Current detection type multi-raw solution concentration automatic proportioning process

Abstract

The application provides a current detection type multi-raw solution concentration automatic proportioning process, which comprises the following production steps: (1) setting an adding mass parameter and an electric conductivity parameter according to the approximate concentration of the concentrated solution A and the concentrated solution B; (2) quickly adding clean water into a mixing container; (3) adding the concentrated solution A into the mixing container at a large flow rate, and judging after measuring the electric conductivity; (4) continuously quickly adding the concentrated solution B into the mixing container, and judging after measuring the electric conductivity; (5) circulating the liquid in the mixing container by using a liquid pump; and (6) sending a liquid preparation information. The solution mixing mode is faster, and the accurate proportioning of the multi-solution concentration can be quickly realized only by measuring the mass and the fixed pressure electric conductivity of the solution, the accurate mixing cost of the solution is lower, and the feedback adjustment process is provided, so that the accuracy of the solution concentration is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of wafer processing solution proportioning technology, specifically to a current-detection-based automatic proportioning process for multiple raw materials. Background Technology

[0002] In wafer fabrication, solutions with specific compositions are needed to immerse or spray the wafer surface. These solutions require dilution with water to prepare the necessary concentration ratios for wafer spraying. However, the concentration of the prepared solution is often unstable, and the concentration of the mixed spray solution changes over time. Therefore, the wafer spray solution needs to be prepared in real-time before spraying. However, the components of the stock solutions used to prepare the mixed spray solutions are also usually unstable. For example, ammonia and hydrogen peroxide, with their high concentrations, undergo continuous redox reactions during dilution and preparation of immersion or spray solutions, causing their concentrations to change over time. Therefore, the specific concentration before preparation is uncertain. Furthermore, different reaction conditions during mixing can also lead to inaccurate solution ratios. Therefore, in traditional methods of diluting and preparing immersion or spray solutions, the concentration of the prepared solution needs to be measured in real-time to ensure that the measured solution concentration meets the usage requirements.

[0003] Since ions exist in solutions, ion concentration can be detected by inserting two electrodes into the solution and measuring the conductivity between the electrodes. However, this method can only detect the concentration of a single solution and cannot specifically detect different components in mixed solutions. In wafer fabrication, the solutions used for soaking or spraying have special compositions and often require mixing different stock solutions in specific proportions. Traditional conductivity measurements cannot detect the specific ionic components in the solution; instead, specialized optical concentration meters are needed to specifically measure the concentration of each drug in the solution. However, the purchase and use of optical concentration meters are very expensive, significantly increasing the cost of wet wafer fabrication. Furthermore, single-point concentration testing of the solution cannot guarantee the accurate concentration of the concentrated raw material and the resulting solution during mixing. Therefore, the concentration of solutions mixed using traditional concentration measurement methods is often not accurate enough, affecting the quality of wafer production. Summary of the Invention

[0004] To address the above problems, this invention provides an automatic multi-source solution concentration ratio process that uses current detection to measure the concentration of a mixed solution to achieve the required ratio through process design and conductivity measurement.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: the current detection type automatic multi-solvent concentration mixing process includes the following production steps:

[0006] (i) Based on the approximate concentrations of the supplied concentrated solution A and concentrated solution B, the initial addition masses of clean water, concentrated solution A, and concentrated solution B are set as h, a, and b, respectively. The mixing container is designed with positive and negative electrodes. The conductivity value m of the diluted solution A under constant voltage is set, and the conductivity value n of the mixed solution after adding solution B under constant voltage is set, where n < m; m and n are both range values.

[0007] (ii) Quickly add clean water into the mixing container and monitor the total mass of the mixing container in real time. When the mass of the liquid in the mixing container is close to the target mass h, add pure water at a small flow rate. When the mass of the liquid in the mixing container reaches the set mass h, stop adding pure water.

[0008] (III) Add concentrated solution A to the mixing container at a high flow rate. When the liquid mass in the mixing container is close to the target mass h+a, add concentrated solution A at a low flow rate. When the liquid mass in the mixed solution reaches the set value h+a, stop adding the solution. After stopping the addition of concentrated solution A, apply a constant voltage to the positive and negative electrodes and detect the conductivity between the positive and negative electrodes in the mixing container. When the conductivity reaches the set value m, proceed directly to step (IV). If the conductivity is not the set value m, determine whether the conductivity is too high or too low. In this way, the concentration of the solution can be determined based on the concentration corresponding to the conductivity. Redesign the values ​​of h, a, and b. If the conductivity is less than m, restart step (III). When the conductivity reaches the set value m, proceed to step (IV). If the conductivity is greater than m, redesign the values ​​of h, a, and b and start from step (II). When the conductivity reaches the set value m, proceed to step (IV).

