JP2008045191A - Apparatus and method for depositing coating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating film depositing apparatus capable of crushing coarse coagulated powder or the like forming a factor of impairing the film growth by the etching effect or the like in the AD method, and easily increasing the rate of generation of primary particles, and having excellent film deposition rate and film deposition efficiency, and a coating film depositing method using the apparatus. <P>SOLUTION: The coating film depositing apparatus comprises an aerosol generation device 9 for forming aerosol by diffusing particles of ceramic or the like in a gas, a vacuum chamber 3, and an aerosol jet nozzle 2 arranged in the vacuum chamber 3, and performs the film deposition by jetting aerosol onto a base material 5 from the aerosol jet nozzle 2 by the aerosol deposition method. Aerosol is jetted from the aerosol jet nozzle 2 at the angle of ejection symmetric to the perpendicular to the base material 5, and particles are collided with each other before collision with the base material 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an aerosol deposition method (hereinafter referred to as AD method) in which fine particles in an aerosol ejected from an aerosol ejection nozzle collide with each other and then collide with a substrate to form a ceramic coating. And a film forming method using the apparatus.

As a method for forming a film on a substrate, there is a method for forming a film or structure of a brittle material called a fine particle beam deposition method or an AD method. In the AD method, an aerosol containing fine particles of a brittle material is sprayed from a nozzle toward the substrate, the fine particles collide with the substrate, and the polycrystalline structure of the brittle material is directly applied to the substrate using the mechanical impact force. It is the method of forming.
In order to improve the film forming efficiency, it is preferable that only the primary particles collide with the substrate. As a method for increasing the ratio of primary particles, a method is known in which a classification device is incorporated in a film forming apparatus and aerosol with a high content ratio of primary particles is injected from an aerosol injection nozzle (see, for example, Patent Document 1). Further, there is known a method in which a classification device and a crushing device are incorporated in a film forming apparatus, and an aerosol having a high primary particle content ratio is injected from an aerosol injection nozzle (for example, see Patent Document 2).

However, these methods have a drawback that the apparatus becomes large. In addition, even when such an apparatus is used, there is a possibility of re-aggregation when passing through the injection nozzle.
That is, an example of the nozzle tip shape in the conventional AD method will be described with reference to FIG. As shown in FIG. 3, the nozzle 12 has a rectangular discharge opening 12a, and injects aerosol containing fine particles from the opening 12a. When the fine particles in the aerosol pass through the discharge opening 12a where the flow path is suddenly narrowed, they are violently contacted between the particles and easily re-aggregated and sprayed onto the base material 5 mounted on the XY table 4. The ejected coarse ceramic aggregate powder collides with the substrate 5 with almost no collision between the aggregate powders. Coarse ceramic agglomerated powder that has collided with the base material becomes a factor that hinders film growth due to an etching effect or the like, and the density of deposits and structures does not increase and the mechanical strength decreases. There is a problem that the uniformity of 5a and the structure is impaired.
Japanese Patent Laid-Open No. 11-21677 JP 2001-181859 A

  The present invention has been made in order to cope with such problems. In the AD method, coarse agglomerated powder, which becomes a factor that hinders film growth due to an etching effect or the like, is crushed and the generation ratio of primary particles is easily achieved. An object of the present invention is to provide a film forming apparatus excellent in film forming speed and film forming efficiency and a film forming method using the apparatus.

  The coating film forming apparatus of the present invention comprises an aerosol generator for dispersing fine particles in a gas to form an aerosol, a vacuum chamber, and an aerosol injection nozzle disposed in the vacuum chamber. An apparatus for forming a film that forms a film by spraying an aerosol onto a base material from a nozzle and colliding with the aerosol spray nozzle before the fine particles sprayed from the discharge opening of the spray nozzle collide with the base material The nozzle is capable of causing the fine particles to collide with each other.

The fine particles are ceramic fine particles having an average particle size of 0.1 μm to 2 μm. The ceramic fine particles are alumina fine particles.
The gas is an inert gas containing argon, nitrogen, or helium.

  The film forming method of the present invention comprises an aerosol forming step in which fine particles are dispersed in a gas to form an aerosol, and a film is formed by injecting and colliding the aerosol from an aerosol injection nozzle onto a substrate in a vacuum chamber. A film forming method by an AD method comprising a film process, wherein the film forming process is a process of colliding fine particles ejected from an aerosol spray nozzle with each other and then colliding with a substrate. And

  The film forming apparatus of the present invention includes an aerosol generating device in which fine particles are dispersed in a gas to form an aerosol, a vacuum chamber, and an aerosol injection nozzle disposed in the vacuum chamber. Since the fine particles injected from the discharge opening of the injection nozzle can collide with the fine particles before colliding with the base material, the agglomerated powder is crushed and broken by the collision of the fine particles. Since the fine particles collide with the base material, the uniformity of the coating on the base material is excellent, and the film forming speed and film forming efficiency are improved.

  In the film forming method of the present invention, the film formation step is a step of causing the fine particles injected from the aerosol injection nozzle to collide with each other and then colliding with the base material. Since the fine particles having a reduced ratio of the agglomerated powder collide with the base material, the uniformity of the coating on the base material is excellent, and the film forming speed and film forming efficiency are improved.

In the present invention, the AD method comprises an aerosol in which fine particles such as ceramics are dispersed in a gas, sprayed from an aerosol spray nozzle toward a base material, and the aerosol collides with the surface of the base material at a high speed, and consists of a constituent material of the fine particles. This is a method of forming a film on a substrate. In general, ceramic fine particles are likely to partially aggregate to form secondary particles due to interparticle deposition during stationary storage or collision between particles during aerosol formation, and easily form ceramic aggregated powder. The aerosol containing coarse ceramic fine particles such as ceramic aggregate powder inhibits the film formability and denseness of the ceramic coating.
Therefore, in the film forming apparatus of the present invention and the film forming method using the apparatus, the aerosol is sprayed onto the base material from the aerosol spray nozzle, and the fine particles collide with each other before the collision with the base material. It is crushed to improve the film characteristics and to improve the film forming speed and film forming efficiency. Fine ceramic fine particles such as primary particles in the aerosol are pulverized by collision to form a clean new surface and cause low-temperature bonding. Therefore, bonding between the fine particles can be realized at room temperature.

A configuration example of a film forming apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 4 is a diagram showing a configuration of a film forming apparatus when a film is formed on the substrate surface.
As shown in FIG. 4, the film forming apparatus 1 based on the AD method includes an aerosol generator 9 and a vacuum chamber 3. In the vacuum chamber 3, a base material 5 on which a ceramic film is to be formed and an aerosol injection nozzle 2 are disposed. The vacuum chamber 3 is kept under reduced pressure by the vacuum pump 8. The particulate filter 7 is provided in order to prevent ceramic particulates from being mixed into the vacuum pump 8.
The ceramic fine particles are mixed with the carrier gas supplied from the gas supply facility 6 in the aerosol generator 9 to form an aerosol. The aerosol is supplied to the aerosol injection nozzle 2 in the vacuum chamber 3 by the flow of the carrier gas and the suction of the vacuum pump 8. The aerosol supplied to the aerosol injection nozzle 2 includes ceramic fine particles and agglomerated powder in which a part of the ceramic fine particles are aggregated to form secondary particles.
The supply speed of the aerosol to the aerosol injection nozzle 2 is adjusted by the supply pressure of the carrier gas from the gas supply facility 6 and the degree of pressure reduction in the vacuum chamber 3. An inert gas is used as the aerosol carrier gas. Usable inert gases include argon, nitrogen, helium and the like.

The aerosol is injected from the aerosol injection nozzle 2 at a portion B in the figure, and before reaching the base material 5, the fine particles in the aerosol collide with each other and the aggregated powder is crushed on the base material 5 Colliding to form a ceramic coating. Details of the aerosol injection nozzle 2 will be described later with reference to FIGS. 1 and 2.
The substrate 5 is fixed on the XY table 4 and moved in the axial direction in the vacuum chamber 3 (A in the figure).
In the above-described configuration, any device / part or the like normally used in the AD method can be used for the aerosol generator other than the aerosol injection nozzle 2.

