Organic solvent collection apparatus, substrate processing apparatus, and organic solvent collection method

Abstract

(Project) Provides a technology capable of circulating a mixture of organic solvent and water under conditions suitable for a dehydrator and a filter, respectively. (Solution) An organic solvent recovery device comprises a recovery tank (Tk1), a dehydration circulation unit (60), and a purification circulation unit (80). The recovery tank (Tk) stores a mixture of organic solvent and water discharged from a processing unit (4) that processes a substrate. The dehydration circulation unit (60) includes a dehydration circulation pipe (61) connected to the recovery tank (Tk1) and a circulating dehydrator (62) that separates water from the mixture, and generates a first concentrate, which is a mixture with an increased solvent concentration of organic solvent, by circulation through the dehydration circulation pipe (61). The purification circulation unit (80) includes a purification circulation pipe (81) that circulates the first concentrate and a filter (82) that captures impurities in the first concentrate, and generates a reusable solution with a reduced impurity content in the first concentrate by circulating the first concentrate through the purification circulation pipe (81).

Description

Technology Field

[0001] The present disclosure relates to an organic solvent recovery apparatus, a substrate processing apparatus, and an organic solvent recovery method. Background Technology

[0002] Patent Document 1 discloses an IPA recovery system for recovering water-containing IPA (isopropyl alcohol) discharged from a processing unit that processes a substrate. The IPA recovery system includes a storage tank, a circulation pipe, a pump, a dewatering unit, and a filter. Water-containing IPA from the processing unit is supplied to the storage tank. The circulation pipe is connected to the storage tank and returns water-containing IPA from the storage tank to the storage tank. A pump is installed in the circulation pipe and transfers water-containing IPA from the upstream end of the circulation pipe toward the downstream end. A filter is installed in the circulation pipe and removes foreign substances from the water-containing IPA. A dewatering unit is installed in the circulation pipe and removes water from the water-containing IPA.

[0003] The IPA recovery system circulates aqueous IPA through a circulation path that includes a storage tank and circulation piping. Through this circulation, the aqueous IPA passes through a filter and a dewatering unit. As a result, the IPA concentration of the circulating aqueous IPA increases, and impurities in the aqueous IPA are reduced. In other words, through this circulation, aqueous IPA with a high concentration and cleanliness is stored in the storage tank. The aqueous IPA in this storage tank is then supplied back to the processing unit. This allows for a reduction in the amount of IPA waste. Prior art literature

[0004] Japanese Patent Publication No. 2017-41505 The problem to be solved

[0005] When a dehydration unit and a filter are installed on the same circulation path, it is difficult to circulate aqueous IPA under conditions (e.g., pressure, flow rate, or temperature) suitable for both the dehydration unit and the filter. For this reason, it was difficult to achieve both efficient improvement of solvent concentration through moisture removal by the dehydration unit and efficient purification by the filter.

[0006] Therefore, the present disclosure aims to provide a technology capable of circulating a mixture of an organic solvent and water under conditions suitable for a dehydrator and a filter, respectively. means of solving the problem

[0007] A first embodiment is an organic solvent recovery device comprising: a recovery tank for storing a mixture of organic solvent and water discharged from a processing unit for processing a substrate; a dehydration circulation pipe connected to the recovery tank; a dehydration circulation unit including a circulating dehydrator installed in the dehydration circulation pipe and also separating water from the mixture, and generating a first concentrate which is the mixture with an increased solvent concentration of the organic solvent by circulation through the dehydration circulation pipe; a purification circulation pipe for circulating the first concentrate; and a purification circulation unit including a filter installed in the purification circulation pipe and also capturing impurities of the first concentrate, and generating a reusable solution which is the first concentrate with a reduced impurity content by circulating the first concentrate through the purification circulation pipe.

[0008] A second embodiment is an organic solvent recovery device according to a first embodiment, wherein the circulating dehydrator comprises a membrane separator having a separation membrane that allows water to pass through.

[0009] A third embodiment is an organic solvent recovery device according to a first or second embodiment, wherein the circulating dehydrator includes a dehydration temperature tank for heating the mixture.

[0010] A fourth embodiment is an organic solvent recovery device according to a first or second embodiment, wherein the purification circulation unit further includes a purification temperature tank that heats or cools the first concentrate flowing through the purification circulation pipe.

[0011] A fifth embodiment is an organic solvent recovery device according to a fourth embodiment, wherein the purification temperature tank cools the first concentrate flowing through the purification circulation pipe.

[0012] A sixth embodiment is an organic solvent recovery device according to any one of the first to fifth embodiments, further comprising a purification tank and a first liquid transfer pipe that causes the first concentrate from the recovery tank to flow toward the purification tank, and the purification circulation pipe returns the first concentrate from the purification tank to the purification tank.

[0013] A seventh embodiment is an organic solvent recovery device according to any one of the first to sixth embodiments, further comprising a recovery switching unit that switches the recovery destination of the mixture from the processing unit between the first recovery tank and the second recovery tank, wherein the first dehydration circulation pipe returns the mixture from the first recovery tank to the first recovery tank, and the second dehydration circulation pipe returns the mixture from the second recovery tank to the second recovery tank.

[0014] The eighth embodiment is an organic solvent recovery device according to the seventh embodiment, wherein the first dewatering circulation pipe comprises a first upstream pipe having an upstream end connected to the first recovery tank, a first downstream pipe having a downstream end connected to the first recovery tank, and a common circulation pipe connected between the first upstream pipe and the first downstream pipe, and the second dewatering circulation pipe comprises a second upstream pipe having an upstream end connected to the second recovery tank, a second downstream pipe having a downstream end connected to the second recovery tank, and the common circulation pipe connected between the second upstream pipe and the second downstream pipe, wherein the circulating dewatering device is installed in the common circulation pipe, and the dewatering circulation unit further comprises a circulation switching valve unit that switches between circulation through the first dewatering circulation pipe and circulation through the second dewatering circulation pipe.

[0015] A ninth embodiment is an organic solvent recovery device according to any one of the first to eighth embodiments, further comprising a concentrate supply unit that switches the supply source from the recovery tank between the first purification tank and the second purification tank, wherein the first purification circulation pipe returns the first concentrate from the first purification tank to the first purification tank, and the second purification circulation pipe returns the first concentrate from the second purification tank to the second purification tank, and the first filter is installed in the first purification circulation pipe and the second filter is installed in the second purification circulation pipe.

[0016] The 10th embodiment is an organic solvent recovery device according to any one of the first to 9 embodiments, comprising a separation discharge pipe through which a separation fluid, mainly composed of water separated from the mixture by the circulating dehydrator, flows, and a decomposer installed in the separation discharge pipe and decomposing the organic solvent contained in the separation fluid.

[0017] The 11th embodiment is an organic solvent recovery device according to the 10th embodiment, further comprising a condenser installed in the separation discharge pipe upstream of the decomposer and condensing the vapor of the organic solvent contained in the separation fluid, and the decomposer electrolyzes the organic solvent which is a liquid.

[0018] The 12th embodiment is an organic solvent recovery device according to any one of the 1st to 10th embodiments, further comprising: a separation discharge pipe through which a separation fluid, mainly composed of water separated from the mixture by the circulating dehydrator, flows; a separation dehydrator installed in the separation discharge pipe and separating the organic solvent from the separation fluid; and a return pipe connected to the separation dehydrator and adding a second concentrate containing the organic solvent separated from the separation fluid by the separation dehydrator to the first concentrate.

[0019] The 13th embodiment is an organic solvent recovery device according to the 12th embodiment, wherein the separation dehydrator is installed in the separation discharge pipe and includes an adsorption filter that adsorbs the organic solvent, a heating unit that heats the adsorption filter to release the organic solvent from the adsorption filter and discharges the organic solvent into the return pipe, and a condenser installed in the return pipe.

[0020] The 14th embodiment is an organic solvent recovery device according to the 13th embodiment, wherein the first heating unit heats the first adsorption filter and the second heating unit heats the second adsorption filter, and the organic solvent recovery device comprises a dehydration switching unit that switches the adsorption filter through which the separation fluid flows between the first adsorption filter and the second adsorption filter, and a discharge switching unit that switches the adsorption filter communicating with the condenser between the first adsorption filter and the second adsorption filter.

[0021] The 15th embodiment is a substrate processing device comprising an organic solvent recovery device according to any one of the 1st to 14th embodiments, said processing unit, a supply tank to which said reuse solution is supplied and which said reuse solution is stored, and a second liquid transfer pipe connecting said supply tank and said processing unit.

[0022] The 16th embodiment is a method for recovering an organic solvent, comprising: a dehydration circulation process that generates a first concentrate with an increased solvent concentration of the organic solvent in the mixture by circulating the mixture through a dehydration circulation path including a circulating dehydrator that separates water from a mixture of an organic solvent and water; and a purification circulation process that generates a reusable solution with a reduced content of the impurities in the first concentrate by circulating the first concentrate through a purification circulation path including a filter that captures impurities in the first concentrate.

[0023] The 17th embodiment is a method for recovering an organic solvent according to the 16th embodiment, wherein, in the dehydration circulation process, the mixture is heated, and in the purification circulation process, the first concentrate is cooled. Effects of the invention

[0024] According to the first, fifth, and sixth embodiments, a mixed liquid can be circulated through a dehydration circulation pipe under conditions according to a circulating dehydrator, and a first concentrated liquid can be circulated through a purification circulation pipe under conditions according to a filter.

[0025] According to the second embodiment, the size of the apparatus can be reduced compared to that of a distiller.

[0026] According to the third embodiment, water can be efficiently separated from the mixture.

[0027] According to the fourth embodiment, the temperature of the mixture can be adjusted to a temperature suitable for the filter.

[0028] According to the fifth embodiment, even when the purification thermostat raises the temperature of the mixed solution, the first concentrate, which is at a high temperature, can be cooled to near room temperature. Because of this, thermal deformation of the filter can be suppressed, and the filter can capture impurities with high efficiency.

[0029] According to the sixth embodiment, by supplying the first concentrate, which is at a high temperature, to a purification tank through the first liquid transfer pipe, the temperature of the first concentrate can be reduced by heat dissipation while passing through the first liquid transfer pipe.

[0030] According to the seventh embodiment, the mixed liquid from the treatment unit can be recovered in the second recovery tank while the mixed liquid is circulating through the first dehydration circulation pipe, and the mixed liquid from the treatment unit can be recovered in the first recovery tank while the mixed liquid is circulating through the second dehydration circulation pipe. That is, the mixed liquid from the treatment unit can be recovered even while the mixed liquid is circulating through the first dehydration circulation pipe or while the mixed liquid is circulating through the second dehydration circulation pipe. Conversely, this prevents the mixed liquid with a low solvent concentration discharged from the treatment unit from entering the circulating mixed liquid. Therefore, the decrease in the solvent concentration of the circulating mixed liquid can be prevented.

[0031] According to the eighth embodiment, since the circulating dewatering device is used commonly in the first dewatering circulation piping and the second dewatering circulation piping, the device size and manufacturing cost can be reduced.

[0032] According to the ninth embodiment, circulation through the first filter and circulation through the second filter can be performed in parallel. As a result, a reusable solution with a lower impurity content can be produced.

[0033] According to the 10th embodiment, the drainage treatment of the separated fluid at the discharge site can be simplified.

[0034] According to the 11th embodiment, the organic solvent vapor is condensed and then the organic solvent is electrolyzed, so the organic solvent can be decomposed more reliably.

[0035] According to the 12th embodiment, a second concentrate containing an organic solvent in the separated fluid separated by a circulating dehydrator is joined to the first concentrate. Because of this, the amount of waste from the organic solvent can be further reduced.

[0036] According to the 13th embodiment, organic solvents can be separated more reliably from a separation fluid with a low solvent concentration.

[0037] According to the 14th embodiment, discharge by one of the first and second adsorption filters can be carried out in parallel with adsorption by the other of the first and second adsorption filters.

[0038] According to the 17th embodiment, the first concentrate, which is at a high temperature, can be cooled to near room temperature. Because of this, thermal deformation of the filter can be suppressed, and the filter can capture impurities with high efficiency. Brief explanation of the drawing

[0039] FIG. 1 is a plan view schematically showing an example of a substrate processing device. FIG. 2 is a side view schematically showing an example of a processing unit. FIG. 3 is a schematic diagram showing an example of an organic solvent recovery unit according to a first embodiment. Figure 4 is a flowchart showing an example of the operation of an organic solvent recovery unit. FIG. 5 is a schematic diagram showing an example of an organic solvent recovery unit according to a second embodiment. FIG. 6 is a schematic diagram showing an example of the operation of an organic solvent recovery unit. FIG. 7 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 8 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 9 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 10 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 11 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 12 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 13 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 14 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 15 is a schematic drawing showing an example of an organic solvent recovery unit according to a third embodiment. FIG. 16 is a schematic diagram showing a first example of an organic solvent recovery unit according to a fourth embodiment. FIG. 17 is a schematic diagram showing a second example of an organic solvent recovery unit according to a fourth embodiment. FIG. 18 is a schematic diagram illustrating an example of the operation of an organic solvent recovery unit according to the second example of the fourth embodiment. FIG. 19 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 20 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 21 is a diagram illustrating an example of operation of an organic solvent recovery unit. FIG. 22 is a diagram illustrating an example of operation of an organic solvent recovery unit. Specific details for implementing the invention

[0040] The embodiments are described in detail below with reference to the drawings. In addition, for the purpose of facilitating understanding, the dimensions or number of parts in the drawings may be exaggerated or simplified as necessary. Furthermore, parts having the same configuration and function are denoted by the same reference numerals, and redundant descriptions are omitted in the following explanation.

[0041] Additionally, in the descriptions below, identical components are denoted by the same reference numeral, and their names and functions are also assumed to be identical. Accordingly, detailed descriptions of them may be omitted to avoid duplication.

[0042] Furthermore, in the description below, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments and are not limited to the order in which they may occur.

[0043] Where expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless specifically stated otherwise, such expressions shall not only strictly indicate such positional relationships but also indicate a state of relative displacement with respect to angle or distance within the range where tolerances or equivalent functionality are obtained. Where expressions indicating the same state (e.g., "identical," "equal," "homogeneous," etc.) are used, unless specifically stated otherwise, such expressions shall not only strictly indicate a state of being quantitatively identical but also indicate a state where differences exist within the range where tolerances or equivalent functionality are obtained. Where expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, unless specifically stated otherwise, such expressions shall not only strictly indicate such shape geometrically but also indicate a shape having, for example, irregularities or chamfers within the range where equivalent effects are obtained. Where the expressions “have,” “have,” “have,” “include,” or “have” are used for one component, such expressions are not exclusive expressions that exclude the existence of other components. Where the expression “at least one of A, B, and C” is used, such expressions include only A, only B, only C, any two of A, B, and C, and all of A, B, and C.

[0044] <First Embodiment>

[0045] <1. Substrate Processing Device>

[0046] A substrate processing device (100) according to an embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic plan view showing an example of a substrate processing device (100).

[0047] The substrate processing device (100) is a so-called single-wafer processing device that processes substrates (W) to be processed one by one. The substrate (W) to be processed in the substrate processing device (100) is, for example, a semiconductor substrate. Also, the shape of the substrate (W) to be processed is, for example, a disc shape.

[0048] The substrate processing device (100) comprises a load port (1), an indexer robot (2), a main transport robot (3), a processing unit (4), an organic solvent recovery unit (5), and a control unit (6).

[0049] A load port (1) is an interface for moving a substrate (W) into and out of a carrier (C), which is a type of receiving container that accommodates multiple substrates. A load port (1) is installed in multiple numbers (three in the example of the drawing). The multiple load ports (1) are arranged in a row in a horizontal direction, for example. The carrier (C) may be of a type that stores the substrate (W) in a sealed space (for example, FOUP (Front Opening Unified Pod), SMIF (Standard Mechanical Interface) Pod, etc.) or may be of a type that exposes the substrate (W) to the outside air (for example, OC (Open Cassette), etc.).

