JP3359297B2 - Flat heat pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IPM (Intellige
nt power module), IGBT (Insulated Gate Bipolar
The present invention relates to a flat heat pipe used for heat radiation (cooling) of a heat-generating electronic component such as a transistor.

[0002]

2. Description of the Related Art In recent years, electronic equipment incorporates a high-output, highly integrated component such as a microprocessor. Microprocessors are extremely integrated,
Since a large amount of information is processed and controlled at high speed, a large amount of heat is released. Various cooling systems have been proposed to cool chips and the like, which are high-output and highly integrated components. One of the typical cooling systems is a heat pipe. The heat pipes include a round pipe-shaped heat pipe and a planar heat pipe. For cooling a component to be cooled of an electronic device such as a CPU, a flat heat pipe is preferably used because it can be easily attached to the component to be cooled and a wide contact surface can be obtained.

Further, the heat pipe is divided into a top heat mode in which a component to be cooled is located at an upper position and a bottom heat mode in which a component to be cooled is located at a lower position at a mounting position of the component to be cooled. In the top heat mode, a normal wick is used, and in the bottom heat mode, the wick is removed. A space serving as a flow path of the working fluid is provided inside the heat pipe, and heat is transferred by the working fluid contained in the space undergoing a phase change such as evaporation and condensation or movement.

The details of a heat pipe having a sealed cavity and transferring heat by the phase transformation and movement of the working fluid contained in the cavity are as follows. On the heat-absorbing side of the heat pipe, the working fluid evaporates due to the heat generated by the component to be cooled which has been transmitted through the material of the container constituting the heat pipe, and the vapor moves to the heat radiating side of the heat pipe. On the heat radiation side, the vapor of the working fluid is cooled and returns to the liquid state again. The working fluid that has returned to the liquid phase in this way moves (recirculates) to the heat absorbing side again. Heat transfer is performed by such phase transformation and movement of the working fluid. In a gravity-type heat pipe, the working fluid in a liquid phase state due to the phase transformation moves (refluxes) to the heat-absorbing side by gravity or capillary action.

Japanese Patent Application Laid-Open No. 9-119788 discloses a flat heat pipe having a heat generating portion and a condensing portion (hereinafter, referred to as "prior art"). FIG. 9 shows an outline of the flat heat pipe. As shown in FIG. 9, the flat heat pipe of the prior art includes an evaporator 13a, a condenser 13b,
A panel body 3 having a heat pipe circuit 3a for connecting the evaporating unit 13a and the condensing unit 13b and circulating a working fluid is provided. The evaporating unit 13a is provided with a plate 7 on which a heating element such as an electronic component is placed. The fin is attached to the condenser 13b. Heat pipe circuit 3a described above
A working fluid is sealed therein.

Further, as shown in FIG. 9, the prior art flat heat pipe is an L-shaped or inverted L-shaped flat heat pipe, and the evaporating section 13a and the condensing section 13b are connected at a right angle. The heat released from a heating element such as an electronic component that is conducted through the plate 7 that is in close contact with the evaporator 13a is
It is conveyed to the condensing section 13b by the working fluid through the heat pipe circuit 3a, and dissipates heat into the air through fins that are in close contact with the condensing section.

[0007]

However, the prior art flat heat pipe has the following problems. That is, as described above, the prior art flat heat pipe is an L-shaped or inverted L-shaped flat heat pipe, and the evaporating section 13a and the condensing section 13b are connected at a right angle. That is, the heat pipe circuit 3a has a right-angled corner. Therefore, both the steam flow of the working fluid that has become steam in the evaporating section and the working fluid stream that is condensed and circulated in the condensing section are forced to switch from the horizontal direction to the vertical direction or from the vertical direction to the horizontal direction. There is a problem that it is difficult to ensure a smooth flow of the fluid and / or the working fluid.

In particular, when the heating element is mounted at a high position in the vertical direction of the evaporating section, the cooling of the heating element requires
It is necessary to raise the level of the hydraulic fluid. However, when the liquid level of the working fluid is increased, the steam flow path and the return flow path of the working liquid become narrower, the flow path resistance increases, and smooth heat transport becomes difficult, and the heat resistance increases. Thermal performance decreases.

