JP4930120B2 - Film forming apparatus and film forming method - Google Patents

Description

The present invention relates to a film forming apparatus, and Narumakukata method.

  There is a method called aerosol deposition (AD method) as a method of manufacturing a piezoelectric actuator used for an ink jet head of an ink jet printer. In the AD method, an aerosol in which fine particles of a piezoelectric material such as lead zirconate titanate (PZT) are dispersed in a gas is sprayed toward the surface of the substrate, and the fine particles that collide with the substrate are deposited on the substrate. Etc. are formed.

For example, Patent Document 1 (Japanese Patent Laid-Open No. 2003-293159) discloses an apparatus for performing film formation using such an AD method. This apparatus includes an aerosol forming chamber for generating aerosol, a film forming chamber for spraying the generated aerosol onto a substrate, and a nozzle provided in the film forming chamber. The aerosol generated in the aerosol forming chamber is guided to the nozzle through the transport pipe, and is ejected from the nozzle toward the substrate.
JP 2003-293159 A

  In the AD method as described above, it is important to keep the concentration of aerosol sprayed from the nozzle constant in order to form a uniform and good quality film. However, it is difficult to stabilize the aerosol concentration due to various factors such as solidification of the aerosol in the aerosol forming chamber and clogging of material particles in the transport pipe and / or nozzle.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a film forming apparatus and a film forming method capable of easily controlling the concentration of aerosol sprayed toward a substrate. .

Means for Solving the Problems and Effects of the Invention

  According to the first aspect of the present invention, there is provided a film forming apparatus for forming a film, wherein the material particles forming the film are mixed with core particles having a particle diameter larger than the material particles, and the core particles are mixed. A mixing part for adhering the material particles to the surface, and a collision wall, connected to the mixing part, and colliding the core particle with the material particles adhering to the collision wall to collide the core particle and the material particle A separation unit that separates the core particles to which the material particles are attached, a transfer unit that transports the core particles from the mixing unit to the separation unit, and the material particles that are connected to the separation unit and separated by the collision wall. There is provided a film forming apparatus including an aerosol generation unit that generates an aerosol by being dispersed in a carrier gas, and a nozzle that is connected to the aerosol generation unit and ejects the aerosol.

According to the first aspect of the present invention, since the material particles are attached to the surface of the core particle having a large particle size in the mixing unit, as compared with the case where only the material particle having a small particle size passes through the transfer unit , Hard to cause clogging. Therefore, the core particles to which the material particles are attached can be stably transferred to the separation unit, and the concentration of aerosol generated in the aerosol unit can be kept stable.

The film forming apparatus of the present invention may further include a control unit that is provided in the transfer unit and controls the supply amount of the core particles to which the material particles supplied to the separation unit are attached . In this case, by adjusting the amount of core particles having a relatively large particle size, it is possible to control the concentration of the aerosol, etc., so that the concentration of the aerosol generated in the aerosol generating section can be easily and reliably kept stable. be able to.

In the film forming apparatus of the present invention, a fluidizing unit that generates a fluidized bed of the core particles to which the material particles adhere may be provided between the mixing unit and the separating unit.

  In this case, the core particles having material particles attached to the surface in the mixing part are fluidized and stirred in the fluidizing part. At this time, the material particles that are only weakly adhered to the surface of the core particles are peeled off from the core particles, and only the material particles that are strongly adhered remain on the surface of the core particles. In this way, the accuracy of aerosol concentration control can be improved by removing the material particles that are excessively attached to the surface of the core particles before being sent to the separation unit.

  In the film forming apparatus of the present invention, the core in which the material particles are adhered from the mixture containing the core particles and the material particles mixed in the mixing unit is provided between the mixing unit and the separation unit. A separation unit that separates the particles from the material particles released from the core particles may be provided.

  In this case, a separation unit that separates the core particles to which the material particles are attached and the separated material particles is provided between the mixing unit and the separation unit. Here, not all the material particles adhere to the core particles in the mixing portion, and the material particles in a free state remain without being attached to the core particles. Therefore, by providing a separation unit to separate the core particles to which the material particles are attached from the free material particles, only the core particles to which the material particles are attached can be sent to the collision part. Thereby, the precision of aerosol concentration control can be improved.

  In the film forming apparatus of the present invention, the separating unit collects the separated material particles separated and connects the collected material particles collected to the mixing unit to the mixing unit. A material recovery unit to be supplied may be provided.

  In this case, the separation unit is provided with a material recovery unit that recovers the separated and separated material particles, and the recovered material particles are supplied from the material recovery unit to the mixing unit. Therefore, the recovered material particles can be easily returned to the aerosol generation system, and the material particles can be easily reused.

In the film forming apparatus of the present invention, the downstream side of the transfer unit connected to the separation unit may be lower than the upstream side.

In this case, the transfer unit that guides the core particles to the separation unit is provided with a height difference between the downstream side that reaches the separation unit and the upstream side thereof. Here, in order to detach the material particles from the core particles, the core particles must collide with the collision wall with an appropriate collision force. According to the present invention, in the transfer unit , the upstream side is located before the separation unit. By appropriately adjusting the height difference from the downstream side, the collision force of the core particles against the collision wall can be easily adjusted.

  In the film forming apparatus of the present invention, the separation unit is connected to the mixing unit, collects the core particles separated from the material particles, and supplies the collected core particles to the mixing unit A recovery unit may be provided.

