JP4784989B2 - Powder film forming equipment - Google Patents

Description

  The present invention relates to a powder film forming apparatus for forming a powder film on a surface of a substrate by attaching fine particles.

When forming a powder film by attaching fine particles to the surface of the substrate, for example, fine particles having a size in the nanometer to micrometer range are used. When a powder film having a porous structure (porous structure) is formed using such fine particles, the specific surface area becomes very large, and for example, a highly active catalyst material can be obtained.
Conventionally, as an apparatus for forming a powder film on the surface of a substrate, for example, there are apparatuses disclosed in Patent Documents 1 and 2.

Patent Document 1 discloses a powder film forming apparatus to which an aerosol deposition method that can form a ceramic film on a substrate by impact and solidification by, for example, injecting a powder raw material that is ceramic fine particles onto a substrate or the like. It is disclosed.
In the aerosol deposition method, a powder raw material having a particle diameter of several tens to several hundreds of nanometers is usually aerosolized, pressurized by an injection nozzle, and then deposited on a film-deposited material such as a substrate disposed in a low-pressure chamber. When the fine particle material is solidified by spraying, a powder film is formed.

  The injection nozzle in the apparatus of Patent Document 1 is an angle in which the introduction direction of the assist gas introduced from the second introduction passage is, for example, less than 90 degrees with respect to the introduction direction of the aerosol gas containing fine particles introduced from the first introduction passage. So that the injection pressure of the aerosol gas is increased.

  As a result, the flow rate of the aerosol gas increases. Further, since the assist gas easily flows along the inner wall of the injection nozzle, it is possible to prevent the fine particle material of the aerosol gas from adhering to the inner wall. As a result, a high-quality film can be stably formed for a long time.

  Patent Document 2 discloses a powder film forming apparatus in which fine particle generating means is configured by a processing container disposed inside a casing and a press head disposed inside the processing container. In this apparatus, the transport state of the fine particles generated by the fine particle generating means until reaching the substrate is controlled. Accordingly, the fine particles can be attached to the substrate while preventing the fine particles from aggregating, and a uniform powder film can be formed on the surface of the substrate.

JP 2005-163058 A JP 2006-150160 A

In order to increase the activity of the powder film formed on the substrate, it is necessary to increase the specific surface area. Therefore, it is preferable to reduce the particle size of the fine particles to be deposited on the substrate as much as possible. For example, so-called nanoparticles having a particle size of about 1 to 100 nm are suitable.
However, when the particle size is reduced, the fine particles collide with each other and tend to aggregate easily after the fine particles are jetted to the surface of the substrate. For this reason, the particle size constituting the powder film is not stable, and a homogeneous powder film cannot be formed. As a result, the specific surface area of the powder film cannot be sufficiently increased.

  In the apparatus of Patent Document 1, the quality of the film formed by the aerosol deposition method depends on the gas flow rate at the time of spraying, and generally the higher the quality, the higher the quality of the film formed. In this apparatus, an assist gas is introduced into an aerosol gas containing a powder raw material to increase the spray pressure of the aerosol gas and increase the collision speed with the substrate. However, in this apparatus, since the powder raw material produced separately is made to collide with a board | substrate through the path | route in an injection nozzle, there exists a possibility that microparticles may aggregate in the meantime.

  In the apparatus of Patent Document 2, the fine particles generated by the fine particle generating means float on the inside of the casing and adhere to the substrate disposed outside the processing container. Therefore, a better powder film can be formed if the fine particles generated in the processing container can be prevented from aggregating until the fine particles reach the substrate.

  Accordingly, an object of the present invention is to provide a powder capable of forming a homogeneous powder film on a substrate surface using extremely small size particles while more effectively suppressing aggregation of the powder raw material when forming the powder film. The object is to provide a body film forming apparatus.

  In order to achieve the above object, the first characteristic configuration of the powder film forming apparatus according to the present invention includes a processing container for containing and holding the powder raw material and an inner peripheral surface of the processing container in order to make the powder raw material fine particles. A fine particle generating means for applying a mechanical external force to the powder raw material to pulverize the powder raw material by the relative movement of the pressing member arranged in proximity is provided, and the fine particles generated by the fine particle generating means are attached. The substrate holding means for holding the substrate to be disposed is arranged at a position adjacent to the fine particle generating means along the direction of the inner peripheral surface of the processing container.

