited to the pipe shape. For example, in CPL, an evaporator and a condenser are physically separated, and an evaporator and a condenser are a gas phase tube through which a gas phase working fluid flows and a liquid phase tube through which a liquid phase working fluid flows. There is a device connected to each other (see, for example, Patent Document 2). The CPL has an advantage that the influence of gravity is small because the pressure when the working fluid evaporates due to the heat of the heating element and the capillary force of the flow path are used as the driving force of the working fluid.
JP 2000-216578 A (paragraphs [0004] and [0021], FIG. 1) JP 2004-85186 A (paragraph [0041], FIG. 1)

  However, since the device of Patent Document 1 is assumed to be mounted on a vehicle, it is only affected by the inclination of the vehicle and centrifugal force, and the device is turned upside down and the condensing part evaporates. It is not assumed to be located below the part. In particular, it is assumed that a heat transport device for cooling an electronic component built in a portable device or the like is reversed from a certain posture in the vertical direction, that is, in the direction of gravity. Even in such a case, it is desired that heat can be transported by reliably circulating the working fluid.

  In view of the circumstances as described above, it is an object of the present invention to provide a heat transport device capable of exhibiting a desired heat transport capability in any posture and an electronic device equipped with the heat transport device.

  In order to achieve the above object, a heat transport device according to the present invention includes an evaporating portion that circulates the working fluid and absorbs heat by an evaporating action of the working fluid, and a first flow for circulating the working fluid. The working fluid in a state in which a heat load is applied to the evaporation unit and a force is applied to the working fluid in the first flow path toward the evaporation unit. A condensing part that releases heat by the condensing action of the working fluid, and a third flow path that circulates the working fluid evaporated in the evaporating part to the condensing part, A fourth flow path for allowing the working fluid condensed in the condensing unit to flow to the evaporating unit.

  For example, when no heat load is applied to the evaporation section and the working fluid in the first flow path is in a state where the working fluid is directed toward the evaporation section, the working fluid is all It becomes a liquid phase and accumulates in the evaporation part. When a thermal load is started from such a state (hereinafter, the heat transport device is activated), conventionally, there is a possibility that a gaseous working fluid may be mixed into the fourth flow path. It was. However, in the present invention, even in such a state, the condensing unit has the first flow path that causes the capillary force to act on the working fluid, so that the heat transport device can be activated or stopped. It is always possible to reliably cause the liquid-phase working fluid to flow into the fourth flow path and prevent the gas-phase working fluid from being mixed into the fourth flow path. Thereby, even when the evaporation unit is disposed below the condensing unit, the working fluid can be reliably supplied to the evaporation unit via the fourth flow path, and the desired heat transport capability is exhibited. be able to.

  The force that causes the working fluid in the first flow path to go to the evaporation section includes, for example, gravity when the evaporation section is arranged closer to the center of gravity than the first flow path. Alternatively, it is a concept including a body force such as centrifugal force. The center of gravity is the place where the heat transport device is placed, and is the center of the largest source of gravity that acts on the heat transport device. For example, the center of the earth.

  The heat transport device of the present invention may have a structure in which the evaporation section and the condensation section are physically separated, or may be a single plate.

  According to an aspect of the present invention, the first flow path is in a state in which no heat load is applied to the evaporation section and the first flow path is generated in order to generate a capillary force in the working fluid. A plurality of grooves deeper than the depth of the working fluid in a liquid phase state are provided in a state in which a force is exerted so that the working fluid in the path is directed to the evaporation section. Thereby, capillary force can be made to act by the 1st channel.

  According to an aspect of the present invention, the working fluid has a liquid depth of the working fluid in order to weaken or eliminate the capillary force in a state where a thermal load is applied to the evaporation unit. It becomes deeper than the depth of each groove. In order to realize the present invention, the amount of the working fluid may be adjusted in advance so that the depth of the working fluid is deeper than the depth of each groove.

  According to one aspect of the present invention, the evaporation section has a second flow path having a capillary force substantially the same as that of the first flow path. As a result, the capillary force is balanced between the first flow path and the second flow path, so that the working fluid is reliably circulated even if the evaporation section is closer to the center of gravity than the condensing section or vice versa. To achieve the desired heat transport capability.

