JP3613335B2 - Electrochemical treatment method such as electroplating and electrochemical reaction apparatus thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is suitable for an electrochemical treatment such as electroplating, and pressurizes the reaction bath to cause an electrochemical reaction, thereby suppressing the electrolysis of the solvent of the electrolytic solution, thereby making the electrochemical reaction rational and efficient. Perform well, obtain a dense and thin metal film, improve productivity, reduce the size and weight of equipment, perform each treatment process safely and rationally, and reduce the amount of waste liquid in each treatment process The present invention relates to an electrochemical treatment method such as electroplating, which can prevent environmental pollution, and an electrochemical reaction device thereof.
[0002]
[Prior art]
The conventional electroplating process is roughly divided into a pretreatment process, a plating process, and a posttreatment process. Among these, the pretreatment process involves degreasing and pickling, and these are usually performed by storing a predetermined treatment liquid in a dedicated bath and heating, and immersing the object to be treated in this treatment liquid for a predetermined time. Yes.
Therefore, a plurality of bathtubs and their work space are required, the equipment cost is expensive, the work environment is poor due to being forced to work under the situation where the treatment liquid is scattered and harmful gas is generated, and There was a problem that it took a long time to immerse and the productivity was poor
[0003]
In order to solve such a problem, the applicant introduced a substance in a supercritical state, an electrolyte solution, and a surfactant into the reaction bath, electroplated under these emulsion states, and plated. After that, we developed an electrochemical reaction method that vaporizes the supercritical material and discharges it outside the bath so that the reaction bath and electrodes can be cleaned without the need for a cleaning solution. Already proposed as 253572
[0004]
However, the electrochemical reaction method requires a large amount of energy to heat and pressurize the reaction bath in a supercritical state at a high temperature and a high pressure, which increases the operating cost and the large weight of the equipment. There was a problem that led to an increase in equipment costs.
[0005]
By the way, in electroplating or the like, hydrogen gas or oxygen gas is generated by electrolysis of the electrolytic solution, and the bubbles stay or move on the surface to be processed, thereby causing plating defects or plating unevenness. There is a problem that electric energy is consumed for the generation, the plating is hindered, and current efficiency is lowered.
[0006]
In order to solve such a problem, for example, an electroless plating apparatus disclosed in Japanese Patent Application Laid-Open No. 2000-226671 has a surface to be processed facing upward in a sealed space, the pressure in the space is set to atmospheric pressure or higher, and This pressure is pulsated to dissolve hydrogen gas bubbles generated in the reduction reaction during electroless copper plating into the plating solution and to promote separation from the surface to be processed.
[0007]
However, in electroless plating, hydrogen gas and the like are inevitably generated along with the deposition reaction of the plating, so the method of suppressing the generation of gas is because the deposition of the plating is lowered and the plating itself cannot be performed. Not practical.
That is, in electroless plating, plating is performed after allowing the generation of hydrogen gas, etc., and for an unfavorable hydrogen gas, an appropriate stabilizer is added to the bath, or nitrogen gas is used. It corresponded.
Therefore, the electroless plating method that allows generation of hydrogen gas or the like cannot be used for electroplating or the like.
[0008]
Moreover, in the case of electroplating by the above-described method, an electrode must be disposed to face the surface to be processed, and in such a case, hydrogen gas generated from the surface to be processed stays in the electrode and is contained in the electrolytic solution. This method cannot be used for electroplating because it prevents energization and makes electroplating difficult.
[0009]
[Problems to be solved by the invention]
The present invention solves such a problem, and is suitable for electrochemical treatment such as electroplating. For example, the reaction bath is pressurized to cause an electrochemical reaction, and the electrolysis of the solvent of the electrolytic solution is suppressed. The reaction can be carried out rationally and efficiently, and a dense and thin metal film can be obtained, productivity can be improved and the equipment can be reduced in size and weight, and each processing step can be performed safely and rationally. It is an object of the present invention to provide an electrochemical treatment method such as electroplating and an electrochemical reaction device for reducing the amount of waste liquid in the process and preventing environmental pollution.
[0010]
[Means for Solving the Problems]
For this reason, the invention of claim 1 accommodates the cathode and anode electrode materials in a reaction bath capable of accommodating an electrolytic material,AboveReaction bathUnder pressure of the reaction bath.In the electrochemical treatment method such as electroplating for electrochemical reaction in the reaction bath, the reaction bathSurfactant is added to and stirred, and the pressurized liquid and the electrolyte solution are emulsified and electrochemically reacted, and the surfactant is efficiently applied to hydrogen gas and oxygen gas refined under pressure. Work, quickly remove the gas from the surface to be treated, and quickly melt it into the electrolyte solution.Trying to
[0011]
The invention of claim 2 is the reaction bath.Before the electrochemical reaction in the step, the pressurized liquid is introduced into the reaction bath, the electrode material is washed, or the oxide film is removed, so that the pretreatment with the pressurized liquid is performed and stable. Realize the electrochemical reactionI try to do it.
