KR102474898B1 - Microwave heating apparatus and manufacturing method of aluminum nitride using the same - Google Patents

Abstract

A microwave heating device according to the present invention includes a housing, a drum unit rotatably disposed in the housing, into which an object to be heated and gas are introduced, and at least one magnetron for heating the drum unit by applying microwaves to the drum unit. should include Using the microwave heating device and the aluminum nitride manufacturing method using the same of the present invention, aluminum nitride can be manufactured even at a lower temperature than the existing method, so the manufacturing time is short. In addition, the microwave heating device of the present invention has the advantage of significantly reducing the amount of power compared to the electric heating device.

Description

Microwave heating apparatus and manufacturing method of aluminum nitride using the same {Microwave heating apparatus and manufacturing method of aluminum nitride using the same}

The present invention relates to a microwave heating device and a method for producing aluminum nitride using the same, and more particularly, to aluminum nitride powder having excellent properties such as thermal conductivity, insulation, and dielectric constant, using a microwave heating device instead of a conventional heating furnace. It relates to a microwave heating device for producing aluminum nitride with excellent physical properties in a short time and a method for producing aluminum nitride using the same.

Aluminum nitride (AIN) has better thermal conductivity and electrical insulation than alumina.

In addition, the aluminum nitride has a coefficient of thermal expansion similar to that of a Si wafer and excellent mechanical strength, and thus is applied to heat dissipation substrates or components.

Specifically, the aluminum nitride is used for aluminum nitride parts for semiconductor devices, aluminum nitride substrates bonded to metal thin films, heat sinks for LEDs, heat sinks for high-power Si devices, substrates for compound semiconductors, substrates for laser devices, substrates for power control of hybrid vehicles, etc. .

In particular, when the aluminum nitride is used for components for semiconductor manufacturing equipment, it is used for heaters, electrostatic chucks, ceramic chamber components, etc. because of its excellent thermal conductivity, thermal expansion, and plasma resistance.

In addition, aluminum nitride having a thermal conductivity of 200 W/m·K or more is actively used as a heat sink for laser diodes or white LEDs.

On the other hand, the aluminum nitride can be produced by a reduction nitriding method among various manufacturing methods. The reduction nitriding method (Carbothermal Reduction-Nitridation) has a reaction formula of Al ₂ O ₃ + 3C + N ₂ = 2AIN + 3CO and has a reaction formula of 1,600 It reacts at a temperature of ~1,800 °C. In general, when aluminum nitride is produced by the reduction nitriding method, a general furnace is used. In addition, the general furnace takes a long time to raise the temperature to the reaction temperature of 1,600 to 1,800 ° C. There were disadvantages such as long time required, low productivity, and high manufacturing cost.

Korean Patent Publication No. 10-2015-0114468 A1 (2015.10.12.)

The purpose of the present invention is to provide a microwave heating device capable of producing aluminum nitride having excellent physical properties as well as excellent productivity due to rapid temperature rise and shortened reaction time, and a method for producing aluminum nitride using the same. there is

In order to solve the above problems, the microwave heating device according to a preferred embodiment of the present invention is rotatably disposed in the housing, the housing, and the microwave is applied to the drum unit and the drum unit into which the heating object and the gas are introduced. and at least one heating unit for heating the drum unit by applying

The heating unit includes a magnetron that generates microwaves, and a waveguide that is connected to the drum unit and applies microwaves generated by the magnetron to the drum unit.

The drum unit has a reaction space into which the object to be heated and the gas are introduced, and is disposed on both sides of a tube heated by the microwave, an insulating material surrounding an outer surface of the tube, and the tube in a longitudinal direction, respectively. It includes a shaft rotatably supported by the housing.

The shaft is connected to one side of the tube in the longitudinal direction, has an input passage formed therein to input the gas and the object to be heated into the reaction space, and an input shaft having a temperature sensor disposed therein, and the other side of the tube. It is connected to and includes an exhaust shaft formed with an exhaust flow path for discharging the gas and the object to be heated inside the reaction space to the outside.

The drum unit may further include an exhaust pipe connected to the exhaust shaft and having an inside connected to the exhaust passage.

It may further include a rotation driving unit that is power-connected to the shaft and rotates the drum unit.

A body portion supporting the housing may be further included.

Method for producing aluminum nitride (AIN) using a microwave device according to a preferred embodiment of the present invention, preparing a mixture by mixing alumina granules and carbon powder, injecting the mixture into the microwave heating device and nitrogen ( A pretreatment step of supplying a gas containing N ₂ ), and a step of producing aluminum nitride.