  According to an aspect of the present invention, the fourth flow path has a connection end connected to the condensing part, and the first flow path is an end disposed near the connection end. Part. For example, there is a concern that the liquid level may move due to vibration of the heat transport device and bubbles may be mixed into the fourth channel, or bubbles may be mixed into the fourth channel when the heat load is excessive. When bubbles are generated in this way, the supply resistance of the liquid-phase working fluid from the condensing unit is provided. According to the present invention, the liquid-phase working fluid is stably supplied from the end of the first flow path. 4 channels can be supplied.

  A heat transport device according to another aspect of the present invention includes an evaporator that circulates a working fluid and absorbs heat by the evaporation of the working fluid, and a first flow path for circulating the working fluid. In a state in which no heat load is applied to the evaporator and a force is exerted on the working fluid in the first flow path toward the evaporation section, the working fluid is subjected to capillary force. A condenser for releasing heat by the condensing action of the working fluid; and a condenser connected between the evaporator and the condenser, the working fluid evaporated by the evaporator being the condenser And a second pipe that is connected between the evaporator and the condenser and that circulates the working fluid condensed in the condenser to the evaporator.

  In the present invention, since the condenser has the first flow path that applies the capillary force to the working fluid, the liquid is surely placed in the second pipe even when the heat transport device is started or stopped. It is possible to prevent the gas phase working fluid from being mixed into the second pipe by flowing the phase working fluid. Accordingly, even when the evaporator is disposed below the condenser, the working fluid can be reliably supplied to the evaporator via the fourth flow path, and a desired heat transport capability is exhibited. be able to.

  An electronic apparatus according to the present invention includes a heating element, an evaporating part that circulates the working fluid, absorbs heat of the heating element by an evaporating action of the working fluid, circulates the working fluid, and heats It is possible to hold the working fluid by a capillary force in a state where no load is applied and a force is applied so that the working fluid in the first flow path is directed to the evaporation section. And a condensing part for releasing heat by the condensing action of the working fluid, a third flow path for circulating the working fluid evaporated in the evaporation part to the condensing part, and the working fluid condensed in the condensing part. And a fourth flow path that circulates to the evaporation section.

  Examples of the heating element include an electronic component such as an IC and a resistor, a heat radiating fin (heat sink), and the like. Electronic devices include computers (in the case of personal computers, laptop computers or desktop computers), PDAs (Personal Digital Assistance), electronic dictionaries, cameras, display devices, audio / visual devices, Examples include mobile phones, game machines, and other electrical appliances.

  As described above, according to the present invention, a desired heat transport capability can be exhibited regardless of the posture.

  FIG. 1 is a plan view of a heat transport device according to an embodiment of the present invention. FIG. 2 is a side view of the heat transport device 10 shown in FIG. 3 is a cross-sectional view taken along the line AA shown in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line BB shown in FIG.

  The heat transport apparatus 10 includes an evaporator 1 that evaporates the working fluid accommodated therein and absorbs heat of the heating element 15, and a condenser 2 that condenses the evaporated working fluid and releases heat. . For example, an IC such as a CPU (Central Processing Unit) is used as the heating element 15. Between the evaporator 1 and the condenser 2, a gas phase pipe 3 for circulating the working fluid evaporated in the evaporator 1 to the condenser 2, and a liquid for circulating the working fluid condensed in the condenser 2 to the evaporator 1. The phase tube 4 is connected. Two gas phase tubes 3 and two liquid phase tubes 4 are provided. Usually, these two are all used, but two are provided so that the heat transport device 10 can operate even if one of the two becomes unusable for some reason, such as dryout. .

  As the working fluid, for example, pure water, ethanol, methanol, acetone, isopropyl alcohol, alternative chlorofluorocarbon, ammonia or the like is used. As the gas phase tube 3, for example, a metal material such as copper, aluminum, or stainless steel is used, but the material is not necessarily limited to a metal and may be a resin material. The liquid phase tube 4 is also made of the same material as the gas phase tube 3.

