HEAT TRANSPORTING UNIT AND ELECTRONIC DEVICE

Abstract

A heat transporting unit comprises an upper plate, a lower plate opposing the upper plate, an internal space formed by the upper plate and the lower plate and operable to enter a refrigerant, a plurality of paths dividing the internal space in a first direction, and a plurality of grooves being provided at a bottom surface of the internal space. The plurality of the paths and the plurality of the grooves are connected by capillary channels in a region, and are divided by sidewalls in another region.

Description

REFERENCE To RELATED APPLICATIONS

The Present Application claims priority to prior-filed Japanese Patent Application No. 2009-186534, entitled “Heat Transporting Unit And Electronic Device,” and filed 11 Aug. 2009, the contents of which is fully incorporated in its entirety herein.

BACKGROUND OF THE PRESENT APPLICATION

The Present Application relates, generally, to a heat transporting unit and an electronic device operable to transport heat received from a heating element, e.g., a semiconductor integrated circuit (IC), a Light Emitting Device (LED), a power device or an electronic device.

Electronic devices, such as a semiconductor ICs, LEDs or other power devices, typically have many uses, such as in industrial apparati or the like. However, these electronic devices include heating elements that generate heat as a result of the current running therein. When the temperature in the heating element becomes higher than a constant temperature, a problem exists in that optimal operation of the device can not be guaranteed. As a result, the heat may influence other parts, and may cause performance degradation of the device or the industrial apparatus.

Accordingly, a cooling device, such as a heat pipe, possessing a cooling effect according to vaporization and condensation properties of a sealed refrigerant has been proposed in order to refrigerate such heating elements. In such cooling devices, generally, when a sealed refrigerant evaporates, the device takes heat from a heating element, and the refrigerant begins to flow. The evaporated refrigerant is then condensed by radiating heat, and the condensed refrigerant circulates back to its original location (i.e., where it evaporated). By the repetition of this vaporization and the condensation, the device refrigerates the heating element.

The cooling mechanism of the device possesses a heat receiving member (e.g., an evaporated refrigerant) for taking heat from a heating element, a heat transporting member (in which the evaporated refrigerant moves and the condensed refrigerant circulates) for transporting the taken heat, and a heat radiating member for radiating the transported heat. An example of a typical device is disclosed in Japanese Patent Application No. 2004-037001 (“the '001 Application”), which generally discloses the movement of the refrigerant, evaporated by heat from a heating element, and refrigeration of the evaporated refrigerant by a secondary cooling device such as a heat sink. Additionally, Japanese Patent Application No. H11-101585 (“the '585 Application”) discloses an electronic board possessing a cooling function.

The electronic component, i.e., the target for cooling, is preferably a large semiconductor IC, such as a CPU or a dedicated IC, or a compact electronic part, such as a high-luminance LED. Of course, the size of such a compact electronic part is small. Thus, in this case, a plurality of electronic parts may often be used as one set. For this reason, in the cooling device using a heat pipe, a plurality of compact electronic parts needs to be refrigerated.

In a cooling device using a heat pipe, it is important to improve the efficiency of heat transportation (determined according to the speed between the diffusion of the evaporated refrigerant and the circulation of the refrigerant, and the number of cycles in a unit period) in order to improve the ability of the device to cool. Preferably, a heat transporting member, provided with a conventional heat pipe, includes a wick. Difficulties may arise in that the refrigerant evaporated by the heat receiving member, and the refrigerant condensed by the heat radiating member, may not easily enter the pipe. This may be because of an influence of the physical connection structure between the heat receiving or heat radiating members, and the pipe. Thus, the speed of heat transportation in the heat transporting member may be slow.

The heat transportation member disclosed in the '001 Application encompasses the entire internal space of the board, and possesses a plate-like shape. Accordingly, the diffusion of the evaporated refrigerant and the circulation of the condensed refrigerant are performed in the entire internal space. When the heating element targeted for cooling is a large-sized semiconductor IC, for example, even if the entire internal space is used as the heat transporting member, constant heat transporting efficiency can be obtained. However, when cooling a plurality of compact heating elements, such as LEDs, since the heat generation area of the heating element and the heat generation and transporting areas of the heat pipe are unbalanced, the efficiency of heat transportation, relative to the size and ability of the heat pipe, is poor. Further, since the amount of the refrigerant is large relative to the caloric value of the heating element, the efficiency of refrigerant evaporation is also poor. Thus, the efficiency of the circulation becomes poor as well.

The '585 Application discloses a heat pipe (also possessing a plate-like shape) wherein fine pores are aligned. In this heat pipe, each pore diffuses the evaporated refrigerant and circulates the condensed refrigerant. However, the pores are divided into pores wherein the heat transporting is intense and pores wherein the heat transporting is poor, according to the number and the caloric value of the heating element connecting to the heat pipe. Although the efficiency of heat transportation is determined according to the speed and the number of cycles of the diffusion of the evaporated refrigerant and the circulation of the condensed refrigerant, more refrigerant is necessary for cooling a heating element possessing a high caloric value. In the heat pipe disclosed in the '585 Application, since the refrigerant enters every pore, the pores must be divided into pores wherein the amount of refrigerant is inadequate and pores wherein the amount of refrigerant is excessive. Thus, the efficiency of heat transportation of the heat pipe abates.

Moreover, in the heat pipe disclosed in the ‘585 Application, the pores are void. Thus, it is possible to diffuse the evaporated refrigerant, but impossible to efficiently circulate the condensed refrigerant. In addition, although it is preferred to transfer the heat of the heating element to a position away from the heating element at high speed, heat can not be transported with a high degree of efficiency in the electronic board and the heat pipe of the ‘585 Application. This is because the speed of diffusion of the evaporated refrigerant and the speed of the circulation of the condensed refrigerant are both reduced, since the evaporated refrigerant and the condensed refrigerant collide in the electronic board and/or the heat pipe.

Finally, although a metal plate may often be used as a heat transporting member, only heat transportation according to principals of thermal conductivity can be performed in a metal plate. Thus, there is a limit for the efficiency of heat transportation. Further, as mentioned above, in a cooling device using a conventional heat pipe, although it deals with various heating elements, the heat can not be transported at high speed.

SUMMARY OF THE PRESENT APPLICATION

An object of the Present Application is to provide a heat transporting unit, operable to flexibly deal with various kinds of heating elements targeted for cooling, and to transport heat taken from a heating element at high speed. A heat transporting unit according to the Present Application can rapidly and effectively transport heat from a heating element in a constant first direction. To be more specific, even when the heating element is small compared to the heat transporting unit, heat transportation corresponding to a quantity of heat generated by the heating element is performed since the heat is transported via every path of the paths that are composed by dividing an internal space therein. When heat transportation is insufficient only using a refrigerant sealed into a certain path, the refrigerant may be exchanged via a communication path. Therefore, the efficiency of heat transportation in the paths is flexibly improved.

Additionally, the evaporated refrigerant diffuses in the paths, and the condensed refrigerant circulates in grooves. As such, the evaporated refrigerant and the condensed refrigerant neither meet nor interfere with each other. As a result, moving velocities of the refrigerants become higher, and the heat transporting unit can transport heat with high efficiency. At this time, capillary channels provided with an end part of the heat transporting unit enable the condensed refrigerant to come and go between the paths and the grooves. When surface treatment, such as chamfering, metal plating or the like, is performed on at least a part of the paths and the grooves, the refrigerants can move more smoothly.