In preparing the mixture, the alumina granules and the carbon powder may be mixed in a weight ratio of 1:0.5 to 5.

The alumina granules may be made of alumina.

In the pretreatment step, a nitrogen atmosphere is formed by supplying a gas containing nitrogen (N ₂ ) at a flow rate of 5 to 20 LMP (Liter/Min) for 10 to 60 minutes.

The step of producing the aluminum nitride is a process of raising the temperature at a rate of 3 to 6 °C/min so that the internal temperature of the microwave heating device drum unit is 1,400 to 1,600 °C, and the internal temperature of the microwave heating device drum unit is 1,400 °C. The process of manufacturing aluminum nitride by maintaining at ~1,600 ° C for 2 to 24 hours, the process of cooling so that the internal temperature of the microwave heating device drum unit is 700 ~ 750 ° C, and the internal temperature of the microwave heating device drum unit It includes a process of removing carbon from the aluminum nitride by maintaining at 700 to 750 ° C. for 1 to 6 hours, and a process of recovering the aluminum nitride from which the carbon has been removed.

In the process of producing the aluminum nitride, the drum of the heated microwave heating device may continuously rotate at a speed of 0.1 to 2 rpm per minute, or may repeat rotation and stop in units of 1 to 120 seconds (sec).

Using the microwave heating device and the aluminum nitride manufacturing method using the same of the present invention, aluminum nitride can be manufactured even at a low temperature, so there is an effect that the manufacturing time is short. In addition, the microwave heating device of the present invention has the advantage of significantly reducing the amount of power compared to the electric heating device.

1 and 2 are perspective views showing a microwave heating device according to an embodiment of the present invention.
Figure 3 is a flow chart showing a method for producing aluminum nitride using a microwave heating device according to another embodiment of the present invention.
4 shows the results of XRD analysis of aluminum nitride according to an embodiment of the present invention.
5A to 5F show SEM images of aluminum granules before and after reaction in one embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

The advantages and features of the present invention, and how to achieve them, will become clear with reference to the detailed description of the following embodiments in conjunction with the accompanying drawings.

However, the present invention is not limited by the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

In addition, in the description of the present invention, if it is determined that related known technologies may obscure the gist of the present invention, a detailed description thereof will be omitted.

Figures 1a and 1b is a perspective view showing a microwave heating device according to an embodiment of the present invention.

A microwave heating apparatus according to an embodiment of the present invention includes a housing 100, a drum unit 200 rotatably disposed in the housing 100, and into which an object to be heated and gas are introduced, and the drum unit 200 At least one heating unit 400 for heating the drum unit 200 by applying microwaves to the above is provided.

The material of the housing 100 may be at least one selected from the group consisting of iron, stainless and aluminum, and the shape of the housing 100 is not limited.

In addition, the housing 100 may serve as a support means or a protection means for the drum unit 200 provided therein.

The housing 100 further includes a waveguide 310 connected to the drum unit 200 and applying microwaves generated by the magnetron 300 to the drum unit 200 .

The heating part 400 is connected to the magnetron 300 generating microwaves and the drum part 200, and the waveguide 310 applies the microwaves generated by the magnetron 300 to the drum part 200. ).

That is, the waveguide 310 serves to apply microwaves generated by the magnetron 300 to the drum unit 200 .

The magnetron 300 is not limited as long as it can generate and transmit microwaves to the drum unit 200 when a predetermined voltage is applied.

The drum unit 200 has a reaction space into which the object to be heated and the gas are introduced, a tube 210 heated by the microwave, an insulator 220 surrounding the outer surface of the tube 210, and Shafts 230 are disposed on both sides of the tube 210 in the longitudinal direction and are rotatably supported by the housing 100 .

The tube 210 is made of a ceramic material, has a hollow center, and the shape is not limited.

In addition, a coating layer may be formed on the inner and outer surfaces of the tube 210, but this is not limited thereto.

The coating layer (not shown) may be formed to prevent disassembly of the tube 210, but is not limited thereto.

The tube 210 is heated by the microwave introduced into the housing 100, and an object to be heated in the reaction space can be heated by the heated tube 210.

The tube 210 is provided with a heat insulating material 220 in a form surrounding an outer surface of the tube 210 to prevent heat from being discharged to the outside.

The heat insulator 220 is made of a material that transmits microwaves and prevents heat from leaking to the outside. Accordingly, the microwave generated from the magnetron 300 passes through the insulator 220 to generate heat in the tube 210, and the heated tube 210 can heat the object to be heated in the reaction space.