  As shown in FIG. 2, the evaporator 1 includes a rectangular upper substrate 11 and a lower substrate 12. The upper substrate 11 is made of glass, for example, Pyrex (registered trademark) glass is used. On the other hand, the lower substrate 12 is made of silicon. One end portions 3a and 4a of the gas phase tube 3 and the liquid phase tube 4 described above are inserted into and connected to a connection hole 11b (see FIG. 2) provided in the upper substrate 11. For example, the vapor phase tube 3 and the liquid phase tube 4 and the upper substrate 11 are joined by solder (not shown). On the side of the lower substrate 12 facing the upper substrate 11, a plurality of grooves 12 a constituting a flow path of the working fluid are formed along the longitudinal direction (X direction) of the liquid phase tube 4, for example. The grooves 12 a are respectively provided on both sides of the lower substrate 12 in the Y direction so as to correspond to the two liquid phase tubes 4. On the side of the upper substrate 11 that faces the lower substrate 12, a plurality of grooves 11a that form a flow path of the working fluid are formed in a direction (Y direction) orthogonal to the grooves 12a. Further, on the side of the lower substrate 12 facing the upper substrate 11, a space 12b is formed in a concave shape between the grooves 12a on both sides. During the operation of the heat transport device 10, the space 12b contains a gaseous working fluid that has evaporated through the groove 11a.

  The groove 12a of the lower substrate 12, the groove 11a of the upper substrate 11, the connection hole 11b, and the like are produced by, for example, photolithography, cutting, or laser processing.

  Like the evaporator 1, the condenser 2 includes a rectangular upper substrate 13 and a lower substrate 14. The upper substrate 13 is made of glass, for example, Pyrex (registered trademark) glass is used. On the other hand, the lower substrate 14 is made of silicon.

  As shown in FIGS. 1, 3, and 4, on the side of the upper substrate 13 facing the lower substrate 14, a flow path 13 a for circulating the working fluid flowing out from the other end 3 b of the gas phase tube 3, A space 13b constituting a path is formed. The flow path 13a is formed in a U-shape so that the vapor-phase working fluid flowing out from the other end 3b of the gas-phase tube 3 can be circulated as long as possible to condense. The upper substrate 13 is provided with a reservoir 13d for storing a liquid-phase working fluid. That is, the condenser 2 and the reservoir 13d are integrally provided. The reservoir 13 d communicates with a plurality of grooves 14 c formed in the lower substrate 14. As shown in FIG. 3, the groove 14c extends in the X direction so as to intersect the flow path 13a below the flow path 13a. The other end 4b of the liquid phase tube 4 is inserted into the connection hole 13e and joined to the upper substrate 13 by, for example, solder 16, and the groove 14c communicates with the connection hole 13e. The lower substrate 14 is formed with a plurality of grooves 14a serving as flow paths in a direction (Y direction) perpendicular to the grooves 14c, and the grooves 14a are also communicated with the space 13b. Further, the upper substrate 13 is provided with an injection hole 13c for injecting the working fluid into the condenser 2 when the heat transport device 10 is manufactured. The reservoir 13d communicates with the injection hole 13c. When the working fluid is injected from the injection hole 13c, the working fluid is stored in the reservoir 13d.

  On the upper surface of the upper substrate 13, a lid 5 for covering the injection hole 13c and sealing the inside of the condenser 2 is mounted. The lid 5 is attached to the upper substrate 13 by, for example, an adhesive or a screw (not shown). As a material of the lid 5, for example, a metal such as copper, aluminum, or stainless steel is used, but the material is not necessarily limited to a metal and may be a resin material.

  The flow path 13a, the space 13b, the connection hole 13e, the groove 14c, the reservoir 13d, and the like are provided in two each, corresponding to the fact that two liquid phase tubes 4 and two gas phase tubes 3 are provided, for example. ing. The groove 14a and groove 14c of the lower substrate 14, the flow path 13a, the space 13b, the connection hole 13e, the reservoir 13d, the injection hole 13c, and the like of the upper substrate 13 are produced by, for example, photolithography, cutting, or laser processing. .

  As shown in FIGS. 3 and 4, the width p of one groove 14a of the lower substrate 14 is designed to be equal to or larger than the width q of one groove 14c. Thereby, the capillary force of the groove 14c can be the same as or larger than that of the groove 14a and the channel 13a.

  Further, the width p is set so that the width and depth of the groove 12a formed in the lower substrate 12 of the evaporator 1 are substantially the same. As a result, the capillary force is balanced between the groove 12a and the groove 14c, so that the working fluid is reliably recirculated regardless of whether the evaporator 1 is closer to the center of gravity than the condenser 2 or vice versa. The desired heat transport capability can be exhibited.

