JP2004267990A - Apparatus for making composite structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recover and reuse a material fine particle in an aerosol without being associated with formation of a structure, and a powder carrier gas used for the formation of the structure in an aerosol deposition method. <P>SOLUTION: An apparatus for making the structure is to make the structure by causing the aerosol in which the material fine particle supplied from a powder supply vessel is dispersed into gas to come into collision with a substrate. The apparatus for making the structure is constituted of a powder recovery mechanism having a suction cylinder which sucks the aerosol provided in the vicinity of a collision area of the aerosol and the substrate, and a fine particle recovery vessel which is connected to the suction cylinder and captures to store the material fine particle in the aerosol; non-return means allowing only one direction flow from the fine particle recovery vessel to the powder supply vessel; and a powder transport mechanism provided closer to the fine particle powder supply vessel side than the non-return means, and having a drive source which produces a flow from the fine particle recovery vessel to the powder supply vessel. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a composite structure manufacturing apparatus for manufacturing a composite structure composed of a substrate and a material structure by spraying an aerosol containing material fine particle powder onto a substrate to form a material structure on the substrate.
[0002]
[Prior art]
As a method of forming a film on a substrate, in the case of a thick film having a thickness of several μm or more, a thermal spraying method is generally known, but other gas deposition methods have been proposed (for example, see Non-Patent Document 1).
In this method, ultrafine particles of metal or ceramics are aerosolized by gas agitation, accelerated through a fine nozzle, a compacted layer of ultrafine particles is formed on the surface of the substrate, and this is heated and fired to form a coating. Form.
[0003]
As a prior art that improves the gas deposition method of Non-Patent Document 1, there is a method of forming a film or structure of a brittle material called a fine particle beam deposition method or an aerosol deposition method. In this method, an aerosol containing fine particles of a brittle material is jetted from a nozzle toward a substrate at a high speed, and the fine particles collide with the substrate, and the polycrystalline structure of the brittle material is applied to the substrate using the mechanical impact force. This is a method of directly forming (see, for example, Patent Documents 1 and 2).
[0004]
The technique disclosed in Patent Document 1 is to prevent the ultra-fine particles from aggregating into large particles when transferring the aerosol containing the above-described ultra-fine particles or when heating and evaporating ceramics or the like. A classifier is arranged in the middle path.
[0005]
In Patent Literature 2, ultrafine particles such as ceramics having a particle size in a range of 10 nm to 5 μm are dispersed in a gas to form an aerosol, and then jetted toward a substrate as a high-speed flow of ultrafine particles from a nozzle to deposit the deposit. Let it form. At this time, a structure has been devised to make the structure produced by irradiating the ultrafine particles and the substrate with high-energy atoms such as ions, atoms, molecular beams, and low-temperature plasma.
[0006]
[Non-patent document 1]
Seiichiro Kashu: Metals January 1989 [Patent Document 1]
JP-A-11-21677 [Patent Document 2]
Disclosed in Japanese Patent Application Laid-Open No. 2000-212766
[Problems to be solved by the invention]
A complex structure forming apparatus using a gas deposition method or an aerosol deposition method has a structure in which a nozzle and a substrate are arranged in a container such as a chamber. In a reduced pressure environment, fine particles are ejected from the nozzle.
[0008]
A gas deposition method in which a compact layer is formed using ultrafine metal particles, or fine powder of a brittle material is dispersed in a gas to form an aerosol, which is sprayed from a nozzle toward the substrate and In the aerosol deposition method for directly forming a structure of a brittle material, the utilization efficiency of the fine particles used is poor. In particular, in the aerosol deposition method, the structure of the injected fine particles is substantially 1%. In most cases, the particles that account for the majority of the particles that did not contribute to the formation of the structure are scattered in the device on the gas flow after the collision, adhere to the inner wall of the chamber, or are sucked into the vacuum pump, etc. . For this reason, the frequency of cleaning the inside of the chamber is high, and there is a concern that the function may be degraded due to mixing of powder into the vacuum pump.
