JP2007014889A - Array-coating method and apparatus for microparticle by supercritical fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an array-coating method and apparatus which can perform array-control of microparticles with high precision. <P>SOLUTION: The array-coating method of microparticles fills a material comprising microparticles or microparticles and vehicle, and a fluid in a supercritical state in a high-pressure container, stirs them to prepare a mixture uniformly dispersed with the material and fluid, and sprays the mixture to an object. The stirring is performed by turning stirring blades for generating a rising stream inside the high-pressure container. The array-coating apparatus of microparticles has: a supply part charged with a material comprising microparticles or microparticles and vehicle; a pressure control part for controlling the pressure of the fluid to feed it to a stirring part; the stirring part for stirring the material and the fluid in a supercritical state inside a high-pressure container to prepare a mixture uniformly dispersed with the material and fluid; and a spray part for spraying the mixture. In the apparatus, the stirring part has stirring blades for generating a rising stream inside the high-pressure container. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention utilizes the characteristics of supercritical fluids (SCF) to produce fine structures by arranging fine particles, automatically supplying fine particles, controlling the arrangement of fine particles on a substrate, The present invention relates to an array coating method and apparatus for fine particles that maintain an array shape. In particular, the present invention applies and develops a rapid expansion of supercritical solution (RESS) method, and fine particles that can maintain the arranged shape after the fine particles are arranged and controlled in two and three dimensions. The present invention relates to an array coating method and apparatus.

  Conventionally, when fine particles are arranged on a substrate, the fine particles are made fluid by mixing the dispersion medium and the fine particles, and the fine particles are arranged and controlled in a two-dimensional direction and a three-dimensional direction by a method such as printing and coating. There are a method of maintaining the array shape by the dispersion medium and a method of self-aligning the fine particles by evaporation of the dispersion medium.

  However, when trying to maintain the arrangement shape with a dispersion medium, the fine particles having fluidity have a drawback that the arrangement in the three-dimensional direction tends to collapse and expands in the two-dimensional direction. On the other hand, if the fluidity of the dispersion medium and the fine particles is lowered in order to prevent the arrangement of the fine particles in the three-dimensional direction, printing or coating cannot be performed well, so the fine particle arrangement in the two-dimensional and three-dimensional directions is controlled. There is a disadvantage that can not be. Further, when trying to self-align the fine particles by evaporation of the dispersion medium, there is a drawback that the evaporation time of the dispersion medium cannot be extremely shortened.

  Therefore, a fine particle arrangement control method for maintaining a controlled arrangement shape of fine particles on a substrate, in which a supercritical fluid is mixed in a mixture of fine particles and a dispersion medium and uniformly dispersed, and the fluidity of the mixture The inventors have proposed a method that makes it possible to shorten the evaporation time of the dispersion medium while controlling the arrangement in the two-dimensional direction and the three-dimensional direction (Patent Document 1).

  By the way, the conventional high-pressure vessel for stirring a mixture of supercritical fluid and fine particles, etc., is made by opening the lid of the high-pressure vessel for mixing and putting materials (fine particles, etc.), and then closing the lid to make it sealed. Supplying a supercritical fluid from a liquid (Patent Document 2), injecting a supercritical fluid after pouring the material into a high-pressure vessel for mixing (Patent Document 3), supercritical with a high-pressure pump after the material is in a solution state There exists what is supplied in a fluid (patent document 4).

Further, as a means for spraying paint or the like, there is one in which the flow of paint is intermittently accompanied by on / off of the operation of the spray gun in order to obtain a stable discharge amount (Patent Document 5). At this time, a patterning mask may be used to form a pattern on the substrate. In order to improve the adhesion between the substrate and the patterning mask, a magnet or the like is installed on the lower side of the substrate to improve the adhesion. (Patent Document 6).
JP 2005-118984 A JP 2002-356403 A JP 2002-309124 A JP 2004-148174 A JP-A-7-88408 JP 7-45662 A

  As shown in FIG. 14, a conventional apparatus using a general RESS method is composed of a supercritical fluid supply part f, a solute dissolution part g, a particle generation part h, and a particle recovery part i. When using fine particles to control the arrangement, as shown in FIG. 15, when supplying a material 74 such as fine particles, it is necessary to open and close the lid 73 of the high-pressure vessel every time, resulting in poor production efficiency. There was a problem that air and the like mixed in and affected the quality.

  In addition, in order to arrange and control the fine particles in a desired shape on the substrate using the characteristics of the supercritical fluid, it is necessary to uniformly disperse the supercritical fluid and the fine particles and the dispersion medium in the high-pressure vessel. is important. However, the apparatus of FIG. 15 has a problem that when the fine particles 77 as a material are stirred by the stirrer 75, the fine particles 77 gather on the lower and inner walls of the high-pressure vessel 76 and cannot be uniformly stirred (see FIG. 16). Moreover, since the supercritical carbon dioxide is sent into the high-pressure vessel 76 in order to maintain the injection pressure during spraying, there is a problem that the concentration of fine particles sprayed from the nozzle is continuously non-uniform. It was.

  It is also a problem to be solved to control the amount of fine particles according to the pattern to be formed and to arrange and control the fine particles without using a dispersion medium.

  In addition, when a pattern is formed on a substrate using a supercritical fluid, there is also a problem that if the patterning mask is used, the mask is lifted by spraying.

