JP5495299B2 - Bubble generation method and apparatus, and processing apparatus using the apparatus - Google Patents

Description

  The present invention relates to a bubble generation method and apparatus for generating extremely fine bubbles called micro-nano bubbles and nano bubbles in a liquid, and a processing apparatus such as a cleaning apparatus using the apparatus.

  2. Description of the Related Art Conventionally, there has been proposed an ultrafine bubble generating device that can stay in water for a long time and generate ultrafine bubbles having a very small diameter and high solubility (Patent Document 1). In this ultrafine bubble generating device, a gas flow is injected into a liquid (water) being pumped so that the fine bubbles are included in the liquid, and the reduced flow nozzle having a fluid guide surface portion in which the liquid containing the fine bubbles gradually spreads. The fine bubbles in the liquid are crushed and spread in a flat plane when they are pumped, and are further broken down by the surface tension to become finer ultrafine bubbles.

JP 2003-245533 A

  By the way, in recent years, it is considered to use a liquid containing these ultrafine bubbles (ultrafine bubbles) for processing such as cleaning of the surface of an object. It is said that the potential at the interface between the ultrafine bubble and the liquid promotes the cleaning effect and oxidation action, and the energy when the ultrafine bubble attached to the object surface bursts contributes to the removal of dirt from the object surface. When a liquid containing ultrafine bubbles is used for the treatment of an object surface as described above, the cleaning effect and the oxidizing action are greater as the total surface area of the ultrafine bubbles contained in the liquid is larger.

  However, in the above-described conventional ultrafine bubble generating device, when the liquid containing fine bubbles is pumped through the contracted flow nozzle, the fine bubbles in the liquid are crushed and spread in a plane, and then the external action is performed. It is difficult to expect efficient splitting of fine bubbles because it naturally breaks down by surface tension.

  The present invention has been made in view of such circumstances, and provides a bubble generation method and apparatus capable of more efficiently miniaturizing bubbles in a liquid, and a processing apparatus having the bubble generation mechanism. Is.

  In the bubble generation method according to the present invention, the bubble mixing mechanism mixes fine bubbles in the supply liquid, supplies the bubble mixed liquid generated by the bubble mixing mechanism to the liquid storage tank, and stores the bubble mixed in the liquid storage tank. By returning the liquid as the supply liquid to the bubble mixing mechanism, the bubble mixed liquid circulation step for circulating the bubble mixed liquid between the bubble mixing mechanism and the storage tank, and the bubble mixed liquid circulation step are completed. And a pressurizing step for pressurizing the bubble mixed liquid in the liquid storage tank.

  With such a configuration, the bubble mixed liquid in which the fine bubbles are mixed is stored in the liquid storage tank, and the bubble mixed liquid stored in the liquid storage tank is pressurized. When many of the fine bubbles inside shrink by pressurization, they can be stabilized by the electrostatic action of ions in the liquid and become bubbles of even smaller size at the same time.

  In the bubble generating method according to the present invention, the pressurizing step can be configured to increase the internal pressure of the liquid storage tank by pressurizing and supplying gas to the liquid storage tank.

  With such a configuration, when gas is pressurized and supplied to the liquid storage tank in order to pressurize the bubble mixed liquid, the pressurized gas can be melted into the bubble mixed liquid in the liquid storage tank. Therefore, a bubble mixed liquid having a high dissolved gas concentration can be generated. When such a bubble mixed liquid having a high dissolved gas concentration is pressure-released, extremely fine bubbles can be further generated.

  In the bubble generation method according to the present invention, in the bubble mixture liquid circulation step, the bubble mixing mechanism injects a gas from a gas supply source into the supply liquid, mixes fine bubbles with the supply liquid, and adds the addition liquid. The pressure step can be configured to pressurize and supply the gas from the gas supply source to the liquid storage tank.

  With such a configuration, a gas supply source for generating the bubble mixed liquid and a gas supply source for pressurizing the bubble mixed liquid in the liquid storage tank can be shared.

  Furthermore, in the bubble production | generation method which concerns on this invention, it can comprise so that the said pressurization step may be performed at least until the quantity of the dissolved gas in the bubble mixed liquid in the said storage tank becomes a predetermined quantity.

  With such a configuration, the dissolved gas concentration that contributes to the generation of extremely fine bubbles at the time of pressure release can be further increased. From the viewpoint that the generation amount of fine bubbles at the time of pressure release can be increased, it is preferable to perform at least the pressurizing step until the dissolved gas in the liquid storage tank becomes supersaturated.

