JP2010037573A - Regenerating method and regenerating apparatus of electroless plating solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regenerating method of electroless plating solution by which unnecessary ions of the deteriorated electroless plating solution can highly prectsely be removed to a target concentration. <P>SOLUTION: The method for regenerating the electroless plating solution (hereinafter described as a plating solution) deteriorated due to accumulation of unnecessary ions comprises: a step of circulating and supplying the plating solution to a desalting chamber by using an electrodialysis unit having desalting chambers and thickening chambers alternately disposed and partitioned with a plurality of positive ion exchange membranes and anion exchange membranes; and a step of applying a voltage between anode plates and cathode plates to perform electrodialysis allowing the unnecessary ions accumulated in the plating solution to transfer from the plating solution side to the dilute electrolyte solution side to thereby remove the ions and to regenerate the plating solution. The regenerating method of the plating solution controls the electric conductivity conditions of the plating solution by electric conductivity of the plating solution decreasing in the accumulated unnecessary ion concentration a change in the electric conductivity of the dilute electrolyte of the increasing ion concentration. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electroless plating solution regeneration method and a regeneration apparatus.

  Electroless plating solutions such as nickel, copper and gold contain nickel ions, copper ions, gold ions and the like as metal ions, and sodium hypophosphite, hydrazine, formalin, alkylaminoborane and the like as reducing agents. When metal is deposited using an electroless plating solution, the concentration of metal ions and reducing agent in the plating solution decreases, and thus electroless plating treatment is performed while replenishing these ions. For example, in the case of electroless nickel plating, when electroless nickel plating is continuously performed for a long period of time, hypophosphite ions that are reducing agents are oxidized and accumulated as phosphite ions. Further, since nickel sulfate is mainly used as a supplement for consumed nickel ions, sulfate ions are also accumulated without being consumed. Furthermore, since supplementation of hypophosphite ions is mainly supplemented as sodium hypophosphite, sodium ions are accumulated. These deteriorate the performance of the plating solution and cause adverse effects on the precipitation properties and physical properties. For this reason, if plating is performed for a certain period, it is necessary to discard the plating solution.

Since the deteriorated electroless plating waste liquid contains a large amount of metal ions, compounds containing P and B as reducing agents, and organic acids such as EDTA and lactic acid, wastewater treatment is very difficult. It is a big environmental problem because it is discarded as waste.
As a method for solving such a problem, Patent Document 1 discloses a method for selectively removing and regenerating phosphite ions and sulfate ions, which are unnecessary components in the plating solution, by electrodialysis.
Japanese Patent Publication No. 5-83635

When electroless plating solution is regenerated by electrodialysis, useful and expensive metal ions, reducing agents, etc. are removed at the same time. Therefore, it is economical to efficiently remove ions to be removed with an optimal amount of electricity. The following two items are important.
1. Unnecessary ion concentration of deteriorated plating solution at the start of electrodialysis,
2. Transition of unnecessary ion concentration of plating solution deteriorated during electrodialysis.

In the conventional example, there is no document that mentions the above items.
And in patent document 1, only the dialysis time and the electric quantity of an electric current value are described. When controlling by dialysis time or electric quantity, there are the following problems. The concentration of unwanted ions in the deteriorated plating solution at the start of electrodialysis is not constant in electroless plating due to side reactions and self-decomposition of the reducing agent. Analyzing methods such as capillary electrophoresis are necessary to know the concentration. It is. Since the analysis method requires time and an advanced analyzer, it is generally estimated from consumed metal ions, but the variation of the unnecessary ion concentration of the plating solution is large. Moreover, the concentration transition of unnecessary ions during electrodialysis is generally influenced by the composition and each concentration and is not constant.

  The present invention has been made in view of such background art, and even when the concentration of unnecessary ions composed of accumulated ions of a deteriorated electroless plating solution fluctuates, the unnecessary ions are accurately obtained to a target concentration. An electroless plating solution regeneration method and a regeneration device that can be removed well are provided.

