JP3068948B2 - Sputtering equipment for powder coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus used for powder coating by sputtering in a rotating drum.

[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 means for coating the powder particles, there are known a method of performing electroplating or electroless plating by suspending the powder, and a method of forming a predetermined film on the powder in a fluidized state by sputtering. ing.
The present inventors also introduced a sputtering apparatus using a rotating drum as an apparatus for coating powder by sputtering in JP-A-2-153068.

[0004] In this powder coating apparatus, as shown in FIG. 1, a reduced-pressure heat treatment chamber 1 containing powder particles P before coating is connected to a rotary drum 2 having a sputtering source 3 built therein.

[0005] The powder particles P are accommodated in a container 1b provided with a heating coil 1a, and are supplied to the inside of the rotary drum 2 via a supply conduit 1e by a screw feeder 1d driven by a motor 1c. The supply conduit 1e is supported by a bearing 2f provided on one end face of the rotary drum 2.
A gas introduction pipe 1g is provided concentrically with the supply pipe 1e so as to feed the inert gas into the inside of the rotary drum 2.

[0006] The rotary drum 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 drum 2 around a horizontal axis. The sputtering device 3 is fixedly arranged in the rotary drum 2 by an arm 3b hermetically supported by a bearing 3a at an end surface (right side in FIG. 1) opposite to the end surface into which the supply conduit 1e is inserted. The target plate 3c, which is slightly shorter than the axial length, is arranged obliquely downward. It is an object of the present invention to provide a vapor-deposited Zn-based steel strip or a vapor-deposited Zn-Mg-plated steel strip having excellent corrosion resistance by forming a layer.

The powder particles P supplied to the axial end of the rotary drum 2 from the supply conduit 1 e are distributed over the entire length of the drum shaft as the rotary drum 2 rotates, and flow on the inner bottom surface of the rotary drum 2. The coating material is beaten out of the target plate 3c by the impact of the plasma of Ar or the like, flies in the rotary drum 2 and adheres to the powder particles P in a flowing state. When a predetermined coating layer is formed, the rotating drum 2
Is opened to take out the coated powder particles P.

Further, as a powder coating apparatus having an increased production capacity, a target plate driving unit 5 and a drum driving unit 6 are arranged on both sides of a vacuum chamber 4 so as to be able to retreat along guide rails 5a, 6a as shown in FIG. Device was developed. The target plate drive unit 5 cantileverly supports a sputtering device 3 similar to that shown in FIG. The drum drive unit 6 meshes with a drive shaft in the vacuum chamber 4 and
Is provided with a drive shaft for rotating the rotary drum 2 inside.

The target plate drive unit 5 and the drum drive unit 6 are connected to the vacuum chamber 4 via hermetic joints 5b, 6b at their respective forward positions. Since the guide rail 6a is provided on the upper surface of the movable base 6c, the drum drive unit 6 moves in the X direction retreating from the vacuum chamber 4 and further in the Y direction perpendicular to the vacuum chamber 4.

[0010] rotated at the initial position _{P 0} shown in FIG. 2 drum 2
Interior cleaned of, were charged raw material powder to be sputtered, to move the rotary drum 2 and the drum drive unit 6 by the traveling of the moving platform 6c to the standby position P ₁ that matches the axis of the vacuum chamber 4. The target drive unit 5, the cleaning, the charge of the target material, such as carried out at the standby position P _1. Then, to advance the target plate driving unit 5 and the drum drive unit 6 in the operative position P _2, it is connected to the vacuum chamber through a gas-tight joint 5b, 6b.

After the inside of the vacuum chamber 4 is evacuated by the rotary pump 7a and the diffusion pump 7b of the vacuum system 7, a predetermined coating is applied to the raw material powder by sputtering while rotating the rotary drum 2 inside the vacuum chamber 4. . Then, the feed to the initial position P ₀ via the standby position P _1, rotating the coated powder drum 2
Remove from According to this method, the rotary drum 2 having a large diameter can be used, so that the production capacity is improved.