  In this case, the separation unit is provided with a core collection unit that collects the core particles separated from the material particles. And this core collection | recovery part is connected to the mixing part, and the collect | recovered core particle is supplied to a mixing part. Therefore, the recovered core particles can be easily returned to the aerosol generation system again, and the core particles can be easily reused.

  In the film forming apparatus of the present invention, the mixing unit may be provided with a downward gradient along a predetermined direction from a supply position where the core particles or the material particles are supplied, and the core particles or the material particles May flow along the predetermined direction.

  In this case, the mixing section is provided with a downward gradient that descends along the flow direction of the particles. Therefore, when both particles roll down on this downward gradient and contact each other, the material particles are evenly spread over the entire surface of each core particle, and there is almost no variation in the amount of adhesion of the material particles between the core particles. In other words, the adhesion amount of the material particles is almost equal. In addition, the material particles adhere strongly to the core particles due to the frictional force and pressure generated between each particle or between the gradient surface of the mixing portion and the particles, so that the material particles once adhered to the core particles reach the separation portion. It can be prevented from peeling off before. Thereby, the material particles can be stably supplied by controlling the transfer amount of the core particles.

  In the film forming apparatus of the present invention, an aerosol concentration detector may be provided between the aerosol generator and the ejection nozzle.

  In this case, since the aerosol concentration detector is provided between the aerosol generation unit and the ejection nozzle, the detected aerosol concentration can be fed back to the control unit to adjust the transfer amount of the core particles. It can respond quickly to unexpected fluctuations in aerosol concentration.

  In the film forming apparatus of the present invention, the mixing unit may be provided with a flow rate detector for detecting the flow rate of the core particles.

  In this case, since the flow rate detector for detecting the flow rate of the core particles is provided in the mixing unit, the detected flow rate of the core particles is fed back to the control unit to adjust the transfer amount of the core particles. And can respond quickly to unexpected fluctuations in the amount of core particles transferred.

  In the film forming apparatus of the present invention, the collision wall may be a mesh having a size that allows the core particles to pass therethrough, and the core recovery unit may include a mesh having a size that the core particles cannot pass through.

  In this case, the core particles can pass through the mesh that is the collision wall, but the mesh contained in the core recovery portion cannot pass through, so that the core particles can be reliably recovered.

In the film forming apparatus of the present invention, the control unit is configured to adjust a supply amount of the core particles to which the material particles supplied to the separation unit are attached, and the supply unit to the mixing unit. A second adjustment valve that adjusts the supply amount of the material particles may be included.

  In this case, since the control unit independently includes valves for adjusting the supply amounts of the core particles and the material particles, the aerosol concentration can be controlled easily and reliably.

  In the film forming apparatus of the present invention, the first adjustment valve and the second adjustment valve may have a horizontal plate for adjusting the opening of the valve.

  In this case, since the first and second regulating valves are regulating valves of the type that adjusts the opening of the valve by inserting and removing the horizontal plate, the supply amount of the core particles and the material particles is easily controlled linearly. be able to.

  According to a second aspect of the present invention, there is provided a film forming method for forming a film on a substrate, comprising mixing material particles and core particles having a particle size larger than the material particles, A mixing step of attaching the material particles to the surface, a transfer step of transferring the core particles to which the material particles obtained in the mixing step are attached while controlling the transfer amount, and the transfer of the core particles that have been transferred by the transfer step A separation step of applying an impact force to the core particles to separate the material particles from the core particles; an aerosol generation step of dispersing the material particles separated in the collision step in a carrier gas to generate an aerosol; and the aerosol A film forming step of forming a film of the material particles by adhering the material particles to the substrate by ejecting the material toward the substrate.

  According to the second aspect of the present invention, after the material particles are attached to the core particles having a larger particle size than the material particles and transferred, an impact force is applied to the transferred core particles to cause the material particles to be the core particles. And is dispersed in a carrier gas to generate an aerosol. Here, the core particles having a somewhat large particle diameter are easier to control the amount of transfer in the system than the fine material particles used for film formation, and are less likely to clog. Therefore, by appropriately controlling the transfer amount of the core particles from the process of attaching the material particles to the core particles to the process of releasing the material particles from the core particles, the supply amount of the material particles is controlled, As a result, the aerosol concentration can be stabilized.

  In the film forming method of the present invention, the material particles having a primary average particle diameter of 1 μm or less may be used, and the core particles having an average particle diameter of 100 μm or more and 200 μm or less may be used.

  In this case, the material particles have a primary average particle size of 1 μm or less, and the core particles have an average particle size of 100 μm or more and 200 μm or less. Here, in the aerosol generation step, it is necessary to form the aerosol by scattering only the material particles of the two particles separated from each other with the gas. For this reason, it is necessary to set an appropriate size difference between the material particles and the core particles. On the other hand, if the core particles are too small, clogging is likely to occur in the system, and the operation efficiency is lowered. Considering these circumstances, it is appropriate that the material particles have a primary average particle size of 1 μm or less and the core particles have an average particle size of 100 μm or more and 200 μm or less. The primary average particle diameter means an average particle diameter in a state without aggregation.

  In the film forming method of the present invention, a porous material may be used as the core particle.

  In this case, since a porous material is used as the core particles, the material particles enter the pores of the core particles and are firmly fixed. Therefore, the material particles once attached to the core particles can be prevented from peeling off before reaching the separation step. Thereby, the supply amount of the material particles by controlling the transfer amount of the core particles can be stabilized.

  In the film forming method of the present invention, the core particle may be one of zirconia and alumina. In this case, since zirconia or alumina is used as the core particle, the core particle has a sufficient hardness and has little wear, so there is no fear of being scraped by friction with the material particles.

