Liquid dilution device and liquid dilution method

Abstract

Provided are a liquid dilution device (10) and a liquid dilution method. The device comprises: at least two first-stage dilution tanks (1), which are used for introducing a stock solution and a dilution medium to perform first-stage dilution so as to obtain a first diluted liquid; and at least two second-stage dilution tanks (2), wherein each second-stage dilution tank (2) is in communication with the at least two first-stage dilution tanks (1) and used for introducing the first diluted liquid and the dilution medium to perform second-stage dilution so as to obtain a second diluted liquid, and the second diluted liquid is supplied to a usage site (30). The liquid dilution device (10) is configured to make the at least two first-stage dilution tanks (1) alternately supply the first diluted liquid to the second-stage dilution tanks (2), and make the at least two second-stage dilution tanks (2) alternately supply the second diluted liquid to the usage site (30); and the device can continuously and stably formulate a diluted liquid having a target concentration.

Description

Liquid dilution device and method

[0001] This application claims priority to Chinese Patent Application No. 202411290600.6, filed September 13, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of semiconductor equipment cleaning, and more particularly, to a liquid dilution device and method. BACKGROUND

[0003] In industrial processes, liquid dilution is a common operation, and the accuracy of the dilution liquid concentration will directly affect the product quality of the subsequent process. In the semiconductor manufacturing process, the demand for liquid dilution is particularly significant. For example, in the cleaning process, concentrated ammonia water needs to be diluted to a specific concentration for cleaning wafers. However, the existing liquid dilution method is difficult to accurately control the concentration of the dilution liquid, and it is even more difficult to meet the needs of 2 / 3 nm advanced process nodes which are very sensitive to the concentration and temperature of the dilution liquid.

[0004] Therefore, there is an urgent need for a liquid dilution device that can accurately control the concentration and temperature, and can continuously and stably prepare dilution liquid that meets the target concentration and temperature. SUMMARY

[0005] Therefore, there is an urgent need for a liquid dilution device that can accurately control the concentration and temperature, and can continuously and stably prepare dilution liquid that meets the target concentration and temperature.

[0006] In a first aspect, a liquid dilution device is provided, comprising: at least two primary dilution tanks for passing a stock solution and a dilution medium to perform primary dilution to obtain a first dilution liquid; at least two secondary dilution tanks, each in communication with the at least two primary dilution tanks, for passing the first dilution liquid and the dilution medium to perform secondary dilution to obtain a second dilution liquid, which is used to supply to a use site; the liquid dilution device is configured to alternately supply the first dilution liquid from the at least two primary dilution tanks to the secondary dilution tanks, and alternately supply the second dilution liquid from the at least two secondary dilution tanks to the use site.

[0007] The primary dilution tank and the secondary dilution tank are provided with a liquid level controller and a liquid outlet pipe, and a switch valve is provided on the liquid outlet pipe for detecting the liquid level in the tank and controlling the opening and closing of the switch valve on the corresponding liquid outlet pipe of the dilution tank. The primary dilution tank and the secondary dilution tank are also provided with a self-circulation pipe for fully mixing the dilution liquid in the tank.

[0008] Exemplarily, the first-stage dilution tank comprises a first tank and a second tank, and the first-stage dilution tank alternately supplies the first dilution liquid to the second-stage dilution tank, specifically, when the liquid level of the first tank reaches a lower limit liquid level value, the first tank is switched to the second tank to supply the first dilution liquid to the second-stage dilution tank.

[0009] Exemplarily, the second-stage dilution tank comprises a third tank and a fourth tank, and the second-stage dilution tank alternately supplies the second dilution liquid to the use site, specifically, when the liquid level of the third tank reaches a lower limit liquid level value, the third tank is switched to the fourth tank to supply the second dilution liquid to the use site.

[0010] Optionally, each of the first-stage dilution tank and the second-stage dilution tank is provided with a vent for discharging air in the tank, and / or a liquid discharge port for discharging liquid in the tank, and / or an overflow port.

[0011] Optionally, the capacity of the first-stage dilution tank is less than the capacity of the second-stage dilution tank.

[0012] Optionally, a liquid supply pipe is arranged between the second-stage dilution tank and the use site, and the liquid supply pipe is provided with a temperature detector and a temperature regulator, the temperature detector is used to detect the actual temperature of the second dilution liquid and send it to the temperature regulator, and the temperature regulator is used to compare the actual temperature with a target temperature, and adjust the temperature of the second dilution liquid to the target temperature when the actual temperature is different from the target temperature.

[0013] Based on the above, the highly diluted liquid with uniform mixing degree and accurate concentration control can be obtained by passing the stock solution through the first-stage dilution and then through the second-stage dilution, and at least two dilution tanks are arranged for each stage of dilution, which can alternately supply the dilution liquid, save the dilution time, and inhibit the concentration fluctuation of the dilution liquid caused by the circulation dilution in a single dilution tank. In addition, the temperature detector and the temperature regulator arranged on the liquid supply pipe can further accurately control the temperature of the dilution liquid supplied to the use site, and meet the requirements of advanced processes on the temperature of the dilution liquid.