[0050] The indexer robot (2) is a conveying device that conveys a substrate (W). As an example, the indexer robot (2) is a horizontal multi-joint robot and is equipped with a pair of hands (21, 21) that hold the substrate (W) and an arm (22) connected to each hand (21). In addition, the indexer robot (2) is equipped with a driving mechanism (not shown) for pivoting each hand (21) to bend, pivot, and raise each arm (22). The indexer robot (2) conveys the substrate (W) between a carrier (C) placed in a load port (1) and a main conveying robot (3). That is, the indexer robot (2) accesses the carrier (C) placed in the load port (1) and performs an outgoing operation (i.e., an operation of taking out the substrate (W) contained in the carrier (C) with the hand (21)) and an incoming operation (i.e., an operation of receiving the substrate (W) held in the hand (21) into the carrier (C). In addition, the indexer robot (2) accesses the receiving position and performs the receiving of the substrate (W) in conjunction with the main transport robot (3).

[0051] The main transport robot (3) is a transport device that transports a substrate (W). As an example, the main transport robot (3) is a horizontal multi-joint robot and is equipped with a pair of hands (31, 31) that hold the substrate (W) and an arm (32) connected to each hand (31). In addition, the main transport robot (3) is equipped with a driving mechanism (not shown) for pivoting each hand (31) to bend, pivot, and raise each arm (32). The main transport robot (3) transports the substrate (W) between the indexer robot (2) and each processing unit (4). That is, the main transport robot (3) accesses a watering position and performs watering of the substrate (W) between the indexer robot (2). Additionally, the main transport robot (3) accesses the processing unit (4) and performs an incoming operation (i.e., an operation of bringing the substrate (W) held in the hand (31) into the processing unit (4)) and an outgoing operation (i.e., an operation of bringing the substrate (W) in the processing unit (4) out to the hand (31).

[0052] The processing unit (4) performs a predetermined treatment on the substrate (W) using a processing solution (e.g., a chemical solution, a rinse solution, and IPA). Here, for example, a plurality of processing units (4) stacked vertically (e.g., three) form a single tower, and the tower is installed in multiple numbers (four in the example of the drawing) so as to surround the main transport robot (3). The specific configuration of the processing unit (4) will be explained later.

[0053] The organic solvent recovery unit (5) recovers the organic solvent from the processing unit (4) and, in addition, purifies the recovered organic solvent and supplies it back to the processing unit (4). As an example, an organic solvent recovery unit (5) may be installed in a one-to-one correspondence with each of the multiple towers, and each organic solvent recovery unit (5) may perform the recovery and supply of organic solvent to each processing unit (4) included in the corresponding tower. The specific configuration of the organic solvent recovery unit (5) will be explained later.

[0054] The control unit (6) controls the operation of each part (load port (1), indexer robot (2), main transport robot (3), processing unit (4), and organic solvent recovery unit (5)) provided by the substrate processing device (100). The control unit (6) is configured, for example, by a general computer having an electrical circuit. As an example, the control unit (6) is configured to include a CPU (Central Processor Unit) as a central processing unit that performs various calculation processing (data processing), a ROM (Read Only Memory) in which basic programs are stored, a RAM (Random Access Memory) used as a work area when the CPU performs a predetermined processing (data processing), a memory device composed of non-volatile memory devices such as flash memory and a hard disk device, and bus lines connecting these to each other. A program defining the processing to be executed by the control unit (6) may be stored in the memory device or RAM, etc. In this case, for example, by the CPU executing the program, each part of the substrate processing device (100) may be controlled by the control unit (6), and the processing defined by the program may be executed in the substrate processing device (100). That is, by the CPU executing the program, a circuit that performs the processing defined by the program may be realized in the control unit (6). Above all, some or all of the control performed by the control unit (6) (some or all of the circuit realized in the control unit (6)) may be executed (realized) by hardware such as a dedicated logic circuit.

[0055] <2. Processing Unit>

[0056] The processing unit (4) will be described with reference to FIG. 2. FIG. 2 is a schematic side view showing an example of the processing unit (4).

[0057] <2-1. Configuration of the Processing Unit>

[0058] The processing unit (4) performs a predetermined treatment on the substrate (W) using a processing solution (e.g., a chemical solution, a rinse solution, and IPA). The processing unit (4) is equipped with, for example, a spin chuck (41), a cup (42), and a nozzle (43). The spin chuck (41), the cup (42), and the nozzle (43) are accommodated in a processing chamber (44).

[0059] The spin chuck (41) maintains the substrate (W) in a horizontal position (a position in which the thickness direction of the substrate (W) follows the vertical direction) and rotates the substrate (W) around an axis (rotation axis) (A) that extends vertically through the center of its main surface. Specifically, the spin chuck (41) is provided with, for example, a spin base (411). The spin base (411) is a disc-shaped member and is positioned so that the thickness direction follows the vertical direction. A plurality of chuck pins (412) are installed on the upper surface of the spin base (411). The plurality of chuck pins (412) are arranged at equal intervals along a circumference corresponding to the periphery of the substrate (W). A link mechanism (not shown) is connected to the plurality of chuck pins (412) to move them between a contact position and an open position. A "contact position" is a position in which the chuck pin (412) contacts the periphery of the substrate (W). The “open position” is a position where the chuck pin (412) is separated from the periphery of the substrate (W). When each of the plurality of chuck pins (412) is positioned in a contact position, the substrate (W) is held (chucked) in a horizontal position above the spin base (411). Also, when each of the plurality of chuck pins (412) is positioned in an open position, the holding of the substrate (W) is released. The link mechanism switches the position of the chuck pin (412) according to instructions from the control unit (6). That is, the timing for holding the substrate (W), the timing for releasing the holding of the substrate (W), etc., are controlled by the control unit (6). Also, the spin base (411) is connected to the spin motor (414) through a shaft part (413) installed coaxially with the rotation axis (A). The shaft part (413) and the spin motor (414) are housed in the cover (415). The spin motor (414) rotates the shaft portion (413) around the rotation axis (A). As a result, the spin base (411), and furthermore, the substrate (W) held above it, rotates around the rotation axis (A). The spin motor (414) rotates the spin base (411) according to instructions from the control unit (6).That is, the number of rotations of the spin base (411) (furthermore, the substrate (W)), the timing of the start of rotation, the timing of the end of rotation, etc. are controlled by the control unit (6).

[0060] A cup (42) receives a processing liquid discharged from a substrate (W) that is maintained and rotated by a spin chuck (41). Specifically, the cup (42) is provided with, for example, a cylindrical guide portion (421) positioned coaxially with the rotation axis (A), an inclined portion (422) that extends upward and contracts in diameter as it extends upward, and a liquid receiving portion (423) that extends downward and forms an annular groove that is open upward and extends from the bottom of the guide portion (421). A cup-side recovery pipe (specifically, for example, a cup-side recovery pipe for medicinal liquid (not shown) and a cup-side recovery pipe (424) for IPA) is installed in the liquid receiving portion (423) to recover the liquid received therefrom. Additionally, a cup lifting mechanism (425) is connected to the cup (42) to raise and lower it between a lower position and an upper position. The “lower position” is a position where the upper end of the cup (42) (specifically, the upper end of the inclined portion (422)) is positioned below the substrate (W) held in the spin chuck (41). The “upper position” is a position where the upper end of the cup (42) is positioned above the substrate (W) held in the spin chuck (41). The cup lifting mechanism (425) raises and lowers the cup (42) according to instructions from the control unit (6). That is, the position of the cup (42) is controlled by the control unit (6).

[0061] The nozzle (43) discharges a processing liquid toward the upper surface of the substrate (W) held in the spin chuck (41). Here, for example, a separate nozzle (43) is installed for each type of processing liquid. That is, a nozzle (43) for discharging a chemical liquid (hereinafter also called the "chemical liquid nozzle (43a)"), a nozzle (43) for discharging a rinse liquid (hereinafter also called the "rinse liquid nozzle (43b)"), and a nozzle (43) for discharging IPA (hereinafter also called the "IPA nozzle (43c)") are installed.

[0062] The chemical solution nozzle (43a) discharges the chemical solution toward the upper surface of the substrate (W) held in the spin chuck (41). The chemical solution nozzle (43a) is connected to a chemical solution supply source (433a) through a chemical solution pipe (432a) interposed with a chemical solution valve (431a). When the chemical solution valve (431a) is opened, the chemical solution is supplied to the chemical solution nozzle (43a) through the chemical solution pipe (432a), and the chemical solution is discharged from the chemical solution nozzle (43a). The chemical solution valve (431a) is opened and closed according to instructions from the control unit (6). That is, the timing of the discharge of the chemical solution from the chemical solution nozzle (43a) is controlled by the control unit (6). The chemical solution is, for example, hydrofluoric acid. Above all, the chemical solution is not limited to hydrofluoric acid, but may be a solution containing at least one of sulfuric acid, acetic acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, ammonia water, hydrogen peroxide water, organic acid (e.g., citric acid, oxalic acid, etc.), organic alkali (e.g., TMAH: tetramethylammonium hydroxide, etc.), surfactant, and corrosion inhibitor.

[0063] The rinse liquid nozzle (43b) discharges rinse liquid toward the upper surface of the substrate (W) held in the spin chuck (41). The rinse liquid nozzle (43b) is connected to a rinse liquid supply source (433b) through a rinse liquid pipe (432b) interposed with a rinse liquid valve (431b). When the rinse liquid valve (431b) is opened, rinse liquid is supplied to the rinse liquid nozzle (43b) through the rinse liquid pipe (432b), and rinse liquid is discharged from the rinse liquid nozzle (43b). The rinse liquid valve (431b) is opened and closed according to instructions from the control unit (6). That is, the discharge timing of the rinse liquid from the rinse liquid nozzle (43b) is controlled by the control unit (6). The rinse liquid is, for example, pure water (deionized water). Above all, the rinse solution is not limited to pure water, but may be any one of carbonated water, electrolytic ionized water, hydrogen water, ozone water, and hydrochloric acid water at a diluted concentration (e.g., about 10 to 100 ppm).

[0064] The IPA nozzle (43c) discharges IPA (i.e., a liquid with IPA as its main component) toward the upper surface of the substrate (W) held in the spin chuck (41). The IPA nozzle (43c) is connected to an organic solvent recovery unit (5) through an IPA pipe (432c) interposed with an IPA valve (431c). When the IPA valve (431c) is opened, IPA is supplied to the IPA nozzle (43c) through the IPA pipe (432c), and IPA is discharged from the IPA nozzle (43c). The IPA valve (431c) is opened and closed according to instructions from the control unit (6). That is, the timing of the discharge of IPA from the IPA nozzle (43c) is controlled by the control unit (6).

[0065] Additionally, a nozzle movement mechanism for moving the nozzle between a processing position and a withdrawal position may be connected to at least one of the chemical solution nozzle (43a), the rinse solution nozzle (43b), and the IPA nozzle (43c). The “processing position” is the position where the processing solution discharged from the nozzles (43a, 43b, 43c) is supplied to the substrate (W) held in the spin chuck (41). The “withdrawal position” is the position where the nozzles (43a, 43b, 43c) are located outside (outside in the radial direction) the periphery of the substrate (W) held in the spin chuck (41) when viewed from above. In this case, the nozzle movement mechanism moves the nozzles (43a, 43b, 43c) according to instructions from the control unit (6). That is, the position of the nozzles (43a, 43b, 43c) is controlled by the control unit (6).

[0066] <2-2. Operation of the Processing Unit>

[0067] An example of the operation of the processing unit (4) is described. The operation performed in the processing unit (4) is performed under the control of the control unit (6) (i.e., by the control unit (6) controlling the chuck pin (412), spin motor (414), cup lifting mechanism (425), chemical liquid valve (431a), rinse liquid valve (431b), IPA valve (431c), etc.).

[0068] When a substrate (W) is brought into the processing chamber (44) by the main transport robot (3), the spin chuck (41) holds the substrate (W). Subsequently, the spin chuck (41) begins to rotate.

[0069] In this state, the liquid valve (431a) opens. Then, the liquid is discharged from the liquid nozzle (43a) toward the upper surface of the substrate (W) that is rotated while held in the spin chuck (41). As a result, the liquid is supplied to the entire upper surface of the substrate (W), and the substrate (W) is treated with the liquid (liquid treatment process). For example, if hydrofluoric acid is used as the liquid, foreign substances such as particles are removed from the substrate (W). During the liquid treatment process, the cup (42) is positioned in an upper position. Therefore, the liquid scattered around the substrate (W) is received in the cup (42). That is, the liquid scattered around the substrate (W) is received by the inclined portion (422), guided downward by the guide portion (421), and collected in the liquid receiving portion (423). The medicine liquid collected in the cup (42) (i.e., the medicine liquid collected in the liquid receiving part (423)) is recovered through the medicine liquid cup side recovery pipe (not shown).

[0070] After a predetermined amount of time has elapsed since the discharge of the chemical solution began, the chemical solution valve (431a) is closed. Then, the discharge of the chemical solution from the chemical solution nozzle (43a) is stopped. Subsequently, the rinse solution valve (431b) is opened. Then, the rinse solution is discharged from the rinse solution nozzle (43b) toward the upper surface of the substrate (W) that is held and rotated by the spin chuck (41). As a result, the rinse solution is supplied to the entire upper surface of the substrate (W), and the chemical solution attached to the substrate (W) is washed away by the rinse solution (rinsing process). Even while the rinse process is being performed, the cup (42) is positioned in an upper position. Accordingly, the chemical solution and rinse solution scattered around the substrate (W) are collected in the cup (42). The chemical solution and rinse solution collected in the cup (42) are recovered through the recovery pipe (not shown) on the side of the chemical solution cup.

[0071] After a predetermined amount of time has elapsed since the discharge of the rinse liquid began, the rinse liquid valve (431b) is closed. Then, the discharge of the rinse liquid from the rinse liquid nozzle (43b) is stopped. Subsequently, the IPA valve (431c) is opened. Then, IPA is discharged from the IPA nozzle (43c) toward the upper surface of the substrate (W) that is held and rotated by the spin chuck (41). As a result, IPA is supplied to the entire upper surface of the substrate (W), and the rinse liquid attached to the substrate (W) is replaced with IPA (IPA supply process). Even while the IPA supply process is being performed, the cup (42) is positioned in an upper position. Accordingly, the rinse liquid and IPA scattered around the substrate (W) are collected in the cup (42). The rinse liquid and IPA collected in the cup (42) are recovered through the IPA cup-side recovery pipe (424).

[0072] At a point when a predetermined amount of time has elapsed since the start of IPA supply, the IPA valve (431c) is closed. Then, the discharge of IPA from the IPA nozzle (43c) is stopped. At this stage, the rinse liquid on the substrate (W) is completely replaced with IPA, and a liquid film of IPA covering the entire upper surface of the substrate (W) is formed. Subsequently, the spin chuck (41) begins high-speed rotation. As a result, the substrate (W) is rotated at high speed, and the IPA on the substrate (W) is blown around the substrate (W) by centrifugal force (spin dry process). Even while the substrate (W) is rotating at high speed, the cup (42) is positioned at the upper position. Therefore, the IPA scattered around the substrate (W) is received in the cup (42). The IPA received in the cup (42) is recovered through the IPA cup-side recovery pipe (424).

[0073] After a predetermined amount of time has elapsed since the high-speed rotation of the spin chuck (41) began, the rotation of the spin chuck (41) is stopped. At this stage, the IPA is removed from the substrate (W), and the substrate (W) is dried. The dried substrate (W) is removed from the processing chamber (44) by the main transport robot (3).

[0074] With this, the series of processing steps for one substrate (W) is completed. In the processing unit (4), the above series of operations is repeated so that a plurality of substrates (W) are processed one by one in succession.

[0075] <3. Overview of the organic solvent recovery unit (5) (organic solvent recovery device)>

[0076] The configuration of the organic solvent recovery unit (5) will be explained with reference to FIG. 3. FIG. 3 is a schematic diagram showing an example of the organic solvent recovery unit (5) according to the first embodiment. Below, the overview of the organic solvent recovery unit (5) will be explained first, and then each component of the organic solvent recovery unit (5) will be explained in detail.

[0077] The organic solvent recovery unit (5) includes a recovery tank (Tk1), a dehydration circulation unit (60), a purification circulation unit (80), and a liquid transfer pipe (second liquid transfer pipe) (85). The recovery tank (Tk1) stores the recovered liquid discharged from each processing unit (4). The recovered liquid is a mixture of an organic solvent and water. The organic solvent is, for example, an organic solvent that is more volatile than water or an organic solvent with low surface tension, and a specific example is IPA (isopropyl alcohol). The mixture from each processing unit (4) flows into the recovery tank (Tk1) through the recovery pipe (51) and is stored in the recovery tank (Tk1). That is, the mixture is recovered in the recovery tank (Tk1).