According to the first characteristic configuration, the fine particle generating means generates the fine particles from the inner peripheral surface of the processing container, and the substrate holding means is disposed at a position adjacent to the fine particle generating means along the direction of the inner peripheral surface of the processing container. Therefore, the generated fine particles can reach the substrate before agglomeration.
That is, the fine particles that are generated from the inner peripheral surface of the processing container and then float immediately reach the vicinity of the substrate holding means. The fine particles flow to the surface of the substrate held by the substrate holding means, and the fine particles adhere to the surface of the substrate in a dispersed state.
Thus, in this configuration, the generated fine particles can be more effectively adhered to the surface of the substrate before agglomeration, and a homogeneous powder film can be formed on the surface of the substrate.

  A second characteristic configuration of the powder film forming apparatus according to the present invention is such that the processing container is fixed, the pressing member is rotatable, and the substrate is held in a recess formed in a part of an inner peripheral surface of the processing container. It is in the point which provided the means.

According to said 2nd characteristic structure, since the aspect of the relative movement in a processing container and a press member was specified to the structure which a press member rotates, the aspect of this invention can be made into a simple structure.
Further, the generated fine particles can be immediately attached to the substrate of the recess by simply setting the substrate holding means in the recess formed in a part of the inner peripheral surface. For this reason, aggregation of fine particles can be prevented and a homogeneous powder film can be formed.

  The fine particles circulate and float on the air flow generated by the relative rotation of the processing container and the pressing member. Adhere to.

  Further, when the substrate holding means is housed in a recess formed in a part of the inner peripheral surface of the processing container, the substrate can be disposed at a position that does not hinder the relative rotation of the pressing member and the processing container.

  A third characteristic configuration of the powder film forming apparatus according to the present invention is that the substrate holding means is configured to be able to change a holding posture of the substrate to be held.

As in the third feature configuration, if the holding posture of the substrate can be changed, the angle at which the fine particles adhere to the substrate can be appropriately set. Thereby, for example, the vertical velocity component with respect to the substrate when the generated fine particles collide with the substrate can be adjusted. Usually, when the vertical velocity component is increased, the density of the formed powder film increases and the specific surface area decreases. On the other hand, when the vertical velocity component is lowered, the density of the formed powder film is reduced and the specific surface area is increased.
In this way, a powder film having desired properties can be easily formed by variously changing the fine particle density and specific surface area of the powder film.

  According to a fourth characteristic configuration of the powder film forming apparatus of the present invention, a rectifying means capable of adjusting at least one of the spray angle and the spray amount of the fine particles with respect to the substrate is provided between the fine particle generating means and the substrate. It is in the point prepared for.

  With this configuration, even if the position of the substrate becomes a problem, the fine particles can be reliably sprayed onto the substrate by adjusting the spray angle of the fine particles by the rectifying means. Moreover, the amount of spraying per area of a board | substrate can be changed by controlling the spraying amount of microparticles | fine-particles.

  Thus, according to this configuration, it is possible to control the adhesion state of the fine particles to the substrate by the rectifying unit without controlling the operation of the substrate holding unit.

  A fifth characteristic configuration of the powder film forming apparatus according to the present invention lies in that a shielding member for blocking generated fine particles from reaching the substrate is provided.

  According to the fifth characteristic configuration, it is possible to appropriately control the timing at which the generated fine particles are exposed to the substrate, that is, the start timing / completion timing of the formation of the powder film, the exposure time of the substrate, and the like. Therefore, exposure of the substrate can be appropriately performed in a state where fine particles having a desired particle diameter are sufficiently generated.

Embodiments of the present invention will be described below with reference to the drawings.
In the powder film forming apparatus of the present invention, for example, a porous structure (porous structure) powder film can be formed by attaching nano-sized fine particles to the surface of a substrate for electrode formation such as a sensor or a fuel cell. it can.

As the fine particles, for example, fine particles formed by applying a mechanical external force such as a compressive force, a shear force, and an impact force to a bulk solid that is a material of the fine particles can be used.
Further, fine particles grown to a certain size by attaching or bonding a fine particle material around a substance serving as a nucleus of the fine particles may be used. The fine particles may be made of a single material or fine particles generated by synthesizing a plurality of materials.

  In the present embodiment, a case will be described in which a powder made of a single material such as a metal oxide is used as a raw material, and fine particles (generated powder) generated from the powder raw material are used for forming a powder film.

[Powder film forming equipment]
As shown in FIGS. 1 to 4, a powder film forming apparatus X according to the present invention includes a processing container 2 that contains and holds a powder raw material m and an inner peripheral surface of the processing container 2 in order to make the powder raw material m fine particles. By the relative movement of the pressing member 1 disposed in proximity to 2a, a fine particle generating means B is provided that applies a mechanical external force to the powder raw material m to pulverize the powder raw material m. Substrate holding means 4 for holding the substrate A to which the fine particles generated by the fine particle generating means B are attached is disposed at a position adjacent to the fine particle generating means B along the direction of the inner peripheral surface 2a of the processing container 2. .

  It is assumed that at least one of the pressing member 1 and the processing container 2 rotates. In this embodiment, the case where the processing container 2 is fixed and the pressing member 1 rotates inside the processing container 2 is illustrated. The embodiment is not limited to this embodiment, and the pressing member 1 may be fixed and the processing container 2 may rotate, or the pressing member 1 and the processing container 2 may rotate in opposite directions. In any case, the powder raw material m to which a mechanical external force is applied by the pressing force of the pressing member 1 and the processing container 2 is pulverized.

(Pressing member)
The pressing member 1 is configured by a press head 1 </ b> A that is held by the processing container 2 and is rotatable about the axis Z <b> 1 of the processing container 2. The press head 1 </ b> A here has a substantially egg shape, and a processing surface 1 a that is curved in a convex shape is formed at the tip of the pressing head 1 </ b> A so as to face the inner peripheral surface 2 a of the processing container 2. In the present embodiment, the press head 1A provided with a single processing surface 1a is illustrated, but the present invention is not limited to this, and a configuration may be provided that includes a plurality of processing surfaces 1a.
Further, the shape of the press head 1A is not limited to the egg shape, and may be formed in a rod shape or the like. Further, the rotor may be formed so as to have a circular rotor in cross section, and an appropriate number of processing surfaces may be provided on the peripheral edge of the rotor.

The powder film forming apparatus X is provided with a rotation drive unit 12 including a motor, a pulley, a belt, and the like that rotate the shaft body 11. The rotation drive unit 12 rotates the shaft body 11 to rotate the press head 1 </ b> A relative to the processing container 2. Then, the processing surface 1a of the press head 1A is moved relative to the inner peripheral surface 2a of the processing container 2 along the inner peripheral surface 2a.
Thus, by moving the processing surface 1a of the press head 1A relative to the inner peripheral surface 2a, it is very strong against the powder raw material m in the gap 7 between the inner peripheral surface 2a and the processing surface 1a. Mechanical energy such as compressive force and shear force is applied. As a result, the powder is crushed, and a fine powdery generated powder C whose surface is activated is obtained. Therefore, in the present embodiment, the processing surface 1a and the inner peripheral surface 2a are particularly referred to as the fine particle generation means B. In the fine particle generation means B, the portion where the generated powder C is generated is the portion where the processing surface 1a and the inner peripheral surface 2a face each other and are closest to each other.

(Processing container)
The processing container 2 is a cylindrical member that is fixedly installed on the base 5 and has a horizontal axis Z1. The axis Z1 may be in the vertical direction.
Inside the processing container 2, a cylindrical processing chamber 3 in which the press head 1A rotates is formed. The processing chamber 3 is a fine particle generation space, and the generated powder C is circulated and suspended in the processing chamber 3.
A gap 7 is formed between the processing surface 1a of the press head 1A and the inner peripheral surface 2a, and the powder raw material m supplied from the raw material charging means 90 is deposited on the inner peripheral surface 2a.

  A jacket (not shown) can be provided on the outer periphery of the processing container 2. In order to keep the temperature in the processing container 2 at an optimum temperature, this jacket distributes treated water or the like that can be set to be freely heated or cooled.

(Substrate holding means)
The substrate holding means 4 is disposed at a position adjacent to the fine particle generating means B along the direction of the inner peripheral surface 2 a of the processing container 2. The “adjacent position” is any position on the inner space side of the processing chamber 3 or in the concave portion provided on the inner peripheral surface 2a as long as it is a position adjacent to the fine particle generating means B. Good.
In this embodiment, the board | substrate holding means 4 is accommodated in the recessed part 31 provided in a part of said inner peripheral surface 2a. Since the film is formed on the substrate A in the concave portion 31, the concave portion 31 is referred to as a film forming portion 31 in the following description.
The entire inner peripheral surface 2a is a fine particle generation site. Therefore, in the cross-sectional view, the film forming unit 31 is adjacent to the fine particle generating unit B upstream and downstream along the rotation direction of the press head 1A.
In the present embodiment, the film forming unit 31 is located above the axis Z1 of the processing container 2 and is recessed in the vertical direction.

The substrate holding means 4 holds the substrate A on which the produced powder C is adhered to form the powder film F on the surface. In this embodiment, the board | substrate holding means 4 is comprised with a rod-shaped holding member. Thereby, the board | substrate A can be hold | maintained easily. Further, when the air flow of the generated powder C is desired to flow through the back portion of the substrate A, the back space of the substrate holding means 4 is not reduced, and the air flow can flow smoothly.
Further, the substrate holding means 4 may be configured to bring the substrate A close to and away from the processing chamber 3.
In addition, for example, the substrate A can be directly fixed to the wall surface of the film forming unit 31, or the end of the substrate A can be fixed to a part of the film forming unit 31. Thereby, since the depth of the film-forming part 31 can be made shallow, the processing container 2 can be downsized.

In the powder film forming apparatus X of the present invention, the material of the substrate A is not particularly limited. Therefore, as the substrate A, for example, various materials such as a metal substrate such as copper, a glass substrate, a plastic substrate, a resin substrate, a ceramic substrate, and a weakly heat-resistant substrate constituting electrodes can be used.
The produced powder C adheres to the surface of the substrate A by van der Waals force, electrostatic force, chemical bond, or the like. Therefore, it is possible to select the substrate material so as to obtain a desired adhesion state.

  Such a substrate A is held by the substrate holding means 4 and is housed in a film forming section 31 provided on a part of the inner peripheral surface 2a. At this time, the substrate A can be separated by a predetermined distance so as not to come into contact with the press head 1A during the relative rotation of the press head 1A and the processing container 2.

  Inside the processing chamber 3, fine particles (generated powder C) generated by the mechanical external force applied to the powder raw material m during the relative rotation of the press head 1A and the processing container 2 float inside the apparatus main body. To do.

  In this apparatus, since the substrate holding means 4 is disposed at a position adjacent to the fine particle generating means B, the generated powder C can reach the substrate A before agglomeration. The produced powder C that floats after being produced immediately reaches the vicinity of the substrate holding means 4. The produced powder C flows along the surface of the substrate A held by the substrate holding means 4, and the produced powder C adheres to the substrate in a dispersed state, and a homogeneous powder film F is formed.

  Furthermore, in the apparatus of the present invention, the substrate holding means 4 is housed in the film forming section 31 that is recessed in a part of the inner peripheral surface 2a. Therefore, the produced powder C can be immediately attached to the substrate A.

  In this embodiment, a mode in which one substrate A is attached to the substrate holding means 4 is illustrated. However, the present invention is not limited to this, and a plurality of substrates A may be disposed on the substrate holding means 4.

The substrate holding means 4 includes an angle changing mechanism 42 that can change the holding posture of the substrate A to be held. The angle changing mechanism 42 includes, for example, an axis parallel to the axis Z1 and changes the installation angle of the substrate A around the axis.
By changing the installation angle of the substrate A, the vertical velocity component with respect to the substrate A when the produced powder C collides with the substrate A can be adjusted. Usually, when the vertical velocity component is increased, the density of the formed powder film F increases and the specific surface area decreases. Conversely, when the vertical velocity component is lowered, the density of the formed powder film F is reduced and the specific surface area is increased.

  Thus, since the vertical velocity component of the produced powder C that collides with the substrate A can be controlled, the desired properties can be obtained by variously changing the fine particle density and specific surface area of the powder film F formed on the surface of the substrate A. The powder film F can be easily formed.

As shown in FIGS. 2 to 3, the substrate holding unit 4 may include a rectifying unit 6 that can adjust at least one of the spray angle and the spray amount of the generated powder C with respect to the substrate A. Even if the position of the substrate A becomes a problem, the rectifying means 6 can reliably spray the generated powder C toward the substrate A, and the generated powder C adheres to the substrate A. The state can be controlled.
By providing the rectifying means 6, for example, fine particles can be attached to only one surface of the substrate A, or the generated powder C can be attached to both surfaces of the substrate A. For example, when controlling so that the produced powder C adheres to both surfaces of the substrate A, as shown in FIG. 2, the flow of the produced powder C branches in two directions, the front surface direction and the back surface direction of the substrate A. A plate-like member 61 is appropriately adjusted as the rectifying means 6 and provided immediately before the substrate A.
Further, according to the rectifying means 6, the fine particle density of the produced powder C adhering to the substrate A can be controlled over time. By this control, it is possible to form multilayer powder films having different fine particle densities.

Further, an air supply means 62 may be provided as the rectifying means 6 as shown in FIG. 3 so that the amount of spraying of the produced powder C onto the substrate A can be adjusted.
Usually, the adhesion of the fine particles to the surface of the substrate A is performed by further adding the newly generated fine particles to the surface of the already adhered fine particles. There may be a case where the first fine particle density until the first predetermined time elapses after the fine particles adhere to the substrate A is different from the second fine particle density until the second predetermined time elapses thereafter.
In such a case, it is possible to control the spray amount of the produced powder C onto the substrate A by supplying air of various strengths toward the substrate A or changing the air supply angle.
Thereby, the fine particle density of the fine particles on the substrate A is controlled with time so that almost all of the generated powder C adheres to the substrate A, or only a part of the generated powder C adheres to the substrate A. Thus, the amount of spraying per area of the substrate A can be changed.

  Further, a throttle member (not shown) that can adjust the passing amount of the generated powder C as the rectifying means 6 may be provided immediately before the substrate A in order to control the spraying amount of the generated powder C onto the substrate A.

  In addition, when the rectifying means 6 is provided, the air amount in the apparatus main body is kept constant, and the generated powder C is sucked from the gas outflow portion 29 by the vacuum pump 44 so that the product powder C flows smoothly. 2 to 3 exemplify the case where the gas outflow part 29 is provided in the film forming part 31. However, the present invention is not limited to this. For example, a gas outflow portion can be provided on a wall surface (not shown) of the processing container 2.

In the present embodiment, a shielding member 41 that blocks the generated powder C from reaching the substrate A is provided.
For example, as shown in FIG. 4, the substrate holding means 4 is configured as a shaft body that can be rotated by an axis Z2 different from the axis Z1 of the processing container 2. The substrate holding means 4 can be provided with one or more substrates A. In this embodiment, a case where two substrates A are provided is illustrated. At this time, the substrate A is provided in each of the two substrate storage portions 32 recessed in the substrate holding means 4.
The shielding member 41 is configured by a peripheral portion other than the substrate storage portion 32 in the substrate holding means 4. At this time, by rotating the substrate holding means 4 about the axis Z2, the substrate storage portion 32 and the shielding member 41 can be configured to face the processing chamber 3 alternately.
As shown in FIG. 4A, when the substrate storage portion 32 does not face the processing chamber 3 and the shielding member 41 faces the processing chamber 3, the generated powder C can be blocked from reaching the substrate A. it can. On the other hand, as shown in FIG. 4B, when the substrate storage portion 32 faces the processing chamber 3, the produced powder C reaches the substrate A, and a powder film F can be formed on the surface thereof.

  Thereby, by retracting the shielding member 41 from the processing chamber 3 side at an appropriate timing, the timing of exposing the substrate A to the generated fine particles, that is, the start timing / completion timing of the formation of the powder film F, and The exposure time of the substrate A can be appropriately controlled.

For example, at the start of the fine particle generation processing, the shielding member 41 keeps the generated particles C from reaching the substrate A, and after performing the fine particle generation processing for a certain time, the substrate holding means 4 is centered on the axis Z2. To the state in which the substrate storage portion 32 (substrate A) faces the processing chamber 3 side. Thereby, it is possible to prevent the produced powder C having a large particle diameter during the pulverization from adhering to the substrate A. In addition, since the film thickness can be easily controlled by adjusting the timing at which the shielding means 41 faces the processing chamber 3, the powder film F having desired characteristics can be easily formed.
At this time, if the film forming unit 31 is configured to be opened downward, the powder in the middle of pulverization is less likely to stay in the film forming unit 31 during the fine particle generation process, and thus the generated powder C can be efficiently generated. Can do.
In the present embodiment, the substrate A can be easily replaced by rotating the substrate holding means 4.

  Further, in the present embodiment, two processing containers may be opposed to each other with the substrate holding unit 4 as the center. In this case, by rotating the substrate holding means 4, the processing chamber in which the substrate faces can be easily switched from one processing chamber to the other processing chamber. For this reason, for example, if different powder raw materials are supplied to each processing container and the fine particle generation processing is performed, a powder film having a plurality of layers having different properties can be quickly formed.

