KR20230014469A - Method of Coating for powder, and Apparatus adopting the method - Google Patents

Abstract

An apparatus for coating fine powder is described. A coating method includes the steps of: positioning a reaction vessel containing powder to be coated inside a process chamber in which powder coating is performed; oscillating the reaction vessel up and down at a predetermined stroke distance with a separately provided striking device to lift the powder in the reaction vessel upward of the reaction vessel; and supplying a coating material into the process chamber and allowing floating powder to come in contact with the coating material to perform coating on the powder. The present disclosure proposes the coating method and apparatus capable of improving coating quality for fine particles.

Description

Powder coating method and apparatus {Method of Coating for powder, and Apparatus adopting the method}

The present invention relates to a powder coating method and apparatus, and more particularly, to a method of coating a target material or a reactant on the surface of fine particles and a coating apparatus applying the same.

A coating device for fine particles performs coating such as chemical vapor deposition (CVD), atomic layer deposition (ALD), and physical vapor deposition (PVD) on fine particles in a process chamber or reaction vessel. In this coating device, in order to coat the surface of each fine particle in a powder state, the powder is scattered in the space inside the reaction vessel in a drum-type rotating reaction vessel or the powder is stirred in a vibrating reaction vessel to perform coating.

1 shows an example of a conventional coating device (Patent Publication No. 10-2019-0122068, Patent Document 2) using a rotary drum.

As shown in FIG. 1, a drum-type reaction vessel 11 in which the powder to be coated 20 is accommodated is provided in the chamber 10. The reaction vessel 11 is connected to a rotating device 12 provided outside the chamber 10 and rotates at a predetermined speed. Meanwhile, a sputtering target 16 is provided in the reaction container 11 and is connected to an RF power source 15 provided outside the chamber 10 . The chamber 10 is connected to an external vacuum exhaust device 13 and is also connected to a reaction gas supply unit 14 into which reaction gas from the outside is injected.

As shown in FIG. 2, the drum-shaped reaction vessel 11 is rotated around a horizontal axis of rotation, and the powder 20, which is a deposition target, is accommodated therein.

The powder 20 repeatedly rises and falls along the inner surface of the rotating reaction container 11 . The powder 20 is located below the reaction vessel 11 by gravity, and is transported upward along the inner surface of the rotating reaction vessel 11 (A), and then falls downward by gravity when it goes up to a certain height. . However, the limitation of this conventional method is that there is a limit to the height of lifting the powder to a high place inside the reaction vessel, and therefore it is difficult to sufficiently secure a residence time in the air.

On the other hand, Japanese Patent No. 6199145 (Patent Document 6) proposes a method of stirring the powder to be coated with an auxiliary vibrating material in the reaction vessel while causing vibration in the reaction vessel itself, and proceeding with coating of the powder particles in this state. do. The figure of FIG. 2 is a partial excerpt from a drawing published in the patent publication of Japanese Patent No. 6199145.

As shown in FIG. 2, the reaction vessel 14 in which the powder to be coated is accommodated is vibrated by the vibration device 15 installed at the bottom thereof, so that the powder to be coated therein is stirred by the vibration of the reaction vessel. it is meant to be When the reaction vessel is vibrated in a vertical or horizontal direction, the powder to be coated is vibrated in a vertical or horizontal direction, and at this time, the stirring sphere 22 accommodated in the reaction vessel 14 also vibrates. Vibration of the stirring sphere 22 causes a collision with the powder agitated by the reaction vessel 14. Therefore, as the powder particles collide with the stirring sphere with the vibration of the reaction vessel, the surface of the powder particles toward the sputtering target is smoothly changed, enabling even coating on the entire surface.

The powder coating device using such a vibrating reaction vessel has a structure in which the coating proceeds at the bottom of the reaction vessel without suspending the powder in the air, and while stirring the powder accumulated on the bottom of the reaction vessel by the vibration and stirring sphere of the reaction vessel, the top The sputtering particles 28 supplied from are brought into contact with the surface of the powder particles.

According to this method, since the coating is performed while stirring the powder at the bottom of the vibrating reaction vessel, the sputtering particles are not sufficiently supplied to the bottom of the reaction vessel, so that the coating for the powder entry proceeds very slowly, and a large amount of powder coating is virtually impossible .

In the coating of the fine powder particles, it is required to conduct research on a method that can not only uniformly coat the entire coated surface of the particles but also process them in large quantities.

KR 10-2014-0006420 A KR 10-2019-0122068 A KR 10-2008-0084140 A JP 03-153864 A JP 2015-067890 A JP 6199145 B

The present disclosure proposes a coating method and apparatus capable of improving coating quality for fine particles.