  An object of the present invention is to provide an array coating method and apparatus that can perform array control of fine particles with higher accuracy by solving the above-described problems.

The gist of the present invention is the following first to sixth fine particle array coating methods.
According to a first aspect of the present invention, a mixture of fine particles or a material composed of fine particles and a dispersion medium and a fluid in a supercritical state is injected into a high-pressure vessel and stirred to obtain a mixture in which the material and the fluid are uniformly dispersed. The fine particle array coating method is characterized in that the stirring is performed by rotating a stirring blade that generates an upward flow in the high-pressure vessel. .
According to a second aspect of the present invention, in the first aspect, the material and the fluid are injected into the high-pressure vessel by injecting a supercritical fluid into the high-pressure vessel and ejecting the material by one spray. Is sucked into the cylinder, and then all the material in the cylinder is injected into the high-pressure vessel.
According to a third invention, in the first invention, the material and the fluid are injected into the high-pressure vessel by injecting a fluid having a pressure lower than that in the supercritical state into the high-pressure vessel, and subsequently setting the pressure in the high-pressure vessel to the supercritical state. An arbitrary amount of material is injected into the high-pressure vessel while adjusting at a lower pressure than the state, and then a fluid in a supercritical state is injected into the high-pressure vessel.
According to a fourth invention, in the first invention, when the material is composed of only fine particles, the material is injected into the high-pressure vessel by injecting the material into a high-pressure vessel in a vacuum state or a state close to a vacuum state. Subsequently, a fluid in a supercritical state is injected into the high-pressure vessel.
A fifth invention is characterized in that, in any one of the first to fourth inventions, the capacity of the high-pressure vessel is the same as the amount of the mixture injected by one spray.
According to a sixth invention, in any one of the first to fifth inventions, the object is a patterning mask and a substrate sandwiched between a magnet plate and an upper frame made of a magnetic material or a magnet. To do.

In addition, the gist of the present invention is the following seventh to twelfth fine particle array coating apparatus.
According to a seventh aspect of the present invention, there is provided a supply unit into which a material comprising fine particles or fine particles and a dispersion medium is charged, a pressure adjusting unit that adjusts a fluid and sends the fluid to a stirring unit, and a material and a supercritical fluid in a high-pressure vessel In the fine particle arrangement device comprising a stirring unit that stirs the mixture and a mixture in which the material and the fluid are uniformly dispersed, and a spray unit that sprays the mixture, the stirring unit generates a rising flow in the high-pressure vessel. An array coating apparatus for fine particles, comprising wings.
An eighth invention is characterized in that, in the seventh invention, the supply section has a cylinder for sucking an arbitrary amount of material and feeding it to the stirring section.
In a ninth aspect based on the eighth aspect, the supply section has means for delivering the material sucked into the cylinder at an arbitrary pressure, and the pressure adjusting section is optionally disposed in a high-pressure container of the stirring section. It has the means to adjust to the pressure of this.
A tenth invention is characterized in that, in the seventh, eighth or ninth invention, the stirring section has a vacuum pump for adjusting the inside of the high-pressure vessel to a vacuum state or a state close to a vacuum state.
An eleventh invention is characterized in that, in any one of the seventh to tenth inventions, the volume of the high-pressure vessel is the same as the amount of the mixture injected by one spray.
In a twelfth invention according to any one of the seventh to eleventh inventions, a magnet plate, an upper frame made of a magnetic material or a magnet, a patterning mask and a substrate sandwiched between them, at a position facing the spray portion. It is characterized by comprising an arrangement part composed of

According to the present invention, the supercritical fluid and the material such as the fine particles and the dispersion medium can be uniformly mixed regardless of the viscosity of the fluid to be sprayed, so that the arrangement control of the fine particles can be performed with higher accuracy. Become.
It is also possible to control the amount of fine particles in the mixture and to uniformly mix the fine particles with the supercritical fluid without using a dispersion medium.
In addition, when the patterning mask is used, it is possible to prevent the mask from being lifted during spraying.

First, an outline of the prior art on which the present invention is predicated will be described, and then the specific contents of the present invention will be described.
1. Outline of prior art on which the present invention is implemented (1) RESS method
The RESS method is a technique for rapidly depositing a solute from a supersaturated state by injecting SCF in which various solutes are dissolved into a low pressure region from a nozzle, and has been used for the purpose of producing fine particles since the 1980s. Metal alkoxide dissolved in Supercritical Carbon Dioxide (SC-CO2) has been sprayed by a rapid expansion method for the purpose of developing fine particle and nano-order ultrafine particle production technology. Research into patterning has been carried out, and it has been realized to form patterns with thicknesses on the order of μm in a fine pitch region of about 50-100 μm (Inoue Hitoshi: High Pressure Science and Technology, No. 1 Vol. 12, No. 4, 2002, p337-344). By developing this research result, we succeeded not only in generating fine particles from solution, but also in forming films by dispersing ready-made fine particles in SC-CO2 and spraying them onto the substrate through a nozzle. The invention described in Document 1.

