JP2011038700A - Heat transport unit, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat transport unit and an electronic apparatus capable of flexibly corresponding to the type of heating element to be a cooling object, and capable of transporting heat taken from the heating element at high speed. <P>SOLUTION: The heat transport unit (1) includes an upper plate (2), a lower plate (3) facing the upper plate (2), an internal space (4) formed by the upper plate (2) and the lower plate (3) and capable of sealing a refrigerant, a plurality of passages (5) partitioning the internal space (4) along a first direction, and a plurality of grooves (10) set on a bottom face of the internal space (4). The plurality of passages (5) and the plurality of grooves (10) are connected by capillary flow passages (12), (13) in areas of one part, and they are separated by partitions (11) in other areas. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat transport unit and an electronic device that efficiently transports heat received from a heating element such as a semiconductor integrated circuit, an LED element, a power device, and an electronic component.

  Electronic parts such as semiconductor integrated circuits, LED elements, and power devices are used in electronic equipment, industrial equipment, and automobiles. These electronic components are heating elements that generate heat due to a current flowing inside. If the heat generation of the heating element exceeds a certain temperature, there is a problem that the operation cannot be guaranteed, which adversely affects other parts and the housing, and as a result, the performance of the electronic device or the industrial device itself may be deteriorated.

  In order to cool such a heat generating body, the cooling device using the heat pipe which has the cooling effect by vaporization and condensation of the enclosed refrigerant | coolant is proposed.

  The heat pipe takes heat from the heating element and moves when the refrigerant sealed inside vaporizes. The vaporized refrigerant is cooled and condensed by heat dissipation, and the condensed refrigerant recirculates again. By repeating this vaporization and condensation, the heat pipe cools the heating element.

  The cooling mechanism of the heat pipe is transported by a heat receiving member that takes away the heat from the heating element (the refrigerant evaporates), a heat transport member that transports the taken heat (the evaporated refrigerant moves and the condensed refrigerant flows back), And a heat radiating member that dissipates the heat (cools and condenses the evaporated refrigerant). Here, Patent Document 1 proposes an example of a heat pipe. Patent Document 1 discloses a technique in which a refrigerant vaporized by heat from a heating element is moved to a separate member through a pipe, and the separate member is cooled by a secondary cooling member such as a heat sink. Patent Document 2 discloses an electronic substrate having a cooling function.

In recent years, electronic components to be cooled are not only relatively large semiconductor integrated circuits such as CPUs (Central Processing Units) and dedicated ICs, but also very small electronic devices such as high-intensity LEDs (Light Emitting Devices). Often parts. Such a small electronic component is not only small in size, but often includes a plurality of electronic components. For this reason, a cooling device using a heat pipe often needs to cool a plurality of small electronic components.
JP 2004-37001 A JP-A-11-101585

  In cooling devices using heat pipes, it is important to improve the cooling capacity by improving the heat transport efficiency (determined by the speed of vaporized refrigerant diffusion and refrigerant reflux and the number of cycles per unit period). is there.

  The heat transport member included in the heat pipe in the prior art is a pipe including a wick, and it is difficult for the refrigerant evaporated from the heat receiving member to enter the pipe, or the refrigerant condensed by the heat radiating member enters the pipe. It has the problem that it is difficult. This is because it is affected by the physical connection structure between the heat receiving member or the heat radiating member and the pipe. For this reason, the speed of heat transport in a pipe provided with a wick that is a heat transport member is low.

  The heat pipe of Patent Document 1 uses the entire internal space of a flat plate material as a heat transport member. For this reason, the entire internal space diffuses the vaporized refrigerant and recirculates the condensed refrigerant. If the heating element to be cooled is a large semiconductor integrated circuit, a certain heat transport efficiency can be obtained even if the entire internal space is used as a heat transport member. However, when cooling a plurality of small heat generating elements such as LEDs, the heat generating area of the heat generating element and the heat receiving and heat transporting area of the heat pipe are unbalanced, and the heat transport efficiency with respect to the size and capacity of the heat pipe is low. bad. This is because the amount of refrigerant increases with respect to the amount of heat generated by the heating element, and the efficiency of vaporization of the refrigerant deteriorates. The efficiency of reflux is also reduced.

  Patent Document 2 discloses a plate heat pipe in which pores are aligned. In the case of a plate heat pipe disclosed in Patent Document 2, each pore performs diffusion of vaporized refrigerant and reflux of condensed refrigerant. However, depending on the number of heating elements in contact with the plate-type heat pipe and the amount of heat generation, the pores are divided into pores with high heat transport and pores with poor heat transport. The heat transport efficiency is determined by the diffusion rate of the vaporized refrigerant and the recirculation speed of the condensed refrigerant and the number of cycles. At this time, more refrigerant is required for cooling the heating element having a high calorific value. In the plate-type heat pipe of Patent Document 2, since the refrigerant is sealed for each pore, the refrigerant is divided into pores with insufficient refrigerant or excess refrigerant, and heat transport as a whole plate-type heat pipe is performed. Inefficiency.

  Moreover, since the plate-type heat pipe of Patent Document 2 has only pores as gaps, it can diffuse the vaporized refrigerant, but cannot efficiently recirculate the condensed refrigerant. In addition, although it is required to transport the heat of the heating element as a heat source to a position away from the heating element at high speed, an electronic substrate having a cooling function as disclosed in Patent Document 2 or a flat plate-shaped heat Pipes cannot transport heat with high efficiency.

  This is because the vaporized refrigerant that diffuses through the electronic board or the flat plate-shaped heat pipe collides with the refrigerant that condenses and recirculates, so that the respective speeds of the diffusion of the vaporized refrigerant and the reflux of the condensed refrigerant This is because of a decrease.

  Alternatively, a metal plate such as copper or aluminum is widely used as a heat transport member. However, since the metal plate can only transport heat according to the thermal conductivity, there is a limit to improving the heat transport efficiency. There is.

  As described above, in the cooling device using the heat pipe of the prior art, heat cannot be transported at a high speed while flexibly supporting various heating elements.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a heat transport unit and an electronic device that can flexibly cope with the type of heating element to be cooled and can transport heat taken from the heating element at high speed.

  In view of the above problems, the heat transport unit of the present invention is formed by an upper plate, a lower plate facing the upper plate, an upper plate and a lower plate, and an internal space capable of enclosing a refrigerant and an internal space are defined as the first space. A plurality of passages divided along the direction, and a plurality of grooves provided on the bottom surface of the internal space, wherein the plurality of passages and the plurality of grooves are connected to each other by a capillary channel in some areas, and others Are separated by partition walls.

  The heat transport unit of the present invention can efficiently and efficiently transport the heat from the heating element in the first direction which is a certain direction. In particular, even when the heating element is very small compared to the heat transport unit, heat is transported in each of the passages divided into a plurality of sections, so that heat transport is performed in accordance with the heat generation amount of the heating element. Is called.

  In addition, when heat transport is insufficient with only the refrigerant sealed in a certain passage, the refrigerant is exchanged through the communication passage, so the heat transport efficiency in the passage that is the main body of heat transport is high. Increase in flexibility.

  Further, the vaporized refrigerant diffuses in the passage, and the condensed refrigerant flows back through the groove, so that the vaporized refrigerant and the condensed refrigerant do not collide or interfere with each other. As a result, the moving speeds of the vaporized refrigerant and the condensed refrigerant are increased, and the heat transport unit can transport heat with high efficiency. At this time, the condensed refrigerant can go back and forth between the passage and the groove separated by the partition wall by the capillary channel provided at the end of the heat transport unit.

  Since at least a part of the passage and the groove is subjected to surface treatment such as chamfering or metal plating, the movement of the vaporized refrigerant and the condensed refrigerant becomes smooth.

