JP2012222070A - Liquid management system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a management system in which the concentration and the volume of liquid can be maintained within a certain range while circulating the liquid between a mixing tank and a cleaning device.SOLUTION: The liquid management system has: a mixing tank 4 in which a cleaning liquid containing alcohol and pure water is prepared; alcohol supply means for supplying alcohol to the mixing tank 4; pure water supply means for supplying pure water to the mixing tank 4; circulation means for circulating the cleaning liquid between the mixing tank 4 and a cleaning device 100; liquid volume measuring means for measuring the volume of the cleaning liquid in the mixing tank 4; concentration measuring means for measuring the component concentration of the cleaning liquid; first control means for performing liquid volume adjustment processing based on the measurement results of the liquid volume measuring means; and second control means for performing concentration adjustment processing based on the measurement results of the concentration measuring means.

Description

  The present invention relates to a system for managing a liquid used for cleaning and drying of semiconductor wafers, LCD (Liquid Crystal Display) substrates, MEMS (Micro Electro Mechanical Systems), and the like.

  A mixture of alcohol and water may be used for cleaning or drying a semiconductor wafer or the like. Patent Document 1 describes a semiconductor wafer cleaning / drying apparatus using a liquid obtained by mixing isopropyl alcohol (IPA (isopropyl alcohol)) and ultrapure water as a cleaning liquid. Specifically, the apparatus described in Patent Document 1 includes a processing tank in which wafers are cleaned and dried, a cleaning liquid mixing unit that adjusts a cleaning liquid supplied to the processing tank to a predetermined concentration in advance, and a cleaning liquid mixing unit. And a cleaning liquid supply section for moving the cleaning liquid from the cleaning tank to the cleaning tank.

  The cleaning liquid mixing unit includes an IPA tank and a mixing tank connected to the IPA tank. The mixing tank is also connected to a supply source of ultrapure water provided outside. Furthermore, an IPA replenishment pump is provided in the middle of the pipe connecting the IPA tank and the mixing tank. On the other hand, the cleaning liquid supply unit is provided with an IPA concentration meter that measures the IPA concentration in the cleaning liquid supplied to the treatment tank.

  In the apparatus described in Patent Document 1 having the above-described configuration, a predetermined amount of IPA and ultrapure water are independently supplied to the mixing tank, and a cleaning liquid having a predetermined concentration is produced. Then, the cleaning liquid in the mixing tank is supplied to the treatment tank via the cleaning liquid supply unit.

  Here, when a decrease in the IPA concentration in the cleaning liquid is detected by the IPA densitometer, the IPA replenishment pump is activated, and IPA is additionally supplied from the IPA tank to the mixing tank. That is, the IPA concentration is adjusted by replenishing IPA.

Japanese Patent Laying-Open No. 2003-29795 ([0023] to [0027], [0037] to [0038], FIG. 1)

  In cleaning a semiconductor wafer or the like, it is ideal that a cleaning solution having a constant IPA concentration is always circulated in a constant amount. That is, it is ideal that the amount (liquid level) of the cleaning liquid in the mixing tank is maintained within a certain range. However, in practice, the liquid level in the mixing tank changes. For example, not only IPA but also water evaporates from the cleaning liquid circulating in the system. Also, part of the cleaning liquid may adhere to the wafer to be cleaned and be taken out of the system. In such a case, the liquid level of the cleaning liquid in the mixing tank decreases. On the other hand, moisture may adhere to the wafer to be cleaned and be brought into the system. In this case, the liquid level of the cleaning liquid in the mixing tank rises. In this regard, in the semiconductor wafer cleaning / drying apparatus described in Patent Document 1, the liquid level of the cleaning liquid in the mixing tank is not managed. Therefore, in the semiconductor wafer cleaning / drying apparatus described in Patent Document 1, the amount (liquid level) of the cleaning liquid in the mixing tank is not considered when adjusting the concentration of the cleaning liquid. However, if the cleaning liquid concentration is adjusted when the level of the cleaning liquid in the mixing tank is rising, that is, when the amount of the cleaning liquid in the system is increasing, the amount of IPA required for concentration adjustment increases. End up. Note that a plurality of level sensors are provided in the mixing tank in the semiconductor wafer cleaning / drying apparatus described in Patent Document 1, but the level sensors are used for the amount of ultrapure water supplied to the mixing tank. However, it is not for managing the amount (liquid level) of the cleaning liquid in which ultrapure water and IPA are mixed.

