Chemical refining system

Abstract

To provide stable supply of high-purity chemicals.SOLUTION: A chemical refining system 10 is installed next to chemical liquid using equipment 1 and refines chemical liquid transported by a chemical liquid transport vehicle and supplies it to the chemical liquid using equipment 1, and includes a chemical liquid storage portion 11 that stores the chemical liquid, a supply line L11 connected to the chemical liquid storage portion 11 to supply the chemical liquid from the chemical liquid transport vehicle to the chemical liquid storage portion 11, a supply line L12 that connects the chemical liquid storage portion 11 to a chemical liquid supply tank 2 of the chemical liquid using equipment 1, and a purification device 13 that is installed on the supply line L12 and refines the chemical liquid stored in the chemical liquid storage portion 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a chemical solution purification system. [Background technology]

[0002] Highly purified chemicals are used in the manufacturing processes of electronic devices such as semiconductors (see, for example, Patent Documents 1 and 2). These highly purified chemicals are transported by tanker truck from chemical manufacturers and used by device manufacturers for purposes such as wafer cleaning. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-32781 [Patent Document 2] Japanese Patent Application Publication No. 2016-171213 Summary of the Invention [Problem to be solved by the invention]

[0004] Transporting chemicals by tanker truck involves the risk of contamination, which can lead to reduced device yields. This requires device manufacturers to take measures to prevent contamination, such as installing purification methods like filters, which incurs costs. For chemical manufacturers, transporting chemicals by tanker truck also has the disadvantage of potentially causing product loss and transport costs due to contamination.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a chemical liquid purification system that stably supplies high-purity chemical liquids. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the chemical liquid purification system of the present invention is a chemical liquid purification system that is installed adjacent to chemical liquid-using equipment and refines chemical liquid transported by a chemical liquid transport vehicle and supplies it to the chemical liquid-using equipment, and includes a chemical liquid storage section that stores the chemical liquid, a supply line connected to the chemical liquid storage section for supplying the chemical liquid from the chemical liquid transport vehicle to the chemical liquid storage section, a supply line that connects the chemical liquid storage section to a chemical liquid supply tank of the chemical liquid-using equipment, and a purification device that is installed on the supply line and refines the chemical liquid stored in the chemical liquid storage section.

[0007] Such a chemical purification system enables stable supply of high-purity chemicals purified by a purification device to points of use (e.g., wafer cleaning devices) of chemical-using facilities (e.g., device manufacturers) via supply lines. This reduces the risk of contamination associated with transporting chemicals in chemical transport vehicles (e.g., tank trucks) for device manufacturers. It also reduces the risk of product loss and return costs for chemical manufacturers. [Effects of the Invention]

[0008] As described above, according to the present invention, a highly pure chemical solution can be stably supplied. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a chemical liquid purification system according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a schematic configuration diagram of a chemical liquid purification system according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic configuration diagram of a chemical liquid purification system according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Components common to the following embodiments will be denoted by the same reference numerals in the drawings, and redundant descriptions will be omitted where appropriate.

[0011] (First embodiment) 1 is a schematic diagram of a chemical liquid purification system according to a first embodiment of the present invention. Note that the configuration of the chemical liquid purification system shown in the figure is merely an example, and it goes without saying that it can be modified as needed, for example, by adding valves or measuring instruments.

[0012] The chemical solution purification system 10 is installed alongside chemical solution-using equipment 1 of a device manufacturer or the like, and refines chemical solutions transported from the chemical solution manufacturer in tank trucks (chemical solution transport vehicles) and supplies the refined chemical solutions to the chemical solution-using equipment 1. There are no particular limitations on the chemical solutions that can be used, but examples include various organic solvents such as alcohols (isopropyl alcohol, methanol, ethanol, etc.), ketones (cyclohexanone, methyl isobutyl ketone, acetone, methyl ethyl ketone, etc.), esters (propylene glycol monomethyl ether acetate, butyl acetate, etc.), aromatics, and amines (N-methylpyrrolidone, etc.), as well as mixtures thereof.

[0013] The chemical liquid purification system 10 includes a supply line L11, a chemical liquid storage tank 11, a supply line L12, a liquid transfer pump 12, and a purification device 13.

[0014] The supply line L11 is configured so that one end is connected to the chemical storage tank 11 and the other end can be connected to the discharge port of the tank truck (not shown) via a hose and a joint (e.g., a coupler) in order to supply the chemical from the tank truck to the chemical storage tank 11. The other end of the supply line L11 may branch into two or more branches, each of which can be connected to the discharge port of the tank truck. The chemical storage tank 11 functions as a storage unit that stores the chemical supplied from the tank truck through the supply line L11. The supply line L12 is connected to the chemical storage tank 11 at one end and to the chemical supply tank 2 of the chemical-using equipment 1 at the other end. A liquid delivery pump 12 and a purification device 13 are provided on the supply line L12. The liquid delivery pump 12 has the function of circulating the chemical stored in the chemical storage tank 11 through the supply line L12. The refining device 13 has a function of purifying the liquid chemical in the liquid chemical storage tank 11, which is supplied via the supply line L12. The refining device 13 is not particularly limited as long as it is used for purifying the liquid chemical, and for example, an ion exchanger (such as a granular ion exchange resin or a monolithic organic porous ion exchanger), a filtration membrane (such as a microfiltration membrane (MF membrane) or an ultrafiltration membrane (UF membrane)), a distillation column, a moisture adsorbent (such as zeolite), etc. can be used alone or in combination.

