JP2019113232A - heat pipe - Google Patents

Abstract

To provide a heat pipe capable of obtaining a high heat exchange ratio.SOLUTION: A heat pipe 1 has a flat plate shape as a whole. An upper member is a flat plate-shaped member in which a groove part 10c for sending a coolant in an in-plane direction of a bottom face. A lower member has a flat plate shape in which a groove part 11c for sending a coolant in an in-plane direction of a top face is formed. An intermediate member is one or a plurality of members sandwiched between the upper member and the lower member. In the heat pipe 1, the upper member and the lower member are connected via the intermediate member, and an internal space 20 filled with a coolant is formed under reduced pressure. There are formed: a vapor diffusion flow channel 21 for communicating the groove part 10c of the upper member with the groove part 11c of the lower member in a state of forming the internal space 20 by the intermediate member, and allowing an evaporated coolant to pass; and a capillary flow channel 22 for sending a condensed coolant by capillary phenomenon between the groove part 10c of the upper member and the groove part 11c of the lower member. A flow channel cross sectional area of the capillary flow channel 22 is changed in a flow channel direction.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a heat pipe.

  A heat is provided with a vapor diffusion passage in which a refrigerant is sealed in a sealed space under reduced pressure and a refrigerant which has become a vapor is diffused by heat transmitted from a heat source, and a capillary channel (wick) which sends condensed refrigerant by capillary action. Pipes are disclosed.

Japanese Patent Application Publication No. 2002-039693 Japanese Patent Application Publication No. 2004-077120

  In the heat exchange ratio of the heat pipe as described above, what is important is the ability to deliver the condensed refrigerant in the capillary channel. The higher this capacity, the better the heat pipe performance can be.

  This invention is made in view of the said situation, and it aims at providing the heat pipe which can obtain a high heat exchange ratio.

The heat pipe according to the first aspect of the present invention is
It is a flat heat pipe as a whole,
A flat plate-like upper member in which a groove portion for sending the refrigerant in the in-plane direction of the lower surface is formed;
A flat plate-like lower member in which a groove for feeding the refrigerant is formed in the in-plane direction of the upper surface;
One or more intermediate members sandwiched between the upper member and the lower member;
Equipped with
The upper member and the lower member are joined via the intermediate member to form an internal space in which the refrigerant is sealed under reduced pressure,
By the intermediate member,
A vapor diffusion channel that connects the groove of the upper member and the groove of the lower member in a state in which the internal space is formed, and allows the vaporized refrigerant to pass therethrough;
A capillary channel for sending the condensed refrigerant by capillary action between the groove of the upper member and the groove of the lower member;
Is configured,
In the capillary channel, the channel cross-sectional area changes in the channel direction.

In this case, the capillary flow path includes a first portion having a first flow path cross-sectional area to which the condensed refrigerant can enter and a second flow path cut-off capable of liquid transfer of the condensed refrigerant by capillary action And a second portion having an area;
Between the first portion and the second portion, an edge for causing gas-liquid interface vibration to the condensed refrigerant is provided.
You may do it.

Further, the intermediate member is configured by being stacked in a plurality.
In each of the intermediate members,
A partition is provided to prevent movement of the refrigerant between the vapor diffusion channel and the capillary channel.
You may do it.

The cross-sectional area of the vapor diffusion channel is uniform or larger according to the flow direction of the vapor,
You may do it.

  According to the present invention, in the capillary channel, the channel cross-sectional area changes in the channel direction. For this reason, where the condensed refrigerant is difficult to enter the capillary channel, the channel cross-sectional area of the channel is increased, or where the capillary phenomenon should occur, the channel cross-sectional area of the channel is decreased. be able to. As a result, since the capillary force can be increased without impairing the water permeability, a high heat exchange ratio can be obtained.

