JPH07109171A - Graphite thermal conductor and cold plate using the same - Google Patents

Abstract

PURPOSE:To obtain a lightweight graphite thermal conductor excellent in heat shielding and radiating properties by heat-treating one or more polymeric films such as polyoxadiazole so as to provide graphite films having a prescribed thermal conductivity. CONSTITUTION:This graphite thermal conductor which is a composite layered structure is produced by heat-treating one or more polymeric films selected from polyoxadiazole, an aromatic polyimide, an aromatic polyamide and p- phenylenevinylene having <=400mum thickness at >=2400 deg.C, providing graphite films having >=500W/m.K thermal conductivity, then, as necessary, applying an epoxy resin, etc., dissolved in a solvent onto each graphite film, contact bonding the epoxy resin, etc., to the graphite film, drying the coated epoxy resin, etc., forming a polymeric film and further forming a metallic layer such as copper or aluminum on each polymeric film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphite heat conductor, and more particularly, it is used for controlling heat generated from various electronic devices, electronic parts thereof, high density semiconductors, etc., that is, for radiating and cooling. The present invention relates to a graphite heat conductor used for controlling heat of a heating element such as an electronic device mounted on a spacecraft such as a spacecraft or an artificial satellite.

[0002]

2. Description of the Related Art In recent years, how to control heat generated from highly integrated semiconductors forming various electronic devices,
How to cool and radiate heat has become very important.

For example, the problem of heat generation in a high-density semiconductor is important, and how to cool it is becoming one of the points in the design of computer equipment.

Although effective cooling requires a good combination of convection, radiation and conduction, to cool small parts such as high density semiconductors, heat is transferred primarily to another source by heat conduction. Cool to the low temperature area.

Therefore, in order to cool the heat from the heating element of the electronic device or the like, means for transferring the heat to the radiator provided outside the electronic device is required. As one of the above, a cold plate is provided for each heating element.

At present, as a cold plate, for example, the structures shown in FIGS. 11 to 14 are considered.

FIG. 11 shows a construction in which the heat generating element 4 is directly installed on the heat receiving element 1, and FIG. 12 shows its XX section.

FIG. 13 shows a structure in which a rod-shaped metal 6 such as aluminum is installed between the heating element 4 and the heat receiving element 1.
FIG. 14 shows the YY cross section.

In any structure, the principle of heat radiation is
This is due to the fact that the heat generated from electronic devices is conducted to the cold plate in the spacecraft.

As a specific structure, a pipe 6 for inflowing a coolant such as water and freon and a pipe 7 for outflowing the coolant are provided at the end of the heat receiving body 5.

A fin 9 also serving as a flow path is installed inside the heat receiving body 5, and a coolant is circulated between an external radiator and a cold plate by a pump (not shown).

The heat generated in the heat generating body 8 is conducted to the heat receiving body 5 directly or through the metal rod 10 and is transferred to the refrigerant inside the heat receiving body 5.

The heat of this refrigerant is radiated to the outer space by heat radiation by an external radiator.

For such a cold plate, a metal material excellent in thermal conductivity has been used conventionally.

[0015]

However, of these metal materials, silver, which has the highest heat conductivity, is expensive, while the heat conductivity of relatively inexpensive iron, aluminum, etc. is not sufficient.

Copper is an excellent one among them, but its thermal conductivity (403 W / m · K) is not sufficient and it is heavy.

Therefore, in order to perform more effective cooling and heat dissipation, it is essential to develop a new material having excellent thermal conductivity.

In recent years, technological progress in the aerospace field has been remarkable, and how to effectively cool and radiate electronic equipment under such conditions has become a major issue.

In the first place, in outer space, since it is vacuum and weightless, heat transfer due to the convection phenomenon of air cannot be expected.

However, when air is present in the spacecraft, it is possible to cool the heat source by the forced air cooling method using a fan, but since the heat radiating place is in outer space, the final cooling is not possible. You must rely on heat radiation.

However, the forced cooling system using this fan has a problem that power consumption increases.

When the heating element is directly installed on the heat receiving element, a cold plate is required for each heating element, which increases the equipment cost and makes it difficult to freely move the electronic equipment.

