JP2008007804A - Film-forming apparatus and film-forming method using the apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film-forming apparatus and method, capable of uniformly forming a dense ceramic film on a surface of a substrate, particularly on an outer circumferential curved surface of the substrate such as a bearing periphery part, by the AD method. <P>SOLUTION: The film-forming apparatus 1 is equipped with an aerosol-generating device 11, a vacuum chamber 2, a mask 6 which is arranged inside the vacuum chamber 2 and has an aperture in a prescribed manner relative to the substrate 7 serving as a film formation target, a rotary member 5 that has a circumferential curved surface and rotates in the circumference direction, and an aerosol injection nozzle 12. An aerosol is injected by the aerosol injection nozzle 12 and made to undergo primary collision against the circumferential curved surface of the rotary member 5, and ceramic particulates in the aerosol rebounding from the circumferential curved surface of the rotary member 5 are made to undergo secondary collision against the surface of the substrate 7 via the mask 6 to form the ceramic film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a film forming apparatus for forming a film on the surface of a substrate, particularly a circumferential curved surface of the substrate such as a bearing outer peripheral portion, by an aerosol deposition (hereinafter referred to as AD) method, and a film using the device. It relates to a forming method.

As a method of forming a dense ceramic film at room temperature, ultrafine particles made of brittle materials such as ceramics are aerosolized with an inert gas, ejected from a small nozzle at high speed, and sprayed and collided onto a substrate to form a film. The AD method is known (see Patent Document 1).
In this method, it is difficult to form a film on an outer peripheral curved surface such as a cylindrical surface because it is necessary to perform aerosol injection with the normal of the curved surface as an incident direction or nozzle movement at a constant speed. For this improvement, for example, a method of forming a film while rotating a cylindrical workpiece such as a bearing outer ring may be considered. However, the discharge speed of fine particles from a minute nozzle is determined by the flow rate of the carrier gas, the chamber pressure, and the differential pressure inside the nozzle. In addition, since it is determined by the nozzle shape, only a very narrow speed control can be performed, and it is very difficult to determine conditions for improving the film forming speed.

In addition, an ultra-thin ultra-fine particle film on the order of nanometers can be formed, and the surface of the material fine particles can be made new and active to form a fine particle thin film with strong inter-particle bonding. In order to make it possible to take various layer configurations of the ultrafine particle thin film, the reflective surface and the substrate are placed in a decompressed film forming chamber, the material fine particles are aerosolized and collide with the reflective surface, and then on the substrate. The technique of making it adhere is known (refer patent document 2).
However, with this method, the speed of the fine particles reflected from the reflecting surface does not exceed that of the reflecting surface, and since the mask does not pass through, the flying speed of the fine particles is not uniform and the uniformity of the film after film formation is insufficient. There is a problem of doing.
Japanese Patent No. 3348154 JP 2002-45735 A

  The present invention has been made in order to cope with such a problem, and is a film capable of uniformly forming a dense ceramic film on the surface of the substrate, particularly on the circumferential curved surface of the substrate such as the outer peripheral portion of the bearing in the AD method. It is an object to provide a forming apparatus and a film forming method using the apparatus.

The coating film forming apparatus of the present invention comprises an aerosol generating apparatus in which ceramic fine particles are dispersed in a gas to form an aerosol, and a vacuum chamber, and a predetermined amount of a substrate on which a film is to be formed is provided in the vacuum chamber. A film forming apparatus comprising: a mask having an opening; a rotating member having a circumferential curved surface and rotating in a circumferential direction; and an aerosol injection nozzle for injecting the aerosol toward the rotating member. The apparatus injects the aerosol from the aerosol injection nozzle, primarily collides with the circumferential curved surface of the rotating member, and reflects the ceramic fine particles in the aerosol reflected from the circumferential curved surface of the rotating member on the surface of the substrate. A ceramic film is formed by secondary collision through a mask.
The surface of the substrate on which the ceramic coating is formed is a circumferentially curved surface, and the ceramic coating is formed while the substrate is rotated in the circumferential direction or moved in the axial direction. An XY table is used, and the rotation in the circumferential direction is performed using an object rotating motor installed on the positioning XY table.
The raw ceramic fine particles are brittle materials and have a fine particle diameter of 0.01 to 2 μm.
The gas is an inert gas containing argon, nitrogen, or helium.