  A heat transport unit according to a first aspect of the present invention includes an upper plate, a lower plate facing the upper plate, an upper plate and a lower plate, and an internal space in which a refrigerant can be sealed, and an internal space. A plurality of passages divided along one direction, and a plurality of grooves provided on the bottom surface of the internal space, the plurality of passages and the plurality of grooves are connected by a capillary channel in a partial region, It is separated by a partition in the other region.

  With this configuration, the vaporized refrigerant moves in the passage, and the condensed refrigerant moves in the groove. Since the passage and the groove are separated by the partition wall, the vaporized refrigerant and the condensed refrigerant do not interfere or collide with each other during movement.

  In the heat transport unit according to the second invention of the present invention, in addition to the first invention, the upper plate and the lower plate have a flat plate shape, the internal space also has a flat plate shape, and the plurality of passages The plurality of grooves are formed in the upper plate side space in the space, and are formed on the lower plate side in the internal space while facing the plurality of passages through the partition walls.

  With this configuration, the movement of the evaporated refrigerant and the movement of the condensed refrigerant are performed via different passages. Further, the refrigerant can reciprocate and circulate because the passage for moving the evaporated refrigerant and the groove for moving the condensed refrigerant face each other. As a result, the heat transport unit can transport heat along the first direction.

  In the heat transport unit according to the third aspect of the present invention, in addition to the first or second aspect, each of the plurality of passages faces at least one of the plurality of grooves.

  With this configuration, the heat transport unit can efficiently transport the condensed refrigerant.

  In the heat transport unit according to the fourth aspect of the present invention, in addition to any of the first to third aspects, the plurality of grooves are provided along the first direction.

  With this configuration, the heat transport unit moves the condensed refrigerant along the first direction.

  In the heat transport unit according to the fifth aspect of the present invention, in addition to any one of the first to fourth aspects, the plurality of passages and the plurality of grooves are one end along the first direction. It has a first end and a second end opposite to the first end, and the capillary channel is provided in each of the first end and the second end.

  With this configuration, the heat transport unit can receive heat at one end and discard the heat at the other end.

  In the heat transport unit according to the sixth invention of the present invention, in addition to any of the first to fifth inventions, the partition wall has a plurality of internal through holes, and the plurality of internal through holes are capillary channels. Form.

  With this configuration, a capillary channel can be easily formed.

  In the heat transport unit according to the seventh aspect of the present invention, in addition to any of the first to sixth aspects, at least one of the passage and the groove has a chamfered corner.

  With this configuration, the passage and the groove efficiently move the evaporated refrigerant and the condensed refrigerant.

  In the heat transport unit according to the eighth aspect of the present invention, in addition to any one of the first to seventh aspects, at least one of the passage and the groove is metal-plated.

  With this configuration, the passage and the groove efficiently move the evaporated refrigerant and the condensed refrigerant.

  In the heat transport unit according to the ninth aspect of the present invention, in addition to the eighth aspect, the metal plating is selected from at least one metal of gold, silver, copper, aluminum, nickel, cobalt, and alloys thereof.

  With this configuration, the passage and the groove efficiently move the evaporated refrigerant and the condensed refrigerant.

  In the heat transport unit according to the tenth aspect of the present invention, in addition to any one of the first to ninth aspects, the heat transport unit further includes a communication path through which the refrigerant can move between the plurality of paths.

  With this configuration, since the refrigerant can be exchanged between the passages, a passage that requires more refrigerant can obtain a necessary amount of refrigerant than a passage that does not.

  In the heat transport unit according to the eleventh invention of the present invention, in addition to any of the fifth to tenth inventions, the capillary channel includes a passage and a groove at the first end and the second end. The refrigerant is vaporized by receiving heat from the heating element at the first end, the vaporized refrigerant diffuses from the first end to the second end of the passage, and the vaporized refrigerant at the second end is Condensed and condensed refrigerant recirculates from the passage to the groove via the capillary channel, and the condensed refrigerant recirculated to the groove moves from the second end to the first end and further at the first end. Return to the passageway.

  With this configuration, the heat transport unit can efficiently transport the heat of the heating element along the first direction. Furthermore, since the vaporized refrigerant and the condensed refrigerant do not interfere with each other or collide with each other, the heat transport efficiency is also high.

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

  In addition, the heat pipe in this specification refers to the cooling of the heating element by repeating that the refrigerant sealed in the internal space is vaporized by receiving heat from the heating element and the evaporated refrigerant is cooled and condensed. Means a member, component, apparatus, or device that realizes the function to perform. In addition, the heat transport unit in the present specification means a member, component, apparatus, or device having a function of transporting heat from a heating element by moving a refrigerant.

(Embodiment 1)
(Conceptual explanation of heat pipe)
Since the heat transport unit of the present invention utilizes the function and operation of the heat pipe, the concept of the heat pipe will be described first.

  The heat pipe encloses a refrigerant inside, and a surface serving as a heat receiving surface is in contact with a heating element such as an electronic component. The internal refrigerant is vaporized by receiving heat from the heating element, and takes the heat of the heating element when vaporized. The vaporized refrigerant moves through the heat pipe. This movement carries the heat of the heating element. The moved and evaporated refrigerant is cooled and condensed on a heat radiation surface or the like (or by a secondary cooling member such as a heat sink or a cooling fan). The refrigerant that has condensed into a liquid recirculates inside the heat pipe and moves to the heat receiving surface again. The refrigerant that has moved to the heat receiving surface is vaporized again and takes the heat of the heating element.

  The heat pipe cools the heating element by repeating the vaporization and condensation of the refrigerant. For this reason, it is preferable that the heat pipe has a vapor diffusion path for diffusing the vaporized refrigerant and a capillary flow path for refluxing the condensed refrigerant.

  The heat pipe has a cylindrical shape and has a structure in which the refrigerant vaporized in the vertical direction is diffused and the refrigerant condensed in the vertical direction is recirculated, and the heat receiving portion in contact with the heating element and the cooling for cooling the refrigerant Some have a structure in which the part is separate and connected by a pipe.

  Heat pipes having these structures are unsuitable when the volume is large (particularly, the volume tends to increase in the vertical direction) and the mounting space is narrow. For this reason, a flat and thin heat pipe is often desired. For this reason, a flat heat pipe has also been proposed.

(Overview)
An overall outline of the heat transport unit according to Embodiment 1 will be described with reference to FIGS.

  FIG. 1 is a perspective view of a heat transport unit according to Embodiment 1 of the present invention. FIG. 2 is a top view of the heat transport unit according to Embodiment 1 of the present invention. FIG. 3 is a side sectional view of the heat transport unit according to Embodiment 1 of the present invention.

  The heat transport unit 1 includes an upper plate 2, a lower plate 3 facing the upper plate 2, and an internal space 4 formed by the upper plate 2 and the lower plate 3. The internal space 4 has a plurality of passages 5, 6, 7, 8, 9 that divide the internal space 4 along the first direction, and has a plurality of grooves 10 provided on the bottom surface of the internal space 4. . The plurality of passages 5 to 9 and the groove 10 are connected to each other by the capillary channels 12 and 13 in some areas, and are separated by the partition wall 11 in other areas. The partition wall 11 separates the internal space 4 vertically (the upper plate 2 is on the upper side and the lower plate 3 is on the lower side).

  The heat transport unit 1 has a plurality of passages 5 to 9 on the upper side of the internal space 4 as shown in FIG. Furthermore, the heat transport unit 1 has a groove 10 facing the passages 5 to 9 below the internal space 4 with a partition wall 11 therebetween. In addition, FIG. 1 has shown the state by which the edge part of the heat transport unit 1 was cut, and the capillary flow path does not appear in FIG.

