WO2020026860A1

WO2020026860A1 - Heat transport device, heat transfer sheet, heat transport composite body, electronic device, and method for producing heat transport device

Info

Publication number: WO2020026860A1
Application number: PCT/JP2019/028535
Authority: WO
Inventors: 弘幸良尊; 荒巻　慶輔
Original assignee: デクセリアルズ株式会社
Priority date: 2018-07-31
Filing date: 2019-07-19
Publication date: 2020-02-06
Also published as: JP2020020510A; JP7184559B2

Abstract

The purpose of the present invention is to provide a heat transport device which is capable of suppressing an abrupt increase in the surface temperature, while having excellent heat transport characteristics. In order to solve the above-described problem, a heat transport device 1 according to the present invention is characterized by comprising: a heat transport device main body 20 which is positioned in a metal case 10, and which has a wick and a working liquid; and a heat storage material part 30 which is positioned in the metal case 10, and which is filled with a heat storage material 31 that has a phase transition temperature. This heat transport device 1 is also characterized in that the heat transport device main body 20 and the heat storage material part 30 are integrated with each other.

Description

Heat transport device, heat conductive sheet, heat transport composite, electronic equipment, and method of manufacturing heat transport device

The present invention provides a heat transport device, a heat conductive sheet, a heat transport composite, and an electronic device capable of suppressing a sharp rise in surface temperature while having excellent heat transport characteristics, and having excellent heat transport characteristics. The present invention relates to a method for manufacturing a heat transport device capable of obtaining a heat transport device capable of suppressing a rapid rise in surface temperature while reducing the temperature.

In recent years, electronic devices have been following the trend of miniaturization, but since the power consumption cannot be largely changed due to the variety of applications, measures to dissipate heat inside and outside the devices have become even more important.

放熱 As a measure for heat dissipation in the electronic devices described above, a heat sink or a heat sink made of a metal material having high thermal conductivity such as copper or aluminum is widely used. These heat radiating components having excellent thermal conductivity are arranged close to electronic components, such as semiconductor packages, which are heat generating portions in the electronic device, in order to achieve a heat radiating effect or reduce the temperature inside the device. Further, a heat pipe is one of the heat dissipating components (heat transport devices) having a high heat transport capability.

The principle of the heat pipe is that the base of the heat sink has a hollow structure, and a liquid (operating fluid) that is easily volatilized is sealed in the base. , Heat is released and returns to liquid. This repetition lowers the thermal resistance value as compared with a normal heat sink. When mounted on a thin mobile terminal, the heat pipe is flattened and used. However, there is a limit to thinning because a round tube having a complicated internal structure is flattened.

Therefore, the heat transport device is required to be further reduced in thickness, and a technology corresponding to this is a thin “vapor chamber”. The vapor chamber has a structure in which a capillary phenomenon is generated between two metal plates, such as a surface-type or plate-type heat pipe, and they are bonded together. For example, in Patent Literature 1, a wick material for generating a capillary pressure is provided on at least one of the upper surface and the lower surface facing each other in the thickness direction of a flat closed container, and the upper surface and the lower surface are provided with a wick material. A flat heat pipe (vapor chamber) in which a support is disposed between the heat pipes is disclosed.

JP 2004-238672 A

However, in the technique of Patent Document 1, although a certain heat transfer characteristic can be realized, there is a problem that the surface temperature of the vapor chamber rapidly rises, which causes the surface temperature of the electronic device to rise. In electronic devices such as smartphones, from the viewpoint of safety, it is important that the surface temperature does not become too high. Therefore, the development of a technology capable of suppressing a rapid increase in the surface temperature of the vapor chamber has been desired. .

The present invention has been made in view of the above circumstances, and has excellent heat transport characteristics, a heat transport device capable of suppressing a rapid rise in surface temperature, a heat conductive sheet, a heat transport composite, and An object is to provide an electronic device. Another object of the present invention is to provide a method for manufacturing a heat transport device capable of obtaining a heat transport device having excellent heat transport characteristics and capable of suppressing a rapid rise in surface temperature. Aim.

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, as for the heat transport device, a heat transport device having the same configuration as the vapor chamber (the configuration having the wick and the working fluid in the metal housing). By providing the main body, excellent heat transport characteristics are realized, and further, within the metal housing, a heat storage material portion filled with a heat storage material having a phase transition temperature is provided, and the heat storage material portion and the heat transport device main body are provided. It has been found that by integrating the heat transfer, heat transmitted from the heat transport device body can be accumulated with high efficiency, and a rapid rise in surface temperature can be suppressed.