[0012]
Claim3In the invention of the present invention, an electrochemical reaction is caused in the reaction bath.After that, the pressurized liquid is introduced into the reaction bath, the electrode material is washed or dried, and the post-treatment with the pressurized liquid is performed to obtain the stability of the next electrochemical reaction.I try to do it.
[0013]
Claim4The invention ofAbout 1-7 by introducing liquefied carbon dioxide into the reaction bath . By applying pressure to 3 MPa, the electrochemical reaction is realized in a lower pressure state than in the supercritical state, thereby reducing energy consumption, reducing the size and weight of equipment, and reducing operating costs.I try to do it.
[0014]
Claim5The invention ofThe cathode and anode electrode materials are accommodated in a reaction bath capable of accommodating an electrolyte, a pressurized liquid is introduced into the reaction bath so that pressurization is possible, and an electrochemical reaction is performed under the pressurized state of the reaction bath. In an electrochemical reaction apparatus such as electroplating that is made possible, a surfactant is added to the reaction bath so that it can be stirred, and the pressurized liquid and the electrolyte solution are emulsified to enable electrochemical reaction. , Make the surfactant efficiently work against hydrogen gas and oxygen gas refined under pressure, quickly peel off the gas from the surface to be treated, and quickly melt it into the electrolyte solutionI try to do it.
[0015]
Claim6The invention of the reaction bathBefore the electrochemical reaction, the pressurized liquid can be introduced into the reaction bath, the electrode material can be washed, or the oxide film can be removed, and the pretreatment with the pressurized liquid can be performed to stabilize Realized electrochemical reactionTrying to
[0016]
Claim7The invention of the reaction bathAfter the electrochemical reaction, the pressurized liquid can be introduced into the reaction bath, the electrode material can be washed or dried, and the post-treatment with the pressurized liquid can be performed. The stability of the reactionI try to do it.
[0017]
Claim8The invention ofLiquefied carbon dioxide is introduced into the reaction bath so that the pressure can be increased to about 1 to 7.3 MPa, and the electrochemical reaction is realized in a lower pressure state than in the supercritical state. Reduce weight and reduce operating costsI try to do it.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will now be given of illustrated embodiments in which the present invention is applied to electroplating (nickel plating) which is an electrochemical treatment method. In FIGS. 1 to 10, reference numeral 1 denotes a stainless steel plating tank which is an electrochemical reaction bath. The inner surface is lined with vinyl chloride or hard rubber, and a lid (not shown) is airtightly and detachably attached to the upper opening.
[0019]
A direct current power source 2 that is an external electric field is provided outside the plating tank 1, and an anode 3 that is an electrode material that conducts to the positive electrode side, and a cathode 4 that is an electrode material and is a treatment object that conducts to the negative electrode side. Is accommodated in the plating tank 1.
In the embodiment, a pure nickel plate is used for the anode 3 and a Hull cell test brass plate is used for the cathode 4.
[0020]
In the figure, 5 is a switch inserted in the power supply circuit of the power source 2 and is turned on only during an electrochemical reaction, that is, during electroplating, so that the anode 3 and the cathode 4 can be energized. Reference numeral 6 denotes a stirrer such as a stirrer provided at the bottom of the plating tank 1, which stirs the pressure liquid introduced into the plating tank 1, in the embodiment, liquefied carbon dioxide, and an electrolyte solution or acid solution containing a surfactant. It is possible.
[0021]
A gas container 8 filled with about 6 MPa of, for example, liquefied carbon dioxide 7, which is a pressurized medium or a pressurized substance, outside the plating tank 1, and an electrolyte solution tank 11 containing different types of electrolyte solutions 9 and 10. 12, an acid solution tank 14 containing an acid solution 13 having a pH of 7 or less, a storage tank 16 containing liquefied carbon dioxide 15 after use, an acid solution 17 containing a surfactant after use, or after use A plurality of reservoirs 20 to 22, which are electrolyte reservoirs 18 and 19 containing the surfactant, are disposed.
[0022]
In this case, the pressurized substance or medium may be either liquid or gas, but harmless, safe and chemically stable carbon dioxide is preferred when the solvent for dissolving the electrolyte solutions 9 and 10 is water. However, the pressurized liquid of the present invention can include any liquid that is insoluble in the electrolyte solution.
[0023]
In addition, as other pressurized substances, gases such as nitrogen and argon, spindle oils not mixed with the electrolyte solutions 9 and 10, fats and oils such as hexane, benzene and toluene, and halogenated hydrocarbons such as chloroform are used. Can do. When the solvent is an organic electrolyte such as propylene carbonate, acetonylyl, polyethylene oxide, etc., gases that do not react with these solvents, various pressure substances that phase separate and ions do not migrate to the phase, etc. Can be used.
[0024]
Furthermore, the pressurizing substance or pressurizing medium can be used by mixing a plurality of kinds of liquids or gases. For example, by adopting a substance having a low liquefaction pressure, the strength of the plating tank 1 can be reduced. Can be manufactured at low cost.