Accordingly, an object of the present invention is to provide a flat heat pipe which has high thermal performance and can be used for cooling heat-generating electronic components such as CPU, MCM, IPM and the like, and has a reliable operation. Is to do.

[0010]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned conventional problems. as a result,
At the corner between the heat generating part and the condensing part of the L-shaped or inverted L-shaped flat heat pipe, by providing a short path part for short-circuiting between the heat generating part and the condensing part, it becomes vapor in the evaporating part. A passage for a steam flow through which the working fluid passes,
A passage for the working fluid flow which is condensed and recirculated in the condenser section can be secured respectively, so that a smooth flow of the steam flow and the working fluid flow can be secured, and a plane having high thermal performance and reliable in its operation. It has been found that a mold heat pipe can be provided.

[0011] The present invention has been made based on the above findings, and a first aspect of the flat heat pipe of the present invention is a heat pipe extending in a horizontal direction, a condenser section extending in a vertical direction, and An intermediate portion between the heat generating portion and the condensing portion, the intermediate portion including a short path portion that linearly short-circuits between the heat generating portion and the condensing portion, and the short path portion has a predetermined inclination. A flat heat pipe having a corner, having a passage wider than the passage for the working fluid in the heat generating portion and the condensing portion, in which the working fluid is sealed, sealed, and integrally formed. is there.

A second aspect of the flat heat pipe according to the present invention is a heat generating portion extending in a horizontal direction, a condensing portion extending in a vertical direction, and the heat generating portion between the heat generating portion and the condensing portion. And a middle section having a short path section that short-circuits between the condenser section and the condenser section, the short path section having a predetermined radius of curvature, and a working fluid in the heat generating section and the condenser section. A flat heat pipe having a passage wider than a passage for use therein, in which a working fluid is sealed, sealed, and integrally formed.

[0013] A third aspect of the flat heat pipe of the present invention is a heat generating portion extending in a horizontal direction, a condensing portion extending in a vertical direction, and the heat generating portion interposed between the heat generating portion and the condensing portion. And an intermediate portion having a short path portion that linearly short-circuits between the condensation portion, and the short path portion has a predetermined inclination angle,
The passage for the working fluid is expanded from the heat generating portion to the intermediate portion, and the passage for the working fluid is reduced from the intermediate portion to the condensing portion. It is a planar heat pipe formed integrally.

According to a fourth aspect of the flat heat pipe of the present invention, a heat generating portion extending in a horizontal direction, a condensing portion extending in a vertical direction, and the heat generating portion are provided between the heat generating portion and the condensing portion. And an intermediate portion having a short path portion for curvilinear shortcut between the condenser portion and the condensing portion, wherein the short path portion has a predetermined radius of curvature, and the working fluid extends from the heat generating portion to the intermediate portion. The passage for the working fluid is enlarged, and the passage for the working fluid is reduced from the intermediate portion to the condensing portion. The working fluid is sealed, sealed, and integrally formed in the flat heat pipe. It is.

According to a fifth aspect of the flat heat pipe of the present invention, the height of the short path portion when the heat generating portion is arranged in the horizontal direction and the evaporating portion is arranged in the vertical direction, A planar heat pipe with a height in the range of 0.05 to 0.2.

According to a sixth aspect of the flat heat pipe of the present invention, there is provided a heat generating portion extending in a horizontal direction, a condensing portion extending in a vertical direction, and the heat generating portion interposed between the heat generating portion and the condensing portion. And a middle section having a short path section that short-circuits between the condenser section and the condenser section, and has a passage wider than a passage for working fluid in the heating section and the condensation section. A flat heat pipe in which a working fluid is sealed, hermetically sealed, and integrally formed, wherein a height of the short path portion is in a range of 0.05 to 0.2 of a height of the heat pipe. Inside is a flat heat pipe.