[0014] In some possible implementations, the liquid supply pipe is further provided with a concentration detector, which is used to detect the actual concentration of the second dilution liquid in the liquid supply pipe, and when the actual concentration is different from a target concentration, the stock solution or the dilution medium is supplemented to make the actual concentration of the second dilution liquid reach the target concentration; optionally, the liquid dilution device further comprises a software control unit for supplementing the stock solution or the dilution medium.

[0015] Optionally, the liquid supply pipe is in communication with a first supplementary branch pipe for supplying the stock solution and a second supplementary branch pipe for supplying the dilution medium, and the first supplementary branch pipe and the second supplementary branch pipe are both provided with a pneumatic valve and a flow meter.

[0016] In this implementation, according to the measurement value of the concentration detector, the flow rate of the stock solution and the dilution medium is added or adjusted by the software control unit, so as to accurately control the concentration of the dilution liquid supplied to the use site.

[0017] In a second aspect, a liquid dilution method is provided, comprising: feeding stock solution and dilution medium into at least one primary dilution tank to perform primary dilution, to obtain a first dilution solution; feeding the first dilution solution from the at least one primary dilution tank into at least one secondary dilution tank, and feeding dilution medium into the secondary dilution tank to perform secondary dilution, to obtain a second dilution solution; alternately feeding the second dilution solution from the secondary dilution tank to a use site; during the feeding of the dilution solution from any dilution tank, restarting the dilution process in a dilution tank of the same level whose liquid level is less than or equal to a lower limit liquid level value, and when the liquid level of the dilution tank feeding the dilution solution reaches the lower limit liquid level value, switching to feeding the dilution solution from a dilution tank of the same level which has completed the dilution process. The lower limit liquid level value is greater than 0.

[0018] In some possible implementations, during the feeding of the dilution solution from any dilution tank, restarting the dilution process in a dilution tank of the same level whose liquid level is less than or equal to a lower limit liquid level value specifically comprises: obtaining a time T1 required for the current dilution tank to feed the dilution solution, and a time T2 required for the dilution tanks of the same level to complete the dilution process;

[0019] Within a preset time T after the current dilution tank starts to feed the dilution solution, restarting the dilution process in a dilution tank of the same level whose liquid level is less than or equal to a lower limit liquid level value, wherein T≤T1-T2.

[0020] Optionally, a liquid feeding value is set according to the preset time T, and when the liquid level of the dilution tank currently feeding the dilution solution reaches the liquid feeding value, restarting the dilution process in a dilution tank of the same level whose liquid level is less than or equal to a lower limit liquid level value.

[0021] In some possible implementations, during the primary dilution and the secondary dilution, when the liquid level of any dilution tank reaches an upper limit liquid level value, the feeding of the liquid is stopped.

[0022] In some possible implementations, before feeding the primary dilution solution or the secondary dilution solution, the primary dilution solution or the secondary dilution solution is subjected to self-circulation in the tank.

[0023] In some possible implementations, before feeding the second dilution solution to the use site, the actual concentration of the second dilution solution is detected; when the actual concentration is the same as a target concentration, the second dilution solution is fed to the use site; and when the actual concentration is different from the target concentration, the stock solution or the dilution medium is supplemented to make the actual concentration of the second dilution solution reach the target concentration.

[0024] Exemplarily, the second diluent is supplied to the use site through a supply pipe, the supply pipe is provided with a concentration detector for detecting the concentration of the second diluent in the supply pipe, and the supply pipe is in communication with a first supplementary branch pipe for supplying the stock solution and a second supplementary branch pipe for supplying the dilution medium, and the first supplementary branch pipe and the second supplementary branch pipe are each provided with a pneumatic valve and a flow meter.

[0025] Optionally, the replenishing of the stock solution specifically comprises: opening the pneumatic valve on the first supplementary branch pipe to guide the stock solution into the supply pipe.

[0026] Optionally, the replenishing of the dilution medium specifically comprises: opening the pneumatic valve on the second supplementary branch pipe to guide the dilution medium into the supply pipe.

[0027] In some possible implementations, before the second diluent is supplied to the use site, the actual temperature of the second diluent is detected, and when the actual temperature is the same as the target temperature, the second diluent is supplied to the use site, and when the actual temperature is different from the target temperature, the temperature of the second diluent is adjusted to the target temperature.

[0028] In summary, in the liquid dilution device and the liquid dilution method, the stock solution is diluted in two stages, the liquid inflow of each stage of dilution is controlled respectively, and the concentration of each stage of dilution is accurately controlled; and at least two dilution tanks are used for alternating work in each stage of dilution process, so that the device can be continuously supplied with liquid before one dilution tank is empty, the operation of the device does not need to be stopped in the whole dilution process, the dilution time is shortened, and the concentration fluctuation of the dilution liquid is inhibited; in addition, the concentration detector and the temperature detector and the temperature regulator are arranged on the supply pipe, so that the concentration and the temperature of the dilution liquid are further accurately controlled, and therefore, the liquid dilution device can continuously and stably prepare the dilution liquid meeting the target concentration and the target temperature.

[0029] SUMMARY

[0030] The features and performances of the present application are further described by the following examples and the accompanying drawings.