[0025]
These liquid storage tanks 20 to 22 are connected to return pipes 49 to 51 communicating with the respective solution tanks 11, 12, and 14 to separate or separate the used solutions 17 to 19 from the surfactant. Without being adjusted to a slightly higher concentration and regenerated, it is refluxed to each of the solution tanks 11-13.
[0026]
The gas container 8 communicates with the upper part of the plating tank 1 through a conduit 23, and a compression pump 24 and a pressure regulating valve 25, which are pressure pumps, are inserted into the pipe 23.
The compression pump 24 can pressurize the carbon dioxide 7 to a predetermined pressure, and in the embodiment, the carbon dioxide 7 can be pressurized to 1 to 8 MPa.
[0027]
The carbon dioxide 7 is subjected to various treatment steps of plating work in a pressurized and liquefied state, that is, before each treatment of degreasing treatment, oxide film removal, so-called pickling treatment, plating treatment, and drying after plating treatment. During the cleaning process of the plating tank 1 and the cathode 4 executed in the meantime, it can be introduced into the plating tank 1.
[0028]
A heating means 26 such as a heater is disposed on the downstream side of the conduit 23 so that the pressure liquid carbon dioxide 7 can be heated to 0 to 31 ° C. below its critical temperature during the plating process.
The tanks 11 to 13 communicate with the lower part of the plating tank 1 through conduits 27 to 29, and valves 30 to 32 and a common liquid feed pump 33 are inserted into the pipes 27 to 29.
[0029]
Among these, the valves 30 and 31 are opened for a predetermined time before the plating process, and the electrolyte solutions 9 and 10 containing a predetermined surfactant can be introduced into the plating tank 1 via the liquid feed pump 33. .
The valve 32 is opened for a certain period of time before pickling so that an acid solution 13 containing a predetermined surfactant can be introduced into the plating tank 1 via a liquid feed pump 33.
[0030]
In the figure, 34 to 36 are surfactants to be added to the electrolyte solutions 9 and 10 and the acid solution 13, and can be introduced through a pump (not shown) as appropriate when the solutions 9, 10, and 13 are supplied.
In this case, each density ratio of the liquefied carbon dioxide, the acid solution 13 and the electrolyte solutions 9 and 10 is set to 1: 5 to 5: 1 so that the emulsion can be made uniform by the surfactant. I have to.
[0031]
The storage tank 16 communicates with the upper part of the plating tank 1 through a conduit 37, and a valve 38 is inserted in the pipe 37. The valve 38 is opened for a certain period of time before each of the degreasing treatment, pickling, plating treatment, and drying treatment, and before washing of the object 4 to be treated, and the liquid carbon dioxide 15 after use is stored in the storage tank 16. It is possible to introduce to.
[0032]
In the figure, 39 is a return pipe having one end connected to the storage tank 16, the other end connected to the compression pump 24, and a column 40 capable of absorbing water and oil / fat is inserted into the pipe 39.
When a predetermined amount of carbon dioxide 15 is stored in the storage tank 16, the carbon dioxide 15 is guided to the column 40, impurities are removed, oxygen gas and hydrogen gas are reacted and removed, and a clean initial state is obtained. This is regenerated and can be returned to the compression pump 24.
[0033]
The liquid reservoirs 20 to 22 communicate with the lower part of the plating tank 1 through conduits 41 to 43, and valves 44 to 46 are inserted into these pipes 41 to 43, respectively.
Among these, the valve 44 is opened for a certain time after the cathode 4 is pickled, so that the pickling solution 17 after use can be introduced into the reservoir 20 together with the surfactant 36.
In addition, the valves 45 and 46 are opened for a certain time after each plating process, so that the used electrolyte solutions 18 and 19 can be introduced into the liquid reservoirs 21 and 22 together with the surfactants 34 and 35.
[0034]
In addition, 47 in the figure is a washing water tank inserted in parallel with the liquid feeding pump 33 and the conduits 27 to 29. After the solutions 9, 10, 13 are fed to the plating tank 1, the inside of the pump 33 can be washed. I have to.
Reference numeral 48 denotes an entrainer made of an organic solvent such as alcohol or hexane, which is selectively introduced into a conduit 23 between the gas container 8 and the compressor 24 so that persistent oils and fats can be degreased.
[0035]
The electrochemical reaction apparatus such as electroplating configured as described above is a multi-step process of pre-plating treatment, that is, degreasing, pickling, and cleaning, plating treatment, post-plating treatment, that is, recovery of the workpiece 4 and drying. Is performed in a single plating tank 1, compared to conventional plating methods and equipment that require a dedicated bath for each treatment, the structure is simple, the installation space is compact, and equipment costs are reduced. Can be planned.
[0036]
In addition, the apparatus of the present invention stores various discharges discharged from the degreasing, pickling, washing, and plating treatment drying operations, that is, pickling solutions containing liquefied carbon dioxide and surfactants, electrolyte solutions, and the like. In addition, it is discharged to a plurality of liquid storage tanks 20 to 22 to avoid the discharge to the outside, and this is rationally processed as described later, so that an expensive and large-scale waste water treatment facility as in the past is required. do not do.