  The coating film forming method of the present invention is a coating film forming method by an aerosol deposition method in which an aerosol in which ceramic fine particles are dispersed in a gas is sprayed onto a substrate from an aerosol spray nozzle and collided in a vacuum chamber. Then, using the coating film forming apparatus, the aerosol is sprayed from the aerosol spray nozzle, primarily collides with the circumferential curved surface of the rotating member, and the ceramic fine particles in the aerosol reflected from the circumferential curved surface of the rotating member are A ceramic coating is formed by secondary collision with the surface of the substrate through a mask.

Since the coating film forming apparatus of the present invention can change the circumferential speed (angular velocity ω × radius r) of the rotating member, it reflects at the collision position with respect to the primary collision velocity of the aerosol colliding with the rotating member. It is possible to control the aerosol reflection speed, that is, the secondary collision speed of the aerosol to the substrate, and in particular, a secondary collision speed obtained by accelerating the reflection speed can be obtained.
Further, by causing the ceramic fine particles to secondarily collide with the surface of the substrate through the mask, it is possible to form the film only with the ceramic fine particles having the same flying speed and flying direction, and the film forming state is stabilized.
In addition, the fine particles made of brittle materials such as ceramics are primarily collided with a rotating member that rotates in the circumferential direction, so that the aggregated fine particle mass in the aerosol can be crushed. Secondary collision can be performed, and the film formation efficiency is improved.
As a result, the film forming apparatus of the present invention is excellent in film forming efficiency and can form a ceramic film uniformly on the surface of the substrate. Even if the surface of the substrate on which the ceramic coating is formed is a circumferential curved surface that is difficult to form, the ceramic coating is applied using the above apparatus while rotating the substrate in the circumferential direction or moving in the axial direction. By forming, a ceramic film can be uniformly and efficiently formed on the circumferential curved surface of the substrate.

  The coating film forming method of the present invention is such that the aerosol sprayed from the aerosol spray nozzle using the above-described coating film forming apparatus is first collided with the rotating member to crush the ceramic fine particle lump, and then the aerosol is reflected from the rotating member. Controls the speed and direction of the ceramic fine particles inside to cause secondary collision with the surface of the base material, so that a ceramic film can be uniformly formed on the surface of the base material such as the outer periphery of the bearing, improving film formation efficiency. Can be made.

A configuration example of a film forming apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing an example of a film forming apparatus, and is a diagram showing a configuration in which a film is formed on the outer peripheral curved surface of a bearing outer ring as a base material.
As shown in FIG. 1, a film forming apparatus 1 using an AD method includes an aerosol generating device 11 and a vacuum chamber 2. The aerosol generating apparatus 11 having ceramic fine particles therein includes a gas supply facility 10 outside, and an aerosol composed of ceramic fine particles and a carrier gas is formed by the carrier gas supplied from the gas supply facility 10, and the flow of the carrier gas and the vacuum The aerosol is supplied to the aerosol injection nozzle 12 in the vacuum chamber 2 by the suction of the pump 14.
An inert gas is used as the aerosol carrier gas. Usable inert gases include argon, nitrogen, helium and the like.

