WO2014192581A1 - METHOD AND DEVICE FOR TREATING IODINE-CONTAINING ETCHING SOLUTION WHICH CONTAINS Au - Google Patents

METHOD AND DEVICE FOR TREATING IODINE-CONTAINING ETCHING SOLUTION WHICH CONTAINS Au Download PDF

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Publication number
WO2014192581A1
WO2014192581A1 PCT/JP2014/063275 JP2014063275W WO2014192581A1 WO 2014192581 A1 WO2014192581 A1 WO 2014192581A1 JP 2014063275 W JP2014063275 W JP 2014063275W WO 2014192581 A1 WO2014192581 A1 WO 2014192581A1
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iodine
etching solution
potential
cathode
concentration
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PCT/JP2014/063275
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French (fr)
Japanese (ja)
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千絵 古堅
広宣 小久保
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アサヒプリテック株式会社
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Priority to CN201480021400.9A priority Critical patent/CN105164317B/en
Priority to JP2014543381A priority patent/JP5669995B1/en
Publication of WO2014192581A1 publication Critical patent/WO2014192581A1/en
Priority to HK16101230.0A priority patent/HK1213303A1/en

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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00—Etching metallic material by chemical means
    • C23F1/46—Regeneration of etching compositions
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
    • C25C1/20—Electrolytic production, recovery or refining of metals by electrolysis of solutions of noble metals

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  • the present invention relates to a method and apparatus for processing an Au-containing iodine-based etching solution. Specifically, the present invention relates to a technique for efficiently recovering metallic Au from an iodine-containing iodine-based etching solution by electrolysis at a high recovery rate and recovering the iodine (I 3 ⁇ ) concentration to restore the etching ability.
  • Au for example, Au plating
  • Au plating is used for integrated circuit boards such as semiconductors and electronic parts such as terminal terminals and connectors.
  • An iodine-based etchant is widely used as an Au etchant.
  • the iodine-based etching solution is a solution in which iodine (I 2 ) is dissolved in an aqueous solution of potassium iodide (KI), and iodine exists as I 3 ⁇ in the aqueous solution and reacts with the iodine (I 3 ⁇ ). Then, Au is etched (dissolved).
  • the used iodine-based etchant after etching Au contains Au ions (for example, iodide complex [AuI 2 ] ⁇ ). Since Au is an expensive material, various techniques for recovering Au from used iodine-based etching solutions have been proposed. An electrolysis method is widely used as a technique for recovering Au from a used iodine-based etching solution.
  • the electrolysis method is a method in which Au-containing iodine-based etching solution is electrolyzed to deposit Au on the cathode surface and recovered.
  • the used etching solution after recovering Au is discarded without being reused because iodine (I 3 ⁇ ) having etching ability is reduced (I ⁇ ) and the etching ability is reduced. It was.
  • Patent Document 1 discloses a method of recovering iodine (I 3 ⁇ ) by oxidizing Au (I ⁇ ) reduced by recovering Au by performing electrolysis treatment of a used iodine-based etching solution. Techniques have been proposed that allow the etching capacity to be regenerated and reused.
  • the physical properties (composition, iodine concentration, etc.) of the etching solution containing Au vary depending on the iodine concentration in the object to be processed and the iodine-based etching solution. Therefore, while recovering Au in a high yield, It was very difficult to perform the regeneration stably.
  • the present invention has been made paying attention to the above-mentioned circumstances, and the object thereof is to recover the iodine (I 3 ⁇ ) concentration from the Au-containing etching solution at a high recovery rate and preferably to adjust the iodine (I 3 ⁇ ) concentration before use.
  • the purpose is to establish a technique that can recover the etching performance by recovering to almost the same level as the state of the etching solution.
  • the present invention that has solved the above problems is a method of treating an etching solution that recovers the iodine (I 3 ⁇ ) concentration while recovering the Au in the Au-containing iodine-based etching solution by electrolysis. Is carried out while maintaining the cathode potential at ⁇ 0.7 V or more (when the reference potential is the reference electrode Ag / AgCl) and the anode potential at +1.0 V or less (when the reference potential is the reference electrode Ag / AgCl). Has a summary.
  • the electrolysis is performed by diaphragm electrolysis in which a cathode and an anode are partitioned by a diaphragm.
  • the diaphragm electrolysis is performed by supplying the Au-containing iodine-based etchant continuously from the supply source of the Au-containing iodine-based etchant to the cathode side partitioned by the diaphragm and recovering Au.
  • a method of supplying iodine (I 3 ⁇ ) concentration to the partitioned anode side It is also a preferred embodiment that the iodine concentration on the cathode side partitioned by the diaphragm is adjusted to such an extent that re-dissolution of Au deposited on the cathode does not occur.
  • the cathode for electrolysis, the anode, the reference electrode serving as a reference for the electrode potential of the cathode or the anode, and the reference And a power source for controlling the current or the voltage between the electrodes so that the electrode potential on the side where the reference electrode is installed is within a predetermined range based on the potential measured by the electrode, and the reference electrode is not installed
  • the electrode on the side has physical means for adjusting the electrode potential to be within a predetermined range.
  • means for adjusting the wetted area of the electrode on the side where the reference electrode is not installed is preferable.
  • the cathode potential and anode potential during electrolysis are appropriately controlled, so that Au in the Au-containing etching solution can be recovered at a high recovery rate and the iodine (I 3 ⁇ ) concentration is recovered. Then, the etching ability can be regenerated. Further, by partitioning with a diaphragm, Au deposition on the cathode side and iodine (I 3 ⁇ ) concentration recovery on the anode side can be performed more efficiently, so that the electrolysis time can be shortened.
  • the iodine in the Au-containing iodine-based etching solution in which Au deposited on the cathode is newly supplied because the iodine (I 3 ⁇ ) concentration on the cathode side is controlled. (I 3 ⁇ ) prevents re-dissolution and Au can be recovered with good yield.
  • the electrode potential and the anode potential can be easily controlled appropriately.
  • FIG. 1 is a schematic view showing a configuration example of diaphragm electrolysis.
  • FIG. 2 is a schematic view showing another configuration example of diaphragm electrolysis.
  • FIG. 3 is a schematic view showing another configuration example of diaphragm electrolysis.
  • FIG. 4 is a schematic view showing another configuration example of diaphragm electrolysis.
  • FIG. 5 is a schematic diagram showing a configuration example in which the wire connected to the electrode B is moved up and down by the wire length adjusting means.
  • FIG. 6 is a schematic view showing a configuration example in which a plurality of liquid discharge valves are provided on the side surface of the electrolytic cell.
  • FIG. 7 is a schematic diagram illustrating a configuration example in which the liquid contact areas of the electrode A and the electrode B are different.
  • FIG. 8 is a schematic diagram illustrating a configuration example in which a plurality of electrodes B having different liquid contact areas are provided.
  • the inventors of the present invention recovered Au at a high recovery rate from an iodine-based etching solution (Au-containing etching solution) containing Au after etching (used) by electrolysis, and at the same time iodine (I 3 - )
  • Au-containing etching solution iodine-based etching solution
  • I 3 - iodine
  • the concentration of iodine (I 3 ⁇ ) in the Au-containing etching solution is high, re-dissolution of Au deposited and deposited on the cathode surface by electrolysis (hereinafter sometimes referred to as electrodeposition) may occur. all right.
  • the iodine-based etchant before use for etching (hereinafter also referred to as pre-use etchant) has an iodine (I 3 ⁇ ) concentration that exhibits the etching ability in order to exhibit sufficient etching ability. It is set high.
  • the present inventors reduce the concentration of iodine (I 3 ⁇ ) remaining after electrolysis by increasing the voltage at the time of electrolysis and increasing the reduction rate of iodine (I 3 ⁇ ) at the cathode. It was investigated. As a result, re-dissolution of electrodeposited Au was suppressed and Au could be recovered in high yield, but it was found that the following problems occurred.
  • the pH of the regenerated etching solution became unstable, the iodine (I 3 ⁇ ) concentration was low, and the etching ability was insufficient.
  • the pH of the regenerated etching solution varied greatly compared to the pH of the etching solution before use. Specifically, when a high voltage is applied, the cathode potential becomes lower than the potential at which Au deposition occurs and the pH increases due to the reaction (a) above, or the anode potential becomes higher than the potential at which oxidation of I ⁇ occurs. A phenomenon that the pH was lowered by the reaction of (b) occurred.
  • the etching performance of the regenerated etching solution is higher than that of the pre-use etching solution, so that when reused as it is, Au is excessively etched, which causes the etching failure. It becomes.
  • the pH of the regenerated etching solution becomes higher, the etching performance of the regenerated etching solution becomes lower than that of the pre-use etching solution. Become.
  • the present inventors have further studied to achieve a high Au recovery rate, solve the above problems of pH fluctuation and iodine concentration reduction, and provide a reusable regenerated etching solution. It was.
  • the cathode potential during electrolysis or -0.7 V (if the reference potential and the reference electrode Ag / AgCl, the same applies hereinafter) to maintain the above reaction H 2 at the cathode is generated (a ) Can be suppressed, and precipitation of Au and reduction of iodine (I 3 ⁇ ) can be achieved while maintaining a pH of about the same level as the pre-use etching solution.
  • the cathode potential falls below ⁇ 0.7 V, for example, as shown in Experimental Example 3, the pH rises greatly, so that it cannot be reused as an etching solution as it is.
  • a preferred cathode potential is ⁇ 0.5 V or more, preferably ⁇ 0.1 V or less.
  • the anode potential during electrolysis is set to +1.0 V or less (the reference potential is the reference electrode Ag). In the case of / AgCl, it is necessary to control so that the same can be maintained.
  • a preferred anode potential is +0.6 V or less, preferably +0.3 V or more.
  • the means for maintaining the cathode potential and the anode potential at predetermined values is not particularly limited.
  • a power source that controls the current or the voltage between the electrodes so that the electrode potential is in a predetermined range, and the electrode on the side where the reference electrode is not installed is physically adjusted so that the electrode potential is in the predetermined range. It is desirable to have an objective means.
  • the “electrode potential is in a predetermined range” is a range of electrode potentials necessary for a target reaction at the cathode and the anode.
  • the electrode potential in a predetermined range when used in the processing method of the Au-containing etching solution provided in the present invention is a cathode potential of ⁇ 0.7 V or more and an anode potential of +1.0 V or less.
  • the method for adjusting the electrode potential to be within a predetermined range is not particularly limited.
  • a reference electrode (Ag / AgCl) is installed on either the cathode or anode A side, and the potential of the electrode A on the side where the reference electrode is installed is obtained from the reference electrode (Ag / AgCl) and the electrode A. Based on the information, the current or the interelectrode voltage may be controlled so that the desired potential is obtained.
  • the physical means for adjusting the potential of the other electrode B on which the reference electrode is not installed is not particularly limited.
  • a means for adjusting the liquid contact area between the electrode B and a liquid (for example, an electrolyzed liquid) is desirable.
  • the liquid contact area of the electrode B for example, (1) means for changing the liquid contact area of the electrode B immersed in the liquid by moving the electrode B up and down, and (2) several types of electrodes B having different surface areas are prepared.
  • means for appropriately selecting the electrode B to be used so as to obtain a desired potential can be considered.
  • physical means that can be considered other than adjustment of the wetted area for example, (3) Since the overvoltage varies depending on the material of the electrode B, it is also effective to appropriately select and change the material of the electrode B. Any one or a combination of these means may be used to control the potential of the electrode B.
  • the electrode material include stainless steel and titanium as the cathode, and stainless steel as the anode and titanium coated with an oxide (for example, iridium oxide).
  • the specific device configuration for realizing the above (1) and (2) is not particularly limited.
  • a mechanism for automatically raising and lowering the electrode B according to the potential may be provided (see, for example, FIG. 5.
  • Other configurations are omitted, and other configurations may be the same as those in FIGS. 1 to 4 (the same applies to FIGS. 6 to 8).
  • the potential of the electrode B can be adjusted by moving the electrode B up and down to change the liquid contact area.
  • a plurality of liquid discharge valves having different heights from the electrolytic cell bottom may be provided in the electrolytic cell (see, for example, FIG. 6).
  • the liquid surface height of the liquid can be raised and lowered to adjust the liquid contact area with the electrode B.
  • the voltage potential of the electrode B can be adjusted by changing the area of the electrode B in relation to the area of the electrode A (see, for example, FIG. 7).
  • a mechanism is provided in which a plurality of electrodes B having different liquid contact areas are previously installed and connected to a power source via a current control means such as a controller. (See, for example, FIG. 8).
  • the potential of the electrode B can be adjusted by selecting one or a plurality of electrodes B through which a current is passed through the controller so as to obtain a desired potential.
  • the anode potential tends to increase, so the anode area is made larger than the cathode area. It is desirable.
  • the liquid contact resistance of the anode is reduced, and the anode potential can be controlled to the predetermined value.