[0015] The chemical liquid purification system 10 also includes an analyzer 14, a controller 15, and a reflux line L13.

[0016] The analyzer 14 analyzes the chemical solution refined by the refiner 13, preferably for online analysis of impurities contained in the chemical solution. Examples of impurities to be analyzed include metals, ionic components, fine particles, organic matter, moisture, nonvolatile substances, and fine particle precursors (components that do not dissolve into fine particles in the chemical solution but aggregate to form fine particles upon drying). The specific configuration of the analyzer 14 can be appropriately selected depending on the type of impurity to be analyzed. For example, an inductively coupled plasma mass spectrometer (ICP-MS) or an inductively coupled plasma atomic emission spectrometer (ICP-AES) can be used to analyze metals. Furthermore, an ion exchanger-based concentration method can be used to analyze ionic components (a method in which the chemical solution is passed through an ion exchanger, such as a monolithic organic porous ion exchanger, and the ionic components in the chemical solution trapped on the ion exchanger are eluted into an eluent, and the ionic components in the eluent are quantified). A liquid particle counter (LPC) can be used to analyze fine particles, and a gas chromatograph mass spectrometer (GC-MS) or a gas chromatograph equipped with a flame ionization detector (GC-FID) can be used to analyze organic substances. A Karl Fischer moisture meter or an infrared spectrometer can be used to analyze moisture, and a resistivity meter can also be used when analyzing ionic components together. A high-performance liquid chromatograph (HPLC) can be used to analyze nonvolatile substances. A measurement system or instrument including a condensation particle counter (CPC) (e.g., the Liquid NanoParticle Sizer (LNS) or Scanning TPC (STPC3) manufactured by Kanomax) can be used to analyze fine particle precursors.

[0017] The control device 15 controls whether or not the chemical solution refined by the refining device 13 is supplied to the chemical solution supply tank 2 of the chemical solution-using device 1, based on the analysis results of the analyzing device 14 and whether or not there is a request for chemical solution supply from the chemical solution-using device 1. Here, a request for chemical solution supply from the chemical solution-using device 1 refers to, for example, a state in which the liquid level in the chemical solution supply tank 2 is below a predetermined upper limit liquid level, and this state can be confirmed by a liquid level sensor (not shown) provided in the chemical solution supply tank 2. Specific control by the control device 15 will be described later. The reflux line L13 branches off from the supply line L12 downstream of the refining device 13 and is connected to the chemical solution storage tank 11, and together with the supply line L12, forms a circulation line. An on-off valve V11 is provided in the supply line L12 downstream of the branch point with the reflux line L13, and the reflux line L13 is connected to the chemical solution storage tank 11 via an on-off valve V12.

[0018] The chemical purification system 10 purifies the chemical liquid as follows. That is, when the supply of the chemical liquid from a tank truck (not shown) connected to the supply line L11 to the chemical liquid storage tank 11 is completed, or when the liquid level in the chemical liquid storage tank 11 reaches a certain level or above during the supply of the chemical liquid, the liquid feed pump 12 operates to supply the chemical liquid stored in the chemical liquid storage tank 11 to the purification device 13 through the supply line L12. At the same time, the on-off valve V11 of the supply line L12 is closed and the on-off valve V12 of the reflux line L13 is opened, so that the chemical liquid supplied to the purification device 13 and purified is stored in the chemical liquid storage tank 11 through the supply line L12 and the reflux line L13. In this way, a circulating purification process is performed, and the chemical liquid stored in the chemical liquid storage tank 11 can be purified while being circulated along the circulation lines L12 and L13.

[0019] In parallel with this circulating purification process, the analytical device 14 analyzes the chemical liquid circulating through the circulation lines L12, L13 (specifically, the chemical liquid sampled after being purified by the purification device 13). Furthermore, when a request for chemical supply is received from the chemical-using facility 1, the control device 15 determines whether the quality of the chemical liquid circulating through the circulation lines L12, L13 is good or not based on the analysis results of the analytical device 14. Specifically, it is determined whether indices such as resistivity, metal concentration, water concentration, and organic impurity concentration meet predetermined standards, and if the predetermined standards are met, the quality of the circulating chemical liquid is determined to be good, and if the predetermined standards are not met, the quality is determined to be bad. Here, the predetermined standard depends on the requirements of the process in which the chemical is used in the chemical-using facility 1. For example, when the chemical to be purified is isopropyl alcohol (IPA), the resistivity is greater than 1000 MΩ·cm, preferably greater than 3000 MΩ·cm, and more preferably greater than 5000 MΩ·cm; the metal concentration is less than 100 ng / L, preferably less than 50 ng / L, and more preferably less than 5 ng / L; and the water concentration is less than 100 mg / L, preferably less than 50 mg / L. Note that waste liquid discharged from the analyzer 14 (such as the chemical liquid used in the analysis, e.g., the chemical liquid after passing through an ion exchanger in a concentration method using an ion exchanger, or the chemical liquid discharged from an in-line measuring instrument such as a particle counter or resistivity meter) may be returned to the chemical storage tank 11 and reused to reduce the amount of waste liquid, depending on its contamination status.

