JP2009179847A - Method for producing carbon-coated material, and carbon-coated material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a carbon-coated material where thermal resistance from a metal base material to a radiation body is reduced, and heat output by radiation is remarkably increased, and to provide a carbon-coated material. <P>SOLUTION: By an aerosol deposition process of jetting a carbon material, the surface of a metallic base material 5 held to the inside of a chamber 2 in an aerosol deposition apparatus 1 is jetted with an aerosol composed of the powder of a carbon material and a conveyance fluid produced in a production vessel 7a of an aerosol feeding apparatus 7, so as to form a carbon-coated layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a carbon coating material and a carbon coating material.

In recent years, electronic devices using LSIs such as microprocessors (MPUs), image processing chips, and memories have become more dense and have increased power consumption due to higher performance, so cooling has become important. ing.
Conventionally, when heat countermeasures are completed by proper arrangement in the LSI device, it is common to use an appropriate arrangement of the LSI. Otherwise, use of a heat sink such as a heat sink or a small fan motor has been generally used. However, there is a case where such a heat sink cannot be used in an electronic device in which a thin and light weight (downsizing) is pursued, such as a notebook personal computer or a mobile phone. In order to improve the heat dissipation efficiency of electronic components, various heat dissipation sheets and the like in consideration of heat radiation characteristics have been proposed.
For example, a heat-dissipating heat-dissipating sheet in which an adhesive layer containing a heat conductive filler and a heat radiation layer made of an alumina film on a layer made of aluminum or an aluminum alloy are provided has been proposed (Patent Document 1, Claims) In addition, a heat-radiating film such as silicon dioxide or aluminum oxide is formed on the surface of the heat-absorbing layer made of aluminum, copper, stainless steel or the like having thermal conductivity, and a heat-conductive adhesive is formed on the back surface of the heat-absorbing layer. A heat-dissipating sheet provided with a sheet is also proposed (see Patent Document 2, Claims, etc.).

However, since the heat radiation sheet disclosed in Patent Document 1 forms a heat radiation layer by coating and baking alumina sol on a layer made of aluminum or an aluminum alloy, a long time is required for the film forming process. The heat dissipation sheet disclosed in Patent Document 2 also has a liquid or kaolin containing silicon dioxide or aluminum oxide on the surface of the heat absorbing layer made of aluminum, copper, stainless steel or the like. Since the thermal radiation film is formed by applying the emulsion composition contained therein, there is a problem that a long time is required for the film forming process, and a great amount of time and labor are required.
JP 2005-101025 A JP 2004-200199 A

Therefore, the present applicants have been studying a material suitable for the heat radiation layer or the heat radiation layer and a deposition method thereof.
FIG. 5 shows the spectral emissivity for each material (Ryutaro Tada: types and characteristics of infrared sources, coating engineering (1) 112-19 (1994)).
As shown in the figure, a carbon material with a very high emissivity is suitable as the material for the heat dissipation layer or the heat radiation layer, and it is expected that the heat dissipation characteristics will be improved by the radiation of the carbon material. Have the problem that they are very brittle and have extremely poor reactivity with metals and do not directly bond to metals. For this reason, in a normal metal radiator, a resin paint mixed with a carbon material is applied to the surface of the radiator to form a black radiation layer or a heat radiation layer, and heat conduction is performed by phonons and conduction electrons. There are many cases. However, since heat conduction from the radiator to the carbon material is performed via a resin having a low heat transfer coefficient, the heat resistance to the radiation layer or the heat radiation layer is large, and the heat radiation effect as expected cannot be obtained. There is.

Therefore, the present invention provides a carbon coating material manufacturing method in which a coating layer of a carbon material is formed on a substrate to form a carbon coating material, thereby greatly reducing the heat resistance of the radiator and greatly increasing the amount of heat released by radiation. And it aims at providing a carbon coating material.

  The invention according to claim 1 provides a method for producing a carbon coating material in which a carbon coating layer is formed by spraying a carbon material on a metal substrate by an aerosol deposition method in which the carbon material is sprayed.

  The invention according to claim 2 is a carbon coating in which a carbon material and a metal material are mixed by spraying the carbon material and the metal material onto a metal substrate by an aerosol deposition method in which the carbon material and the metal material are sprayed. A method for producing a carbon coating material for forming a layer is provided.