  In the film forming method of the present invention, the material particles may be PZT particles. In this case, since the material particles are piezoelectric materials, for example, a piezoelectric layer used for an inkjet head of an inkjet printer can be easily formed.

  Hereinafter, an embodiment embodying the present invention will be described in detail with reference to FIGS.

  In FIG. 1, the film-forming apparatus 1 of this embodiment is shown. The film forming apparatus 1 includes an aerosol supply unit U for generating aerosol, a nozzle 51 for ejecting the generated aerosol, and a film forming chamber 50 for attaching the aerosol ejected from the nozzle 51 to the substrate B. I have.

As shown in FIG. 1, the aerosol supply unit U is formed as a circulation path for the core particles C. The material particles M and the core particles C are mixed to adhere the material particles M to the surface of the core particles C. An aerosol generation tank (aerosol generation) that is connected to the mixing unit 10 and the upstream side of the mixing unit 10 and separates the material particles M from the core particles C and disperses the separated material particles M in a carrier gas to generate an aerosol Z. Part) 40 and a transfer part (flow part 20, transport pipe 62, and transfer pipe 65; transfer part ) that connects the downstream side of the mixing part 10 and the aerosol generation tank 40.

  The mixing portion 10 is formed in a tubular shape, and is installed so as to be inclined downward toward a predetermined direction (left side in FIG. 1). In other words, the mixing unit 10 is installed so as to be inclined from the upstream side in the flow direction of the core particle C toward the downstream side. As will be described later, one end (upstream side) of the mixing unit 10 is connected to the aerosol generation tank 40, and the core particles C separated from the material particles M are supplied in the aerosol generation tank 40. In the mixing unit 10, a material supply pipe (material supply path) 63 for supplying the material particles M to the mixing unit 10 is connected to a position slightly downstream of the upstream end. In addition, a flow rate detector (flow meter) 11 that measures the flow rate of the core particles C passing through the inside of the mixing unit 10 is attached at a position slightly downstream of the connection position of the mixing unit 10 with the material supply pipe 63. It has been.

The downstream end of the mixing unit 10 is connected to the flow unit 20. The shape of the flow section 20 is a substantially cylindrical shape having an inner diameter of about 150 mm, the inside thereof is partitioned by a dispersion plate 21, the fluidized bed chamber 22 is formed on the upper side, and the air box 23 is formed on the lower side. . The dispersion plate 21 includes a large number of pores having such a size that the carrier gas can pass but the core particles C cannot pass. As the dispersion plate 21, for example, a porous sintered body or a multi-nozzle plate provided with a large number of nozzles can be used. The dispersion plate 21 is provided slightly below the position where the mixing unit 10 is connected to the fluidized bed chamber 22, and the core particles C and material particles M flowing from the mixing unit 10 are contained in the fluidized bed chamber. 22 is supplied. An air supply device 24 for supplying a carrier gas to the fluidizing unit 20 is connected to the bottom of the wind box 23 via a gas supply pipe 25. When the carrier gas is supplied to the fluidized bed chamber 22 through the gas supply pipe 25 and the air box 23, the core particles C sent from the mixing unit 10 are fluidized.

  The fluidized bed chamber 22 is connected to a transport pipe 62 for transporting the core particles C to the sorting unit 30 by airflow. The inner diameter of the transfer tube 62 is about 28 mm. One end of the transport pipe 62 is inserted from the upper opening of the fluidized bed chamber 22, and a fluidized bed Cf is formed between the dispersion plate 21 and one end of the transport pipe 62. The other end side of the transport pipe 62 extends upward and is connected to the separation unit 30 installed above the flow unit 20. The fluidized bed chamber 22 is provided with a particle scattering prevention plate 26. The particle scattering prevention plate 26 is installed at the lower part of the transport pipe 62 in order to prevent huge particles (such as aggregates) from jumping out from the flowing layer. With this particle scattering prevention plate 26, only the dispersed particles can be conveyed to the upper separation unit 30.

  The separation unit 30 separates and collects the core particles C to which the material particles M are attached and the material particles M (free material particles) that are not attached to the core particles C. The sorting unit 30 includes a known cyclone 31 and a known bag filter (material recovery unit) 32 connected to the subsequent stage of the cyclone 31. The cyclone 31 can collect only the core particles C having a large particle size, and the bag filter 32 can collect the free material particles M having a small particle size.

  A core supply hopper 31A is provided at the bottom of the cyclone 31, and the recovered core particles C can be discharged therefrom. A transfer pipe 65 extends from the lower part of the core supply hopper 31 </ b> A, and one end of the transfer pipe 65 is connected to the aerosol generation tank 40. The transfer pipe 65 descends from the outlet of the core supply hopper 31 </ b> A toward the aerosol generation tank 40 installed obliquely below the core supply hopper 31 </ b> A. . The core supply hopper 31A may be provided independently of the cyclone 31, or may be connected to the cyclone 31 via a pipe. The transfer pipe 65 is provided with a transfer adjustment valve (control unit) 66 that adjusts the fall amount of the core particles C. The transfer adjusting valve 66 adjusts the flow rate of the core particles C by adjusting the opening of the valve (the flow passage area of the transfer pipe) by inserting and removing the horizontal plate. When a valve using such horizontal plate insertion / extraction is used, the opening degree of the valve can be controlled linearly. Therefore, the supply amount of the core particles C compared to the case of using a butterfly valve, a ball valve or the like. Can be adjusted easily.

  The shape of the aerosol generation tank 40 is a bottomed container shape, and one end (downstream end) of the transfer pipe 65 is inserted therein. Inside the aerosol generation tank 40, a collision net (collision wall) 41 and a collection net (core collection unit) 42 are provided. The collision net 41 is formed of a net having a mesh size substantially equal to the average particle diameter of the core particles C, and is provided in an obliquely inclined posture below the downstream end of the transfer pipe 65. The collision net 41 can separate the material particles M from the core particles C by impact of collision. The collection network 42 is formed of a mesh body having a mesh size smaller than the average particle diameter of the core particles C, and is stretched in a slanting posture with a slight gap below the collision net 41. The collection network 42 can collect the core particles C after the material particles M are separated. Furthermore, the upstream end of the mixing unit 10 is connected to the aerosol generation tank 40. The collection net 42 is arranged such that the end portion in the downward direction is aligned with the connection position with the mixing unit 10 in the side wall portion of the aerosol generation tank 40. By arrange | positioning the collection | recovery net | network 42 in this way, the collect | recovered core particle C can be poured into the mixing part 10. FIG.

  One end of an aerosol supply pipe 67 for supplying the aerosol generated in the tank to the ejection nozzle 51 is connected to the ceiling of the aerosol generation tank 40. An aerosol concentration detector 68 capable of detecting the concentration of aerosol passing through the aerosol supply pipe 67 is attached to the aerosol supply pipe 67.

  The bag filter 32 is connected to the mixing unit 10 via a material supply pipe (material supply path) 63. A raw material supply hopper 32A is provided at the bottom of the bag filter 32, and the collected free material particles M can be discharged therefrom. A material supply pipe 63 extends from the lower part of the raw material supply hopper 32 </ b> A, and one end thereof is connected to the mixing unit 10. The material supply pipe 63 descends from the outlet of the raw material supply hopper 32 </ b> A toward the mixing unit 10, and the material particles M are sent to the mixing unit 10 by naturally falling from the bag filter 32. The raw material supply hopper 32A may be provided independently of the bag filter 32, and the bag filter 32 and the raw material supply hopper 32A may be connected via a pipe. The material supply pipe 63 is provided with a supply adjustment valve 64 that adjusts the amount of falling material particles M. The supply adjustment valve 64 adjusts the flow rate of the material particles M by adjusting the opening degree of the transfer pipe 65 by inserting and removing the horizontal plate, similarly to the transfer adjustment valve 66 provided in the transfer pipe 65.

  Next, the film forming chamber 50 will be described. The shape of the film forming chamber 50 is a substantially rectangular parallelepiped, and a stage 52 for mounting the substrate B and an ejection nozzle 51 disposed below the stage 52 are provided therein. The shape of the ejection nozzle 51 is substantially cylindrical, and openings are formed at the upper and lower ends of the ejection nozzle 51. The upper opening is a slit-shaped outlet 51A. The lower opening is connected to the end of the aerosol supply pipe 67, and the aerosol generated in the aerosol generation tank 40 is supplied to the ejection nozzle 51 through the aerosol supply pipe 67.

  The shape of the stage 52 is a rectangular plate, and the stage 52 can be suspended from the ceiling of the film forming chamber 50 in a horizontal posture by the stage moving mechanism 53 to hold the substrate B on the lower surface side of the stage 52. . The stage moving mechanism 53 is driven in response to a command from a control device (not shown), and moves the stage 52 in the surface direction (in a plane parallel to the plate surface). Thereby, the ejection nozzle 51 can be moved relative to the substrate B.

  Further, a vacuum pump P is connected to the film forming chamber 50 via a powder recovery device 54, and the inside thereof can be decompressed.

  The film forming apparatus 1 is provided with a controller 61. The controller 61 contains a microcomputer that stores a control program for controlling the operation of the film forming apparatus 1. The controller 61 receives information from the flow rate detector 11 and the aerosol concentration detector 68. A signal for controlling the supply adjustment valve 64 and the transfer adjustment valve 66 is output.

  Next, a process of forming a film by the film forming apparatus 1 will be described with reference to a flowchart shown in FIG.

  As the core particle C used in the present embodiment, a porous material having a large number of pores for holding the material particles M is preferable. The average particle size is preferably 100 μm or more and 200 μm or less because it is preferable that the average particle size is small enough to prevent clogging in the system and the flow rate can be easily grasped and controlled. Moreover, it is desirable that the hardness of the core particle C is 500 HV or more so that the core particle C is not shaved in various processes described later. Furthermore, it is desirable that the core particles C have low reactivity with the material particles M. Examples of the porous material suitable for the core particle C include ceramic materials such as alumina and zirconia. On the other hand, the material particles M are not particularly limited as long as they are applicable to film formation by the aerosol deposition method (AD method). For example, when a piezoelectric film is to be formed, lead zirconate titanate (PZT) is used. Fine particles of a piezoelectric material such as) can be used. Alternatively, it may be lead magnesium niobate (PMN). Further, when forming an insulating film, fine particles of an insulating material such as alumina and / or zirconia can be used. Or when forming a metal film, metal fine particles, such as gold | metal | money and platinum, can also be used. The primary average particle diameter of the material particles M, that is, the average particle diameter in a state without aggregation is suitably 1 μm or less, and preferably in the range of 0.1 μm to 1 μm. This is because it is desirable that the size of the material particles M is appropriately small as compared with the size of the core particles C. The primary average particle size is measured by (i) a method of measuring the particle size by dispersing the particles in the liquid, irradiating the particles performing Brownian motion with laser light, and observing the scattered light. (Ii) A method in which particles are dispersed while applying a shearing force with a gas in a flow path in a dry method, and the particle size is measured in the same manner as in (i) above, (iii) the particles dispersed by the above two methods An image or an image of particles collected between the aerosol generation tank 40 and the substrate B of the film forming apparatus 1 can be recorded, and an average particle diameter can be obtained based on the image data.