FIG. 1A is a perspective view of a heat pipe according to an embodiment of the present invention. FIG. 1 (B) is a side view of the heat pipe of FIG. 1 (A). It is a disassembled perspective view of the heat pipe of FIG. It is a figure which shows the bottom face and AA cross section of an upper member and a lower member. FIG. 5 is an enlarged perspective view of an inner region of the upper and lower members. It is a figure which shows the upper surface of an intermediate member, and a BB cross section. It is an enlarged view of a capillary channel formation area of an intermediate member. It is a top view of a capillary channel. It is CC sectional drawing of FIG. It is a longitudinal cross-sectional view of the heat pipe of FIG. It is a figure which shows circulation of the refrigerant | coolant in internal space. It is a figure which shows the partition between a vapor | steam diffusion channel and a capillary channel. 12 (A) to 12 (C) are schematic views showing a method of sealing the refrigerant. It is a flowchart of the manufacturing method of the heat pipe of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same or corresponding parts are given the same reference numerals.

  As shown to FIG. 1 (A), the heat pipe 1 which concerns on this Embodiment is a cooling device which has the housing | casing 50 of rectangular flat form shape as a whole which makes thickness direction the upper and lower sides. The heat source body 2 to be cooled is attached to the bottom center of the heat pipe 1.

  As the heat source body 2, an IC (semiconductor integrated device), an LSI (large scale integrated circuit device), a CPU (central processing unit), and the like are assumed. In the heat pipe 1, the bottom central portion to which the heat source body 2 is attached is also referred to as a heat receiving portion 3. The heat received from the heat source body 2 in the heat receiving portion 3 is transmitted to the entire heat pipe 1 and dissipated. Therefore, as the heat pipe 1, a material having high thermal conductivity is used. Such materials include, for example, copper.

  As shown in FIG. 1B, a sealed space (internal space) 20 which is depressurized is provided in a housing 50 of the heat pipe 1. A refrigerant W is sealed in the internal space 20. The heat received by the heat receiving portion 3 vaporizes the refrigerant W and diffuses it throughout the internal space 20. The diffused refrigerant W transfers heat to the outer surface of the heat pipe 1 and then condenses and returns to the heat receiving unit 3. Heat is dissipated from the outer surface of the heat pipe 1. As described above, due to the circulation of the refrigerant W in the internal space 20, the heat pipe 1 disperses heat throughout.

  As shown in FIG. 2, the heat pipe 1 is configured of an upper member 10, a lower member 11, and intermediate members 12A to 12D. Although the number of intermediate members is four in the present embodiment, the present invention is not limited to this. The intermediate member may be one or more.

  As shown in FIG. 3, the upper member 10 is a rectangular flat plate disposed on the uppermost side. The upper surface (+ z surface) of the upper member 10 constitutes the upper surface of the heat pipe 1. The lower surface (-z surface) of the upper member 10 is divided into an outer edge portion 10a provided along the outer edge thereof and an inner region 10b. The outer edge portion 10a constitutes a bonding projection that protrudes to the lower side (−z side) than the inner region 10b. The upper member 10 is diffusion-bonded to the outer edge of the upper surface of the intermediate member 12A at the outer edge portion 10a, as shown in FIG.

  The inner area 10 b constitutes a ceiling of the inner space 20. In the inner region 10b, a groove portion 10c for feeding the refrigerant in the in-plane direction of the lower surface thereof is provided by capillary action. As shown in FIG. 4, a large number of dimples 10d are provided in the inner region 10b, and vertical and horizontal groove portions 10c are formed between the dimples 10d. The groove portion 10c has a channel width and a depth such that the refrigerant W can be sent to the entire surface of the inner region 10b by capillary force against gravity even when the inner region 10b is a vertical surface. It has become.

  The lower member 11 is a rectangular flat plate-like member disposed on the lowermost side and has the same shape and size as the upper member 10, and therefore, will be described using FIG. The lower surface of the lower member 11 constitutes the bottom surface of the heat pipe 1. The heat receiving portion 3 is provided at the center of the lower surface of the lower member 11.

  As shown in FIG. 3, the upper surface of the lower member 11 is divided into an outer edge portion 11 a and an inner region 11 b. The outer edge portion 11a is joined to the outer edge portion of the lower surface of the intermediate member 12D, as shown in FIG. The inner region 11 b constitutes the bottom of the inner space 20. In the inner region 11b, a groove portion 11c for feeding the refrigerant W in the in-plane direction of the lower surface thereof by capillary action is provided.

