Method for manufacturing wick

A method for manufacturing a wick includes: supplying material powder containing metal powder onto a base; heating the material powder on the base to obtain a sintered compact; and rolling the sintered compact. In this situation, when the material powder supplied onto the base is heated to form the sintered compact, the sheet-shaped sintered compact can be formed. Further, when the sintered compact is rolled, a void ratio of the sintered compact can be controlled after forming the sintered compact, thereby controlling the capillarity of the wick.

TECHNICAL FIELD

The present invention relates to a method for manufacturing a wick used in a heat conduction member (a heat radiation member) such as a heat pipe or a vapor chamber, and more particularly to a method for manufacturing a wick which facilitates forming a sheet-shaped wick.

BACKGROUND ART

Recently, in electronic devices such as a personal computer or a mobile terminal, a calorific value and heat generation density of a heating body such as an electronic element have increased with high integration of the electronic element, miniaturization of a device, and the like, and installation of a heat conduction member configured to discharge heat of the heating body is absolutely necessary.

For example, in the above-described devices, a heat conduction member such as a heat pipe or a vapor chamber which moves heat from the heating body by circulation of a working fluid is installed. In such a heat conduction member, capillarity of a wick having a capillary structure produces the circulation of the working fluid.

Here, in the wick, as a hole diameter of a capillary tube decreases, the capillarity increases, and movement of the working fluid is promoted. Thus, in conventional examples, to increase the capillarity, a technology to constitute a wick by using a sintered compact has been suggested (see Patent Documents 1 and 2).

According to this technology, after filling a container with metal powder, externally heating the container provides a wick made of a sintered compact in the container. Alternatively, a mold which approximates a final shape of the wick arranged in the container is prepared, this mold is filled with the metal powder, and then the mold is externally heated, thereby forming the wick made of the sintered compact.

CITATION LIST

Patent Literature

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-70863Patent Document 2: Japanese Unexamined Patent Application Publication No. 2014-13116

SUMMARY OF INVENTION

Technical Problem

However, conventional methods for manufacturing a wick have a fear that forming a sheet-shaped wick becomes difficult.

A problem of the present invention is to provide a method for manufacturing a wick which facilitates forming a sheet-shaped wick.

Solution to Problem

To solve the problem, a method for manufacturing a wick according to a first invention is characterized by including: a step of supplying a raw material containing metal powder; and a step of heating the raw material on the base to obtain a sintered compact.

In the method for manufacturing a wick according to the first invention, heating the raw material supplied onto the base results in forming the sintered compact. Consequently, the wick made of the sheet-shaped sintered compact can be formed.

Here, a frame body, a tray T, a metal belt11a,and the like, which will be described later, correspond to the base.

In the method for manufacturing a wick according to the first invention, a method for manufacturing a wick according to a second invention is characterized in that the raw material contains a binder.

In the method for manufacturing a wick according to the first or second invention, a method for manufacturing a wick according to a third invention is characterized in that the raw material on the base is heated together with the base.

In the method for manufacturing a wick according to any one of the first to third inventions, a method for manufacturing a wick according to a fourth invention is characterized in that the base is made of a metal.

Advantageous Effects of Invention

According to the method for manufacturing a wick of the present invention, forming the sheet-shaped wick can be facilitated.

DESCRIPTION OF EMBODIMENTS

A description will now be given below on an embodiment according to the present invention with reference to the drawings.

First, a configuration of a wick1which is manufactured by a manufacturing method according to the present invention will be described.

FIG.1are cross-sectional views showing the configuration of the wick1. It is to be noted thatFIG.1(a)shows a cross section taken along a longitudinal direction of the wick1, andFIG.1(b)shows a cross section taken along a width direction of the wick1.

As shown inFIG.1, the wick1is formed into a sheet shape (a tabular shape). In this embodiment, the wick1is formed into a rectangular sheet shape. Furthermore, of both end portions of the wick1in the longitudinal direction, one end portion is arranged in a heating receiving section of a heat conduction member, and the other end portion is arranged in a heat radiating section of the heat conduction member. The heat conduction member will be described later.