The present disclosure proposes a coating method and apparatus capable of greatly improving the coating speed for fine particles.

The present disclosure proposes a powder coating method and apparatus suitable for mass production.

Powder coating method according to an embodiment of the present disclosure: silver

A powder supply step of supplying a powder to be coated to a reaction container inside a process chamber in which powder coating is performed;

A powder lifting step of reciprocating the reaction container up and down at a predetermined stroke distance at an arbitrary speed so that the powder stored in the reaction container is lifted upward of the reaction container and then falls to the bottom of the container by its own weight; And

and a powder coating step of supplying the coating material into the process chamber and bringing the coating material into contact with the floating powder to perform coating on the powder.

According to another embodiment of the present disclosure, the reaction vessel in which the powder in the reaction vessel is primarily hit by the impact of the reaction vessel, further comprising a hitting step of hitting the reaction vessel in the process of raising and lowering the reaction vessel Secondary hit by the hitting part of the can be so that it is lifted upwards of the reaction vessel.

According to another embodiment of the present disclosure, the supply of the coating material may be performed by a sputtering device or an ALD device, and the coating material may be supplied into the process chamber by the device.

According to another embodiment of the present disclosure, the striking device may continuously lift the powder upward of the reaction vessel by applying an intermittent shock wave to the bottom of the reaction vessel.

Powder coating apparatus according to an embodiment of the present disclosure:

A housing forming a process chamber isolated from the outside;

a powder reaction container located on the lower side of the process chamber, in which the powder to be coated is accommodated, and in which the powder is lifted;

a reaction vessel oscillator for reciprocating the powder reaction vessel in an up-and-down direction at an arbitrary amplitude to lift the powder accommodated in the reaction vessel upward of the reaction vessel; And

and a coating material supply device positioned above the process chamber to perform coating on the powder floated upward of the reaction container.

According to another embodiment of the present disclosure, a reaction vessel striking device for impacting the powder reaction vessel to weight the powder accommodated in the reaction vessel upwardly in the reaction vessel may be further provided.

According to another specific embodiment, the hitting device may include a rotary hammer that directly hits the reaction container.

According to another specific embodiment, the process chamber by the housing is provided with a transfer path of the reaction vessel surrounding one central region,

On the transfer path, a plurality of unit process areas are arranged in which an arbitrary process for the powder in the reaction vessel is performed,

A vessel transfer device for transferring the reaction vessel along the rotational transfer path is provided at the lower portion of the chamber, and

Unit process modules corresponding to the process are respectively installed on the ceiling of the upper part of the chamber.

According to another specific embodiment, the transfer device includes a swing arm positioned below the chamber, and the reaction vessel and the reaction vessel oscillator may be installed in the swing arm to correspond to the unit process area.

According to another specific embodiment, a source shutter for selectively exposing the unit process module into the process chamber may be provided on the ceiling of the process chamber.

According to another specific embodiment, the unit process module may include a powder supply device and a powder recovery device.

According to another specific embodiment, the unit process module may include at least one of a PVD device and an ALD device for powder coating.

The unit process module may include a preheating device or a preheating module 402 for drying the powder.

The unit process module may include a monitoring device for inspecting the coating state of the powder.

1 schematically discloses a conventional powder coating apparatus.
Figure 2 shows another conventional coating apparatus using a vibrating reaction vessel and a vibrating aid.
3 shows a schematic configuration of a coating apparatus for performing a coating method according to an embodiment of the present disclosure.
4 shows an arrangement structure of multiple unit process modules in a process chamber in a powder coating apparatus according to an embodiment of the present disclosure.
5 is a view illustrating the location and operation of a reaction container transfer device installed below a process chamber in a powder coating apparatus according to an embodiment of the present disclosure.
6 is a cross-sectional view schematically showing a vertical structure of a process chamber in a powder coating apparatus according to an embodiment of the present disclosure.
7 shows powder drying by a preheating module in a powder coating apparatus according to an embodiment of the present disclosure.
8 shows a PVD coating structure for powder in a powder coating apparatus according to an embodiment of the present disclosure.
9 shows an ALD coating structure for powder in a powder coating apparatus according to an embodiment of the present disclosure.
10 shows a structure for monitoring a thin film for coating analysis on coated powder particles in a powder coating apparatus according to an embodiment of the present disclosure.
11 illustrates an operation of a powder recovery module for recovering coated powder in a powder coating apparatus according to an embodiment of the present disclosure.
12 is a process flow diagram of a powder coating method according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments of the concept of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the inventive concept may be modified in many different forms, and the scope of the inventive concept should not be construed as being limited due to the embodiments described below. Embodiments of the inventive concept are preferably interpreted as being provided to more completely explain the inventive concept to those with average knowledge in the art. The same sign means the same element throughout. Further, various elements and areas in the drawings are schematically drawn. Accordingly, the inventive concept is not limited by the relative size or spacing drawn in the accompanying drawings.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the concept of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the expression “comprises” or “has” is intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features or It should be understood that the presence or addition of a number, operation, component, part, or combination thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical terms and scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the concept of the present invention belongs. In addition, commonly used terms as defined in the dictionary should be interpreted as having a meaning consistent with what they mean in the context of the technology to which they relate, and in an overly formal sense unless explicitly defined herein. It will be understood that it should not be interpreted.