  The intermediate members 12A to 12D are rectangular flat members disposed between the upper member 10 and the lower member 11. The shape and size of the outer edge of the intermediate members 12A to 12D are the same as those of the upper member 10 and the lower member 11. As shown in FIG. 5, the outer edge 12a of the lower surface of the intermediate member 12A forms a bonding projection projecting downward with respect to the inner region 12b, and is joined to the outer edge 12a of the upper surface of the intermediate member 12B. Further, the outer edge portion 12a of the lower surface of the intermediate member 12B forms a bonding projection projecting downward with respect to the inner region 12b, and is joined to the outer edge portion 12a of the upper surface of the intermediate member 12C. Further, the outer edge 12a of the lower surface of the intermediate member 12C forms a bonding projection that protrudes downward with respect to the inner region 12b, and is joined to the outer edge 12a of the upper surface of the intermediate member 12D. The outer edge portion 12a of the lower surface of the intermediate member 12D forms a bonding projection projecting downward with respect to the inner region 12b, and is joined to the outer edge portion 11a of the lower member 11.

  Thus, the outer edge portion 10a of the upper member 10, the outer edge portions 12a of the intermediate members 12A to 12D, and the outer edge portion 11a of the lower member 11 are diffusion bonded. Thereby, the side surface of the heat pipe 1 is formed, and the internal space 20 of the heat pipe 1 becomes a sealed space.

  As shown in FIG. 5, in the intermediate members 12A to 12D, a vapor diffusion channel forming area 12c as a void and a capillary channel forming area 12d are provided in the inner area 12b surrounded by the outer edge 12a. ing. The capillary channel formation region 12d is disposed at the central portion of the intermediate members 12A to 12D. In the intermediate members 12A to 12D, the vapor diffusion channel forming area 12c and the capillary channel forming area 12d radially extend from the central capillary channel forming area 12d.

  When the intermediate members 12A to 12D are joined, the respective vapor diffusion channel forming regions 12c and the capillary channel forming regions 12d become coincident with each other. In the internal space 20, the vapor diffusion channel 21 is formed by the vapor diffusion channel forming region 12c, and the capillary channel 22 is formed by the capillary channel forming region 12d.

  The vapor diffusion channel 21 is a gap that communicates the groove 10 c of the upper member 10 and the groove 11 c of the lower member 11 in a state in which the internal space 20 is formed. The vapor diffusion channel 21 is provided to diffuse the vaporized refrigerant W, and passes the vaporized refrigerant W therethrough. The heat received by the heat receiving portion 3 vaporizes the refrigerant W, and the refrigerant W is diffused into the internal space 20 through the vapor diffusion channel 21.

  The capillary channel 22 is provided to return the diffused and condensed refrigerant W to the heat receiving unit 3 to which the heat source body 2 is attached. The capillary channel 22 sends the condensed refrigerant W between the groove 10 c of the upper member 10 and the groove 11 c of the lower member 11 by capillary action.

  As shown in FIG. 6, a plurality of through holes (openings) 23 having the same size are formed by the frame 24 in the vapor diffusion channel formation area 12 c. The size of the through hole 23 is a size that allows the condensed refrigerant W to easily enter based on physical property values such as interfacial tension and viscosity by the refrigerant W and a contact angle determined by the wettability to the surface ( The diameter is larger than the lower limit value to which the refrigerant W can flow. That is, the size of the through hole 23 is such that the capillary phenomenon does not occur in the refrigerant W. When the intermediate members 12A to 12D are joined, as shown in FIG. 7 and FIG. 8, the positions of the upper and lower through holes 23 are shifted by about half of the arrangement pitch of the through holes 23. Thus, the size of the gap formed by the through holes 23 of the intermediate members 12A to 12D adjacent to the upper and lower sides is such that the refrigerant W causes the capillary phenomenon.