(2) Features of SC-CO2
The background of the application technology of the RESS method is based on the excellent physical properties of SCF, which is different from gas and liquid. Table 1 shows the physical properties (density, viscosity, thermal conductivity, diffusion coefficient) of SCF. The density of SCF is close to that of liquid and the viscosity is close to that of gas, but the diffusion coefficient has a value approximately halfway between that of gas and liquid. That is, it can be seen that SC-CO2 is more advantageous in transporting particles and the like because it has better mass transfer characteristics than liquid. One of the major features of SCF is the behavior in which the viscosity changes greatly due to slight changes in temperature and pressure, especially near the critical point. Therefore, it is possible to optimize transport properties by controlling the physical properties of SC-CO2.

(3) Definition of terms Base: In this specification, the base means, for example, a synthetic resin plate that is wired with copper foil on the surface and uses electronic parts such as semiconductors and resistors, and is generally called a printed circuit board. Is.
Fine particles: Originally, fine particles are very fine particles, and the fine particles in the examples refer to, for example, an alloy with silver and other metals, and the size can be in the range from nano units to micro units.
Supercritical fluid: Originally, a supercritical fluid is a fluid at a temperature and pressure that exceed the critical point of a substance. It does not liquefy even at a high density, and its ability to dissolve a substance, dissolution rate, and separation rate are liquid. Bigger than. The supercritical fluid assumed by the present invention includes, for example, supercritical carbon dioxide having a critical temperature of 31.2 ° C. and a critical pressure of 7.38 MPa. Other supercritical fluids that are easy to handle include ethane, propane, methanol, ethanol, ammonia, and xenon.
Dispersion medium: Originally, a dispersion medium refers to a uniform substance that forms a dispersion medium, in which a dispersed phase is dispersed. The dispersion medium assumed by the present invention can maintain a stable state of the fine particles and the entrainer. Examples of the organic dispersion medium include alcohols such as ethanol and ketones such as acetone. As other dispersion media, water, a surfactant, and the like can be considered.

2. Configuration and operation of the device of the present invention The device of the present invention is composed of a supply unit, a stirring unit, a pressure adjusting unit, a spray unit, and an array unit, but each component differs depending on its application. It has three kinds of embodiments. The first aspect is a configuration suitable for a relatively low to medium viscosity fluid (for example, cosmetics, dairy products, inks, latex, oils, creams, resins, paper coating solutions, surface coating agents, etc.). The second aspect is a configuration suitable for controlling the amount of fine particles in a relatively high viscosity fluid (eg, compound, epoxy, paste, putty, sealant, etc.), and the third aspect does not use a dispersion medium. Fine particles (for example, silver, copper, solder, etc. for metal fine particles, TiO2, ZnO, MnO2, Fe2O3, etc. for metal oxide fine particles, carbon, SiO2, CeO2, Al2O3, etc. for inorganic fine particles, organic fine particles, etc. , Flux, polyethylene, polystyrene, etc.). Below, each component is demonstrated concretely.

<Supply section>
A supply part supplies the mixture thrown into the hopper to the stirring part in the stirred state. The first and second aspects include a plunger pump, a plunger (or piston), and a cylinder, and the third aspect includes a powder container.

  According to the first aspect (in the case of a fluid having a low viscosity to a medium viscosity), the dispersion medium and the fine particles are once filled in the cylinder, and then the dispersion medium and the fine particles are uniformly distributed and sent to the stirring unit. be able to. At this time, the capacity of the cylinder is appropriately reduced, and all of the inside of the cylinder is sent to the agitating portion by the pushing operation of the plunger, thereby preventing only fine particles from remaining in the cylinder. In other words, it is pushed out from a small one (dispersion medium) under high pressure, so if the cylinder is made large and the mixture can be supplied several times, only the fine particles remain in the cylinder at the end. It ends up. Therefore, a preferred embodiment of the supply section in the first embodiment includes a cylinder that temporarily stores a mixture of the fine particles and the dispersion medium in an amount ejected by one spray.

  According to the second aspect (in the case of a high-viscosity fluid), the dispersion medium and the fine particles are once sucked into the cylinder, so that the dispersion medium and the fine particles can be sent to the stirring unit in a uniformly dispersed state. . In the second aspect, it is important that the pressure at the time of advancement of the plunger when extruding the mixture in the cylinder can be arbitrarily adjusted. In the second aspect, the reason why only the dispersion medium is not extruded first from the cylinder is to inject a high-viscosity fluid into a high-pressure vessel adjusted to a relatively low pressure. In the second aspect, since the amount of fine particles to be sprayed is adjusted by adjusting the amount of material injected from the cylinder, the capacity of the cylinder is not necessarily small.

  In the third aspect, only the fine particles are supplied from the hopper (in a state where they are not mixed with the dispersion medium) and stored in the powder container. The fine particles in the powder container are sucked into a high-pressure container in a vacuum state or a state close to a vacuum state.

<Stirring unit>
The stirrer is composed mainly of a high-pressure vessel for mixing, a stirrer, and a stirring blade, and mixes the material supplied from the supply unit with the supercritical fluid supplied from the pressure control unit, and stirs them. Disperse evenly and supply to the spray section.
In the present invention, the problem that conventional fine particles gather on the lower and inner walls is eliminated by making the stirring blade in a shape that generates a flow upward (for example, a drill type), and the fine particles are uniformly dispersed in the mixing high-pressure vessel. It was possible to make it. Since the fluidity of the fine particles is improved by uniformly dispersing the mixture of the material and the supercritical fluid, the dispersion medium may not be used depending on the type of the fine particles.

