JP6612198B2 - Powder coating apparatus and method of using the same - Google Patents

Description

  The present invention relates to a powder coating apparatus for coating a thin film on the surface of each particle of a powder, and more particularly to a mechanism for stirring and leveling the powder.

  In order to give a function to the powder, a thin film may be coated on the surface of the particle. As a technique for coating by a dry method, there is a sputtering method, and various types of coating apparatuses for powder using the sputtering method have been proposed (see, for example, Patent Documents 1 to 4).

  In Patent Document 1, a sputtering apparatus including a rotating barrel whose inside is maintained in a vacuum, a target unit disposed in the rotating barrel, and a DC sputtering power source connected to the target unit and capable of generating plasma. A technique for sputtering platinum onto carbon powder using a tantalum is disclosed. Here, coating is performed by sputtering the target while rotating the rotating barrel. And the stirring blade is arrange | positioned in the barrel, and it rocks within the range of the angle of (alpha) centering on the rotating shaft of a rotation barrel, and prevents aggregation of carbon powder.

  Patent Document 2 discloses a technique of coating various metals on the surface of magnetic powder using a sputtering apparatus having a rotating barrel. Also in this document, the stirring blade is disposed in the barrel and swings within an angle range of ± α around the rotation axis of the rotating barrel to prevent the aggregation of the magnetic powder.

  Patent Document 3 discloses a powder coating apparatus that forms a uniform coating layer on the surface of powder particles while stirring the raw material powder charged in the rotating drum and scraping off the raw material powder adhering to the inner wall of the drum. Here, the powder particles in the upper layer portion and the lower layer portion forming the fluidized bed are mixed with each other by the stirring plate, and the individual powder particles are equally subjected to sputtering. The scraper scrapes off the powder that adheres to the drum inner surface and tries to rotate around the drum body, and returns the powder particles to the fluidized bed. Further, the wiper returns the powder particles dropped and deposited on the upper surface of the casing to the fluidized bed.

  Patent Document 4 discloses a powder coating apparatus in which a rotating cylindrical container is arranged in a vacuum container because the structure becomes complicated when the vacuum container itself is rotated. Here, the stirring bar arranged with a clearance between the drum and the drum is rotated or swung by an independent drive unit. Further, a stirring member that moves in conjunction with the stirring bar and abuts against the drum is provided.

JP 2012-182067 A Japanese Patent No. 4183098 JP-A-5-271922 JP 2014-159623 A

  When a film is formed on a substrate using a sputtering apparatus, the substrate is arranged in parallel to the target. According to this, in the powder coating apparatus, it is ideal that the surface of the powder, that is, the surface formed by the aggregate of fine particles is flat along the inner wall surface of the cylindrical drum.

  However, in any of the powder coating apparatuses described in Patent Documents 1 to 4, the powder is placed in a rotating drum. Therefore, the surface of the powder, that is, the surface formed by the aggregate of fine particles forms a mountain shape during film formation and constantly deforms. The powder agitation mechanism of these devices does not work to level the powder surface.

  When the surface of the powder has a mountain shape, for example, a spatter particle coming from the oblique direction toward the powder is blocked by the mountain, or a situation where only a specific portion is easily hit is created. Therefore, it is required that the surface of the powder is leveled when the film is formed.

  Furthermore, in a multi-source sputtering apparatus that simultaneously sputters a plurality of types of targets, since the direction in which the sputtered particles vary depends on the type of target, it is further required that the surface of the powder is leveled.

  Therefore, the present invention is a powder coating apparatus that solves the problems that could not be avoided when using the powder coating apparatus described in Patent Documents 1 to 4, that is, the surface of the powder is leveled during film formation. An object of the present invention is to provide a device having a mechanism.

  As a result of intensive studies, the present inventors have (1) fixed a part that scrapes off the powder adhering to the barrel so as not to depend on the rotation of the barrel, and that the part determines the upper limit position of the powder rushing. And (2) the present invention has been completed by finding that the above-mentioned problems can be solved by providing a powder leveling part that performs a peristaltic motion about the main axis of the barrel. That is, the powder coating apparatus according to the present invention includes a barrel, an evacuation unit that evacuates the barrel, and a sputtering apparatus installed in the barrel, and the main axis of the barrel faces the horizontal direction. The sputtering apparatus forms a coating film on the surface of the powder put in the barrel, and the barrel rotates among the inner side walls of the barrel. Arranged in contact with the side wall of the portion that moves upward, and a powder rise restraining part that defines an upper limit position where the powder creeps, and a position below the powder rise restraining part, on the inner side wall of the barrel The powder leveling parts arranged at intervals and performing a peristaltic motion with the main shaft as a rotation center, and the position of the powder rise suppression part is By powder increase suppressor are connected to a part that supports the sputtering device, characterized in that it is fixed.

