JP4994279B2 - Microbubble generator - Google Patents

Description

The present invention relates to a microbubble generating equipment, about the particular example microbubble generating equipment for generating mountable nanobubbles as cleaning apparatus.

  As an example, the substrate processing apparatus performs processing by supplying liquid such as pure water or a chemical solution to the substrate in the substrate manufacturing process. In this type of substrate processing apparatus, it is necessary to remove particles adhering to the substrate and particles floating in the liquid.

  In order to remove particles on the substrate of the substrate processing apparatus, in Patent Document 1, a microbubble generating unit is connected to the substrate processing apparatus, and pure water containing microbubbles is supplied from the microbubble generating unit to the substrate in the processing tank. Has been proposed to supply.

  The structure of this micro bubble generating part is described in FIG. 9 of Patent Document 1, and the micro bubble generating part has a structure in which a water supply pipe and an air supply path surrounding the water supply pipe are formed in the casing. ing. The air supply path is connected to a nitrogen gas supply unit and a vacuum pump, and the pressure of nitrogen gas flowing through the air supply path can be adjusted by operating the vacuum pump to increase or decrease the pressure in the casing.

Thereby, when the inside of a casing is pressure-reduced, excess gas precipitates from the pure water which flows through a water pipe, becomes supersaturated, and the gas flows out to an air supply path through a hollow element separation membrane. Further, when the inside of the casing is pressurized, the nitrogen gas flowing in the air supply passage is pressurized and melted into the pure water in the water supply pipe through the hollow element separation membrane.
JP 2006-179765 A

  However, in the structure of the microbubble generator described in Patent Document 1, the inside of the air supply path needs to be connected to a vacuum pump, and the pressure of nitrogen gas flowing through the air supply path must be adjusted. In addition, a pressure regulator is required on each of the nitrogen gas supply side and the nitrogen gas discharge side. For this reason, the structure of the microbubble generator is complicated. If the pressure is not accurately adjusted by the vacuum pump, pure water containing microbubbles may not be reliably supplied.

The present invention has been made in view of the above, an object of the structure can be simplified to provide a microbubble generating equipment which can reliably produce a liquid containing a fine small bubbles.

The microbubble generating device of the present invention is a microbubble generating device that generates microbubbles, and has a plurality of first holes having a diameter of 1 μm or less that form the microbubbles by allowing compressed gas to pass therethrough, and the compression A first porous filter having a hollow portion for introducing a gas; a second porous filter disposed in close contact with the outside of the first porous filter and having a plurality of second holes having a diameter exceeding 1 μm; A gas introduction part formed on one end side of the first porous filter for introducing the compressed gas into one end part of the hollow part of the first porous filter; and the first porous filter. A closed portion for closing the other end of the hollow portion, and a casing portion disposed outside the second porous filter, the inner peripheral surface of which is in close contact with the outer peripheral surface of the second porous filter. And the gas A liquid introduction part for introducing a liquid into the second porous filter from a position opposite to the introduction part, and a discharge part for discharging the liquid containing the microbubbles from a position opposite to the liquid introduction part And the casing part having the above.

According to the present invention, it is possible to structure can easily be reduction provides a microbubble generating equipment which can reliably produce a liquid containing a fine small bubbles.

  Embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a first preferred embodiment of the microbubble generating device of the present invention.

  1 includes a first porous filter 11, a second porous filter 12, a gas introduction part 13, a closing part 14, a casing part 15, a gas supply part 20, and a liquid. A supply unit 21 is provided.

The first porous filter 11, the second porous filter 12, and the casing portion 15 are preferably, for example, cylindrical members. The 1st porous filter 11, the 2nd porous filter 12, and the casing part 15 are arrange | positioned coaxially centering | focusing on the central axis CL. The inner peripheral surface 12 </ b> B of the second porous filter 12 is disposed in close contact with the outer peripheral surface 11 </ b> B of the first porous filter 11. The inner peripheral surface 15 C of the casing portion 15 is disposed in close contact with the outer peripheral surface 12 C of the second porous filter 12. In other words, the second porous filter 12 covers the outer peripheral portion of the first porous filter 11, the casing portion 15 covers the outer peripheral portion of the second porous filter 12, and the casing portion 15 is the second porous filter 12. The porous filter 12 and the first porous filter 11 are accommodated.

