JP2008191159A - Method and apparatus for analyzing and apparatus for managing concentration of component of system which makes specific gravity and concentration of component vary - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for easily and accurately analyzing the concentration of components of a system which makes the specific gravity and the concentration of components vary with the passage of time. <P>SOLUTION: An analyzing part 10 is provided with an analyzing cell 11; a load cell 12; an optical sensor 13; and a means 14 for supporting a white agitating member. An analyte supply line Ls; a titration reagent supply line Lt<SB>n</SB>; an indicator supply line LI<SB>n</SB>; a dilution water supply line Lw; and a discharge line Ld are connected to the analyzing cell 11. The weight concentration of components is measured on the basis of the weight of an analyte in the analyzing cell 11 and a titration end point detected by the optical sensor 13 to compute the specific gravity of the system and determine the volume concentration of the components. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a component concentration analysis method and a component concentration analyzer for a system in which specific gravity and component concentration change over time.
The present invention also relates to a component concentration analysis method and a component concentration analysis apparatus suitable for managing the component concentration of a system in which the specific gravity and the component concentration change over time. In particular, the present invention relates to a component concentration analysis method and a component concentration analyzer suitable for managing the concentration of each component in a multicomponent system.

  Furthermore, the present invention relates to a component concentration management device for a system in which specific gravity and component concentration change over time.

  For example, it is known that the component concentration and specific gravity of a surface treatment solution used for wet surface treatment vary with time. However, in order to maintain the quality of the object to be treated, it is necessary to always keep the composition of the surface treatment liquid constant. For this reason, the surface treatment liquid is analyzed at regular intervals to replenish deficient components (Japanese Patent Publication No. 3-65489).

  Currently, commercially available automatic analyzers use a syringe, a tube pump, or the like to determine the volume concentration of a component by titration analysis. However, when a syringe and a tube pump are used, there is a problem that bubbles are generated in the analysis sample or titration reagent, and an accurate measurement value cannot be obtained. Another problem is that due to the aging of the syringe, gas flows from the outside and bubbles are generated, and accurate measurement values cannot be obtained.

  Therefore, a weight concentration analysis method using a load cell is proposed instead of volume analysis using a syringe (Japanese Patent Laid-Open No. 7-134112). However, when a large amount of surface treatment liquid such as industrial wet surface treatment is used, it is general to adjust the component concentration by volume rather than weight. Therefore, it is necessary to convert the weight concentration measured using the load cell into the volume concentration. However, in the conversion from the weight to the volume, an accurate concentration cannot be obtained unless the specific gravity of the test object is constant. That is, in a system in which the component concentration and specific gravity fluctuate with time, such as a wet surface treatment liquid, accurate measurement of component concentration cannot be performed unless a change with time in specific gravity is input. However, when industrially performing continuous wet surface treatment, it is cumbersome and practically impossible to control the concentration of the wet surface treatment liquid by actually measuring the specific gravity that varies over time. Therefore, there is a need for a method and apparatus for easily and precisely controlling, preferably automatically, the component concentration of a system whose specific gravity and component concentration change over time.

On the other hand, in the case of weight concentration analysis, a titration analysis method is generally used in which a reagent is dropped on a specimen to detect a change occurring in the specimen. Changes that occur in the specimen include pH changes, redox potential changes, conductivity changes, color changes, etc., which are measured using a pH meter, redox electrode, conductivity measuring electrode, colorimetric sensor, etc., respectively. ing. However, the pH meter, oxidation-reduction electrode, conductivity measurement electrode, etc. must always be immersed in the sample liquid, and they are frequently replaced due to a decrease in sensitivity due to adhesion of sample components and contaminants. There is a need to. In addition, since the pH meter is a glass electrode, it is fragile, and a KCl solution must be injected every day, and maintenance is complicated. Since the colorimetric sensor requires a calibration curve and is intended for monochromatic light, it is necessary to replace the filter for each component, which is complicated. Therefore, there is a need for a titration analysis method and apparatus that do not require maintenance and can easily detect the titration end point.
Japanese Patent Publication 3-65489 JP 7-134112 A JP 2001-296305 A JP-A-6-273368

An object of the present invention is to provide a simple and accurate component concentration analysis method and apparatus in a system in which specific gravity and component concentration change over time.
Another object of the present invention is to provide a simple and accurate component concentration analysis method and apparatus for a system in which specific gravity and component concentration change over time, incorporating a method and apparatus for easily detecting a titration end point without requiring maintenance. There is to do.

