JP5185012B2 - Cooling unit and electronic equipment - Google Patents

Description

  The present invention relates to a cooling unit and an electronic apparatus for cooling 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 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.

  On the other hand, light emitting devices such as LEDs (Light Emitting Devices) and high-density semiconductor integrated circuits are used not only in high-end electronic devices such as computers and workstations, but also in small computers such as notebook computers, mobile phones, and mobile terminals. It has also been implemented in other electronic devices. In addition, not only electronic devices but also LED (Light Emitting Device) and other high-density semiconductor integrated circuits are installed one after another in engines, control devices, lighting devices, etc. for automobiles, transportation vehicles, and aircraft. Has been. In such small devices and automobiles, the mounting space for the heat pipe is often small or the structure of the mounting space is complicated.

  The heat pipe can easily receive and diffuse heat from the heating element due to the diffusion of the vaporized refrigerant, but often the vaporized refrigerant cannot be sufficiently cooled. For this reason, the heat pipe also has a form having a space for vaporizing the refrigerant by heat from the heating element, a pipe for transmitting the vaporized refrigerant, and a space for cooling and condensing the refrigerant that has reached the pipe. . Thus, the heat pipe having a form in which spaces corresponding to functions are separated is very difficult to mount in a narrow space or a complicated structure space such as a small device or an automobile. In a narrow space or a space with a complicated structure, an integral type or flat plate type heat pipe is suitable.

  However, the integrated or flat heat pipe cannot sufficiently diffuse the vaporized refrigerant, or cannot sufficiently cool the vaporized refrigerant. For this reason, a cooling device in which a heat pipe serving as a base plate is combined with a heat sink has been proposed (for example, see Patent Documents 1 and 2).

Alternatively, a cooling device has been proposed in which a heat pipe capable of cooling a heating element by vaporizing and condensing a sealed refrigerant is erected like a fin on a metal plate serving as a base plate (see, for example, Patent Document 3). Furthermore, a technique in which an electronic component is mounted on each of the plurality of heat radiating fins and cooled by a cooling fan has been proposed (see, for example, Patent Document 4).
JP 2001-244396 A JP 2007-333263 A JP 2007-335669 A JP 2001-237356 A

  However, as described in the background art, in recent years, light emitting elements, electronic components, semiconductor integrated circuits, and the like that generate high heat are variously used in electronic devices and automobiles. In addition, since many and many types of light emitting elements and electronic components are used, the cooling device needs to flexibly cope with the types and mounting states of the light emitting elements and electronic components. For example, it may be necessary to cool a semiconductor integrated circuit that generates a large amount of heat alone, or it may be necessary to cool a large number of light emitting elements. In particular, since the light emitting element needs to secure a space for light rays to be emitted, it needs to be mounted not on the rear surface of the cooling device but on the end portion or the end surface.

  Further, since the mounting space is limited, it is not appropriate to prepare different cooling devices depending on the heating element to be cooled from the viewpoint of mounting, cost and manufacturing process. In addition, since the heat generation amount of the light emitting elements and electronic components is gradually increased and the mounting space is narrowed, the cooling device needs to have a higher cooling capacity.

  Here, Patent Documents 1 and 2 disclose a cooling device in which fins are erected on the surface of a heat pipe enclosing a refrigerant, and the heat pipe and the heat sink are integrated. However, since the fins, which are metal bodies, only dissipate heat from the heat pipe serving as the base plate, the cooling capacity of the cooling devices of Patent Documents 1 and 2 is not high. This is because the heat resistance between the heat pipe and the fin is high and the heat conducted from the heat pipe is conducted without being diffused in the fin.

  Moreover, since the cooling device of patent document 1, 2 has installed the fin upright in the heat pipe used as a baseplate, the cooling device can cool only the heat generating body arrange | positioned at the back surface of a heat pipe.

  Patent Document 3 discloses a cooling device in which a plurality of plate-like heat pipes are erected on a metal plate serving as a base plate. However, even if a heat pipe is used for the fin, the heating element is arranged on the base plate, so that the heat diffusion in the base plate is insufficient and the heat from the base plate cannot reach the fin that is a heat pipe effectively. For this reason, the cooling capacity of the cooling device disclosed in Patent Document 3 is not high. Moreover, since the heat pipe (used as a fin) in the cooling device disclosed in Patent Document 3 does not have a capillary channel, the refrigerant cannot be sufficiently diffused and refluxed. Also from this, the cooling capacity of the cooling device is not high.

  Moreover, since the cooling device disclosed in Patent Document 3 has heat pipes as fins standing on the base plate, the cooling device can cool only the heating elements arranged on the back surface of the base plate.

  Moreover, like patent documents 1-3, the cooling device which combined the heat pipe and the heat sink is a combination with a point with a bad heat conduction between a metal plate and a heat pipe, or a point with a bad heat diffusion in a metal plate. It is difficult to improve the cooling capacity. Moreover, it is difficult for the base plate to optimally diffuse heat to the plurality of fins. As a result, regardless of whether the base plate is a metal plate or a heat pipe, it is difficult to efficiently conduct heat from the heating element disposed on the back surface of the base plate to the fins.

  In particular, it can only cool the heat from the heating element placed on the back of the base plate, and the cooling device of the prior art can flexibly handle various light emitting elements and electronic components that can be mounted on electronic devices and automobiles. Can not. For this reason, the cooling device in a prior art cannot respond to various requests from electronic devices and automobiles.

  The same applies to Patent Document 4.

  An object of the present invention is to provide a cooling unit and an electronic apparatus that can flexibly cope with the type of heating element to be cooled and that has a high cooling capacity even in a narrow mounting space.

In view of the above problems, the cooling unit of the present invention is erected on the surface of the first heat pipe having a flat plate shape and excellent heat diffusion in the radial direction from the central part to the peripheral part, and the surface of the first heat pipe, Each of the first heat pipe and the second heat pipe is provided with a flat plate-like second heat pipe excellent in heat diffusion in one direction from the first end portion to the second end portion facing the first end portion. co Upon cooling a heating element by vaporization and condensation of the encapsulated refrigerant with encapsulating refrigerant integrally includes a vapor diffusion path and the capillary flow path, the first heat pipe, toward the periphery from the center radiation A vapor diffusion path and a capillary channel extending in the direction are formed, and the second heat pipe forms a vapor diffusion path and a capillary channel extending in one direction from the first end to the second end, and the second heat Either the first or second end of the pipe The vapor diffusion path of the second heat pipe, the second heat pipe standing and standing on the surface of the first heat pipe so that is selectively positioned on the surface side of the first heat pipe, A cooling unit that has a shape that spreads from the end to the second end, and realizes the superiority of heat diffusion in one direction .

In the cooling unit of the present invention, since all of the base plate and the fins are constituted by heat pipes having a refrigerant vaporizing / condensing function, the heating element can be cooled with high capacity. In particular, compared with the case where only the base plate is a heat pipe or only the fin is a heat pipe, the cooling unit of the present invention can cool the heating element with high efficiency. Moreover, since all of the base plate and the fins are heat pipes, the cooling unit of the present invention can diffuse the heat of the heating element with high capacity. Also,
In particular, heat conduction from the heating element is optimally performed by combining heat pipes having different thermal diffusion characteristics. As a result, the cooling unit diffuses heat from the heating element from the base plate to the tip of the fin or from the tip of the fin to the base plate.

  Moreover, the cooling unit of the present invention can flexibly cope with the type of heating element to be cooled. In particular, even if the heating element is in contact with the first heat pipe or the heating element is in contact with the tip of the second heat pipe, the entire first heat pipe and second heat pipe constituting the cooling unit are efficient. To be cooled.

  Further, by incorporating heat pipes having different heat diffusion characteristics into the base plate and the fins, the cooling unit can diffuse heat using the entirety of the cooling unit from the front end of the fins or the back side of the base plate.

The cooling unit according to the first aspect of the present invention is provided with a flat plate-like first heat pipe excellent in heat diffusion in the radial direction from the central portion toward the peripheral portion, and standing on the surface of the first heat pipe. , Including a flat plate-like second heat pipe excellent in heat diffusion in one direction from the first end portion to the second end portion facing the first end portion, and each of the first heat pipe and the second heat pipe is , co cooling the heating elements by vaporization and condensation of the encapsulated refrigerant with encapsulating refrigerant integrally includes a vapor diffusion path and the capillary flow path, the first heat pipe toward the peripheral portion from the central portion A vapor diffusion path and a capillary channel extending in the radial direction are formed, and the second heat pipe forms a vapor diffusion path and a capillary channel extending in one direction from the first end to the second end, and the second heat pipe Either the first end or the second end of the heat pipe The vapor diffusion path of the second heat pipe, the second heat pipe standing and standing on the surface of the first heat pipe so that is selectively positioned on the surface side of the first heat pipe, A cooling unit that has a shape that spreads from the end to the second end, and realizes the superiority of heat diffusion in one direction .

With this configuration, the entire cooling unit can be configured by a heat pipe that can diffuse heat by vaporizing and condensing the refrigerant. For this reason, the cooling unit can be efficiently cooled while diffusing the heat from the heating element. In addition, since a highly efficient heat conduction path is formed from the first heat pipe to the second heat pipe (or vice versa), the cooling unit 1 can cool the heating element with high efficiency. Further, with this configuration, a heat conduction path is formed from the back surface of the first heat pipe to the second end of the second heat pipe.

  With this configuration, a heat conduction path is formed from the first heat pipe toward the second heat pipe or from the second heat pipe toward the first heat pipe.

In the cooling unit according to the second aspect of the present invention, in addition to the first aspect, when the heating element is disposed on the back surface of the first heat pipe, the first end is the front side of the first heat pipe. The second heat pipe is attached to the first heat pipe.

  With this configuration, a heat conduction path is formed from the back surface of the first heat pipe to the second end of the second heat pipe. With this formed heat conduction path, the cooling unit diffuses the heat of the heating element disposed on the back surface of the first heat pipe to the second end that is the tip of the second heat pipe. To cool the heating element with high efficiency.

In the cooling unit according to the third aspect of the present invention, in addition to the first or second aspect, when the heating element is disposed at the end of the second heat pipe, the second end is the first heat. Located on the surface side of the pipe, the second heat pipe is attached to the first heat pipe.

  With this configuration, a heat conduction path is formed from the tip of the second heat pipe to the back surface of the first heat pipe. With this formed heat conduction path, the cooling unit uses the entirety of the cooling unit to diffuse the heat of the heating element arranged at the tip of the second heat pipe to the back surface of the first heat pipe with high efficiency. The heating element can be cooled.

In the cooling unit according to the fourth aspect of the present invention, in addition to any one of the first to third aspects , the first end is located on the surface side of the first heat pipe and the second heat pipe is the first. When attached to the heat pipe, a heat conduction path is formed from the back surface of the first heat pipe to the second end of the first heat pipe, and the second end is located on the front side of the first heat pipe. When the second heat pipe is attached to the first heat pipe, a heat conduction path is formed from the first end of the second heat pipe toward the back surface of the first heat pipe.

  With this configuration, even if the heating element is suitable to be disposed on the back surface of the first heat pipe or the heating element is suitable to be disposed at the end of the second heat pipe, the second heat pipe is used. The cooling unit can form a heat conduction path only by changing the combination direction of the pipes. For this reason, the cooling unit can flexibly cope with various types of heating elements and can efficiently cool.

In the cooling unit according to the fifth aspect of the present invention, in addition to any of the first to fourth aspects , the first heat pipe includes an upper plate, a lower plate facing the upper plate, an upper plate and a lower plate. And the intermediate plate has a notch and an internal through hole, the notch forms a vapor diffusion path, and the internal through hole is a capillary tube. A flow path is formed, and the notch is formed from the central portion toward the peripheral portion of the intermediate plate.

  With this configuration, the first heat pipe is thin but has excellent heat diffusion characteristics from the center portion to the end portion, and can diffuse heat by utilizing the whole.

In the cooling unit according to the sixth invention of the present invention, in addition to any of the first to fifth inventions, the second heat pipe includes an upper plate, a lower plate facing the upper plate, an upper plate and a lower plate. One or more intermediate plates laminated between the plates, the intermediate plate has a notch and an internal through hole, the notch forms a vapor diffusion path, the internal through hole is A capillary channel is formed, and the notch is formed from a first end that is one end of the intermediate plate toward a second end facing the first end.

  With this configuration, the second heat pipe is thin but has excellent heat diffusion characteristics from the first end portion toward the second end portion, and can diffuse heat by utilizing the whole.

In the cooling unit according to the seventh aspect of the present invention, in addition to the sixth aspect , the width in the planar direction of the notch portion on the first end side is the planar direction of the notch portion on the second end side. Narrower than the width.

  With this configuration, the thermal diffusion characteristics from the first end to the second end of the second heat pipe are further improved.

In the cooling unit according to the eighth aspect of the present invention, in addition to any one of the first to seventh aspects, the second heat pipe is fitted into a mounting groove formed on the surface of the first heat pipe. Attached.

  With this configuration, the second heat pipe is firmly and reliably attached to the first heat pipe. Furthermore, the thermal resistance between the first heat pipe and the second heat pipe is also reduced.

In the cooling unit according to the ninth aspect of the present invention, in addition to the eighth aspect , at least one of the upper plate and the lower plate included in the second heat pipe is formed from at least one of the first end and the second end. The protrusion has a protrusion, and the protrusion covers at least a part of the outside of the attachment groove.

  With this configuration, the second heat pipe is firmly and reliably attached to the first heat pipe. Furthermore, the thermal resistance between the first heat pipe and the second heat pipe is also reduced.

In the cooling unit according to the tenth aspect of the present invention, in addition to any of the first to ninth aspects, a plurality of second heat pipes are erected on the surface of the first heat pipe.

  With this configuration, the cooling unit has a higher cooling capacity.

In the cooling unit according to the eleventh aspect of the present invention, in addition to any of the sixth to tenth aspects, the plurality of intermediate plates provided in each of the first heat pipe and the second heat pipe are plural, The internal through-holes provided in each of the intermediate plates overlap with each other to form a capillary channel having a cross-sectional area smaller than the horizontal cross-sectional area of the internal through-hole.

  With this configuration, it is possible to form a fine capillary channel with high accuracy while reducing labor of the manufacturing process.

In the cooling unit according to the twelfth invention of the present invention, in addition to any of the sixth to eleventh inventions, each of the upper plate and the lower plate provided in each of the first heat pipe and the second heat pipe , A recess is further provided that communicates with at least one of the capillary channel and the vapor diffusion channel.