According to a seventh aspect of the flat heat pipe of the present invention, when the heat-generating section is arranged in the horizontal direction and the evaporating section is arranged in the vertical direction, the short-path section has the horizontal shortcut of the linear shortcut. Angle between 15 ° and 50
° is a flat heat pipe.

An eighth aspect of the flat heat pipe according to the present invention is a flat heat pipe characterized by being embossed.

Another aspect of the flat heat pipe of the present invention is a flat heat pipe provided with a separated passage for a steam flow from the heat generating portion.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the flat heat pipe of the present invention will be described in detail. The flat heat pipe according to the present invention comprises a closed container having an upper plate and a lower plate. An emboss is formed by crushing the sealed container thus prepared from above and below with a mold. FIG. 4 shows a cross-sectional view of a flat heat pipe having an emboss. A working fluid is sealed in the flat heat pipe. The thus formed emboss is shown in FIG.
As shown in (1), the container has a function of preventing the container from being deformed due to an increase in the internal pressure as the temperature of the internal fluid increases. Furthermore, the flat heat pipe of the present invention can also be manufactured by a roll bonding method. Further, the periphery may be formed by welding or the like.

The container is made of a heat conductive material,
Examples of the heat conductive material include copper, aluminum, steel, stainless steel, nickel, tungsten, tantalum, niobium alloy, inconel, titanium, glass, and ceramics. Among them, copper and aluminum are suitable. Working fluids include water, CFC substitute, acetone, methanol,
Helium, nitrogen, ammonia, Dowsome A, naphthalene, cesium, sodium, lithium, silver and the like can be used.

FIG. 1 is a view schematically showing one embodiment of the flat heat pipe of the present invention. The flat heat pipe of the present invention includes a heat generating section 2, a condenser section 1, and a short path section 4 provided between the heat generating section and the condenser section for short-circuiting between the heat generating section and the condenser section. Middle part 3
And a working fluid is sealed therein, hermetically sealed, and integrally formed. Fins 5 are attached to the condenser section 1. The evaporating section 2 is provided with a heating element mounting section 7 to which a heating element is mounted.

In the flat heat pipe of the present invention, the heat generating portion extends in one direction, for example, the horizontal direction, the condensing portion extends in a direction perpendicular to the one direction, for example, in the vertical direction, and the short path portion generates heat. The space between the section and the condenser section may be, for example, as shown in FIG. Further, in the flat heat pipe according to the present invention, the short path section may be constituted by a short path section that short-circuits a curved line between the heat generating section and the condenser section.

Further, the shape of the shortcut portion may be any shape in which the steam flow path and the return flow path of the working fluid are enlarged in the shortcut portion in addition to the above. That is,
In the short path section, the passage for the working fluid expands, for example, linearly or curvedly from the heating section to the middle section, and the passage for the working fluid extends, for example, linearly or curvedly from the middle section to the condensing section. It may consist of a shrinking one.

In the flat heat pipe of the present invention,
The short path section described above may include a separate passage for the steam flow from the heating section. That is, the steam flow path for the steam flow and the working fluid recirculation flow path for the working fluid may be composed of separate passages. FIG. 3 is a diagram illustrating one embodiment of the planar heat pipe of the present invention having separate passages for the steam flow. When a separate passage is provided by separating the steam flow path and the working fluid recirculation flow path, as shown in FIG. 3, a triangular cutout is formed in the middle part, and the steam flow path and the working fluid recirculation flow path are formed. May be configured.

FIG. 2 is a diagram schematically showing the size of the short path of the flat heat pipe of the present invention. In the flat heat pipe of the present invention, the height of the short path portion when the heat generating portion is arranged in the horizontal direction and the condensing portion is arranged in the vertical direction is in the range of 0.05 to 0.2 of the height of the heat pipe. Is preferably within the range. When the height of the short path portion is less than 0.05 of the height of the heat pipe, a desired effect cannot be obtained. On the other hand, if the height of the short path portion exceeds 0.2 of the height of the heat pipe, the arrangement of peripheral components is greatly restricted. Therefore, the height of the short path part is
The height of the heat pipe is preferably in the range of 0.05 to 0.2.