  In the semiconductor wafer cleaning / drying apparatus described in Patent Document 1, the concentration of the cleaning liquid is adjusted by replenishment with IPA. However, if the IPA concentration exceeds a predetermined value, this cannot be recovered. Therefore, when adjusting the concentration of the cleaning liquid, it is necessary to gradually approach the predetermined concentration while repeating the replenishment of IPA and the concentration measurement many times so that the IPA concentration does not exceed the predetermined value. The amount of replenishment must be small. In general, it takes time and labor to adjust the concentration of the cleaning solution. In particular, in the cleaning of semiconductor wafers, it is necessary to manage the concentration of the cleaning liquid with high accuracy. Therefore, it takes a lot of time and labor to adjust the concentration of the cleaning liquid.

  Further, Patent Document 1 describes that a plurality of mixing tanks that can be used alternately are provided. However, when the mixing tank is switched without stopping the circulation of the cleaning liquid, it becomes difficult to supply a stable cleaning liquid, for example, the amount of the circulating liquid fluctuates before and after the switching. Further, since the cleaning liquid is changed before and after the mixing tank is switched, the state of the cleaning liquid (concentration, temperature, contamination state, etc.) may change, and the process (cleaning, drying) may be affected.

  The present invention has been made in view of the above problems, and its purpose is to maintain the concentration and amount of the liquid within a certain range while circulating the liquid containing alcohol and pure water between the cleaning devices. Is to provide a simple management system.

  A liquid management system for supplying a liquid containing alcohol and pure water to a cleaning device for cleaning an object using the liquid, wherein the liquid is supplied with alcohol and pure water, and the liquid is prepared, and the mixing An alcohol supply means for supplying alcohol to the tank; a pure water supply means for supplying pure water to the mixing tank; a circulating means for circulating the liquid between the mixing tank and the cleaning device; Liquid amount measuring means for measuring the amount of the liquid, concentration measuring means for measuring the component concentration of the liquid in the mixing tank, the alcohol supply means and the pure water based on the measurement result of the liquid amount measuring means By controlling the water supply means, a first control means for performing a liquid amount adjustment process for maintaining the amount of the liquid in the mixing tank within a predetermined liquid amount range, and a measurement result of the concentration measuring means Based on the above Second control means for executing concentration adjustment processing for maintaining the concentration of the liquid component in the mixing tank within a predetermined concentration range by controlling both or one of the alcohol supply means and the pure water supply means; Have.

  According to the present invention, it is possible to maintain the concentration and amount of the liquid within a certain range while circulating the liquid to and from the cleaning device.

It is a block diagram which shows 1st embodiment of this invention. It is a block diagram which shows 2nd embodiment of this invention. It is a block diagram which shows 3rd embodiment of this invention.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described in detail. FIG. 1 is a block diagram showing a basic configuration of a liquid management system 1A according to the present embodiment.

  As shown in FIG. 1, a liquid management system 1 </ b> A according to the present embodiment is connected to a semiconductor wafer cleaning apparatus 100 and supplies a cleaning / drying liquid to the cleaning apparatus 100. Although a detailed description of the cleaning device 100 is omitted here, the cleaning device 100 includes at least a cleaning tank that cleans the semiconductor wafer using the cleaning / drying liquid supplied from the liquid management system 1A.

  As shown in FIG. 1, the liquid management system 1A is supplied with alcohol (IPA in this embodiment) and pure water (ultra pure water in this embodiment), and is collectively referred to as a cleaning / drying liquid (hereinafter referred to as “cleaning liquid”). .) Is prepared, alcohol supply means for supplying IPA to the mixing tank 4, pure water supply means for supplying ultrapure water to the mixing tank 4, and concentration measuring means connected to the mixing tank 4. And a control unit 7 that comprehensively controls the waste liquid tank 6 and the system 1A.

  The alcohol supply means includes at least the IPA supply source 2, the pipe 10, and the valve 15a shown in FIG.

  The IPA supply source 2 includes, for example, a container in which IPA is stored, and a unit that pumps the IPA in the container to the mixing tank 4. Specific examples of means for pumping IPA include nitrogen gas and a pump. The pipe 10 connects the IPA supply source 2 and the mixing tank 4, and forms a flow path for introducing IPA from the IPA supply source 2 to the mixing tank 4. The valve 15 a is provided in the pipe 10 and is controlled by the control unit 7 to adjust the start or stop of IPA introduction, the amount of IPA introduction, and the like.

  The pure water supply means has at least the ultrapure water supply source 3, the pipe 11 and the valve 15b shown in FIG.