When an embodiment is otherwise embodied, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially simultaneously, or may be performed in an order reverse to the order described.

In the accompanying drawings, variations of the shapes shown may be expected, eg depending on manufacturing techniques and/or tolerances. Therefore, the embodiments of the present invention should not be construed as being limited to the specific shape of the region shown in this specification, but should include, for example, a change in shape resulting from the manufacturing process. All terms “and/or” as used herein include each and all combinations of one or more of the recited elements. In addition, what is described as “upper” or “on” in this specification may include not only what is directly on top of contact but also what is on top of non-contact.

Hereinafter, various embodiments of a fine powder particle coating method applying a thin film coating deposition method and an apparatus applying the same will be described. Various types of thin film formation methods, such as sputtering deposition, which is a kind of physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD) coating, may be applied to the coating method and apparatus of the present invention.

The coating target is fine particles with a diameter of several tens of nanometers to several hundred micrometers, which can be used for the manufacture of cosmetic base materials and catalysts, and in particular, the coating can be applied to surface modification of fine particles for various purposes. As an example, powder material particles (powder particles) may be carbon or synthetic resin, and as a coating material, a single material such as Pt or Ru or a compound material by chemical bonding may be used.

Fig. 3 shows the basic configuration of coating fine particles of powder in a coating apparatus for carrying out the coating deposition method of the present invention.

Referring to FIG. 3 , the coating apparatus 1 according to the present embodiment supplies a coating material 403′ into a process chamber 101 in which powder particles are coated, and into the process chamber 101. The coating material supply device 403 and the lower portion of the process chamber 101 are provided with a reaction container 300 accommodating the powder 20 to be coated. And, by physically oscillating the reaction vessel 300 up and down, the reaction vessel 300 is physically oscillated so as to lift the powder 500 inside the reaction vessel 300 upward by oscillating a certain up and down stroke distance. A reaction vessel striking device 210 physically and strongly impacting the oscillator 200 and the bottom of the reaction vessel 300 is provided.

The reaction vessel 300 provides a coating space 301 in which the coating of the lifted powder 500 proceeds in a partially isolated form inside the process chamber 101 . The coating space 301 is a region to which a coating material 403 ′ such as a precursor of an ALD method or particles or particles of a PVD method is supplied by a coating material supply device 403, and also a reaction vessel oscillator 200 and It is also a floating space for the powder 500 to be coated physically contacting the coating material 403' in a state where the powder 500 is lifted by the impact device 210.

A skirt 300a inclined at a predetermined angle, for example, 45 degrees, is formed around the inner circumference of the upper opening of the reaction container 300 . This skirt (300a) has a function of a wall that prevents the powder (500) floating inside the reaction container (300) from escaping to the outside, and the lip (lip), which is the front end of the inner edge, is the lower end of the powder collector to be described later. It is a part that is in close contact.

The reaction vessel oscillator 200 includes an up and down reciprocating first actuator 201 and an operating rod 202 that moves up and down by the first actuator 201 . The upper end of the operating rod 202 is fixed to the lower portion of the reaction vessel 300, and thus the reaction vessel 300 storing the powder 500 is also moved by the up and down reciprocation (oscillating) of the operating rod 202. reciprocating up and down

Oscillating up and down of the reaction container 300 occurs to such an extent that the powder 500 can be highly lifted upwards of the reaction container 300 as if sieving. Due to the upward and downward oscillation of the reaction vessel 300, the powder 500 in the reaction vessel 300 is lifted upwards of the reaction vessel 300, and the powder 500 briefly stays in the upper part of the reaction vessel 300, and then immediately follows. It falls to the bottom of the reaction vessel 300 by gravity.

Coating of the powder 500 proceeds while the reaction vessel oscillator 200 operates. The coating is performed by contacting the coating material 403' supplied by the coating material supply device 403 with the powder floated above the reaction vessel 300, and the contact of the coating material 403' causes the powder to float and fall. persists in the process.