  With this configuration, the recirculation of the vaporized refrigerant that has reached the heat radiation surface is promoted, and the condensed refrigerant can be easily and reliably recirculated from the recess to the capillary channel. In addition, cooling of the vaporized refrigerant is promoted.

  With this configuration, the first heat pipe and the second heat pipe are thin.

  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.

(Embodiment 1)
(Conceptual explanation of heat pipe)
First, the concept of the heat pipe will be described.

  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, the heat pipe needs to have a vapor diffusion path for diffusing the vaporized refrigerant therein and a capillary channel for recirculating 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.

  However, the flat and thin heat pipe has a limited moving space for the refrigerant, and the diffusion of the vaporized refrigerant and the reflux of the condensed refrigerant inside the heat pipe are not efficient. The inefficiency is a state where only a part of the heat pipe diffuses the vaporized refrigerant and recirculates the condensed refrigerant. A flat heat pipe is advantageous in mounting on an electronic device having only a small space, but the cooling performance tends to be insufficient.

  On the other hand, the heat pipe provided in the cooling unit of the present invention has an excellent heat diffusion performance (diffusion of vaporized refrigerant) and a reflux performance of condensed refrigerant while being thin. For this reason, in this invention, both the base plate and the fin in the cooling unit which combined the conventional base plate and the fin can be replaced with a heat pipe. Furthermore, as will be described below, the cooling unit of the present invention can realize a high cooling effect by optimal matching of the thermal diffusion characteristics of the first heat pipe constituting the base plate and the second heat pipe constituting the fin.

(overall structure)
FIG. 1 is a side view of a cooling unit according to Embodiment 1 of the present invention. FIG. 1 shows the inside of the heat pipe constituting the cooling unit as a see-through state.

  The cooling unit 1 includes a first heat pipe 2 and a second heat pipe 3 erected on the first heat pipe 2. That is, the cooling unit 1 has a configuration in which the first heat pipe 2 is a base plate and the second heat pipe 3 is a fin.

  Each of the first heat pipe 2 and the second heat pipe includes vapor diffusion paths 4 and 6 and capillary flow paths 6 and 7, and heat is diffused by vaporizing and condensing the refrigerant sealed inside. Cool down. Specifically, the refrigerant is vaporized by the heat from the heating element, and the vaporized refrigerant diffuses inside the first heat pipe 2 and the second heat pipe 3 via the vapor diffusion paths 4 and 6. The evaporated refrigerant is cooled and condensed, and the condensed refrigerant recirculates. The heat pipe cools the heating element by repeating the vaporization and condensation of the refrigerant. The vaporized refrigerant diffuses heat by diffusion. That is, the diffusion of the evaporated refrigerant indicates the diffusion of heat.

  Here, the cooling unit 1 includes two types of heat pipes, a first heat pipe 2 and a second heat pipe 3, and cools the heating element. The first heat pipe 2 and the second heat pipe 3 have different vaporized refrigerant diffusion characteristics (thermal diffusion characteristics). For example, the first heat pipe 2 has a heat diffusion characteristic from the center to the end, and the second heat pipe 3 has a heat diffusion characteristic from the first end 8 to the second end 9. doing.

  With the configuration in which the first heat pipe 2 and the second heat pipe 3 having different heat diffusion characteristics are combined, the cooling unit 1 is configured by the base plate and the fins as heat pipes, and has a high cooling capacity. Have

  For example, when a heating element is installed on the back surface of the first heat pipe 2, the first heat pipe 2 first takes heat from the heating element. Since the first heat pipe 2 diffuses heat from the central portion toward the end portion, the diffused heat is conducted to the second heat pipe 3 erected on the surface of the first heat pipe 2. Since the second heat pipe 3 has a thermal diffusion characteristic from the first end portion 8 toward the second end portion 9, the heat received from the first heat pipe 2 is transferred to the second heat pipe 3 at the tip (second end). Conducted towards part 9). That is, the heat from the heating element can be diffused using the entire first heat pipe 2 to the second heat pipe 3. If the thermal diffusion is sufficient, the vaporized refrigerant is efficiently condensed. Of course, when either the base plate or the fin is a metal plate as in the prior art, sufficient heat diffusion is not performed. Alternatively, sufficient heat diffusion is not performed in a heat pipe having a weak heat diffusion characteristic in the plane direction.

  In the cooling unit 1 of the first embodiment, in addition to the base plate and the fins being configured by heat pipes, the heating element is obtained by optimal matching of the thermal diffusion characteristics of the first heat pipe 2 and the second heat pipe 3. It can be cooled efficiently.

(First heat pipe)
Next, the first heat pipe 2 will be described.

  FIG. 2 is an inner surface view of the first heat pipe in the first embodiment of the present invention. FIG. 2 shows a state in which the first heat pipe is seen through from the plane direction. FIG. 3 is an exploded side view of the first heat pipe in the first embodiment of the present invention.

  The first heat pipe 2 includes a vapor diffusion path 4 and a capillary channel 5. As is clear from FIG. 2, the vapor diffusion path 4 extends radially from the center to the end. The vaporized refrigerant diffuses in at least one of the planar direction and the thickness direction via the vapor diffusion path 4. Since the first heat pipe 2 has the vapor diffusion path 4 extending radially from the central portion toward the end portion, the vaporized refrigerant diffuses from the central portion toward the end portion. That is, the heat taken away from the heating element by the first heat pipe 2 diffuses from the central portion toward the end portion. The first heat pipe 2 has a heat diffusion characteristic from the center portion toward the end portion.

  The vapor diffusion path 4 is formed by the notch 13, and the capillary flow path 5 is formed by the internal through hole 14.

  The structure of the first heat pipe 2 will be described with reference to FIG.

The first heat pipe 2 has a function of a heat pipe that cools the heating element by vaporizing and condensing the refrigerant. The first heat pipe 2 includes a vapor diffusion path 4 that diffuses the vaporized refrigerant in at least one of the planar direction and the thickness direction, and a capillary channel 5 that recirculates the condensed refrigerant in the vertical direction or the vertical / planar direction. As is clear from FIG. 3, the first heat pipe 2 is thin and flat, but may have various shapes such as a circle, an ellipse, and a polygon. Of course, the first heat pipe 2 that may be curved includes the upper plate 10, the lower plate 11 that faces the upper plate 10, and one or more intermediate plates 12 that are stacked between the upper plate 10 and the lower plate 11. Is provided. The upper plate 10, the lower plate 11, and the intermediate plate 12 are laminated and joined to form an internal space in which the refrigerant can be enclosed. The intermediate plate 12 forms the vapor diffusion path 4 and the capillary channel 5.

  Further, the size of the heat pipe 2 is not particularly limited, but in practice, it may be appropriate to be within a certain size range.

  As an example, the first heat pipe 2 has a square shape of 20 mm square or more and 200 mm square or less, and further has a thickness of 1 mm or more and 5 mm or less. The size defined in this way is introduced from the size of an electronic component that is a heating element to be cooled, the ease of mounting on a circuit board, and the like. This is because the first heat pipe 2 has the size given here as an example, so that the balance between mounting and cooling can be appropriately achieved.

  Of course, the size of the first heat pipe 2 is not limited to this size, and may be determined according to various requirements such as manufacturing requirements, usage requirements, and mounting requirements.

(Upper plate)
The upper plate 10 will be described with reference to FIG.

  The upper plate 10 is flat and has a predetermined shape and area.

  The upper plate 10 is made of metal, resin, or the like, but is made of metal having high thermal conductivity or high rust prevention (durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. It is preferred that Further, the upper plate 10 may have various shapes such as a square, a rhombus, a circle, an ellipse, and a polygon.

  It is also preferable that the upper plate 10 has a recess 15 communicating with at least one of the vapor diffusion path 4 and the capillary flow path 5 on one surface thereof and facing the intermediate plate 12. Since the recess 15 communicates with the capillary channel 5, the condensed refrigerant is easily transmitted from the upper plate 10 to the capillary channel 5. Alternatively, the recess 15 communicates with the vapor diffusion path 4 so that the vaporized refrigerant can easily come into contact with the surface of the upper plate 10 over a wide area, and heat dissipation of the vaporized refrigerant is promoted.

  It is also preferable that the upper plate 10 includes a protruding portion or an adhesive portion that is bonded to the intermediate plate 12. Although the upper plate 10 is referred to as “upper portion” for convenience, it does not have to physically exist at the upper position, and is not particularly distinguished from the lower plate 11. Further, the upper plate 10 may be a surface in contact with the heating element or a surface facing the heating element.

  Further, the upper plate 10 includes a refrigerant inlet 16. When the upper plate 10, the intermediate plate 12, and the lower plate 11 are laminated and joined, an internal space is formed. Since it is necessary to enclose the refrigerant in the internal space, the refrigerant is enclosed from the inlet 16 after joining the upper plate 10 and the like. The inlet 16 is sealed when the refrigerant is sealed, and the internal space is sealed.

  The refrigerant may be sealed from the inlet 16 after being stacked, or may be sealed when the upper plate 10, the lower plate 11, and the intermediate plate 12 are stacked.

(Lower plate)
The lower plate 11 faces the upper plate 10 and sandwiches one or more intermediate plates 12.

  The lower plate 11 is formed of a metal, a resin, or the like, but is formed of a metal having high thermal conductivity or high rust prevention (durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. It is preferred that Moreover, although it may have various shapes, such as a square, a rhombus, a circle, an ellipse, and a polygon, since it forms the 1st heat pipe 2 facing the upper board 10, the same shape as the upper board 10, An area is preferred.

  It is also preferable that the lower plate 11 has a concave portion 15 that communicates with the vapor diffusion path 4 and the capillary flow path 5 on one surface of the lower plate 11 that faces the intermediate plate 12. The recess 15 communicates with the capillary channel 5 so that the condensed refrigerant is easily transmitted from the lower plate 11 to the capillary channel 5. Further, since the recess 15 communicates with the vapor diffusion path 4, the vaporized refrigerant easily comes into contact with a large area on the surface of the lower plate 11, and heat dissipation of the vaporized refrigerant is promoted. This has the same significance as that the recess 15 is provided in the upper plate 10.

  The lower plate 11 is referred to as “lower” for convenience, but does not have to physically exist at the lower position, and is not particularly distinguished from the upper plate 10.

  It is also preferable that the lower plate 11 includes a protrusion or an adhesive portion that is joined to the intermediate plate 12.

  Further, the lower plate 11 may or may not be in contact with the heating element.

(Intermediate plate)
The intermediate plate 12 is a single plate member or a plurality of plate members. In FIG. 3, the first heat pipe 2 has four intermediate plates 12. The intermediate plate 12 is laminated between the upper plate 10 and the lower plate 11.

  The intermediate plate 12 is formed of metal, resin, or the like, but is formed of metal having high thermal conductivity or high rust prevention (durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. It is preferred that Moreover, although it may have various shapes such as a square, a rhombus, a circle, an ellipse, and a polygon, the upper plate 10 and the lower plate 11 are sandwiched between the upper plate 10 and the lower plate 11 to form the first heat pipe 2. The same shape as the lower plate 11 is preferable. Since the upper plate 10 and the lower plate 11 are sandwiched, the area of the intermediate plate 12 may be the same as or slightly smaller than the upper plate 10 and the lower plate 11.

  Further, the intermediate plate 12 may have protrusions and adhesive portions used when connected to the upper plate 10 and the lower plate 11. In addition, the intermediate plate 12 has an internal through hole 14 having a minute cross-sectional area. The internal through hole 14 forms the capillary channel 5.

  Finally, the first heat pipe 2 is formed by stacking and joining the intermediate plate 12 between the upper plate 10 and the lower plate 11. The intermediate plate 12 may be singular or plural. However, as will be described later, in order to form the capillary channel 5 having a smaller cross-sectional area, it is preferable that there are a plurality of intermediate plates 12.

(Intermediate plate, vapor diffusion path and capillary flow path)
Next, the vapor diffusion path 4 and the capillary flow path 5 will be described with reference to FIGS. The intermediate plate 12 forms a vapor diffusion path 4 that diffuses the vaporized refrigerant in at least one of the planar direction and the thickness direction, and a capillary channel 5 that recirculates the condensed refrigerant in the vertical direction or the vertical / planar direction.

  First, the vapor diffusion path 4 will be described.

  The intermediate plate 12 has a notch 13 and an internal through hole 14.

  The notch 13 forms the vapor diffusion path 4 in the first heat pipe 2. When the intermediate plate 12 is laminated between the upper plate 10 and the lower plate 11, the cutout portion 13 forms a gap. This gap becomes the vapor diffusion path 4. As an example, the first heat pipe 2 has a radial vapor diffusion path 4 as shown in FIG.

  Here, the notch portion 13 is formed toward at least one of the planar direction and the thickness direction of the first heat pipe 2, so that the vapor diffusion path 4 also extends in the planar direction and the thickness direction of the first heat pipe 2. It is formed toward at least one side. For this reason, the vaporized refrigerant diffuses in at least one of the planar direction and the thickness direction. Of course, when the lower plate 11 and the upper plate 10 are connected by the notch 13, the refrigerant that is received and vaporized by the lower plate 11 moves in the plane direction and the thickness direction, and the vaporized refrigerant (and heat) ) Reaches from the lower plate 11 to the upper plate 10. That is, the vapor diffusion path 4 moves the vaporized refrigerant in both the planar direction and the thickness direction (of course, either one may be used depending on the shape of the vapor diffusion path 4).

  In particular, as shown in FIG. 2, when the notch 13 is formed radially from the center of the intermediate plate 12, the vapor diffusion path 4 is also formed radially from the center of the first heat pipe 2. Will be. Since the heating element is often installed at a substantially central portion of the first heat pipe 2, the refrigerant receives heat most at the substantially central portion of the first heat pipe 2. For this reason, the refrigerant | coolant of the center part vicinity of the 1st heat pipe 2 vaporizes first. At this time, since the vapor diffusion path 4 is formed radially from the substantially central portion of the first heat pipe 2, the vaporized refrigerant generated near the center diffuses radially, that is, in at least one of the planar direction and the thickness direction. To do. If the vapor diffusion path 4 is formed in both the planar direction and the thickness direction, the vaporized refrigerant diffuses in both the planar direction and the thickness direction. As a result, the vaporized refrigerant (heat taken away from the heating element) reaches the heat radiating surface on the side opposite to the heating element. The heat that reaches the heat radiating surface on the side opposite to the heating element is conducted to the second heat pipe 3.