[0037]
In addition, since each of the treatments is performed using diffusible pressure liquid carbon dioxide, the amount of acid solution or electrolyte solution used can be reduced compared to the conventional plating method in which an object to be treated is immersed in the plating solution. It is possible to reduce the size and weight of the discharge treatment facility.
[0038]
Furthermore, since the apparatus of the present invention uses liquid carbon dioxide that is harmless, safe and chemically stable as a pressurized liquid substance at low temperature and low pressure, compared with the case of electroplating in a supercritical state, the pressure means and heating The ability of the means can be reduced.
[0039]
In addition, since a general-purpose pressurizing pump 24 is used as the pressurizing means for the plating tank 1 and a large pressurizing device with a built-in piston is not required, the equipment can be reduced in size and weight, and the equipment cost can be reduced. -Reduces operating costs.
Therefore, the pressure strength can be reduced compared with the plating tank 1 in the low pressure and supercritical state, and this can be manufactured at low cost.
[0040]
When electroplating is performed using such an electrochemical reaction device, first, for example, on the negative electrode side of the plating tank 1 under the condition that the electrodes 3 and 4 are de-energized, the surface to be processed has been polished. The object 4 is attached, the lid (not shown) is closed, and the plating tank 1 is sealed.
[0041]
Next, the compression pump 24 is driven, the gas container 8 is opened, the liquefied carbon dioxide inside the container 8 is pressurized to a predetermined pressure as necessary, and this is heated by the heating means 26 to the plating tank 1. Introduce.
[0042]
The pressure carbon dioxide flows into the plating tank 1 and comes into contact with the object to be processed 4 in the tank 1 to efficiently remove oils and fats, moisture, foreign matters and the like adhering to the object 4 and the anode 3. Wash.
At this time, if the pressure carbon dioxide is stirred by operating the stirrer 6, the cleaning efficiency is improved, and the use of water and solution as in conventional emulsion cleaning is eliminated. Is encouraged to dry.
[0043]
As described above, since the object to be treated 4 is degreased and washed with the liquefied carbon dioxide-based material under pressure, the present invention uses a harmful degreasing agent as compared with the conventional method of immersing the object to be treated in the degreasing liquid. And improve the working environment, making this safe, quick and easy. Moreover, since the degreasing cleaning is performed in the plating tank 1, a dedicated degreasing tank as in the prior art is not required, and the equipment cost can be reduced accordingly.
[0044]
Then, after washing for a predetermined time, the valve 38 is opened, and instead, the valve 25 is closed and the driving of the compression pump 24 is stopped.
In this way, the liquefied carbon dioxide is guided to the conduit 37 and moves to the storage tank 16. This situation is as shown in FIG.
[0045]
Therefore, the oil and fat, moisture, foreign matter and the like collected in the liquefied carbon dioxide move to the storage tank 16, and a flow is generated in the system during the movement of the carbon dioxide, so that the anode 3 and the workpiece 4 are cleaned. In combination with the aforementioned cleaning, the cleaning accuracy is improved.
Thus, the valve 38 is closed after the used carbon dioxide 15 is discharged to the storage tank 16.
[0046]
Next, after the cleaning, the workpiece 4 is pickled.
At the time of this pickling, the valve 32 is opened while the energization is stopped and the plating tank 1 is airtight, and the acid solution 13 in the acid solution tank 14 is sent to the liquid feed pump 33, and at the same time, the acid solution 13 is poured into the acid solution 13. A predetermined surfactant 36 is added, and these are fed into the plating tank 1.
[0047]
The acid solution 13 and the surfactant 36 form two layers in the plating tank 1 as shown in FIG.
Under this situation, the compression pump 24 is driven, the gas container 8 is opened, the liquefied carbon dioxide in the container 8 is further pressurized to a predetermined pressure as necessary, and this is heated by the heating means 26, Introduce into the plating tank 1.
[0048]
Thus, when the liquefied carbon dioxide under pressure is guided to the plating tank 1, it rapidly mixes the acid solution 13 and the surfactant 36 to make them emulsion, and the fine particles come into contact with the surface of the workpiece 4. Then, rust is removed from the surface of the workpiece 4 to remove the oxide film and activate the surface.
This situation is as shown in FIG. 3 (b). At this time, the stirrer 6 is operated and the emulsion substance is stirred, so that the diffusion is made uniform, the oxide film is removed uniformly and efficiently, and pickling is performed. Efficiency is improved.
[0049]
Then, after pickling for a predetermined time, when the valve 44 is opened, the carbon dioxide is depressurized, the emulsion state disappears, and the acid solution 13 and the surfactant 36 after use are put into the plating tank 1. The layer state is restored.
In this case, since the specific gravity of the acid solution 13 and the surfactant 36 is larger than that of liquefied carbon dioxide, their two-layer state is formed below the liquefied carbon dioxide. This situation is as shown in FIG.
[0050]
Meanwhile, liquefied carbon dioxide under pressure is introduced into the plating tank 1 from the valve 25, and the used acid solution 13 and the surfactant 36 are pushed out by the pressure, and this is led to the conduit 41 to the liquid reservoir 20. Moved and housed. This situation is as shown in FIG.