  The pipe 11 connects the ultrapure water supply source 3 and the mixing tank 4, and forms a flow path for introducing ultrapure water from the ultrapure water supply source 3 to the mixing tank 4. The valve 15 b is provided in the pipe 11 and is controlled by the control unit 7, and adjusts the start or stop of introduction of ultrapure water, the introduction amount of ultrapure water, and the like. The ultrapure water supply source 3 may be an ultrapure water production apparatus that is directly connected to the mixing tank 4 via the pipe 11. The ultrapure water supply source 3 pumps a tank for storing ultrapure water produced by the ultrapure water production apparatus and the ultrapure water stored in the tank to the mixing tank 4 via the pipe 11. You may have a pump etc.

In order to make the concentration of the cleaning liquid in the mixing tank 4 immediately after the supply of IPA and ultrapure water uniform, the mixing tank 4 is preferably provided with a stirring mechanism. For example, circulation of cleaning liquid by a pump or the like, gas ( N ₂ or the like) is preferably blown in and stirred.

  The mixing tank 4 and the concentration measuring means (concentration measuring device 5) are connected to each other via a pipe 12. The mixing tank 4 and the waste liquid tank 6 are connected to each other via a pipe 13. The mixing tank 4 and the cleaning apparatus 100 are connected to each other via a supply pipe 14a and a recovery pipe 14b.

  Here, the component concentration of the cleaning liquid in the mixing tank 4 and the component concentration of the cleaning liquid immediately after flowing out of the mixing tank 4 are substantially the same. Therefore, it is possible to measure the component concentration of the cleaning liquid in the mixing tank 4 both when the concentration measuring device 5 is provided on the pipe 14a and when the concentration measuring device 5 is connected to a pipe branched from the pipe 14a. . That is, the measurement of the cleaning liquid component concentration in the present invention includes both the measurement of the cleaning liquid component concentration in the mixing tank 4 and the measurement of the cleaning liquid component concentration immediately after flowing out of the mixing tank 4.

  Next, the operation of the liquid management system 1A having the above configuration will be described. First, the control unit 7 opens the valves 15a and 15b shown in FIG. 1 simultaneously or sequentially and supplies IPA and ultrapure water from the IPA supply source 2 and the ultrapure water supply source 3 to the mixing tank 4. . Here, IPA and ultrapure water are supplied at a predetermined rate. In other words, a predetermined amount of IPA and ultrapure water are respectively supplied so as to obtain a cleaning liquid having an ideal component concentration (hereinafter referred to as “ideal concentration”). Thereby, IPA and ultrapure water are mixed in the mixing tank 4 to produce a cleaning liquid. However, at this time, the component concentration of the cleaning liquid in the mixing tank 4 does not always completely match the ideal concentration. This is because IPA and ultrapure water are supplied to the mixing tank 4 at a constant rate, but this rate is a calculated rate.

  When IPA and ultrapure water are supplied to the mixing tank 4 to produce a predetermined amount of cleaning liquid, the valves 15a and 15b are closed. Next, the density adjustment process is started. Specifically, a part of the cleaning liquid in the mixing tank 4 is extracted via the pipe 12 under the control of the control unit 7, and the concentration of the component is measured by the concentration measuring device 5. Thereafter, both or one of the valve 15a and the valve 15b are opened again according to the measurement result by the concentration measuring device 5, and both the IPA supply source 2 and the ultrapure water supply source 3 are used. Both or one is replenished to the mixing tank 4. More specifically, the concentration measurement by the concentration measuring device 5 and the replenishment of IPA and / or ultrapure water are repeated several times so that the component concentration of the cleaning liquid in the mixing tank 4 matches the ideal concentration. Further, the supply of IPA and ultrapure water to the mixing tank 4 for producing a predetermined amount of cleaning liquid and the concentration adjustment process can be performed simultaneously. Specifically, while supplying IPA and ultrapure water to the mixing tank 4, a part of the cleaning liquid in the mixing tank 4 is extracted to measure the component concentration, and both the valve 15a and the valve 15b are measured according to the measurement result. Or one side may be opened and closed, and an opening degree may be adjusted. Anyway, the control part 7 in this embodiment functions as a 2nd control means.

  The cleaning liquid extracted for the concentration measurement is returned to the mixing tank 4 or discarded (may be sent to the waste liquid tank 6 or discharged through another line) depending on the degree of contamination. When the concentration measuring device 5 is branched from the pipe 14 a and connected, it may be returned to the pipe 14 a or sent to the cleaning device 100. However, when a Karl Fischer moisture meter is used as the concentration measuring device 5, it is necessary to add a reagent to the cleaning liquid. Therefore, it is preferable not to return the cleaning liquid after concentration measurement to the mixing tank 4.