When a metal rod is used, the weight is increased because the metal rod is installed for each electronic device, and it is difficult to move and maintain the electronic device with a metal rod having no flexibility. Is.

Therefore, recently, it has been proposed to use a graphite film, which is lighter than metal and has excellent heat resistance, as a heat conductive material used in such a cold plate.

The thermal conductivity of such a conventional graphite material is 200 to 500 in single crystal graphite.
W / cm · K, other graphite is at most 20-
It was about 100 W / cm · K.

Therefore, the graphite materials other than the conventional single crystal cannot be practically used as a heat dissipation material.

However, the thermal conductivity of single crystal graphite is 200 to 500 W / mK as described above, and it is believed that such excellent thermal conductivity can be actually realized by the film-like graphite. Then it should be a very good cold plate.

However, it was technically difficult to produce a single crystal graphite film having such high performance by the conventional method.

In order to realize a graphite film having high thermal conductivity, it is necessary that the crystallites of graphite are large and the orientation thereof is high. It was difficult to realize such a structure.

For example, there is a conventional graphite film produced from natural graphite by the expanding method.

However, the graphite film produced by such a method has a thermal conductivity of 20 to 100 W / m.
-It was in the range of K and its thermal conductivity was lower than that of metals such as aluminum.

Further, since the acid used in the production process of the graphite film remains, there is a problem such as metal corrosion due to leaching of the residual acid.

Further, even if such a graphite film having high thermal conductivity can be realized, it is considered that various measures are necessary when actually using it as a thermal conductive material.

The high thermal conductivity of graphite is essentially two-dimensional conduction, and although the heat conduction in the plane parallel to the graphite plane is large, the heat conduction in the direction perpendicular to the film plane is one-third of that. It is about 100.

Therefore, how to improve the film strength while effectively utilizing such conduction,
There are some issues to consider.

The present invention has been made for the purpose of solving the above problems, and effectively utilizes the two-dimensional thermal conductivity of graphite to radiate heat from a heating element such as an electronic device. It is an object of the present invention to provide a highly heat-conductive graphite heat conductor that is efficient, has a light weight, is flexible, and facilitates maintenance of electronic devices and the like.

[0037]

In order to solve the above problems, the present invention provides a graphite heat having a graphite film obtained by heat treatment of a predetermined polymer film and having a thermal conductivity of 500 W / mK or more. It is a conductor.

Further, the graphite heat conductor according to claim 1, wherein the graphite film further has a laminated structure with a predetermined polymer layer.

Further, a metal layer may be formed on the surface of the graphite film and / or the surface of the polymer layer.

Further, it can be obtained by carbonizing a predetermined polymer film by itself and laminating a plurality of them, or laminating a plurality of polymer films and carbonizing them, and then graphitizing them under mechanical pressure. A graphite block, the graphite surfaces of which are oriented parallel to each other and which has thermal conductivity in the direction of the graphite surface, or a predetermined polymer film cut into strips or fibers, is oriented in one direction. After that, a graphite block obtained by performing carbonization and graphitization under mechanical pressure, which has thermal conductivity in the direction of the orientation, or a predetermined high degree of concentric winding. Graph obtained by carbonizing and graphitizing a molecular film under mechanical pressure A site block may be a graphite heat conductor having a graphite block having thermal conductivity in the axial direction of the concentric circles.

The predetermined polymer film of the graphite heat conductor of the present invention is selected from polyoxadiazole, aromatic polyimide, aromatic polyamide and polyparaphenylene vinylene having a thickness of 400 microns or less. It is preferable that the polymer film is at least one kind of polymer film and is obtained by heat-treating the polymer film at a temperature of at least 2400 ° C. or higher.

Further, in another aspect of the present invention, the heat receiving body having a space for receiving the heat generated by the heat generating body and having the refrigerant circulated therein, and the first refrigerant for communicating with the space inside the heat receiving body to allow the refrigerant to flow thereinto. 8. The graphite heat conduction according to claim 1, wherein the pipe, the second pipe communicating with the space inside the heat receiving body and allowing the refrigerant to flow out, and the heat receiving body are connected to each other while being in contact with the heat generating body. It is a cold plate with a body.

[0043]

The present invention has a thermal conductivity of 500 W / m · K or more obtained by heat treatment of a polymer film, 2.26 g /
By using a high-purity graphite film having a density of cm ³ or less and less impurities as a heat conductive material, heat is efficiently released.