  When the operation of the film forming apparatus 1 is started, first, the material particles M and the core particles C are mixed in the mixing unit 10 (mixing step S1). When the core particle C is supplied to the mixing unit 10, the core particle C falls while rolling from the upstream side to the downstream side due to the inclination of the mixing unit 10. At this time, the material particles M are also supplied from the material supply pipe 63 to the mixing unit 10. The material particles M adhere to the surface of the core particles C in the process of rolling along with the core particles C according to the inclination of the mixing unit 10. The adhered material particles M are pressed into the pores of the core particle C by being pressed against the surface of the core particle C between the surface of the core particle C and the inner wall of the mixing unit 10 and are fixed. In this way, the amount of the material particles M taken into the pores of the core particles C is approximately averaged by passing through the step of applying the material particles M to the core particles C while rolling in an inclined path. Can do. Note that the flow rate of the core particles C in the mixing unit 10 is monitored by the flow rate detector 11.

  The core particles C to which the material particles M are attached are sent to the fluidized bed chamber 22 of the fluidizing section 20. In the fluidized bed chamber 22, the core particles C are fluidized by the supplied carrier gas, and a fluidized bed Cf is formed between the dispersion plate 21 and the transport pipe 62 (particle scattering prevention plate 20). At this time, the free material particles M not attached to the core particles C are scattered on the carrier gas flow, and only the core particles C form the fluidized bed Cf.

  Further, since the core particle C moves violently in the fluidized bed Cf, the material particle M having a weak adhesion to the surface of the core particle C is peeled off, and only the material particle M which is relatively strongly fixed in the pores. Left behind. As a result, the amount of the material particles M held by the core particles C is further averaged. Thus, since the amount of the material particles M fixed to the core particles C is approximately averaged by the mixing unit 10 and the fluidizing unit 20, the flow rate of the core particles C in the mixing unit 10 and the core particles C The supply amount of the material particles M that are fixed and supplied to the aerosol generation tank 40 is highly correlated. In other words, the flow rate of the core particles C in the system and the concentration of the aerosol that is finally generated are highly correlated. Therefore, the aerosol concentration can be easily controlled by controlling the flow rate of the core particles C which are larger in size than the material particles M and easy to monitor and control.

  By constantly supplying the carrier gas and the core particles C to the fluidized bed Cf, the core particles C gradually overflow from the fluidized bed Cf, rise in the carrier pipe 62 along the carrier gas flow, and the separation unit 30. It is conveyed to. In the sorting unit 30, first, the core particle C having a large particle size is recovered by the preceding cyclone 31. The free material particles M having a small particle diameter flow to the subsequent bag filter 32 together with the carrier gas, and are collected here. In this way, the core particles C to which the material particles M are attached are separated from the free material particles M. Thereby, since the free material particles M are not mixed with the core particles C and transferred in the separation step and the aerosol generation step, which will be described later, the final amount of the aerosol generated by controlling the transfer amount of the core particles C is controlled. The concentration can be reliably controlled.

  The core particles C collected by the cyclone 31 are discharged from the core supply hopper 31A, are naturally dropped in the transfer pipe 65, and are sent to the aerosol generation tank 40. At this time, the fall amount of the core particle C is adjusted by an opening degree adjusting mechanism by inserting / removing a horizontal plate provided in the transfer adjusting valve 66. The transfer of the core particles C from the fluidizing section 20 to the aerosol generation tank 40 corresponds to the transfer step S2 of the present invention.

The core particles C transferred through the aerosol generation tank 40 and the transfer pipe 65 collide with the collision network 41. Due to the impact at this time, the material particles M fixed to the core particles C are separated (separation step S3). In order to separate the material particles M from the core particles C, it is necessary to cause the core particles C to collide with the collision network 41 at an appropriate speed. Therefore, in the present embodiment, the cyclone 31 on the upstream side of the collision network 41 is provided at a position higher than the collision network 41, and the transfer pipe 65 provided between the collision network 41 and the cyclone 31 is connected to the cyclone 31 (upstream). Side) toward the collision net 41 (downstream side). Thus, the transfer tube 65 is the end portion of the transfer portion, the end portion of the collision network 41 side, and arranged to be lower than the end of the cyclone 31 side is the upstream side. Thus, by providing a height difference between both ends of the transfer pipe 65 and appropriately setting the height difference and / or the inclination of the transfer pipe 65, the falling speed of the core particles C can be adjusted. Thereby, the impact at the time of the core particle C colliding with the collision net | network 41 can be adjusted easily. Furthermore, since the transfer adjustment valve 66 is provided in the transfer pipe 65, the fall amount of the core particle C can be adjusted, and the concentration of the aerosol generated in the aerosol generation tank 40 can be controlled.

  Of the core particles C and material particles M separated from each other, the light material particles M having a small particle size are wound up and dispersed by a carrier gas to form an aerosol (aerosol generation step S4). The generated aerosol is sent to the film forming chamber 50. That is, when the inside of the film formation chamber 50 is depressurized by the vacuum pump P, the aerosol is sucked into the aerosol supply pipe 67 due to the differential pressure between the aerosol generation tank 40 and the film formation chamber 50 and ejected while being accelerated at high speed. It is sent to the nozzle 51. The concentration of the aerosol sent from the aerosol generation tank 40 to the ejection nozzle 51 is monitored by an aerosol concentration detector 68 attached to the aerosol supply pipe 67.

  The aerosol sent to the ejection nozzle 51 is ejected toward the substrate B from the ejection port 51A. The ejected material particles M collide with the substrate B and deposit on the substrate B. The material particles M thus fixed on the substrate B form a piezoelectric film (film forming step S5). At this time, aerosol is sprayed while moving the stage 52 by the stage moving mechanism 53 and gradually shifting the relative position of the ejection nozzle 51 with respect to the substrate b. As a result, a film is formed over the entire surface of the substrate B.

  The aerosol containing the material particles M that have not been deposited on the substrate B after colliding with the substrate B is discharged to the powder recovery device 54 side by the suction force of the vacuum pump P.

  On the other hand, the core particle C having a large particle size and heavy falls through the mesh of the collision net 41 without being wound up by the carrier gas. Since the mesh of the collection network 42 stretched below the collision network 41 is a size that does not allow the passage of the core particles C, the core particles C are collected by the collection network 42. The core particles C roll according to the inclination of the collection network 42 and are supplied to the mixing unit 10 disposed at the downstream end of the collection network 42 for reuse.

  The free material particles M collected by the bag filter 32 are discharged from the raw material supply hopper 32A, fall naturally in the material supply pipe 63, are supplied to the mixing unit 10, and are reused. The material supply pipe 63 is provided with a supply adjustment valve 64. Like the transfer adjustment valve 66, the flow rate of the material particles M is adjusted by adjusting the opening of the valve by inserting and removing the horizontal plate.

  The transfer adjustment valve 66 and the supply adjustment valve 64 are connected to a controller 61, and the opening degree of these valves is automatically controlled by a signal from the controller 61. Information about the flow rate of the core particles C in the mixing unit 10 detected by the flow rate detector 11 and the aerosol concentration in the aerosol supply pipe 67 detected by the aerosol concentration detector 68 is sent to the controller 61. Based on these information, the opening degree of the transfer adjustment valve 66 is controlled. Thus, the aerosol concentration can be stabilized by adjusting the flow rate of the core particles C in the circulation path. The controller 61 adjusts the opening degree of the supply adjustment valve 64 in conjunction with the opening degree adjustment of the transfer adjustment valve 66. Thereby, the supply amount of the material particles M can be adjusted in accordance with the flow rate of the core particles C.

  As described above, according to the present embodiment, the material particle M is attached to the core particle C having a larger particle diameter than the material particle M in the mixing unit 10 and transferred to the aerosol generation tank 40, and then the collision network 41. The material particles M are separated from the core particles C by impact. Then, the separated material particles M are dispersed in the carrier gas in the aerosol generation tank 40 to generate aerosol.

  Here, the core particle C having a somewhat large particle diameter is easier to control the transfer amount in the transfer path and is less likely to be clogged, compared to the fine material particles M used for film formation. Therefore, in the process of attaching the material particles M to the core particles C and in the process of separating the material particles M from the core particles C, the transfer amount of the core particles C is not directly controlled, but the transfer amount of the core particles C is controlled. By appropriately controlling, the supply amount of the material particles M to the aerosol generation tank 40 can be controlled, and consequently, the aerosol concentration can be stabilized.

  Moreover, the fluidized part 20 is provided in the middle of the transfer path from the mixing part 10 to the aerosol generating tank 40 to fluidize the core particles C, thereby forming the fluidized bed Cf. In the fluidizing section 20, the core particles C having the material particles M adhered to the surface thereof in the mixing section 10 are fluidized and stirred. At this time, the material particles M weakly adhering to the surface of the core particle C are peeled off from the core particle C. In this way, the accuracy of aerosol concentration control can be improved by removing the material particles M adhering to the surface of the core particles C before being sent to the aerosol generation tank 40.

  Similarly, in the middle of the transfer path from the mixing unit 10 to the aerosol generating tank 40 (more specifically, between the fluidizing unit 20 and the aerosol generating tank 40), the core particles C to which the material particles M are attached and the free particles are released. A separation unit 30 for separating the material particles M from each other is provided. Here, not all the material particles M adhere to the core particles C in the mixing unit 10, and the material particles M in a free state remain without being attached to the core particles C. Therefore, by providing the separation unit 30 to separate the core particles C to which the material particles M are attached from the free material particles M, only the core particles C to which the material particles M are attached can be sent to the aerosol generation tank 40. . Thereby, the precision of aerosol concentration control can be improved.

  The sorting unit 30 is provided with a bag filter 32 for collecting the separated free material particles M. The bag filter 32 is connected to the mixing unit 10 via a material supply pipe 63, and the collected material particles M are supplied to the mixing unit 10. According to such a configuration, the recovered material particles M can be easily returned to the aerosol generation system again, and the material particles M can be easily reused.

Further, a collision network 41 side end portion of the transfer tube 65 is the end portion of the transfer portion that guides the core particles C to the aerosol generating chamber 40, disposed lower than an upstream end (an end portion of the cyclone 31 side). Here, in order to release the material particles from the core particles, the core particles must collide with the collision network 41 with an appropriate collision force. Therefore, a height difference is provided between the end portion of the transfer portion and the front thereof, and the drop speed of the core particles C is adjusted by adjusting the height difference and / or the inclination of the transfer pipe 65 and the like. Thereby, the collision speed of the core particle C to the collision network 41 can be easily adjusted.

  The aerosol generation tank 40 is provided with a collection network 42 for collecting the core particles C separated from the material particles M. The collection network 42 is connected to the mixing unit 10, and the collected core particles C are supplied to the mixing unit 10. Thereby, the recovered core particles C can be easily returned to the aerosol generation system again, and the core particles C can be easily reused.

  The mixing unit 10 is provided with a downward gradient that descends in a predetermined direction, and the downward direction in the predetermined direction corresponds to the direction in which the material particles M and the core particles C flow. According to such a configuration, the material particles M and the core particles C are in contact with each other while rolling down this downward gradient, so that the material particles M adhere almost uniformly on the surface of each core particle C. In addition, there is almost no variation in the adhesion amount of the material particles M between the core particles C. In addition, the material particles M strongly adhere to the core particles C due to frictional force and pressure generated between the particles and / or between the inner wall surface of the mixing unit 10 and the particles. Therefore, it is possible to prevent the material particles M once attached to the core particles C from being peeled before reaching the aerosol generation tank 40. Thereby, the material particles M can be stably supplied by controlling the transfer amount of the core particles C.

  An aerosol concentration detector 68 is provided in an aerosol supply pipe 67 that connects the aerosol generation tank 40 and the ejection nozzle 51. Further, the mixing unit 10 is provided with a flow rate detector for detecting the flow rate of the core particles C. According to such a configuration, the detected aerosol concentration and the transfer amount of the core particles C can be fed back to the controller 61, and the transfer amount of the core particles C can be adjusted. It can correspond to.

As the material particles M, those having a primary average particle diameter of 1 μm or less and core particles C having an average particle diameter of 100 μm or more and 200 μm or less are used. In the aerosol generation process, it is necessary to form the aerosol by scattering only the material particles M of the material particles M and the core particles C separated from each other by the gas. For this reason, it is desirable that the material particle M and the core particle C have an appropriate size difference. When the core particle C is too small, clogging is likely to occur in a route such as a transfer section , and the operation efficiency is lowered. Considering these circumstances, it is most appropriate that the material particles M have a primary average particle size of 1 μm or less and the core particles C have an average particle size of 100 μm or more and 200 μm or less. Further, a porous material is used as the core particle C. In this way, since the material particles M enter the pores of the core particles C and are firmly fixed, it is possible to prevent the material particles once attached to the core particles C from being peeled off before reaching the separation step. Thereby, the supply amount of the material particles M can be stabilized by controlling the transfer amount of the core particles C.

  The technical scope of the present invention is not limited by the above-described embodiments, and, for example, those described below are also included in the technical scope of the present invention. In addition, the technical scope of the present invention extends to an equivalent range.

  In the above embodiment, the aerosol generation tank 40 in which the separation unit and the aerosol generation unit are integrated is provided, and the collision net 41 is provided therein, but the separation unit and the aerosol generation unit are provided independently, The material particles separated from the core particles in the separation unit may be sent to the aerosol generation unit to be aerosolized.

  In the above embodiment, the fluidizing part 20 and the separating part 30 are provided between the mixing part 10 and the aerosol generating tank 40, but only one of the fluidizing part and the separating part may be provided. It may not be provided.

  In the above embodiment, the bag filter 32 is connected to the mixing unit 10 via the material supply pipe 63, and the recovered material particles M are re-supplied to the mixing unit 10. However, the bag filter and the mixing unit are separated from each other. It is not necessary that the collected material particles are not connected and returned to the aerosol generation system. In the above embodiment, the aerosol generation tank 40 is provided with the recovery network 42 for recovering the core particles C. The recovery network 42 is connected to the mixing unit 10, and the recovered core particles C are supplied to the mixing unit 10. However, the recovered core particles may not be returned to the aerosol generation system.

  In the above embodiment, the supply adjustment valve 64 and the transfer adjustment valve 66 are automatically controlled by a command from the controller 61. However, the opening degree of the valve may be manually adjusted. Further, the mechanism for adjusting the opening degree of these valves is not limited to a type in which a flat plate is inserted and removed, but a butterfly valve, a ball valve or the like can also be used.

In the above embodiment, the transfer tube 65, had been established as down obliquely toward the downstream side, end of the impact wall side of the transfer portion may be disposed lower than the upstream side, for example, You may install so that a transfer pipe may descend | fall vertically.

  In the above embodiment, the mesh is used as the collision wall. However, the collision wall is not limited to the mesh, and for example, a slit having a width approximately the same as the diameter of the core particle and allowing the passage of the core particle is formed. It may be a slit plate. Similarly, a slit plate or the like can be used instead of the collection net.

  In the above embodiment, the core particles C are conveyed by airflow from the fluidized bed chamber 20 to the separation unit 30 provided above, but are conveyed by the lift conveyor 71 as in the film forming apparatus 70 shown in FIG. May be. Further, in the above embodiment, since the mixing unit 10 is formed by an inclined tube, the material particles M adhere to the surface of the core particle C in the process of rolling down the tube. Instead of this, a belt conveyor 72 may be installed between the collection network 42 of the aerosol generation tank 40 and the fluidized bed chamber 20. In this case, the material particles M can be fixed in the pores of the core particles C in the process in which both the material particles M and the core particles C roll on the belt conveyor 72.