  FIG. 2 shows a state in which the heat transport unit 1 is viewed from above, and capillary channels 12 and 13 are shown at both ends of the heat transport unit 1. In FIG. 2, the passage 5 formed in the internal space 4 is indicated by a broken line.

  By combining FIG. 1 and FIG. 2, the overall image of the heat transport unit 1 becomes clear. The heat transport unit 1 has an internal space 4 sandwiched between an upper plate 2 and a lower plate 3 facing the upper plate 2, and the internal space is vertically separated by a partition wall 11 other than the capillary channels 12 and 13. The heat transport unit 1 has a plurality of divided passages 5 to 9 between the upper plate 2 and the partition wall 11. Furthermore, the heat transport unit 1 has a groove 10 in the lower plate 3, and the passages 5 to 9 and the groove 10 face each other with a partition wall therebetween. The passages 5 to 9 and the groove 10 are along the same first direction (longitudinal direction of the heat transport unit 1).

  Here, each of the upper plate 2 and the lower plate 3 preferably has a flat plate shape. In addition, each of the upper plate 2 and the lower plate 3 is preferably a square having a longitudinal direction and a short direction. Since each of the upper plate 2 and the lower plate 3 has a flat plate shape, the internal space 4 also has a flat plate shape. In addition, the heat transport unit 1 also has a flat plate shape and has a longitudinal direction and a lateral direction (the longitudinal direction is the first direction that is the direction of the passages 5 to 9 and the groove 10). A plurality of passages 5 to 9 along the longitudinal direction of the heat transport unit 1 are formed in the flat internal space 4. With the passages 5 to 9 and the groove 10, the heat transport unit 1 reciprocates the vaporized refrigerant and the condensed refrigerant along the longitudinal direction. By the reciprocation of the vaporized refrigerant and the condensed refrigerant in the longitudinal direction, the heat transport unit 1 can transport the heat of the heating element in the longitudinal direction.

  The internal space 4 can enclose a refrigerant therein, and the encapsulated refrigerant is vaporized by heat from the heating element. The vaporized refrigerant condenses when cooled.

  The thermal cooling unit 1 diffuses the vaporized refrigerant in the passages 5 to 9 and causes the condensed refrigerant to recirculate in the groove 10.

  The heat transport mechanism of the heat transport unit 1 will be described with reference to FIG.

  FIG. 3 shows a cross section of the heat transport unit 1 cut along the first direction. The internal space 4 on the upper plate 2 side has a passage 5. The passage 5 faces the groove 10 with a partition wall 11 therebetween. The groove 10 is provided in the lower plate 3 along the first direction. The heat transport unit 1 has capillary channels 12 and 13 at both ends thereof. The passage 5 and the groove 10 are connected only in the region where the capillary channels 12 and 13 are present. That is, the refrigerant can move only in the capillary channels 12 and 13.

  The heat transport unit 1 is in thermal contact with the heating element 20 on the bottom surface of the lower plate 3 at one end. The heating element 20 is an element that emits heat, such as an LED element, an LSI, an IC, or a discrete element. The heating element 20 may be in thermal contact with the surface of the upper plate 2.

  The refrigerant accumulates in a condensed state on the first end 21 side of the groove 10. The condensed refrigerant moves in the capillary channel 12 by capillary action, and the condensed refrigerant moves from the groove 10 to the passage 5. As a result, the condensed refrigerant accumulates on the first end 21 side of the passage 5.

  Since the heat generating body 20 applies heat to the first end portion 21, the condensed refrigerant in the first end portion 21 is vaporized. The vaporized refrigerant moves along the first direction in the passage 5. That is, the vaporized refrigerant moves from the first end 21 to the second end 22. By the movement of the vaporized refrigerant, the heat transport unit 1 can transport the heat received from the heating element 20 along the first direction.

  The vaporized refrigerant reaches the second end 22. The vaporized refrigerant that has reached the second end 22 is cooled at the second end 22. By being cooled, the vaporized refrigerant is condensed again. The refrigerant condensed at the second end 22 moves from the passage 5 to the groove 10 by a capillary phenomenon in the capillary channel 13. The condensed refrigerant that has moved to the groove 10 moves from the second end 22 toward the first end 21 in the groove 10. This is because the groove 10 is a very fine groove and the groove 10 moves the liquid refrigerant. That is, in the groove 10, the condensed refrigerant moves from the second end portion 22 toward the first end portion 21 by a phenomenon close to a capillary phenomenon. When the condensed refrigerant returns to the first end portion 21, the condensed refrigerant again takes heat from the heating element 20 and vaporizes.

  Thus, the vaporized refrigerant moves in the passage 5 from the first end portion 21 toward the second end portion 22, and the condensed refrigerant flows into the groove from the second end portion 22 toward the first end portion 21. Move 10. It is as the movement path | route of the arrow described in FIG.

  As described above, the heat transport unit 1 can continuously transport the heat from the heating element 20 by repeating the reciprocating movement of the refrigerant along the longitudinal direction of the heat transport unit 1.

  Here, the evaporated refrigerant (which is a gas) moves in the passage 5, and the condensed refrigerant (which is a liquid) moves in the groove 10. For this reason, the refrigerant that is gas and the refrigerant that is liquid do not collide or interfere with each other during movement. The space in which the refrigerant moves is not interfered by being partitioned by the partition wall 11, and the refrigerant condensed by the capillary flow paths 12 and 13 provided at both ends passes through the capillary flow paths 12 and 13 and the grooves 10 and 10. Because it moves between the two. In particular, at the first end portion 21, the vaporized refrigerant moves through the passage 5 from the first end portion 21 to the second end portion 22, whereby the atmospheric pressure in the vicinity of the first end portion 21 of the passage 5 decreases. In accordance with the decrease in the atmospheric pressure, the refrigerant condensed in the capillary channel 12 from the groove 10 moves. On the other hand, at the second end 22, the condensed refrigerant is moved by the pressure of the refrigerant moving through the passage 5 and moves through the capillary channel 13. Thus, the condensed refrigerant is likely to recirculate in each of the capillary channels 12 and 13 by the moving pressure of the vaporized refrigerant. Such a physical pressure forms a movement path such as an arrow shown in FIG.

  By this moving path, both the evaporated refrigerant and the condensed refrigerant can move at high speed. That is, the refrigerant can reciprocate between the first end 21 and the second end 22 at high speed. Since the reciprocating movement of the vaporized refrigerant and the condensed refrigerant is high speed, the heat transport unit 1 can transport the heat received from the heating element 20 at high speed. As a result, the heating element 20 can be efficiently cooled.

  As described above, the heat transport unit 1 can transport the heat of the heating element 20 with high efficiency.

  Next, the detail of each part is demonstrated.

(Upper plate)
The upper plate 2 will be described. FIG. 4 is a front view of the upper plate according to the first embodiment of the present invention.

  The upper plate 2 has a flat plate shape, and preferably has a rectangular shape having a short side direction and a long side direction. Of course, it may have a shape that is partially different from a square, or may be curved or bent.

  The upper plate 2 is made of metal, resin, etc., but is made of metal having high thermal conductivity or high rust prevention (or durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. Preferably it is formed.

  The upper plate 2 forms an internal space 4 together with the lower plate 3. For example, the upper plate 2 and the lower plate 3 have convex portions and wall materials for forming the internal space 4 on the periphery thereof, and the upper plate 2 and the lower plate 3 are formed by these convex portions and wall materials. As a result, the internal space 4 is formed between the upper plate 2 and the lower plate 3. When being joined to the lower plate 3, these convex portions and wall materials become side walls around the internal space 4. Of course, these convex portions and wall materials may be separate members or the same members as the upper plate 2.

  The upper plate 2 may have side walls 30 for forming a plurality of passages. When the upper plate 2 is joined to the lower plate 3, the side walls 30 divide the internal space 4 to form a plurality of passages 31.