Further, by combining the graphite film with a polymer film, a metal film, etc., the mechanical strength is increased, and unnecessary temperature is radiated while keeping the temperature of the necessary portion, and the heat is radiated more efficiently.

The graphite block obtained from a plurality of polymer films has a high thermal conductivity and efficiently cools a high density semiconductor or the like.

[0046]

EXAMPLE The heat conductor of the present invention is a graphite film obtained from a special polymer film having a certain thickness or less, which is different from the graphite film obtained by the conventional method. It was made possible by the fact that it has the above-mentioned problems and that there is no metal corrosion due to residual acid, which has been a problem to be solved in the past.

Specifically, polyoxadiazole having a thickness of 400 μm or less, aromatic polyimide,
By using at least one kind of polymer film selected from aromatic polyamide and polyparaphenylene vinylene and heat-treating at a temperature of at least 2400 ° C. or more, it has excellent thermoconductivity as described below, It is a graphite thermal conductor that does not cause corrosion.

As the polymer, polybenzothiazole, polybenzobisthiazole, polybenzoxazole, polybenzobisoxazole, polyamideimide, polyphenylenebenzimidazole, polyphenylenebenzobisimidazole, polythiazole and the like can be used. Is.

First, in the present invention, 400 is used as a starting material.
A film having a thickness of less than or equal to μm is preferably used. The reason is that when a raw polymer film having a thickness of 400 μm or more is used, a good quality graphite film or Obtaining a graphite block is difficult and consists in obtaining a non-uniform tattered graphite film or graphite block.

Further, the thermal conductivity of the graphite film or graphite block obtained from such a film is generally 500 W / m · K or less, which is not suitable as a high performance heat conductor.

Therefore, the thickness range of the raw polymer film to which the manufacturing process of the present invention is effectively applied is 400 μm.
It is considered to be in the range of m or less.

Next, in the present invention, the final highest processing temperature must be 2400 ° C. or higher.

The reason for this is that when the treatment temperature is 2400 ° C. or lower, the obtained film or block is hard and brittle.

However, the heat treatment in the temperature range of at least 1600 ° C. or higher needs to be carried out in an inert gas under normal pressure or under pressure.

Specifically, when the thickness of the raw polymer film is less than 100 μm, heat treatment under normal pressure is often sufficient, but when the thickness is 100 μm or more, under pressure. It is necessary to perform heat treatment at.

[0056] The size of the pressure required at that time may vary depending on the thickness of the film, it is generally preferred that a pressure of 50 Kg / cm ² from 0.1 Kg / cm ^2.

Then, by subjecting the produced graphite film to a rolling treatment as required, a tougher and more flexible graphite film can be obtained.

In summary, according to the present invention, a graphite film obtained by using a polymer film mainly having a specific molecular structure and having a thickness within a specific range is 500 W / m.multidot. It has an excellent thermal conductivity of K or more and has a density of 2.26 g / cm.
^To be much lighter than regular metal at ^{3 and} below,
In terms of the figure of merit of the heat conductor, it is possible to obtain a heat conductor exhibiting far better heat dissipation properties than those using conventional metals.

Further, the graphite film of the present invention is not only highly flexible, but also has the characteristic that it can be freely cut and processed with scissors or a knife.

The graphite film, which is the heat conductor of the present invention, usually has a thickness of 10 to 50 μm. Even when the thickest polymer film of 400 μm is used as the raw material, the final film is obtained. The obtained graphite film has a thickness of about 200 μm, which is not sufficient in terms of strength.

On the other hand, the high thermal conductivity of graphite is
It occurs in the plane direction of the graphite film, and the thermal conductivity in the plane thickness direction is about 1/100 of that.

Therefore, when these graphites are laminated with an appropriate polymer, the strength of the film can be improved, and the two-dimensional conduction characteristics can be more remarkably utilized. Becomes

FIG. 1 is a block diagram showing the structure of such a graphite / polymer composite heat conductor. Polymers that can be used for such purposes include epoxy resin, polyimide,
A wide variety of polymers such as polyamide-imide, polyamide, phenol resin, polycarbonate, polyester, polybenzimidazole, ABS, polystyrene and polyethylene can be used, and particularly polyimide and polyamide-imide having high heat resistance are effective.