FIG. 1 is a diagram showing details of a portion B of FIG. 4 as an embodiment according to the present invention. As shown in FIG. 1, the aerosol injection nozzles 2 b and 2 c inject the aerosol toward the base material 5 from the discharge openings 2 d and 2 e, respectively, at an injection angle α that is symmetric with respect to the perpendicular to the base material 5. The fine particles in the aerosol injected at the injection angle α collide with each other before the collision with the base material 5 attached to the XY table 4, the aggregated powder in the fine particles is crushed, and fine ceramic fine particles such as primary particles. Also, it is pulverized by collision to form a clean new surface, and collides with the substrate 5 to form the coating 5b.
The ceramic particle collision position C indicates the collision position of the ceramic fine particles discharged from the centers of the discharge openings 2d and 2e of the aerosol injection nozzles 2b and 2c, respectively.

FIG. 2 is a diagram showing details of a portion B of FIG. 4 as another embodiment according to the present invention. As shown in FIG. 2, the aerosol injection nozzle 2 f injects the aerosol toward the substrate 5 from the discharge opening 2 g at an injection angle β that is symmetric with respect to the perpendicular to the substrate 5. The fine particles in the aerosol injected at the injection angle β collide with each other before the collision with the base material 5 attached to the XY table 4, the aggregated powder in the fine particles is crushed, and fine ceramic fine particles such as primary particles. Also, it is pulverized by collision to form a clean new surface, and collides with the substrate 5 to form a coating 5c.
The ceramic particle collision position D indicates the collision position of ceramic fine particles discharged from the center of the width of the annular discharge opening 2g of the aerosol injection nozzle 2f.

In FIG. 1 and FIG. 2, the state in which the ceramic fine particles injected from the discharge opening of the aerosol injection nozzle collide with each other before reaching the substrate 5 is schematically shown by using the aerosol injection angle. As described above, the number of aerosol injection nozzles and the discharge opening of the aerosol injection nozzle should be in a state where the ceramic fine particles can collide with each other before the ceramic fine particles injected from the discharge opening of the aerosol injection nozzle reach the substrate. For example, the present invention is not limited to the above embodiment. For example, three or more aerosol injection nozzles can be used, and the shape of the discharge opening can be a complicated shape such as a star or polygon.
In addition, in the case of a complicated shape, a nozzle can also be manufactured with an ultraviolet curable resin using an optical modeling method.

The fine particles that can be used in the film forming apparatus of the present invention may be any fine particles that can form a film, and mainly include ceramic fine particles. Examples of the ceramic fine particles include oxides such as alumina, zirconia, and titania, and fine particles such as silicon carbide and silicon nitride. Among these, alumina fine particles are preferred because the higher the specific gravity of each ceramic, the easier it is to aerosolize when the true specific gravity is smaller.
In addition to ceramic fine particles, fine particles of brittle materials with strong cleavage, such as silicon and germanium, can also be used.

The average particle size of the fine particles used in the present invention is preferably 0.1 μm to 2 μm. If it is less than 0.1 μm, it is easy to agglomerate and aerosolization is difficult, and if it exceeds 2 μm, film formation by AD method cannot be performed (film growth does not occur). In the present invention, the average particle diameter is a value measured by Nikkiso Co., Ltd .: Laser type particle size analyzer Microtrac MT3000.
Further, in order to satisfactorily form a film, it is preferable to previously form cracks in the fine particles using a pulverizer such as a ball mill or a jet mill so that the fine particles are easily pulverized upon collision with the substrate.

The film forming method of the present invention will be described based on the film forming apparatus shown in FIG.
As an aerosol forming step, ceramic fine particles are charged into the aerosol generator 9 and the vacuum pump 8 is activated to decompress the vacuum chamber 3 and the aerosol generator 9. A carrier gas is supplied from the gas supply facility 6 to the aerosol generator 9 to form an aerosol composed of ceramic fine particles and a carrier gas.

  As a film forming process, the base material 5 is attached to the positioning XY table 4 in the vacuum chamber 3 and moved in the horizontal direction (A in the figure), while the aerosol is moved from the aerosol injection nozzle 2 at the portion B in the figure. It sprays with respect to the material 5, and before it reaches | attains on the base material 5, it collides with the base material 5 in the state which collided the ceramic fine particle in aerosol and crushed the aggregated powder, and forms a ceramic film. The film formation is performed until the film thickness reaches a predetermined film thickness depending on the use of the substrate. The details of the aerosol spray nozzle 2 that is sprayed onto the substrate will be described below with reference to FIGS. 1 and 2.

