JP3254088B2 - Powder coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder coating apparatus having a powder recovery mechanism for removing powder coated by sputtering from a rotary barrel.

[0002]

2. Description of the Related Art When a metal film, an inorganic film or the like is formed on powder particles of metals, ceramics, plastics, etc., characteristics different from those of the original powder particles can be given. For example, when tungsten particles, diamond particles, and the like are coated with copper, sinterability is improved, and a sintered body having excellent thermal conductivity is obtained. The copper-coated powder is also used as a filler for electromagnetic shielding. As a means for coating the powder particles, there are known a method of performing electroplating or electroless plating with the powder in a suspended state, a method of forming a predetermined film on the powder in a fluidized state by sputtering, and the like. The present inventors also introduced a sputtering apparatus using a rotary barrel in Japanese Patent Application Laid-Open No. 2-153068 as an apparatus for coating powder by sputtering.

[0003] In this powder coating apparatus, as shown in FIG. 1, a reduced pressure heat treatment chamber 1 containing a raw material powder P is connected to a rotary barrel 2, and the raw material powder is subjected to sputtering coating by a sputtering source 3. The raw material powder P is accommodated in a container 1b provided with a heating coil 1a, and is supplied to the inside of the rotary barrel 2 via a supply conduit 1e by a screw feeder 1d driven by a motor 1c. The supply conduit 1 e is provided with a bearing 1 provided on one end face of the rotary barrel 2.
supported by f. An inert gas introduction pipe 1g provided concentrically with the supply conduit 1e faces the inside of the rotary barrel 2.

[0004] The rotary barrel 2 is supported by a driving roll 2a and a driven roll 2b. The drive roll 2a receives power from the motor 2c and rotates the rotary barrel 2 around a horizontal axis. The sputtering source 3 is fixedly arranged in the rotary barrel 2 by an arm 3b hermetically supported by a bearing 3a at an end face opposite to the end face into which the supply conduit 1e is inserted, and is slightly larger than the axial length of the rotary barrel 2. The short target 3c is arranged obliquely downward. Raw material powder P supplied to the axial end of the rotary barrel 2 from the supply conduit 1e
Are distributed over the entire length of the barrel shaft as the rotary barrel 2 rotates, and flow on the inner bottom surface of the rotary barrel 2. The coating material is beaten from the target 3c by the impact of the plasma of Ar or the like, flies in the rotary barrel 2 and adheres to the raw material powder P in a flowing state. When a predetermined coating layer is formed, the rotating barrel 2 is opened to take out the coated raw material powder P. Alternatively, the thickness of the coating layer can be increased by providing an appropriate external circulation path and repeatedly exposing the raw material powder P to sputtering in the rotary barrel 2.

[0005]

When the size of the equipment is increased in order to increase the production capacity of the powder coating apparatus shown in FIG. 1, various problems that have not been taken into account in a laboratory-scale apparatus become apparent. For example, keeping the distance between the raw material powder P and the target 3c constant, exhausting the inside of the rotating barrel 2, bending deformation of the sputtering source 3, and rotating barrel 2
Impact when rotating, maintenance inside rotating barrel 2
There are inspections. The present inventors have developed mechanisms suitable for a large-sized apparatus which has solved these problems, and some of them have been disclosed in Japanese Patent Application Nos. 4-97375, 4-97376 and 4-97379. Introduced in. In particular, in a large-sized apparatus, it is important to distribute the raw material powder to the rotating barrel with a uniform distribution density in the barrel axis direction.
If the distribution is non-uniform, the raw material powder will be uneven in the barrel axial direction. The inventors of the present invention have found that the provision of a long powder supply gutter which can be advanced and retracted and rotatable eliminates coarse and dense charging of the raw material powder, and has filed a separate application. After the powder supply gutter contains the raw material powder at a uniform packing density in the longitudinal direction, it is inserted into a rotating drum and inverted at a fixed position.

The use of the powder supply gutter makes it possible to distribute the raw material powder to the rotating barrel with a uniform distribution density. However, the problem of removing the coated powder from the rotating barrel after the end of sputtering has not been solved. The removal of the powder is also troublesome as the rotary barrel becomes larger. In addition, since the operation is performed in an environment where dust is generated, the operator tends to avoid the operation. The present invention has been devised to solve such a problem. By utilizing the movement of the powder supply gutter, which is separately proposed, for powder recovery, even if the rotating barrel has a depth, the operator can remove the barrel. An object of the present invention is to efficiently take out coated powder without entering the inside, and to increase the collection yield of the coated powder.