[0020] When the quality of the chemical liquid circulating through the circulation lines L12 and L13 is determined to be good and there is a request for chemical liquid supply from the chemical liquid-using equipment 1, the supply of the chemical liquid to the chemical liquid-using equipment 1 is started. That is, by opening the on-off valve V11 of the supply line L12, at least a portion of the circulating chemical liquid is supplied to the chemical liquid-using equipment 1 through the supply line L12 and stored in the chemical liquid supply tank 2. Thereafter, when the request for chemical liquid supply from the chemical liquid-using equipment 1 ceases, the on-off valve V11 of the supply line L12 is closed to stop the chemical liquid supply. Meanwhile, the circulatory purification process continues to be performed to prevent contamination (elution of impurities from piping, etc.) due to the accumulation of the chemical liquid. The chemical liquid supplied to the chemical liquid supply tank 2 is supplied to a point of use 4, such as a wafer cleaning device, by the action of the supply pump 3. The chemical liquid used therein is then recovered through the waste liquid recovery line L14 and delivered as waste liquid to a waste liquid recovery company.

[0021] As described above, according to this embodiment, it is possible to stably supply the high-purity chemical solution purified by the refining device 13 to the point of use 4 of the chemical solution-using facility 1 through the supply line L12. This reduces the risk of contamination associated with transporting the chemical solution by tanker truck for the chemical solution-using facility 1. Furthermore, it also reduces product loss and the cost of transporting the chemical solution back to the chemical solution manufacturer, thereby reducing total costs. Conventionally, contamination was unavoidable when connecting the tanker truck and the chemical solution-using facility 1 via a joint, so it was necessary to blow out the inside of the line with a certain amount of chemical solution before starting the supply of the chemical solution to the chemical solution-using facility 1. However, this embodiment is advantageous in that it reduces the amount of chemical solution wasted.

[0022] The request for chemical supply from the chemical-using facility 1 may be made before the start of the circulation purification process, such as when the chemical is replenished from a tank truck to the chemical storage tank 11. In this case, depending on the quality of the chemical purified in the purification device 13, the chemical may be supplied to the chemical supply tank 2 without circulating (in a so-called one-pass manner). That is, after the chemical storage tank 11 is replenished with the chemical and the supply of the chemical to the purification device 13 is started, if the control device 15 determines that the quality of the chemical purified in the purification device 13 is good, at least a portion of the chemical may be supplied directly to the chemical supply tank 2.

[0023] (Second embodiment) 2 is a schematic diagram of a chemical liquid purification system according to a second embodiment of the present invention. This embodiment differs from the first embodiment in that two chemical liquid storage tanks are provided as storage sections for storing chemical liquids. The following description will focus on these differences.

[0024] In the first embodiment, even if a chemical liquid supply request is made from chemical liquid using equipment 1 during the circulating purification process, the chemical liquid cannot be supplied to chemical liquid using equipment 1 unless the chemical liquid to be refined meets a predetermined quality standard. Also, if some kind of trouble occurs during the circulating purification process or maintenance becomes necessary as a result, the chemical liquid cannot be supplied during that time. Therefore, there is a risk that the supply of chemical liquid to chemical liquid using equipment 1 will be delayed, and in that case, the chemical liquid must be supplied from a tank truck, which carries the risk of contamination.

[0025] To avoid this, in this embodiment, two chemical liquid storage tanks 11 of the first embodiment are provided in parallel, and accordingly, two liquid feed pumps 12 of the first embodiment are also provided in parallel. That is, the chemical liquid purification system 10 of this embodiment includes first and second chemical liquid storage tanks 11a and 11b and first and second liquid feed pumps 12a and 12b associated therewith. Accordingly, the supply line L11 branches into two on the downstream side and is connected to the two chemical liquid storage tanks 11a and 11b via on-off valves V13a and V13b, respectively. The supply line L12 branches into two on the upstream side and is connected to the two chemical liquid storage tanks 11a and 11b via on-off valves V14a and V14b and liquid feed pumps 12a and 12b, respectively. The reflux line L13 also branches into two on the downstream side and is connected to two chemical liquid storage tanks 11a and 11b via on-off valves V12a and V12b, respectively.

[0026] Furthermore, in this embodiment, in addition to the supply line (hereinafter referred to as the "first supply line") L12, another supply line (hereinafter referred to as the "second supply line") L15 is provided as a configuration for connecting the two chemical liquid storage tanks 11a, 11b and the chemical liquid supply tank 2 of the chemical liquid-using equipment 1. The second supply line L15 branches into two on the upstream side and is connected to the two chemical liquid storage tanks 11a, 11b via on-off valves V15a, V15b, respectively. Specifically, the second supply line L15 is connected between the liquid delivery pumps 12a, 12b and the on-off valves V14a, V14b on the first supply line L12. As will be described in detail later, the second supply line L15 is provided to supply the chemical liquid from one of the two chemical liquid storage tanks 11a, 11b to the chemical liquid supply tank 2 while the other chemical liquid storage tank is performing a circulation purification process.

[0027] The following describes the purification and supply operations of the liquid chemicals by the liquid chemical purification system 10 of this embodiment. In this embodiment, the above-described circulation purification process is performed for each of the liquid chemical storage tanks 11a and 11b, but here, an example will be described in which the circulation purification process for the first liquid chemical storage tank 11a is performed first.