[0009] (iv) Continue to rapidly add concentrated solution B into the mixing container. When the mass of the mixing container is close to the target mass h+a+b, add concentrated solution B at a small flow rate. Stop adding solution when the mass of liquid in the mixed solution reaches the set value h+a+b. Measure the conductivity of the mixed solution under constant voltage. If the conductivity is the set value n, proceed to step (v); if the conductivity is greater than the set value n, continue to add small amounts of concentrated solution B until the conductivity reaches the set value n, then proceed to step (v).

[0010] (v) Circulate the liquid medicine in the mixing container using a liquid pump. During the circulation, heat the mixed liquid medicine. When the temperature of the liquid medicine reaches the set value, measure the conductivity between the positive and negative electrodes of the mixing container. When the conductivity is the set value, shut off the circulation. If the conductivity is not the set value, reset the parameters and repeat steps two, three, four, and five by adding small amounts of the medicine until the new conductivity set value is met, then shut off the circulation.

[0011] (vi) Issue information about the preparation of the medicine solution.

[0012] Preferably, a load cell force sensor for measuring the mass of the mixing container is installed at the lower part of the mixing container.

[0013] Preferably, the concentrated solution A is an HCl solution, and the concentrated solution B is an H2O2 solution.

[0014] Preferably, the mixing container is connected to the clean water system through a large flow valve and a small flow valve, the mixing container is connected to the medicine barrel of the concentrated solution A through a large flow valve and a small flow valve, and the mixing container is connected to the medicine barrel of the concentrated solution B through a large flow valve and a small flow valve.

[0015] Preferably, the mixing container is connected to two or more medicine barrels of the concentrated solution A through valves, and the judgment logic of whether the medicine barrel of the concentrated solution A is emptied is designed in step (2).

[0016] Preferably, the mixing container is connected to two or more medicine barrels of the concentrated solution B through valves, and the judgment logic of whether the medicine barrel of the concentrated solution B is emptied is designed in step (2).

[0017] Preferably, a heating module and a temperature determination module are designed in the mixing container.

[0018] Preferably, in step (4), if the conductivity value is greater than the set value n, continue to add a small mass of the concentrated solution B, measure that the conductivity of the mixed solution remains unchanged or increases, reset the values of h, a, and b, and start again from step (2). When reaching step (4) again until the conductivity reaches the set value n, enter step (5).

[0019] Preferably, when the conductivity in step (4) is less than n, reset the values of h, a, and b, start again from step (2), and when the conductivity reaches the set value n again in step (4), enter step (5).

[0020] Preferably, the feed raw material further includes a concentrated solution C. Before entering step (5), add the concentrated solution C, design the added mass of the concentrated solution as c, set the conductivity value p of the mixed solution after adding the concentrated solution C under a constant voltage, where p < n, and repeat the process of step (4) until the conductivity value of the mixed solution under a constant voltage reaches the p range.

[0021] The beneficial effects of this invention are as follows: In the current-detection type automatic multi-solvent concentration mixing process, when mixing the wafer spray solution, the weights of pure water, concentrated solution A, and concentrated solution B after addition are first set to h, a, and b, respectively. The conductivity values ​​after adding concentrated solution A and concentrated solution B are also set to m and n, respectively. This allows for rapid addition of pure water to reach weight h and concentrated solution A to reach h+a by weighing. Then, the conductivity between the two electrodes of solution A in the mixing container is measured using a constant voltage. The conductivity value is then compared with m, and corresponding operations are performed based on the comparison. The mass values ​​h, a, and b are then redefined based on the comparison. Concentrated solution B is then added again by weighing. When the weight of the mixed solution reaches h+a+b, the conductivity between the two electrodes in the mixing container is measured using a constant voltage. When the conductivity reaches n, the mixture is circulated and heated. This process is used to precisely mix and proportion concentrated solutions that are not entirely accurate. By pre-setting the added mass, it can quickly reach a near-ideal solution ratio. Then, by measuring the conductivity under constant voltage, the solution concentration is determined, and a procedural judgment is made regarding its correctness. After the judgment, the set mass range is readjusted, and the process continues to add solutions according to the corresponding concentration until the set concentration is reached. Furthermore, when adding multiple concentrated solutions, the conductivity change curves differ depending on the addition of different solutions or excess solutions. This allows for the determination of whether different solutions have reached their optimal reaction point based on the conductivity change after adding a small amount of concentrated solution, thus completing the concentration proportioning. This solution mixing method is not only faster, but also achieves precise proportioning of multiple solution concentrations quickly through only mass and constant-voltage conductivity measurement. The cost of precise solution mixing is also lower. Additionally, after the initial preparation of the drug solution, conductivity measurement under constant voltage is performed to further determine whether the concentration proportion after mixing is appropriate, and a feedback adjustment process is available, greatly improving the accuracy of the solution concentration. Attached Figure Description

[0022] Figure 1 It is a curve showing the change in conductivity of pure water and solution during the reaction of ammonia and hydrogen peroxide.

[0023] Figure 2 It is a curve showing the change in conductivity of pure water and solution during the reaction of hydrochloric acid and hydrogen peroxide. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments: Example

[0025] In this real-time example, the change in conductivity during the reaction of ammonia and peroxide is mainly utilized (e.g., Figure 1(As shown) The process steps are set, and the concentration state of the solution is judged according to the change of conductivity during solution mixing, so as to finally achieve the required ratio. In this embodiment, the ratio solution is mainly used to clean the wafer, and the NH4OH solution and H2O2 solution in the solution ratio need to react completely for optimal results. In this real-time example, the concentrated solution A is NH4OH solution and the concentrated solution B is H2O2 solution. Both of these are volatile solutions, so their concentrations are usually approximate values ​​before ratio mixing.

[0026] Electrical conductivity is a measure of a substance's ability to conduct electric current. When a voltage is applied across a conductor, charge carriers flow in a specific direction, generating an electric current. Electrical conductivity is defined by Ohm's law as the ratio of current density to electric field strength. In the following steps, the conductivity value refers to the ratio of voltage to current between the positive and negative electrodes within the mixing container. In the processes described below, conductivity values ​​are used to correspond to solution concentrations.

[0027] The current-detection-based automatic multi-component concentration mixing process includes the following production steps:

[0028] (I) Based on the approximate concentrations of the supplied concentrated solutions A and B, the initial addition masses of clean water, concentrated solution A, and concentrated solution B are set as h, a, and b, respectively. The specific values ​​of h, a, and b are determined based on the usage of the mixed solution, i.e., the volume of the mixing container. Positive and negative electrodes are designed and fixed within the mixing container of the mixing equipment. Based on the mixing temperature, the conductivity value m of the diluted solution A under constant voltage is set, and the conductivity value n of the mixed solution after adding solution B under constant voltage is set, where n < m. m and n are range values, i.e., the two extreme values ​​of m and n correspond to the allowable concentration range of the solution. Values ​​greater than m or n mentioned below refer to the maximum value within their respective ranges, while values ​​less than m or n refer to the minimum value within their respective ranges.

[0029] (ii) At the start of the mixing process, quickly add clean water to the mixing container. A load cell force sensor is installed at the bottom of the mixing container to measure its mass. The load cell force sensor accurately measures the real-time weight of the mixing container; the mass of the container minus its real-time weight gives the mass of the liquid inside the mixing container. When the mass of the liquid in the mixing container approaches the target mass h, add clean water at a small flow rate. When the mass of the liquid in the mixing container reaches the set mass h, stop adding clean water.

[0030] (III) Add concentrated solution A to the mixing container at a high flow rate. When the liquid mass in the mixing container is close to the target mass h+a, add concentrated solution A at a low flow rate. When the liquid mass in the mixing solution reaches the set value h+a, stop adding the solution. After stopping the addition of concentrated solution A, apply a constant voltage to the positive and negative electrodes and detect the conductivity between the positive and negative electrodes in the mixing container. When the conductivity reaches the set value m, the solution concentration in this step has reached the set standard, and proceed directly to step (IV). If the conductivity is not the set value m, determine whether the conductivity is too high or too low. In this way, the concentration of the solution can be determined based on the concentration corresponding to the conductivity. Redesign the values ​​of h, a, and b. If the conductivity is less than m, the corresponding solution concentration is too low. Then restart step (III). When the conductivity reaches the set value m, proceed to step (IV). If the conductivity is greater than m, the corresponding solution concentration is too high. Redesign the values ​​of h, a, and b, and start again from step (II). When the conductivity reaches the set value m, proceed to step (IV).