[0031] Fig. 1 is a schematic structural diagram of a liquid dilution device 10 according to an embodiment of the present application.

[0032] Fig. 2 is a schematic flow chart of a liquid dilution method 100 according to an embodiment of the present application.

[0033] Fig. 3 is a schematic block diagram of a liquid replenishing method 200 according to an embodiment of the present application.

[0034] Preferred embodiments of the present application

[0035] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the description of the present application and the claims and the above description of drawings are intended to cover the non-exclusive inclusion. The terms "first", "second" and the like in the description of the present application and the claims or the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0037] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0038] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected", "attached" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects before and after it.

[0040] The structures, proportions, sizes, etc. shown in the drawings in the present disclosure are merely used to cooperate with the content disclosed in the present disclosure, to be understood and read by those skilled in the art, and do not have technical significance to define the limitations of the present application. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" in the present specification are merely for the convenience of clear description, and are not used to limit the scope of the present application. The change or adjustment of the relative relationship is also considered as the scope of the present application without substantial technical content change. In order to make the drawings as simple as possible, the same parts in the drawings of the present specification are not repeatedly labeled.

[0041] It should be understood that "a plurality of" appearing below means more than two (including two).

[0042] The liquid dilution device in the embodiments of the present application is used to dilute the stock solution twice. Referring to FIG. 1, the liquid dilution device 10 comprises a first-stage dilution tank 1 and a second-stage dilution tank 2. The stock solution is diluted for the first time (first-stage dilution) in the first-stage dilution tank 1 to obtain a first dilution solution, and the concentration of the first dilution solution is between the concentration of the stock solution and the concentration (i.e., target concentration) of a target dilution solution. The first dilution solution is diluted for the second time (second-stage dilution) in the second-stage dilution tank 2 to obtain a second dilution solution, and the concentration of the second dilution solution meets the target concentration. The first-stage dilution tank 1 comprises a first-stage first dilution tank 1a (first tank 1a) and a first-stage second dilution tank 1b (second tank 1b) connected in parallel. The first tank 1a and the second tank 1b are connected in communication with a first liquid supply pipe 11 for supplying a first liquid and a second liquid supply pipe 12 for supplying a second liquid. The first tank 1a and the second tank 1b are respectively provided with a first liquid outlet pipe 18a and a second liquid outlet pipe 18b, and the first liquid outlet pipe 18a and the second liquid outlet pipe 18b are respectively connected in communication with a third liquid supply pipe 13, and the first dilution solution diluted in the first-stage dilution tank 1 is fed into the third liquid supply pipe 13 through the first liquid outlet pipe 18a and / or the second liquid outlet pipe 18b, and the third liquid supply pipe 13 is used to supply the first dilution solution to the second-stage dilution tank 2. The second-stage dilution tank 2 comprises a second-stage first dilution tank 2a (third tank 2a) and a second-stage second dilution tank 2b (fourth tank 2b) connected in parallel, and the third tank 2a and the fourth tank 2b are connected in communication with the third liquid supply pipe 13 and a fourth liquid supply pipe 14 for supplying the second liquid. The third tank 2a and the fourth tank 2b are respectively provided with a third liquid outlet pipe 19a and a fourth liquid outlet pipe 19b, and the third liquid outlet pipe 19a and the fourth liquid outlet pipe 19b are respectively connected in communication with a liquid supply pipe 15, and the second dilution solution diluted in the second-stage dilution tank 2 is fed into the liquid supply pipe 15 through the third liquid outlet pipe 19a and / or the fourth liquid outlet pipe 19b, and the liquid supply pipe 15 is used to supply the second dilution solution to a use site 30. Specifically, in the liquid dilution device 10, when the first-stage dilution is performed, the first liquid and the second liquid are mixed and adjusted in the first tank 1a and / or the second tank 1b to obtain and store the first dilution solution; when the second-stage dilution is performed, the first dilution solution is alternately supplied from the first tank 1a and the second tank 1b to the third tank 2a and / or the fourth tank 2b through the third liquid supply pipe 13, and the second liquid is respectively introduced into the third tank 2a and / or the fourth tank 2b through the fourth liquid supply pipe 14, and the first dilution solution and the second liquid are mixed and adjusted in the second-stage dilution tank 2 to obtain and store the second dilution solution. When the use site 30 needs to be supplied with liquid, the second dilution solution is alternately supplied from the third tank 2a and the fourth tank 2b to the use site 30 through the liquid supply pipe 15.

[0043] Referring again to FIG. 1, the liquid supply pipe 15 is provided with a temperature detector 8 and a temperature regulator 9 connected to each other. The temperature detector 8 is configured to detect whether the temperature of the second diluent in the liquid supply pipe 15 meets the target temperature of the diluent (i.e., the target temperature) and transmit the detection result to the temperature regulator 9. In the case where the target temperature is not met, the temperature regulator 9 is configured to heat or cool the second diluent to adjust the temperature of the second diluent to the target temperature before supplying the second diluent to the use site 30. In one embodiment, the use site 30 is a cleaning chamber. In order to facilitate the flow of the liquid, the first liquid outlet pipe 18a, the second liquid outlet pipe 18b, the third liquid outlet pipe 19a, and the fourth liquid outlet pipe 19b are each provided with a pump 6. The above-mentioned process of alternately supplying the first diluent or the second diluent from the same stage two dilution tanks after each dilution is completed (i.e., the switching action of the same stage dilution tanks) will be described in detail later.