  The present inventors have found that there is a correlation between the concentration of unnecessary ions composed of ions accumulated in a deteriorated electroless plating solution and the conductivity of the electroless plating solution. Based on this, a calibration curve for the unnecessary ion concentration and conductivity of the electroless plating solution is prepared in advance. Based on the result, after measuring the conductivity of the plating solution at the start of electrodialysis and estimating the unnecessary ion concentration, the concentration transition of unnecessary ions during electrodialysis is always observed by the conductivity. And, by performing electrodialysis until the target conductivity of the unnecessary ion concentration is reached, the target electroless plating solution regenerating solution can be obtained accurately without analyzing the ion concentration of the plating solution. As a result, the present invention has been completed.

  A method of regenerating an electroless plating solution that solves the above problem is a method of regenerating an electroless plating solution in which unnecessary ions have accumulated and deteriorated by electrodialysis, and includes at least a plurality of electrodes between the anode plate and the cathode plate. Using the electrodialysis unit having a demineralization chamber and a concentration chamber separated by the cation exchange membrane and the anion exchange membrane by alternately arranging the cation exchange membrane and the anion exchange membrane of the demineralization chamber The step of circulating and supplying the electroless plating solution deteriorated to the step, the step of circulating and supplying the dilute electrolytic solution to the concentration chamber, and the electrodialysis by applying a voltage between the anode plate and the cathode plate were deteriorated. By removing unnecessary ions accumulated in the electroless plating solution by moving from the electroless plating solution side of the desalting chamber to the diluted electrolyte side of the concentration chamber, and regenerating the deteriorated electroless plating solution, the electrodialysis, Accumulated Characterized by having a step of controlling the electrodialysis conditions by ion concentration diminishing degraded electroless plating solution conductivity or unwanted ion concentration was incubated with increasing dilute electrolyte changes in the conductivity of the.

  An electroless plating solution regenerating apparatus that solves the above problems is an apparatus that regenerates an electroless plating solution in which unnecessary ions accumulate and deteriorate by electrodialysis, and includes at least a plurality of electrodes between the anode plate and the cathode plate. An electrodialysis unit having a demineralization chamber and a concentration chamber separated by the cation exchange membrane and the anion exchange membrane by alternately arranging a cation exchange membrane and an anion exchange membrane of The electrolysis is performed by applying a voltage between the anode plate and the cathode plate, a desalting tank that circulates and supplies the electroless plating solution that is circulated, a concentration tank that circulates and supplies the dilute electrolyte solution to the concentration chamber, and Electrodialysis means for removing the ions accumulated in the deteriorated electroless plating solution by moving from the electroless plating solution side of the desalting chamber to the dilute electrolyte side of the concentration chamber and regenerating the deteriorated electroless plating solution; By electrodialysis, A conductivity meter that measures the conductivity of a deteriorated electroless plating solution whose unwanted ion concentration decreases or a diluted electrolyte solution whose unwanted ion concentration increases, and the conductivity measured by the conductivity meter. Control means for controlling electrodialysis conditions by changing the rate is provided.

  According to the present invention, even when the concentration of unnecessary ions composed of accumulated ions of a deteriorated electroless plating solution fluctuates, the method and regeneration of the electroless plating solution that can accurately remove the unnecessary ions to a target concentration. An apparatus can be provided.

  In particular, according to the present invention, even when the concentration of unnecessary ions in the deteriorated plating solution fluctuates, the concentration of unnecessary ions in the deteriorated plating solution at the start of electrodialysis and the concentration transition of unnecessary ions during the electrodialysis are always measured. The unnecessary ion concentration can be controlled so that it can be accurately removed to the target concentration.

Hereinafter, the present invention will be described in detail.
The method for regenerating an electroless plating solution according to the present invention is a method for regenerating an electroless plating solution in which unnecessary ions have accumulated and deteriorated by electrodialysis, and includes a plurality of positive electrodes between at least the anode plate and the cathode plate. Using an electrodialysis unit having a demineralization chamber and a concentration chamber separated by the cation exchange membrane and the anion exchange membrane by alternately arranging ion exchange membranes and anion exchange membranes, the desalination chamber is deteriorated. A step of circulating and supplying the electroless plating solution, a step of circulating and supplying the dilute electrolytic solution to the concentrating chamber, electrodialysis by applying a voltage between the anode plate and the cathode plate, and deteriorated electroless Unnecessary ions accumulated in the plating solution are removed by moving from the electroless plating solution side of the desalting chamber to the dilute electrolyte side of the concentration chamber, and regenerating the deteriorated electroless plating solution. Unnecessary ion Degrees and having a step of controlling the electrodialysis conditions by the diminishing degraded electroless plating solution conductivity or unwanted ion concentration was incubated with increasing dilute electrolyte changes in the conductivity of the.