[0012]

SUMMARY OF THE INVENTION Sputtering apparatus 3
When coating the raw material powder charged into the rotating drum 2 by the above, it is necessary to stabilize the sputtering conditions in order to apply a uniform coating. The stabilization of the sputtering conditions is greatly affected by the distance from the target plate 3c of the sputtering apparatus 3 to the fluidized bed of the raw material powder formed on the inner bottom of the rotating drum 2.

In a structure in which the sputtering device 3 is supported in a cantilever manner in the rotating drum 2, vibration during rotation of the drum,
The impact or the like propagates to the sputtering device 3, and the distance from the target plate 3c to the fluidized bed of the raw material powder is likely to fluctuate irregularly. In addition, the components of the sputtering apparatus 3 undergo thermal deformation due to the temperature rise during sputtering, and the distance from the target plate 3c to the fluidized bed of the raw material powder changes in the axial direction of the rotating drum 2.

When the distance from the target plate 3c to the fluidized bed of the raw material powder is small, a large amount of sputtered particles locally adhere to the powder particles, and a thick coating layer is formed. On the other hand, sputter particles flying from a relatively distant target plate 3c spread over a wide range according to the flying distance,
The amount applied to individual powder particles is reduced. As a result, the coating layer formed on the surface of the powder particles varies. In addition, when the thermal deformation is extreme, abnormal discharge may occur and the operation may not be able to be continued.

The present invention has been devised in order to solve such a problem. In addition to improving the structural strength of a sputtering apparatus, incorporating a cooling mechanism, suppressing thermal deformation, and performing sputtering under a constant condition. And to form a uniform coating layer on the surface of the powder particles.

[0016]

DISCLOSURE OF THE INVENTION The sputtering apparatus for powder coating of the present invention has the following objects.
A semi-cylindrical casing whose inside is divided by a reinforcing plate, a target ring attached to the casing, a water-cooled pipe attached to the inner peripheral surface of the target ring, and mounted on the target ring via a backing plate And a water cooling jacket fixed to the inner surface of the semi-cylindrical casing, and is inserted in a state of being suspended in the axial direction of the rotary drum in a state where a vertical temperature difference is suppressed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. As shown in FIG. 3, the sputtering apparatus of this embodiment has a semi-cylindrical casing 10.
It has. The interior of the casing 10 is divided into two by a reinforcing plate 11, and as shown in FIG. 4, a plurality of partition plates 13 _L1 , 13 _L2 ,.
13 _R1 , 13 _R2 , and the cavities 12 _L1 , 12 _L2
... 12 _Ln , 12 _R1 , 12 _R2 ... 12 _Rn .

Each of the cavities 12 _L1 , 12 _L2.
・ 12 _Ln , 12 _R1 , 12 _R2 ... The inner wall of the casing 10 facing the 12 _Rn has a water cooling jacket 20 _L1 ,
20 _L2 ... 20 _Ln , 20 _R1 , 20 _R2.
0 _Rn is fixed. In the inner space _{20 Ln} of the water-cooled jacket _{20 Ln,} water inlet _{22 Ln} connected to the water supply pipe (not shown) is opened. In addition, the internal space 20 _Ln
Opening the drain outlet _{23 Ln} is connected to the water supply port _{22 Ln-1} of the water-cooled jacket _{20 Ln-1} adjacent to.
Then, drain port _{23 L1} of the water-cooled jacket _{20 L1} is,
It is connected to the water supply port 22 _R1 of the water cooling jacket 20 _R1 ,
Drain outlet _{23 R1} of the water-cooled jacket _{20 R1} is connected to the water supply port _{22 R2} of the water-cooled jacket _{20 R2.} In this manner, the inside of the casing 10, the water cooling jacket _{20 Ln, 20 Ln-1,} ··· 20 Rn-1, 20
A cooling water passage that sequentially passes through _Rn is formed. The cooling water of the water cooling jacket 20 _Rn is sent out of the system via a drain pipe (not shown) connected to the drain port 23 _Rn .