  It is also preferable that the upper plate 2 has metal plating on at least a surface in contact with the internal space 4 (surface through which the vaporized refrigerant passes). This is because the metal plating is applied to promote the diffusion of the vaporized refrigerant. The metal plating may be selected from at least one of gold, silver, copper, aluminum, nickel, cobalt, and alloys thereof. Of course, any of single layer plating, multilayer plating, electrolytic plating, and non-electrolytic plating may be used.

  The upper plate 2 has a name “upper”, but does not have to be physically facing upward, but is a name for convenience. The heating element may be in contact with the upper plate 2 or the lower plate 3.

  Further, the upper plate 2 includes an inlet 32 for injecting a refrigerant. When the upper plate 2 and the lower plate 3 are joined to form the internal space 4, it is necessary to enclose the refrigerant in the internal space 4. The injection port 32 is sealed after injecting the coolant.

  Note that the refrigerant may be sealed from the inlet after joining, or may be sealed when joining. Moreover, it is preferable that the refrigerant is sealed under vacuum or reduced pressure. By being performed under vacuum or reduced pressure, the internal space 4 is in a vacuum or reduced pressure state and the refrigerant is sealed. When the pressure is reduced, the refrigerant vaporization / condensation temperature becomes low, and there is an advantage that the refrigerant vaporization / condensation repeats actively.

(Lower plate)
Next, the lower plate 3 will be described. FIG. 5 is a front view of the lower plate in the first embodiment of the present invention, and FIG. 6 is an enlarged view of a part of the lower plate in the first embodiment of the present invention.

  The lower plate 3 has a flat plate shape, and preferably has a rectangular shape having a short side direction and a long side direction. In particular, since the lower plate 3 is joined to face the upper plate 2, it is also preferable that the lower plate 3 has substantially the same shape and the same area as the upper plate 2. However, the lower plate 3 may have an area or shape different from that of the upper plate 2 as long as it can be joined to the upper plate 2 to form the internal space 4. Of course, it may have a shape that is partially different from a square, or may be curved or bent.

  The lower plate 3 is made of metal, resin, etc., but is made of metal having high thermal conductivity or high rust prevention (or durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. Preferably it is formed.

  Since the lower plate 3 is joined to the upper plate 2 to form an internal space, the lower plate 3 may have a convex portion or a wall material for forming the internal space 4 at the periphery thereof. When being joined to the upper plate 2, these convex portions and wall materials become side walls around the internal space 4. Of course, these convex portions and wall materials may be separate members from the lower plate 3 or the same members. Each of the upper plate 2 and the lower plate 3 may have a convex portion or a wall material, or only one of the upper plate 2 and the lower plate 3 has a convex portion or a wall material. May be.

  The lower plate 3 may have a side wall 34 for forming a plurality of passages. When the lower plate 3 is joined to the upper plate 2, the side walls 34 divide the internal space 4 to form a plurality of passages 5. The side wall 34 may be separate from the side wall 32 included in the upper plate 2 or may be integrated. Of course, the side wall 34 may be separate from or integrated with the lower plate 3.

  In addition, the lower plate 3 includes a plurality of grooves 10 on the surface facing the internal space 4. The plurality of grooves 10 are formed in the lower plate 3 by cutting or the like. The groove 10 is formed along the first direction (longitudinal direction of the lower plate 3). There are a plurality of grooves 10, and each of the plurality of passages 5 opposes at least one groove 10 with a partition wall 11 therebetween.

  It is also preferable that the lower plate 3 has metal plating on at least a surface in contact with the internal space 4 (surface through which the vaporized refrigerant passes). This is because the metal plating is applied to promote the diffusion of the condensed refrigerant. The metal plating may be selected from at least one of gold, silver, copper, aluminum, nickel, cobalt, and alloys thereof. Of course, any of single layer plating, multilayer plating, electrolytic plating, and non-electrolytic plating may be used.

  The lower plate 3 has a name “lower”, but does not have to face physically downward, but is a name for convenience. The heating element may be in contact with the lower plate 3 or the upper plate 2.

  The lower plate 3 includes an inlet 35 for injecting a refrigerant. When the upper plate 2 and the lower plate 3 are joined to form the internal space 4, it is necessary to enclose the refrigerant in the internal space 4. The injection port 35 is sealed after injecting the coolant.

  Note that the refrigerant may be sealed from the inlet after joining, or may be sealed when joining. Moreover, it is preferable that the refrigerant is sealed under vacuum or reduced pressure. By being performed under vacuum or reduced pressure, the internal space 4 is in a vacuum or reduced pressure state and the refrigerant is sealed. When the pressure is reduced, the refrigerant vaporization / condensation temperature becomes low, and there is an advantage that the refrigerant vaporization / condensation repeats actively.

(Intermediate plate)
Next, the intermediate plate will be described.

  It is also preferable that the heat transport unit 1 includes one or more intermediate plates that are sandwiched and stacked between the upper plate 2 and the lower plate 3.

  An internal space 4 formed by joining the upper plate 2 and the lower plate 3 facing the upper plate 2 is separated into upper and lower portions by a partition wall 11. Furthermore, both ends of the partition wall 11 have capillary channels 12 and 13, and the capillary channels 12 and 13 connect the passage 5 and the groove 10.

  The intermediate plate forms the partition wall 11 and the capillary channels 12 and 13. The intermediate plate may be singular or plural.

  When the intermediate plate is singular, the single intermediate plate forms the partition wall 11 and the capillary channels 12 and 13. The capillary channels 12 and 13 are formed by fine internal through holes provided at both ends of the intermediate plate.

  The intermediate plate will be described with reference to FIGS. Here, description will be made on the assumption that the heat transport unit 1 includes a plurality of intermediate plates. Further, the plurality of intermediate plates have different structures.

  FIG. 7 is a front view of the intermediate plate according to Embodiment 1 of the present invention. FIG. 8 is an enlarged view of a part of the intermediate plate in the first embodiment of the present invention. 7 and 8 show the intermediate plate 40 having a structure for forming the partition wall 11.

  The intermediate plate 40 is sandwiched and stacked between the upper plate 2 and the lower plate 3, and has a shape and a size facing the upper plate 2 and the lower plate 3. That is, the intermediate plate 40 is preferably a square having a short side direction and a long side direction, and preferably has substantially the same size as the upper plate 2 and the lower plate 3.

  The intermediate plate 40 includes a plate portion 41 and an internal through hole 42.

  The plate part 41 separates the internal space 4 vertically when the internal space 4 is formed between the upper plate 2 and the lower plate 3. Specifically, the plate part 41 separates the passage 5 formed in the upper part of the internal space 4 and the groove 10 formed in the lower part. This plate portion 41 becomes the partition wall 11.

  Further, the intermediate plate 40 has fine internal through holes 42 in the vicinity of both end portions. Since the internal through hole 42 penetrates a part of the partition wall 11, the passage 5 and the groove 10 are connected through the internal through hole 42.

  Here, the internal through hole 42 is provided in accordance with the position of the passage 5. That is, it is preferable that the internal through hole 42 is not provided on the side wall that divides the plurality of passages. This is because even if the internal through hole is provided on the side wall, the internal through hole does not serve as a capillary channel. As shown in FIG. 8, the internal through holes 42 may be arranged in an orderly manner or may be arranged at random.

  Since at least one intermediate plate 40 is sandwiched and stacked between the upper plate 2 and the lower plate 3, the internal space 4 can be separated into the upper and lower sides of the passage 5 side and the groove 10 side, and the capillary channel 12, Only at 13, the passage 5 and the groove 10 can communicate with each other.

  The internal through hole 42 penetrates from the front surface to the back surface of the intermediate plate 40, and the shape thereof may be circular, elliptical, or rectangular. Or a slit shape may be sufficient. The internal through hole 42 is formed by excavation, pressing, wet etching, dry etching, or the like.

