Film forming apparatus, film forming method, and conductive film manufacturing apparatus

Abstract

The invention provides a film forming apparatus, a film forming method, and an apparatus for manufacturing a conductive film. A film forming apparatus for supplying mist containing fine particles to a substrate and forming a film containing the fine particles on the surface of the substrate, the film forming apparatus comprising: a conductor provided so as to be separated from the surface of the substrate; a mist supply unit that supplies the mist to the surface of the substrate; a transport unit that transports the substrate; and an alternating-current electric field generation unit that applies an alternating-current voltage to at least one of the conductor and the transfer unit.

Description

[0001] This application is a divisional application based on the invention patent application with the invention name “Mist film-forming device and mist film-forming method”, the application date of January 20, 2021, and the application number of 202180010123.1 (international application number PCT / JP2021 / 001749). Technical Field

[0002] The present invention relates to a mist film-forming device and a mist film-forming method for atomizing a solution containing fine material particles (nanoparticles) and spraying the obtained mist onto a substrate to be processed, thereby forming a thin film of a material substance composed of fine particles on the surface of the substrate to be processed. Background Art

[0003] In the manufacturing process of electronic devices, a film forming step (film forming treatment) is implemented. In this film forming step, a thin film composed of various material substances is formed on the surface of the substrate (the object to be processed) on which the electronic device is to be formed. There are various film forming methods in the film forming step. In recent years, the mist film forming method has attracted attention. In this mist film forming method, a mist generated by a solution containing molecules or microparticles (nanoparticles) of a material substance is sprayed onto the surface of the substrate, and the solvent components contained in the mist (solution) attached to the substrate react or evaporate, forming a thin film composed of material substances (metal materials, organic materials, oxide materials, etc.) on the surface of the substrate. As a film forming method similar to the mist film forming method, the electrostatic spray deposition method (electrospray deposition) disclosed in Japanese Patent Gazette No. 2005-281679 is known. The electrostatic spray deposition method is a method of making the liquid to be applied charged with static electricity, so that the charged liquid becomes tiny droplets (mist) or linear bodies and adheres to the object. Japanese Patent Application Laid-Open No. 2005-281679 discloses the following structure: a solution in which a resin for forming a film on the surface of an insulating film is dissolved in a solvent, or a dispersion in which a resin and inorganic particles are dispersed is supplied to a nozzle having a capillary at the front end, and a pressure is applied to the nozzle to achieve a constant flow rate while a high voltage is applied to the nozzle, thereby causing charged droplets or linear bodies with a diameter of a few tenths of a micrometer to tens of micrometers to be ejected from the capillary at the front end of the nozzle to the film surface. In addition, in Japanese Patent Application Laid-Open No. 2005-281679, a film is placed on a conductive plate having an area larger than the film, and a certain potential difference is given between the conductive plate and the nozzle, thereby causing the charged droplets or linear bodies to effectively adhere to the film surface.

[0004] In the electrostatic spray deposition method, the droplets or linear bodies ejected from the capillary of the nozzle also depend on the distance from the nozzle tip to the film surface, or the potential difference between the nozzle and the conductive plate. However, in Japanese Patent Publication No. 2005-281679, by making the diameter of the nozzle tip (capillary) preferably in the range of 0.4 to 1 mm and the voltage applied between the nozzle and the conductive plate preferably in the range of 10 to 20 kV, a structure is formed in which the droplets or linear bodies are ejected from the nozzle tip by electrostatic repulsion. Therefore, there is a tendency that the film thickness formed in the central part where the extension line of the ejection direction of the capillary at the nozzle tip intersects with the film surface is the thickest, and the film thickness becomes thinner as it moves from the central part toward the periphery. Therefore, in order to uniformly form a thin film composed of resin or inorganic particles with an accurate thickness on a large film surface, it is necessary to precisely move the film and the nozzle relative to each other in a two-dimensional manner at a certain speed in a plane parallel to the film surface. Summary of the invention

[0005] The present invention provides a film-forming device, which supplies mist containing particles to a substrate and forms a film containing the particles on the surface of the substrate, wherein the film-forming device comprises: a conductor, which is arranged to be separated from the surface of the substrate; a mist supplying part, which supplies the mist to the surface of the substrate; a conveying part, which conveys the substrate; and an AC electric field generating part, which applies an AC voltage to at least one of the conductor and the conveying part.

[0006] The present invention also provides a conductive film manufacturing apparatus, comprising: a film forming apparatus; and a drying section that dries mist on the substrate on which the film has been formed by the film forming apparatus.

[0007] The present invention also provides a film forming method, which is a film forming method for supplying mist containing particles to a substrate to form a film containing the particles on the surface of the substrate, and includes the following steps: a mist supplying step, supplying the mist to the surface of the substrate transported by a conveying part; an AC electric field generating step, applying an AC voltage to at least one of a conductor and the conveying part, the conductor being arranged to be separated from the surface of the substrate.

[0008] The first embodiment of the present invention relates to a mist film-forming device, which is a mist film-forming device that sprays a mist containing microparticles of a material substance onto a substrate to form a film layer composed of the material substance on the surface of the above-mentioned substrate. The device comprises: a mist generating mechanism that delivers a mist gas, and the mist gas includes a mist generated by atomizing a solution containing the above-mentioned microparticles; a mist ejecting mechanism that allows the above-mentioned mist gas to flow into and eject toward the above-mentioned substrate; an air guiding mechanism having a wall surface that is opposite to the surface of the above-mentioned substrate at a specified interval, and is used to make the above-mentioned mist gas from the above-mentioned mist ejecting mechanism flow along the surface of the above-mentioned substrate; and a mist guiding mechanism that generates a repulsive force between the above-mentioned wall surface of the above-mentioned air guiding component and the above-mentioned mist, and is used to generate an attractive force to attract the above-mentioned mist to the surface of the above-mentioned substrate.

[0009] A second embodiment of the present invention relates to a mist film-forming device, which sprays a mist gas formed by carrying a mist containing microparticles on a carrier gas onto the surface of a substrate, so that the microparticles are formed into a thin film on the surface of the substrate. The device comprises: a mist spray section, which has a nozzle opening section opposite to the surface of the substrate at a specified interval, and sprays the mist gas from the nozzle opening toward the substrate; a mist supply device, which supplies the mist gas to the mist spray section at a specified flow rate, and sets the mist gas sprayed from the nozzle opening to a first temperature lower than the ambient temperature; a moving mechanism, which supports the substrate and moves in a direction along the surface of the substrate; and a substrate temperature control mechanism, which sets the substrate on which the mist gas is sprayed to a second temperature lower than the first temperature.

[0010] The third embodiment of the present invention relates to a mist film-forming method, which is a mist film-forming method in which a mist gas formed by carrying a mist containing microparticles on a carrier gas is sprayed onto the surface of a substrate to be processed, so that the microparticles are formed into a thin film on the surface of the substrate to be processed. The method comprises: using a first temperature regulator to set the temperature of the mist gas sprayed from a mist spraying part toward the surface of the substrate to be processed to a first temperature higher than 0°C and lower than 30°C; using a second temperature regulator to set the temperature of the substrate to be processed to a second temperature lower than the first temperature; and using a moving mechanism to relatively move the substrate to be processed and the mist spraying part along the surface of the substrate to be processed, while spraying the mist gas set to the first temperature onto the surface of the substrate to be processed set to the second temperature.

[0011] The fourth aspect of the present invention relates to a film-forming device, which supplies mist containing microparticles to a substrate to form a film containing the microparticles on the surface of the substrate. The film-forming device includes an air guide component covering at least a portion of the surface of the substrate, and a mist supplying portion supplying the mist to a space between the surface of the substrate and the air guide component. The mist supplying portion includes a charging portion for charging the mist positively or negatively, and a mist ejecting portion ejecting the mist charged by the charging portion into the space. The air guide component has a wall surface opposite to the surface of the substrate, and has an electrostatic field generating portion for causing the wall surface to generate a potential with the same sign as that of the mist charged by the charging portion.

[0012] The fifth embodiment of the present invention relates to a film forming device, which supplies mist containing particles to a substrate to form a film containing the above-mentioned particles on the surface of the substrate, and the film forming device comprises: a mist generating section for atomizing a liquid containing the above-mentioned particles to generate the above-mentioned mist; and a mist supplying section for supplying the above-mentioned mist to the above-mentioned substrate, and the above-mentioned mist supplying section includes a temperature regulating section for setting the temperature of the above-mentioned mist to a first temperature, and a substrate temperature regulating section for setting the temperature of the above-mentioned substrate to a second temperature.

[0013] A sixth aspect of the present invention relates to a conductive film manufacturing apparatus including the film forming apparatus according to the first aspect or the second aspect, and a drying section that dries mist on the substrate on which the film has been formed by the film forming apparatus.

[0014] The seventh aspect of the present invention relates to a film-forming method, which is a film-forming method for supplying mist containing microparticles to a substrate to form a film containing the above-mentioned microparticles on the surface of the above-mentioned substrate, and includes the following steps: a mist supplying step, in which the above-mentioned mist is positively or negatively charged by a charging imparting part, and the charged mist is supplied to the space between an air guide component covering at least a part of the surface of the above-mentioned substrate and the surface of the above-mentioned substrate by a mist ejecting part; and an electrostatic field generating step, in which a wall surface of the above-mentioned air guide component opposite to the surface of the above-mentioned substrate generates a potential with the same sign as that of the charged mist.

[0015] The eighth aspect of the present invention relates to a film forming method, which is a film forming method for supplying mist containing particles to a substrate to form a film containing the above-mentioned particles on the surface of the substrate. The film forming method comprises a mist generating step of atomizing a liquid containing the above-mentioned particles to generate mist, and a mist supplying step of supplying the above-mentioned mist to the above-mentioned substrate. In the above-mentioned mist supplying step, the temperature of the above-mentioned mist is set to a first temperature by a temperature control unit, and the temperature of the above-mentioned substrate is set to a second temperature by a substrate temperature control unit.

[0016] A ninth aspect of the present invention relates to a method for manufacturing a conductive film, comprising a film forming step of forming a conductive film material on the substrate using the film forming method of the fourth aspect or the fifth aspect, and a drying step of drying the substrate after the film formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram showing a schematic overall structure of the mist film forming device MDE according to the first embodiment.

[0018] Figure 2 It is overlooking Figure 1 A perspective view showing the specific appearance of the mist film forming portion of the mist film forming device MDE shown.

[0019] Figure 3A This is a front view of the mist ejection section in the mist film forming section. Figure 3B yes Figure 3A Sectional view in the k1-k2 direction.

[0020] Figure 4 This is a diagram showing a schematic configuration of a mist film forming section of a mist film forming device MDE according to Modification 1 of the first embodiment.

[0021] Figure 5 The configuration of the second modification example based on the first embodiment is as follows: Figure 4 The illustrated rotating drum DR and chamber portion 40 are partial cross-sectional views obtained by cutting along a plane including the center line AXo.

[0022] Figure 6 This is a diagram showing a schematic overall structure of a mist film forming device MDE according to the second embodiment.

[0023] Figure 7 It is shown Figure 6 A diagram showing a specific structure of a nanoparticle deposition homogenization section in a mist film-forming device MDE.

[0024] Figure 8 It is schematically shown for confirmation Figure 7 A diagram showing the structure of a preliminary experimental device for the functions and effects of a deposition homogenization unit.

[0025] Fig. 9 Yes means through Figure 8 A graph showing experimental results of a preliminary experiment 1 for investigating the frequency dependence of an alternating electric field applied to a liquid film containing ITO nanoparticles using a preliminary experiment apparatus.

[0026] Fig.10 Yes means through Figure 8 A graph showing the experimental results of preliminary experiment 2, which was conducted using a preliminary experimental apparatus to investigate the dependence of a liquid film containing ITO nanoparticles on electric field intensity when an alternating electric field was applied.

[0027] Fig.11 Yes means through Figure 8 A graph showing the experimental results of preliminary experiment 3 using a preliminary experimental apparatus to investigate the frequency dependence of the particle size difference of the ITO nanoparticles when an AC electric field is applied to a liquid film containing ITO nanoparticles.

[0028] Figures 12A to 12C It is shown by Figure 6 , Figure 7 1 and 2 are diagrams showing several examples of waveforms of the AC voltage Ev applied between the electrode plates Ef1 to Ef4 and the electrode plate Em by the AC electric field generating unit 90 of the mist film forming device shown in FIG.

[0029] Fig.13 1 and 2 are a plan view and a front view showing the structure of a deposition uniformizing section (electrophoresis imparting section) according to Modification 5.

[0030] Fig.14 This is a diagram showing a schematic configuration of a mist film forming device MDE according to a third embodiment.

[0031] Fig.15 is shown in Figure 2. Fig.14 A diagram showing waveforms of the AC electric field in the mist guiding mechanism of the mist film forming section of the mist film forming device and the deposition uniformizing section (electrophoresis imparting section) after the mist film formation.

[0032] Fig.16 It is shown Fig.14 A circuit diagram showing an example of a specific circuit configuration of the AC electric field generating unit 92 shown.

[0033] Fig.17 This is a diagram showing a schematic configuration of an experimental device for confirming whether or not ITO nanoparticles crystallized in a non-rectangular parallelepiped shape migrate in a solution Lq.

[0034] Fig.18 Is based on Fig.17 Table of experimental results of the experimental setup.

[0035] Fig.19 It is a diagram showing a schematic structure of a mist film forming device MDE according to a fourth embodiment.

[0036] Fig. 20 This is a perspective view showing a schematic configuration of a preliminary experiment device for confirming the effect of the mist film forming method according to the fourth embodiment.

[0037] Fig.21 It means based on Fig. 20 A graph showing the relationship between substrate temperature and nanoparticle film thickness obtained from an experiment of a pre-experimental device.

[0038] Fig. 22 It is a diagram showing a schematic configuration of a mist film forming section of the mist film forming device MDE according to the fifth embodiment.

[0039] Fig.23 It is shown based on Fig.19 A three-dimensional view showing the schematic structure of a mist film-forming device MDE according to a sixth modification in which the mist film-forming device MDE is modified.

[0040] Fig.24A , Fig. 24B is shown for high-speed switching of mist gas Msg to Fig.23 FIG. 2 is a diagram showing the configuration of the valve mechanism 310 in the supply state and the non-supply state in the auxiliary mist spraying portion SMD.

[0041] Fig.25 It is shown Figure 1 The specific structure of the mist generating unit 14 shown is a partial cross-sectional view of Modification Example 7.

[0042] Fig.26 It is shown that the configuration Fig.25 FIG. 1 is a diagram showing the arrangement of four ultrasonic vibrators 14C1 to 14C4 on a plane at the bottom of an outer container 14D of the mist generating unit 14. FIG. DETAILED DESCRIPTION

[0043] Hereinafter, the mist film-forming device and the mist film-forming method involved in the method of the present invention will be described in detail with reference to the accompanying drawings by taking preferred embodiments as an example. It should be noted that the method of the present invention is not limited to these embodiments, but also includes methods in which various changes or improvements are applied. That is, the constituent elements described below include substantially the same elements that can be easily thought of by those skilled in the art, and the constituent elements described below can be appropriately combined. In addition, various omissions, replacements or changes of constituent elements can be made without departing from the gist of the present invention.

[0044] [First embodiment]

[0045] Figure 1 This is a diagram showing a schematic overall structure of the mist film forming device MDE according to the first embodiment. Figure 1 Unless otherwise stated, the XYZ orthogonal coordinate system is set with the gravity direction as the Z direction. Figure 1The arrows shown in the figure set the conveying direction of the flexible sheet substrate P (sometimes also referred to as the substrate P) as the substrate to be processed as the X direction, and the width direction of the sheet substrate P orthogonal to the conveying direction as the Y direction. When the mist film is formed, the surface of the sheet substrate P is set to a horizontal plane parallel to the XY plane in this embodiment. In this embodiment, the sheet substrate P is a flexible sheet with a thickness of about hundreds of microns (μm) to tens of microns, which is long in the X direction and made of a resin such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate) or polyimide as a base material. However, it can also be a metal foil sheet made of other materials such as stainless steel, aluminum, brass, copper and other metal materials by relatively thin rolling; an extremely thin glass sheet with a thickness of less than 100 μm and flexibility; a plastic sheet containing cellulose nanofibers. It should be noted that the sheet substrate P does not necessarily need to be a long strip, and can also be a single sheet substrate with standardized long and short side dimensions such as A4 size, A3 size, B4 size, and B3 size, or a single sheet substrate of irregular shape outside the standard.

[0046] like Figure 1 As shown, the mist film-forming device MDE of this embodiment is roughly composed of the following parts: a conveying unit (conveying part) 5, which supports the sheet substrate P and conveys it along the X direction; a solution tank 10, which stores a solution (dispersion liquid or liquid) Lq in which nanoparticles of a material substance serving as a film-forming substance are dispersed; a mist generating part 14, which efficiently generates mist with a particle size of about several microns to more than ten microns from the solution Lq; a mist ejecting part 30, which supplies the mist gas Msg obtained by placing the mist generated in the mist generating part 14 on the carrier gas CGS via a flexible tube 17, and sprays the mist gas Msg toward the sheet substrate P; a mist recovery part 32, which recovers the mist gas Msg including the mist not attached to the sheet substrate P but suspended; and a chamber part 40, which is arranged in a manner of covering the mist ejecting part 30, the mist recovery part 32, and the sheet substrate P supported by the conveying unit 5, and is used to suppress the mist gas Msg from leaking to the external atmosphere (outside the device). The configuration of each part is further described in detail below.