  In other words, as shown in FIG. 9, the capillary channel 22 sends the first portion 22a having the first channel cross-sectional area to which the condensed refrigerant W can enter and the condensed refrigerant W by capillary action. And a second portion 22b having a possible second flow passage cross-sectional area. Further, the capillary channel 22 is provided with an edge 22 c between the first portion 22 a and the second portion 22 b that causes the condensed refrigerant W to cause gas-liquid interface vibration. In this way, the condensed refrigerant W enters the first portion 22a, easily reaches the edge 22c, causes gas-liquid interface vibration at the edge 22c, and enters the second portion 22b, Capillary action makes it easier to be sent downstream.

  That is, in the present embodiment, when the capillary channel 22 is set to the channel direction in the vertical direction, the horizontal direction and the diagonal direction, it is assumed that the channel cross-sectional area changes in any direction. I can say that.

  The operation of the heat pipe 1 having such a configuration will be described. As shown in FIG. 10, the heat generated from the heat source body 2 is transferred to the heat receiving portion 3, and the heat evaporates the refrigerant W present in the inner region 11b of the lower member 11 of the inner space 20 under reduced pressure. It diffuses through the vapor diffusion channel 21 to the entire internal space 20. Then, most of the vaporized refrigerant W reaches the inner region 10b of the upper member 10, transfers heat, and condenses.

  The refrigerant W condensed in the inner region 10b of the upper member 10 is fed to the capillary channel 22 by capillary action in the groove 10c of the inner region 10b. In the capillary channel 22, the condensed refrigerant W is sent again to the inner region 11 b of the lower member 11 by capillary action.

  The condensed refrigerant W having reached the inner region 10b of the lower member 11 enters the groove 10c formed in the inner region 10b, and returns to the heat receiving portion 3 by capillary action.

  As mentioned above, the circulation cycle of the above-mentioned refrigerant W is formed in this interior space 20, and, thereby, cooling of heat source object 2 is realized.

  Further, in the present embodiment, as shown in FIG. 11, in each of the intermediate members 12A to 12D, the partition wall 25 for preventing the movement of the refrigerant W is provided at the boundary between the vapor diffusion channel 21 and the capillary channel 22. It is done. More specifically, for each of the intermediate members 12A to 12D, a bonding projection 12e is provided at the boundary between the vapor diffusion channel 21 and the capillary channel 22. The bonding projections 12e are diffusion-bonded to the other intermediate members 12A to 12D to form the partition walls 25.

  As shown in FIG. 10, the cross-sectional area of the vapor diffusion channel 21 is uniform in the flowing direction of the vapor of the refrigerant W.

  Since the grooves 10c and 11c that cause capillary action against gravity are formed in the inner region 10b of the upper member 10 and the inner region 11b of the lower member 11, the heat pipe 1 may be horizontally placed. Even when vertically disposed, the refrigerant W obtained by condensing the inner region 10b of the upper member 10 and the inner region 11b of the lower member 11 can easily move. Therefore, the refrigerant W can be efficiently circulated according to the above-described circulation cycle.

  In these intermediate members 12A to 12D and lower member 11, projections are respectively provided on the four side outline positions of the central portion facing heat source 2, and not only the peripheral portion but also the position of the peripheral region of heat source 2 The protrusions are also formed, and the reinforcing portion is formed by direct bonding of the protrusions. As described above, in the heat pipe 1, the reinforcement is provided also in the peripheral region and the like to improve the mechanical strength, and the heat generated from the heat source thermally expands the refrigerant and the substantially central portion bulges outward. It is prevented that the phenomenon to be tried (hereinafter referred to as "popcorn phenomenon") occurs.

  Further, although not shown in FIG. 3 and the like, the upper member 10 is provided with a refrigerant injection hole 5 and an air discharge hole 6 for sealing the refrigerant W, as shown in FIG. 12 (A). In this state, the internal space 20 and the outside communicate with each other only through the refrigerant injection hole 5 and the air discharge hole 6 formed in the upper member 10.

  Next, a method of manufacturing the heat pipe will be described.