In addition, the shielding member 41 is configured so as to cover the film forming unit 31 in FIGS. 1 to 3, and the substrate A becomes the generated powder C in a region until the generated generated powder C reaches the substrate A. A slide opening / closing type shutter (not shown) that can control exposure timing and time may be provided.
In this case, since the powder in the middle of pulverization can be prevented from entering the film forming unit 31, the generated powder C can be generated efficiently. It is desirable that the shutter be integrated with the inner wall of the processing chamber 3. However, even if there is a slight level difference between the shutter and the inner wall, there is no problem if the particles do not stay at the level difference.

Furthermore, a reversing member (not shown) that reverses the direction of the substrate A may be applied as the shielding member 41.
That is, at the start of the fine particle generation process, the substrate A is held by the reversal member so that the powder film forming surface of the substrate A faces the opposite side of the processing chamber 3. Then, after the fine particle generation processing is performed for a predetermined time, the reversing member is rotated by, for example, 180 degrees so that the powder film forming surface of the substrate A faces the processing chamber 3 side. At this time, the reversing member is arranged so as to hold the substrate A inside the film forming unit 31 and not interfere with the rotation of the press head 1A.
Accordingly, since the film thickness can be easily controlled by adjusting the reversal timing of the reversing member, the powder film F having desired characteristics can be easily formed.

<Other configurations>
(Raw material input means)
The raw material charging means 90 described above can be configured to continuously supply the powder raw material to the processing chamber 3.
Thereby, after supplying a certain powder raw material m and performing the fine particle generation process, or while continuing the fine particle generation process, the same powder raw material m is continuously supplied into the processing container 2, and the powder raw material m Since the film of the produced powder C produced from the above can be formed on the surface of the substrate A, continuous operation is possible.

In addition, it is possible to supply a powder raw material m having a different particle size or a different particle size after supplying a certain powder raw material m to perform a fine particle generation process and forming a film on the surface of the substrate A. . Thereby, the powder film F made of a plurality of layers of different materials can be formed on the surface of the substrate A. For example, a powder raw material for forming a primer film for facilitating adhesion of the produced powder C to the substrate A is charged from the raw material charging means 90 and subjected to a fine particle treatment. Then, after forming the primer film on the substrate A, the powder raw material is input from the raw material input means 90, and the generated powder C generated by the fine particle treatment is adhered to the substrate A, thereby generating the generated powder on the primer film. A powder film F in which the body C is laminated can be formed. Thus, the combination by various materials becomes possible and various types of powder films F can be formed.
The raw material charging means 90 can be configured to be freely withdrawn so that, for example, the powder raw material can be supplied into the processing container 2.

(Heating means)
The powder film forming apparatus X may include a heating unit 43 that heats the substrate A.
The heating means 43 is configured such that the substrate A can be heat-treated after the powder film F is formed on the substrate A, for example. Thereby, the residual stress of the substrate A generated when the produced powder C collides with the substrate A can be removed by annealing (annealing) the substrate A at a high temperature after film formation. Therefore, the substrate A having almost no distortion can be manufactured.

(Discharge means)
The powder film forming apparatus X may be provided with discharge means 20 for discharging the produced powder C. The discharge means 20 is configured to be capable of discharging, for example, from the processing surface 1a serving as a discharge portion disposed opposite to the inner peripheral surface 2a to the generated powder C deposited on the inner peripheral surface 2a.
More specifically, the discharging means 20 includes a power supply unit 21 between a conductive wire 22 connected to the press head 1 </ b> A that is insulated from the processing container 2 and a conductive wire 23 connected to the processing container 2. Apply voltage by A discharge plasma is generated by glow discharge or the like in the gap 7 between the processing surface 1a of the press head 1A and the inner peripheral surface 2a of the processing container 2. Therefore, the discharge means 20 can discharge the generated powder C to which mechanical energy is applied in the gap 7 between the inner peripheral surface 2a and the processing surface 1a.

  As a result, while the mechanical energy is applied to the generated powder C through the gap 7 between the inner peripheral surface 2a and the processing surface 1a, the generated powder C is discharged by the discharging means 20, and the powder particles The surface can be activated.