  When a cleaning liquid having an ideal concentration or a concentration close thereto is produced as described above, supply and recovery of the cleaning liquid from the mixing tank 4 to the cleaning device 100 is started. Specifically, the cleaning liquid in the mixing tank 4 is supplied to the cleaning tank of the cleaning apparatus 100 through the pipe 14a by the circulation means, and the used cleaning liquid is collected in the mixing tank 4 through the pipe 14b. Meanwhile, in the cleaning apparatus 100, the semiconductor wafer is cleaned and dried using the supplied cleaning liquid. That is, the cleaning liquid circulates between the liquid management system 1A (mixing tank 4) and the cleaning apparatus 100 (cleaning tank).

  Here, a liquid level measuring means (level sensor) (not shown) is provided in the mixing tank 4, and the liquid level (liquid level) of the cleaning liquid in the mixing tank 4 is continuously or intermittently monitored. . The control unit 7 executes a liquid amount adjustment process based on the monitoring result of the level sensor. Specifically, the amount of the cleaning liquid in the mixing tank 4 can be circulated between a predetermined liquid amount range (between the mixing tank 4 and the cleaning device 100 by monitoring with a level sensor, and the semiconductor wafer is cleaned in the cleaning tank. When a decrease in excess of the range sufficient for drying) is detected, the valves 15a, 15b are opened, and the IPA and ultrapure water source 3 and the ultrapure water source 3 are transferred to the mixing tank 4. Pure water is supplied at a constant rate. On the other hand, when it is detected by monitoring by the level sensor that the amount of the cleaning liquid in the mixing tank 4 has increased beyond a predetermined liquid amount range, the control unit 7 controls the waste liquid means, A part of the cleaning liquid in the mixing tank 4 is discarded. Specifically, a valve (not shown) on the pipe 13 is opened, and a part of the cleaning liquid in the mixing tank 4 is discarded to the waste liquid tank 6. In this way, a constant amount of cleaning liquid having an ideal concentration or a concentration close thereto is always held in the mixing tank 4. That is, the control unit 7 in this embodiment also functions as a first control unit.

  However, while the cleaning liquid circulates as described above, the component concentration of the cleaning liquid changes due to various factors. The most common concentration change is a decrease in IPA concentration, but other concentration changes are possible. Therefore, the concentration adjustment process is performed continuously or intermittently even during the circulation of the cleaning liquid. Specifically, the component concentration of the cleaning liquid is continuously or intermittently measured by the concentration measuring device 5 under the control of the control unit 7 and the component concentration of the cleaning liquid changes beyond a predetermined concentration range. , Both or one of IPA and ultrapure water is replenished to the mixing tank 4. Specifically, according to the measurement result of the concentration measuring device 5, both or one of the valve 15a and the valve 15b is opened, and both or one of the IPA supply source 2 and the ultrapure water supply source 3 are operated. Both or one of IPA and ultrapure water is replenished to the mixing tank 4.

  Here, from the viewpoint of reducing the amount of IPA required for concentration adjustment as much as possible, it is preferable to execute the liquid amount adjustment processing prior to the execution of the concentration adjustment processing. Further, in the liquid amount adjustment process, the amount of the cleaning liquid in the mixing tank 4 is adjusted to an amount that is within a predetermined liquid amount range and does not reach the upper limit of the liquid amount range. IPA and / or pure water are supplied so that the amount of the cleaning liquid in 4 does not exceed the upper limit of the liquid amount range.

  As the concentration measuring device 5, an ultrasonic densitometer, a specific resistance meter, an infrared spectrometer, a Brix meter, a specific gravity meter, or the like can be used. Moreover, as a liquid quantity measurement means, the liquid quantity in the mixing tank 4 may be calculated | required from the load of the mixing tank 4 using a load cell.

  In addition, a pump and a valve are installed on the above-described piping as necessary. Moreover, a filter can also be installed as needed. Furthermore, the temperature of the cleaning liquid may be controlled by installing a heat exchanger on the pipe.