  As shown in FIG. 13, first, the lower member 11, the intermediate members 12A to 12D, and the upper member 10 are sequentially stacked and stacked at optimal positions, and pressed while being heated at a temperature lower than the melting point. The bonding projections 12e such as the outer edge portion 10a are directly bonded (step S1). Thereby, the heat pipe 1 integrated is formed.

  Further, in this step, the vapor diffusion channel 21 is formed in the internal space 20 of the heat pipe 1 by overlapping the vapor diffusion channel forming areas 12c of the intermediate members 12A to 12D, and the capillary channel forming area 12d is formed. As a result, a plurality of capillary flow channels 22 are formed. That is, in this step, a circulation path of the refrigerant W composed of the vapor diffusion channel 21 and the capillary channel 22 is formed.

  At this time, reinforcements 30 are provided on the upper member 10, the intermediate members 12A to 12D, and the lower member 11 below the peripheral region of the refrigerant injection hole 5 and the air discharge hole 6, and a pillar structure is formed by joining them. Be done. The reinforcing portion 30 is provided with a through hole 31 communicating the refrigerant injection hole 5 and the air discharge hole 6 with the internal space 20.

  Subsequently, a predetermined amount of refrigerant W (for example, water) is injected into the internal space 20 from the refrigerant injection hole 5 using a nozzle (not shown) under atmospheric pressure (step S2). Under the present circumstances, the air discharge hole 6 becomes an air discharge port at the time of refrigerant | coolant W supply, and injection of the refrigerant | coolant W to the interior space 20 is performed smoothly. In the case of water, for example, the amount of refrigerant W is preferably equivalent to the total volume of the through holes 31. Further, as the coolant W, in order to extend the life of the heat pipe 1, it is preferable to use ultrapure water free from ion contamination. At this time, if the air discharge hole 6 is evacuated, the refrigerant W can be injected more smoothly.

  Next, a predetermined number of sealing members 7 made of, for example, spherical bodies are prepared in advance, and the sealing members 7 are placed on the refrigerant injection holes 5 and the air discharge holes 6 as shown in FIG. 12 (B) (Step S3). Here, the internal space 20 of the heat pipe 1 and the outside are kept in communication with each other by the gap between the refrigerant injection hole 5 and the air discharge hole 6 and the edge and the sealing member 7. Therefore, degassing in the internal space 20 can be performed from this gap.

  Then, in this state, vacuum degassing by pressure reduction is performed, for example, for about 10 minutes through the gap (step S4). In this step, by performing vacuum degassing through a gap, the air in the internal space 20 can be evacuated, and harmful components can be removed from the internal space 20 together with the air. The arrows in the figure indicate the direction of degassing (gas removal).

  Thereafter, the sealing member 7 is pressed from above for several minutes in the normal temperature state to cause low-temperature pressure deformation (step S5). By thus performing the low-temperature vacuum pressurization process, the sealing member 7 temporarily seals the refrigerant injection hole 5 and the air discharge hole 6. At this time, the refrigerant injection hole 5 and the air discharge hole 6 are closed by the sealing member 7.

  Here, since the support structure is formed by closely attaching the reinforcing portion 30 to a portion facing the peripheral region of the refrigerant injection hole 5 and the air discharge hole 6, the sealing member 7 is pressurized by a press. In this case, the reinforcing portion 30 receives the external force from the press, and the sealing member 7 can be reliably pressurized with the necessary external force by the press without the internal space 20 being crushed.

  When the sealing member 7 is pressurized at a temperature higher than normal temperature, the vapor of the refrigerant W, for example, water vapor is likely to leak to the outside, which is not preferable. Therefore, as temperature which vacuum degassing is performed, normal temperature of about 25 ° C is preferred.

  Next, when the low temperature vacuum pressure treatment is finished, the degree of vacuum is set to, for example, 0.5 KPa under high temperature for, for example, about 10 minutes, and then the sealing member 7 is pressed from above by a press (step S6). As a result, the sealing member 7 is deformed by high temperature pressurization, deeply intrudes into the refrigerant injection hole 5 and the air discharge hole 6, and is further firmly crimped and closed by the sealing member 7.

  That is, the sealing member 7 is plastically deformed mainly by pressurization, and is plastically deformed by heating supplementarily to close the refrigerant injection hole 5 and the air discharge hole 6. Thus, as shown in FIG. 12 (C), the sealing member 7 which is a spherical body is formed into the shape of the refrigerant injection hole 5 and the air discharge hole 6 by plastic deformation, and the refrigerant injection hole 5 and the air discharge hole 6. It is crimped to 6 and becomes a sealing plug substantially, and seals the interior space 20 of the heat pipe 1. Thus, when the refrigerant injection hole 5 and the air discharge hole 6 are closed by the sealing member 7, heating stop, vacuum stop and pressure release by press are performed, and the pressure application, heating and vacuum process are performed. Finish.

  At that time, the outer surface of the sealing member 7 is preferably formed on substantially the same plane as the outer surface of the heat pipe 1. That is, the flatness of the outer surface of the heat pipe 1 is maintained, whereby the adhesion between the heat pipe 1 itself and the radiator attached thereto, such as fins, is improved, and the heat conductivity between the heat pipe 1 is improved without any problem. It is because it can.

  Thereafter, the outer surface of the heat pipe 1 is plated with nickel for corrosion prevention and the like (step S7). Here, if the coolant injection hole 5 and the air discharge hole 6 are closed by using the sealing member 7 made of solder, it is difficult to perform good nickel plating on the solder. In addition, there is a disadvantage that the portion where the air discharge hole 6 is closed is not easily plated with nickel.

  On the other hand, in the present embodiment, since the refrigerant injection hole 5 and the air discharge hole 6 are closed using the sealing member 7 made of the same copper-based metal as the heat pipe 1, such a disadvantage does not occur. The portion in which the injection hole 5 and the air discharge hole 6 are closed can also be nickel plated well.

  According to the manufacturing method of the heat pipe 1 (refrigerant sealing method), the heat pipes 1 are arranged in vacuum, and the sealing member 7 is arranged on the refrigerant injection hole 5 and the air discharge hole 6 of each heat pipe 1. Place and degas the plurality of heat pipes 1 at one time, pressurize and heat the sealing member 7, plastically deform all the sealing members 7, and seal the refrigerant W simultaneously. Can. Thus, the mass productivity of the heat pipe 1 can be enhanced, and the mass productivity can be enhanced, as compared with the sealing method in which the troublesome operations such as the conventional caulking operation, welding and adhesion individually performed for each refrigerant injection hole 5 are performed. Thus, the price of the heat pipe 1 can be reduced.

  In the case where the size of the gap with the sealing member 7 in the refrigerant injection hole 5 is insufficient, the gas injection groove may be provided in the refrigerant injection hole 5 or the sealing member 7.

  As described above in detail, according to the present embodiment, in the capillary channel 22, the channel cross-sectional area changes in the channel direction. For this reason, in a place where the condensed refrigerant W does not easily enter the capillary flow path 22, the flow path cross-sectional area of the flow path is increased, or where the capillary phenomenon should occur, the flow path cross-sectional area of the flow path is decreased. Can be As a result, since the capillary force can be increased without impairing the water permeability, a high heat exchange ratio can be obtained.

  Further, according to the present embodiment, the edge 22c between the first portion 22a and the second portion 22b which causes the refrigerant W condensed into the first portion 22a to enter the gas-liquid interface vibration is caused to enter. Since it can be made to reach quickly, the condensed refrigerant W can be made easy to approach the capillary channel 22. Therefore, a high heat exchange ratio can be obtained.

  Further, according to the present embodiment, the partition 25 separates the vapor diffusion channel 21 and the capillary channel 22. As a result, the amount of heat exchanged between the vaporized refrigerant W and the condensed refrigerant W can be reduced, so that the heat exchange efficiency can be further enhanced.