When discharging is performed by the discharging means 20, the inner peripheral surface 2a and the processing surface 1a are coated with the same material as the generated powder C, so that the inner peripheral surface 2a and the processing surface 1a are contaminated by etching. Can be suppressed.
Moreover, although the discharge means 20 made the part which discharges with respect to the internal peripheral surface 2a the processing surface 1a of the press head 1A, it discharges with respect to the internal peripheral surface 2a from the discharge part different from the said processing surface 1a. It can be set as the structure to perform.

(Ultrasonic wave generation means)
In forming the powder film F on the surface of the substrate A, the powder film forming apparatus X may be provided with an ultrasonic generation means 40 that performs ultrasonic treatment on the substrate A.
That is, since the ultrasonic wave generation means 40 can directly apply ultrasonic treatment to the substrate A to vibrate the substrate A, the fine particle density of the powder film F is reduced when the produced powder C adheres to the substrate A. Can be controlled.

(Water vapor supply means)
A water vapor supply means 24 capable of supplying water vapor S can be provided inside the processing container 2. Specifically, it is possible to provide a steam generator 25 such as a bubbling device and a supply pipe 26 that supplies the steam S generated by the steam generator 25 to the inside of the processing vessel 2. Furthermore, the water vapor partial pressure control for detecting the water vapor partial pressure inside the processing vessel 2 and controlling the water vapor generation amount of the water vapor generator 25 so that the detected water vapor partial pressure becomes a desired target water vapor partial pressure. A device 27 is provided. With these devices, the water vapor partial pressure can be maintained at a suitable water vapor partial pressure within a range equal to or lower than the saturated water vapor pressure.

  For example, when generating a product powder C by synthesizing a plurality of materials, a solid-phase reaction proceeds well and a product powder C is generated by performing fine particle generation processing in the presence of water vapor as in this configuration. Is done.

  1 and 3 are different in cross-sectional position. FIG. 1 shows the water vapor supply means 24 and FIG. 3 shows the rectifying means 6.

(Torque sensor)
By performing the fine particle generation process on the powder raw material m, for example, the powder raw material m that has been agglomerated becomes fine particles. At this time, torque fluctuation is transmitted to the shaft body 11 and the motor via the press head 1A. At this time, for example, if a torque sensor 50 for detecting the torque fluctuation of the shaft body 11 is provided, the fine particle state such as the approximate particle diameter of the powder raw material m in the processing chamber 3 can be grasped.

(Particle state determination means)
The powder film forming apparatus X may be provided with fine particle state determining means 28 for determining the processing state of the produced powder C processed inside the processing container 2.
In the fine particle state determination unit 28, the specific surface area of the generated powder C increases as the processing state of the powder raw material m to which mechanical action is applied inside the processing container 2, and the processing surface 1a and the inner peripheral surface 2a become larger. Utilizing the fact that the resistance in relative movement with increases. Then, when the rotational speed of the shaft body 11 and the torque applied to the shaft body 11 become larger than a predetermined value, it is determined that the processing state of the powder raw material m has reached a desired fine particle state. .

  The fine particle state determination means 28 uses the fact that the specific surface area of the product powder C increases and the amount of generated frictional heat increases as the processing state of the product powder C progresses. When the temperature of C becomes higher than a predetermined value, it is possible to determine that the processing state of the produced powder C has reached a desired fine particle state.

(Power control means)
The powder film forming apparatus X may be provided with a power control unit 30 that controls the power of the rotation driving unit 12 based on the determination result of the fine particle state determination unit 28.
The power control means 30 reduces the power of the rotation drive means 12 when the fine particle state determination means 28 determines that the processing state of the produced powder C has reached the desired fine particle state, thereby reducing the power of the processing surface 1a. It is comprised so that the relative movement speed with the surrounding surface 2a may be reduced.

  Using the powder film forming apparatus X described above, a fine particle generation process was performed under the following conditions to form a powder film on the substrate A. Titanium dioxide was used as a powder raw material.

  “Processing time” in Table 1 refers to a state in which the produced powder C is not blocked from reaching the substrate A by the shielding member 41, that is, a state in which the substrate A faces the processing chamber 3, and fine particles may adhere to the substrate A. Point to time.

  Titanium dioxide before the fine particle production treatment had an average particle size of 10 nm (primary particle size). When this titanium dioxide was used as a powder raw material m and fine particle generation treatment was performed under the conditions shown in Table 1, a film could be formed with titanium dioxide particles having a particle size substantially the same as the primary particle size (FIG. 5).