  Further, when the cleaning liquid is contaminated with impurities by cleaning and drying of the semiconductor wafer, the cleaning liquid may be replaced. However, in the embodiment of the present invention, a part of the contaminated cleaning liquid is passed through the pipe 13. Then, by extracting the waste liquid tank 6 and supplying IPA and ultrapure water to the mixing tank 4, the impurities can be diluted to produce a cleaning liquid having an ideal concentration. Thereby, the cleaning liquid with the ideal concentration can be supplied to the cleaning apparatus without stopping the cleaning process without replacing all of the contaminated cleaning liquid. The extraction of the cleaning liquid and the dilution of impurities may be performed separately or simultaneously. In order to reduce the amount of IPA and ultrapure water used for diluting the impurities, a part of the cleaning solution is extracted to reduce the volume, and then IPA and ultrapure water are supplied to the mixing tank 4 to dilute the impurities. It is preferable to carry out. When the cleaning liquid is contaminated with impurities and the amount of liquid in the mixing tank 4 is reduced, the IPA and ultrapure water are added to the mixing tank 4 without extracting the contaminated cleaning liquid into the waste liquid tank 6. By supplying, it is possible to dilute impurities and make an ideal concentration cleaning solution. In order to monitor the impurity concentration of the cleaning liquid, for example, a particulate detector (particulate meter) is provided on the pipe 14a, 14b or 12 or a branch line thereof, or a sampling line directly connected to the mixing tank 4. The amount of fine particles (impurities) in the cleaning liquid may be monitored. In addition, when the impurity has a property of absorbing light, the amount of the impurity can be monitored by an absorptiometer.

(Embodiment 2)
Next, a second embodiment of the present invention will be described in detail. FIG. 2 is a block diagram showing a basic configuration of the liquid management system 1B according to the present embodiment.

  The liquid management system 1B according to the present embodiment has essentially the same configuration as the liquid management system 1A according to the first embodiment, except that the preparation tank 20 is provided. Therefore, about the structure which is common with 1 A of liquid management systems, the same code | symbol is attached | subjected in FIG. 2, and description is abbreviate | omitted.

  The alcohol supply means in this embodiment has at least the IPA supply source 2, the pipe 10, the valve 15 a, the pipe 21, and a valve (not shown) provided on the pipe 21. The pipe 21 connects the IPA supply source 2 and the preparation tank 20, and forms a flow path for supplying IPA from the IPA supply source 2 to the preparation tank 20. A valve (not shown) provided on the pipe 21 is controlled by the control unit 7 and adjusts the introduction start or introduction stop of IPA, the introduction amount of IPA, and the like.

  The pure water supply means has at least the ultrapure water supply source 3, the pipe 11, the valve 15 b, the pipe 22, and a valve (not shown) provided on the pipe 22. The pipe 22 connects the ultrapure water supply source 3 and the preparation tank 20, and forms a flow path for supplying ultrapure water from the ultrapure water supply source 3 to the preparation tank 20. A valve (not shown) provided on the pipe 21 is controlled by the control unit 7 to adjust the start or stop of introduction of ultrapure water, the introduction amount of ultrapure water, and the like.

  A stirring means is provided in the preparation tank 20, and the IPA supplied to the preparation tank 20 and ultrapure water are uniformly mixed in a short time.

  Next, the operation of the liquid management system 1B having the above configuration will be described. First, under the control of the control unit 7, valves (not shown) provided in the pipes 21 and 22 are opened, and IPA and ultrapure water are supplied from the IPA supply source 2 and the ultrapure water supply source 3 to the preparation tank 20. Supplied. Here, IPA and ultrapure water are supplied at a predetermined rate. Thereby, IPA and ultrapure water are mixed in the preparation tank 20, and a washing | cleaning liquid is made.

  After the cleaning liquid is made in the preparation tank 20 as described above, the cleaning liquid is supplied (transferred) to the mixing tank 4 as necessary. When the amount of the cleaning liquid in the preparation tank 20 decreases, the valves on the pipes 21 and 22 are opened again, and IPA and ultrapure water are supplied again from the IPA supply source 2 and the ultrapure water supply source 3 to the preparation tank 20, A cleaning liquid is made and stored in the preparation tank 20. Between the mixing tank 4 and the cleaning apparatus 100 (cleaning tank), the circulation of the cleaning liquid is started by the circulation means, and the semiconductor wafer is cleaned and dried. On the other hand, the cleaning liquid made and stored in the preparation tank 20 is supplied to the mixing tank 4 as needed under the control of the control unit 7. For example, the control unit 7 supplies the cleaning liquid in the preparation tank 20 to the mixing tank 4 and supplies the liquid in the mixing tank 4 when the amount of the cleaning liquid in the mixing tank 4 decreases beyond a predetermined liquid amount range. The replenishment process which supplements quantity is performed. In such replenishment processing, when the cleaning liquid is contaminated with impurities, a part of the cleaning liquid in the mixing tank 4 is extracted into the waste liquid tank 6 and then the cleaning liquid in the preparation tank 20 is supplied to the mixing tank 4 to remove impurities. In some cases, a step of diluting to lower the impurity concentration is included. Furthermore, when the cleaning liquid is contaminated with impurities and the amount of liquid in the mixing tank 4 is reduced, the cleaning liquid in the preparation tank 20 is mixed without extracting the contaminated cleaning liquid into the waste liquid tank 6. By supplying to the tank 4, the process of diluting impurities to produce an ideal concentration cleaning liquid may be included. Anyway, the control part 7 in this embodiment functions as a 3rd control means which performs the replenishment process which supplies the cleaning liquid in the preparation tank 20 to the mixing tank 4. FIG.