The stroke distance of the operating rod 202 may be adjusted in the range of 1 to 100 mm. Adjustment of the stroke is required according to the size or specific gravity of the particles of the powder 500, and this adjustment can be easily applied through an automated recipe.

According to the operation of the operating rod 202, all the particles accommodated in the reaction vessel 300 are suspended in the air above the reaction vessel 300, and the flight time of the suspended powder particles corresponds to the long and short stroke distance. it is changed After reaching the apex of the lifted powder particles, the particles fall freely due to gravity, and react with the operation rod 202 before completely falling and closing to the bottom of the reaction container 300 to increase the effect of even agitation and dispersion of the particles. By lifting the container 300 up, the falling particles can be effectively floated again.

In this series of processes, the coating effect during levitation can be greatly improved by adjusting the stroke distance and frequency of the operating rod 202. The operating frequency of the operating rod 202 can be set in the range of 1 to 60 Hz, but However, the stroke distance and frequency should be appropriately adjusted according to the scale of the entire system. The pattern and speed of oscillation of the reaction vessel by the oscillator 200 can be freely implemented according to the size and characteristics of the powder particles to be coated, thereby optimizing the lifting, stirring and scattering effects of the powder. can Meanwhile, the oscillator 200 may have a function as a simple lifting device of the reaction container 300 . This is to approach the powder gate through which powder is discharged from the powder supply module 401 to be described later when supplying the powder 500 to the reaction container 300, and after the supply of the powder 500 is completed, it can descend to its original state. .

The hitting device 210 includes a pivoting hammer 212 that strikes the bottom of the reaction container 300 and a second actuator 211 acting on it. When the impact hammer 212 first hits the bottom of the reaction vessel 300 with an appropriately adjusted force, the impacted bottom of the reaction vessel 300 strongly secondarily hits the powder 500 . Accordingly, the hit powder 500 particles float upward in the reaction vessel 300, and then fall by gravity.

The hitting of the bottom of the reaction container 300 by the hitting hammer 212 not only lifts the powder 500 high, but also breaks up the powder lumps that have been agglomerated during the coating process, thereby releasing the agglomeration between the particles. The striking force and the striking frequency of the striking device 210 may be appropriately adjusted by the second actuator 211 .

In this embodiment, the application of the reaction vessel oscillator 200, which lifts the powder high by moving the reaction vessel up and down, is basic, and the striking device 210 may be selectively applied.

On the other hand, the impact device 210 mentioned as an optional element can also be usefully used for the purpose of separating powder particles adhering to the reaction vessel in the process of recovering the coated powder. In addition, as the coating of the powder proceeds, the powder 500 may adhere to the entire inner wall including the bottom or side surface of the reaction container 300 . The coagulated powder 500 does not fall well even by the oscillation of the operating rod 202 by the oscillator 200. However, the impact force applied to the reaction vessel 300 by the impact hammer 212 easily separates the lump of powder 500 adhering to the inner wall of the reaction vessel, thereby forming a powder that is normally coated in the reaction vessel 300. can be included in flow 501.

The first actuator 201 of the oscillator 200 and the second actuator 211 of the impact device 210 may have a mechanical, electrical or electro-mechanical operation structure. For example, an electromagnet voice coil motor structure or a general mechanical rotation-linear motion conversion structure using an electric motor, a garden ruler, and a crank may be applied to the first and second actuators.

According to another embodiment, the oscillator 200 for lifting the powder 500 moves up and down while shaking the reaction vessel 300 from side to side as well as up and down, or moves up and down while rotating the reaction vessel 300. Various types of oscillation generation methods, such as moving, may be applied.

Figure 4 is a plan view schematically showing an embodiment of a powder coating apparatus according to the present disclosure, showing a structure in which several unit process modules for powder coating are disposed in one process chamber.

Inside the process chamber 101, components such as the reaction vessel 300 described in FIG. 3, the reaction vessel oscillator 200, and the impact device 210 are located, and near the bottom of the lowermost process chamber 101 A vessel transfer device 407 using the reaction vessel 300 is installed (see Fig. 6), which will be described in detail later.

A plurality of unit process modules 401, 402, 403, 404, and 405 are arranged at random angles around a shutter driver 405a, which is an element of a shutter device 406 to be described later, on the ceiling of the process chamber 101 as a center. is installed in one circular batch line. The arrangement of the unit process modules 401, 402, 403, 404, and 405 disposed on one circular arc corresponding to the transfer trajectory of the reaction container 300 is as follows. 4, the powder supply module 401 is disposed at the position of 9 o'clock, which is the starting position of the coating process, followed by the preheating module 402, the first PVD module 403a, the second PVD module 403b, The ALD module 403c, the inspection module 404, and the recovery module 405 are arranged in a circular shape.