A flange 30 having a rectangular inner peripheral surface 31 is fixed to both end edges of the casing 10. Inner circumference 3
1, a water cooling pipe 32 is brazed. Also,
A concave groove into which the sealing material 33 is inserted is formed on the lower surface of the flange 30, and bolt holes 34 are formed at appropriate intervals.

The backing plate 40 is made of copper having good heat conductivity, and is fixed to the flange 30 by screwing a bolt 42 into the bolt hole 34 via a mounting portion 41. A plurality of projections and depressions are formed on the back surface of the backing plate 40, and magnets 43a to 43c that regulate the flying direction of sputtered particles are arranged. A water cooling jacket 45 having a cooling water passage 44 formed therein is provided on the back surface of the backing plate 40.

The target plate 50 mounted on the front side of the backing plate 40 is, as shown in FIG.
The divided plates 50 ₁ , 50 _2, ..., 50 _n divided in the longitudinal direction and the width direction of the casing 10 are fixed to the backing plate 40 by fixing brackets 51 (see FIG. 3). I have. Also, backing plate 4
0, magnetic shields 52 and 53 for preventing magnetic fluxes from the magnets 43a to 43c from leaking outside.
(See FIG. 3) are provided in duplicate. Further, on the outer periphery of the flange 30, there is disposed a jet pipe 54 for feeding Ar gas toward the target plate 50. On the outer periphery of the target plate 50, a jacket 59 through which cooling water passes is provided.

When this sputtering apparatus A is incorporated in the powder coating apparatus described with reference to FIG. 2, it is cantilevered by a target drive unit 60 as shown in FIG. That is, the connection fitting 61 is fixed to one end of the sputtering apparatus A, and the sputtering apparatus A is connected to the arm 62 inserted through the target drive unit 60 via the connection fitting 61.
Connect. Since the arm 62 is rotatably supported by the bearings 63 to 64, the target plate 50 of the sputtering apparatus A is rotated at an appropriate inclination angle by the rotating drum 8.
0.

As described with reference to FIG. 2, the target drive unit 60 and the drum drive unit 70 move in the left-right direction in FIG. The target drive unit 5 shown in FIG. 2 is in the operating position advanced toward the vacuum chamber 4, and a flange plate 5 c provided on the front surface of the target drive unit 5 is hermetically connected to a flange 4 a provided at an end of the vacuum chamber 4. Is done. Drum drive unit 6
The flange plate 6d is also hermetically connected to the flange 4b at the opposite end of the vacuum chamber 4.

Power from a motor 72 is transmitted to a drive shaft 71 of the drum drive unit 70 via a transmission 73. The drive shaft 71 projects into the vacuum chamber 10 via an airtight joint 74 such as a magnetic seal or the like, and is connected to a drive shaft 76 in the chamber via a coupling 75.
The in-chamber drive shaft 76 is rotatably supported by bearings 77a and 77b attached to the inner surface of the vacuum chamber 10. The drive gears 78a and 78b mounted on the in-chamber drive shaft 76 mesh with the external gears 82a and 82b on the rotary drum 80 side, respectively.

The drive shaft 71 and the drive shaft 76 in the chamber
Supplies the power from the motor 72 to the external gears 82a and 82b.
To rotate the drum main body 81. Also, a powder stirring mechanism that stirs the raw material powder supplied into the drum body 81 during sputtering to perform uniform powder coating, a water cooling mechanism that suppresses a temperature rise of the drum body 81 during sputtering, and the like, have a drive shaft. 71 to the power transmission system of the drive shaft 76 in the chamber may be provided in the same manner.