  Furthermore, an object of the present invention is a simple and accurate component concentration analysis method that can be applied to a component concentration management method and apparatus for maintaining a constant component concentration of a surface treatment liquid in a treatment tank in a wet surface treatment apparatus, for example. And providing an apparatus.

  Still another object of the present invention is to provide a component concentration management apparatus that maintains the component concentration in a system in which the specific gravity and the component concentration change over time accurately within a certain range.

  ADVANTAGE OF THE INVENTION According to this invention, the specific gravity of the system from which specific gravity and a component density | concentration fluctuate with time is calculated | required by calculation, and the component density | concentration analysis method which converts a component weight density | concentration into a component volume density | concentration is provided. This analysis method can be applied to any system as long as the specific gravity and the component concentration fluctuate over time, but a system that is required to always maintain an accurate component concentration, such as a wet surface treatment, for example, It is optimal for systems that require continuous precise control of component concentrations, such as semiconductor manufacturing processes that perform industrial wet surface treatment. Specifically, for example, the present invention can be applied to concentration management of an etching solution for dissolving and removing a specific amount of copper from an electric circuit board such as a printed board.

  In the present invention, for calculating the specific gravity of a system that varies over time, a relational expression between the specific gravity of the system that varies over time and the component weight concentration is created in advance, and the measured value of the component weight concentration is substituted into the relational expression. And it can carry out by calculating | requiring specific gravity.

For example, a case where a relational expression between the specific gravity of a system using water as a solvent and a ternary system consisting of hydrogen peroxide, sulfuric acid and copper as a solute and the weight concentration of each component will be described.
As a sample preparation reagent, a combination of hydrogen peroxide = 5% (50 g / kg), sulfuric acid = 40% (400 g / kg) and copper = 2% (20 g / kg) was used. Prepare a sample and use a water bath or the like to bring all of the samples to the same temperature (20 ° C to 40 ° C).

For each of the 8 prepared samples, the specific gravity is measured by the following procedure using a pycnometer (50 ml) and an electronic balance as specific gravity measuring equipment.
(1) The dry weight of the pycnometer is measured with an electronic balance to obtain the tare weight.
(2) Fill each sample into a pycnometer and measure the tare weight with an electronic balance.
(3) Specific gravity (at 20 ° C) is expressed by the following formula 1.

Calculated by
Table 2 below shows the component concentration (% by weight) and the measured specific gravity of each sample.

  The specific gravity d of the ternary system of hydrogen peroxide, sulfuric acid and copper using water as a solvent can be obtained by the following relational expression 2.

  Below a certain concentration, the increase in the component and the increase in the specific gravity can be expressed by a linear expression (straight line), so the influence of each component on the specific gravity is expressed by the following expression.

  However, when two or more components are combined, as shown in Table 3 below, when the concentration of a certain component is changed, the slope of the linear expression with respect to the specific gravity of the other component changes.

  The present inventors have inferred that each component affects each other and changes the specific gravity, and found that it can be solved by obtaining a coefficient of mutual influence of each component and introducing it into the specific gravity calculation formula. . The influence of each component on the specific gravity is as follows.

  Based on the above calculation, the specific gravity calculation formula (each concentration is weight%) of the hydrogen peroxide / sulfuric acid / copper solution of Formula 2 can be expressed as follows.

  Next, the weight density of each component, hydrogen peroxide, sulfuric acid, and copper is measured, and the weight density measurement value of each component is substituted into the specific gravity calculation formula to obtain the specific gravity of the system. Next, the volume concentration of each component can be obtained by calculation from the specific gravity of the system and the measured weight concentration value of each component.

  The above specific gravity calculation formula is obtained for a ternary system of hydrogen peroxide, sulfuric acid, and copper, but it will be easily understood that the coefficients are different if the components of the system are different. The present method can be applied to various component systems by measuring in advance the weight concentration of each component of the system to be measured and the specific gravity of the system, and obtaining an arithmetic expression. In addition, in calculating the specific gravity calculation expression, it is also possible to obtain the specific gravity calculation expression by regression analysis or the like other than the above.

  In the present invention, the weight of the specimen can be measured by measuring the weight of the collected specimen using a weight sensor such as a load cell. When measuring the weight using a load cell, accurate weight measurement can be performed without precisely controlling the supply of the sample and titration reagent, and the remaining liquid can be measured without the need for a liquid level sensor. Can be detected and overflow can be prevented.