When the polymer is thermosetting, these polymers, or precursors thereof dissolved in a solvent, are applied onto the graphite film 1 and pressure-bonded and dried to form the polymer film 2. The steps may be repeated in this order.

In the case of a thermoplastic polymer, polymer layers and graphite films may be alternately laminated and then thermocompression bonded.

The composite of the graphite film and the metal is very effective in compensating for the drawback of graphite being two-dimensionally conductive.

Furthermore, when the outermost surface layer is a metal layer,
This layer effectively acts as a reflective film for reflecting radiant heat.

Such a composite of a graphite film, a polymer layer and a metal layer improves the strength of graphite,
It is very effective in utilizing dimensional conductivity and reflecting radiant heat.

FIG. 2 is a structural view of a composite of such a graphite film 1, a polymer layer 2 and a metal layer 3.

In this composite, the graphite film 1, the polymer layer 2, and the metal layer are alternately laminated, and the metal layer 3 is further provided as the outermost layer.

The outermost metal layer 3 works effectively as a reflection film for radiant heat, and copper, aluminum, silver or the like can be effectively used as this metal.

The above-described heat conductor made of a graphite film or a heat conductor made of a composite of a graphite film and a polymer, a metal or the like is used in an electronic device or the like in a spacecraft when these are used in space. It is possible to efficiently dissipate heat from the heating element, and to realize the weight reduction and cost reduction of the spacecraft.

Further, due to the sufficient flexibility of the heat conductor, maintenance of electronic equipment and the like can be facilitated.

Further, the thermal conductivity of the graphite film is 2
In order to compensate for the drawback of being three-dimensional, the raw polymer film is carbonized by laminating a single polymer film or a plurality of carbon films, or by carbonizing and then laminating a plurality of them, and then graphitized under mechanical pressure to obtain a graphite surface. You may produce the graphite block which was orientated in parallel.

If the graphite block thus obtained is cut along a surface perpendicular to the graphite surface, a graphite block having high thermal conductivity only in one surface direction can be obtained.

FIG. 3 shows a block diagram of such a graphite block. This graphite block is installed so that one end of the high heat conduction surface is in contact with a heat source such as a high density semiconductor and is used as a heat conductor.

If necessary, the ends or the entire
It is also possible to insulate with SiC (silicon carbide) or the like.

A block-shaped graphite thermal conductor having thermal conductivity in only one direction is shown in FIG.
Alternatively, it can be manufactured as shown in FIG.

First, in FIG. 4, a polymer film cut into strips or fibers is oriented in one direction, and then carbonized and graphitized under mechanical pressure.

Next, this is cut along a plane perpendicular to the orientation axis to obtain a graphite block having high thermal conductivity only in the uniaxial direction.

Further, as shown in FIG. 5, even if the polymer film wound concentrically is carbonized or graphitized under mechanical pressure, high thermal conductivity is imparted only in the uniaxial direction. A block-shaped graphite heat conductor can be produced.

Hereinafter, the graphite heat conductor of the present invention will be described more specifically based on each example.

Example 1 Thickness 50 μm, Width 500 m
m, 700 mm long polypyromellitimide (Dup
The Kapton H film manufactured by ONT) was preheated at 1000 ° C. and then at 3000 ° C.

After that, a rolling process is performed by passing it between two rollers to obtain a thickness of 40 μm, a width of 400 mm and a length of 560.
A mm graphite film was obtained.

Then, as shown in FIG. 6, one side of this graphite film was cut into a strip shape.

Next, as shown in FIG. 7, the strip-shaped portions were bundled together, and as shown in FIG. 8, a flexible heat insulating material 4 was wrapped around the bundled portions.

The heat conductor of the graphite film thus formed is placed under the heating element 8 of an electronic device or the like as shown in a perspective view in FIG. 9, and the end portions of the bundled parts of the graphite film 2 are attached. , And is connected to the heat receiving body 5 as shown in FIG.

The density and thermal conductivity of the graphite thermal conductor obtained in this example were compared with the density and thermal conductivity of conventionally used metals, and the results are shown in (Table 1).