  In the above-described embodiment, the material particles separated in the separation unit are used for generation of aerosol and used for film formation. However, according to the particle supply device 200 shown in FIG. Material particles (first particles) separated from particles (second particles) may be supplied for any application. Here, the particle supply apparatus 200 has the same configuration as the film formation apparatus 1 except that the film formation chamber 50 and the aerosol supply pipe 67 are not included. In the particle supply device 200, it is not necessary to generate aerosol in the separation unit 40. For example, material particles that have passed through the collection network 42 may be used as particles supplied from the particle supply device. Further, in the particle supply apparatus, the fluidizing part and / or the separating part can be omitted.

Schematic diagram of film forming apparatus of this embodiment Schematic side sectional view of the flow section of the present embodiment Schematic side sectional view of the cyclone of this embodiment Schematic side sectional view of the aerosol generating part of the present embodiment The flowchart which shows the film-forming method of this invention Schematic of film forming apparatus according to another embodiment Schematic of an embodiment of a particle supply device according to the present invention

DESCRIPTION OF SYMBOLS 1 ... Film-forming apparatus 10 ... Mixing part 11 ... Flow rate detector 20 ... Flow part (transfer part )
30 ... Separation part 31 ... Cyclone (core recovery part)
32 ... Bug filter (material recovery part)
40 ... Aerosol generation tank (separation part, aerosol generation part)
41 ... Collision network (collision wall)
51 ... Jet nozzle 62 ... Conveying pipe (transfer section )
65 ... transfer pipe (transfer section )
66 ... Transfer adjustment valve (control unit)
68 ... Aerosol concentration detector C ... Core particles Cf ... Fluidized bed M ... Material particles

Claims (18)

A film forming apparatus for forming a film,
A mixing unit for mixing the material particles forming the film and the core particles having a larger particle diameter than the material particles, and attaching the material particles to the surface of the core particles;
A separation unit that has a collision wall, is connected to the mixing unit, and separates the core particle and the material particle by colliding the core particle with the material particle adhering to the collision wall;
A transfer unit for transferring the core particles to which the material particles are attached from the mixing unit to the separation unit;
An aerosol generating unit connected to the separating unit and dispersing the material particles separated by the collision wall in a carrier gas to generate an aerosol;
A nozzle that is connected to the aerosol generating section and ejects the aerosol;
A film forming apparatus comprising: The film forming apparatus according to claim 1, further comprising a control unit that is provided in the transfer unit and controls a supply amount of the core particles to which the material particles supplied to the separation unit are attached . 3. The film forming apparatus according to claim 1, wherein a fluidizing unit that generates a fluidized bed of the core particles to which the material particles are attached is provided between the mixing unit and the separating unit.   Between the mixing part and the separating part, the core particles to which the material particles are adhered and the core particles are released from the mixture containing the core particles and the material particles mixed in the mixing part. The film forming apparatus according to claim 1, further comprising a separation unit that separates the material particles that are being separated.   The separation unit is provided with a material recovery unit that collects the separated material particles separated and supplies the separated material particles connected to the mixing unit to the mixing unit. The film forming apparatus according to claim 4. The film forming apparatus according to claim 1, wherein a downstream side of the transfer unit connected to the separation unit is lower than an upstream side.   The separation unit is provided with a core recovery unit that is connected to the mixing unit, recovers the core particles separated from the material particles, and supplies the recovered core particles to the mixing unit. Item 7. The film forming apparatus according to any one of Items 1 to 6.   The mixing unit is provided with a downward gradient along a predetermined direction from a supply position to which the core particles or the material particles are supplied, and the core particles or the material particles flow along the predetermined direction. Item 8. The film forming apparatus according to any one of Items 1 to 7.   The film forming apparatus according to claim 1, wherein an aerosol concentration detector is provided between the aerosol generating unit and the ejection nozzle.   The film forming apparatus according to claim 1, wherein a flow rate detector that detects a flow rate of the core particles is provided in the mixing unit.   The film forming apparatus according to claim 7, wherein the collision wall is a mesh having a size through which the core particles can pass, and the core recovery unit includes a mesh having a size through which the core particles cannot pass. The control unit adjusts the supply amount of the material particles supplied to the mixing unit, and a first adjustment valve that adjusts the supply amount of the core particles to which the material particles supplied to the separation unit adhere. The film forming apparatus according to claim 2, comprising a second adjustment valve.   The film formation apparatus according to claim 12, wherein the first adjustment valve and the second adjustment valve have a horizontal plate that adjusts an opening degree of the valve. A film forming method for forming a film on a substrate,
A mixing step of mixing material particles and core particles having a particle size larger than the material particles, and attaching the material particles to the surface of the core particles;
A transfer step of transferring the core particles to which the material particles obtained in the mixing step are attached while controlling the transfer amount;
A separation step of separating the material particles from the core particles by applying an impact force to the core particles transferred by the transfer step;
An aerosol generating step of generating an aerosol by dispersing the material particles separated in the collision step in a carrier gas;
Forming a film of the material particles by attaching the material particles to the substrate by ejecting the aerosol toward the substrate; and
A film forming method including:   The film forming method according to claim 14, wherein the material particles having a primary average particle diameter of 1 μm or less are used, and the core particles having an average particle diameter of 100 μm or more and 200 μm or less are used.   The film forming method according to claim 14, wherein a porous material is used as the core particle.   The film forming method according to claim 14, wherein the core particle is one of zirconia and alumina.   The film forming method according to claim 14, wherein the material particles are PZT particles.

Images