  In the powder coating apparatus according to the present invention, the powder rise suppressing component is preferably a brush or a spatula. A brush or spatula can efficiently scrape powder from the barrel.

  In the powder coating apparatus according to the present invention, the leveling part is preferably a bar or a plate. The bar or plate can easily level the powder in a mountain shape.

  In the powder coating apparatus according to the present invention, when the leveling part swings in a direction opposite to the rotation direction of the barrel, the lowest side position of the inner side wall of the barrel or the position beyond the position. It is preferable to wrap. The leveling part can level the whole powder uniformly.

  In the powder coating apparatus according to the present invention, it is preferable that the leveling part is folded under the powder rise restraining part when performing a peristaltic motion along the rotation direction of the barrel. The leveling part can stir the entire powder while passing through the powder. In the powder coating apparatus according to the present invention, it is preferable that the position of the powder rise suppressing component and the boundary position of the irradiation region of the sputtered particles coincide with each other.

  The method of using the powder coating apparatus according to the present invention is a method of using the powder coating apparatus according to the present invention, wherein the amount of powder to be put into the barrel is such that the leveling part swings in the rotational direction of the barrel. The amount of powder that is sometimes passed through the interior of the powder pile and smoothed when the peristaltic motion is opposite to the direction of rotation of the barrel.

  The powder coating apparatus of the present invention can prevent the powder from rotating together with the barrel due to the rotation of the barrel. At this time, since the upper limit position of the powder rush is determined, the sputtered particles can be efficiently applied to the powder. Further, the powder tends to have a mountain shape due to the rotation of the barrel. By smoothing the mountain, the sputter particles can be easily applied to the entire powder.

It is a whole block diagram of the powder coating apparatus which concerns on this embodiment. It is the schematic of the AA cross section about a target unit, a barrel, a powder rise suppression component, and a leveling component. It is a perspective schematic diagram about a target unit and a barrel. It is the schematic for demonstrating the relationship between the direction of a target, and the position of powder. It is the schematic for demonstrating the motion by the angle adjustment mechanism of a target unit. In the powder coating apparatus which concerns on this embodiment, it is the schematic explaining the motion which stirs and equalizes powder. The leveling parts move in the order of (a), (b), (c), (d), and (e) in chronological order, and return to (a) again to be repeated. It is the schematic which shows another example of the cross-sectional shape of a leveling part, (a) is an example when a leveling part is plate shape, (b) is the 1st when a leveling part is a cross-sectional semicircle shape. One example, (c), shows a second example when the leveling part has a semicircular cross section. It is the schematic for demonstrating the motion of the powder when a leveling part moves to the rotation direction R of a barrel. It is the schematic for demonstrating the motion of the powder when a leveling part moves to the direction opposite to the rotation direction R of a barrel.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

  Prior to explaining the mechanism for leveling the powder surface, the film forming mechanism will be explained first. The powder coating apparatus according to the present embodiment is a rotating barrel type sputtering apparatus that can coat a whole particle surface of a powder. Here, explanation will be given while illustrating a multi-source sputtering apparatus. In addition, the apparatus of the cited literatures 1-4 is a unitary sputtering apparatus. In this embodiment, a mechanism for leveling the surface of the powder can be installed in either a multi-element or single-unit sputtering apparatus.

  First, reference will be made to FIGS. FIG. 1 is an overall configuration diagram of a powder coating apparatus according to the present embodiment. FIG. 2 is a schematic diagram of an AA cross section of a target unit, a barrel, a powder rise suppressing component, and a leveling component. FIG. 3 is a schematic perspective view of the target unit and the barrel. As shown in FIG. 1, the powder coating apparatus 100 according to the present embodiment includes a barrel 3, an exhaust unit 4 that evacuates the barrel 3, and a sputtering apparatus 2 installed in the barrel 3. The barrel 3 has the main axis C oriented in the horizontal direction and rotates about the main axis C, and the sputtering apparatus 2 forms a coating film on the surface of the powder 7 put in the barrel 3. Here, as shown in FIG. 2, the sputtering apparatus 2 attaches two or more targets 6 (6a, 6b, 6c, three in FIG. 2), so that the fixing unit 10 (10a, 10b, 10c). Further, as shown in FIG. 3, when the target 6 (6a, 6b, 6c) is attached to the fixed portion 10 (10a, 10b, 10c), the sputtering apparatus 2 has the spindle 6a, 6b, 6c They are arranged in parallel with each other at the same level in the direction of C.