[0047] Figure 1The conveying unit 5 shown in the figure comprises: a roller 5A that rotates around a central axis AXa parallel to the Y axis; a roller 5B that rotates around a central axis AXb that is spaced a predetermined distance from the central axis AXa in the X direction and is arranged parallel to the central axis AXa; an endless belt 5C that is laid between the two rollers 5A and 5B and flatly supports the sheet substrate P with the upper surface of the flat portion; and a support table 5D that is arranged on the back side of the flat portion of the belt 5C that supports the sheet substrate P and flatly supports the belt 5C. The width of the belt 5C in the Y direction is set to be slightly larger than the width (short side dimension) of the substrate P in the Y direction, and the belt 5C vacuum-adsorbs the substrate P through the area corresponding to the upper surface of the support table 5D, and conveys and drives the substrate P in a state of not contacting the upper surface of the support table 5D (or in a state of low friction) through a static pressure gas layer (air bearing) generated between the upper surface of the support table 5D and the back of the belt 5C. The conveying unit 5 of this structure is disclosed in, for example, International Publication No. 2013 / 150677. The belt 5C is preferably a metal thin plate (conductive thin plate) such as stainless steel with high rigidity and flatness. It should be noted that, on the downstream side (-X direction side) of the belt 5C, in order to make the sheet substrate P adsorbed on the belt 5C without wrinkles, clamping rollers 5E and 5F are provided on the sheet substrate P to give tension in the long side direction.

[0048] The solvent (including dispersion medium) of the solution Lq stored in the solution tank 10 is pure water, which is easy to handle and highly safe. In the solvent (pure water), nanoparticles of a material such as indium tin oxide (ITO) as a material of a transparent conductive film are dispersed at a desired concentration as an example of a material substance. The solution Lq in the solution tank 10 is intermittently or continuously supplied to the mist generating unit (atomizer) 14 by a precision pump 12. The mist generating unit 14 is set in a sealed external container 14D (refer to Fig.25 ) is provided with: an internal container (cup) 14A for accumulating the solution Lq from the precision pump 12; and an ultrasonic vibrator 14C, which applies vibration of about 2.4 MHz to the solution Lq via the internal container 14A to generate mist from the liquid surface of the solution Lq. Furthermore, a carrier gas CGS adjusted to a specified flow rate (or pressure) is supplied to the upper space of the internal container 14A of the mist generating part 14 through a pipe 16 using a flow regulating valve 15. In the above-mentioned structure, the precision pump 12, the ultrasonic vibrator 14C and the flow regulating valve 15 each receive instructions from a higher-level control controller (such as a general control computer) not shown in the figure, and are driven with appropriate drive amount, timing, interval, etc.

[0049] It should be noted that, when nanoparticles as film-forming materials are easily aggregated in pure water, by making the solvent of the solution Lq contain a surfactant at a specified concentration, the aggregation of nanoparticles can be suppressed and the dispersibility can be maintained. In addition, when it is not desired that the solution Lq contain a surfactant, for example, as disclosed in International Publication No. 2017 / 154937, a vibrator for applying ultrasonic vibration (frequency 200KHz or less) for suppressing the aggregation of nanoparticles can be set in the solution Lq in the internal container 14A. It should be noted that when non-rectangular ITO nanoparticles (crystals with consistent orientation) made by the method disclosed in International Publication No. 2019 / 138707 and International Publication No. 2019 / 138708 are used as nanoparticles of ITO (indium tin oxide), even in a solution Lq formed by pure water without containing a surfactant, a dispersed state can be maintained for a long time without aggregation or precipitation.

[0050] In addition to the ITO nanoparticles exemplified, the nanoparticles that can be formed into films by the mist film forming device MDE can also be nanoparticles of commonly used materials (conductive materials, insulating materials, semiconductor materials). Nanoparticles are generally considered to be particles smaller than 100nm, but in mist film forming, as long as the size is smaller than the particle size of the mist (several microns to more than ten microns) and can be captured in the mist and suspended by the carrier gas CGS. As such nanoparticles, metal systems can use gold nanoparticles, platinum nanoparticles, silver nanoparticles, copper nanoparticles, or carbon nanorods (tubes) refined into good conductors, etc., oxide systems can use iron oxide nanoparticles, zinc oxide nanoparticles, silicon oxide (silica) nanoparticles, etc., and nitride systems can use silicon nitride nanoparticles, aluminum nitride nanoparticles, etc. In addition, as semiconductor systems, carbon nanorods (tubes) refined into semiconductors, silicon nanoparticles, etc. can also be used. As the silicon nanoparticles, for example, silicon nanoparticles whose molecules are capped with hydrocarbons can be formed into a film (coated) on the surface of a semiconductor layer forming a pn junction solar cell to improve efficiency as disclosed in International Publication No. 2016 / 185978.

[0051] In addition, if Figure 1As shown, the mist generated in the internal container 14A of the mist generating section 14 passes through the tube 17 as the carrier gas CGS flows, becomes the mist gas Msg and is supplied to the mist ejection section 30. In addition to the clean atmosphere (H2O: clean air) from which dust (particles) is removed, the carrier gas CGS can also be an inert gas such as clean nitrogen (N2) and argon (Ar). In the present embodiment, mist film formation is simply performed under an atmospheric pressure environment at room temperature, so the carrier gas CGS is clean air or nitrogen. However, in the case of a configuration in which the mist gas Msg sprayed from the mist ejection section 30 to the sheet substrate P is irradiated with a plasma in a non-thermal equilibrium state (plasma-assisted mist film formation method), as disclosed in, for example, International Publication No. 2016 / 133131 pamphlet, the carrier gas CGS can be argon.

[0052] It should be noted that, when it is necessary to set the temperature of the mist gas Msg sprayed from the mist ejection unit 30 to be higher (or lower) than normal temperature, a temperature control mechanism (heater, cooler, etc.) is provided to adjust the temperature of the carrier gas CGS, the temperature in the mist generating unit 14, or the temperature in the pipe 17 to a set value as required. Figure 1 As shown, the mist generating unit 14 (internal container 14A) may be disposed above the mist ejecting unit 30 in the gravity direction (Z direction).

[0053] The mist gas Msg supplied from the upper part of the mist ejection unit 30 is sprayed onto the substrate P at a predetermined flow rate (wind speed) from a slit-shaped opening (nozzle opening) formed at the bottom of the mist ejection unit 30 opposite to the sheet substrate P. The nozzle opening is formed with a length covering the width dimension of the substrate P in the Y direction, or with a length shorter than the width dimension, and is formed with a width of about 1 mm to several mm in the X direction, which is the long side direction of the substrate P. When the conveying (moving) direction of the long side direction of the substrate P is set to the +X direction, the mist recovery unit 32 is arranged on the downstream side of the mist ejection unit 30 in the conveying direction of the substrate P. The mist gas Msg sprayed downward (-Z direction) from the nozzle opening at the bottom of the mist spraying section 30 flows toward the downstream side (+X direction) along the surface of the sheet substrate P passing through the chamber section 40 due to the decompression effect (negative pressure) of the mist recovery section 32. During this period, the mist adheres to the surface of the sheet substrate P, and forms a thin liquid film on the surface of the sheet substrate P made of the solvent of the mist (pure water in this embodiment).

[0054] A recovery port (recovery opening) extending in a slit shape in the Y direction is formed at the bottom of the mist recovery unit 32, and the remaining mist gas Msg' including the mist not attached to the sheet substrate P flows into the recovery opening, and is collected into the mist gas collection unit 34 having a decompression source such as a vacuum pump via a pipe 33 connected to the upper part of the mist recovery unit 32. The mist contained in the remaining mist gas Msg' captured by the mist gas collection unit 34 (hereinafter also referred to as the collection unit 34) is restored to the state of the solution Lq by condensation, and is sent to the collection tank 36 via the pipe 35A. The solution Lq accumulated in the collection tank 36 is appropriately replenished to the solution tank 10 for reuse.

[0055] In addition, in this embodiment, as described in detail later, in order to prevent the droplets that grow due to the accumulation of mist attached to the inner wall surface of the mist ejection part 30 from dripping onto the sheet substrate P along the inner wall surface from the nozzle opening at the bottom of the mist ejection part 30, a droplet collecting part (capturing part) 30T is provided at the lower part of the mist ejection part 30. Similarly, in order to prevent the droplets that grow due to the accumulation of mist (remaining mist) attached to the inner wall surface of the mist recovery part 32 from dripping onto the sheet substrate P along the inner wall surface from the recovery opening at the bottom of the mist recovery part 32, a droplet collecting part (capturing part) 32T is provided at the lower part of the mist recovery part 32. The droplets captured by the droplet collecting part 30T become the original solution Lq state and are sucked by the small pump 37 through the tube 35B and sent to the capture tank 36. Similarly, the liquid droplets collected by the liquid droplet collecting section 32T are in the state of the original solution Lq and are sucked by the small pump 37 through the tube 35C and sent to the collecting tank 36 .

[0056] In the chamber 40, a plate-shaped air guide member (also called a skirt member or a rectifying member) 40A is provided to form a predetermined space along the +Z direction from the surface of the sheet substrate P in order to allow the mist gas Msg to flow smoothly between the nozzle opening at the bottom of the mist ejection unit 30 and the recovery opening at the bottom of the mist recovery unit 32. Figure 1From the composition, it can be seen that the surface of the sheet substrate P moves in the +X direction while being exposed to the laminar flow of the mist gas Msg from the nozzle opening of the mist ejection unit 30 to the recovery opening of the mist recovery unit 32. By adjusting the relationship between the moving speed of the sheet substrate P based on the conveying unit 5 and the flow rate of the mist gas Msg flowing along the surface of the sheet substrate P, the thickness of the film formed by the nanoparticles (such as ITO) finally deposited on the surface of the sheet substrate P can be changed. The materials constituting the chamber unit 40 (air guiding member 40A), the mist ejection unit 30, the mist recovery unit 32, the droplet trapping units 30T, 32T, etc. are preferably resin materials with stable chemical properties, excellent heat resistance, chemical resistance, high electrical insulation, and good processability. As such resin materials, fluororesins (fluorocarbon resins) such as polytetrafluoroethylene (Poly-Tetra-Fluoro-Ethylene: PTFE) containing fluorine atoms and carbon atoms are suitable.

[0057] In Figure 1 In the composition, when the ejection flow rate per unit time of the mist gas Msg ejected from the nozzle opening of the mist ejection unit 30 is set to Qf (mL / second) and the exhaust flow rate per unit time of the recovery opening of the mist recovery unit 32 is set to Qv (mL / second), it is preferably set to the relationship of Qf≒Qv or the relationship of Qf<Qv. According to fluid simulation, when the exhaust flow rate Qv is 1.5 times or more of the ejection flow rate Qf, almost all of the mist gas Msg sprayed into the chamber unit 40 can be recovered. The balance between the ejection flow rate Qf and the exhaust flow rate Qv can be easily set by controlling the flow rate adjustment valve 15 of the carrier gas CGS and the flow rate adjustment of the decompression source of the mist gas trapping unit 34 connected to the pipe 33.

[0058] It should be noted that Figure 1 Although the illustration is omitted in , a treatment unit for making the surface of the sheet substrate P lyophilic can be provided on the upstream side of the chamber unit 40 (or the pinch rollers 5E, 5F). In addition, a drying unit for evaporating a thin liquid film (water film) with a thickness of about several micrometers to several tens of micrometers covering the surface of the sheet substrate P that has just completed mist film formation in the chamber unit 40 can be provided on the downstream side of the chamber unit 40.

[0059] Furthermore, in the present embodiment, in order to increase the adhesion rate of the mist contained in the mist gas Msg on the sheet substrate P, a mist supply unit 31 is provided. The mist supply unit 31 supplies the mist to the space between the surface of the sheet substrate P and the chamber unit 40. The mist supply unit 31 includes a mist ejection unit 30 and a mist charging device (charging imparting unit) 60 that imparts negative charge to the mist in the mist gas Msg supplied to the space of the mist ejection unit 30 via the tube 17. Thus, the mist ejection unit 30 can supply the mist charged by the mist charging device 60 to the space between the surface of the sheet substrate P and the chamber unit 40. Furthermore, in the present embodiment, an electrostatic field generating device (electrostatic field generating unit) 70 is provided that applies an electrostatic field in the Z direction to the space in the chamber unit 40 so that the charged mist effectively adheres to the sheet substrate P. The mist charging device 60 repeatedly applies high voltage pulses of several kV or more between a pair of electrodes Ea and Eb disposed on the upper portions of the inner wall surfaces of the mist ejection section 30 that are opposite to each other in the X direction, so as to generate discharge (corona discharge, etc.) between the electrodes Ea and Eb, thereby causing the mist to be negatively charged. The electrostatic field generating device 70 applies the negative pole of the electrostatic field to the electrode plate Ec installed in a plane on the lower portions of the inner wall surfaces of the mist ejection section 30 that are opposite to each other in the X direction, and the electrode plate Ed installed in a plane on the inner wall surface (parallel to the XY plane) of the air guide part 40A of the chamber section 40, via the wiring 70a. In addition, the electrostatic field generating device 70 applies the positive pole of the electrostatic field to the contact head (brush) 71 that contacts the belt (made of stainless steel) 5C at the roller 5A side of the conveying device.

[0060] The potential difference between the positive and negative electrodes of the electrostatic field generating device 70 is appropriately adjusted between several V and several hundred V according to the flow rate of the mist gas Msg flowing in the chamber portion 40, the conveying speed of the sheet substrate P, the type of solvent of the mist, the type of nanoparticles contained in the mist, the target film thickness of the thin film formed by the nanoparticles, etc. Since the mist contained in the mist gas Msg ejected from the nozzle opening of the mist ejection portion 30 is negatively charged, a force (repulsive force) is applied to the mist suspended in the chamber portion 40 to keep it away from the negative electrode plate Ed on the side of the air guide component 40A, and a force (Coulomb force) is applied to attract it to the positive side of the belt 5C. Since the belt 5C is in close contact with the sheet substrate P, the mist flowing in the +X direction along with the mist gas Msg in the chamber portion 40 is deflected in a manner toward the surface of the sheet substrate P, and the adhesion rate of the mist on the surface of the sheet substrate P is improved.

[0061] The charged mist is subjected to a force in the -Z direction (Coulomb force) only in the space where the electrode plate Ed on the air guide part 40A side and the belt 5C are opposite. Therefore, when the distance in the X direction from the nozzle opening of the mist ejection part 30 to the recovery opening of the mist recovery part 32 is short, the length of the electrode plate Ed in the X direction also becomes short. If the flow rate of the mist gas Msg is fast, a large amount of mist may be recovered by the mist recovery part 32 before it effectively adheres to the sheet substrate P. In this case, it is sufficient to increase the potential difference between the electrode plate Ed and the belt 5C applied by the electrostatic field generating device 70. On the contrary, when the flow rate of the mist gas Msg flowing in the chamber part 40 is slow, since a large amount of mist adheres to the sheet substrate P, the liquid film (water film) covering the surface of the sheet substrate P reaches an excessive thickness (for example, more than 0.5 mm), and a flow of liquid (solvent) is generated on the surface of the sheet substrate P. In this case, it is sufficient to reduce the potential difference between the electrode plate Ed and the belt 5C applied by the electrostatic field generating device 70. It should be noted that the absolute value of the potential difference applied by the electrostatic field generating device 70 is preferably a constant voltage of direct current. For example, the belt 5C side can be made zero potential (grounded), and the electrode plate Ed side can be made a pulsating voltage (AC voltage) whose absolute value of voltage changes with a predetermined amplitude and a predetermined frequency around the negative neutral point potential (average potential). In other words, the neutral point potential (average potential) is the average value of the maximum and minimum potentials of the pulsating voltage (AC voltage).

[0062] Figure 2 Observed from above Figure 1 The mist film forming device MDE shown in FIG. 1 is a perspective view of the arrangement of the film forming unit composed of the mist spraying unit 30, the mist recovery unit 32, and the chamber unit 40. Figure 3A Viewed from the +X direction Figure 1 , Figure 2 The mist ejection unit 30 is a front view of the structure in the YZ plane. Figure 3B yes Figure 3A A cross-sectional view of the mist ejection portion 30 as viewed in the direction of arrow k1 - k2 . Figure 2 , Figure 3A , Figure 3B Among the components in Figure 1 The same components or members as those described in the drawings are marked with the same symbols or numbers, and their detailed descriptions are omitted or simplified.

[0063] Figure 2 In the embodiment, the upper part of the mist ejection part 30 is connected to Figure 1 The pipe 17 shown in the figure is equivalent to two pipes 17a and 17b. The pipes 17a and 17b are respectively Figure 1The mist gas Msg generated by one mist generating unit 14 is branched and supplied to the mist ejection unit 30, but the number of the tubes 17 may be 3 or more. By arranging the plurality of tubes 17 at a predetermined interval in the Y direction of the mist ejection unit 30 in this way, the mist gas Msg is supplied to the internal space of the mist ejection unit 30, which can suppress the mist from Figure 3A , Figure 3B The uneven flow distribution (or flow velocity distribution) of the mist gas Msg in the Y direction of the nozzle opening 30A extending in the Y direction in a slit shape at the bottom of the mist ejection unit 30 shown can be uniformized. It should be noted that in order to increase the total flow rate of the mist gas Msg, the mist generating unit 14 can be respectively provided corresponding to each of the two tubes 17a and 17b (or three or more tubes).