[0009]
Further, since a mechanical device such as an XY stage is installed in the chamber, fine particles adhere to the driving portion and the sensor portion, which may cause a functional failure. Therefore, measures such as providing a powder recovery filter in front of the vacuum pump have been devised, but in this case, the suction performance of the vacuum pump is absolutely reduced by the filter itself, or the powder gradually accumulates in the filter. There is a problem that the intake performance gradually deteriorates. Even if a large amount of fine particles as a raw material are prepared, all but a part of the structure become waste, so that a great waste of resources and cost is generated.
[0010]
In particular, when producing a composite structure such as a large area or a large amount of a film-forming body by the present method, a long production time is required due to the problem of film-forming efficiency, etc., and the amount of gas used and scattered. The consumption of material fine powder is intense, it is severe that affects the cost and leads to the practical application of this process, and the equipment and equipment for collecting the recovered material powder and separated gas and specifically reusing them The actual operation method is important because the recovery operation needs to be performed in a reduced pressure environment. Accordingly, the present invention provides a method for forming a composite structure, such as a gas deposition method or an aerosol deposition method, in which a material fine particle powder or the like is ejected from a nozzle toward a substrate to form a material structure directly on the substrate. The present invention relates to a composite structure manufacturing apparatus for specifically reusing a material powder and a separated gas collected by a method.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention includes an aerosol generator that generates an aerosol in which material particles supplied from a powder supply container are dispersed in a gas, and a nozzle that ejects the generated aerosol at a high speed. In a structure manufacturing apparatus for manufacturing a structure by causing an aerosol to collide with a substrate, an aerosol that is installed near a collision portion between the aerosol and the substrate and does not contribute to the formation of the structure after colliding with the substrate is provided. A powder collection mechanism having a suction cylinder for inhaling, a particle collection container connected to the suction cylinder and capturing and storing material fine particles in the aerosol that does not contribute to the formation of the structure; and Backflow preventing means for permitting only one-way flow to the powder supply container, and the fine particle powder container provided closer to the fine particle powder supply container than the backflow preventing means, Characterized in that it consists of a powder transfer mechanism and a drive source that occurs flow to the powder supply container from. The joining of the particulate collection container and the powder supply container of the aerosol generator shown here does not necessarily have to be joined by piping, and the partition may have a structure through a backflow prevention means.
[0012]
As a result, the powder recovery mechanism and the powder transport mechanism can be made smaller and simpler. Further, as the backflow prevention means referred to here, a backflow prevention valve or a solenoid valve having a backflow prevention mechanism is effective. A drive source for transporting the collected and reused powder to the powder supply container is provided in the powder supply container of the aerosol generator and has a mechanism for efficiently transporting the powder. As a driving source for transporting the powder to the powder supply container, a vacuum pump or a powder transport mechanism that sucks the powder by electrostatic force can be considered.
[0013]
In the vacuum pump for powder transfer shown here, powder is involved in the transfer of the powder, causing problems such as deterioration of pump oil and wear of mechanical parts. By installing a filter, a longer life and more stable quality are ensured.
[0014]
In a composite structure manufacturing apparatus characterized by being composed of such element mechanism parts, deterioration of the stage function / pump function and increase in the degree of vacuum in the structure forming chamber are suppressed, and the manufactured structure is manufactured. Quality instability can be eliminated. Further, since the frequency of cleaning the inner wall of the forming chamber can be reduced and the scattered raw material powder can be reused, it is possible to significantly reduce the cost. It contributes to cost reduction of the composite structure manufactured by this method. In particular, this effect is remarkable when an expensive raw material powder material containing diamond or a noble metal is used.
[0015]
In one embodiment of the present invention, the powder collection container is equipped with a sensor for sensing the weight or volume of the collected powder, and when this sensor detects that an arbitrary set amount of powder has been collected. The driving source installed in the powder transport mechanism operates to transport the powder.
Further, the powder supply container is equipped with a sensor for sensing the weight or volume of the powder for supply, and when this sensor becomes equal to or less than an arbitrary set amount, a drive source installed in the powder transport mechanism operates. It is characterized by conveying powder.
[0016]
In this composite structure manufacturing apparatus, powder can be automatically supplied. This leads to improved productivity and cost reduction.
This function is satisfied when the sensors installed in various containers are installed in at least one of the powder recovery container and the powder supply container. In addition, as a driving source of the powder transport, a vacuum pump or a powder transport mechanism that suctions by an electrostatic force can be considered. In the vacuum pump for powder transfer shown here, powder is involved in the transfer of the powder, causing problems such as deterioration of pump oil and wear of mechanical parts. By installing a filter, a longer life and more stable quality are ensured.