  In the liquid management system 1B, the liquid amount adjustment process and the concentration adjustment process are performed as needed under the control of the control unit 7. For example, in the circulation process of the cleaning liquid between the mixing tank 4 and the cleaning apparatus 100, the cleaning liquid made in the preparation tank 20 is supplied to the mixing tank 4 as necessary (with the above replenishment process) and the concentration Depending on the measurement result by the measuring device 5, both or one of IPA and ultrapure water is replenished to the mixing tank 4 so that the component concentration of the cleaning liquid in the mixing tank 4 matches the ideal concentration. That is, the control unit 7 in the present embodiment also functions as a first control unit and a second control unit.

  Here, the case where the cleaning liquid made in the preparation tank 20 is moved to the mixing tank 4 has been described. However, the cleaning liquid may be simultaneously prepared in each of the mixing tank 4 and the preparation tank 20. In this case, similarly to the liquid management system 1A, supply of IPA and ultrapure water to the mixing tank 4 and concentration adjustment are performed, and a cleaning liquid is produced in the mixing tank 4. At the same time, valves (not shown) provided in the pipes 21 and 22 are opened, and IPA and ultrapure water are supplied from the IPA supply source 2 and the ultrapure water supply source 3 to the preparation tank 20 at a constant rate. The Thereby, in each of the mixing tank 4 and the preparation tank 20, a cleaning liquid in which IPA and ultrapure water are mixed at a predetermined ratio is simultaneously formed. Also in this case, the cleaning liquid in the preparation tank 20 is supplied to the mixing tank 4 as necessary.

  In any case, in the liquid management system 1B according to the present embodiment, a cleaning liquid in which IPA and ultrapure water are mixed at a constant ratio is always prepared in the preparation tank 20. Therefore, replenishment of the cleaning liquid, concentration adjustment, and dilution / reduction of impurities can be performed more quickly. Furthermore, the fluctuations in the component concentration of the cleaning liquid can be reduced more than when the concentration of the cleaning liquid is adjusted by supplying IPA and ultrapure water directly to the mixing tank 4.

  In addition, the piping layout shown by FIG. 2 is an example, and can be changed suitably. For example, the pipe 21 shown in FIG. 2 may be connected to the IPA supply source 2 via the pipe 10. In other words, the pipe 21 may be branched from the pipe 10. Further, the pipe 22 shown in FIG. 2 may be connected to the ultrapure water supply source 3 through the pipe 11. In other words, the pipe 22 may be branched from the pipe 11.

  Further, a level sensor may be provided in the preparation tank 20 to perform the liquid level management of the cleaning liquid. In this case, when the level of the cleaning liquid in the preparation tank 20 is detected by monitoring with the level sensor, IPA and ultrapure water are supplied to the preparation tank 20.

(Embodiment 3)
Next, a third embodiment of the present invention will be described in detail. FIG. 3 is a block diagram showing a basic configuration of the liquid management system 1C according to the present embodiment.

  The liquid management system 1C according to the present embodiment has essentially the same configuration as the liquid management system 1B according to the second embodiment, except that the leveling tank 30 is provided. Therefore, about the structure which is common in the liquid management system 1B, the same code | symbol is attached | subjected in FIG. 3, and description is abbreviate | omitted.

  The alcohol supply means in this embodiment has at least the IPA supply source 2, the pipe 10, the valve 15 a, the pipe 21, the valve (not shown) on the pipe 21, the pipe 34, and the valve 36 a on the pipe 34. The pipe 34 is branched from the pipe 21 and forms a flow path for supplying IPA from the IPA supply source 2 to the leveling tank 30. The valve 36a provided on the pipe 34 is controlled by the control unit 7 and adjusts the start or stop of introduction of IPA, the introduction amount of IPA, and the like.