[0028] As described above, first, a circulation purification process (hereinafter also referred to as "first circulation purification process") for the first chemical liquid storage tank 11a is performed. Specifically, first, the discharge port of a tank truck (not shown) and the supply line L11 are connected via a hose and a joint (for example, a coupler), and the on-off valve V13a of the supply line L11 is opened, thereby starting the supply (replenishment) of the chemical liquid from the tank truck to the first chemical liquid storage tank 11a. Then, when a liquid level sensor (not shown) confirms that the liquid level in the first chemical liquid storage tank 11a has reached a predetermined upper limit liquid level (naturally, also when the tank of the tank truck is empty), the on-off valve V13a of the supply line L11 is closed, and the supply of the chemical liquid to the first chemical liquid storage tank 11a is terminated. Thereafter, the first liquid feed pump 12a is operated, and at the same time, the on-off valve V14a of the first supply line L12 and the on-off valve V12a of the return line L13 are opened, and the on-off valve V11 of the first supply line L12 is closed. As a result, the liquid chemical stored in the first liquid chemical storage tank 11a is supplied to the purification device 13 through the first supply line L12 by the operation of the first liquid feed pump 12a. The liquid chemical purified in the purification device 13 is then stored in the first liquid chemical storage tank 11a through the first supply line L12 and the return line L13. In this way, the first circulation purification process is performed, and the liquid chemical stored in the first liquid chemical storage tank 11a can be purified while being circulated along the circulation lines L12 and L13.

[0029] Preferably, after the first chemical liquid storage tank 11a is replenished with the chemical liquid, the on-off valve V13b of the supply line L11 is opened, so that the second chemical liquid storage tank 11b continues to be replenished with the chemical liquid during the first circulation purification process. When a liquid level sensor (not shown) confirms that the liquid level in the second chemical liquid storage tank 11b has reached a predetermined upper limit liquid level, the on-off valve V13b of the supply line L11 is closed, and the replenishment of the chemical liquid to the second chemical liquid storage tank 11b is terminated.

[0030] The first circulation purification process is performed until a chemical solution satisfying a predetermined quality standard is obtained. That is, during the first circulation purification process, the analyzer 14 analyzes the chemical solution circulating through the circulation lines L12 and L13, and based on the analysis results, the control device 15 determines whether the quality of the chemical solution circulating through the circulation lines L12 and L13 is good. Specifically, it determines whether indicators such as resistivity, metal concentration, water concentration, and organic impurity concentration meet predetermined standards. If the predetermined standards are met, the quality of the circulating chemical solution is determined to be good. If the predetermined standards are not met, the quality is determined to be bad. The quality standards used here depend on the requirements of the process in which the chemical solution is used in the chemical-using equipment 1, but they may be the same as or stricter than those used when determining whether the chemical solution can be supplied to the chemical-using equipment 1. When the quality of the circulating chemical liquid is determined to be good, the first liquid feed pump 12a is stopped, and the on-off valve V14a of the first supply line L12 and the on-off valve V12a of the reflux line L13 are closed. This stops the circulation of the chemical liquid and ends the first circulation purification process. As a result, the first chemical liquid storage tank 11a transitions to a standby state, i.e., a state in which the chemical liquid that has been refined to a high purity by the circulation purification process and determined to be of good quality is stored.

[0031] When the first chemical liquid storage tank 11a transitions to the standby state in this way, a circulation purification process (hereinafter also referred to as "second circulation purification process") is then performed in the second chemical liquid storage tank 11b. Specifically, the second liquid feed pump 12b is operated, and at the same time, the on-off valve V14b of the first supply line L12 and the on-off valve V12b of the return line L13 are opened, and the on-off valve V11 of the first supply line L12 is closed. As a result, the chemical liquid stored in the second chemical liquid storage tank 11b is supplied to the purification device 13 through the first supply line L12 by the action of the second liquid feed pump 12b. Then, the chemical liquid purified in the purification device 13 is stored in the second chemical liquid storage tank 11b via the first supply line L12 and the return line L13. In this way, the second circulation purification process is carried out, and the chemical stored in the second chemical storage tank 11b can be purified while being circulated along the circulation lines L12 and L13.

[0032] The second circulation purification process is carried out until a chemical solution that meets the same quality standards as that obtained by the first circulation purification process is obtained, and is continued thereafter to prevent contamination due to accumulation of the chemical solution.

[0033] In this chemical purification process, when a request for chemical supply is made from chemical-liquid-using equipment 1 during the second circulation purification process, the chemical is supplied from first chemical-liquid-storage tank 11a, which is in a standby state, rather than from second chemical-liquid-storage tank 11b, which is currently performing the second circulation purification process. That is, first liquid-transfer pump 12a is operated and on-off valve V15a of second supply line L15 is opened, so that the high-purity chemical stored in first chemical-liquid-storage tank 11a is supplied to chemical-liquid-using equipment 1 through second supply line L15 and stored in chemical-liquid-supply tank 2. Thereafter, when the request for chemical supply from chemical-liquid-using equipment 1 ceases, first liquid-transfer pump 12a is stopped and on-off valve V15a of second supply line L15 is closed. In this way, the supply of chemical liquid from the first chemical liquid storage tank 11a to the chemical liquid using equipment 1 is stopped, and the first chemical liquid storage tank 11a is maintained in a standby state in preparation for the next request for chemical liquid supply from the chemical liquid using equipment 1.