The present invention has been made based on the above findings, and the gist is as follows.
(1) A heat transport device main body having a wick and a working fluid in a metal housing, and a heat storage material portion filled with a heat storage material having a phase transition temperature in the metal housing. A heat transport device, wherein the heat storage material section is integrated.
(2) The heat transport device according to (1), wherein the heat storage material has a phase transition temperature in a range of 30 to 100 ° C.
(3) The heat transport device according to (1), wherein the heat storage material has a latent heat per unit mass of 150 / g or more.
(4) The heat transport device according to (1), wherein the heat storage material has a latent heat per unit volume of 150 J / cm ³ or more.
(5) The heat transport device according to any one of the above (1) to (4), wherein the heat storage material has crystallization water.
(6) The heat transport device according to (5), wherein the heat storage material is a hydrate of a metal salt.
(7) The heat transport device according to any one of (1) to (6), wherein the heat transport device is a vapor chamber, a heat pipe, or a heat spreader.
(8) A heat conductive sheet containing a polymer matrix component and a heat conductive filler, wherein the heat conductive sheet is adjacent to the heat transport device according to any one of the above (1) to (7). A heat conductive sheet, wherein the heat conductive sheet is provided.
(9) A heat transport composite, comprising: the heat transport device according to any one of (1) to (7); and a heat conductive sheet provided adjacent to the heat transport device.
(10) An electronic apparatus including a heat source, a heat radiating member, and a heat transport device provided between the heat source and the heat radiating member, wherein the transport device is one of the above (1) to (7). An electronic apparatus, which is the heat transport device according to any one of the above.
(11) The method for manufacturing a heat transport device according to any one of (1) to (7), wherein the metal plates are etched, and then the etched metal plates are overlapped to perform diffusion bonding. A step of manufacturing a metal housing, and a step of manufacturing a heat transport device main body by evacuating the inside of the metal housing, injecting a coolant serving as a working liquid, and sealing it, Producing a heat storage material part by injecting and sealing a heat storage material after evacuation of the heat transfer device.

Advantageous Effects of Invention According to the present invention, it is possible to provide a heat transport device, a heat conductive sheet, a heat transport composite, and an electronic device that have excellent heat transport characteristics and can suppress a rapid rise in surface temperature. . Further, according to the present invention, it is possible to provide a method for manufacturing a heat transport device capable of obtaining a heat transport device having excellent heat transport characteristics and capable of suppressing a rapid rise in surface temperature. Become.

FIG. 2 is a cross-sectional view schematically showing one embodiment of the heat transport device of the present invention. It is sectional drawing which showed typically other Embodiment of the heat transport device of this invention. (A) is a cross-sectional view schematically showing another embodiment of the heat transport device of the present invention, and (b) is a cross-sectional view schematically showing another embodiment of the heat transport device of the present invention. FIG. FIG. 3 is a diagram illustrating a process flow in one embodiment of the method for manufacturing a heat transport device of the present invention. It is the figure explaining the flow of the process about other embodiments of the manufacturing method of the heat transport device of the present invention. FIG. 1 is a cross-sectional view schematically illustrating an embodiment of an electronic apparatus according to the invention. It is the perspective view which showed typically the assembly state about the semiconductor device of each sample in an Example. FIG. 4 is a diagram illustrating a relationship between a time lapse and a surface temperature of a semiconductor device of each sample in an example.

Hereinafter, an example of an embodiment of the present invention will be specifically described with reference to the drawings. In the drawings, the dimensions of each component are shown at a different ratio from the actual dimensions for convenience of explanation.
<Heat transport device>
First, the heat transport device of the present invention will be described.
In the present invention, as shown in FIG. 1, a heat transport device main body 20 having a wick and a working fluid is filled in a metal housing 10, and a heat storage material 31 having a phase transition temperature is filled in the metal housing 10. And a heat storage material section 30.
The heat transport device 1 of the present invention is characterized in that the heat transport device main body 20 and the heat storage material section 30 are integrated.
By integrating the heat transport device body 20 and the heat storage material section 30, the heat absorbed by the heat transport device body 20 from the heating element is not immediately released to the outside, but is temporarily stored at high efficiency. It is possible to accumulate in the material section 30, and it is possible to suppress a rapid increase in the surface temperature of the heat transport device 1 itself, and in turn, the surface temperature of the entire semiconductor device.

On the other hand, in a conventional heat transport device such as a vapor chamber or a heat pipe, since a heat storage material portion is not provided in the device, a rapid rise in surface temperature cannot be suppressed.
In the case where a sheet or the like capable of storing heat is provided on the surface of the conventional heat transport device, the heat transport device main body 20 and the heat storage material section 30 are not integrated, although some heat storage effect can be obtained. Therefore, the efficiency of heat transport to the heat storage material section 30 is low, and sufficient heat storage cannot be performed, so that it is difficult to suppress a rapid rise in surface temperature. In addition, since a heat storage sheet or the like is provided on the heat transport device as a separate member, there is a problem that the dimensions of the entire heat transport device become large and space saving is hindered.