  As described above, the intermediate plate 12 has the notch 13 and the vapor diffusion path 4 extending in at least one of the planar direction and the thickness direction is formed, so that the vaporized refrigerant is formed inside the first heat pipe 2. Diffuses in at least one of the planar direction and the thickness direction. As a result, the heat from the heating element diffuses in the plane direction in the first heat pipe 2 from the center toward the periphery.

  As shown in FIG. 2, the cutout portion 13 (that is, the vapor diffusion path 4) may not be radial but may be another shape. In addition, even if the vaporized refrigerant diffuses in the plane direction because the vapor diffusion path 4 is radial, the cooling capacity of the heating element is not sufficient if the refrigerant that has been diffused and cooled and condensed does not recirculate at high speed. . The first heat pipe 2 has a capillary flow path 5 that efficiently recirculates the refrigerant condensed after being diffused by using the entire surface of the first heat pipe 2 efficiently, so that the first heat pipe 2 has a high planar direction and a high thickness direction. At least one diffusion (and reflux) performance is achieved. Furthermore, the condensed refrigerant can be recirculated with further efficiency by the recess 15 communicating with the capillary channel 5. The concave portion 15 also has a role of promoting the reflux of the condensed refrigerant.

  Next, the capillary channel 5 will be described.

  The intermediate plate 12 has an internal through hole 14. The internal through-hole 14 is a minute through-hole and forms a capillary channel 5 through which condensed refrigerant recirculates. When the intermediate plate 12 has the cutout portion 13 as shown in FIG. 2, an internal through hole 14 is formed in a portion other than the cutout portion 13.

  Here, when there is a single intermediate plate 12, the internal through hole 14 provided in the intermediate plate 12 becomes the capillary channel 5 as it is.

  On the other hand, when there are a plurality of intermediate plates 12, only a part of the internal through-holes 14 provided in each of the plurality of intermediate plates 12 overlap, and the cross-sectional area in the planar direction of the internal through-holes 14 A capillary channel 5 having a small cross-sectional area is formed. Thus, when there are a plurality of intermediate plates 12, the capillary channel 5 having a cross-sectional area smaller than the cross-sectional area of the internal through hole 14 itself is formed, so that the condensed refrigerant recirculates in the capillary channel 5. Can be more effective. This is because the movement of the liquid by capillary action is promoted by the small cross-sectional area of the capillary.

  Here, each of the intermediate plates 12 is provided with a plurality of internal through holes 14. This is because the plurality of internal through holes 14 can form the capillary channel 5 having a plurality of channels.

  The internal through hole 14 penetrates from the front surface to the back surface of the intermediate plate 12, and the shape thereof may be circular, elliptical or rectangular. However, since the capillary passage 5 is formed by overlapping a part of the internal through hole 14, the internal through hole 14 is suitably square.

  The internal through hole 14 may be formed by excavation, pressing, wet etching, dry etching, or the like.

  When there are a plurality of intermediate plates 12, the internal through hole 14 is provided in each of the plurality of intermediate plates 12. Here, since the plurality of intermediate plates 12 are stacked such that only a part of the internal through holes 14 overlap each other, the positions of the internal through holes 14 may be shifted for each adjacent intermediate plate 12. Is appropriate. For example, the position of the internal through-hole 14 in a certain intermediate plate 12 and the position of the internal through-hole 14 in another intermediate plate 12 adjacent to this intermediate plate 12 are such that a part of the cross section of the internal through-hole 14 overlaps. It's off. As described above, the position of the internal through-hole 14 is shifted for each adjacent intermediate plate 12, so that when the plurality of intermediate plates 12 are stacked, the cross-sectional area of the internal through-hole 14 is smaller than the plane sectional area. A capillary channel 5 having an area is formed.

  The capillary channel 5 has a cross-sectional area smaller than the cross-sectional area of the internal through-hole 14 in the planar direction, with a part of the internal through-holes 14 overlapping when the plurality of intermediate plates 12 are stacked. Such holes having a cross-sectional area smaller than the cross-sectional area of the internal through-hole 14 are stacked in the vertical direction of the first heat pipe 2, and the vertical holes are connected to form a vertical flow path. Is done. 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.

  In addition, when the capillary channel 5 having a smaller cross-sectional area than the inner through hole 14 is formed so that only a part of the inner through hole 14 overlaps, rather than directly processing the capillary channel 5, There is also an advantage that it can be manufactured easily.

  In addition, although the capillary flow path 5 recirculates the condensed refrigerant | coolant, it can also pass the vaporized refrigerant | coolant.

  It is also preferable that the capillary channel 5, the corner of the recess 15 and the corner of the notch 13 are chamfered or R is provided. The cross section of the capillary channel 5 may have various cross sectional shapes such as a hexagon, a circle, an ellipse, a square, and a polygon. The cross-sectional shape of the capillary channel 5 is determined by the shape of the internal through hole 14 and the way in which the internal through holes 14 are overlapped. Moreover, a cross-sectional area is determined similarly.

  As described above, as an example of the first heat pipe, the configuration having excellent thermal diffusion characteristics from the center portion toward the end portion as illustrated in FIGS. 2 and 3 and the description thereof has been described.

(Second heat pipe)
Next, the 2nd heat pipe 3 is demonstrated using FIG. 4, FIG. 4 and 5 are internal views of second heat pipe 3 according to Embodiment 1 of the present invention. 4 and 5 show the internal structure of the second heat pipe 3.

  The second heat pipe 3 has a vapor diffusion path 6 from the first end 8 toward the second end 9, and has a heat diffusion characteristic from the first end 8 toward the second end 9. Excellent. Similarly to the first heat pipe 2, the vapor diffusion path 6 is formed by the notch 13 of the intermediate plate.

  Here, in order to obtain the thermal diffusion characteristics from the first end 8 toward the second end 9, in the second heat pipe 3, the vapor diffusion path 6 extends from the first end 8 to the second end 9. It is growing. This is as shown in FIGS. The capillary channel 7 is formed in a portion other than the vapor diffusion path 6, and the vapor diffusion path 6 and the capillary channel 7 are alternately arranged in parallel like a horizontal stripe inside the second heat pipe 3.

  For example, FIG. 4 shows an example of the second heat pipe 3, but the vapor diffusion path 6 has a divergent shape from the first end 8 to the second end 9. In other words, the cross-sectional area of the vapor diffusion path 6 in the planar direction on the second end 9 side is wider than the cross-sectional area of the vapor diffusion path 6 in the planar direction on the first end 8 side. Thus, the second heat pipe 3 is directed from the first end portion 8 toward the second end portion 9 by the vapor diffusion path 6 having a shape in which the cross-sectional area increases from the first end portion 8 to the second end portion 9. Has thermal diffusion properties. In FIG. 4, the vapor diffusion path 6 has a divergent shape, but there may be bending or refraction between the first end 8 and the second end 9, and the cross-sectional area increases or decreases. There may be fluctuations.

  Alternatively, as shown in FIG. 5, the vapor diffusion path 6 may be formed from the first end 8 to the second end 9 while maintaining a certain width. That is, the vapor diffusion path 6 may be formed as a straight line having a constant width. Also in this case, the second heat pipe 3 has a thermal diffusion characteristic from the first end 8 to the second end 9. In addition, a capillary channel 7 is formed in a portion other than the vapor diffusion channel 6. The same applies to the second heat pipe 3 shown in FIG. The vapor diffusion path 6 is formed as a straight line having the same width from the first end portion 8 to the second end portion 9, but may be a curved line or may have a bent portion. Differences may occur.

  Further, in the second heat pipe 3, the vapor diffusion path 6 is formed from the first end portion 8 toward the second end portion 9, and reaches each of the first end portion 8 and the second end portion 9. The vapor diffusion path 6 does not need to be formed as long as the vapor diffusion path 6 that connects the vicinity of the first end 8 and the vicinity of the second end 9 may be formed.

  As described above, the second heat pipe 3 has a thermal diffusion characteristic different from that of the first heat pipe 2, and the thermal diffusion characteristic diffuses heat from the first end 8 toward the second end 9. It is excellent for. On the other hand, as described above, the first heat pipe 2 has excellent thermal diffusion characteristics from the center to the end. Since the second heat pipe 3 is erected on the surface of the first heat pipe 2 having different heat diffusion characteristics as described above, not only the cooling unit 1 is configured by the heat pipe but also a heating element. It is possible to form a heat conduction path that can cool the water more efficiently.

  These vapor diffusion paths 6 are formed by the notches 13 of the intermediate plate 12.

  The second heat pipe 3 is, as described with reference to FIG. 3, an upper plate 10, a lower plate 11 facing the upper plate 10, and a single or a plurality of layers stacked between the upper plate 10 and the lower plate 11. An intermediate plate 12 is provided. The intermediate plate 12 has a notch 13 and an internal through hole 14, the notch 13 forms the vapor diffusion path 6, and the internal through hole 14 forms the capillary channel 7.

  The upper plate 10, the intermediate plate 12, and the lower plate 11 are laminated and joined to form the second heat pipe 3, as in the case of the first heat pipe 2. Further, the formation of the vapor diffusion path 6 and the internal through hole 14 (or the overlap of the internal through hole 14) by the notch 13 and the capillary flow path 14 are the same as in the case of the first heat pipe 2.

(Manufacturing process)
Here, the manufacturing process of the 1st heat pipe 2 and the 2nd heat pipe 3 is demonstrated.

  The first heat pipe 2 and the second heat pipe 3 are manufactured by stacking and joining the upper plate 10, the lower plate 11, and the intermediate plate 12.

  The manufacturing process will be described with reference to FIG.

  The upper plate 10, the lower plate 11, and the plurality of intermediate plates 12 (four intermediate plates 12 in FIG. 3) are matched to each other so as to overlap at the same position. In addition, the plurality of intermediate plates 12 are adjusted to a positional relationship such that only a part of each of the internal through holes 14 provided in each of the plurality of intermediate plates 12 overlaps.

  At least one of the upper plate 10, the lower plate 11, and the plurality of intermediate plates 12 has a joint protrusion.

  The upper plate 10, the lower plate 11, and the plurality of intermediate plates 12 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.

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 the injection port 16 opened in a part of the upper plate 10 and the lower plate 11. Thereafter, the inlet 16 is sealed to complete the first heat pipe 2 and the second heat pipe 3. The refrigerant is sealed under vacuum or reduced pressure. By being performed under vacuum or reduced pressure, the internal space of the first heat pipe 2 is in a vacuum or reduced pressure state, and the refrigerant is enclosed. When the pressure is reduced, the refrigerant vaporization / condensation temperature becomes low, and there is an advantage that the refrigerant vaporization / condensation repeats actively.

(Description of operation)
Next, the operation of the cooling unit 1 will be described.

  First, the whole image of the cooling unit 1 is shown in a perspective view and a side view. FIG. 6 is a perspective view of the cooling unit according to Embodiment 1 of the present invention, and FIG. 7 is a side view of the cooling unit according to Embodiment 1 of the present invention. As shown in FIGS. 6 and 7, a plurality of second heat pipes 3 are erected on the surface of the first heat pipe 2. That is, the 1st heat pipe 2 has a role of a baseplate, and the 2nd heat pipe 3 has a role of a fin. The first heat pipe 2 is excellent in heat diffusion characteristics from the central part toward the end part, and the second heat pipe 3 is excellent in heat diffusion characteristics from the first end part 8 to the second end part 9. That is, the cooling unit 1 is configured by a combination of heat pipes having different heat diffusion characteristics.

  The second heat pipe 3 is attached such that one of the first end 8 and the second end 9 is located on the surface side of the first heat pipe 2. Here, there are various heating elements to be cooled by the cooling unit 1. The position where the heating element is arranged varies depending on the type of the heating element. The combination of the first heat pipe 2 and the second heat pipe 3 can be changed depending on the arrangement position of the heating elements.

  As a first example, when the heating element is a semiconductor integrated circuit or an electronic component that exhibits a large amount of heat alone, the heating element is disposed on the back surface 20 of the first heat pipe 2. Since the heating element itself often has a certain size, the heating element is disposed on the back surface 20 of the first heat pipe 2 which is the position of the base plate of the cooling unit 1. FIG. 8 shows this state. FIG. 8 is a schematic diagram showing a cooling state of the cooling unit according to Embodiment 1 of the present invention.

  The heating element 25 is disposed on the back surface of the first heat pipe 2. Also on the back surface, it is disposed particularly near the center of the back surface. The heating element 25 is an electronic element having a relatively large size of heat generation, such as a semiconductor integrated circuit or an electronic component. Thus, when the heating element 25 is disposed on the back surface of the first heat pipe 2, the second heat pipe 3 has its first end 8 positioned on the surface side of the first heat pipe 2, Stand up. That is, the second heat pipe 3 extends in the order of the first end 8 and the second end 9 from the first heat pipe 2 side. The second end 9 is the tip farthest from the heating element 25 in the cooling unit 1.

  The first heat pipe 2 is excellent in heat diffusion from the central portion toward the end portion. First, the 1st heat pipe 2 takes away the heat from the heat generating body 25 arrange | positioned in the center part of the back surface. By taking heat away, the refrigerant inside the first heat pipe 2 is vaporized to become a vaporized refrigerant. Since the first heat pipe 2 has the vapor diffusion path 4 from the central portion toward the end portion, the vaporized refrigerant diffuses in the planar direction and the thickness direction from the central portion to the end portion. As a result, the heat deprived in the vicinity of the heating element 25 diffuses widely on the surface 27 of the first heat pipe 2.

  The heat spread on the surface 27 of the first heat pipe 2 is conducted to the second heat pipe 3 standing on the surface 27. When there are a plurality of second heat pipes 3, heat is conducted to each of the plurality of second heat pipes 3. Specifically, heat is conducted from the surface 27 of the first heat pipe 2 to the first end 8 of the second heat pipe 3. The second heat pipe 3 is excellent in heat diffusion characteristics from the first end portion 8 toward the second end portion 9. For this reason, the heat conducted to the first end 8 is efficiently diffused to the second end 9. The second end portion 9 is the tip farthest from the heating element 25 and easily dissipates heat to the external environment. As a result, heat is dissipated at the second end portion 9 (of course, at other sites), and the vaporized refrigerant flows back through the capillary channel 7.

  Here, the second heat pipe 3 is thin and has a capillary flow path 7 formed by the internal through-hole 14 and a recess 15 communicating with the capillary flow path 7 so that the second heat pipe 3 extends in the vertical direction as shown in FIG. Even when standing, the condensed refrigerant can be recirculated. Of course, the second heat pipe 3 can diffuse the vaporized refrigerant even when it is erected in the vertical direction for the same reason.

  Similarly to the heat dissipated by the second heat pipe 3, the refrigerant is cooled in the first heat pipe 2, and the condensed refrigerant recirculates.