The coating material supplying device 403 that supplies the coating material 403' includes the first source module 403a, the second source module 403b, the third source module 403c, and the like.

These unit process modules are disposed above the process chamber and are accessible to the inside of the process chamber 101 through a shutter device 406 provided on the ceiling of the process chamber 101 .

The shutter device 406 includes a shutter driver 405a positioned at the center of the ceiling of the process chamber 101 and a rotatable source shutter 406b positioned near the ceiling inside the process chamber 101 . The source shutter 406b includes an aperture 406c formed at a position corresponding to the unit process modules. The source shutter 406b is rotated at regular angular intervals by the shutter driver 406a, and the aperture 406c is arranged to correspond to one of the unit process modules. The source shutter 406b has one aperture 406c and is positioned to correspond to a specific unit process module in which a process is performed so that the process module can perform a given process inside the process chamber. The rest of the unit process modules that do not proceed are blocked from being exposed to the inside of the process chamber.

The rotatable source shutter 406c opens an internal process chamber for a process module progressed by rotation of the shutter driver 406a, and isolates all but the corresponding process module from the process chamber and source particles that may be introduced from the process chamber. , gas, etc. to protect other process modules. That is, the source shutter 406c selectively opens any one source module among a plurality of source modules so that the function of the corresponding source can be applied to the process. At the same time, unused source modules are shielded to prevent contamination of unused source modules during other source processes. In order to increase the anti-fouling effect, the shutter device 406 may include an up/down function of the source shutter 406c and may also include an additional sealing member.

As described above, the unit process module includes the powder supply module 401 for supplying powder to be coated to the reaction vessel 300 located in the process chamber 101, and drying the powder in the reaction vessel 300 to remove moisture. A preheating module 402, a plurality of coating material supply devices 403 such as PVD, CVD, and ALD that perform coating on powder, for example, a first source module 403a such as PVD, a first source module such as PVD or CVD A second source module 403b, a third source module 403c such as ALD, a coating state monitoring module 404 for powder particles, and a powder recovery module 405 equipped with a suction device may be included, and these units Some of the process modules may be excluded as optional elements or may further include other types of unit process modules.

Meanwhile, the reaction vessel 300 is moved to be positioned directly below the patented unit process module according to the process in each of the unit process modules whose position is fixed on the ceiling of the process chamber 101, which will be described later by rotation. This is done by the container transfer device 407 (FIG. 6) or the swing arm 407a (FIG. 6), which will be described in more detail in the description of FIG.

The rotating vessel transport device or swing arm has a structure for transporting the reaction vessel 300 so that the reaction vessel 300 is located directly below the unit process module, and is located in the lower part of the process chamber 101 with the shutter device up and down. installed facing each other.

5 is a schematic plan view showing the inside of a process chamber of a powder coating apparatus according to an embodiment of the present disclosure.

As shown in FIG. 5, a reaction container transfer device 407 including a swing arm 407b and a swing-arm actuator 407a driving the swing arm 407 is installed below the process chamber 101. The reaction vessel transfer device 407 transfers the reaction vessel 300 to an area where the aforementioned unit process modules are located. The swing arm 407b can rotate 360 degrees.

Hereinafter, an embodiment of the powder coating method according to the present invention is described, and the schematic structure and operation of each unit process and unit process modules are also described by each unit process module.

6 is a cross-sectional view schematically showing the vertical structure of the process chamber 101, showing a state in which the reaction vessel 300 is positioned under the powder supply module 401 by the swing arm 407b and the powder 500 is supplied. Illustrate schematically.

Near the outer end (left side in the drawing) of the swing arm 407b, a reaction vessel 300 and an oscillator 200 below it are installed. In addition, impact devices 210 corresponding to both sides of the lower portion of the reaction container 300 are installed on the swing arm 407b. The reaction vessel 300 is moved along the disposition line of the above-described several unit process modules by rotation of the swing arm 407b, and the reaction vessel 300 is placed directly under one unit process module such as the powder supply module 401. ) is positioned.

The powder supply module 401 includes a powder storage container 401a, a powder supply pipe 401d in which a powder transfer screw 401c is located, a motor 401b for operating the screw 401c, and a powder supply nozzle. (401d) and a powder gate valve (401e).

A coolant supply function may be added to cool the oscillator 200 while maintaining the vacuum function. In the process chamber 101, as in a general structure, an exhaust device 101b including a valve and a high vacuum pump is installed to exhaust the process chamber.

A source shutter 406b driven by a shutter driver 406a is provided directly below the ceiling 101a of the process chamber. The source shutter 406b selectively opens one source module so that the corresponding source module can be applied to a coating process.