Here, the heat transport device 1 is a device for absorbing a heat of a heating element (an electronic component such as a semiconductor package) in an electronic device and dissipating the heat to reduce the temperature inside the device. Specifically, a vapor chamber, a heat pipe, a heat spreader, or the like can be used. Among these, the heat transport device 1 of the present invention is preferably a vapor chamber. This is because it is desired to have a better heat transport effect and to suppress a rise in the surface temperature of the device.

In addition, that the heat transport device main body 20 and the heat storage material section 30 are integrated means that the heat transport device main body 20 and the heat storage material section 30 are connected to each other to form one member (the heat transport device 30). This is the state where 1) is formed. In the heat transport device 1 of the present invention, for example, as shown in FIG. 1, a configuration in which the heat transport device main body 20 and the heat storage material section 30 are present in one and the same metal casing 10 is exemplified.

厚 The thickness T (see FIG. 1) of the heat transport device 1 is not particularly limited, and can be appropriately changed according to design contents and the like. For example, from the viewpoint of space saving, it is preferably 1.0 mm or less, more preferably 0.8 mm or less. The thickness T of the heat transport device 1 is preferably 0.1 mm or more, and more preferably 0.2 mm or more, from the viewpoint of the heat transport characteristics and heat storage efficiency of the heat transport device 1.

(Heat transport device body)
The heat transport device 1 of the present invention includes a heat transport device main body 20, as shown in FIG.
The heat transport device main body 20 is a member having a wick and a hydraulic fluid inside the metal housing 10 and responsible for the heat transport effect of the heat transport device 1 of the present invention.

The metal casing 10 constituting the heat transport device main body 20 is not particularly limited, and a casing made of a known metal can be used.
Although there is no particular limitation on the type of metal, copper, aluminum, titanium, nickel, silver, or an alloy thereof is used because it has a certain strength, high thermal conductivity, and an electromagnetic wave shielding function. Is preferred.

The wick and the working fluid in the metal casing 10 are members for carrying out heat transport in the heat transport device main body 20, and the working fluid is evaporated in the metal casing 10 (in contact with the heating element). The working fluid that has absorbed heat and evaporated in a gaseous phase moves to a cooling portion (a portion not in contact with the heating element) in the metal housing 10 and emits heat in the cooling portion. As a result, the cycle in which the working fluid condensed and becomes a liquid phase moves to the evaporating section again is repeated.

The wick included in the metal casing 10 is not particularly limited, and a known technique (a technique used in a conventional vapor chamber or a heat pipe) may be used according to required heat transport performance and the like. It can be used as appropriate.
For example, a structure capable of moving the hydraulic fluid by capillary pressure, such as a fine uneven structure, a porous structure, a fiber structure, a mesh structure, and a groove structure, may be mentioned.

Also, the location of the wick is not particularly limited. For example, from the viewpoint that the hydraulic fluid can be moved efficiently, it is preferable that the hydraulic fluid is continuously provided inside the metal housing 10. For example, it can be provided on at least one of the inner wall surfaces 10a of the metal housing 10.
Further, the wick can be obtained by processing the inner wall surface 10a of the metal housing 10 by etching or the like to form an uneven structure, or separately formed on the inner wall surface 10a of the metal housing 10. It can also be obtained by coating fibers, nets, structures having irregularities and the like.

The working fluid in the metal casing 10 is not particularly limited, and a known technique can be appropriately used according to the required heat transport performance and the like. For example, water, alcohols, chlorofluorocarbon, and the like can be used in terms of the ease of phase change between the liquid phase and the gas phase.

The heat transport device main body 20 may include members other than the above-described wick and hydraulic fluid in the metal housing 10 as necessary. For example, a member for assisting the strength of the metal housing 10, a member for assisting movement of the hydraulic fluid, and the like are included.

(Heat storage material department)
The heat transport device 1 of the present invention includes a heat storage material section 30 as shown in FIG.
The heat storage material section 30 is a member in which the metal housing 10 is filled with a heat storage material 31 having a phase transition temperature. By being provided in a state integrated with the heat transport device main body 20, the heat of the heat transport device main body 20 is absorbed and accumulated, and an effect of suppressing a rapid rise in surface temperature is exhibited.

Here, the heat storage material 31 filled in the metal housing 10 is a material having a phase transition temperature (a phase transition can be performed by a change in temperature). When the heat storage material 31 has a phase transition temperature, when the heat transport device body 20 generates heat, a certain amount of heat can be absorbed and accumulated.

The heat storage material 31 has a phase transition temperature, and the phase transition temperature is preferably in the range of 30 to 100 ° C, more preferably in the range of 30 to 40 ° C or in the range of 70 to 100 ° C. preferable. When the phase transition temperature of the heat storage material 31 is in the range of 30 to 100 ° C., heat absorption when the heat transport device body 20 generates heat can be effectively performed, and the heat transport device 1 can be used in electronic equipment. This is because the heat storage efficiency when used can be further improved.
Further, by setting the phase transition temperature of the heat storage material 31 in the range of 30 to 40 ° C., it is possible to more reliably reduce the risk of burns when coming into contact with the human body. CPU (central processing unit) can be protected.