  The bubble generating apparatus according to the present invention includes a bubble mixing mechanism that mixes fine bubbles into a supply liquid, a liquid storage tank that stores the bubble mixed liquid generated by the bubble mixing mechanism, and the bubble mixed liquid from the liquid storage tank. A return mechanism for returning to the bubble mixing mechanism as a supply liquid, a pressurizing mechanism for pressurizing the bubble mixed liquid in the liquid storage tank, and a bubble for circulating the bubble mixed liquid through the liquid storage tank, the return mechanism, and the bubble mixing mechanism It has a configuration having a mixed liquid circulation mode and a switching mechanism for switching between a pressurizing mode for pressurizing the bubbles in the liquid storage tank by the pressurizing mechanism.

  With such a configuration, when switched to the bubble mixed liquid circulation mode, the bubble mixed liquid mixed with fine bubbles is stored in the liquid storage tank while increasing the amount of the mixed bubbles, and when switched to the pressure mode, When many fine bubbles mixed in the bubble mixed liquid in the entire liquid storage tank contract by pressurization, they can be stabilized by the electrostatic action of ions in the liquid and become bubbles of a finer size all at once.

  In the bubble generating apparatus according to the present invention, the pressurizing mechanism may include a gas supply mechanism that pressurizes and supplies gas into the liquid storage tank.

  With such a configuration, when gas is pressurized and supplied to the liquid storage tank in order to pressurize the bubble mixed liquid, the pressurized gas can be melted into the bubble mixed liquid in the liquid storage tank. Therefore, a bubble mixed liquid having a high dissolved gas concentration can be generated.

  Further, in the bubble generating device according to the present invention, the bubble mixing mechanism includes a gas supply source and a gas ejection mechanism that ejects gas from the gas supply source to the supply liquid, and the gas in the pressurization mechanism The supply mechanism pressurizes and supplies the gas from the gas supply source to the liquid storage tank, and the switching mechanism supplies the gas from the gas supply source to the gas ejection mechanism in the bubble mixing mechanism and the pressurization. It can be set as the structure which has the gas switching mechanism switched to either of the said gas supply mechanisms in a mechanism.

  With such a configuration, the gas supply source as the bubble mixing mechanism and the gas supply source as the gas supply mechanism in the pressurizing mechanism can be shared.

  The processing apparatus according to the present invention includes any one of the bubble generating apparatuses described above, a processing head unit that ejects processing liquid, and the processing liquid that contains the bubble mixture from the liquid storage tank in the fine bubble generating apparatus. It has the structure which has the process liquid supply mechanism pressurized and supplied as a liquid.

  With such a configuration, since the bubble mixed liquid containing the fine bubbles from the bubble generating device is ejected from the processing head as the processing liquid, the object to be processed by the bubble mixed liquid containing the fine bubbles ejected from the processing head unit. Will be able to handle.

  The processing apparatus which concerns on this invention WHEREIN: It can be set as the structure which has a means to detect the quantity of dissolved gas of the bubble mixed liquid stored in the said storage tank of the said bubble production | generation apparatus.

  With such a configuration, it becomes possible to know the amount of dissolved gas in the bubble mixed liquid that can be used for processing by releasing the pressure, so when the pressure is released and the bubble mixed liquid is used for processing. The handling of gas in the bubble generator can be determined in advance so that many fine bubbles are generated. For example, it is possible to determine the pressurization time when the bubble mixed liquid stored in the liquid storage tank in the bubble generator is pressurized with gas.

  According to the bubble generating method and apparatus according to the present invention, when many fine bubbles in the bubble mixed liquid in the entire liquid storage tank contract by pressurization, they are stabilized and all at once by the electrostatic action of ions in the liquid. Furthermore, since it can be a bubble of a fine size, the bubble in the liquid can be made finer more efficiently.

  Moreover, according to the processing apparatus which concerns on this invention, a non-processed object can be processed now with the bubble mixed liquid containing a fine bubble.