  A preferred embodiment of the stirring unit of the present invention is provided with a stirring blade for generating an upward flow in the mixture in the high-pressure vessel, and a mixture of supercritical fluid, fine particles and dispersion medium in an amount ejected by one spray. A high-pressure container for mixing is provided. Since all the mixture in the mixing high-pressure vessel is sprayed for each spray, the mixture in the mixing high-pressure vessel is always uniformly dispersed.

《Pressure control unit》
The pressure adjusting unit has a known configuration, and a pressure adjusting valve provided in the middle of a cylinder storing a fluid, a pressure adjusting high-pressure vessel, and a pipe connecting the two, and a pressure change due to a temperature change are prevented. This heater is the main component.

<Spray part>
The spray unit has a known configuration, and a pipe for deriving a mixture of the fine particles, the dispersion medium and the supercritical fluid in the high-pressure vessel for mixing, a nozzle provided at the end of the pipe, and a mixture passing through the pipe are fixed. The main components are a heater for maintaining the temperature and an opening / closing valve provided in the middle of the pipe. By opening the opening / closing valve, a mixture of fine particles, dispersion medium and supercritical fluid is sent to the nozzle and arranged. Sprayed on the part.
When the capacity of the mixing high-pressure vessel is reduced, all the mixture in the mixing high-pressure vessel is sprayed by one spray. Therefore, when the area of a board | substrate is more than fixed, it will spray in multiple times.

<Array section>
The array portion is a magnetic material or magnet that sandwiches the patterning mask and the substrate by the magnetic force of the patterning mask, a lower fixing jig (magnet plate) that is a magnet placed under the substrate, and the lower fixing jig. And an upper fixing jig (upper frame). By spraying the mixture onto the substrate from the spray section through the patterning mask, the desired position and the height of the array can be limited. Conventionally, since the patterning mask is thin, there is a risk of floating when spraying at a high pressure. However, in the present invention, the patterning mask is made of a magnetic material, and a lower fixing jig and a magnetic material or magnet that are powerful magnets are used. Adhesion is enhanced by restraining it with an upper fixing jig. The patterning mask is preferably made of a magnetic material.
The upper fixing jig may be provided with an opening in accordance with the patterning mask, or may simply be a frame so as to be compatible with various patterning masks.

  Hereinafter, details of the present invention will be described with reference to examples, but the present invention is not limited to the examples.

The apparatus of the present embodiment has a configuration suitable for a fluid having a relatively low viscosity to a medium viscosity, and has a feature in a material delivery method from a supply unit to a stirring unit.
As shown in FIG. 1, the fine particle array coating apparatus of the present embodiment includes a pressure adjusting unit a that adjusts supercritical carbon dioxide to a pressure suitable for spraying, a supply unit b that supplies fine particles as a material to the stirring unit, It is composed of a stirring part c for mixing supercritical carbon dioxide, fine particles and a dispersion medium, a spray part d for spraying a mixture of supercritical carbon dioxide, fine particles and a dispersion medium, and an array part e for arranging fine particles on a substrate. Yes.

FIG. 2 is a drawing for explaining the basic configuration of the fine particle array coating apparatus of the present invention.
In the figure, the reference numerals assigned to the components of the apparatus are: 1 is a carbon dioxide cylinder, 2 is a high-pressure vessel for pressure regulation, 3 is a high-pressure vessel for mixing, 4 is a pump, 5 is a valve for regulating pressure, and 6 is a valve for regulating flow rate. , 7 is an agitator, 8 is an opening / closing valve, 9 is a nozzle, 10 is a patterning mask, 11 is a substrate, 12 is a fixture jig, 13 is a hopper, 14 is a plunger pump, 15 to 20 are pipes, 21 to 23 Is a pressure gauge, 24 to 26 are pressure gauges, 27 to 29 are safety valves, 30 to 37 are valves, 38 is an exhaust pump, 39 is a heat exchanger, and 40 is a cooler.

<< Pressure adjustment part a >>
The pressure adjusting unit includes a carbon dioxide cylinder 1, a pressure adjusting high-pressure vessel 2 including heaters 21 and 22, a pipe 15 connecting both, a pressure adjusting valve 5 provided in the middle of the pipe 15, and a pressure adjusting unit. A pipe 16 branched so as to bypass the valve 5, a pump 4 provided in the middle of the pipe 16, and a flow rate adjusting valve for adjusting the amount of regulated supercritical carbon dioxide supplied to the mixing high-pressure vessel 3 The carbon dioxide in the carbon dioxide cylinder 1 is regulated by the pressure regulating valve 5 and the pump 4, and the supercritical carbon dioxide having a flow rate required by the flow regulating valve 6 is Supplied to the pressure regulating high-pressure vessel 2.
The heaters 21 and 22 provided in the pressure regulating high-pressure vessel 2 adjust the temperature of the regulated supercritical carbon dioxide in order to prevent pressure fluctuations due to temperature changes. Is maintained at a constant pressure.

<< Supply part b >>
The supply unit includes a valve 37 that is a check valve provided in the middle of the pipe that connects the hopper 13 and the plunger pump 14, and the pipe 19 and the pipe 19 that connect the plunger pump 14 and the high-pressure container 3 for mixing. The valve 36 is a check valve provided on the way, and the open / close valve 32.