Further, in the flat heat pipe according to the present invention, when the heat-generating portion is arranged in the horizontal direction and the condensing portion is arranged in the vertical direction, the angle of the short-cut portion with the horizontal direction of the short-cut portion is 15 ° or more. Preferably it is 50 °.

Further, the flat heat pipe of the present invention is
It is preferable to use it by installing it at an angle in the range of 30 ° to 90 ° from the horizontal plane. Further, the fins may be fixed to the flat heat pipe of the present invention by brazing or screws.

FIG. 10 is a view showing a state in which a component to be cooled is mounted on an evaporating portion by using a flat heat pipe having a short path portion according to the present invention and a conventional inverted L-shaped flat heat pipe. The result of having investigated the heat distribution state of the flat type heat pipe at the time of performing cooling is shown. In FIG. 10, A
Shows the heat distribution state of the conventional inverted L-shaped flat heat pipe, and B shows the heat distribution state of the flat heat pipe having the short path portion of the present invention. Each temperature range is shown on the right side of FIG.

As is apparent from FIG. 10, in the conventional inverted L-shaped flat heat pipe, there is no shortcut between the evaporating section and the condensing section, and the right-angled shape is clearly shown. A substantially uncooled heat spot at a temperature higher than 90 ° C. is shown in the evaporating section, and it is shown that most of the area around the evaporating section is a high temperature range of 75 to 90 ° C. Further, it is clearly shown that the above-mentioned high-temperature region of 75 to 90 ° C. stays in the evaporating section and is prevented from moving to the condensing section. Furthermore, most of the condensing section is in a temperature range of 70 to 75 ° C., which indicates that cooling is insufficient.

On the other hand, in the flat heat pipe having the short path portion according to the present invention, the shape of the short path portion clearly sheet-cut between the evaporating portion and the condensing portion is clearly shown. . A high temperature range exceeding 70 ° C. is not found in the evaporating section, a relatively low temperature range of 60 to 70 ° C. is spread, and further, the temperature range moves to the condensing section along the short path section. ing. Furthermore, in the condensing section, most of them are in a lower temperature range of 55 to 60 ° C and a lower temperature range of less than 55 ° C.

As is apparent from the above description, in the flat heat pipe having the short path section of the present invention, heat is efficiently transferred from the evaporating section to the condensing section. It can be seen that the recirculation of the working fluid to the evaporating section is performed smoothly.

According to the flat heat pipe of the present invention,
Since a short path section that provides a shortcut between the heat generating section and the condensing section is provided in the intermediate section, a sufficiently large steam flow path and a return flow path for the working fluid can be secured, and the flow path resistance is reduced. Increases thermal performance and enables smooth heat transport. Therefore, the flat heat pipe of the present invention has
It is suitable for cooling heat-generating electronic components such as PM and IGBT.

[0034]

EXAMPLE 1 As shown in FIG. 5, an upper plate and a lower plate each made of an aluminum plate having a thickness of 1 mm each have a short path portion in which a short-circuit between the heat generating portion and the condensing portion is linearly short-cut. The container was formed and embossed with a press mold. Then, vacuum was drawn to produce a flat heat pipe in which alternative Freon was sealed as a working fluid. The edges were brazed. The respective sizes at that time were as follows. The height H of the heat pipe in the vertical direction is 300 mm, the height h of the short path is 40 mm, the inclination angle θ of the short path is 45 degrees, the horizontal length e of the heat pipe is 313 mm, and the width of the evaporator is c. : 140 mm, length b of the evaporating section to the short path section b: 184 mm, width d of the condensing section: 90 mm, length a of the condensing section to the short path section: a: 120 mm. The thickness of the flat heat pipe manufactured as described above was 4 mm.

When the flat heat pipe manufactured as described above was applied to cooling of an IGBT, heat generated from the IGBT could be effectively transferred, and a good cooling effect was obtained.