  • the Au-containing etching solution When the Au-containing etching solution is electrolyzed with the cathode potential and anode potential adjusted to a predetermined value as described above, Au ions can be deposited on the cathode as metallic Au. Further, the reaction (a) in which H 2 is generated at the cathode can be suppressed. Further, the reaction (b) in which O 2 is generated at the anode can be suppressed, and precipitation of I 2 can be prevented. Therefore, the pH of the regeneration etchant is approximately equal to the pH before the etchant used, and iodine (I 3 -) concentration of iodine prior to use etching solution (I 3 -) can be restored to substantially the same concentration.
  • the pH almost equal to that of the pre-use etchant means that the etching ability equivalent to that of the pre-use etchant can be exhibited.
  • the specific amount of change varies somewhat depending on the pH of the etching solution before use, but is generally within a range of ⁇ 0.5 of the pH of the etching solution before use.
  • the iodine (I 3 ⁇ ) concentration substantially equivalent to the pre-use etching solution means an iodine (I 3 ⁇ ) concentration that can dissolve and remove at least unnecessary Au as the etching solution.
  • an iodine (I 3 ⁇ ) concentration that can dissolve and remove at least unnecessary Au as the etching solution.
  • the iodine (I 3 ⁇ ) concentration in the etching solution before use is 100%, if the iodine (I 3 ⁇ ) concentration is within the range of ⁇ 50%, unnecessary Au
  • the iodine (I 3 ⁇ ) concentration be ⁇ 10%, and still more preferable that the iodine (I 3 ⁇ ) concentration be within ⁇ 5%. It is. In order to approach the iodine (I 3 ⁇ ) concentration in the etching solution before use, it is desirable to appropriately control the electrode potential to prevent iodine precipitation and the like.
  • the Au-containing etching solution is supplied to an electrolysis tank in which a cathode and an anode are installed and electrolyzed. At that time, if Au deposited on the cathode is not re-dissolved by I 3 ⁇ generated at the anode, This is desirable because the time required for electrolysis can be shortened. Specifically, it is desirable to perform electrolysis of a diaphragm provided with a diaphragm that can be electrically connected and does not allow an Au-containing etching solution to pass through.
  • the Au-containing etching solution can be adjusted to different liquid qualities in the cathode chamber and the anode chamber by dividing the electrolysis tank into the anode side (anode chamber) and the cathode side (cathode chamber) by the diaphragm.
  • the concentration of iodine (I 3 ⁇ ) in the Au-containing etching solution supplied to the cathode chamber is high, the iodine cannot be sufficiently reduced at the cathode potential, and the precipitated Au may be redissolved.
  • the iodine concentration (I 3 ⁇ ) on the cathode chamber side may be reduced by dilution or the like to such an extent that iodine (I 3 ⁇ ) can be sufficiently reduced at the cathode potential.
  • the above problem is that the Au-containing etching solution is continuously supplied from the supply source of the Au-containing etching solution (for example, an Au-containing etching solution storage tank or etching apparatus) to the electrolysis tank. Often occur when electrolysis is performed continuously.
  • the iodine (I 3 ⁇ ) concentration contained in the Au-containing etching solution supplied to the cathode chamber may not be constant, and when the iodine concentration (I 3 ⁇ ) becomes high, it precipitates. This is because Au is redissolved.
  • the supply amount of the Au-containing etching solution to the cathode chamber is [current (A (ampere))> iodine concentration (of the Au-containing etching solution supplied to the cathode side).
  • the supply amount of the Au-containing etching solution in consideration of the iodine (I 3 ⁇ ) concentration, re-dissolution of the precipitated Au can be suppressed and the Au recovery rate can be increased.
  • the specific iodine (I 3 ⁇ ) concentration in the cathode chamber is not particularly limited, but is preferably 60 mmol / L or less, more preferably 20 mmol / L or less.
  • FIG. 1 is an example of a schematic configuration diagram of diaphragm electrolysis.
  • the diaphragm electrolysis tank is composed of a cathode chamber 2 and an anode chamber 7 partitioned by a diaphragm 5.
  • the diaphragm 5 is a film that can conduct electricity and does not allow liquid to pass through the cathode chamber 2 and the anode chamber 7, and examples thereof include a cation exchange membrane and a microporous film.
  • the cathode chamber 2 is provided with a cathode 3 and a reference electrode 4 (Ag / AgCl).
  • An anode 6 is installed in the anode chamber 7.
  • the cathode potential may be controlled at a constant potential so that the potential difference between the reference electrode 4 and the cathode is measured and fed back to the DC power source 9 so that the cathode potential can be kept constant.
  • the set value of the interelectrode voltage and current may be controlled by a computer so that the cathode potential is maintained within the predetermined range based on the feedback.
  • the used etching solution tank 1 stores an Au-containing etching solution that is used for etching Au and discharged during the manufacturing process of the electronic material.
  • the liquid property of the Au-containing etching solution targeted in the present invention is not particularly limited, and may be basic, neutral, or acidic. However, if the pH of the etching solution is strongly basic or strongly acidic, the object to be plated may be damaged. Therefore, the pH of the etching solution before use is often adjusted to about 1 to 7 in many cases. Therefore, the pH of the Au-containing etching solution after use is generally about 1-7.
  • the concentration of Au in the Au-containing etching solution is not particularly limited.
  • an Au-containing etching solution contains approximately 0.1 to 10 g / L of Au.
  • electrolysis can be performed stably regardless of the concentration of Au.
  • the iodine (I 3 ⁇ ) concentration in the Au-containing etching solution is not particularly limited because it varies depending on the etching conditions and the like, but is generally about 10 to 200 mmol / L.
  • the used etchant tank 1 and the cathode chamber 2 are connected by a pipe line via the pump P1, and the Au-containing etchant is supplied to the cathode chamber 2.
  • the cathode chamber 2 and the anode chamber 7 are connected by a pipe line via a pump P2, and an etching solution (used etching solution) after Au deposition is finished is supplied to the anode chamber 7.
  • an etching solution used etching solution
  • the oxidation of iodine is mainly performed, and the regeneration of the etching ability (recovery of iodine (I 3 ⁇ ) concentration) is performed.
  • the electrolytic solution previously filled in the anode chamber 7 is not particularly limited, and for example, an iodine-based etching solution may be filled.
  • the electrolytic solution previously filled in the anode chamber 7 is not particularly limited as long as it has a property of conducting electricity.
  • the anode chamber 7 may be filled with the iodine-based etching solution before use.
  • Anode chamber 7 and the electric deconstructed etchant tank 8 is connected in line via the pump P3, iodine (I -) is oxidized, iodine (I 3 -) concentration was restored reproduction etchant electrical It is supplied to the decomposed etching solution tank 8.
  • the pH of the regenerated etching solution supplied to the electrolyzed etching solution tank 8 is substantially the same as that of the pre-use etching solution (preferably ⁇ 0.5), and iodine (I) of the iodine-based etching solution previously filled in the cathode chamber. 3 ⁇ ) Although there are some fluctuations depending on the concentration, the iodine (I 3 ⁇ ) concentration is equivalent to the pre-use etching solution (preferably ⁇ 50%). Therefore, the regenerated etching solution can be used as it is for the etching of Au.
  • the Au deposited on the cathode 3 may be recovered from the cathode 3 by any means, and can be easily recovered by scraping means such as a scraper.
  • the cathode potential and the anode potential during electrolysis are appropriately controlled, so that Au can be recovered in a high yield, and the used etching solution has substantially the same pH as the etching solution before use. And can be regenerated to an equivalent iodine concentration.
  • the anode chamber 7 (capacity 300 mL) was provided with an anode 6 (electrode having a titanium surface coated with iridium oxide; surface area 26.4 cm 2 ). Incidentally, it was set to the surface area of the cathode surface area of the anode chamber 7 such that the desired anodic potential is obtained twice (13.2cm 2) (26.4cm 2) .
  • a potassium iodide aqueous solution (iodine-based etching solution A: potassium iodide concentration 80 g / L, iodine (I 3 ⁇ ) concentration: 3 g / L (about 10 mmol / L)) in which iodine is dissolved in advance. Filled. Also in the anode chamber 7, an aqueous potassium iodide solution in which iodine is dissolved in advance (iodine-based etching solution B: potassium iodide concentration 80 g / L, iodine (I 3 ⁇ ) concentration: 40 g / L (about 150 mmol / L)) Filled.
  • iodine-based etching solution A potassium iodide concentration 80 g / L, iodine (I 3 ⁇ ) concentration: 3 g / L (about 10 mmol / L)
  • an Au-containing etching solution (dissolved Au concentration 1.2 g / L, potassium iodide concentration 80 g / L, iodine (I 3 ⁇ ) concentration 40 g / L (about 150 mmol / L)) is used from the used etching solution tank 1. Electrolysis was performed by continuously supplying the cathode chamber 2 while adjusting the supply amount with the pump P1.
  • a direct current power source 9 is measured so that the potential difference between the reference electrode 4 (Ag / AgCl) installed in the cathode chamber 2 and the cathode 3 is measured and the cathode potential is maintained at ⁇ 0.3 V (vs. Ag / AgCl). Controlled the output.
  • the anode potential was maintained at +0.6 V or less (vs. Ag / AgCl) by adjusting the anode area.
  • the supply amount of the Au-containing etching solution is 17 mL / hr based on the iodine (I 3 ⁇ ) concentration, iodine reduction rate, cathode potential ( ⁇ 0.3 V), and current density (9 mA / cm 2 ).
  • the reduction amount of iodine in the cathode chamber 2 was made to exceed the supply amount of the used etching solution.
  • the used etching solution in the cathode chamber 2 in which Au was deposited by electrolysis and the Au concentration decreased was supplied to the anode chamber 7 by the pump P2.
  • the supply amount of the pump P2 was controlled so as to be about the same as the supply amount of the Au-containing etching solution from the pump P1 (17 mL / hr).
  • iodine ions reduced by the reaction in the cathode chamber 2 are oxidized, and iodine (I 3 ⁇ ) is regenerated. Then, the regenerated etching solution whose iodine (I 3 ⁇ ) concentration has been recovered by such an oxidizing action is supplied to the electrolyzed etching solution tank 8 via the pump P3 in substantially the same amount (17 mL / hr).
  • the composition of each of the Au-containing etchant in the used etchant tank 1 and the regenerated etchant in the electrolyzed etchant tank 8 was examined and described in Table 1.
  • the composition of the pre-use etchant was examined in advance before the etchant was used for etching Au.
  • the Au concentration contained in the regenerated etching solution was less than 5 mg / L, and Au could be recovered in a high yield.
  • the pH of the etching solution before use and the pH of the regenerated etching solution are both 3.3, and the iodine (I 3 ⁇ ) concentration of the regenerated etching solution obtained during the electrolysis without changing the pH.
  • the iodine (I 3 ⁇ ) concentration was the same as that of the pre-use etching solution, and the composition was almost the same, so that it was confirmed that it was in a state suitable for reuse.
  • Example 2 Next, the change in pH of the liquid before and after electrolysis in the range of the cathode potential and anode potential specified in the present invention was examined.
  • the following experiment was conducted using an electrolysis test facility having the configuration shown in FIG. In addition, it is the structure similar to the said Experimental example 1 except having supplied the reproduction
  • capacitance 100mL capacity of the cathode chamber 2 and the anode chamber 7 was 100 mL, the surface area of the cathode was 3 cm 2 , and the surface area of the anode was 9 cm 2 .
  • Electrolysis was performed for 1 hour, and the cathode potential, the anode potential, the pH of the cathode chamber and the pH of the anode chamber were examined. The results are shown in Table 2.
  • Example 3 The change in pH in the cathode chamber when the cathode potential range specified in the present invention was outside the range was examined. Except that the cathode potential was changed to -1.0 V (vs. Ag / AgCl), the following experiment was conducted in the same manner as in Experimental Example 2, using the same electrolysis test facility as shown in FIG. Went. The results are shown in Table 3.
  • Example 4 The pH variation in the anode chamber when the anode potential range defined in the present invention was out of the range was examined.
  • the following experiment was conducted using an electrolysis test facility having the configuration shown in FIG. FIG. 3 is a batch type membrane electrolysis.
  • the cathode titanium plate (surface area 2.9 cm 2), the anode using the electrode produced by coating the surfaces of the titanium plate with iridium oxide (surface area 8.8 cm 2).
  • the Au-containing etching solution used in Experimental Example 1 dissolved Au concentration 1.2 g / L, potassium iodide concentration 80 g / L, iodine (I 3 ⁇ ) concentration 40 g / L (approximately 150 mmol / L)
  • the anode chamber 7 was filled with the iodine-based etching solution B in advance.
  • Electrolysis When performing the electrolysis, the electrolysis was performed while adjusting the cathode potential to maintain -0.7 V (vs. Ag / AgCl). Electrolysis was started from +0.48 V (electrolysis time 0 minutes), and the anode potential was raised to +1.89 V (electrolysis time 240 minutes) at the end of electrolysis. Electrolysis was performed for 4 hours, and the change in pH of the anode chamber was examined. The results are shown in Table 4.