In the vacuum chamber 2, a base material 7 that is a ceramic film formation target and has a circumferential curved surface, an aerosol injection nozzle 12, a rotating member 5 that has a circumferential curved surface and rotates in the circumferential direction (A in the figure), A mask 6 having a predetermined opening with respect to the substrate 7 is disposed. The base material 7 is attached to an object rotation motor 9 that is connected to the positioning XY table 8. The aerosol injection nozzle 12 is for injecting an aerosol containing ceramic fine particles from the tip of the nozzle to cause a primary collision with the rotating member 5.
A vacuum pump 14 is provided outside the vacuum chamber 2, and the aerosol generator 11 and the vacuum chamber 2 are kept under reduced pressure by the vacuum pump 14. The particulate filter 13 is provided to prevent the ceramic particulates from entering the vacuum pump 14.
The material of the rotating member is not particularly limited as long as it is a material that is not easily damaged by the collision of the ceramic fine particles. Preferably, a ceramic material that is the same kind as the ceramic fine particles or harder than the ceramic fine particles is preferable from the viewpoint of preventing foreign matter contamination. Further, the shape is a disc shape having a thickness larger than the long side of the rectangular nozzle opening.

Details of the injection and collision of the ceramic fine particles in the film forming apparatus of the present invention will be described with reference to FIG. FIG. 2 is an enlarged view of a portion C in FIG.
As shown in FIG. 2, the ceramic fine particles 3 in the aerosol sprayed from the aerosol spray nozzle 12 connect the collision position D and the outer circumferential center O of the rotating member to the collision position D of the circumferential curved surface of the rotating member 5. Colliding with an angle of incidence and velocity with respect to the straight line DO. The incident fine particles 3 are crushed at the time of the collision. The crushed incident fine particles 3 recoil as reflected fine particles 4a having a reflection angle and a velocity corresponding to the incident angle with respect to the straight line DO when the rotating member is not rotated. The reflection direction is shifted in the tangential direction 4b at the collision position by the peripheral speed of the rotating member 5 rotating in A), and the flying fine particles 4 having the accelerated flying direction and velocity travel toward the base material 7.
The flying fine particles 4 are blocked by the mask 6, but only the mask processing fine particles 4 c that can pass through the opening 6 a of the mask 6 toward the center of the outer circumference of the base material 7 can collide with the base material 7. Since the masked fine particles 4c collide with the base material 7 at a predetermined speed toward the center of the outer circumference of the base material 7, a uniform ceramic film can be efficiently formed.

Further, the size and speed of the masked fine particles 4c that collide with the base material 7 are controlled by the speed at the time of primary collision of the incident fine particles 3, the rotational speed of the rotating member 5, the shape of the opening 6a of the mask 6, and the like. By passing through the mask 6 having the opening 6a, the mask-treated fine particles 4c collide perpendicularly with the outer circumferential curved surface of the substrate 7 so that the film is efficiently formed.
The material of the mask is not limited as long as an extra fine particle flight component due to the velocity distribution in the fine particle beam can be shielded. Preferably, metal or organic and inorganic plates that are not easily damaged can be employed. In addition, the mask may be about 1000 times as large as the opening (for example, if the opening is 1 mm × 10 mm = 10 mm ² , 10 cm ² or more), and the opening 6a generates a particle beam. It is good also as a shape corresponding to the nozzle cross-sectional shape (rectangular shape) to make.
The installation position of the mask is, for example, installed such that the opening 6a is perpendicular to a straight line DO ′ that connects the primary collision position D with the rotating member and the center of the outer circumference of the substrate (O ′), and the installation distance to the substrate. It is desirable that the distance be such that even if the reflective fine particles from the substrate are re-reflected on the back surface of the mask and re-enter the substrate, the film formation is not affected.
The mask processing fine particles 4c collide perpendicularly with the substrate 7 through the opening 6a of the mask. At the time of this collision, the base material 7 is rotated (B in the figure) by the object rotating motor 9 and is moved in the axial direction by the positioning XY table 8, and a predetermined surface is formed on the outer circumferential curved surface of the base material 7. A film thickness ceramic coating is formed. The movement of the positioning XY table 8 in the axial direction and the rotation of the object rotating motor 9 may be performed individually or simultaneously.