Further, the heat storage material 31 preferably has a latent heat per unit mass of 150 J / g or more, more preferably 200 J / g. When the latent heat per unit mass of the heat storage material 31 is 150 J / g or more, heat absorption when the heat transport device body 20 generates heat can be efficiently performed. Further, from the viewpoint that the temperature rise can be suppressed for a long time and the heat storage efficiency when the heat transport device 1 is used in an electronic device can be further increased, the latent heat per unit mass of the heat storage material 31 is reduced by 150%. It is preferably in the range of 300 to 300 J / g, more preferably in the range of 200 to 300 J / g.

Further, the heat storage material 31 preferably has a latent heat per unit volume of 150 J / cm ³ or more, more preferably 200 J / cm ³ or more. When the latent heat per unit volume of the heat storage material 31 is 150 J / cm ³ or more, heat absorption when the heat transport device main body 20 generates heat can be efficiently performed. Further, from the viewpoint that the temperature rise can be suppressed for a longer time and the heat storage efficiency when the heat transport device 1 is used in the electronic device can be further increased, the latent heat per unit volume of the heat storage material 31 is defined as: It is preferably in the range of 150 to 600 J / cm ³ , more preferably in the range of 200 to 600 J / cm ³ .

The type of the heat storage material 31 is not particularly limited, but preferably has water of crystallization from the viewpoint of obtaining a better heat storage effect. This is because the heat storage material 31 has crystal water, so that the heat storage amount can be increased, and a rise in surface temperature can be suppressed more reliably.
Here, the heat storage material 31 having the crystallization water is not particularly limited, but is preferably a hydrate of a metal salt from the viewpoint that the heat storage amount is large and a better heat storage effect can be obtained.

Examples of the hydrate of the metal salt include lithium perchlorate trihydrate (LiClO ₃ .3H ₂ O), potassium fluoride tetrahydrate (KF.4H ₂ O), and manganese (II) nitrate hexahydrate. Hydrate (Mn (NO ₃ ) ₂ .6 H ₂ O), calcium chloride hexahydrate (CaCl ₂ .6 H ₂ O), lithium nitrate trihydrate (LiNO ₃ .3H ₂ O), sodium sulfate Decahydrate (Na ₂ SO ₄ · 10 H ₂ O), sodium carbonate decahydrate (Na ₂ CO ₃ · 10 H ₂ O), calcium bromide tetrahydrate (CaBr ₂ · 4 H ₂ O) , lithium bromide dihydrate _{_{(LiBr 2 · 2H 2 O)}} , disodium hydrogen phosphate twelve dihydrate _{_{_{(Na 2 HPO 4 · 12H 2}}} O), zinc nitrate hexahydrate (Zn (NO ₃₎ _₂ · 6H ₂ O), potassium fluoride dihydrate (KF · 2H ₂ O), magnesium iodide dihydrate _{_{(MgI 2 · 2H 2 O)}} , calcium nitrate tetrahydrate (Ca (NO ₃₎ _₂ · 4H ₂ O), iron (III) nitrate nonahydrate _{_{(Fe (NO 3) 3 ·}} 9H 2 O), sodium metasilicate tetrahydrate Objects _{_{_{(Na 2 SiO 3 · 4H 2}}} O), dipotassium hydrogen phosphate heptahydrate _{_{_{(K 2 HPO 4 · 7H 2}}} O), magnesium sulphate heptahydrate _{_{(MgSO 4 · 7H 2 O)}} , sodium thiosulfate Pentahydrate (Na ₂ S ₂ O ₃ .5H ₂ O), calcium nitrate trihydrate (Ca (NO ₃ ) ₂ .3H ₂ O), iron chloride (III) dihydrate (FeCl ₃ .2H ₂ O), nickel (II) nitrate hexahydrate (Ni (NO ₃ ) ₂ · 6H ₂ O), sodium acetate trihydrate (CH ₃ COONa · 3H ₂ O), magnesium chloride tetrahydrate (MgCl ₂・ 4H ₂ O), trisodium phosphate dodecahydrate (Na ₃ PO ₄・ 12H ₂ O), lithium acetate dihydrate (CH ₃ COOLi ・ 3H ₂ O), sodium diphosphate dodecahydrate And the like (Na ₂ P ₂ O ₇ .12H ₂ O).
Among these, sodium acetate trihydrate, zinc nitrate hexahydrate, sodium carbonate decahydrate, and phosphoric acid are preferred from the viewpoints of large heat storage, relatively easy processing, and low corrosion. It is preferable to use at least one of disodium hydrogen dodecahydrate.