Abstract

The purpose of the present invention is to establish a technique which enables the collection of Au from a used iodine-containing etching solution with a high collection rate and also enables the restoring of the concentration of iodine (I3 -) in the etching solution to recover the etching ability of the etching solution. A method for treating a iodine-containing etching solution that contains Au, which comprises electrolyzing the etching solution to collect Au from the etching solution and restore the concentration of iodine (I3 -), wherein the electrolysis is carried out while keeping the cathode potential at -0.7 V or more (wherein the reference potential is a potential of a reference electrode Ag/AgCl) and the anode potential at +1.0 V or less (wherein the reference potential is a potential of a reference electrode Ag/AgCl).

Description

Ａｕ含有ヨウ素系エッチング液の処理方法、および処理装置Method and apparatus for processing Au-containing iodine-based etching solution
　本発明はＡｕ含有ヨウ素系エッチング液の処理方法、および処理装置に関する。詳細には電気分解によりＡｕ含有ヨウ素系エッチング液から金属Ａｕを高い回収率で効率良く回収すると共に、ヨウ素（Ｉ3 -）濃度を回復してエッチング能力の再生を図る技術に関するものである。 The present invention relates to a method and apparatus for processing an Au-containing iodine-based etching solution. Specifically, the present invention relates to a technique for efficiently recovering metallic Au from an iodine-containing iodine-based etching solution by electrolysis at a high recovery rate and recovering the iodine (I 3 − ) concentration to restore the etching ability.
　半導体などの集積回路基板や、ターミナル端子やコネクタなどの電子部品には導電性や耐久性の観点からＡｕ（例えばＡｕめっき）が使用されている。Ａｕめっきされた基板や電子部品の表面を微細加工する際に、不要なＡｕはエッチング液で溶解・除去している。Ａｕのエッチング液としては、ヨウ素系エッチング液が汎用されている。ヨウ素系エッチング液とは、ヨウ化カリウム（ＫＩ）水溶液にヨウ素（Ｉ2）を溶解させたものであり、ヨウ素は該水溶液中でＩ3 -として存在し、該ヨウ素（Ｉ3 -）と反応してＡｕがエッチング（溶解）される。 From the viewpoint of conductivity and durability, Au (for example, Au plating) is used for integrated circuit boards such as semiconductors and electronic parts such as terminal terminals and connectors. When finely processing the surface of an Au-plated substrate or electronic component, unnecessary Au is dissolved and removed with an etching solution. An iodine-based etchant is widely used as an Au etchant. The iodine-based etching solution is a solution in which iodine (I 2 ) is dissolved in an aqueous solution of potassium iodide (KI), and iodine exists as I 3 − in the aqueous solution and reacts with the iodine (I 3 − ). Then, Au is etched (dissolved).
　Ａｕをエッチングした後の使用済みヨウ素系エッチング液にはＡｕイオン（例えばヨウ化物錯体［ＡｕＩ2］-）が含まれている。Ａｕは高価な材料であるため、使用済みヨウ素系エッチング液からＡｕを回収する技術が各種提案されている。使用済みヨウ素系エッチング液からＡｕを回収する技術として電気分解法が汎用されている。 The used iodine-based etchant after etching Au contains Au ions (for example, iodide complex [AuI 2 ] − ). Since Au is an expensive material, various techniques for recovering Au from used iodine-based etching solutions have been proposed. An electrolysis method is widely used as a technique for recovering Au from a used iodine-based etching solution.
　電気分解法はＡｕ含有ヨウ素系エッチング液を電気分解して陰極表面にＡｕを析出させて回収する方法である。Ａｕを回収した後の使用済みエッチング液は、エッチング能力を有するヨウ素（Ｉ3 -）が還元（Ｉ-）されてエッチング能力が低下していることから、再利用されることなく、廃棄処分されていた。 The electrolysis method is a method in which Au-containing iodine-based etching solution is electrolyzed to deposit Au on the cathode surface and recovered. The used etching solution after recovering Au is discarded without being reused because iodine (I 3 − ) having etching ability is reduced (I − ) and the etching ability is reduced. It was.
　しかしながら近年、環境汚染防止や経済的要請から、使用済みヨウ素系エッチング液からＡｕを回収するだけでなく、使用済みヨウ素系エッチング液のエッチング能力（ヨウ素（Ｉ3 -）濃度）を再生（回復）し、ヨウ素系エッチング液として再利用することが望まれている。例えば特許文献１には、使用済みヨウ素系エッチング液を隔膜電気分解処理することで、Ａｕを回収すると共に、還元されたヨウ素（Ｉ-）を酸化させてヨウ素（Ｉ3 -）を回復させてエッチング能力の再生を図り、再利用を可能とする技術が提案されている。 However in recent years, environmental pollution and economic requirements, not only the recovery of Au from used iodine-based etching solution, the etching ability of the used iodine-based etching solution (iodine (I 3 -) concentration) play (Recovery) However, it is desired to be reused as an iodine-based etching solution. For example, Patent Document 1 discloses a method of recovering iodine (I 3 − ) by oxidizing Au (I − ) reduced by recovering Au by performing electrolysis treatment of a used iodine-based etching solution. Techniques have been proposed that allow the etching capacity to be regenerated and reused.
特開平３－２０２４８４号公報Japanese Patent Laid-Open No. 3-202484
　しかしながらエッチングに使用した後のＡｕ含有ヨウ素系エッチング液（以下、Ａｕ含有エッチング液ということがある）を隔膜電気分解処理すると陰極側でＡｕが析出（電着）する下記反応（Ｉ）と同時に、
　　［ＡｕＩ2］-　＋　ｅ-　→　Ａｕ＋２Ｉ-　・・・（Ｉ）
　一旦電着したＡｕが再溶解する下記反応（ＩＩ）が起こるため、
　　２Ａｕ　＋　Ｉ-　＋　Ｉ3 -　→　２ＡｕＩ2 -・・・（ＩＩ）
　Ａｕの回収率が極めて低くなってしまうという問題があった。 However, simultaneously with the following reaction (I) in which Au is deposited (electrodeposited) on the cathode side when the Au-containing iodine-based etching solution (hereinafter also referred to as Au-containing etching solution) used for etching is subjected to diaphragm electrolysis treatment,
[AuI 2 ] − + e − → Au + 2I − (I)
Since the following reaction (II) occurs in which Au once electrodeposited is redissolved,
2Au + I − + I 3 − → 2AuI 2 − (II)
There was a problem that the Au recovery rate would be extremely low.
　特にＡｕ含有エッチング液の物性（組成、ヨウ素濃度など）は、被処理物やヨウ素系エッチング液中のヨウ素濃度などによっても変わってくるため、高収率でＡｕの回収を行いつつ、エッチング液の再生も安定して行うことは非常に困難であった。 In particular, the physical properties (composition, iodine concentration, etc.) of the etching solution containing Au vary depending on the iodine concentration in the object to be processed and the iodine-based etching solution. Therefore, while recovering Au in a high yield, It was very difficult to perform the regeneration stably.
　本発明は上記のような事情に着目してなされたものであって、その目的は、Ａｕ含有エッチング液からＡｕを高い回収率で回収しつつ、ヨウ素（Ｉ3 -）濃度を好ましくは使用前のエッチング液の状態とほぼ同レベルまで回復させてエッチング能力の再生もできる技術を確立することにある。 The present invention has been made paying attention to the above-mentioned circumstances, and the object thereof is to recover the iodine (I 3 − ) concentration from the Au-containing etching solution at a high recovery rate and preferably to adjust the iodine (I 3 − ) concentration before use. The purpose is to establish a technique that can recover the etching performance by recovering to almost the same level as the state of the etching solution.
　上記課題を解決し得た本発明とは、電気分解によりＡｕ含有ヨウ素系エッチング液中のＡｕを回収すると共に、ヨウ素（Ｉ3 -）濃度を回復するエッチング液の処理方法であって前記電気分解は陰極電位を－０．７Ｖ以上（基準電位を参照電極Ａｇ／ＡｇＣｌとした場合）、及び陽極電位を＋１．０Ｖ以下（基準電位を参照電極Ａｇ／ＡｇＣｌとした場合）に維持して行うことに要旨を有する。 The present invention that has solved the above problems is a method of treating an etching solution that recovers the iodine (I 3 − ) concentration while recovering the Au in the Au-containing iodine-based etching solution by electrolysis. Is carried out while maintaining the cathode potential at −0.7 V or more (when the reference potential is the reference electrode Ag / AgCl) and the anode potential at +1.0 V or less (when the reference potential is the reference electrode Ag / AgCl). Has a summary.
　前記電気分解は、隔膜で陰極と陽極が仕切られた隔膜電気分解で行うことも好ましい実施態様である。 It is also a preferred embodiment that the electrolysis is performed by diaphragm electrolysis in which a cathode and an anode are partitioned by a diaphragm.
　また前記隔膜電気分解は、前記Ａｕ含有ヨウ素系エッチング液の供給源から前記隔膜で仕切られた陰極側に連続的に前記Ａｕ含有ヨウ素系エッチング液を供給してＡｕを回収した後、前記隔膜で仕切られた陽極側に供給してヨウ素（Ｉ3 -）濃度を回復させる方法であって、
　前記隔膜で仕切られた陰極側のヨウ素濃度は、陰極に析出したＡｕの再溶解が生じない程度に調整することも好ましい実施態様である。
　また実施においては、前記隔膜で仕切られた陰極側に供給するＡｕ含有ヨウ素系エッチング液の供給量を下記式（１）を満足するように調整することも好ましい。
　電流（Ａ（アンペア））＞Ｉ3 -濃度Ａ×供給量Ｂ×Ｆ　・・・（１）
　（式中、
　　　Ｉ3 -濃度Ａ：陰極側に供給されるＡｕ含有ヨウ素系エッチング液のヨウ素（Ｉ3 -）濃度（ｍｏｌ／Ｌ）、
　　　供給量Ｂ：Ａｕ含有ヨウ素系エッチング液の陰極側への供給量（Ｌ／ｓｅｃ）
　　　Ｆ：ファラデー定数（Ａ（アンペア）・ｓｅｃ／ｍｏｌ）） The diaphragm electrolysis is performed by supplying the Au-containing iodine-based etchant continuously from the supply source of the Au-containing iodine-based etchant to the cathode side partitioned by the diaphragm and recovering Au. A method of supplying iodine (I 3 − ) concentration to the partitioned anode side,
It is also a preferred embodiment that the iodine concentration on the cathode side partitioned by the diaphragm is adjusted to such an extent that re-dissolution of Au deposited on the cathode does not occur.
In implementation, it is also preferable to adjust the supply amount of the Au-containing iodine-based etching solution supplied to the cathode side partitioned by the diaphragm so as to satisfy the following formula (1).
Current (A (ampere))> I 3 - Concentration A × supply amount B × F ··· (1)
(Where
I 3 - Concentration A: Iodine Au containing iodine-based etching solution to be supplied to the cathode side (I 3 -) concentration (mol / L),
Supply amount B: Supply amount of Au-containing iodine-based etching solution to the cathode side (L / sec)
F: Faraday constant (A (ampere) · sec / mol))
　また本発明では陰極電位と陽極電位を前記の範囲に制御するための装置として、電気分解用の陰極、および陽極と、前記陰極、または前記陽極の電極電位の基準となる参照電極と、前記参照電極により測定される電位に基づいて前記参照電極を設置した側の電極電位が所定の範囲になるように電流または電極間電圧を制御する電源と、を有し、前記参照電極を設置しなかった側の電極は、電極電位が所定の範囲となるように調整する物理的手段を有することも好ましい実施態様である。 Further, in the present invention, as an apparatus for controlling the cathode potential and the anode potential within the above ranges, the cathode for electrolysis, the anode, the reference electrode serving as a reference for the electrode potential of the cathode or the anode, and the reference And a power source for controlling the current or the voltage between the electrodes so that the electrode potential on the side where the reference electrode is installed is within a predetermined range based on the potential measured by the electrode, and the reference electrode is not installed It is also a preferred embodiment that the electrode on the side has physical means for adjusting the electrode potential to be within a predetermined range.
　前記物理的手段としては、前記参照電極を設置しなかった側の電極の接液面積を調整する手段が好ましい。 As the physical means, means for adjusting the wetted area of the electrode on the side where the reference electrode is not installed is preferable.