  As indicated by the arrows in FIG. 8, when the heating element 25 is disposed on the back surface of the first heat pipe 2, heat from the back surface of the first heat pipe 2 toward the second end of the second heat pipe 3. A conduction path 26 is formed. By forming the heat conduction path 26, the entire cooling unit 1 is used for cooling the heating element. That is, the cooling unit 1 realizes thermal diffusion using the vaporization / condensation of the refrigerant from the base plate to the tips of the fins, and can cool the heating element with high efficiency.

  Further, the first heat pipe 2 having the role of the base plate and the second heat pipe 3 having the role of the fins are separate bodies, and the refrigerant is separately encapsulated, so that the refrigerant is vaporized, diffused, Condensation and reflux are performed independently in each heat pipe. For this reason, there are few obstruction factors in the diffusion and recirculation of the refrigerant. As a result, the thermal diffusion in the first heat pipe 2 and the thermal diffusion in the second heat pipe 3 are performed appropriately.

  Further, the first heat pipe and the second heat pipe have a configuration in which the intermediate plate 12, the upper plate 10, and the lower plate 11 that form the vapor diffusion paths 4 and 6 and the capillary flow paths 5 and 7 are laminated. , Has excellent heat diffusion ability. In addition, the configuration in which the recess 15 communicates with the vapor diffusion paths 4 and 6 and the capillary flow paths 5 and 7 increases the diffusion capacity of the vaporized refrigerant and the reflux capacity of the condensed refrigerant. Since each of the first heat pipe 2 and the second heat pipe 3 has such a structure, the heat diffusion and refrigerant recirculation ability of the heat pipe alone are also high. For this reason, even if the second heat pipe 3 is erected on the first heat pipe 2, each heat pipe can realize appropriate heat diffusion and reflux, and the cooling capacity of the heating element in the entire cooling unit 1 is excellent. Yes.

  When either the base plate or the fin is formed of a metal plate as in the prior art, the heat diffusion efficiency in the base plate or the fin is low, and sufficient heat diffusion as the entire cooling unit cannot be realized. In addition, if the combination of the heat diffusion characteristics of the heat pipe serving as the position of the base plate and the heat pipe serving as the position of the fin is inappropriate, sufficient heat diffusion cannot be realized. If the thermal diffusion is insufficient, the cooling of the heating element is also insufficient. Of course, even when a single heat pipe has a thin flat plate shape, if the diffusion capacity and reflux capacity of the refrigerant are low, there is not sufficient cooling capacity as a cooling unit.

  The cooling unit 1 according to the first embodiment can form a heat conduction path from the first heat pipe 2 where the base plate is positioned to the tip of the second heat pipe 3 where the fin is positioned, and can cool the heating element 25 with high efficiency.

  Next, as a second example, it may be necessary to cool a plurality of small light emitting elements. An LED (Light Emitting Device) is small, but generates a large amount of heat to emit light. A plurality of light emitting elements may be used. For this reason, it is often necessary to cool the entire plurality of light emitting elements.

  However, since the light emitting element emits light from the element itself, it is not preferable to cool the light emitting element so that it is hidden behind the heat pipe. In such a case, it is necessary to cool the light emitting element by arranging the light emitting element at the end of the heat pipe. In this case, the cooling unit 1 cools the heating element by forming a heat conduction path from the second heat pipe 3 toward the first heat pipe 2.

  FIG. 9 is a schematic diagram showing a cooling state of the cooling unit according to Embodiment 1 of the present invention. Unlike FIG. 8, the heat generating body 30 is arrange | positioned at the edge part of the 2nd heat pipe. Thus, when the heating element 30 is disposed at the end of the second heat pipe 3, the second end 9 of the second heat pipe 3 is located on the surface side of the first heat pipe 2, The second heat pipe 3 is erected. In FIG. 9, the single second heat pipe 3 is erected, but a plurality of second heat pipes 3 may be erected.

  The heating element 30 is a small light emitting element or electronic element such as an LED, and is disposed at the first end 8. Since the second heat pipe 3 is excellent in heat diffusion characteristics from the first end portion 8 toward the second end portion 9, the second heat pipe 3 transfers heat from the heating element 30 from the first end portion 8. Conducted to the second end 9. That is, heat is conducted from the heating element 30 toward the first heat pipe 2. The heat conducted from the second end portion 9 diffuses from the center portion of the first heat pipe 2 toward the end portion. Moreover, since it also diffuses in the thickness direction of the first heat pipe 2, the heat eventually reaches the back surface of the first heat pipe 2 and is dissipated from the back surface to the external environment.

  As shown in FIG. 9, the cooling unit 1 forms a heat conduction path from the heating element 30 to the first heat pipe 2, and generates heat at the end portion (first end portion 8) of the second heat pipe 3. The body 30 can be cooled using the entire cooling unit 1. At this time, heat diffusion and refrigerant recirculation inside the second heat pipe 3 and the first heat pipe 2 are the same as described in FIG. The entire cooling unit 1 is composed of heat pipes that vaporize and condense refrigerant, and in addition, heat conduction that is optimal for cooling a small heating element 30 by combining heat pipes with different thermal diffusion characteristics. A path can be formed. As a result, the cooling unit 1 can reliably and efficiently cool a plurality of small heating elements.

  In addition, the heat generating body 30 may be single or plural, and may be disposed on a part or all of the plurality of second heat pipes 3.

  As described above, the cooling unit 1 can flexibly respond to the characteristics of the heating element to be cooled. In particular, only by changing the combination direction of the second heat pipe 3 with respect to the first heat pipe 2, bidirectional heat conduction from the first heat pipe 2 to the second end portion 9 and from the second end portion 9 to the first heat pipe 2 is achieved. A path can be formed. For this reason, the cooling unit 1 can optimally cope with the internal structure of the space in which the heating element or the cooling unit 1 is mounted. For example, depending on the mounting space, it may be easy to arrange the heating element on the back surface of the first heat pipe 2, or the heating element may be easily arranged on the end of the second heat pipe 3. In such a case, for example, in the cooling unit 1, the first heat pipe 2 and the second heat pipe 3 are provided separately, and the standing direction of the second heat pipe 3 may be determined at the time of mounting. Is preferred. Alternatively, a version of the cooling unit 1 in which the first end 8 is in contact with the first heat pipe 2 and a version of the cooling unit 1 in which the second end 9 is in contact with the first heat pipe 2 are prepared. In addition, it is possible to consider a distribution mode in which it is left to the selection of the user who implements.

  As described above, the cooling unit 1 according to Embodiment 1 can cool the heating element with high efficiency while flexibly supporting various heating elements by combining heat pipes having different thermal diffusion characteristics.

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

  In the second embodiment, a modification of the first heat pipe 2 and a modification of the cooling unit that combines the modifications will be described.

  FIG. 10 is an inner surface view of the first heat pipe that is similar to that described in the first embodiment. The first heat pipe 2 has a vapor diffusion path 4 that extends radially from the center toward the end. The vapor diffusion path 4 is formed by the notch 13 of the intermediate plate 12. Further, unlike the first heat pipe 2 shown in FIG. 2, the first heat pipe 2 shown in FIG. 10 is formed with a vapor diffusion path 4 so as to surround the central portion in a substantially circular shape. The first heat pipe 2 having such a vapor diffusion path 4 realizes heat diffusion from the center portion toward the end portion and realizes heat conduction with the second heat pipe 3.

  By the way, a cooling unit implement | achieves a high cooling capability by combining the 1st heat pipe and 2nd heat pipe from which a thermal-diffusion characteristic differs. At this time, heat is exchanged between the first heat pipe and the second heat pipe. Since heat exchange is performed at the location where the second heat pipe 3 is erected on the first heat pipe 2, heat conduction is promoted at the connecting portion between the first heat pipe 2 and the second heat pipe 3. It is also preferable that the first heat pipe 2 has the heat diffusion characteristics to be performed.

(Example 1)
FIG. 11 shows an example in which the first heat pipe 2 performs thermal diffusion with respect to the connection position with the second heat pipe 3 to be erected. FIG. 11 is an inner surface view of the first heat pipe in the second embodiment of the present invention.

  The first heat pipe 40 shown in FIG. 11 mainly diffuses heat to the standing position of the second heat pipe 3 to be erected. The notch 13 forms vapor diffusion paths 42 and 43. In portions other than the vapor diffusion paths 42 and 43, the capillary channel 5 is formed. The vapor diffusion path 42 and the vapor diffusion path 43 are integrated to form one vapor diffusion path.

  The vapor diffusion path 42 is formed in the longitudinal direction of the first heat pipe 40. Furthermore, the vapor diffusion path 42 is formed along the standing position 41 of the second heat pipe 3 standing on the first heat pipe 40. On the other hand, the vapor diffusion path 43 is formed from the center to the end of the first heat pipe 40 and connects the vapor diffusion paths 42 to each other. For this reason, a moving path (heat conduction path) of the vaporized refrigerant from the vapor diffusion path 43 to the vapor diffusion path 42 is formed.

  It is assumed that a heating element is arranged near the center of the back surface of the first heat pipe 40. In this case, heat is received at the central portion and the refrigerant is vaporized. The vaporized refrigerant diffuses from the central portion toward the end portion via the vapor diffusion path 43. The vaporized refrigerant that diffuses toward the end enters the vapor diffusion path 42 connected in the middle of the vapor diffusion path 43 and diffuses. Since the vapor diffusion path 42 is formed along the standing position 41, the vaporized refrigerant that has entered the vapor diffusion path 42 diffuses along the standing position 41. As a result, heat concentrates along the standing position 41. The heat concentrated along the standing position 41 is conducted to the second heat pipe 3, diffuses from the first end 8 to the second end 9 of the second heat pipe 3, and is dissipated to the external environment.

  Thus, since the 1st heat pipe 40 represented in Example 1 can conduct heat with high efficiency to the 2nd heat pipe 3 installed upright, it can cool a heating element with high efficiency.

  In addition, when a heating element is disposed at the end portion (first end portion 8) of the second heat pipe 3, heat diffuses from the first end portion 8 of the second heat pipe 3 to the second end portion 9. In the standing position 41, heat is conducted from the second end portion 9 to the first heat pipe 40. The conducted heat diffuses in accordance with the diffusion of the vaporized refrigerant in the first heat pipe 40. The diffused heat reaches the back surface of the first heat pipe 40 and is dissipated to the external environment. Even in this case, since the vapor diffusion path 42 of the first heat pipe 40 is formed along the standing position 41 of the second heat pipe 3, heat conduction from the second heat pipe 3 to the first heat pipe 40. Is efficient. As a result, the cooling unit 1 can cool the heating element disposed at the end of the second heat pipe 3 with high efficiency.

  In addition, since a part of the capillary channel 5 is provided so as to intersect with a part of the vapor diffusion path, the recirculation of the refrigerant in the first heat pipe 40 is promoted.

(Example 2)
Next, another example of the first heat pipe will be described with reference to FIG.

  FIG. 12 is an inner surface view of the first heat pipe in the second embodiment of the present invention.

  The heat pipe 50 shown in FIG. 12 mainly diffuses heat to the standing position 41 of the second heat pipe 3 to be erected. The notch 13 forms vapor diffusion paths 51 and 52. In portions other than the vapor diffusion paths 51 and 52, the capillary flow path 5 is formed. The vapor diffusion path 51 and the vapor diffusion path 52 are integrated to form one vapor diffusion path.

  The vapor diffusion path 51 is formed in the longitudinal direction of the first heat pipe 50. Furthermore, the vapor diffusion path 51 is formed along the standing position 41 of the second heat pipe 3 standing on the first heat pipe 50. On the other hand, the vapor diffusion path 52 connects the vapor diffusion paths 51 to each other. For this reason, a moving path (heat conduction path) of the vaporized refrigerant from the vapor diffusion path 52 to the vapor diffusion path 51 is formed.

  It is assumed that a heating element is disposed near the center of the back surface of the first heat pipe 50. In this case, heat is received at the central portion and the refrigerant is vaporized. The vaporized refrigerant diffuses from the central portion toward the end portion via the vapor diffusion path 52. The vaporized refrigerant that diffuses toward the end enters the vapor diffusion path 51 that is connected in the middle of the vapor diffusion path 52 and diffuses. Since the vapor diffusion path 51 is formed along the standing position 41, the vaporized refrigerant that has entered the vapor diffusion path 51 diffuses along the standing position 41. As a result, heat concentrates along the standing position 41. The heat concentrated along the standing position 41 is conducted to the second heat pipe 3, diffuses from the first end 8 to the second end 9 of the second heat pipe 3, and is dissipated to the external environment.

  Thus, since the 1st heat pipe 40 represented in Example 1 can conduct heat with high efficiency to the 2nd heat pipe 3 installed upright, it can cool a heating element with high efficiency.

  In addition, when a heating element is disposed at the end portion (first end portion 8) of the second heat pipe 3, heat diffuses from the first end portion 8 of the second heat pipe 3 to the second end portion 9. In the standing position 41, heat is conducted from the second end portion 9 to the first heat pipe 50. The conducted heat diffuses in accordance with the diffusion of the vaporized refrigerant in the first heat pipe 50. The diffused heat reaches the back surface of the first heat pipe 50 and is dissipated to the external environment. Even in this case, since the vapor diffusion path 51 of the first heat pipe 50 is formed along the standing position 41 of the second heat pipe 3, heat conduction from the second heat pipe 3 to the first heat pipe 50 is performed. Is efficient. As a result, the cooling unit 1 can cool the heating element disposed at the end of the second heat pipe 3 with high efficiency.

  As described above, the cooling unit according to Embodiment 2 can improve the efficiency of heat conduction between the first heat pipe and the second heat pipe. As a result, the cooling unit that is a combination of the first heat pipe where the base plate is positioned and the second heat pipe where the fins are positioned can cool the heating element efficiently. In particular, the cooling ability by the refrigerant of each of the first heat pipe and the second heat pipe can be maximized by combining the first heat pipe and the second heat pipe. In addition, even when the heating element is arranged on the first heat pipe where the base plate is positioned, or when the heating element is arranged at the end of the second heat pipe where the fin is positioned, the heat diffusion is performed from any direction. Done.

(Embodiment 3)
Next, a third embodiment will be described.

  In Embodiment 3, a structure when the second heat pipe is erected on the surface of the first heat pipe will be described. The second heat pipe 3 is erected on the surface of the first heat pipe 2. At this time, one or a plurality of second heat pipes 3 are erected on the surface of the first heat pipe 2.

  The second heat pipe 3 may be bonded to the surface of the first heat pipe 2 with an adhesive, may be welded, or may be thermally bonded. Further, the second heat pipe 3 may be fitted and attached to an attachment groove formed on the surface of the first heat pipe 2. When the second heat pipe 3 is fitted and attached to the attachment groove, the protruding portion protruding from at least one of the first end 8 and the second end 9 of the second heat pipe 3 is the first heat pipe. 2 to assist in joining.

  FIG. 13 is a side view of a part of the cooling unit according to Embodiment 3 of the present invention.

  The first heat pipe 2 has a mounting groove 60 on its surface. The attachment groove 60 is provided on the surface of the first heat pipe 2 and at the attachment position of the second heat pipe 3. The mounting groove 60 is formed, for example, by cutting or etching a predetermined position of the upper plate 10 of the first heat pipe 2.

  The second heat pipe 3 is attached by fitting into the attachment groove 60. At this time, the protruding portion 62 protruding from at least one of the first end portion 8 and the second end portion 9 of the second heat pipe 3 assists the attachment. The protruding portion 62 is formed by having at least one of the upper plate 10, the lower plate 11, and the intermediate plate 12 of the second heat pipe 3 having a larger area than the other plates. In FIG. 13, a protruding portion 62 protrudes from the upper plate 10 and the lower plate 11. The protrusion 62 is bent along the outer edge of the attachment groove 60, and the protrusion 62 is attached to the first heat pipe 2 with a welding agent, an adhesive, or the like. At this time, a thermal bonding agent 61 (a material obtained by adding a filler or the like to thermal grease or thermal grease) may be interposed between the protrusion 62 and the mounting groove 60. Moreover, the protrusion part 62 and the attachment groove | channel 60 may be joined by heat press. The second heat pipe 3 is attached to the first heat pipe 2 firmly and reliably by attaching the second heat pipe 3 by the protrusion 62 in the attachment groove 60.

  Moreover, in FIG. 13, although the protrusion part 62 is attached over the side surface of an attachment groove, and the surface of the 1st heat pipe 2, you may attach in another aspect. Further, the protrusion 62 may be formed by the protrusion of the intermediate plate 12.

  As described above, in the cooling unit according to Embodiment 3, the second heat pipe 3 stands upright firmly and reliably on the surface of the first heat pipe 2.

  In addition, since the protrusion 62 is formed when at least one of the upper plate 10, the lower plate 11, and the intermediate plate 12 of the second heat pipe 3 has a larger area than the other, the protrusion 62 is formed in the second heat pipe 3. The heat resistance between them is small. For this reason, the thermal resistance between the protrusion part 62 and the 2nd heat pipe 3 which exchanges heat with the 1st heat pipe 2 becomes small, and heat conduction between the protrusion part 62 and the 2nd heat pipe 3 Is efficient.

  In addition, since the first heat pipe 2 and the projecting portion 62 are in contact with each other over a wide area by the thermal bonding agent (as shown in FIG. 13, the projecting portion 62 is bent to reach the surface protruding from the concave surface in the mounting groove 60. The protrusion 62 is in contact with the first heat pipe 2), and the thermal resistance between the first heat pipe 2 and the protrusion 62 is also reduced. Thus, the thermal resistance in each connection part of the 1st heat pipe 2, the protrusion part 62, and the 2nd heat pipe 3 is small, and the 1st heat pipe 2 and the 2nd heat pipe 3 are highly efficient in heat mutually. Can be conducted. As a result, the cooling unit 1 in which two types of heat pipes having different heat diffusion characteristics are combined can cool the heating element with high efficiency and can cool the heating element with bidirectionality.

(Embodiment 4)
Next, a fourth embodiment will be described. In the fourth embodiment, an electronic device in which the cooling unit described in the first to third embodiments is mounted will be described.

  FIG. 14 is an internal view of the electronic device according to the fourth embodiment of the present invention. The electronic device 70 shown in FIG. 14 includes a heating element that generates heat, such as a semiconductor integrated circuit, an electronic element, an electronic component, a light emitting element, and an optical element, and has a function of performing a predetermined process. Furthermore, the electronic device 70 has a narrow space or a complex space, and it is not easy to mount a cooling unit or a cooling device.

  The electronic device 70 is an electronic device that is required to be thin and small, such as a car TV, an aircraft personal monitor, a car navigation system, a mobile phone, a mobile terminal, a notebook personal computer, a PDA, and an electronic notebook. Alternatively, it is a device having a complicated internal space that is inevitable to cope with heat generation, such as an automobile, a transportation vehicle, a transportation device, a medical device, an industrial device, and an industrial robot.

  The electronic device 70 includes a casing 71, and the casing 71 stores an electronic substrate 72, a heating element 73 such as an electronic component, and the cooling unit 1. The cooling unit 1 has a combination of the first heat pipe 2 and the second heat pipe 3 as described in the first to third embodiments. Specifically, the second heat pipe excellent in heat diffusion from the first end 8 to the second end 9 on the surface of the first heat pipe 2 excellent in heat diffusion from the center to the end. 3 stands upright. For this reason, the 1st heat pipe 2 serves as a position of a baseplate, and the 2nd heat pipe 3 serves as a position of a fin.

  In FIG. 14, the plurality of second heat pipes 3 are erected on the surface of the first heat pipe 2, but may be singular.

  In FIG. 14, the heating element 73 is disposed on the back surface of the first heat pipe 2, but the heating element 73 may be disposed via the thermal bonding agent 74. Moreover, the heating element 73 arrange | positioned may be single or plural.

  As shown in FIG. 15, the first heat pipe 2 has excellent thermal diffusion characteristics from the center portion toward the end portion. FIG. 15 is a schematic diagram showing the thermal diffusion characteristics of the first heat pipe in the fourth embodiment of the present invention.

  The first heat pipe 2 has excellent thermal diffusion characteristics from the center portion toward the end portion, as indicated by the arrows in FIG. As described in the first and second embodiments, the thermal diffusion characteristic according to this arrow is due to the fact that at least a part of the vapor diffusion path 4 is formed along the direction from the center to the end. At least a part of the vapor diffusion path 4 is radial or a vapor diffusion path connecting a plurality of vapor diffusion paths is formed, so that the first heat pipe 2 is excellent from the center to the end. It has excellent heat diffusion characteristics.

  Due to this heat diffusion characteristic of the first heat pipe 2, the heat taken from the heating element 73 disposed on the back surface is diffused from the center portion to the end portion of the first heat pipe 2, while the heat is also in the thickness direction. Since it diffuses, heat diffuses to the surface where the second heat pipe 3 is erected.

  On the other hand, as shown in FIG. 16, the second heat pipe 3 has excellent thermal diffusion characteristics from the first end portion 8 toward the second end portion 9. FIG. 16 is a schematic diagram showing the thermal diffusion characteristics of the second heat pipe in the fourth embodiment of the present invention.

  The second heat pipe 3 has excellent thermal diffusion characteristics from the first end portion 8 toward the second end portion 9 as indicated by arrows in FIG. As described in the first and second embodiments, at least a part of the vapor diffusion path 4 is formed along the direction from the first end 8 toward the second end 9 in the thermal diffusion characteristics according to the arrow. It depends on The second heat pipe 3 has excellent thermal diffusion characteristics from the first end 8 toward the second end 9.

  Due to this thermal diffusion characteristic of the second heat pipe 3, the heat conducted from the surface of the first heat pipe 2 diffuses from the first end 8 to the second end 9 inside the second heat pipe 3. When the first end portion 8 is erected in contact with the surface of the first heat pipe 2, the second single portion 9 is located at the tip of the second heat pipe 3, so that the inside of the second heat pipe 3 Is diffused from the tip of the second heat pipe 3. That is, the heat of the heating element 73 disposed on the back surface of the first heat pipe 2 is transferred from the center of the first heat pipe 2 through the surface of the first heat pipe 2 and the second heat pipe 3 to the second heat pipe. 3 is dissipated from the second end (the tip of the cooling unit 1). This is the same as described with reference to FIG.

  The heat of the heating element 73 is dissipated from the tip of the second heat pipe 3. However, since the second heat pipe 3 is positioned as a fin in the cooling unit 1, the second end 9 of the second heat pipe 3. The heat release from is sufficiently performed. Furthermore, since all of the members that constitute the cooling unit 1 called the first heat pipe 2 and the second heat pipe 3 and that conduct heat are heat pipes with refrigerant diffusion, the cooling unit 1 has a high heat diffusion capacity ( Associated with this). In particular, since a heat conduction path is formed from the heating element 73 to a position where heat is finally dissipated, the cooling unit 1 can cool the heating element 73 by diffusing heat with high efficiency.

  Here, the case where the heating element 73 is disposed on the back surface of the first heat pipe 2 has been described. However, as shown in FIG. 9, heat is generated at the tip (first end portion 8) of the second heat pipe 3. A body 73 may be arranged. In this case, the heat from the heating element 73 is conducted in the order of the first end 8, the first end 9, the surface of the first heat pipe 2, and the back surface of the second heat pipe 2. Heat is dissipated from the back surface of the first heat pipe 2. At this time, the second heat pipe 3 may be erected so that the second end 9 is positioned on the surface of the first heat pipe 2.

  As described above, the cooling unit 1 is configured by a thin heat pipe as a whole, thereby not only cooling the heating element with high efficiency by vaporizing and condensing the refrigerant, but also the back surface of the first heat pipe 2 and the second heat pipe. The heating element can be optimally cooled by flexibly corresponding to various types of heating elements arranged at the end of the pipe 3.

  In addition, each of the first heat pipe 2 and the second heat pipe 3 is thin, and since it does not require a cooling fan or the like due to efficient heat diffusion, it is optimal for the electronic device 70 having a narrow space or a complex space. Can be implemented. For example, the cooling unit 1 can be easily mounted in a complicated space in the vicinity of a light or an engine of an automobile or transportation equipment. For this reason, the cooling unit 1 has a high replacement capability with respect to the conventional cooling device.

  For example, as shown in FIG. 17, in the electronic device 75, the cooling unit 1 may be mounted so as to cool a plurality of heating elements 77 positioned in the lateral direction. In an automobile headlamp or the like, the light emitting element may be positioned sideways. That is, it is in a state like a heating element 77 shown in FIG. FIG. 17 is an inner surface view of the electronic device according to the fourth embodiment of the present invention.

  As described above, even when the heating element 77 is positioned sideways, if the cooling unit 1 is mounted sideways, the heat conduction path from the first heat pipe 2 to the second end 9 of the second heat pipe 3 is increased. It is formed. Also in this case, the heat from the heating element 77 is diffused from the back surface of the first heat pipe 2 to the surface of the first heat pipe 2, and then the heat is conducted to the second heat pipe 3 so that the first end portion Heat diffuses from 8 to the second end 9. Finally, heat is dissipated from the second end 9 which is the tip of the second heat pipe 3 to the external environment.

  As described above, the electronic device 70 on which the cooling unit 1 is mounted can cool a heating element located in a narrow space or a complex space with high efficiency. Further, the electronic device 70 can flexibly correspond to various heating elements.

  Another example of the electronic device is illustrated in FIG. FIG. 18 is a perspective view of an electronic device according to Embodiment 4 of the present invention. The electronic device 82 is an electronic device that is required to be thin and small, such as a car TV or a personal monitor.

  The electronic device 82 includes a display 83, a light emitting element 84, and a speaker 85. The cooling unit 1 is housed inside the electronic device 82, and the heating element is cooled.

  By using such a cooling unit 1, cooling of the heating element can be realized without hindering downsizing and thinning of the electronic device.

  When considered in this way, the cooling unit 1 can be 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 a light, an engine, or a control computer unit of an automobile or industrial equipment. It can be suitably replaced with a heat dissipating frame, a cooling device or the like that is mounted on. Since the cooling unit 1 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 cooling unit 1 has a wide application range.

  Note that the cooling units and electronic devices described in the first to fourth embodiments are examples for explaining the gist of the present invention, and include modifications and alterations without departing from the gist of the present invention.

(Embodiment 5)
Next, a fifth embodiment will be described.

  Electronic devices mounted with cooling units and heat pipes, transportation devices, industrial devices, and the like have narrow spaces and complex spaces. The cooling unit and the heat pipe are thin or flat, and require a certain area.

  In electronic equipment and transportation equipment having such a narrow space or complicated space, there is no room for mounting a heat sink or a cooling fan for cooling the heating element. Moreover, it does not have the space margin which mounts a heat pipe. In particular, various components and various members are stored in a complicated manner in the device, and the mounting space having a certain extent (in terms of thickness and area) is very small.

  For example, an electronic board having a cooling function proposed in Japanese Patent Application Laid-Open No. 11-101585 requires a certain area, so that such a narrow space or a complex space is unsuitable from the mounting surface. In particular, this electronic board has a planar shape, but the heating element to be cooled is curved, small heating elements are scattered, or the heating element is in contact with a part of the curved case. Therefore, the flat electronic substrate has a problem that it is difficult to contact these heating elements.

  The cooling system proposed in Japanese Patent No. 3233808 is a technique for moving and cooling heat from a heating element to a heat radiating member, and it is necessary to mount the heat radiating member inside an electronic device. However, in an electronic device having only a small space, it is difficult to mount a heat dissipation member (such as a cooling fan or a liquid cooling jacket). Further, this cooling system has a problem that it is difficult to mount a path for moving the heat taken from the heating element. In addition, since this cooling system has a heat receiving portion and a heat radiating portion, it is difficult to implement in a device in a complex space.

  Here, in a cooling system such as an electronic component using a refrigerant such as a heat pipe or a liquid cooling jacket, a flat plate cooling device, a combination of a plurality of members (particularly, a first member that receives heat and vaporizes the refrigerant) There are many cooling devices in which there are many heat pipes in which the second member that condenses the evaporated refrigerant, and the first member and the second member are connected by a pipe having a capillary tube.

  Any of these cooling devices has a problem that it is difficult to mount in a narrow space or a complex space.

  In order to deal with such problems, a curved heat pipe is proposed.

  If the heat pipe has a curved shape, the heating element to be cooled is curved, or a plurality of heating elements to be cooled are positioned on the curved plane, and it is necessary to avoid other members when mounting. Even if there is a case, the heat pipe can be mounted while reliably contacting the heating element.

  In the fifth embodiment, a heat pipe having a curved shape capable of meeting such complicated mounting requirements will be described.

(Heat pipe with curved shape)
First, as one side surface of a heat pipe having a curved shape, the heat pipe having a curved shape has the following configuration.

  A heat pipe having a curved shape is laminated between a curved upper plate, a curved lower plate facing the upper plate, an upper plate and a lower plate, and at least a vapor diffusion path and a capillary flow path. A main body portion having one or a plurality of curved intermediate plates forming a part is provided.

(Second side)
In the heat pipe having the curved shape of the second side surface, in addition to the heat pipe having the curved shape of the first side surface, the intermediate plate has a notch portion and an internal through hole, and the notch portion forms a vapor diffusion path. The internal through-hole forms a capillary flow path, the vapor diffusion path diffuses the vaporized refrigerant in at least one of the planar direction and the thickness direction, and the capillary flow path condenses the condensed refrigerant in the vertical direction or the vertical / planar direction. To reflux.

(Third aspect)
In the heat pipe having the curved shape of the third side surface, in addition to the heat pipe having the curved shape of the second side surface, there are a plurality of intermediate plates, and the internal through holes provided in each of the plurality of intermediate plates are Only a part of each overlaps to form a capillary channel having a cross-sectional area smaller than the cross-sectional area of the internal through hole in the plane direction.

(4th side)
In the heat pipe having the curved shape of the fourth side surface, in addition to the heat pipe having the curved shape of any one of the first side surface to the third side surface, each of the upper plate and the lower plate includes a capillary channel and a vapor diffusion channel. A concave portion communicating with at least one is further provided.

(5th side)
In the heat pipe having the curved shape of the fifth side surface, in addition to the heat pipe having the curved shape of any one of the first side surface to the fourth side surface, at least one of the upper plate, the lower plate and the intermediate plate is another plate. And a protrusion to be joined.

(Sixth aspect)
In the heat pipe having the curved shape of the sixth side surface, in addition to the heat pipe having the curved shape of any one of the first side surface to the fifth side surface, each of the upper plate, the lower plate, and the intermediate plate has an external through hole. Then, the external through hole provided in the upper plate, the external through hole provided in the lower plate, and the external through hole provided in the intermediate plate are overlapped to form a via hole.

(Seventh aspect)
In the heat pipe having the curved shape of the seventh side surface, in addition to the heat pipe having the curved shape of the sixth side surface, the via hole has an electrical wiring layer that electrically connects the surfaces of the upper plate and the lower plate.

(8th side)
In the heat pipe having the curved shape of the eighth side surface, in addition to the heat pipe having the curved shape of the seventh side surface, the upper plate mounts the first electronic component, the lower plate mounts the second electronic component, The component and the second component are electrically connected via the electrical wiring layer.

(9th side)
In the heat pipe having the curved shape of the ninth side surface, in addition to the heat pipe having the curved shape of any one of the first side surface to the eighth side surface, an extension plate protruding from a part or all of the side surface of the main body portion is further provided. The extension plate is formed such that at least one of the upper plate, the lower plate, and the intermediate plate has a larger area than the other.

(Tenth aspect)
In the heat pipe having the curved shape of the tenth side surface, in addition to the heat pipe having the curved shape of the ninth side surface, the extension plate has a first heat radiating surface and a second heat radiating surface formed by being bent at the refracting portion. And at least one part of a 1st thermal radiation surface and a 2nd thermal radiation surface can be in thermal contact with the housing | casing of an electronic device.

(11th side)
In the heat pipe having the curved shape of the eleventh side surface, in addition to the heat pipe having the curved shape of the tenth side surface, the extension plate further has a third heat radiating surface formed by being bent at the second refracting portion, At least a part of the first heat radiating surface, the second heat radiating surface, and the third heat radiating surface can be in thermal contact with the housing of the electronic device.

(Twelfth aspect)
In the heat pipe having the curved shape of the twelfth side surface, in addition to the heat pipe having the curved shape of any one of the ninth side surface to the eleventh side surface, the extension plate has electrical wiring.

(13th side)
In the heat pipe having the curved shape of the thirteenth side surface, in addition to the heat pipe having the curved shape of any one of the first side surface to the thirteenth side surface, a temperature measuring unit that measures a temperature difference between at least two locations of the main body portion; A comparison unit that compares the temperature difference with a predetermined threshold and outputs a comparison result, and based on the comparison result, the operation state of the main body is determined based on the cooling capacity of the heat pipe, and the determination result is output. A section.

(14th side)
In the heat pipe having the curved shape of the fourteenth side surface, in addition to the heat pipe having the curved shape of the thirteenth side surface, the temperature measuring unit has a horizontal temperature difference that is a temperature difference between the central part and the peripheral part on the surface of the main body part , And at least one of a vertical temperature difference which is a temperature difference between the front surface and the back surface of the main body.

  In order to facilitate mounting in a narrow space or complex space, a heat pipe having a curved shape as described above is proposed. The heat pipe having the curved shape as described above will be described below.

  FIG. 19 is a perspective view of a heat pipe having a curved shape according to Embodiment 5 of the present invention.

  A heat pipe 100 having a curved shape is laminated between a curved upper plate 101, a curved lower plate 102 facing the upper plate 101, an upper plate 101 and a lower plate 102, and a vapor diffusion path and a capillary tube. A main body portion 104 having one or a plurality of curved intermediate plates 103 that form at least a part of the flow path is provided. FIG. 19 shows a perspective view from the exterior of the heat pipe 100, so the inside cannot be seen. For this reason, in FIG. 19, the vapor diffusion path and the capillary channel cannot be shown, but the inside of the main body 104 includes the vapor diffusion path and the capillary channel formed as described in the first to fourth embodiments. I have.

  As is clear from FIG. 19, the main body 104 has a curved shape as a whole. Thus, the heat pipe 100 having a curved shape can be easily mounted even in a narrow space or a complex space.

  For example, as shown in FIG. 20, the heat pipe 100 having a curved shape can cool a plurality of heating elements having different arrangement directions by utilizing the curved shape. FIG. 20 is a mounting diagram of a heat pipe having a curved shape according to the fifth embodiment of the present invention.

  The heating elements 105 have different arrangement directions. For example, when the mounting substrate is complicated and complicated, or the frame is complicated and complicated, the heat pipe has a curved shape as shown in FIGS. Any of these can be contacted. As a result, the heat pipe 100 having a curved shape can cool all the heating elements 105.

  Thus, the heat pipe 100 having a curved shape can cool a plurality of heating elements having different arrangement directions.

  Alternatively, when the frame is complicated and complicated, it may be difficult to mount a flat heat pipe. In such a case, it is necessary to mount while avoiding the frame, but the heat pipe 100 having a curved shape can cope with this. FIG. 21 is a mounting diagram of a heat pipe having a curved shape according to the fifth embodiment of the present invention. FIG. 21 shows a case where, for example, an electronic device or a transportation device has a frame 106 having a complicated shape inside. A heating element 105 to be cooled is mounted on a part of the frame 106. With a flat heat pipe, even if it can contact the heating element 105, it is difficult to mount it inside the frame 106. On the other hand, if the heat pipe 100 has a curved shape, the heat pipe 100 can be in contact with the heating element 105 and can be mounted inside the frame 106.

  Thus, the heat pipe 100 having a curved shape has an advantage of being easily mounted in a narrow space or a complex space.

  Next, the details of the heat pipe 100 having a curved shape will be described.

  FIG. 22 is an exploded view of the heat pipe in the fifth embodiment of the present invention. FIG. 22 shows a state in which the heat pipe 100 is disassembled into an upper plate 101, a lower plate 102, and an intermediate plate 103.

  The upper plate 101, the lower plate 102, and the intermediate plate 103 are each curved. One or a plurality of curved intermediate plates 103 are laminated between the curved upper plate 101 and the curved lower plate 102 opposed thereto. In FIG. 22, four intermediate plates 103 are laminated. FIG. 23 is an exploded view of the heat pipe in the fifth embodiment of the present invention. The details of the heat pipe 100 having a curved shape will be described with reference to FIG.

  A curved intermediate plate 103 is sandwiched and stacked between the curved upper plate 101 and the curved lower plate 102. The intermediate plate 103 includes a notch 110 and an internal through hole 111, the notch 110 forms a vapor diffusion path 114, and the internal through hole 111 forms a capillary channel 115. Further, at least one of the upper plate 101 and the lower plate 102 has a recess 112.

  At least one of the upper plate 101, the lower plate 102, and the intermediate plate 103 has a protrusion 113, and the protrusion 113 is bonded when the upper plate 101, the lower plate 102, and the intermediate plate 103 are joined to each other. Become an agent. When the projection 113 is joined as an adhesive, the main body 104 having a curved shape is formed, and the vapor diffusion path 114 and the capillary channel 115 are formed therein. In this way, the curved upper plate 101, lower plate 102, and intermediate plate 103 are joined together, so that the heat pipe 100 having a curved shape is made. The heat pipe 100 encloses a refrigerant therein, the vaporized refrigerant diffuses inside the main body 104 via the vapor diffusion path 114, and the condensed refrigerant flows back through the capillary channel 115. By repeating the vaporization and condensation of the refrigerant, the heat pipe 100 having a curved shape can cool the heating element.

  Thus, the heat pipe 100 having a curved shape can be obtained by laminating and joining the curved upper plate 101, lower plate 102, and intermediate plate 103.

  Except for being curved, the upper plate 101, the lower plate 102, and the intermediate plate 103 have the same structure and function as described in the first embodiment.

(Upper plate)
The upper plate 101 will be described.

  The upper plate 101 has a curved shape.

  The upper plate 101 is made of metal, resin, or the like, but is made of metal having high thermal conductivity or high rust prevention (durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. It is preferred that The upper plate 101 may have a curved shape, and may have a circular shape or a square shape as a whole.

  It is also preferable that the upper plate 101 has a recess 112 communicating with at least one of the vapor diffusion path 114 and the capillary flow path 115 on one surface of the upper plate 101 facing the intermediate plate 103. Since the recess 112 communicates with the capillary channel 115, the condensed refrigerant is easily transmitted from the upper plate 101 to the capillary channel 115. Alternatively, the recess 112 communicates with the vapor diffusion path 114 so that the vaporized refrigerant can easily come into contact with a large area on the surface of the upper plate 101, and heat dissipation of the vaporized refrigerant is promoted.

  It is also preferable that the upper plate 101 includes a protruding portion or an adhesive portion that is bonded to the intermediate plate 103. The upper plate 101 is referred to as an “upper portion” for the sake of convenience, but does not have to physically exist at the upper position, and is not particularly distinguished from the lower plate 102. Further, the upper plate 101 may be a surface in contact with the heating element or a surface facing the heating element.

  The upper plate 10 includes a refrigerant inlet. When the upper plate 101, the intermediate plate 102, and the lower plate 102 are laminated and joined, an internal space is formed. Since it is necessary to enclose the refrigerant in the internal space, the refrigerant is enclosed from the inlet after the upper plate 101 and the like are joined. The inlet is sealed when the refrigerant is sealed, and the internal space is sealed.

  The refrigerant may be sealed from the inlet after the stacking, or may be sealed when the upper plate 101, the lower plate 102, and the intermediate plate 103 are stacked.

(Lower plate)
The lower plate 102 faces the upper plate 101 and sandwiches one or more intermediate plates 103. Further, the lower plate 101 is curved.

  The lower plate 102 is formed of metal, resin, or the like, but is formed of metal having high thermal conductivity or high rust prevention (durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. It is preferred that

  It is also preferable that the lower plate 102 has a concave portion 112 that communicates with the vapor diffusion path 114 and the capillary channel 115 on one surface of the lower plate 102 that faces the intermediate plate 103. The recess 112 communicates with the capillary channel 115 so that the condensed refrigerant is easily transmitted from the lower plate 102 to the capillary channel 115. Further, since the recess 112 communicates with the vapor diffusion path 114, the vaporized refrigerant can easily come into contact with a large area on the surface of the lower plate 102, and heat dissipation of the vaporized refrigerant is promoted. This has the same significance as that the concave portion 112 is provided in the upper plate 101.

  The lower plate 102 is referred to as “lower” for convenience, but does not have to physically exist at the lower position and is not particularly distinguished from the upper plate 101.

  It is also preferable that the lower plate 102 includes a protruding portion or an adhesive portion that is bonded to the intermediate plate 103.

  Further, the lower plate 102 may or may not be in contact with the heating element.

(Intermediate plate)
The intermediate plate 103 is a single plate member or a plurality of plate members. In FIG. 23, the heat pipe 100 has four intermediate plates 103. The intermediate plate 103 is stacked between the upper plate 101 and the lower plate 102.

  The intermediate plate 103 is formed of metal, resin, or the like, but is formed of metal having high thermal conductivity or high rust prevention (durability) such as copper, aluminum, silver, aluminum alloy, iron, iron alloy, and stainless steel. It is preferred that

  Further, the intermediate plate 103 may have protrusions and adhesive portions used when connected to the upper plate 101 and the lower plate 102. In addition, the intermediate plate 103 has an internal through hole 111 having a minute cross-sectional area. The internal through hole 111 forms a capillary channel 115.

  Finally, the intermediate plate 103 is laminated and bonded between the upper plate 101 and the lower plate 102, whereby the heat pipe 100 is formed. The intermediate plate 103 may be singular or plural. However, as will be described later, in order to form the capillary channel 115 having a smaller cross-sectional area, it is preferable that there are a plurality of intermediate plates 103.

(Intermediate plate, vapor diffusion path and capillary flow path)
Next, the vapor diffusion path 114 and the capillary channel 115 will be described. The intermediate plate 103 forms a vapor diffusion path 114 that diffuses the vaporized refrigerant in at least one of the planar direction and the thickness direction, and a capillary channel 115 that recirculates the condensed refrigerant in the vertical direction or the vertical / planar direction.

  First, the vapor diffusion path 114 will be described.

  The intermediate plate 103 has a notch 110 and an internal through hole 111.

  The notch 110 forms a vapor diffusion path 114. When the intermediate plate 103 is laminated between the upper plate 101 and the lower plate 102, the notch 110 forms a gap. This gap becomes the vapor diffusion path 114.

  Here, the notch portion 110 is formed toward at least one of the planar direction and the thickness direction of the heat pipe 100, so that the vapor diffusion path 114 also faces at least one of the planar direction and the thickness direction of the heat pipe 100. Formed. For this reason, the vaporized refrigerant diffuses in at least one of the planar direction and the thickness direction. Of course, when the lower plate 102 and the upper plate 101 are connected by the notch portion 110, the refrigerant that is received and vaporized by the lower plate 102 moves in the plane direction and the thickness direction, and the vaporized refrigerant (and heat) ) Reaches from the lower plate 102 to the upper plate 101. That is, the vapor diffusion path 114 moves the vaporized refrigerant in both the planar direction and the thickness direction (of course, either one may be used depending on the shape of the vapor diffusion path 114).