Embodiment 2 As shown in FIG. 6, a container having a short path portion in which a heat-generating portion and a condensing portion are curvilinearly short-cut by an upper plate and a lower plate each made of an aluminum plate having a thickness of 1 mm. And embossed with a press mold. Then, vacuum was drawn to produce a flat heat pipe in which alternative Freon was sealed as a working fluid. The respective sizes at that time were as follows. Vertical height of heat pipe H: 300m
m, height h of the short path part: 40 mm, radius of curvature r of the short path part: 50 mm, horizontal length e of the heat pipe e: 313 mm, width e of the evaporating part c: 140 mm, and a distance from the evaporating part to the short path part. Length b: 184 mm, width d of the condensing part: 90 mm, length a to the short path part of the condensing part a: 120 mm. The thickness of the flat heat pipe manufactured as described above was 4 mm.

When the flat heat pipe manufactured as described above was applied to cooling of an IGBT, heat generated from the IGBT could be effectively transferred, and a good cooling effect was obtained.

Embodiment 3 As shown in FIG. 7, an upper plate and a lower plate each made of an aluminum plate having a thickness of 1 mm provide a linear shortcut between the heat-generating portion and the condensing portion. The part was cut off to form a container having a short path part in which the passage for the vapor flow and the passage for the return liquid were completely separated, and embossed with a press die.
Then, vacuum was drawn to produce a flat heat pipe in which alternative Freon was sealed as a working fluid. The respective sizes at that time were as follows. Vertical height H of the heat pipe: 300 mm, height h of the short path portion: 40 mm, inclination angle θ of the short path portion: 45
, The horizontal length e of the heat pipe e: 313 mm, the width c of the evaporating part c: 140 mm, the length b to the short path part of the evaporating part b: 184 mm, the width d of the condenser part: 90 mm, the short path part of the condenser part Length a: 120 mm and width w of the steam flow passage: 15 mm. The thickness of the flat heat pipe manufactured as described above was 4 mm.

When the flat heat pipe manufactured as described above was applied to cooling of a TGBT, heat generated from the IGBT could be effectively transferred, and a good cooling effect was obtained.

Embodiment 4 As shown in FIG. 8, an upper plate and a lower plate, each made of an aluminum plate having a thickness of 1 mm, make a short cut between the heat generating portion and the condensing portion in a curved manner. The part was cut off to form a container having a short path part in which the passage for the vapor flow and the passage for the return liquid were completely separated, and embossed with a press die.
Then, vacuum was drawn to produce a flat heat pipe in which alternative Freon was sealed as a working fluid. The respective sizes at that time were as follows. Vertical height H of the heat pipe: 300 mm, height h of the short path portion: 40 mm, radius of curvature r of the short path portion: 5
0 mm, horizontal length e of the heat pipe: 313 m
m, width c of the evaporating section: 140 mm, length b to the short path section of the evaporating section: 184 mm, width d of the condensing section: 90 m
m, length of the condensing section up to the short path section a: 120 m
m, and the width w of the steam flow passage was 15 mm. The thickness of the flat heat pipe manufactured as described above was 4 mm.

When the flat heat pipe manufactured as described above was applied to cooling of an IGBT, heat generated from the IGBT could be effectively transferred, and a good cooling effect was obtained.

Example 5 Example 5 is the same as Example 1 except that a copper plate was used instead of the aluminum plate in Example 1. That is, as shown in FIG. 5, an upper plate and a lower plate each made of a copper plate having a wall thickness of 1 mm form a container having a short path portion in which the heat generating portion and the condensing portion are linearly short-cut, and And embossed with a press die. Then, vacuum was drawn to produce a flat heat pipe in which water was sealed as a working fluid. The respective sizes at that time were as follows. Vertical height H of the heat pipe: 300 mm, height h of the short path portion: 40 mm, inclination angle θ of the short path portion: 45 degrees,
The horizontal length e of the heat pipe is 313 mm, the width c of the evaporating section is 140 mm, the length b of the evaporating section to the short path section is 184 mm, the width of the condensing section is 90 mm, and the length of the condensing section is 90 mm. Length a: 120 mm. The thickness of the flat heat pipe thus manufactured is 4 mm
Met.