　本発明によれば、電気分解中の陰極電位、および陽極電位を適切に制御しているため、Ａｕ含有エッチング液中のＡｕを高い回収率で回収できると共に、ヨウ素（Ｉ3 -）濃度を回復してエッチング能力の再生もできる。また隔膜で仕切ることにより、陰極側のＡｕ析出と陽極側のヨウ素（Ｉ3 -）濃度回復がより効率的に行なえるため、電解時間を短縮できる。また連続的にＡｕ含有エッチング液を供給する場合も、陰極側のヨウ素（Ｉ3 -）濃度を制御しているため陰極に析出したＡｕが新たに供給されたＡｕ含有ヨウ素系エッチング液中のヨウ素（Ｉ3 -）により再溶解することを防止し、Ａｕを収率良く回収できる。 According to the present invention, the cathode potential and anode potential during electrolysis are appropriately controlled, so that Au in the Au-containing etching solution can be recovered at a high recovery rate and the iodine (I 3 − ) concentration is recovered. Then, the etching ability can be regenerated. Further, by partitioning with a diaphragm, Au deposition on the cathode side and iodine (I 3 − ) concentration recovery on the anode side can be performed more efficiently, so that the electrolysis time can be shortened. Further, when the Au-containing etching solution is continuously supplied, the iodine in the Au-containing iodine-based etching solution in which Au deposited on the cathode is newly supplied because the iodine (I 3 − ) concentration on the cathode side is controlled. (I 3 − ) prevents re-dissolution and Au can be recovered with good yield.
 また本発明の処理装置を用いると、容易に電極電位と陽極電位を適切に制御することができる。 Moreover, when the processing apparatus of the present invention is used, the electrode potential and the anode potential can be easily controlled appropriately.
図１は、隔膜電気分解の一構成例を示す概略図である。FIG. 1 is a schematic view showing a configuration example of diaphragm electrolysis. 図２は、隔膜電気分解の他の構成例を示す概略図である。FIG. 2 is a schematic view showing another configuration example of diaphragm electrolysis. 図３は、隔膜電気分解の他の構成例を示す概略図である。FIG. 3 is a schematic view showing another configuration example of diaphragm electrolysis. 図４は、隔膜電気分解の他の構成例を示す概略図である。FIG. 4 is a schematic view showing another configuration example of diaphragm electrolysis. 図５は、電極Ｂを接続したワイヤをワイヤ長調節手段で上下させる構成例を示す概略図である。FIG. 5 is a schematic diagram showing a configuration example in which the wire connected to the electrode B is moved up and down by the wire length adjusting means. 図６は、電解槽側面に液体排出バルブを複数設けた構成例を示す概略図である。FIG. 6 is a schematic view showing a configuration example in which a plurality of liquid discharge valves are provided on the side surface of the electrolytic cell. 図７は、電極Ａと電極Ｂの接液面積が異なる構成例を示す概略図である。FIG. 7 is a schematic diagram illustrating a configuration example in which the liquid contact areas of the electrode A and the electrode B are different. 図８は、接液面積の異なる複数の電極Ｂを設けた構成例を示す概略図である。FIG. 8 is a schematic diagram illustrating a configuration example in which a plurality of electrodes B having different liquid contact areas are provided.
　本発明者らは、電気分解法により、Ａｕをエッチングした後（使用済み）のＡｕを含有するヨウ素系エッチング液（Ａｕ含有エッチング液）からＡｕを高い回収率で回収すると共に、ヨウ素（Ｉ3 -）濃度を回復してＡｕ含有エッチング液のエッチング能力を高いレベルで安定して再生（以下、使用済みエッチング液の再生ということがある。）する方法を提供するため、鋭意研究を重ねた。 The inventors of the present invention recovered Au at a high recovery rate from an iodine-based etching solution (Au-containing etching solution) containing Au after etching (used) by electrolysis, and at the same time iodine (I 3 - ) In order to provide a method for recovering the concentration and stably regenerating the etching ability of the Au-containing etching solution at a high level (hereinafter, sometimes referred to as regeneration of the used etching solution), earnest research was repeated.
　まず、従来の電気分解法によって使用済みエッチング液の再生を行った場合に、Ａｕの回収率が低くなる原因について検討した。その結果、Ａｕ含有エッチング液中のヨウ素（Ｉ3 -）濃度が高いと、電気分解によって陰極表面に付着して析出（以下、電着ということがある。）したＡｕの再溶解が起こることがわかった。すなわち、エッチングに使用する前のヨウ素系エッチング液（以下、使用前エッチング液ということがある。）は、十分なエッチング能力を発揮させるために、エッチング能力を発揮するヨウ素（Ｉ3 -）濃度が高く設定されている。そのため、Ａｕ含有エッチング液には溶解したＡｕだけでなく、消費されなかったヨウ素（Ｉ3 -）が残存している。残存しているヨウ素（Ｉ3 -）は、電気分解時に還元されて、Ｉ-となり（前記（Ｉ）の反応）、Ａｕを溶解する能力を喪失するが、Ａｕ含有エッチング液に高濃度でヨウ素（Ｉ3 -）が含まれていると、電気分解で還元されずに残存したヨウ素（Ｉ3 -）によって析出したＡｕが再溶解されてしまうことがわかった（前記（ＩＩ）の反応）。 First, the reason why the recovery rate of Au was lowered when the used etching solution was regenerated by the conventional electrolysis method was examined. As a result, when the concentration of iodine (I 3 − ) in the Au-containing etching solution is high, re-dissolution of Au deposited and deposited on the cathode surface by electrolysis (hereinafter sometimes referred to as electrodeposition) may occur. all right. In other words, the iodine-based etchant before use for etching (hereinafter also referred to as pre-use etchant) has an iodine (I 3 − ) concentration that exhibits the etching ability in order to exhibit sufficient etching ability. It is set high. Therefore, not only dissolved Au but also iodine (I 3 − ) that has not been consumed remains in the Au-containing etching solution. Residual iodine (I 3 − ) is reduced during electrolysis to become I − (reaction (I) above), and loses the ability to dissolve Au. It was found that when (I 3 − ) was contained, Au precipitated by the remaining iodine (I 3 − ) that was not reduced by electrolysis was redissolved (the reaction of (II) above).
　そこで本発明者らは、電気分解する際の電圧を高くして、陰極でのヨウ素（Ｉ3 -）還元率を高めることで、電気分解後に残存するヨウ素（Ｉ3 -）濃度を低減することを検討した。その結果、電着したＡｕの再溶解が抑制され、Ａｕを高収率で回収できるが、次のような問題が生じることがわかった。 Therefore, the present inventors reduce the concentration of iodine (I 3 − ) remaining after electrolysis by increasing the voltage at the time of electrolysis and increasing the reduction rate of iodine (I 3 − ) at the cathode. It was investigated. As a result, re-dissolution of electrodeposited Au was suppressed and Au could be recovered in high yield, but it was found that the following problems occurred.
　Ａｕの回収率を高めるために高電圧にすると、陰極では下記水素発生反応（ａ）が起こった。
　　２Ｈ2Ｏ　＋　２ｅ-　→２ＯＨ-　＋Ｈ2　・・・（ａ）
　また陽極では下記酸素発生反応（ｂ）が起こると共に、ヨウ素（固体：Ｉ2）が析出し、再生エッチング液（電気分解でエッチング能力が再生されたエッチング液）のヨウ素（Ｉ3 -）濃度が低下した。
　　２Ｈ2Ｏ　→　Ｏ2　＋　４ｅ-　＋　４Ｈ+　・・・（ｂ） When a high voltage was applied to increase the Au recovery rate, the following hydrogen generation reaction (a) occurred at the cathode.
2H 2 O + 2e − → 2OH − + H 2 (a)
In addition, the following oxygen generation reaction (b) occurs at the anode, and iodine (solid: I 2 ) precipitates, and the concentration of iodine (I 3 − ) in the regenerated etching solution (etching solution whose etching ability has been regenerated by electrolysis) Declined.
2H 2 O → O 2 + 4e − + 4H + (b)
　そのため、再生エッチング液のｐＨが不安定になると共に、ヨウ素（Ｉ3 -）濃度が低く、エッチング能力が不十分であることがわかった。上記（ａ）、（ｂ）の反応が生じた結果、再生エッチング液のｐＨは使用前エッチング液のｐＨと比べて大きな変動が生じた。具体的には、高電圧をかけると陰極電位がＡｕの析出が起こる電位よりも低くなり上記（ａ）の反応によってｐＨが上がる、あるいは陽極電位がＩ－の酸化が起こる電位よりも高くなり上記（ｂ）の反応によってｐＨが下がる現象が起こった。例えば再生エッチング液のｐＨが低くなった場合、使用前エッチング液と比べて再生エッチング液のエッチング性能が高くなってしまうため、そのまま再利用すると、Ａｕが過度にエッチングされてしまい、エッチング不良の原因となる。また再生エッチング液のｐＨが高くなった場合、使用前エッチング液と比べて再生エッチング液のエッチング性能が低くなってしまうため、そのまま再利用すると、Ａｕのエッチングが十分行えず、エッチング不良の原因となる。 For this reason, it was found that the pH of the regenerated etching solution became unstable, the iodine (I 3 − ) concentration was low, and the etching ability was insufficient. As a result of the reactions (a) and (b) described above, the pH of the regenerated etching solution varied greatly compared to the pH of the etching solution before use. Specifically, when a high voltage is applied, the cathode potential becomes lower than the potential at which Au deposition occurs and the pH increases due to the reaction (a) above, or the anode potential becomes higher than the potential at which oxidation of I − occurs. A phenomenon that the pH was lowered by the reaction of (b) occurred. For example, when the pH of the regenerated etching solution is lowered, the etching performance of the regenerated etching solution is higher than that of the pre-use etching solution, so that when reused as it is, Au is excessively etched, which causes the etching failure. It becomes. In addition, when the pH of the regenerated etching solution becomes higher, the etching performance of the regenerated etching solution becomes lower than that of the pre-use etching solution. Become.
　またヨウ素が析出するとＩ2として析出した分、再生エッチング液中のヨウ素（Ｉ3 -）濃度が低下してエッチング能力が不足することがわかった。 In addition, it was found that the iodine (I 3 − ) concentration in the regenerated etching solution was lowered and the etching ability was insufficient due to the precipitation of iodine as I 2 .
　したがってＡｕ含有エッチング液を電気分解してエッチング能力を再生（好ましくはヨウ素（Ｉ3 -）濃度を使用前エッチング液とほぼ同レベルまで回復）して、再利用を可能とするためには、使用前エッチング液と再生エッチング液とでヨウ素濃度や、ｐＨの変動を抑える必要があることがわかった。
　以上の知見に基づいて、本発明者らは高いＡｕ回収率を達成すると共に、上記ｐＨ変動やヨウ素濃度低下の問題を解決して、再利用可能な再生エッチング液を提供すべく更に研究を重ねた。 Therefore, it is necessary to electrolyze the Au-containing etching solution to regenerate the etching ability (preferably the iodine (I 3 − ) concentration is restored to almost the same level as the pre-use etching solution) to enable reuse. It has been found that it is necessary to suppress fluctuations in iodine concentration and pH between the pre-etching solution and the regenerated etching solution.
Based on the above findings, the present inventors have further studied to achieve a high Au recovery rate, solve the above problems of pH fluctuation and iodine concentration reduction, and provide a reusable regenerated etching solution. It was.
　その結果、Ａｕ含有エッチング液を電気分解してＡｕの回収とヨウ素（Ｉ3 -）濃度の回復を行う場合に、電気分解中の陰極電位と陽極電位を所定の範囲に制御することが有効であることを見出した。 As a result, it is effective to control the cathode potential and anode potential during electrolysis within a predetermined range when the Au-containing etching solution is electrolyzed to recover Au and recover the iodine (I 3 − ) concentration. I found out.
　具体的には、電気分解中の陰極電位を－０．７Ｖ以上（基準電位を参照電極Ａｇ／ＡｇＣｌとした場合、以下同じ）に維持することで、陰極でＨ2が発生する上記反応（ａ）を抑制して、使用前エッチング液とほぼ同じ程度のｐＨに維持しつつ、Ａｕの析出とヨウ素（Ｉ3 -）の還元を図ることができる。一方、陰極電位が－０．７Ｖを下回ると例えば実験例３に示すようにｐＨが大きく上昇してしまうため、そのままではエッチング液として再利用できない。好ましい陰極電位は－０．５Ｖ以上であって、好ましくは－０．１Ｖ以下である。 Specifically, the cathode potential during electrolysis or -0.7 V (if the reference potential and the reference electrode Ag / AgCl, the same applies hereinafter) to maintain the above reaction H 2 at the cathode is generated (a ) Can be suppressed, and precipitation of Au and reduction of iodine (I 3 − ) can be achieved while maintaining a pH of about the same level as the pre-use etching solution. On the other hand, when the cathode potential falls below −0.7 V, for example, as shown in Experimental Example 3, the pH rises greatly, so that it cannot be reused as an etching solution as it is. A preferred cathode potential is −0.5 V or more, preferably −0.1 V or less.