As the conductivity of the deteriorated plating solution in which the accumulated concentration of unnecessary ions decreases, it is preferable to use a conductivity obtained by correcting the amount of dehydration by electrodialysis.
As the conductivity of the diluted electrolyte solution in which the concentration of unnecessary ions increases, it is preferable to use a conductivity obtained by correcting moisture increase due to electrodialysis.

  The present invention measures in advance the relationship between the unnecessary ion concentration of the deteriorated electroless plating solution containing accumulated ions and the conductivity at that time, and based on the measurement result, the conductivity of the plating solution at the start of electrodialysis and By constantly observing the conductivity during electrodialysis and performing electrodialysis until the target unnecessary ion concentration is reached, the target regenerative solution can be accurately obtained without analyzing the ion concentration of the plating solution. can do.

In the present invention, unnecessary ions in the electroless plating solution represent oxidized ions of a reducing agent and counter ions such as stabilizers and supplementary metal ions.
A method and apparatus for regenerating a deteriorated electroless plating solution according to the present invention will be described with reference to FIG.

FIG. 1 is a schematic view showing an embodiment of an electroless plating solution regenerating apparatus according to the present invention.
An electroless plating solution regenerating apparatus according to the present invention is an apparatus for regenerating an electroless plating solution in which unnecessary ions have accumulated and deteriorated by electrodialysis, and includes a plurality of positive electrodes between at least an anode plate and a cathode plate. An ion exchange membrane and an anion exchange membrane are alternately arranged, and an electrodialysis unit having a desalination chamber and a concentration chamber partitioned by the cation exchange membrane and the anion exchange membrane, Desalting tank that circulates and supplies electrolytic plating solution, concentration tank that circulates and supplies dilute electrolytic solution to the concentration chamber, and electrodialyzes by applying voltage between the anode plate and cathode plate to cause deterioration. Electrodialysis means for removing the ions accumulated in the electroless plating solution transferred from the electroless plating solution side of the desalting chamber to the dilute electrolytic solution side of the concentration chamber, and regenerating the deteriorated electroless plating solution, Accumulated due to dialysis A conductivity meter for measuring the conductivity of a deteriorated electroless plating solution whose ion concentration is decreasing or a diluted electrolyte solution whose unnecessary ion concentration is increasing, and the conductivity measured by the conductivity meter Control means for controlling electrodialysis conditions according to changes is provided.

  In the method of regenerating the electroless plating solution (hereinafter also referred to as plating solution) of the present invention, the deteriorated plating solution to be regenerated is supplied to the desalting chamber 8 of the electrodialysis unit 1 for electrodialysis. The electrodialysis apparatus used as the electrodialysis unit 1 is not particularly limited, and any known structure can be used as long as the cation exchange membrane 6 and the anion exchange membrane 7 are alternately arranged between the anode plate 2 and the cathode plate 3. The electrodialysis unit 1 can be used without any particular limitation. For example, a cation exchange membrane 6 and an anion exchange membrane 7 are alternately arranged between both electrodes via a chamber frame, and a desalting chamber 8 and a concentration chamber 9 are formed by these both ion exchange membranes and the chamber frame. The electrodialysis unit 1 having the structure as described above can be used.

What is necessary is just to select suitably the number of membranes used for the electrodialysis unit 1, a membrane area, the flow-path space | interval (membrane space | interval) of the desalination chamber 8 and the concentration chamber 9, etc. according to the kind and processing amount of the plating solution to process.
The cation exchange membrane 6 is not particularly limited, and for example, Selemion CMV (manufactured by AGC Engineering), Neoceptor CM-1 (manufactured by Astom), Nafion 324 (manufactured by DuPont) and the like can be used. The anion exchange membrane 7 is not particularly limited, and Selemion AMV (manufactured by AGC Engineering), Neoceptor AM-X (manufactured by Astom) or the like can be used. An electrolyte solution such as an aqueous sodium sulfate solution may be appropriately selected and supplied to the anode chamber 4 and the cathode chamber 5 located at both ends of the electrodialysis unit 1. In general, the polar liquid diaphragm 10 is composed of a cation exchange membrane.