It is a figure which shows the substrate cleaning apparatus as a processing apparatus containing the bubble production | generation apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows the aspirator which comprises the principal part of the bubble mixing mechanism used for the bubble generator in the substrate cleaning apparatus shown in FIG. It is a figure which shows the principle of the mechanism in which the fine bubble in a liquid destroys by pressurization. It is a figure which shows the principle of the mechanism in which the fine bubble in a liquid changes into a finer bubble by pressurization. It is a figure which shows the two fluid nozzle unit which can be used as a principal part of the bubble mixing mechanism used for the bubble generator in the board | substrate washing | cleaning apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A substrate cleaning apparatus including a bubble generating apparatus according to an embodiment of the present invention is configured as shown in FIG.

  In FIG. 1, the substrate cleaning apparatus 10 includes a liquid storage tank 11 that stores a cleaning liquid W (for example, composed of pure water), and a delivery pipe that extends from a predetermined portion near the bottom of the liquid storage tank 11. 12 a is connected to the input port of the pump 13. The transmission pipe 12b extending from the output port of the pump 13 is connected to a liquid introduction part 141 (see FIG. 2) of the aspirator 14 which is a main part of the bubble mixing mechanism as will be described later. A transmission pipe 12 c extending from the gas-liquid discharge part 142 (see FIG. 2) of the aspirator 14 is connected to a predetermined portion of the top surface of the liquid storage device 11. Thereby, a circulation system of the cleaning liquid W returning from the liquid storage tank 11 to the liquid storage tank 11 through the aspirator 14 (bubble mixing mechanism) is formed.

From the nitrogen gas supply unit 15, two branch pipes 16a and 16b extend. One delivery pipe 16a is connected to a gas introduction part 143 (see FIG. 2) of the aspirator 14. The feed pipe 16a is provided with a regulator 17a and an on-off valve 18a for adjusting the pressure of the nitrogen gas supplied from the nitrogen gas supply unit 15 to the aspirator 14. The other transmission pipe 16 b extending from the nitrogen gas supply unit 15 is connected to a predetermined portion on the top surface of the liquid storage tank 11. A regulator 17b and an on-off valve 18b for adjusting the pressure of nitrogen gas supplied from the nitrogen gas supply unit 15 to the liquid storage tank 11 are provided in the transmission pipe 16b.

  A bubble mixing mechanism is configured by the nitrogen gas supply unit 15, the aspirator 14, the feed pipe 16a connecting them, the regulator 17a and the on-off valve 18a provided in the feed pipe 16a. The aspirator 14 which is the main part of the bubble mixing mechanism is configured as shown in FIG.

In FIG. 2, the aspirator 14 is coupled so that the liquid introduction part 141, the gas-liquid discharge part 142, and the gas introduction part 143 are T-shaped. As described above, the liquid introduction part 141 to which the transmission pipe 12b extending from the pump 13 is connected communicates with the gas-liquid discharge part 142 to which the transmission pipe 12c leading to the liquid storage tank 11 is connected via the throttle part 144. doing. The gas introduction part 143 connected to the feed pipe 16a extending from the nitrogen gas supply part 15 continues from the liquid introduction part 141 to the gas-liquid discharge part 142 via the gas-liquid mixing part 145 located immediately after the throttle part 144. It is connected to the passage. The gas-liquid discharge part 142 has a shape such that the cross section gradually widens from the end on the gas-liquid mixing part 145 side.

  In the bubble mixing mechanism including the aspirator 14 having such a structure as a main element, the cleaning liquid W pumped from the liquid storage tank 11 to the aspirator 14 through the transmission pipe 12b by the pump 13 is used as a supply liquid for the bubble mixing mechanism. 14 from the liquid inlet 141 to the gas-liquid outlet 142 through the throttle 144 at high speed. At that time, nitrogen gas supplied from the nitrogen gas supply unit 15 through the transmission pipe 16 a is drawn into the gas introduction unit 143, and the nitrogen gas is transferred from the liquid introduction unit 141 to the gas-liquid discharge unit 142 in the gas-liquid mixing unit 145. Fine bubbles (bubbles) are mixed in the cleaning liquid W that escapes at high speed. As a result, the cleaning liquid W in which fine bubbles are mixed (hereinafter, appropriately referred to as bubble mixed cleaning liquid W) is discharged from the gas-liquid discharge portion 143 of the aspirator 14.