　一方、陽極電位が高い場合、陽極でＩ2が析出してしまい、再生エッチング液のヨウ素（Ｉ3 -）濃度を十分に回復できず、再利用できない。また例えば実験例４に示すようにｐＨが大きく低下してしまうため、再生エッチング液として要求されるエッチング能力が不足する。したがってＩ2の析出を抑制して、ヨウ素の酸化反応を進行させてヨウ素（Ｉ3 -）濃度を回復させるためには、電気分解中の陽極電位を＋１．０Ｖ以下（基準電位を参照電極Ａｇ／ＡｇＣｌとした場合、以下同じ）に維持できるように制御する必要がある。好ましい陽極電位は＋０．６Ｖ以下であって、好ましくは＋０．３Ｖ以上である。なお、電気分解中、陽極電位は常に一定の値を維持する必要はなく、上記所定の値を満足するのであれば、変動してもよい。 On the other hand, when the anode potential is high, I 2 is deposited at the anode, and the iodine (I 3 − ) concentration of the regenerated etching solution cannot be sufficiently recovered and cannot be reused. Further, for example, as shown in Experimental Example 4, since the pH is greatly lowered, the etching ability required as a regenerated etching solution is insufficient. Therefore, in order to suppress the precipitation of I 2 and advance the oxidation reaction of iodine to recover the iodine (I 3 − ) concentration, the anode potential during electrolysis is set to +1.0 V or less (the reference potential is the reference electrode Ag). In the case of / AgCl, it is necessary to control so that the same can be maintained. A preferred anode potential is +0.6 V or less, preferably +0.3 V or more. During the electrolysis, the anode potential need not always be maintained at a constant value, and may vary as long as the predetermined value is satisfied.
　陰極電位と陽極電位を所定の値に維持するための手段は特に限定されない。好ましい処理装置としては、電気分解用の陰極、および陽極と、前記陰極、または陽極の電極電位の基準となる参照電極と、参照電極により測定される電位に基づいて前記参照電極を設置した側の電極電位が所定の範囲になるように電流または電極間電圧を制御する電源と、を有し、参照電極を設置しなかった側の電極は、電極電位が所定の範囲となるように調整する物理的手段を有するものであることが望ましい。「電極電位が所定の範囲」とは、陰極、および陽極において目的とする反応に必要な電極電位の範囲である。例えば本発明で提供する上記Ａｕ含有エッチング液の処理方法に用いる場合における所定の範囲の電極電位とは陰極電位－０．７Ｖ以上、陽極電位＋１．０Ｖ以下である。 The means for maintaining the cathode potential and the anode potential at predetermined values is not particularly limited. As a preferable processing apparatus, a cathode and an anode for electrolysis, a reference electrode serving as a reference for the electrode potential of the cathode or the anode, and a side on which the reference electrode is installed based on a potential measured by the reference electrode A power source that controls the current or the voltage between the electrodes so that the electrode potential is in a predetermined range, and the electrode on the side where the reference electrode is not installed is physically adjusted so that the electrode potential is in the predetermined range. It is desirable to have an objective means. The “electrode potential is in a predetermined range” is a range of electrode potentials necessary for a target reaction at the cathode and the anode. For example, the electrode potential in a predetermined range when used in the processing method of the Au-containing etching solution provided in the present invention is a cathode potential of −0.7 V or more and an anode potential of +1.0 V or less.
　また電極電位を所定の範囲となるように調整する方法としても特に限定されない。例えば陰極または陽極のいずれか一方の電極Ａ側に参照電極（Ａｇ／ＡｇＣｌ）を設置し、参照電極を設置した側の電極Ａの電位は、参照電極（Ａｇ／ＡｇＣｌ）と電極Ａから得られる情報に基づいて上記所望の電位となるように電流または電極間電圧を制御すればよい。参照電極を設置しなかったもう一方の電極Ｂの電位を調整する物理的手段は特に限定されない。例えば電極Ｂと液体（例えば被電気分解液）との接液面積を調整する手段が望ましい。電極Ｂの接液面積を調整する手段としては例えば（１）電極Ｂを上下させることにより液体に浸漬する電極Ｂの接液面積を変更する手段や、（２）表面積の異なる電極Ｂを数種類準備して所望の電位となるように使用する電極Ｂを適宜選択する手段などが考えられる。接液面積の調整以外に考えられる物理的手段として、例えば（３）電極Ｂの材料により過電圧が変わるため、電極Ｂの材料を適宜選択・変更することも有効である。これらの手段をいずれか１つ、あるいは複数組み合わせて電極Ｂの電位を制御してもよい。なお、電極材料としては、陰極はステンレスやチタンが例示され、陽極はステンレス、チタンに酸化物（例えば酸化イリジウム）を被覆したものが例示される。 Also, the method for adjusting the electrode potential to be within a predetermined range is not particularly limited. For example, a reference electrode (Ag / AgCl) is installed on either the cathode or anode A side, and the potential of the electrode A on the side where the reference electrode is installed is obtained from the reference electrode (Ag / AgCl) and the electrode A. Based on the information, the current or the interelectrode voltage may be controlled so that the desired potential is obtained. The physical means for adjusting the potential of the other electrode B on which the reference electrode is not installed is not particularly limited. For example, a means for adjusting the liquid contact area between the electrode B and a liquid (for example, an electrolyzed liquid) is desirable. As means for adjusting the liquid contact area of the electrode B, for example, (1) means for changing the liquid contact area of the electrode B immersed in the liquid by moving the electrode B up and down, and (2) several types of electrodes B having different surface areas are prepared. Thus, means for appropriately selecting the electrode B to be used so as to obtain a desired potential can be considered. As physical means that can be considered other than adjustment of the wetted area, for example, (3) Since the overvoltage varies depending on the material of the electrode B, it is also effective to appropriately select and change the material of the electrode B. Any one or a combination of these means may be used to control the potential of the electrode B. Examples of the electrode material include stainless steel and titanium as the cathode, and stainless steel as the anode and titanium coated with an oxide (for example, iridium oxide).
　上記（１）（２）を実現する具体的な装置構成としては、特に限定されない。例えば上記（１）の方法で電極Ｂの接液面積を変更する手段としては、電位に応じて電極Ｂを自動的に上下させる機構を設けてもよい（例えば図５参照。なお、図中、他の構成は省略しており、他の構成として図１～図４と同様でもよい。図６～図８についても同じ）。電極Ｂを上下させて接液面積を変えることで、電極Ｂの電位を調整できる。あるいは電解槽に電解槽底からの高さの異なる液体排出バルブを複数設けてもよい（例えば図６参照）。液体排出バルブを適宜開閉することで、液体の液面高さを上下させて電極Ｂとの接液面積を調整できる。また電極Ｂの面積を電極Ａの面積との関係で変更することで（例えば図７参照）、電極Ｂの電圧電位を調整することが可能である。また上記（２）の方法で電極Ｂの電位を調整する手段としては、予め接液面積の異なる複数の電極Ｂを設置して制御器などの電流制御手段を介して電源と接続させる機構を設けてもよい（例えば図８参照）。所望の電位となるように制御器を介して電流を流す電極Ｂを一本または複数選択することで、電極Ｂの電位を調整できる。また、上記電極電位の調整手段と共に、電解液を攪拌や循環させることも電極電位の調整に好適であるため、必要に応じて、攪拌手段や循環設備を設けてもよい。これら手段は複数組み合わせて電極Ｂの接液面積を制御してもよい。 The specific device configuration for realizing the above (1) and (2) is not particularly limited. For example, as a means for changing the wetted area of the electrode B by the method (1), a mechanism for automatically raising and lowering the electrode B according to the potential may be provided (see, for example, FIG. 5. Other configurations are omitted, and other configurations may be the same as those in FIGS. 1 to 4 (the same applies to FIGS. 6 to 8). The potential of the electrode B can be adjusted by moving the electrode B up and down to change the liquid contact area. Alternatively, a plurality of liquid discharge valves having different heights from the electrolytic cell bottom may be provided in the electrolytic cell (see, for example, FIG. 6). By appropriately opening and closing the liquid discharge valve, the liquid surface height of the liquid can be raised and lowered to adjust the liquid contact area with the electrode B. Further, the voltage potential of the electrode B can be adjusted by changing the area of the electrode B in relation to the area of the electrode A (see, for example, FIG. 7). As a means for adjusting the potential of the electrode B by the method (2), a mechanism is provided in which a plurality of electrodes B having different liquid contact areas are previously installed and connected to a power source via a current control means such as a controller. (See, for example, FIG. 8). The potential of the electrode B can be adjusted by selecting one or a plurality of electrodes B through which a current is passed through the controller so as to obtain a desired potential. Moreover, since it is also suitable for adjustment of an electrode potential to stir and circulate electrolyte solution with the said electrode potential adjustment means, you may provide a stirring means and circulation equipment as needed. A plurality of these means may be combined to control the liquid contact area of the electrode B.
　例えば上記電極Ａとして陰極の電位を参照電極を用いて制御し、上記電極Ｂとして陽極の接液面積を調整する場合は、陽極電位が上昇する傾向にあるため陰極面積よりも陽極面積を大きくすることが望ましい。陽極面積を大きくすることで陽極の接液抵抗が低減され、陽極電位を上記所定の値に制御できる。 For example, when the potential of the cathode as the electrode A is controlled using a reference electrode and the liquid contact area of the anode as the electrode B is adjusted, the anode potential tends to increase, so the anode area is made larger than the cathode area. It is desirable. By increasing the anode area, the liquid contact resistance of the anode is reduced, and the anode potential can be controlled to the predetermined value.
　上記のように所定の値に調整した陰極電位と陽極電位でＡｕ含有エッチング液を電気分解すると、Ａｕイオンを金属Ａｕとして陰極に析出させることができる。また陰極でＨ2が発生する上記反応（ａ）を抑制できる。更に陽極でＯ２が発生する上記反応（ｂ）を抑制し、かつＩ２の析出も防止できる。そのため、再生エッチング液のｐＨは使用前エッチング液のｐＨとほぼ同等であり、またヨウ素（Ｉ3 -）濃度も使用前エッチング液のヨウ素（Ｉ3 -）濃度とほぼ同等まで回復できる。 When the Au-containing etching solution is electrolyzed with the cathode potential and anode potential adjusted to a predetermined value as described above, Au ions can be deposited on the cathode as metallic Au. Further, the reaction (a) in which H 2 is generated at the cathode can be suppressed. Further, the reaction (b) in which O 2 is generated at the anode can be suppressed, and precipitation of I 2 can be prevented. Therefore, the pH of the regeneration etchant is approximately equal to the pH before the etchant used, and iodine (I 3 -) concentration of iodine prior to use etching solution (I 3 -) can be restored to substantially the same concentration.
　使用前エッチング液とほぼ同等のｐＨとは、使用前エッチング液と同等のエッチング能力を発揮できることである。具体的な変化量は使用前エッチング液のｐＨにより多少変わるが、おおむね使用前エッチング液のｐＨの±０．５の範囲内である。再生エッチング液のｐＨを使用前エッチング液のｐＨ±０．５の範囲内とするためには、陰極室、陽極室におけるｐＨの変化量を±０．５の範囲内とすることが望ましい。 The pH almost equal to that of the pre-use etchant means that the etching ability equivalent to that of the pre-use etchant can be exhibited. The specific amount of change varies somewhat depending on the pH of the etching solution before use, but is generally within a range of ± 0.5 of the pH of the etching solution before use. In order to set the pH of the regenerated etching solution within the range of pH ± 0.5 of the pre-use etching solution, it is desirable that the amount of change in pH in the cathode chamber and the anode chamber be within the range of ± 0.5.
　使用前エッチング液とほぼ同等のヨウ素（Ｉ3 -）濃度とは、エッチング液として少なくとも不要なＡｕを溶解・除去できる程度のヨウ素（Ｉ3 -）濃度を意味する。例えばエッチング条件にもよるが、使用前エッチング液のヨウ素（Ｉ3 -）濃度を１００％としたときに、その±５０％の範囲内のヨウ素（Ｉ3 -）濃度であれば、不要なＡｕを溶解・除去することが可能であり、エッチング効率を向上させる観点からは±２０％のヨウ素（Ｉ3 -）濃度であることがより好ましい。また再生エッチング液を使用前エッチング液として利用するためには、±１０％のヨウ素（Ｉ3 -）濃度であることが更に好ましく、より更に好ましくは±５％以内のヨウ素（Ｉ3 -）濃度である。使用前エッチング液のヨウ素（Ｉ3 -）濃度に近づけるためには、電極電位を適切に制御してヨウ素の析出等を防ぐことが望ましい。 The iodine (I 3 − ) concentration substantially equivalent to the pre-use etching solution means an iodine (I 3 − ) concentration that can dissolve and remove at least unnecessary Au as the etching solution. For example, although depending on the etching conditions, if the iodine (I 3 − ) concentration in the etching solution before use is 100%, if the iodine (I 3 − ) concentration is within the range of ± 50%, unnecessary Au In view of improving the etching efficiency, it is more preferable that the iodine (I 3 − ) concentration be ± 20%. In order to use the regenerated etching solution as a pre-use etching solution, it is more preferable that the iodine (I 3 − ) concentration be ± 10%, and still more preferable that the iodine (I 3 − ) concentration be within ± 5%. It is. In order to approach the iodine (I 3 − ) concentration in the etching solution before use, it is desirable to appropriately control the electrode potential to prevent iodine precipitation and the like.