If the electrodialysis energization conditions are below the limit current density, normal operating conditions can be applied. For example it is possible to perform the electrodialysis in 10A / dm ² about 0.1.
The plating solution to be regenerated in the regeneration method of the present invention is an electroless plating solution of nickel, copper, gold or the like. The basic components of a general electroless plating solution are as follows: As a metal source, nickel salt such as nickel sulfate, copper salt such as copper sulfate, gold salt such as potassium gold cyanide; Hypophosphites such as sodium phosphate, potassium hypophosphite and ammonium hypophosphite, alkylaminoboranes such as formaldehyde, formalin and dimethylaminoborane: acetic acid, citric acid and malic acid as complexing agents for metal ions Organic acids such as lactic acid, succinic acid, EDTA: negative catalytic metals such as lead and bismuth are used as stabilizers. Furthermore, a precipitation accelerator etc. are contained as needed. There is no restriction | limiting in particular about the composition, It can be made into the electroless-plating liquid processing object of well-known various compositions. However, the regeneration object of the present invention is not limited to the plating solution containing these components.

  The deteriorated plating solution is supplied to the desalting tank 11 of the electrodialysis unit 1, and the diluted electrolyte is supplied to the concentration tank 12. The deteriorated plating solution is circulated through the desalting tank 11 and the desalting chamber 8, and the diluted electrolyte is circulated through the concentrating tank 12 and the concentrating chamber 9. By applying a voltage from the power source 16 between the anode plate and the cathode plate and performing electrodialysis, ions accumulated in the deteriorated electroless plating solution are diluted from the electroless plating solution side of the desalting chamber 8 to the dilute electrolysis in the concentration chamber 9. Transfer to the liquid side and remove to regenerate the deteriorated electroless plating solution. The electrodialysis is performed by electrodialysis means including the power source 16 and the electrodialysis unit 1.

  The ions removed by migration are, for example, cation exchange membranes, where the cation of the stabilizer counter ion moves to the cathode side, and the anion such as the reducing agent oxide ion or metal counter ion It moves to the anode side and moves through the installed anion exchange membrane.

  When the temperature of the deteriorated plating solution supplied is high, metal is deposited on the electrode, ion exchange membrane, etc. in the electrodialysis unit, and the efficiency of electrodialysis decreases. In addition, the ion exchange membrane, piping, and the like are easily damaged or deformed by heat. If the liquid temperature is too low, the components contained in the desalted liquid and the concentrated liquid are crystallized and the pipes are likely to be clogged. For this reason, it is preferable to maintain the liquid temperature of the electroless plating solution, desalting solution, and concentrated solution to be processed at about 15 to 50 ° C.

  In electroless plating, replenishment is performed for ions that decrease with the deposition of metal, so the concentration of these ions is kept constant. However, the metal salt is mainly used as a replenishment product of the reducing agent and metal ions. Therefore, sodium and potassium are accumulated in the plating solution without being consumed.

  When the deteriorated plating solution is circulated and supplied to the desalting tank 11 and the desalting chamber 8 and is electrolyzed, all ions in the plating solution are reduced in proportions and are diluted in the concentration tank 12 and the concentration chamber 9. Due to the transition to the electrolyte, the ions in the dilute electrolyte increase. Among the migrating ions, the amount of oxidation product ions in the reducing agent is large, and the amount migrating by electrodialysis is also large, so the oxidation product ions are representative ions that show an increase or decrease in all ions. Become. Therefore, in the present invention, the relationship between the oxidation product ion concentration and the conductivity of the plating solution for measurement is measured in advance, a calibration curve is created based on the measurement result, and the plating solution at the start of dialysis and at the end of dialysis Alternatively, the conductivity of the diluted electrolyte is measured to estimate the oxidizing bioion concentration. Here, the plating solution for measurement used at the time of preparing the calibration curve uses the metal ion and reducing agent ion amount as the reference concentration at the time of plating use, and measures the conductivity by changing the concentration of the oxidation product ion of the reducing agent. It is preferable to create a calibration curve.