  Returning to FIG. 1, a nozzle head in which a feed pipe 22 a extending from a predetermined portion of the bottom of the liquid storage tank 11 is connected to an input port of a pump 24 and a feed pipe 22 b extending from an output port of the pump 24 has a plurality of nozzles 30 (processing head unit). A glass substrate 100 serving as an object to be cleaned (object to be processed) is disposed so as to face the nozzle head 30 (a plurality of nozzles). The glass substrate 100 may be placed on a turntable installed so as to face the nozzle head 30 or may be transported below the nozzle head 30 by a transport mechanism. . An opening / closing valve 23 is provided in the feed pipe 22 a extending from the liquid storage tank 11 to the pump 24.

  An exhaust pipe 20 that is open to the atmosphere is connected to a predetermined portion of the top surface of the liquid storage tank 11. The exhaust pipe 20 is provided with an on-off valve 21. Further, a dissolved gas sensor 19 that detects the concentration of nitrogen gas dissolved in the cleaning liquid W is provided in the vicinity of the bottom of the liquid storage tank 11. The concentration of dissolved nitrogen gas in the cleaning liquid W detected by the dissolved gas sensor 19 can be monitored by a processing apparatus not shown.

  The operation of the substrate cleaning apparatus 10 will be described.

  First, the on-off valve 18b provided on the feed pipe 16b extending from the nitrogen gas supply section 15 to the liquid storage tank 11 is closed, and the on-off valve 18a provided on the feed pipe 16a extending from the nitrogen gas supply section 15 to the aspirator 14 is closed. Is released. Further, the on-off valve 23 provided on the feed pipe 22 a extending from the liquid storage tank 11 to the pump 24 is closed, and the on-off valve 21 provided on the exhaust pipe 20 is closed.

  When the pump 13 is started in this state, the cleaning liquid W in the liquid storage tank 11 is supplied to the liquid introduction part 141 (see FIG. 2) of the aspirator 14 through the transmission pipes 12a and 12b, and nitrogen gas is supplied. Nitrogen gas from the section 15 is supplied to the gas introduction section 143 (see FIG. 2) of the aspirator 14 through the feed pipe 16a while being adjusted to a predetermined pressure by the regulator 17a. In the aspirator 14 (see FIG. 2), the nitrogen gas from the gas introduction unit 143 is fine bubbles (for example, Microbubbles having a diameter of about 10 to 100 μm are mixed, and bubble mixed cleaning liquid W (bubble mixed liquid) is discharged from gas-liquid discharge unit 142. Then, the bubble mixed cleaning liquid W from the aspirator 14 is returned to the liquid storage tank 11 through the transmission pipe 12c.

  While the pump 13 is operating, the bubble mixed cleaning liquid W circulates between the liquid storage tank 11 and the aspirator 14 through the transmission pipes 12a, 12b and 12c. While the bubble mixed cleaning liquid W circulates, in the aspirator 14, nitrogen gas is always mixed as fine bubbles in the bubble mixed cleaning liquid W, and the number of fine bubbles in the bubble mixed cleaning liquid W increases. Go.

Then, for example, the pump 13 is stopped at a timing at which it is expected that the density of bubbles in the bubble mixed cleaning liquid W in the liquid storage tank 11 has reached a relatively high predetermined level. This Okudori pipe 12a from the liquid storage tank 11, 12b, 12c and A Supireta 14 circulation bubble mixed cleaning liquid W to return to reservoir 11 is completed through, then extending the aspirator 14 from the nitrogen gas supply unit 15 The on-off valve 18a provided on the delivery pipe 16a is closed, while the on-off valve 18b provided on the delivery pipe 16b extending from the nitrogen gas supply unit 15 to the liquid storage tank 11 is released. The density (number) of bubbles in the bubble mixed cleaning liquid W in the liquid storage tank 11 is measured using, for example, a particle counter or a particle size distribution meter, and the measured value is compared with a predetermined reference value. The operation of the pump 13 can be feedback controlled. In this case, the pump 13 is stopped when the measured value reaches the reference value.

  In this state, the nitrogen gas from the nitrogen gas supply unit 15 is adjusted to a relatively high predetermined pressure (for example, a pressure higher than the pressure at the time of bubble generation) by the regulator 17b while passing through the transmission pipe 16b to the liquid storage tank 11. Supplied. By continuing to supply this high-pressure nitrogen gas to the liquid storage tank 11, the atmospheric pressure (nitrogen gas pressure) in the liquid storage tank 11 rises. The bubble mixed cleaning liquid W is pressurized by the increase of the nitrogen gas pressure in the liquid storage tank 11, and a large number of fine bubbles in the bubble mixed cleaning liquid W are simultaneously contracted by the pressure to be changed into finer bubbles. Specifically, the fine bubbles in the bubble mixed cleaning liquid W are changed to finer bubbles as follows.