  Moreover, the some intermediate | middle board 40 provided with the board part 41 and the internal through-hole 42 may be laminated | stacked. When a plurality of intermediate plates 40 are laminated between the upper plate 2 and the lower plate 3, the thickness of the partition wall 11 is increased and the passage 5 and the groove 10 are reliably separated. In addition, since the internal through holes 42 are stacked in the vertical direction of the internal space, the capillary channels 12 and 13 having a high capillary force are formed.

  For example, when there are a plurality of intermediate plates 40, the internal through holes 42 are provided in each of the plurality of intermediate plates 40. Here, when the position of the internal through hole 42 is shifted for each adjacent intermediate plate 40, the plurality of intermediate plates 40 are stacked such that only a part of the internal through hole 42 overlaps each other. . For example, the position of the internal through hole 42 in a certain intermediate plate 40 and the position of the internal through hole 42 in another intermediate plate 40 adjacent to this intermediate plate 40 are arranged so that a part of the cross section of the internal through hole 42 overlaps. It's off. As described above, the position of the internal through hole 42 is shifted for each adjacent intermediate plate 40, so that when the plurality of intermediate plates 40 are stacked, the cross-sectional area of the internal through hole 42 is smaller than the cross-sectional area in the plane direction. Capillary channels 12, 13 having an area are formed.

  The capillary channels 12 and 13 have a cross-sectional area smaller than the cross-sectional area of the internal through-hole 42 in the planar direction, with a part of the internal through-holes 42 overlapping when the plurality of intermediate plates 40 are stacked. Since the passage 5 and the groove 10 communicate with each other through a hole having a cross-sectional area smaller than the cross-sectional area of the internal through-hole 42, the capillary channels 12 and 13 recirculate the condensed refrigerant with a high capillary force.

  When the capillary channels 12 and 13 having a smaller cross-sectional area than the inner through-hole 42 are formed so that only a part of the inner through-hole 42 overlaps, the capillary channels 12 and 13 are directly processed. There is also an advantage that it can be manufactured easily rather than doing so.

  In addition, although the capillary channels 12 and 13 recirculate the condensed refrigerant | coolant, it can also pass the vaporized refrigerant | coolant.

  Moreover, it is also suitable that the corner | angular part of the capillary flow paths 12 and 13 is chamfered or R is provided. The cross sections of the capillary channels 12 and 13 may have various cross sectional shapes such as hexagons, circles, ellipses, squares, and polygons. The cross-sectional shape of the capillary channels 12 and 13 is determined by the shape of the internal through hole 42 and the way in which the internal through holes 42 are overlapped. Moreover, a cross-sectional area is determined similarly.

  Next, the slit intermediate plate laminated between the upper plate 2 and the lower plate 3 together with the intermediate plate 40 will be described with reference to FIG.

  By stacking the intermediate plate 40 between the upper plate 2 and the lower plate 3, the internal space 4 is separated into a region where the passage 5 is formed and a region where the groove 10 is formed. At this time, the intermediate plate 40 has a plate portion 41, and a space is hardly generated between the plate portion 41 and the upper plate 2. Since the passage 5 is formed between the plate portion 41 and the upper plate 2, another member capable of forming the passage 5 is preferably laminated between the upper plate 2 and the intermediate plate 40.

  On the other hand, since the plate portion 41 of the intermediate plate 40 is laminated so as to cover the groove 10 formed by cutting on the lower plate 3, the capillary force in the reflux of the condensed refrigerant is increased. For this reason, it is not necessary to stack other members between the lower plate 3 and the intermediate plate 40.

  Here, it is assumed that the passage 5 is formed between the upper plate 2 and the intermediate plate 40 and the groove 10 is formed between the lower plate 3 and the intermediate plate 40.

  FIG. 9 is a front view of the slit intermediate plate according to Embodiment 1 of the present invention.

  The slit intermediate plate 45 is laminated together with the intermediate plate 40. Unlike the intermediate plate 40, the slit intermediate plate 45 does not have the plate portion 41 and includes a slit 46 that forms the passage 5. The number of slits 46 is the same as the number of passages 5.

  When the slit intermediate plate 45 is stacked in the internal space 4, the slit 46 becomes the passage 5, and the frame 47 that separates adjacent slits becomes the side wall of the passage 5. The slit 46 extends to the region of the internal through hole 42 of the intermediate plate 40. The internal through hole 42 communicates with the slit 46, and the internal through hole 42 communicates the passage 5 and the groove 10 as the capillary channels 12 and 13.

  Although a single slit intermediate plate 45 may be stacked, the height of the passage 5 can be increased by stacking a plurality of slit intermediate plates 45.

  The slit intermediate plate 45 of FIG. 9 does not have an internal through hole, and the internal through hole 42 of the intermediate plate 40 laminated together communicates with the slit 46, but the slit intermediate plate 45 is connected to the internal through hole 42. It is also preferable to have an internal through hole communicating with (all or a part of the cross section of the internal through hole communicates). When the intermediate plate 40 and the slit intermediate plate 45 are laminated, the plate portion 41 of the intermediate plate 40 and the slit 46 of the slit intermediate plate 45 overlap to form the passage 5. Further, when the intermediate plate 40 and the slit intermediate plate 45 are laminated, the internal through holes 42 of the intermediate plate 40 and the internal through holes of the slit intermediate plate 45 overlap with each other partially or partially, so that the capillary channels 12, 13 are overlapped. Is formed. The capillary channels 12 and 13 formed in this way have a small cross-sectional area and a high capillary force.

  In addition, when each of the upper board 2, the lower board 3, the intermediate board 40, and the slit intermediate board 45 is laminated | stacked, it is also suitable for these members to have the protrusion and convex part used as an adhesive agent. .

  Further, since the upper plate 2, the lower plate 3, the intermediate plate 40, and the slit intermediate plate 45 are laminated to form the heat transport unit 1, the upper plate 2, the lower plate 3, the intermediate plate 40, and the slit intermediate are formed as necessary. The plate 45 may be metal-plated or surface-treated. Since each member is subjected to metal plating or surface processing, the formed passages 5 and grooves 10 move the refrigerant at a faster speed.

As described above, the heat transport unit 1 is formed by stacking the upper plate 2, the lower plate 3, the intermediate plate 40, and the slit intermediate plate 45 (passage).
Next, the passage 5 will be described.

  The passage 5 is provided on the upper plate 2 side of the internal space 4. Note that the provision of the passage 5 on the upper plate 2 does not mean that the passage 5 must be present on the physical upper side when the heat transport unit 1 is installed. The heat transport unit 1 may be installed horizontally with respect to the ground surface or may be installed vertically.

  The passage 5 is formed by laminating the upper plate 2, the slit intermediate plate 45 and the intermediate plate 40 in this order. When these members are laminated in this order, the upper plate 2 and the plate portion 41 of the intermediate plate 40 serve as the lid of the groove 10, and the slit 46 of the slit intermediate plate 45 forms a gap to form the passage 5. The slit 46 is divided by a frame 47, and the frame 47 is in contact with the upper plate 2 and the intermediate plate 40. For this reason, the frame 47 becomes the side wall of the passage 5 as it is.

  In addition, the slit 46 is formed in the longitudinal direction of the slit intermediate plate 45, so that the passage 5 is also formed in the longitudinal direction of the heat transport unit 1. In the vicinity of both ends of the passage 5, there are internal through holes 42 provided in the intermediate plate 40, and the capillary channels 12 and 13 formed by the internal through holes 42 communicate the passage 5 with the groove 10.