When the flat heat pipe manufactured as described above was applied to cooling of an IGBT, heat generated from the IGBT could be effectively transferred, and a good cooling effect was obtained.

Embodiment 6 As shown in FIG. 9, an upper plate and a lower plate, each made of an aluminum plate having a thickness of 1 mm, are short-circuited so that the space between the heat generating portion and the condensing portion expands outward in a curved manner. Forming a container with a path portion, and
Embossing was performed with a press die. Then, vacuum was drawn to produce a flat heat pipe in which alternative Freon was sealed as a working fluid. The respective sizes at that time were as follows. The height H of the heat pipe in the vertical direction is 300 mm, and the height h of the short path portion is 40 m.
m, radius of curvature r of the short path portion: 50 mm, horizontal length e of the heat pipe e: 313 mm, width c of the evaporating portion:
140 mm, length b: 1 to the short pass part of the evaporating part
84 mm, width d of the condensing part: 90 mm, and length a to the short path part of the condensing part a: 120 mm. The thickness of the flat heat pipe manufactured as described above was 4 mm.

When the flat heat pipe manufactured as described above was applied to cooling of an IGBT, heat generated from the IGBT could be effectively transferred, and a good cooling effect was obtained.

COMPARATIVE EXAMPLE 1 As shown in FIG. 11, an inverted L-shaped container in which the heat generating portion and the condensing portion are connected at right angles by an upper plate and a lower plate each made of an aluminum plate having a thickness of 1 mm. Formed and embossed with a press mold. Then, vacuum was drawn to produce a flat heat pipe in which water was sealed as a working fluid. The respective sizes at that time were as follows. The height H in the vertical direction of the heat pipe was 300 mm, the length e in the horizontal direction of the heat pipe was 313 mm, the width c of the evaporator was 140 mm, and the width d of the condenser was 90 mm. The thickness of the flat heat pipe manufactured as described above was 4 mm.

When the flat heat pipe manufactured as described above was applied to cooling of an IGBT, there was a local temperature rise in the heat generating portion. The sizes of the heat pipes described in the embodiments, such as the width and the length, are shown as specific examples, and are not limited thereto.

As described above, a conventional L-shaped or
According to the inverted L-shaped flat heat pipe, the steam flow and the return liquid flow are not smooth, the heat resistance is large, and the desired cooling effect cannot be obtained. According to the heat pipe, by providing a short path portion for short-circuiting between the heat generating portion and the condensing portion at a corner between the heat generating portion and the condensing portion of the L-shaped or inverted L-shaped planar heat pipe, the evaporation can be achieved. A passage for the steam flow through which the working fluid that has become the vapor passes in the section, and a passage for the working fluid flow that is condensed and circulated in the condensing section are secured, respectively, to ensure a smooth flow of the steam flow and the working fluid flow. As a result, a flat heat pipe having high thermal performance and reliable operation was obtained.

[0049]

As described above, according to the present invention, a passage for the steam flow through which the working fluid vaporized in the evaporating section passes and a passage for the working fluid flow which is condensed and circulated in the condensing section are secured. As a result, a smooth flow of the vapor flow and the working fluid flow can be ensured, and a flat heat pipe having high thermal performance and reliable operation can be provided, and heat-generating electrons such as IPM and IGBT can be provided. It can be used to cool parts and has high industrial value.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a flat heat pipe of the present invention.

FIG. 2 is a diagram schematically showing the size of a short path of the flat heat pipe of the present invention.

FIG. 3 is a view showing one embodiment of the flat heat pipe of the present invention in which a passage for a steam flow is provided in a short path portion.

FIG. 4 is a diagram schematically showing a cross section of a portion where an emboss is formed in the flat heat pipe of the present invention.

FIG. 5 is a view showing one embodiment of the flat heat pipe of the present invention having a short path portion which is linearly short-cut.