  The powder coating apparatus 100 according to the present embodiment is a rotary barrel type multi-source sputtering apparatus that can coat a whole powder particle surface. This apparatus can simultaneously sputter two or more targets, and each target is individually connected to a power source 1. For example, if two or more types of targets are mounted, a plurality of materials can be sputtered simultaneously. Further, since the output of each target can be adjusted individually, it is possible to perform sputtering at an arbitrary ratio.

  The barrel 3 is supported by a drive roll 5a and a driven roll 5b. The drive roll 5a can receive power from the drive motor 5 and rotate the main shaft C of the barrel 3 as a horizontal axis. The barrel 3 is provided with a barrel main body 3d having an open upper end of the cylinder and a lid 3e that closes the barrel main body 3d, and is sealed with an O-ring (not shown). Powder 7 is put into the barrel 3 from the opening of the barrel body 3d. Further, the barrel 3 may have a vertically or horizontally divided structure instead of having the barrel body 3d and the lid 3e. In this case, the powder 7 is charged at the time of division.

  Barrel 3 also serves as a vacuum vessel. The exhaust means 4 for evacuating exhausts the gas in the internal space of the barrel 3. The exhaust means 4 is airtightly held by a vacuum seal type bearing 4a.

  A sputtering apparatus 2 installed in the barrel 3 is connected to a sputtering power source 1 installed outside the barrel 3. The sputtering power source 1 may be either a direct current power source or a high frequency power source. The sputtering apparatus 2 is inserted into the barrel 3 by an arm 1b that is airtightly held by a vacuum seal type bearing 1a. In the airtightly held arm 1b, a target cooling water passage inlet 1c, a target cooling water passage outlet 1d, and an argon gas inlet 1e are incorporated.

  Two or more sputtering apparatuses 2 are installed in the barrel 3 (in FIG. 2, three sputtering apparatuses 2a, 2b, and 2c are installed). The above targets 6 can be installed (in FIG. 2, three targets 6a, 6b, 6c are installed). The sputtering apparatus 2 has one fixing portion 10 (10a, 10b, 10c) per target. That is, in FIG. 2, the three sputtering apparatuses 2a, 2b, and 2c have the fixing portions 10a, 10b, and 10c, respectively. Moreover, the sputtering power sources 1 are separately connected to the sputtering apparatuses 2a, 2b, and 2c, and the outputs are controlled separately. Thereby, the sputtering apparatus 2 becomes a multi-source sputtering apparatus.

  The fixing unit 10 is a backing plate that holds the target 6. A target 6 is attached to the front side of the backing plate by a mounting bracket. On the front side of the backing plate, a shield cover serving as a counter electrode for generating plasma is attached at a predetermined distance from the backing plate. On the other hand, a plurality of recesses for accommodating magnets are formed on the back side of the backing plate. A cooling water passage connected to the target cooling water passage inlet 1c and the target cooling water passage outlet 1d is disposed on the back side of the backing plate.

  When the target 6 is attached to the fixed portion 10, the targets 6 a, 6 b, 6 c are arranged in parallel to each other at the same level position with respect to the direction of the main axis C as shown in FIG. 3. For example, it is preferable that the positions of the centers of gravity of the targets 6a, 6b, and 6c in the direction of the main axis C are aligned with each other. Further, when the sizes of the targets 6a, 6b, and 6c in the direction of the main axis C are the same, it is preferable that the positions of both ends of each target in the direction of the main axis C are aligned with each other. Since the barrel 3 rotates around the main axis C, if the targets 6a, 6b, 6c are arranged in parallel to each other at the same level position with respect to the direction of the main axis C, they jump out of the targets 6a, 6b, 6c. Since the sputtered particles uniformly hit the powder put in the rotating barrel 3, composition unevenness hardly occurs. In addition, the length of each target 6a, 6b, 6c in the direction of the main axis C is preferably slightly shorter than the length of the barrel 3 in the axial direction in order to avoid interference.