[0044] The first liquid is the original liquid to be diluted, and the second liquid is the dilution medium for diluting the first liquid. As the second liquid, there is no particular limitation, and depending on the use purpose, ultrapure water or pure water, water in which an electrolyte or a gas is dissolved, an alcohol such as isopropyl alcohol, etc. can be used. In addition, as the first liquid, there is no particular limitation as long as it is used for the purpose of dilution, and depending on the use purpose, water in which an electrolyte or a gas such as carbonic acid or ammonia is dissolved, an alcohol such as isopropyl alcohol, etc. can be used. Exemplarily, in the case where the prepared diluent is used for cleaning of a semiconductor wafer, it is preferable to use ultrapure water as the second liquid and to use ammonia water as the first liquid, and the liquid dilution device 10 is configured to dilute the ammonia water (concentrated ammonia water) twice to generate dilute ammonia water of a target concentration and supply the dilute ammonia water to the cleaning chamber. It should be understood that the above-mentioned ultrapure water refers to treated water obtained by removing ionic and non-ionic substances from raw water (original water) using an ultrapure water manufacturing device, and specifically refers to treated water having a specific resistance value of 18 MΩ·cm or more.

[0045] Each of the first dilution tank 1 and the second dilution tank 2 is respectively provided with a self-circulation pipe 16 for internally circulating the liquid in the corresponding dilution tank to uniformly mix the dilution liquid. The first liquid outlet pipe 18a and the second liquid outlet pipe 18b, and the third liquid outlet pipe 19a and the fourth liquid outlet pipe 19b are respectively provided with an on-off valve 5, and the on-off valve on the liquid outlet pipe of the corresponding dilution tank is in a closed state during the first dilution and the second dilution. The side of each dilution tank is provided with a liquid level controller 17 for detecting the liquid level in the tank, and in the case that the liquid level in the tank is detected to be less than or equal to a preset lower limit liquid level, the on-off valve on the liquid outlet pipe of the dilution tank is closed, and the switching of the dilution tank of the same stage is performed to continue the dilution process; in the case that the liquid level in the tank is detected to reach a preset upper limit liquid level, the on-off valve on the liquid inlet pipe of the dilution tank is closed. The upper part of each dilution tank is further connected with an air vent pipe and an overflow drain pipe (not shown) for discharging the air in the dilution tank, wherein the overflow drain pipe is used to discharge the excess liquid through the pipeline to the plant end, avoiding direct overflow from the top of the dilution tank to affect the machine. The lower part of each dilution tank is further connected with a liquid discharge pipe (not shown), which can discharge the liquid in the dilution tank when the dilution tank needs to be drained. For example, the washing tank water used for cleaning the dilution tank is discharged before dilution. Wherein, the air vent pipe, the overflow drain pipe and the liquid discharge pipe connected with each dilution tank are independently provided, and in the case of diluting concentrated ammonia water, the ammonia gas can be prevented from affecting the concentration of the diluted ammonia water.

[0046] Optionally, the capacity of the second dilution tank 2 is greater than the capacity of the first dilution tank 1. For example, in the process of diluting concentrated ammonia water, the amount of dilution medium liquid required for the second dilution is large, that is, more water needs to be mixed in for the second dilution than for the first dilution, so the capacity of the dilution tank for the second dilution is greater than the capacity of the dilution tank for the first dilution. It should be noted that the capacities of the dilution tanks of the same stage are the same, that is, the capacities of the first tank 1a and the second tank 1b are the same, and the capacities of the third tank 2a and the fourth tank 2b are the same. The capacity of the first dilution tank 1 provided in the embodiment of the present application is 30L, and the capacity of the second dilution tank 2 is 60L, but the capacity of the dilution tank is not limited in the present application.

[0047] The liquid dilution device 10 further comprises a software control unit 20 for controlling the switching action of the dilution tanks of the same stage. In addition, the software control unit 20 is also used to obtain the actual concentration of the second dilution liquid, and compare it with the target concentration to supplement the first liquid or the second liquid to the second dilution liquid. Specifically, a concentration detector 7 is arranged on the liquid supply pipe 15 to detect the concentration of the second dilution liquid in the liquid supply pipe 15 in real time, and the software control unit 20 can at least control the pneumatic valve 3 on the corresponding liquid inlet pipe based on the measurement value of the concentration detector 7 to supplement the first liquid or the second liquid, so that the actual concentration of the second dilution liquid meets the target concentration.

[0048] The liquid dilution method using the liquid dilution device 10 shown in FIG. 1 will be described below. FIG. 2 schematically shows a block diagram of the liquid dilution method 100 of the present embodiment. As shown in FIG. 2, the liquid dilution method 100 includes the following processes:

[0049] S110, primary dilution: the stock solution and the dilution medium are introduced into the primary dilution tank, the stock solution and the dilution medium are mixed in the primary dilution tank to obtain the first dilution liquid, the first dilution liquid is stored in the primary dilution tank, and the first dilution liquid is supplied from the primary dilution tank to the secondary dilution tank in the secondary dilution process.