  The invention according to claim 3 provides a carbon coating material in which a carbon material is directly coated on a metal substrate without using a resin.

  The invention according to claim 4 provides a carbon coating material in which a carbon material and a metal material are directly coated in a mixed state on a metal substrate without using a resin.

  ADVANTAGE OF THE INVENTION According to this invention, a carbon coating layer can be formed on a base material, a thermal resistance with respect to heat conduction is small, and a carbon coating material with a large heat dissipation can be provided.

  Hereinafter, with reference to an accompanying drawing, the example of the manufacturing method of the carbon covering material and carbon covering material concerning the present invention is explained. In addition, the carbon coating material which concerns on this invention shall be attached by making it closely_contact | adhere to the adhesive surface with respect to the heat radiating surface of a heat-emitting component with the heat conductive adhesive layer containing a heat conductive filler. In addition, the carbon coating material according to the present embodiment is used for cooling a heat generating component, for example, an electronic component. It is also used for LSI cooling.

FIG. 1 is an explanatory view of an aerosol deposition apparatus used in the method for producing a carbon coating material according to the present invention.
The aerosol deposition apparatus 1 is provided with a chamber 2 as a processing chamber. On one side of the chamber 2, an XY stage 3 is provided movably along an X axis (for example, horizontal direction) and a Y axis (for example, vertical direction), and a substrate holder 4 is provided integrally with the XY stage 3. For example, a metal sheet 5 is held on the substrate holder 4 as a metal base material. In addition, a nozzle 6 is provided on the other side in the chamber 2 in order to form a carbon coating layer (described later) so as to cover the adherend surface of the metal sheet 5. The metal sheet 5 is formed of a highly versatile metal, for example, a sheet of copper or an alloy thereof excellent in heat conduction, and the nozzle port 6 a of the nozzle 6 faces the surface to be attached to the metal sheet 5. Note that, for example, an interval of about 10 mm is provided between the nozzle port (jet port) 6a and the surface to which the metal sheet 5 is attached. Further, the chamber 2 is provided with an exhaust pipe 9 for exhausting the atmosphere in the chamber. The exhaust pipe 9 is provided with a filter device 10 for purifying the exhaust gas, and the inside of the chamber 2 is decompressed by exhaust. A vacuum pump 11 is provided.

An aerosol composed of a carbon material powder (including powder, particles (fine particles)) and a carrier fluid (hereinafter referred to as a carbon coating layer forming aerosol) is ejected from the nozzle 6 to the nozzle 6 to form a metal sheet 5. A first aerosol supply device 7 is attached for spraying on the adherend surface. In the first aerosol supply device 7, a carbon coating layer forming aerosol, a metal material, for example, an aerosol composed of powder of copper or its alloy and a carrier fluid (hereinafter referred to as a mixing aerosol), The second aerosol supply device 8 is attached so that it can be mixed upstream of the nozzle 6 and ejected from the nozzle 6.

The first aerosol supply device 7 supplies a first aerosol generation container 7a for generating a carbon coating layer forming aerosol and a carrier fluid to the first aerosol generation container 7a to generate a carbon coating layer forming aerosol. An upstream pipe 7b, a downstream pipe 7c for supplying the carbon coating layer forming aerosol generated in the first aerosol generating container 7a to the nozzle 6, and a gas cylinder 7d as a carrier fluid supply source are provided.
A pressure reducing valve 7e is provided in the upstream pipe 7b of the first aerosol supply device 7, and a first mass flow controller 7f for adjusting the flow rate of the carrier fluid is provided on the downstream side of the pressure reducing valve 7e. Further, a first on-off valve 7h is provided on the downstream side of the first mass flow controller 7f of the upstream side pipe 7b in order to switch supply / stop of the carrier fluid, and the downstream side pipe 7c of the first aerosol supply device 7 includes In order to switch supply / stop of the aerosol to the nozzle 6, a second on-off valve 7i is provided.

  The first aerosol generating container 7a, that is, the first aerosol generating chamber 7j is charged with powder of carbon material, and the gas cylinder 7d is filled with an inert gas, for example, liquid nitrogen as a carrier fluid.