  In the present invention, the component concentration is preferably measured by titration analysis. The end point of the titration can be detected by measuring the redox electrode potential, measuring the conductivity, measuring the pH, measuring the light transmittance with a colorimetric sensor, etc. by a titration method. However, considering the maintenance and handling problems of redox electrodes, conductivity measuring electrodes, pH meters and colorimetric sensors, titration analysis using titration indicators according to the components is performed, and the end point of titration analysis The detection is preferably performed by detecting a change in color according to the component. For example, when the component to be measured is hydrogen peroxide, potassium permanganate can be used as a titration reagent, and oxidation / reduction titration analysis can be performed with the end point of titration when the color of the test solution changes from colorless to purple. it can. When the component to be measured is sulfuric acid, use sodium hydroxide as the titration reagent, methyl orange as the indicator, and perform neutralization titration with the time when the color of the test solution changes from red to yellow as the titration end point. be able to. When the measurement target component is copper, ammonia is used as a complexing agent, EDTA (ethylenediaminetetraacetic acid) is used as a titration reagent, and 5-Br-PAPS (2- (5-Bromo-2-pyridylazo)- 5- [Nn-propyl-N (3-sulfopropyl) amino] -phenol, disodium salt, dihydrate; molecular formula C17H19BrN4Na2O4S · H2O) is used as an indicator, and the time when the color of the test solution changes from purple to green is the titration end point. Can be performed by chelate titration analysis. As will be apparent to those skilled in the art, the titration method, titration reagent and indicator can be appropriately selected according to the component to be measured.

  It is preferable to detect the change in the color of the test liquid using an optical sensor. The optical sensor is not particularly limited as long as it can detect the test object and the color change of the indicator added to the test object, and any optical sensor can be used. For example, the reflected light reflected by the object or the transmitted light transmitted through the object is received for each light of different wavelengths, for example, red, green, and blue, and each received light An optical sensor such as a color identification sensor that detects the color of an object based on the amount of received light can be preferably used. Since such an optical sensor does not require the sensor part to be immersed in the test solution, there is no problem such as contamination or damage to the sensor part, maintenance is not required, and the titration end point can be detected easily. preferable.

  In addition, according to the present invention, an analysis unit for measuring the component weight concentration of a test sample collected from a system in which the specific gravity and the component concentration change over time, and the specific gravity of the system from the measured component weight concentration value of the test sample. And a calculation unit that calculates the component volume concentration of the test object.

  The analysis unit includes an analysis cell that receives the test object, an optical sensor that detects a color at the end of titration of the test object provided outside the analysis cell, and a load cell provided outside the analysis cell. It is preferable.

  The optical sensor may be any optical sensor. In the analysis cell, it is preferable that a white stirring member supporting means that also functions as a reflecting portion is provided at the focal position of the irradiation light from the optical sensor. The white stirring member support means may be one in which a normal stirring blade support rotating shaft is made of white Teflon (registered trademark) or the like, as long as it can reflect light from the optical sensor. By providing the optical sensor outside the analysis cell, there is no problem such as contamination or breakage of the sensor, no influence on the test object, and no maintenance is required.

The load cell can measure the weight of the collected specimen and the weight of the dropped titration reagent and indicator as needed.
In this way, by providing an optical sensor for detecting the end point of the sample titration and a load cell for measuring the weight of the sample outside the analysis cell, the problem of sensor contamination, damage and maintenance can be solved. The weight concentration of ingredients can be measured easily. An accurate component concentration can be obtained by calculating the specific gravity of the system that fluctuates with time from the measured component weight concentration value of the test object and converting it to a volume concentration.

  Further, according to the present invention, a treatment tank including a system in which the specific gravity and the component concentration change with time, an analysis unit for measuring the component weight concentration of the test sample collected from the system, and the obtained test product A calculation unit that calculates the specific gravity of the system and the component volume concentration of the test object from the component weight concentration of the system; There is provided a component concentration management device comprising a component supply unit that receives a component supply signal from the control unit and supplies a component to the processing tank.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
FIG. 1 shows an example of an etching treatment tank in a case where a copper substrate is etched with a hydrogen peroxide-sulfuric acid etching solution (H ₂ O ₂ / H ₂ SO ₄ ) as a system in which specific gravity and component concentration change with time. It is a schematic explanatory drawing which shows the analysis part of the component concentration analyzer of this invention when applied to a system.