[0051]
As described above, since the present invention removes the oxide film of the object 4 to be treated with liquefied carbon dioxide under pressure, the use of an acid solution compared to the conventional pickling method in which the object to be treated is immersed in an acid solution. The amount can be reduced and this can be done quickly and easily.
Further, since pickling is performed in the plating tank 1, a dedicated pickling tank as in the prior art is not required, and the equipment cost can be reduced correspondingly.
[0052]
Thus, when the acid solution 17 is completely discharged, the valve 44 is closed, and the valve 38 is opened instead. The used liquefied carbon dioxide in the plating tank 1 is converted into carbon dioxide under the introduction. Extruded, guided to the conduit 37, moved to the storage tank 15, and accommodated.
[0053]
At that time, when the carbon dioxide moves, a flow is generated in the system, and the anode 3 and the workpiece 4 are cleaned.
In this case, the discharge order of the acid solution 17 and the liquefied carbon dioxide after use may be reversed from that described above. However, if it is performed as described above, both can be discharged rationally and efficiently with high precision.
[0054]
Then, after discharging the used carbon dioxide, the valve 38 is closed, and pressurized and heated liquefied carbon dioxide 7 is introduced into the plating tank 1.
If it does in this way, the inside of the plating tank 1 will be pressurized and heated, this carbon dioxide will contact the to-be-processed object 4, and the water | moisture content adhering to this to-be-processed object 4 and the anode 3 will be wash | cleaned quickly and efficiently. .
At that time, if the stirring bar 6 is operated to stir carbon dioxide, the diffusion is promoted and the cleaning efficiency is improved.
[0055]
After cleaning and drying the workpiece 4, the compression pump 24 is stopped, the pressure regulating valve 25 is closed, the introduction of liquefied carbon dioxide is stopped, and the valve 38 is opened instead. The liquefied carbon dioxide is guided to the conduit 37 and stored in the storage 16.
At that time, when the carbon dioxide moves, a flow is generated in the system, and the anode 3 and the workpiece 4 are cleaned.
Therefore, various pretreatments are finished in the plating tank 1 and the dried object 4 is placed.
[0056]
Under such circumstances, the valve 30 or 31, in this example, the valve 30 is opened, and the electrolyte solution 9 in the electrolyte solution tank 11 is sent to the liquid feed pump 33, and at the same time, a predetermined surfactant 34 is added to the solution 9. These are fed into the plating tank 1.
[0057]
The electrolyte solution 9 and the surfactant 34 form two layers in the plating tank 1 as shown in FIG.
Under this condition, the gas container 8 is opened, the compression pump 24 is driven, and the liquefied carbon dioxide 7 in the gas container 8 is appropriately pressurized (1 to 8 MPa), and this is heated to heat the plating tank 1. To introduce.
[0058]
Thus, when the pressurized liquefied carbon dioxide is led to the plating tank 1, it is rapidly mixed with the electrolyte solution 9 and the surfactant 34 to become emulsion, and the fine particles diffuse into the plating tank 1 with high density. And contacts the surface of the workpiece 4.
[0059]
When the switch 5 is closed under this condition and the anode 3 and the cathode 4 are energized, the pure nickel as the anode piece is electrolyzed and deposited on the emulsified electrolyte solution 9, which adheres to the surface of the workpiece 4. To do.
At that time, the stirrer 6 is operated to stir the emulsion substance so that the electrolytic nickel ions are evenly distributed and adhered to the surface of the object 4 to be treated. This situation is as shown in FIG.
[0060]
In this case, since the electrolytic nickel ions are electrolyzed, deposited and adhered in the plating tank 1 under pressure, the electrolytic nickel ions are quickly diffused and uniformly distributed in the plating tank 1 to be treated. It adheres to the front and back surfaces of the object 4.
Therefore, compared with the conventional plating method in which the anode material is electrolyzed, deposited and adhered in an electrolyte solution at normal pressure, so-called plating is better, and a uniform and dense nickel film is formed on the front and back surfaces of the object 4 to be processed. And a good finished surface can be obtained.
[0061]
For this reason, unlike the conventional plating method, there is no hassle to separate the plating of the front surface and the back surface of the object to be processed 4 and the productivity can be improved correspondingly, and even when the object to be processed 4 has a complicated shape, This can be done easily without requiring an auxiliary electrode.
[0062]
On the other hand, during such a plating process, hydrogen gas or oxygen gas is generated by electrolysis of the electrolyte solution 13, that is, water, and the bubbles stay on the surface of the workpiece 4, or the workpiece 4 is processed by the stirring. There is a risk of moving the surface to cause missing plating or uneven plating.
[0063]
At the time of electrolysis of the electrolyte solution 13 or water, the volume changes from a small volume of liquid to a large volume in a gas state. However, under the pressure of pressurizing the inside of the plating tank 1 with liquefied carbon dioxide as in the embodiment, the reaction Shifts in the direction of small volume and suppresses the electrolysis.