[0034] On the other hand, if it is confirmed that the liquid level in the first chemical storage tank 11a has reached a predetermined lower limit before the request for chemical supply from the chemical-using equipment 1 is discontinued, the supply of chemical from the first chemical storage tank 11a is stopped, and the chemical determined to be of good quality continues to be supplied from the second chemical storage tank 11b, which is performing the second circulation purification process. Specifically, by opening the on-off valve V11 of the first supply line L12, at least a portion of the chemical circulating through the circulation lines L12 and L13 including the second chemical storage tank 11b is supplied to the chemical-using equipment 1 through the first supply line L12 and stored in the chemical supply tank 2. Thereafter, when the request for chemical supply from the chemical-using equipment 1 is discontinued, the second liquid delivery pump 12b is stopped, and the on-off valves V11 and V14b of the first supply line L12 and the on-off valve V12b of the reflux line L13 are closed. As a result, the supply of chemical liquid from the second chemical liquid storage tank 11b to the chemical liquid using equipment 1 is stopped, and the circulation of the chemical liquid is also stopped, the second circulation purification process is terminated, and the second chemical liquid storage tank 11b transitions to a standby state.

[0035] When second chemical liquid storage tank 11b transitions to a standby state, the first circulating purification process, which is the circulating purification process of first chemical liquid storage tank 11a, is performed again. Specifically, preferably, chemical liquid is replenished to first chemical liquid storage tank 11a while the second circulating purification process is being performed, and when second chemical liquid storage tank 11b transitions to a standby state, the first circulating purification process is initiated using the same procedure as described above. The first circulating purification process is continued even after a chemical liquid that meets the predetermined quality standard is obtained in order to prevent contamination due to accumulation of chemical liquid.

[0036] As described above, in this embodiment, the first circulation purification process and the second circulation purification process are alternately and repeatedly performed, and when a request for chemical liquid supply is received from chemical liquid using equipment 1, the chemical liquid is supplied to chemical liquid supply tank 2 from one of the two chemical liquid storage tanks 11a, 11b that is not performing the circulation purification process, i.e., the chemical liquid storage tank in a standby state. This allows the chemical liquid to be quickly supplied to chemical liquid supply tank 2 even if chemical liquid supply requests are frequently received from chemical liquid using equipment 1. Furthermore, even if some kind of trouble occurs during the circulation purification process and maintenance is required as a result, the supply of chemical liquid to chemical liquid using equipment 1 is not delayed. As a result, a high-purity chemical liquid can be stably supplied to chemical liquid supply tank 2.

[0037] However, since the chemical liquid remains in the standby chemical liquid storage tanks 11a and 11b, there is a risk of contamination, and the quality of the chemical liquid in the standby chemical liquid storage tanks 11a and 11b may be reduced. Therefore, as shown in the figure, it is preferable that a purification device (second purification device) 16, separate from the purification device (first purification device) 13 provided on the first supply line L12, is provided on the second supply line L15. This allows the chemical liquid in the standby chemical liquid storage tanks 11a and 11b to be purified again and supplied to the chemical liquid supply tank 2, thereby minimizing the impact of contamination due to retention. The second purification device 16 may have a configuration similar to that of the first purification device 13. However, in practice, the second purification device 16 may be configured to remove contaminants such as eluates from the chemical liquid storage tanks 11a and 11b. For example, the second purification device 16 may be configured to combine a granular ion exchange resin with an MF membrane.

[0038] In this embodiment, two chemical liquid storage tanks 11a, 11b are provided in parallel, but the number of chemical liquid storage tanks is not limited to this, and three or more chemical liquid storage tanks may be provided in parallel. In this case, too, the circulation purification process is performed sequentially for each chemical liquid storage tank until a request for chemical liquid supply is received from chemical liquid using equipment 1, and the chemical liquid storage tanks transition to a standby state in the order in which the circulation purification process is completed. Then, when a request for chemical liquid supply is received from chemical liquid using equipment 1, if there is a standby chemical liquid storage tank, the chemical liquid (preferably purified by second purification device 16) is supplied from the standby chemical liquid storage tank to chemical liquid supply tank 2 through second supply line L15 while the circulation purification process currently being performed is continued. Note that when there are multiple standby chemical liquid storage tanks, the chemical liquid may be supplied from any of the chemical liquid storage tanks, but it is preferable that the chemical liquid be supplied to chemical liquid supply tank 2 from the chemical liquid storage tank that transitioned to the standby state first.

[0039] (Third embodiment) 3 is a schematic diagram of a chemical liquid purification system according to a third embodiment of the present invention. This embodiment differs from the second embodiment in that it includes a configuration for recovering and reusing chemical liquids used in chemical-using equipment. The following description will focus on these differences.

[0040] The chemical solution purification system 10 of this embodiment includes a recovery device 20 that recovers and regenerates the chemical solution used in the chemical solution-using facility 1 and supplies the regenerated chemical solution to the chemical solution storage tanks 11a and 11b. The recovery device 20 includes a waste liquid tank 21, a waste liquid analysis unit 22, a waste liquid pump 23, a chemical solution regeneration unit 24, a regenerated chemical solution analysis unit 25, and a recovery control unit 26. The recovery control unit 26 is not necessarily provided, and its function may be performed by the control device 15 of the chemical solution purification system 10.