The analysis unit 10 is equipped with an analysis cell 11 for receiving the test object, the titration reagent and the indicator, and a load cell 12 for measuring the weight of the test object, the titration reagent and the indicator, and the test object An optical sensor 13 for detecting the titration end point and a white stirring member support means 14 that also functions as a reflection portion of the optical sensor 13 are provided. A stirring blade 14a is attached to the white stirring member support means 14, and the test object is stirred. The reflection part of the optical sensor 13 is located in the lower part as much as possible so as to prevent end point detection different from the actual detection due to the influence of stirring during stirring of the stirring blade 14a. The analysis cell 11 includes an analyte supply line Ls for supplying an analyte to the analysis cell 11, and one or more titration reagent supply lines Lt _n (n is 1) for supplying various titration reagents to the analysis cell 11. 1 or more indicator supply lines LI _n (n is an integer of 1 or more) for supplying various indicators to the analysis cell 11, a dilution water supply line Lw for supplying dilution water to the analysis cell 11, and A discharge line Ld for discharging the test object after the measurement is completed from the analysis cell 11 is connected thereto.

  The calculation unit (not shown) calculates the weight concentration of each component from the weight of each component measured in the analysis cell 11, and based on the relational expression input in advance from the calculation result of the weight concentration, The specific gravity is calculated, and the volume concentration of each component is calculated from the specific gravity of the obtained system and the weight concentration measurement value of each component. As the arithmetic unit, an arithmetic processing device using a normal microprocessor, for example, a personal computer, a sequencer, a dedicated control board, or the like can be used as appropriate. In the embodiment shown in FIG. 2, an external monitor is provided as an output unit for outputting the measurement value calculated by the calculation unit to the outside as an electric signal, and the measurement value can be monitored. Examples of the measurement value output to the external monitor include the component weight concentration, the specific gravity of the system, and the component volume concentration, as well as any physical property or chemical property of the treatment liquid in the treatment tank 3.

Next, the procedure of the component concentration analysis method of the present invention will be described.
Table 4 shows the procedure for applying the component concentration analysis method of the present invention to the sulfuric acid-hydrogen peroxide etching solution (H ₂ O ₂ / H ₂ SO ₄ / Cu).

Table 5 shows the procedure for applying the component concentration analysis method of the present invention to the dry film peeling solution (NaOH / Na ₂ CO ₃ ).

Incidentally, if omitted analysis step of NaOH in the procedure shown in Table 5, it is also possible analysis of the dry film developer _(Na 2 CO _3). A KOH / K ₂ CO ₃ -based dry film remover or a K ₂ CO ₃ -based dry film developer can also be used.

Table 6 shows the procedure for applying the component concentration analysis method of the present invention to the copper blackening solution (Na ₂ ClO ₂ / NaOH / Na ₂ CO ₃ ).

  In any of the component concentration analysis procedures shown in Tables 4 to 6, residues such as organic substances in the analysis cell can be removed by washing with potassium permanganate as a post-analysis treatment. The influence on the analysis can be eliminated.

Next, an embodiment of a component concentration management device incorporating the component concentration analyzer of the present invention will be described. FIG. 2 is a schematic explanatory view showing an embodiment of the component concentration management apparatus of the present invention.
The component concentration management apparatus shown in FIG. 2 includes a component concentration analyzer 1, a processing tank 3, and a component supply control unit 4 that include the analysis unit 10 shown in FIG. At this time, the replenishment pump may be directly controlled from the component concentration analyzer 1 without using the component supply controller 4. A first component supply line L1 and a second component supply line L2 are connected to the processing tank 3. A specimen supply line Ls is laid from the processing tank 3 to the analysis cell 11, and the specimen collected from the processing tank 3 is supplied to the analysis cell 11. The component concentration analyzer 1 is configured to store the weight concentration measurement value of each component based on the specific gravity of the system determined by the calculation unit (not shown) based on the weight of the test object and the titration amount measured by the analysis unit 10. The component volume concentration converted into the concentration and the component concentration setting value of the processing tank 3 are compared to calculate the insufficient capacity of the insufficient component, and a control signal for adding the insufficient capacity of the insufficient component is output, and the component supply control unit Or by directly controlling the operation of the pumps provided in the first component supply line L1 and the second component supply line L2 to replenish the first component and / or the second component by an insufficient volume. The volume concentration of the first component and the second component in the treatment tank 3 is managed to the set concentration.

Example 1
For the eight types of samples shown in Table 2, the calculated specific gravity values were obtained by this method and compared with the measured specific gravity values.

