FLOW DIVIDER AND LIQUID PROCESSING SYSTEM

A flow divider includes a flow divider main body having a guide flow path; an inlet through which a liquid is guided into the guide flow path; and a first outlet and a second outlet through which the liquid is discharged to an outside from the guide flow path. The first outlet is located above the second outlet, and when a bubble exists in the liquid within the guide flow path, a volume of the bubble flowing out to the outside along with the liquid through the second outlet is smaller than a volume of the bubble flowing out to the outside along with the liquid through the first outlet.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Patent Application No. 2023-135034 filed on Aug. 22, 2023, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The various aspects and embodiments described herein pertain generally to a flow divider and a liquid processing system.

BACKGROUND

There is known a system configured to supply a required amount of processing liquid to a processing device from a circulation line while circulating the processing liquid in a tank and the circulation line (see Patent Document 1 and Patent Document 2).Patent Document 1: Japanese Patent Laid-open Publication No. 2022-003666Patent Document 2: International Publication No. 2022/009661

SUMMARY

In an exemplary embodiment, a flow divider includes a flow divider main body having a guide flow path; an inlet through which a liquid is guided into the guide flow path; and a first outlet and a second outlet through which the liquid is discharged to an outside from the guide flow path. The first outlet is located above the second outlet, and when a bubble exists in the liquid within the guide flow path, a volume of the bubble flowing out to the outside along with the liquid through the second outlet is smaller than a volume of the bubble flowing out to the outside along with the liquid through the first outlet.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the drawings are schematic and the shapes and sizes of individual components in the drawings may not necessarily match the actual shapes and sizes of the components, and dimensional relationships between the individual components and relations in sizes of the individual components may sometimes be different from actual values. Even between the drawings, there may exist parts having different dimensional relationships or different ratios.

In the following description, the X direction, Y direction, and Z direction are directions perpendicular to each other. The X and Y directions are horizontal directions, and the Z direction is a height direction (vertical direction) perpendicular to the horizontal directions. Thus, the horizontal directions perpendicular to the height direction (Z direction) is a direction in which an XY plane (horizontal plane) extends.

FIG.1is a diagram schematically illustrating an example of a liquid processing system80.

The liquid processing system80shown inFIG.1has a carry-in/out station91and a processing station92. The carry-in/out station91includes a placement section81provided with a plurality of carriers C, and a transfer section82equipped with a first transfer mechanism83and a delivery section84. Each carrier C accommodates therein a plurality of substrates W horizontally. The substrate W is typically made of a semiconductor wafer, but is not limited thereto. The processing station92is equipped with a plurality of processing devices90disposed on both sides of a transfer path86, and a second transfer mechanism85configured to be moved back and forth along the transfer path86.

The substrate W is taken out from the carrier C and loaded in the delivery section84by the first transfer mechanism83, and taken out from the delivery section84by the second transfer mechanism85. Then, the substrate W is carried into the corresponding processing device90by the second transfer mechanism85to be subjected to a predetermined process in the corresponding processing device90. Afterwards, the substrate W is taken out from the corresponding processing device90and loaded in the delivery section84by the second transfer mechanism85, and then returned back into the carrier C in the placement section81by the first transfer mechanism83. Further, the substrate W may be returned to the carrier C after being processed in two or more processing devices90.

In the above-described liquid processing system80, two or more of the plurality of processing devices90may have the same configuration or different configurations, and may perform the same process or different processes. Each processing device90is capable of performing various types of processes on the substrate W by applying various kinds of processing fluids (for example, processing liquids such as a chemical liquid, a rinse liquid, and a cleaning liquid) to the substrate W. The processing fluid (processing liquid) that can be used in each processing device90is not particularly limited, and may contain a component that changes a surface property of the substrate W or may be pure water (DIW (De-Ionized Water)).

The liquid processing system80is equipped with a controller93. The controller93is implemented by, for example, a computer, and includes an operation processor and a storage. The storage of the controller93stores therein a program and data for various types of processes performed in the liquid processing system80. The operation processor of the controller93appropriately reads and executes the program stored in the storage, thus controlling the various mechanisms of the liquid processing system80to perform the various types of processes.