[0050] The primary dilution includes three processes of mixing, storage, and liquid supply. The liquid dilution device provided by the present application includes at least two primary dilution tanks, and the stock solution can be diluted in the at least two primary dilution tanks to obtain the first dilution liquid simultaneously or sequentially. In the mixing process, each primary dilution tank stops introducing the stock solution and the dilution medium when the liquid level in the tank reaches the upper limit liquid level value. After the mixing is completed, the first dilution liquid is stored in the primary dilution tank for the secondary dilution. In the secondary dilution process, the primary dilution tank supplies the first dilution liquid to the secondary dilution tank. The primary dilution is a process that is repeated multiple times, and after the first dilution liquid in each primary dilution tank is supplied, the mixing process is started again to ensure that the primary dilution tank can continuously supply the first dilution liquid.

[0051] In the process of supplying the first dilution liquid in the first dilution tank, if the supply is not ended until the primary dilution tank is empty, the gas in the dilution tank will enter the third liquid inlet pipe, and the gas will enter the secondary dilution tank in the next liquid supply process, thereby causing the concentration of the prepared second dilution liquid to change. Therefore, in the liquid supply process, each primary dilution tank stops supplying the first dilution liquid when the liquid level in the tank reaches the lower limit liquid level value.

[0052] S120, secondary dilution: the first dilution liquid and the dilution medium are introduced into the secondary dilution tank, the first dilution liquid and the dilution medium are mixed in the secondary dilution tank to obtain the second dilution liquid, the second dilution liquid is stored in the secondary dilution tank, and the second dilution liquid is supplied from the secondary dilution tank to the use site when the use site needs the dilution liquid with the target concentration.

[0053] The secondary dilution also includes three processes of mixing, storage and supply. The liquid dilution device provided in the application includes at least two secondary dilution tanks, and the first dilution liquid can be diluted in the at least two secondary dilution tanks to obtain the second dilution liquid synchronously or sequentially. In the mixing process, each secondary dilution tank stops the first dilution liquid and the dilution medium from being supplied when the liquid level in the tank reaches the upper limit liquid level value. After the mixing is completed, the second dilution liquid is stored in the secondary dilution tank and waits to be supplied to the use site. In the process of being supplied to the use site, the secondary dilution tank supplies the second dilution liquid to the use site. The secondary dilution is a process that is repeated for multiple times, and after the second dilution liquid in each secondary dilution tank is supplied, the mixing process is started again to ensure that the secondary dilution tank can supply the second dilution liquid continuously.

[0054] S130, supplying the second dilution liquid to the use site.

[0055] Since each dilution stage includes at least two dilution tanks, the process of the primary dilution tank supplying the first dilution liquid to the secondary dilution tank and the process of the secondary dilution tank supplying the second dilution liquid to the use site both involve the switching of the dilution tanks of the same stage. The switching of the dilution tanks of the same stage will be described in detail below by taking the example of the first tank 1a and the second tank 1b alternately supplying the first dilution liquid to the secondary dilution tank 2 through the third liquid inlet pipe 13. In the secondary dilution process, the first supply mode of supplying the first dilution liquid from the first tank 1a to the third liquid inlet pipe 13 can be switched to the second supply mode of supplying the first dilution liquid from the second tank 1b to the third liquid inlet pipe 13, and then the third liquid inlet pipe 13 supplies the first dilution liquid to the secondary dilution tank 2 for the second dilution. Thus, it is not necessary to stop the operation of the device, and the second dilution liquid can be continuously and stably prepared. The switching action will be described below by taking the example of switching from the first supply mode to the second supply mode.

[0056] Before selecting the first supply mode or the second supply mode, it is first determined whether the primary dilution tank meets the supply condition, and the supply condition is that the mixing process in the primary dilution tank is completed and the liquid level in the tank is higher than the lower limit liquid level value. In the primary dilution tank that meets the supply condition, any primary dilution tank is selected to supply the first dilution liquid to the secondary dilution tank. Taking the first supply mode as an example, in the first supply mode, the first dilution liquid in the first tank 1a is supplied to the third liquid inlet pipe 13 by opening the on-off valve 5 on the first liquid outlet pipe 18a of the first tank 1a, and then flows into the third tank 2a and / or the fourth tank 2b for the second dilution. At this time, the on-off valve 5 on the second liquid outlet pipe 18b of the second tank 1b is in a closed state.

[0057] When the liquid level controller 17 detects that the liquid level in the first tank la is less than or equal to the lower limit liquid level value, the on-off valve 5 on the first liquid outlet pipe 18a is closed and the on-off valve 5 on the second liquid outlet pipe 18b of the second tank lb is opened, so that the first diluent liquid in the second tank lb is supplied to the third liquid inlet pipe 13 and then flows into the third tank 2a and / or the fourth tank 2b for the second dilution. At this time, the on-off valve 5 on the second liquid outlet pipe 18a of the first tank la is in the closed state. Thus, the switching from the first supply mode in which the first diluent liquid is supplied from the first tank la to the third liquid inlet pipe 13 to the second supply mode in which the first diluent liquid is supplied from the second tank lb to the third liquid inlet pipe 13 is completed.