[0064] Figure 2 In the Figure 1 One of the high voltage electrodes Ea of the mist charging device 60 shown is fixed at a position such as Figure 3B As shown in FIG. 1 , the insulating ceramic plate 30Na is provided on the wall surface on the -X direction side of the mist ejection portion 30, and the other electrode Eb is fixed on the wall surface as shown in FIG. Figure 3B As shown, the insulating ceramic plate 30Nb is provided on the wall surface on the +X direction side of the mist ejection portion 30. Figure 3A , Figure 3B As shown, in this embodiment, the electrode Ea is a needle with a sharp front end and is installed on the ceramic plate 30Na at a certain interval in the Y direction, and the electrode Eb is installed on the ceramic plate 30Nb as a plate (or rod, line) extending in the Y direction along which the multiple needle-shaped electrodes Ea are arranged.

[0065] like Figure 3B As shown, when the internal space of the mist ejection part 30 is observed in the XZ plane, it is surrounded by inner wall surfaces that are parallel to the YZ plane and opposed at a certain interval in the X direction from the upper end (top plate) connected to the tube 17 (17a) along the -Z direction to the height position Zu. The opposed inner wall surfaces are formed in such a way that the intervals in the X direction gradually decrease from the height position Zu to the nozzle opening 30A at the bottom of the mist ejection part 30, and finally the width in the X direction shrinks to less than a few mm at the position of the nozzle opening 30A. On each inner wall surface of the mist ejection part 30 that is opposed in the X direction, as shown in FIG. Figure 3A As shown, there is a substantially entire Y direction of the inner wall surface. Figure 1 The electrode plate Ec shown. The electrode plate Ec applies repulsive force to the mist charged by the mist charging device 60, reducing the adhesion of the mist to the inner wall surface of the internal space. However, when the inner wall surface of the mist ejection part 30 is made of a fluororesin (PTFE) with high liquid repellency, the electrode plate Ec can be omitted.

[0066] like Figure 2 , Figure 3BAs shown, a droplet collecting portion 30T extending in the Y direction is provided below each of the outer wall portions in the +X direction and -X direction of the mist ejection portion 30. The droplet collecting portion 30T is connected to a slit (groove) 30s formed in a manner extending in the Y direction on the inner wall surface slightly separated from the nozzle opening portion 30A at the bottom of the mist ejection portion 30 in the +Z direction. The thickness (groove width) of the slit 30s in the Z direction is set to a degree that the droplets flowing along the inner wall surface of the mist ejection portion 30 are absorbed by the capillary phenomenon, for example, set to 0.5 mm to 2 mm. In addition, the inner surface of the slit 30s is subjected to a highly lyophilic surface treatment (forming a lyophilic coating film, etc.). The droplet collecting portion 30T is formed by Figure 1 , Figure 2 The suction force of the small pump 37 shown sucks out the liquid droplets accumulated in the slit 30s at appropriate intervals and sends them to the collection tank 36 through the tube 35B.

[0067] exist Figure 2 The mist recovery section 32 shown in the figure also has a droplet collecting section 32T extending in the Y direction below each of the outer wall sections in the +X direction and -X direction. A slit (groove) extending in the Y direction is also formed on the inner wall surface slightly separated from the slit-shaped recovery opening at the bottom of the mist recovery section 32 in the +Z direction. The droplet collecting section 32T is formed by Figure 1 , Figure 2 The suction force of the small pump 37 shown sucks out the liquid droplets accumulated in the slit 30s at appropriate intervals and sends them to the collection tank 36 through the tube 35C.

[0068] like Figure 1 As shown in FIG. 1 , a planar electrode plate Ed is provided on the inner wall surface (parallel to the XY plane) of the air guide member 40A of the chamber portion 40. Figure 2 In the figure, the electrode plate Ed is shown as two electrode plates Ed1 and Ed2 divided along the conveying direction (X direction) of the sheet substrate P. The electrode plate Ed1 arranged on the upstream side of the conveying direction of the sheet substrate P is connected to the connection terminal JH1 protruding from the upper outer wall surface of the air guide component 40A, and the connection terminal JH1 is connected to the Figure 1 Similarly, the electrode plate Ed2 arranged on the downstream side of the conveying direction of the sheet substrate P is connected to the connection terminal JH2 protrudingly provided on the upper outer wall surface of the air guide component 40A, and the connection terminal JH2 is connected to the wiring 70a on the negative electrode side of the electrostatic field generating device 70.

[0069] In such Figure 2In the case where the electrode plate Ed is divided in the conveying path between the mist ejection section 30 and the mist recovery section 32 in the chamber section 40, the negative voltage applied to the electrode plate Ed1 on the upstream side and the negative voltage applied to the electrode plate Ed2 on the downstream side can be adjusted to different values. To this end, it can be constructed in the following manner: a variable resistor is set between the positive and negative poles of the voltage output section of the electrostatic field generating device 70, and the voltage (negative polarity) after voltage division by the variable resistor is applied to either of the electrode plates Ed1 and Ed2, and the voltage before voltage division (negative polarity) is applied to the other. By making the negative polarity potentials applied to the electrode plates Ed1 and Ed2 different on the upstream and downstream sides of the conveying direction of the sheet substrate P, the degree of adhesion of the mist on the surface of the sheet substrate P can be adjusted in time. It should be noted that the division of the electrode plate Ed can also be set to more than 3 along the conveying direction of the sheet substrate P through the chamber section 40, and each of the divided electrode plates is set to a different negative potential.

[0070] [Modification 1]

[0071] In the first embodiment described above, the following configuration is set: when mist film formation is performed, the sheet substrate P is supported on the horizontally moving belt 5C, so that the surface of the sheet substrate P becomes horizontal (parallel to the XY plane) and the mist gas Msg is sprayed. In the case of a configuration in which the sheet substrate P is supported by the belt 5C as described above, the sheet substrate P can be a single sheet substrate with a fixed length and width, such as an A4 version, an A3 version, or a B4 version. However, for a long sheet substrate of tens to hundreds of meters, when mist film formation is performed continuously in a stable film thickness state by a roll-to-roll method, the sheet substrate may generate wrinkles due to vacuum adsorption on the belt 5C, etc. Therefore, it is considered to use a conveying mechanism that supports a portion of the long side direction of the sheet substrate in close contact with the outer peripheral surface of a rotating drum to continuously move the sheet substrate.

[0072] Figure 4 This is a diagram showing a schematic modified structure of a mist film forming section in a mist film forming device using a conveying mechanism (conveying section) using a rotating drum. Figure 4 The orthogonal coordinate system XYZ is consistent with the previous Figure 1 to Figure 3B The coordinate system XYZ in each figure is the same, the Z direction is set as the vertical direction (gravity direction), and the XY plane is set as the horizontal plane. Figure 4 Among the parts shown, for the previous Figure 1 to Figure 3B The same components as shown or components having equivalent functions are denoted by the same symbols.

[0073] Figure 4In the figure, a metal drum DR made of iron and aluminum rotates around a center line AXo parallel to the Y axis, and has an outer peripheral surface DRa with a certain radius Rd from the center line AXo. The length of the outer peripheral surface DRa in the Y direction is set to be slightly longer than the width dimension of the short side direction (Y direction) of the long strip-shaped sheet substrate P. The radius Rd also depends on the width dimension, but can be set relatively freely. As an example, it is set in the range of 5cm≦Rd≦50cm. At both ends of the drum DR in the Y direction, a metal shaft Sft is provided coaxially with the center line AXo. The shaft Sft is mounted on the main frame (frame) of the mist film forming device MDE via a bearing, and is connected to the torque shaft of a rotational drive source (motor or reducer) not shown in the figure, so that the drum DR rotates at a specified angular velocity. On the shaft Sft separated from the end of the drum DR in the Y direction in the Y direction, an encoder measurement scale disk SD is fixed coaxially with the center line AXo. On the surface side of the scale disk SD perpendicular to the center line AXo (the surface parallel to the XZ plane), in an area at a certain radius from the center line AXo, a scale Gm read by the encoder head EH1 is engraved in a ring-shaped manner along the circumferential direction. The encoder head EH1 is arranged opposite to the side surface of the scale disk SD (parallel to the XZ plane) and is used to optically detect the position change of the grid of the scale Gm (for example, a diffraction grating engraved at a pitch of 20 μm along the circumferential direction) that moves along the circumferential direction as the rotating drum DR rotates clockwise, and measures the circumferential movement amount of the outer peripheral surface DRa or the circumferential movement speed of the outer peripheral surface DRa according to the rotation angle position of the rotating drum DR.

[0074] The sheet substrate P has a rotation axis parallel to the center line AXo, and is folded back by the roller 5G arranged below the drum DR. A certain tension is given to a part of the outer peripheral surface DRa of the drum DR, and after being wound in a state supported in an arc shape, it is mounted on the roller 5H arranged above the drum DR and has a rotation axis parallel to the center line AXo, and is transported along the long side direction. At this time, the sheet substrate P is in close contact with the outer peripheral surface DRa within a range of about 90 degrees from the angular position (entry position) Ct1 of the circumference of the drum DR to the angular position (disengagement position) Ct2. The mist film forming part composed of the mist spraying part 30, the mist recovery part 32 and the chamber part 40 is arranged in a circumferentially curved manner within the angular range of the entry position Ct1 and the disengagement position Ct2 of the outer peripheral surface DRa of the drum DR.

[0075] like Figure 4As shown, the chamber portion 40 has an air guide member 40A that is curved in a manner to form a certain spacing space with the outer peripheral surface DRa or the surface of the sheet substrate P in the radial direction of the rotating drum DR. In the conveying direction of the sheet substrate P, on the upstream side of the air guide member 40A, the mist ejection portion 30 is arranged in a manner that the ejection direction (the direction of the line CL) of the mist gas Msg sprayed from the nozzle opening 30A of the mist ejection portion 30 is inclined at an angle -θu relative to the horizontal plane (XY plane). By directing the nozzle opening 30A of the mist ejection portion 30 obliquely upward in this way, it is possible to prevent the mist from being attached to the inner wall surface of the mist ejection portion 30 and the accumulated droplets from the nozzle opening 30A from dripping onto the sheet substrate P along the inner wall surface. The mist gas Msg ejected from the nozzle opening 30A flows through a space between the curved inner wall surface of the air guide member 40A facing the sheet substrate P and the surface of the sheet substrate P along the circumferential direction of the outer peripheral surface DRa of the drum DR, and the remaining mist gas Msg′ is recovered by the mist recovery unit 32 .

[0076] The electrode plate Ed connected to the wiring 70a on the negative electrode side of the electrostatic field generating device 70 is attached to the curved inner wall surface of the wind guide member 40A in a curved manner, and the contact head 71 in contact with the shaft Sft of the drum DR is connected to the positive electrode of the electrostatic field generating device 70 via the wiring 70b. Thus, an electrostatic field that attracts the mist to the sheet substrate P side is formed between the curved electrode plate Ed and the outer peripheral surface DRa of the drum DR.

[0077] After passing through the chamber 40, a thin liquid film is formed on the entire surface of the sheet substrate P by mist film formation, and the sheet substrate P is conveyed from the detachment position Ct2 toward the roller 5H in a state of being inclined upward at an angle of +θp relative to the horizontal plane (XY plane). The liquid film (solvent) on the surface of the sheet substrate P is dried (evaporated) during the conveyance from the detachment position Ct2 to the roller 5H, and a deposited film (conductive film) composed of nanoparticles contained in the mist is formed on the surface of the sheet substrate P. The distance L from the detachment position Ct2 to the roller 5H is set by the product of the conveyance speed Vp of the sheet substrate P (the rotation speed of the drum DR) and the time Tv from the completion of drying (evaporation) of the liquid film covering the surface of the sheet substrate P immediately after the mist film formation is completed (L = Vp·Tv). It should be noted that a mechanism can be prepared that can change the position of roller 5H in the Z direction or X direction so that the inclination angle +θp of the sheet substrate P from the detachment position Ct2 to roller 5H can be adjusted within the range of 0°≦θp<50° according to the type of mist solvent (liquid film).

[0078] It should be noted that the encoder head EH1 is arranged opposite to the scale Gm of the scale disk SP in the same orientation as the chamber portion 40 when viewed from the center line AXo, or in the same orientation as the nozzle opening 30A of the mist ejection portion 30. Therefore, in the case where the mist gas Msg leaks from the gap between the chamber portion 40 and the outer peripheral surface DRa of the drum DR, there is a possibility that the mist gas Msg adheres to the optical components in the encoder head EH1 and causes poor reading of the scale Gm (reduction in signal strength, etc.). In this case, Figure 4 As shown by the dotted line in , the encoder head EH2 can be arranged at a position that is point-symmetrical to the encoder head EH1 on the center line AXo (rotated about 180 degrees), that is, at a position farthest from the chamber portion 40. Figure 4 In the configuration of the encoder head EH1 or EH2, the encoder head EH1 or EH2 is arranged so as to face the side perpendicular to the center line AXo of the scale disk SD. However, in the case where the scale Gm is formed along the outer peripheral surface parallel to the center line AXo of the scale disk SD, the encoder head EH1 (or EH2) and the scale disk SD can be arranged as shown in the second modification. Figure 5 shown.

[0079] [Modification 2]

[0080] Figure 5 Is to use the inclusion Figure 4 The partial cross-sectional view is a view in which the drum DR and the chamber portion 40 are cut along a plane passing through the nozzle opening 30A of the mist spraying portion 30 and the center line AXo and the line CL shown. Figure 5 In the embodiment, the drum DR is a hollow structure to achieve lightness, and the shaft Sft is set in a manner that passes through both ends of the drum DR in the Y direction. The sheet substrate P is closely supported by the outer peripheral surface DRa of the radius Rd of the drum DR. The scale disk SD of the encoder measurement system is coaxially fixed to the -Y direction side of the drum DR with the shaft Sft. Figure 5 The radius of the scale disk SD is set to be substantially the same as the radius Rd of the drum DR (relative to the radius ±10% of the radius Rd), and the scale Gm is formed on the outer peripheral surface of the scale disk SD. Therefore, the encoder head EH1 (or EH2) is arranged along the radial direction of the scale disk SD in a manner opposite to the scale Gm.

[0081] The inner wall surface of the air guide part 40A of the chamber part 40 is arranged to bend along the outer peripheral surface Dra of the drum DR in a circumferential direction so as to form a space with a certain interval ΔSv (several mm to more than ten mm) from the surface of the sheet substrate P in the radial direction. The mist gas Msg from the nozzle opening 30A of the mist ejection part 30 is ejected from the normal direction of the surface of the sheet substrate P and flows in the space with the interval ΔSv in the circumferential direction. In this modified example, in order to suppress the mist gas Msg from leaking from the space with the interval ΔSv toward the Y direction (encoder head EH1 side), flange parts (skirt parts) 41A and 41B extending in the radial direction are provided at the ends of the air guide part 40A in the Y direction. The flange parts 41A and 41B are formed in a fan shape when viewed from the YZ plane perpendicular to the center line AXo, and are formed in a manner such that the distance between the front end position of the axis Sft side of the flange parts 41A and 41B and the center line AXo is less than the radius Rd of the drum DR. The interval between each flange portion 41A, 41B and the side end surface of the drum DR in the Y direction is set to be a small gap of, for example, about 1 mm to several mm.

[0082] Thus, the mist gas Msg leaking from the space of interval ΔSv toward the outside direction (Y direction) of the chamber portion 40 flows in a manner such that it flows from the gap between the flange portions 41A, 41B and the side end surfaces of the drum DR in the Y direction toward the direction of the axis Sft (radial direction), thereby preventing spraying near the encoder head EH1. In addition, in this modified example, a disc-shaped windshield plate 45 is provided coaxially with the axis Sft between the scale disk SD and the side end surface of the drum DR in the -Y direction. The radius of the windshield plate 45 from the center line AXo is set to be larger than the radius Rd of the drum DR (or the radius of the scale disk SD), preferably as shown in FIG. Figure 5 As shown in FIG. 1 , the flange 41A is set to cover the radial distance from the center line AXo to the encoder head EH1. Thus, the mist gas Msg leaking from the flange 41A toward the outside (Y direction) of the chamber 40 from the space of the interval ΔSv can be prevented from being sprayed onto the scale Gm of the scale disk SD. It should be noted that, if the mist gas Msg leaking out can be sufficiently prevented from being sprayed onto the encoder head EH1 or the scale Gm of the scale disk SD, either the flange 41A or the windshield 45 can be omitted.

[0083] In addition, in order to maintain a fixed radial spacing ΔSv between the curved inner wall surface of the air guide component 40A installed in the chamber portion 40 (or the front end of the nozzle opening portion 30A of the mist ejection portion 30) and the sheet substrate P, in this modified example, rotating bodies (bearings) 43A and 43B are installed on the inner side (rotating drum DR side) of each of the flange portions 41A and 41B, and the rotating axes are arranged parallel to the center line AXo, abut against the end of the Y direction of the outer peripheral surface DRa of the rotating drum DR, and can rotate freely. When the rotating body 43A is observed in the XZ plane, it is respectively provided at two locations separated in the circumferential direction of the fan-shaped flange portion 41A. Similarly, when the rotating body 43B is observed in the XZ plane, it is respectively provided at two locations separated in the circumferential direction of the fan-shaped flange portion 41B. The chamber portion 40 is as shown in FIG. Figure 4 As shown, the rotating bodies 43A and 43B are arranged on the -X direction side of the rotating drum DR, so that they are forced in the +X direction so that the rotating bodies 43A and 43B at the four locations are always in contact with the outer peripheral surface DRa of the rotating drum DR. It should be noted that the rotating bodies 43A and 43B arranged at the four locations can also be configured as air cushions that eject gas in a manner that forms an air bearing (static pressure gas layer) between the rotating bodies and the outer peripheral surface DRa.