Steam passages s through which a vaporized working fluid (steam) flows are provided on at least one surface of an upper surface and a lower surface of the wick1. As shown inFIG.1(b), in this embodiment, on the upper surface of the wick1, the steam passages s are provided. Moreover, the steam passages s are grooves formed in a reticular pattern (a matrix pattern/line-column pattern). It is to be note that the wick1may be configured with no steam passages s provided thereon. When such a configuration is adopted, the steam passages are provided on a later-described container side.

Additionally, protrusions p configured to suppress boiling vibration are provided on at least one surface of the upper surface and the lower surface of the wick1. As shown inFIG.1(a), in this embodiment, on the upper surface of the wick1, the plurality of protrusions p aligned in a reticular pattern (a matrix pattern/line-column pattern) are provided. That is, on the upper surface of the wick1, a plurality of protrusion rows each formed of the plurality of protrusions p aligned along the longitudinal direction are formed along the width direction. Each protrusion p is formed into a prismatic shape which protrudes upward. Further, in this embodiment, a space between two protrusions adjacent to each other constitutes the steam passage s. As a result, in this embodiment, forming the steam passages s in the reticular pattern (the matrix pattern/line-column pattern) on the upper surface of the wick1enables forming the plurality of protrusions p aligned in the reticular pattern (the matrix pattern/line-column pattern) on the upper surface of the wick1. It is to be noted that the wick1may be configured with no protrusions p provided thereto.

Here, shapes/configurations of the steam passages sand the protrusions p can be appropriately changed. That is, each steam passage s can take any shape/configuration as long as the vaporized (evaporated) working fluid can be caused to reach a portion arranged in the heat receiving section to a portion arranged in the heat radiating section in the wick1. For example, on the upper surface of the wick1, the steam passages s may be constituted by providing one or more grooves, which extend in the longitudinal direction, along the width direction. Alternatively, on the upper surface of the wick1, each steam passage s may be constituted of a space between two protrusions adjacent to each other after irregularly arranging the plurality of protrusions. Furthermore, a shape of each protrusion p may be any other shape such as a columnar shape.

The wick1is made of a sintered compact and has a porous structure.

The wick1is made of Cu, Fe, Ni, Cr, Ti, Al, Ag, and Sn or an alloy of these materials. In particular, the wick1is preferably made of Cu or Al.

An average void ratio of the wick1(whole) preferably falls within the range of 5 to 90%. That is, when the average void ratio of the wick falls below 5%, there is a fear that voids do not become communicating holes. On the other hand, when the average void ratio of the wick1exceeds 90%, there is a risk that strength becomes insufficient. Thus, the average void ratio of the wick1preferably falls within the range of 5 to 90%, particularly the range of 10 to 70%.

A thickness of the wick1preferably falls within the range of 0.05 to 1.0 mm. That is, to reduce the thickness of the wick1to be less than 0.05 mm, material powder must be micronized, which increases a material cost. Moreover, when the thickness of the wick1falls below 0.05 mm, the strength becomes insufficient, and handling becomes difficult. Additionally, with a reduction in thickness of the heat conduction material in recent years, when the thickness of the wick1exceeds 1.0 mm, arrangement in the heat conduction material becomes difficult. Thus, the thickness of the wick1preferably falls within the range of 0.05 to 1.0 mm, particularly the range of 0.1 to 0.6 mm. Here, the thickness of the wick1refers to a dimension of a portion having a maximum thickness (a maximum dimension) in the wick1.

A description will now be given on a method for manufacturing the wick1.

FIG.2are cross-sectional views showing an example of a base.

To manufacture the wick1, material powder is first produced.

As the material powder, it is possible to use a combination of one or more metal powders (alloy powder) among Cu powder, Fe powder, Ni powder, Cr powder, Ti powder, Al powder, Ag powder, Sn powder, and the alloy powder.

As the alloy powder, it is possible to use alloy powder composed of one or more metals among Cu, Fe, Ni, Cr, Ti, Al, Ag, and Sn.