The capillary force differs depending on the combination of the material of the lower substrate 12 or 14 and the working fluid. Capillary force is a pressure difference at the interface, and generally the pressure difference ΔP between the inside and outside of a certain surface is expressed by the following equation (1) when the liquid forms a part of a sphere.
ΔP = [(1 / r _x ) + (1 / r _y )] σ (1)
r _x is the radius of curvature in the x direction, r _y is the radius of curvature in the y direction, and σ is the surface tension (see FIG. 5).

As shown in FIG. 5, for example, when the working fluid 19 in the groove 14a, if the width p of the groove of 14a was _{r x, r y} is (the direction perpendicular to the paper surface of FIG. 5) along the depth of the wall 14d Therefore, it is considered that it is sufficiently larger than r _x , that is, 1 / r _y = 0. Further, if the contact angle θ of the liquid is used as the component of the surface tension acting in the vertical direction (vertical direction in FIG. 5), the pressure difference between the inside and outside of the working fluid is expressed as the following equation (2).

ΔP = (2 / q) σ cos θ (2)
Therefore, for example, when it is desired to make the capillary force substantially the same in the groove 11a, the groove 12a, the groove 14a, and the groove 14c, and the lower substrates 12 and 14 are made of the same material, the widths of the grooves 11a, 12a, 14a, and 14c are increased. It should be almost the same.

  FIG. 6 is an enlarged cross-sectional view of the vicinity of the groove 14 a of the condenser 2. In FIG. 4, the size and width p of the groove 14 a and the like are greatly drawn for easy understanding of the drawing. Actually, for example, when the outer diameter of the tube 3 or 4 is 1 to 5 mm, as shown in FIG. 6A, the width p of the groove 14a is set to, for example, 10 to 50 μm, specifically 20 μm. Degree. The width of the wall 14d is almost the same value as p, and the line and space between the wall 14d and the groove 14a is 1: 1. The depth h of the groove is, for example, 50 to 300 μm, specifically about 200 μm. With this size, it is possible to prevent bubbles from entering the groove 14a and the like.

  For example, when the heat transport device 10 is placed so that the evaporator 1 and the condenser 2 are almost at the same height from the ground, or when the condenser 2 is placed below the evaporator 1, FIG. As shown, the amount of the working fluid 19 is adjusted when the heat transport device 10 is manufactured so that the depth of the liquid is deeper than the groove 14a. As described above, when the amount of the working fluid is excessively large, there is a possibility that the heat transport capability is decreased. However, even if the amount of working fluid is large, there is no problem because the heat radiation area in the condenser 2 can be increased by the relatively small groove such as the groove 14a. In the experiment of the present inventor, it has been confirmed that the heat dissipation efficiency is rather improved.

  On the other hand, in a state where the evaporator 1 is not subjected to a heat load and the evaporator 1 is disposed below the condenser 2, the liquid phase working fluid present in the groove 14a is shown in FIG. It is set to be a quantity. That is, even when the force toward the evaporator 1 acts on the working fluid due to gravity when the heat transport device 10 is not in operation, the working fluid 19 applies a capillary force to the working fluid 19 in the groove 14a. Is set to such an amount that can be generated. Thereby, it is possible to prevent the working fluid from flowing out to the evaporator 1 side.

  Further, when the evaporator 1 is under a heat load, the working fluid 19 has a larger area as shown in FIG. 6A regardless of the posture of the heat transport device 10. preferable.

  Note that the phrase “the evaporator 1 is closer to the center of gravity than the condenser 2” means that the condenser 2 is closer to the ground than the evaporator 1, and naturally includes the case where the heat transport device 10 is disposed obliquely.

  A non-operating state in which no heat load is applied to the heat transport device 10 will be described.

  For example, as described above, when the evaporator 1 is disposed below the condenser 2 and the evaporator 1 is not subjected to a heat load, the liquid-phase working fluid has conventionally been an evaporator. May flow out to the side. However, as described in FIG. 6B and as shown in FIG. 7A, in the condenser 2, the working fluid 19 is held by the capillary force of the groove 14a, and the working fluid to the evaporator 1 side is retained. 19 outflow can be prevented. Therefore, there is always only the liquid phase working fluid in the liquid phase pipe 4. As a result, it is possible to prevent the liquid from running out or dry out during operation of the heat transport device 10 described later, and to obtain a desired heat transport capability. In particular, the groove 14 c extends to the vicinity of the connection end 4 b of the liquid phase tube 4. That is, since the end of the groove 14c communicating with the reservoir 13d is in the vicinity of the connection end 4b, the liquid-phase working fluid can be stably supplied into the liquid-phase tube 4 from the groove 14c.