[Another embodiment 1]
In the embodiment described above, the case where fine particles of powder made of a single material are used for forming the powder film F has been described, but the present invention is not limited to this.
For example, fine powder for forming an electrode material of a fuel cell, that is, a mixed powder obtained by mixing rare earth metal oxide powder and oxide or carbonate powder of another metal that is not a rare earth metal is powdered. The mixed powder is pulverized as a body raw material and synthesized with each other to obtain a generated powder (synthetic powder).

  In this case, the resulting powder is subjected to processing such as grinding, precision mixing, particle compositing, interparticle solid phase reaction, etc. by applying mechanical external force such as compression force, shear force, impact force, etc. to the mixed powder. It is produced by a method called a mechanochemical method in which a required mechanical energy is applied to a powder and a plurality of powders are combined and activated to produce a synthesized powder (synthetic powder).

The generated powder is generated using, for example, a mixed powder obtained by mixing one or more rare earth metal oxide powders selected from La (lanthanum) or the like and a powder of another metal material. Here, the other metal material is exemplified by oxides of other metals such as Mn (manganese) or carbonates of other metals such as Sr (strontium).
By applying mechanical energy such as compressive force and shearing force to the mixed powder by the fine particle generation means B described above, a solid phase reaction between the rare earth metal oxide and another metal material in the mixed powder. Give rise to
Accordingly, LaMnO ₃ (lanthanum manganese oxide) or La _1-x Sr _x MnO ₃ (lanthanum strontium manganese oxide: LSM) in which a part of La in LaMnO ₃ is replaced with Sr (strontium) is used. A synthetic powder that is a perovskite oxide can be produced.

[Another embodiment 2]
In the above-described embodiment, the case where the processing container 2 is fixed and the press head 1 </ b> A rotates inside the processing container 2 is illustrated. However, the present invention is not limited to this, and the press head 1A can be fixed and the processing container 2 can be rotated.
In this case, the substrate holding means 4 can be disposed in the internal space of the processing chamber 3. Specifically, the substrate holding means 4 is provided downstream of the press head 1A with the rotation direction of the processing container 2 as a reference. At this time, the substrate holding means 4 is disposed at a position adjacent to the processing surface 1a of the press head 1A which is the fine particle generating means B.
Also in this case, the produced powder C can flow along the surface of the substrate A immediately after being produced, and can be attached to the substrate A in a state where the fine particles are dispersed.

  The powder film forming apparatus of the present invention can be applied as a film forming apparatus for forming a powder film by attaching fine particles generated by applying mechanical external force to a powder raw material to a substrate such as an electrode.

Overall configuration diagram of powder film forming apparatus in the present invention Schematic diagram of the main part near the rectifying means Schematic diagram of the main part near the rectifying means Schematic view of the vicinity of the shielding means The figure which showed the enlarged photograph of the formed powder film

Explanation of symbols

X Powder film forming apparatus A Substrate B Fine particle generation means C Fine particles (generated powder)
m Powder raw material Z1 Shaft core 1 Press member (press head)
2 Processing container 4 Substrate holding means 6 Rectifying means 31 Recessed part (film forming part)
41 Shielding member

Claims (5)

A mechanical external force is applied to the powder raw material by relatively moving a processing container containing and holding the powder raw material and a pressing member disposed close to the inner peripheral surface of the processing container in order to make the powder raw material into fine particles. A fine particle generating means for pulverizing the powder raw material,
Powder film formation in which substrate holding means for holding a substrate to which the fine particles generated by the fine particle generating means are attached is disposed at a position adjacent to the fine particle generating means along the direction of the inner peripheral surface of the processing container. apparatus.   2. The powder film forming apparatus according to claim 1, wherein the processing container is fixed, the pressing member is rotatable, and the substrate holding means is provided in a recess formed in a part of an inner peripheral surface of the processing container. .   The powder film forming apparatus according to claim 1, wherein the substrate holding unit is configured to be able to change a holding posture of the substrate to be held.   The rectification | straightening means which can adjust at least any one among the spray angle and spraying quantity of the said microparticles | fine-particles with respect to the said board | substrate was provided between the said microparticle production | generation means and the said board | substrate. Powder film forming device. The powder film forming apparatus according to any one of claims 1 to 4, further comprising a shielding member that blocks generated fine particles from reaching the substrate.