In the present invention, the ceramic fine particles used as the aerosol raw material for forming the ceramic film may be any fine particles that can form a film, and any ceramic fine particles can be used. Examples thereof include oxides such as alumina, zirconia, and titania, and fine particles such as silicon carbide and silicon nitride.
The average particle size of the ceramic fine particles that can be used in the present invention is 0.01 μm to 2 μm. If it is less than 0.01 μm, it is easy to agglomerate and it is difficult to form an aerosol. In the present invention, the average particle diameter is a value measured by Nikkiso Co., Ltd .: Laser type particle size analyzer Microtrac MT3000.
In addition, as the base material to be coated, various members required for heat and abrasion resistance, durability, corrosion resistance and insulation resistance used in various industrial machines, for example, members constituting a bearing, particularly circumferential curved surfaces The member etc. which have are mentioned.

The film forming method of the present invention will be described with reference to FIGS. The film forming method of the present invention is a method of forming a film on a substrate using the above-described film forming apparatus and utilizing the AD method.
The base material 7 is attached to an object rotating motor 9 connected to the positioning XY table 8, a predetermined amount of ceramic fine particles is put into the aerosol generator 11, the vacuum pump 14 is activated, and the aerosol generator 11 and the vacuum chamber The inside of 2 is set to a predetermined reduced pressure. A carrier gas is supplied from the gas supply facility 10 to the aerosol generator 11 to generate an aerosol composed of ceramic fine particles and a carrier gas, which is supplied to the vacuum chamber 2 by the carrier gas flow and the suction of the vacuum pump 14, and aerosol injection. Aerosol is ejected from the nozzle 12 to collide with the circumferential curved surface of the rotating member 5 (see FIG. 1).

The aerosol is injected from the aerosol injection nozzle 12 and the collision position D and the outer circumference of the rotating member are brought into the collision position D of the circumferential curved surface of the rotating member 5 rotating in the circumferential direction (A in the figure) at a predetermined rotational speed. The incident fine particles 3 are primarily collided with a predetermined incident angle and velocity with respect to the straight line DO connecting the center O to break up the fine particle lump.
The pulverized fine particles are given a flying direction and a velocity that are accelerated while shifting the reflection direction in the tangential direction 4b at the collision position D by the peripheral speed of the rotating member 5 rotating in the circumferential direction (A in the figure). It advances toward the base material 7 as the flying fine particles 4. The traveling flying fine particles 4 are blocked by the mask 6, and only the mask processing fine particles 4c having a predetermined flying direction and speed with respect to the base material 7 and passing through the opening 6a of the mask 6 are caused to collide with the base material 7 (FIG. 2).

  The substrate 7 is rotated by the object rotating motor 9 (B in the figure) and moved in the axial direction by the positioning XY table 8 while moving the mask processing fine particles 4c toward the center of the outer circumference of the substrate 7 at a predetermined speed. The uniform ceramic coating can be efficiently formed on the outer circumferential curved surface of the substrate 7 by causing the substrate 7 to collide with the substrate 7.

Example Rotation of an object using a coating film forming apparatus 1 shown in FIG. 1 in which a bearing outer ring (manufactured by SUJ2: outer diameter 35 mm × inner diameter 27 mm × width 15 mm) as a base material 7 is connected to a positioning XY table 8 Attached to the motor 9 and charged with 100 g of alumina fine particles (Taimicron TM-DAR, average particle size 0.16 μm) by the aerosol generator 11, the vacuum pump 14 was started, and the aerosol carrier gas was Helium gas (pure helium G1 manufactured by Taiyo Nippon Sanso Co., Ltd.) was introduced into the aerosol generator 11. The decompression condition was several Torr.
The aerosol generator 11 generates an aerosol composed of alumina fine particles and a carrier gas, which is supplied to the vacuum chamber 2 by the carrier gas flow and the suction of the vacuum pump 14, and the aerosol injection nozzle 12 (opening 10 mm). X1 mm) is sprayed from aerosol and collides with the circular curved surface of a disk-shaped rotating member 5 (alumina, rotating at 1910 rpm, outer diameter 200 mm x width 25 mm) rotating at a peripheral speed of 50 m / sec. The ceramic fine particle lump in the aerosol is crushed and the reflection direction and the reflection speed of the ceramic fine particle beam recoiling from the collision position are controlled by the incident angle at the collision position and the rotation speed of the rotating member 5 to form a rectangular shape. A ceramic coating is formed by secondarily colliding with the outer peripheral curved surface of the bearing outer ring through a mask 6 having an opening 6a (rectangular shape 11 mm × 1.5 mm: corresponding to the particle beam surface). Made. An alumina coating is applied to the outer peripheral curved surface of the bearing outer ring by the object rotating motor 9 (rotation speed is 10 rpm) with the bearing outer ring and the positioning XY table 8 (axial moving speed 5 mm / min) connected to the motor. Formed.