  If the targets are arranged in order along the direction of the main axis C without arranging the targets shown in FIG. 3, the powder is difficult to mix in the direction of the main axis C, so that only the sputtered particles that have jumped out from one target hit the film. The composition unevenness occurs. That is, since a plurality of types of sputtered particles jumping out from a plurality of targets do not reach the surface of the powder particles at the same time, a uniform alloy film, double oxide film, double nitride film, or double carbide film cannot be formed. If each target is arranged in order along the direction of the main axis C and the orientation of the target surface is adjusted so that the target particles protruding from each target gather in a predetermined area, the above problem can be solved. It is limited to a part of the barrel side wall in the C direction. As a result, the amount of powder that can be processed per volume of the barrel is small, and thus the productivity is poor. Even if the same type of target is used, productivity is similarly poor.

  Reference is now made to FIG. FIG. 4 is a schematic diagram for explaining the relationship between the direction of the target and the position of the powder. In the powder coating apparatus 100 according to the present embodiment, as shown in FIG. 4, each of the targets 6 a, 6 b, 6 c has a target surface parallel to the normal lines ha, hb, hc of the target surface to the inner side wall 3 a of the barrel 3. When projected toward the front, it is preferable that the projections are directed in an overlapping direction before reaching the inner side wall 3a. Since the elements (sputtered particles) jumping out from the targets 6a, 6b, and 6c reach the powder 7 put in the barrel 3 in a more mixed state, the elements are uniformly taken in from the targets. A thin film can be deposited on the surface of the powder particles. Specifically, the position before reaching the inner side wall 3a is preferably the surface of the powder 7. For example, when the radius of the barrel 3 (the distance between the main axis C and the inner side wall 3a) is r, the inner side wall 3a is separated from the inner side wall 3a. The range is from 0.05r to 0.15r toward the main axis C. The targets 6a, 6b, and 6c are more preferably oriented so that the normal passing through the center of gravity of the target surface overlaps on the inner side wall 3a or the surface of the particles of the powder 7. FIG. 3 shows a form in which normals (ha, hb, hc) passing through the center of gravity of the target surface are directed in an overlapping direction on the surface of the powder particles. Even when the sizes of the targets 6a, 6b, and 6c are not uniform, the elements jumping out from the targets 6a, 6b, and 6c can be mixed more and reach the powder. Furthermore, it is preferable to set the size of the target or the opening of the shield cover and the orientation of the target so that the projections completely overlap on the inner side wall 3a or on the surface of the powder particles. The composition unevenness is further suppressed.

In the powder coating apparatus 100 according to this embodiment, it is preferable that the targets 6a, 6b, and 6c have different compositions. Composition unevenness can be reduced when an alloy film, a double oxide film, a double nitride film, a double carbide film, or the like is formed. As an alloy film, there is an example in which a Pt—Au alloy film is formed on the surface of a glass bead using a platinum target and a gold target. In addition, if the composition of each target 6a, 6b, 6c is made the same, the same effect as increasing the film-forming amount within a predetermined time can be obtained. That is, the film formation rate can be increased. The combination of the compositions of the targets 6a, 6b, and 6c can be selected as appropriate. For example, when an oxide target such as SiO ₂ or TiO ₂ is used, the deposition rate is slow, so two or three are sputtered simultaneously. As a result, the deposition rate can be increased. For example, when the target is a three, each target (6a, 6b, 6c) a _{(SiO 2, SiO 2, SiO} 2), to such _{(TiO 2, TiO 2, TiO} 2). In addition, when a composite film is formed using a target with a high deposition rate (for example, metal) and a target with a low deposition rate (for example, an oxide), the target with a low deposition rate is relatively increased. The number of targets with a low film speed is set to be larger than the number of targets with a high film formation speed. For example, when there are three targets, two targets with a low film formation rate are set, and one target with a high film formation rate is set. For example, each target (6a, 6b, 6c) is set to (Pt, SiO ₂ , SiO ₂ ).

  Reference is now made to FIG. FIG. 5 is a schematic diagram for explaining the movement of the angle adjustment mechanism of the target unit. In the powder coating apparatus 100 according to the present embodiment, as shown in FIG. 5, each fixing portion 10 a, 10 b, 10 c is attached to the target unit 2 </ b> U in order to fix the relative orientation relationship of each attached target. It is preferable that the target unit 2U is mounted so as to be rotatable about the main axis C, and an angle adjusting mechanism 8 of the target unit 2U is further provided. When the barrel 3 is rotated, the powder 7 rises. The angle of the target unit 2U can be adjusted in accordance with the degree of the rise. The target unit 2U has, for example, a configuration in which the fixing units 10a, 10b, and 10c are fixed by fixing the sputtering devices 2a, 2b, and 2c to one housing, or each sputtering device 2a, There is a form in which the fixing portions 10a, 10b, and 10c are fixed by fixing the arms 2b and 2c with the arm 12. The angle adjusting mechanism 8 adjusts the angle of each target 6a, 6b, 6c attached to each fixing portion 10a, 10b, 10c while keeping the distance from the main axis C constant. Even if the powder 7 moves up with the rotation of the barrel 3 by the angle adjusting mechanism 8, the relative positional relationship between the targets 6 a, 6 b, 6 c and the powder 7 can be kept constant.