[0041] The waste liquid tank 21 is connected to the waste liquid recovery line L14 and functions as a storage unit that recovers and stores the chemical liquid (waste liquid) used at the point of use 4. An on-off valve V21 is provided in the waste liquid recovery line L14, and a waste liquid transfer line L21 is connected to the waste liquid recovery line L14 upstream via an on-off valve V22. The waste liquid transfer line L21 is provided to transfer the waste liquid discharged from the point of use 4 through the waste liquid recovery line L14 to a waste liquid recovery facility (not shown). The waste liquid analyzer 22 is provided in the waste liquid recovery line L14 upstream of the connection with the waste liquid transfer line L21 and performs online analysis of the waste liquid discharged from the point of use 4, preferably, analysis of impurities contained in the waste liquid. The waste liquid analyzer 22 is not particularly limited, but for example, when the target is waste liquid used for cleaning (drying) electronic devices such as semiconductors and containing water as the main impurity, a resistivity meter or a moisture meter can be used.

[0042] A chemical return line L22 is connected to the waste liquid tank 21, and a waste liquid pump 23 and a chemical regeneration unit 24 are provided in this order on the chemical return line L22. The waste liquid pump 23 functions to circulate the waste liquid in the waste liquid tank 21 through the chemical return line L22. The chemical regeneration unit 24 functions to purify and regenerate the waste liquid in the waste liquid tank 21 supplied through the chemical return line L22. The chemical regeneration unit 24 is not particularly limited as long as it is used to regenerate (purify) chemicals, and for example, a unit similar to the refining device 13 can be used. The regenerated chemical analysis unit 25 is provided on the chemical return line L22 downstream of the chemical regeneration unit 24, and performs online analysis of the regenerated chemical regenerated by the chemical regeneration unit 24, preferably, analysis of impurities contained in the regenerated chemical. The regenerated chemical analysis unit 25 is not particularly limited, and for example, an appropriate unit can be selected from the known configurations described above depending on the type of impurity to be analyzed. An on-off valve V23 is provided on the chemical return line L22 downstream of the regenerated chemical analysis unit 25, and a chemical discharge line L23 is connected to the upstream side of the on-off valve V23 via an on-off valve V24. The chemical return line L22 branches into two on the downstream side and is connected to two chemical storage tanks 11a and 11b via on-off valves V25a and V25b, respectively.

[0043] The recovery control unit 26 controls the operation of the recovery device 20. Specifically, based on the analysis results of the waste liquid analysis unit 22, the recovery control unit 26 controls whether or not to store the waste liquid from the point of use 4 in the waste liquid tank 21, and based on the analysis results of the regenerated chemical analysis unit 25, the recovery control unit 26 controls whether or not to supply the regenerated chemical regenerated by the chemical regenerator 24 to the chemical storage tanks 11a, 11b. The recovery and regeneration operations of such waste liquid will be described below. The regenerated chemical is supplied to either of the two chemical storage tanks 11a, 11b that is capable of receiving the chemical. However, the following description will be given taking as an example a case where the regenerated chemical is supplied (replenished) to the first chemical storage tank 11a.

[0044] Recovery of waste liquid from the point of use 4 is performed as follows. First, the on-off valve V21 of the waste liquid recovery line L14 is closed and the on-off valve V22 of the waste liquid transfer line L21 is open. In other words, while the waste liquid discharged from the point of use 4 is being transferred to the waste liquid recovery facility via the waste liquid transfer line L21, the waste liquid analysis unit 22 analyzes the waste liquid. Then, based on the analysis results of the waste liquid analysis unit 22, the recovery control unit 26 determines the degree of contamination of the waste liquid. Specifically, it is determined whether or not indicators such as resistivity, metal concentration, water concentration, and organic impurity concentration meet predetermined standards. If the predetermined standards are met, the waste liquid is determined to be slightly contaminated. If the predetermined standards are not met, the waste liquid is determined to be not slightly contaminated. Here, the predetermined criteria are, for example, when the chemical liquid to be purified is IPA, the resistivity is greater than 1000 MΩ cm, preferably greater than 3000 MΩ cm, the metal concentration is less than 100 ng / L, preferably less than 50 ng / L, and the water concentration is less than 100 mg / L, preferably less than 50 mg / L.

[0045] If the recovery control unit 26 determines that the contamination of the waste liquid is not light, the transfer of the waste liquid to the waste liquid recovery facility continues, but if it determines that the contamination is light, the waste liquid is recovered into the waste liquid tank 21. That is, the on-off valve V21 of the waste liquid recovery line L14 is opened and the on-off valve V22 of the waste liquid transfer line L21 is closed, so that the waste liquid from the point of use 4 is supplied to and stored in the waste liquid tank 21 through the waste liquid recovery line L14. Thereafter, when a liquid level sensor (not shown) confirms that the liquid level in the waste liquid tank 21 has reached a predetermined upper limit liquid level, the on-off valve V21 of the waste liquid recovery line L14 is closed and the on-off valve V22 of the waste liquid transfer line L21 is opened, so that the recovery of the waste liquid into the waste liquid tank 21 is stopped. The waste liquid from the use point 4 is transferred to a waste liquid recovery facility through a waste liquid transfer line L21 and taken over by a waste liquid recovery company until the liquid level in the waste liquid tank 21 drops and the waste liquid can be accepted, and if it is determined that the contamination is light, it is recovered again in the waste liquid tank 21.