[0017]
In another embodiment of the present invention, a gas recovery container connected to a chamber for producing the fine particle recovery container and a structure through a backflow prevention unit to recover discharged gas, and the gas recovery container A gas compression mechanism for increasing the pressure of the gas collected in the above, and switching means that can be connected to the aerosol generator as a gas supply mechanism for transporting a starting or replenishing gas. It is characterized by.
The gas recovery container is provided with a pressure gauge for measuring the pressure in the container, and the gas is transported from the gas recovery container to the aerosol generator until the pressure measured by the pressure gauge becomes less than an arbitrarily set pressure. Then, when the pressure becomes lower than an arbitrarily set pressure, the switching means is switched to an aerosol generator and a gas supply mechanism used for starting or replenishing gas.
[0018]
The gas recovery container shown here compresses the recovered gas, which requires considerable internal pressure, so it is safer to use a pressure-resistant container.As a gas compression mechanism, the volume inside the container is used for mechanical devices. There is a method of increasing the internal pressure by changing the pressure, or a method of simply suctioning the carrier gas and pressurizing it using a compressor.
[0019]
When the pressure in the gas recovery container is increased by pressurization, a check valve is installed on the pipe for collecting exhaust gas or the joint with the pipe so that the recovered gas does not escape from the recovery pipe. Valve for preventing gas from flowing back to the aerosol generator of the recovery container, or a solenoid valve having a backflow prevention mechanism, or a pipe used to switch the gas supply mechanism with the gas supply mechanism is closed. Pressurization in the container becomes possible. As the switching valve shown here, if it is an electromagnetic valve having a three-way cock, complicated control is required, but it is considered to be effective.
[0020]
Furthermore, in such a system, 100% of the gas discharged and recovered from the powder recovery mechanism and the structure forming chamber cannot always be recovered at the start of the structure formation and during the structure formation. In the piping for conveying gas from the collection container to the aerosol generator, it is necessary to connect the gas supply mechanism used for starting or gas replenishment via the above-mentioned switching valve, and the aerosol generator The gas supply switching to the gas supply is operated in conjunction with the pressure gauge installed in the collection container, and the gas pressure in the gas collection container whose pressure has been increased due to the pressurization process is detected by the pressure gauge, and the pressure becomes higher than the arbitrarily set pressure. At this point, the switching valve is switched, the aerosol generator is connected to the gas collection container, and the pressurized collected gas is transported to the aerosol generator.
[0021]
Thus, by using this gas recovery mechanism. This makes it possible to significantly reduce the amount of powder carrier gas supplied from the gas supply mechanism used for forming the structure, and contributes to the cost reduction of the composite structure manufactured by this method. In particular, this effect is remarkable when an expensive gas such as He gas is used as a carrier gas.
[0022]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows an example of a composite structure manufacturing apparatus comprising a powder recovery mechanism, a powder transport mechanism, a gas recovery container, and a recovered gas transport mechanism according to claim 6. As an embodiment, a composite structure manufacturing apparatus 1 having a powder recovery mechanism, a powder transport mechanism, a gas recovery container, and a recovered gas transport mechanism is shown. A gas supply mechanism 101 such as a gas cylinder has a three-way switching valve 103. The nozzle 108 is connected to the aerosol generator 104 via the gas transport pipe 102 and installed downstream of the aerosol generator 104 via the aerosol transport pipe 106 in the structure forming chamber 107. The powder supply container 105 in the aerosol generator 104 is filled with material fine particles, for example, aluminum oxide fine particle powder. At the end of the nozzle 108, a substrate 109 is fixedly disposed on an XY stage 110. The distance from the tip of the nozzle 108 to the substrate 109 is 10 mm. The structure forming chamber 107 is connected to a vacuum pump 115 via a filter 114 for removing powder. A suction tube 111 having a hollow shape and an opening of 60 mm in length and width facing the substrate direction is arranged so as to surround the nozzle 108, and a particle collection container 113 is provided via a pipe 112. Further on the downstream side, the fine particle collecting container 113 is installed via a powder removing filter 116 on a vacuum pump 117 for sucking the fine powder into the fine particle collecting container 113. The exhaust of the respective vacuum pumps 115 and 117 passes through pipes 118 and 119, is connected to a gas recovery container 121 via a check valve 120, and is connected to a three-way switching valve 103 via a pipe 126. It is a connected structure. The gas recovery container 121 is provided with a gas compression mechanism 122 for pressurizing the recovered gas, and the gas recovery container 121 is provided with a pressure gauge 123 for measuring the internal pressure of the container. The three-way switching valve 103 to be operated is connected to a wiring 125 via a control box 124 in which a sequence circuit is incorporated. On the other hand, the powder collecting container 113 is connected to the powder supply container 105 of the aerosol generator 104 via a powder conveying pipe 127 via a backflow prevention electromagnetic valve 128.