The program and the data stored in the storage of the controller93may have been recorded on a computer-readable recording medium, and may be installed from the recording medium into the storage. The computer-readable recording medium may be, by way of non-limiting example, a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), a memory card, or the like.

FIG.2is a partial cross sectional view schematically illustrating an example of the processing device90.

The processing device90shown inFIG.2includes a chamber70, a substrate holding mechanism71, a processing liquid supply72, and a recovery cup73.

The substrate holding mechanism71, the processing liquid supply72, and the recovery cup73are disposed inside the chamber70. A fan filter unit (FFU)74is provided at a ceiling portion of the chamber70to form a downflow within the chamber70. The substrate holding mechanism71includes a holder75, a supporting column76, and a driver77. The holder75is configured to hold the substrate W horizontally. The supporting column76extends in a vertical direction. A base end (lower end portion inFIG.2) of the supporting column76is supported by the driver77, and a leading end (upper end portion inFIG.2) of the supporting column76supports the holder75horizontally. The driver77is configured to rotate the supporting column76(besides, the holder75as well) around a vertical axis passing through the center of the supporting column76(besides, the holder75as well). In this way, as the holder75is rotated together with the supporting column76, the substrate W (seeFIG.1) held by the holder75is also rotated.

The processing liquid supply72is configured to supply a processing liquid to the substrate W held by the holder75. The processing liquid supply72has a plurality of nozzles, and is connected to a liquid supply system10. Each nozzle is configured to discharge the processing liquid supplied from the liquid supply system10to the substrate W. For example, the plurality of nozzles are configured to respectively correspond to a plurality of types of processing liquids supplied from the liquid supply system10.

The recovery cup73is disposed to surround the holder75, and serves to collect the processing liquid scattered from the substrate W. A drain port78is formed at a bottom of the recovery cup73, and the processing liquid collected by the recovery cup73is drained to the outside of the processing device90through the drain port78. Further, an exhaust port79is formed at the bottom of the recovery cup73, and a gas (downflow) supplied from the FFU74is exhausted to the outside of the processing device90through the exhaust port79.

Now, the liquid supply system10configured to supply the processing liquid to the processing liquid supply72of the processing device90will be explained.

FIG.3is a diagram schematically illustrating a configuration example of a liquid processing system80without having a flow divider to be described later (see a reference numeral15inFIG.5andFIG.6) that is effective in reducing bubbles B in a processing liquid L.FIG.3mainly shows a circulation structure of the processing liquid L.

In the liquid processing system80shown inFIG.3, the liquid supply system10has a tank11, and a circulation line20connected to the tank11. The processing liquid L is stored in a storage space Ts of the tank11. The circulation line20is provided with a circulation pump25configured to force-feed the processing liquid L. As the circulation pump25is driven under the control of the controller93, the processing liquid L is flown out from the tank11through one end of the circulation line20, and is returned back into the tank11through the circulation line20.

The circulation line20is extended to pass through the liquid supply system10and the processing device90. The circulation line20in the example shown inFIG.3is configured to be shared by the plurality of processing devices90. A plurality of supply lines87branched off from the circulation line20are respectively connected to the processing liquid supplies72of the plurality of processing devices90, and the processing liquid L is supplied to each processing liquid supply72from the circulation line20through the corresponding supply line87.

FIG.3shows the circulation structure for the processing liquid L of a single kind. When multiple kinds of processing liquids are discharged from the respective processing liquid supplies72, the circulation structure for the processing liquid L as shown inFIG.3may be provided for each processing liquid. In this case, circulation lines of the multiple circulation structures are respectively connected to the individual processing liquid supplies72, and the multiple kinds of processing liquids are respectively supplied to the individual processing liquid supplies72from the circulation lines of the multiple circulation structures.

FIG.4AtoFIG.4Eare schematic diagrams showing an example state of the bubbles B in the processing liquid L in the circulation line20shown inFIG.3(particularly a location between the tank11and the circulation pump25; see a reference sign ‘IV’ inFIG.3).FIG.4AtoFIG.4Eillustrate example states of the bubbles B in the processing liquid L in the circulation line20over time in this order.

As shown inFIG.4AtoFIG.4E, in the liquid supply system10ofFIG.3, which is not provided with a flow divider to be described later functioning as a gas-liquid separation mechanism, the processing liquid L continues to flow out from the tank11into the circulation line20together with the bubbles B which are contained therein without being reduced. For this reason, as shown inFIG.4AtoFIG.4E, the number and the total volume of the bubbles B in the processing liquid L in the circulation line20do not change significantly with a lapse of time, and, as a result, the bubbles B that has grown in the processing liquid L to have a large diameter may be supplied to the processing device90.

FIG.5is a diagram schematically showing an example configuration of the liquid processing system80including a flow divider15effective for reducing the bubbles B in the processing liquid L.FIG.5mainly shows a circulation structure of the processing liquid L.

The liquid processing system80shown inFIG.5is equipped with a tank11, a flow divider15connected to the tank11via an inlet line19, and a first circulation line21and a second circulation line22connected to the flow divider15and the tank11.

The tank11is a liquid storage to which the first circulation line21and the second circulation line22provided in parallel are connected, and is connected to the flow divider15(particularly, an ‘inlet’ to be described later; see a reference numeral ‘40’ inFIG.6A) via the inlet line19. The tank11may be a main tank that is not supplied with the processing liquid L from another tank, or may be a sub-tank/buffer tank that is supplied with the processing liquid L from another tank (main tank or the like).

The processing liquid L is stored in a storage space Ts formed by the internal space of the tank11. The inlet line19is opened to a location (for example, at a bottom) in the storage space Ts where the processing liquid L is stored. On the other hand, the first circulation line21and the second circulation line22are opened to a space (for example, at a ceiling) above the stored liquid (processed liquid L) in the storage space Ts.

For example, the processing liquid L returned to the tank11via the first circulation line21and the second circulation line22may be returned back into the storage space Ts by flowing along an inner wall surface of the tank11that defines the storage space Ts.

A gas is dissolved in the processing liquid L stored in the storage space Ts. Some of the gas in the processing liquid L is released from the processing liquid L while it is stored in the tank11, but some other may continue to stay in the processing liquid L in the form of bubbles.

The processing liquid L is supplied into the flow divider15from the tank11through the inlet line19. When the inlet line19has a step-shaped portion or a bent portion, the bubbles in the processing liquid L may grow significantly when the processing liquid L flowing through the inlet line19passes through such a step-shaped or bent portion.

The flow divider15divides the processing liquid L supplied through the inlet line19into the processing liquid L to be sent to the first circulation line21and the processing liquid L to be sent to the second circulation line22.

In particular, the flow divider15of the present exemplary embodiment divides the processing liquid L such that the volume of the bubbles B flowing out of the flow divider15together with the processing liquid L through the first circulation line21becomes greater than the volume of the bubbles B flowing out to the outside together with the processing liquid L through the second circulation line22.

An example configuration of the flow divider15will be described later (seeFIG.6). Briefly, the processing liquid L is guided to an internal flow path (guide flow path) within the flow divider15via the inlet, and the processing liquid L flows out from the guide flow path into the first circulation line21and the second circulation line22via a first outlet and a second outlet, respectively.

The first circulation line21is connected to the flow divider15(in particular, the ‘first outlet’ to be described later; see a reference numeral ‘41’ inFIG.6) and the tank11, and is provided with a liquid sending device28provided to send the processing liquid L in the first circulation line21from the flow divider15to the tank11. A specific configuration of the liquid sending device28is not limited, and it is possible to configure the liquid sending device28by, for example, a pump or an ejector.

In the example shown inFIG.5, all of the processing liquid L flown out from the flow divider15into the first circulation line21is returned back into the tank11. However, at least some of the processing liquid L flown into the first circulation line21may need to be returned to the tank11.

The processing liquid L returned to the tank11via the first circulation line21is discharged from above the processing liquid L stored in the storage space Ts of the tank11. As a result, the release (defoaming) of the bubbles B from the processing liquid L is promoted, so that the bubbles B in the processing liquid L can be reduced.

The second circulation line22is connected to the flow divider15(in particular, the ‘second outlet’ to be described later; see a reference numeral ‘42’ inFIG.6), and is provided with a circulation pump (liquid sending device)25configured to send the processing liquid L in the second circulation line22downstream.

The second circulation line22is extended to pass through the liquid supply system10and the processing device90, and the processing liquid L is supplied form the second circulation line22to the processing devices90that performs a process by using the processing liquid L. The second circulation line22in the present exemplary embodiment is configured to be shared by the plurality of processing devices90. A plurality of supply lines87branched off from the second circulation line22are respectively connected to the processing liquid supplies72of the plurality of processing devices90, and the processing liquid L is supplied to each processing liquid supply72from the second circulation line22through the corresponding supply line87.

FIG.5shows a circulation structure of the processing liquid L of a single kind. When multiple kinds of processing liquids are discharged from the respective processing liquid supplies72, the circulation structure for the corresponding processing liquid L as shown inFIG.5may be provided for each processing liquid. In this case, circulation lines of the multiple circulation structures are respectively connected to the individual processing liquid supplies72, and the multiple kinds of processing liquids are respectively supplied to the individual processing liquid supplies72from the circulation lines of the multiple circulation structures.

In the processing liquid L flown out from the flow divider15into the second circulation line22, at least some of the processing liquid L that has not been supplied to the processing liquid supply72of the processing device90is returned to the tank11via the second circulation line22.

According to the above-described liquid processing system80shown inFIG.5, the flow divider15enables the processing liquid L with the reduced bubbles B to be supplied into the second circulation line22that leads to the processing device90.

Meanwhile, the processing liquid L with the enhanced bubbles B is sent by the flow divider15into the first circulation line21that is not connected to the processing device90, and is finally returned back into the tank11. At least some of the dissolved gas in the processing liquid L returned to the tank11via the first circulation line21is released into an upper space within the storage space Ts under the pressure release in the tank11. The dissolved gas in the processing liquid L is reduced in the tank11in this way, and the processing liquid L with the reduced dissolved gas is sent back to the flow divider15through the inlet line19.

Now, the flow divider15belonging to the liquid supply system10will be explained.

FIG.6is a cross-sectional view showing an example of the flow divider15.

The flow divider15shown inFIG.6includes a flow divider main body30having a guide flow path R, an inlet40through which the processing liquid L is guided to the guide flow path R, and the first outlet41and the second outlet42through which the processing liquid L is discharged from the guide flow path R to the outside. The first outlet41is located above the second outlet42.

The guide flow path R includes an inflow guideway R0through which the processing liquid L from the inlet40is introduced, a first outflow guideway R1located between the inflow guideway R0and the first outlet41, and a second outflow guideway R2located between the inflow guideway R0and the second outlet42.

The inflow guideway R0extends in a height direction (Z direction; a first direction). The first outflow guideway R1and the second outflow guideway R2are located deviated from the inflow guideway R0in a horizontal direction (a second direction) perpendicular to the height direction. The processing liquid L is guided in the height direction (particularly, an upward direction) in the inflow guideway R0, and is then guided in the horizontal direction to be introduced into the first outflow guideway R1or the second outflow guideway R2.

In the example illustrated inFIG.6, the inlet40is connected to the inflow guideway R0of the guide flow path R at a sidewall32of the flow divider main body30, and defines a direction of the flow of the processing liquid L supplied from the inlet line19so that the processing liquid L is discharged into the inflow guideway R0toward a guide partition31. The first outlet41is connected to the first outflow guideway R1including a top portion of the guide flow path R at a ceiling wall33of the flow divider main body30. The second outlet42is connected to the second outflow guideway R2including a bottom of the guide flow path R at a bottom wall34of the flow divider main body30.

The flow divider main body30has the guide partition31, a shoulder member35, and a tapered member36.

The guide partition31extends in the height direction (Z direction) and partitions at least a part of the inflow guideway R0.

The guide partition31shown inFIG.6extends from the bottom wall34toward the ceiling wall33, and forms, between the ceiling wall33and the guide partition31, a connection guideway Rc through which the processing liquid L can flow. At least a part of the inflow guideway R0is formed by a space outside the guide partition31in the guide flow path R. Meanwhile, at least a part of the second outflow guideway R2is formed by a space inside the guide partition31in the guide flow path R.

Further, at least a part of the first outflow guideway R1(including at least a part of a space formed by the tapered member36) is formed by a space in the guide flow path R facing the space inside the guide partition31in an upward direction (a direction from the bottom wall34toward the ceiling wall33).

In this way, at least a part of the inflow guideway R0and at least a part of the second outflow guideway R2are separated with the guide partition31therebetween. The guide partition31shown inFIG.6has an annular shape in a plan view seen from above, and the portion of the inflow guideway R0and the portion of the second outflow guideway R2separated by the guide partition31are arranged concentrically.

The shoulder member35defines a part of the inflow guideway R0, and forms a shoulder surface Ss extending in a direction perpendicular to the height direction (that is, a horizontal direction). The tapered member36defines at least a part of the first outflow guideway R1, and forms a tapered surface St whose diameter (that is, a size in the horizontal direction) gradually decreases toward the first outlet41. The shoulder surface Ss and the tapered surface St are connected to each other. Although the shoulder surface Ss and the tapered surface St are directly connected to each other in the example shown inFIG.6, they may be indirectly connected via another surface (not shown).

In addition, the processing liquid L may be guided to be directed toward the first outlet41in a swirling flow in at least a part of the first outflow guideway R1(for example, in the portion defined by the tapered surface St). This swirling flow of the processing liquid L can be created in any of various ways. By way of example, by studying the structure of the guide flow path R (for example, the structure of the inflow guideway R0and the first outflow guideway R1) or the shape and the state of the surface forming the first outflow guideway R1, it is possible to create the swirling flow of the processing liquid L in the portion of the first outflow guideway R1formed by the tapered surface St.

In the flow divider15having the above-described configuration, the portion of the second outflow guideway R2defined by the guide partition31has a cross sectional area in the horizontal direction larger than that of the portion of the inflow guideway R0defined by the guide partition31. For this reason, a downward movement speed (descending speed) of the processing liquid L in the second outflow guideway R2is slower than an upward movement speed (ascending speed) of the processing liquid L in the inflow guideway R0. As a result, it is possible to effectively suppress the bubbles B, which are buoyant in the upward direction in the processing liquid L, from flowing out into the second circulation line22via the second outflow guideway R2.

Further, in order to suppress the flow of the bubbles B into the second circulation line22via the second outflow guideway R2, it is desirable that the descending speed of the processing liquid L in the second outflow guideway R2is as slow as possible. On the other hand, equal to or more than a required amount of the processing liquid L (for example, equal to or more than a flow rate of the processing liquid L required to be supplied to one or more processing devices90connected to the second circulation line22) needs to be flown out from the second outflow guideway R2into the second circulation line22.

Furthermore, the bubbles B having a large diameter have a higher tendency to generate particles than the bubbles B having a small diameter. For this reason, in order to suppress the increase of the particles, it is effective to suppress the large-diameter bubbles B from flowing out into the second circulation line22through the second outflow guideway R2. By effectively suppressing the bubbles B from flowing out to the second circulation line22through the second outflow guideway R2to be introduced into the circulation pump (liquid sending device)25, the increase of the particles can be effectively suppressed.

In addition, as the diameter of the bubble B increases, the buoyant force on the bubble B increases, making it difficult for the bubble B to descend and flow out to the second circulation line22through the second outflow guideway R2.

Considering these comprehensively, in order to suppress the bubbles B with the diameter of about 5 mm or more from flowing out to the second circulation line22through the second outflow guideway R2, the processing liquid L may be made to flow downwards at a speed lower than, e.g., 0.0006 m/sec in the second outflow guideway R2.

According to the flow divider15ofFIG.6described above, when the bubbles B are present in the processing liquid L in the guide flow path R, the volume of the bubbles B flowing out to the outside along with the processing liquid L through the second outlet42is smaller than the volume of the bubbles B flowing out to the outside along with the processing liquid L through the first outlet41. In addition, the number of the bubbles B flowing out to the outside along with the processing liquid L through the second outlet42tends to be smaller than the number of the bubbles B flowing out to the outside along with the processing liquid L through the first outlet41.

In this way, the flow divider15guides some of the processing liquid L, which is supplied from the tank11through the inlet line19, into the second circulation line22through the second outlet42in the state that the amount of the bubbles contained therein is reduced. Therefore, an operation of the circulation pump25provided in the second circulation line22can be effectively suppressed from being disturbed by the bubbles B, so that the operation stability of the circulation pump25is improved. Furthermore, since the processing liquid L with the reduced bubbles B is supplied to each processing device90to which the processing liquid L is supplied from the second circulation line22, the generation of particles is suppressed, so that a high-quality process can be performed by using the processing liquid L.

Moreover, a flow rate of the processing liquid L flowing out from the guide flow path R to the outside (first circulation line21) via the first outlet41may be set to be smaller than a flow rate of the processing liquid L flowing out from the guide flow path R to the outside (second circulation line22) through the second outlet42. In this case, it is possible to effectively suppress the bubbles B in the processing liquid L from being introduced into the second circulation line22through the second outlet42.

Additionally, in the flow divider15, by allowing the processing liquid L to flow strongly toward the guide partition31and the shoulder member35, the flow of the processing liquid L is disturbed, so that the gas (bubbles B) can be effectively separated from the processing liquid L.

FIG.7AtoFIG.10Bare diagrams illustrating a gas-liquid separation action of the flow divider15(particularly, the guide partition31and the shoulder member35), and illustrate an example of the state of the bubbles B in the processing liquid L near the guide partition31and the shoulder member35over time in this order.FIG.7A,FIG.8A,FIG.9A, andFIG.10Aare enlarged cross sectional views of the flow divider15shown inFIG.6, andFIG.7B,FIG.8B,FIG.9B, andFIG.10Bare enlarged cross sectional view of the second circulation line22(particularly, a portion between the flow divider15and the circulation pump25) (seeFIG.5).

FIG.7AandFIG.7Billustrate a state in which the processing liquid L is filled in the flow divider15and the second circulation line22, but does not flow downstream and remains stagnant. As shown inFIG.7AandFIG.7B, while the processing liquid L is not flowing, the processing liquid L in the flow divider15uniformly contains the bubbles B, and the processing liquid L in the second circulation line22may also uniformly contain the bubbles B.

FIG.8AtoFIG.10Bshow a state in which the processing liquid L filled in the flow divider15and the second circulation line22is flowing downstream. As depicted inFIG.8A, the processing liquid L in the flow divider15flows downstream while uniformly containing the bubbles B having a relatively small diameter. Then, as the processing liquid L in the flow divider15continues to flow downstream, the bubbles B in the processing liquid L gradually combine with each other and grow to have a large volume, as shown inFIG.9AandFIG.10A.

Such growth of the bubbles B is highly likely to proceed under a situation where the flow of the processing liquid L is disturbed so the contact between the bubbles B is promoted. Thus, the binding and the growth may be accelerated near the guide partition31and the shoulder member35.

In particular, the bubbles B having a relatively large size and receiving a relatively large buoyant force tend to stay on the shoulder surface Ss extending in the horizontal direction. The bubbles B remaining on the shoulder surface Ss grow further and have a large size due to collision and binding of additional bubbles B in a subsequent process. The bubbles B, which have grown large to some extent on the shoulder surface Ss, are moved from the shoulder surface Ss by the processing liquid L flowing downstream in a subsequent process, and are then moved downstream through the connection guideway Rc.

Since the bubbles B moving downstream in this way receive a large buoyant force according to their size (volume), they tend to easily move toward the first outlet41through the first outflow guideway R1located above.

In particular, in the flow divider15shown inFIG.6toFIG.10B, the tapered surface St extends in an obliquely upward direction from an end of the shoulder surface Ss. With this configuration, the bubbles B can be smoothly moved from the shoulder surface Ss to the tapered surface St, and are guided toward the first outlet41by the tapered surface St. Thus, the outflow of the bubbles B from the first circulation line21is accelerated. As a result, it is possible to more effectively suppress the bubbles B from flowing out to the second circulation line22via the second outflow guideway R2and the second outlet42(seeFIG.8BtoFIG.10B).

First Modification Example

FIG.11presents an enlarged cross sectional view of an example of the flow divider15according to a first modification example. InFIG.11, parts identical or corresponding to those of the flow divider15shown inFIG.6toFIG.10Bdescribed above will be assigned same reference numerals, and detailed description thereof will be omitted.

The flow divider main body30may have a protrusion50that protrudes downwards from an inner wall of the flow divider main body30that defines at least one of the inflow guideway R0and the first outflow guideway R1.

In the example shown inFIG.11, at the shoulder member35of the flow divider main body30, the protrusion50having a triangular cross section is provided at a position facing the guide partition31in the height direction (Z direction). By providing such a protrusion50, it is possible to promote the staying and the growth of the bubbles B in the processing liquid L, which is advantageous in causing a stronger buoyant force to act on the bubbles B.

The bubbles B, which have grown to a certain extent on the shoulder surface Ss, are moved from the shoulder surface Ss so as to pass through the connection guideway Rc and go beyond the protrusion50by the subsequent processing liquid L flowing downstream, as shown by a dotted line inFIG.11. Then, the bubbles B are moved downstream.

Further, the protrusion50is not limited to the example shown inFIG.11.

FIG.12is a perspective view showing another example of the flow divider15according to the first modification example, and shows the flow divider15cut in half.

The protrusion50does not necessarily need to face the guide partition31in the height direction (Z direction). For example, as in the example shown inFIG.12, the protrusion50may be provided at a position distanced farther from the first outlet41than the guide partition31in the horizontal direction. Alternatively, the protrusion50may be provided at a position closer to the first outlet41than the guide partition31is in the horizontal direction.

Additionally, the protrusion50may be provided on the tapered surface St that defines at least a part of the inflow guideway R0and/or the first outflow guideway R1.

In addition, the protrusion50may have a cross-sectional shape other than the triangle, may have a symmetrical or asymmetrical cross-sectional shape.

Second Modification Example

FIG.13presents an enlarged cross sectional view of an example of the flow divider15according to a second modification example.FIG.14provides an enlarged cross sectional view of another example of the flow divider15according to the second modification example. InFIG.13andFIG.14, parts identical or corresponding to those of the flow divider15shown inFIG.6toFIG.10Bdescribed above will be assigned the same reference numerals, and detailed description thereof will be omitted.

The flow divider main body30may have a first divided main body30A and a second divided main body30B configured to be detachably attached to each other.

As an example, as shown inFIG.13, the ceiling wall33of the flow divider main body30may be configured to be separated from the sidewall32and the bottom wall34. Alternatively, as shown inFIG.14, the bottom wall34of the flow divider main body30may be configured to be separated from the sidewall32and the ceiling wall33.

A main body connector30C configured to detachably fix the first divided main body30A and the second divided main body30B to each other is not particularly limited. Such a main body connector30C may be, by way of example, a fastening member having a threaded portion, or may be a fastening member using concave-convex fitting other than the screw. The main body connector30C may be configured as a part of the first divided main body30A and the second divided main body30B, and may include a member separated from the first divided main body30A and the second divided main body30B.

Further, the flow divider main body30may include three or more divided main bodies that are configured to be detachably attached to each other.

As in this modification example, as the flow divider main body30of the flow divider15has a detachable structure, maintenance of the flow divider15can be easily performed. For example, an inner wall surface of the flow divider main body30can be easily cleaned, or the divided main bodies can be replaced in a convenient way.