After the inside of the vacuum chamber 4 is evacuated to a vacuum atmosphere, the Ar gas, which has been turned into plasma, is sent from the ejection pipe 54 toward the surface of the target plate 50 while applying a high voltage of 400 V to the target plate 50. The constituent atoms of the target plate 50 are excited by the Ar plasma, fly toward the raw material powder at the bottom of the rotating drums 2, 80, and adhere to the surfaces of the individual powder particles.

At this time, the heat of the target plate 50 is removed through the backing plate 40, and is kept at a low temperature of 500 ° C. or less. Further, the hollow portions 12 _L1 , 12 _L2 ... Between the backing plate 40 and the casing 10.
_.. , 12 _Ln , 12 _R1 , 12 _R2 ... 12 _Rn function as heat insulating layers, and water cooling jackets 20 _L1 , 20 _L2 .
Due to the water cooling action of 0 _Ln , 20 _R1 , 20 _R2 ... 20 _Rn , the casing 10 is maintained at room temperature, and no thermal deformation occurs. The rigid strength of the casing 10 is the same as that of the casing 1.
., 13 _L1 , 13 _L2 , 13 _Ln , 13 _R1 , 13 _R2 ...
_-Increased by 13 _Rn .

The sputtering apparatus A supported by the casing 10 does not hang down the free end side of the sputtering apparatus A due to thermal deformation even in the state of being cantilevered as shown in FIG. The distance between 50 and the inner bottom surface of rotating drum 80 is kept constant in the axial direction of rotating drum 80. Therefore, trouble such as abnormal discharge does not occur, and the raw material powder charged in the rotating drum 80 is sputtered under stable conditions, and a uniform coating layer is formed on the surface of each powder particle.

In the above embodiment, the sputtering apparatus A is disposed in the rotary drums 2 and 80 in a cantilever manner. However, the present invention is not limited to this, and both ends of the sputtering apparatus A can be supported by both the target driving units 5 and 60 and the drum driving units 6 and 30. In this case, the deformation of the sputtering apparatus A due to its own weight is suppressed, and the distance from the target plate 50 to the inner surfaces of the rotating drums 2 and 80 is more accurately maintained.

[0030]

As described above, according to the present invention, the target plate is supported by the cylindrical casing, and the water cooling jacket is attached to the inner surface of the casing, so that the target plate is suspended in the rotating drum. Nevertheless, the distance between the target plate and the inner surface of the drum is kept constant. Therefore, the sputtering conditions are stabilized, and it becomes possible to produce a powder with a uniform coating at a high yield.

[Brief description of the drawings]

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

FIG. 2 is a large powder coating apparatus developed by the present inventors.

FIG. 3 is an axial sectional view of a sputtering apparatus according to an embodiment of the present invention.

FIG. 4 is a view of the sputtering apparatus viewed from below with a target plate removed.

FIG. 5 is a view of the sputtering apparatus viewed from below with a target plate attached.

FIG. 6 shows a state in which the sputtering apparatus is cantilevered and arranged in a rotating drum.

[Explanation of symbols]

A sputtering apparatus 2 rotating drum 10
Casing 11 Reinforcement plate 20 _L1 , 20 _L2 ... 20
_Ln , 20 _R1 , 20 _R2 ... 20 _Rn water cooling jacket 3
0 Target ring 32 Water cooling pipe 40 Backing plate 50 Target plate

────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Publication No. 60-8303 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 14/00-14/58 B22F 1 / 02

Claims (1)

(57) [Claims] 1. A semi-cylindrical casing having an interior divided by a reinforcing plate, a target ring attached to the casing, a water-cooled pipe attached to an inner peripheral surface of the target ring, and a backing on the target ring. A target plate mounted via a plate, and a water-cooled jacket fixed to the inner surface of the semi-cylindrical casing, and suspended in the axial direction of the rotating drum in a state in which a vertical temperature difference is suppressed. A sputtering apparatus for powder coating characterized by being inserted by: