TWI588482B - Electrochemical detection of mixed solution concentration method - Google Patents

Description

Method for electrochemically detecting the concentration of a mixed solution

The present invention relates to a method for detecting a concentration, and more particularly to a method for electrochemically detecting the concentration of a mixed solution.

The use of wet etching to etch the electrode is a relatively common manufacturing method in the current electronic product manufacturing process, and is applied to the technical fields including display panels, semiconductors, and circuit boards. The etching solution for general etching is, for example, "Etching solution for copper or copper alloy" in US Pat. No. US20130270217, which contains an acid group-containing chelating agent, hydrogen peroxide, and surface activity having an oxyethylene chain. Agent. As such, it is capable of selectively etching copper or copper alloy on a microelectronic substrate comprising copper or a copper alloy and a nickel-containing material.

And as the reaction time increases, the decrease of the reactants in the etching solution and the increase of the product cause a change in the concentration of the etching solution, which affects the speed and quality of the etching. For this reason, in the conventional method, when an etching solution is used After the time, the entire barrel of etchant must be replaced to ensure the quality and speed of the overall etching. However, in an etchant mixed with different substances, only one or two substances may be consumed by etching. In fact, only the addition of the specific substance is required to restore the quality and speed of the etching, and the entire etchant is completely etched. The replacement is a bit wasteful. Therefore, there are many methods for measuring the concentration of the etching solution, such as measuring the transmittance of the etching solution by optical means, comparing the specific gravity of the etching liquid before and after the reaction, or estimating the reaction rate by using the change in temperature.

However, none of the above methods can understand the consumption of individual components in the etching solution, and even the most commonly used optical measurement methods are also difficult to measure due to low concentration, low resolution, and are susceptible to environmental background values. Correction and expensive price of the machine are not conducive to real-time monitoring of the production line. Therefore, how to detect the concentration of various chemical substances in the etching solution quickly, simply and at low cost is really desirable by the relevant industry. Solve the problem.

The main object of the present invention is to solve the problem that the concentration change of various chemical substances in the etching liquid cannot be measured.

Another object of the present invention is to solve the problem that the conventional measurement method is cumbersome and expensive to use.

To achieve the above object, the present invention provides a method for electrochemically detecting the concentration of a mixed solution, comprising the steps of:

S1: using a cyclic voltammetry method to obtain a first redox potential of a first substance and a second redox potential of a second substance, and according to different known concentrations of the plurality of first substance aqueous solution and the plurality of second substances The aqueous solution respectively establishes a first substance concentration reference comparison data and a second substance concentration reference comparison data;

S2: obtaining an unknown concentration and mixing a mixed aqueous solution of the first substance and the second substance, and titrating the mixed aqueous solution onto an electrode test piece;

S3: applying the first oxidation-reduction potential to the electrode test piece to obtain a first current signal of the mixed aqueous solution;

S4: Comparing the first current signal with the first substance concentration reference data to confirm the concentration of the first substance in the mixed aqueous solution.

In summary, the present invention has the following features:

1. The concentration of the first substance in the mixed aqueous solution can be known by directly titrating the mixed aqueous solution onto the electrode test piece and applying the first current signal obtained after the first oxidation-reduction potential. The measurement method is simple and fast.

Second, since the electrode test piece is a low-cost disposable electrode, it does not need to use an expensive machine for measurement, and the process cost can be reduced.

The detailed description and technical content of the present invention will now be described as follows:

Referring to FIG. 1 to FIG. 9 , the present invention is a method for electrochemically detecting the concentration of a mixed solution, comprising the following steps:

S1: performing cyclic voltammetry on a first substance and a second substance, respectively, and taking a first oxidation-reduction potential of the first substance and a second oxidation-reduction potential of the second substance, and according to different The concentration of the first aqueous solution of the first substance and the aqueous solution of the plurality of second substances respectively establish a first substance concentration reference alignment data and a second substance concentration reference alignment data. In this embodiment, the first substance may be 3-amino-1,2,4-triazole, isopropanolamine, isobutanolamine, malic acid, malonic acid, gluconolactone or lactic acid. One of them.

In a more detailed description, in step S1, the following steps may be further included:

S1A: The first oxidation-reduction potential of the first substance and the second oxidation-reduction potential of the second substance are respectively obtained by cyclic voltammetry.

S1B: the first substance is prepared with different known concentrations of the first substance aqueous solution, and the first redox potential is applied to the first substance aqueous solution by a timed peening method to obtain a first The current response data of the first substance having different current changes in the concentration of the aqueous solution, and the current response data of the first substance is as shown in FIG. 2, wherein the first substance is 3-amino-1, 2, 4- Triamazole is used as an example and is formulated in a volume molar concentration, while the concentrations of line segment A, line segment B, line segment C, line segment D, and line segment E are 0.005M, 0.05M, 0.15M, 0.30M, and 0.50, respectively. M.

S1C: the second substance is formulated into different known concentrations of the second substance aqueous solution, and the second redox potential is applied to the second substance aqueous solution by timed peening method to obtain a second The second material current response data of the concentration of the aqueous solution with different current changes.

S1D: establishing the first substance concentration reference comparison data and the second substance concentration reference comparison data according to the first substance current response data and the second substance current response data, respectively. Please refer to "Figure 2" for the appropriate time as a reference line, for example, 10 seconds, and obtain the corresponding current of the first substance aqueous solution at different concentrations, and further make a current-to-concentration comparison data. The first substance concentration reference alignment data as shown in "Fig. 3" can be formed.

And "Fig. 3" to "Fig. 9" are different reference materials of the first substance concentration established by the first substance, and the first substance of "Fig. 3" is 3-amino-1, 2, 4 -Triamazole, the linear correlation coefficient (R ² ) is 0.9508, the first substance of "Fig. 4" is isopropanolamine, and the linear correlation coefficient is 0.9943. The first substance of "Fig. 5" is isobutyl Alcoholamine, the linear correlation coefficient is 0.932, the first substance in Fig. 6 is malic acid, and the linear correlation coefficient is 0.8814. The first substance in Fig. 7 is malonic acid, and the linear correlation coefficient is 0.8688. The first substance of "Fig. 8" is gluconolactone, and its linear correlation coefficient is 0.8586. The first substance of "Fig. 9" is lactic acid, and its linear correlation coefficient is 0.9822. Since the above linear correlation coefficients are all above 0.85, they are highly accurate as reference data comparison. Among them, 3-amino-1,2,4-triazole is a widely used intermediate for organic synthesis, which is highly chelating after oxidation, and therefore, when measured by oxidation-reduction potential, The conductivity of the solution decreases, causing the higher concentration of the solution to reduce the ability to transfer current, so the substance exhibits a counter-trend in the etching solution, and the higher the concentration, the smaller the response current.

The above steps are used to establish a reference database of values. If the tests are performed the same, only one database needs to be created. In the future, each measurement can be based on the same reference database as the criterion for the measured values. .

S2: Obtaining a mixed aqueous solution, the concentration of the mixed aqueous solution is unknown, and mixing the first substance and the second substance, and titrating the mixed aqueous solution onto an electrode test piece. In this embodiment, the mixed aqueous solution is a copper etching solution, and the copper etching solution comprises 3-amino-1,2,4-triazole, isopropanolamine, isobutanolamine, malic acid, and propylene Acid, gluconolactone, lactic acid and the like. The electrode test piece integrates the working electrode, the reference electrode and the auxiliary electrode into a single planar three-stage electrode.

S3: applying the first oxidation-reduction potential to the electrode test piece, and obtaining a first current signal of the mixed aqueous solution. In the present embodiment, if the first substance to be measured is 3-amino-1,2,4-triazole, the first redox potential is set according to the value determined by cyclic voltammetry. Between 0.35 volts and 0.45 volts; if the first substance is isopropanolamine, the first redox potential is set between 0.30 volts and 0.35 volts; if the first substance is isobutanolamine Setting the first redox potential to be between 0.15 volts and 0.25 volts; if the first substance is malic acid, setting the first redox potential to be between -0.19 volts and -0.24 volts; When a substance is malonic acid, the first redox potential is set to be between -0.24 volts and -0.29 volts; if the first substance is gluconolactone, the first redox potential is set to be 0 volts. Between -0.1 volts; if the first substance is lactic acid, the first redox potential is set to be between 0.6 volts and 0.7 volts.

S4: comparing the first current signal with the first substance concentration reference data to confirm the concentration of the first substance in the mixed aqueous solution, as shown in FIG. 3, for example, if the first current signal is At 100 μA, the concentration of the first substance was determined to be 210 mM.

S5: If the concentration of the second substance in the mixed aqueous solution is also determined, the second redox potential may be further applied to the electrode test piece to obtain a second current signal of the mixed aqueous solution.

S6: comparing the second current signal with the second substance concentration to compare the data to confirm the concentration of the second substance in the mixed aqueous solution, and the method is the same as the first substance, and no further description is provided herein. .

In summary, the present invention has the following features:

1. The concentration of the first substance in the mixed aqueous solution can be known by directly titrating the mixed aqueous solution onto the electrode test piece and applying the first current signal obtained after the first oxidation-reduction potential. The measurement method is simple and fast.

Second, only need to titrate the mixed aqueous solution to the electrode test piece, the material concentration can be accurately confirmed by the measured current value, without the influence of the external environmental background value, the accuracy and accuracy are high.

3. The copper etching solution is applied to the invention, and the concentration of each chemical component in the copper etching solution can be quickly and accurately measured during the etching process of the copper etching solution, thereby supplementing each chemical component. Not only is it highly reliable, but it also avoids replacing the entire barrel of copper etching solution, which can reduce production costs.

Fourth, by using the low-cost disposable electrode test piece to measure, replacing the traditional expensive machine, the process cost can be reduced.

Therefore, the present invention is highly progressive and conforms to the requirements of the invention patent application, and the application is filed according to law, and the praying office grants the patent as soon as possible.

The present invention has been described in detail above, but the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the scope of the invention. That is, the equivalent changes and modifications made by the scope of the present application should remain within the scope of the patent of the present invention.

S1~S6, S1A~S1D‧‧‧ steps
A~E‧‧‧ line segment

FIG. 1 is a schematic flow chart of a preferred embodiment of the present invention. 2 is a schematic diagram of current response data according to a preferred embodiment of the present invention. 3 to 9 are schematic diagrams showing data of concentration reference ratios according to different embodiments of the present invention.

S1~S6, S1A~S1D‧‧‧ steps

Claims (12)

A method for electrochemically detecting the concentration of a mixed solution, comprising the steps of: S1: respectively obtaining a first redox potential of a first substance and a second redox potential of a second substance by cyclic voltammetry, and Establishing a first substance concentration reference alignment data and a second substance concentration reference comparison data according to different known concentrations of the plurality of first substance aqueous solutions and the plurality of second substance aqueous solutions; S2: obtaining an unknown concentration and mixing the first a mixed aqueous solution of a substance and the second substance, titrating the mixed aqueous solution onto an electrode test piece; S3: applying the first redox potential to the electrode test piece to obtain a first current signal of the mixed aqueous solution; S4: Comparing the first current signal with the first substance concentration reference data to confirm the concentration of the first substance in the mixed aqueous solution. The method for electrochemically detecting the concentration of the mixed solution according to claim 1, wherein in the step S1, the method further comprises the steps of: obtaining the first redox potential of the first substance and the second substance; The second redox potential; S1B: formulating the aqueous solution of the first substance at different known concentrations, and applying the first redox potential to the first aqueous solution by timed peening method, thereby obtaining a The first substance current response data of the concentration of the first substance aqueous solution and the different current changes; S1C: formulating the second known substance aqueous solutions of different known concentrations, and applying the second redox potential to the timed peening method The second substance aqueous solution obtains a second substance current response data according to the concentration of the second substance aqueous solution; and S1D: according to the first substance current response data and the second substance current respectively The first substance concentration reference comparison data and the second substance concentration reference comparison data are established in response to the data. The method for electrochemically detecting the concentration of the mixed solution according to claim 1, wherein after step S4, the method further comprises the steps of: S5: applying the second redox potential to the electrode test piece to obtain the a second current signal of the mixed aqueous solution; and S6: comparing the second current signal with the second substance concentration to confirm the concentration of the second substance in the mixed aqueous solution. A method for electrochemically detecting the concentration of a mixed solution as described in claim 1, wherein in step S2, the mixed aqueous solution is a copper etching solution. The method for electrochemically detecting the concentration of a mixed solution as described in claim 4, wherein the copper etching solution comprises 3-amino-1,2,4-triazole, isopropanolamine, isobutanolamine , malic acid, malonic acid, gluconolactone and lactic acid. The method for electrochemically detecting the concentration of a mixed solution according to claim 5, wherein in the step S3, if the first substance is 3-amino-1,2,4-triazole, the setting is set. The first redox potential is between 0.35 volts and 0.45 volts. The method for electrochemically detecting the concentration of the mixed solution according to claim 5, wherein in the step S3, if the first substance is isopropanolamine, setting the first redox potential to be 0.30 volt. Between 0.35 volts. The method for electrochemically detecting the concentration of the mixed solution according to claim 5, wherein in the step S3, if the first substance is isobutanolamine, setting the first redox potential to be 0.15 volt. Between 0.25 volts. The method for electrochemically detecting the concentration of a mixed solution according to claim 5, wherein in step S3, if the first substance is malic acid, setting the first redox potential to be -0.19 volts to -0.24 volts between. The method for electrochemically detecting the concentration of the mixed solution according to claim 5, wherein in the step S3, if the first substance is malonic acid, setting the first redox potential to be -0.24 volts. Between -0.29 volts. The method for electrochemically detecting the concentration of a mixed solution according to claim 5, wherein in the step S3, if the first substance is gluconolactone, setting the first redox potential to be 0 volt. Between -0.1 volts. The method for electrochemically detecting the concentration of a mixed solution according to claim 5, wherein in step S3, if the first substance is lactic acid, setting the first redox potential to be between 0.6 volts and 0.7 volts. between.