  For the measurement of conductivity, a conductivity meter 13 is used, and there is no particular limitation, and a commercially available product is used. In the case of an immersion type conductivity meter, it is preferable that it is installed in the circulation path of the plating solution or dilute electrolyte and can always be monitored. In the case of a water flow type, it is preferable that the plating solution in the desalting tank or the dilute electrolytic solution in the concentration tank is always circulated so that the conductivity can always be monitored.

  Next, the electrodialysis conditions are controlled by the change in the conductivity measured by the conductivity meter by the control means including the personal computer 14 and the controller 15. The conductivity meter 13 is connected to the personal computer 14, and the conductivity of the plating solution or dilute electrolyte is always output to the personal computer. Then, an unnecessary ion concentration is calculated with a calibration curve prepared in advance to calculate electrodialysis conditions, and the controller 15 controls ON / OFF of the power supply 16. As a result, the electrodialysis conditions can be controlled by changing the conductivity of the plating solution in which the accumulated ion concentration decreases or the conductivity of the diluted electrolyte in which the ion concentration increases due to the electrodialysis.

The calculation of electrodialysis conditions is performed as follows.
The total transfer amount based on the liquid amount (L) from the initial concentration (g / L) and target concentration (g / L) of the target ions (g / L) obtained from the conductivity so that the dialysis treatment is completed within a predetermined time. (g) is calculated, and by performing a specific ion movement amount (g / a · H · dm 2) and current values to be used from the total membrane area (dm ²⁾ seek (a) dialysis of an ion-exchange membrane used Dialysis treatment can be performed for a certain time (H). In this case, the end of dialysis is determined by the set conductivity value. Furthermore, when dialysis is performed at a predetermined current value, the dialysis end time can be calculated in the same manner.

  In addition, during electrodialysis, ions in the plating solution move from the plating solution side (demineralization chamber 8) to the dilute electrolyte solution side (concentration chamber 9), and water in the deteriorated plating solution also moves to the plating solution side. It moves from (desalting chamber 8) to a dilute electrolyte (concentration chamber 9). When reusing the plating solution after electrodialysis, the plating solution is adjusted by correcting for the loss of water and the necessary components removed by electrodialysis. The conductivity of the liquid needs to be corrected for water increase. In the case of a plating solution as a means for correcting water, there is a method in which water is supplied up to the amount of liquid at the start of dialysis while electrodialysis is performed or the amount of water reduced by electrodialysis is measured and the conductivity is corrected by calculation. In the case of a diluted electrolyte, there is a method of measuring the amount of water increased by electrodialysis and correcting the conductivity by calculation.

  As described above, after measuring the conductivity of the deteriorated plating solution at the start of electrodialysis and estimating the oxidation product concentration of the reducing agent in the plating solution, the target oxidation is measured while measuring the conductivity during electrodialysis. By performing electrodialysis until the conductivity of the product concentration is reached, the target regenerating solution can be accurately obtained without analyzing the concentration of the oxidized product in the plating solution.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
The SPC material (iron material) was continuously subjected to electroless nickel plating using 500 L of electroless nickel plating solution. The composition of the plating solution used is as follows.

Nickel ion 5.5g / L
Hypophosphite ion 20g / L
Complexing agent (malic acid, etc.) 60 g / L

[Create calibration curve]
In the measurement plating solution having the above composition, the conductivity is measured by adjusting with phosphorous acid Na so that the concentration of phosphite ions, which are unnecessary ions, is 25, 75, 125, 175, and 225 g / L. FIG. 2 showing the relationship between phosphoric acid concentration and conductivity was prepared. From FIG. 2, the calibration curve shown in the following formula 1 was obtained.
Phosphite ion [g / L] = 10 × Conductivity [S / m] −25 (Formula 1)

[Plating treatment]
During the plating process, the nickel ion concentration and pH of the electroless nickel plating solution are automatically managed by an automatic controller (Kanizen Co., Ltd. CAAC-752ST). Plating was performed up to 5 turns, with 1 turn being the time at which nickel ions equivalent to the amount of nickel ions present in the plating solution were replenished during the bathing. The composition of the plating solution before the electrodialysis treatment is as follows.

Nickel ion 5.5g / L
Hypophosphite ion 20g / L
Complexing agent (malic acid, etc.) 60 g / L
Phosphite ion 110 to 140 g / L

  The plating solution was electrodialyzed under the following conditions using the electroless plating solution regenerating apparatus shown in FIG.

The dialysis time was 10 hours, and the anion exchange membrane used in the electrodialysis unit was Selemion AMV manufactured by AGC Engineering, and the cation exchange membrane was Selemion CMV manufactured by AGC Engineering. The membrane area of the ion exchange membrane is 5 dm ² , 150 anion exchange membranes and 150 cation exchange membranes are arranged in parallel, and the deteriorated plating solution is conducted while circulating through the desalting tank and the desalting chamber of the electrodialysis unit. The rate was measured.

  Calculate phosphite concentration from conductivity value using calibration curve, electrodialysis conditions until conductivity of degraded plating solution is 5.0 S / m and target phosphite ion concentration in solution is 25 g / l The dialysis conditions were calculated so that was constant over 10 hours. The results are shown in Table 1. Dialysis treatment was performed until the conductivity reached 5.0 S / m under the constraint of the calculated current (A).

(Calculation of electrodialysis conditions)
As the intrinsic value of the anion exchange membrane to be used, the total amount of migration (g) was determined from 0.35 g / 1A / 1H / 1 dm ² and the amount of liquid 500 L as the phosphite migration amount, and the area of the anion exchange membrane 750 dm ² (150 sheets) * Each current value (A) was calculated from 5 dm ² / sheet) and dialysis time 10 (H). Intrinsic phosphorous acid transfer amount was obtained from the conductivity measuring solution.

  Then, whether the phosphite ion concentration was 25 g / l after dialysis was confirmed by measuring the phosphite ion concentration with a capillary electrophoresis apparatus (G1600A manufactured by Agilent Technologies).

The concentration chamber of the electrodialysis unit was in a state of being filled with the concentrate obtained when the same electrodialysis was performed in advance.
Electrolysis was performed while circulating a 10% aqueous sodium sulfate solution in the anode chamber and cathode chamber of the electrodialysis unit.

In addition, the conductivity of the deteriorated plating solution or dilute electrolyte is measured with a conductivity meter (D-54 flow-type conductivity electrode 3652-10D manufactured by Horiba, Ltd.) as needed, and output to a personal computer to calculate electrodialysis conditions. The power was controlled by the controller.
The above evaluation was performed 10 times, and the results are shown in Table 2. As a result, it was possible to control the target phosphorous acid concentration with an error of ± 10%.

Example 2
As in Example 1, 500 L of electroless nickel plating was used to continuously treat the SPC material part as an object to be plated, and electroless nickel plating was performed for about 5 turns. The composition of this plating solution is shown below.

Nickel ion 5.5g / L
Hypophosphite ion 20g / L
Complexing agent (malic acid, etc.) 60 g / L
Phosphite ion concentration 110-140g / L

  This plating solution is electrodialyzed under the same conditions as in Example 1, and the electrodialysis is performed until the phosphite ion concentration reaches 25 g / L while correcting the conductivity by calculation in consideration of dehydration from the plating solution. The same evaluation as in Example 1 was performed.

The correction of the conductivity by dehydration from the plating solution was performed by calculating the dehydration amount from a liquid level gauge and converting it to the original equivalent of 500L.
The above was repeated 5 times, and the results are shown in Table 3. As a result, it became possible to control the target phosphorous acid concentration with an error of ± 5%. When the movement of water due to electrodialysis was corrected and management was performed using conductivity, it was possible to perform more accurate management.

Comparative Example 1
In the same manner as in Example 1, using 500 L of electroless nickel plating solution, the SPC material parts were continuously processed as an object to be plated, and electroless nickel plating was performed for about 5 turns. The composition of this plating solution is shown below.