For this reason, generation | occurrence | production of hydrogen gas and oxygen gas is suppressed, those bubbles retain on the surface of the to-be-processed object 4, the situation which moves is suppressed, and the plating defect by this and plating unevenness are prevented.
[0064]
In addition, the gas and oxygen gas have high solubility in the electrolyte solution 9 under the pressure as described above. Therefore, the amount of the gas or oxygen gas that adheres to and stays on the surface of the object to be processed 4 is reduced. To prevent plating defects and uneven plating.
[0065]
In addition, under the pressure as described above, the bubbles of hydrogen gas and oxygen gas are compressed and refined or crushed, so that the surface of the workpiece 4 is denser than the conventional plating method performed under atmospheric pressure. In addition, a uniform and thin plating film can be obtained, and the plating solution enters the details of the workpiece 4 so that the through hole can be easily plated.
Therefore, even if the amount of the plating metal or electrodeposition material to be used is reduced with respect to the object to be plated, the same plating as before can be obtained, which is particularly advantageous for the plating of noble metal.
[0066]
Further, since the generated gas is miniaturized as described above, the surfactant works efficiently, and the generated gas adhering to the surface of the object to be processed 4 is quickly peeled off to promote dissolution in the electrolyte solution 9. Together, it prevents plating defects and uneven plating.
[0067]
On the other hand, as described above, the present invention suppresses electrolysis of water at the time of plating, thereby reducing the electric energy consumption and using it for plating and electrodeposition, so that the current efficiency is improved.
In addition, when the plating tank 1 is pressurized, the liquid inside is compressed, the ion concentration per unit volume is increased, and the electrical resistance value thereof is decreased. In turn, it improves current efficiency.
[0068]
And even if the inside of the plating tank 1 is pressurized in this way and the electrolysis of water is suppressed, there is no hindrance to the electrochemical reaction of the plating, rather the current efficiency is improved, and a thin and good plating can be obtained. .
[0069]
FIG. 8 shows the scope of application of the present invention, in which electroplating is performed in the plating tank 1 in a milky state under a liquid phase at a lower temperature and lower pressure than in the supercritical state.
Therefore, it is possible to reduce the capacity of the pressurizing means and the heating means from the supercritical state, to reduce the equipment size and weight and to reduce the equipment cost, and to save energy and reduce the operating cost.
Further, before and after electroplating, supply and discharge of liquefied carbon dioxide realizes discharge of various solutions after the pretreatment process and use, and cleaning and drying of the plating tank 1, the workpiece 4 and the electrode 3.
[0070]
Various characteristics of electroplating according to the present invention are as shown in FIGS.
Of these, FIG. 9 compares the amount of plating deposited when liquefied carbon dioxide is pressurized and electroplated with the amount of plating deposited in the supercritical state, and is comparable to plating in the supercritical state. Show. In addition, since the current efficiency according to the present invention is improved as described later, the plating is efficiently deposited.
[0071]
FIG. 10 compares the current efficiency with respect to the electrolyte solution when electroplating by pressurizing liquid carbon dioxide with that of supercritical carbon dioxide, which is generally inferior to the supercritical state. It was confirmed to be superior to the method.
[0072]
Thus, after the plating process is completed, when the switch 5 is turned off, the stirrer 6 is stopped and the valve 45 is opened, the carbon dioxide is depressurized, the emulsion state disappears, and the electrolyte solution 10 and the surface activity. The agent 34 recovers the two-layer state. This situation is as shown in FIG.
[0073]
Thereafter, the valve 45 is opened, and the used electrolyte solution 18 is pushed out from the plating tank 1 together with the surfactant 34, and is led to the reservoir tank 21 through the conduit 42 and accommodated. Then, the electrolyte solution 18 is discharged. After that, the valve 45 is closed, and the valve 38 is opened instead to push out the used liquefied carbon dioxide from the plating tank 1 and lead it from the conduit 37 to the gas tank 16 to be accommodated.
At that time, when the carbon dioxide moves, a flow is generated in the system, and the anode 3 and the workpiece 4 are cleaned.
[0074]
Thus, after discharging the used carbon dioxide, the valve 38 is closed and the liquefied carbon dioxide 7 is introduced into the plating tank 1.
If it does in this way, the said carbon dioxide will contact the to-be-processed object 4, and will wash | clean the water | moisture content adhering to this to-be-processed object 4 and the anode 3 efficiently.
At this time, if the stirrer 6 is operated to stir the liquefied carbon dioxide, the cleaning efficiency is improved.
[0075]
After cleaning and drying the object to be processed 4, the compression pump 24 is stopped and the valve 25 is closed, the introduction of liquefied carbon dioxide is stopped, the lid (not shown) of the plating tank 1 is opened, and the object after plating is processed. If the processed material 4 is taken out, a series of plating operations are completed.
[0076]
When a predetermined amount of used liquefied carbon dioxide is stored in the storage tank 16, an external valve is opened, and the used carbon dioxide is guided to the column 40 via the return pipe 39. It absorbs water and fats and oils in carbon dioxide, removes impurities, reacts with oxygen gas and hydrogen gas, regenerates to a clean initial state, returns to the compression pump 24 in a timely manner, and is reused.