Accordingly, one aspect of the Present Application provides a heat transporting unit comprising an upper plate; a lower plate opposing the upper plate; an internal space formed by the plates, the internal space being operable to seal a refrigerant therein; a plurality of paths dividing the internal space in a first direction; and a plurality of grooves provided on a bottom surface of the internal space. Further, the paths and the grooves are connected to each other at a partial region by capillary channels, and separated at another partial region by dividing walls. This arrangement enables the evaporated refrigerant to move in the plurality of paths, and the condensed refrigerant to move on the plurality of grooves. Since the paths and the grooves are separated by the dividing walls, the refrigerants neither meet nor interfere with each other.

Another aspect of the Present Application provides a heat transporting unit wherein the upper plate is of a plate-like shape and includes a first space of a plate-like shape of an upper plate side. Further, the lower plate is of a plate-like shape and includes a second space of a plate-like shape of a lower plate side. Further, the paths are formed in the first space of the upper plate side, and the grooves oppose the plurality of paths via the dividing walls and are formed in the second space of the lower plate side. With this arrangement, the evaporated refrigerant and the condensed refrigerant move via ways different from each other. Since the paths for causing the evaporated refrigerant to move and the grooves for causing the condensed refrigerant to move oppose to each other, the refrigerants can perform reciprocation circulation. As a result, the heat transporting unit can transport heat in the first direction.

Another aspect of the Present Application provides a heat transporting unit wherein each path opposes one or more grooves. This arrangement enables the heat transporting unit to transport the condensed refrigerant with high efficiency.

Another aspect of the Present Application provides a heat transporting unit wherein the grooves are formed in the first direction. This arrangement enables the heat transporting unit to cause the condensed refrigerant to move in the first direction.

Another aspect of the Present Application provides a heat transporting unit wherein the paths and the grooves include first end parts of an end in the first direction and second end parts of another end in the first direction. Further, the capillary channels are provided with the first end parts and the second end parts. This arrangement enables the heat transporting unit to receive heat at one end parts, and to radiate the heat at the other end parts.

Another aspect of the Present Application provides a heat transporting unit wherein each dividing wall includes a plurality of internal through holes, which form the capillary channels. With this arrangement, the capillary channels can be formed easily.

Another aspect of the Present Application provides a heat transporting unit wherein corner portions of at least one of the paths and the grooves are chamfered. Another aspect of the Present Application provides a heat transporting unit wherein metal-plating is performed on surfaces of at least one of the paths and the grooves. Another aspect of the Present Application provides a heat transporting unit wherein the metal-plating includes metal such as gold, silver, copper, aluminum, nickel or cobalt, and any alloys thereof. With either of these arrangements, the paths and the grooves cause the evaporated refrigerant and/or the condensed refrigerant to move with high efficiency.

Another aspect of the Present Application provides a heat transporting unit further comprising communication paths where the refrigerant can move from one to another of the paths, allowing refrigerant to be exchanged between the paths. Thus, when the one path needs a greater amount of refrigerant than another, it can obtain the needed refrigerant.

A final aspect of the Present Application provides a heat transporting unit wherein the capillary paths connect the paths and the grooves at the first end parts and the second end parts. Further, the refrigerant receives heat from the heating element at the first end parts, allowing it to evaporate. The evaporated refrigerant diffuses in the paths from the first end parts to the second end parts, and is condensed at the second end parts. The condensed refrigerant circulates from the paths to the grooves via the capillary channels. The refrigerant circulating in the grooves and condensed moves in the grooves from the second end parts to the first end parts, and further circulates from the grooves to the paths at the first end parts. With this arrangement, the heat transporting unit can transport heat of the heating element in the first direction with a high degree of efficiency. Furthermore, since the evaporated refrigerant and the condensed refrigerant neither meet nor interfere with each other, heat transporting efficiency thereof is improved.

BRIEF DESCRIPTION OF THE FIGURES

The organization and manner of the structure and operation of the Present Application, together with further objects and advantages thereof, may best be understood by reference to the following Detailed Description, taken in connection with the accompanying Figures, wherein like reference numerals identify like elements, and in which:

FIG. 1 is a perspective diagram of a heat transporting unit according to one embodiment of the Present Application;

FIG. 2 is a top view of the heat transporting unit of FIG. 1;

FIG. 3 is a sectional side view of the heat transporting unit of FIG. 1;

FIG. 4 is a front view of an upper plate according to one embodiment of the Present Application;

FIG. 5 is a front view of a lower plate according to one embodiment of the Present Application;

FIG. 6 is an enlargement for a part of the lower plate of FIG. 4;

FIG. 7 is a front view of an intermediate plate according to one embodiment of the Present Application;

FIG. 8 is an enlargement for a part of the lower plate of FIG. 5;

FIG. 9 is a front view of the intermediate plate of FIG. 7, shown with a slit;

FIG. 10 is a top view of a heat transporting unit according to one embodiment of the Present Application;

FIG. 11 is a mimetic diagram of an electronic device according to one embodiment of the Present Application;

FIG. 12 is a perspective diagram of the electronic device of FIG. 11; and

FIG. 13 is an exploded view of the heat transporting unit of FIG. 10, showing the manufacturing process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the Present Application may be susceptible to embodiment in different forms, there is shown in the Figures, and will be described herein in detail, specific embodiments, with the understanding that the disclosure is to be considered an exemplification of the principles of the Present Application, and is not intended to limit the Present Application to that as illustrated.

In the illustrated embodiments, directional representations—i.e., up, down, left, right, front, rear and the like, used for explaining the structure and movement of the various elements of the Present Application, are relative. These representations are appropriate when the elements are in the position shown in the Figures. If the description of the position of the elements changes, however, it is assumed that these representations are to be changed accordingly.

In addition, a “heat pipe” shall mean a member, a part, an apparatus or a device for refrigerating or cooling a heating element. Preferably, the heating element heats a refrigerant within an internal space of the heat pipe to evaporate, and then the evaporated refrigerant is condensed by refrigeration. This process is repeated until the element is cooled. Moreover, a “heat transporting unit” shall mean a member, a part, an apparatus or a device able to transport heat from the heating element by the movement of the refrigerant.

Regarding the heat pipe, a refrigerant enter inside the heat pipe. A surface to be a heat-receiving surface is connected to the heating element, for example, an electronic part. The inside of the refrigerant evaporates, and takes the heat of the heating element. The evaporated refrigerant then moves inside the heat pipe. The movement means transporting the heat of the heating element. The evaporated refrigerant will be refrigerated and condensed at a heat radiating surface or the like (alternatively, by a secondary cooling member such as a heat sink and/or a cooling fan). The condensed refrigerant is then circulated inside the heat pipe and moves to the heat-receiving surface again, where the process repeats.

By repetition, the heat pipe cools the heating element. For this reason, the heat pipe preferably includes a vapor diffusion path for diffusing the evaporated refrigerant and a capillary channel for circulating the condensed refrigerant. The heat pipe may also possess a structure in which the evaporated refrigerant is diffused and in which the condensed refrigerant is circulated in a vertical direction, while the shape of the heat pipe is cylindrical; and a structure in which a heat receiving unit connecting to the heating element and a cooling unit refrigerating the refrigerant are different units, but connected by the heat pipe. Further, the volume of the heat pipe possessing these structures is large (the volume in the vertical direction, especially, tends to be large). Thus, the heat pipe is not preferable in the case when the space to be mounted is small. For this reason, a thin heat pipe possessing a plate-like shape is often desired, and, accordingly, the heat pipe possessing the plate-like shape is also proposed.