[0084] According to the first embodiment and variant examples 1 and 2, a mist film-forming device can be obtained by providing the following components: a mist generating unit 14 as a mist generating mechanism, which delivers a mist gas Msg, wherein the mist gas Msg includes a mist generated by atomizing a solution Lq containing particles of a material substance; a mist ejecting unit 30 as a mist ejecting mechanism, which causes the mist gas Msg to flow into and eject toward the sheet substrate P as a substrate to be processed; and a wind guide component 40A configured to form a mist ejecting unit 30. The chamber portion 40 serving as an air-guiding mechanism has an inner wall surface opposite to the surface of the sheet substrate P at a predetermined interval (ΔSv) so that the mist gas Msg from the mist ejection portion 30 flows along the surface of the sheet substrate P; and an electrostatic field generating device 70, which serves as a mist inducing mechanism for generating a repulsive force (repulsive force) between the inner wall surface of the air-guiding component 40A of the chamber portion 40 and the mist in order to generate an attractive force to attract the mist to the surface of the sheet substrate P, and generates an electrostatic field between the belt 5C (or rotating drum DR) supporting the sheet substrate P and the electrode plate Ed arranged on the air-guiding component 40A.

[0085] [Second embodiment]

[0086] Figure 6 is a schematic diagram showing the overall structure of the mist film forming device MDE according to the second embodiment, wherein the orthogonal coordinate system XYZ and Figure 1 Similarly, the setting is performed so that the Z direction is the gravity direction. Figure 6 The mist film forming device MDE is the same as the above Figure 4Similarly, the following structure is adopted: the long sheet substrate P is transported in the longitudinal direction by the rotation of the drum DR which supports the long sheet substrate P in the form of a cylindrical surface, and mist film formation is performed on the drum DR. Figure 6 In the mist film forming device MDE, for the above Figures 1 to 4 Components and structures having the same functions are marked with the same symbols, and their descriptions are omitted or simplified. In this embodiment, the solvent (pure water, etc.) of the thin liquid film formed on the surface of the sheet substrate P by mist film formation uses electricity to vibrate the nanoparticles contained in the liquid film before drying, so that the uneven thickness distribution of the nanoparticles deposited on the surface of the sheet substrate P becomes uniform.

[0087] Figure 6 In the embodiment, the sheet substrate P is hung around the conductive outer peripheral surface Dra of the drum DR via the roller 5G, and after mist film formation is performed at the lower part of the chamber part 40 having the mist spraying part 30 and the mist recovery part 32, it is conveyed roughly horizontally along the +X direction while maintaining a certain tension from the upper end part of the outer peripheral surface DRa of the drum DR in the +Z direction. The horizontally conveyed sheet substrate P is supported by a plurality of rollers 5J arranged along the conveying direction (X direction), and is bent downward (-Z direction) by the last roller 5H. In the present embodiment, in the horizontal conveying path of the sheet substrate P supported by the plurality of rollers 5J, a drying step is performed for the liquid film (solvent such as pure water) formed on the surface of the sheet substrate P by mist film formation. In order to implement the drying step, an exhaust drying section (drying section) 85 is arranged above the horizontal conveying path based on the plurality of rollers 5J, which sucks up the gas (air) near the surface of the horizontally conveyed sheet substrate P through the exhaust duct 86.

[0088] In addition, in the chamber section 40 constituting the mist film forming section of the present embodiment, a mist recovery section 32' similar to the mist recovery section 32 is installed not only on the downstream side of the mist ejection section 30 but also on the upstream side in the curved conveying direction of the sheet substrate P, and the remaining mist gas Msg' flowing from the mist ejection section 30 to the upstream side is discharged through the pipe 33'. Figure 1 The mist gas collecting section 34 shown in FIG. 1 is used to capture the mist gas Msg ejected from the nozzle opening 30A of the mist ejection section 30 of the present embodiment. When viewed in the XZ plane, the ejection direction of the mist gas Msg is as follows: Figure 6 As shown by the line CL in FIG. 8 , it is set to be inclined in the range of 0° to −90° (preferably −45°) with respect to a plane which is parallel to the YZ plane and includes the center line AXo.

[0089] The rotating drum DR is rotated by a motor included in a rotating drive unit 80 coupled to the shaft Sft, and the rotating drive unit 80 performs servo control on the motor based on speed information measured by a detection signal from an encoder head EH2 that reads the scale Gm of the scale disk SD and command information from a drive circuit 82, so that the outer peripheral surface DRa (sheet substrate P) of the rotating drum DR moves precisely at the commanded peripheral speed. The command information provided to the drive circuit 82 is produced by a control unit (CPU) 100 that uniformly controls the entire device.

[0090] In addition, in the present embodiment, on the back side (-Z direction side) of the sheet substrate P that is separated from the drum DR and moves along the horizontal conveying path, a plurality of electrode plates Ef1 to Ef4 are arranged in parallel with the sheet substrate P between the respective X directions of the plurality of rollers 5J. The electrode plates Ef1 to Ef4 are arranged at a certain interval (for example, several mm or more) from the back side of the sheet substrate P. In addition, on the upper surface side (+Z direction side) of the sheet substrate P that is separated from the drum DR and moves along the horizontal conveying path, a mesh electrode plate (mesh electrode) Em having an area covering the entire electrode plates Ef1 to Ef4 is arranged between the sheet substrate P and the exhaust drying section 85 in parallel with the sheet substrate P. The electrode plate Em is arranged at a certain interval (for example, several mm or more) from the upper surface of the sheet substrate P. The interval (inter-electrode gap) between the electrode plate Em and the electrode plates Ef1 to Ef4 in the Z direction is substantially constant in the X direction, and is set to a range of 10 to 30 mm as an example. Between the electrode plates Ef1 to Ef4 and the electrode plate Em, an AC potential is applied from the AC electric field generating unit 90 via the wirings Wa and Wb. The AC potential is set by a command from the control unit 100.

[0091] Figure 7 Shown by Figure 6 The detailed structure of the nanoparticle deposition uniformizing section (also called a particle vibration section or a migration imparting section) composed of the electrode plate Em and the electrode plates Ef1 to Ef4 and the AC electric field generating section 90 is shown. Figure 7 In Figure 6The same reference numerals are used for the same components as those shown. Regarding the electrode plate Em, for example, numerous openings Emh are opened in a matrix on a stainless steel plate, and a mesh is formed by thin linear portions. The electrode plates Ef1 to Ef4 are also formed of stainless steel plates, and the interval between them and the electrode plate Em in the Z direction is set to Zh. The AC electric field generating unit 90 includes: an oscillation circuit 90A that generates an AC signal (sine wave) at a frequency fp corresponding to the command information Sfc from the control unit 100; and an adjustment circuit 90B that deforms the waveform of the AC signal (sine wave) according to the command information Swc from the control unit 100, and adjusts the amplitude of the AC signal according to the command information Svc and applies it to the wirings Wa and Wb. It should be noted that the AC voltage Ev of the frequency fp applied between the electrode plate Em and the electrode plates Ef1 to Ef4 is a peak amplitude value or an effective amplitude value.

[0092] like Figure 7 As shown, during the period when the sheet substrate P moves at a speed Vp along the +X direction, as the solvent (pure water, etc.) dries, an evaporation component wx is generated from a liquid film (here, for convenience, referred to as Lq) composed of a solution Lq with a thickness Δh formed on the surface (upper surface) of the sheet substrate P, and is sucked by the exhaust drying section 85 through the opening Emh of the mesh electrode plate Em. In the liquid film Lq, countless nanoparticles np exist in a state of being deposited on the surface of the sheet substrate P or in a suspended state. In this state, when an AC electric field with a frequency fp and intensity varying along the Z direction is applied to the liquid film Lq by the AC electric field generating section 90, the nanoparticles np vibrate under the action of the swimming force fz corresponding to the intensity of the AC electric field, and the unevenness of the deposition state is improved, so that the film thickness distribution based on the deposition of the nanoparticles np becomes uniform. The electric field generated by the AC voltage Ev is preferably continued until the liquid film Lq on the surface of the sheet substrate P is substantially dried.

[0093] Therefore, when the drying time until the liquid film Lq on the sheet substrate P is substantially dried is set to Tvp, the length HGx of the electric field space between the electrode plate Em and the electrode plates Ef1 to Ef4 in the X direction can be set to HGx≧Tvp·Vp according to the speed Vp of the sheet substrate P. In addition, the drying time Tvp of the liquid film Lq varies according to the temperature of the sheet substrate P, the temperature and humidity of the surrounding environment, the air volume of the surrounding gas blown to the sheet substrate P, etc. In order to shorten the drying time Tvp as much as possible, a heater unit can be provided to make the temperature of the electrode plates Ef1 to Ef4 arranged on the back side of the sheet substrate P to be a value above room temperature (24°C), for example, several tens of degrees Celsius to 100 degrees Celsius.

[0094] In this way, it was confirmed through preliminary experiments that the state of the film composed of nanoparticles finally formed on the sheet substrate P is improved by applying an alternating electric field before the liquid film Lq on the sheet substrate P is dried. Figure 8The following is a configuration of a preliminary experiment apparatus for confirming how the film-forming state of a thin film composed of nanoparticles changes when an alternating electric field is applied to a liquid film Lq. Figure 8 In the orthogonal coordinate system XYZ, the Z direction is the direction of gravity, and the XY plane orthogonal to it is a horizontal plane. In the preliminary experimental device, a 50 mm square glass substrate P' is used as a sample of the mist gas Msg sprayed for a certain period of time. The glass substrate P' is placed on a conductive film formed on the upper surface of an insulating base plate BPd as an electrode plate Ef, and pillars HSP with a height of Zh in the Z direction are provided on both sides of the base plate BPd in ​​the X direction. The insulating top plate BPu is placed on the upper part of the pillar HSP in parallel with the base plate BPd. A conductive film serving as an electrode plate Em is formed under the top plate BPu. A sinusoidal AC voltage Ev (frequency fp) is applied between the conductive films serving as the electrode plates Ef and Em via a switch Swo.

[0095] In preliminary experiment 1, a solution Lq containing ITO nanoparticles with a particle size of 30 to 50 nm (average particle size 40 nm) at a specified concentration (for example, 10 wt.%) is first converted into a mist gas Msg. After being sprayed for a certain period of time on the surface of a glass substrate P' placed on a bottom plate BPd to form a liquid film Lq, the frequency fp of the AC voltage Ev applied until the liquid film Lq dries is used to investigate the resistance change of the film formed of the ITO nanoparticles. Fig. 9 The frequency fp (Hz) of the AC voltage Ev is taken as the horizontal axis, and the resistance value (KΩ / cm 2 ) is a graph of experimental result 1 of preliminary experiment 1 with . In preliminary experiment 1, the electrode interval Zh between electrode plate Ef and electrode plate Em (height of support HSP) was kept at 20 mm, the AC voltage Ev (effective value) was set to 20 V (i.e., the effective value of the AC electric field strength was set to 1 V / mm), and the glass substrate P' was replaced to form a liquid film Lq, and the resistance values ​​of ITO nanoparticles formed under each AC electric field with a frequency fp of 1 Hz, 10 Hz, 100 Hz, 1 KHz, 10 KHz, 100 KHz, 1 MHZ, 10 MHz, and 100 MHz were measured.

[0096] like Fig. 9 As shown, it is determined that in the case of the ITO nanoparticles used in the preliminary experiment 1, the resistance value of the thin film composed of the ITO nanoparticles is approximately halved when the frequency fp is between 200 Hz and 20 kHz. Fig. 9 The highest resistance value obtained when the frequency fp is 0 Hz (no AC electric field is applied) or an AC electric field of 10 MHz or more is about 100 KΩ / cm 2It is believed that the reason why the resistance value is reduced by applying such an AC electric field is that the ITO nanoparticles in the liquid film Lq vibrate due to their polarization, and the local density state of the ITO nanoparticles deposited on the surface of the glass substrate P' is relaxed along the surface, and the contact paths (conduction paths) between the ITO nanoparticles in the surface are increased, thereby improving the conductivity of the thin film composed of ITO nanoparticles on average.

[0097] Next, as a preliminary experiment 2, the AC voltage Ev was set to 20V and the frequency fp was set to 10 kHz, and the resistance value change of a thin film composed of ITO nanoparticles (average particle size 40 nm) was investigated at intervals of 5 mm within the range of electrode interval Zh of 5 mm to 50 mm. Fig.10 The horizontal axis represents the resistance value (KΩ / cm2) of the thin film of ITO nanoparticles with the electrode interval Zh (mm) as the horizontal axis. 2 ) is a graph of experimental results 2 of preliminary experiment 2 with the vertical axis. In preliminary experiment 2, based on the findings obtained in preliminary experiment 1, the frequency fp of the AC electric field is set to 10KHz, which is the minimum resistance value. Fig.10 As shown, in the preliminary experiment 2, when the electrode interval Zh is 40 mm or more, no decrease in the resistance value is observed, and as the electrode interval Zh is narrowed from 40 mm to 20 mm, the resistance value gradually decreases, and when the electrode interval Zh is 20 mm or less, the resistance value becomes substantially constant. Through this preliminary experiment 2, it is determined that in the case of the ITO nanoparticles used in the experiment, the effective value of the intensity of the AC electric field applied during the drying of the liquid film Lq is 0.5 V / mm (20 V / 40 mm) or more, preferably 1 V / mm or more.

[0098] Furthermore, as a preliminary experiment 3, the alternating voltage Ev was set to 20V and the electrode interval Zh was set to 20mm. In order to compare with the ITO nanoparticles with an average particle size of 40nm used in preliminary experiments 1 and 2, the dependence on the frequency fp was investigated in the case of extremely small ITO nanoparticles with an average particle size of 10nm. In preliminary experiment 3, the electrode interval Zh was kept at 20mm, the alternating voltage Ev (effective value) was set to 20V, and the glass substrate P' was replaced to form a liquid film Lq, and the resistance values ​​of the ITO nanoparticles with an average particle size of 10nm formed under each alternating electric field with a frequency fp of 1Hz, 10HZ, 100HZ, 1KHz, 10KHz, 100KHz, 1MHZ, and 10MHz were measured.

[0099] Fig.11 The frequency fp (Hz) of the AC voltage Ev is taken as the horizontal axis, and the resistance value (KΩ / cm 2 ) is a graph of experimental results 3 of pre-experiment 3 with y as the vertical axis. Fig.11As shown, it is determined that in the case of ITO nanoparticles with an average particle size of 10 nm used in Preliminary Experiment 3, the resistance value of the thin film composed of ITO nanoparticles is approximately halved when the frequency fp is between 10 Hz and 1 kHz. Fig.11 In the case of an AC field with a frequency fp of 0 Hz (no AC field applied) or an AC field with a frequency fp of 10 MHz or more, the maximum resistance of a film composed of ITO nanoparticles with an average particle size of 40 nm is about 100 KΩ / cm 2 (Same as the previous preliminary experiment 1), the maximum resistance value of the film composed of ITO nanoparticles with an average particle size of 10nm is about 150KΩ / cm 2 From this preliminary experiment 3, it was found that even if nanoparticles are made of the same material, the frequency band of the alternating electric field that generates the electrophoretic force fz is different due to the difference in particle size.

[0100] Based on the above preliminary experimental findings, Figure 6 , Figure 7 The electrode spacing Zh between the electrode plates Ef1 to Ef4 and the electrode plate Em of the mist film forming device MDE shown in the figure, and the effective value and frequency fp of the AC voltage Ev applied between the electrodes by the AC electric field generating unit 90. The optimal values ​​of the spacing Zh, the AC voltage Ev, and the frequency fp vary depending on the type of solution Lq, the type and particle size of the nanoparticles, etc., and therefore Figure 8 Such a preliminary experimental device is used to determine. It should be noted that one reason why nanoparticles generate a swimming force fz in the liquid film Lq is believed to be that nanoparticles have polarizability.

[0101] In addition, through Figure 6 , Figure 7 The waveform of the AC voltage Ev applied between the electrode plates Ef1 to Ef4 and the electrode plate Em by the AC electric field generating unit 90 of the mist film forming device MDE shown in FIG. Figures 12A to 12C Deformation occurs as shown. Fig. 12A In the example, the AC voltage is a typical sine wave WF1, whose characteristics are determined by the frequency fp and the effective value Eva (1 / [2 0.5 ]) to indicate. Fig. 12B is a sawtooth wave WF2 with a peak value of ±Evp, Fig. 12C The burst waveform WF3 is a sine wave of frequency fp that is attenuated by amplitude modulation every time Tb (Tb>1 / fp). In addition, the waveform of the AC electric field may be a rectangular wave whose duty ratio (the proportion of the duration of the high level in one cycle of 1 / fp) can be adjusted at frequency fp.