  Further, according to the present embodiment, the cross-sectional area of the vapor diffusion channel 21 is uniform in the flowing direction of the vapor of the refrigerant W. Thereby, it is possible to suppress the deformation of the vapor diffusion channel 21 and the capillary channel 22 due to the pressure change due to the movement of the refrigerant W. The cross-sectional area of the vapor diffusion channel 21 may be increased in the flow direction of the vapor of the refrigerant W. In this way, it is possible to suppress the deformation of the vapor diffusion channel 21 and the capillary channel 22 due to the pressure change due to the movement of the refrigerant W.

In addition, although it can be said that water (pure water, distilled water, etc.) with large latent heat is optimal as the refrigerant W, it is not necessarily limited to water, and for example, ethanol, methanol, acetone etc. are preferable. The upper member, middle plate and lower member constituting the main body of the heat pipe are preferably copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy, stainless steel or the like having good thermal conductivity.

  As the ratio of the outer edge portion of each member, the size of the reinforcing portion, etc. increases, the internal pressure that can be handled increases, but the cooling efficiency decreases. Therefore, their design index is determined based on the required internal pressure and cooling efficiency.

  Further, the size, position, number, and the like of the refrigerant injection hole 5 and the air discharge hole 6 are determined so that the time required for exhausting can be as fast as possible. The shapes of the coolant injection hole 5 and the air discharge hole 6 desirably have a structure capable of completely sealing after deformation of the sealing member, although they have sufficient gaps in the initial state.

  The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope of the present invention. In addition, the embodiment described above is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is indicated not by the embodiments but by the claims. And, various modifications applied within the scope of the claims and the meaning of the invention are considered to be within the scope of the present invention.

  The present invention can be applied to a heat pipe for cooling a heat source body.

  DESCRIPTION OF SYMBOLS 1 heat pipe, 2 heat source body, 3 heat receiving part, 5 refrigerant injection hole, 6 air discharge hole, 7 sealing member, 10 upper member, 10a outer edge portion, 10b inner region, 10c groove portion, 10d dimple, 11 lower member, 11a Outer edge, 11b inner region, 11c groove, 11d dimple, 12A, 12B, 12C, 12D intermediate member, 12a outer edge, 12b inner region, 12c vapor diffusion channel forming region, 12d capillary channel forming region, 12e projection for joining , 20 internal space, 21 vapor diffusion channel, 22 capillary channel, 22a first portion, 22b second portion, 22c edge, 23 through hole (opening), 24 frame, 25 partition, 30 reinforcing portion, 31 Through hole, 50 cases, W refrigerant

Claims (4)

It is a flat heat pipe as a whole,
A flat plate-like upper member in which a groove portion for sending the refrigerant in the in-plane direction of the lower surface is formed;
A flat plate-like lower member in which a groove for feeding the refrigerant is formed in the in-plane direction of the upper surface;
One or more intermediate members sandwiched between the upper member and the lower member;
Equipped with
The upper member and the lower member are joined via the intermediate member to form an internal space in which the refrigerant is sealed under reduced pressure,
By the intermediate member,
A vapor diffusion channel that connects the groove of the upper member and the groove of the lower member in a state in which the internal space is formed, and allows the vaporized refrigerant to pass therethrough;
A capillary channel for sending the condensed refrigerant by capillary action between the groove of the upper member and the groove of the lower member;
Is configured,
In the capillary channel, the channel cross-sectional area changes in the channel direction,
heat pipe. The capillary channel has a first portion having a first channel cross-sectional area to which the condensed refrigerant can enter and a second channel cross-sectional area capable of transporting the condensed refrigerant by capillary action. And a second part,
Between the first portion and the second portion, an edge for causing gas-liquid interface vibration to the condensed refrigerant is provided.
A heat pipe according to claim 1. The intermediate member is configured by being stacked in a plurality.
In each of the intermediate members,
A partition is provided to prevent movement of the refrigerant between the vapor diffusion channel and the capillary channel.
A heat pipe according to claim 1 or 2. The cross-sectional area of the vapor diffusion channel is uniform or larger according to the flow direction of the vapor,
The heat pipe according to any one of claims 1 to 3.

Images