  Next, a mechanism for leveling the surface of the powder will be described with reference to FIGS. FIG. 6 is a schematic diagram for explaining the movement of stirring and leveling the powder in the powder coating apparatus according to the present embodiment. The leveling parts move in the order of (a), (b), (c), (d), and (e) in chronological order, and return to (a) again to be repeated. In the powder coating apparatus 100 according to the present embodiment, as shown in FIGS. 1 and 6, the inner wall 3 a of the barrel 3 is disposed in contact with the side wall of the portion that moves upward by the rotation of the barrel 3. The powder rise restraining part 13 for determining the upper limit position where the powder 7 approaches, and the lower side of the powder rise restraining part 13 are arranged at intervals on the inner side wall 3a of the barrel 3 and swings with the main shaft C as the center of rotation. And a leveling part 9 of the powder 7 that moves. The side wall of the inner side wall 3a of the barrel 3 that moves upward by the rotation of the barrel 3 is the right half of the circle formed by the side wall of the barrel 3, as illustrated in FIG. FIG. 6 shows a case where the leveling part 9 is a round bar type with a circular cross section.

  The powder rise suppressing component 13 is preferably a brush or a spatula. The brush or spatula can scrape off the powder 7 from the barrel 3 efficiently. The powder rise suppression component 13 is fixed to, for example, a portion that supports the sputtering apparatus 2 of FIG. The powder rise restraining part 13 should just be fixed to the part which does not move with it even if the barrel 3 rotates. By doing so, the powder rise suppressing component 13 can prevent the powder 7 from rotating in the same manner as the barrel 3 due to the rotation of the barrel 3. Further, since the position of the powder rise suppressing component 13 is fixed, the position becomes the upper limit position for the powder 7 to rise. By matching the position of the powder rise suppressing component 13 and the boundary position of the irradiation region of the sputtered particles, the sputtered particles can be irradiated onto the powder 7 more efficiently. That is, since the sputtered particles can be applied in a state where the surge of the powder 7 is retained by the powder rise suppressing component 13, the irradiation efficiency of the sputtered particles can be increased.

  The leveling part 9 is preferably a bar or a plate. When the leveling part 9 is a bar, the cross-sectional shape may be a circle, a semi-circle, an ellipse, a semi-ellipse, or a polygon such as a triangle or a rectangle. Further, when the leveling part 9 is a plate, there is a form in which the shape of the cross section is a rectangle having a long side and a short side. The bar or plate can easily level the pile 7b of the powder 7. The leveling part 9 is fixed to the rotating shaft of the agitating motor 9b held airtight by the vacuum seal type bearing 9a shown in FIG. 1, and the range of the angle θ shown in FIG. Swing inside. This rotation axis is coaxial with the main axis C which is the rotation axis of the barrel 3. In the present embodiment, the range of the angle θ preferably includes the existence range of the powder 7 during the barrel rotation. The rocking angle and rocking speed can be adjusted as appropriate according to the agglomeration state of the powder 7, but it is necessary to set the rocking speed and the rocking speed so that the powder does not fly due to the rocking speed being too fast. For example, the swing speed is set to 2 reciprocations / minute, but may be 1 to 10 reciprocations / minute. The leveling component 9 may be intermittently swung.

  When the leveling part 9 performs a peristaltic motion along the rotation direction R of the barrel 3 (see, for example, FIGS. 6A to 6C), the leveling part 9 may be folded under the powder rise suppression part 13. preferable. It is preferable to make the point between the peak of the peak 7a of the powder 7 and the powder rise suppressing component 13 a turning point. For example, it is more preferable that a place where the leveling part 9 is in contact with the powder rise suppressing part 13 is set as a turning point, or a place within 20 mm below the powder rising suppressing part 13 is set as a turning point. When the leveling part 9 performs the peristaltic motion in the direction opposite to the rotation direction R of the barrel 3, the entire powder 7 can be leveled uniformly.