FIG. 3 is a diagram illustrating the state of (1) material suction and (2) material discharge in the supply unit. First, (1) during material suction, when the plunger 41 operates in a direction (in the direction of the arrow) to draw the fine particles 43 and the dispersion medium 44 in the hopper 13 into the cylinder 42, the valve 37 opens and the valve 32 closes. The cylinder 42 is filled with a certain amount of fine particles 43 and a dispersion medium 44.
Next, in (2) material discharge, when the plunger 41 is operated in the direction of pushing out the fine particles 43 and the dispersion medium 44 in the cylinder 42 (in the direction of the arrow), the valve 32 is opened and the valve 37 is closed, A certain amount of fine particles 43 and a dispersion medium 44 are filled in the mixing high-pressure vessel 3.

<< Stirrer c >>
The agitation unit is composed of a mixing high-pressure vessel 3 and a stirrer 7. The pressure-regulated supercritical carbon dioxide sent into the mixing high-pressure vessel 3 by the pipe 17 and the mixing pressure by the pipe 19 are mixed. The fine particles and the dispersion medium supplied into the container 3 are agitated and mixed by the agitator 7.
FIG. 4 is a detailed cross-sectional view of the high-pressure vessel for mixing, and is an image diagram in which fine particles are being stirred. 3 is a mixing high-pressure vessel, 7 is a stirrer, 45 is a lid of the mixing high-pressure vessel, 46 to 48 are joints (for connecting the pipes 18 to 20 of FIG. 2 and the mixing high-pressure vessel 3), 49 is Supercritical carbon dioxide.

Since the volume of the mixing high-pressure vessel 3 is about 14.5 cc and the volume of the drill is about 12.5 cc, the effective capacity of the mixing high-pressure vessel 3 is about 2 cc. For example, when the mixture is filled with about 2 cc, and the sprayed area is about 20 cm ² to 100 cm ² , the thickness of the sprayed fine particles is about 100 μm to 20 μm.
The stirrer 7 is provided with a stirring blade 78 cut so that the tip of the rotary drill becomes a flat surface, and thereby an upward flow is generated in the high-pressure vessel 3 for mixing. The stirrer blade 78 of the stirrer uses a solid end mill (S4MDD2000) manufactured by Mitsubishi Materials Corporation, and has a helical screw structure with four blades, a twist angle of 30 °, a diameter of 20 mm, and a groove length of 45 mm.
The motor for rotating the agitating blade 78 is a speed control motor (PSH-540-001P) manufactured by Oriental Motor, variable speed range 90 ~ 1500rpm, allowable torque 55mN · m ~ 200mN · m, left and right It corresponds to rotation. For example, as a condition for uniformly stirring arbitrary fine particles, if stirring is performed in the right direction at 800 rpm, a propulsive force is generated in the vertical direction, and the fluid moves from the upper part toward the lower part. As a result, an upward flow is generated from the inner central portion of the mixing high-pressure vessel 3 toward the periphery, so that the settled fine particles are also lifted and stirred.

<Spray part d>
The spray section is composed of an opening / closing valve 8, a nozzle 9 and a heater 23, and in the high pressure vessel 3 for mixing, a mixture of uniformly stirred fine particles, a dispersion medium, and supercritical carbon dioxide opens the opening / closing valve 8. Then, it is sent from the pipe 20 to the nozzle 9 and sprayed.
The heater 23 absorbs heat when a mixture of fine particles, a dispersion medium, and supercritical carbon dioxide is sprayed, and thus is provided for the purpose of stabilizing the spray at a constant temperature.

  As shown in FIG. 5, the spray unit of the fine particle array coating apparatus of this embodiment passes through a pipe 20 connected to the mixing high-pressure vessel 3, and a mixture of fine particles, a dispersion medium, and supercritical carbon dioxide is supplied to the valve 8. Sent. By opening and closing the valve 8 at regular intervals for a short time, a fluid 50 of a mixture of fine particles, a dispersion medium, and supercritical carbon dioxide is sprayed from the nozzle 9 onto the substrate 51. The amount of fine particles and dispersion medium sprayed at one time is the maximum amount filled in the mixing high-pressure vessel 3. Therefore, by controlling the opening and closing time of the valve 8 and the amount of fine particles and dispersion medium charged in the mixing high-pressure vessel 3, fine particles of a constant concentration can be sprayed. It is possible to form a film 52 of fine particles whose arrangement is uniformly controlled.

  Control of each part necessary to enable uniform and uniform array control of fine particles per unit area no matter how many times spraying will be described with reference to FIG. First, fine particles, a dispersion medium, and the like, which are materials of the plunger 41, are sucked into the cylinder 42 by a certain amount, and the whole amount is discharged into the mixing high-pressure vessel 3. Subsequently, in the high-pressure vessel 3 for mixing, the fine particles and dispersion medium as materials are uniformly stirred and mixed with supercritical carbon dioxide, and then the opening and closing valve 8 is opened. 50 is sprayed, and all the fine particles, the dispersion medium, etc., which are the materials in the mixing high-pressure vessel 3 are discharged. At this time, each part is controlled by the timing chart shown in FIG. In order to maintain the injection pressure, new supercritical carbon dioxide is sent into the mixing high-pressure vessel 3, and thus the mixing high-pressure vessel 3 is filled with supercritical carbon dioxide after the completion of discharge. By repeating this process, each spray is uniform and fine particles having a constant concentration are ejected. Therefore, it is possible to control the arrangement of fine particles uniformly per unit area regardless of the number of sprays.