[0031] (iv) Continue to rapidly add concentrated solution B to the mixing container. When the mass of the mixing container is close to the target mass h+a+b, add concentrated solution B at a small flow rate. Stop adding solution when the mass of liquid in the mixed solution reaches the set value h+a+b. Measure the conductivity of the mixed solution under constant voltage. If the conductivity is the set value n, proceed to step (v); if the conductivity is greater than the set value n (refer to...). Figure 1 (If the amount of concentrated solution B added is too small at this point), continue adding small amounts of concentrated solution B until the conductivity reaches the set value n, then proceed to step (five). In this embodiment, when setting the value of b, try to set it to a smaller value to avoid adding too much concentrated solution B.

[0032] (v) Circulate the liquid medicine in the mixing container using a liquid pump. Heat the mixed liquid medicine while circulating it. When the temperature of the liquid medicine reaches the set value, measure the conductivity between the positive and negative electrodes of the mixing container. When the conductivity is the set value, the circulation is turned off. If the conductivity is not the set value, reset the parameters and repeat steps two, three, four, and five by adding a small amount of the medicine until the new conductivity setting value is met, and then turn off the circulation.

[0033] (vi) Issue information about the preparation of the medicine solution.

[0034] In this embodiment, the water washing solution used for rinsing wafers is mainly used, and the solutions used for mixing are all volatile solutions (ammonia and hydrogen peroxide), both of which have unstable concentrations. Therefore, the solution is prepared and used immediately. Compared with the traditional mixing method, in this mixing process, a large amount of solution is added first, and when it approaches the set point, it is slowly added to the set point. This solution mixing method is not only faster, but also can quickly achieve a precise ratio of the two solution concentrations by measuring the mass and the constant voltage conductivity of the solution. Compared with the traditional solution concentration detection method, the detection and mixing cost is lower. At the same time, after the initial completion of the chemical solution, the conductivity under constant voltage is measured to further determine whether the concentration ratio after mixing is appropriate, and there is a feedback adjustment process, which greatly improves the accuracy of the solution concentration.

[0035] The following table shows the monitoring results under HACH.

[0036] The mixing process, and the determination of conductivity of the solution after further addition after mixing:

[0037]

[0038] In the above experiment, pure water, ammonia, and hydrogen peroxide were added sequentially. Ammonia was added in the later stages of the first experiment, while hydrogen peroxide (excess hydrogen peroxide) was added in the later stages of the second experiment. The concentrations of each added liquid were monitored online using HACH, allowing for accurate determination of the changes in the conductivity curve during the addition of different solutions. Figure 1 As shown.

[0039] The experimental parameters above show that the conductivity is low when pure water is first added, rises rapidly upon the addition of ammonia, decreases upon the addition of hydrogen peroxide, and increases slightly upon the addition of excess hydrogen peroxide after the reaction is complete. The conductivity exhibits three distinct changes during solution addition. By observing these trends, the state of the reaction between ammonia and hydrogen peroxide can be deduced. In practical operation, by analyzing the conductivity values ​​at different stages of liquid injection, the approximate amount of a drug solution of uncertain concentration can be determined. Then, by observing the change in conductivity after adding a small amount of the corresponding concentrated solution, the reaction status of the mixed solution can be accurately determined, thus enabling precise judgment of the reaction state. This allows for accurate determination of whether the required liquid dosage has been achieved. Therefore, in actual mixing, the reaction process can be accurately judged without the need for a HACH apparatus, significantly reducing the complexity of the mixing process.