[0058] Since the mixing process of the dilution tank requires a certain time to complete, in order to ensure that the dilution tanks of the same stage can continuously supply the diluent liquid, during the process in which any one dilution tank supplies the diluent liquid, the dilution tank in which the liquid level is less than or equal to the lower limit liquid level value in the remaining tanks of the same stage restarts the mixing process. For example, while the second tank lb supplies the first diluent liquid to the third liquid inlet pipe 13, if the liquid level in the first tank la is less than or equal to the lower limit liquid level value, the on-off valves 5 of the first liquid inlet pipe 11 and the second liquid inlet pipe 12 corresponding to the first tank la are opened, so that the first liquid and the second liquid are mixed in the first tank la to prepare the first diluent liquid and store the first diluent liquid. At this time, the on-off valve 5 on the first liquid outlet pipe 18a of the first tank la is in the closed state, and the prepared first diluent liquid is stored in the first tank la for the next supply of the first diluent liquid to the third liquid inlet pipe 13.

[0059] As described above, in the switching of the dilution tanks of the same stage, when the liquid level in the first tank la is less than or equal to the lower limit liquid level value, the first tank la stops supplying the liquid and restarts the mixing, while the second tank lb starts supplying the liquid to supply the first diluent liquid stored in the tank to the third liquid inlet pipe 13, so that the supply of the first diluent liquid is uninterrupted. Also, while one tank supplies the liquid, the other tank of the same stage restarts the mixing to prepare the first diluent liquid, which can shorten the preparation time and accelerate the dilution process, thereby preventing the concentration fluctuation of the diluent liquid. For example, when the dilution of ammonia water is prepared, the accelerated dilution process can prevent the concentration change caused by the evaporation of ammonia water.

[0060] In addition, in the above example, since the mixing process requires time, in order to ensure uninterrupted supply of the diluent, a critical time for the second tank 1b to start mixing is obtained according to the time required by the first supply mode and the time required for the first tank 1a to supply the first liquid and the second liquid into the second tank 1b to prepare the first diluent. That is, before the time for the first tank 1a to supply the first diluent reaches the critical time, the second tank 1b starts the mixing process, and it is ensured that the second tank 1b completes the preparation of the first diluent before the liquid level in the first tank 1a reaches the lower limit level, so as to ensure uninterrupted supply of the first diluent. A preset liquid level can also be set according to the above critical time, and the preset liquid level needs to be greater than the lower limit level. When the liquid level in the first tank 1a reaches the preset liquid level before the liquid level in the first tank 1a reaches the preset liquid level during the supply process, the mixing process of the second tank 1b is started, and it is ensured that the second tank 1b completes the preparation of the first diluent before the liquid level in the first tank 1a reaches the preset liquid level. However, the time for the second tank 1b to prepare the first diluent is not limited to this.

[0061] It should be noted that before the first-stage dilution S110, the staff needs to determine the preset input amount of each liquid required for each stage of dilution in advance. For example, the concentration of the target diluted ammonia water is 100000:1, and the first-stage dilution is performed according to the ratio of 100:1 of water and concentrated ammonia water to obtain the first diluent, and the concentration of the first diluent is between the concentration of the concentrated ammonia water and the target concentration. On the basis of the first-stage dilution, the second-stage dilution is performed according to the ratio of 1000:1 of water and the first diluent to obtain the second diluent, and the concentration of the second diluent meets the target concentration. Then, according to the preset input amount determined in advance, the various liquids are introduced into the corresponding dilution tank, and it is necessary to ensure that the actual input amount during the dilution process is equal to the preset input amount of the liquid determined in advance, so as to ensure the accuracy of the concentration of the diluent. Referring to FIG. 1, the first liquid inlet pipe 11, the second liquid inlet pipe 12, the third liquid inlet pipe 13, and the fourth liquid inlet pipe 14 are sequentially provided with flow meters 4 and on-off valves 5 in the direction of liquid flow. The flow meter 4 is used to measure the flow of the corresponding liquid flowing into the dilution tank through the corresponding liquid inlet pipe. When the flow meter 4 detects that the input amount of the liquid of the corresponding liquid inlet pipe reaches the preset input amount, the on-off valve 5 on the corresponding liquid inlet pipe is in a closed state. In this case, the actual input amount of the liquid is controlled by the flow meter 4, and the flow meter 4 can accurately detect the flow of the liquid flowing in the liquid inlet pipe, so that the actual input amount of each liquid can be equal to the preset input amount, and thus the concentration of the diluent is more accurate.

[0062] Based on the above, in the first dilution process, two dilution tanks in the first dilution process alternately dilute the original liquid to obtain and store the first dilution liquid, and alternately supply the first dilution liquid to the second dilution tank through the third liquid inlet pipe for secondary dilution; two dilution tanks in the second dilution process alternately dilute the first dilution liquid to obtain and store the second dilution liquid, and alternately supply the second dilution liquid to the use site through the liquid supply pipe. In the above two-stage dilution process, two tanks are used for each stage of dilution, and the device does not need to stop running, which speeds up the dilution process, suppresses the concentration fluctuation of the dilution liquid, ensures the accuracy and uniformity of each dilution, and improves the stability of the dilution liquid and the accuracy of the concentration control.