  Here, the corner of the passage 5 is also preferably chamfered or provided with R. Chamfering and R are formed by chamfering the corners of the upper plate 2, the lower plate 3, the intermediate plate 40, and the slit intermediate plate 45, and by laminating these members.

  It is also preferable that the surface of the passage 5 has metal plating. The metal plating is selected from at least one of gold, silver, copper, aluminum, nickel, cobalt, and alloys thereof, and electrolytic plating, non-electrolytic plating, and the like are used.

  The passage 5 is formed along the longitudinal direction of the heat transport unit 1 and diffuses the vaporized refrigerant along the longitudinal direction. At this time, the condensed refrigerant (which is a liquid) recirculates through the groove 10 separated from the passage 5, so that the passage 5 can diffuse the vaporized refrigerant without receiving interference of the condensed refrigerant. For this reason, the passage 5 can diffuse the vaporized refrigerant at a very high speed.

(groove)
Next, the groove will be described.

  The groove 10 is provided in the lower plate 3. The groove 10 preferably has a cross-sectional area with which a capillary phenomenon works to recirculate the condensed refrigerant, and does not have a large cross-sectional area like the passage 5. For this reason, the groove 10 is formed not by laminating the intermediate plates but by cutting the lower plate 3 directly.

  A plurality of excavations are cut along the longitudinal direction of the lower plate 3 to form the grooves 10. The groove 10 faces the passage 5 through the partition wall 11. Further, it is preferable that the plurality of grooves 10 face one passage 5. It is because the quantity of the refrigerant | coolant which diffuses and the refrigerant | coolant which recirculates can be balanced because one channel | path 5 and the some groove | channel 10 oppose. This is because, by balancing the diffusing refrigerant and the recirculating refrigerant, the speed at which the passage 5 diffuses the refrigerant and the groove 10 circulates the refrigerant further improves.

  Further, the groove 10 communicates with the internal through hole 42 of the intermediate plate 40. Since the internal through-hole 42 forms the capillary channels 12 and 13, the groove 10 communicates with the passage 5 through the capillary channels 12 and 13.

  The groove 10 is also preferably chamfered at the corners or provided with R as in the case of the passage 5. Chamfering and R are formed by chamfering the corners of the upper plate 2, the lower plate 3, the intermediate plate 40, and the slit intermediate plate 45, and by laminating these members.

  It is also preferable that the surface of the groove 10 has metal plating. The metal plating is selected from at least one of gold, silver, copper, aluminum, nickel, cobalt, and alloys thereof, and electrolytic plating, non-electrolytic plating, and the like are used.

  By these processes, the groove 10 can recirculate the refrigerant condensed at high speed.

  In addition, the groove | channel 10 may have various cross-sectional shapes, such as a triangle, a square, and a semicircle.

(Capillary channel)
The capillary channels 12 and 13 are formed by the internal through holes 42 (or the lamination of the internal through holes 42 of the plurality of intermediate plates 40). The capillary channels 12 and 13 reflux the condensed refrigerant by a capillary phenomenon.

  The vaporized refrigerant is cooled and condensed at the end opposite to the heating element. The cooled and condensed refrigerant is present at the end of the passage 5. A capillary channel 13 exists at the end of the passage 5. The capillary channel 13 recirculates the condensed refrigerant from the passage 5 to the groove 10.

  Further, the condensed refrigerant that has moved from the end to the other end (end where the heating element is present) through the groove 10 returns from the groove 10 to the passage 5 through the capillary channel 12. As a result, the condensed refrigerant is supplied to the passage 5.

  When a plurality of intermediate plates (which may be the intermediate plate 40 or the slit intermediate plate 45) having the internal through-holes 42 are laminated to form the capillary channels 12 and 13, only a part of the internal through-holes 42 is formed. They are stacked so as to overlap each other. Capillary channels 12 and 13 having a cross-sectional area smaller than the cross-sectional area of the internal through-hole 42 are formed by only a part of the overlap.

  Holes having a cross-sectional area smaller than the cross-sectional area of the internal through-hole 42 are stacked in the vertical direction of the capillary flow paths 12 and 13, and the vertical flow paths are connected by connecting the vertical holes to each other. It is formed. Moreover, since it becomes a stepped hole in the vertical direction, a flow path that can flow in the plane direction as well as the vertical direction is formed. The flow path formed in the vertical / planar direction has a very small cross-sectional area, and the condensed refrigerant is circulated in the vertical direction or the vertical / planar direction.

  As a result, the capillary channels 12 and 13 recirculate the condensed refrigerant efficiently.

(Refrigerant circulation)
The refrigerant circulates back and forth between the passage 5 and the groove 10.

  This will be described with reference to FIG. The heating element 20 is in thermal contact with the heat transport unit 1 at the first end 21. The heat transport unit 1 vaporizes the refrigerant at the first end by the heat received from the heating element 20. The vaporized refrigerant moves from the first end 21 toward the second end 22 in the passage 5. The vaporized refrigerant that has moved through the passage 5 from the first end 21 toward the second end 22 is cooled and condensed at the second end 22. The condensed refrigerant flows back through the capillary channel 13. Due to this reflux, the condensed refrigerant moves from the passage 5 to the groove 10.

  The condensed refrigerant that has moved to the groove 10 moves along the groove 10 from the second end 22 toward the first end 21. As a result of the movement, the condensed refrigerant reaches the first end 21 side of the groove 10. The condensed refrigerant flows through the capillary channel 12 and moves from the groove 10 to the passage 5.

  The condensed refrigerant that has reached the passage 5 is vaporized again by the heat from the heating element 20 and moves through the passage 5.

  As described above, the vaporized refrigerant moves through the passage 5 and the condensed refrigerant moves through the groove 10, so that the gaseous refrigerant and the liquid refrigerant interfere or collide in the same space. It can circulate without. This circulation enables the heat transport unit to transport the heat of the heating element along a certain direction with high efficiency.

(Embodiment 2)
Next, a second embodiment will be described.

  FIG. 10 is a top view of the heat transport unit according to Embodiment 2 of the present invention. The state which looked at the heat transport unit 50 from the top is shown, and a part of internal structure is seen through with the broken line.

  The heat transport unit 50 shown in FIG. 10 further includes a communication path 51 in which the refrigerant can move between the plurality of paths 5.

  The plurality of passages 5 are separated by side walls 54, like passages 5a, 5b, and 5c.

  For this reason, the passage 5 only communicates with the opposing groove (not shown in FIG. 10) through the capillary channels 12 and 13. The refrigerant contained in a certain passage 5a circulates only in the groove facing the passage 5a. By this circulation, the heat transport unit can transport the heat of the heating element at high speed along the first direction.

  On the other hand, as shown in FIG. 10, a minute heating element 52 may come into thermal contact with the heat transport unit 50. For example, light emitting elements such as LEDs are very small and may have a size smaller than the width of the passage 5 of the heat transport unit 50. In FIG. 10, the heating element 522 is in thermal contact with the passages 5b and 5d, but the heating element is not in thermal contact with the other passages.

  In the passages 5b and 5d in which the heating element 52 is in thermal contact, the refrigerant is vaporized by receiving heat, and the vaporized refrigerant moves. The vaporized refrigerant that has moved is cooled and condensed, and the condensed refrigerant flows back through the capillary channel 13 from the passages 5b and 5d to the grooves facing the passages 5b and 5d. The condensed refrigerant that has been refluxed moves through the groove and moves again from the capillary channel 12 to the channels 5b and 5d.

  By the way, in other passages where the heating element 52 is not in thermal contact (for example, the passages 5a and 5c), since the amount of heat received is small, only a small amount of refrigerant is vaporized. For this reason, these passages do not require much refrigerant. On the other hand, in the passages 5b and 5d with which the heating element 52 is in contact, a large amount of refrigerant is required to transport heat from the heating element 52.