  The pure water supply means has at least the ultrapure water supply source 3, the pipe 11, the valve 15 b, the pipe 22, a valve (not shown) on the pipe 22, a pipe 35, and a valve 36 b on the pipe 35. The pipe 35 is branched from the pipe 22 and forms a flow path for supplying ultrapure water from the ultrapure water supply source 3 to the leveling tank 30. The valve 36b provided on the pipe 35 is controlled by the control unit 7, and adjusts the start or stop of introduction of ultrapure water, the introduction amount of ultrapure water, and the like.

  The leveling tank 30 is located between the preparation tank 20 and the mixing tank 4, is connected to the preparation tank 20 via a pipe 31, and is connected to the mixing tank 4 via a pipe 32. Further, the leveling tank 30 is connected to the concentration measuring device 5 through a pipe 33. In FIG. 3, the concentration measuring device 5 is connected to both the mixing tank 4 and the leveling tank 30. That is, the concentration measuring device 5 in this embodiment functions as both the first concentration measuring means and the second concentration measuring means. However, a concentration measuring device for the mixing tank 4 and a concentration measuring device for the leveling tank 30 may be provided separately.

  Next, the operation of the liquid management system 1C having the above configuration will be described. First, under the control of the control unit 7, valves (not shown) provided on the pipes 21 and 22 are opened, and IPA and ultrapure water are supplied from the IPA supply source 2 and the ultrapure water supply source 3 to the preparation tank 20. Supplied to each. Here, IPA and ultrapure water are supplied at a predetermined rate. Thereby, IPA and ultrapure water are mixed in the preparation tank 20, and a washing | cleaning liquid is made.

  After the cleaning liquid is made in the preparation tank 20 as described above, the cleaning liquid is supplied (transferred) from the preparation tank 20 to the leveling tank 30. Next, density adjustment processing is executed. Specifically, a part of the cleaning liquid in the leveling tank 30 is extracted via the pipe 33 under the control of the control unit 7, and the concentration of the component is measured by the concentration measuring device 5. Thereafter, both or one of the valves 36a and 36b is opened according to the measurement result by the concentration measuring device 5, and the IPA and / or ultrapure water is leveled from the IPA supply source 2 and / or the ultrapure water supply source 3. The tank 30 is replenished. More specifically, the concentration measurement by the concentration measuring device 5 and the replenishment of IPA and / or ultrapure water are repeated several times so that the component concentration of the cleaning liquid in the leveling tank 30 matches the ideal concentration.

  The cleaning liquid in the leveling tank 30 produced as described above is supplied to the mixing tank 4 as needed under the control of the control unit 7. For example, the controller 7 supplies the cleaning liquid in the leveling tank 30 to the mixing tank 4 and supplies the cleaning liquid in the mixing tank 4 when the amount of the cleaning liquid in the mixing tank 4 decreases beyond a predetermined liquid amount range. A replenishment process for supplementing the liquid volume is executed. In the replenishment process, when the cleaning liquid in the mixing tank 4 is contaminated with impurities, a part of the cleaning liquid in the mixing tank 4 is extracted into the waste liquid tank 6 and then the cleaning liquid in the leveling tank 30 is mixed with the mixing tank 4. In some cases, there is a step of reducing the impurity concentration by diluting impurities. Further, when the cleaning liquid is contaminated with impurities and the amount of liquid in the mixing tank 4 is reduced, the cleaning liquid in the leveling tank 30 is removed without extracting the contaminated cleaning liquid into the waste liquid tank 6. By supplying to the mixing tank 4, the process of diluting impurities to produce a cleaning solution with an ideal concentration may be included. Anyway, the control part 7 in this embodiment functions as a 3rd control means.

  Also in the liquid management system 1C according to the present embodiment, when the amount of the cleaning liquid in the preparation tank 20 decreases after the cleaning liquid has moved from the preparation tank 20 to the leveling tank 30, the controller 7 causes the pipes 21 and 22 on The valve is opened again. Further, after the cleaning liquid moves from the leveling tank 30 to the mixing tank 4, when the amount of the cleaning liquid in the leveling tank 30 decreases, the cleaning liquid prepared in the preparation tank 20 is supplied (transferred) to the leveling tank 30. . That is, in the liquid management system 1 </ b> C according to the present embodiment, a cleaning liquid in which IPA and ultrapure water are mixed at a constant ratio is always prepared in the preparation tank 20. Further, a cleaning liquid adjusted to an ideal concentration is always prepared in the leveling tank 30. The cleaning liquid prepared in the preparation tank 20 is supplied to the leveling tank 30 as necessary, and the cleaning liquid prepared in the leveling tank 30 is supplied to the mixing tank 4 as needed. Therefore, replenishment of the cleaning liquid, concentration adjustment, dilution and reduction of impurities can be performed more quickly and with high accuracy. Furthermore, the fluctuations in the component concentration of the cleaning liquid can be reduced more than when the concentration of the cleaning liquid is adjusted by supplying IPA and ultrapure water directly to the mixing tank 4.