Therefore, it is possible to eliminate the waste of releasing carbon dioxide after use into the atmosphere and to prevent deterioration of the working environment due to the release.
[0077]
Further, when a predetermined amount of the used acid solution 17 and the electrolyte solutions 18 and 19 are stored in the liquid storage tanks 20 to 22, they are separated from the surfactant mixed therein or prepared to a slightly high concentration without separation. After the regeneration, the solution is refluxed to the solution tanks 11, 12, and 14.
Accordingly, there is no troublesome complicated pumping back of the plating solution or the like after the collection of the workpiece 4 as in the prior art.
[0078]
In addition, when performing so-called overlap plating in which a plurality of plating layers are formed on the workpiece 4, the above-described pretreatment is performed without removing the workpiece 4 from the plating tank 1 after the completion of the first plating. Plating.
Therefore, unlike the conventional overplating, after the end of plating, the object to be processed 4 is taken out from the plating tank one by one, moved to each tank, and the pretreatment is not carried out, thereby improving the productivity.
[0079]
FIG. 11 shows another embodiment of the present invention, and the same reference numerals are used for components corresponding to the above-described embodiment.
FIG. 11 shows only the main part of the embodiment, and the supply and discharge of pressurized liquid carbon dioxide to each reaction bath 1 and 1a, the configuration of the storage part, the supply and discharge of various solutions, and the storage part. The configuration of is omitted in the drawing, and the relevant part is substantially the same as FIG.
[0080]
In this embodiment, a plurality of substantially identical reaction baths 1, 1 a, two in the embodiment are arranged side by side, these are communicated by conduits 52, 53, and valves 54, 55 are inserted into the conduits 52, 53. To do.
These reaction baths 1, 1 a can execute the same processing step, that is, a series of plating processing steps alternately in time, and a part of the series of plating processing steps in one reaction bath 1, for example, pretreatment In the other reaction bath 1a, the rest of the series of plating processes, for example, plating and post-processing are executed.
[0081]
That is, a part of the plating process for the object to be processed 4 is performed in one reaction bath 1, for example, pretreatment such as degreasing and pickling, and various gases and solutions after use are stored in the storage tank (not shown). To do.
In the other reaction bath 1a, the pretreatment step has already been completed and the plating process is performed, and the processed object 4 after the plating process is recovered, washed, and dried, and various gases and solutions after use are stored in the storage tank ( (Not shown).
This situation is like step 1. In this case, carbon dioxide for the reaction bath 1 a is introduced into the conduit 52 downstream from the valve 54.
[0082]
Next, in step 2, the reaction bath 1 has already finished the pretreatment process and executed the plating process, and the processed object 4 after the plating process is collected, washed and dried, and the various gases and solutions after use are stored in the above-mentioned manner. It accommodates in a tank (not shown).
On the other hand, in the reaction bath 1a, the plating process is finished, a new object 4 is attached, pretreatment such as degreasing and pickling of the object 4 is performed, and various gases and solutions after use are stored. It accommodates in a tank (not shown).
[0083]
As described above, in this embodiment, the entire plating process is independently performed in the plurality of reaction baths 1 and 1a to improve the productivity of a series of plating operations.
[0084]
In addition, the method of depositing and adhering the electrolyzed electrode material to the other electrode material as in the above-described embodiment can be applied in principle to the same electroforming and anodic oxide film forming methods, and the same effect as described above. Can be obtained.
In addition, the present invention can be applied to an electrolytic method in which an electrolytic substance and an electrode substance are accommodated in a reaction bath, one electrode substance is electrolyzed, and this is collected on the other electrode substance side. Therefore, it can be applied to, for example, electrolytic refining of metal, electrolytic extraction, electrolytic polishing, etc., and the same effect as described above can be obtained.
[0085]
【The invention's effect】
As described above, the present invention provides a reaction bath.A surfactant is added to and stirred, and the pressurized liquid and the electrolyte solution are emulsified and electrochemically reacted. Therefore, the surfactant is efficiently used against hydrogen gas and oxygen gas that are refined under pressure. Work, quickly peel off the gas from the surface to be treated, and quickly melt into the electrolyte solutionbe able to.
[0086]
The invention of claim 2 is the reaction bath.Since the pressurized liquid is introduced into the reaction bath and the electrode material is washed or the oxide film is removed before the electrochemical reaction in the step, the pretreatment with the pressurized liquid is executed and stabilized. An effective electrochemical reactionbe able to.
[0087]
Claim3In the invention of the present invention, an electrochemical reaction is caused in the reaction bath.After that, since the pressurized liquid is introduced into the reaction bath and the electrode material is washed or dried, the post-treatment with the pressurized liquid is performed to obtain the stability of the next electrochemical reaction. There is an effect.
[0088]
Claim4The invention ofAbout 1-7 by introducing liquefied carbon dioxide into the reaction bath . Since the pressure is increased to 3 MPa, the electrochemical reaction is realized at a pressure lower than the supercritical state, thereby saving energy, reducing the size and weight of the equipment, and reducing operating costs.Can.