7 shows a state in which moisture and the like are removed from the powder 500 contained in the reaction vessel 300 by preheating by the preheating module 402 having a halogen heater.

In the drying step, the reaction container 300 leaves the lower part of the powder supply module 401 and is transferred to the lower part of the preheating module 402 by the swing arm 407b. The powder 500 made of fine particles easily reacts with moisture in the air and has a property of easily aggregating with each other.

Therefore, prior to coating the powder, moisture in the powder is removed through high-temperature heating and the agglomerated powder is separated. At this time, a halogen lamp or the like that can quickly heat to a high temperature state in a standby state can be applied. While drying the powder by operating a halogen lamp, etc., the oscillator 200 is used to oscillate the reaction container 300 up and down to lift the powder 500 in the reaction container 300 above the container to increase the drying effect In addition, the striking device 210 is operated to separate the coagulated particles and at the same time separate the powder particles adhering to the surface of the reaction vessel 300.

During the process of drying, the operation of the oscillator 200 continues, so the powder is lifted upward from the reaction container 300, stays in the air for a while, and then falls by gravity, and in this process, the powder particles Sufficient, rapid, and evenly supplied heat energy enables rapid and effective drying of powder.

8 visually shows a coating method for powder particles after the reaction vessel 300 is transferred to the lower portion of the PVD device as a source module.

A sputtering method may be applied to coat the powder with a thin film. To this end, the source modules 403a and 403b of the reaction container 300 in the process chamber 101 are positioned under the sputtering cathode by the operation of the container transfer device 407 . When the oscillator 200 is operated, the powder in the reaction vessel 300 floats high upwards of the vessel, stays there for a while, and then flows 501 of the powder falling to the bottom of the vessel. While the reaction vessel 300 oscillates up and down, sputtering of the source material to the powder particles proceeds. In the thin film formation of the powder particles, a metal or non-metal thin film is formed on the surface of the powder particles depending on the type of sputtering target.

In the present disclosure, by using a sputter cathode equipped with targets of various materials as a source module, a multilayer sputter layer suitable for a desired purpose can be formed regardless of metal or non-metal materials.

9 schematically shows the powder coating step after the reaction vessel 300 is transferred to the lower part of the ALD device as the source module.

As another method for coating a thin film on powder, ALD deposition is used. To this end, the reaction vessel 300 in the process chamber 101 is transferred to the lower portion of the ALD module, which is the source module 403c, by the operation of the vessel transfer device 407.

While the oscillator 200 operates and the powder in the reaction vessel 300 floats high upwards of the vessel, stays there for a while, and then falls to the bottom of the vessel, while the powder flow 501 is formed, the ALD detects the precursors. By supplying alternately, an ALD thin film is formed on the surface of the powder particles.

The ALD deposition method can evenly coat a thin film shell with a precise thickness of a metal oxide film and a chemically bonded thin film of various types on fine powder particles. As in this embodiment, it is possible to create various core/shell structures suitable for application fields by applying sputtering and ALD in combination.

10 shows thin film monitoring for coating analysis on coated powder particles.

The powder that has undergone the coating process by PVD or ALD goes through the process of evaluating the uniformity of the coating film.

The coated powder is transferred to the lower part of the monitoring module 404 by the vessel transfer device 407 while being contained in the reaction vessel 300 .

The monitoring module 404 may include a thin film analysis device and the like. For example, a LIBS (Laser Induced Breakdown Spectroscopy) analyzer that can check how evenly a thin film is deposited on the surface of a powder particle is used as a monitoring module.

As shown in FIG. 10, the analysis of the coating powder by the monitoring module 404 proceeds while levitating the powder of the reaction vessel 300 high above the reaction vessel 300 by oscillating up and down the reaction vessel 300. .

In order to monitor the uniformity of the coating film, the LIBS analyzer of the monitoring module 404 is operated, and the high-power laser beam is irradiated to the powder particles that are scattered by floating to the upper part of the reaction vessel 300. The powder particles colliding with the high-power laser beam generate plasma according to the local discharge phenomenon, and the light generated by the plasma is detected through the collecting lens of the probe. The detected light is analyzed by a spectrum analyzer to analyze the constituent materials of the coating film, that is, elements. An additional deposition process is performed according to the set value of the analysis amount of the detected element, or if sufficient deposition is made to reach the set value or more, the next thin film is deposited or the deposition process is completed to recover the powder.

11 schematically shows and explains the operation of the powder recovery module that recovers the coated powder.

The powder 500 after the coating process is moved to the powder recovery module 405 by the reaction container 300 . The powder recovery module 405 recovers the powder 500 from the reaction container 300 to a cyclone collection tank 405c by vacuum suction.