　Ａｕ含有エッチング液は陰極と陽極が設置されている電気分解槽に供給して電気分解するが、その際、陰極に析出したＡｕが、陽極で発生したＩ3 -によって再溶解されないようにすると、電気分解にかかる時間を短縮できるため望ましい。具体的には、電気的導通が可能であって、かつＡｕ含有エッチング液を通さない隔膜を設けた隔膜電気分解をすることが望ましい。 The Au-containing etching solution is supplied to an electrolysis tank in which a cathode and an anode are installed and electrolyzed. At that time, if Au deposited on the cathode is not re-dissolved by I 3 − generated at the anode, This is desirable because the time required for electrolysis can be shortened. Specifically, it is desirable to perform electrolysis of a diaphragm provided with a diaphragm that can be electrically connected and does not allow an Au-containing etching solution to pass through.
　また隔膜電気分解の場合、隔膜によって電気分解槽を陽極側（陽極室）と陰極側（陰極室）に分けることで、Ａｕ含有エッチング液を陰極室と陽極室で夫々異なる液質に調整できる。例えば陰極室に供給するＡｕ含有エッチング液のヨウ素（Ｉ3 -）濃度が高い場合、上記陰極電位では該ヨウ素を十分に還元できず、析出したＡｕの再溶解が生じることがある。そのため、上記陰極電位で十分にヨウ素（Ｉ3 -）を還元できる程度まで陰極室側のヨウ素濃度（Ｉ3 -）を希釈などによって低減させてもよい。 In the case of diaphragm electrolysis, the Au-containing etching solution can be adjusted to different liquid qualities in the cathode chamber and the anode chamber by dividing the electrolysis tank into the anode side (anode chamber) and the cathode side (cathode chamber) by the diaphragm. For example, when the concentration of iodine (I 3 − ) in the Au-containing etching solution supplied to the cathode chamber is high, the iodine cannot be sufficiently reduced at the cathode potential, and the precipitated Au may be redissolved. Therefore, the iodine concentration (I 3 − ) on the cathode chamber side may be reduced by dilution or the like to such an extent that iodine (I 3 − ) can be sufficiently reduced at the cathode potential.
　Ａｕ含有エッチング液のヨウ素濃度が高い場合の上記問題は、Ａｕ含有エッチング液の供給源（例えばＡｕ含有エッチング液の貯留槽やエッチング装置）から連続的にＡｕ含有エッチング液を電気分解槽に供給して連続式で電気分解する際に生じることが多い。連続式で電気分解する場合、陰極室に供給されたＡｕ含有エッチング液に含まれるヨウ素（Ｉ3 -）濃度が一定していないことがあり、ヨウ素濃度（Ｉ3 -）が高くなると、析出したＡｕが再溶解されるためである。 When the iodine concentration of the Au-containing etching solution is high, the above problem is that the Au-containing etching solution is continuously supplied from the supply source of the Au-containing etching solution (for example, an Au-containing etching solution storage tank or etching apparatus) to the electrolysis tank. Often occur when electrolysis is performed continuously. In the case of continuous electrolysis, the iodine (I 3 − ) concentration contained in the Au-containing etching solution supplied to the cathode chamber may not be constant, and when the iodine concentration (I 3 − ) becomes high, it precipitates. This is because Au is redissolved.
　そこで本発明では、連続式で電気分解する場合は、陰極室へのＡｕ含有エッチング液の供給量が、［電流（Ａ（アンペア））＞ヨウ素濃度（陰極側に供給されるＡｕ含有エッチング液のＩ3 -濃度（ｍｏｌ／Ｌ））×Ａｕ含有ヨウ素系エッチング液の陰極側への供給量（Ｌ／ｓｅｃ）×Ｆ（ファラデー定数：Ａ（アンペア）・ｓｅｃ／ｍｏｌ）］を満足するように調整することが望ましい。ヨウ素（Ｉ3 -）濃度を考慮してＡｕ含有エッチング液の供給量を調整することで、析出したＡｕの再溶解を抑制してＡｕの回収率を高めることができる。 Therefore, in the present invention, when electrolysis is performed continuously, the supply amount of the Au-containing etching solution to the cathode chamber is [current (A (ampere))> iodine concentration (of the Au-containing etching solution supplied to the cathode side). I 3 - concentration (mol / L)) supply amount to the cathode side of × Au-containing iodine-based etching solution (L / sec) × F (Faraday constant: a (ampere) · sec / mol)] so as to satisfy It is desirable to adjust. By adjusting the supply amount of the Au-containing etching solution in consideration of the iodine (I 3 − ) concentration, re-dissolution of the precipitated Au can be suppressed and the Au recovery rate can be increased.
　上記したように連続式で電気分解する場合、陰極室のヨウ素（Ｉ3 -）濃度は、析出したＡｕの再溶解が生じない程度に調整することが望ましい。具体的な陰極室のヨウ素（Ｉ3 -）濃度は特に限定されないが、好ましくは６０ｍｍｏｌ／Ｌ以下、より好ましくは２０ｍｍｏｌ／Ｌ以下である。陰極室内のヨウ素濃度を適切に調整することによって、Ａｕの回収率を高めることができる。 When electrolysis is performed continuously as described above, it is desirable to adjust the iodine (I 3 − ) concentration in the cathode chamber to such an extent that the dissolved Au does not re-dissolve. The specific iodine (I 3 − ) concentration in the cathode chamber is not particularly limited, but is preferably 60 mmol / L or less, more preferably 20 mmol / L or less. By appropriately adjusting the iodine concentration in the cathode chamber, the Au recovery rate can be increased.
　なお、一度に一定量を処理するバッチ式の場合、陰極室側のヨウ素（Ｉ3 -）濃度が高くても上記電位条件でＡｕを高い回収率で回収できる。バッチ式の場合、電気分解中に新たにヨウ素（Ｉ3 -）が供給されないため、陰極室内のヨウ素（Ｉ3 -）が還元されてヨウ素（Ｉ3 -）濃度が漸減し、Ａｕの再溶解が抑制されるからである。 Note that in the case of a batch system in which a certain amount is processed at a time, Au can be recovered at a high recovery rate under the above potential conditions even if the iodine (I 3 − ) concentration on the cathode chamber side is high. For batch-type, newly iodine during electrolysis - because is not supplied, the cathode chamber of the iodine (I 3) (I 3 - ) is reduced iodine (I 3 -) concentration is decreasing, re-dissolution of Au This is because it is suppressed.
　以下、Ａｕ含有エッチング液の処理方法として、本発明の好ましい実施形態である隔膜電気分解に基づいて説明するが、本発明は下記実施態様に限定されず、適宜変更を加えて実施することができる。 Hereinafter, a method for treating an Au-containing etching solution will be described based on diaphragm electrolysis, which is a preferred embodiment of the present invention. However, the present invention is not limited to the following embodiment, and can be implemented with appropriate modifications. .
　Ａｕ含有エッチング液の電気分解には、各種公知の電気分解装置を用いることができる。図１は、隔膜電気分解の概略構成図の一例である。隔膜電気分解槽は、隔膜５で仕切られた陰極室２と陽極室７で構成されている。なお、隔膜５は、電気的導通が可能で、かつ陰極室２と陽極室７とで液体を透過させない性質を有する膜であり、例えば陽イオン交換膜、マイクロポーラスフィルムなどが例示される。陰極室２には陰極３と参照電極４（Ａｇ／ＡｇＣｌ）が設置されている。また陽極室７には陽極６が設置されている。 Various known electrolyzers can be used for electrolysis of the Au-containing etching solution. FIG. 1 is an example of a schematic configuration diagram of diaphragm electrolysis. The diaphragm electrolysis tank is composed of a cathode chamber 2 and an anode chamber 7 partitioned by a diaphragm 5. The diaphragm 5 is a film that can conduct electricity and does not allow liquid to pass through the cathode chamber 2 and the anode chamber 7, and examples thereof include a cation exchange membrane and a microporous film. The cathode chamber 2 is provided with a cathode 3 and a reference electrode 4 (Ag / AgCl). An anode 6 is installed in the anode chamber 7.
　陰極電位は、参照電極４と陰極との電位差を測定して直流電源９にフィードバックし、陰極電位が一定に維持できるように定電位制御すればよい。あるいは該フィードバックに基づいて陰極電位が上記所定の範囲に維持されるように電極間電圧や電流の設定値をコンピューターで制御してもよい。 The cathode potential may be controlled at a constant potential so that the potential difference between the reference electrode 4 and the cathode is measured and fed back to the DC power source 9 so that the cathode potential can be kept constant. Alternatively, the set value of the interelectrode voltage and current may be controlled by a computer so that the cathode potential is maintained within the predetermined range based on the feedback.
　使用済みエッチング液槽１には、電子材料の製造過程でＡｕのエッチングに使用されて排出されたＡｕ含有エッチング液が貯留されている。本発明で対象とするＡｕ含有エッチング液の液性は特に限定されず、塩基性、中性、酸性のいずれであってもよい。もっともエッチング液のｐＨが強塩基性や強酸性であると被メッキ物にダメージを与える恐れがあるため、使用前エッチング液のｐＨは１～７程度に適宜調整されていることが多い。そのため使用後のＡｕ含有エッチング液もおおむねｐＨは１～７程度である。 The used etching solution tank 1 stores an Au-containing etching solution that is used for etching Au and discharged during the manufacturing process of the electronic material. The liquid property of the Au-containing etching solution targeted in the present invention is not particularly limited, and may be basic, neutral, or acidic. However, if the pH of the etching solution is strongly basic or strongly acidic, the object to be plated may be damaged. Therefore, the pH of the etching solution before use is often adjusted to about 1 to 7 in many cases. Therefore, the pH of the Au-containing etching solution after use is generally about 1-7.
　Ａｕ含有エッチング液中のＡｕの濃度も特に限定されない。例えばＡｕ含有エッチング液にＡｕはおおむね０．１～１０ｇ／Ｌ程度含まれている。本発明ではＡｕの濃度の多少に関わらず、安定して電気分解することができる。またＡｕ含有エッチング液中のヨウ素（Ｉ3 -）濃度もエッチング条件等によって変動するため特に限定されないが、おおむね１０～２００ｍｍｏｌ／Ｌ程度含まれている。 The concentration of Au in the Au-containing etching solution is not particularly limited. For example, an Au-containing etching solution contains approximately 0.1 to 10 g / L of Au. In the present invention, electrolysis can be performed stably regardless of the concentration of Au. Further, the iodine (I 3 − ) concentration in the Au-containing etching solution is not particularly limited because it varies depending on the etching conditions and the like, but is generally about 10 to 200 mmol / L.
　使用済みエッチング液槽１と陰極室２はポンプＰ１を介して管路で接続されており、Ａｕ含有エッチング液は陰極室２へ供給される。 The used etchant tank 1 and the cathode chamber 2 are connected by a pipe line via the pump P1, and the Au-containing etchant is supplied to the cathode chamber 2.
　陰極室２と陽極室７はポンプＰ２を介して管路で接続されており、Ａｕの析出が終わった後のエッチング液（使用済みエッチング液）が陽極室７へ供給される。陽極室７では主にヨウ素の酸化が行われ、エッチング能力の再生（ヨウ素（Ｉ3 -）濃度の回復）が行われる。なお、隔膜を設けた場合には、電気分解前に予め陽極室７にも電解液を入れておく必要がある。連続式で電気分解する場合は、陽極室７に予め充填しておく電解液としては特に限定されず、例えばヨウ素系エッチング液を充填しておけばよい。ヨウ素（Ｉ3 -）濃度は、おおむね１０～２００ｍｍｏｌ／Ｌ程度に調整しておくことも望ましい。またバッチ式で電気分解する場合は、陽極室７に予め充填しておく電解液としては、電気を通す性質を有するものであれば特に限定されない。例えば再生エッチング液の液質を使用前エッチング液と同程度に復元する観点からは、使用前のヨウ素系エッチング液を陽極室７に充填しておけばよい。 The cathode chamber 2 and the anode chamber 7 are connected by a pipe line via a pump P2, and an etching solution (used etching solution) after Au deposition is finished is supplied to the anode chamber 7. In the anode chamber 7, the oxidation of iodine is mainly performed, and the regeneration of the etching ability (recovery of iodine (I 3 − ) concentration) is performed. In addition, when a diaphragm is provided, it is necessary to put electrolyte solution into the anode chamber 7 in advance before electrolysis. In the case of continuous electrolysis, the electrolytic solution previously filled in the anode chamber 7 is not particularly limited, and for example, an iodine-based etching solution may be filled. It is also desirable to adjust the iodine (I 3 − ) concentration to about 10 to 200 mmol / L. In addition, when the electrolysis is performed in a batch manner, the electrolytic solution previously filled in the anode chamber 7 is not particularly limited as long as it has a property of conducting electricity. For example, from the viewpoint of restoring the quality of the regenerated etching solution to the same level as that of the pre-use etching solution, the anode chamber 7 may be filled with the iodine-based etching solution before use.