[0089]
Claim5Invention to the reaction bathSurfactant is added so that it can be stirred, and the pressurized liquid and electrolyte solution are emulsified to enable electrochemical reaction. Therefore, the surface activity is reduced against hydrogen gas and oxygen gas refined under pressure. Make the agent work efficiently, quickly peel off the gas from the surface to be treated, and quickly melt it into the electrolyte solution.Can.
[0090]
Claim6The invention of the reaction bathBefore the electrochemical reaction in the above, the pressurized liquid is provided so as to be introduced into the reaction bath, the electrode material is washed, or the oxide film can be removed, so that the pretreatment with the pressurized liquid is performed, A stable electrochemical reaction can be realized.
[0091]
Claim7In the invention of the present invention, an electrochemical reaction is caused in the reaction bath.After that, since the pressurized liquid can be introduced into the reaction bath and the electrode material can be washed or dried, the post-treatment with the pressurized liquid is executed, and the stability of the next electrochemical reaction is improved. There is an effect to be obtained.
[0092]
Claim8The invention ofSince liquefied carbon dioxide was introduced into the reaction bath so that the pressure could be increased to about 1 to 7.3 MPa, the electrochemical reaction was realized in a lower pressure state than in the supercritical state, thereby saving energy and reducing the equipment. Reduces size and weight or reduces operating costsCan.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an embodiment of the present invention, in which a multi-step plating process is performed using a single reaction bath.
FIG. 2 is an explanatory view showing a degreasing and cleaning process of the plating process.
FIGS. 3A and 3B are explanatory views sequentially showing an oxide film removal and an object activation process in the plating process. FIGS.
FIG. 4 is an explanatory view showing an acid solution discharging and cleaning step of the plating treatment.
FIG. 5 is an explanatory view showing the steps of the plating process in order.
FIG. 6 is an explanatory view showing an electrolyte solution discharging and cleaning step of the plating process.
FIG. 7 is an explanatory view showing drying and cleaning steps of the plating process.
FIG. 8 is a phase diagram showing a range of application of the present invention to plating treatment.
FIG. 9 is a characteristic diagram showing the amount of plating deposited on an electrolyte solution when the present invention is plated using liquid carbon dioxide, and is compared with the amount of plating deposited using supercritical carbon dioxide.
FIG. 10 is a characteristic diagram showing the current efficiency with respect to the amount of the electrolyte solution when the present invention is plated using liquid carbon dioxide, and is compared with the current efficiency using supercritical carbon dioxide.
FIG. 11 is an explanatory view showing a main part of a second embodiment of the present invention, in which plating processing is performed using two reaction baths, respectively.
[Explanation of symbols]
1,1a Reaction bath
3 Electrode material (anode)
4 Electrode material (cathode)
9,11 Electrolyte solution
13 Acid solution (Oxide film removal solution)
16, 20-22 Reservoir
34-36 Surfactant

Claims (8)

It can accommodate reaction bath electrolyte material containing a cathode and an anode of the electrode material, pressurized by introducing a pressurized liquid to said reaction bath, electroplating for electrochemical reaction under a pressurized state of the reaction bath In the electrochemical treatment method, the surfactant is added to the reaction bath and stirred, and the pressurized liquid and the electrolyte solution are emulsified to cause an electrochemical reaction. Electrochemical processing methods such as plating. Prior to electrochemical reaction in the reaction bath, and introducing the pressurized liquid into the reaction bath, the electrode material is washed, or electrochemical treatment method of an electro-plating according to claim 1, wherein the removal of oxide film . After electrochemical reaction in the reaction bath, the pressure introducing pressure liquid into the reaction bath, the electrode material is washed, or electrochemical treatment method of an electro-plating according to claim 1 wherein the drying. The electrochemical treatment method such as electroplating according to any one of claims 1 to 3, wherein liquefied carbon dioxide is introduced into the reaction bath and pressurized to about 1 to 7.3 MPa . The cathode and anode electrode materials are accommodated in a reaction bath capable of accommodating an electrolyte, a pressurized liquid is introduced into the reaction bath so that pressurization is possible, and an electrochemical reaction is performed under the pressurized state of the reaction bath. In an electrochemical reaction apparatus such as electroplating that can be performed, a surfactant is added to the reaction bath so that it can be stirred, and the pressurized liquid and the electrolyte solution are emulsified to enable electrochemical reaction. Electrochemical reaction equipment such as electroplating, characterized by that. Before Ru is an electrochemical reaction in the reaction bath, the provided to be introduced pressurized liquid into the reaction bath, the electrode material is washed, or electroplating or the like removable to claims 5, wherein an oxide film Electrochemical reactor. After electrochemical reaction in said reaction bath, said pressure provided to be introduced pressure liquid into the reaction bath, the electrode material is washed, or dryable to claims 5 electrochemical reactions such as electroplating according apparatus. The electrochemical reaction apparatus such as electroplating according to any one of claims 5 to 7, wherein liquefied carbon dioxide is introduced into the reaction bath so as to be pressurized to about 1 to 7.3 MPa .

Images