[0078] The dewatering circulation unit (60) includes a dewatering circulation pipe (61) and a circulating dewatering machine (62). The dewatering circulation pipe (61) is connected to a recovery tank (Tk1). The dewatering circulation pipe (61) is a pipe that returns the mixed liquid from the recovery tank (Tk1) to the recovery tank (Tk1).

[0079] The circulating dehydrator (62) is interposed in the dehydration circulation pipe (61). Because of this, a mixed liquid is introduced into the circulating dehydrator (62). The circulating dehydrator (62) separates water from the introduced mixed liquid and causes the water to flow into the separation discharge pipe (65). The mixed liquid after separation continues to circulate through the dehydration circulation pipe (61). Due to this dehydration, the concentration of the organic solvent in the mixed liquid immediately after the circulating dehydrator (62) in the dehydration circulation pipe (61) (hereinafter referred to as solvent concentration) becomes higher than the solvent concentration of the mixed liquid immediately before the circulating dehydrator (62). Since the dehydration circulation unit (60) circulates the mixed liquid through the dehydration circulation pipe (61), the mixed liquid continues to be introduced into the circulating dehydrator (62). Because of this, the circulating dehydrator (62) continues to separate water from the mixed liquid. As a result, the solvent concentration of the circulating mixed liquid increases over time. In the following description, the mixture in which the solvent concentration has increased above a predetermined solvent standard value is referred to as the first concentrate. Also, the liquid separated from the mixture by the circulating dehydrator (62) is referred to as the separated liquid. The separated liquid is almost entirely water. The dehydration circulation unit (60) generates the first concentrate by circulating the mixture.

[0080] In the example of FIG. 3, a purification tank (Tk2) is installed in the organic solvent recovery unit (5). The first concentrate from the recovery tank (Tk1) is supplied to the purification tank (Tk2) by the concentrate supply unit (70) described later. The purification tank (Tk2) stores the first concentrate.

[0081] The purification circulation unit (80) includes a purification circulation pipe (81) and a filter (82). The purification circulation pipe (81) is a circulation pipe that circulates the first concentrate. In the example of FIG. 3, the purification circulation pipe (81) is connected to a purification tank (Tk2). The purification circulation pipe (81) is a pipe that returns the first concentrate from the purification tank (Tk2) to the purification tank (Tk2).

[0082] The filter (82) is interposed in the purification circulation pipe (81). Because of this, the first concentrate flows into the filter (82). The filter (82) captures impurities in the first concentrate. Due to this capture, the impurity content in the first concentrate immediately after the filter (82) is lower than the impurity content in the first concentrate immediately before the filter (82). Since the purification circulation unit (80) circulates the first concentrate through the purification circulation pipe (81), the first concentrate continues to flow into the filter (82). Because of this, the filter (82) continues to capture impurities from the first concentrate. As a result, the impurity content of the first concentrate being circulated decreases over time. That is, the cleanliness of the first concentrate increases over time. Hereinafter, the first concentrate in which the impurity content has been reduced to below a predetermined impurity standard is also referred to as the reusable solution. The purification circulation unit (80) generates a reusable solution by circulating the first concentrate.

[0083] The second liquid transfer pipe (85) is a pipe that allows the recycled liquid generated by the purification circulation unit (80) to flow toward the supply tank (Tk3). The recycled liquid in the supply tank (Tk3) is supplied to each processing unit (4).

[0084] As described above, the organic solvent recovery unit (5) increases the solvent concentration of the mixed liquid discharged from the processing unit (4) to produce a first concentrate, and then reduces the impurity content of the first concentrate to produce a reusable solution. This reusable solution is supplied back to the processing unit (4). That is, the substrate processing device (100) reuses the organic solvent in the mixed liquid discharged from the processing unit (4). According to this, the amount of organic solvent discarded can be reduced, allowing the organic solvent to be used more effectively. In other words, the organic solvent recovery unit (5) contributes to liquid conservation.

[0085] Furthermore, in the organic solvent recovery unit (5), the circulating dehydrator (62) is installed in the dehydration circulation pipe (61), and the filter (82) is installed in the purification circulation pipe (81). That is, the circulating dehydrator (62) and the filter (82) are installed in different circulation pipes. Because of this, the dehydration circulation unit (60) can circulate the mixed liquid under a first condition according to the circulating dehydrator (62), and the purification circulation unit (80) can circulate the first concentrated liquid under a second condition according to the filter (82). The first and second conditions are, for example, various conditions such as flow rate, pressure, and temperature for the fluid flowing through each circulation pipe, and as a specific example, a condition regarding temperature. In this case, as described in detail later, the dewatering circulation unit (60) can circulate the mixed liquid at a temperature suitable for the circulating dewatering machine (62), and the purification circulation unit (80) can circulate the first concentrated liquid at a temperature suitable for the filter (82). Additionally, in this view, a filter for capturing impurities does not need to be installed in the dewatering circulation pipe (61), and a dewatering machine for water separation does not need to be installed in the purification circulation pipe (81).

[0086] <3-1. Specific example of organic solvent recovery unit (5)>

[0087] (a1) Recovery tank (Tk1)

[0088] The recovery tank (Tk1) is connected to each cup (42) through the recovery pipe (51). That is, the cup (42) (specifically, the cup-side recovery pipe (424) connected to the cup (42)) is connected to the upstream portion of the recovery pipe (51). Here, for example, the recovery pipe (51) is connected to the cup (42) provided by each of the multiple processing units (4) belonging to the same tower. The downstream end of the recovery pipe (51) is connected to the recovery tank (Tk1). A recovery valve (52) is interposed in the recovery pipe (51). Additionally, although not shown in FIG. 3, a buffer tank may be installed between the recovery tank (Tk1) and the processing unit (4).

[0089] The recovery tank (Tk1) can be accommodated in a first receiving box (50a) (see FIG. 1). As an example, the first receiving box (50a) is placed on the outside of the outer wall (100a) of the substrate processing device (100) (for example, under the clean room where the substrate processing device (100) is installed (for example, the lower floor)).

[0090] (b1) Dehydration circulation unit (60)

[0091] In the example of FIG. 3, the dewatering circulation unit (60) includes, in addition to the dewatering circulation pipe (61) and the circulating dewatering machine (62), a pump (dewatering side liquid transfer pump) (63), a first switching valve (641), and a second switching valve (642).

[0092] The dewatering circulation pipe (61) forms a circulation path through which liquid stored in the recovery tank (Tk1) flows out of the recovery tank (Tk1) and returns to the recovery tank (Tk1). In the example of FIG. 3, the upstream end of the dewatering circulation pipe (61) is connected to the bottom of the recovery tank (Tk1), and the downstream end of the dewatering circulation pipe (61) is connected to the top of the recovery tank (Tk1).

[0093] The circulating dehydrator (62) may be, for example, a distiller, a misting separator, or a membrane separator. The circulating dehydrator (62) may separate the liquid from the mixture by heating the mixture. In the example of FIG. 3, the circulating dehydrator (62) includes a membrane separator (621) and a dehydration temperature unit (622). The membrane separator (621) includes a first path (621a), a second path (621b), and a separation membrane (621c). The first path (621a) is interposed in the dehydration circulation pipe (61) and constitutes a part of the dehydration circulation path of the dehydration circulation unit (60). For this reason, the mixture passes through the first path (621a). The separation membrane (621c) separates the first path (621a) and the second path (621b). The separator (621c) is a membrane that allows water in the mixture to pass through and almost completely blocks organic solvents. A portion of the water in the mixture introduced into the first path (621a) passes through the separator (621c) and enters the second path (621b).

[0094] The separator (621c) may be a zeolite membrane, an organic membrane, or a CNT (carbon nanotube) membrane. The zeolite membrane is, for example, a tetrahedral structure (SiO4). 4- and (AlO4) 5-The membranes have a crystal structure in which they are interconnected. The organic membrane is, for example, an organic membrane such as polyvinyl alcohol, chitosan, and polyimide. The CNT membrane is, for example, a membrane obtained by adding carbon nanotubes to a membrane such as polyamide. Alternatively, a two-dimensional material may be used as the material for the membrane (621c). The two-dimensional material is a material composed of a single layer of atoms, for example, molybdenum sulfide (MoS2), or a composite atomic layer compound consisting of a precycle transition metal (such as titanium or vanadium) and a light element (such as carbon or nitrogen). Alternatively, a MOF (Metal Organic Frameworks) material or a carbon material (for example, graphene or graphene oxide) may be applied as the material for the membrane (621c). Here, a zeolite membrane is applied as the membrane (621c).

[0095] The upstream end of the separation discharge pipe (65) is connected to the second path (621b). The separated liquid is discharged to the outside (e.g., a wastewater treatment unit of a factory facility) through the separation discharge pipe (65). A pressure reducing pump that reduces the pressure of the second path (621b) may be installed in the separation discharge pipe (65). As shown in FIG. 3, a discharge valve (66) is interposed in the separation discharge pipe (65). Additionally, the separated liquid separated by the circulating dewatering machine (62) may contain a small amount of organic solvent. A treatment unit for treating the organic solvent in such separated liquid may be installed in the separation discharge pipe (65). An example of such treatment is described in the third and fourth embodiments.

[0096] The dewatering temperature control unit (622) is installed in the dewatering circulation pipe (61) and adjusts the temperature of the mixed liquid flowing through the dewatering circulation pipe (61). In the example of FIG. 3, the dewatering temperature control unit (622) is installed upstream of the membrane separator (621). The dewatering temperature control unit (622) has a heating function. That is, the dewatering temperature control unit (622) includes a heater. The heater may be an electric resistance heater having a heating wire, an optical heater having a light source, or an electronic cooling unit having a Peltier element. By heating the mixed liquid with the dewatering temperature control unit (622), the high-temperature mixed liquid can be introduced into the membrane separator (621). Since the velocity of molecules in the mixed liquid is higher as the temperature increases, water molecules in the high-temperature mixed liquid can easily pass through the separator membrane (621c). For this reason, the membrane separator (621) can separate the liquid from the mixture with higher efficiency. Furthermore, the dehydration circulation unit (60) can increase the solvent concentration of the mixture to above a predetermined solvent standard value in a shorter time.

[0097] The dewatering side liquid transfer pump (63) is interposed in the dewatering circulation pipe (61). As an example, the dewatering side liquid transfer pump (63) is installed at a position upstream of the circulating dewatering machine (62). The first switching valve (641) and the second switching valve (642) are interposed in the dewatering circulation pipe (61). The first switching valve (641) is installed at a position downstream of the circulating dewatering machine (62). The second switching valve (642) is installed at a position upstream of the dewatering side liquid transfer pump (63).

[0098] Various sensors may be interposed in the dewatering circulation pipe (61). For example, the dewatering circulation pipe (61) may contain a concentration sensor (Sn63) for detecting the concentration of an organic solvent (here, for example, IPA) in the fluid flowing through the dewatering circulation pipe (61), a flow sensor (flow meter) (Sn64) for detecting the flow rate of the fluid flowing through the dewatering circulation pipe (61), a pressure sensor (Sn61) for detecting the pressure of the fluid flowing through the dewatering circulation pipe (61), and a temperature sensor (Sn62) for detecting the temperature of the fluid flowing through the dewatering circulation pipe (61). The concentration sensor (Sn63) is interposed, for example, at a location downstream of the circulating dewatering machine (62). The flow sensor (Sn64) is interposed, for example, at a location upstream of the dewatering side liquid transfer pump (63). The pressure sensor (Sn61) is positioned, for example, downstream of the dewatering side liquid transfer pump (63) and upstream of the circulating dewatering machine (62). The temperature sensor (Sn62) is positioned, for example, downstream of the dewatering temperature tank (622) and upstream of the membrane separator (621).

[0099] (c1) Purification Tank (Tk2)

[0100] A first concentrate is supplied to the purification tank (Tk2) by the concentrate supply unit (70) described later. The purification tank (Tk2) is housed, for example, in a first receiving box (50a) (see FIG. 1).

[0101] (d1) Concentrate supply unit (70)

[0102] In the example of FIG. 3, a concentrate supply unit (70) is installed in the organic solvent recovery unit (5). The concentrate supply unit (70) supplies a first concentrate from the recovery tank (Tk1) to the purification tank (Tk2). The concentrate supply unit (70) includes a first liquid transfer pipe (71), a first liquid transfer valve (72), and a dewatering side liquid transfer pump (63), which is an example of a liquid transfer unit.

[0103] In the example of FIG. 3, the purification tank (Tk2) is connected to the dewatering circulation pipe (61) through the first liquid transfer pipe (71). That is, the downstream end of the first liquid transfer pipe (71) is connected to the purification tank (Tk2), and the upstream end of the first liquid transfer pipe (71) is connected to the dewatering circulation pipe (61). The upstream end of the first liquid transfer pipe (71) is connected to the dewatering circulation pipe (61) at a location between the dewatering side liquid transfer pump (63) and the first switching valve (641). As an example, the upstream end of the first liquid transfer pipe (71) is connected to a location downstream of the dewatering temperature tank (622) (preferably downstream of the temperature sensor (Sn62)) and upstream of the membrane separator (621). In addition, although different from FIG. 3, the upstream end of the first liquid transfer pipe (71) may be connected to a location downstream of the circulating dehydrator (62). Also, the upstream end of the first liquid transfer pipe (71) does not necessarily have to be connected to the dehydration circulation pipe (61), but may be connected to the recovery tank (Tk1). In this case, a pump different from the dehydration side liquid transfer pump (63) is installed in the first liquid transfer pipe (71). A first liquid transfer valve (72) is interposed in the first liquid transfer pipe (71).

[0104] (e1) Purification circulation unit (80)

[0105] In the example of FIG. 3, the purification circulation unit (80) includes, in addition to the purification circulation pipe (81) and filter (82), a pump (purification side liquid transfer pump) (83), a switching valve (84), and a purification temperature control unit (87).

[0106] In the example of FIG. 3, the purification circulation pipe (81) forms a circulation path through which liquid stored in the purification tank (Tk2) flows out of the purification tank (Tk2) and returns to the purification tank (Tk2). In the example of FIG. 3, the upstream end of the purification circulation pipe (81) is connected to the bottom of the purification tank (Tk2), and the downstream end of the purification circulation pipe (81) is connected to the top of the purification tank (Tk2).

[0107] The filter (82) captures impurities in the first concentrate flowing through the purification circulation pipe (81). The impurities may be, for example, foreign substances generated by processing in the treatment unit (4). The filter (82) may, for example, be formed in a mesh shape, or may have a composition in which fine particles are collected or aggregated. The filter (82) may, for example, be composed of resin. In the example of FIG. 3, an air venting pipe (88) is connected to the filter (82).

[0108] A purification temperature controller (87) is installed in a purification circulation pipe (81) and adjusts the temperature of the first concentrate flowing through the purification circulation pipe (81). In the example of FIG. 3, the purification temperature controller (87) is installed upstream of the filter (82). The purification temperature controller (87) has at least one of a heating function and a cooling function. The purification temperature controller (87) includes, for example, an electronic cooling unit (for example, a Peltier element). The purification temperature controller (87) heats or cools the first concentrate to adjust the temperature of the first concentrate to a temperature suitable for the filter (82). As described above, when the dehydration temperature controller (622) heats the mixture, the first concentrate at a high temperature is supplied to the purification tank (Tk2). In this case, the purification temperature controller (87) cools the first concentrate, thereby introducing the first concentrate, which has a relatively low temperature, into the filter (82). That is, the purification temperature controller (87) adjusts the temperature of the first concentrate to be lower than the temperature of the mixed liquid being circulated by the dehydration circulation unit (60). In the example described above, since the temperature of the mixed liquid is adjusted to be high by the dehydration temperature controller (622) in the dehydration circulation unit (60), the purification temperature controller (87) adjusts the temperature of the first concentrate to a value closer to room temperature than the temperature of the mixed liquid. Room temperature is, for example, the temperature of the room where the substrate processing device (100) is installed, and as a specific example, 25 degrees Celsius.