From Table 7, it can be seen that the error rate is 0% for any sample, and no error is observed. Therefore, it was confirmed that the specific gravity value of the system in which the specific gravity and the component concentration fluctuate can be accurately and easily obtained by the method of the present invention.
Example 2
_Two samples of sulfuric acid-hydrogen peroxide etching solution (H ₂ O ₂ / H ₂ SO ₄ / Cu) of any concentration (H ₂ O ₂ : H ₂ SO ₄ : Cu = 39.0 g / L: 94.9 g) / L: 39.0 g / L, specific gravity of the system = 1.16865 and H ₂ O ₂ : H ₂ SO ₄ : Cu = 30.0 g / L: 192.7 g / L: specific gravity of the system = 1.19870), applying the component concentration analysis method of the present invention (the procedure is as shown in Table 4), measuring the weight concentration of each component, and calculating the specific gravity of the system and the volume concentration of each component Asked. The specific gravity and volume concentration of the same sample were also determined by manual analysis. The average values of the five analyzes were compared, and the error rate of the calculated value with respect to the actual measurement value was obtained. The results are shown in Table 8 and Table 9 below.

The present invention provides a simple and accurate component concentration analysis method and apparatus in a system in which specific gravity and component concentration change over time.
In addition, according to the present invention, there is provided a simple and accurate component concentration analysis method and apparatus for a system in which specific gravity and component concentration fluctuate over time, incorporating a method and apparatus for easily detecting a titration end point without maintenance. Provided.

  Furthermore, according to the present invention, for example, a simple and accurate component concentration analysis method applicable to a component concentration management method and apparatus for maintaining a constant component concentration of a surface treatment liquid in a treatment tank in a wet surface treatment apparatus or the like. And an apparatus are provided.

Furthermore, according to the present invention, there is provided a component concentration management device that maintains the component concentration in a system in which the specific gravity and the component concentration change over time accurately within a certain range.
The component concentration analysis method and apparatus and the component concentration management apparatus of the present invention enable accurate and simple control of the component concentration of a processing solution such as wet surface treatment in which the specific gravity and component concentration of the system fluctuate with time. .

FIG. 1 is a schematic explanatory view showing a component concentration analyzer of the present invention. FIG. 2 is a schematic explanatory view showing an embodiment of the component concentration management apparatus of the present invention.

Explanation of symbols

1: Component concentration analyzer 3: Processing tank 4: Component supply control unit 10: Analysis unit 11: Analysis cell 12: Load cell 13: Optical cell 14: Reflecting unit (white stirring member supporting means)
Ls: analyte supply line Lt _n : titration reagent supply line LI _n : indicator supply line Lw: dilution water supply line Ld: discharge line

Claims (7)

  Samples are collected from a system with varying specific gravity and component concentration, the weight of the sample is measured, and a color change is measured for each wavelength of light using a titration indicator corresponding to each component of the sample. By performing titration analysis to detect the end point of light received and detected based on the amount of light received for each wavelength of light, the component weight concentration of the test object is measured, and from the obtained component weight concentration measurement value, the system A component concentration analysis method, wherein a specific gravity is obtained by calculation, and a component volume concentration is obtained from the measured value of the component weight concentration and the calculated value of the specific gravity.   The calculation of the specific gravity of the system is performed by preparing a relational expression between the specific gravity of the system and the component weight concentration in advance and substituting the measured value of the component weight concentration into the relational expression. The method described. The specific gravity of the system in the case where the system in which the specific gravity and the component concentration vary is a ternary system is expressed by the following formula:

The method according to claim 2, wherein:   An analysis cell that accepts a sample collected from a system whose specific gravity and component concentration fluctuate, and a color change at the titration end point of each component of the test sample provided outside the analysis cell is received for each wavelength of light. An optical sensor that detects light based on the amount of light received for each wavelength of light, and a load cell that measures the weight of the test object provided outside the analysis cell, and the component weight concentration of the test object is determined. A component concentration analyzer comprising: an analyzer for measuring; and a calculator for calculating the specific gravity of the system and the component volume concentration of the test object from the measured component weight concentration of the test object.   The apparatus according to claim 4, wherein a white stirring member supporting means that also functions as a reflection portion of an optical sensor is provided inside the analysis cell.   The apparatus according to claim 4, further comprising an output unit that outputs the measurement value calculated by the calculation unit to the outside as an electrical signal. A treatment tank containing a system in which the specific gravity and the component concentration fluctuate;
An analysis cell that accepts a specimen collected from the system in the processing tank, and changes in the color of the titration end point of each component of the specimen provided outside the analysis cell for each wavelength of light. An optical sensor that detects based on the amount of received light for each wavelength, and a load cell that measures the weight of the test object provided outside the analysis cell, and measures the component weight concentration of the test object The analysis department;
A calculation unit for calculating the specific gravity of the system and the component volume concentration of the test object from the obtained component weight concentration of the test object,
A control unit that outputs a component supply signal according to a difference between the measured value of the component capacity concentration and the set value of the component capacity concentration;
A component supply unit that receives a component supply control signal from the control unit and supplies the component to the processing tank;
A component concentration management device comprising:

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