  Further, since the groove 12a and the like in the evaporator 1 and the groove 14a and the like in the condenser 2 have substantially the same capillary force, the condenser 2 is disposed below the evaporator 1 contrary to the above. There is no problem even if it is. That is, as described above, the capillary forces of the two balance each other, so that regardless of the posture of the heat transport device 10, the working fluid 19 can be reliably refluxed to exhibit a desired heat transport capability. it can.

  On the other hand, conventionally, as shown in FIG. 7B, when the evaporator 101 is disposed below the condenser 102 and the evaporator 101 is not subjected to a thermal load, The liquid phase working fluid 19 accumulates in the evaporator 101, the gas phase tube 103, and the liquid phase tube 104 by gravity. In the state shown in FIG. 7B, spaces or bubbles other than the liquid phase working fluid are generated in the liquid phase pipe 104. From this state, when the heat load is applied to the evaporator 1 and the heat transport device 10 is activated, if the heat load is excessive, the liquid phase pipe 104 has a liquid load as shown in FIG. The phase working fluid may be lost. Alternatively, not only in such a situation, but depending on the posture of the heat transport device, for example, the condenser 102 may be disposed below the evaporator, and the gas-phase working fluid may be mixed into the liquid phase tube 104. If a gas phase working fluid is present in the liquid phase tube 104, the working fluid may not be recirculated well, and a desired heat transport capability may not be obtained. However, the heat transport device 10 according to the present embodiment solves these problems.

  Next, the operation of heat transport when a heat load is applied to the heat transport apparatus 10 will be described.

  The heat generated by the heating element 15 is transmitted to the lower substrate 12, and the working fluid flowing through the groove 11a of the evaporator 1 is evaporated by this heat. The evaporated working fluid flows through the gas phase pipe 3 and flows into the flow path 13 a in the condenser 2. The working fluid flows through the flow path 13a and further accumulates in the space 13b via the groove 14a, thereby transferring heat to the upper substrate 13 and the lower substrate 14 to condense. When the upper substrate 13 is made of glass and the lower substrate 14 is made of silicon, the lower substrate 14 particularly contributes to heat conduction due to the difference in thermal conductivity between the two. The heat transmitted to the upper substrate 13 and the lower substrate 14 is released to the outside of the condenser 2. The liquid-phase working fluid accumulated in the space 13b flows into the connection hole 13e via the groove 14a and further flows into the liquid-phase tube 4.

  The working fluid condensed in the condenser 2 flows through the liquid phase tube 4 and flows into the groove 12a in the evaporator 1, and the working fluid is again returned to the groove 11a by the capillary force generated in the working fluid, for example, in the groove 11a. Evaporates due to the heat of the heating element 15. In this way, the heat of the heating element 15 is transported to the condenser 2 side, and the operation as described above is repeated, whereby the heat generated by the heating element 15 is released to the outside of the condenser 2 to cool the heating element 15. can do.

  The heat transport device 10 according to the present embodiment further has the following operational effects due to the presence of the reservoir 13d in the condenser 2.

  For example, the working fluid stored in the reservoir 13d can be prevented from flowing out from the reservoir 13d to the evaporator 1 when the heat transport device 10 is not operating. Thereby, it can prevent that the working fluid of a liquid phase accumulates in the evaporator 1 too much by gravity. As a result, the heat transport device can operate without requiring a starter.

  The presence of the reservoir 13d in the condenser 2 has an advantage that the amount of the working fluid can be easily adjusted when the heat transport device 10 is manufactured. The reason is that since the working fluid in the condenser 2 is almost in the liquid phase, it may be considered that the volume of the reservoir 13d directly affects the amount of working fluid in the liquid phase state. That is, by adjusting the volume of the reservoir 13d, the amount of working fluid can be adjusted, whereby the operating temperature range of the heat transport device 10 and the maximum heat transport amount can be set.