For example, as shown in FIG. 3 (a), ions H ⁺ in the gas-liquid interface of water bubbles B in the bubble mixed washing liquid W, OH ^- but gather, under normal pH conditions OH ^- bubble because increases B Is negatively charged. Then, the electrolyte ions E in the cleaning liquid W are attracted to the negatively charged bubbles B (electrostatic action). In this state, as shown in FIG. 3B, the nitrogen gas N _{2 in the} bubble B is dissolved in the cleaning liquid W by pressurization, and the bubble B contracts. As the surface area of the interface decreases due to the shrinkage of the bubble B, the charge on the interface is concentrated. Then, as shown in FIG. 3C, some of the bubbles B rapidly disappear based on the energy stored as charges (generation of radicals), and the nitrogen gas N ₂ dissolves into the cleaning liquid W. .

On the other hand, for example, as shown in FIG. 4A as in FIG. 3A, the bubble B contracts while the electrolyte ions E in the cleaning liquid W are attracted to the interface of the bubble B. When the attached electrolyte ions E are electrically balanced with H ⁺ and OH ⁻ ions (by electrostatic action) to form an electric double layer, bubbles B are formed in a state as shown in FIG. Contraction stops. As a result, the fine bubbles B initially included in the cleaning liquid W are changed to stable and finer bubbles B (for example, extremely fine bubbles having a diameter of 10 μm or less called micro-nano bubbles or nano-bubbles).

  Since the entire bubble mixed cleaning liquid W is pressurized, in the bubble mixed cleaning liquid W, the above-described disappearance (see FIG. 3) and miniaturization (see FIG. 4: micro-nano bubbles and nano-bubbles) of many bubbles B are simultaneously performed. As the time elapses, the number of micronized bubbles B (nano bubbles and micro nano bubbles) in the bubble mixed cleaning liquid W increases.

  While the bubble mixed cleaning liquid W is pressurized by the nitrogen gas supplied from the nitrogen gas supply unit 15 to the liquid storage tank 11, in the bubble mixed cleaning liquid W, as described above, the bubbles B are refined and disappeared. As a result, the nitrogen gas is dissolved, but the nitrogen gas in contact with the surface of the bubble mixed cleaning liquid W in the liquid storage tank 11 is also dissolved in the bubble mixed cleaning liquid. When the concentration of dissolved nitrogen gas (the amount of dissolved nitrogen gas) in the cleaning liquid W detected by the dissolved gas sensor 19 is a predetermined concentration (predetermined amount), preferably oversaturated, the on-off valve 18b is closed. The supply of nitrogen gas from the nitrogen gas supply unit 15 to the liquid storage tank 11 is stopped. Note that the supply of the nitrogen gas is stopped at a timing at which the concentration of the dissolved nitrogen gas in the cleaning liquid W is expected to be a predetermined concentration, preferably a supersaturated state (for example, a timing after a predetermined time has elapsed from the start of pressurization). (Pressurization can be stopped).

  In this state, the on-off valve 21 provided in the exhaust pipe 20 is released. Then, the pressure in the liquid storage tank 11 rapidly decreases from the high pressure state to the atmospheric pressure, and the nitrogen gas dissolved in the bubble mixed cleaning liquid W at a predetermined concentration (supersaturated state) due to the rapid pressure decrease. Appears as a very fine bubble. This further increases the number of extremely fine bubbles (nano bubbles and micro / nano bubbles) in the bubble mixed cleaning liquid.

  When the number of extremely fine bubbles contained in the bubble mixed cleaning liquid W in the liquid storage tank 11 is increased in this manner, the on-off valve 23 is released. In this state, when the pump 24 is started, the bubble mixed cleaning liquid W in the liquid storage tank 11 is pumped to the nozzle head 30 through the transmission pipes 22a and 22b. Then, the bubble mixed cleaning liquid W discharged from the plurality of nozzles of the nozzle head 30 is sprayed onto the surface of the glass substrate 100, thereby cleaning (processing) the surface of the glass substrate 100. The bubble mixed cleaning liquid W sprayed on the glass substrate 100 contains many extremely fine bubbles (nano bubbles and micro / nano bubbles), and the surface of the glass substrate 100 is excellent due to the cleaning effect and oxidation action of the extremely fine bubbles. Will be able to be cleaned.