  In particular, when the notch 110 is formed radially from the center of the intermediate plate 103, the vapor diffusion path 114 is also formed radially from the center of the heat pipe 100. Since the heating element is often installed at the substantially central portion of the heat pipe 100, the refrigerant receives heat most at the substantially central portion of the heat pipe 100. For this reason, the refrigerant | coolant of the center part vicinity of the heat pipe 100 vaporizes first. At this time, if the vapor diffusion path 114 is formed radially from the substantially central portion of the heat pipe 100, the vaporized refrigerant generated in the vicinity of the center diffuses radially, that is, in at least one of the planar direction and the thickness direction. If the vapor diffusion path 114 is formed in both the planar direction and the thickness direction, the vaporized refrigerant diffuses in both the planar direction and the thickness direction. As a result, the vaporized refrigerant (heat taken away from the heating element) reaches the heat radiating surface on the side opposite to the heating element. The heat that has reached the heat radiating surface opposite to the heating element is conducted to the heat pipe 100.

  As described above, the intermediate plate 103 has the notch 110 and the vapor diffusion path 114 extending in at least one of the planar direction and the thickness direction is formed, so that the vaporized refrigerant is planar in the heat pipe 100. It diffuses in at least one of the direction and the thickness direction. As a result, the heat from the heating element diffuses in the plane of the heat pipe 100 from the center toward the periphery.

  The heat pipe 100 has a capillary flow path 115 that efficiently recirculates the condensed refrigerant after being diffused by utilizing the entire surface of the heat pipe 100, thereby diffusing at least one of a high plane direction and a thickness direction. (And reflux) performance is realized. Furthermore, the condensed refrigerant can be recirculated with further efficiency by the recess 112 communicating with the capillary channel 115. The recess 112 also has a role of promoting the reflux of the condensed refrigerant.

  Next, the capillary channel 115 will be described.

  The intermediate plate 103 has an internal through hole 14. The internal through-hole 111 is a minute through-hole, and forms a capillary channel 115 through which condensed refrigerant recirculates. When the intermediate plate 103 has the notch 110, an internal through hole 111 is formed in a portion other than the notch 110.

  Here, when there is a single intermediate plate 103, the internal through hole 111 provided in the intermediate plate 103 becomes the capillary channel 5 as it is.

  On the other hand, when there are a plurality of intermediate plates 103, only a part of the internal through-holes 111 provided in each of the plurality of intermediate plates 103 overlap, and the cross-sectional area in the planar direction of the internal through-holes 111 overlaps. A capillary channel 115 having a smaller cross-sectional area is formed. In this way, when there are a plurality of intermediate plates 103, the capillary channel 115 having a cross-sectional area smaller than the cross-sectional area of the internal through-hole 111 itself is formed, so that the condensed refrigerant recirculates in the capillary channel 115. Can be more effective. This is because the movement of the liquid by capillary action is promoted by the small cross-sectional area of the capillary.

  Here, each of the intermediate plates 103 is provided with a plurality of internal through holes 111. This is because the plurality of internal through holes 111 can form a capillary channel 115 having a plurality of channels.

  The internal through-hole 111 penetrates from the front surface to the back surface of the intermediate plate 103, and the shape thereof may be circular, elliptical, or rectangular. However, since a part of the internal through-holes 111 overlap to form the capillary channel 115, it is appropriate that the internal through-hole 111 is square.

  The internal through hole 111 may be formed by excavation, pressing, wet etching, dry etching, or the like.

  When there are a plurality of intermediate plates 103, the internal through holes 111 are provided in each of the plurality of intermediate plates 103. Here, since the plurality of intermediate plates 103 are stacked such that only a part of the internal through-holes 111 overlap each other, the positions of the internal through-holes 111 may be shifted for each adjacent intermediate plate 103. Is appropriate. For example, the position of the internal through-hole 111 in a certain intermediate plate 103 and the position of the internal through-hole 111 in another intermediate plate 103 adjacent to this intermediate plate 103 are such that a part of the cross section of the internal through-hole 111 overlaps each other. It is off. As described above, the position of the internal through-hole 111 is shifted for each adjacent intermediate plate 103, so that when the plurality of intermediate plates 103 are stacked, the cross-sectional area of the internal through-hole 111 is smaller than the cross-sectional area in the planar direction. A capillary channel 115 having an area is formed.

  When the plurality of intermediate plates 103 are stacked, the capillary channel 115 has a cross-sectional area smaller than the cross-sectional area in the planar direction of the internal through-hole 111 with a part of the internal through-holes 111 overlapping each other. Holes having a cross-sectional area smaller than the cross-sectional area of the internal through-hole 111 are stacked in the vertical direction of the heat pipe 100 and the vertical holes are connected to form a vertical flow path. . 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.

  In addition, when the capillary channel 115 having a smaller cross-sectional area than the inner through-hole 111 is formed so that only a part of the inner through-hole 111 overlaps, rather than directly processing the capillary channel 115, There is also an advantage that it can be manufactured easily.

  In addition, although the capillary channel 115 recirculates the condensed refrigerant, it can also pass the vaporized refrigerant.

  In addition, the capillary channel 115, the corners of the recess 112 and the corners of the notch 110 are preferably chamfered or provided with R. The cross section of the capillary channel 115 may have various cross sectional shapes such as a hexagon, a circle, an ellipse, a rectangle, and a polygon. The cross-sectional shape of the capillary channel 115 is determined by the shape of the internal through-hole 111 and the way in which the internal through-holes 111 are overlapped. Moreover, a cross-sectional area is determined similarly.

(Manufacturing process)
Here, the manufacturing process of the heat pipe 100 will be described.

  The heat pipe 100 is manufactured by stacking and joining the upper plate 101, the lower plate 102, and the intermediate plate 103.

  The manufacturing process will be described with reference to FIG.

  The upper plate 101, the lower plate 102, and the plurality of intermediate plates 103 (four intermediate plates 103 in FIG. 23) are matched to each other so as to overlap each other at the same position. In addition, the plurality of intermediate plates 103 are adjusted to a positional relationship such that only a part of each of the internal through holes 111 provided in each of the plurality of intermediate plates 12 overlaps.

  At least one of the upper plate 101, the lower plate 102, and the plurality of intermediate plates 103 has a joint protrusion.

  The upper plate 101, the lower plate 102, and the plurality of intermediate plates 103 are aligned and stacked, 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.

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, a refrigerant is injected through an injection port opened in part of the upper plate 101 and the lower plate 102. Thereafter, the inlet is sealed and the heat pipe 100 is completed. The refrigerant is sealed under vacuum or reduced pressure. By being performed under vacuum or reduced pressure, the internal space of the heat pipe 100 is in a vacuum or reduced pressure state and the refrigerant is enclosed. When the pressure is reduced, the refrigerant vaporization / condensation temperature becomes low, and there is an advantage that the refrigerant vaporization / condensation repeats actively.

(Heat pipe with via hole)
In the curved heat pipe 100, it is also preferable that each of the upper plate 101, the lower plate 102, and the intermediate plate 103 has external through holes, and the external through holes overlap to form a via hole.

  FIG. 24 is a side view of the heat pipe in the fifth embodiment of the present invention. As shown in FIG. 24, the heat pipe 100 having a curved shape has a via hole 120 formed by overlapping external through holes. The via hole 120 penetrates from the surface of the upper plate 101 to the surface of the lower plate 102. Via holes 120, for example, electronic components mounted on the surface of the upper plate 101 and electronic components mounted on the surface of the lower plate 102 can be electrically connected. For example, the electrical wiring is passed through the via hole to electrically connect the electronic component mounted on the upper plate 101 and the electronic component mounted on the lower plate 102.

  Alternatively, an electrical wiring layer may be formed in the via hole, and the electronic component mounted on the upper plate 101 and the electronic component mounted on the lower plate 102 may be electrically connected. The electric wiring layer is formed of a conductive film or a plating layer.

  Since the via hole 120 is penetrated from the front surface to the back surface of the heat pipe 100 having a curved shape, an electronic component as a heating element can be brought into contact with or mounted on both surfaces of the heat pipe 100 having a curved shape. In particular, the electronic components on the front surface and the electronic components on the back surface can be electrically connected. Alternatively, a signal from the electronic component on the back surface can be extracted to the front surface.

  The via holes 120 are formed by overlapping the external through holes. However, since the plate-like members are stacked, the inner wall of the via hole 120 is sealed. For this reason, the sealing of the internal space of the heat pipe 100 having a curved shape does not occur. Of course, in order to enhance the sealing, it is also appropriate that the outer peripheries of the external through holes protrude in advance and the protruding portions overlap each other.

(Heat pipe with extension plate)
It is also preferable that the heat pipe 100 having a curved shape further includes an extension plate 121 protruding from a part or all of the side surface of the main body 104. The extension plate 121 is formed by having at least one of the upper plate 101, the lower plate 102, and the intermediate plate 103 having a larger area than the other. FIG. 25 is a side view of the heat pipe in the fifth embodiment of the present invention. The heat pipe 100 includes an extension plate 121 that protrudes from the main body portion 104.

  In FIG. 25, the extension plate 121 is formed such that the intermediate plate 103 has a larger area than the upper plate 101 and the lower plate 102. The extension plate 121 is bent at the refracting portion and has a first heat radiating surface 122, a second heat radiating surface 123, and a third heat radiating surface 124. The heat pipe 100 can be mounted inside the housing 125 of the electronic device, and at least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 can be in thermal contact with the housing 125. It is. The term “thermally contactable” means that at least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 are in direct contact with the housing or through a thermal bonding agent. It is to do.

  Since at least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 can be in thermal contact with the housing 125, the heat pipe 100 can remove the heat taken away from the heating element by the first heat radiating surface 11. Heat can be radiated to the housing 125 through at least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124. At least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 is a part of the intermediate plate 103 in addition to having a certain area. There is almost no increase in thermal resistance with the extension plate 121. For this reason, the heat taken away from the heating element by the main body 104 is efficiently conducted to at least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124. Furthermore, since at least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 is in thermal contact with the housing 125, the conducted heat is exhausted to the housing 125. it can. That is, at least a part of the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 can reinforce the dissipation of heat taken from the heating element.

  As a result, the heat pipe 100 efficiently cools the heating element even in a narrow space by the extension plate 121 and the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 formed on the extension plate 121. it can. In particular, the first heat radiating surface 11, the second heat radiating surface 123, and the third heat radiating surface 124 can be mounted in a narrow space, and heat can be directly dissipated from these heat radiating surfaces to the housing 125. 100 does not require a secondary cooling member such as a cooling fan or a liquid cooling jacket. Also from this, the heat pipe 100 is easy to mount in a narrow space, and the cooling effect is not impaired.

  Further, the extension plate 121 may have electrical wiring.

  For example, when an electronic component mounted on the main body 104 and an external electronic component are electrically connected, the electrical wiring is formed on the extension plate 121 so that the electronic components are reliably electrically connected.

  The electrical wiring includes, for example, a wiring pattern or a printed pattern formed on the extension plate 121. Or a flexible substrate may be affixed on the extension plate 121, and the extension plate 121 itself may be formed with a flexible substrate.

  FIG. 26 is a perspective view of a heat pipe in the fifth embodiment of the present invention. The heat pipe 100 shown in FIG. 26 forms an extension plate 121 with a flexible substrate. In addition, the extension plate 121 has an electrical wiring 130. The electrical wiring 130 is connected to an electronic component 131 mounted on the surface of the main body 104. The other side of the electrical wiring 130 can be connected to an external electronic component or an electrical slot, and enables electrical exchange with the electronic component 131.

  As described above, the electrical wiring 130 is formed on the extension plate 121, thereby enabling electrical connection between the electronic component mounted on the main body 104 and the outside.

(Heat pipe with self-diagnosis function)
Next, a heat pipe having a self-diagnosis function will be described with reference to FIG.

  FIG. 27 is a block diagram of a heat pipe in the fifth embodiment of the present invention. The heat pipe 100 having a curved shape is mounted in a narrow space or a complex space. Electronic devices and industrial devices having such a narrow space or complex space are often difficult for the user to open and close and maintain, and the user can determine performance degradation or failure of the heat pipe 100 having a curved shape. Is preferred.

  For example, even if the cooling capacity of the heat pipe 100 having a high refrigerant (in other words, heat) diffusion performance is high, an unexpected situation may occur in a casing having a small space. For example, heat may be accumulated in the internal space, and the heat generation of the heating element may exceed the spec. In this case, heat generation exceeding the cooling capacity of the heat pipe 100 having a curved shape that matches the heat generation specifications of the heating element occurs, and the cooling capacity of the heat pipe 100 having a curved shape becomes insufficient. If this happens, it may cause malfunction of electronic equipment and industrial equipment. Alternatively, it may cause malfunction or failure of the heat pipe 100 itself.

  Therefore, as shown in FIG. 27, a heat pipe having a self-diagnosis function is proposed. In FIG. 27, the heat pipe 100 having a curved shape looks like a flat plate, but for the convenience of the drawing, it originally has a curved shape.

  The heat pipe 100 having a curved shape includes a main body 140, a self-diagnosis unit 145, a temperature measurement unit 146, a comparison unit 147, and a determination unit 148. The heat pipe 100 having a curved shape itself cools the heating element by vaporizing and condensing the enclosed refrigerant.

  The heat pipe 100 having a curved shape has a main body 140 having a function as a heat pipe for cooling the heating element, and self-diagnosis means 145 for diagnosing the operation state of the main body 140 based on the cooling capacity of the heat pipe. doing. The self-diagnosis unit 145 includes a temperature measurement unit 146, a comparison unit 147, and a determination unit 148.

  The main body 140 is a portion that exhibits the cooling function of the heat pipe 100 having a curved shape, and has a curved shape. The main body 140 has an internal space whose periphery is sealed, and the internal space encloses the refrigerant. The main body 140 has a vapor diffusion path 141 through which vaporized refrigerant diffuses and a capillary channel 142 through which condensed refrigerant flows back. Here, the vapor diffusion path 141 diffuses the vaporized refrigerant in the plane and in the thickness direction. The capillary channel 142 recirculates the refrigerant condensed in the vertical direction or the vertical / planar direction.

  For this reason, the main body 140 diffuses the refrigerant in a plane and a thickness direction (a plane and a thickness direction of the flat main body 140). In other words, the heat of the heating element is diffused and moved in the plane and the thickness direction in the main body 140. The evaporated refrigerant dissipates heat on the surface of the main body 140 and is cooled, but since the evaporated refrigerant diffuses widely in the plane direction of the main body 140, the surface of the main body 140 can be efficiently utilized to every corner. The vaporized refrigerant can be cooled.