During the recovery process, the head 405a of the recovery module 405 is fixed to the skirt 300a of the reaction vessel 300 within the process chamber 101 . The head 405a has the shape of a cap capable of sealing the opening of the reaction vessel 300, and at this time, the skirt 300a of the reaction vessel 300 comes into close contact with the head 405a to maintain an airtight state. to keep it firm.

The head 405a may also include a nozzle 405f for supplying nitrogen into the reaction container 300 .

In order to recover the powder 500, first, high-purity N2 is injected from the nozzle 405f of the recovery head 405a, and at the same time, the vacuum inhaler 405e provided in the discharge pipe 405b to which the head 405a is connected is operated. . The powder 500 is scattered in the reaction container 300 by the injected N2 gas and floats in the air. At this time, the powder is sucked in by the head 405a maintaining a low pressure (vacuum state) by the vacuum aspirator 405e and sent to the cyclone recovery tank 405c, and the powder in the reaction vessel is completely removed. The fine powder sucked through the head 405a is sent to the recovery tank 405c and collected, and the N2 gas is discharged to the outside through the exhaust pipe 405d.

Through the cyclone recovery container 405c, the gas escapes through the exhaust port and deposited fine powder particles are collected in the recovery tank. The recovered fine powder particles may be replaced on a tank basis or periodically recovered.

Figure 11 is the overall flow chart of the powder coating process steps according to the present invention.

Step 1 (S1): First, powder is supplied to the reaction vessel in the process chamber. Powder supply is performed through a powder supply module provided outside the process chamber.

Step 2 (S2): Heat the powder accommodated in the reaction container to remove moisture contained in the powder.

Step 3 (S3): After powder is supplied to the reaction vessel, the reaction vessel is repeatedly oscillated up and down a predetermined stroke distance up and down by an oscillator so that the powder in the reaction vessel is lifted upwards of the reaction vessel.

Step 4 (S4): In a state in which the powder is lifted upward of the reaction vessel, PVD sputtering particles, CVD source gas, or ALD precursor are supplied to the upper side of the reaction vessel to perform coating on the lifted powder particles, and the second Steps and the third step are repeated a predetermined number of times (N) for a predetermined period. In this process, one of the first to third source modules such as PVD, CVD, ALD, etc. is selected and the powder coating process is performed.

Step 5 (S5): The coating film on the powder particles is inspected to determine whether the coating is successful, and if more coating is required, the step 3 is performed, and when the coating is completed, the step 6 (S6) is performed. fulfill

Sixth step (S6); The coated powder is recovered to the outside of the process chamber using a vacuum suction module or the like.

The above process is an approximate process of the powder coating method according to the present invention, and a more specific and detailed sequence below is as follows.

Sequence 1: The inside of the process chamber is filled up to atmospheric pressure with N2 to purge all substances that interfere with coating, such as oxygen and moisture, and at the same time prevent the impact that may occur due to the pressure difference between the powder supply device and the process chamber, resulting in stable powder supply. Create an enjoyable atmosphere.

Sequence 2: After completely purging the process chamber with N2, the swing arm of the transfer device is rotated to the powder supply position to transfer the container to the lower part of the powder supply module.

Sequence 3: Match the aperture of the source shutter to the powder supply position so that the powder supply module directly faces the reaction vessel in the process chamber.

Sequence 4: Open the powder gate valve of the powder supply module to enable powder supply.

Sequence 5: The reaction vessel is moved closer to the powder supply nozzle by the linear motion (elevation operation) of the oscillator supporting the reaction vessel from the bottom.

Sequence 6: By operating the motor of the powder supply module, a predetermined amount of powder is supplied to the reaction vessel.

Sequence 7: Close the gate valve of the powder feeder when powder supply is complete.

Sequence 8: Evacuate the process chamber to lower the preset vacuum pressure for PVD, CVD, ALD, etc.

Sequence 9: Rotate the container transfer device to transfer the container to the bottom of the preheating module, and match the aperture of the source shutter to the preheating module to open the preheating module and the container directly.

Sequence 10: By operating the oscillator, the powder is repeatedly induced to float and fall to the top of the container, and at the same time, the preheating module is operated to dry the floating powder.

Sequence 11: Match the aperture of the source shutter to the source module to be used for thin film coating so that the corresponding source module can directly view the inside of the process chamber through the aperture.

Sequence 12: By moving the vessel transfer device, the reaction vessel is transferred directly below the corresponding source module.

Sequence 13: In sequences 11 and 12, powder particles are coated through the corresponding source module. At this time, multi-layer deposition of particles on the powder is performed according to a recipe such as sputtering/ALD, ALD/sputtering, sputtering A/sputtering B/sputtering C, etc. through a plurality of source modules.