Further, a binder such as a thermoplastic resin or a wax may be added to the material powder.

Moreover, a binder such as a thermoplastic resin or wax may be added to the material powder.

Furthermore, in some cases, when a plurality of components are mixed to produce the material powder, segregation/size segregation is apt to occur. Thus, in this case, a liquid which is 0.5 ml/kg or less (e.g., an oil whose viscosity is 20 mm2/s or less) may be added to the material powder. As a result, the segregation/size segregation can be suppressed.

The material power is then supplied onto the base.

The base may take any shape as long as the material powder can be mounted thereon. However, the base must be made of a material having high heat resistance such as refractory metal, ceramics, or carbon. Additionally, a surface of the base onto which the material powder is supplied is preferably flat.

For example, as the base, a frame body (not shown), a tray T (seeFIG.2,FIG.4, andFIG.5), a metal belt11a(seeFIG.3), or the like can be used.

As shown inFIG.2, the tray T is configured to include a tray main body t1and a lid body t2. The tray main body t1is formed into a substantially rectangular box shape (a frame shape) whose upper surface is opened so that it can be filled with the material powder. The lid body t2is formed into a substantially rectangular tabular shape so that the upper surface of the tray main body t1can be closed. Since the tray T includes the lid body t2, the material powder filled in the tray main body t1can be prevented from scattering.

Here, as shown inFIG.2(a), when a bottom surface of the lid body t2is formed flat, the material powder can be accommodated in the tray main body t1in an uncompressed state. On the other hand, as shown inFIG.2(b), when a convex portion, which is inserted into an upper end portion of the tray main body t1, is formed on the bottom surface of the lid body t2, the material powder can be accommodated in the tray main body t1in a slightly compressed state.

Subsequently, the material powder which has been supplied onto the base is smoothened.

That is, a thickness (a height) of the material powder which has been supplied onto the base is uniformized.

At this moment, the material powder which has been supplied onto the base can be smoothened with the use of smoothening means such as a plate material or a roller.

For example, in case of using the tray T as the base, after filling the tray main body t1with the material powder, leveling off the excess material powder with the upper end portion of the tray main body t1determined as a reference by using the plate material enables smoothening the material powder. Then, to prevent the material powder from moving or scattering, the lid body t2is put.

On the other hand, as will be described later, in case of using the metal belt11aas the base, the material powder can be smoothened by using a roller13. Alternatively, the metal belt11amay be formed into a concave shape (a frame shape). When such a configuration is adopted, after filling the metal belt11awith the material powder, leveling off the excess material powder with an upper limit portion of the metal belt11adetermined as a reference by using the plate material realizes smoothening the material powder.

Here, bulk density of the material powder before sintering is preferably set to fall within the range of 10 to 50% to true density (material density with no void), particularly the range of 15 to 35% to the true density. Furthermore, a thickness of the material powder before sintering preferably falls within the range of 0.1 to 2.0 mm, particularly the range of 0.15 to 1.5 mm.

Then, the material powder which has been supplied onto the base is sintered (heated).

That is, the material powder on the base is sintered in a predetermined sintering atmosphere/at a predetermined sintering temperature to form a sintered compact. When the material powder is sintered, metal particles adjacent to each other are subjected to the diffusion bonding, and the metal particles are coupled to form the porous sintered compact.

At this moment, as the sintering atmosphere, a vacuum, a neutral gas (a nitrogen gas, an argon gas, or the like), a reducing gas (an ammonia decomposition gas, a hydrogen gas, an endothermic gas, or the like), or the like is appropriately selected in correspondence with a composition of the material powder.

Moreover, the sintering temperature is appropriately selected in the range of 400 to 1050° C. in correspondence with the composition of the material powder.

For example, in case of using pure copper powder as the material powder, the ammonia decomposition gas is preferably selected as the sintering atmosphere, and a temperature in the range of 800 to 1050° C. is preferably selected as the sintering temperature.

The sintered compact taken out from the base is then rolled.