[0007]

According to the present invention, there is provided a powder coating apparatus for coating powder particles by sputtering in a rotary barrel maintained in a vacuum atmosphere. An elongate powder supply gutter having a powder accommodating portion which is free to advance, retreat and rotate, disposes the powder, has an open upper portion, and has a length corresponding to an effective sputtering area in the rotary barrel; And a collection pipe that opens toward the inner surface of the rotary barrel near the tip in the direction, and the other end of the collection pipe communicates with the collection tank via a cyclone.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a powder coating apparatus according to this embodiment, as shown in FIG. 2, a moving base 20 is arranged on one side of an apparatus main body 10, and a target 30 and a powder distribution mechanism 40 are mounted on the moving base 20. ing. As shown in FIG. 3, the apparatus main body 10 constitutes a double-structured vacuum chamber in which a rotary barrel 11 is surrounded by an outer cylinder 12. The apparatus main body 10 has one side closed by the moving flange 13 and the other side
Is closed by the flange 31. The rotary barrel 11 includes a flange 16 formed on a peripheral surface of a driven gear 15 that meshes with a drive gear 14 provided on the outer cylinder 12 side.
It rotates by the power transmitted through 4 and 15. In the vicinity of the bottom of the rotary barrel 11, a stirring screw 17 swinging in the same direction as the rotary barrel 11 and in the opposite direction is arranged. The stirring screw 17 is rotated by the power transmitted through the rotary barrel 11 and further oscillates by the power transmitted through the oscillating gear 18, thereby uniformly stirring the raw material powder P during sputtering. Further, in order to perform sputtering under a certain condition, a cooling pipe 19 is attached to the outer peripheral surface of the rotary barrel 11, and the temperature inside the rotary barrel 11 is compensated by cooling water flowing through the cooling pipe 19.

In the upper part of the outer cylinder 12, a suction duct 51 of an evacuation system 50 is opened. The inside of the device body 10
The pressure is reduced by the evacuation system 50, and the inside of the rotary barrel 11 is maintained in a reduced-pressure atmosphere suitable for sputtering. The movable gantry 20 is mounted on a gantry 21 so that the
It is installed in. The movable base 20 has a target 30 and a powder distribution mechanism 4 that are movable in the horizontal direction of FIG.
0 is mounted. Thereby, the target 30 and the powder distribution mechanism 40 can move in the axial direction and the orthogonal direction of the rotary barrel 11. Moving frame 20, target 30
The movement of the powder distribution mechanism 40 is controlled by a controller 22 provided on the side surface of the gantry 21. The position indicated by the solid line in FIG. 2 is the fixed position of the target 30. Target 3
0 is inserted into the rotary barrel 11 from this position. The target 30 indicated by the dashed line is at a standby position for performing operations such as maintenance and inspection. The target 30 includes a plurality of target bodies 32 corresponding to a large-sized equipment configuration.
Are arranged in parallel and mounted on the housing 33. The housing 33 is supported in a cantilevered state, and the rotary barrel 11 is supported.
Is inserted into the rotating barrel 11 from an opening on one side.

As shown in FIG. 4, the powder distribution mechanism 40
A powder supply gutter 42 protrudes in a cantilevered state from a body 41 running along a rail 23 provided on the movable gantry 20. The powder supply gutter 42 has a powder container having a length corresponding to the effective sputtering area in the rotary barrel 11 and extends along the rail 23. The powder supply gutter 42 has a substantially U-shaped cross section with the upper part opened, and the inside serves as a powder container. The powder supply gutter 42 is attached to the rotating part 43 of the body 41. Thus, the powder supply gutter 42 is connected to the rail 2
3 can be rotated in addition to moving forward and backward. Since the fed raw material powder P is discharged by reversing the powder supply gutter 42, the powder supply gutter 42 may have an upwardly open cross-sectional shape that does not have an acute corner like a rectangular cross section. preferable. The body 41 is provided with a powder recovery mechanism 60. A recovery pipe 63 extends from a recovery tank 61 of the powder recovery mechanism 60 via a cyclone 62. A suction tube 64 connected to a vacuum source (not shown) is connected to the cyclone 62. An air cylinder 65 is provided at the tip of the powder supply gutter 42 as shown in FIG. The recovery pipe 63 is connected to the piston of the air cylinder 65 in the vicinity of the tip, and moves up and down with the vertical movement of the piston.

When collecting the coated powder after the end of the sputtering, the powder supply gutter 42 is inserted into the rotary barrel 11 with the tip of the collection tube 63 raised by the air cylinder 65. When the tip of the collection tube 63 exceeds the edge 35 of the rotary barrel 11, the air cylinder 65
To bring the tip of the collection tube 63 into contact with the powder in the rotary barrel 11. Then, the vacuum source is operated, and the powder accumulated at the bottom of the rotary barrel 11 is sucked by the collection pipe 63. After the powder is collected, the tip of the collection tube 63 is connected to the rotating barrel 11.
And the powder supply gutter 42 is retracted. The stop position of the air cylinder 65 for lowering the tip of the collection pipe 63 is set in two stages according to the amount of powder supplied into the rotary barrel 11.

The powder supply trough 42 in the-line of FIG.
Above the powder tank 4 supported by the support frame 44
5 are arranged. The raw material powder P is sent from the powder tank 45 to the entire length of the storage section of the powder supply gutter 42. The powder supply gutter 42 filled with the raw material powder P reaches the-position by the movement of the movable gantry 20 in the-direction, and is aligned with the axis of the rotary barrel 11. Then, as shown in FIG. 6, after being inserted into the rotary barrel 11 (a), the raw material powder P is discharged to the rotary barrel 11 by inversion and pulled out from the rotary barrel 11 (b). The position where the powder supply gutter 42 is inverted is detected by a sensor 49 (FIG. 2). These movements are entirely controlled by the power control panel 71 and the control system controller 22. The raw material powder P to be coated is dried by a vacuum dryer 74 as needed.