  In the example of FIG. 1, the length of the first porous filter 11 in the central axis CL direction is slightly smaller than the length of the second porous filter 12 in the central axis CL direction. The length of the second porous filter 12 in the direction of the central axis CL is set smaller than the length of the casing portion 15 in the direction of the central axis CL.

As shown in FIG. 1, the gas introducing portion 13 is a cylindrical member made of , for example, metal or plastic, and is connected to the one end portion 22 side of the hollow portion 24 of the first porous filter 11. The outer diameter of the gas introduction part 13 is the same as the outer diameter of the first porous filter 11. The closing part 14 is a disk-shaped member made of, for example, metal or plastic, and closes the other end 23 side of the hollow part 24 of the first porous filter 11.

One end portion 25 of the second porous filter 12 covers a part of the outer peripheral surface of the gas introduction portion 13. A space portion 28 is formed between the other end portion 26 of the second porous filter 12 and the wall portion 27 of the casing portion 15. The space 28 is provided to temporarily store the liquid supplied from the liquid supply unit 21 and pressurize and supply the liquid to the other end 26 of the second porous filter 12.

The casing portion 15 is a substantially cylindrical member made of, for example, metal or plastic, and has a large diameter portion 29 and a small diameter portion 30, and the inner peripheral surface of the large diameter portion 29 has the second porous filter 12. Covering. The small diameter portion 30 is formed to protrude from the wall portion 27 of the large diameter portion 29 along the central axis CL direction, and the small diameter portion 30 is connected to the liquid supply portion 21.

  The first porous filter 11 and the second porous filter 12 shown in FIG. 1 will be further described.

  The first porous filter 11 shown in FIG. 1 has a plurality of first holes having a diameter of 1 μm or less, and has a hollow portion 24. The second porous filter 12 is disposed in close contact with the outside of the first porous filter 11 and has a plurality of second holes having a diameter exceeding 1 μm.

  FIG. 2 shows a configuration example of the first porous filter 11 and the second porous filter 12.

  The diameter of the plurality of first holes of the first porous filter 11 is preferably 0.01 μm or more and 1 μm or less. When the diameter of the first pore is less than 0.01 μm, the minimum diameter of the porous mesh that has been put into practical use is 20 nm (= 0.02 μm) on average. Therefore, in consideration of manufacturing variations, the minimum diameter is set to 10 nm, which is half of the minimum diameter. The diameter of the plurality of first holes of the first porous filter 11 is more preferably 20 nm (= 0.02 μm). When the thickness exceeds 1 μm, bubbles exceeding 1 μm become microbubble regions, and liquid easily passes through. In the embodiment of the present invention, since the main object is to create microbubbles having the size of the nanobubble region, the maximum diameter of the first porous mesh is 1 μm.

Moreover, the diameter of the plurality of second holes of the second porous filter 12 is preferably greater than 1 [mu] m, is 100μm or less. Since the purpose is to send microbubbles having a diameter of the second pore of 1 μm or less in one-way from the first porous filter side to the second porous filter side, the maximum size of the first pore of the first porous filter The value is set to be equal to or smaller than the minimum value of the second hole of the second porous filter. In addition, when the plurality of second pore diameters of the second porous filter 12 exceeds 100 μm, the gas that has passed through the mesh of the first porous filter moves to the liquid side on the mesh side of the second porous filter. There is a possibility that the gases gather and become larger, and if it exceeds 100 μm, the bubbles will exceed the microbubble size , so a restriction is provided. In order to utilize nanobubbles more effectively, 50 μm or less is desirable.

The first porous filter 11 and the second porous filter 12 shown in FIG. 2 constitute a microbubble generation mechanism, and the first porous filter 11 is a porous film such as a polymer film. For example, it is composed of a craze portion 31 and a film portion 32. Craze portion 31 is formed in the hole portion of the film unit 32 has a plurality of fibrils 33, between each fibril 33 is void 34. The void 34 is the first hole of the first porous filter 11.

When compressed gas is given along the direction of arrow S in FIG. 2 with a pressure of, for example, 0.3 to 3.0 kg / cm 2, the compressed gas passes through the voids 34 between the fibrils 33 and passes through the microbubbles. (Also referred to as microbubbles) occurs.