  When the leveling part 9 performs a peristaltic motion in a direction opposite to the rotation direction R of the barrel 3 (see, for example, FIG. 6D to FIG. 6E), of the inner side wall 3 a of the barrel 3, It is preferable to fold back at a position 3c beyond the lowest position 3b (see, for example, FIGS. 6 (e) to 6 (a)). When the leveling part 9 performs a peristaltic motion in the rotation direction of the barrel 3, the entire powder 7 can be agitated. The position 3c beyond the lowest position 3b is preferably a position beyond the boundary where the powder 7 exists. For example, the vertical direction may be 0 °, and a position of 1 to 45 ° in the direction opposite to the rotation direction R may be used as the turning point.

  The relationship between the peristaltic motion of the leveling part 9 and the motion of the powder 7 will be described. First, the powder 7 moves up in the rotation direction R by the rotation of the barrel 3. At this time, the powder 7 moves up while creating a mountain 7a. Here, when the leveling part 9 performs a peristaltic movement along the rotation direction R of the barrel 3 (see, for example, FIG. 6A to FIG. 6C), it enters the pile 7a of the powder 7. (See FIG. 6B.) Further, when moving to the front of the powder rise restraining part 13, the mountain 7a is removed (see FIG. 6C). As a result, the powder 7 is stirred including the inside. Next, when the leveling part 9 is reversed and performs a peristaltic movement in a direction opposite to the rotation direction R of the barrel 3 (see, for example, FIGS. 6D to 6E), the peak 7b of the powder 7 is used. (See FIG. 6D). When the turn-up point of the leveling part 9 is reached (see FIG. 6E), the surface of the powder 7 is leveled flat. As a result, the sputtered particles are likely to hit the entire powder 7 uniformly, and in particular, in the case of multi-source sputtering, it is possible to suppress film composition unevenness. In addition, that the surface of the powder 7 is planarized means that the said surface is leveled along the shape of the inner surface of the side wall of a barrel. Here, the amount of powder to be put into the barrel 3 is that the leveling part 9 passes through the inside of the peak 7a of the powder 7 when the swinging movement 9 is performed in the rotation direction R of the barrel 3, and the rotation direction R of the barrel is The amount of powder pile 7b to be leveled when performing a peristaltic motion in the opposite direction.

  Furthermore, the form in which the powder 7 is stirred by the leveling part 9 and the form in which the powder 7 is leveled will be described in more detail with reference to FIGS. FIG. 7 is a schematic view showing another example of the cross-sectional shape of the leveling part, where (a) shows an example when the leveling part has a plate shape, and (b) shows a leveling part with a semicircular cross section. (C) shows a second example when the leveling part has a semicircular cross section. FIG. 8 is a schematic view for explaining the movement of the powder when the leveling part moves in the rotation direction R of the barrel. In FIG. 8, a solid arrow extending from the smoothing part 9 as a starting point indicates a moving direction of the smoothing part 9 (the same direction as the R direction). FIG. 9 is a schematic view for explaining the movement of powder when the leveling part moves in the direction opposite to the rotation direction R of the barrel. In FIG. 9, a solid-line arrow extending from the leveling part 9 as a starting point indicates the direction in which the leveling part 9 is moving (the direction opposite to the R direction). As shown in FIGS. 7A and 7C, the leveling part 9 has a first surface 9 c that faces the rotation direction R of the barrel 3. The first surface 9c is preferably inclined in the direction opposite to the rotational direction R as it approaches the main axis C (not shown in FIG. 7, see FIG. 6). That is, when approaching the powder rise restraining part 13, it is preferable to incline so as to scoop up the powder 7. As shown in FIG. 8, when the leveling part 9 moves in the rotation direction R, the powder 7 is scooped up on the first surface 9c. That is, the powder 7 that is above the lower end of the first surface 9 c passes over the leveling part 9 and forms a flow 7 f 1 of the powder 7. On the other hand, the powder 7 below the lower end of the first surface 9 c passes below the leveling part 9 and forms a flow 7 f 2 of the powder 7. Thus, since the leveling part 9 has the 1st surface 9c, the efficiency of stirring of the powder 7 can be improved more. The first surface 9c preferably has irregularities, and when the powder 7 is scooped up by the first surface 9c, the powder 7 is likely to be mixed. When the leveling part 9 shown in FIG. 7B moves in the rotation direction R, the powder 7 hitting the leveling part 9 is divided into upper and lower parts to form a powder flow. Will be.