[0109] In this way, when the first concentrate, which is close to room temperature, is introduced into the filter (82), deformation of the filter (82) due to heat can be suppressed. That is, thermal expansion or thermal contraction of the filter (82) can be suppressed. If the filter (82) is significantly deformed by heat, there is a risk that the coarseness of the sieve mesh of the filter (82) will deviate from the desired range. If the coarseness of the sieve mesh of the filter (82) deviates from the desired range, the efficiency of capturing impurities by the filter (82) decreases, or it becomes difficult for the first concentrate to pass through the filter (82). In the example described above, since the purification temperature control unit (87) cools the first concentrate, the filter (82) can capture impurities with high efficiency and also allow the first concentrate to pass through appropriately.

[0110] The purification side liquid delivery pump (83) is interposed in the purification circulation pipe (81). For example, the purification side liquid delivery pump (83) is installed upstream of the filter (82). The switching valve (84) is interposed in the purification circulation pipe (81). For example, the switching valve (84) is installed downstream of the filter (82).

[0111] Various sensors are interposed in the purification circulation pipe (81). A pressure sensor (Sn81) for detecting the pressure of the fluid flowing through the purification circulation pipe (81) and a temperature sensor (Sn82) for detecting the temperature of the fluid flowing through the purification circulation pipe (81) are interposed. For example, the pressure sensor (Sn81) is interposed at a position downstream of the purification side liquid delivery pump (83) and upstream of the filter (82). For example, the temperature sensor (Sn82) is interposed at a position downstream of the purification temperature controller (87) and upstream of the filter (82).

[0112] (f1) Supply tank (Tk3)

[0113] A reuse solution is supplied to the supply tank (Tk3) by the reuse solution supply unit (89) described later. The supply tank (Tk3) is housed in the second receiving box (50b) (see FIG. 1). As an example, the second receiving box (50b) is placed on the inner side of the outer wall (100a) of the substrate processing device (100).

[0114] (g1) Reuse solution supply unit (89)

[0115] In the example of FIG. 3, a reuse solution supply unit (89) is installed in the organic solvent recovery unit (5). The reuse solution supply unit (89) supplies the reuse solution to the supply tank (Tk3). The reuse solution supply unit (89) includes a second liquid transfer pipe (85), a second liquid transfer valve (86), and a purification side liquid transfer pump (83), which is an example of a liquid transfer unit.

[0116] In the example of FIG. 3, the supply tank (Tk3) is connected to the purification circulation pipe (81) through the second liquid transfer pipe (85). That is, the downstream end of the second liquid transfer pipe (85) is connected to the supply tank (Tk3), and the upstream end of the second liquid transfer pipe (85) is connected to the purification circulation pipe (81). Specifically, the upstream end of the second liquid transfer pipe (85) is connected to the purification circulation pipe (81) at a location between the purification side liquid transfer pump (83) and the switching valve (84). As an example, the upstream end of the second liquid transfer pipe (85) is connected to the purification circulation pipe (81) at a location upstream of the filter (82) and downstream of the purification temperature controller (87). A second liquid transfer valve (86) is interposed in the second liquid transfer pipe (85). Additionally, the upstream end of the second liquid transfer pipe (85) does not necessarily have to be connected to the purification circulation pipe (81), but may be connected to the purification tank (Tk2). In this case, a pump different from the purification side liquid transfer pump (83) is installed in the second liquid transfer pipe (85).

[0117] (h1) Supply of new liquid

[0118] The supply tank (Tk3) is connected to the fresh liquid source (403) through the fresh liquid pipe (401). That is, the downstream end of the fresh liquid pipe (401) is connected to the supply tank (Tk3), and the upstream end of the fresh liquid pipe (401) is connected to the fresh liquid source (403). The fresh liquid source (403) is a source of unused organic solvent (e.g., IPA with a concentration of 99.8 wt% or more) that has never been supplied to the substrate (W). A fresh liquid valve (402) is interposed in the fresh liquid pipe (401).

[0119] The supply tank (Tk3) is connected to the IPA nozzle (43c) through the third liquid transfer pipe (404). That is, the supply tank (Tk3) is connected to one end of the third liquid transfer pipe (404), and the IPA nozzle (43c) (specifically, the IPA pipe (432c) connected to the IPA nozzle (43c)) is connected to the other end of the third liquid transfer pipe (404). Here, for example, the third liquid transfer pipe (404) is connected to the IPA nozzle (43c) provided by each of the plurality of processing units (4) belonging to the same tower.

[0120] A pump (supply-side liquid pump) (405) is interposed in the third liquid transfer pipe (404). Additionally, a filter (407) is interposed in the third liquid transfer pipe (404) at a position downstream of the supply-side liquid pump (405). Furthermore, a temperature control device (406) is interposed in the third liquid transfer pipe (404) at a position upstream of the filter (407) and downstream of the supply-side liquid pump (405).

[0121] Various sensors are interposed in the third liquid transfer pipe (404). For example, a temperature sensor (Sn41) that detects the temperature of the fluid flowing through the third liquid transfer pipe (404) is interposed in the third liquid transfer pipe (404). The temperature sensor (Sn41) is interposed, for example, upstream of the filter (407) and downstream of the temperature controller (406). The temperature controller (406) adjusts the temperature of the reusable liquid supplied to the processing unit (4) to a predetermined temperature range according to the processing of the substrate (W).

[0122] <3-2. Example of operation of organic solvent recovery unit (5)>

[0123] FIG. 4 is a flowchart illustrating an example of the operation of an organic solvent recovery unit (5). Here, a mixed liquid is stored in a recovery tank (Tk1). First, the dewatering circulation unit (60) circulates the mixed liquid through a dewatering circulation pipe (61) (Step S1: Dewatering circulation process). Specifically, the control unit (6) opens the first switching valve (641), the second switching valve (642), and the discharge valve (66), and operates the dewatering side liquid transfer pump (63). As a result, the mixed liquid circulates through a dewatering circulation path including the recovery tank (Tk1) and the dewatering circulation pipe (61). Through this circulation, the mixed liquid continues to pass through a circulating dewatering machine (62). Because of this, the circulating dewatering machine (62) continues to separate the liquid from the mixed liquid, and the liquid is continuously discharged to the outside through the separation discharge pipe (65). Accordingly, the solvent concentration of the circulating mixed liquid increases over time.

[0124] Here, the control unit (6) operates the dewatering temperature unit (622) during the circulation of the mixed liquid. For example, the control unit (6) starts the operation of the dewatering temperature unit (622) at the start of the circulation of the mixed liquid. The control unit (6) may control the dewatering temperature unit (622) based on, for example, the temperature detected by the temperature sensor (Sn62). As a result, the temperature of the mixed liquid can be controlled with high precision. The dewatering temperature unit (622) heats the mixed liquid to, for example, 40 degrees Celsius or higher. The dewatering temperature unit (622) may adjust the temperature of the mixed liquid to 50 degrees Celsius or higher, 60 degrees Celsius or higher, or 70 degrees Celsius or higher. As a result, the membrane separator (621) can separate the separated liquid from the mixed liquid with high efficiency.

[0125] The control unit (6) causes the dewatering circulation unit (60) to circulate the mixed liquid until the solvent concentration of the circulating mixed liquid becomes greater than or equal to a predetermined solvent reference value. The solvent reference value may be, for example, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, or 98 wt% or more. For example, the control unit (6) may compare the solvent concentration detected by the concentration sensor (Sn63) with the solvent reference value, and when the solvent concentration becomes greater than or equal to the solvent reference value, cause the dewatering circulation unit (60) to stop the circulation. Specifically, the control unit (6) closes the first switching valve (641), the second switching valve (642), and the discharge valve (66), and stops the dewatering side liquid transfer pump (63) and the dewatering temperature tank (622).

[0126] Through this circulation, a mixed liquid with a high solvent concentration (i.e., a first concentrate) is stored in the recovery tank (Tk1). Additionally, the control unit (6) may cause the dehydration circulation unit (60) to stop the circulation by triggering the elapsed time of a predetermined dehydration time. The dehydration time is pre-set, for example, to be longer than the time required for the solvent concentration to exceed the solvent reference value. The dehydration time may be set, for example, to be tens of minutes or hours.

[0127] In the example of FIG. 4, the concentrate supply unit (70) then supplies the first concentrate from the recovery tank (Tk1) to the purification tank (Tk2) (step S2: concentrate supply process). Specifically, the control unit (6) opens the second switching valve (642) and the first liquid transfer valve (72) and operates the dewatering side liquid transfer pump (63). As a result, the first concentrate in the recovery tank (Tk1) is supplied to the purification tank (Tk2) through at least the first liquid transfer pipe (71). When a sufficient amount of the first concentrate is supplied to the purification tank (Tk2), the control unit (6) closes the second switching valve (642) and the first liquid transfer valve (72) and stops the dewatering side liquid transfer pump (63).

[0128] Next, the purification circulation unit (80) circulates the first concentrate through the purification circulation pipe (81) (Step S3: purification circulation process). Specifically, the control unit (6) opens the switching valve (84) and operates the purification side liquid transfer pump (83). As a result, the first concentrate circulates through a purification circulation path including the purification tank (Tk2) and the purification circulation pipe (81). Through this circulation, the first concentrate continues to pass through the filter (82). Because of this, the filter (82) continues to capture impurities from the first concentrate. Therefore, the impurity content of the first concentrate being circulated is reduced over time.

[0129] Here, the control unit (6) operates the purification temperature unit (87) during the circulation of the first concentrate. As an example, the control unit (6) starts the operation of the purification temperature unit (87) at the start of the circulation of the first concentrate. The control unit (6) may control the purification temperature unit (87) based on, for example, the temperature detected by the temperature sensor (Sn82). As a result, the temperature of the first concentrate can be controlled with high precision. The purification temperature unit (87) cools the first concentrate to, for example, 40 degrees Celsius or lower. The purification temperature unit (87) may adjust the temperature of the first concentrate to 35 degrees Celsius or lower, or to 30 degrees Celsius or lower. In addition, the purification temperature unit (87) may adjust the temperature of the first concentrate to 20 degrees Celsius or higher. As a result, the filter (82) can capture impurities in the first concentrate with high efficiency.

[0130] The control unit (6) causes the purification circulation unit (80) to circulate the first concentrate until, for example, the impurity content of the first concentrate becomes less than or equal to a predetermined impurity threshold. For example, when a predetermined purification time has elapsed since the start of circulation of the first concentrate, the control unit (6) closes the switching valve (84) and stops the purification side liquid transfer pump (83) and the purification temperature controller (87). The purification time is, for example, pre-set to be longer than the time required for the impurity content to become less than or equal to the impurity threshold. Additionally, a sensor for detecting the amount of impurities in the first concentrate may be installed, and the control unit (6) may cause the purification circulation unit (80) to stop circulation when the amount of impurities detected by the sensor becomes less than or equal to the threshold. Through this circulation, the first concentrate (i.e., the reusable liquid) with a reduced impurity content is stored in the purification tank (Tk2).

[0131] Next, the reuse solution supply unit (89) supplies the reuse solution to the supply tank (Tk3) (step S4: reuse solution supply process). Specifically, the control unit (6) opens the second liquid transfer valve (86) and operates the purification side liquid transfer pump (83). As a result, the reuse solution in the purification tank (Tk2) is supplied to the supply tank (Tk3) through at least the second liquid transfer pipe (85).

[0132] As described above, the organic solvent recovery unit (5) separates the separated liquid from the mixed liquid discharged from the processing unit (4) to produce a first concentrated liquid with increased solvent concentration (step S1), and captures impurities in the first concentrated liquid to produce a reusable liquid with reduced impurity content in the first concentrated liquid (step S3). Then, the substrate processing device (100) supplies this reusable liquid back to the processing unit (4) (step S4). Because of this, the amount of waste organic solvent can be reduced, and the organic solvent can be effectively utilized.

[0133] In addition, in the example described above, the circulating dehydrator (62) includes a membrane separator (621). Since the membrane separator (621) is smaller in size compared to the distiller, the size of the device can be reduced.

[0134] In addition, in the example described above, since the dehydration temperature unit (622) heats the mixture, the membrane separator (621) can separate the separated liquid from the mixture with high efficiency. Meanwhile, since the purification temperature unit (87) cools the first concentrate, the filter (82) can capture impurities in the first concentrate with high efficiency.

[0135] In addition, in the example described above, a purification tank (Tk2) is installed, and the high-temperature first concentrate in the recovery tank (Tk1) is supplied to the purification tank (Tk2) through the first liquid transfer pipe (71). As the first concentrate passes through the first liquid transfer pipe (71), the first concentrate dissipates heat, so the first concentrate cooled by natural heat dissipation is stored in the purification tank (Tk2). Because of this, the temperature of the first concentrate can be reduced more quickly in the purification circulation unit (80).

[0136] <Second Embodiment>

[0137] FIG. 5 is a schematic diagram showing an example of an organic solvent recovery unit (5) according to a second embodiment.

[0138] (a2) Recovery tank (Tk1)

[0139] In the second embodiment, as a recovery tank (Tk1), a first recovery tank (Tk11) and a second recovery tank (Tk12) are installed.

[0140] (b2) Recovery switching unit (50)

[0141] In the second embodiment, a recovery switching unit (50) is installed in the organic solvent recovery unit (5). The recovery switching unit (50) switches the recovery location of the mixed liquid from the processing unit (4) between the first recovery tank (Tk11) and the second recovery tank (Tk12). In the example of FIG. 5, the recovery switching unit (50) includes a recovery pipe (51) and a switching valve unit (520). The recovery pipe (51) includes a common recovery pipe (510), a first branch pipe (511), and a second branch pipe (512). The common recovery pipe (510) is connected to each processing unit (4) on its upstream side. The downstream end of the common recovery pipe (510) is connected to the upstream end of the first branch pipe (511) and the upstream end of the second branch pipe (512). The downstream end of the first branch pipe (511) is connected to the first recovery tank (Tk11), and the downstream end of the second branch pipe (512) is connected to the second recovery tank (Tk12).

[0142] The switching valve section (520) switches between a state in which the processing unit (4) is connected to the first recovery tank (Tk11) and a state in which the processing unit (4) is connected to the second recovery tank (Tk12). In the example of FIG. 3, the switching valve section (520) includes a first recovery valve (521) and a second recovery valve (522). The first recovery valve (521) is interposed in the first branch pipe (511), and the second recovery valve (522) is interposed in the second branch pipe (512).

[0143] When the control unit (6) opens the first recovery valve (521) and closes the second recovery valve (522), the mixed liquid is supplied to the first recovery tank (Tk11), and when the control unit (6) closes the first recovery valve (521) and opens the second recovery valve (522), the mixed liquid is supplied to the second recovery tank (Tk12). As described below, the recovery switching unit (50) alternately switches the recovery destination between the first recovery tank (Tk11) and the second recovery tank (Tk12).

[0144] (c2) Dehydration circulation unit (60)

[0145] The dewatering circulation unit (60) includes a first dewatering circulation path (601) passing through a first recovery tank (Tk11) and a second dewatering circulation path (602) passing through a second recovery tank (Tk12). As an example, the first dewatering circulation path (601) is shared with the second dewatering circulation path (602) in the common circulation pipe (610) described later. The first dewatering circulation path (601) includes a first recovery tank (Tk11) and a first dewatering circulation pipe (611), and the second dewatering circulation path (602) includes a second recovery tank (Tk12) and a second dewatering circulation pipe (612). The first dewatering circulation pipe (611) includes a first downstream pipe (6111), a common circulation pipe (610), and a first upstream pipe (6121), and the second dewatering circulation pipe (612) includes a second downstream pipe (6112), a common circulation pipe (610), and a second upstream pipe (6122). The upstream end of the first upstream pipe (6121) is connected to, for example, the bottom of the first recovery tank (Tk11), and the upstream end of the second upstream pipe (6122) is connected to, for example, the bottom of the second recovery tank (Tk12). The downstream end of the first upstream pipe (6121) and the downstream end of the second upstream pipe (6122) are connected to the upstream end of the common circulation pipe (610). The downstream end of the common circulation pipe (610) is connected to the upstream end of the first downstream pipe (6111) and the upstream end of the second downstream pipe (6112). The downstream end of the first downstream pipe (6111) is connected to the upper part of the first recovery tank (Tk11), for example, and the downstream end of the second downstream pipe (6112) is connected to the upper part of the second recovery tank (Tk12), for example. In this connection relationship, the common circulation pipe (610) is connected between the first downstream pipe (6111) and the first upstream pipe (6121), and is also connected between the second downstream pipe (6112) and the second upstream pipe (6122).For this reason, the common circulation pipe (610) is used in the first dewatering circulation path (601) and the second dewatering circulation path (602).