  On the other hand, the second porous filter 12 is, for example, a nonwoven fabric disposed in close contact with the film portion 32 of the first porous filter 11. The second porous filter 12 is generated by separating the microbubbles from the voids 34 between the fibrils 33 from the first porous filter 11 so that the microbubbles are discharged without causing the coalescence of the microbubbles. It plays the role of generating the liquid 70 containing microbubbles.

  Next, returning to FIG. 1, the gas supply unit 20 and the liquid supply unit 21 shown in FIG. 1 will be described.

  The gas supply unit 20 illustrated in FIG. 1 includes a process gas gas storage unit 40, a flow rate regulator 41, and a regulator 42. The gas storage unit 40 stores, for example, oxygen gas, nitrogen gas, or air as a process gas. The process gas in the gas storage unit 40 is introduced into the hollow portion 24 of the first porous filter 11 through the gas introduction unit 13 while adjusting the applied pressure by the regulator 42 through the flow rate regulator 41. ing.

The liquid supply unit 21 shown in FIG. 1 is disposed on the opposite side of the gas supply unit 20, and the liquid supply unit 21 passes the liquid into the casing unit 15 through the liquid introduction unit 55 of the small diameter portion 30 of the casing unit 15. Pressurized and supplied. This liquid is, for example, water, an acidic liquid or an alkaline liquid.

  Next, a microbubble generation method using the microbubble generator 10 described above will be described.

The process gas in the gas storage unit 40 shown in FIG. 1 is adjusted in the hollow portion 24 of the first porous filter 11 through the gas introduction unit 13 while adjusting the applied pressure by the regulator 42 through the flow rate regulator 41. Introduce. At the same time, the liquid supply part 21 pressurizes and supplies the liquid into the casing part 15 through the liquid introduction part 55 of the small diameter part 30 of the casing part 15. In this case, the process gas passes through the first porous filter 11 from the hollow portion 24 of the first porous filter 11, but since the process gas has the closing portion 14, the process gas enters the space portion 28 side of the casing portion 15. Instead, all process gas passes through the first porous filter 11.

When the process gas compressed with, for example, a pressure of 0.3 to 3.0 kg / cm 2 is supplied to the first porous filter 11 along the arrow S direction in FIG. 2, the compressed process gas is supplied to each fibril 33. Microbubbles are generated by passing through the voids 34 therebetween. The second porous filter 12 is disposed in intimate contact with the film portion 32 of the first porous filter 11, and the second porous filter 12 removes microbubbles from the voids 34 between the fibrils 33. By separating from the first porous filter 11, microbubbles are generated by discharging the microbubbles as they are without causing coalescence of the microbubbles. Therefore, the liquid 70 containing microbubbles can be discharged to the outside from the one end portion 25 of the second porous filter 12 in the vicinity of the gas introduction portion 13. One end portion 25 of the second porous filter 12 is a discharge portion for discharging the liquid 70 containing microbubbles.

  In this way, immediately after the pressurized process gas is passed through the first porous filter 11 to generate a large number of microbubbles, the large number of microbubbles comes into contact with the liquid passing through the second porous filter 12. The liquid 70 containing the microbubbles is generated so that the plurality of microbubbles do not stick to each other. In order to prevent the plurality of microbubbles from sticking to each other in this way, the thickness of the second porous filter 12 in the radial direction is increased so that the liquid can pass through the second porous filter 12. It is desirable to secure a passage.

  The above-described microbubble generating device 10 can simplify the structure and can reliably generate microbubbles and a liquid containing microbubbles.

  The microbubble generating device 10 described above can generate micro-nano bubbles or nano bubbles by passing a plurality of first holes having a diameter of several tens of nanometers of the first porous filter 11 while pressurizing the process gas. it can.

(Second Embodiment)
FIG. 3 is a view showing a second preferred embodiment of the microbubble generator of the present invention.

The microbubble generator 10B of the second embodiment shown in FIG. 3 differs from the microbubble generator 10B of the first embodiment shown in FIG. 1 in the shape of the casing portion 15B. Other constituent elements of the microbubble generating device 10B are substantially the same as the corresponding constituent elements of the microbubble generating device 10 shown in FIG.