  The second aerosol supply device 8 includes a second aerosol generation container 8 a, an upstream pipe 8 b for supplying a carrier fluid to the second aerosol generation container 8 a, an aerosol, and a downstream pipe of the first aerosol supply apparatus 7. And a downstream pipe 8c for joining with 7c.

Since the upstream pipe 8b of the second aerosol supply device 8 also serves as the gas cylinder 7d, one end portion is provided between the pressure reducing valve 7e of the upstream pipe 7b of the first aerosol supply device 7 and the first mass flow controller 7f. The other end is connected and inserted into the second aerosol generating container 8a. One end of the downstream pipe 8 c of the second aerosol supply device 8 is inserted into the second aerosol generation container 8 a and the other end is connected to the downstream pipe 7 c of the first aerosol supply device 7.
The upstream side pipe 8b of the second aerosol supply device 8 is provided with a second mass flow controller 8d and a third on-off valve 8e from the upstream side to the downstream side, and the downstream pipe 8c of the second aerosol supply device 8 is connected to the downstream side pipe 8c. A fourth on-off valve 8f is provided.
And the metal material, for example, the powder of copper or its alloy, is charged in the 2nd aerosol production container 8a, ie, the 2nd aerosolization chamber 8g.

Next, with reference to FIG. 1 thru | or FIG. 3, the manufacturing method of the carbon coating material which concerns on this Embodiment is demonstrated.
FIG. 2 is a cross-sectional view of the carbon coating material according to the embodiment of the present invention.
In the present embodiment, first, an aerosol coating that sprays carbon coating layer forming aerosol, which is made of carbon material powder, which is a carbon coating layer forming material, and N ₂ gas, as a transport fluid, onto the adherend surface of the metal sheet 5. The carbon coating layer 5a is formed on the deposition surface of the metal sheet 5 by colliding with the deposition surface of the metal sheet 5 by the position method.

When the carbon coating layer 5a is formed, first, the inside of the chamber 2 is under atmospheric pressure with the first on-off valve 7h, the second on-off valve 7i, the third on-off valve 8e, and the fourth on-off valve 8f being closed, preferably Depressurize to vacuum. Next, the third on-off valve 8e, the fourth on-off valve 8f, and the second on-off valve 7i are closed, and only the first on-off valve 7h is opened. Thereby, the N ₂ gas that is the carrier fluid is introduced only into the first aerosolization chamber 7j. The introduction of N ₂ gas stirs the first aerosolization chamber 7j and stirs the powder of the carbon coating layer forming material in the first aerosolization chamber 7j so that the aerosol for forming the carbon coating layer is generated. The

Next, the third on-off valve 8e and the fourth on-off valve 8f are closed, the first on-off valve 7h and the second on-off valve 7i are opened, and at the same time, the metal sheet is scanned by scanning the XY stage 3 in the X-axis direction and the Y-axis direction. 5 is scanned in the X-axis and Y-axis directions, and the carbon coating layer forming aerosol ejected from the nozzle 6 is caused to collide uniformly with the adherend surface of the metal sheet 5.

At this time, the speed of the carbon material powder is adjusted by the first mass flow controller 7f so that a new surface activated by crushing appears. For this reason, the powder of the carbon material in the aerosol for forming the carbon coating layer is crushed by the collision with the adherend surface of the metal sheet 5, and the new surface is exposed. With this new surface, the crushed powders are joined together on the adherend surface of the metal sheet 5, the carbon coating layer 5a is formed on the adherend surface of the metal sheet 5, and the carbon coating material covering the carbon coating layer 5a 12 is obtained.
That is, the carbon coating layer 5a is directly and integrally joined to the adherend surface of the metal sheet 5 without using a resin binder.
Since the metal sheet 5 has a good thermal conductivity and the carbon coating layer 5a made of a carbon material has good radiation, the thermal resistance value from the metal sheet 5 to the carbon coating layer 5a is bonded through a resin binder having a high thermal resistance. Compared with, it is greatly reduced.
Therefore, the radiation amount of the carbon coating material 12 is significantly increased as compared with the conventional case, and the heat radiation amount of the carbon coating material 12 is significantly increased as compared with the conventional technology. For this reason, heat-generating components that require stabilization of operating characteristics, especially electronic components of electronic devices that are pursued to be thinner and lighter (such as notebook computers and mobile phones) can be cooled well. Can be stabilized.