[0146] In the example of FIG. 5, the circulating dehydrator (62) and the dehydration side liquid pump (63) are interposed in the common circulation pipe (610). A first downstream valve (6411) is interposed in the first downstream pipe (6111), a second downstream valve (6412) is interposed in the second downstream pipe (6112), a first upstream valve (6421) is interposed in the first upstream pipe (6121), and a second upstream valve (6422) is interposed in the second upstream pipe (6122). The first downstream valve (6411), the second downstream valve (6412), the first upstream valve (6421), and the second upstream valve (6422) form a circulation switching valve section (640) that switches the circulation path of the mixed liquid between the first dehydration circulation path (601) and the second dehydration circulation path (602).

[0147] In the example of FIG. 5, various sensors identical to those in the first embodiment are interposed in the common circulation pipe (610).

[0148] When the control unit (6) opens the first downstream valve (6411) and the first upstream valve (6421) and operates the dewatering side liquid transfer pump (63), the mixed liquid circulates through the first dewatering circulation path (601). Through this circulation, the solvent concentration of the mixed liquid can be improved by using the circulating dewatering machine (62) on the first dewatering circulation path (601). As a result, the mixed liquid with a high solvent concentration (i.e., the first concentrate) can be stored in the first recovery tank (Tk11).

[0149] Meanwhile, when the control unit (6) opens the second downstream valve (6412) and the second upstream valve (6422) and operates the dewatering side liquid transfer pump (63), the mixed liquid circulates through the second dewatering circulation path (602). Through this circulation, the solvent concentration of the mixed liquid can be improved by using the circulating dewatering machine (62) on the second dewatering circulation path (602). As a result, the mixed liquid with a high solvent concentration (i.e., the first concentrate) can be stored in the second recovery tank (Tk12).

[0150] As described below, the dehydration circulation unit (60) circulates the mixed liquid through the second dehydration circulation path (602) while recovering the mixed liquid by the first recovery tank (Tk11), and circulates the mixed liquid through the first dehydration circulation path (601) while recovering the mixed liquid by the second recovery tank (Tk12).

[0151] (d2) Purification Tank (Tk2)

[0152] In the example of Fig. 5, a first purification tank (Tk21) and a second purification tank (Tk22) are installed as purification tanks (Tk2).

[0153] (e2) Concentrate supply unit (70)

[0154] The concentrate supply unit (70) supplies the first concentrate from one of the first recovery tank (Tk11) and the second recovery tank (Tk12) to one of the first purification tank (Tk21) and the second purification tank (Tk22). As an example, the concentrate supply unit (70) has a source switching function that switches the source of the first concentrate between the first recovery tank (Tk11) and the second recovery tank (Tk12), and a supply location switching function that switches the supply location of the first concentrate between the first purification tank (Tk21) and the second purification tank (Tk22).

[0155] The concentrate supply unit (70) includes a first liquid transfer pipe (71) and a switching valve unit (720) as a supply source switching function unit. The first liquid transfer pipe (71) includes a common liquid transfer pipe (710), a first branch pipe (711), and a second branch pipe (712). The upstream end of the common liquid transfer pipe (710) is connected to a common circulation pipe (610) as an example, and the downstream end of the common liquid transfer pipe (710) is connected to the upstream end of the first branch pipe (711) and the upstream end of the second branch pipe (712). The downstream end of the first branch pipe (711) is connected to a first purification tank (Tk21), and the downstream end of the second branch pipe (712) is connected to a second purification tank (Tk22).

[0156] The switching valve section (720) switches between a state in which the common circulation pipe (610) is connected to the first purification tank (Tk21) and a state in which the common circulation pipe (610) is connected to the second purification tank (Tk22). In the example of FIG. 5, the switching valve section (720) includes a first liquid transfer valve (721) and a second liquid transfer valve (722). The first liquid transfer valve (721) is interposed in the first branch pipe (711), and the second liquid transfer valve (722) is interposed in the second branch pipe (712).

[0157] In the example of FIG. 5, the source switching function of the concentrate supply unit (70) is formed by a first upstream pipe (6121), a second upstream pipe (6122), a part of the common circulation pipe (610), a first upstream valve (6421), and a second upstream valve (6422). The first upstream valve (6421) and the second upstream valve (6422) form a switching valve section that switches between a state in which the first recovery tank (Tk11) is connected to the common circulation pipe (610) and a state in which the second recovery tank (Tk12) is connected to the common circulation pipe (610).

[0158] The control unit (6) can change the combination of the supply source and the supply location by switching the opening and closing of the first upstream valve (6421), the second upstream valve (6422), the first liquid transfer valve (721), and the second liquid transfer valve (722). For example, the control unit (6) opens the first upstream valve (6421) and the second liquid transfer valve (722) and operates the dewatering side liquid transfer pump (63). As a result, the first concentrate is supplied from the first recovery tank (Tk11) to the second purification tank (Tk22).

[0159] As described below, the concentrate supply unit (70) alternately switches the supply source between the first recovery tank (Tk11) and the second recovery tank (Tk12), and alternately switches the supply source between the first purification tank (Tk21) and the second purification tank (Tk22).

[0160] (f2) Purification circulation unit (80)

[0161] In the example of FIG. 5, the purification circulation unit (80) includes a first purification circulation path (801) passing through a first purification tank (Tk21) and a second purification circulation path (802) passing through a second purification tank (Tk22). In the example of FIG. 5, the first purification circulation path (801) includes a first purification tank (Tk21) and a first purification circulation pipe (811), and the second purification circulation path (802) includes a second purification tank (Tk22) and a second purification circulation pipe (812). The upstream end of the first purification circulation pipe (811) is connected to the bottom of the first purification tank (Tk21), for example, and the downstream end of the first purification circulation pipe (811) is connected to the top of the first purification tank (Tk21), for example. The upstream end of the second purification circulation pipe (812) is connected to the bottom of the second purification tank (Tk22), for example, and the downstream end of the second purification circulation pipe (812) is connected to the top of the second purification tank (Tk22), for example.

[0162] In the example of FIG. 5, a first filter (821) is interposed in the first purification circulation pipe (811), and a second filter (822) is interposed in the second purification circulation pipe (812). The first filter (821) and the second filter (822) are identical to the filter (82) and capture impurities in the first concentrate. In the example of FIG. 5, an air venting pipe (88) is connected to each of the first filter (821) and the second filter (822).

[0163] In addition, in the example of FIG. 5, a first purification temperature tank (871) is installed in the first purification circulation pipe (811), and a second purification temperature tank (872) is installed in the second purification circulation pipe (812). The first purification temperature tank (871) and the second purification temperature tank (872) are identical to the purification temperature tank (87) and adjust the temperature of the first concentrate. For example, the first purification temperature tank (871) and the second purification temperature tank (872) cool the first concentrate. As an example, the first purification temperature tank (871) is installed upstream of the first filter (821), and the second purification temperature tank (872) is installed upstream of the second filter (822).

[0164] A first purification side liquid pump (831) is interposed in the first purification circulation pipe (811), and a second purification side liquid pump (832) is interposed in the second purification circulation pipe (812). In the example of FIG. 5, the first purification side liquid pump (831) is installed upstream of the first purification temperature tank (871), and the second purification side liquid pump (832) is installed upstream of the second purification temperature tank (872). Additionally, a first switching valve (841) is interposed in the first purification circulation pipe (811), and a second switching valve (842) is interposed in the second purification circulation pipe (812). In the example of FIG. 5, the first switching valve (841) is installed at a position downstream of the first filter (821), and the second switching valve (842) is installed at a position downstream of the second filter (822). In the example of FIG. 5, various sensors identical to those in the first embodiment are interposed in each of the first purification circulation pipe (811) and the second purification circulation pipe (812).

[0165] When the control unit (6) opens the first switching valve (841) and operates the first purification side liquid transfer pump (831), the first concentrate circulates through the first purification circulation path (801). Through this circulation, the impurity content of the first concentrate can be reduced by using the first filter (821) on the first purification circulation path (801). As a result, the first concentrate (i.e., the reusable liquid) with a low impurity content can be stored in the first purification tank (Tk21).

[0166] Meanwhile, when the control unit (6) opens the second switching valve (842) and operates the second purification side liquid transfer pump (832), the first concentrate circulates through the second purification circulation path (802). Through this circulation, the impurity content of the first concentrate can be reduced by using the second filter (822) on the second purification circulation path (802). As a result, the first concentrate (i.e., the reusable liquid) with a low impurity content can be stored in the second purification tank (Tk22).

[0167] (g2) Reuse solution supply unit (89)

[0168] The reuse solution supply unit (89) supplies the reuse solution to the supply tank (Tk3) from each of the first purification tank (Tk21) and the second purification tank (Tk22). The reuse solution supply unit (89) switches the source of the reuse solution between the first purification tank (Tk21) and the second purification tank (Tk22).

[0169] The reuse liquid supply unit (89) includes a second liquid transfer pipe (85), a switching valve unit (860), and a first purification side liquid transfer pump (831) and a second purification side liquid transfer pump (832), which are examples of the liquid transfer unit. The second liquid transfer pipe (85) includes a common liquid transfer pipe (850), a first branch pipe (851), and a second branch pipe (852). As an example, the upstream end of the first branch pipe (851) is connected to the first purification circulation pipe (811) at a location between the first switching valve (841) and the first purification side liquid transfer pump (831), and the upstream end of the second branch pipe (852) is connected to the second purification circulation pipe (812) at a location between the second switching valve (842) and the second purification side liquid transfer pump (832). The downstream end of the first branch pipe (851) and the downstream end of the second branch pipe (852) are connected to the upstream end of the common liquid transfer pipe (850). The downstream end of the common liquid transfer pipe (850) is connected to, for example, the upper part of the supply tank (Tk3).

[0170] The switching valve section (860) switches between a state in which the first purification tank (Tk21) is connected to the supply tank (Tk3) and a state in which the second purification tank (Tk22) is connected to the supply tank (Tk3). In the example of FIG. 5, the switching valve section (860) includes a first liquid transfer valve (861) and a second liquid transfer valve (862). The first liquid transfer valve (861) is interposed in the first branch pipe (851), and the second liquid transfer valve (862) is interposed in the second branch pipe (852).

[0171] When the control unit (6) opens the first liquid transfer valve (861) and operates the first purification side liquid transfer pump (831), the reuse solution is supplied from the first purification tank (Tk21) to the supply tank (Tk3). Also, when the control unit (6) opens the second liquid transfer valve (862) and operates the second purification side liquid transfer pump (832), the reuse solution is supplied from the second purification tank (Tk22) to the supply tank (Tk3). As described below, the reuse solution supply unit (89) alternately switches the supply source supplying the reuse solution to the supply tank (Tk3) between the first purification tank (Tk21) and the second purification tank (Tk22).

[0172] <Operation of organic solvent recovery unit (5)>

[0173] Next, an example of the operation of the organic solvent recovery unit (5) will be described. FIG. 6 is a schematic diagram illustrating an example of the operation of the organic solvent recovery unit (5). FIG. 6 also schematically illustrates an example of the time change of the liquid storage amount (hereinafter also referred to as the recovery storage amount) in each of the first recovery tank (Tk11) and the second recovery tank (Tk12). FIG. 6 also schematically illustrates an example of the time change of the liquid storage amount (hereinafter also referred to as the purification storage amount) in each of the first purification tank (Tk21) and the second purification tank (Tk22). FIG. 6 also schematically illustrates an example of the time change of the reuse liquid storage amount (hereinafter also referred to as the supply storage amount) in the supply tank (Tk3). FIG. 7 to 14 are diagrams for explaining an example of the operation of the organic solvent recovery unit (5). In Figures 7 to 14, the piping through which fluid flows is shown as a thick line, and the open valve is shown in black.

[0174] In the example of FIG. 6, at time t0, the first recovery tank (Tk11) and the second recovery tank (Tk12) are almost empty, and the first concentrate (or reusable liquid) is stored in the first purification tank (Tk21) and the second purification tank (Tk22).

[0175] In the example of FIG. 6, first, the first recovery tank (Tk11) recovers the mixed liquid. That is, the recovery switching unit (50) selects the first recovery tank (Tk11) as the recovery destination for the mixed liquid from the processing unit (4). Specifically, as shown in FIG. 7, the control unit (6) opens the first recovery valve (521) and closes the second recovery valve (522). Because of this, the amount of recovered liquid in the first recovery tank (Tk11) increases over time.

[0176] Additionally, in the example of FIG. 6, circulation is initially performed through each of the first purification circulation path (801) including the first purification tank (Tk21) and the second purification circulation path (802) including the second purification tank (Tk22). Specifically, as shown in FIG. 7, the control unit (6) opens the first switching valve (841) and the second switching valve (842) and operates the first purification side liquid transfer pump (831) and the second purification side liquid transfer pump (832). Through these circulations, the impurity content of the first concentrate in the first purification tank (Tk21) and the second purification tank (Tk22) decreases over time. The control unit (6) may also operate the first purification temperature control unit (871) and the second purification temperature control unit (872), as in the first embodiment. As a result, the first filter (821) and the second filter (822) can capture impurities with high efficiency.

[0177] The purification circulation unit (80) may continue circulation through the first purification circulation path (801) even after the impurity content of the first concentrate in the first purification tank (Tk21) has become below the impurity standard value. That is, circulation through the first purification circulation path (801) may continue even after the reuse solution has been stored in the first purification tank (Tk21). As a result, the impurity content of the reuse solution in the first purification tank (Tk21) can be further reduced. The same applies to circulation through the second purification circulation path (802).

[0178] However, since the recycled liquid in the supply tank (Tk3) is supplied to the processing unit (4), the supply storage amount of the supply tank (Tk3) decreases over time (see time t0 to time t1). Because of this, the supply storage amount becomes below a predetermined supply threshold. The supply threshold may be zero or a value slightly greater than zero. In addition, the storage amount stored in each tank can be detected by a storage amount sensor (e.g., a liquid level sensor) not shown installed in each tank.

[0179] When the supply storage amount falls below the supply threshold, for example, the purification circulation unit (80) stops circulation through the second purification circulation path (802), and the reuse solution supply unit (89) begins supplying the reuse solution from the second purification tank (Tk22) to the supply tank (Tk3) (see time t1). Specifically, as shown in FIG. 8, the control unit (6) closes the second switching valve (842) and opens the second liquid transfer valve (862). As a result, circulation through the second purification circulation path (802) is stopped, and the reuse solution is supplied from the second purification tank (Tk22) to the supply tank (Tk3). Due to this supply, the supply storage amount increases over time, and the purification storage amount of the second purification tank (Tk22) decreases over time.

[0180] When a sufficient amount of recycled solution is supplied to the supply tank (Tk3), the recycled solution supply unit (89) stops supplying the recycled solution to the supply tank (Tk3) (see time t2). Specifically, as shown in FIG. 9, the control unit (6) closes the second liquid transfer valve (862) and stops the second purification side liquid transfer pump (832). For example, at time t2, the second purification tank (Tk22) is almost empty. Due to this supply stoppage, the supply storage amount decreases again over time.

[0181] Meanwhile, since the mixed liquid from the processing unit (4) is supplied to the first recovery tank (Tk11), the amount of recovered liquid stored in the first recovery tank (Tk11) increases with the passage of time. When the amount of recovered liquid stored in the first recovery tank (Tk11) exceeds a predetermined circulation threshold, the recovery switching unit (50) switches the recovery destination of the mixed liquid from the processing unit (4) from the first recovery tank (Tk11) to the second recovery tank (Tk12). In FIG. 6, the recovery switching unit (50) switches the recovery destination to the second recovery tank (Tk12) at time t2. Specifically, as shown in FIG. 9, the control unit (6) closes the first recovery valve (521) and opens the second recovery valve (522). As a result, the amount of recovered liquid stored in the second recovery tank (Tk12) increases with the passage of time.