  In the substrate cleaning apparatus 10 as described above, when many fine bubbles in the bubble mixed cleaning liquid W in the entire liquid storage tank 11 contract by pressurization, they are stabilized by the electrostatic action of ions in the cleaning liquid W and simultaneously. In addition, since the bubbles have a finer size, the bubbles in the cleaning liquid can be more effectively miniaturized. Since the cleaning liquid W containing the extremely fine bubbles is sprayed onto the glass substrate 100, the surface of the glass substrate 100 can be cleaned well by the effect of the extremely fine bubbles in the cleaning liquid W. .

Instead of the aspirator 14 as the main part of the bubble mixing mechanism, a two-fluid nozzle unit 40 as shown in FIG. 5 can be used. The two-fluid nozzle unit 40 includes a cleaning liquid storage unit 41 that stores a cleaning liquid (bubble mixed cleaning liquid) W and a gas tank unit 42 that stores high-pressure nitrogen gas. The two-fluid nozzle head 40 is formed with a plurality of nozzles 45 extending downward from the cleaning liquid reservoir 41. Although not shown, a gas passage is formed so as to open outward from the tips of the plurality of nozzles 45 from the gas tank section 42 through the outer periphery of the cleaning liquid storage section 41. A delivery pipe 12 b extending from the pump 13 is connected to the outer wall portion of the two-fluid nozzle head 40 to form a cleaning liquid inlet 43 communicating with the cleaning liquid storage section 41 and a transmission pipe extending from the nitrogen gas supply section 15. A gas introduction port 44 connected to the gas tank portion 42 is formed.

  In such a two-fluid nozzle head 40, the cleaning liquid W that is pressure-fed through the transmission pipe 12b is introduced into the cleaning liquid reservoir 41 through the cleaning liquid inlet 43, and the high-pressure that is supplied through the transmission pipe 16a. Nitrogen gas is introduced into the gas tank 42 through the gas inlet 44. When the cleaning liquid W stored in the cleaning liquid reservoir 41 is discharged from each nozzle 45, high-pressure nitrogen gas is jetted from the gas tank section 42 to the tip of each nozzle 45 through the gas passage. As a result, the cleaning liquid discharged from each nozzle 45 is atomized into a mist (mist) and the nitrogen gas becomes fine bubbles and is mixed into each mist. The diameter of the mist particle of the cleaning liquid W ejected from each nozzle 45 is about several tens of μm, and the diameter of the bubble of nitrogen gas contained therein is smaller than the diameter of the mist particle.

The mist-shaped bubble mixed cleaning liquid W ejected from each nozzle 45 of the two-fluid nozzle head 40 having the above-described structure is collected and returned to the liquid storage tank 11 through the transmission pipe 12c. As a result, the bubble mixed washing liquid W is circulated between the secondary fluid head nozzles 40 as the principal portion of the savings liquid tank 11 and the bubble mixing mechanism. The circulation of the bubble mixed cleaning liquid W increases the number of fine bubbles in the bubble mixed cleaning liquid in the liquid storage tank 11 as in the case of the aspirator 14.

  In the substrate cleaning apparatus 10 described above, the bubble mixed cleaning liquid W in the liquid storage tank 11 is pressurized by nitrogen gas held at a relatively high predetermined pressure (for example, a pressure higher than the pressure at the time of bubble generation). However, the bubble mixed cleaning liquid W in the liquid storage tank 11 can be pressurized by a mechanical mechanism such as a piston mechanism instead of a gas such as nitrogen gas. However, when the bubble mixed cleaning liquid W is pressurized with a gas such as nitrogen gas, the gas can be expected to melt from the surface of the bubble mixed cleaning liquid. Therefore, the concentration of dissolved gas in the bubble mixed cleaning liquid W can be increased. From this point of view, it is preferable to pressurize the bubble mixed cleaning liquid W with a gas such as the nitrogen gas.

  Further, in the substrate cleaning apparatus 10 described above, the nitrogen gas from the nitrogen gas supply unit 15 is mixed in the cleaning liquid W (supplied to the aspirator 14), and the bubble mixed cleaning liquid W stored in the liquid storage tank 11 is pressurized. However, it is also possible to supply gas (for example, nitrogen gas) from separate sources.