  Further, when there is the reservoir 13d, the internal volume in the condenser 2 can be increased, so that the heat with respect to the variation in the amount of working fluid and the presence of non-condensable gas (for example, gas generated by a chemical reaction between the working fluid and silicon). Although the robustness of the transport device 10 is improved, in the conventional reservoir 13d, a liquid-phase working fluid and a gas-phase working fluid are mixed. When the reservoir is close to the evaporator, the temperature is high and the proportion of the gas phase increases, so the amount of the liquid phase working fluid in the condenser 2 increases and the heat dissipation efficiency decreases. However, the temperature of the reservoir 13d of the heat transport device 10 according to the present embodiment is the temperature of the heat dissipating part (for example, the lower substrate 14) of the condenser 2 that becomes the lowest temperature in the heat transport device 10 by being attached to the condenser 2. It will be near and will be almost filled with a liquid phase. As a result, high robustness can be realized without reducing the condensation efficiency of the condenser 2.

  Alternatively, if the amount of the liquid-phase working fluid in the condenser 2 is reduced in order to maintain or improve the condensation efficiency, it has been easy to cause liquid breakage due to disturbance (vibration or the like) in the past. Since 13d is in the condenser 2, it is difficult for the liquid to run out.

  Furthermore, as described above, if the capillary force of the groove 14c is made larger than that of other parts, for example, the working fluid flowing through the flow path 13a can be guided to the groove 14c and guided to the reservoir 13d. Thereby, it becomes possible to always store the working fluid in the storage section regardless of the posture of the heat transport device 10.

  FIG. 8 is a perspective view showing a heat transport device according to another embodiment of the present invention. FIG. 9 is a plan view of the heat transport device 20 shown in FIG. 10 is a cross-sectional view taken along the line CC shown in FIG. In this embodiment, the description of the same members and functions of the heat transport apparatus 10 according to the above embodiment will be simplified or omitted, and different points will be mainly described.

  The heat transport device 20 includes, for example, two substrates 21 and 22. The upper substrate 21 is made of, for example, glass, and the lower substrate 22 is made of, for example, silicon. The heat transport device 20 includes an evaporation unit 25, a gas phase channel 22a through which a gas phase working fluid flows, a condensing unit 27, a liquid phase channel 22b through which a liquid phase working fluid flows, and a reservoir 21d. Have. The reservoir 21d, the evaporation channel 21a provided in the evaporation unit 25, and the condensation channel 21b provided in the condensation unit 27 are formed in the upper substrate 21. The gas phase channel 22a, the liquid phase channel 22b, the groove 22c provided between the reservoir 21d and the condensation channel 21b, the groove 22d provided in the evaporation unit 25, and the groove 22e provided in the condensation unit 27 are: Each is formed on the lower substrate 22.

  The groove 22c and the groove 22e are formed with the smallest flow path volume in the condensing part 27. Thereby, the largest capillary force in the condensing part 27 is generated. The groove 22d of the evaporation section 25 is formed to have a depth and a width that have substantially the same capillary force as the groove 22c and the groove 22e, for example.

  Also in the heat transport device 20 according to the present embodiment, when the evaporator 25 is disposed below the condenser 27 when not in operation, the liquid phase as shown in FIG. Set to the amount of working fluid. That is, when the heat transport device 20 is in such a state, the amount of the working fluid is set in advance at the time of manufacture so that the depth of the liquid phase working fluid becomes shallower than the groove 22e or the groove 22c. Thereby, even if the heat transport apparatus 20 is placed in any posture, it is possible to prevent the liquid from running out or dry out. During operation, the heat transport device 20 can be in any state as shown in FIGS. 5A and 5B, similar to the heat transport device 10.

  The present invention is not limited to the embodiment described above, and various modifications are possible.

  The shapes of the evaporator 1, the condenser 2, the heat transport device 20, and the like described in the above embodiments are rectangular plates. However, the shape and size are not limited. For example, it can be formed in a disk shape or an elliptical plate shape. Moreover, it may have a three-dimensional thickness instead of a plate shape.

  Further, the arrangement, shape, length, and the like of the grooves 11a, 13a, 14a, and 14c that constitute the flow path of the working fluid are not limited to the embodiment. For example, the cross-sectional shape of the groove 14c or the like can be V-shaped. However, when the shape is V-shaped, the width becomes wider toward the top of the groove. Therefore, it is preferable to form a V-shaped groove having such a width that bubbles do not enter. In addition, the width of the upper part can be made wider by making the wall 14d stepped.