[0182] Additionally, when the recovery switching unit (50) switches the recovery location of the mixed liquid to the second recovery tank (Tk12), the dehydration circulation unit (60) begins to circulate the mixed liquid through the first dehydration circulation path (601) including the first recovery tank (Tk11) (see time t2). That is, the dehydration circulation unit (60) circulates the mixed liquid through the dehydration circulation path including the recovery tank that is not used for recovery among the first recovery tank (Tk11) and the second recovery tank (Tk12). Specifically, as shown in FIG. 9, the control unit (6) opens the first downstream valve (6411), the first upstream valve (6421), and the discharge valve (66), and operates the dehydration side liquid transfer pump (63). Due to this circulation, the solvent concentration of the mixed liquid in the first recovery tank (Tk11) increases with the passage of time. Additionally, the control unit (6) may operate the dehydration temperature unit (622) during this circulation, just as in the first embodiment. As a result, the circulating dehydrator (62) can separate the liquid from the mixture with high efficiency.

[0183] As described above, during the recovery of the mixed liquid by the second recovery tank (Tk12), the mixed liquid is circulated through the first dehydration circulation path (601). Conversely, during this circulation, the mixed liquid from the processing unit (4) is not supplied to the first recovery tank (Tk11). Therefore, it is possible to avoid the mixed liquid with a low solvent concentration flowing into the circulating mixed liquid. Furthermore, since the temperature of the mixed liquid from the processing unit (4) is not within a range suitable for separation by the circulating dehydrator (62), if the mixed liquid from the processing unit (4) flows into the circulating mixed liquid, there is a risk that the temperature of the circulating mixed liquid will fluctuate and fall outside the said range. In this case, there is a risk of causing a decrease in separation efficiency. According to the example described above, such a decrease in separation efficiency can also be avoided.

[0184] When the solvent concentration of the mixture in the first recovery tank (Tk11) exceeds the solvent reference value, the dehydration circulation unit (60) stops the circulation (see time t3). Next, the concentrate supply unit (70) supplies the first concentrate from the first recovery tank (Tk11) to the second purification tank (Tk22), which has a storage volume below a predetermined replenishment reference value. The replenishment reference value can be pre-set, for example, to zero or a value slightly greater than zero. Specifically, as shown in FIG. 10, the control unit (6) closes the first downstream valve (6411) and opens the second liquid transfer valve (722). By closing the first downstream valve (6411), the circulation of the mixture is stopped. Here, since the dehydration side liquid transfer pump (63) is continuously operating, the first concentrate is supplied from the first recovery tank (Tk11) to the second purification tank (Tk22). Due to this supply, the recovery storage volume of the first recovery tank (Tk11) decreases over time, and the purification storage volume of the second purification tank (Tk22) increases over time.

[0185] When a sufficient amount of the first concentrate is supplied to the second purification tank (Tk22), the concentrate supply unit (70) stops supplying the first concentrate to the second purification tank (Tk22) (see time t4). Specifically, as shown in FIG. 11, the control unit (6) closes the second liquid transfer valve (722) and stops the dewatering side liquid transfer pump (63). In the example of FIG. 6, the first recovery tank (Tk11) is almost empty at time t4.

[0186] Next, the purification circulation unit (80) begins to circulate the first concentrate through the second purification circulation path (802) including the second purification tank (Tk22) (see time t4). Specifically, as shown in FIG. 11, the control unit (6) opens the second switching valve (842) and operates the second purification side liquid transfer pump (832). Through this circulation, the impurity content of the first concentrate in the second purification tank (Tk22) decreases over time. The control unit (6) may operate the second purification temperature control unit (872) as in the first embodiment. Additionally, the purification circulation unit (80) may start circulation while the first concentrate is being supplied to the second purification tank (Tk22) (i.e., from time t3 to time t4).

[0187] When the supply storage amount falls below the supply standard value again, the reuse solution supply unit (89) begins to supply the reuse solution to the supply tank (Tk3) (see time t5). Here, the impurity content of the first concentrate in the second purification tank (Tk22) is assumed not yet to be below the impurity standard value. Therefore, the reuse solution supply unit (89) supplies the reuse solution from the first purification tank (Tk21) to the supply tank (Tk3). Prior to this supply, the purification circulation unit (80) may stop the circulation through the first purification circulation path (801). Specifically, as shown in FIG. 11, the control unit (6) closes the first switching valve (841) and opens the first liquid transfer valve (861). Due to this supply, the purification storage amount of the first purification tank (Tk21) decreases over time, and the supply storage amount increases over time.

[0188] When a sufficient amount of recycled solution is supplied to the supply tank (Tk3), the recycled solution supply unit (89) stops supplying the recycled solution to the supply tank (Tk3) (see time t6). Specifically, as shown in FIG. 12, the control unit (6) closes the first liquid transfer valve (861) and stops the first purification side liquid transfer pump (831). In the example of FIG. 6, at time t6, the first purification tank (Tk21) is almost empty. Due to this supply stoppage, the supply storage amount decreases again over time.

[0189] Meanwhile, when the recovery storage amount of the second recovery tank (Tk12) exceeds a predetermined circulation standard value, the recovery switching unit (50) switches the recovery destination of the mixed liquid from the processing unit (4) from the second recovery tank (Tk12) to the first recovery tank (Tk11). In FIG. 6, the recovery switching unit (50) switches the recovery destination to the first recovery tank (Tk11) at time t6. Specifically, as shown in FIG. 12, the control unit (6) opens the first recovery valve (521) and closes the second recovery valve (522). As a result, the recovery storage amount of the first recovery tank (Tk11) increases with the passage of time.

[0190] As described above, the recovery switching unit (50) switches the recovery location to the first recovery tank (Tk11) at time t6. Here, after time t4, when the first concentrate in the first recovery tank (Tk11) has been fully supplied to the second purification tank (Tk22), the first recovery tank (Tk11) receives the mixed liquid from the processing unit (4). That is, the organic solvent recovery unit (5) terminates the generation of the first concentrate in the first recovery tank (Tk11) (time t2 to time t3) and the supply of the first concentrate from the first recovery tank (Tk11) to the second purification tank (Tk22) (time t3 to time t4) by time t6. In other words, to satisfy this condition, the capacity of the circulating dehydrator (62), the pressure (target value), flow rate (target value), and temperature (target value) of the circulating mixture, and the flow rate (target value) of the mixture supplied to the second purification tank (Tk22) can be set.

[0191] Next, the dewatering circulation unit (60) begins to circulate the mixture through the second dewatering circulation path (602) including the second recovery tank (Tk12) (see time t6). Specifically, as shown in FIG. 12, the control unit (6) opens the second downstream valve (6412), the second upstream valve (6422), and the discharge valve (66), and operates the dewatering side liquid transfer pump (63). Through this circulation, the solvent concentration of the mixture in the second recovery tank (Tk12) increases over time. The control unit (6) may operate the dewatering temperature unit (622) as in the first embodiment.

[0192] As described above, during the recovery of the mixed liquid by the first recovery tank (Tk11), the mixed liquid is circulated through the second dehydration circulation path (602). In other words, during this circulation, the mixed liquid from the processing unit (4) is not supplied to the second recovery tank (Tk12). Therefore, the inflow of the mixed liquid from the processing unit (4) into the circulating mixed liquid can be avoided. Consequently, the decrease in solvent concentration and temperature fluctuation of the circulating mixed liquid caused by such inflow can be avoided.

[0193] When the solvent concentration of the mixture in the second recovery tank (Tk12) exceeds the solvent reference value, the dehydration circulation unit (60) stops circulation through the second dehydration circulation path (602) (see time t7). Next, the concentrate supply unit (70) begins supplying the first concentrate from the second recovery tank (Tk12) to the first purification tank (Tk21), where the storage volume is below the replenishment reference value. Specifically, as shown in FIG. 13, the control unit (6) closes the second downstream valve (6412) and opens the first liquid transfer valve (721). By closing the second downstream valve (6412), the circulation of the mixture is stopped. Here, since the dehydration side liquid transfer pump (63) is continuously operating, the first concentrate is supplied from the second recovery tank (Tk12) to the first purification tank (Tk21). Due to this supply, the recovery storage volume of the second recovery tank (Tk12) decreases over time, and the purification storage volume of the first purification tank (Tk21) increases over time.

[0194] When a sufficient amount of the first concentrate is supplied to the first purification tank (Tk21), the concentrate supply unit (70) stops supplying the first concentrate to the first purification tank (Tk21) (see time t8). Specifically, as shown in FIG. 14, the control unit (6) closes the first liquid transfer valve (721) and stops the dewatering side liquid transfer pump (63). In the example of FIG. 6, at time t8, the second recovery tank (Tk12) is almost empty.

[0195] Next, the purification circulation unit (80) begins to circulate the first concentrate through the first purification circulation path (801) including the first purification tank (Tk21) (see time t8). Specifically, as shown in FIG. 14, the control unit (6) opens the first switching valve (841) and operates the first purification side liquid transfer pump (831). Through this circulation, the impurity content of the first concentrate in the first purification tank (Tk21) decreases over time. The control unit (6) may operate the first purification temperature control unit (871) as in the first embodiment. Additionally, the purification circulation unit (80) may start circulation while the first concentrate is being supplied to the first purification tank (Tk21) (i.e., from time t7 to time t8).

[0196] When the supply storage amount falls below the supply standard again, the reuse solution supply unit (89) begins to supply the reuse solution to the supply tank (Tk3) (see time t9). Here, the impurity content of the first concentrate in the first purification tank (Tk21) is not yet below the impurity standard. Meanwhile, the reuse solution with an impurity content below the impurity standard is stored in the second purification tank (Tk22). That is, here, the reuse solution is stored in the second purification tank (Tk22) until time t9. That is, from the start of circulation through the second purification circulation path (802) (time t4) until time t9, when the storage amount of the supply tank (Tk3) falls below the supply standard for the second time, the impurity content of the first concentrate in the second purification tank (Tk22) becomes below the impurity standard. Conversely, so that this condition is met, the capacity of the second filter (822), and the pressure (target value), flow rate (target value), and temperature (target value) of the first concentrate being circulated can be set in advance.

[0197] While the purification circulation unit (80) stops circulation through the second purification circulation path (802), the reuse solution supply unit (89) supplies the reuse solution from the second purification tank (Tk22) to the supply tank (Tk3). Specifically, the control unit (6) closes the second switching valve (842) and opens the second liquid transfer valve (862), as shown in FIG. 14. Due to this supply, the purification storage volume of the second purification tank (Tk22) decreases over time, and the supply storage volume increases over time.

[0198] When a sufficient amount of recycled solution is supplied to the supply tank (Tk3), the recycled solution supply unit (89) stops supplying the recycled solution to the supply tank (Tk3) (see time t10).

[0199] Meanwhile, when the recovery storage amount of the first recovery tank (Tk11) exceeds a predetermined circulation standard value, the recovery switching unit (50) switches the recovery destination of the mixed liquid from the processing unit (4) from the first recovery tank (Tk11) back to the second recovery tank (Tk12). In the example of FIG. 6, the recovery switching unit (50) switches the recovery destination to the second recovery tank (Tk12) at time t10. Specifically, as shown in FIG. 14, the control unit (6) closes the first recovery valve (521) and opens the second recovery valve (522). As a result, the recovery storage amount of the second recovery tank (Tk12) increases with the passage of time.

[0200] As described above, the recovery switching unit (50) switches the recovery location to the second recovery tank (Tk12) at time t10. Here, after time t8, when the first concentrate in the second recovery tank (Tk12) has been fully supplied to the first purification tank (Tk21), the second recovery tank (Tk12) receives the mixed liquid from the processing unit (4). That is, the organic solvent recovery unit (5) terminates the generation of the first concentrate in the second recovery tank (Tk12) (time t6 to time t7) and the supply of the first concentrate from the second recovery tank (Tk12) to the first purification tank (Tk21) (time t7 to time t8) by time t10. In other words, to satisfy this condition, the capacity of the circulating dehydrator (62), the pressure (target value), flow rate (target value), and temperature (target value) of the circulating mixture, and the flow rate (target value) of the mixture supplied to the first purification tank (Tk21) can be set.

[0201] Afterwards, the organic solvent recovery unit (5) repeats the operation described above.

[0202] As described above, in the second embodiment, a first recovery tank (Tk11) and a second recovery tank (Tk12) are installed, and the recovery switching unit (50) alternately switches the recovery destination of the mixed liquid from the processing unit (4) between the first recovery tank (Tk11) and the second recovery tank (Tk12). Furthermore, the organic solvent recovery unit (5) performs the generation of a first concentrate in the second recovery tank (Tk12) and the supply of the first concentrate from the second recovery tank (Tk12) to the first purification tank (Tk21) while recovering the mixed liquid from the first recovery tank (Tk11). Likewise, the organic solvent recovery unit (5) performs the generation of a first concentrate in a first recovery tank (Tk11) and the supply of the first concentrate from the first recovery tank (Tk11) to a second purification tank (Tk22) while recovering the mixture in the second recovery tank (Tk12).

[0203] As a result, the organic solvent recovery unit (5) can continuously recover the mixture from the processing unit (4) while generating the first concentrate. Furthermore, the mixture from the processing unit (4) does not flow into the circulating mixture. Because of this, a decrease in the solvent concentration of the circulating mixture caused by such inflow can be avoided. Additionally, temperature fluctuations of the circulating mixture caused by such inflow can also be avoided. Therefore, the circulating dehydrator (62) can separate the separated liquid from the mixture with high efficiency.

[0204] In addition, in the example described above, the dewatering circulation unit (60) has a circulating dewatering machine (62) installed in the common circulation pipe (610). Because of this, the circulating dewatering machine (62) can be used in both the first dewatering circulation path (601) and the second dewatering circulation path (602). Therefore, the size of the device and manufacturing costs can be reduced.

[0205] This is particularly beneficial for a substrate processing device (100) in which a mixture is continuously discharged from a plurality of processing units (4). That is, since either the first recovery tank (Tk11) or the second recovery tank (Tk12) is always used to recover the mixture from the processing unit (4), there is no need to perform circulation through the first dehydration circulation path (601) and circulation through the second dehydration circulation path (602) in parallel, and the circulations can be performed alternately. For this reason, even if the circulation dehydrator (62) is used in both the first dehydration circulation path (601) and the second dehydration circulation path (602), the circulation of the first dehydration circulation path (601) and the circulation of the second dehydration circulation path (602) can be properly realized.

[0206] In addition, in the example described above, a first purification tank (Tk21) and a second purification tank (Tk22) are installed, and the purification circulation unit (80) includes a first filter (821) installed in the first purification circulation path (801) and a second filter (822) installed in the second purification circulation path (802). As a result, the purification circulation unit (80) can perform the circulation of the first concentrate through the first purification circulation path (801) and the circulation of the first concentrate through the second purification circulation path (802) in parallel (for example, time t4 to time t5 and time t8 to time t9). Because of this, the circulation time of the first concentrate can be extended, and a reusable solution with a lower impurity content can be produced.

[0207] <Third Embodiment>

[0208] When the circulating dehydrator (62) separates water from the mixture, it is possible to separate a small amount of organic solvent from the mixture. For example, the separator (621c) almost completely blocks the organic solvent, but in reality, a small portion of the organic solvent in the mixture may pass through the separator (621c). In other words, the separator (621c) can be described as a membrane that allows water to pass through more easily than organic solvent. That is, the ratio of the amount of water passing through the separator (621c) to the amount of water flowing into the membrane separator (621) is higher than the ratio of the amount of organic solvent passing through the separator (621c) to the amount of organic solvent flowing into the membrane separator (621).

[0209] As described above, the separation liquid may contain a small amount of organic solvent. Therefore, in the third embodiment, the organic solvent contained in the separation liquid is treated.

[0210] FIG. 15 is a schematic diagram showing an example of an organic solvent recovery unit (5) according to a third embodiment. The organic solvent recovery unit (5) according to the third embodiment differs from the first or second embodiment in that it has a separation liquid treatment unit (90).

[0211] The separation liquid treatment unit (90) is interposed in the separation discharge pipe (65). Separation liquid is introduced into the separation liquid treatment unit (90). The separation liquid contains a small amount of organic solvent. The solvent concentration of the separation liquid is lower than the solvent concentration of the mixed liquid. The separation liquid treatment unit (90) processes the separation liquid to further reduce the solvent concentration of the separation liquid. In the example of FIG. 15, the separation liquid treatment unit (90) includes a decomposer (92). The decomposer (92) is interposed in the separation discharge pipe (65). Separation liquid is introduced into the decomposer (92). The decomposer (92) decomposes the organic solvent in the separation liquid. Specifically, the decomposer (92) decomposes the organic solvent into water and other components. The other components include, for example, carbon dioxide.

[0212] The decomposer (92) may decompose organic solvents, for example, by electrolysis. For example, the decomposer (92) includes a tank for storing the incoming separation liquid, a pair of electrodes immersed in the separation liquid within the tank, and a power source that applies voltage between the pair of electrodes. By applying voltage between the pair of electrodes, the organic solvent in the separation liquid is decomposed.

[0213] However, liquid vapor may also flow through each pipe. For example, water vapor and organic solvent vapor may flow through each pipe. If the organic solvent is more volatile than water, it is easy for organic solvent vapor to be generated within the pipe. In particular, in the example of FIG. 15, the circulating dehydrator (62) includes a dehydration temperature tank (622) to separate the liquid from the mixture while heating the mixture. For this reason, the temperatures of the mixture and the liquid are relatively high. Since the mixture and the liquid evaporate as the temperature increases, for example, vapor of the mixture flows through the dehydration circulation pipe (61), and as a result, vapor of the liquid is introduced into the upstream end of the separation discharge pipe (65). The higher the temperature, the greater the proportion of liquid vapor. Hereinafter, the liquid and the liquid vapor are collectively referred to as the separation fluid. The main component of the separation fluid is water.

[0214] Thus, in the example of FIG. 15, the separation liquid processing unit (90) also includes a condenser (91). The condenser (91) is interposed in the separation discharge pipe (65) at a position upstream of the decomposer (92). Separation fluid is introduced into the condenser (91). The condenser (91) condenses at least the vapor of the organic solvent. That is, the vapor of the organic solvent changes into a liquid. The condenser (91) includes, for example, a heat exchanger and a cooling source. The heat exchanger is interposed in the separation discharge pipe (65). The cooling source cools the heat exchanger. For example, the cooling source may supply a refrigerant to the heat exchanger. The refrigerant may be a gas or a liquid. Alternatively, the cooling source may be an electronic cooling unit installed in the heat exchanger. The separation fluid passing through the heat exchanger is cooled by having heat removed by the heat exchanger. As a result, at least the vapor of the organic solvent changes into a liquid. The condenser (91) condenses most or all of the vapor of the organic solvent. Also, the condenser (91) can condense most or all of the water vapor.

[0215] As a result, the amount of organic solvent vapor flowing into the decomposer (92) can be reduced, while the amount of liquid organic solvent flowing into the decomposer (92) can be increased. Because of this, the decomposer (92) can electrolyze the organic solvent more reliably. The decomposer (92) only needs to decompose most or all of the organic solvent (liquid).

[0216] In the example of FIG. 15, a first discharge valve (661) and a second discharge valve (662) are installed as discharge valves (66). The first discharge valve (661) is interposed in the separation discharge pipe (65) at a position upstream of the separation liquid processing unit (90), and the second discharge valve (662) is interposed in the separation discharge pipe (65) at a position downstream of the separation liquid processing unit (90).

[0217] The control unit (6) operates the separation liquid processing unit (90) while the mixed liquid is being circulated by the dehydration circulation unit (60). Specifically, the control unit (6) operates the cooling source of the condenser (91) and the power supply of the decomposer (92). For example, the control unit (6) starts the operation of the separation liquid processing unit (90) at the start of the circulation of the mixed liquid by the dehydration circulation unit (60), and stops the operation of the separation liquid processing unit (90) at the stop of the circulation of the mixed liquid by the dehydration circulation unit (60).

[0218] Additionally, when the third embodiment is applied to the second embodiment, the control unit (6) operates the separation liquid processing unit (90) during the circulation of the mixed liquid through the first dehydration circulation path (601) and during the circulation of the mixed liquid through the second dehydration circulation path (602), respectively.

[0219] Additionally, if the decomposer (92) has a tank, the decomposer (92) may electrolyze the separated liquid when a sufficient amount of separated liquid is stored in the tank. In this case, the decomposition of the organic solvent does not necessarily have to be carried out during the circulation of the mixed liquid.

[0220] As described above, in the third embodiment, the separation liquid treatment unit (90) decomposes the organic solvent in the separation liquid. Because of this, the discharge treatment unit at the discharge source (e.g., the discharge treatment unit of a factory facility) can easily process the separation liquid. In addition, in the example described above, the condenser (91) condenses the vapor of the organic solvent, and then the decomposer (92) electrolyzes the organic solvent in the separation liquid. Because of this, the amount of organic solvent flowing downstream from the separation liquid treatment unit (90) can be more effectively reduced.

[0221] <Fourth Embodiment>

[0222] <Example 1>

[0223] FIG. 16 is a schematic diagram showing a first example of an organic solvent recovery unit (5) according to a fourth embodiment. The organic solvent recovery unit (5) according to the first example of a fourth embodiment differs from the organic solvent recovery unit (5) according to a third embodiment in that it is an internal configuration of a separation liquid processing unit (90).

[0224] The separation liquid processing unit (90) according to the fourth embodiment separates the organic solvent from the separation fluid. Then, the separation liquid processing unit (90) discharges the separation fluid after the organic solvent has been separated to the outside and adds the separated organic solvent to the first concentrate. In the example of FIG. 16, the separation liquid processing unit (90) supplies the separated organic solvent to a purification tank (Tk2).

[0225] Additionally, the separation liquid processing unit (90) can actually separate water from the separation fluid. Therefore, below, the liquid separated from the separation fluid by the separation liquid processing unit (90) is also referred to as the second concentrate. The second concentrate may contain not only an organic solvent but also a small amount of water. The main component of the second concentrate is an organic solvent, and the solvent concentration is high. The second concentrate may consist only of an organic solvent.

[0226] In the example of FIG. 16, the separation liquid processing unit (90) includes a separation dehydrator (93) and a return pipe (94). The separation dehydrator (93) is interposed in the separation discharge pipe (65). Hereinafter, the part of the separation discharge pipe (65) upstream of the separation dehydrator (93) is referred to as the upstream discharge pipe (65a), and the part downstream is referred to as the downstream discharge pipe (65b). The separation dehydrator (93) is also connected to the upstream end of the return pipe (94). A separation fluid is introduced into the separation dehydrator (93) through the upstream discharge pipe (65a). This separation fluid may contain a small amount of organic solvent. The separation dehydrator (93) separates a second concentrate from the separation fluid. The separation dewatering machine (93) allows the separated fluid (mainly water) after the second concentrate is separated to flow into the downstream discharge pipe (65b) and the second concentrate to flow into the return pipe (94). The return pipe (94) is a pipe that combines the second concentrate with the first concentrate. In the example of FIG. 16, the downstream end of the return pipe (94) is connected to a purification tank (Tk2).

[0227] Here, different examples of a circulating dehydrator (62) and a separating dehydrator (93) are described. The circulating dehydrator (62) and the separating dehydrator (93) differ from each other in that they have a lower limit of the applicable range of solvent concentration. The applicable range of solvent concentration refers to the applicable range of solvent concentration of the fluid flowing into the dehydrator. If a fluid with a solvent concentration below this lower limit of the applicable range flows into the dehydrator, it may cause problems with the dehydrator. For example, the dehydrator may not be able to sufficiently separate water from the fluid. The corresponding lower limit of the circulating dehydrator (62) is higher than the corresponding lower limit of the separating dehydrator (93). That is, the circulating dehydrator (62) is a dehydrator for high solvent concentration compared to the separating dehydrator (93). In other words, the separating dehydrator (93) is a dehydrator for low solvent concentration compared to the circulating dehydrator (62). If the separator (621c) is a zeolite membrane, the lower limit may be about 50 wt%. For example, if a mixture with a low solvent concentration is introduced into the zeolite membrane, there is a risk that the zeolite membrane may be damaged.

[0228] The separation dehydrator (93) includes, for example, an adsorption filter (93a) that captures an organic solvent, a heating unit (93b) that heats the adsorption filter (93a), and a condenser (961). The adsorption filter (93a) is, for example, activated carbon. The adsorption filter (93a) captures an organic solvent by means of adsorption. The adsorption filter (93a) separates the organic solvent from the separation fluid by capturing the organic solvent in the separation fluid. The lower limit of the applicable range of solvent concentration for the adsorption filter (93a) is lower than the lower limit of the separation membrane (621c), and, for example, may be 10 wt% or less, 5 wt% or less, 2 wt% or less, 1 wt% or less, or 0.1 wt% or less.

[0229] The heating unit (93b) heats the adsorption filter (93a) while the separation fluid is not flowing through the adsorption filter (93a), thereby releasing an organic solvent (e.g., steam) from the adsorption filter (93a). The organic solvent released from the adsorption filter (93a) flows into the return pipe (94). The heating unit (93b) may be an electric resistance heater having a heating wire or an optical heater having a light source. Additionally, the heating unit (93b) may include a heating pipe having a downstream end connected to the adsorption filter (93a), a gas supply source supplying gas through the heating pipe, and a heater that heats the gas flowing through the heating pipe. When a high-temperature gas (e.g., nitrogen) is supplied to the adsorption filter (93a), the adsorption filter (93a) is heated by heat exchange between the gas and the adsorption filter (93a). In addition, the adsorption filter (93a) can recover its adsorption capacity by releasing an organic solvent.

[0230] A second discharge valve (662) is interposed in the downstream discharge pipe (65b), and a return valve (95) is interposed in the return pipe (94).

[0231] Also, in the example of FIG. 16, the separation liquid processing unit (90) also includes a condenser (961). The condenser (961) is interposed in the downstream discharge pipe (65b). As an example, the condenser (961) is installed at a position downstream of the second discharge valve (662). The condenser (961) condenses the steam (mainly water vapor) contained in the separation fluid (mainly water and steam) that has passed through the separation dehydrator (93). The configuration of the condenser (961) is, for example, the same as that of the condenser (91).

[0232] The condenser (962) is interposed in the return pipe (94). For example, the condenser (962) is installed downstream of the return valve (95). The condenser (962) condenses the vapor of the organic solvent from the separation dehydrator (93). The configuration of the condenser (962) is, for example, identical to that of the condenser (91).

[0233] The control unit (6) opens the first discharge valve (661) and the second discharge valve (662) and also closes the return valve (95), causing the dewatering circulation unit (60) to circulate the mixture. During the circulation of this mixture, the separated fluid from the circulating dewatering unit (62) flows into the separating dewatering unit (93) through the upstream discharge pipe (65a). As an example, the separated fluid flows into the adsorption filter (93a).

[0234] The adsorption filter (93a) captures organic solvents in the separated fluid. Because of this, during circulation by the dehydration circulation unit (60), the amount of organic solvent captured by the adsorption filter (93a) increases over time. The separated fluid (mainly water and water vapor) that has passed through the adsorption filter (93a) is introduced into the condenser (961). The condenser (961) condenses the vapor and converts it into a separated liquid. The separated liquid that has passed through the condenser (961) is discharged to the outside.

[0235] Additionally, the control unit (6), while the dehydration circulation unit (60) has stopped the circulation, closes the first discharge valve (661) and the second discharge valve (662), opens the return valve (95), and operates the heating unit (93b). The heating unit (93b) heats the adsorption filter (93a) to release the organic solvent (vapor) from the adsorption filter (93a). The organic solvent flows into the condenser (962) on the return pipe (94). The condenser (962) condenses the vapor of the organic solvent to convert it into a liquid organic solvent. The condenser (962) may condense most or all of the vapor of the organic solvent. The second concentrate passing through the condenser (962) is supplied to the purification tank (Tk2).

[0236] As described above, in the fourth embodiment, the separation liquid treatment unit (90) separates part or all of the organic solvent in the separation fluid from the separation fluid. Because of this, the organic solvent in the separation fluid can be reduced in the fourth embodiment as well. Therefore, the discharge treatment unit at the discharge location can easily process the separation liquid. Meanwhile, the separated organic solvent (second concentrate) is added to the first concentrate. In the example described above, the second concentrate is supplied to the purification tank (Tk2). Because of this, the amount of waste organic solvent can be further reduced. Additionally, the second concentrate may be supplied to the recovery tank (Tk1).

[0237] <Example 2>

[0238] FIG. 17 is a schematic diagram showing a second example of an organic solvent recovery unit (5) according to a fourth embodiment. The organic solvent recovery unit (5) according to the second example of a fourth embodiment differs from the organic solvent recovery unit (5) according to a second embodiment in that it has or does not have a separation liquid treatment unit (90).

[0239] In the example of FIG. 17, the separation liquid processing unit (90) includes a first separation dehydrator (931), a second separation dehydrator (932), a dehydration conversion unit (97), and a purification conversion unit (99).

[0240] The dewatering switching unit (97) switches the discharge path of the separated fluid from the circulating dewatering unit (62) between a path passing through the first separation dewatering unit (931) and a path passing through the second separation dewatering unit (932). As an example, the dewatering switching unit (97) includes a separation discharge pipe (65), a first branch valve (971), and a second branch valve (972). The separation discharge pipe (65) includes an upstream common pipe (650), a first branch pipe (651), a second branch pipe (652), and a downstream common pipe (653).

[0241] The upstream end of the upstream common pipe (650) is connected to a circulating dewatering machine (62), and the downstream end of the upstream common pipe (650) is connected to the upstream end of the first branch pipe (651) and the upstream end of the second branch pipe (652). The downstream end of the first branch pipe (651) and the downstream end of the second branch pipe (652) are connected to the upstream end of the downstream common pipe (653). The downstream end of the downstream common pipe (653) is connected to the outside (e.g., a discharge treatment unit of a factory facility).

[0242] The first separation dehydrator (931) is interposed in the first branch pipe (651), and the second separation dehydrator (932) is interposed in the second branch pipe (652). An example of the configuration of the first separation dehydrator (931) and the second separation dehydrator (932) is the same as that of the separation dehydrator (93). However, in the second example, the condenser (961) is shared between the first separation dehydrator (931) and the second separation dehydrator (932). That is, the first separation dehydrator (931) includes a first adsorption filter (931a), a first heating unit (931b), and a condenser (961), and the second separation dehydrator (932) includes a second adsorption filter (932a), a second heating unit (932b), and a condenser (961). The first adsorption filter (931a) and the second adsorption filter (932a) are identical to the adsorption filter (93a), and the first heating unit (931b) and the second heating unit (932b) are identical to the heating unit (93b). The condenser (962) condenses the vapor of the organic solvent from each of the first adsorption filter (931a) and the second adsorption filter (932a).

[0243] The first branch valve (971) is interposed in the first branch pipe (651), and the second branch valve (972) is interposed in the second branch pipe (652). The first branch valve (971) is installed upstream of the first separation dehydrator (931), and the second branch valve (972) is installed upstream of the second separation dehydrator (932). In the example of FIG. 17, the third branch valve (973) is interposed in the part of the first branch pipe (651) downstream of the first separation dehydrator (931), and the fourth branch valve (974) is interposed in the part of the second branch pipe (652) downstream of the second separation dehydrator (932).

[0244] As described below, this dewatering switching unit (97) can switch the discharge path according to the dewatering circulation path circulating in the dewatering circulation unit (60). For example, the dewatering switching unit (97) selects a discharge path including a first separation dewatering unit (931) during circulation through the first dewatering circulation path (601). As a result, the separated fluid separated from the first dewatering circulation path (601) flows through the first separation dewatering unit (931), and an organic solvent is adsorbed on the first adsorption filter (931a). Meanwhile, the dewatering switching unit (97) selects a discharge path including a second separation dewatering unit (932) during circulation through the second dewatering circulation path (602). As a result, during circulation through the second dewatering circulation path (602), an organic solvent is adsorbed on the second adsorption filter (932a). Since the first dehydration circulation path (601) and the second dehydration circulation path (602) are switched alternately, the discharge path is also switched alternately.

[0245] In the example of FIG. 17, the separation liquid processing unit (90) also includes a condenser (961) and a discharge switching unit (98). The condenser (961) is interposed in the downstream common pipe (653) and condenses the vapor of the separation fluid from each of the first separation dehydrator (931) and the second separation dehydrator (932).