[0046] The waste liquid regeneration process by the chemical regeneration unit 24 is initiated when the liquid level in the waste liquid tank 21 reaches a certain level or above and a request for chemical supply is made from the first chemical storage tank 11a (for example, when it is confirmed that the liquid level in the first chemical storage tank 11a has fallen below a predetermined upper limit). That is, the waste liquid in the waste liquid tank 21 is supplied to the chemical regeneration unit 24 by operating the waste liquid pump 23. The regenerated chemical is then first discharged from the chemical return line L22 through the chemical discharge line L23 to the outside by closing the on-off valve V23 in the chemical return line L22 and opening the on-off valve V24 in the chemical discharge line L23. In parallel with this, the regenerated chemical is analyzed by the regenerated chemical analysis unit 25, and based on the analysis results, the recovery control unit 26 determines whether the quality of the regenerated chemical is good. Specifically, it is determined whether or not indicators such as resistivity, metal concentration, water concentration, and organic impurity concentration meet predetermined standards. If the predetermined standards are met, the quality of the regenerated chemical liquid is determined to be good. If the predetermined standards are not met, the quality is determined to be poor. The quality standards in this case may be the same as the quality of the chemical liquid supplied from the tank truck. Note that the waste liquid discharged from the regenerated chemical liquid analysis unit 25 (the regenerated chemical liquid used for analysis) may be returned to the waste liquid tank 21 and reused, depending on its contamination status, in order to reduce the amount of waste liquid.

[0047] If the recovery control unit 26 determines that the quality of the regenerated chemical liquid is good, the supply of the regenerated chemical liquid to the first chemical liquid storage tank 11a is started. That is, the on-off valve V24 of the chemical liquid discharge line L23 is closed and the on-off valves V23 and V25a of the chemical liquid return line L22 are opened, thereby supplying the regenerated chemical liquid to the first chemical liquid storage tank 11a through the chemical liquid return line L22. Thereafter, when the request for chemical liquid supply from the first chemical liquid storage tank 11a ceases (for example, when it is confirmed that the liquid level in the first chemical liquid storage tank 11a has reached a predetermined upper limit), or when it is confirmed that the liquid level in the waste liquid tank 21 has reached a predetermined lower limit, the on-off valves V23 and V25a of the chemical liquid return line L22 are closed, and the supply of the regenerated chemical liquid to the first chemical liquid storage tank 11a is stopped. At the same time, the waste liquid pump 23 is stopped, and the waste liquid regeneration process by the chemical regeneration unit 24 is also stopped.

[0048] If a request for supply of the regenerated chemical liquid from the second chemical liquid storage tank 11b is made before the supply of the regenerated chemical liquid to the first chemical liquid storage tank 11a is stopped (for example, when it is confirmed that the liquid level in the second chemical liquid storage tank 11b has fallen below a predetermined upper limit liquid level), the regenerated chemical liquid is supplied to the second chemical liquid storage tank 11b following the supply of the regenerated chemical liquid to the first chemical liquid storage tank 11a. That is, while the waste liquid is being collected in the waste liquid tank 21 and the waste liquid regeneration process by the chemical liquid regeneration unit 24 is continuing, the on-off valve V25b of the chemical liquid return line L22 is opened and the on-off valve V25a of the same line L22 is closed. In this way, the regenerated chemical liquid is supplied to the second chemical liquid storage tank 11b until the request for chemical liquid supply from the second chemical liquid storage tank 11b disappears (for example, it is confirmed that the liquid level in the second chemical liquid storage tank 11b has reached a predetermined upper limit liquid level) or it is confirmed that the liquid level in the waste liquid tank 21 has reached a predetermined lower limit liquid level.

[0049] In this way, in this embodiment, it is possible to regenerate and reuse waste liquid that meets predetermined standards among the waste liquid discharged from chemical-using equipment 1, thereby reducing the amount of waste liquid handed over to waste liquid recovery companies. As a result, the cost of collecting waste liquid is reduced, thereby achieving further cost reductions.

[0050] In this embodiment, the regenerated chemical regenerated by the chemical regenerating unit 24 is supplied to one of the two chemical storage tanks 11a, 11b. However, the supply destination of the regenerated chemical is not limited thereto. For example, if neither of the two chemical storage tanks 11a, 11b can accept the chemical, the regenerated chemical regenerated by the chemical regenerating unit 24 may be supplied to another reuse destination via the chemical transfer line L22 and the chemical discharge line L23 for reuse as, for example, a valuable resource or a semi-high-purity product. This also applies when the quality of the regenerated chemical is determined to be poor. Furthermore, although only one waste liquid tank 21 is provided in this embodiment, two or more waste liquid tanks may be provided in parallel. In this case, if neither of the two chemical storage tanks 11a, 11b can accept the chemical when the liquid level in one waste liquid tank reaches a predetermined upper limit, collection of waste liquid into one waste liquid tank may be stopped, followed by collection of waste liquid into the other waste liquid tank. Furthermore, when the regenerated chemical solution regenerated by the chemical solution regenerating unit 24 is supplied to one of the two chemical solution storage tanks 11a, 11b, once the liquid level in one of the waste liquid tanks reaches a predetermined lower limit liquid level, the waste liquid may be continuously supplied from the other waste liquid tank to the chemical solution regenerating unit 24. It goes without saying that in this embodiment as well, the number of chemical solution storage tanks is not limited to two, and may be three or more. [Explanation of symbols]