  As an embodiment of the present invention, as shown in FIG. 1, the aerosol is directed toward the substrate 5 at an injection angle α that is symmetrical to the perpendicular to the substrate 5 from the discharge openings 2 d and 2 e of the aerosol injection nozzles 2 b and 2 c, respectively. By spraying and colliding the fine particles before colliding with the base material 5 attached to the XY table 4, the agglomerated powder in the fine particles is crushed and fine ceramic fine particles such as primary particles are also crushed by the collision. And since the clean new surface is formed, the film-forming efficiency of the coating 5b formed by colliding with the base material 5 can be improved.

  As another embodiment of the present invention, as shown in FIG. 2, the aerosol is sprayed from the discharge opening 2g of the aerosol spray nozzle 2f toward the base material 5 at a spray angle β that is symmetrical to the perpendicular to the base material 5, and XY By colliding the fine particles before colliding with the base material 5 attached to the table 4, the agglomerated powder in the fine particles is crushed, and fine ceramic fine particles such as primary particles are also pulverized by the collision to produce a clean new life. Since the surface is formed, the film formation efficiency of the coating 5c formed by colliding with the base material 5 can be improved.

Using the coating film forming apparatus 1 shown in FIG. 4 and the aerosol injection nozzle shown in FIG. 1, a coating made of alumina fine particles is applied to the substrate 5 (SUJ2, made 30 mm × 30 mm × 2 mm (mirror finish)) by the AD method. Formed by. As the aerosol injection nozzle 2, a discharge opening 2a size of 10 mm × 1 mm and an injection angle of 30 degrees (see FIG. 1) were used.
In the AD method, a coating was formed by spraying an aerosol containing alumina fine particles toward the substrate 5 from the discharge opening 2a of the fixed aerosol spray nozzle 2 under a reduced pressure of 100 Pa or less in the vacuum chamber 3. . The base material 5 was reciprocated at a stroke of 15 mm at a speed of 10 mm / min to form a film for 10 minutes.
The alumina fine particles used were AKP-50 manufactured by Sumitomo Chemical Co., Ltd., having an average particle size of 0.16 μm and heat-dried under reduced pressure of 10 Pa or less. Nitrogen was used as the carrier gas, and the particle velocity was controlled by the carrier gas flow rate.

  When the formed substrate was ultrasonically washed with an ethanol solution and observed in cross section, an α-alumina coating 5b having a dense, transparent and smooth surface was formed with a thickness of 4 μm.

  Since the film forming apparatus of the present invention can efficiently form a dense and uniform film, it can be suitably used for forming a ceramic film on various industrial parts.

It is a figure which shows the detail of the B section of FIG. 4 as one Example which concerns on this invention. It is a figure which shows the detail of the B section of FIG. 4 as another Example which concerns on this invention. It is a figure which shows the film formation by the conventional aerosol injection nozzle. It is a figure which shows one Example of the film formation apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating film formation apparatus 2 Aerosol injection nozzle 2a Discharge opening 3 Vacuum chamber 4 XY table 5 Base material 6 Gas supply equipment 7 Fine particle filter 8 Vacuum pump 9 Aerosol generator

Claims (5)

An aerosol generator for dispersing fine particles in a gas to form an aerosol, a vacuum chamber, and an aerosol injection nozzle disposed in the vacuum chamber, and the aerosol is formed from the aerosol injection nozzle as a base A film forming apparatus that forms a film by being jetted onto and colliding with the film,
The aerosol forming nozzle is a film forming apparatus characterized in that the fine particles injected from the discharge opening of the injection nozzle can collide with the fine particles before colliding with the base material.   2. The film forming apparatus according to claim 1, wherein the fine particles are ceramic fine particles having an average particle diameter of 0.1 to 2 [mu] m.   The film forming apparatus according to claim 2, wherein the ceramic fine particles are alumina fine particles.   The film forming apparatus according to claim 1, wherein the gas is an inert gas containing argon, nitrogen, or helium. An aerosol forming step in which fine particles are dispersed in a gas to form an aerosol; and a film forming step in which the aerosol is sprayed onto a substrate from an aerosol spray nozzle in a vacuum chamber to collide with the substrate. A method of forming a film by an aerosol deposition method,
The film forming step is a step of colliding fine particles ejected from an aerosol spray nozzle with each other and then colliding with a base material.

Images