[0246] The discharge switching unit (98) switches the supply source for supplying organic solvent to the condenser (962) between the first adsorption filter (931a) and the second adsorption filter (932a). As an example, the discharge switching unit (98) includes a common return pipe (940), a first branch pipe (941), a second branch pipe (942), and a switching valve unit (980). The upstream end of the first branch pipe (941) is connected to the first adsorption filter (931a), the upstream end of the second branch pipe (942) is connected to the second adsorption filter (932a), and the downstream end of the first branch pipe (941) and the downstream end of the second branch pipe (942) are connected to the upstream end of the common return pipe (940).

[0247] The switching valve section (980) switches between a state where the first adsorption filter (931a) is connected to the condenser (962) and a state where the second adsorption filter (932a) is connected to the condenser (962). In the example of FIG. 17, the switching valve section (980) includes a first discharge valve (981) and a second discharge valve (982). The first discharge valve (981) is interposed in the first branch pipe (941), and the second discharge valve (982) is interposed in the second branch pipe (942). The condenser (962) is interposed in the common return pipe (940). The condenser (962) condenses the vapor of the organic solvent and causes the second concentrate to flow downstream.

[0248] The discharge switching unit (98) alternately switches the supply source for the second concentrate between the first separation dehydrator (931) and the second separation dehydrator (932), as described below.

[0249] In the example of FIG. 17, a purification switching unit (99) is installed in the organic solvent recovery unit (5). The purification switching unit (99) switches the supply source of the second concentrate from the separation liquid processing unit (90) between the first purification tank (Tk21) and the second purification tank (Tk22). As an example, the purification switching unit (99) includes a common return pipe (940), a first branch pipe (943), a second branch pipe (944), and a switching valve unit (990). The upstream end of the first branch pipe (943) and the upstream end of the second branch pipe (944) are connected to the downstream end of the common return pipe (940). The downstream end of the first branch pipe (943) is connected to the first purification tank (Tk21), and the downstream end of the second branch pipe (944) is connected to the second purification tank (Tk22).

[0250] The switching valve section (990) switches between a state in which the condenser (962) is connected to the first purification tank (Tk21) and a state in which the condenser (962) is connected to the second purification tank (Tk22). In the example of FIG. 17, the switching valve section (990) includes a first purification valve (991) and a second purification valve (992). The first purification valve (991) is interposed in the first branch pipe (943), and the second purification valve (984) is interposed in the second branch pipe (944).

[0251] The purification switching unit (99) alternately switches the purification tank (Tk2) that supplies the second concentrate between the first purification tank (Tk21) and the second purification tank (Tk22), as described below.

[0252] <Example of operation of the organic solvent recovery unit (5)>

[0253] FIG. 18 is a schematic diagram illustrating an example of the operation of an organic solvent recovery unit (5) according to the second example of the fourth embodiment. FIGS. 19 to 22 are diagrams for explaining an example of the operation of the organic solvent recovery unit (5). Here, the operation of the recovery conversion unit (50), the dehydration circulation unit (60), the concentrate supply unit (70), the purification circulation unit (80), and the reuse solution supply unit (89) is the same as in the second embodiment. For this reason, the following description will focus on the separated liquid processing unit (90).

[0254] As shown in FIG. 18, during the circulation of the mixed liquid through the first dehydration circulation path (601) including the first recovery tank (Tk11) (time t2 to time t3), the first separation dehydrator (931) separates the organic solvent from the separated fluid. Specifically, as shown in FIG. 19, the control unit (6) opens the discharge valve (66), the first branch valve (971), and the third branch valve (973), and with the condenser (961) in operation, causes the dehydration circulation unit (60) to start circulation. As a result, the separated fluid from the circulation dehydrator (62) passes through the first separation dehydrator (931) and the condenser (961) in this order and is discharged to the outside. Since the separated fluid flows into the first separation dehydrator (931), the amount of organic solvent captured by the first adsorption filter (931a) increases with the passage of time.

[0255] In the example of FIG. 18, the control unit (6) terminates the separation of the organic solvent from the separated fluid by the first separation dehydrator (931) with the cessation of circulation through the first dehydration circulation path (601) (time t3). Specifically, the control unit (6) closes the discharge valve (66), the first branch valve (971), and the third branch valve (973), and stops the condenser (961). Next, the separation liquid processing unit (90) supplies the second concentrate from the first separation dehydrator (931) to the second purification tank (Tk22). Specifically, as shown in FIG. 20, the control unit (6) opens the first discharge valve (981) and the second purification valve (992), and operates the first heating unit (931b) and the condenser (962) of the first separation dehydrator (931). As a result, the organic solvent is released from the first adsorption filter (931a) of the first separation dehydrator (931) and supplied to the second purification tank (Tk22) as a second concentrate through the condenser (962).

[0256] In the example of FIG. 18, the supply of the second concentrate from the first separation dehydrator (931) to the second purification tank (Tk22) is carried out in parallel with the supply of the first concentrate from the first recovery tank (Tk11) to the second purification tank (Tk22) by the concentrate supply unit (70) (time t3 to time t4). Also, in the example of FIG. 18, the supply of the second concentrate from the first separation dehydrator (931) to the second purification tank (Tk22) ends at time t4, but it is not necessarily limited to this. This is because the time required for the discharge of the organic solvent in the first adsorption filter (931a) may differ from the time of supply of the first concentrate from the first recovery tank (Tk11) to the second purification tank (Tk22).

[0257] Additionally, as shown in FIG. 18, during the circulation of the mixed liquid through the second dehydration circulation path (602) including the second recovery tank (Tk12) (time t6 to time t7), the second separation dehydrator (932) separates the organic solvent from the separated fluid. Specifically, as shown in FIG. 21, the control unit (6) opens the discharge valve (66), the second branch valve (972), and the fourth branch valve (974), and operates the condenser (961). As a result, the separated fluid from the circulation dehydrator (62) passes through the second separation dehydrator (932) and the condenser (961) in this order and is discharged to the outside. Since the separated fluid flows into the second separation dehydrator (932), the amount of organic solvent captured by the second adsorption filter (932a) increases with the passage of time.

[0258] In the example of FIG. 18, the control unit (6) terminates the separation of the organic solvent from the separated fluid by the second separation dehydrator (932) with the cessation of circulation through the second dehydration circulation path (602) (time t7). Specifically, the control unit (6) closes the discharge valve (66), the second branch valve (972), and the fourth branch valve (974), and stops the condenser (961). Next, the separation liquid processing unit (90) supplies the second concentrate from the second separation dehydrator (932) to the first purification tank (Tk21). Specifically, as shown in FIG. 22, the control unit (6) opens the second discharge valve (982) and the first purification valve (991), and operates the second heating unit (932b) and the condenser (962) of the second separation dehydrator (932). As a result, the organic solvent is released from the second adsorption filter (932a) of the second separation dehydrator (932) and supplied to the first purification tank (Tk21) as a second concentrate through the condenser (962).

[0259] In the example of FIG. 18, the supply of the second concentrate from the second separation dehydrator (932) to the first purification tank (Tk21) is carried out in parallel with the supply of the first concentrate from the second recovery tank (Tk12) to the first purification tank (Tk21) by the concentrate supply unit (70) (time t7 to time t8). Also, in the example of FIG. 18, the supply of the second concentrate from the second separation dehydrator (932) to the first purification tank (Tk21) ends at time t8, but it is not necessarily limited to this. This is because the time required for the discharge of the organic solvent in the second adsorption filter (932a) may differ from the time of supply of the first concentrate from the second recovery tank (Tk12) to the first purification tank (Tk21).

[0260] As described above, the separation liquid processing unit (90) can capture the organic solvent in the separated fluid through the first dehydration circulation path (601) by the first adsorption filter (931a) of the first separation dehydrator (931), and can capture the organic solvent in the separated fluid through the second dehydration circulation path (602) by the second adsorption filter (932a) of the second separation dehydrator (932). And, the separation liquid processing unit (90) releases an organic solvent from the first adsorption filter (931a) of the first separation dehydrator (931) during the suspension of circulation through the first dehydration circulation path (601) to supply the second concentrate to the second purification tank (Tk22), and during the suspension of circulation through the second dehydration circulation path (602), releases an organic solvent from the second adsorption filter (932a) of the second separation dehydrator (932) to supply the second concentrate to the second purification tank (Tk22).

[0261] In addition, since two first separation dehydrators (931) and second separation dehydrators (932) are installed as separation dehydrators (93), one may release the organic solvent while the other is actively capturing the organic solvent. For example, in FIG. 18, the release from the first adsorption filter (931a) of the first separation dehydrator (931) may end after time t5. In this case, the release from the first adsorption filter (931a) of the first separation dehydrator (931) is carried out in parallel with the adsorption of the second adsorption filter (932a) of the second separation dehydrator (932). Since the release time can be extended, the organic solvent captured in the first adsorption filter (931a) can be released more reliably. The same applies to the second adsorption filter (932a).

[0262] As described above, the organic solvent recovery device (organic solvent recovery unit (5)), the substrate processing device (100), and the organic solvent recovery method have been described in detail; however, the above description is illustrative in all aspects and the disclosure is not limited thereto. Furthermore, the various variations described above may be applied in combination as long as they do not contradict one another. Additionally, it is interpreted that numerous variations not exemplified may be conceived without departing from the scope of the disclosure. Explanation of the symbols

[0263] 100: Substrate processing device 4: Processing unit 50: Recovery switching unit 60: Dehydration circulation unit 61: Dehydration circulation piping 610: Common circulation piping 611: 1st Dewatering Circulation Piping 6111: 1st Downstream Piping 6112: 2nd downstream piping 612: 2nd dewatering circulation piping 6121: 1st upstream pipe 6122: 2nd upstream pipe 62: Circulating dehydrator 621: Membrane separator 622: Dehydration temperature tank 640: Circulation switching valve section 65: Separate discharge piping 70: Concentrate supply unit 71: 1st Liquid Transfer Pipeline 80: Purification Circulation Section 81: Purification circulation piping 82: Filter 821: 1st Filter 822: 2nd Filter 85: 2nd liquid transfer piping 91, 962: Condenser 92: Decomposer 93: Separator / Dehydrator 93a: Adsorption filter 931a: First adsorption filter 932a: Second adsorption filter 93b: Heating unit 931b: First heating section 932b: Second heating section 94: Return piping 97: Dehydration switch 98: Release Switch Tk1: Recovery Tank Tk11: 1st Recovery Tank Tk12: 2nd Recovery Tank Tk2: Purification Tank Tk21: 1st Purification Tank Tk22: 2nd Purification Tank Tk3: Supply Tank W: Substrate

Claims

Claim 1 An organic solvent recovery device comprising: a recovery tank for storing a mixture of organic solvent and water discharged from a processing unit for processing a substrate; a dehydration circulation pipe connected to the recovery tank; a dehydration circulation unit that generates a first concentrate, which is the mixture with an increased solvent concentration of the organic solvent, by circulation through a dehydration circulation path including the dehydration circulation pipe and the recovery tank; a purification circulation pipe that circulates the first concentrate; and a purification circulation unit that generates a reusable solution, which is the first concentrate with a reduced impurity content, by circulating the first concentrate through the purification circulation pipe, and a filter that is installed in the purification circulation pipe and captures impurities of the first concentrate. Claim 2 An organic solvent recovery device according to claim 1, wherein the circulating dehydrator comprises a membrane separator having a separation membrane that allows water to pass through. Claim 3 An organic solvent recovery device according to claim 1 or claim 2, wherein the circulating dehydrator comprises a dehydration temperature tank for heating the mixture. Claim 4 An organic solvent recovery device according to claim 1 or claim 2, wherein the purification circulation unit further comprises a purification temperature heater that heats or cools the first concentrate flowing through the purification circulation pipe. Claim 5 In claim 4, the purification temperature tank is an organic solvent recovery device that cools the first concentrate flowing through the purification circulation pipe. Claim 6 An organic solvent recovery device according to claim 1 or claim 2, further comprising a purification tank and a first liquid transfer pipe that causes the first concentrate from the recovery tank to flow toward the purification tank, wherein the purification circulation pipe returns the first concentrate from the purification tank to the purification tank. Claim 7 An organic solvent recovery device according to claim 1 or claim 2, further comprising a recovery switching unit that switches the recovery location of the mixture from the processing unit between the first recovery tank and the second recovery tank, wherein the first dehydration circulation pipe returns the mixture from the first recovery tank to the first recovery tank, and the second dehydration circulation pipe returns the mixture from the second recovery tank to the second recovery tank. Claim 8 An organic solvent recovery device according to claim 7, wherein the first dewatering circulation pipe comprises a first upstream pipe having an upstream end connected to the first recovery tank, a first downstream pipe having a downstream end connected to the first recovery tank, and a common circulation pipe connected between the first upstream pipe and the first downstream pipe, and the second dewatering circulation pipe comprises a second upstream pipe having an upstream end connected to the second recovery tank, a second downstream pipe having a downstream end connected to the second recovery tank, and the common circulation pipe connected between the second upstream pipe and the second downstream pipe, wherein the circulating dewatering device is installed in the common circulation pipe, and the dewatering circulation unit further comprises a circulation switching valve unit that switches between circulation through the first dewatering circulation pipe and circulation through the second dewatering circulation pipe. Claim 9 An organic solvent recovery device according to claim 6, further comprising a concentrate supply unit that switches the supply source from the recovery tank between the first purification tank and the second purification tank, wherein the first purification circulation pipe returns the first concentrate from the first purification tank to the first purification tank, and the second purification circulation pipe returns the first concentrate from the second purification tank to the second purification tank, and wherein the first filter is installed in the first purification circulation pipe and the second filter is installed in the second purification circulation pipe. Claim 10 An organic solvent recovery device according to claim 1, wherein the circulating dehydrator comprises a separation membrane that allows water to pass through more easily than the organic solvent in the mixture, a separation discharge pipe through which a separated fluid separated from the mixture flows as the mixture passes through the separation membrane of the circulating dehydrator, and a decomposer installed in the separation discharge pipe and decomposing the organic solvent contained in the separated fluid. Claim 11 An organic solvent recovery device according to claim 10, further comprising a condenser installed in the separation discharge pipe upstream of the decomposer and condensing the vapor of the organic solvent contained in the separation fluid, wherein the decomposer electrolyzes the organic solvent in liquid. Claim 12 An organic solvent recovery device according to claim 1, wherein the circulating dehydrator comprises a separation membrane that allows water to pass through more easily than the organic solvent in the mixture, a separation discharge pipe through which a separated fluid separated from the mixture flows by the mixture passing through the separation membrane of the circulating dehydrator, a separation dehydrator installed in the separation discharge pipe and separating the organic solvent from the separated fluid, and a return pipe connected to the separation dehydrator and adding a second concentrate containing the organic solvent separated from the separated fluid by the separation dehydrator to the first concentrate. Claim 13 An organic solvent recovery device according to claim 12, wherein the separation dehydrator is installed in the separation discharge pipe and comprises an adsorption filter that adsorbs the organic solvent, a heating unit that heats the adsorption filter to release the organic solvent from the adsorption filter and discharge the organic solvent into the return pipe, and a condenser installed in the return pipe. Claim 14 An organic solvent recovery device according to claim 13, wherein the first heating unit heats the first adsorption filter and the second heating unit heats the second adsorption filter, and the organic solvent recovery device comprises a dehydration switching unit that switches the adsorption filter through which the separation fluid flows between the first adsorption filter and the second adsorption filter, and a discharge switching unit that switches the adsorption filter communicating with the condenser between the first adsorption filter and the second adsorption filter. Claim 15 A substrate processing apparatus comprising an organic solvent recovery device as described in claim 1 or claim 2, said processing unit, a supply tank to which the reusable solution is supplied and which stores the reusable solution, and a second liquid transfer pipe connecting said supply tank and said processing unit. Claim 16 A method for recovering an organic solvent, comprising: a dehydration circulation process that generates a first concentrate with increased solvent concentration of the organic solvent in the mixture by circulating the mixture through a dehydration circulation path including a circulating dehydrator that separates water from a mixture of an organic solvent and water discharged from a processing unit that processes a substrate and a recovery tank that stores the mixture; and a purification circulation process that generates a reusable solution with reduced content of the impurities in the first concentrate by circulating the first concentrate through a purification circulation path including a filter that captures impurities in the first concentrate. Claim 17 A method for recovering an organic solvent according to claim 16, wherein, in the dehydration circulation process, the mixture is heated, and in the purification circulation process, the first concentrate is cooled.

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