Further, it is possible to change properties of constituent materials or the like for each divided main body. By way of example, only a divided main body including the ceiling wall33(the first divided main body30A inFIG.13andFIG.14) may be made of a transparent material (for example, transparent resin or quartz). In this case, while allowing the sidewall32and/or the bottom wall34to have a structure (constituent material or the like) featuring excellent strength, it is possible to visually check the state of the bubbles B in the guide flow path R within the flow divider main body30through the ceiling wall33.

In addition, it may be also possible to prepare multiple types of divided main bodies with different structures for a specific divided main body, and to select and use an optimal type of divided main body according to a situation in which it is used. By way of example, for a divided main body including the bottom wall34(the second divided main body30B inFIG.13andFIG.14), multiple divided main bodies with different cross-sectional area/volume ratios of the inflow guideway R0and the second outflow guideway R2, which are defined by the guide partition31, in the horizontal direction may be prepared. In this case, depending on the situation, it is possible to select and use a divided main body with optimal cross-sectional area/volume ratios.

Third Modification Example

FIG.15is a diagram schematically illustrating an example configuration of the liquid processing system80according to a third modification example, which mainly illustrates a circulation structure of the processing liquid L. InFIG.15, parts identical or corresponding to those of the liquid processing system80shown inFIG.5described above will be assigned the same reference numerals, and detailed description thereof will be omitted.

In a single circulation structure, there may be provided a plurality of flow dividers15configured to allow the processing liquid L with the reduced bubbles B to flow out to the second circulation line22via the second outlet42.

In the example shown inFIG.15, a first flow divider15A and a second flow divider15B are provided in series.

The inlet line19is connected to the first flow divider15A, and the first flow divider15A serves to send the processing liquid L supplied from the tank11via the inlet line19into the first circulation line21and the second circulation line22.

The second flow divider15B is provided at a location between the first flow divider15A and the circulation pump25in the second circulation line22, and serves to send the processing liquid L supplied from a location upstream of the second circulation line22into the first circulation line21and the second circulation line22(particularly, a downstream side thereof).

Each of the first flow divider15A and the second flow divider15B may have the same configuration as the above-described flow divider15(seeFIG.6toFIG.14). That is, in the first and second flow dividers15A and15B, the volume of the bubbles B flowing into the second circulation line22along with the processing liquid L through the second outlet42is smaller than the volume of the bubbles B flowing into the first circulation line21along with the processing liquid L through the first outlet41.

As illustrated inFIG.15, by providing the plurality of flow dividers15A and15B, the processing liquid L in which the bubbles B are more effectively reduced can be supplied to the processing liquid supply72of each processing device90.

Other Modification Examples

A specific configuration of the guide flow path R in the flow divider15(the first flow divider15A and the second flow divider15B) is not particularly limited. In the above-described example (FIG.6, etc.), at least a part of the first outflow guideway R1is defined by the tapered surface St. However, at least a part of the inflow guideway R0and/or the second outflow guideway R2may be defined by the tapered surface.

It will be appreciated that the disclosure in the present specification is illustrative in all aspects and is not intended to be limiting. In the above-described exemplary embodiments and modification examples, various omissions, replacement and modifications may be made without departing from the scope and spirit of the claims. For example, the above-described exemplary embodiments and modification examples may be combined in whole or in part, and exemplary embodiments other than those described above may be combined with the above-described exemplary embodiments or modification examples. In addition, the effects of the present disclosure described in this specification are merely examples, and other effects may result.

Furthermore, a technical category for embodying the above-described technical concept is not particularly limited. By way of example, the above-described technical concept may be embodied by a computer-executable program for executing one or multiple sequences (processes) included in a method of manufacturing or using the above-described apparatus on a computer. Further, the above-described technical concept may be embodied by a computer-readable non-transitory recording medium in which such a computer-executable program is stored.

According to the exemplary embodiment, it is possible to provide the technique advantageous for sending the liquid, which may contain the bubbles, while reducing the bubbles.