That is, the sintered compact is rolled by using a rolling apparatus.

Rolling the sintered compact enables reducing a thickness of the sintered compact, uniformizing the thickness of the sintered compact, improving surface roughness of the sintered compact, and increasing sintering density.

In particular, rolling the sintered compact enables controlling the thickness/density/void ratio of the sintered compact and controlling a thickness/density/void ratio/capillarity of the wick1.

The rolling apparatus is configured to include a pair of rollers arranged at a predetermined interval. At the time of rolling, each roller is rotated. Additionally, the sintered compact passes between the pair of rollers, whereby it is rolled with a desired thickness and desired density.

Here, at the time of rolling the sintered compact, one rolling apparatus alone may be used to roll the sintered compact, or a plurality of rolling apparatuses may be used to roll the sintered compact in a step-by-step manner.

Further, at the time of rolling the sintered compact, the sintered compact may be rolled by the rolling apparatus while being heated at a predetermined heating temperature. At this moment, the heating temperature is appropriately selected in correspondence with the composition of the material powder.

Here, an average void ratio of the sintered compact (whole) after rolling preferably falls within the range of 5 to 90%, particularly the range of 10 to 70%. Furthermore, the thickness of the sintered compact after rolling preferably falls within the range of 0.05 to 1.0 mm, particularly the range of 0.1 to 0.6 mm. Here, the thickness of the sintered compact after rolling refers to a dimension of a portion having a maximum thickness (a maximum dimension) in the sintered compact.

Then, various kinds of processing are applied to the sintered compact after rolling.

For example, in the sintered compact, steam passages s, protrusions p, and the like are formed. They can be formed by press working, machining, etching processing, or the like.

(Manufacturing Line of Wick1)

A description will now be given on a first example of a manufacturing line (manufacturing facilities) of the wick1.

FIG.3is a view showing the first example of the manufacturing line of the wick1.

The wick1can be manufactured with the use of, e.g., the manufacturing line10shown inFIG.3.

The manufacturing line10is configured to include a belt conveyer11, a hopper12, a roller13, a sintering furnace14, rolling apparatuses15and16, and a cutting apparatus17.

The belt conveyer11is configured to include a metal belt11awhich circulates by rotation of a truck. The metal belt11ais made of a refractory metal.

The hopper12is configured to include a storage tank12awhich stores the material powder. Further, the hopper12supplies the material powder stored in the storage tank12aonto an upper surface of the metal belt11a. At this moment, the hopper12operates in such a manner that an amount of the material powder supplied per unit time becomes fixed.

The roller13is arranged above the metal belt11aso that its rotation shaft extends along a direction orthogonal to a traveling direction of the metal belt11a. In particular, the roller13is arranged in such a manner that an interval between the metal belt11aand itself becomes a predetermined interval.

The sintering furnace14is formed into a box shape, and constituted in such a manner that the metal belt11apasses through the inside thereof. In the sintering furnace14, a heater is arranged so that the material powder arranged on the metal belt11acan be heated in a predetermined atmosphere.

Each of the rolling apparatuses15and16is configured to include a pair of rollers. In the manufacturing line10, the sintered compact is rolled by the two rolling apparatuses15and16in a step-by-step manner.

The cutting apparatus17is configured to include a pair of cutting blades. The pair of cutting blades are opened and closed at a predetermined cycle. Consequently, the sintered compact passes between the pair of cutting blades to be cut into a desired length.

In the manufacturing line10, the material powder is first supplied onto the upper surface of the metal belt11aby the hopper12(a filling apparatus).

The material powder supplied to the upper surface of the metal belt11ais carried from the upstream side toward the downstream side by the circulation of the metal belt11a.

That is, the material powder which has been supplied onto the upper surface of the metal belt11afirst passes underneath the roller12. At this moment, the material powder supplied onto the upper surface of the metal belt11ais smoothened by an outer peripheral surface of the roller12, and a thickness (a height) of the material power is uniformized.

The material powder arranged on the upper surface of the metal belt11athen passes through the inside of the sintering furnace14. At this moment, the material powder supplied onto the upper surface of the metal belt11ais heated by the heater, and a sintered compact is formed.

The sintered compact arranged on the upper surface of the metal belt11athen passes through the respective rolling apparatuses15and16. At this moment, the sintered compact is rolled by the respective rolling apparatuses15and16.

The sintered compact arranged on the upper surface of the metal belt11athen passes through the cutting apparatus17. At this moment, the sintered compact is cut into a desired length by the pair of cutting blades.

Thereafter, processing to form steam passages s, protrusions p, and the like is performed to the sintered compact. It is to be noted that, the processing to form the steam passages s, the protrusions p, and the like may be performed to the sintered compact before passing through the cutting apparatus17.

A description will now be given on a second example of the manufacturing line (manufacturing facilities) of the wick1.

FIG.4is a view showing the second example of the manufacturing line of the wick1.

The wick1can be likewise manufactured with the use of a manufacturing line20shown inFIG.4.

The manufacturing line20is configured to include a belt conveyer21, a filling apparatus22, a filling base23, a sintering furnace24, rolling apparatuses25and26, and a press apparatus27.

The filling base23is configured to include a tray installing section on which a tray T can be installed (mounted).

The filling apparatus22is configured to include a storage tank22awhich stores the material powder and a powder box22bwhich reciprocate on an upper surface of the filling base23.

The powder box22bis formed in to a box shape so that the material powder can be accommodated therein. Furthermore, one or more opening portions (through holes) are provided in a bottom surface of the powder box22b. In this embodiment, each opening portion is formed into a slit shape extending in a direction orthogonal to a traveling direction of the powder box22b. Moreover, the plurality of opening portions which are parallel to each other are provided in the bottom surface of the powder box22b. It is to be noted that the number/shape/size of the opening portions can be appropriately set.

In the filling apparatus22, the material powder stored in the storage tank22ais supplied into the powder box22bthrough a hose22c. Additionally, the powder box22bis reciprocated on an upper surface of the filling base23along a predetermined direction by a non-illustrated driving mechanism. At this moment, when the powder box22bpasses above the tray T installed on the tray installing section, the material powder accommodated in the powder box22bis caused to fill the tray T by its own weight through the opening portions.

The belt conveyer21is configured to include a metal belt21awhich circulates by rotation of a track. Further, the belt conveyer21can carry the tray T arranged on the metal belt21aby the circulation of the metal belt21a.

The sintering furnace24is formed into a box shape, and configured in such a manner that the tray T installed on the metal belt21acan pass through the inside thereof. In the sintering furnace24, a heater is arranged, and the material powder filling the tray T can be heated in a predetermined atmosphere.

Each of the rolling apparatuses25and26is configured to include a pair of rollers. Each of the rolling apparatuses25and26can roll the sintered compact by the pair of rollers.

The press apparatus27is configured to include a pair of press molds. Furthermore, the press apparatus27can form steam passages s, protrusions p, and the like on the sintered compact by opening/closing (compression) of the pair of press molds.

In the manufacturing line20, the empty tray T is first installed on the tray installing section of the filling base23.

Then, the tray T installed on the tray installing section is filled with the material powder by the filling apparatus22. That is, on the upper surface of the filling base23, the powder box22bis reciprocated. Consequently, the tray T installed on the tray installing section is filled with the material powder in the powder box22b.

Then, a plate material is used to level off the excess material powder with an upper end portion of a tray main body t1determined as a reference, and then a lid body t2is put. Here, the excess material powder may be leveled off by the reciprocation of the powder box22bwith the upper end portion of the tray main body t1determined as a reference.

Subsequently, the tray T is installed on the upper surface of the metal belt21a. Consequently, the tray T is carried from the upstream side toward the downstream side by the circulation of the metal belt21a.

The tray T carried by the metal belt21apasses through the inside of the sintering furnace24. At this moment, the material powder filling the tray T is heated by a heater24, thereby forming a sintered compact.

Then, the sintered compact is taken out from the tray T, and the taken-out sintered compact is rolled by the respective rolling apparatuses25and26in a step-by-step manner. Consequently, the sintered compact can have a desired thickness/average void ratio.

Subsequently, the rolled sintered compact is compressed by the press apparatus27. Consequently, steam passages s, protrusions p, and the like are formed on the sintered compact.

A description will now be given on a third example of the manufacturing line (the manufacturing facilities) of the wick1.

FIG.5is a view showing the third example of the manufacturing line of the wick1.

The wick1can be likewise manufactured by the manufacturing line30shown inFIG.5.

A basic configuration of the manufacturing line30is the same as the manufacturing line. Thus, in the configuration of the manufacturing line30, the same structures as those in the manufacturing line20are denoted by the same reference signs to omit a description thereof.

The manufacturing line30is different from the manufacturing line20in that a vertical sintering furnace34is arranged in place of the horizontal sintering furnace24. In this connection, a carrier apparatus31is arranged in place of the belt conveyer21in the manufacturing line30.

The carrier apparatus31is configured to include circulating means31a, and a plurality of tray mounting sections31bwhich are circulated by rotation of the circulating means31a. Further, the carrier apparatus31can carry trays T mounted on the respective tray mounting sections31bupward (toward a vertical direction).

The sintering furnace34is formed into a box shape so that the trays T mounted on the respective mounting sections31bcan pass through the inside thereof. In the sintering furnace34, a heater is arranged so that material powder filling the trays T can be heated in a predetermined atmosphere.

In the manufacturing line30, the empty trays T are first installed on the tray installing sections of a filling base23.

Then, the trays T installed on the tray installing sections are filled with the material powder by a filling apparatus22.

Subsequently, a plate material is used to level off the excess material powder with an upper end portion of each tray main body t1determined as a reference, and a lid body t2is put.

Then, the trays T are installed on upper surfaces of the tray mounting sections31a. Consequently, the trays T are carried upward by rotation (circulation) of the circulating means31a.

The trays T carried upward pass through the inside of the sintering furnace24. At this moment, the material powder filling the trays T is heated by the heater34, thereby forming sintered compacts.

Then, the sintered compacts are taken out from the trays T, and the taken-out sintered compacts are rolled by respective rolling apparatuses25and26by a step-by-step manner. Consequently, the sintered compacts can have a desired thickness/average void ratio.

Subsequently, the rolled sintered compacts are compressed by a press apparatus27. Consequently, steam passages s, protrusions p, and the like are formed on the sintered compacts.

In the manufacturing line30, the vertical sintering furnace34is applied, and the trays T are carried along the vertical direction by the carrier apparatus31(according to an elevator system). Consequently, as compared with the manufacturing line20, space saving of the facilities can be achieved.

Here, apparent density of the material powder before sintering changes in correspondence with a state of the material powder such as a composition (a lot) of the material powder or a working environment where the material powder is handled. Thus, when manufacturing the wick1, natural filling density of the material powder before sintering must be adjusted (changed) in correspondence with a state of the material powder.

At this moment, changing configurations of sintering jigs, e.g., changing a thickness of the frame body or changing a depth of the tray T enables adjusting the natural filling density of the material powder before sintering. However, preparing the sintering jigs having different configurations in accordance with a state of the material powder is not realistic.

Thus, in the manufacturing line10, a mechanism which adjusts (changes) a powder height (a storage amount) of the material powder stored in the storage tank12aof the hopper12may be provided. When such a configuration is adopted, adjusting a weight of the material powder itself stored in the storage tank12aenables adjusting bulk density (filling bulk density) of the material powder which is supplied (filled) onto the base (the metal belt11a).

Alternatively, in the manufacturing lines20and30, a mechanism which adjusts (changes) a powder height (a storage height) of the material powder accommodated (stored) in the powder box22bof the filling apparatus22may be provided. When such a configuration is adopted, adjusting a weight of the material powder itself accommodated in the powder box22benables adjusting the bulk density (the filling bulk density) of the material powder supplied (filled) onto the base (the tray T).