Next, a method for producing a carbon coating material for forming the carbon coating layer 5b in which the carbon material and the metal material are mixed on the metal sheet 5 as the metal substrate by the aerosol deposition apparatus 1 will be described.
First, as a preparatory step, the first aerosolization chamber 7b is charged with a carbon material, for example, a general-purpose carrier powder, and the second aerosolization chamber 8g is charged with a metal material, for example, copper powder. The pressure in the chamber 2 is the same as that in the case of the carbon coating layer 5a. However, since the metal powder tends to agglomerate when it is not electrically neutral, and it is difficult to return it to the powder even by agitation of the carrier fluid, the surface of the metal powder is previously oxidized by natural oxidation. An oxide film is formed on the surface to enable the behavior as a powder.

When the preparation process is completed, the first on-off valve 7h and the third on-off valve 8e are opened, and the other on-off valves (second on-off valve 7i and fourth on-off valve 8f) are closed. As a result, N ₂ gas is introduced into the first aerosolization chamber 7j and the second aerosolization chamber 8g. In the first aerosolization chamber 7j, a carbon covering layer forming aerosol in which copper powder and N ₂ gas are mixed is generated, and in the second aerosolization chamber 8g, a metal in which copper powder and N ₂ gas are mixed. A mixing aerosol is produced.

Next, the first on-off valve 7h, the second on-off valve 7i, the third on-off valve 8e, and the fourth on-off valve 8f are opened, and at the same time, the XY stage 3 is scanned in the X-axis direction and the Y-axis direction. Scanning in the X-axis direction and the Y-axis direction of the XY stage causes the aerosol, in which the carbon coating layer forming aerosol and the mixing aerosol are merged, to collide with the adherend surface of the metal sheet 5. Thereby, since the powder of the carbon material is crushed and the active surface is exposed, the carbon coating layer (hereinafter, mixed layer) in which the carbon material and copper as the metal powder are mixed on the carbon coating layer 5 b of the metal sheet 5. 5b is formed. The mixed layer 5b is directly and integrally joined to the adherend surface of the metal sheet 5 without a resin binder, and the metal, that is, copper has good heat conduction, and the carbon material has good radiation. The thermal resistance from 5 to the metal material and the carbon material is reduced.
For this reason, the amount of heat released due to the radiation of the carbon coating material 12 is significantly increased as compared with the case where the carbon coating material 12 is bonded via a resin binder having a high thermal resistance.
Further, in the carbon coating layer, the metal material also functions as a physical buffer material, and therefore, impact cracking and chipping of the carbon coating layer 5b can be prevented as much as possible.

FIG. 3 shows another embodiment of the aerosol deposition apparatus in which the carbon coating layer forming aerosol and the mixing aerosol are ejected from separate nozzles.
In the aerosol deposition apparatus 15, a second nozzle 14 is provided in the chamber 2 adjacent to the nozzle 6, and the downstream pipe 8 c of the second aerosol supply apparatus 8 is downstream of the first aerosol supply apparatus 7. It is cut off from the pipe 7 c and connected to the second nozzle 14.
Other configurations are the same as those of the aerosol deposition apparatus 1 described with reference to FIG. 1, and therefore, the same reference numerals are given here and the description thereof is omitted.
By this aerosol deposition device 15, the aerosol for mixing the metal material ejected from the second nozzle 14 is joined to the aerosol of the carbon coating layer forming material ejected from the nozzle 6, and the joined aerosol is the carbon coating layer 5 a of the metal sheet 5. Can collide with the surface. Therefore, also in this embodiment, as described above, the switching between the first on-off valve 7h, the second on-off valve 7i, the third on-off valve 8e and the fourth on-off valve 8f, and the XY stage 3 in the X-axis direction, Y Only by scanning in the axial direction, the carbon coating layer 5a or the mixed layer 5b can be formed on the metal sheet 5 as shown in FIG.