　陽極室７と電気分解済みエッチング液槽８はポンプＰ３を介して管路で接続されており、ヨウ素（Ｉ-）が酸化され、ヨウ素（Ｉ3 -）濃度が回復した再生エッチング液は、電気分解済みエッチング液槽８へ供給される。 Anode chamber 7 and the electric deconstructed etchant tank 8 is connected in line via the pump P3, iodine (I -) is oxidized, iodine (I 3 -) concentration was restored reproduction etchant electrical It is supplied to the decomposed etching solution tank 8.
　電気分解済みエッチング液槽８へ供給された再生エッチング液のｐＨは使用前エッチング液とほぼ同等（好ましくは±０．５）であり、また陰極室に予め充填したヨウ素系エッチング液のヨウ素（Ｉ3 -）濃度によって多少の変動はあるが、ヨウ素（Ｉ3 -）濃度も使用前エッチング液と同等（好ましくは±５０％）である。したがって再生エッチング液をそのままエッチング液としてＡｕのエッチングに利用することができる。 The pH of the regenerated etching solution supplied to the electrolyzed etching solution tank 8 is substantially the same as that of the pre-use etching solution (preferably ± 0.5), and iodine (I) of the iodine-based etching solution previously filled in the cathode chamber. 3 − ) Although there are some fluctuations depending on the concentration, the iodine (I 3 − ) concentration is equivalent to the pre-use etching solution (preferably ± 50%). Therefore, the regenerated etching solution can be used as it is for the etching of Au.
　また、図２のように再生エッチング液を使用済みエッチング液槽１に供給することも可能であるし、図４のように液の移動にポンプを用いず、オーバーフローさせることも可能である。 Further, it is possible to supply the regenerated etching solution to the used etching solution tank 1 as shown in FIG. 2, and it is possible to overflow the solution without using a pump as shown in FIG.
　なお、陰極３で析出したＡｕは陰極３から任意の手段で回収すればよく、例えばスクレーパーなどの掻き取り手段によって、容易に回収できる。 Note that the Au deposited on the cathode 3 may be recovered from the cathode 3 by any means, and can be easily recovered by scraping means such as a scraper.
　以上、本発明によれば、電気分解中の陰極電位、および陽極電位を適切に制御しているため、Ａｕを高収率で回収できると共に、使用済みエッチング液を使用前エッチング液とほぼ同じｐＨであり、かつ同等のヨウ素濃度に再生することができる。 As described above, according to the present invention, the cathode potential and the anode potential during electrolysis are appropriately controlled, so that Au can be recovered in a high yield, and the used etching solution has substantially the same pH as the etching solution before use. And can be regenerated to an equivalent iodine concentration.
　本願は、２０１３年５月３１日に出願された日本国特許出願第２０１３－１１６２０５号に基づく優先権の利益を主張するものである。２０１３年５月３１日に出願された日本国特許出願第２０１３－１１６２０５号の明細書の全内容が、本願に参考のため援用される。 This application claims the benefit of priority based on Japanese Patent Application No. 2013-116205 filed on May 31, 2013. The entire contents of the specification of Japanese Patent Application No. 2013-116205 filed on May 31, 2013 are incorporated herein by reference.
　以下、実施例を挙げて本発明をより具体的に説明するが、本発明はもとより下記実施例によって制限を受けるものではなく、前・後記の趣旨に適合し得る範囲で適当に変更を加えて実施することも勿論可能であり、それらはいずれも本発明の技術的範囲に包含される。 EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.
　（実験例１）
　本発明の方法に基づいて、Ａｕ含有エッチング液からＡｕの回収、およびヨウ素濃度（Ｉ3 -）の回復を行った。図１に示す構成を有する電気分解試験設備を用いて以下の実験を行った。隔膜５には陽イオン交換膜（デュポン社製：ナフィオン４２４（登録商標））を用いた。また陰極室２（容量３００ｍＬ）には陰極３（チタン板；表面積１３．２ｃｍ2）と参照電極４（Ａｇ／ＡｇＣｌ）を設置した。また陽極室７（容量３００ｍＬ）には陽極６（チタンの表面を酸化イリジウムで被覆した電極；表面積２６．４ｃｍ2）を設置した。なお、所望の陽極電位が得られるように陽極室７の表面積を陰極表面積（１３．２ｃｍ2）の２倍（２６．４ｃｍ２）に設定した。 (Experimental example 1)
Based on the method of the present invention, Au was recovered from the Au-containing etching solution and the iodine concentration (I 3 − ) was recovered. The following experiment was conducted using an electrolysis test facility having the configuration shown in FIG. As the diaphragm 5, a cation exchange membrane (manufactured by DuPont: Nafion 424 (registered trademark)) was used. In the cathode chamber 2 (capacity 300 mL), a cathode 3 (titanium plate; surface area 13.2 cm 2 ) and a reference electrode 4 (Ag / AgCl) were installed. The anode chamber 7 (capacity 300 mL) was provided with an anode 6 (electrode having a titanium surface coated with iridium oxide; surface area 26.4 cm 2 ). Incidentally, it was set to the surface area of the cathode surface area of the anode chamber 7 such that the desired anodic potential is obtained twice (13.2cm 2) (26.4cm 2) .
　陰極室２には、予めヨウ素を溶解させたヨウ化カリウム水溶液（ヨウ素系エッチング液Ａ：ヨウ化カリウム濃度８０ｇ／Ｌ、ヨウ素（Ｉ3 -）濃度：３ｇ／Ｌ（約１０ｍｍｏｌ／Ｌ））を充填した。また陽極室７にも、予めヨウ素を溶解させたヨウ化カリウム水溶液（ヨウ素系エッチング液Ｂ：ヨウ化カリウム濃度８０ｇ／Ｌ、ヨウ素（Ｉ3 -）濃度：４０ｇ／Ｌ（約１５０ｍｍｏｌ／Ｌ））を充填した。 In the cathode chamber 2, a potassium iodide aqueous solution (iodine-based etching solution A: potassium iodide concentration 80 g / L, iodine (I 3 − ) concentration: 3 g / L (about 10 mmol / L)) in which iodine is dissolved in advance. Filled. Also in the anode chamber 7, an aqueous potassium iodide solution in which iodine is dissolved in advance (iodine-based etching solution B: potassium iodide concentration 80 g / L, iodine (I 3 − ) concentration: 40 g / L (about 150 mmol / L)) Filled.
　続いて、Ａｕ含有エッチング液（溶解Ａｕ濃度１．２ｇ／Ｌ、ヨウ化カリウム濃度８０ｇ／Ｌ、ヨウ素（Ｉ3 -）濃度４０ｇ／Ｌ（約１５０ｍｍｏｌ／Ｌ））を使用済みエッチング液槽１からポンプＰ１で供給量を調整しながら、連続的に陰極室２に供給して電気分解を行った。 Subsequently, an Au-containing etching solution (dissolved Au concentration 1.2 g / L, potassium iodide concentration 80 g / L, iodine (I 3 − ) concentration 40 g / L (about 150 mmol / L)) is used from the used etching solution tank 1. Electrolysis was performed by continuously supplying the cathode chamber 2 while adjusting the supply amount with the pump P1.
　その際、陰極室２に設置した参照電極４（Ａｇ／ＡｇＣｌ）と陰極３との電位差を測定して陰極電位が－０．３Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）に維持されるように直流電源９の出力を制御した。陽極電位は上記陽極面積の調整により＋０．６Ｖ以下（ｖｓ．Ａｇ／ＡｇＣｌ）に維持した。 At that time, a direct current power source 9 is measured so that the potential difference between the reference electrode 4 (Ag / AgCl) installed in the cathode chamber 2 and the cathode 3 is measured and the cathode potential is maintained at −0.3 V (vs. Ag / AgCl). Controlled the output. The anode potential was maintained at +0.6 V or less (vs. Ag / AgCl) by adjusting the anode area.
　なお、Ａｕ含有エッチング液の供給量は、ヨウ素（Ｉ3 -）濃度、ヨウ素還元率、陰極電位（－０．３Ｖ）、および電流密度（９ｍＡ／ｃｍ2）に基づいて、１７ｍＬ／ｈｒとなるように調整し、陰極室２でのヨウ素の還元量が使用済みエッチング液の供給量を上回るようにした。 The supply amount of the Au-containing etching solution is 17 mL / hr based on the iodine (I 3 − ) concentration, iodine reduction rate, cathode potential (−0.3 V), and current density (9 mA / cm 2 ). Thus, the reduction amount of iodine in the cathode chamber 2 was made to exceed the supply amount of the used etching solution.
　電気分解してＡｕが析出され、Ａｕ濃度が減少した陰極室２内の使用済みエッチング液は、ポンプＰ２で陽極室７に供給した。その際、ポンプＰ１からのＡｕ含有エッチング液の供給量と同程度（１７ｍＬ／ｈｒ）になるようにポンプＰ２の供給量を制御した。 The used etching solution in the cathode chamber 2 in which Au was deposited by electrolysis and the Au concentration decreased was supplied to the anode chamber 7 by the pump P2. At that time, the supply amount of the pump P2 was controlled so as to be about the same as the supply amount of the Au-containing etching solution from the pump P1 (17 mL / hr).
　陽極室７では、前記陰極室２での反応に伴い還元されたヨウ素イオンが酸化され、ヨウ素（Ｉ3 -）が再生される。そしてこのような酸化作用を受けてヨウ素（Ｉ3 -）濃度が回復した再生エッチング液は、ポンプＰ３を介して電気分解済みエッチング液槽８にポンプＰ１からの供給量とほぼ同量（１７ｍＬ／ｈｒ）となるように供給した。 In the anode chamber 7, iodine ions reduced by the reaction in the cathode chamber 2 are oxidized, and iodine (I 3 − ) is regenerated. Then, the regenerated etching solution whose iodine (I 3 − ) concentration has been recovered by such an oxidizing action is supplied to the electrolyzed etching solution tank 8 via the pump P3 in substantially the same amount (17 mL / hr).
　上記隔膜電気分解は、８時間継続した。 The above diaphragm electrolysis was continued for 8 hours.
　電気分解後、使用済みエッチング液槽１のＡｕ含有エッチング液、および電気分解済みエッチング液槽８の再生エッチング液の各液の組成について調べて表１に記した。なお、使用前エッチング液の組成は、エッチング液をＡｕのエッチングに使用する前に予め調べた。 After the electrolysis, the composition of each of the Au-containing etchant in the used etchant tank 1 and the regenerated etchant in the electrolyzed etchant tank 8 was examined and described in Table 1. The composition of the pre-use etchant was examined in advance before the etchant was used for etching Au.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１より、本発明の条件を満足する電気分解条件で処理することにより、再生エッチング液中に含まれるＡｕ濃度は５ｍｇ／Ｌ未満であり、Ａｕを高収率で回収できた。また使用前のエッチング液のｐＨと再生エッチング液のｐＨはいずれも３．３であり、ｐＨが変動することなく、更に、電気分解中に得られた再生エッチング液のヨウ素（Ｉ3 -）濃度は１５０～１６０ｍｍｏｌ／Ｌであり、使用前エッチング液と同等のヨウ素（Ｉ3 -）濃度であり、ほぼ同じ組成であるため、再利用に適した状態であることが確認された。 From Table 1, by performing the treatment under the electrolysis conditions satisfying the conditions of the present invention, the Au concentration contained in the regenerated etching solution was less than 5 mg / L, and Au could be recovered in a high yield. Moreover, the pH of the etching solution before use and the pH of the regenerated etching solution are both 3.3, and the iodine (I 3 − ) concentration of the regenerated etching solution obtained during the electrolysis without changing the pH. Was 150 to 160 mmol / L, and the iodine (I 3 − ) concentration was the same as that of the pre-use etching solution, and the composition was almost the same, so that it was confirmed that it was in a state suitable for reuse.