[0023]
The operation of the composite structure manufacturing apparatus 1 based on the aerosol deposition method according to the present invention will be described below. First, at the time of starting, the gas supply mechanism 101 is operated, the three-way switching valve 103 is opened in the control box 124 in which the sequence circuit is incorporated, and the gas transport pipe 102 connected to the gas supply mechanism 101 and the aerosol generator 104 is opened. And the aerosol generator 104 is operated at the same time to generate an aerosol in which the material particles in the powder supply container and the carrier gas are mixed at an appropriate ratio. Further, the vacuum pumps 115 and 117 are operated to generate a pressure difference between the aerosol generator 104 and the structure forming chamber 107. The aerosol is accelerated through the aerosol transport pipe 106 and is ejected from the nozzle 108 toward the substrate 109. The substrate 109 is oscillated by the XY stage 110, and while changing the aerosol collision position, a film-like material structure is formed on the substrate 109 by the collision of the fine particles. At this time, many fine particles do not contribute to the formation of the structure, and fly back in all directions after the collision with the substrate, but this is received by the suction tube 111 provided near the aerosol collision position and scattered in the structure formation chamber 107. Reduce the amount of fine particles. The sucked aerosol particles are introduced into the powder collecting container 113 through the transfer pipe 112, and the gas and the material fine particles are separated. After passing through the powder removing filter 116, the gas is sucked by the vacuum pump 117. Through a pipe 119 to join an exhaust pipe 118 of a vacuum pump 115 installed to serve to lower the entire internal pressure of the structure forming chamber 107 to a certain level.
[0024]
A vacuum pump 115 installed downstream of the powder removal filter 114 serves to reduce the entire internal pressure of the structure forming chamber to a certain level, and a vacuum pump 117 guides the flow of the aerosol toward the suction cylinder 111 to rectify the flow. Plays. By providing this mechanism, it is possible to greatly reduce the amount of the brittle material particles that dissipate in the structure forming chamber 107. Therefore, the material particles adhere to the mechanism of the XY stage 109, and abnormalities such as a limiter may occur. Failures, such as causing motion, have been greatly reduced, and the frequency of cleaning the interior walls has been reduced. In addition, since the number of material particles flowing into the vacuum pump 115 was reduced, the function of the pump deteriorated with use time, and the problem that the degree of vacuum in the structure forming chamber 107 gradually increased was solved. Since the degree of vacuum in the structure forming chamber 107 is a major factor affecting the mechanical and electrical characteristics of the structure to be formed, the elimination of this problem contributes to the stability of the quality of the structure.
[0025]
The gas that has passed through the exhaust pipe 118 is collected in the gas recovery container 121 via the check valve 120. The collected gas activates the gas pressurizing mechanism 122 at an arbitrarily set time, pressurizes the gas stored in the gas recovery container 121, and the pressure gauge 123 senses the pressure, and the arbitrarily set pressure is set. At this time, the three-way switching valve 103 is operated by the wiring 125 through the control box 124 in which the sequence circuit connected by the wiring 125 is incorporated, and the pressurized gas collection container 121 and the gas are connected. The compressed gas is sent to the aerosol generator 104 by connecting the transport pipe 102.