The shaft 230 is disposed on both sides of the tube 210 in the longitudinal direction, and is supported by the housing 100 so that the drum unit 200 inside the housing 100 can rotate.

In addition, the shaft 230 is connected to one side of the tube 210 in the longitudinal direction, and an input passage for introducing the gas and the object to be heated into the reaction space is formed therein, and the temperature sensor 234 It consists of an input shaft 231 and an exhaust shaft 232 connected to the other side of the tube 210 and formed with an exhaust flow path for discharging the gas and the object to be heated in the reaction space to the outside.

The temperature sensor 234 can detect the temperature of the object to be heated, is attached to the input shaft 231 and can sense the temperature of the object to be heated, and the heating temperature and heating by an additionally installed control device (not shown). Time etc. can be adjusted.

The temperature sensor 234 is capable of measuring the internal temperature of the drum unit 200, and is not limited thereto as long as it can measure a temperature in the range of 200 to 2,500 °C.

The shape of the input passage and the exhaust passage is not limited.

The input passage is a passage through which the object to be heated is introduced into the drum unit 200, that is, the tube 210, and may further include a roller or the like that automatically drives and transfers the object to be heated.

The drum unit 200 further includes an exhaust pipe 233 connected to the exhaust shaft 232 and having an inside connected to the exhaust passage.

The drum unit 200 includes a rotation driving unit 250 connected to the shaft 230 by power.

The drum unit 200 may be made of a metal material such as iron, stainless steel, or aluminum, and the shape may be manufactured as desired, such as a square, hexagonal, or circular shape, and the size or model of any shape is not limited.

The microwave heating device further includes a body part 1 supporting the housing 100.

A blower 320 connected to the magnetron 300 is further included.

In the present invention, when the object to be heated is operated at the same time as input and the microwave generated in the magnetron 300 is applied to the drum unit 200 through the waveguide 310, the tube 210 absorbs the microwave and generates heat, The generated heat is transferred to the inside of the tube 210, and the object to be heated can be heated through the transferred heat.

In addition, when the temperature of the object to be heated reaches a certain temperature, the output of the microwave may be reduced to maintain a certain temperature by a control device (not shown).

Hereinafter, a method for manufacturing aluminum nitride using a microwave heating apparatus according to an embodiment of the present invention will be described in detail with reference to FIG. 2 .

A method for producing aluminum nitride using a microwave device according to another embodiment of the present invention includes preparing a mixture by mixing alumina granules and carbon powder (S100), and microwave heating according to any one of claims 1 to 8 A pretreatment step (S200) of introducing the mixture into the apparatus and supplying a gas containing nitrogen (N ₂ ), and a step (S300) of producing aluminum nitride.

In the step of preparing the mixture (S100), the alumina granules and the carbon powder may be mixed in a weight ratio of 1:0.5 to 5, preferably in a weight ratio of 1:1.

In addition, the alumina granules may be made of alumina.

In the pretreatment step (S200), a nitrogen atmosphere may be formed by supplying a gas containing nitrogen (N ₂ ) at a flow of 5 to 20 LMP (Liter/Min) for 10 to 60 minutes.

The pretreatment step (S200) is a step of preparing before manufacturing aluminum nitride, and is a step for discharging air occupying the reaction space and forming a nitrogen atmosphere.

In addition, nitrogen gas may be continuously supplied with a flow of 5 to 20 LMP (Liter/Min) to maintain the reaction space in a nitrogen atmosphere.

The nitrogen gas may have a purity of 95% or more.

The step of producing the aluminum nitride using the microwave heating device (S300) is performed at a rate of 3 to 6 °C/min so that the internal temperature of the microwave heating drum unit 200 becomes 1,400 to 1,600 °C after the pretreatment step. The process of raising the temperature and maintaining the internal temperature of the microwave heating device drum unit 200 at 1,400 to 1,600 ° C for 2 to 24 hours to produce aluminum nitride and the internal temperature of the microwave heating device drum unit 200 The process of cooling to 700 ~ 750 ℃ and the process of removing the carbon of the aluminum nitride by maintaining the internal temperature of the microwave heating device drum unit 200 at 700 ~ 750 ℃ for 1 to 6 hours, and the carbon A process of recovering the removed aluminum nitride is further included.

In addition, the supply of gas containing nitrogen may be cut off in the process of detaching at an internal temperature of the microwave heating device drum unit at 700 to 750 ° C.