Examples of the heat storage material 31 having no crystallization water include, for example, paraffin, vanadium dioxide, and sugar alcohol (sorbitol, xylitol, adonitol, threitol, D-mannitol, pentaerythritol, dalcitol, etc.).
Among them, it is preferable to use paraffin from the viewpoint of a large heat storage amount.

The heat storage material 31 may be filled in the entire space in the metal housing 10 or may be filled at a predetermined filling rate.
However, from the viewpoint of obtaining an excellent heat storage amount, the filling rate of the heat storage material 31 in the metal housing 10 is preferably 60% by volume or more, and more preferably 70% by volume or more. In addition, when considering that the inside of the metal housing 10 does not become too high in pressure, it is preferable to set the range of 60% by volume to less than 100% by volume, or 70% by volume to less than 100% by volume.

Furthermore, the heat storage material section 30 may include a filler other than the heat storage material 31 as necessary. For example, it is a melting point adjusting agent, a supercooling inhibitor, a diluent, or an auxiliary agent for filling the metal housing 10 with the heat storage material 31.

In the heat transport device 1 of the present invention, the position where the heat storage material section 30 is provided is integrated with the heat transport device main body 20 so that the heat of the heat transport device main body 20 can be absorbed and accumulated. There is no particular limitation if possible.
For example, as shown in FIG. 1 and FIG. 3 (b), a structure in which the heat transport device main body 20 and the heat storage material section 30 are laminated, or as shown in FIG. 2 and FIG. A structure in which the transport device body 20 and the heat storage material section 30 are arranged side by side is exemplified.
Among these, from the viewpoint of more surely preventing a rapid rise in surface temperature, a structure in which the heat transport device main body 20 and the heat storage material portion 30 are laminated (for example, as shown in FIGS. 1 and 3B). Are preferred. In addition, the heat transport device main body 20 is provided at a position in contact with a heating element such as a semiconductor element, and the position in contact with a heat radiator and other members, from the viewpoint that the heat transport characteristics and the surface temperature suppression effect can be realized at a higher level. It is most preferable that the heat storage material section 30 is provided at the bottom. Further, from the viewpoint of suppressing the thickness of the entire heat transport device, the heat transport device main body 20 and the heat storage material portion 30 are provided side by side (for example, a structure as shown in FIGS. 2 and 3A). Is preferred.

Furthermore, in the heat transport device 1 of the present invention, the ratio occupied by the heat storage material section 30 (volume of the heat storage material section 30 / volume of the heat transport device 1 × 100%) ensures that the surface temperature increases sharply. From the viewpoint of suppression, the content is preferably 10% by volume or more. Further, from the viewpoint of saving the space of the heat transport device 1 of the present invention, the ratio occupied by the heat storage material section 30 is preferably 50% by volume or less.
In addition, as shown in FIG. 2, when there are a plurality of the heat storage material portions 30, the ratio of the heat storage material portion 30 is a ratio of the total volume. Further, as shown in FIG. 1, the volume ratio of the metal casing 10 at the boundary between the heat transport device main body 20 and the heat storage material section 30 is calculated so as to be equally divided.

In the case where a strongly acidic material is used as the heat storage material 31, it is preferable that a coating for corrosion resistance is applied to the inner wall of the metal housing 10 constituting the heat storage material portion 30. This is because a reduction in the heat storage effect due to corrosion of the metal housing 10 can be prevented.

<Method of manufacturing heat transport device>
Next, a method for manufacturing the heat transport device of the present invention will be described.
In the method for manufacturing a heat transport device of the present invention, for example, as shown in FIG. 4, after etching a metal plate, the etched metal plates are overlapped, and diffusion bonding is performed to produce a metal housing. Steps (FIGS. 4A and 4B);
A step of producing a heat transport device main body by evacuating the inside of the metal casing and then injecting and sealing a coolant serving as a working fluid (FIGS. 4C and 4D);
After the inside of the metal housing is evacuated, a heat storage material is injected and sealed to form a heat storage material portion (FIGS. 4E and 4F).
Through the above-described steps, the heat transport device of the present invention can be obtained. With respect to the obtained excellent heat transport device, it is possible to suppress a sharp rise in surface temperature while having heat transport characteristics.

(Metal casing manufacturing process)
In the method for manufacturing a heat transport device according to the present invention, the metal plate is etched, and then the etched metal plate is overlapped and diffusion bonded to form a metal housing (hereinafter referred to as “metal housing”). Manufacturing process ”).
In this metal housing manufacturing step, a plurality of metal plates including a metal plate etched to form a wick of the heat transport device main body 20 are stacked. Then, the superposed metal plates are bonded by diffusion bonding to form one metal housing 10.