  At least two temperature detection portions 143 and 144 are provided on the surface of the main body 140.

  The temperature measurement unit 146 measures the temperature difference between the temperature detection portions 143 and 144. The temperature measurement unit 146 outputs the measured temperature difference to the comparison unit 147. The comparison unit 147 compares the temperature difference with a predetermined threshold and outputs the comparison result to the determination unit 148.

  The determination unit 148 determines the operating state of the main body unit 140 based on the comparison result and outputs the determination result. At this time, the determination unit 148 determines the operating state of the main body 140 based on the temperature difference between at least two positions of the main body 140. The main body 140 cools the heating element by the diffusion of the vaporized refrigerant and the reflux of the condensed refrigerant. That is, its diffusivity creates cooling capacity. For this reason, the fact that the temperature difference between two different locations is high indicates that the diffusion performance is insufficient and the cooling capacity is insufficient. For this reason, the determination part 148 can determine the state of the diffusion performance of the main body part 140, that is, the operation state, based on the temperature difference between at least two places.

  The determination unit 148 outputs a determination result. An electronic device or user on which the heat pipe 100 having a curved shape is mounted can receive the determination result. As a result, according to the determination result from the determination unit 148, the user and the electronic device can take subsequent control and measures, and the malfunction or failure of the electronic device, or the malfunction of the heat pipe 100 itself having a curved shape, Failure can be prevented beforehand.

  The self-diagnosis unit 145 determines the operation state of the main body 140 described as described above based on the cooling capacity of the heat pipe. Details of each part will be described below.

(Temperature detection part)
In the temperature detection parts 143 and 144, temperature sensors are installed, and the temperature of each part is transmitted to the temperature measurement unit 146.

  Various sensors such as a commercially available temperature sensor and a thermocouple are used as the temperature sensor. For example, a metal plating pattern formed on the surface of the main body 140 is used.

  In addition, the temperature detection part may be two places or three places or more.

(Temperature measurement unit)
The temperature measurement unit 146 measures a temperature difference at the temperature detection portions 143 and 144. In measuring the temperature difference, the temperature at the absolute value at each of the temperature detection portions 143 and 144 may be measured to measure the temperature difference, or the temperature difference may be measured from the beginning.

  The temperature measurement unit 146 can measure temperature differences at various positions of the main body 140 depending on the installation positions of the temperature detection parts 143 and 144. For example, the temperature measurement unit 146 measures the temperature difference (horizontal temperature difference) between the central part and the peripheral part on the surface of the main body part 140. Of course, the temperature measuring unit 146 may measure a temperature difference between the peripheral part and the peripheral part which are different positions on the surface of the main body part 140.

  As described above, the temperature measurement unit 146 does not measure the absolute temperature at a specific position of the main body 140, but measures the temperature difference between at least two locations. The main body 140 generates heat by diffusing the refrigerant. This is because it has the property of cooling the body. Since the cooling capacity of the main body 140 as a heat pipe depends on its diffusion performance, the cooling capacity can be estimated by measuring the diffusion capacity. Here, the superiority or inferiority of the diffusion performance can be estimated by the temperature difference at different positions in the main body 140.

  For example, when the temperature difference between the central part and the peripheral part on the surface of the main body part 140 is large, it indicates that the heat received at the central part is not sufficiently diffused in the plane direction. This indicates that the cooling capacity is insufficient (the heat generated by the heating element exceeds the cooling capacity).

  Conversely, a small temperature difference between the central portion and the peripheral portion on the surface of the main body 140 indicates that the heat received at the central portion can be sufficiently diffused in the plane direction. This indicates that the heat generated by the heating element does not exceed the cooling capacity of the main body 140.

  As described above, the temperature measurement unit 146 does not provide the absolute temperature at a specific portion of the main body 140 as a cooling capacity determination material, but uses at least two temperature differences of the main body 140 as a cooling capacity determination material. provide. As described above, the operation state of the main body 140 is determined based on at least two temperature differences rather than the absolute temperature, so that the operation state of the heat pipe having a high refrigerant diffusion performance can be more accurately determined. .

  The temperature measurement unit 146 outputs the measured temperature difference to the comparison unit 147.

(Comparison part)
The comparison unit 147 compares the temperature difference received from the temperature measurement unit 146 with a predetermined threshold value. The predetermined threshold is determined according to the cooling capacity required for the heat pipe 100 having a curved shape, the specifications of the electronic device on which the heat pipe 100 having the curved shape is mounted, and the like.

  For example, an experiment is performed by applying heat to a certain heat pipe, and the degree of temperature difference is measured to determine whether the operation of the heat pipe is practically not performed. The threshold value may be determined based on this temperature difference.

  The predetermined threshold is prepared as a reference for determining whether or not the cooling capacity of the main body 140 is sufficient for the heat generation of the heating element.

  The comparison unit 147 compares the temperature difference received as an electrical signal with a threshold value stored in a memory or the like as an electrical signal using a comparator, an AND circuit, or the like. For the comparison method, various known techniques may be applied.

  An example of a simple configuration from temperature measurement to comparison will be described with reference to FIG. FIG. 28 is a circuit diagram of a circuit for performing temperature measurement to comparison in the fifth embodiment of the present invention.

  A metal plating pattern is formed in the temperature detection portions 143 and 144, and the output of this pattern is connected to the operational amplifier 150 as shown in FIG. Since the voltage output from the pattern is proportional to the temperature at the temperature detection portions 143 and 144, the difference between the voltages of the two signals input to the operational amplifier 150 indicates the temperature difference at the temperature detection portions 143 and 144. Yes.

  The operational amplifier 150 outputs different signals depending on whether or not the voltage difference between the two input signals is greater than or equal to a predetermined value. For example, when a potential difference between two signals is less than a predetermined value (a temperature difference between two locations is less than a predetermined threshold value), a plus potential signal is output. Conversely, if the potential difference between the two signals is greater than or equal to a predetermined value (the temperature difference between the two locations is greater than or equal to a predetermined threshold value), a negative potential signal is output.

  As described above, the simple circuit shown in FIG. 28 can be compared with the threshold value after measuring the temperature difference between at least two places of the main body 2.

(Judgment part)
Next, the determination unit 148 will be described.

  Based on the comparison result from the comparison unit 147, the determination unit 148 determines the operation state of the main body 140 based on the cooling capacity of the heat pipe. More specifically, the determination unit 148 determines whether or not the heat generated by the heating element exceeds the cooling capacity of the main body 140 (in other words, the heat pipe 100 having a curved shape). This is because if the heat generated by the heating element exceeds the cooling capacity of the main body 140, it may cause malfunction or failure of the electronic device or malfunction or failure of the heat pipe 100 having a curved shape.

  Based on the comparison result, the determination unit 148 outputs either a signal indicating that the heat generated by the heating element exceeds the cooling capacity of the main body 140 or a signal indicating that the heat generation capacity of the main body 140 does not exceed the cooling capacity. And output as a determination result. The determination result may be output as an electrical signal. For example, if the determination result is a 1-bit electrical signal, when the value of this electrical signal is “0”, it indicates that the heat generated by the heating element exceeds the cooling capacity of the main body 140, and the value of the electrical signal When “1” is “1”, it indicates that the heat generated by the heating element does not exceed the cooling capacity of the main body 140.

  The determination result can be used as a signal for a user or an electronic device.

  As a result, the user or the electronic device itself can obtain in advance information that leads to an operation failure or failure of the electronic device or the heat pipe 100 having a curved shape, and can prevent such operation failure or failure.

  Note that the self-diagnosis unit 145 may be configured as an electronic circuit and provided as an electronic substrate separately or integrally with the main body 140.

  The self-diagnosis unit 145 determines the operation state of the main body 140 with reference to the cooling capacity of the heat pipe, which determines the operation state of the curved heat pipe 100 itself with reference to the cooling capacity. It is synonymous with that.

  As described above, the operation state from the viewpoint of the cooling capacity of the heat pipe can be accurately and appropriately grasped. As a result, it is possible to prevent malfunctions and failures of electronic devices and heat pipes.

Side view of cooling unit according to Embodiment 1 of the present invention. The inner surface figure of the 1st heat pipe in Embodiment 1 of the present invention The disassembled side view of the 1st heat pipe in Embodiment 1 of this invention Inner view of second heat pipe 3 according to the first embodiment of the present invention. Inner view of second heat pipe 3 according to the first embodiment of the present invention. The perspective view of the cooling unit in Embodiment 1 of this invention Side view of cooling unit according to Embodiment 1 of the present invention. The schematic diagram which shows the cooling state of the cooling unit in Embodiment 1 of this invention. The schematic diagram which shows the cooling state of the cooling unit in Embodiment 1 of this invention. Inner view of first heat pipe that is similar to that described in the first embodiment The inner surface figure of the 1st heat pipe in Embodiment 2 of the present invention The inner surface figure of the 1st heat pipe in Embodiment 2 of the present invention Side view of a part of the cooling unit in Embodiment 3 of the present invention Inner view of electronic apparatus according to Embodiment 4 of the present invention The schematic diagram which shows the thermal-diffusion characteristic of the 1st heat pipe in Embodiment 4 of this invention The schematic diagram which shows the thermal-diffusion characteristic of the 2nd heat pipe in Embodiment 4 of this invention Inner view of electronic apparatus according to Embodiment 4 of the present invention The perspective view of the electronic device in Embodiment 4 of this invention The perspective view of the heat pipe which has the curved shape in Embodiment 5 of this invention Mounting diagram of heat pipe having curved shape in embodiment 5 of the present invention Mounting diagram of heat pipe having curved shape in embodiment 5 of the present invention Exploded view of heat pipe in embodiment 5 of the present invention Exploded view of heat pipe in embodiment 5 of the present invention Side view of heat pipe in Embodiment 5 of the present invention Side view of heat pipe in Embodiment 5 of the present invention The perspective view of the heat pipe in Embodiment 5 of this invention Block diagram of heat pipe in Embodiment 5 of the present invention The circuit diagram of the circuit which performs from temperature measurement to comparison in Embodiment 5 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling unit 2 1st heat pipe 3 2nd heat pipe 4 Vapor diffusion path 5 Capillary flow path 6 Vapor diffusion path 7 Capillary flow path 8 1st end part 9 2nd end part 10 Upper board 11 Lower board 12 Intermediate board 13 Cutting Notch 14 Internal through hole 15 Recess

Claims (13)

A flat plate-like first heat pipe excellent in heat diffusion in the radial direction from the central part to the peripheral part ;
A flat plate-like second heat pipe that is erected on the surface of the first heat pipe and is excellent in heat diffusion in one direction from the first end portion to the second end portion facing the first end portion. Prepared,
Wherein each of the first heat pipe and the second heat pipe, to co Cooling the heating elements by vaporization and condensation of the encapsulated refrigerant with encapsulating refrigerant integrally includes a vapor diffusion path and the capillary flow passage, The first heat pipe forms the vapor diffusion path and the capillary flow path extending in a radial direction from the central portion toward the peripheral portion,
The second heat pipe forms the vapor diffusion path and the capillary flow path extending in one direction from the first end toward the second end,
The second heat pipe is located on the surface side of the first heat pipe so that either the first end or the second end of the second heat pipe is selectively positioned on the first heat pipe. Standing on the surface
The vapor diffusion path of the second heat pipe has a divergent shape from the first end portion to the second end portion, and is a cooling unit that realizes the superiority of the one-way heat diffusion .   When a heating element is disposed on the back surface of the first heat pipe, the first end is positioned on the front surface side of the first heat pipe, and the second heat pipe is attached to the first heat pipe. The cooling unit according to claim 1. When the heating element is disposed at the end of the second heat pipe, the second end is positioned on the surface side of the first heat pipe, and the second heat pipe is the first heat pipe. The cooling unit according to claim 1 or 2 , wherein the cooling unit is attached. When the first end is located on the front side of the first heat pipe and the second heat pipe is attached to the first heat pipe, the first heat pipe A heat conduction path toward the second end is formed;
When the second end is located on the surface side of the first heat pipe and the second heat pipe is attached to the first heat pipe, the first end from the first end of the second heat pipe The cooling unit according to any one of claims 1 to 3 , wherein a heat conduction path toward the back surface of the heat pipe is formed. The first heat pipe is
An upper plate,
A lower plate facing the upper plate;
Having one or more intermediate plates laminated between the upper plate and the lower plate;
The intermediate plate has a notch and an internal through hole, the notch forms the vapor diffusion path, the internal through hole forms the capillary channel, and the notch The cooling unit according to any one of claims 1 to 4, wherein the cooling unit is formed from a central portion toward a peripheral portion of the intermediate plate. The second heat pipe is
An upper plate,
A lower plate facing the upper plate;
Having one or more intermediate plates laminated between the upper plate and the lower plate;
The intermediate plate has a notch and an internal through hole, the notch forms the vapor diffusion path, the internal through hole forms the capillary channel, and the notch The cooling unit according to any one of claims 1 to 5 , wherein the cooling unit is formed from a first end which is one end of the intermediate plate toward a second end facing the first end. The cooling unit according to claim 6 , wherein a width of the cutout portion in the planar direction on the first end side is narrower than a width of the cutout portion on the second end side in the planar direction. The cooling unit according to any one of claims 1 to 7 , wherein the second heat pipe is fitted and attached to a mounting groove formed on a surface of the first heat pipe. At least one of the upper plate and the lower plate of the second heat pipe has a protruding portion that protrudes from at least one of the first end portion and the second end portion, and the protruding portion is the attachment groove. The cooling unit according to claim 8, which covers at least a part of the outside.
The cooling unit according to any one of claims 1 to 9 , wherein a plurality of the second heat pipes stand on the surface of the first heat pipe. There are a plurality of intermediate plates provided in each of the first heat pipe and the second heat pipe, and only a part of the internal through holes provided in each of the plurality of intermediate plates overlap each other. The cooling unit according to any one of claims 6 to 10 , wherein a capillary channel having a cross-sectional area smaller than a horizontal cross-sectional area of the internal through hole is formed. Wherein each of said upper plate and said lower plate is provided on each of the first heat pipe and the second heat pipe, claim 6, further comprising a recess for at least one communication with the capillary channel and the vapor diffusion path The cooling unit according to any one of 11 . The cooling unit according to any one of claims 1 to 12 ,
In the cooling unit, a heating element disposed on either the back surface of the first heat pipe and the end of the second heat pipe;
An electronic apparatus comprising a housing for storing the cooling unit and the heating element.

Images