<< Array part e >>
The arrangement portion is composed of a patterning mask 10, a substrate 11, and a fixing jig 12 composed of an upper member and a lower member that sandwich the patterning mask 10 and the substrate 11.

As shown in FIG. 7, patterning using the arrangement portion in the present embodiment is performed by placing a lower fixing jig 12 (for example, a magnet 54) under the substrate 11, and patterning the mask 10 on the substrate 11. The upper fixing jig 12 (for example, an iron thin plate 53) is installed and clamped on the upper side. The pipe 20 connected to the mixing high-pressure vessel 3 is moved to a position opposed to the arrangement portion, and a fluid 50 having a certain concentration of fine particles is sprayed from the nozzle 9 via the opening / closing valve 8.
By spraying the fluid 50 having a constant concentration of fine particles at regular intervals in a short time, the fine particles can be arranged and controlled in accordance with the pattern of the patterning mask 10.

FIG. 8 illustrates an example of a fixing jig 12 for controlling the arrangement of fine particles on a substrate. In the figure, 53 is an iron thin plate, 55 is an opening portion of an iron thin plate matching the pattern, 10 is a patterning mask, Reference numeral 56 denotes an opening of the patterning mask, 11 denotes a substrate, and 54 denotes a magnet.
A magnet 54 is placed under the substrate 11, an iron thin plate 53 is placed on the patterning mask 10, and the substrate 11 and the patterning mask 10 are sandwiched, so that even the patterning mask 10 having no magnetism is subjected to a strong magnetic force. Fixing with the iron thin plate 53 improves the adhesion between the substrate 11 and the patterning mask 10.
Further, since the opening 55 of the iron thin plate is wide open so as to cover the opening 56 of the patterning mask, the fine particles pass through the opening 55 of the iron thin plate and the opening 56 of the patterning mask, so Arranged on the substrate 11 according to the pattern.

<Operation>
The operation of the apparatus of this embodiment will be described with reference to FIG.
(1) Material Suction When the plunger 41 is operated so that the material is sucked into the cylinder 42 from the hopper 13, the valve 37 is opened, the valve 36 is closed, and the fine particles 43 and the dispersion medium 44 are placed in the cylinder 42. Is filled. At this time, the mixing high-pressure vessel 3 is filled with supercritical carbon dioxide 49.
(2) Material discharge In order to inject the material in the cylinder 42 into the mixing high-pressure vessel 3, the plunger 41 is operated in the opposite direction to (1), and the supercritical carbon dioxide 49 is generated at a pressure greater than 7.38 MPa. The fine particles 43 and the dispersion medium 44 are pushed out into the mixing high-pressure vessel 3. At this time, the valve 36 is open and the valve 37 is closed.
(3) Material stirring The entire amount of the fine particles 43 and the dispersion medium 44 in the cylinder 42 are injected into the high-pressure vessel 3 for mixing. Subsequently, the stirring blade 78 is rotated by the stirrer 7, and an ascending flow is generated in the mixing high-pressure vessel 3 to stir the fine particles, the dispersion medium, and the supercritical carbon dioxide so that they are uniformly dispersed. Thereafter, the mixture of the fine particles, the dispersion medium, and the supercritical carbon dioxide in the mixing high-pressure vessel 3 is all sprayed in one spray, whereby the fine particle film 52 that is uniformly arranged and controlled per unit area in a fixed amount. Can be formed.
By repeating the processes (1) to (3), the material concentration does not vary each time, and uniform spraying can be performed.

The apparatus of the present embodiment has a configuration suitable for a fluid having a relatively high viscosity, and is characterized by a material delivery method from the supply unit to the stirring unit.
As shown in FIG. 10, the apparatus of this embodiment is different from the apparatus of Embodiment 1 in part of the supply section b and the pressure adjustment section a, 57 is a valve for opening and closing, 58 is a valve for adjusting pressure, and 59 and 60 are A pressure gauge, 61 is a controller, and 62 is a dispenser system.

  For example, the pressure of the plunger of the dispenser system 62 is measured with the pressure gauge 60, and the pressure of the mixing high-pressure vessel 3 is measured with the pressure gauge 59. The pressure in the mixing high-pressure vessel 3 is adjusted by the pressure adjusting valve 58 via the controller 61, and the plunger pressure is adjusted by the dispenser system 62, so that the mutual pressure is optimally controlled, thereby smoothing the fine particles. Can be injected into the mixing high-pressure vessel 3.