Sequence 14: During or after the coating process is completed, move to the coating film uniformity monitoring module to analyze the current film uniformity, if additional coating is required, additional coating process is performed from the source, uniform coating over the set value is confirmed, and the following sequence transition to 15

Sequence 15: Fill the inside of the process chamber with N2 to atmospheric pressure.

Sequence 16: Transfer the reaction vessel to the powder recovery position with the swing arm of the vessel transfer device.

Sequence 17: Open the powder recovery module to the process chamber by moving the aperture of the source shutter to the powder recovery position.

Sequence 18: Activate the oscillator to bring the reaction vessel close to the head of the powder recovery module.

Sequence 19: The head of the powder recovery module is lowered and tightly adhered to the opening of the container.

Sequence 20: N2 is sprayed into the reaction container using a nozzle equipped with a powder collector head to lift the powder, and the coated powder is recovered using a vacuum aspirator.

Sequence 21: After completion of powder recovery, the powder recovery head is lifted and separated from the reaction vessel, and the reaction vessel is returned to its normal position by lowering the operating rod of the oscillator.

Sequence 24: Repeat the above sequence through automation.

According to the coating method and apparatus of the present disclosure, it is possible to coat the surface of particles having a size of several tens of nanometers to several hundreds of micrometers with various materials for surface modification.

According to the present disclosure, the apparatus continuously performs a series of processes related to coating in one process chamber, and in particular, metals, metal oxide films, and ceramics are formed on the surface of fine particles by various types of coating methods such as PVD, CVD, and ALD. It is possible to coat various materials required for surface modification of powder, such as an insulating film.

In addition, not only a single process for each coating method, but also a complex process of sputtering and ALD is possible in one chamber, so it is very easy to configure a shell of metal, non-metal, metal oxide, silicon oxide, etc. as a composite layer on the fine particle powder core. Do.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (12)

A powder supply step of supplying a powder to be coated to a reaction container inside a process chamber in which powder coating is performed;
A powder lifting step of reciprocating the reaction container up and down at a predetermined stroke distance at an arbitrary speed so that the powder stored in the reaction container is lifted upward of the reaction container and then falls to the bottom of the container by its own weight; And
and a powder coating step of supplying the coating material into the process chamber and bringing the coating material into contact with the floating powder to perform coating on the powder. According to claim 1,
In the powder lifting step, the reaction vessel is hit from the bottom so that the powder in the reaction vessel is secondarily hit by the hitting portion of the reaction vessel so that it is lifted upwards of the reaction vessel. According to claim 1,
Coating of the powder is a powder coating method in which a sputtering or ALD process is performed in a complex manner in one process chamber. According to claim 1,
A powder coating method of performing complex coating in one process chamber by installing a powder supply module, a powder recovery module by a vacuum inhaler, and a coating material supply device of a plurality of coating sources therebetween in the one process chamber. A housing forming one process chamber isolated from the outside;
a powder reaction container located on the lower side of the process chamber, in which the powder to be coated is accommodated, and in which the powder is lifted;
a reaction vessel oscillator for reciprocating the powder reaction vessel in an up-and-down direction at an arbitrary amplitude to lift the powder accommodated in the reaction vessel upward of the reaction vessel; And
A powder coating apparatus having a; coating material supply device located above the process chamber to perform coating on the powder floated upward of the reaction container. According to claim 5,
A powder coating apparatus further comprising: a reaction vessel striking device for impacting the powder reaction vessel to buoy the powder accommodated in the reaction vessel upward of the reaction vessel. According to claim 6,
The powder coating device, wherein the striking device includes a rotary hammer that directly hits the reaction vessel. According to any one of claims 5 to 7,
The process chamber by the housing is provided with a transfer path of the reaction vessel surrounding one central region,
A plurality of unit process modules in which an arbitrary process for the powder in the reaction vessel is performed is disposed on the transfer path,
A vessel transfer device for transferring the reaction vessel along the rotational transfer path is provided at the lower portion of the chamber, and
A powder coating apparatus in which a unit process module corresponding to the process is installed on the ceiling of the upper part of the chamber. According to claim 8
The container transfer device includes a swing arm positioned below the process chamber, and the reaction vessel and the reaction vessel oscillator are installed on the swing arm to correspond to the unit process area. According to claim 8,
A shutter device having an aperture for selectively exposing the unit process module into the process chamber is provided on the ceiling of the process chamber, the powder coating apparatus. According to claim 10,
The unit process module includes a preheating device or a preheating module 402 for drying the powder. According to claim 10,
The unit process module includes a monitoring module for inspecting the coating state of the powder, powder coating apparatus.

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