The coated powder is supplied to a powder supply trough 4
Rotating barrel 11 using the movement of (a) ← → (b) of FIG.
Recovered from. First, the stirring screw 17 is moved along the inner periphery of the rotary barrel 11 so as not to hinder the collecting operation. Then, the powder supply gutter 42 is inserted into the rotary barrel 11 with the opening facing downward, and when the tip of the collection pipe 63 exceeds the edge 35 of the rotary barrel 11, the air cylinder 65 is driven to collect the powder. The distal end of the tube 63 is lowered until it contacts the powder. Next, the collection tube 63 is reciprocated once inside the rotary barrel 11 along the axial direction. If there is a large amount of powder to be collected, stop the lowering of the collecting tube 63 so that the tip of the collecting tube 63 is kept at a position several cm away from the inner peripheral surface of the rotary barrel 11 in order to increase the suction amount. .
In this state, after the recovery pipe 63 is reciprocated one time along the axial direction inside the rotary barrel 11, the tip of the recovery pipe 63 is further lowered by the air cylinder 65, and the same recovery operation is repeated. Further, by rotating the rotary barrel 11 during powder recovery, most of the powder is recovered without unrecovered powder remaining in the rotary barrel 11.

The movement of the collecting pipe 63 is automatically controlled. Further, since the air cylinder 65 is used for raising and lowering the recovery pipe 63, unlike a motor using electricity, the metal powder or the coating powder is prevented from being ignited by heat. The coating powder accumulated in the lower part of the rotating barrel 11 is thus removed from the powder supply trough 42.
The liquid is sucked into a collecting pipe 63 that moves integrally with the collecting pipe 63, and is separated into solid and gas by a cyclone 62. At this time, if the powder supply gutter 42 is swung in the direction indicated by the arrow in FIG. 4 via the rotating part 43, the tip opening of the collection tube 63 faces a wide area on the bottom surface of the rotary barrel 11, so that the coating powder is quickly removed. Collected. Also, a part of the recovery pipe 63 faces the inside of the powder supply gutter 42 and the powder supply gutter 42
It can also be used to clean the interior of the car.

[0015]

As described above, according to the present invention, by inserting a powder supply gutter filled with raw material powder into a rotating barrel and inverting the same, the effective sputtering area with a uniform density distribution in the axial direction of the rotating barrel. Raw material powder is distributed. Further, the coated powder is sucked from the bottom of the rotating barrel by a collecting pipe provided integrally with a powder supply gutter for charging the raw material powder into the rotating barrel, and collected in a tank via a cyclone. The recovery pipe uses the movement of the powder supply gutter that moves back and forth in the axial direction of the rotating barrel,
It is moved over a wide area on the bottom of the rotating barrel. With the installation of the powder supply gutter and the recovery pipe, the uniformly coated powder is
After being efficiently removed from the rotating barrel and separated into gas and air, it is collected in a tank. Further, the collection operation in a dust-generating environment, which is often disliked by workers, is automated, which is particularly suitable for a large-sized powder coating apparatus.

[Brief description of the drawings]

FIG. 1 shows a powder coating apparatus proposed by the present inventors.

FIG. 2 is a layout of a powder coating apparatus according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a state in which a raw material powder is coated, as viewed from a barrel axial direction (a) and an orthogonal direction (b)

FIG. 4 Powder distribution mechanism with powder supply gutter

FIG. 5 Elevating mechanism of the recovery pipe

FIG. 6 is a powder supply gutter that moves back and forth in the axial direction of the rotary barrel

[Explanation of symbols]

11: Rotating barrel 20: Moving frame 23: Rail 30: Target 40: Powder distribution mechanism 41: Airframe 42: Powder supply gutter 43: Rotating unit 45: Powder tank 60: Powder recovery mechanism 61: Recovery tank
62: cyclone 63: collection tube 64: suction tube
65: Air cylinder

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Shirokura 7-1 Takaya Shinmachi, Ichikawa-shi, Chiba Nisshin Steel Co., Ltd. New Materials Research Laboratory (72) Inventor Hiroyuki Kawakami 1-1-1 Kokubuncho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Kokubu Plant of Hitachi, Ltd. (56) References JP-A-2-153068 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 14/00-14 / 58 C23C 16/00-16/56 B22F 1/02

Claims (1)

(57) [Claims] 1. An apparatus for coating powder particles by sputtering in a rotary barrel maintained in a vacuum atmosphere, wherein the raw powder is distributed to said rotary barrel, and is freely movable forward and backward , and an upper portion is opened, and the inside of the rotary barrel is opened. Valid
Has a powder container of a length corresponding to the sputtering area
A long powder supply gutter and a tip in the longitudinal direction of the powder supply gutter
A turn that opens toward the inner surface of the rotary barrel near the tip
A Osamukan, characterized in that the other end of the recovery tube was in communication with the recovery tank via the cyclone powder coating
Equipment .