<Operation>
The operation of the apparatus of this embodiment will be described with reference to FIG.
(1) Pressure adjustment The pressure in the mixing high-pressure vessel 3 is set to a pressure lower than the supercritical state in order to facilitate injection of the fine particles 43 and the dispersion medium 44 in the syringe 63. Since the pressure is reduced in the mixing high-pressure vessel 3, the fluid is carbon dioxide 65 which is not in a supercritical state. On the other hand, since the fine particles 43 and the dispersion medium 44 in the syringe 63 have a high viscosity, they are combined and relatively uniformly dispersed.
(2) Material injection By pushing out the plunger 64, the fine particles 43 and the dispersion medium 44 are injected into the mixing high-pressure vessel 3. At this time, by adjusting the stroke of the plunger 64, the injection amount of the fine particles 43 is determined, so that the concentration of the fine particles during spraying can be adjusted.
(3) Supercritical carbon dioxide (SC-CO2) injection In order to raise the pressure in the mixing high-pressure vessel 3 adjusted to a pressure lower than the supercritical state to the supercritical state after completion of material injection, Inject supercritical carbon dioxide 49. At this time, the valve 35 is in an open state and the valve 36 is in a closed state.
(4) Material Stirring In order to uniformly disperse the fine particles 43, the dispersion medium 44, and the supercritical carbon dioxide 49 in the high pressure vessel 3 for mixing, stirring is performed with a stirring blade 78. By spraying a mixture of finely dispersed fine particles, a dispersion medium, and supercritical carbon dioxide, it is possible to form a fine particle film 52 that is quantitatively and uniformly controlled per unit area.
By repeating the above processes (1) to (4), the material concentration does not vary each time, and uniform spraying can be performed.

The apparatus of the present embodiment is an array coating apparatus for fine particles that sprays fine particles without using a dispersion medium, targeting fine particles in a powder state.
As shown in FIG. 12, the apparatus of the present embodiment is partly different from the apparatus of Embodiments 1 and 2 in the supply part b and the pressure adjustment part a, 66 is a fine particle powder, 67 is a powder metering feeder, 68 is a powder hopper, 69 is a butterfly valve, 70 is a powder container, 71 is a vacuum pump, and 72 is a filter (for collecting fine particles).

<Operation>
The operation of the apparatus of this embodiment will be described with reference to FIG.
(1) Vacuum state The inside of the mixing high-pressure vessel 3 is brought into a vacuum state or a state close to a vacuum state by the vacuum pump 71.
(2) Material suction When the valves 32 and 36 are opened, the fine particles 43 are sucked from the powder container 70 into the high-pressure mixing container 3 close to a vacuum state.
(3) Supercritical carbon dioxide (SC-CO2) injection In order to bring the inside of the high-pressure vessel 3 for mixing into a supercritical state, the valve 35 is opened, the valves 32 and 36 are closed, and the supercritical dioxide is introduced from the pipe 18. Carbon 49 is injected into the mixing high-pressure vessel 3.
(4) Material stirring The fine particles 43 and the supercritical carbon dioxide 49 in the mixing high-pressure vessel 3 are stirred so that both are uniformly dispersed. By spraying a mixture of uniformly dispersed fine particles and supercritical carbon dioxide, it is possible to form a fine particle film 52 that is quantitatively and uniformly controlled per unit area.
By repeating the above processes (1) to (4), the material concentration does not vary each time, and uniform spraying can be performed.

Since the present invention can spray fine particles without using an organic solvent as in the prior art, it is expected to be used in a wide range of fields as an environmentally conscious device.
For example, in the electronics industry, in the surface mounting field, solder printing, flux coating, electrode wiring formation, etc. In the display field as well, in the display field, light emitting material coating, transparent conductive film material coating, electromagnetic wave shielding material coating, liquid crystal spacer coating, etc. Similarly, in the field of memory materials, such as arrangement and formation of electrodes, application of magnetic recording materials, arrangement of microcapsules of electronic paper, and the like can be mentioned. Also, in the fields of machinery and optical industries, in the field of injection molding, the arrangement of molding materials, the application of mold release agents, etc., in the same field of polishing, the application of abrasives to abrasive sheets, and also in the field of lenses, the micro lens array Molding, filter membrane molding, and the like. In the materials and chemical industries, in the sensor field, thin film molding such as titanium dioxide and zinc oxide for gas sensors, magnetic material application for magnetic sensors, etc. In the plastic and paper fields as well, antibacterial sheets and photocatalyst application to sanitary products Application of non-slip material to power belts and flooring materials, application of adhesive particles to paper and film, and the like. In the environment and energy industries, photocatalyst particle arrangements in dye-sensitized solar cells, formation of catalyst layers in fuel cells, photocatalysts in environmental purification, fine particle arrangement of strong oxidizers, formation of ceramic films in zeolite, etc. . In the bio and medical industries, drug application to sheets, cosmetic material application to sheets, manufacture of microreactors by self-arrangement, manufacture of actuators, manufacture of filters, etc. include application to drug delivery systems.