[0040] In this real-time example, when mixing concentrated ammonia and hydrogen peroxide solutions, if the addition of the second solution (hydrogen peroxide) proceeds smoothly, the above steps are followed. However, if an excessive amount of concentrated hydrogen peroxide is added initially, the conductivity value in step (iv) of the above production process will also exceed the set value n. In this case, by continuing to add small amounts of concentrated solution B, the conductivity of the mixed solution will be measured to be close to constant or increase. Then, according to... Figure 1 As shown, if the concentration of hydrogen peroxide solution is added too quickly, it can be determined that an excessive amount has been added. In this case, the values ​​of h, a, and b can be reset, and the process can restart from step (ii). When step (iv) is reached again and the conductivity reaches the set value n, step (v) is initiated. Therefore, this mixing process has a strong real-time measurement and error correction capability, making the entire mixing process fast, efficient, and accurate.

[0041] In actual production, the mixing container is connected to the clean water system via high-flow and low-flow valves, the mixing container is connected to the tank of concentrated solution A via high-flow and low-flow valves, and the mixing container is connected to the tank of concentrated solution B via high-flow and low-flow valves. Thus, during the mixing process, the flow rate of the solution is controlled by the high-flow and low-flow valves. Both the high-flow and low-flow valves can be solenoid valves for convenient control.

[0042] Furthermore, the mixing container is connected to two or more concentrated solution A tanks via valves. Step two includes logic to determine whether the concentrated solution A tanks are emptied. Similarly, the mixing container is connected to two or more concentrated solution B tanks via valves, and step two also includes logic to determine whether the concentrated solution B tanks are emptied. When the concentrated solution in one tank is depleted, it can be directly introduced into another tank without interrupting the reaction process to replace the concentrated solution tank. The mixing container is equipped with a heating module and a temperature detection module. This allows for convenient monitoring and control of the solution reaction temperature, thereby achieving optimal reaction results. Example

[0043] In this real-time example, the change in conductivity during the reaction of hydrochloric acid and peroxide is mainly utilized. The concentrated solution A provided in this real-time example is a hydrochloric acid solution (HCl), and the concentrated solution B is a hydrogen peroxide solution (H₂O₂). Both are volatile solutions and need to be prepared to achieve the exact reaction conditions. Due to the volatility of these two solutions…

[0044] Therefore, its concentration is usually an approximate value before formulation. The procedure is the same as that of Example 1 and will not be described in detail here. By observing the change in conductivity during the solution mixing process, the concentration state during solution formulation can be judged accordingly, and finally the formulation requirements can be achieved. In this example, the formulated solution is mainly used to clean the wafer, and it is optimal that the HCI solution and H2O2 solution in the solution formulation react completely.

[0045]

[0046] According to the above experimental data, a conductivity change trend graph of the concentrated HCI solution and H2O2 solution during the water-adding mixing reaction can be simply plotted, as Figure 2 shown. In this experiment, when the concentrated hydrochloric acid solution is added, the conductivity rises rapidly. After adding hydrogen peroxide, the conductivity decreases. Although the conductivity also decreases after adding an excessive amount of hydrogen peroxide, its change trend is completely different. Therefore, the reaction change of the mixed solution can be judged based on the change trend of the conductivity measurement value after adding a small amount of concentrated liquid medicine.

[0047] In this example, when the conductivity in step (iv) is less than n (refer to Figure 2 , at this time, the addition amount of concentrated solution B is too large), then re-design the values of h, a, and b, start from step (ii) again, and when the conductivity reaches the set value n in step (iv) again, enter step (v). This is an error correction method set for this formulation (hydrochloric acid and hydrogen peroxide formulation). Through this formulation method, the formulation concentration can be quickly adjusted, making the entire formulation process fast, efficient, and accurate. However, during actual implementation, try to set the value of b to be relatively small, and achieve the formulation requirements by subsequent small-flow addition. Example

[0048] The above two examples are both water-adding mixing of two concentrated liquid medicines, but this patented technology can also be used in the addition formulation of more solutions, and the formulation process of the first two solutions is the same as that of Example 1. If the feedstock also contains concentrated solution C, add concentrated solution C before entering step (v), design the mass of the added concentrated solution C as c, and set the conductivity value p of the mixed solution under a constant voltage after adding concentrated solution C, where p < n. Repeat the process of step (iv) until the conductivity value of the mixed solution under a constant voltage reaches the p range. In this way, the automatic formulation of three concentrated solutions can be achieved, with a convenient and fast process and accurate judgment.