  The communication path 51 communicates with a plurality of paths 5 (for example, the path 5b and the path 5c), and enables the vaporized refrigerant to move between the paths. If movement of the vaporized refrigerant in the plurality of passages is possible, the refrigerant can be supplied to the passages 5b and 5d that require a large amount of refrigerant from other passages. The passages 5b and 5d can transport heat received from the heating element 52 using the refrigerant supplied from the other passages.

  As described above, since the heat transport unit 50 includes the communication passage 51, the refrigerant sealed in the internal space can be efficiently removed even when a small heating element contacts only a part of the plurality of passages 5. Can be used to transport heat.

  The communication path 51 communicates the paths 5 with each other, but adjacent grooves may communicate with each other.

  When the communication path 51 allows the grooves to communicate with each other, the condensed refrigerant can move between the grooves. Also in this case, a groove (and thus a passage) that requires more refrigerant can obtain a necessary refrigerant than a groove (and thus a passage) that does not. As a result, heat transport can be realized at different levels for each passage and groove.

  The communication path 51 may be formed by making a hole in the side wall 54 or may be formed by laminating the side wall 54 in which a hole has been made in advance. Moreover, it is also suitable that the surface of the communication path 51 is metal-plated or surface-treated so that a refrigerant | coolant can move easily. It is also preferable that the corners are chamfered or R is provided.

(Heat dissipation part)
Next, a heat transport unit further including a heat radiating unit will be described with reference to FIG.

  In FIG. 11, the heat transport unit is shown as an electronic device stored in a housing. FIG. 11 is a schematic diagram of an electronic device according to the second embodiment of the present invention.

  The electronic device 60 includes a housing 61 and an electronic board 64 stored inside the housing. The electronic board 64 has a heating element 61 mounted thereon. The heating element 61 is an electronic component that generates heat.

  The heat transport unit 70 is in thermal contact with the heating element 61 at the contact portion 71.

  The heat transport unit 70 has the same function and configuration as the heat transport units 1 and 50 described in the first and second embodiments.

  The heating element 61 is in thermal contact with one end of the heat transport unit 70. The heat transport unit 70 transports the heat received from the heating element 61 to the other end. In the transportation, as described in the first and second embodiments, the vaporized refrigerant moves through the passage, the condensed refrigerant moves through the groove, and the longitudinal direction of the heat transportation unit 70 is changed from one end to the other. The refrigerant circulates at the end. The heat of the heating element 61 is transported by the circulation of the refrigerant.

  The heat transport unit 70 has a heat radiating portion 63 that cools the vaporized refrigerant at the end opposite to the end where the heating element 61 is in thermal contact. In FIG. 11, a cooling fan is shown as an example of the heat radiating unit 63.

  The cooling fan cools the end of the heat transport unit 70. The moved vaporized refrigerant is accumulated at the end, and the cooling fan cools the vaporized refrigerant. The evaporated refrigerant is condensed to be liquid by being cooled. The condensed refrigerant returns to the groove from the passage through the capillary channel.

  As described above, the heat transport unit 70 includes the heat radiating unit 63, so that the heat transport unit 70 can efficiently cool the refrigerant that has been vaporized and transported. For this reason, it is preferable that the heat radiating unit 63 cools the end of the heat transport unit 70 opposite to the heating element 61. By cooling the end on the opposite side, the condensation of the vaporized refrigerant is promoted, and the heat transport unit 70 can transport the heat taken from the heating element 61 at a higher speed along the first direction.

  The heat transport unit 70 also preferably has a contact portion 71 that is in thermal contact with the heating element 61.

  The contact portion 71 facilitates thermal contact between the heating element 61 and the heat transport unit 70. For example, it is also preferable that the contact portion 71 has a thermal bonding material (TIM “Terminal Interface Material”).

  As the thermal bonding material, thermal grease or a material obtained by adding a filler to thermal grease is used. These thermal bonding materials may be applied to the contact portion 71.

  The contact portion 71 has a thermal bonding material, so that the thermal resistance with the heating element 61 can be reduced. Thanks to the reduced thermal resistance, the heat transport unit 70 can transfer the heat from the heating element 61. It becomes easier to receive heat.

  The heating element 61 may be in thermal contact with the upper plate side (that is, the side where the passage is present) in the heat transport unit 70, or may be thermally contacted with the lower plate side (ie, the side where the groove is present). You may do it. The refrigerant may be circulated by the heat received from the heating element 61.

  As described above, when the heat transport unit 70 is in thermal contact with the heating element 61 included in the electronic device 60, the heat generated by the heating element 61 is efficiently transported to a position away from the heating element 61. The As a result, the heating element 61 is efficiently cooled. That is, malfunction due to heat generation of the electronic device 60 can be prevented.

  Further, the heat transport unit 70 is very thin because it is formed by stacking thin flat plate upper and lower plates. For this reason, it does not hinder downsizing of electronic equipment. In particular, the electronic device stores many elements having a large area but a small thickness, such as the electronic substrate 64. For this reason, mounting space is left in the plane direction, but there is almost no mounting space in the thickness direction. In this situation, the heat transport unit 70 is thin and can transport heat in the planar direction, and thus is suitable for cooling the heating element 61.

  As described above, the heat transport unit 70 can be stored in the electronic device 60 without hindering the downsizing / thinning of the electronic device, and the heating element 61 can be efficiently cooled.

  As an example of the electronic device, it is also preferable to use a portable terminal as shown in FIG. FIG. 12 is a perspective view of an electronic device according to Embodiment 2 of the present invention.

  The electronic device 80 is an electronic device that is required to be thin and small, such as a car TV or a personal monitor.

  The electronic device 80 includes a display 83, a light emitting element 84, and a speaker 85. The heat transport unit 1 is stored inside the electronic device 80, and the cooling of the heating element is realized.

  By using such a heat transport unit 70, the heating element can be cooled without hindering the downsizing and thinning of the electronic device. That is, the heat transport unit 70 can transport and cool the heat from the heating element at high speed, and can suppress the heat generation of the heating element.

  The heat transport unit 70 is replaced with a heat radiating fin or a liquid cooling device mounted on a notebook personal computer, a portable terminal, a computer terminal, or the like, or mounted on a light, an engine, or a control computer unit of an automobile or industrial equipment. It can be replaced with a heat dissipating frame or a cooling device. Since the heat transport unit 70 has a higher cooling capacity than the conventionally used radiating fins and radiating frames, it can naturally be reduced in size. Furthermore, it is possible to flexibly handle the heating element, and various electronic components can be cooled. As a result, the heat transport unit 70 has a wide range of applications.

  In FIG. 11, the heat transport unit 70 has a flat plate shape, but is formed by stacking thin plate members, and can be bent or curved. Even in this case, the refrigerant vaporized in the passage is diffused, and the refrigerant condensed in the groove separated from the passage through the capillary passage is recirculated, so that the heat transport unit can transport heat with high efficiency. In particular, since there is no interference between the evaporated refrigerant and the condensed refrigerant, the heat transport efficiency is high.

  For example, depending on the shape inside the electronic device, it may be difficult to mount the heat transport unit 70 unless the heat transport unit 70 is in a curved state. In such a case, the curved heat transport unit 70 is mounted.

(Manufacturing process)
Next, the manufacturing process will be described. FIG. 13 is an exploded view of the heat transport unit showing the manufacturing process in the second embodiment of the present invention.

  The upper plate 2, the lower plate 3, the intermediate plate 40, and the slit intermediate plate 45 are laminated and joined to produce the heat transport unit 1. The lower plate 3 has a groove 10 in advance.