The large-diameter portion 29 of the casing portion 15 </ b> B shown in FIG. 3 has a plurality of through holes 60. These through holes 60 are arranged, for example, at the same interval in a region corresponding to the second porous filter 12 in the large diameter portion 29.

  Thereby, in addition to the liquid 70 containing microbubbles, the liquid 71 containing microbubbles can be discharged from these through holes 60, and the discharge efficiency of the liquid containing microbubbles can be improved.

(Third embodiment)
FIG. 4 is a diagram showing a third preferred embodiment of the microbubble generating device of the present invention.

  In the example shown in FIG. 4, the microbubble generator 10 is applied as a cleaning device to, for example, a single-wafer type substrate processing apparatus 100.

The substrate processing apparatus 100 includes a substrate holding unit 90 , a supply nozzle operation unit 72, a downflow filter-equipped fan 73, a cup 74, a supply nozzle 75, and a processing chamber 76.

The substrate holding unit 90 includes a disk base member 77, a rotating shaft 78, and a motor 79, and the substrate W is detachably fixed on the base member 77. In the processing chamber 76, a cup 74, a supply nozzle 75, a base member 77, and a rotating shaft 78 are accommodated. The base member 77 can continuously rotate in the R direction by the motor 79 operating according to a command from the control unit 80.

  The supply nozzle 75 is disposed above the substrate W, and the supply nozzle 75 can be moved in the Z direction (vertical direction) and the X direction (radial direction of the substrate) by the operation of the operation unit 72.

  One end 25 of the microbubble generator 10 is connected to a supply nozzle 75 via a tube 81. Accordingly, since the liquid 70 containing microbubbles can be supplied to the supply nozzle 75 via the tube 81, the liquid 70 containing microbubbles can be ejected from the substrate W through the supply nozzle 75. By injecting the liquid 70 containing microbubbles onto the surface of the substrate W in this way, the contaminants such as positively charged particles are encased by the minus potential of the microbubbles, and the contaminants are combined with the microbubbles. It can be removed from the surface of the substrate W.

  Note that the microbubble generating device 10B shown in FIG. 3 can also be applied as a cleaning device to the single-wafer type substrate processing apparatus 100, for example.

The microbubble generating apparatus for generating microbubbles of the present invention has a plurality of first holes having a diameter of 1 μm or less that forms microbubbles by passing compressed gas, and has a hollow portion for introducing compressed gas. A first porous filter; a second porous filter disposed in close contact with the outside of the first porous filter and having a plurality of second holes having a diameter of more than 1 μm; and one end of a hollow portion of the first porous filter A gas introduction part formed on one end part side of the first porous filter for introducing compressed gas to the part, a closing part for closing the other end part of the hollow part of the first porous filter, and a second part A casing portion disposed outside the porous filter, the inner peripheral surface thereof being disposed in close contact with the outer peripheral surface of the second porous filter, and the second porous portion from a position opposite to the gas introduction portion. For introducing liquid into the quality filter It is characterized by comprising a casing part having a liquid introduction part and a discharge part for releasing a liquid containing microbubbles from a position opposite to the liquid introduction part.

Accordingly, the first porous filter can generate a large number of microbubbles only by supplying compressed gas and liquid, and the second porous filter prevents the microbubbles from sticking to each other and includes the microbubbles. A liquid can be generated, equipment such as a vacuum pump is not required, the structure can be simplified, and a liquid containing microbubbles can be reliably generated. Moreover, the microbubble produced | generated by the 1st porous filter can be discharged without staying in a 2nd porous filter only by flowing a liquid through a 2nd porous filter.

  The first porous filter is a cylindrical member. Thereby, many microbubbles can be produced | generated toward a 2nd porous filter from a cylindrical 1st porous filter.

  A 2nd porous filter is a cylindrical member arrange | positioned closely with respect to the outer peripheral surface of a 1st porous filter. Thereby, it is possible to reliably prevent a large number of microbubbles generated from the first porous filter from sticking to each other, and to reliably generate a liquid containing microbubbles.

  The casing part is a cylindrical member, and the inner peripheral surface of the casing part is disposed in close contact with the outer peripheral surface of the second porous filter. As a result, the casing can securely hold the first porous filter and the second porous filter while allowing the liquid to pass through the second porous filter.