  Also in the liquid management system 1 </ b> C according to the present embodiment, the concentration adjustment treatment and the liquid amount adjustment processing are performed as needed under the control of the control unit 7, and the maintenance and management for setting the component concentration of the cleaning liquid to the ideal concentration are achieved. Of course. That is, the control unit 7 in this embodiment also functions as a first control unit and a second control unit.

  In the liquid management system 1 </ b> C according to this embodiment, the cleaning liquid can be simultaneously produced in two or more of the mixing tank 4, the preparation tank 20, and the leveling tank 30.

  In addition, the piping layout shown by FIG. 3 is an example, and can be changed suitably. For example, in FIG. 3, a pipe 34 connecting the IPA supply source 2 and the leveling tank 30 is branched from the pipe 21, and a pipe 35 connecting the ultrapure water supply source 3 to the leveling tank 30 is branched from the pipe 22. Has been. However, the IPA supply source 2 and the leveling tank 30 may be directly connected by an independent pipe. Further, the ultrapure water supply source 3 and the leveling tank 30 may be directly connected by an independent pipe.

  Further, a level sensor may be provided in the leveling tank 30 to manage the liquid level of the cleaning liquid. In this case, when a level drop of the cleaning liquid in the leveling tank 30 is detected by monitoring with the level sensor, IPA from the IPA supply source 2 and ultrapure water from the ultrapure water supply source 3 to the leveling tank 30 are detected. The cleaning liquid is supplied from the preparation tank 20. On the other hand, when an increase in the level of the cleaning liquid in the leveling tank 30 is detected by monitoring with the level sensor, a part of the cleaning liquid in the leveling tank 30 is discharged via a pipe (not shown).

DESCRIPTION OF SYMBOLS 1A Liquid management system 1B Liquid management system 1C Liquid management system 2 IPA supply source 3 Ultrapure water supply source 4 Mixing tank 5 Concentration measuring device 6 Waste liquid tank 7 Control part 10, 11, 21, 22, 31, 32, 34, 35 Piping 15a, 15b, 36a, 36b Valve 20 Preparation tank 30 Leveling tank

Claims (4)

A liquid management system for supplying a liquid containing alcohol and pure water to a cleaning apparatus for cleaning an object using the liquid,
A mixing tank in which alcohol and pure water are supplied to prepare the liquid;
Alcohol supply means for supplying alcohol to the mixing tank;
Pure water supply means for supplying pure water to the mixing tank;
A circulating means for circulating the liquid between the mixing tank and the cleaning device;
A liquid amount measuring means for measuring the amount of the liquid in the mixing tank;
Concentration measuring means for measuring the component concentration of the liquid in the mixing tank;
Liquid amount adjustment processing for maintaining the amount of the liquid in the mixing tank within a predetermined liquid amount range by controlling the alcohol supply unit and the pure water supply unit based on the measurement result of the liquid amount measurement unit. First control means for executing
A concentration that maintains the component concentration of the liquid in the mixing tank within a predetermined concentration range by controlling both or one of the alcohol supply unit and the pure water supply unit based on the measurement result of the concentration measurement unit. And a second control means for executing the adjustment process. The cleaning liquid management system according to claim 1,
The cleaning liquid management system, wherein the liquid amount measuring means is a level sensor that monitors the liquid level of the liquid in the mixing tank. The cleaning liquid management system according to claim 1,
Having waste liquid means for discharging the liquid in the mixing tank;
In the liquid amount adjustment process executed by the first control unit, the waste liquid unit is controlled based on the measurement result of the liquid amount measuring unit, and the amount of the liquid in the mixing tank is changed to the liquid amount. A cleaning fluid management system that includes a process of maintaining within range. The cleaning liquid management system according to claim 1 or 2,
Prior to the execution of the concentration adjustment process by the second control means, the liquid amount adjustment process by the first control means is executed,
In the liquid amount adjustment process, the amount of the liquid in the mixing tank is adjusted to an amount that is within the liquid amount range and does not reach the upper limit of the liquid amount range,
In the concentration adjustment process, a cleaning liquid management system in which both or one of alcohol and pure water is supplied to the mixing tank so that the amount of the liquid in the mixing tank does not exceed the upper limit of the liquid amount range.

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