[0089]

[Table 1]

According to this comparison result, the graphite heat conductor has a characteristic value which is about ½ or less in density and about 3.3 times or more in heat conductivity as compared with aluminum.

Further, compared with silver and copper, which have excellent thermal conductivity, the density is about 1/9 or less, and the thermal conductivity is about 2.0 times.

Therefore, it is 6.0 as compared with aluminum.
The efficiency is more than doubled. According to the study by the present inventor,
Such improvement in properties is due to the fact that the thickness of the raw material polymer is 400μ.
It lasts up to about m or less.

Further, in the portion connecting the heat generating body 8 and the heat receiving body 5, since the heat insulating material 4 and the graphite inside thereof have flexibility, the electronic equipment can be easily moved and the maintenance is easy.

Furthermore, when there are a plurality of heating elements 8, the portions that connect several heating elements and the heat receiving elements can be gathered in, for example, one heat receiving element, so that the number of heat receiving elements can be reduced. It is possible to reduce the weight of the cold plate itself and the equipment cost.

According to the heat conductor of this embodiment, heat can be efficiently dissipated from the heat generating body such as electronic equipment, and when used in a spacecraft, the spacecraft can be made lighter and lower in cost. Can be realized.

Comparative Example 1 Thickness 500 μm, Width 500 m
m, 700 mm long polyimide film at 1000 ° C
Pre-heat treatment at a pressure of 50 Kg / cm ² and 28
Heat treatment was performed at 00 ° C. Then, it is rolled by passing it between two rollers to obtain a thickness of 400 μm, a width of 400 mm,
A graphite film having a length of 560 mm was obtained.

However, the graphite film thus obtained was fragile and not uniform, and the strength was weak.

The thermal conductivity of this graphite film was 20 W / m · K, which was extremely low.

Example 2 Thickness 50 μm, Width 500 m
m, 700 mm long polyoxadiazole (POD manufactured by Furukawa Electric Co., Ltd.) was preheated at 1000 ° C., and then 2
Heat treatment was performed at 900 ° C.

[0100] After that, a rolling process is carried out by passing it between two rollers to obtain a thickness of 35 µm, a width of 400 mm and a length of 560.
A mm graphite film was obtained.

Then, this graphite film was processed by the same method as in Example 1 and placed under a heating element such as an electronic device by the same method, and the end of the bundled portion of the graphite film was used as a heat receiving element. Connected

The graphite film thus evaluated had a thermal conductivity of 750 W / m · K.
It also showed excellent heat dissipation characteristics.

According to the study by the present inventor, such characteristics were maintained until the thickness of the raw material polymer was about 400 μm or less.

(Example 3) A graphite film was prepared by the method described in Example 1, and then a solution-form polyimide precursor (Trenis made by Toray Industries, Inc.) was added to the film.
It was applied to a thickness of 0 μm.

After drying under reduced pressure, 20 films that had not been sufficiently imidized were laminated and thermocompression bonded.

In this case, the temperature is 300 ° C. and the pressure is 10K.
It was g / cm ² . Thermocouples were placed inside and on the surface of the film thus obtained, the edges of the film were irradiated and heated with an infrared lamp and one end was cooled at 0 ° C.

As a comparative experiment, a polyimide film having the same thickness was used to measure temperature with a thermocouple.

As a result, in the graphite composite material according to this example, when the temperature of the film surface was 200 ° C., the internal temperature was 52 ° C.

On the other hand, in the case of the polyimide film, when the temperature of the film surface is 200 ° C., the internal temperature is 1
It was 08 ° C.

From this, it was found that the graphite composite film according to this example had an excellent heat dissipation effect.

(Example 4) A graphite film was prepared by the method described in Example 1, and then a solution-form polyimide precursor (Trenis manufactured by Toray Industries, Inc.) was applied to the surface of the film to a thickness of 10 µm. did.

After drying under reduced pressure, 20 films which had not been sufficiently imidized were laminated and thermocompression bonded.

In this case, the temperature is 300 ° C. and the pressure is 10K.
It is g / cm ² . Aluminum was vapor-deposited on the surface of the obtained film to a thickness of about 2 μm.

Thermocouples were installed inside and on the surface of the film thus obtained, and one end of the film was irradiated and heated by an infrared lamp and one end was cooled at 0 ° C.