  The gas introduction part and the liquid introduction part are arranged on the same central axis, and the closing part is arranged between the gas introduction part and the liquid introduction part. Thereby, the first porous filter can be passed so that all of the compressed gas does not leak, and the liquid is prevented from entering the first porous filter.

  The first porous filter is a polymer film having a plurality of fibrils, and has a first hole between the fibrils. Thereby, many microbubbles can be produced | generated from compressed gas.

  The second porous filter is a nonwoven fabric. Thereby, while having a simple structure, the second porous filter can surely prevent a large number of microbubbles generated from the first porous filter from sticking to each other and can allow liquid to pass through. The contained liquid can be reliably generated.

  The casing portion is formed with a plurality of through holes that communicate with the second porous filter. Thereby, the liquid containing a microbubble can be reliably produced | generated from a some through-hole.

  The microbubble generator of the present invention includes, for example, a substrate such as a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, etc. mounted on a substrate processing apparatus for processing with a liquid, It can be used to remove impurities such as particles in the liquid.

  Furthermore, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments of the present invention.

  For example, the shapes of the first porous filter, the second porous filter, and the casing portion do not necessarily have to be cylindrical, and any shape can be adopted. For example, you may delete some components from all the components shown by embodiment of this invention. Furthermore, you may combine the component covering different embodiment suitably.

1 is a diagram illustrating a first preferred embodiment of a microbubble generator of the present invention. It is a figure which shows the cross-sectional structure example of a 1st porous filter and a 2nd porous filter. It is a figure which shows preferable 2nd Embodiment of the microbubble production | generation apparatus of this invention. It is a figure which shows preferable 3rd Embodiment of the microbubble production | generation apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Microbubble production | generation apparatus 11 1st porous filter 12 2nd porous filter 13 Gas introduction part 14 Closure part 15 Casing part 20 Gas supply part 21 Liquid supply part 24 Hollow part 25 One end part of 2nd porous filter 70 Microbubble Liquid containing

Claims (9)

A microbubble generator for generating microbubbles,
A plurality of first holes of 1μm or less diameter forming the microbubbles by passing a compressed gas, a first porous filter having a hollow portion for introducing the compressed gas,
A second porous filter disposed in close contact with the outside of the first porous filter and having a plurality of second holes having a diameter of more than 1 μm;
A gas introduction part formed on one end part side of the first porous filter for introducing the compressed gas into one end part of the hollow part of the first porous filter; A closing portion for closing the other end of the hollow portion;
A casing portion disposed outside the second porous filter, the inner peripheral surface thereof being disposed in close contact with the outer peripheral surface of the second porous filter, and a position opposite to the gas introduction portion said casing part having said liquid introducing portion for introducing a liquid to the second porous filter, and a release section for releasing the liquid containing the microbubbles from a position opposite to the liquid inlet portion from When,
A microbubble generator characterized by comprising:   The microbubble generator according to claim 1, wherein the first porous filter is a cylindrical member.   3. The microbubble generating device according to claim 2, wherein the second porous filter is a cylindrical member disposed in close contact with an outer peripheral surface of the first porous filter.   The minute casing according to claim 3, wherein the casing part is a cylindrical member, and an inner peripheral surface of the casing part is arranged in close contact with an outer peripheral surface of the second porous filter. Bubble generator.   The said gas introduction part and the said liquid introduction part are arrange | positioned on the same center axis | shaft, and the said closing part is arrange | positioned between the said gas introduction part and the said liquid introduction part. Microbubble generator.   6. The microscopic structure according to claim 1, wherein the first porous filter is a polymer film having a plurality of fibrils, and the first pores are provided between the fibrils. Bubble generator.   The microbubble generator according to claim 6, wherein the second porous filter is a non-woven fabric.   The microbubble generator according to claim 7, wherein a plurality of through holes communicating with the second porous filter are formed in the casing part. The diameter of the plurality of first holes of the first porous filter is 0.01 μm or more and 1 μm or less,
2. The microbubble generating device according to claim 1, wherein a diameter of the plurality of second holes of the second porous filter is more than 1 μm and not more than 100 μm.

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