Nickel ion 5.5g / L
Hypophosphite ion 20g / L
Complexing agent (malic acid, etc.) 60 g / L
Phosphite ion concentration 110-140g / L

  For this plating solution, the dialysis time required for the phosphite ion concentration to reach 25 g / L based on the relationship between the amount of phosphite ion removal inherent in this experimental apparatus, the time, and the amount of current obtained from a conventional experiment. It was calculated as 4 hours, and electrodialysis was performed under the same conditions as in Example 1. After electrodialysis, the phosphite ion concentration of the plating solution was measured with a capillary electrophoresis apparatus and confirmed.

  The above was performed 10 times and the results are shown in Table 4. An error of ± 20% occurred with respect to the target phosphite ion concentration.

  The method for regenerating an electroless plating solution of the present invention can accurately remove a target concentration even when the concentration of accumulated unnecessary ions in a deteriorated electroless plating solution fluctuates. It can be used for desalination of soy sauce and soy sauce.

It is the schematic which shows one embodiment of the reproducing | regenerating apparatus of the electroless-plating liquid which concerns on this invention. It is a figure which shows the relationship between the phosphorous acid density | concentration and electroconductivity of the electroless-plating liquid in this invention.

Explanation of symbols

1 Electrodialysis Unit 2 Anode Plate 3 Cathode Plate 4 Anode Chamber 5 Cathode Chamber 6 Cation Exchange Membrane 7 Anion Exchange Membrane 8 Desalination Chamber (Plating Solution)
9 Concentration chamber (dilute electrolyte)
10 Diaphragm 11 Desalination tank (plating solution)
12 Concentration tank (dilute electrolyte)
13 Conductivity meter 14 PC 15 Controller 16 Power supply

Claims (4)

  This is a method of regenerating electroless plating solution that has accumulated and deteriorated unnecessary ions by electrodialysis, and at least a plurality of cation exchange membranes and anion exchange membranes are arranged between the anode and cathode plates. Circulating and supplying a deteriorated electroless plating solution to the desalting chamber using an electrodialysis unit having a desalting chamber and a concentration chamber partitioned by the cation exchange membrane and the anion exchange membrane, Circulating and supplying the dilute electrolyte to the concentration chamber, applying a voltage between the anode plate and the cathode plate to perform electrodialysis, and removing unnecessary ions accumulated in the deteriorated electroless plating solution in the desalting chamber Transfer from the electroplating solution side to the dilute electrolyte side of the concentration chamber and remove it, regenerate the deteriorated electroless plating solution, deteriorated electroless plating where the accumulated unnecessary ion concentration decreases by the electrodialysis liquid The method of reproducing an electroless plating solution, characterized in that the conductivity or unwanted ion concentration includes the step of controlling the electrodialysis conditions by conductivity changes in incubated with increasing dilute electrolyte.   2. The method for regenerating an electroless plating solution according to claim 1, wherein the conductivity of the deteriorated plating solution in which the accumulated unnecessary ion concentration decreases is a conductivity obtained by correcting the amount of dehydration by electrodialysis. .   2. The method for regenerating an electroless plating solution according to claim 1, wherein the conductivity of the diluted electrolyte solution in which the concentration of unnecessary ions increases is a conductivity obtained by correcting moisture increase by electrodialysis.   A device that regenerates electroless plating solution that has accumulated and deteriorated from unwanted ions by electrodialysis, and has a plurality of cation exchange membranes and anion exchange membranes arranged alternately at least between the anode and cathode plates. An electrodialysis unit having a desalting chamber and a concentrating chamber partitioned by the cation exchange membrane and the anion exchange membrane, and a desalting tank for circulating and supplying a deteriorated electroless plating solution to the desalting chamber. A concentration tank that circulates and supplies dilute electrolyte to the concentration chamber, and electrodialyzes by applying a voltage between the anode plate and the cathode plate to remove ions accumulated in the deteriorated electroless plating solution. The electroless plating means to remove the electroless plating solution from the electroless plating solution side of the concentration chamber and remove it by regenerating the deteriorated electroless plating solution, and the accumulated unnecessary ion concentration is reduced by the electrodialysis. Deteriorated electroless Conductivity meter for measuring conductivity of dilute electrolyte whose conductivity or unwanted ion concentration increases, and control means for controlling electrodialysis conditions by change of conductivity measured by said conductivity meter An apparatus for regenerating an electroless plating solution, comprising:

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