(Configuration of Heat Conduction Member)

The wick1can be applied (used) to a heat conduction member (a heat radiation member) such as a heat pipe or a vapor chamber.

The heat conduction member (not shown) is configured to include a container, a working fluid, and the wick1.

The container is configured to seal (hermetically contain) the working fluid and the wick1therein. As a shape of the container, a cylindrical shape, a flat shape, or the like is appropriately selected in correspondence with an intended use. The container is made of a material with a high heat conductivity such as Cu or Al.

The container according to this embodiment is a rectangular sheet-shaped case made of native copper. Furthermore, in the container, one end portion of both end portions along the longitudinal direction is determined as a heat receiving section, and the other end portion is determined as a heat radiating section.

In the heat conduction member according to this embodiment, the container is formed by bonding a plate material made of native copper, a sheet material, or the like in a bag-like shape by sputtering, welding, or the like.

Furthermore, the wick1and the working fluid are sealed in the container. The wick1and the working fluid are sealed in the container in a state where the inside of the container is vacuum-deaired. Consequently, the inside of the wick having the porous structure is impregnated with the working fluid.

In the heat conduction member, the wick1is arranged along the container. That is, in the container, one end portion of both the end portions in the longitudinal direction of the wick1is arranged in the heat receiving section, and the other end portion is arranged in the heat radiating section.

The heat receiving section of the heat conduction member is arranged in a state where it adheres to a heating body such as a CPU through heat conductive grease. Consequently, heat of the heating body is conducted to the heat receiving section.

In the heat conduction member, the working fluid is heated by the heat conducted to the heat receiving section, and the heated working fluid is vaporized (evaporated). Moreover, the working fluid vaporized by the heat receiving section passes through the steam passages s and flows into the heat radiating section. Here, the heat radiating section has a relatively low temperature with respect to the heat receiving section. Consequently, the working fluid which has flowed into the heat radiating section is cooled by the heat radiating section, and the cooled working fluid is liquefied (condensed). At this moment, the heat conducted from the heating body is discharged as latent heat. Additionally, the working fluid liquefied in the heat radiating section is absorbed into the wick1by the capillarity of the wick1, passes through the inside of the wick, and is refluxed from the heat radiating section to the heat receiving section. Thus, repeating the circulation of the working fluid enables continuing movement of the heat from the heat receiving section to the heat radiating section, thereby continuously discharging the heat of the heating body.

Here, the heat conduction member can be applied to cooling of various kinds of electronic devices (a personal computer, a mobile terminal, and the like), cooling of a nickel-metal-hydride battery or a lithium battery used in a car, or the like.

(Functions/Effects of Method for Manufacturing Wick1)

According to the method for manufacturing the wick1, the sintered compact is formed by heating the material powder supplied onto the base. Consequently, the sheet-shaped sintered compact can be formed.

Further, according to the method for manufacturing the wick1, the sintered compact is rolled. Consequently, after forming the sintered compact, a void ratio of the sintered compact can be controlled, thereby controlling the capillarity of the wick1. In particular, after forming the sintered compact, a thickness of the sheet-shaped sintered compact can be controlled, thereby reducing a thickness of the wick1.

Furthermore, according to the method for manufacturing the wick1, the material powder supplied onto the base is smoothened. Consequently, in the rolled sintered compact, the density can be prevented from becoming nonuniform, thus avoiding the nonuniform capillarity of the wick1.

Moreover, according to the method for manufacturing the wick1, the steam passages s, the protrusions p, and the like are formed on the surface of the rolled sintered compact. Consequently, in the sintered compact having the porous structure, since the steam passages s, the protrusions p, and the like are formed, the steam passages s, the protrusions p, and the like can be easily formed as compared with a case where the steam passages are formed on the container side.

Additionally, according to the method for manufacturing the wick1, the container of the heat conduction member and the wick1can be individually formed. Consequently, it is not necessary to take a method for forming the wick in the container by externally heating the container after filling the container with the metal powder, and deterioration of the container due to heating can be avoided.

REFERENCE SIGNS LIST