[0063] In some embodiments, due to volatilization, decomposition, etc. of the first liquid in each dilution tank during the two dilution processes, the concentration of the second dilution liquid may deviate from the target concentration of the target dilution liquid. In order to make the concentration of the dilution liquid supplied to the use site 30 more accurate, before performing S130 in the liquid dilution method 100, a liquid supplementing method 200 is also performed, in which the software control unit 20 can control the pneumatic valve 3 on the corresponding liquid inlet pipe to supplement the first liquid or the second liquid based on at least the measurement value of the concentration detector 7 on the liquid supply pipe 15, so that the concentration of the second dilution liquid meets the target concentration, and the concentration of the dilution liquid is more accurately controlled.

[0064] Referring to FIG. 3, the liquid supplementing method 200 specifically includes the following steps:

[0065] S210, obtaining the actual concentration of the second dilution liquid in the liquid supply pipe.

[0066] S220, comparing the actual concentration with the target concentration. If the actual concentration is the same as the target concentration, the second dilution liquid is directly supplied to the use site; if the actual concentration is different from the target concentration, the first liquid or the second liquid is supplemented into the liquid supply pipe to make the actual concentration reach the target concentration.

[0067] Specifically, if the actual concentration is lower than the target concentration, the first liquid is supplemented into the liquid supply pipe, and the actual concentration of the second dilution liquid in the liquid supply pipe is continuously monitored during the supplementing process until the target concentration is reached. If the actual concentration is higher than the target concentration, the second liquid is supplemented into the liquid supply pipe, and the actual concentration of the second dilution liquid in the liquid supply pipe is continuously monitored during the supplementing process until the target concentration is reached.

[0068] In one embodiment, the liquid supply pipe 15 is connected to a first replenishment branch for supplying the first liquid and a second replenishment branch (not shown) for supplying the second liquid, respectively. The first replenishment branch is connected in parallel to the first liquid inlet pipe 11, and the second replenishment branch is connected in parallel to the second liquid inlet pipe 12. Each of the replenishment branches is provided with a pneumatic valve, a flow meter and a switch valve. In this case, when the concentration detector 7 detects that the concentration of the second diluent in the liquid supply pipe 15 is lower than the target concentration, the pneumatic valve of the first replenishment branch is opened under the control of the software control unit 20 to introduce the first liquid into the liquid supply pipe 15, and the first liquid is replenished until the second diluent reaches the target concentration. During this process, only the pneumatic valve of the first replenishment branch is controlled, and the pneumatic valves of the other liquid inlet pipes are closed. When the concentration detector 7 detects that the concentration of the second diluent in the liquid supply pipe 15 is higher than the target concentration, the pneumatic valve of the second replenishment branch is opened under the control of the software control unit 20 to introduce the second liquid into the liquid supply pipe 15, and the second liquid is replenished until the second diluent reaches the target concentration. During this process, only the pneumatic valve of the second replenishment branch is controlled, and the pneumatic valves of the other liquid inlet pipes are closed. In this embodiment, the liquid can be quickly replenished to make the second diluent reach the target concentration, and when problems occur during the replenishment process, the replenishment branch containing the first liquid or the second liquid can be quickly checked and repaired.

[0069] In some embodiments, in order to meet the temperature requirements of the target diluent in the advanced process, a temperature adjustment process is further included before S130 in the liquid dilution method 100. In one embodiment, the temperature adjustment process specifically includes: using the temperature detector 8 to measure the actual temperature of the second diluent in the liquid supply pipe 15, and if the actual temperature is the same as the target temperature, directly supplying the second diluent to the use site, and if the actual temperature does not meet the target temperature, first using the temperature regulator 9 to adjust the temperature of the second diluent to the target temperature, and then supplying the second diluent to the use site.

[0070] It should be noted that the above-mentioned various components are cooperated through electrical connection, and the specific cooperation can be referred to the prior art, which will not be described here.

[0071] Therefore, the liquid dilution device 10 can continuously and stably prepare the dilute ammonia water with the target concentration and the target temperature, and supply the dilute ammonia water to the cleaning chamber through the liquid supply pipe.