  Next, as shown in FIGS. 7A and 7B, the leveling component 9 has a second surface 9 d that faces in the direction opposite to the rotation direction R of the barrel 3. The second surface 9d is inclined with respect to the radial direction of the barrel. Specifically, as it approaches the main axis C (not shown in FIG. 7; see FIG. 6 for the position of the C axis), the rotation direction R It is preferable to be inclined in the opposite direction. That is, when moving away from the powder rise restraining part 13, it is preferable to incline so that the powder 7 is pressed. As shown in FIG. 9, when the leveling part 9 moves in the direction opposite to the rotation direction R, the powder 7 is pushed down by the second surface 9d. That is, the powder 7 below the upper end of the second surface 9d is moved in the direction opposite to the rotation direction R and easily passes under the leveling part 9, thereby forming a flow 7f4 of the powder 7. On the other hand, the powder 7 above the upper end of the second surface 9d passes over the leveling part 9 and forms a flow 7f3 of the powder 7. When the amount of the powder 7 is decreased, the flow 7f3 of the powder 7 is not seen. And the surface of the powder 7 after the leveling part 9 has passed is leveled. Thus, when the leveling component 9 has the second surface 9d, the surface of the powder 7 can be leveled by the second surface 9d when the leveling component 9 moves in the direction opposite to the rotation direction R. . The second surface 9d preferably has a smooth surface, and the powder 7 can be pushed down smoothly by the second surface 9d. When the leveling part 9 shown in FIG. 7C moves in the direction opposite to the rotation direction R, the powder 7 hitting the leveling part 9 is divided into upper and lower parts to form a powder flow. Compared with the case where the leveling part 9 shown in FIG. 7 (a) and FIG. 7 (b) is used, the powder 7 can be leveled thicker.

  In addition, when the leveling component 9 is in the shape of a square bar or a plate, it is preferable that the corners are rounded because corners may cause abnormal discharge.

  The speed of the peristaltic movement of the leveling part 9 is preferably the same when moving along the rotational direction R of the barrel 3 and when moving in the opposite direction. Further, the speed of the peristaltic movement of the leveling part 9 may be different when moving along the rotation direction R and when moving in the opposite direction.

(Modification Example 1)
The barrel 3 may be placed in a vacuum chamber (not shown). In this case, since it is not necessary to seal the barrel 3, the structure of the barrel can be simplified.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not construed as being limited to the examples.

Example 1
A powder having a Pt—Au alloy thin film formed on the surface of a glass bead is produced using the powder coating apparatus shown in FIG. First, one Pt target (purity 99.9%, target surface 150 × 35 mm) was prepared and attached to the fixing portion 10a. Also, one Au target (purity 99.99%, target surface 150 × 35 mm) was prepared and attached to the fixing portion 10c. A blank was used without attaching a target to the fixed portion 10b. The sputtering power source 1 was a high frequency power source (frequency 13.56 MHz). Next, after evacuating to 3 × 10 ⁻³ Pa or less with no powder in the barrel 3, argon gas is flowed to adjust the pressure so as to maintain a pressure of 0.4 Pa, and sputtering is performed. The rates of the Pt target and Au target according to the output of the power source were confirmed. Subsequently, 150 g of glass beads having a diameter of 1 mm were put into the barrel 3 and evacuated to 1.3 × 10 ⁻³ Pa, and then adjusted so as to maintain a pressure of 0.4 Pa by flowing argon gas. . Then, 200 W was applied to the Pt target and 100 W was applied to the Au target, and the barrel 3 was rotated to form a film on the glass bead surface while the leveling part 9 (round bar type) was being swung. The amount of powder (150 g) placed in the barrel is such that when the leveling part is peristaltic in the direction of rotation of the barrel, it passes through the interior of the pile of powder and perturbs in the direction opposite to that of the barrel. Sometimes it was the amount to level the powder pile. Note that the output of the high-frequency power source was obtained by calculating from the sputtering rate confirmed above so that Pt-50 wt% Au. The film formation time was 30 minutes. When the glass beads taken out after the film formation were analyzed, it was confirmed that a Pt-48 wt% Au alloy thin film was formed on the surface. The composition of the thin film was determined using an ICP emission spectroscopic analyzer (SPECTRO-CIROS manufactured by Rigaku).