  The outer peripheral curved surface of the formed bearing outer ring was ultrasonically cleaned with an ethanol solution and cross-sectioned. As a result, an α-alumina coating having a dense, uniform, transparent and smooth surface was formed with a thickness of 6 μm.

  The film forming apparatus of the present invention and the film forming method using the apparatus can uniformly form a dense ceramic film on the surface of the base material, particularly on the outer circumferential surface of the base material such as the outer periphery of the bearing in the AD method. Therefore, it can be suitably used for forming a ceramic film on various industrial parts.

It is a figure which shows one Example of the film formation apparatus of this invention. It is an enlarged view of the C section of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating film formation apparatus 2 Vacuum chamber 3 Incident fine particle 4 Flying fine particle 4a Reflective fine particle 4b Tangential direction 4c Mask processing fine particle 5 Rotating member 6 Mask 7 Base material 8 XY table 9 Rotating motor 10 Gas supply equipment 11 Aerosol generator 12 Aerosol injection nozzle 13 Particulate filter 14 Vacuum pump

Claims (5)

An aerosol generating device for dispersing ceramic fine particles in a gas to form an aerosol, and a vacuum chamber, a mask having a predetermined opening with respect to a substrate on which a film is to be formed, and a circle in the vacuum chamber A film forming apparatus having a rotating member having a circumferential curved surface and rotating in a circumferential direction, and an aerosol injection nozzle for injecting the aerosol toward the rotating member,
The coating film forming apparatus sprays the aerosol from the aerosol spray nozzle, primarily collides with a circumferential curved surface of the rotating member, and reflects ceramic fine particles in the aerosol reflected from the circumferential curved surface of the rotating member on the substrate. A film forming apparatus, wherein a ceramic film is formed by causing secondary collision with the surface through the mask.   The surface of the substrate on which the ceramic coating is formed is a circumferentially curved surface, and the ceramic coating is formed while the substrate is rotated in the circumferential direction or moved in the axial direction. The film forming apparatus according to claim 1, wherein the film is formed using an XY table, and the rotation in the circumferential direction is performed using an object rotation motor installed on the positioning XY table.   3. The film forming apparatus according to claim 1, wherein the raw material ceramic fine particles are a brittle material and have a fine particle diameter of 0.01 to 2 [mu] m.   The film forming apparatus according to claim 1, wherein the gas is an inert gas containing argon, nitrogen, or helium. A method of forming a film by an aerosol deposition method, in which an aerosol in which ceramic fine particles are dispersed in a gas is jetted onto a substrate from an aerosol jet nozzle and collided in a vacuum chamber,
The coating film forming apparatus according to any one of claims 1 to 4, wherein the aerosol is sprayed from the aerosol spray nozzle and primarily collides with a circumferential curved surface of the rotating member, and the circumferential curved surface of the rotating member. A ceramic film is formed by causing ceramic fine particles in the aerosol reflected from the substrate to secondarily collide with the surface of the substrate through a mask to form a ceramic film.

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