Referring to FIGS. 1-2, a heat transporting unit 1 is provided with an upper plate 2, a lower plate 3 opposing the upper plate 2, and an internal space 4 formed of the upper plate 2 and the lower plate 3. The internal space 4 is provided with paths 5-9, which divide the internal space 4 in the first direction, and grooves 10, provided at the bottom surface of the internal space 4. The paths 5-9 and the groove 10 are connected to capillary channels 12, 13 in part of a region, and are divided by a dividing wall 11 in another part of a region. The dividing wall 11 divides the internal space 4 into upper and lower sides (with the upper plate 2 is the upper side, and the lower plate 3 is the lower side). The heat transporting unit 1 is further provided with the paths 5-9 on the upper side of the internal space 4. Furthermore, the heat transporting unit 1 is provided with the groove 10 opposing the paths 5-9 at the lower side of the internal space 4 while the dividing wall 11 divides the internal space 4. In addition, FIG. 1 illustrates where the end part of a heat transporting unit 1 is cut, and the capillary channel does not appear in FIG. 1. FIG. 2 illustrates the capillary channels 12, 13 on the both end parts of the heat transporting unit 1. In addition, in FIG. 2, the path 5 formed of the internal space 4 is shown by the dashed lines.

FIGS. 1-2 clearly show the entire image of the heat transporting unit 1, which is provided with the internal space 4, which is sandwiched by the upper plate 2 and the lower plate 3. The internal space 4 is divided into the upper and lower sides by the dividing wall 11, except for the capillary channels 12-13. Moreover, the heat transporting unit 1 is provided with the plurality of paths 5-9, divided between the upper plate 2 and the dividing wall 11. Furthermore, the heat transporting unit 1 is provided with the groove 10 at the lower plate 3. The paths 5-9 and the groove 10 oppose each other while being divided by the dividing walls. Moreover, the paths 5-9 and the groove 10 are in a first direction (a longitudinal direction of the heat transporting unit 1).

It is preferable that each of the upper plate 2 and the lower plate 3 possesses a plate-like shape, and, moreover, be of rectangular shape. Since each of the upper plate 2 and the lower plate 3 possesses a plate-like shape, the internal space 4 also possesses a plate-like shape. In addition, the heat transporting unit 1 possesses a plate-like shape, having a longitudinal and a lateral direction (the longitudinal directions are the first directions, which are the directions of the paths 5-9 and the groove 10). The paths 5-9 in the longitudinal direction of the heat transporting unit 1 are formed in the internal space 4. According to the paths 5-9 and the groove 10, the heat transporting unit 1 reciprocates the evaporated refrigerant and the condensed refrigerant in the longitudinal direction. By the reciprocating in the longitudinal direction of the refrigerants, the heat transporting unit 1 can transport the heat of the heating element in the longitudinal direction. Further, the refrigerant can enter the internal space 4, where it is evaporated by the heat from the heating element. The evaporated refrigerant will be condensed when refrigerated. The heat transporting unit 1 diffuses the evaporated refrigerant in the paths 5-9, and the condensed refrigerant is circulated in the groove 10.

FIG. 3, which illustrates the mechanism of the heat transporting of the heat transporting unit 1, illustrates the section which the heat transporting unit 1 is cut in the first direction. The internal space 4 on the side of the upper plate 2 possesses the path 5. The path 5 opposes the groove 10 while the dividing wall 11 divides. In the lower plate 3, the groove 10 is formed in the first direction. The heat transporting unit 1 possesses the capillary channels 12-13 on both end parts. Only in the region where the capillary channels 12-13 exist are the path 5 and the groove 10 are connected. In other words, the refrigerant can move only in the capillary channels 12-13.

The heat transporting unit 1 thermally touches a heating element 20 at the bottom surface of the lower plate 3 of one of the end parts. The heating element 20 is an element which emits heat, such as a LED element. In addition, the heating element 20 may thermally touch the front surface of the upper plate 2. Further, the refrigerant is accumulated on a side of a first end part 21 of the groove 10 when condensed. This condensed refrigerant moves in the capillary channel 12 due to capillarity, and the moves from the groove 10 to the path 5. Consequently, the condensed refrigerant is accumulated on the side of the first end part 21 of the path 5.

When the heating element 20 gives heat to the first end part 21, the condensed refrigerant of the first end part 21 evaporates. The evaporated refrigerant moves in the path 5 in the first direction. In other words, the evaporated refrigerant moves from the first end part to a second end part 22. By this movement, the heat transporting unit 1 can transport the heat received from the heating element 20 in the first direction. Once the evaporated refrigerant reaches the second end part 22, it is refrigerated, and thus, condensed again. The condensed refrigerant then moves from the path 5 to the groove 10 due to the capillarity in the capillary channel 13. The condensed refrigerant moves in the groove 10 from the second end part 22 to the first end part 21. In other words, in the groove 10, the condensed refrigerant moves from the second end part 22 to the first end part 21 due to a phenomenon similar to capillarity. When the condensed refrigerant returns to the first end part 21, the process is repeated, and the refrigerant, which has been condensed, takes the heat from the heating element 21. Thus, the evaporated refrigerant moves in the path 5 from the first end part 21 to the second end part 22. The condensed refrigerant moves in the groove 10 from the second end part 22 to the first end part 21. The movement is indicated by a rout of arrow described in FIG. 3.

Herein, the evaporated refrigerant moves in the path 5, and the condensed refrigerant moves in the groove 10. For this reason, the refrigerants neither collide nor interfere with each other when moving. Since the space where the refrigerant moves is divided by the dividing wall 11, there is no interference. This is because, according to the capillary channels 12-13 being provided with the both ends, the condensed refrigerant moves between the path 5 and the groove 10 via the capillary channels 12-13. In particular, in the first end part 21, since the evaporated refrigerant moves in the path 5 from the first end part 21 to the second end part 22, air pressure near the first end part 21 of the path 5 decreases. As a result, the condensed refrigerant moves on the capillary channel 12 from the groove 10. On the other hand, in the second end part 22, the condensed refrigerant moves in the capillary channel 13 because it is pushed by the pressure moving on the path 5. Thus, due to the pressure of the evaporated refrigerant in movement, the condensed refrigerant tends to be circulated in each of the capillary channels 12-13 more easily. As a result of this physical pressure, the movement path shown by the arrow is formed.

According to the movement path, the evaporated refrigerant and the condensed refrigerant can move at high speed. In other words, the refrigerant can move back and forth between the first end part 21 and the second end part 22 at high speed. Thus, the heat transporting unit 1 can transport the heat received from the heating element 20 at high speed. As a result, the heating element 20 can be refrigerated efficiently.

Referring to FIG. 4, the upper plate 2 possessing the plate-like shape is a rectangle preferably possessing a lateral direction and a longitudinal direction. Of course, the shape may be different from the rectangle (i.e., it may be curved or bended). Further, it is preferable that the upper plate 2 be formed of a metal with a high thermal conductivity, such as copper, aluminum, tungsten, titanium, resin or the like. The upper plate 2 forms the internal space 4 as well as the lower plate 3. For example, the upper plate 2 and the lower plate 3 possess convex sections and wall materials for forming the internal space 4 neighboring thereto. Since the upper plate 2 and the lower plate 3 are connected via these convex sections and wall materials, the internal space 4 is formed between the upper plate 2 and the lower plate 3. When connected to the lower plate 3, these convex sections or the wall materials become sidewalls for surroundings of the internal space 4. Of course, these convex sections and wall materials may be or may not be the same member of the upper plate 2.

The upper plate 2 may possess a sidewall 30 for forming a plurality of paths. When the upper plate 2 is connected to the lower plate 3, the sidewall 30 divides the internal space 4 in order to form a plurality of paths 31. Moreover, it is preferable that the upper plate 2 possesses metal plating at the side where it touches the internal space 4 (i.e., the side where the evaporated refrigerant passes). The metal plating promotes the diffusion of the evaporated refrigerant. It is preferred that the metal plating comprise gold, silver, copper, aluminum, nickel or cobalt, as well as any alloys of the above. Of course, any of single layer plating, multilayer plating, electrolytic plating, and nonelectrolyte plating can be used. Moreover, the upper plate 2 is provided with an injection port 32 operable to enter the refrigerant. When the internal space 4 is formed by connecting the upper plate 2 and the lower plate 3, it is necessary to enter the refrigerant in the internal space 4. The injection port 32 is entered after entering the refrigerant. Finally, although the upper plate 2 is named as “upper,” it does not have to be upper physically. The heating element may touch the upper plate 2 or the lower plate 3.

In addition, the refrigerant may be sealed from the injection port after connecting, and may be injected at the time of connecting. Moreover, it is preferable that the entering of the refrigerant is performed under a vacuum or decompression. By performing under a vacuum or decompression, the condition of the internal space 4 becomes under vacuum or reduced pressure, and the refrigerant will be entered. Under reduced pressure, there is a level at which the temperature of vaporization and condensation of the refrigerant becomes lower and the repetition of the vaporization and condensation of the refrigerant becomes more active.

Referring to FIGS. 5-6, it is preferable that the lower plate 3 be a rectangle possessing a plate-like shape with a lateral and longitudinal direction. Further, since the lower plate 3 is connected opposing the upper plate 2, it is preferable that the lower plate 3 possesses substantially the same shape and the area as the upper plate 2. However, as long as the lower plate 3 is connected to the upper plate 2 and it forms the internal space 4, the area and shape of the lower plate 3 may different from these of the upper plate 2. Of course, the shape may be partially different from the rectangle, and the shape may be curved or bended. Further, it is preferable that the lower plate 3 be formed of a metal with a high thermal conductivity, such as copper, aluminum, tungsten, titanium or resin.

Since the lower plate 3 forms the internal space by connecting to the upper plate 2, the lower plate 3 may possess convex sections or wall materials neighboring thereto. When connecting to the upper plate 2, these convex sections or wall materials become sidewalls surrounding the internal space 4. Of course, these convex sections or wall materials may be or may not be the same members of the lower plate 3. In addition, each of the upper plate 2 and the lower plate 3 may possess the convex sections or wall materials. Either one of the upper plate 2 or the lower plate 3 may have the convex sections or wall materials.

The lower plate 3 may possess sidewalls 34 in order to form a plurality of paths. When the lower plate 3 is connected to the upper plate 2, the sidewalls 34 divide the internal space 4, forming the plurality of paths 5. The sidewall 34 may be different from or the same as the sidewall 32 included in the upper plate 2. Of course, the side wall 34 may be different from or the same as the lower plate 3. In addition, the lower plate 3 is provided with a plurality of grooves 10 on the surface opposing the internal space 4. The plurality of grooves 10 are formed by cutting in the lower plate 3. The groove 10 is formed in the first direction (the longitudinal direction of the lower plate 3). The groove 10 is of plurality, and each of the plurality of paths 5 is opposed to at least one of the grooves 10 on the other side of the dividing wall 11.

Moreover, it is preferable that the lower plate 3 possesses metal plating at the side touching the internal space 4 (i.e., the side where the evaporated refrigerant passes) at least. The metal plating promotes the diffusion of the evaporated refrigerant. As with the upper plate 2, the metal plating of the lower plate 3 may be gold, silver, copper, aluminum, nickel or cobalt, as well as any alloys of these. Further, any of single layer plating, multilayer plating, electrolytic plating, and nonelectrolyte plating can be the metal plating. Moreover, the lower plate 3 is provided with an injection port 35 operable to enter the refrigerant. When the upper plate 2 and the lower plate 3 are connected and the internal space 4 is formed, it is necessary to enter the refrigerant into the internal space 4. The injection port 35 is sealed after entering the refrigerant. Finally, although the upper plate 2 is named as “lower,” it does not have to be lower physically. Further, the heating element may touch the lower plate 3 or the upper plate 2.

In addition, the refrigerant may be entered from the injection port after connecting, or may be entered at the time of connecting. Moreover, it is preferable that the refrigerant is entered under a vacuum or decompression. By performing under a vacuum or decompression, the condition of the internal space 4 becomes under vacuum or reduced pressure, and the refrigerant will be entered. Under reduced pressure, there is a merit that the temperature of vaporization and condensation of the refrigerant becomes lower and the repetition of the vaporization and condensation of the refrigerant becomes more active.

It is also preferable that the heat transporting unit 1 possesses an intermediate plate or a plurality of intermediate plates, which is laminated between the upper plate 2 and the lower plate 3. The internal space 4, which is formed by connecting the upper plate 2 and the lower plate 3 opposing to the upper plate 2, is divided into the upper and lower sides by the dividing wall 11. Furthermore, the both end parts of the dividing wall 11 possess the capillary channels 12 and 13. The capillary channels 12 and 13 connect the path 5 and the groove 10.

The intermediate plate forms the dividing wall 11 and the capillary channels 12 and 13. In addition, the intermediate plate may be singular or plural.

When the intermediate plate is singular, the intermediate plate forms the dividing wall and the capillary channels 12 and 13. The capillary channels 12 and 13 are formed of a microscopical internal through hole provided with the both end parts of the intermediate plate.

The intermediate plate will be explained using FIGS. 7 to 9. In addition, in the explanation, it is premised that the heat transporting unit 1 is provided with a plurality of intermediate plates. Moreover, each of the plurality of intermediate plates possesses different structure.

Referring to FIGS. 7-8, the intermediate plate 40, which is laminated between the upper plate 2 and the lower plate 3, possesses a shape and size opposing to the upper plate 2 and the lower plate 3. In other words, it is preferable that the intermediate plate 40 is the rectangle possessing the lateral direction and the longitudinal direction, and also possesses the substantially same size with the upper plate 2 and the lower plate 3. The intermediate plate 40 is provided with a board 41 and an internal through hole 42.

When the internal space 4 is formed between the upper plate 2 and the lower plate 3, the board 41 divides the internal space 4 into the upper and lower sides. Specifically, the board 41 divides the path 5 forming on the upper side of the internal space 4 and the groove 10 forming on the lower side. The board 41 becomes the dividing wall 11.

Moreover, the intermediate plate 40 possesses the microscopical internal through hole 42 near the both end parts. Since the internal through hole 42 passes through the part of the dividing wall 11, the path 5 and the groove 10 are connected via the internal through hole 42.

Herein, the internal through hole 42 is formed according to the position of the path 5. In other words, it is preferable that the internal through hole 42 is not formed on the sidewall which divides each of the plurality of paths. This is because even though the internal through hole is provided on the sidewall, this internal through hole does not play a role of a capillary channel. As shown in FIG. 8, the internal through hole 42 may be lined systematically or at random.

Since at least one of the intermediate plates 40 is laminated between the upper plate 2 and the lower plate 3, the internal space 4 is divided into the upper side and the lower side of the path 5 and the groove 10, and the path 5 and the groove 10 can communicate only in the capillary channels 12 and 13.

The internal through hole 42 passes through from the front surface to the rear surface of the intermediate plate 40. The shape of the internal through hole 42 may be circular, elliptic, or rectangle. Alternatively, the shape may be a slit-like shape. The internal through hole 42 is formed by digging, press, wet etching, dry etching, or the like.

Moreover, a plurality of the intermediate plates 40 including the board 41 and the internal through hole 42 may be laminated. When the plurality of the intermediate plates 40 is laminated between the upper plate 2 and the lower plate 3, the thickness of the dividing wall 11 increases, and the path 5 and the groove 10 are surely divided. In addition, since the internal through hole 42 is laminated in the upper and lower sides of the internal space, the capillary channels 12 and 13 with high capillary force are formed.

For example, when the intermediate plate 40 is of plurality, the internal through hole 42 is formed in each of the plurality of the intermediate plates 40. Herein, when the position of an internal through hole 42 is shifted for every intermediate plate 40 being adjacent thereto, the plurality of the intermediate plates 40 is laminated so that only some parts of the internal through hole 42 may overlap, respectively. For example, the position of the internal through hole 42 in an intermediate plate 40 and the position of the internal through hole 42 in another intermediate plate 40 being adjacent to this intermediate plate 40 are overlapped by shifting a part of the sections of the internal through holes 42. When the plurality of the intermediate plates 40 is laminated by shifting the position of the internal through hole 42 for every intermediate plate 40 being adjacent thereto, the capillary channels 12 and 13, which have a cross-section area smaller than the cross-section area of the horizontal direction of an internal through hole 42, are formed.

In the capillary channels 12 and 13, when the plurality of the intermediate plates 40 is laminated, some parts of the internal through holes 42 are overlapped. Thus, the capillary channels 12 and 13 possess a cross-section area which is smaller than the cross-section area of the internal through hole 42 in the horizontal direction. Since the hole possessing the cross-section area, which is smaller than the cross-section area of such internal through hole 42, communicates in the path 5 and the groove 10, the condensed refrigerant circulates in the capillary channels 12 and 13 with high capillary force.

In addition, when the capillary channels 12 and 13 possessing the cross-section area, which is smaller than that of the internal through hole 42, is formed by overlapping some parts of the internal through hole 42, there is also a merit that it can be manufactured easier comparing to a case where processing the capillary channels 12 and 13 directly.

In addition, the condensed refrigerant circulates in the capillary channels 12 and 13, and the evaporated refrigerant may pass in the capillary channels 12 and 13.

Moreover, it is also preferable that angle portions of the capillary channels 12 and 13 are beveled or “R” is prepared. Sections of the capillary channels 12 and 13 may have various shapes, such as a hexagon, a circular form, an ellipse form, a rectangle, a polygon, or the like. The shape of the cross-section for the capillary channels 12 and 13 is determined by the shape of the internal through hole 42 and how the internal through holes 42 are overlapped. Moreover, a cross-section area is determined similarly.

Referring to FIG. 9, since the intermediate plate 40 is laminated between the upper plate 2 and the lower plate 3, the internal space 4 is divided into a region forming the path 5 and a region forming the groove 10. At this time, the intermediate plate 40 possesses the board 41, there is hardly a space between the board 41 and the upper plate 2. Since the path 5 is formed between the board 41 and the upper plate 2, it is preferable that another member forming the path 5 between the upper plate 2 and the intermediate plate 40.

On the other hand, since the board 41 of the intermediate plate 40 is laminated in order to cover the groove 10 formed in the lower plate 3 by cutting, the capillary force in the circulation of the condensed refrigerant increases. For this reason, it is not necessary to laminate another member in the lower plate 3 and the intermediate 40.

In addition, it is premised that the path 5 is formed between the upper plate 2 and the intermediate 40 and the groove 10 is formed in the lower plate 3 and the intermediate plate 40.

Further, an intermediate plate with slit 45 is laminated with the intermediate plate 40. Dissimilar to the intermediate plate 40, the intermediate plate with slit 45 does not possess the board 41, but is provided with a slit 46 forming the path 5. The number of the slits 46 is the same as the number of the paths 5.

When the intermediate plate with slit 45 is laminated in the internal space 4, the slit 46 becomes the path 5, and a frame 47, which divides slits being adjacent to each other, becomes the sidewalls of the path 5. The slit 46 reaches to even the region of the internal through hole 42 which the intermediate plate 40 possesses. The internal through hole 42 communicates with the slit 46. The internal through hole 42 communicates with the path 5 and the groove 10 as the capillary channels 12 and 13.

One intermediate plate with slit 45 may be laminated, however, the height of the path 5 can be higher by laminating a plurality of the intermediate plates with slits 45.

In addition, it is preferable that the intermediate plate with slit 45 in FIG. 9 does not possess the internal through hole, the internal through hole 42 which is possessed by the intermediate plate 40 being also laminated, communicates with the slit 46, and the intermediate plate with slit 45 possesses the internal through hole communicating with the internal through hole 42 (a part or the entire of the sections for the internal through hole communicates). When the intermediate plate 40 and the intermediate plate with slit 45 are laminated, the board 41 of the intermediate plate 40 and the slit 46 of the intermediate plate with slit 45 are overlapped, and the path 5 will be formed. Furthermore, when the intermediate plate 40 and the intermediate plate with slit 45 are laminated, the entire of or the parts of the internal through hole of the intermediate plate 40 and the internal through hole of the intermediate plate with slit 45 are overlapped with each other, and the capillary channels 12 and 13 will be formed. The capillary channels 12 and 13, which are formed as mentioned above, possess the small cross section area, and high capillary force.

In addition, when each of the upper plate 2, the lower plate 3, the intermediate plate 40 and the intermediate plate with slit 45 is laminated, it is preferable that these members possess a projection or a convex section used as a adhesive.

Moreover, since the laminated heat transporting unit 1 is formed by laminating the upper plate 2, the lower plate 3, the intermediate plate 40, and the intermediate plate with slit 45, metal plating or surface treatment may be performed for the upper plate 2, the lower plate 3, the intermediate plate 40, and the intermediate plate with slit 45 if necessary. By performing the metal plating or the surface treatment for each member, the refrigerant can be moved in the path 5 and the groove 10 to be formed at higher speed.

As mentioned above, the heat transporting unit 1 is formed by laminating the upper plate 2, the lower plate 3, the intermediate plate 40, and the intermediate plate with slit 45.

The path 5 is provided on the side of the upper plate 2 of the internal space 4. In addition, even though the path 5 is provided on the side of the upper plate 2, the path 5 does not need to be physically on the upper side of the heat transporting unit 1 when the heat transporting unit 1 is provided. The heat transporting unit 1 may be provided being horizontally or vertically to the surface of the ground earth surface.

The path 5 is formed by laminating in the order of the upper plate 2, the intermediate plate with slit 45, and the intermediate plate 40. When these members are laminated in this order, the upper plate 2 and the board 41 of the intermediate plate 40 become lids of the groove 10. The path 5 is formed by the space of the slits of the intermediate plate with slit 45. The slit 46 is divided by the frame 47. The frame 47 touches the upper plate 2 and the intermediate plate 40. For this reason, the frame 47 becomes the sidewalls of the path 5 as it is.

Moreover, since the slit 46 is formed in the longitudinal direction of the intermediate plate with slit 45, the path 5 is also formed in the longitudinal direction of the heat transporting unit 1. The internal through hole 42 being provided on the intermediate plate 40 exists near the both ends of the path 5. The path 5 and the groove 10 communicates with each other in the capillary channels 12 and 13 being formed by the internal through hole 42.

Herein, it is also preferable that angle portions of the path 5 are beveled or “R” is prepared. Since the angle portions of the upper plate 2, the lower plate 3, and the intermediate plate 40, and the intermediate plate with slit 45 are beveled, the chamfer and “R” are formed by laminating these members.

Moreover, it is preferable that the front surface of the path 5 possesses the metal plating. At least one of gold, silver, copper, aluminum, nickel, cobalt, or these alloys, may be selected for the metal plating. Electrolytic plating, nonelectrolyte plating, or the like can be used.

The path 5 is formed in the longitudinal direction of the heat transporting unit 1, and diffuses the evaporated refrigerant in the longitudinal direction. At this time, since the condensed refrigerant (liquid) circulates in the groove 10 being separated by the path 5, the path 5 can diffuse the evaporated refrigerant without receiving interference of the condensed refrigerant. For this reason, the path 5 can diffuse the evaporated refrigerant at very high speed.

A groove 10 is provided on the lower plate 3. Since the condensed refrigerant circulates in the groove 10, it is preferable that the groove 10 possesses a size of the cross section area, in which capillary action occurs, and does not possess a large cross section area such as the path 5 possesses. For this reason, the groove 10 is not formed by laminating the intermediate plates, but is formed by cutting the lower plate 3 directly.

The groove 10 is formed by cutting a plurality of dug-in parts in the longitudinal direction of the lower plate 3. The groove 10 opposes to the path 5 via the dividing wall 11. Moreover, it is preferable that the plurality of grooves 10 opposes to one path 5. The reason is that since one path 5 and the plurality of grooves 10 opposes to each other, it is possible to hold the balance between the amount of the refrigerant to be diffused and the amount of the refrigerant to be circulated. The reason is also that since the balance between the amount of the refrigerant to be diffused and the amount of the refrigerant to be circulated is held, the path 5 diffuses the refrigerant and the speed, which the refrigerant circulates in the groove 10, further improves.

Moreover, the groove 10 communicates with the internal through hole 42, which the intermediate plate 40 possesses. Since the internal through hole 42 forms the capillary channels 12 and 13, the groove 10 communicates with the path 5 via the capillary channels 12 and 13.

Similar to the path 5, it is also preferable that angle portions of the grove 10 are beveled or “R” is prepared. Since the angle portions of the upper plate 2, the lower plate 3, the intermediate plate 40, and the intermediate plate with slit 45 are beveled, the chamfer and “R” are formed by laminating these members.

Moreover, it is preferable that the front surface of the groove 10 possesses the metal plating. At least one of gold, silver, copper, aluminum, nickel, cobalt, or these alloys, may be selected for the metal plating. Electrolytic plating, nonelectrolyte plating, or the like can be used.

According to the processing, the condensed refrigerant can circulated in the groove 10 at high speed.

In addition, the section of the shape for the groove 10 may vary such as a triangle, a rectangle, a semicircle, or the like.

Capillary channels 12 and 13 are formed of the internal through hole 42 (alternatively, laminating of the internal through hole 42 which the plurality of the intermediate plates 40 possesses). The condensed refrigerant circulates in the capillary channels 12 and 13 according to the capillary action.

The evaporated refrigerant is refrigerated at the end part, which is the other side of the heating element, and then is condensed. This refrigerated and condensed refrigerant exists at the end part of the path 5. The capillary channel 13 exists at the end part of this path 5. The capillary channel 13 makes this condensed refrigerant circulate from the path 5 to the groove 10.

Furthermore, the condensed refrigerant, which is moved from the end part to another end part (an end part where a heating element exists) via the groove 10, circulates from the groove 10 to the path 5 via the capillary channel 12. As a result, the condensed refrigerant is supplied to the path 5.

When the laminated capillary channels 12 and 13 are formed by laminating the plurality of the intermediate plates (it may be the intermediate 40 or the intermediates plate with slit 45) possessing the internal through hole 42, only some parts of the internal through holes 42 are overlapped and laminated. Since only some parts are overlapped, the capillary channels 12 and 13 possessing a cross section area, which is smaller than the cross section area of the internal through hole 42, are formed.

A hole possessing a smaller cross section area comparing to the cross section area of such an internal through hole 42 is laminated in the vertical direction of the capillary channels 12 and 13, and each hole in the vertical direction connects each other. Thus, a channel in the vertical direction can be formed. Moreover, since the holes are stair-like in the vertical direction, a channel, whose circulation is in the vertical direction and the horizontal direction, is formed. The channel formed in the vertical and horizontal directions possesses a very small cross section area, and makes the condensed refrigerant circulate in the vertical direction or the vertical and horizontal directions.

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

A refrigerant circulates back and forth between the path 5 and the groove 10. Referring to FIG. 3, the heating element 20 touches the heat transporting unit 1 thermally in the first end part 21. The heat transporting unit 1 makes the refrigerant evaporate in the first end part by the heat received from the heating element 20. The evaporated refrigerant moves in the path 5 from the first end part 21 to the second end part 22. The evaporated refrigerant, which moves in the path 5 from the first end part 21 to the second end part 22, is refrigerated and condensed in the second end part 22. The condensed refrigerant circulates in the capillary channel 13. According to the circulation, the condensed refrigerant moves from the path 5 to the groove 10.

The condensed refrigerant, which has moved to the groove 10, moves in the groove 10 from the second end part 22 to the first end part 21. As the result of the movement, the condensed refrigerant reaches the side of the first end part 21 of the groove 10. This condensed refrigerant circulates in the capillary channel 12 and moves from the groove 10 to the path 5.

The condensed refrigerant, which has reached the path 5, evaporates by the heat from the heating element 20 again, and moves in the path 5.

When the evaporated refrigerant moves in the path 5, and the condensed refrigerant moves in the groove 10 repeatedly, a refrigerant being vapor and a refrigerant being liquid can be circulated in the same space without interference or collision. According to this circulation, the heat transporting unit can transport the heat of the heating element in a certain direction with high efficiency.

Referring to FIG. 10, which illustrates another embodiment of the according to the Present Application, a heat transporting unit 50 is shown from the top, and a part of the internal structure is seen through dashed lines. The heat transporting unit 50 shown in FIG. 10 is further provided with a communicating path 51 wherein a refrigerant can move in each of the plurality of paths. The plurality of paths 5 are divided by sidewalls 54 into such as a path 5a, a path 5b, and a path 5c, respectively.

For this reason, the path 5 only communicates with a groove (it is not shown in FIG. 10), which opposes to the path 5, via the capillary channels 12 and 13. A refrigerant included in the path 5a circulates only in the groove opposing to the path 5a. According to this circulation, the heat transporting unit can transport the heat of the heating element in the first direction at high speed.

On the other hand, as shown in FIG. 10, a microscopic heating element 52 may touch thermally in the heat transporting unit 50. For example, a light emitting element such as an LED is very small. The width of the light emitting element light may be smaller than the path 5 of the heat transporting unit 50. In FIG. 10, a heating element 522 touches the path 5b and the path 5d thermally, heating elements do not touch thermally the other paths.

In the paths 5b and 5d where the heating element 52 touch thermally, the refrigerant evaporates by receiving the heat, and the evaporated refrigerant moves therein. The moved and evaporated refrigerant is refrigerated and condensed. Then, the condensed refrigerant circulates from the paths 5b and 5d to the groove opposing to the paths 5b and 5d via the capillary channel 13. The circulated and condensed refrigerant moves in the groove, and then moves to the path 5b and 5d from the capillary channel 12 again.

Since the amount of caloric value to be received is small in another paths where the heating element 52 does not thermally touch (for example, the path 5a, the path 5c, or the like), only a few of refrigerants evaporates. For this reason, these paths do not require a lot of refrigerants. On the other hand, in the paths 5b and 5d where the heating element 52 touches, many refrigerants are required for transporting the heat from the heating element 52.

In the communicating path 51, the plurality of the paths 5 communicates with each other (for example, the path 5b and the path 5c), thus it is possible to move the evaporated refrigerant between the paths. When the evaporated refrigerant can move between the plurality of the paths, it is possible to supply the refrigerant to the paths 5b and 5d requiring a lot of refrigerants from the paths not requiring refrigerants. It is possible to transport the heat received from the heating element 52 using the refrigerants supplied from the other paths.

Thus, since the heat transporting unit 50 is provided with the communicating path 51, even when a compact heating element touches only a part of the plurality of the paths 5, the heat can be transported by using the refrigerant sealed in the internal space efficiently.

In addition, the communicating path 51 makes the paths 5 communicate with each other, it may make the grooves, which are adjacent to each other, communicate with each other.

When the communicating path 51 makes the grooves communicate with each other, the condensed refrigerant can move between the grooves. In this case, a groove (eventually, a path) requiring more refrigerants can acquire more necessary refrigerants comparing to a groove (eventually, a path) not requiring more refrigerants. As a result, it is possible to realize heat transporting for every path or groove at a different level.

The communicating path 51 may be formed by digging a hole in the sidewall 54, and may be formed by laminating the sidewalls 54 where holes have been already dug. A hole may be dug and formed in a sidewall 54 and a communicating path 51 may be formed by the sidewall 54 by which the hole is dug beforehand being laminated. Moreover, it is preferable that metal plating or front surface processing is performed for the front surface of the communicating path 51 for the refrigerant moving easier. It is also preferable that angle portions of the groove 10 are beveled or “R” is prepared.

Referring to FIG. 11, the heat transporting unit is shown as an electronic device stored in a case. FIG. 11 is a mimetic diagram of an electronic device according to the Present Application.

The electronic device 60 is provided with an electronic board 64 stored in a heating element 61 and inside of the case. The heating element 61 is mounted in the electronic board 64. The heating element 61 is an electronic part which emits heat.

In a contacting part 71, a heat transporting unit 70 touches the heating element 61 thermally.

The heat transporting unit 70 possesses the same function and structure as the heat transporting units 1 and 5.

The heating element 61 thermally touches one of the end parts of the heat transporting unit 70. The heat transporting unit 70 transports the heat received from this heating element 61 to the other end part. In transporting, the evaporated refrigerant moves in the path, the condensed refrigerant moves in the groove, and the refrigerant circulates in the longitudinal direction of the heat transporting unit 70 form one end part to the other end part. The heat of the heating element 61 is transported by the circulation of this refrigerant.

The heat transporting unit 70 is provided with a heat radiating unit 63 operable to refrigerate the evaporated refrigerant at the end part, which is the other side of the end part where the heating element 61 thermally touches. A cooling fan is shown as an example of the heat radiating unit 63 in FIG. 11.

The cooling fan refrigerates the end part of the heat transporting unit 70. The moved and evaporated refrigerants are accumulated in this end part. The cooling fan refrigerates this evaporated refrigerant. By refrigerating the evaporated refrigerant, the refrigerant is condensed, and becomes liquid. The condensed refrigerant circulates from the path to the groove via the capillary channel.

Thus, since the heat transporting unit 70 is provided with the heat radiating unit 63, the heat transporting unit 70 can efficiently refrigerate the evaporated and transported refrigerant. For this reason, it is preferable that the heat radiating unit 63 refrigerates the end part, which is the other side of the heating element 61 in the heat transporting unit 70. By refrigerating the other side of the end part, condensation of the evaporated refrigerant is promoted, and the heat transporting unit 70 can transport the heat taken from the heating element 61 in the first direction faster.

Moreover, it is also preferable that the heat transporting unit 70 is provided with the contacting part 71 which touches heating element 61 thermally.

The contacting part 71 makes the heating element 61 thermally touch the heat transporting unit 70 much easier. For example, it is also preferable that the contacting part 71 is provided with a TIM (thermal interface material).

A material, such as thermal grease or thermal grease for which a filler is added, is used for a thermal interface material. It is enough that these thermal interface materials are applied to the contacting part 71.

Since the contacting part 71 is provided with the thermal interface material, the thermal resistance with the heating element 61 becomes smaller. The small thermal resistance makes the heat transporting unit 70 receive the heat from the heating element 61 much easier.

In addition, the heating element 61 may thermally touch the upper plate side of the heat transporting unit 70, or may thermally touch the lower plate side (in other words, a side where the groove exists). According to the heat received from the heating element 61, the refrigerant is circulated.

As mentioned above, since the heat transporting unit 70 thermally touches to the heating element 61 included in the electronic device 60, the heat generated from the heating element 61 can be transported efficiently from the heating element 61 to a position being away from the heating element 61. As a result, the heating element 61 can be refrigerated efficiently. In other words, it is possible to prevent from the malfunction due to the heat generation of the electronic device 60.

Moreover, since the heat transporting unit 70 is formed by laminating an upper plate or a lower plate possessing a thin plate-like shape, it is very compact. For this reason, the downsizing of an electronic device is not obstructed. Similar to the electronic board 64, even though an electronic device possesses a large area, a lot of components, whose thickness is small, are stored. For this reason, although the mounting space is left in the horizontal direction, most mounting spaces are not left in the thickness direction. In this situation, since the heat transporting unit 70 possesses a thin shape and can transport the heat in the horizontal direction, it is suitable for refrigerating the heating element 61.

As mentioned above, without obstructing downsizing and making thinner shape for the electronic device, the heat transporting unit 70 can efficiently refrigerate the heating element 61.

As an example of the electronic device, it is also preferable that a portable terminal as shown in FIG. 12 is used. An electronic device 80 is an electronic device, such as a car television and a personal monitor, for which a thin shape and a small size are required.

The electronic device 80 is provided with a display 83, a light emitting element 84, and a speaker 85. The heat transporting unit 1 is stored inside of this electronic device 80, it is possible to realize refrigerating the heating element.

By using such a heat transporting unit 70, it is possible to realize the heating element without obstructing downsizing and making thinner shape for the electronic device. In other words, the heat transporting unit 70 can transport the heat from the heating element at high speed and refrigerate. Thus, it suppresses the heat generation of the heating element.

The heat transporting unit 70 can be replaced with a heat radiating fin, a liquid-cooled device, or the like, which is mounted in a notebook personal computer, a portable terminal, a computer terminal, or the like. The heat transporting unit 70 can be also replaced with a heat radiating frame, a cooling device, or the like, which is mounted in a light, an engine, and a control computer unit of an automobile and an industrial apparatus. Since the heat transporting unit 70 possesses a higher cooling ability comparing to the heat radiating fin and the heat radiating frame which are used conventionally, it can be naturally downsized. Furthermore, the flexible correspondence to the heating element is also possible, and various kinds of electronic parts can be targeted for refrigerating. As a result, the heat transporting unit 70 possesses a large applicability range.