  Further, although the upper substrate 11 and the like are glass substrates and the lower substrate 12 and the like are silicon substrates, for example, materials such as copper, aluminum, stainless steel, or a combination thereof may be used.

It is a top view which shows the heat transport apparatus which concerns on one embodiment of this invention. It is a side view of the heat transport apparatus shown in FIG. It is the sectional view on the AA line shown in FIG. It is the BB sectional view taken on the line shown in FIG. It is a figure for demonstrating the surface tension which acts on a working fluid. It is an expanded sectional view near the groove | channel which generate | occur | produces the capillary force of a condenser, (A) is a state in which a liquid level is above the upper end of a wall, (B) shows the state in which a liquid level is below the upper end of a wall. . It is the schematic diagram which compared operation | movement of the heat transport apparatus with a prior art and this Embodiment, (A) shows this Embodiment, (B) and (C) show a conventional thing. It is a perspective view which shows the heat transport apparatus which concerns on other embodiment of this invention. It is a top view of the heat transport apparatus shown in FIG. It is CC sectional view taken on the line shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Evaporator 2 ... Condenser 3 ... Gas phase tube 4 ... Liquid phase tube 3a, 4a ... One end part 3b, 4b ... Other end part 10, 20 ... Heat transport apparatus 11a, 12a, 13a, 14a, 14c, 21a, 21b, 22a, 22b, 22c, 22d, 22e ... groove (flow path)
12b, 13b ... space (flow path)
DESCRIPTION OF SYMBOLS 15 ... Heat generating body 19 ... Working fluid 25 ... Evaporating part 27 ... Condensing part

Claims (7)

An evaporating part for circulating the working fluid and absorbing heat by the evaporating action of the working fluid;
A first flow path for circulating the working fluid, wherein the working fluid in the first flow path is directed to the evaporation section in a state where no heat load is applied to the evaporation section; A condensing part capable of holding the working fluid by a capillary force in a state where a large force is working, and releasing heat by a condensing action of the working fluid;
A third flow path for circulating the working fluid evaporated in the evaporation section to the condensation section;
And a fourth flow path for allowing the working fluid condensed in the condensing part to flow to the evaporating part. The heat transport device according to claim 1,
The first flow path is in a state in which no heat load is applied to the evaporation section in order to generate a capillary force in the working fluid, and the working fluid in the first flow path is not in the evaporation section. A heat transport device having a plurality of grooves deeper than the depth of the working fluid in a liquid phase in a state where a force toward the head is working. The heat transport device according to claim 2,
The working fluid has a depth of the working fluid that is deeper than the depth of each of the grooves in order to weaken or eliminate the capillary force in a state where a thermal load is applied to the evaporation section. Heat transport device. The heat transport device according to claim 1,
The heat transport apparatus according to claim 1, wherein the evaporation section includes a second flow path having substantially the same capillary force as the first flow path. The heat transport device according to claim 4,
The fourth flow path has a connection end connected to the condensing part,
The heat transport device according to claim 1, wherein the first flow path has an end disposed in the vicinity of the connection end. An evaporator that circulates the working fluid and absorbs heat by the evaporation of the working fluid;
There is a flow path for circulating the working fluid, and there is a force that the working fluid in the first flow path is directed to the evaporation section in a state where no heat load is applied to the evaporator. In the working state, the working fluid can be held by capillary force, and a condenser that releases heat by the condensing action of the working fluid;
A first pipe connected between the evaporator and the condenser and allowing the working fluid evaporated in the evaporator to flow to the condenser;
And a second pipe connected between the evaporator and the condenser and configured to circulate the working fluid condensed in the condenser to the evaporator. A heating element;
An evaporating section that circulates the working fluid and absorbs heat of the heating element by an evaporating action of the working fluid;
In a state where the working fluid is circulated, a heat load is not applied to the evaporation unit, and a force is applied so that the working fluid in the first flow path is directed to the evaporation unit. A condensing part capable of holding the working fluid by capillary force and releasing heat by the condensing action of the working fluid;
A third flow path for circulating the working fluid evaporated in the evaporation section to the condensation section;
An electronic device comprising: a fourth flow path for allowing the working fluid condensed in the condensing unit to flow to the evaporating unit.

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