In the process of producing the aluminum nitride, the heated drum unit 200 of the microwave heating device may continuously rotate at a speed of 0.1 to 2 rpm per minute, or may repeat rotation and stop in units of 1 to 120 sec. At this time, it is natural that the rotation per minute is also a speed of 0.1 to 2 rpm/min.

This is because the rotation of the microwave heating device increases the time for the mixture to react with nitrogen, thereby reducing the reaction time.

Hereinafter, the present invention will be described in more detail by examples and experimental examples. However, the following examples and experimental examples are only for exemplifying the present invention, and the scope of the present invention is not limited only to these.

Example

After mixing alumina granules and carbon (C) powder at a weight ratio of 1:1, aluminum nitride was prepared according to Table 1 below using the microwave heating device described above. At this time, the microwave power of the microwave heating device was carried out at 10 ~ 30 KW / m.

STEP hold time temperature note One 0.5 hours 25 ℃ N2 gas input 15LPM (Liter/Min) 2 5 hours 1,350 ℃ Heating rate 4.5 ℃/minN ₂ gas maintenance 3 12 hours 1,350 ℃ Rotate heating device 1 rpm/min N ₂ gas maintenance 4 - about 720 ℃ Maintain natural cooling N ₂ gas 5 2 hours about 720 ℃ Carbon removal N ₂ gas cut off, air input 6 - 25 ℃ natural cooling

Experimental Examples The aluminum nitride prepared according to Example 1 was analyzed by XRD. And the results are shown in Figure 3 and Table 2.

Quantitative analysis results (WPPF) Phae's name Content (%) Aluminum Nitride 93.3(4) Triyttrium pentaaluminium 4.65(9) Yttrium aluminum oxide 1.93(6)

As can be seen in FIG. 4, it can be confirmed that aluminum nitride is manufactured in (110) and (201). In addition, it can be confirmed that it contains 6 to 10% of yttria or calcium oxide used as a catalyst.

In the above, the present invention has been described in detail using preferred embodiments, but the scope of the present invention is not limited to specific embodiments, and should be interpreted by the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

1: body part 100: housing
200: drum unit 210: tube
220: insulation 230: shaft
231: input shaft 232: exhaust shaft
233: exhaust pipe 234: temperature sensor
250: rotation drive unit 300: magnetron
310: waveguide 320: blower
400: heating unit
S100: mixture preparation step
S200: pre-processing step
S200: aluminum nitride manufacturing step

Claims (13)

delete delete delete delete delete delete delete Preparing a mixture by mixing alumina granules and carbon powder;
A pretreatment step of injecting the mixture into a microwave heating device and supplying a gas containing nitrogen (N2), and
A method for producing aluminum nitride using a microwave device comprising the step of producing aluminum nitride,
To prepare the mixture,
Mixing the alumina granules and carbon powder at a weight ratio of 1:1,
The step of producing the aluminum nitride,
A process of raising the temperature at a rate of 3 to 6 ° C / min so that the internal temperature of the microwave heating device drum unit is 1,400 to 1,600 ° C;
A process of manufacturing aluminum nitride by maintaining the internal temperature of the microwave heating device drum unit at 1,400 to 1,600 ° C. for 2 to 24 hours;
A process of cooling the inside temperature of the microwave heating device drum unit to 700 to 750 ° C;
The step of removing carbon from the aluminum nitride by maintaining the internal temperature of the drum part of the microwave heating device at 700 to 750 ° C. for 1 to 6 hours;
Recovering the aluminum nitride from which the carbon has been removed,
The microwave heating device,
housing,
A drum unit rotatably disposed in the housing and into which an object to be heated and a gas are introduced; and
At least one heating unit for heating the drum unit by applying microwaves to the drum unit;
The drum part,
A tube having a reaction space into which the object to be heated and the gas flows, and which is heated by the microwave;
An insulating material surrounding the outer surface of the tube, and
And a shaft disposed on both sides of the tube in the longitudinal direction and rotatably supported by the housing,
The drum unit continuously rotates at a speed of 0.1 to 2 rpm per minute and repeats rotation and stop in units of 1 to 120 seconds (sec),
A method for producing aluminum nitride using a microwave device. delete delete In paragraph 8,
In the preprocessing step,
A method for producing aluminum nitride using a microwave device to form a nitrogen atmosphere by supplying a gas containing nitrogen (N ₂ ) at a flow of 5 to 20 LMP (Liter / Min) for 10 to 60 minutes. delete delete

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