  In the above-described embodiment, the bubble mixed liquid is sprayed onto the glass substrate 100 as the object to be cleaned as the cleaning liquid W, but the bubble mixed liquid is processed other than cleaning (for example, decomposition of organic matter). It can also be used.

  As described above, the bubble generation method and apparatus according to the present invention have an effect that the bubbles in the liquid can be more efficiently miniaturized, and are extremely fine bubbles called micro-nano bubbles and nano bubbles. It is useful as a bubble generation method and apparatus for generating water in a liquid.

DESCRIPTION OF SYMBOLS 10 Substrate cleaning apparatus 11 Liquid storage tank 12a, 12b, 12c Delivery pipe 13 Pump 14 Aspirator 16a, 16b Delivery pipe 17a 17b Regulator 18a, 18b On-off valve 19 Dissolved gas sensor 20 Exhaust pipe 21 On-off valve 22a, 22b Delivery pipe 23 On-off valve 24 Pump 30 Nozzle head (processing head unit)
40 Two-fluid nozzle head 41 Cleaning liquid storage section 42 Air tank section 43 Cleaning liquid inlet 44 Air inlet 45 Nozzle 100 Glass substrate (object to be cleaned)
141 Liquid introduction part 142 Gas-liquid discharge part 143 Gas introduction part 144 Restriction part 145 Gas-liquid mixing part

Claims (10)

A bubble mixing mechanism that mixes fine bubbles into the supply liquid;
A liquid storage tank for storing the bubble mixed liquid generated by the bubble mixing mechanism;
A return mechanism for returning the bubble mixed liquid from the liquid storage tank to the bubble mixing mechanism as the supply liquid;
A pressurizing mechanism for pressurizing the bubble mixed liquid in the liquid storage tank;
A switching mechanism that switches between a bubble mixed liquid circulation mode for circulating the bubble mixed liquid through the liquid storage tank, a return mechanism, and a bubble mixing mechanism, and a pressure mode for pressurizing the bubbles in the liquid storage tank by the pressure mechanism. A bubble generating device. The pressurizing mechanism, bubble generating device according to claim 1, further comprising a gas supply mechanism pressure supplies gas to the liquid storage tank. The bubble mixing mechanism has a gas supply source and a gas ejection mechanism for ejecting the gas from the gas supply source to the supply liquid,
The gas supply mechanism in the pressurization mechanism pressurizes and supplies the gas from the gas supply source to the liquid storage tank,
The switching mechanism, the gas from the gas supply source, and the gas ejection mechanism in the bubble mixing mechanism, according to claim 2, further comprising a gas switching mechanism for switching to either of said gas supply mechanism in the pressing mechanism Bubble generator.
A bubble generation device according to any one of claims 1 to 3 ;
A processing head unit for ejecting the processing liquid;
A processing apparatus comprising: a processing liquid supply mechanism that pressurizes and supplies the bubble mixed liquid as the processing liquid from the liquid storage tank in the bubble generating apparatus to the processing head. The processing apparatus of Claim 4 which has a means to detect the quantity of dissolved gas of the bubble mixed liquid stored in the said storage tank of the said bubble production | generation apparatus. The bubble mixing mechanism mixes fine bubbles with the supply liquid, supplies the bubble mixed liquid generated by the bubble mixing mechanism to the storage tank, and uses the bubble mixed liquid stored in the storage tank as the supply liquid to mix the bubbles. A bubble mixed liquid circulation step for circulating the bubble mixed liquid between the bubble mixing mechanism and the storage tank by returning to the mechanism;
A pressure generating step of pressurizing the bubble mixed liquid in the liquid storage tank after the bubble mixed liquid circulation step is completed. The bubble generation method according to claim 6 , wherein the pressurizing step pressurizes and supplies gas to the liquid storage tank to increase an internal pressure of the liquid storage tank. In the bubble mixed liquid circulation step, the bubble mixing mechanism jets a gas from a gas supply source to the supply liquid to mix fine bubbles with the supply liquid,
The bubble generating method according to claim 7 , wherein the pressurizing step pressurizes and supplies the gas from the gas supply source to the liquid storage tank. The bubble generating method according to claim 7 or 8 , wherein at least the pressurizing step is performed until the amount of dissolved gas in the bubble mixed liquid in the liquid storage tank reaches a predetermined amount. The bubble generating method of Claim 9 which performs the said pressurization step at least until the said dissolved gas in the said storage tank will be in a supersaturated state.

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