FIG. 2 is a basic configuration diagram showing each part constituting the apparatus of Example 1. 1 is a basic configuration diagram of an apparatus according to Embodiment 1. FIG. It is an image figure which shows the supply state of the material in the apparatus of Example 1. FIG. FIG. 5 is a detailed cross-sectional view of a mixing high-pressure vessel and an image diagram of stirring fine particles. It is an image figure at the time of spraying the fluid of fine particles intermittently. It is a time chart which shows the relationship between each mechanism and material regarding intermittent spraying. It is an image figure of patterning of fine particles using an arrangement part. It is side part sectional drawing which shows the structure of an arrangement | sequence part. It is explanatory drawing of filling of the material and supercritical fluid in Example 1, and stirring. FIG. 3 is a basic configuration diagram of an apparatus according to a second embodiment. It is explanatory drawing of filling of the material and supercritical fluid in the apparatus of Example 2, and stirring. FIG. 6 is a basic configuration diagram of an apparatus according to a third embodiment. It is explanatory drawing of filling of the material and supercritical fluid in the apparatus of Example 3, and stirring. It is a basic block diagram of the apparatus regarding the microparticle production | generation and collection | recovery by the conventional supercritical fluid rapid expansion method. It is explanatory drawing of material injection | throwing-in to the container for high pressures of the apparatus of FIG. It is explanatory drawing of the stirring in the container for high pressures of the apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbon dioxide cylinder 2 High pressure vessel for pressure regulation 3 High pressure vessel for mixing 4 Pump 5 Pressure adjustment valve 6 Flow rate adjustment valve 7 Stirrer 8 Opening / closing valve 9 Nozzle 10 Patterning mask 11 Substrate 12 Fixing jig 13 Hopper 14 Plunger pump 15 to 20 Pipes 21 to 23 Heaters 24 to 26 Pressure gauges 27 to 29 Safety valves 30 to 37 Valves 38 Exhaust pumps 39 Heat exchangers 40 Coolers 41 and 64 Plungers 42 Cylinders 43 Fine particles 44 Dispersion media 45 Caps of high pressure containers for mixing 46 to 48 Joint 49 Supercritical carbon dioxide 50 Mixture fluid 51 Substrate 52 Fine particle film 53 Iron thin plate 54 Magnet 55 Iron thin plate opening 56 Patterning mask opening 57 Opening / closing valve 58 Pressure adjusting valve 59, 60 Pressure gauge 61 Controller 62 Dispenser system 63 Syringe 65 Carbon dioxide 66 Particulate powder 67 Powder metering feeder 68 Powder hopper 69 Butterfly valve 70 Powder container 71 Vacuum pump 72 Filter 73 High pressure container lid 74 Particulate material 75 Stirrer with stirrer blade 76 High pressure container 77 Particulate 78
a pressure adjusting unit b supplying unit c stirring unit d spraying unit e arranging unit f supercritical fluid supplying unit g solute dissolving unit h particle generating unit i particle collecting unit

Claims (12)

Fine particles or a material composed of fine particles and a dispersion medium and a fluid in a supercritical state are injected into a high-pressure vessel, and they are agitated to form a mixture in which the materials and fluid are uniformly dispersed, and the mixture is sprayed onto the object. An array coating method of fine particles,
The stirring is performed by rotating a stirring blade that generates an upward flow in the high-pressure vessel.   Injecting the material and the fluid into the high-pressure vessel involves injecting a supercritical fluid into the high-pressure vessel, sucking the amount of material injected by a single spray into the cylinder, and then The method for coating fine particles according to claim 1, wherein the material is injected into a high-pressure vessel.   Injection of the material and the fluid into the high-pressure vessel is performed by injecting a fluid having a pressure lower than the supercritical state into the high-pressure vessel, and then adjusting the pressure in the high-pressure vessel at a pressure lower than the supercritical state. The fine particle array coating method according to claim 1, wherein a fluid in a supercritical state is subsequently injected into the high pressure vessel. When the material consists only of fine particles,
2. The fine particle array coating according to claim 1, wherein the material is injected into the high-pressure vessel by injecting the material into a high-pressure vessel in a vacuum state or near a vacuum state, and subsequently injecting a fluid in a supercritical state into the high-pressure vessel. Method.   The method for arranging and applying fine particles according to any one of claims 1 to 4, wherein the capacity of the high-pressure vessel is the same as the amount of the mixture sprayed by one spray.   6. The fine particle array coating method according to claim 1, wherein the object is a patterning mask and a substrate sandwiched between a magnet plate and an upper frame made of a magnetic material or a magnet. A supply unit into which fine particles or a material composed of fine particles and a dispersion medium is charged, a pressure adjusting unit that regulates a fluid and sends the fluid to a stirring unit, and a material that stirs a material and a fluid in a supercritical state in a high-pressure vessel; In an apparatus for arranging fine particles, comprising a stirring unit that makes a mixture in which fluid is uniformly dispersed, and a spray unit that sprays the mixture,
The fine particle array coating apparatus, wherein the stirring section includes a stirring blade that generates an upward flow in the high-pressure vessel.   The fine particle array coating apparatus according to claim 7, wherein the supply unit includes a cylinder that sucks an arbitrary amount of material and delivers the material to a stirring unit. The supply unit has means for sending the material sucked into the cylinder at an arbitrary pressure,
9. The fine particle array coating apparatus according to claim 8, wherein the pressure adjusting unit includes means for adjusting the inside of the high pressure container of the stirring unit to an arbitrary pressure.   10. The fine particle array coating apparatus according to claim 7, 8 or 9, wherein the stirring section has a vacuum pump for adjusting the inside of the high-pressure vessel to a vacuum state or a state close to a vacuum state.   11. The fine particle array coating apparatus according to claim 7, wherein a capacity of the high-pressure vessel is equal to an amount of a mixture sprayed by one spray. 12. The apparatus according to claim 7, further comprising: an array portion including a magnet plate, an upper frame made of a magnetic material or a magnet, and a patterning mask and a substrate sandwiched between the magnet plate and the spray portion at a position facing the spray portion. Fine particle array coating device.