[0049] The above examples are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A current-detection-based automatic mixing process for multiple stock solutions, comprising the following production steps: (a) Based on the concentrations of concentrated solution A and concentrated solution B supplied, the initial addition masses of clean water, concentrated solution A and concentrated solution B are set as h, a and b, respectively. Positive and negative electrodes are designed in the mixing container. The conductivity value m of diluted solution A under constant voltage is set, and the conductivity value n of the mixed solution after adding solution B under constant voltage is set, where n < m. (ii) Quickly add clean water into the mixing container and monitor the total mass of the mixing container in real time. When the mass of the liquid in the mixing container is close to the target mass h, add pure water at a small flow rate. When the mass of the liquid in the mixing container reaches the set mass h, stop adding pure water. (III) Add concentrated solution A to the mixing container at a high flow rate. When the liquid mass in the mixing container is close to the target mass h+a, add concentrated solution A at a low flow rate. When the liquid mass in the mixing solution reaches the set value h+a, stop adding the solution. After stopping the addition of concentrated solution A, apply a constant voltage to the positive and negative electrodes and detect the conductivity between the positive and negative electrodes in the mixing container. When the conductivity reaches the set value m, proceed directly to step (IV). If the conductivity is not the set value m, determine whether the conductivity is too high or too low, and redesign the values ​​of h, a, and b. If the conductivity is less than m, restart step (III). When the conductivity reaches the set value m, proceed to step (IV). If the conductivity is greater than m, redesign the values ​​of h, a, and b, and restart from step (II). When the conductivity reaches the set value m, proceed to step (IV). (iv) Continue to rapidly add concentrated solution B into the mixing container. When the mass of the mixing container is close to the target mass h+a+b, add concentrated solution B at a small flow rate. When the mass of the liquid in the mixed solution reaches the set value h+a+b, stop adding the solution and measure the conductivity of the mixed solution under constant voltage. If the conductivity is the set value n, proceed to step (v); if the conductivity value is greater than the set value n, continue to add small amounts of concentrated solution B and measure the conductivity of the mixed solution. Continue to add small amounts of concentrated solution B and measure the conductivity of the solution until the conductivity reaches the set value n and proceed to step (v). (v) Circulate the liquid medicine in the mixing container using a liquid pump. During the circulation, heat the mixed liquid medicine. When the temperature of the liquid medicine reaches the set value, measure the conductivity between the positive and negative electrodes of the mixing container. When the conductivity is the set value, shut off the circulation. If the conductivity is not the set value, reset the parameters and repeat steps two, three, four, and five by adding small amounts of the medicine until the new conductivity set value is met, then shut off the circulation. The concentrated solution A is an ammonia solution or an HCl solution, and the concentrated solution B is an H2O2 solution.

2. The current-detection type automatic multi-source solution concentration ratioing process according to claim 1, characterized in that: A load cell force sensor is installed at the bottom of the mixing container to measure the mass of the mixing container.

3. The current-detection type automatic multi-source solution concentration ratioing process according to claim 1, characterized in that: The mixing container is connected to the clean water system via a high-flow valve and a low-flow valve. The mixing container is also connected to the tank of concentrated solution A via a high-flow valve and a low-flow valve. The mixing container is further connected to the tank of concentrated solution B via a high-flow valve and a low-flow valve.

4. The current-detection type automatic multi-source solution concentration ratioing process according to claim 1, characterized in that: The mixing container is connected to two or more concentrated solution A tanks via valves, and step two includes logic for determining whether the concentrated solution A tanks are emptied; the mixing container is connected to two or more concentrated solution B tanks via valves, and step two includes logic for determining whether the concentrated solution B tanks are emptied.

5. The current-detection type automatic multi-source solution concentration ratioing process according to claim 1, characterized in that: The mixing container is equipped with a heating module and a temperature determination module.

6. The current-detection type automatic multi-source solution concentration ratioing process according to claim 1, characterized in that: If the conductivity value is greater than the set value n in step (iv), continue to add small mass of concentrated solution B. If the conductivity of the mixed solution remains unchanged or increases, reset the values ​​of h, a, and b, and start again from step (ii). When step (iv) is reached again, proceed to step (v) until the conductivity reaches the set value n.

7. The current-detection type automatic multi-source solution concentration ratioing process according to claim 1, characterized in that: When the conductivity is less than n in step (iv), the values ​​of h, a, and b are redesigned and the process restarts from step (ii). When the conductivity reaches the set value n in step four, the process proceeds to step (v).

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