[0102] Fig. 12C Such a burst waveform WF3 is used Fig. 12B Such sawtooth wave WF2 Fig. 12A The sine wave WF1 is amplitude modulated, and as frequency components, it contains the frequency 1 / Tb determined by the time Tb and the frequency fp of the sine wave WF1. Therefore, according to Fig. 9 Experimental results 1. Fig.11 The experimental result 3 shows that, for example, the frequency fp can be set to 1 kHz to 10 kHz and the frequency 1 / Tb can be set to 50 to 500 Hz. When the AC electric field is generated at a plurality of different frequencies, even if nanoparticles with large particle size deviations (for example, the minimum particle size is 10 nm and the maximum particle size is 100 nm) are mixed in the liquid film Lq on the surface of the sheet substrate P, the swimming force fz can be effectively given to each of the nanoparticles.

[0103] [Variation 3]

[0104] Figure 6 In the deposition homogenization section composed of electrode plates Em, Ef1 to Ef4 and AC electric field generating section 90, during the drying step in which the sheet substrate P is horizontally transported along the +X direction, an AC electric field of a certain intensity is applied to the liquid film Lq on the surface of the sheet substrate P at a certain frequency fp. However, since the four electrode plates Ef1 to Ef4 arranged on the back side of the sheet substrate P are divided along the horizontal transport path of the sheet substrate P, the AC voltage Ev and frequency fp applied to the electrode plates Ef1 to Ef4 can also be different. For this reason, Figure 7 It is necessary to provide a plurality of oscillation circuits 90A and adjustment circuits 90B in the AC electric field generating unit 90 shown.

[0105] [Variation 4]

[0106] about Figure 7 The deposition homogenization section shown, which is composed of the electrode plates Em, Ef1 to Ef4 and the AC electric field generating section 90, can function as long as a liquid film Lq is formed on the sheet substrate P with a thickness that allows the nanoparticles np to migrate (for example, several times or more of the particle size of the nanoparticles). Therefore, the step of forming the liquid film Lq on the sheet substrate P is not limited to the mist film forming method, and the liquid film Lq can be formed by various printing methods (gravure printing, screen printing, die coating printing, etc.) and inkjet coating devices. In particular, when tiny droplets containing metal nanoparticles are selectively applied to the surface of the substrate P by inkjet to form a conductive wiring pattern, electrode pattern, etc., before the applied droplets are dried, the substrate P is passed through Figure 7 Such a deposition uniformization portion can thereby reduce the resistance value of the wiring pattern and electrode pattern composed of nanoparticles formed on the substrate P.

[0107] [Variation 5]

[0108] In the second embodiment, modifications 3 and 4, Figure 7 An alternating electric field is applied between the electrode plate Em and the electrode plates Ef1 to Ef4 shown, that is, in a direction perpendicular to the extension surface of the liquid film Lq on the sheet substrate P. However, by changing the structure and arrangement of the electrode plates, the direction of the swimming force fz acting on the nanoparticles in the liquid film Lq can be changed so that it has not only a longitudinal (Z direction) vector but also a transverse (in the XY plane) vector.

[0109] Fig.13 The structure of the deposition uniformization section (electrophoresis imparting section) of Modification Example 5 is shown. Fig.13 The upper section is a top view of the structure in the XY plane as viewed from above, and the lower section is a front view of the structure in the XZ plane as viewed from the side. In variant example 5, instead of the electrode plate Em arranged on the upper surface side of the sheet substrate P, a plurality of electrode wires (electric wires or steel wires) Em' extending in a straight line in the Y direction (the conveying direction of the sheet substrate P) are arranged at certain intervals in the X direction (the conveying direction of the sheet substrate P). The two ends of the Y direction of each of the plurality of electrode wires Em' are fixed to a metal frame TF1, and are connected to the metal frame TF1 from the above. Figure 7 The wiring Wb of the AC electric field generating unit 90 is connected. In addition, in the modification example 5, instead of the electrode plates Ef1 to Ef4 arranged on the back side of the sheet substrate P, a plurality of electrode wires (electric wires or steel wires) Ef' are arranged at a certain interval in the X direction (the conveying direction of the sheet substrate P) so as to extend in a straight line in the Y direction in a manner longer than the width (Y direction dimension) of the sheet substrate P. The two ends of each of the plurality of electrode wires Ef' in the Y direction are fixed to the metal frame TF2, and are connected to the metal frame TF2 from the above. Figure 7 The wiring Wa of the AC electric field generating unit 90 is connected.

[0110] When viewed in the XY plane, the plurality of electrode lines Em' on the upper surface side of the sheet substrate P and the plurality of electrode lines Ef' on the back side of the sheet substrate P are alternately arranged at a certain interval in the X direction. When an AC voltage Ev is applied between the frames TF1 and TF2 via the wirings Wa and Wb, as shown in FIG. Fig.13 As shown in the lower section of , an AC electric field Fe inclined in the X direction is generated between each electrode line Em' on the upper side and each electrode line Ef' on the lower side. Therefore, a swimming force fz inclined in the X direction, that is, a swimming force in the Z direction and a swimming force in the X direction are imparted to the nanoparticles in the liquid film Lq on the surface of the sheet substrate P. As a result, the nanoparticles in the liquid film Lq also actively move (micro-vibrate) in a lateral direction along the surface of the sheet substrate P, which can improve the uniformity of the deposition state of the thin film composed of the dried nanoparticles.

[0111] It should be noted that Fig.13The multiple electrode lines Em' and the multiple electrode lines Ef' shown can also be tilted as a whole at a certain angle (for example, 45° or 90°) relative to the Y axis (or X axis) in the XY plane while maintaining parallelism with each other. In addition, when observed in the XY plane, the multiple electrode lines Em' and the electrode lines Ef' do not need to be straight lines, but can also be bent into an arc (bow shape), or bend into a serrated or wavy shape.

[0112] According to the above-mentioned second embodiment and variants 3 to 5, a film forming device is provided, which is a film forming device for depositing microparticles (nanoparticles np) with a specified thickness on the surface of a sheet substrate P as a processed substrate, and comprises: a mist film forming section for forming a liquid film Lq composed of a solution containing nanoparticles np with a specified thickness on the surface of the sheet substrate P, or a liquid film forming section composed of a coating device based on a printing method or an inkjet method; and a deposition uniformization section as a swimming imparting section for applying an alternating electric field to the liquid film Lq formed on the surface of the sheet substrate P before evaporation or volatilization, and imparting a swimming force fz to the nanoparticles np in the liquid film Lq. It should be noted that Figure 6 In the mist film-forming device MDE shown, since the sheet substrate P is tightly supported by a rotating drum DR having a conductive outer peripheral surface, a first electrode (Em) can be set on the inner wall surface of the chamber portion 40 opposite to the sheet substrate P, and the outer peripheral surface of the rotating drum DR can be used as the second electrode (Ef), and an AC electric field can be applied between the first electrode (Em) and the second electrode (Ef).

[0113] [Third embodiment]

[0114] Fig.14 The schematic structure of the mist film forming device MDE according to the third embodiment is shown. Fig.14 The orthogonal coordinate system XYZ is the same as above Figure 1 , Figure 6 The orthogonal coordinate system XYZ is set in the same manner. Figure 2 The mist film forming section shown in the figure is different from that of the second embodiment. Figure 7 The deposition homogenization section shown is combined. Therefore, Fig.14 Among the components in Figure 1 , Figure 6 Components having substantially the same configuration or the same function are denoted by the same reference numerals.

[0115] Fig.14In the embodiment, the sheet substrate P is supported by the horizontal part of the metal endless belt 5C mounted between the rollers 5A and 5B and transported in the -X direction, and the mist gas Msg from the mist film forming part composed of the mist spraying part 30, the mist recovery part 32 and the chamber part 40 is sprayed on the surface of the horizontally supported sheet substrate P. The belt 5C is electrically connected to the wiring Wa from the AC electric field generating part 92 via the contact head 71, and the electrode plate Ed provided above the sheet substrate P in the chamber part 40 (in the +Z direction) is electrically connected to the wiring Wb from the AC electric field generating part 92. In this embodiment, the belt 5C, the electrode plate Ed and the AC electric field generating part 92 also constitute a mist guiding mechanism.

[0116] The sheet substrate P, on which the liquid film (Lq) is formed by the mist film forming unit, is separated from the belt 5C at the position of the roller 5B and is transported to the deposition homogenization unit along a straight conveying path inclined about 45° downward from the horizontal plane (XY plane). Figure 6 The structure is similarly provided with a plurality of rollers 5J and a plurality of electrode plates Ef1 to Ef4 arranged on the back side of the sheet substrate P, and a mesh electrode plate Em arranged on the upper surface side of the sheet substrate P. Furthermore, the electrode plates Ef1 to Ef4 are electrically connected to the wiring Wa from the AC electric field generating unit 92, and the electrode plate Em is electrically connected to the wiring Wb from the AC electric field generating unit 92. In the present embodiment, the deposition uniformization unit is also composed of the electrode plates Ef1 to Ef4, the electrode plate Em, and the AC electric field generating unit 92. It should be noted that the electrode plates Ef1 to Ef4 may also be changed to the above-mentioned Fig.13 The electrode plates Em are changed to the above-mentioned multiple electrode lines Ef'. Fig.13 Multiple electrode lines Em' as shown.

[0117] In this embodiment, the electrostatic field generated in the mist guiding mechanism and the alternating electric field generated in the deposition homogenizing section are provided by one alternating electric field generating section 92. As described in the above-mentioned embodiments and variations, in the mist guiding mechanism, the electrode plate Ed is made to have a negative polarity relative to the belt 5C as a whole so as to guide the negatively charged mist to the sheet substrate P side. Therefore, as an example, the alternating electric field generating section 92 generates Fig.15 It is constructed in the manner of the AC voltage Ev shown. Fig.15 In the figure, the vertical axis is set to the AC voltage Ev, the horizontal axis is set to time, and the neutral point potential (average potential) of the waveform of the AC voltage Ev whose amplitude is the effective value Eva and whose intensity changes in a sinusoidal manner at a frequency fp is set to -Ene (V) which is on the negative side relative to the zero potential (the ground potential of the main body). The absolute value |Eva| of the effective value Eva of the amplitude and the absolute value |Ene| of the neutral point potential -Ene are set to have a relationship of |Ene|≧|Eva|.

[0118] Will Fig.15 The AC voltage Ev is applied to Fig.14 When the band 5C in the middle is between the electrode plate Ed, the magnitude of the force that attracts the mist to the sheet substrate P side changes with time at a frequency fp, but since the average strength of the electrostatic field is the neutral point potential -Ene, the effect of increasing the adhesion rate of the mist on the sheet substrate P can be obtained to the same extent as in the first embodiment. Fig.14 The electrode plates Ef1 to Ef4 of the deposition uniformization section (electrophoresis imparting section) shown in the figure are applied to the electrode plate Em. Fig.15 When the AC voltage Ev is applied, an AC electric field which is stably biased to the negative electrode side and changes in amplitude with an effective value Eva is applied to the liquid film Lq on the sheet substrate P, thereby imparting a swimming force fz to the nanoparticles in the liquid film Lq as in the above-mentioned second embodiment.

[0119] Fig.16 Shows the generation Fig.15 An example of a specific circuit in the AC electric field generating unit 92 of the AC voltage Ev is to use a differential amplifier OPA that can operate at a relatively high power supply voltage ±Vcc (for example, ±50V or more). The voltage +Eni from the DC variable power supply DCO is applied to the inverting input terminal (-) of the differential amplifier OPA via the resistor RS1, and a resistor RS2 is connected between the inverting input terminal (-) and the output terminal of the differential amplifier OPA. The voltage +Eni from the variable power supply DCO generates Fig.15 The neutral point potential (bias voltage) -Ene is shown. A resistor RS4 is connected between the non-inverting input terminal (+) of the differential amplifier OPA and the ground potential (0V), and a voltage of -0V is applied to the non-inverting input terminal (+) of the differential amplifier OPA via the series connection of the coupling capacitor CC1 and the resistor RS3. Figure 7 The oscillation circuit 90A shown in FIG. 1 outputs a sinusoidal AC voltage Evi having a frequency fp. The capacitance of the capacitor CC1 is determined by the series resistance value of the resistors RS3 and RS4 so that the low frequency cutoff frequency of the frequency fp of the AC voltage Evi is about 1 Hz.

[0120] exist Fig.16In the circuit structure, if the resistors RS1 and RS3 have the same resistance value, and the resistors RS2 and RS4 have the same resistance value, the output voltage Vout relative to the ground potential (connected to the wiring Wa) at the output end of the differential amplifier OPA is Vout = (RS2 / RS1) · (Evi-Eni). Since the AC voltage Evi is a waveform with a sinusoidal amplitude that changes over time, its peak value is Epi and the time is t, and it is expressed as Evi = Epi·sin(2π·fp·t). When the peak value Epi of the AC voltage Evi and the absolute value of the voltage +Eni from the variable power supply DCO are set to the relationship of Epi≦Eni, the output voltage Vout is as above Fig.15 The output voltage Vout of the differential amplifier OPA is applied to the Fig.14 The electrode plates Ed and Em are shown.

[0121] As an example, the resistors RS1 and RS3 are set to 20KΩ, the resistors RS2 and RS4 are set to 100KΩ, and Fig.15 The neutral point potential (average potential) -Ene in the Fig.15 When the peak value Evp of the amplitude of the AC voltage Ev in the generator is set to 22V, the voltage +Eni based on the variable power supply DCO is set to +5V, and the peak value of the amplitude of the AC voltage Evi from the oscillation circuit 90A is set to 4.4V (effective value is about 3.08V). Fig.15 As shown in the figure, the circuit configuration of the AC voltage Ev that varies in amplitude with a frequency fp based on a neutral point potential (bias potential) Ene other than 0 V (ground potential) is not limited to Fig.16 The circuit configuration can also be realized by various other circuit configurations.

[0122] In this embodiment, if Fig.14 As shown, in order to horizontally transport the sheet substrate P in the mist film forming section, a conveyor transport method based on rollers 5A, 5B and belt 5C is used, but it can also be as described above. Figure 6 As shown, in the mist film forming section, a roller conveying method is used in which the sheet-like substrate P is wound around a drum DR and conveyed.

[0123] As described above, according to the third embodiment, the electrostatic field generating section that generates an electrostatic field between the electrode plate Ed and the belt 5C as a mist guiding mechanism provided in the mist film forming section can be used as an AC electric field generating section that generates an AC electric field between the electrode plates Ef1 to Ef4 and the electrode plate Em as a deposition homogenizing section (swimming imparting section) (the deposition homogenizing section realizes the homogenization of the deposition distribution of the nanoparticles in the liquid film on the substrate during the drying process immediately after the mist film forming is completed), and the device structure can be simplified. In addition, when an AC electric field is applied to the liquid film Lq on the sheet substrate P by the deposition homogenizing section (swimming imparting section), the neutral point potential (Ene) and the amplitude range of the AC electric field are biased to one polarity side (negative polarity), so that the nanoparticles np polarized in the liquid film Lq can be given a swimming force (vibration), and a guiding force that is attracted to the sheet substrate P side can also be given.

[0124] It should be noted that, in an experiment in which two electrode needles were immersed at a specified interval in a solution Lq (liquid film Lq) in which ITO nanoparticles crystallized into a non-rectangular shape by the preparation method disclosed in International Publication No. 2019 / 138707 and International Publication No. 2019 / 138708 were dispersed, and a DC voltage was applied between the electrode needles for a certain period of time, a thin film deposited by ITO nanoparticles was formed on the surface of one electrode needle. Fig.17 The schematic structure of the experimental device is shown. A solution Lq (the solvent is pure water) in which non-rectangular ITO nanoparticles are dispersed at a specified concentration is accumulated at a certain depth in a container CK such as a flat dish. Two gold-plated electrode needles SHa and SHb separated by a distance dX in a direction parallel to the liquid surface are immersed in the solution perpendicular to the liquid surface, and 40V is applied between the electrode needles SHa and SHb by a DC variable power supply DCO.

[0125] In this experiment, the interval dX between the two electrode needles SHa and SHb was changed while the voltage of the DC variable power supply DCO was set to 40V, and the film formation (deposition) of ITO nanoparticles on one electrode needle was visually confirmed. Since the surfaces of the electrode needles SHa and SHb were gold-plated, when the ITO nanoparticles began to deposit, the immersed part of the electrode needle SHb began to change color to gray, so it was easy to visually observe. The results of the experiment, such as Fig.18 As shown, no deposition can be confirmed when the interval dX is greater than 10 mm. When the interval dX is 2 mm, 5 mm, and 7 mm, when the electrode is directly immersed in the solution Lq, non-rectangular ITO nanoparticles form a film (deposit) on one electrode needle. Therefore, it can be considered that the area (space) where the electric field acts between the electrode needles SHa and SHb gives the ITO nanoparticles a kinetic force (repulsive force or attractive force).

[0126] [Fourth embodiment]

[0127] Fig.19 The schematic structure of the mist film forming device MDE of the fourth embodiment is shown, and the orthogonal coordinate system XYZ is consistent with the above Figure 1 , Figure 4 , Figure 6 , Fig.14 Similarly, the Z direction is the gravity direction (vertical direction), and the XY plane is the horizontal direction. Figure 1 to Figure 3B or Fig.14 The conveyor conveying method shown in the figure moves the sheet substrate P in the longitudinal direction while spraying the mist gas Msg on the surface of the sheet substrate P to form a liquid film Lq. Fig.19 In the device configuration shown, for the above Figure 1 to Figure 3B or Figure 6 The components and mechanisms shown in the figure that perform the same functions are marked with the same symbols, and their descriptions are simplified or omitted.