  Here, a plurality of intermediate plates 40 and a slit intermediate plate 45 are laminated between the upper plate 2 and the lower plate 3. As shown in FIG. 7, the intermediate plate 40 includes a plate portion 41 and an internal through hole 42. For this reason, the intermediate plate 40 serves as a lid for the groove provided in the lower plate 3. One or a plurality of (three in FIG. 13) slit intermediate plates 45 are laminated on the intermediate plate 40. As shown in FIG. 9, the slit intermediate plate 45 includes a slit 46 and a frame 47. When the slit intermediate plate 45 and the upper plate 2 are laminated, a plurality of passages 5 are formed. In order to increase the height of the passage 5, a plurality of slit intermediate plates 45 are preferably stacked.

  Each of the upper plate 2, the lower plate 3, the plurality of intermediate plates 40, and the slit intermediate plate 45 is matched to a predetermined positional relationship. In addition, the plurality of intermediate plates 40 and the slit intermediate plate 45 are adjusted to a positional relationship such that only a part of each of the internal through holes 42 provided in each of the plurality of intermediate plates 40 and the slit intermediate plate 45 overlap. .

  At least one of the upper plate 2, the lower plate 3, the plurality of intermediate plates 40, and the slit intermediate plate 45 has a joint protrusion.

  The upper plate 2, the lower plate 3, the plurality of intermediate plates 40, and the slit intermediate plate 45 are stacked after being aligned, and are directly joined and integrated by heat press. At this time, each member is directly joined by the joining projection.

  Here, the direct bonding refers to applying heat treatment while pressing the surfaces of the two members to be bonded together, and firmly bonding the atoms together by an atomic force acting between the surface portions. That is, the surfaces of the two members can be integrated without using an adhesive. At this time, the bonding protrusion realizes strong bonding. That is, since the bonding protrusions are crushed and the contact area is increased, thermal bonding is realized, so that the bonding protrusions play a high role.

As a condition of direct bonding at a heat press, the press pressure ^is in the range of ^{40kg / cm 2 ~150kg / cm 2} , the temperature is preferably in the range of 250 to 400 ° C..

  Next, the refrigerant is injected through an injection port opened in a part of the upper plate 2 and the lower plate 3. Thereafter, the inlet is sealed to complete the heat transport unit. The refrigerant is sealed under vacuum or reduced pressure. By being performed under vacuum or reduced pressure, the internal space of the heat diffusing unit or heat transport unit is in a vacuum or reduced pressure state, and the refrigerant is sealed. When the pressure is reduced, the refrigerant vaporization / condensation temperature becomes low, and there is an advantage that the refrigerant vaporization / condensation repeats actively.

  The heat transport unit 1 is manufactured through the above manufacturing steps. In addition, the manufacturing process shown here is an example, and may be manufactured by another manufacturing process.

  As described above, the heat transport unit and the electronic device described in the first and second embodiments are examples for explaining the gist of the present invention, and include modifications and modifications without departing from the gist of the present invention.

It is a perspective view of the heat transport unit in Embodiment 1 of this invention. It is a top view of the heat transport unit in Embodiment 1 of this invention. It is a sectional side view of the heat transport unit in Embodiment 1 of this invention. It is a front view of the upper board in Embodiment 1 of the present invention. It is a front view of the lower board in Embodiment 1 of the present invention. It is a one part enlarged view of the lower board in Embodiment 1 of this invention. It is a front view of the intermediate board in Embodiment 1 of invention. FIG. 3 is an enlarged view of a part of the intermediate plate in the first embodiment of the present invention. It is a front view of the intermediate board in Embodiment 1 of this invention. It is a top view of the heat transport unit in Embodiment 2 of this invention. It is a schematic diagram of the electronic device in Embodiment 2 of this invention. It is a perspective view of the electronic device in Embodiment 2 of this invention. It is an exploded view of the heat transport unit which shows the manufacturing process in Embodiment 2 of this invention.

1, 50, 70 Heat transport unit 2 Upper plate 3 Lower plate 4 Internal space 5, 6, 7, 8, 9 Passage 10 Groove 11 Partition 12, 13 Capillary flow channel 20 Heating element 21 First end 22 Second end 30, 34 Side wall 32, 35 Inlet 40 Intermediate plate 41 Plate portion 42 Internal through-hole 45 Slit intermediate plate 46 Slit 47 Frame 51 Communication path 52 Heat generating element 54 Side wall 60, 80 Electronic device 61 Heat generating element 62 Housing 63 Heat dissipation element 64 Electronic board 71 Contact part 83 Display 84 Light emitting element 85 Speaker

Claims (14)

An upper plate (2);
A lower plate (3) facing the upper plate (2);
An internal space (4) formed by the upper plate (2) and the lower plate (3) and capable of enclosing a refrigerant;
A plurality of passages (5) dividing the internal space (4) along a first direction;
A plurality of grooves (10) provided on the bottom surface of the internal space (4),
The plurality of passages (5) and the plurality of grooves (10) are connected in some areas by capillary flow paths (12), (13) and separated in other areas by partition walls (11). Heat transport unit (1). The upper plate (2) and the lower plate (3) have a flat plate shape, and the internal space (4) also has a flat plate shape,
The plurality of passages (5) are formed in the space on the upper plate (2) side in the internal space (4),
The plurality of grooves (10) are formed on the lower plate (3) side in the internal space (4) while facing the plurality of passages (5) through the partition walls (11). Heat transport unit (1).   The heat transport unit (1) according to claim 1 or 2, wherein each of the plurality of passages (5) is opposed to at least one groove (10) of the plurality of grooves (10).   The heat transport unit (1) according to any one of claims 1 to 3, wherein the plurality of grooves (10) are provided along the first direction.   The plurality of passages (5) and the plurality of grooves (10) are provided on a side opposite to the first end (21) and the first end (21) which is one end along the first direction. The first end (21) and the second end (22) are provided at each of the first end (21) and the second end (22). To 4. The heat transport unit (1) according to any one of items 1 to 4.   The partition wall (11) has a plurality of internal through holes (42), and the plurality of internal through holes (42) form the capillary channels (12), (13). The heat transport unit (1) according to any one of the above.   The heat transport unit (1) according to any one of claims 1 to 6, wherein at least one of the passage (5) and the groove (10) has chamfered corners.   The heat transport unit (1) according to any one of claims 1 to 7, wherein a surface of at least one of the passage (5) and the groove (10) is metal-plated.   The heat transport unit (1) according to claim 8, wherein the metal plating is selected from at least one metal selected from gold, silver, copper, aluminum, nickel, cobalt, and alloys thereof.   The heat transport unit (50) according to any one of claims 1 to 9, further comprising a communication passage (51) through which the refrigerant can move between the plurality of passages (5). The capillary channels (12), (13) connect the passage (5) and the groove (10) at the first end (21) and the second end (22),
The refrigerant is vaporized by receiving heat from the heating element (20) at the first end (21), and the vaporized refrigerant passes through the passage (5) from the first end (21) to the second end. Diffuses over (22)
The refrigerant vaporized at the second end (22) is condensed, and the condensed refrigerant is refluxed from the passage (5) to the groove (10) via the capillary channel (13).
The condensed refrigerant flowing back into the groove (10) moves in the groove (10) from the second end (22) to the first end (21), and further in the first end (21). The heat transport unit (1) according to any one of claims 5 to 10, wherein the heat is returned to the passage (5) from the groove (10).   The heat transport unit (70) according to any one of claims 5 to 11, further comprising a heat radiating portion (63) for cooling the refrigerant vaporized at the second end (22).   The heat transport unit (70) according to any of claims 5 to 12, further comprising a contact portion (71) in thermal contact with the heating element at the first end (21). The heat transport unit (1), (50), (70) according to any of claims 1 to 13,
A heating element (61) in thermal contact with the contact portion;
An electronic substrate (64) on which the heating element is mounted;
An electronic device (60) comprising a housing (62) for storing the electronic substrate.