　（実験例２）
　次に本発明で規定する陰極電位、陽極電位の範囲における電気分解前後の液のｐＨ変化を調べた。図２に示す構成を有する電気分解試験設備を用いて以下の実験を行った。なお、陽極室７から再生エッチング液をポンプＰ３を介して使用済みエッチング液槽１（容量１００ｍＬ）に供給した以外は、上記実験例１と同様の構成である。陰極室２、および陽極室７の各容量は１００ｍＬとし、陰極の表面積は３ｃｍ2、陽極の表面積は９ｃｍ2とした。 (Experimental example 2)
Next, the change in pH of the liquid before and after electrolysis in the range of the cathode potential and anode potential specified in the present invention was examined. The following experiment was conducted using an electrolysis test facility having the configuration shown in FIG. In addition, it is the structure similar to the said Experimental example 1 except having supplied the reproduction | regeneration etching liquid from the anode chamber 7 to the used etching liquid tank 1 (capacity | capacitance 100mL) via the pump P3. Each capacity of the cathode chamber 2 and the anode chamber 7 was 100 mL, the surface area of the cathode was 3 cm 2 , and the surface area of the anode was 9 cm 2 .
　陰極電位が－０．７Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）に維持されるように直流電源９の出力を制御すると共に、Ａｕ含有エッチング液の供給量を１０ｍＬ／ｈｒに調整した以外は上記実験例１と同様にして隔膜電気分解を行った。 Experimental Example 1 except that the output of the DC power supply 9 was controlled so that the cathode potential was maintained at −0.7 V (vs. Ag / AgCl) and the supply amount of the Au-containing etching solution was adjusted to 10 mL / hr. Diaphragm electrolysis was performed in the same manner as described above.
　電気分解を１時間行い、陰極電位、陽極電位、陰極室のｐＨと陽極室のｐＨの変動を調べた。結果を表２に示す。 Electrolysis was performed for 1 hour, and the cathode potential, the anode potential, the pH of the cathode chamber and the pH of the anode chamber were examined. The results are shown in Table 2.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２より、陰極電位と陽極電位を本発明の範囲内で制御すると、陰極室（３．３→３．８）、陽極室（３．６→３．６）共にｐＨ変化は±０．５以内となることが確認された。 From Table 2, when the cathode potential and the anode potential are controlled within the range of the present invention, the pH change is ± 0.5 in both the cathode chamber (3.3 → 3.8) and the anode chamber (3.6 → 3.6). It was confirmed to be within.
　（実験例３）
　本発明で規定する陰極電位の範囲を外れた場合の陰極室におけるｐＨ変化を調べた。陰極電位を－１．０Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）に変更した以外は、上記実験例２と同じく図２に示す構成を有する電気分解試験設備を用い、実験例２と同じ方法で以下の実験を行った。結果を表３に示す。 (Experimental example 3)
The change in pH in the cathode chamber when the cathode potential range specified in the present invention was outside the range was examined. Except that the cathode potential was changed to -1.0 V (vs. Ag / AgCl), the following experiment was conducted in the same manner as in Experimental Example 2, using the same electrolysis test facility as shown in FIG. Went. The results are shown in Table 3.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表３より、陰極電位を－０．７Ｖよりも低く設定した場合（－１．０Ｖ）、陰極室内の液のｐＨが３．３（電解開始０分）から７．１（電解開始６０分）に変動しており、ｐＨが＋０．５を超えて大きく変動した。 From Table 3, when the cathode potential is set lower than -0.7 V (-1.0 V), the pH of the liquid in the cathode chamber is 3.3 (0 minutes from electrolysis) to 7.1 (60 minutes from electrolysis). The pH fluctuated greatly exceeding +0.5.
　（実験例４）
　本発明で規定する陽極電位の範囲を外れた場合の陽極室におけるｐＨ変動を調べた。
　図３に示す構成を有する電気分解試験設備を用いて以下の実験を行った。図３はバッチ式の隔膜電気分解である。陰極にはチタン板（表面積２．９ｃｍ2）、陽極にはチタン板の表面を酸化イリジウムで被覆した電極（表面積８．８ｃｍ2）を用いた。 (Experimental example 4)
The pH variation in the anode chamber when the anode potential range defined in the present invention was out of the range was examined.
The following experiment was conducted using an electrolysis test facility having the configuration shown in FIG. FIG. 3 is a batch type membrane electrolysis. The cathode titanium plate (surface area 2.9 cm 2), the anode using the electrode produced by coating the surfaces of the titanium plate with iridium oxide (surface area 8.8 cm 2).
　陰極室２（容量１００ｍＬ）には上記実験例１で用いたＡｕ含有エッチング液（溶解Ａｕ濃度１．２ｇ／Ｌ、ヨウ化カリウム濃度８０ｇ／Ｌ、ヨウ素（Ｉ3 -）濃度４０ｇ／Ｌ（約１５０ｍｍｏｌ／Ｌ））を充填すると共に、陽極室７（容量１００ｍＬ）には予め上記ヨウ素系エッチング液Ｂを充填した。 In the cathode chamber 2 (capacity 100 mL), the Au-containing etching solution used in Experimental Example 1 (dissolved Au concentration 1.2 g / L, potassium iodide concentration 80 g / L, iodine (I 3 − ) concentration 40 g / L (approximately 150 mmol / L)) and the anode chamber 7 (capacity 100 mL) was filled with the iodine-based etching solution B in advance.
　電気分解を行うに際しては、陰極電位が－０．７Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）を維持するように調整して電気分解を行った。陽極電位は＋０．４８Ｖ（電解時間０分）から電解を開始し、電解終了時には＋１．８９Ｖ（電解時間２４０分）となるように陽極電位を上昇させた。電気分解を４時間行い陽極室のｐＨの変動を調べた。結果を表４に示す。 When performing the electrolysis, the electrolysis was performed while adjusting the cathode potential to maintain -0.7 V (vs. Ag / AgCl). Electrolysis was started from +0.48 V (electrolysis time 0 minutes), and the anode potential was raised to +1.89 V (electrolysis time 240 minutes) at the end of electrolysis. Electrolysis was performed for 4 hours, and the change in pH of the anode chamber was examined. The results are shown in Table 4.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表４より、陽極電位を＋１．０Ｖを超えて高くすると陽極室内の液のｐＨが３．６（電解時間０分、陽極電位＋０．４８Ｖ）から２．１（電解時間４時間、陽極電位＋１．８９Ｖ）に変動しており、ｐＨが－０．５を超えて大きく変動した。 From Table 4, when the anode potential is increased beyond +1.0 V, the pH of the liquid in the anode chamber is changed from 3.6 (electrolysis time 0 minutes, anode potential +0.48 V) to 2.1 (electrolysis time 4 hours, anode potential + 1). .89V), and the pH greatly fluctuated beyond -0.5.
　１　使用済みエッチング液槽
　２　陰極室
　３　陰極
　４　参照電極
　５　隔膜
　６　陽極
　７　陽極室
　８　電気分解済みエッチング液槽
　９　直流電源 DESCRIPTION OF SYMBOLS 1 Used etching liquid tank 2 Cathode chamber 3 Cathode 4 Reference electrode 5 Diaphragm 6 Anode 7 Anode chamber 8 Electrolyzed etching liquid tank 9 DC power supply

Claims (6)

  1. 　電気分解によりＡｕ含有ヨウ素系エッチング液中のＡｕを回収すると共に、ヨウ素（Ｉ3 -）濃度を回復するエッチング液の処理方法であって、
    　前記電気分解は陰極電位を－０．７Ｖ以上（基準電位を参照電極Ａｇ／ＡｇＣｌとした場合）、及び陽極電位を＋１．０Ｖ以下（基準電位を参照電極Ａｇ／ＡｇＣｌとした場合）に維持して行うことを特徴とするＡｕ含有ヨウ素系エッチング液の処理方法。     A method for treating an etching solution that recovers the concentration of iodine (I 3 − ) while recovering Au in an Au-containing iodine-based etching solution by electrolysis,
    In the electrolysis, the cathode potential is maintained at −0.7 V or more (when the reference potential is the reference electrode Ag / AgCl) and the anode potential is maintained at +1.0 V or less (when the reference potential is the reference electrode Ag / AgCl). A method for treating an Au-containing iodine-based etching solution, characterized in that
  2. 　前記電気分解は、隔膜で陰極と陽極が仕切られた隔膜電気分解である請求項１に記載の処理方法。 The processing method according to claim 1, wherein the electrolysis is diaphragm electrolysis in which a cathode and an anode are partitioned by a diaphragm.
  3. 　前記隔膜電気分解は、前記Ａｕ含有ヨウ素系エッチング液の供給源から前記隔膜で仕切られた陰極側に連続的に前記Ａｕ含有ヨウ素系エッチング液を供給してＡｕを回収した後、前記隔膜で仕切られた陽極側に供給してヨウ素（Ｉ3 -）濃度を回復させる方法であって、
    　前記隔膜で仕切られた陰極側のヨウ素濃度は、陰極に析出したＡｕの再溶解が生じない程度に調整するものである請求項２に記載の処理方法。     The diaphragm electrolysis is performed by supplying the Au-containing iodine-based etchant continuously from the supply source of the Au-containing iodine-based etchant to the cathode side partitioned by the diaphragm and collecting Au, and then partitioning with the diaphragm. A method for recovering iodine (I 3 − ) concentration by supplying to the anode side,
    The processing method according to claim 2, wherein the iodine concentration on the cathode side partitioned by the diaphragm is adjusted to such an extent that re-dissolution of Au deposited on the cathode does not occur.
  4. 　前記隔膜で仕切られた陰極側に供給するＡｕ含有ヨウ素系エッチング液の供給量を下記式（１）を満足するように調整するものである請求項３に記載の処理方法。
    　電流（Ａ（アンペア））＞Ｉ3 -濃度Ａ×供給量Ｂ×Ｆ　・・・（１）
    　（式中、
    　　　Ｉ3 -濃度Ａ：陰極側に供給されるＡｕ含有ヨウ素系エッチング液のヨウ素（Ｉ3 -）濃度（ｍｏｌ／Ｌ）、
    　　　供給量Ｂ：Ａｕ含有ヨウ素系エッチング液の陰極側への供給量（Ｌ／ｓｅｃ）
    　　　Ｆ：ファラデー定数（Ａ（アンペア）・ｓｅｃ／ｍｏｌ））     The processing method according to claim 3, wherein the supply amount of the Au-containing iodine-based etching solution supplied to the cathode side partitioned by the diaphragm is adjusted so as to satisfy the following formula (1).
    Current (A (ampere))> I 3 - Concentration A × supply amount B × F ··· (1)
    (Where
    I 3 - Concentration A: Iodine Au containing iodine-based etching solution to be supplied to the cathode side (I 3 -) concentration (mol / L),
    Supply amount B: Supply amount of Au-containing iodine-based etching solution to the cathode side (L / sec)
    F: Faraday constant (A (ampere) · sec / mol))
  5. 　電気分解によりＡｕ含有ヨウ素系エッチング液中のＡｕを回収すると共に、ヨウ素（Ｉ3 -）濃度の回復に用いられる装置であって、
    　電気分解用の陰極、および陽極と、
    　前記陰極、または前記陽極の電極電位の基準となる参照電極と、
    　前記参照電極により測定される電位に基づいて前記参照電極を設置した側の電極電位が所定の範囲になるように電流または電極間電圧を制御する電源とを有し、
    　前記参照電極を設置しなかった側の電極は、電極電位が所定の範囲となるように調整する物理的手段を有することを特徴とするＡｕ含有ヨウ素系エッチング液の処理装置。     A device that recovers Au in an Au-containing iodine-based etching solution by electrolysis and is used to recover iodine (I 3 − ) concentration,
    A cathode and an anode for electrolysis;
    A reference electrode serving as a reference for the electrode potential of the cathode or the anode;
    A power source for controlling the current or the voltage between the electrodes so that the electrode potential on the side where the reference electrode is installed is in a predetermined range based on the potential measured by the reference electrode,
    The processing apparatus for an Au-containing iodine-based etching solution, wherein the electrode on the side where the reference electrode is not provided has physical means for adjusting the electrode potential to be within a predetermined range.
  6. 　前記物理的手段は、前記参照電極を設置しなかった側の電極の接液面積を調整する手段である、請求項５に記載のＡｕ含有ヨウ素系エッチング液の処理装置。
          The said physical means is a processing apparatus of the Au containing iodine type etching liquid of Claim 5 which is a means to adjust the liquid-contact area of the electrode of the side which did not install the said reference electrode.
PCT/JP2014/063275 2013-05-31 2014-05-20 METHOD AND DEVICE FOR TREATING IODINE-CONTAINING ETCHING SOLUTION WHICH CONTAINS Au WO2014192581A1 (en)

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JP6167254B1 (en) * 2017-02-15 2017-07-19 松田産業株式会社 Method of recovering Au from iodine-based etching waste liquid and regenerating the etching solution

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CN105965030A (en) * 2016-06-20 2016-09-28 昆山鸿福泰环保科技有限公司 Technique for recovering gold from gold iodide liquid waste
JP6167254B1 (en) * 2017-02-15 2017-07-19 松田産業株式会社 Method of recovering Au from iodine-based etching waste liquid and regenerating the etching solution
WO2018150811A1 (en) * 2017-02-15 2018-08-23 松田産業株式会社 Method for recovering au from iodine etching waste liquid and regenerating etching solution

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