[0072] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements shall be encompassed within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A liquid dilution device characterized by The liquid dilution device comprises: at least two primary dilution tanks for feeding a stock solution and a dilution medium to obtain a first dilution solution through primary dilution; at least two secondary dilution tanks, each in communication with the at least two primary dilution tanks, for feeding the first dilution solution and a dilution medium to obtain a second dilution solution through secondary dilution, the second dilution solution being used for supply to a use site; the liquid dilution device is configured to make the at least two primary dilution tanks supply the first dilution solution to the secondary dilution tanks alternately, and make the at least two secondary dilution tanks supply the second dilution solution to the use site alternately. The liquid dilution device according to claim 1, wherein The primary dilution tank comprises a first tank and a second tank, and the primary dilution tank supplies the first dilution solution to the secondary dilution tank alternately, specifically, when the liquid level of the first tank reaches a lower limit liquid level value, the first tank is switched to the second tank to supply the first dilution solution to the secondary dilution tank. The liquid dilution device according to claim 1, wherein The secondary dilution tank comprises a third tank and a fourth tank, and the secondary dilution tank supplies the second dilution solution to the use site alternately, specifically, when the liquid level of the third tank reaches a lower limit liquid level value, the third tank is switched to the fourth tank to supply the second dilution solution to the use site. The liquid dilution device according to claim 1, wherein The primary dilution tank and the secondary dilution tank are provided with a self-circulation pipe. The liquid dilution device according to any one of claims 1-3, characterized in that The primary dilution tank and the secondary dilution tank are provided with a liquid level controller and a liquid outlet pipe, and the liquid outlet pipe is provided with an on-off valve, which is used for detecting the liquid level in the dilution tank and controlling the opening and closing of the on-off valve on the corresponding liquid outlet pipe of the dilution tank. The liquid dilution device according to claim 1, wherein A liquid supply pipe is arranged between the secondary dilution tank and the use site, and the liquid supply pipe is provided with a temperature detector and a temperature regulator; The temperature detector is used for detecting the actual temperature of the second dilution solution and sending it to the temperature regulator; The temperature regulator is used for comparing the actual temperature with a target temperature, and adjusting the temperature of the second dilution solution to the target temperature when the actual temperature is different from the target temperature. The liquid dilution device according to claim 6, characterized in that The liquid supply pipe is also provided with a concentration detector; The concentration detector is used for detecting the actual concentration of the second dilution solution, and supplementing the stock solution or the dilution medium to make the actual concentration of the second dilution solution reach a target concentration when the actual concentration is different from the target concentration. The liquid dilution device according to claim 7, characterized in that The liquid dilution device further comprises a software control unit for supplementing the stock solution or the dilution medium. The liquid dilution device according to claim 1, wherein The capacity of the primary dilution tank is less than that of the secondary dilution tank. The liquid dilution device according to claim 1, wherein The primary dilution tank and the secondary dilution tank are provided with an exhaust port. The liquid dilution device according to claim 1, wherein The primary dilution tank and the secondary dilution tank are provided with a liquid discharge port. The liquid dilution device according to claim 1, wherein The primary dilution tank and the secondary dilution tank are provided with an overflow port. A liquid dilution method characterized by, The liquid dilution device comprises: feeding a stock solution and a dilution medium into at least one primary dilution tank to obtain a first dilution solution through primary dilution; the at least one primary dilution tank supplies the first dilution solution to at least one secondary dilution tank, and feeds the dilution medium into the at least one secondary dilution tank to obtain a second dilution solution through secondary dilution; the at least one secondary dilution tank supplies the second dilution solution to a use site alternately; In the process of supplying dilution liquid by any dilution tank, the dilution tank with liquid level less than or equal to the lower limit liquid level value in other dilution tanks of the same level restarts the dilution process, and when the liquid level of the dilution tank supplying dilution liquid reaches the lower limit liquid level value, the dilution tank which has completed the dilution process in the same level is switched to supply dilution liquid. The liquid dilution method according to claim 13, characterized in that The lower limit liquid level value is greater than 0. The liquid dilution method according to claim 13, characterized in that The process of restarting the dilution process by the dilution tank with liquid level less than or equal to the lower limit liquid level value in other dilution tanks of the same level in the process of supplying dilution liquid by any dilution tank is specifically: Obtaining the time T1 required for the current dilution tank to supply dilution liquid, and the time T2 required for other dilution tanks of the same level to complete the dilution process; In the preset time T after the current dilution tank starts to supply dilution liquid, the dilution tank with liquid level less than or equal to the lower limit liquid level value in other dilution tanks of the same level restarts the dilution process, wherein T≤T1-T2. The liquid dilution method according to claim 15, characterized in that Setting the liquid inlet value according to the preset time T, and before the liquid level of the current dilution tank supplying dilution liquid reaches the liquid inlet value, the dilution tank with liquid level less than or equal to the lower limit liquid level value in other dilution tanks of the same level restarts the dilution process. The liquid dilution method according to claim 13, characterized in that In the process of the first dilution and the second dilution, when the liquid level of any dilution tank reaches the upper limit liquid level value, the liquid inlet is stopped. The liquid dilution method according to claim 13, characterized in that Before supplying the first dilution liquid or the second dilution liquid, the first dilution liquid or the second dilution liquid is self-circulated in the tank. The liquid dilution method according to claim 13, characterized in that Before supplying the second dilution liquid to the use site, detecting the actual concentration of the second dilution liquid; When the actual concentration is the same as the target concentration, supplying the second dilution liquid to the use site, and when the actual concentration is different from the target concentration, supplementing the stock solution or the dilution medium to make the actual concentration of the second dilution liquid reach the target concentration. The liquid dilution method according to claim 13, characterized in that Before supplying the second dilution liquid to the use site, detecting the actual temperature of the second dilution liquid; When the actual temperature is the same as the target temperature, supplying the second dilution liquid to the use site, and when the actual temperature is different from the target temperature, adjusting the temperature of the second dilution liquid to the target temperature.

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