As a comparative experiment, a polyimide film having the same thickness was used to measure temperature with a thermocouple.

As a result, in the graphite composite material according to the present invention, when the temperature of the film surface was 200 ° C.,
The internal temperature was 44 ° C.

On the other hand, in the case of a polyimide film, the internal temperature is 1 when the film surface temperature is 200 ° C.
It was 02 ° C.

From this, it was found that the graphite composite film according to this example had an excellent heat dissipation effect.

The aluminum layer formed by vapor deposition on the surface of the graphite film may be provided on the polymer layer side as shown in FIG. 2 or on the opposite graphite film side, depending on the purpose. Of course, in some cases, it is possible to form both of them and the intermediate region inside thereof.

(Example 5) 1 part of polypyromellitimide (Kapton H film manufactured by Dupont) having a thickness of 50 μm was used.
000 sheets were laminated and preheated at 1000 ° C.

Then, after the pretreatment, the block is taken out,
Heat treatment was performed at 2900 ° C. using an ultra-high temperature hot press.

A graphite block was produced by applying a pressure of 300 Kg / cm ² at 2900 ° C. for 1 hour.

Thus, a graphite block having a thickness of 10 mm, a width of 20 mm and a length of 20 mm was obtained.

Next, this block was cut along a plane perpendicular to the graphite surface to a thickness of 5 mm, and the thickness was 5 mm and the width was 10 m.
A block with m and a length of 20 mm was obtained.

A thermocouple was installed under this graphite block and the surface of the graphite was heated by an infrared heater.

As a comparative experiment, copper blocks of the same size were heated under the same conditions. As a result, when the thermocouple installed under the graphite block was 100 ° C., the thermocouple under the copper block was 83 ° C., demonstrating the excellent thermal conductivity of the graphite block of this example. .

Example 6 Polypyromellitimide (Kapton H film made by Dupont) having a thickness of 50 μm was cut into a piece having a length of 50 mm and a width of 1 mm, and the pieces were arranged in a graphite box in a certain direction to obtain 50 kg / cm ² . Preheat treatment was performed at 1000 ° C. while applying pressure.

Then, the block obtained after the pretreatment was taken out and heat-treated at 2900 ° C. using an ultrahigh temperature hot press.

A graphite block was prepared by applying a pressure of 300 Kg / cm ² at 2900 ° C. for 1 hour.

Thus, a graphite block having a thickness of 10 mm, a width of 20 mm and a length of 50 mm was obtained.

Next, this block was cut to a thickness of 5 mm on a surface perpendicular to the graphite surface, and the thickness was 5 mm and the width was 10 m.
A block with m and a length of 20 mm was obtained.

A thermocouple was installed under this graphite block and the surface of the graphite was heated by an infrared heater.

As a comparative experiment, copper blocks of the same size were heated under the same conditions. When the thermocouple installed under the graphite block was 100 ° C., the thermocouple under the copper block was 85 ° C., which proved the excellent thermal conductivity of the graphite block according to this example.

Example 7 Polypyromellitimide (Dupont, Kapton H film) having a thickness of 50 μm was concentrically wound and packed in a graphite box having a length of 50 mm and a width of 20 mm.

Then, a preheat treatment was performed at 1000 ° C. while applying a pressure of 50 Kg / cm ² .

Then, the block obtained after the pretreatment was taken out and heat-treated at 2900 ° C. using an ultrahigh temperature hot press.

A graphite block was prepared by applying a pressure of 300 Kg / cm ² at 2900 ° C. for 1 hour.

Thus, a graphite block having a thickness of 10 mm, a width of 20 mm and a length of 50 mm was obtained.

Next, this block was cut along a plane perpendicular to the graphite surface to a thickness of 5 mm, and the thickness was 5 mm and the width was 10 m.
A block with m and a length of 20 mm was obtained.

A thermocouple was installed under this graphite block, and the surface of the graphite was heated with an infrared heater.

As a comparative experiment, copper blocks of the same size were heated under the same conditions. When the thermocouple installed under the graphite block was 100 ° C., the thermocouple under the copper block was 878 ° C., demonstrating the excellent thermal conductivity of the graphite block of this example.

[0142]

In summary, the present invention is a graphite heat conductor obtained by heat treatment of a polymer film, and can radiate and cool more effectively than conventional metal heat conductors.