[0128] In the present embodiment, in the conveyor transport mechanism composed of rollers 5A, 5B, and belt 5C, the portion of belt 5C that supports the sheet substrate P in a planar state while moving linearly from roller 5A toward roller 5B is arranged to be tilted at a certain angle from the XY plane in the moving direction of the sheet substrate P. That is, roller 5B located on the downstream side in the transport direction of the sheet substrate P is arranged to be higher in the Z direction than roller 5A. As the surface of the sheet substrate P is tilted in the transport direction like this, the mist film forming section composed of the mist spraying section 30, the mist recovery section 32, 32', and the chamber section 40 is also arranged to be tilted as a whole. In addition, as described above Figure 1 Similarly, a support table 5D' that supports the belt 5C and the sheet substrate P in a planar shape between the rollers 5A and 5B is arranged to be inclined in the conveying direction relative to the XY plane. On the support surface of the support table 5D', a plurality of groups of ejection holes and suction holes are formed in a two-dimensional manner at a certain interval. The ejection holes eject pressurized gas toward the back side of the belt 5C, and the suction holes suck the ejected gas near the ejection holes, thereby forming an air bearing layer (gas layer) between the back side of the belt 5C and the support surface.

[0129] In this embodiment, in order to make the air bearing layer formed between the support surface of the support table 5D' and the back side of the belt 5C lower than the temperature (or ambient temperature) of the mist gas Msg ejected from the nozzle opening 30A of the mist ejection unit 30, a supply / exhaust unit 200, a temperature control (cooling) (temperature control unit) unit 202, and a temperature sensor 204 are provided. The supply / exhaust unit 200 exhausts the gas of the air bearing layer through a pipe TPc that is fully connected to a plurality of suction holes formed on the support surface of the support table 5D', and supplies pressurized gas to the temperature control (cooling) unit 202 through a pipe TPa. The temperature control (cooling) unit 202 supplies the temperature-controlled gas for the air bearing layer through a pipe TPb that is fully connected to a plurality of ejection holes formed on the support surface of the support table 5D'. The temperature sensor 204 outputs measurement information (actual measurement value) 204s corresponding to the temperature of the gas flowing through the pipe TPc recovered from the air bearing layer to the temperature control (cooling) unit 202. The temperature control (cooling) unit 202 performs servo control on the temperature of the gas so that the measurement information (actual measurement value) 204 s matches the target temperature information (command value) 100 a from the control unit (CPU) 100 .

[0130] The control unit 100 and the above Figure 6 As shown in , in this embodiment, a control signal is output to the drive circuit unit 82' of the drive unit 80' of the motor or reducer that includes the rotating drive roller 5A to convey the belt 5C. In addition, in this embodiment, a temperature control unit 212 is provided, which drives the temperature adjustment element (for example, Peltier element) 210A provided inside the roller 5A and the temperature adjustment element (for example, Peltier element) 210B provided inside the roller 5B to set it to a specified temperature corresponding to the target temperature information 10 from the control unit 100. The temperature adjustment elements (temperature adjustment unit) 210A and 210B respectively make the temperature of the outer peripheral surface of the rollers 5A and 5B in contact with the belt 5C the same as the temperature of the air bearing layer formed on the supporting surface of the support table 5D'. Through the cooperation of such temperature adjustment elements 210A and 210B and the temperature adjustment (cooling) unit 202, the belt 5C is set to the target temperature instructed by the control unit 100, and the sheet substrate P closely supported by the belt 5C is also set to the target temperature.

[0131] It should be noted that, when the belt 5C is a thin metal plate such as stainless steel, the temperature adjustment element 210B in the roller 5B (downstream side of the sheet substrate P) can be omitted due to its fast heat conduction, and the temperature of the belt 5C can be adjusted only by the temperature adjustment element 210A on the roller 5A side, and the temperature adjustment element 210A and the temperature control unit 212 can also be omitted. In addition, the temperature sensor 204 is set as a temperature sensor for measuring the temperature of the gas passing through the pipe TPc, but a temperature sensor composed of a semiconductor or the like can be embedded in the support surface of the support table 5D' to measure the temperature of the support surface or the temperature of the gas in the air bearing layer, and the measurement signal is sent to the temperature control (cooling) unit 202 as the measurement information (actual measurement value) 204s.

[0132] In this embodiment, in order to make the mist in the mist gas Msg ejected from the nozzle opening 30A of the mist ejection unit 30 effectively adhere to the surface of the sheet substrate P, the target temperature information 100a and 100b from the control unit 100 is set so that the temperature of the sheet substrate P is lower than the temperature of the mist gas Msg (or the ambient temperature). Fig.19 When the temperature of the environment of the mist film forming device MDE is set to Tev°C, the temperature of the mist gas Msg sprayed by the nozzle opening 30A of the mist ejection unit 30 is set to Tms°C, and the temperature of the sheet substrate P (film-forming object) is set to Tfs°C, it is preferably set to a relationship of Tev≧Tms>Tfs. At this time, the temperature is adjusted by the temperature control (cooling) unit 202 and the temperature control unit 212 so that the temperature Tfs of the sheet substrate P becomes the freezing temperature of the solvent liquid of the solution Lq as the source of the mist, or becomes a temperature slightly higher than the freezing temperature.

[0133] In order to confirm the optimum value of the temperature of the sheet substrate P which has been cooled, etc., Fig. 20 The pre-experimental setup shown investigates the temperature dependence of the fog adhesion rate. Fig. 20 The pre-experimental device is provided with: a glass substrate P' as a sample is placed, a temperature control unit (substrate temperature control unit) 230 that can cool the temperature of the glass substrate P' from room temperature (ambient temperature) to -5°C; and a tube 17 from a mist generator configured in such a way that mist gas Msg is sprayed along the surface of the glass substrate P'. As an example, the tube 17 is similar to the above Figure 1 The flexible tube 17 (PTFE: fluororesin material) connected from the mist generating unit 14 to the mist ejecting unit 30 is the same. The tube 17 is arranged in the order of inner diameter (diameter) The center line 17x (the line passing through the center point of the circular opening of the front end opening 17T) of the mist gas Msg ejected from the circular front end opening 17T of 15 mm is set in a manner substantially parallel to the surface of the glass substrate P'. It should be noted that the glass substrate P' is cut out of a glass plate (or a semiconductor wafer) with a thickness of 0.5 mm, the surface of which is treated to be lyophilic, into a square of approximately 25 mm square.

[0134] Here, the center line 17x is set to be parallel to the X-axis of the orthogonal coordinate system XYZ with the Z direction as the gravity direction. Therefore, the surface of the glass substrate P' is set to be parallel to the XY plane, the normal line Lz passing through the center point of the surface of the glass substrate P' is set to be parallel to the Z axis, and the opening surface of the front end opening 17T of the tube 17 is set to be parallel to the YZ plane. In addition, the glass substrate P' (rectangular) is mounted on the temperature control unit 230 in such a manner that the end face Eg on the side of the tube 17 is approximately parallel to the Y axis and the distance from the front end opening 17T of the tube 17 to the end face Eg in the X direction is always approximately constant (for example, 10 mm). In addition, the front end opening 17T of the tube 17 is set in such a manner that the distance between the surface of the glass substrate P' and the center line 17x in the Z direction is, for example, the inner diameter The weight is fixed by a supporting member (not shown) at a constant value in a range of 0.5 to 1.5 times.

[0135] The temperature control unit (substrate temperature control unit) 230 includes: a temperature control plate portion 230A on which a glass substrate P' is placed; a supply port portion 230B into which a temperature control liquid (cooling liquid) LLc for adjusting the temperature of the temperature control plate portion 230A flows; a discharge port portion 230C from which the temperature control liquid LLc is discharged; and a temperature sensor 230S. The temperature control liquid LLc is sent to the supply port portion 230B from a cooling device (cooling water and warm water circulation device) which is separately provided via a pipe, and is returned to the cooling device from the discharge port portion 230C via a pipe. The temperature sensor 230S sends a detection signal Sgt corresponding to the temperature of the temperature control liquid LLc to the cooling device, and the cooling device uses the detection signal Sgt as a feedback signal to perform temperature control so that the temperature control liquid LLc reaches a specified target temperature. It should be noted that the temperature sensor 230S for measuring the temperature of the temperature control liquid LLc can also be provided on the cooling device side.

[0136] In use Fig. 20In the experiment of the experimental device, the target temperature of the cooling device was set as follows: the temperature of the glass substrate P' was changed to the room temperature (ambient temperature) of +27°C, and the temperature was changed from +25°C to -5°C at 5°C intervals. In addition to the temperature change of the glass substrate P', in order to confirm the influence of the temperature of the mist gas Msg sprayed from the tube 17, the experiment was also conducted when the mist gas Msg was changed to +10°C, +30°C, and +50°C. In order to utilize Fig. 20 The experiment was conducted using an experimental device, and non-rectangular ITO nanoparticles (average particle size of 30 nm) prepared by the method disclosed in International Publication No. 2019 / 138707 and International Publication No. 2019 / 138708 were dispersed at a concentration of 10 wt.% in the above-mentioned Figure 1 The solution (pure water) Lq in the internal container 14A of the mist generating unit (atomizer) 14 shown.

[0137] In addition, using Figure 1 The flow rate regulating valve 15 of the carrier gas CGS shown in the figure sets the spraying time (film forming time) of the mist gas Msg so that each glass substrate P' as a sample is fixed to 5 minutes (300 seconds), and the flow rate of the mist gas Msg sprayed from the front end opening 17T of the tube 17 is a fixed value (10L / min) for any glass substrate P'. In addition, the temperature of the mist gas Msg introduced into the Figure 1 However, in order to conduct a more rigorous experiment, before placing the glass substrate P' on a predetermined position on the temperature control plate portion 230A, a rod-shaped thermometer consisting of an alcohol column or a mercury column is inserted into the mist gas Msg ejected near the front end opening 17T to directly measure the temperature, and the temperature of the carrier gas CGS is managed in such a way that it reaches a predetermined temperature (+10°C, +30°C, +50°C).

[0138] In the experiment, the mist gas Msg was first sprayed (fog film formation) from the front end opening 17T of the tube 17 for 5 minutes while the temperature of the mist gas Msg was set to +10°C and the temperature of the temperature control plate 230A (and the glass substrate P' placed thereon) was set to +27°C (room temperature). After that, the glass substrate P' was removed from the temperature control plate 230A and dried. In order to investigate the thickness of the thin film composed of non-rectangular ITO nanoparticles formed on the dried glass substrate P', the height difference (i.e., film thickness) between the surface of the glass substrate P' and the upper surface of the thin film, which was obtained by partially scraping off the thin film in the center portion of the glass substrate P', was measured using a stylus-type film thickness measuring instrument (e.g., Surface Profiler P16 manufactured by KLA-Tencor).

[0139] Next, the temperature of the temperature control plate 230A (and the glass substrate P' placed thereon) was changed to +25°C, +20°C, +15°C, +10°C, +5°C, 0°C, and -5°C, respectively, and mist film formation was performed on the surface of the glass substrate P' using mist gas Msg at +10°C, and the thickness of the thin film composed of ITO nanoparticles after drying was investigated. As a result, when the temperature of the mist gas Msg was set to +10°C, the relationship between the film thickness of the thin film composed of ITO nanoparticles formed and the temperature of the substrate was as follows: Fig.21 The curve graph shown is shown in characteristic A. Fig.21 It is a graph showing the substrate temperature dependency of the film thickness of the formed thin film, where the horizontal axis represents the substrate temperature (° C.) and the vertical axis represents the film thickness (nm) of the thin film (ITO nanoparticles).

[0140] When the temperature of the mist gas Msg is +10°C, as shown in characteristic A, when the substrate temperature is between +27°C (room temperature) and +10°C, the film thickness of the formed thin film is about 350nm and does not change. However, when the substrate temperature is +5°C, 0°C, or -5°C, which is lower than +10°C (lower than the temperature of the mist gas Msg), the film thickness of the formed thin film increases to about 1.43 times, or about 500nm. This means that when the mist film is formed, the mist contained in the mist gas Msg is more attracted to the glass substrate P' side, which has a temperature lower than that of the mist, that is, the adhesion rate of the mist on the substrate surface is increased. Therefore, by making the temperature of the sheet substrate P, which is the film-forming body, lower than the temperature of the mist gas Msg, the adhesion rate of the mist can be increased, and the liquid film layer formed on the surface of the film-forming body by the aggregation of countless mists (with a particle size of several μm) can be grown faster.

[0141] It should be noted that when the substrate temperature is -5°C, the mist (pure water) attached to the surface of the glass substrate P' will freeze immediately, so a layer (ice layer) composed of thin frost will be formed on the surface of the glass substrate P' after the mist spray time (5 minutes). In this case, as time passes after the mist spray, the ice layer will also change into a liquid film layer, and the liquid film will evaporate (or gasify) soon, so the thickness of the thin film obtained by the deposition of ITO nanoparticles can also be measured.

[0142] Next, the temperature of the carrier gas CGS was adjusted to raise the temperature of the mist gas Msg to +30°C, and the same experiment as the +10°C case was performed. The relationship between the substrate temperature and the film thickness of the ITO nanoparticle film was as follows: Fig.21As shown in characteristic B in the curve diagram. When the temperature of the glass substrate P' is room temperature, i.e., +27°C (or +25°C), if the temperature of the mist gas Msg is +30°C, the film thickness is about 200nm, and the film formation amount (film formation rate) is reduced compared to the film thickness (about 350nm) when the temperature of the mist gas Msg is +10°C. In addition, the temperature of the glass substrate P' was set to +20°C, +15°C, +10°C, +5°C, and 0°C, respectively, and the film thickness of the formed ITO nanoparticle thin film was measured. As a result, in the area where the substrate temperature was below +10°C, as shown in characteristic B, the change in film thickness relative to the substrate temperature showed the same tendency as in the case of the mist gas Msg at a temperature of +10°C. When the substrate temperature was below +5°C, a film thickness of about 500nm was obtained.

[0143] Furthermore, the temperature of the carrier gas CGS was adjusted, and the temperature of the mist gas Msg was raised to +50°C. The same experiment as in the cases of +10°C and +30°C was conducted. As a result, the relationship between the substrate temperature and the film thickness of the ITO nanoparticle film was as follows: Fig.21 As shown in the characteristic C in the curve diagram. When the temperature of the glass substrate P' is room temperature, i.e., +27°C (or +25°C), if the temperature of the mist gas Msg is +50°C, the film thickness is about 160nm, and the film formation amount (film formation rate) becomes less than half compared to the film thickness (about 350nm) when the temperature of the mist gas Msg is +10°C. Next, the temperature of the glass substrate P' was set to +20°C, +15°C, +10°C, +5°C, and 0°C, respectively, and the film thickness of the formed ITO nanoparticle thin film was measured. The film thickness when the substrate temperature was +10°C was about 300nm, which was about twice the film thickness of 160nm when the substrate temperature was room temperature (+27°C) or +25°C. In addition, the film thickness when the substrate temperature was +5°C was about 480nm, which was about three times the film thickness of 160nm when the substrate temperature was room temperature (+27°C) or +25°C.

[0144] The results of the preliminary experiment above show that by making the substrate temperature lower than the temperature of the mist gas Msg, the mist adhesion rate (liquid film growth rate) can be increased, and the film formation rate of the thin film composed of nanoparticles can be increased. In addition, it is also determined that when the solution as the source of the mist is pure water, if the substrate temperature is set to a range of +10°C to 0°C, and more preferably to a range of +5°C to 0°C, the mist adhesion rate can be maximized regardless of the temperature of the mist gas Msg.

[0145] In addition, Fig. 20In the experimental apparatus, the mist gas Msg is ejected from the front end opening 17T of the tube 17 into an open space at room temperature +27°C in a manner that follows the surface of the glass substrate P' in the horizontal direction. In this case, if the temperature of the mist gas Msg is higher than room temperature +27°C, the mist gas Msg ejected from the front end opening 17T of the tube 17 will have an upward (+Z direction) lifting force (buoyancy), and in the case of the glass substrate P' set to the same temperature as the ambient temperature, the amount of mist adhering (falling) to its surface will decrease. However, it is considered that if the temperature of the glass substrate P' is sufficiently lower than the temperature of the mist gas Msg, the temperature of a part of the mist gas Msg across the surface of the glass substrate P' will be lower than the surrounding temperature (room temperature), a part of the mist gas Msg will have a downward force (sedimentation force), and the mist adhesion will increase.

[0146] Here, in Fig.19 In the mist film forming apparatus MDE shown, when the temperature of the mist gas Msg ejected from the nozzle opening 30A of the mist ejection unit 30 toward the substrate P in the chamber unit 40 is set to Tms (°C), the temperature of the surface of the substrate P adjusted via the support table 5D' and the belt 5C temperature-controlled by the temperature control (cooling) unit 202 is set to Tpp (°C), and the temperature in the chamber unit 40 (the temperature of the internal space of the chamber unit 40, or the temperature of the inner wall surface defining the internal space) is set to Tct (°C), it is preferable to set the temperature Tpp to be equal to or higher than the freezing temperature of the solution that is the source of the mist, and to establish the relationship Tpp < Tms ≤ Tct. It should be noted that when the mist gas Msg is continuously sprayed into the chamber unit 40 for a long time, the temperature Tct inside the chamber unit 40 (inner wall surface) and the temperature Tms of the mist gas Msg will merge and become the same.