(Example 2)
Using the powder coating apparatus shown in FIG. 1, a powder in which a two-layer film of a Ti thin film (lower layer) and an Au thin film (upper layer) is formed on the surface of glass beads is produced. First, one Ti target (purity 99.9%, target surface 150 × 35 mm) was prepared and attached to the fixing portion 10b. Also, one Au target (purity 99.99%, target surface 150 × 35 mm) was prepared and attached to the fixing portion 10c. A blank was used without attaching a target to the fixed portion 10a. The sputtering power source 1 was a high frequency power source (frequency 13.56 MHz). Next, sputtering is performed in a state where no powder is put in the barrel 3, and after vacuuming to 3 × 10 ⁻³ Pa or less, argon gas is supplied to adjust the pressure so as to maintain a pressure of 0.4 Pa. The rates of the Ti target and Au target according to the output of the power source were confirmed. Subsequently, 150 g of glass beads having a diameter of 1 mm were put into the barrel 3 and evacuated to 2.1 × 10 ⁻³ Pa, and then adjusted to maintain a pressure of 0.4 Pa by flowing argon gas. Thereafter, 200 W was applied only to the Ti target, the barrel 3 was rotated, and sputtering was performed for 30 minutes while the leveling part 9 (round bar type) was swung to form a Ti film on the glass bead surface. Subsequently, 200 W was applied only to the Au target, the barrel 3 was rotated, and the leveling part 9 (round bar type) was swung to perform sputtering for 1 hour, and an Au film was further formed on the surface of the Ti film. . As a result, glass beads on which two layers of Ti (lower layer) / Au (upper layer) were formed were obtained without opening the barrel 3 to the atmosphere on the way. The amount of powder (150 g) placed in the barrel is such that when the leveling part is peristaltic in the direction of rotation of the barrel, it passes through the interior of the pile of powder and perturbs in the direction opposite to that of the barrel. Sometimes it was the amount to level the powder pile. The deposited thin film had good adhesion. If the Au film is directly formed on the glass beads, the adhesion is poor. Therefore, a Ti film was formed as an intermediate layer for improving adhesion.

DESCRIPTION OF SYMBOLS 1 Sputtering power supply 1a Vacuum seal type bearing 1b Arm 1c Target cooling water passage inlet 1d Target cooling water passage outlet 1e Argon gas inlet 2 Sputtering device 3 Barrel 3a Barrel inner side wall 3b Barrel lowest position 3c Barrel lower position 3d Barrel body 3e Lid 4 Exhaust means 4a Vacuum seal bearing 5 Drive motor 5a Drive roll 5b Drive roll 6, 6a, 6b, 6c Target 7 Powder 7a, 7b Powder piles 7f1, 7f2, 7f3, 7f4 Flow 8 Angle adjustment mechanism 9 Leveling part 9a Vacuum seal type bearing 9b Stirring motor 9c First surface 9d Second surface 10, 10a, 10b, 10c Fixing part 12 Arm 13 Powder rise suppression component ha, hb, hc Target surface method Wire 2U Target unit 100 Powder coating Rotating device R Barrel rotation direction C Spindle

Claims (7)

A barrel, an exhaust means for evacuating the barrel, and a sputtering apparatus installed in the barrel, wherein the barrel has a main axis facing a horizontal direction and rotates about the main axis In the powder coating apparatus, the sputtering apparatus forms a coating film on the surface of the powder put in the barrel.
Of the inner side wall of the barrel, disposed in contact with the side wall of the portion that moves upward by the rotation of the barrel, a powder rise suppression component that defines an upper limit position where the powder rushes, and
The powder leveling part which is arranged at a position lower than the powder rise restraining part and spaced from the inner side wall of the barrel and performs a peristaltic motion with the main shaft as a rotation center;
The powder coating apparatus is characterized in that the position of the powder rise restraining component is fixed by being connected to a portion where the powder rise restraining component supports the sputtering apparatus.   The powder coating apparatus according to claim 1, wherein the powder rise suppressing component is a brush or a spatula.   The powder coating apparatus according to claim 1, wherein the leveling part is a bar or a plate.   2. The leveling part is folded back at the lowest position or beyond the inner side wall of the barrel when performing a peristaltic motion in a direction opposite to the rotation direction of the barrel. The powder coating apparatus as described in any one of -3.   The powder coating according to any one of claims 1 to 4, wherein the leveling part is folded under the powder rise restraining part when performing a peristaltic movement along the rotation direction of the barrel. apparatus.   The powder coating apparatus according to any one of claims 1 to 5, wherein a position of the powder rise suppressing component and a boundary position of an irradiation region of the sputtered particles coincide with each other. It is the usage method of the powder coating apparatus as described in any one of Claims 1-6,
The amount of powder put into the barrel is such that when the leveling part performs a peristaltic motion in the direction of rotation of the barrel, the peristaltic motion passes in the direction opposite to the direction of rotation of the barrel. A method of using a powder coating apparatus, characterized in that the amount of powder is leveled when the powder is applied.

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