Moreover, in FIG. 11, although the heat transporting unit 70 possesses the plate-like shape, it is formed by laminating thin boards. Thus, it is possible to be bended or curved. Even in this case, the evaporated refrigerant is diffused in the path, and circulates in the capillary channel. Then, the condensed refrigerant circulates in the groove which is separated by the path. Thus, the heat transporting unit can transport the heat with high efficiency. Since the evaporated refrigerant and the condensed refrigerant do not interfere with each other, the heat transporting efficiency is high.

For example, depending on the shape of the inside for the electronic device, the shape of the heat transporting unit 70 has to be curved in order to be mounted for some cases. In such a case, the curved heat transporting unit 70 is mounted.

Referring to FIG. 13, the heat transporting unit 1 is manufactured by laminating and connecting the upper plate 2, the lower plate 3, the intermediate plate 40, and the intermediate plate with slit 45. The lower plate 3 possesses the groove 10 beforehand.

A plurality of the intermediate plates 40 and the intermediate plates with slit 45 are laminated between the upper plate 2 and the lower plate 3. As shown in FIG. 7, the intermediate plate 40 is provided with the board 41 and the internal through hole 42. For this reason, the intermediate plate 40 becomes a lid for the groove with which a lower plate 3 is provided. A single of or a plurality of the intermediate plates with slit 45 (three plates in FIG. 13) are laminated on the intermediate plate 40. As shown in FIG. 9, the intermediate plate with slit 45 possesses the slit 46 and the frame 47. When the intermediate plate with slit 45 and the upper plate 2 are laminated, a plurality of the paths 5 is formed. In order to increase the height of the path 5, it is preferable that the plurality of the intermediate plates with slit 45 is laminated.

Each of the upper plate 2, the lower plate 3, and the plurality of the intermediate plates 40 and the intermediate plates with slit 45 is matched with the predetermined position relationship, respectively. In addition, the plurality of the intermediate plates 40 and the intermediate plates with slit 45 is overlapped with each of parts of the internal through holes 42, which is provided in each of the plurality of the intermediate plates 40 and the intermediate plates with slit 45, respectively.

At least one of the upper plate 2, the lower plate 3, and the plurality of the intermediate plates 40 and the intermediate plates with slit 45 possesses a bonding projection.

After each position is matched, the upper plate 2, the lower plate 3, and the plurality of the intermediate plates 40 and the intermediate plates with slit 45 are laminated, and then are joined directly by heat press in order to be unified. At this time, each member is directly joined by the bonding projection.

Herein, direct joining means that pressing and heat processing are performed while surfaces of two members to be bonded are adhered, and also means that each of atoms according to the atomic force, which occurs between the surfaces, is firmly bonded. Thus, the surfaces of the two members can be unified without using adhesives. At this time, it is possible to realize the firm bonding by the bonding projection. In other words, the thermal bonding is realized by crushing the bonding projection and increasing the area of contact. Thus, the bonding projection plays a high role in bonding.

As for a condition for the direct joining in the heat press, pressure is preferably of 40 kg/cm² to 150 kg/cm², and temperature is preferably of 250 to 400° C.

Next, the refrigerant is injected through an injection port made in the part of the upper plate 2 or the lower plate 3. Then, the injection port is sealed, and the heat transporting unit is completed. In addition, the refrigerant is entered under a vacuum or decompression. By performing under a vacuum or decompression, the status of the internal space of the thermal diffusing unit or the heat transporting part becomes under a vacuum or decompression. Then, the refrigerant is entered. When it is under decompression, the temperature of vaporization and condensation of a refrigerant becomes low. Thus, there is a merit of promoting the repetition of the vaporization and condensation of the refrigerant.

While a preferred embodiment of the Present Application is shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the foregoing Description and the appended Claims.

Claims

1. A heat transporting unit (1) comprising:

an upper plate (2);

a lower plate (3) opposing to said upper plate (2);

an internal space (4) formed by said upper plate (2) and said lower plate (3), said internal space being operable to seal a refrigerant therein;

a plurality of paths (5) dividing said internal space in a first direction; and

a plurality of grooves (10) provided on a bottom surface of said internal space (41);

wherein: said plurality of paths (5) and said plurality of grooves (10) are connected to each other at a partial region by capillary channels (12) and (13); and said plurality of paths (5) and said plurality of grooves (10) are separated from each other at another partial region by dividing walls (11).

2. The heat transporting unit (1) of claim 1, wherein:

said upper plate (2) is of a plate-like shape and includes a first space, which is of a plate-like shape, of an upper plate (2) side;

said lower plate (3) is of a plate-like shape and includes a second space, which s of a plate-like shape, of a lower plate side;

said plurality of paths (5) are formed in the first space of the upper plate side; and

said plurality of grooves (10) oppose to said plurality of paths (5) via the dividing walls (1 I), and are formed in the second space of the lower plate (3) side.

3. The heat transporting unit (1) of claim 2, wherein each of said plurality of paths (5) opposes to one or more grooves among said plurality of grooves (10).

4. The heat transporting unit (1) of claim 3, wherein said plurality of grooves (10) are formed in the first direction.

5. The heat transporting unit (1) of claim 4, wherein said plurality of paths (5) and said plurality of grooves (10) include first end parts (21) of an end in the first direction, and second end parts (22) of another end in the first direction.

6. The heat transporting unit (1) of claim 5, wherein the capillary channels (12) and (13) are provided with the first end parts (21) and the second end parts (22), respectively.

7. The heat transporting unit (1) of claim 6, wherein each of the dividing walls (11) includes a plurality of internal through holes (42).

8. The heat transporting unit (1) of claim 7, wherein the plurality of internal through holes (42) form the capillary channels (12) and (13).

9. The heat transporting unit (1) of claim 8, wherein corner portions of at least one of said plurality of paths (5) and said plurality of grooves (10) are chamfered.

10. The heat transporting unit (1) of claim 9, wherein metal-plating is performed on surfaces of at least of said plurality of paths (5) and said plurality of grooves (10).

11. The heat transporting unit (1) of claim 10, wherein the metal-plating is performed with metal selected from a group consisting of gold, silver, copper, aluminum, nickel, cobalt, and alloy thereof.

12. The heat transporting unit (1) of claim 11, further comprising communication paths (51) where the refrigerant can move from one to another of said plurality of paths (5).

13. The heat transporting unit (1) of claim 12, wherein the capillary paths (12) and (13) connect said plurality of paths (5) and said plurality of grooves (10) at the first end parts (21) and the second end parts (22).

14. The heat transporting unit (1) of claim 13, wherein the refrigerant receives heat from the heating element (20) at the first end parts (21) to evaporate.

15. The heat transporting unit (1) of claim 14, wherein the evaporated refrigerant diffuses in said plurality of paths (5) from the first end parts (21) to the second end parts (22).

16. The heat transporting unit (1) of claim 15, wherein the evaporated refrigerant is condensed at the second end parts (22).

17. The heat transporting unit (1) of claim 16, wherein the condensed refrigerant circulate from said plurality of path (5) to said plurality of grooves (10) via the capillary channels (13).

18. The heat transporting unit (1) of claim 17, wherein the refrigerant that is circulating on said plurality of grooves (10) and that is condensed moves on said plurality of grooves (10) from the second end parts (22) to the first end parts (21), and further circulates from said plurality of grooves (10) to said plurality of paths (5) at the first end parts (21).

19. The heat transporting unit (1) of claim 18, further comprising a heat radiating unit (63) for refrigerating the refrigerant evaporated at the second end parts (22).

20. The heat transporting unit (70) of claim 19, further comprising a contacting part (71) for thermally contacting with a heat element at the first end parts (21).