An embodiment according to the present invention will be described below with reference to FIGS.
In this example, the carbon coating material 12 was formed by forming the carbon coating layer 5a made of a carbon material on the metal sheet 5 which is a metal substrate, using the aerosol deposition apparatus 1 described in FIG.
A copper sheet was used as the metal sheet 5, and a carbon black powder having an average particle size (average particle size) of 10 to 50 nm was used as the carbon material. Carbon black powder can be obtained from Degussa, Germany under the trade name of PRINTEX XE and from Mitsubishi Chemical Corporation under the trade name of Ketchen Black.
The carbon black powder was charged into the first aerosolization chamber 7j, and a nitrogen cylinder was used as the gas cylinder 7d. An interval of about 10 mm was provided between the nozzle opening (spout port) 6a and the adherend surface of the metal sheet 5.
The flow rate value of the first mass flow controller 7f was adjusted so that the carbon black powder was ejected from the nozzle 6 toward the adherend surface of the metal sheet 5 at a high speed of 10 m / min to 1000 m / min.

When the carbon coating layer 5a was formed, the pressure in the chamber was set to about 1 Pa to 1000 Pa by exhausting the vacuum pump 11. Next, the third on-off valve 8e and the fourth on-off valve 8f are closed, the first on-off valve 7h and the second on-off valve 7i are opened, and at the same time, the metal sheet is scanned by scanning the XY stage 3 in the X-axis and Y-axis directions. The aerosol for forming the carbon coating layer was sprayed onto the 5 adherend surface. At this time, the powder flew in the first aerosolization chamber, and a carbon coating layer 5 a made of a carbon material was formed on the deposition surface of the metal sheet 5. In this case, the rate of film formation varies greatly depending on the shape and state of the nozzle 6, but in this embodiment, spraying of the aerosol for forming the carbon coating layer is performed 50 times depending on the size of the carbon black powder and the film forming conditions. The thickness of the carbon coating layer was set to about 100 nm by reciprocating. However, if the contact between the Ketchen Black and the base material is good, heat transfer by phonons and free electrons occurs efficiently, so any thickness may be used. As the carbon material, Ketchen Black, which has excellent electrical conductivity in terms of characteristics, may be used.
When the surface of the carbon coating layer 5a is observed with an electron microscope after the carbon coating layer 5a is formed, the carbon material is cracked by collision and has a small particle size. This is presumed that a new surface was generated by cracking or the like due to the collision of the carbon black powder, and a strong adhesive force was generated. Moreover, since the carbon material on the surface of the carbon coating layer 5a is cracked by collision and has a small particle size, it can be seen that even in this state, the carbon material functions sufficiently as the surface of the heat dissipation material.
In addition, it is confirmed that when the mixed layer 5b in which the carbon material and copper are mixed is formed on the adhesion surface of the metal sheet 5, not only the surface design but also physical durability such as cracking is further improved. is doing.

In the embodiment according to the present invention, a carbon material such as a general-purpose carbon material, graphite, or Ketchen black is used as the carbon material of the carbon coating material. Fullerene or a derivative thereof may be used.
Furthermore, in this Embodiment, although the metal sheet 5 was illustrated as a metal base material, this invention is not limited to this. For example, the metal substrate may be a metal radiator such as a heat sink. In addition, the carbon coating layer 5a or the mixed layer 5b is formed on the metal sheet 5 to form the carbon coating material for cooling the heat-generating component. However, if the material has good radiation characteristics, Alternative materials may be used. In this case, material selection is made according to required heat dissipation characteristics and cost.
Thus, the present invention can be modified in various ways, and the present invention naturally extends to such modified invention.

It is explanatory drawing which shows the structure of the aerosol deposition apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the carbon coating material which concerns on this invention. It is sectional drawing which shows the other structure of the carbon coating material which concerns on this invention. It is explanatory drawing which shows other embodiment of the aerosol deposition apparatus which concerns on embodiment of this invention. It is a figure which shows the spectral emissivity according to material.

Explanation of symbols

5 Metal sheet (metal substrate)
5a Carbon coating layer 5b Carbon coating layer (mixed layer)
12 Carbon coating material

Claims (4)

  A method for producing a carbon coating material, comprising forming a carbon coating layer by spraying a carbon material on a metal substrate by an aerosol deposition method.   A method for producing a carbon coating material, wherein a carbon coating layer in which a carbon material and a metal material are mixed is formed on a metal substrate by spraying the carbon material and the metal material by an aerosol deposition method.   A carbon coating material in which a carbon material is directly coated on a metal substrate without using a resin.   A carbon coating material in which a carbon material and a metal material are directly coated in a mixed state on a metal substrate without using a resin.

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