In the metal casing manufacturing step, the number of metal plates to be overlapped and the shape of the etching performed on the metal plates are not particularly limited, and can be appropriately changed according to required performance.
For example, when manufacturing the metal housing 10 used for the heat transport device 1 (the heat transport device 1 as shown in FIG. 1) in which the heat transport device main body 20 and the heat storage material unit 30 are stacked, FIG. As shown in FIG. 4A, a metal plate 12 that has been etched to form the heat transport device body 20, a metal plate 13 that forms the heat storage material section 30, and a metal plate 11 that serves as a lid The three metal plates can be overlapped.
Moreover, when manufacturing the metal housing | casing 10 used for the heat transport device 1 (the heat transport device 1 as shown in FIG. 2) in which the said heat transport device main body 20 and the said heat storage material part 30 were provided in parallel. As shown in FIG. 5A, a metal plate 14 having been subjected to etching 14a for forming the heat transport device main body 20 and etching 14b for forming the heat storage material section 30, and a metal plate serving as a lid 11 and two metal plates can be overlapped.

The

metal plates

12, 13, and 14 for forming the heat transport device body 20 and the heat storage material section 30 have a working liquid hole 12 a and a heat storage material hole so that a working liquid and a heat storage material described later can be injected. 13a is provided.

In the diffusion bonding, a base material (metal plate) is brought into close contact with the base material, and under a temperature condition equal to or lower than the melting point of the base material, pressure is applied so as not to cause plastic deformation as much as possible. It is a method of joining.
The conditions for the diffusion bonding are not particularly limited, and can be set according to the conditions of the metal plate. In order to prevent oxidation of the metal, it is preferable to perform the treatment in an inert gas atmosphere or in a vacuum.

(Heat transport device body manufacturing process)
In the method for manufacturing a heat transport device of the present invention, after the above-described metal housing manufacturing step, the inside of the metal housing is evacuated, a coolant serving as a working fluid is injected, and the heat seal device is sealed to manufacture the heat transport device main body. (Hereinafter, referred to as a “heat transport device body manufacturing step”).
In this heat transport device main body manufacturing process, the heat transport device main body 20 portion of the heat transport device 1 of the present invention is manufactured by injecting a working fluid into the obtained metal casing 10.

(4) The working fluid to be injected is injected through a working fluid hole 12a provided in the metal casing 10, as shown in FIGS. 4 (c) and 5 (c). The conditions for the injection are not particularly limited, except that the injection is performed after the inside of the metal housing is evacuated, and the injection can be performed by a known method.

In addition, the conditions of the sealing (FIGS. 4D and 5D) in the heat transport device main body manufacturing step are not particularly limited as long as the method can seal the working fluid hole 12a. Not done. For example, a method of sealing by laser welding, ultrasonic bonding, or the like can be given.

(Heat storage material part manufacturing process)
In the method for manufacturing a heat transport device according to the present invention, after the above-described heat transport device main body manufacturing step, the inside of the metal housing 10 is evacuated, and then the heat storage material 31 is injected and sealed, so that the heat storage material section is formed. 30 (hereinafter, referred to as a “heat storage material section manufacturing step”).
In the heat storage material section manufacturing step, the heat storage material 31 is injected into the obtained metal casing 10 to manufacture the heat storage material section 30 of the heat transport device 1 of the present invention.

(4) The heat storage material 31 to be injected is injected through the heat storage material hole 13a provided in the metal casing 10, as shown in FIGS. 4 (e) and 5 (e). The conditions for the injection are not particularly limited, except that the injection is performed after the inside of the metal housing is evacuated, and a known method can be appropriately selected according to the type of the heat storage material 31.

Also, as for the conditions of the sealing (FIGS. 4 (f) and 5 (f)) in the heat storage material part manufacturing step, the heat storage material holes 13a are formed similarly to the sealing in the heat transport device main body manufacturing step. There is no particular limitation as long as it can be sealed.

After the heat storage material section manufacturing step, the heat transport device 1 of the present invention is obtained.
Note that the method for manufacturing a heat transport device of the present invention can include, as necessary, steps other than the above-described metal casing manufacturing step, heat transport device main body manufacturing step, and heat storage material section manufacturing step. For example, there are a step of processing the surface of the obtained heat transport device 1 and a step of bonding another member to the obtained heat transport device 1.

<Heat conductive sheet>
Next, the heat conductive sheet of the present invention will be described.
The heat conductive sheet of the present invention is a heat conductive sheet containing a polymer matrix component and a heat conductive filler, and is provided adjacent to the above-described heat transport device of the present invention.
By providing the heat conductive sheet containing the polymer matrix component and the heat conductive filler adjacent to the heat transport device of the present invention, further excellent heat transport characteristics can be realized by a synergistic effect. Further, since the heat conductive sheet of the present invention is provided adjacent to the heat transport device of the present invention, an effect of suppressing a rapid rise in surface temperature can be obtained.