[0147] Therefore, in Fig.19In the mist film-forming device MDE shown, the temperature (Tpp) of the sheet substrate P adjusted by the temperature control (cooling) unit 202 and the temperature control unit 212 is set to 0°C to +5°C as an example, and the temperature (Tms) of the mist gas Msg ejected from the nozzle opening 30A of the mist ejection unit 30 is set to +5°C to +10°C, which is lower than the room temperature (ambient temperature) and close to the temperature of the sheet substrate P as an example. It should be noted that the temperature (Tms) of the mist gas Msg can be the same as the set temperature (Tpp) of the substrate P within the range where the mist will not freeze. By lowering the temperature (Tpp) of the sheet substrate P within the range where the mist will not freeze, the adhesion rate of the mist can be increased, and the liquid film formed on the surface of the substrate P can be grown quickly, which can result in an increase in the film formation rate of the thin film composed of nanoparticles contained in the mist. The increase in film formation rate will bring about the increase in the conveying speed of the sheet substrate P and the reduction in the flow rate (flow velocity) of the mist gas Msg from the mist spraying section 30 (reduction in the consumption of the solution Lq in the mist generating section 14), thereby enabling more effective utilization of the nanoparticles of the material substance to be formed.

[0148] [Fifth embodiment]

[0149] like Fig.19 The structure for cooling the sheet substrate P as shown above can also be applied to the above Figures 4 to 6 The mist film forming apparatus shown supports the sheet-like substrate P with a rotating drum DR and transports it in the longitudinal direction. Fig. 22 The structure of the mist film forming device MDE of the fifth embodiment using the rotary drum DR is shown, and the basic structure and basic components are the same as those described above. Figures 4 to 6 The components shown in the figure are the same, and the components with the same functions as these components are marked with the same symbols. In addition, the orthogonal coordinate system XYZ is also the same as Figure 4 In this embodiment, in order to cool the outer peripheral surface Dra of the drum DR supporting the sheet substrate P, a plurality of ( Fig. 22 There are 12 tubular cooling tubes (heat exchange tubes) HF, through which the temperature-controlled fluid (temperature-controlled gas or liquid) supplied from the temperature adjustment unit (cooler) 202 via the tube TPb passes. Fig. 22 In this case, multiple cooling pipes HF are extended parallel to the center line AXo at a certain radius from the rotation center line AXo of the drum DR, and are arranged at a certain angular interval (30 degrees in this modified example) in the circumferential direction of the outer peripheral surface DRa of the drum DR.

[0150] The temperature control fluid supplied through the pipe TPb is supplied in a manner of circulating in the 12 cooling pipes HF through the port portion JS provided at the portion of the shaft Sft of the drum DR and the flow path Fv provided in the drum DR. The temperature control fluid circulated in the cooling pipe HF is sent back to the temperature control unit 202 through the internal flow path Fv, the port portion JS, and the pipe TPc, and is controlled to a predetermined temperature again and sent to the pipe TPb. In addition, in the present embodiment, in order to pre-temperature-control (cool) the sheet substrate P before entering the drum DR, a configuration is provided in which the outer peripheral surface of the roller 5G' arranged on the upstream side of the drum DR is set to a temperature lower than the ambient temperature using the temperature control fluid from the temperature control unit 202.

[0151] As mentioned above Figure 4 As described in the device configuration, the sheet substrate P is in contact (close contact) with the outer peripheral surface DRa in the range from the entry position Ct1 to the exit position Ct2 in the circumferential direction of the drum DR, and the chamber portion 40 constituting the mist film forming portion is curved into a cylindrical shape in the circumferential direction in the angular range from the entry position Ct1 to the exit position Ct2, and is arranged in a manner to cover the sheet substrate P. In the chamber portion 40, Figure 6 The configuration is similarly provided with a mist ejection unit 30 and a mist recovery unit 32, 32', but in this embodiment, in order to prevent the line CL indicating the ejection direction of the mist gas Msg ejected from the nozzle opening 30A of the mist ejection unit 30 from intersecting with the position ( Fig. 22 The mist ejection portion 30 is inclined so as to be parallel to the normal line of the tangent plane of the position where the line CLj extending radially from the center line AXo passes.

[0152] In the case of the present embodiment, the mist ejection unit 30 is tilted so that the nozzle opening 30A side of the mist ejection unit 30 is located closer to the +Z direction than the tube 17 side, that is, so that the +X direction side of the line CL is higher than the -X direction side when viewed in the XZ plane. With such a configuration, even if a part of the mist in the mist gas Msg is gathered on the inner wall surface of the mist ejection unit 30 to form droplets and adhere, the possibility that the droplets will grow larger and fall from the nozzle opening 30A along the inner wall surface to the sheet substrate P becomes extremely small. In addition, as Fig. 22 As shown, the liquid droplets attached to the inner wall surface of the mist ejection unit 30 flow down in the -Z direction of gravity, so a droplet capture unit (collection unit) 30u may be provided at the lowermost portion of the inner wall surface.

[0153] In addition, if the inner wall surface of the air guide member 40A of the chamber portion 40 is appropriately made lyophilic, the mist will become a liquid film covering the inner wall surface of the air guide member 40A before it is locally gathered and becomes liquid droplets (particles), and the liquid film will soon flow downward (-Z direction) along the inner wall surface. Therefore, in this embodiment, a collecting portion 40u for the liquid film flowing down along the inner wall surface of the air guide member 40A is provided near the lowermost end of the chamber portion 40 in the gravity direction.

[0154] like Fig. 22 As shown, when the temperature of the outer peripheral surface Dra of the drum DR is lower than the room temperature (ambient temperature), the sheet substrate P starts to contact (closely adhere) with the low-temperature outer peripheral surface DRa at the entry position Ct1, and is cooled during the period of moving from the entry position Ct1 to the separation position Ct2. In the case of this embodiment, mist film formation (adhesion of mist to the substrate surface) is mainly performed between the position of the nozzle opening 30A of the mist ejection unit 30 (the position of the line CLj) and the position of the mist recovery unit 32 on the downstream side (near the separation position Ct2). Therefore, during the period of moving the sheet substrate P from the position of the line CLj to the position of the separation position Ct2, the sheet substrate P needs to be maintained at the target temperature.

[0155] For example, when the temperature of the sheet substrate P on the upstream side of the entry position Ct1 is room temperature (for example, +20°C to +25°C) and the temperature of the outer peripheral surface DRa of the drum DR is set to between 0°C and +5°C, when the thermal conductivity of the substrate P is low, the temperature of the surface of the substrate P may not be sufficiently reduced to the temperature of the outer peripheral surface DRa of the drum DR during the time when the sheet substrate P moves from the entry position Ct1 to the position of the line CLj (the position directly below the nozzle opening 30A). Therefore, in this embodiment, the temperature of the surface of the roller 5G' arranged on the upstream side of the drum DR is reduced to, for example, below +10°C (or to around 0°C) by the temperature regulating fluid (coolant) from the temperature adjustment unit 202. The sheet substrate P is pre-cooled during the time of contact (close contact) with the roller 5G'. Assuming that the diameter of the outer peripheral surface of the roller 5G' is When the wrap angle (angle range of contact) of the sheet substrate P on the roller 5G' is Δθr (degrees) and the conveying speed of the sheet substrate P is Vp (mm / second), the time Tph (second) is given by to decide.

[0156] The sheet substrate P pre-cooled by the roller 5G' is cooled to a temperature close to the temperature of the outer peripheral surface DRa of the drum DR (0°C to +5°C) when it reaches the entry position Ct1 of the outer peripheral surface DRa of the drum DR. Thereafter, it reaches a state of being in harmony with the temperature of the target outer peripheral surface DRa while moving from the entry position Ct1 to the position of the line CLj (the position directly below the nozzle opening 30A), thereby performing mist film formation (mist spraying).

[0157] In the above embodiment, the ejection direction (line CL) of the mist gas Msg from the nozzle opening 30A of the mist ejection section 30 is tilted toward the downstream side of the conveying direction of the sheet substrate P, so that the flow rate of the mist gas Msg flowing from the nozzle opening 30A to the space of the mist recovery section 32 on the downstream side in the space within the chamber section 40 (the space between the air guide part 40A and the substrate P) can be greater than the flow rate of the mist gas Msg flowing from the nozzle opening 30A to the space of the mist recovery section 32' on the upstream side. The structure in which the ejection direction of the mist gas Msg from the nozzle opening 30A of the mist ejection section 30 is tilted from the direction perpendicular to the sheet substrate P is also applicable to the above-mentioned Figure 1 to Figure 3B , Figure 4 , Figure 6 , Fig.14 , Fig.19 The mist film-forming devices are shown respectively.

[0158] It should be noted that in Fig.19 , Fig. 22 In the mist film forming device MDE shown in the figure, when the temperature of the mist gas Msg ejected from the nozzle opening 30A of the mist ejection unit 30 is set to a first temperature in the range of 0°C to 15°C, the mist gas Msg is ejected from the nozzle opening 30A of the mist ejection unit 30 to a first temperature in the range of 0°C to 15°C. Fig.19 The temperature control (cooling) unit 202, Fig. 22 The temperature of the sheet substrate P that is cooled by the substrate temperature adjustment mechanism of the temperature adjustment unit (cooler) 202 is set to a second temperature in the range of 0°C to 15°C that is lower than the first temperature. However, when the solvent of the solution Lq that is the source of the mist is pure water, if the temperature of the sheet substrate P is set to 0°C, the attached mist may freeze into frost, so the temperature of the sheet substrate P is actually set to a temperature higher than 0°C (for example, above +4°C).

[0159] [Variation 6]

[0160] Fig.23 It shows the above Fig.19 A perspective view showing a schematic structure of a mist film forming device MDE which is a modified example of the mist film forming device shown in (Fourth Embodiment). Fig.23 In the orthogonal coordinate system XYZ, the Z axis is the gravity direction, and the XY plane orthogonal to the Z axis is set to be parallel to the surface of the sheet substrate P on which the mist film is formed. Fig.19 In the same manner, in this variation, the sheet substrate P can also be tilted in the long side direction (X direction) relative to the XY plane. It should be noted that Fig.23 In the embodiment, a plurality of substrates are provided below the sheet substrate P (in the -Z direction). Fig.19 The sheet substrate P is also cooled down in temperature by using the same components as the rollers 5A, 5B, the belt 5C, and the support table 5D' described above.

[0161] Fig.23 In the embodiment, a chamber 40 is provided on the upstream side of the conveying direction (+X direction) of the sheet substrate P conveyed in a planar shape so as to cover the surface of the sheet substrate P, and the chamber 40 is provided with: a mist ejection section 30 to which the mist gas Msg is supplied via two tubes 17a, 17b; and mist recovery sections 32, 32' which recover the remaining amount of the mist gas Msg ejected into the chamber 40 and discharge it to the outside via tubes 33, 33'. In addition, a slit-shaped nozzle opening 30A ( Fig.23 Between the surface of the sheet substrate P and the sheet substrate P, for example, as disclosed in the pamphlet of International Publication No. 2016 / 133131, two electrode rods Ema and Emb for irradiating the mist gas Msg sprayed from the mist ejection portion 30 to the sheet substrate P with a plasma in a non-thermal equilibrium state are fixed to the chamber portion 40 in a manner extending in the Y direction and parallel to each other at a certain interval in the X direction.

[0162] In this modification, based on Fig.21 According to the findings in the preliminary experiment, the temperature of the sheet substrate P passing through the bottom of the chamber part 40 is lowered to below 0°C, for example, to -5°C, and the temperature of the mist gas Msg sprayed from the mist spraying part 30 is set to a temperature at which the mist (pure water) does not freeze, for example, to a temperature of about +5°C to +10°C. Therefore, the mist attached to the surface of the sheet substrate P passing through the bottom of the chamber part 40 freezes and forms a film in the form of turbid frost. In the conveying direction (+X direction) of the sheet substrate P, an observation unit OVS for observing the surface state of the sheet substrate P is provided on the downstream side of the chamber part 40.

[0163] The observation section OVS is provided with: two imaging units CV1 and CV2 arranged at a certain height upward (in the +Z direction) from the surface of the sheet substrate P and arranged at a predetermined interval in the Y direction; and an illumination unit ILU for illuminating the imaging area on the sheet substrate P. The imaging range of the imaging unit CV1 is set so as to cover the half area Aim in the -Y direction of the width of the sheet substrate P in the Y direction, and the imaging range of the imaging unit CV2 is set so as to cover the half area in the +Y direction of the width of the sheet substrate P. The image information successively captured by the imaging units CV1 and CV2 is sent to an image analysis unit (not shown), which analyzes the frost state (concentration distribution of turbidity, etc.) of the turbidity formed on the surface of the sheet substrate P, and particularly identifies the area where the turbidity is thin.

[0164] In the conveying direction of the sheet substrate P, an auxiliary mist spray section SMD is provided on the downstream side of the observation section OVS. The auxiliary mist spray section SMD has, above the sheet substrate P: a guide member 300 whose length in the Y direction is longer than the width of the sheet substrate P; a slider 302 that is guided by a straight guide surface 300a formed on the side of the guide member 300 in the X direction and can move in the Y direction; and an auxiliary mist spray section 304 and auxiliary mist recovery sections 305A, 305B that are fixed to the slider 302 and spray mist gas Msg toward the surface of the sheet substrate P. In addition, a slit-shaped opening section 300b extending in the Y direction is formed in the center of the guide member 300 in the X direction, and the opening section 300b is set to a size that allows the pipe mp1 that supplies the mist gas Msg to the auxiliary mist spray section 304 during the movement of the slider 302 in the Y direction, and the pipe mp2 that discharges the mist gas Msg' recovered by the auxiliary mist recovery sections 305A, 305B to pass through.

[0165] A slender nozzle opening for spraying mist gas Msg is formed on the bottom portion of the auxiliary mist spraying section 304 that is opposite to the sheet substrate P, and its length in the X direction is shorter than the dimension of the area Aim in the X direction, and the width in the Y direction is formed to be less than several mm. A slit-shaped opening for sucking mist gas Msg' is formed in parallel with the slit-shaped nozzle opening formed on the bottom portion of the auxiliary mist spraying section 304 on the bottom portion of each of the auxiliary mist recovery sections 305A and 305B that are arranged side by side in the Y direction across the auxiliary mist spraying section 304. The slider section 302 is driven by a driving source such as a linear motor to move the nozzle opening on the bottom portion of the auxiliary mist spraying section 304 to any Y-direction position within the width dimension range of the sheet substrate P in the Y direction.

[0166] The auxiliary mist spraying section 304 locally performs additional mist film formation on a thin portion of the film formed in a frosty, turbid film state on the sheet substrate P observed by the camera units CV1 and CV2 of the observation section OVS. For this purpose, the following mechanism is provided: after the nozzle opening of the auxiliary mist spraying section 304 is positioned in a manner opposite to the area on the sheet substrate P where additional mist film formation is performed, the mist gas Msg is sprayed from the nozzle opening toward the sheet substrate P in a short time. This mechanism is, for example, Fig.24A and Fig. 24B As shown. Fig.24A , Fig. 24B The schematic structure of the valve mechanism 310 provided in the flow path for supplying the mist gas Msg to the auxiliary mist ejection unit 304 is shown. The valve mechanism 310 is connected to the supply valve 310. Figure 1 The mist generating unit 14 shown in the figure has a pipe mp0 for the mist gas Msg, a pipe mp1 for sending the mist gas Msg toward the auxiliary mist ejection unit 304, and a pipe mp2 for sending the mist gas Msg toward the auxiliary mist ejection unit 304. Figure 1The mist gas collecting section 34 shown is a pipe mp3 for sending out the mist gas Msg.

[0167] The valve mechanism 310 includes a rotary valve portion 310S having a T-shaped passage formed therein consisting of three ports a, b, and c so as to switch the flow path of the mist gas Msg by rotating a plunger (driving source) 312 90 degrees clockwise or counterclockwise. Fig.24A The rotary valve portion 310S is shown in a state where the mist gas Msg supplied from the pipe mp0 flows into the pipe mp1 via the passage from the port portion b to the port portion c (supply state of the mist gas Msg). Fig. 24B The rotary valve section 310S is shown Fig.24A The state after rotating 90 degrees clockwise from the state of the auxiliary mist ejection part 304 is the state in which the rotary valve part 310S is switched so that the mist gas Msg supplied from the tube mp0 flows to the tube mp3 via the passage from the port part a to the port part b (the non-supply state of the mist gas Msg). The flow path switching based on the rotary valve part 310S is performed at a high speed by the plunger (driving source) 312, so the spraying of the mist gas Msg from the auxiliary mist ejection part 304 to the sheet substrate P can be limited to a short time at any time point.