[0051] 1 Chemical solution equipment 2 Chemical supply tank 3. Supply pump 4 Use Points 10. Chemical purification system 11, 11a, 11b Chemical storage tank 12, 12a, 12b Liquid transfer pump 13,16 Purification equipment 14 Analyzer 15 Control device 20 Recovery Device 21 Waste liquid tank 22 Wastewater Analysis Department 23 Wastewater pump 24 Chemical Solution Regeneration Department 25 Regenerative Chemical Analysis Department 26 Recovery control section L11 Supply Line L12 Supply line (first supply line) L13 Reflux line L14 Waste liquid collection line L15 Second supply line L21 Waste liquid transfer line L22 Chemical return line V11, V12, V12a to V15a, V12b to V15b, V21 to V24, V25a, V25b On-off valves

Claims

1. A chemical solution purification system that is installed next to a chemical solution-using facility, purifies a chemical solution transported by a chemical solution transport vehicle, and supplies the purified chemical solution to the chemical solution-using facility, a drug solution storage section that stores the drug solution; a supply line connected to the chemical storage unit to supply the chemical from the chemical transport vehicle to the chemical storage unit; a supply line connecting the chemical liquid storage unit and a chemical liquid supply tank of the chemical liquid using equipment; a purification device provided in the supply line for purifying the chemical stored in the chemical storage section.

2. an analyzer for analyzing the chemical solution purified by the purification device; 2. The chemical liquid purification system according to claim 1, further comprising: a control device that controls whether or not the purified chemical liquid is supplied to the chemical liquid supply tank based on the analysis result of the analysis device and whether or not there is a request for chemical liquid supply from the chemical liquid using facility.

3. 3. The chemical solution refining system according to claim 2, wherein the control device, when receiving a request for chemical solution supply from the chemical solution using facility, determines whether the quality of the refined chemical solution is good based on the analysis results, and supplies the refined chemical solution to the chemical solution supply tank if it determines that the quality is good.

4. a reflux line branching from the supply line downstream of the purification device and connected to the chemical solution storage section, the reflux line constituting a circulation line together with the supply line; 3. The chemical solution purification system according to claim 2, wherein the control device executes a circulation purification process of circulating the chemical solution stored in the chemical solution storage section along the circulation line until a request for chemical solution supply is received from the chemical solution-using facility.

5. 5. The chemical solution purification system according to claim 4, wherein, when a request for chemical solution supply is received from the chemical solution-using facility, the control device determines whether the quality of the chemical solution circulating through the circulation line is good based on the analysis result, and if it determines that the quality is good, supplies at least a portion of the circulating chemical solution to the chemical solution supply tank.

6. the chemical solution storage unit has a plurality of tanks arranged in parallel with each other, The control device the circulation purification process is sequentially performed for each tank until a request for chemical supply is received from the chemical-using facility; 5. The chemical liquid purification system according to claim 4, wherein while the circulating purification process is being performed in each of the tanks, it is determined based on the analysis results whether the quality of the chemical liquid circulating through the circulation line is good, and if it is determined that the quality is good, the circulation of the chemical liquid is stopped to terminate the circulating purification process, the tank is put into a standby state, and then the circulating purification process is performed on a next tank.

7. the plurality of tanks are connected to the chemical liquid supply tank via the supply line, and are also connected to the chemical liquid supply tank via a supply line separate from the supply line; 7. The chemical solution purification system according to claim 6, wherein, when a request for chemical solution supply is received from the chemical solution-using facility and there is a tank in a standby state, the control device supplies the chemical solution from the standby tank to the chemical solution supply tank through the separate supply line while continuing the circulatory purification process being performed at that time.

8. 8. The chemical liquid refining system according to claim 7, wherein when a request for chemical liquid supply is received from the chemical liquid using equipment, if there are multiple tanks in the standby state, the control device supplies the chemical liquid to the chemical liquid supply tank from the tank that first transitioned to the standby state.

9. 9. The chemical solution purification system according to claim 7, further comprising: another purification device provided on the other supply line for purifying the chemical solution to be supplied from the standby tank to the chemical solution supply tank.

10. 9. The chemical solution refining system according to claim 1, further comprising a recovery device that recovers and regenerates the chemical solution used in the chemical solution-using facility and supplies the regenerated chemical solution to the chemical solution storage section.

11. 11. The chemical liquid purification system according to claim 10, wherein the recovery device comprises: a waste liquid storage section that stores the used chemical liquid; a regeneration section that regenerates the chemical liquid stored in the waste liquid storage section; an analysis section that analyzes the chemical liquid regenerated by the regeneration section; and a control section that controls whether or not the regenerated chemical liquid is supplied to the chemical liquid storage section based on an analysis result of the analysis section.

12. the recovery device has a separate analysis unit that analyzes the used chemical solution, The chemical solution refining system according to claim 11 , wherein the control unit controls whether or not the used chemical solution is stored in the waste liquid storage unit based on the analysis result of the other analysis unit.

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