FIG. 6 is a diagram showing one embodiment of the planar heat pipe of the present invention having a short path portion which is curvilinearly short-cut.

FIG. 7 is a linear shortcut, and
It is a figure which shows one Embodiment of the flat type heat pipe of this invention which has the short path part which has the isolate | separated steam flow path.

FIG. 8 is a curvilinear shortcut, and
It is a figure which shows one Embodiment of the flat type heat pipe of this invention which has the short path part which has the isolate | separated steam flow path.

FIG. 9 illustrates one embodiment of the planar heat pipe of the present invention having a short path section that is curvilinearly short-cut so as to bulge outward and further has a separated steam flow passage. is there.

FIG. 10 is a diagram showing a heat distribution state of the flat heat pipe of the present invention and a conventional inverted L-shaped flat heat pipe.

FIG. 11 is a view schematically showing a conventional inverted L-shaped flat heat pipe.

[Explanation of symbols]

 1. Condensing section 2. Heating part 3. Middle part 4. Short pass section 5. Fins 6. Emboss 7. Heating element mounting part 8. Passage 9. Upper plate 10. Lower plate

Claims (8)

(57) [Claims] 1. A heating section extending in a horizontal direction, a condenser section extending in a vertical direction, and a straight line shortcut between the heating section and the condenser section between the heating section and the condenser section. An intermediate portion having a short path portion, wherein the short path portion has a predetermined inclination angle,
A planar heat pipe having a passage wider than a passage for a working fluid in the heat generating part and the condensing part, in which a working fluid is sealed, sealed, and integrally formed. 2. A heating section extending in a horizontal direction, a condensation section extending in a vertical direction, and a short cut between the heating section and the condensation section between the heating section and the condensation section. An intermediate portion having a short path portion, the short path portion having a predetermined radius of curvature, and having a passage wider than a passage for working fluid in the heat generating portion and the condensing portion. A flat heat pipe in which a working fluid is sealed, hermetically sealed, and integrally formed. 3. A heat generating portion extending in a horizontal direction, a condensing portion extending in a vertical direction, and a linear shortcut between the heat generating portion and the condensing portion between the heat generating portion and the condensing portion. An intermediate portion having a short path portion, wherein the short path portion has a predetermined inclination angle, a passage for working fluid expands from the heat generating portion to the intermediate portion, and A flat heat pipe in which a working fluid passage is reduced from the space to the condensing portion, in which the working fluid is sealed, hermetically sealed, and integrally formed. 4. A heat generating portion extending in a horizontal direction, a condenser portion extending in a vertical direction, and a short cut between the heat generating portion and the condenser portion in a curved manner between the heat generating portion and the condenser portion. An intermediate portion having a short path portion, wherein the short path portion has a predetermined radius of curvature, a passage for working fluid expands from the heat generating portion to the intermediate portion, and the intermediate portion A flat heat pipe in which a working fluid passage is reduced from the space to the condensing portion, in which the working fluid is sealed, hermetically sealed, and integrally formed. 5. A height of the short path portion when the heat generating portion is arranged in a horizontal direction and the evaporating portion is arranged in a vertical direction, and a height of the short path portion is in a range of 0.05 to 0.2 of a height of the heat pipe. The flat heat pipe according to any one of claims 1 to 4, wherein 6. A heat generating portion extending in a horizontal direction, a condensing portion extending in a vertical direction, and a curvilinear shortcut between the heat generating portion and the condensing portion between the heat generating portion and the condensing portion. And an intermediate portion having a short path portion, which has a passage wider than a passage for the working fluid in the heat generating portion and the condensing portion. The working fluid is sealed inside, sealed, and integrally formed. A flat heat pipe, wherein the height of the short path portion is in the range of 0.05 to 0.2 of the height of the heat pipe. 7. An angle of the short path portion with the horizontal direction of the short-cut portion when the heating portion is arranged in a horizontal direction and the evaporating portion is arranged in a vertical direction, is 15 ° to 50 °. The flat heat pipe according to claim 1. 8. The flat heat pipe according to claim 1, wherein embossing is performed.