[0168] In the above modified example, based on the film formation state on the sheet substrate P observed by the camera units CV1 and CV2 of the observation unit OVS (the concentration distribution of the turbid white mist frozen into a frosty state), the thin film thickness portion on the sheet substrate P is determined, and the slide unit 302 is moved in such a manner that the auxiliary mist spray unit SMD (auxiliary mist ejection unit 304) is opposed to the portion, and the rotary valve unit 310S of the valve mechanism 310 is moved from Fig. 24B The status is temporarily switched to Fig.24A In this state, additional mist film formation is performed only on the thin film thickness portion. As a result, the thickness unevenness of the surface of the sheet substrate P passing under the auxiliary mist spray section SMD is reduced, forming a thin film composed of nanoparticles with improved uniformity. After passing through the auxiliary mist spray section SMD, the sheet substrate P returns to a normal temperature of about 25°C, for example, and the liquid film frozen into a frost-like state on the sheet substrate P changes into a liquid state and is dried. It should be noted that during Fig.23 The downstream side of the mist film forming device MDE shown in the figure can be as described above. Figure 7 , Fig.13 , Fig.14 As shown in FIG. 1 , a structure for applying an alternating electric field to the liquid film on the surface of the sheet-like substrate P is provided.

[0169] [Variation 7]

[0170] Fig.25 It is shown Figure 1The partial cross-sectional view of the modified example of the mist generating unit 14 shown in the figure is set as the gravity direction (up and down direction) of the orthogonal coordinate system XYZ, and the XY plane is set as the horizontal plane for the convenience of explanation. Fig.25 The mist generating section 14 is shown cut along a plane parallel to the XZ plane. Fig.25 Among the components in Figure 1 Components of the mist generating unit 14 having the same functions are denoted by the same reference numerals. Fig.26 is to use a surface parallel to the XY plane to Fig.25 The height Cj of the mist generating portion 14 in the Z direction is cut off and the bottom side is observed from above. Fig.25 , Fig.26 The mist generating unit 14 shown is used as a generating device of the mist gas Msg used in the above-mentioned embodiments, modifications or preliminary experiments.

[0171] Fig.25 In the figure, the mist generating section 14 has: an outer container 14D having a rectangular cross-sectional shape in the XY plane, a plurality of ultrasonic vibrators 14C1, 14C2, etc. arranged at the bottom, and filled with liquid (water) Wq for propagating ultrasonic vibrations; an inner container (cup) 14A having a circular cross-sectional shape in the XY plane, arranged so as to be submerged in the liquid Wq, and storing a solution Lq as the source of the mist in a specified capacity; a cover member 14E supporting the inner container 14A at a specified position in the space within the outer container 14D and sealing the upper opening of the outer container 14D; and a cover member 14B sealing the upper opening of the inner container 14A. The cover member 14B is provided with: a cover member for passing through the cover member 14B; Figure 1 The flow rate regulating valve 15 shown includes a tube 16 as an inlet port for introducing the carrier gas CGS, a tube 17 as an outlet port for ejecting the mist gas Msg, and a tube 18 for replenishing the solution Lq.

[0172] The height (position in the Z direction) of the liquid level of the solution Lq in the inner container 14A is set to about half of the inner container 14A to form an appropriate space above the liquid level, and is set to be approximately the same as the height of the liquid level of the liquid Wq filling the outer container 14D. The inner container 14A is made of translucent polypropylene resin, and the outer container 14D is made of transparent acrylic resin. The front end portion (inflow port portion) 16E of the tube 16 for introducing the carrier gas CGS is bent 90 degrees in a direction parallel to the liquid surface so that the carrier gas CGS will not be directly sprayed onto the liquid surface of the solution Lq. As a result, the carrier gas CGS sprayed from the front end portion 16E will not be directly sprayed onto the liquid surface of the solution Lq, but will reflux along the cylindrical inner wall surface of the inner container 14A in the space above the liquid surface of the inner container 14A, thereby avoiding suppressing the generation of mist gushing out from the liquid surface of the solution Lq.

[0173] Fig.25 The ultrasonic vibrators 14C1, 14C2 schematically shown in FIG. Fig.26 As shown in FIG. 1 , the ultrasonic vibrator 14C1, 14C2, 14C3, and 14C4 are respectively fixed to the four corners of the bottom of the external container 14D. The ultrasonic vibrators 14C1, 14C2, 14C3, and 14C4 are each formed by housing a thin vibration plate Vpu and a drive unit Sdu with a built-in drive circuit in a waterproof metal shell. Fig.26 As shown in FIG. 1 , each vibration plate Vpu is arranged so as to be located near the periphery of the circular bottom portion of the inner container 14A when viewed in the XY plane. Fig.26 The driving unit Sdu shown in the figure supplies a driving signal and a control circuit 400 for power supply, and selectively drives and controls (on / off control). When all four ultrasonic vibrators 14C1 to 14C4 are driven, the amount of mist generated from the liquid surface of the solution Lq can be maximized, and the amount of mist generated can be adjusted (reduced) by reducing the number of ultrasonic vibrators 14C1 to 14C4 driven. It should be noted that the control circuit 400 also controls the flow regulating valve 15 for adjusting the flow rate of the carrier gas CGS.

[0174] When the immersion type ultrasonic vibrators 14C1 to 14C4 are driven for a long time (tens of minutes), the temperature will rise to about tens of degrees Celsius (°C), and the temperature of the surrounding liquid Wq will also rise to about 40°C. The temperature of the liquid Wq will also be transferred to the solution Lq via the internal container 14A, and the temperature of the solution Lq will also rise to about 40°C. Along with this, the temperature in the space above the liquid surface in the internal container 14A also rises, and the temperature of the carrier gas CGS and the mist gas Msg also rises to above normal temperature (for example, 25°C). Therefore, due to the increase in the temperature of the mist gas Msg sprayed from the mist ejection unit 30 shown in each embodiment and modified example to the sheet substrate P, the adhesion rate of the mist on the surface of the sheet substrate P decreases. Therefore, in this modified example, a cooler (temperature regulator) 402 is provided for cooling the temperature of the liquid Wq in the external container 14D. The cooler 402 supplies the liquid Wq, which is temperature-controlled based on the temperature setting information from the control circuit 400 and the measured temperature from the temperature sensor 14S arranged in the external container 14D, into the external container 14D via the supply pipe 14G at a specified flow rate, and recovers the liquid Wq in the external container 14D from the recovery pipe 14H and circulates it.

[0175] The set temperature of the liquid Wq is set to about 10°C below room temperature as an example, and the cooler 402 performs feedback control on the temperature of the circulating liquid Wq so that the measured temperature obtained by the temperature sensor 14S becomes the set temperature (10°C). Thus, the liquid Wq is supplied from the inner container 14A to the mist ejection unit 30 (or Fig.23 The mist gas Msg of the auxiliary mist spray section SMD in the embodiment is set to a first temperature higher than 0°C and lower than 30°C, for example, a temperature of about 10°C. It should be noted that, when the liquid Wq is an antifreeze liquid (a coolant such as ethylene glycol), the cooler 402 has the ability to cool the temperature of the liquid Wq to below 0°C, for example, to close to -20°C. In addition, when the solvent of the solution Lq stored in the internal container 14A is pure water, the temperature of the liquid Wq will not be set to below 0°C in order to avoid freezing. However, when a surfactant is added to pure water as the solvent of the solution Lq to inhibit the aggregation of nanoparticles, the freezing temperature of the solution Lq can also be set to below 0°C. In addition, the temperature of the solution Lq can be set to below 0°C. Fig.25 The carrier gas CGS introduced into the space in the inner container 14A through the tube 16 as the inflow port portion shown is set to the same temperature as the solution Lq.

[0176] As shown above, in the mist generating unit 14 using the immersion type ultrasonic vibrators 14C1 to 14C4, in the structure of transmitting the ultrasonic vibration to the solution Lq in the internal container 14A via the liquid Wq, the heat release of the ultrasonic vibrators 14C1 to 14C4 causes the temperature of the liquid Wq to rise and the temperature of the solution Lq to rise. As a result, the temperature of the mist generated from the liquid surface of the solution Lq also rises to above normal temperature. As a result, the temperature of the mist gas Msg sprayed onto the sheet substrate P during mist film formation is higher than the temperature of the surrounding environment (normal temperature), and the adhesion rate of the mist on the sheet substrate P is reduced. However, as shown in this modified example, the reduction in the adhesion rate can be suppressed by suppressing the temperature rise of the liquid Wq and lowering the temperature using a cooler (temperature regulator, temperature regulating unit) 402. In addition, according to this modified example, by Figure 19 to Figure 22 By combining such a structure for lowering the temperature of the sheet substrate P, the relationship of ambient temperature (normal temperature) > temperature of the mist gas Msg > temperature of the sheet substrate P can be set, and the adhesion rate of the sprayed mist on the sheet substrate P can be increased.

[0177] According to this variation, in order to form a thin film composed of particles of a material substance on the surface of a processed object as a sheet substrate P by mist film formation, a mist generating device for generating mist from a solution Lq in which particles are dispersed is constructed as follows: an internal container 14A for storing the solution Lq in a manner that forms a predetermined space above the liquid surface; an external container 14D provided with ultrasonic vibrators 14C1 to 14C4 for atomization at the bottom, filled with a liquid Wq for propagating ultrasonic vibrations and containing the internal container 14A in a manner that is sunken in the liquid Wq; and The pipe 16 as an inflow port for allowing the carrier gas CGS to flow into the space of the inner container 14A at a predetermined flow rate; the front end portion 16E; the pipe 17 as an outflow port for placing the mist generated from the liquid surface of the solution Lq in the inner container 14A by driving the ultrasonic vibrators 14C1 to 14C4 on the carrier gas CGS and causing it to flow out to the outside of the inner container 14A as the mist gas Msg; and the cooler (thermostat) 402 as a temperature control device for adjusting the temperature of the solution Lq stored in the inner container 14A to be lower than the ambient temperature. In this modified example, the cooler (thermostat) 402 as the temperature control device is configured as follows: by cooling the temperature of the liquid Wq filled in the outer container 14D to be lower than the ambient temperature, the temperature of the solution Lq is adjusted through the inner container 14A.

[0178] [Other Modifications]

[0179] In each of the above embodiments and modifications, when the nanoparticles of the material substance contained in the mist sprayed onto the sheet substrate P as the mist gas Msg have the characteristic of being polarized, by applying an alternating electric field to the liquid film on the sheet substrate P formed after the mist film is formed, the film thickness distribution of the nanoparticles on the sheet substrate P can be made uniform. In the case where the nanoparticles of the material substance used for film formation do not have the characteristic of being polarized but have the characteristic of being magnetic, by burying a magnetizer (permanent magnet, electromagnet, etc.) in the substrate supporting surface of the support table 5D, 5D' and the rotating drum DR supporting the sheet substrate P, the adhesion rate of the mist in the mist gas Msg on the sheet substrate P can also be increased. In addition, by applying an alternating magnetic field to the liquid film on the sheet substrate P formed after the mist film is formed, the film thickness distribution of the nanoparticles on the sheet substrate P can also be made uniform.

[0180] In addition, in each of the above embodiments and modifications, the solution Lq is atomized using the ultrasonic vibrator 14C (14C1 to 14C4) as the mist generating unit (mist generating device) 14, but a structure in which a predetermined amount of granular dry ice is put into the internal container 14A storing the solution Lq at predetermined intervals can also be adopted to generate mist from the liquid surface of the solution Lq. In this case, the space above the internal container 14A is filled with cold carbon dioxide (CO2) generated by the gasification of dry ice. The carbon dioxide forms a mist gas Msg through the tube 17 together with the carrier gas CGS supplied from the tube 16 (front end 16E) and is supplied to the mist ejection unit 30. The temperature of the mist gas Msg ejected from the nozzle opening 30A of the mist ejection unit 30 is lower than the ambient temperature (for example, +20°C to +30°C), so the adhesion rate of the mist on the sheet substrate P can be increased.

[0181] In the above embodiments and modifications, the formation of a deposited film of nanoparticles by mist film formation on almost the entire surface of a sheet substrate P is exemplified. However, as disclosed in International Publication No. 2013 / 176222, after a photosensitive silane coupling agent is applied to the surface of the sheet substrate P, a highly liquid-repellent portion and a highly lyophilic portion are formed in the layer of the photosensitive silane coupling agent by a UV-based pattern exposure device, and the mist is actively attached to the highly lyophilic portion, thereby patterning only a partial area on the sheet substrate P to form a deposited film composed of nanoparticles.

[0182] Alternatively, as in screen printing, a mask made of a thin magnetic metal foil (preferably a stainless steel foil with a thickness of 100 μm or less) partially formed with openings is brought into close contact with the surface of a sheet substrate P, and mist filming is performed from above the mask, so that a laminated film composed of nanoparticles is formed only on the portion of the sheet substrate P corresponding to the opening of the mask. In this case, the following configuration can be used: a permanent magnet or an electromagnet is embedded in a support table 5D, 5D' or a rotating drum DR supporting the back of the sheet substrate P, and the mask is forced to be in close contact with the surface of the sheet substrate P by magnetic force. In this case, after the liquid film corresponding to the opening of the mask formed on the sheet substrate P by mist filming is dried, the mask is peeled off from the surface of the sheet substrate P. As in the above-mentioned embodiments, the sheet substrate P (or mask) can be cooled during mist filming, or an AC electric field can be applied to the liquid film before the liquid film dries to cause micro-vibrations of the nanoparticles.

[0183] Explanation of symbols

[0184] 5A, 5B...Roller 5C...Belt

[0185] 5D, 5D' ... support table 10 ... solution tank

[0186] 14…Mist generating unit

[0187] 14C, 14C1~14C4…Ultrasonic vibrator

[0188] 16, 17, 18... pipe 30... mist ejection part

[0189] 30A... Nozzle opening 31... Mist supply unit

[0190] 32, 32' ... mist recovery unit 40 ... chamber unit (air guide mechanism)

[0191] 60…Mist charging device

[0192] 70…Electrostatic field generating device (electrostatic field generating unit)

[0193] 90, 92 ... AC electric field generating unit 100 ... control unit (CPU)

[0194] 202…Temperature control (cooling) unit (temperature control section)

[0195] 212 ... Temperature control unit 402 ... Cooler (thermostat)

[0196] AXo…Center Line

[0197] CGS…Carrier gas

[0198] DR…Rotating drum Ea, Eb…Electrode

[0199] Ec, Ed...Electrode plates Ef1~Ef4, Em...Electrode plates

[0200] Ef', Em'...Electrode wire HF...Cooling tube (heat exchange tube)

[0201] Lq…Solution Msg…Mist gas supplied

[0202] Msg'…exhausted mist gas np…nanoparticles (microparticles)

[0203] OVS...Observation part P...Sheet substrate

[0204] SMD…Auxiliary mist spray part Wq…Liquid

Claims

1. A film forming device, which supplies mist containing fine particles to a substrate to form a film containing the fine particles on the surface of the substrate, wherein: The film forming device comprises: a conductor disposed apart from a surface of the substrate; a mist supplying unit that supplies the mist to the surface of the substrate; a conveying unit for conveying the substrate; as well as An AC electric field generating unit applies an AC voltage to at least one of the conductor and the transport unit.

2. The film forming device according to claim 1, wherein: The film forming device includes an air guide member that covers at least a portion of the surface of the substrate. The conductor is arranged on the wind guiding component.

3. The film forming device according to claim 1, wherein: The AC electric field generating unit generates a potential difference between the conductor and the transporting unit.

4. The film forming apparatus according to claim 1, wherein: The mist supply unit includes a charge imparting unit that positively or negatively charges the mist. The mist supplying section supplies the mist charged by the charge imparting section.

5. The film forming apparatus according to claim 1, wherein: The AC electric field generating unit applies an AC voltage that changes over time with a predetermined amplitude around an average potential with an absolute value greater than 0 to at least one of the conductor and the transport unit.

6. The film forming apparatus according to claim 1, wherein: The AC electric field generating unit applies an AC voltage to the conductor, the voltage of which changes with time at a predetermined amplitude around an average potential less than 0.

7. The film forming apparatus according to claim 1, wherein: The transport unit includes a drum having a conductive outer peripheral surface that supports the substrate in an arc shape.

8. A manufacturing device for a conductive film, comprising: The film forming device according to any one of claims 1 to 7; as well as A drying unit dries the mist on the substrate on which the film has been formed by the film forming device.

9. A film forming method, which is a method for supplying mist containing fine particles to a substrate to form a film containing the fine particles on the surface of the substrate, comprising the following steps: a mist supplying step of supplying the mist to a surface of the substrate transported by a transporting unit; The AC electric field generating step applies an AC voltage to at least one of a conductor and the transporting unit, wherein the conductor is provided to be separated from the surface of the substrate.

10. The film forming method according to claim 9, wherein: In the mist supplying step, the mist is supplied between an air guide member and the surface of the substrate, the air guide member covering at least a portion of the surface of the substrate, The conductor is arranged on the wind guiding component.

11. The film forming method according to claim 9, wherein: In the AC electric field generating step, a potential difference is generated between the conductor and the transporting unit.

12. The film forming method according to claim 9, wherein: In the mist supplying step, the mist is positively or negatively charged and the charged mist is supplied.

13. The film forming method according to claim 9, wherein: In the AC electric field generating step, an AC voltage that changes over time with a predetermined amplitude around an average potential having an absolute value greater than 0 is applied to at least one of the conductor and the transport unit.

14. The film forming method according to claim 9, wherein: In the AC electric field generating step, an AC voltage is applied to the conductor, the voltage of which changes with time at a predetermined amplitude around an average potential less than 0.

15. The film forming method according to claim 9, wherein: The transport unit includes a drum having a conductive outer peripheral surface that supports the substrate in an arc shape.

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