Further, the two-dimensional heat conduction and the one-dimensional heat conduction characteristics can be utilized to provide a heat conductor having a role of heat insulation and heat dissipation.

Further, it can be used as a heat dissipation and heat conductor for space and aircraft equipment due to its light weight.

[Brief description of drawings]

FIG. 1 is a structural diagram of a graphite-polymer composite heat conductor of the present invention.

FIG. 2 is a structural diagram of a composite of the same graphite film, polymer and metal.

FIG. 3 is a diagram showing a graphite block thermal conductor having high thermal conductivity only in the same plane direction.

FIG. 4 is a diagram showing a block-shaped graphite heat conductor to which high heat conductivity is imparted only in the same axial direction.

FIG. 5 is a diagram showing a block-shaped graphite heat conductor to which high heat conductivity is imparted only in the same axis direction.

FIG. 6 is a view showing a graphite film in which the same side is cut into a strip shape.

FIG. 7 is a configuration diagram in which strip-shaped portions of the graphite film of FIG. 6 are bundled into one.

FIG. 8 is a configuration diagram in which a flexible heat insulating material is wrapped around the bundled portion of FIG.

FIG. 9 is a perspective view of the graphite film of FIG. 8 installed under a heating element of an electronic device or the like.

FIG. 10 is a configuration diagram in which the graphite film of FIG. 9 is installed in a cold plate.

FIG. 11 is a plan view showing a conventional cold plate.

12 is a sectional view of the cold plate of FIG. 11 taken along line XX.

FIG. 13 is a plan view showing a conventional cold plate.

14 is a sectional view of the cold plate of FIG. 13 taken along line YY.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Graphite film 2 Polymer layer 3 Metal layer 4 Heat insulating material 5 Heat receiving body 6 Refrigerant inflow pipe 7 Refrigerant outflow pipe 8 Heating element 9 Fin 10 Metal rod

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H01L 23/373 23/473 H01L 23/46 Z (72) Inventor Jun Ehara Osaka Prefecture Kadoma City 1006 Kadoma, Matsushita Denki Sangyo Co., Ltd.

Claims (8)

[Claims] 1. A graphite heat conductor having a graphite film, which is obtained by heat treatment of a predetermined polymer film and has a thermal conductivity of 500 W / m · K or more. 2. The graphite heat conductor according to claim 1, wherein the graphite film further has a laminated structure with a predetermined polymer layer. 3. The graphite heat conductor according to claim 1, further comprising a metal layer formed on at least the surface of the graphite film and / or the surface of the polymer layer. 4. Obtained by carbonizing a predetermined polymer film by itself and then laminating a plurality of them, or by laminating a plurality of predetermined polymer films and carbonizing them, and then graphitizing under mechanical pressure. A graphite heat conductor comprising graphite blocks, the graphite planes of which are oriented parallel to each other, and the graphite blocks having thermal conductivity in the direction of the graphite planes. 5. A graphite block obtained by unidirectionally orienting a predetermined polymer film cut into strips or fibers, and then carbonizing and graphitizing under mechanical pressure, A graphite heat conductor having a graphite block having thermal conductivity in the orientation direction. 6. A graphite block obtained by carbonizing and graphitizing a predetermined polymer film wound in a substantially concentric circular shape under mechanical pressure, wherein the graphite block has thermal conductivity in the axial direction of the concentric circle. Graphite heat conductor having a graphite block having. 7. The predetermined polymer film is at least one kind of polymer film selected from polyoxadiazole, aromatic polyimide, aromatic polyamide, and polyparaphenylene vinylene having a thickness of 400 microns or less. The polymer film is at least 2400
It is obtained by heat treatment at a temperature of ℃ or more.
7. The graphite heat conductor according to any one of 1 to 6. 8. A heat receiving body having a space in which a refrigerant flows inside for receiving heat generated by a heat generating body, a first pipe communicating with the space inside the heat receiving body and allowing the refrigerant to flow therein, and the heat receiving body. A second pipe communicating with an internal space of the refrigerant for flowing the refrigerant, and the graphite heat conductor according to any one of claims 1 to 7, which connects the heat receiving body while being in contact with the heat generating body. Cold plate.