熱 The heat conductive sheet is not particularly limited as long as it contains a polymer matrix component and a heat conductive filler, and can be appropriately selected according to required performance. For example, in addition to the polymer matrix component and the thermally conductive filler, a magnetic metal powder for improving electromagnetic wave shielding properties can be included.

For example, the polymer matrix component is a component serving as a base material of the heat conductive sheet of the present invention, and a known resin or the like can be appropriately selected. For example, one of the polymer matrix components includes a thermosetting resin, and examples of the thermosetting resin include a crosslinkable rubber, an epoxy resin, a polyimide resin, a bismaleimide resin, a benzocyclobutene resin, and a phenol resin. , Unsaturated polyester, diallyl phthalate resin, silicone, polyurethane, polyimide silicone, thermosetting polyphenylene ether, thermosetting modified polyphenylene ether, and the like. These may be used alone or in combination of two or more.

Further, the thermal conductive filler is not particularly limited, and a known thermal conductive filler can be appropriately selected.
The heat conductive filler may be a fibrous material. Here, “fibrous” refers to a shape having a high aspect ratio (about 6 or more).
Furthermore, the kind of the heat conductive filler is not particularly limited as long as it is a material having high heat conductivity, and examples thereof include metals such as silver, copper, and aluminum, alumina, aluminum nitride, silicon carbide, and graphite. Ceramics, carbon fibers and the like. These thermal conductive fillers may be used alone or in a combination of two or more. However, among the heat conductive fillers, it is preferable to use carbon fibers from the viewpoint of obtaining higher heat conductivity.

磁性 As the magnetic metal powder, for example, an amorphous metal powder or a crystalline metal powder can be used. Examples of the amorphous metal powder include Fe-Si-B-Cr, Fe-Si-B, Co-Si-B, Co-Zr, Co-Nb, and Co-Ta powders. Examples of the crystalline metal powder include pure iron, Fe-based, Co-based, Ni-based, Fe-Ni-based, Fe-Co-based, Fe-Al-based, Fe-Si-based, and Fe-Si-Al-based. And Fe-Ni-Si-Al type. Further, as the crystalline metal powder, a microcrystalline metal obtained by adding a trace amount of N (nitrogen), C (carbon), O (oxygen), B (boron), etc. Powder can be used.

In addition, the heat conductive sheet of the present invention, in addition to the above-described polymer matrix component and heat conductive filler, magnetic metal powder as an optional component, may optionally contain other components depending on the purpose. is there.
Examples of other components include an inorganic filler, a thixotropic agent, a dispersant, a curing accelerator, a retarder, a tackifier, a plasticizer, a flame retardant, an antioxidant, a stabilizer, and a colorant.

<Heat transport composite>
Next, the heat transport composite of the present invention will be described.
A heat transport composite of the present invention includes the above-described heat transport device of the present invention and a heat conductive sheet provided adjacent to the heat transport device.
In the heat transport composite of the present invention, by providing the heat conductive sheet and the heat transport device of the present invention adjacent to each other, further excellent heat transport characteristics can be realized by a synergistic effect. Further, since the heat transport composite of the present invention includes the heat transport device of the present invention, an effect of suppressing a rapid rise in surface temperature can be obtained.
The heat conductive sheet used in the heat transport composite of the present invention is not particularly limited as long as it has heat conductive properties. For example, the same thing as the above-mentioned heat conductive sheet of the present invention can be used.

<Electronic equipment>
Next, the electronic device of the present invention will be described.
The electronic device of the present invention is an electronic device including a heat source, a heat radiating member, and a heat transport device provided between the heat source and the heat radiating member.
And the electronic device of the present invention is characterized in that the transport device is the above-described heat transport device of the present invention.
Since the electronic device of the present invention includes the heat transport device of the present invention, excellent heat transport characteristics can be realized and a rapid rise in surface temperature can be suppressed.

An example of the electronic device of the present invention will be described with reference to FIGS.
FIG. 6A is a schematic cross-sectional view illustrating an example of the electronic device of the present invention. The electronic device shown in FIG. 6A includes a heat transport device 1, a heat conductive sheet 2, an electronic component 3, a heat sink 5, and a wiring board 6.
The electronic component 3 is a semiconductor package such as a BGA, for example, and is mounted on the wiring board 6.

The heat transport device 1 is the above-described heat transport device of the present invention, and is provided between the heat conductive sheet 2 and the heat sink 5 as a heat radiating member, as shown in FIG. Heat generated from the electronic component 3 as a heat source is transmitted to the heat sink 5 through the heat conductive sheet 2 and the heat transport device 1 and is radiated. At this time, since the heat transport device 1 of the present invention has a heat storage effect, it is possible to suppress a rapid rise in the surface temperature of the electronic device.