[0026]
Further, when the pressure gauge 123 detects that the gas pressure in the gas recovery container 121 has become lower than the arbitrarily set gas pressure, the three-way switching valve 103 is provided via a control box 124 in which a sequence circuit is incorporated. Operates, and the supply side of the carrier gas is switched to the gas supply mechanism 101. As a result, the collected carrier gas can be efficiently reused, gas resources can be effectively used, and this greatly contributes to cost reduction in manufacturing structures.
[0027]
On the other hand, the material powder collected by the powder collection container 113 after the material fine particle powder and the gas are separated by the cyclone method or the like is supplied to the powder supply container 105 of the aerosol generator 104 by a powder level sensor. The powder is conveyed to the powder supply container 105 of the aerosol generator 104 through the powder conveyance pipe 127 via a check valve 128 which moves in conjunction with the flow. By collecting and reusing the material powder that has not contributed to the formation of the structure, the powder resources can be effectively used, which contributes to a reduction in the cost of manufacturing the structure.
[0028]
【The invention's effect】
As described above, according to the present invention, in the formation of a material structure by the aerosol deposition method, the exhaust gas of the gas used for transporting the material fine particles and the powder that has been discarded because the usage efficiency is extremely low conventionally is used. The gas was collected without dissipating into the structure forming chamber and collected in a gas collection container, and after pressurization, reused as a carrier gas.
[Brief description of the drawings]
FIG. 1 is a schematic view illustrating a composite structure manufacturing apparatus according to one embodiment of the present invention.
101 gas supply mechanism 102 gas transfer pipe 103 three-way switching valve 104 aerosol generator 105 powder supply container 106 aerosol transfer pipe 107 structure forming chamber 108 nozzle 109 substrate 110 XY stage 111 Suction cylinder 112 ... Pipe 113 ... Particle collection container 114 ... Powder removal filter 115 ... Vacuum pump 116 ... Powder removal filter 117 ... Vacuum pump 118 ... Pipe 119 ... Pipe 120 ... Backflow prevention valve 121 ... Gas collection container 122 ... Gas compression mechanism 123 Pressure gauge 124 Control box 125 Wiring 126 Pipe 127 Powder transport pipe 128 Backflow prevention solenoid valve

Claims (5)

It has an aerosol generator that generates an aerosol in which material particles supplied from a powder supply container are dispersed in a gas, and a nozzle that jets the generated aerosol at high speed. In the composite structure manufacturing apparatus to be
A suction tube that is installed near a collision portion between the aerosol and the substrate and that sucks aerosol that does not contribute to the formation of the structure after colliding with the substrate; A powder recovery mechanism having a fine particle recovery container for capturing and storing material fine particles in an aerosol that does not
Backflow prevention means for permitting only one-way flow from the fine particle collection container to the powder supply container, and provided on the fine particle powder supply container side with respect to the reverse flow prevention means; A powder transport mechanism having a drive source for generating a flow to the supply container,
A composite structure manufacturing apparatus characterized by comprising: The fine particle collection container is equipped with a sensor for sensing the weight or volume of the collected powder, and when the sensor detects that an arbitrary set amount of powder has been collected, the sensor is installed in the powder transfer mechanism. The composite structure manufacturing apparatus according to claim 1, wherein the driving source operates to transport the powder. The powder supply container is equipped with a sensor for detecting the weight or volume of the powder for supply, and when this sensor becomes equal to or less than an arbitrary set amount, a driving source installed in the powder transport mechanism operates to operate the powder. The composite structure manufacturing apparatus according to claim 1, wherein the composite structure is transported. 2. The composite structure manufacturing apparatus according to claim 1, wherein the gas recovery container is connected to the particulate collection container and a chamber chamber for manufacturing the structure through a backflow prevention unit, and collects discharged gas; A gas compression mechanism for increasing the pressure of the gas collected in the collection container, and switching means that can be selectively connected to the aerosol generator with a gas supply mechanism for conveying a starting or replenishing gas. An apparatus for manufacturing a composite structure, comprising: The gas recovery container is provided with a pressure gauge for measuring the pressure in the container, and the gas is transported from the gas recovery container to the aerosol generator until the pressure measured by the pressure gauge becomes less than an arbitrarily set pressure. The composite structure according to claim 4, wherein the switching means is switched to an aerosol generator and a gas supply mechanism used for starting or replenishing gas when the pressure becomes lower than an arbitrarily set pressure. Production equipment.

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