The electronic device shown in FIG. 6B includes the heat transport device 1, the electronic component 3, the heat sink 5, and the wiring board 6.
The heat generated from the electronic component 3 as a heating element is transmitted to the heat sink 5 through the heat transport device 1 and is radiated. Also in this case, since the heat transport device 1 of the present invention has a heat storage effect, it is possible to suppress a rapid rise in the surface temperature of the electronic device.

The electronic device of the present invention may include other members such as an electromagnetic wave shielding member and an electronic component, if necessary, in addition to the above-described heat source, heat radiating member, and heat transport device.

Next, the present invention will be specifically described based on examples. However, the present invention is not limited to the following examples.

As shown in FIG. 7, after a model of an apparatus including a heating element and a heat transport device having a metal plate and / or a heat storage material portion is prepared as a sample, the heat storage material is analyzed by finite element analysis (FEM analysis). With respect to the temperature of the front surface (the back surface of the model of the device shown in FIG. 7), the transition with the passage of time was calculated. FIG. 8 shows the calculation results.

Note that (1) the heating element was a chip with a power consumption of 5.8 W, assuming a semiconductor element.
(2) For the metal plate, a 0.1 mm thick copper plate (thermal conductivity: 398 W / mK) or a 0.2 mm thick vapor chamber (metal housing: copper, hydraulic fluid: water, thermal conductivity: 20000 W / mK) ) Was used.
Furthermore, as for (3) the heat storage material section, it is assumed that the metal casing is filled with disodium hydrogen phosphate dodecahydrate (filling rate: 75% by volume), thickness: 0.2 mm, density: The sheet was 1.52 g / cm ³ , heat storage per mass: 280 J / g, and heat storage per volume 320 J / cm ³ in consideration of the filling factor. In addition, a model without a heat storage material part was also manufactured.
In addition, in the model of the device serving as each sample of the embodiment, it is assumed that the metal plate and the heat storage material unit are stacked and integrated.

From the results shown in FIG. 8, when the sample of the heat transport device (model of the vapor chamber + the heat storage material section) included in the scope of the present invention is used, the rise in the surface temperature is suppressed for a long time (about 250 seconds). I understand. On the other hand, when samples of other heat transport devices (copper plate + heat storage material part, copper plate only, model of vapor chamber only) were used, the surface temperature was immediately increased.

REFERENCE SIGNS LIST 1 heat transport device 2 heat conductive sheet 3 electronic component 5 heat sink 6 wiring board 10 metal housing 11 metal plate serving as lid 12 etched metal plate for constituting heat transport device main body 12 a working fluid hole 13 heat storage Metal plate 13a for forming the material portion 13a Hole for heat storage material 14 Metal plate 14a subjected to etching for forming the heat transport device body and the heat storage material portion 14a Etching for forming the heat transport device body 14b Heat storage material portion 20 Heat transport device body 30 Thermal storage material section 31 Thermal storage material T Thickness of thermal transport device

Claims

In a metal housing, a heat transport device body having a wick and a working fluid,
A heat storage material portion filled with a heat storage material having a phase transition temperature in a metal housing,
The heat transport device, wherein the heat transport device body and the heat storage material section are integrated.
熱 The heat transport device according to claim 1, wherein the heat storage material has a phase transition temperature in a range of 30 to 100 ° C.
The heat transport device according to claim 1, wherein the heat storage material has a latent heat per unit mass of 150 J / g or more.
The heat storage material is characterized in that the latent heat per unit volume is in the range of 150 J / cm 3 or more, the heat transport device according to claim 1.
(5) The heat transport device according to any one of (1) to (4), wherein the heat storage material has water of crystallization.
6. The heat transport device according to claim 5, wherein the heat storage material is a hydrate of a metal salt.
The heat transport device according to any one of claims 1 to 6, wherein the heat transport device is a vapor chamber, a heat pipe, or a heat spreader.
A heat conductive sheet containing a polymer matrix component and a heat conductive filler,
The heat conductive sheet, wherein the heat conductive sheet is provided adjacent to the heat transport device according to any one of claims 1 to 7.
A heat transport composite comprising the heat transport device according to any one of claims 1 to 7, and a heat conductive sheet provided adjacent to the heat transport device.
A heat source, a heat dissipating member, and a heat transport device provided between the heat source and the heat dissipating member, comprising:
An electronic apparatus, wherein the transport device is the transport device according to any one of claims 1 to 7.
A method for manufacturing a heat transport device according to any one of claims 1 to 7,
After etching the metal plate, a step of fabricating a metal housing by overlapping the etched metal plates and performing diffusion bonding,
After evacuating the inside of the metal housing, a coolant serving as a working fluid is injected and sealed, whereby a heat transport device body is manufactured.
After evacuating the inside of the metal housing, a heat storage material is injected and sealed, thereby producing a heat storage material portion.
A method for manufacturing a heat transport device, comprising: