JPH05279875A - Etching with alkaline ammonical etchant solution and device and method for reproducing the same etchant solution - Google Patents

Abstract

PURPOSE: To enable the continuous recovery of an active component of an etchant soln. by electrolyzing used etchant soln., thereby removing a metal.

CONSTITUTION: A copper metal is etched in an etching chamber 10 by the use of the alkaline ammonical etchant soln. Part of the etchant soln. having a reduced etching capability is introduced into an electrolyzer 30 from a waste etchant soln. vessel 20 to electrolytically treat this soln. The soln., in which the copper content is reduced and is activated by this treatment, is moved to a fresh etchant soln. storage tank 40 and is returned to the etching chamber 10. Oxygen and ammonia for maintaining the pH value of an etching bath for processing are added directly to the etching chamber 10. Oxygen and ammonia in a gaseous mixture generated in the elctrolytic stage are utilized, too. Further, pptd. nitrate is treated and removed in a crystal vessel 60.

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching bath for dissolving metals, and more particularly to an apparatus for regenerating an alkaline ammoniacal etching solution having reduced etching ability as a result of increased concentration of etched metal.

[0002]

Solutions for etching metals from the surface of substrates have found widespread use in various technical fields.
The most notable of these techniques is that the non-conductive surface of the copper cladding is patterned with a resist material to protect the selected portion of the underlying copper metal, which is then contacted with a copper etchant to remove the non-conductive material. The manufacture of a printed circuit that selectively removes copper from a protected area.

Although a wide variety of copper etchants are potentially useful in this type of process, consideration of undesired aggressiveness to other types of metals and materials, as well as consideration of the desired high copper etch rate, is commercially available. The critical etchant range is very narrow. The types of etchants that have been of late interest are alkali ammoniacal etchants, typically cupric sulfate, ammonium sulfate or similar non-halogen ammonium salts,
And the pH of the liquid is 8.0 to 10.0, preferably 8.5.
It is an aqueous solution consisting of ammonium hydroxide sufficient to adjust to 9.5. This type of solution has the advantage of not producing noticeable waste products which are difficult to treat, in contrast to the commercially widely used cupric chloride alkali ammoniacal etchants. is there. Disadvantageously,
Although these cupric sulphate containing solutions give copper dissolution rates only about 1/3 of the dissolution rates found for cupric chloride containing solutions, this problem sacrifices other advantages of the etchant. It was overcome by the improvements shown in U.S. Pat. No. 4,784,785 which described the use of additives which greatly increased the etch rate without.

During the course of etching operations using these solutions, the solutions become more efficient as the active components are consumed or transformed (eg Cu ⁺² → Cu ⁺¹ ) and the concentration of the etched metal increases. Becomes progressively smaller. It has been proposed that these solutions can be regenerated by electrolytic removal of the etched metal and oxidation of the resulting liquid (eg oxidation with air or oxygen containing gas). See, for example, U.S. Pat. Nos. 4,557,811 and 4,564,428. However, in practice, the apparatus and method proposed in this respect are inadequate in many respects, in particular in that they do not achieve a constant steady state etching efficiency throughout the method.

[0005]

The problem to be solved is to maintain an appropriate etching efficiency by carrying out the recovery of the active component of the etching solution and the removal of the etched metal from the etching solution in a continuous or semi-continuous manner. Thus, there is provided an apparatus and method for effectively etching copper from the surface of a substrate using an alkaline ammoniacal etchant.

[0006]

According to the present invention, an alkaline ammoniacal etching liquid for processing used for etching copper in an etching chamber is used as a "waste etching liquid" from the etching chamber.
As a result of copper etching, the waste etching solution is collected and transferred to a waste etching solution collection or storage container; the waste etching solution from the waste etching storage container is extracted into an electrolytic cell to electrolyze the waste etching solution. At least a portion of the etched metal (eg, copper) contained in the electrolytic cell is removed from the electrolytic cell in the form of elemental metal that has been extruded at the cathode; thus treated waste copper etchant having a reduced copper content is removed. The "fresh etching solution" is extracted from the electrolytic cell and transferred to a fresh etching solution collection or storage container; and the fresh etching solution is extracted from the fresh etching storage container and transferred to the etching chamber, and processing alkaline ammonia in the etching chamber is used. A reactive etchant; a device and method are provided.

[0007]

DETAILED DESCRIPTION OF THE INVENTION As part of a regeneration process, an oxygen-containing gas is used to oxidize cuprous to cupric and ammonia is used to maintain the proper pH of the working etchant. These rejuvenating additives can be used at any one or more stages in the total etching and rejuvenation system. In a preferred embodiment of the present invention, oxygen and ammonia, for example, are at least periodically supplied to an etching chamber containing an alkaline ammoniacal etching liquid for processing to provide a suitable pH.
And the formation of cuprous metal by the reaction of the cuprous metal formed during the etching (ie, the cupric metal of the working etchant with the metallic copper to be etched; where the metal is oxidized (Cu ⁰ → Cu ⁺¹ ), Cupric is reduced (Cu ⁺²
→ Cu ⁺¹ )) is oxidized and returns to the (Cu ⁺² ) state.
Once a portion of this working etchant is withdrawn as waste etchant (with reduced etching capacity due to copper oxide buildup), it is then treated in the electrolytic cell (reduction to copper metal at the cathode). Its copper ion content is reduced. In this electrolytic treatment, oxygen and ammonia are also released, and cuprous ions are still present in the electrolyzed solution. From this point, the electrolyzed etchant is transferred to the fresh etchant reservoir and from there into the etching chamber, without the addition of ammonia and / or oxygen,
Can be transferred. This depends on the fact that in the etching chamber, the necessary addition of these gases to the total processing etchant takes place when necessary. However, as an alternative, the addition of oxygen and / or ammonia can also be carried out to the electrolyzed etching solution before it is transferred to the etching chamber. For example, the addition of oxygen and / or ammonia may be carried out in a fresh etchant reservoir
And / or at a point during transfer to or from the storage container.

In this most preferred embodiment, at least part of the oxygen and / or ammonia additions made during any of the steps of the process can utilize the gas evolved during electrolysis as their source.

Additives used during alkaline ammoniacal etching as etch rate enhancers, such as small amounts of ammonium halides, water soluble anions containing S, Se or Te, organic thio compounds, and, optionally, those described in the aforementioned US patents. The water-soluble noble metal salts, as described above, are generally not regenerated by themselves in this way, and thus to the working etching solution used in the etching chamber and / or to the fresh etching liquid before being transferred to the etching chamber, Directly metered periodically or continuously.

In the course of this method, during the electrolytic treatment,
In particular, nitrate may be formed during the electrolytic treatment when a chloride-containing rate-increasing additive is used in an alkaline ammoniacal etching solution. These nitrates all have limited solubility in alkaline ammoniacal etchants, and due to the tightness of the overall etch and regenerator system, nitrates should be at a reasonably low concentration (ie below the saturation concentration at the temperature of interest). If not maintained, the entire process precipitates and progressively accumulates in the system as it continues through the etching and regeneration steps.In a preferred embodiment of the invention, the step of removing these nitrates from the system is performed. These steps are performed by withdrawing the etchant from an appropriate stage in the overall process (eg from the etching chamber or waste etchant reservoir or fresh etchant) and treating this withdrawal portion to determine its nitrate content. Is eliminated (at least by crystallization) or at least reduced and then treated in this way In a preferred embodiment, the required degree of nitrate reduction is achieved by at least a periodic step of a portion of the working alkaline ammoniacal etchant withdrawn from the etch chamber. It is done by processing.

The apparatus and method according to the present invention is ultimately designed to keep the alkaline ammoniacal etchant at a substantially constant composition, preferably one that ensures efficient and rapid etching. In this way, a high degree of reliable compatibility is inherent in this method used for etching large amounts of copper clad substrates. Therefore,
The dwell time established for a particular substrate with a nearly uniform amount of copper to be etched makes one too worried about the compositional changes of the etchant that may lead to inadequate etching at this predetermined time. It can be reliably applied throughout the entire process of etching a large number of such substrates, without needing to do so. At the same time, of course, efficient regeneration of the etchant generally results in improved process economics.

In known regeneration methods, the limited ability of a particular operation, as a function of the amount of solution to be treated and / or the time required to complete such treatment, is often processed. It results in a wide fluctuation of the composition of the etching solution, and thus of its etching rate at a given time over the course of the whole process.
In contrast, in the present invention, the apparatus and method are such that withdrawal from the etchant for regeneration and replenishment occurs at regular periodic intervals or continuously, thereby maintaining a substantially constant etchant composition. It is designed and arranged to be It also allows the storage of waste etchant and storage of fresh liquor by the use of these liquors, thus allowing the regeneration to take place substantially independently of the etching.

The apparatus and method of the present invention may be combined with sensors for on-stream measurement of appropriate system parameters (eg pH, dissolved oxygen, specific gravity, level sensors, etc.), and as needed for these measurement characteristics. It is preferable to operate in combination with an accompanying control device that responds with.

[0014]

The present invention will be described in detail with reference to the accompanying FIG. As mentioned above, the apparatus and method of the present invention relates to an alkaline ammoniacal etchant used for copper etching, in particular its non-halogenated copper and ammonium salts containing oxygen in the anionic form, such as cupric sulfate and ammonium sulfate. It applies to such etchants, especially those containing etch rate enhancing additives such as those shown in US Pat. No. 4,784,785.

The terms "waste etching solution" and "regeneration of waste etching solution" as used in the present invention mean a true "waste" etching solution in the sense that all the ability to etch copper has been lost. is not. Rather, this term is used to facilitate the description of alkaline ammoniacal etchants that have been used to etch copper, resulting in reduced active etching components and increased concentrations of etched material (in the form of copper salts). It is something.

Referring to FIG. 1, a working alkaline ammoniacal etchant is contacted in an etching chamber 10 with a substrate to be etched. The etching method can be a dip etching method. In this case,
The substrate is immersed in the working etching bath in a suitable container. Alternatively, the etching method can be a spray etching method, in which case the etching liquid is supplied to a suitable spraying device (not shown) housed in a container of suitable size, sprayed onto the substrate, and The spray liquid flowing out is collected. It is possible to provide a facility for circulating the flowing out etching solution and returning it to the spraying device in the etching chamber 10. Typically, the etching method is carried out at a processing bath temperature in the range of room temperature to 130 ° F.

A predetermined portion of the etching liquid for processing in the etching chamber 10 is withdrawn as a waste etching liquid from there (for example by a pump 16) to a line 15 and sent to a waste etching liquid storage tank (20) for accumulation. It is then withdrawn for further processing if necessary. That is, a part of the waste etching liquid from the waste etching liquid storage tank 20 is extracted from there (for example, via the pump 26) to the line 25 and sent to the electrolytic cell 30. The electrolytic cell 30 includes an anode and a cathode connected to a rectifier, and is operated at a current density effective for depositing at least a part of etched metal (copper) contained in the waste etching solution on the cathode in a metal state or It can be a parallel set of containers. Oxygen and ammonia are released during electrolysis which keeps a suitable pH (e.g. 8-10) for evacuation and oxidation of cuprous to cupric as described below and in the etching bath. For use in other stages of the process.

Further, as described above, nitrate may be generated during the electrolytic operation, particularly during the electrolytic operation when the chloride-containing etching rate increasing additive is added to the processing etching bath. Such nitrates are treated as described below.

The fresh etchant from the now-depleted electrolytically depleted electrolytic cell 30 is withdrawn in line 35 (eg, via pump 36) to a fresh etchant reservoir 40 until needed. Stored.

From the fresh etching reservoir 40, fresh etching liquid (eg, via pump 46) is fed into line 4
It is taken out to the etching chamber 10 through 5 and mixed there with an alkaline ammoniacal etching liquid for processing.

In the etching and regeneration method, cuprous oxygen (either itself or an oxygen-containing gas) is used for the cupric ions required in the processing alkaline ammoniacal etching solution, and the etching bath for processing is used. pH
It is necessary to use ammonia to keep the.
As shown in FIG. 1, oxygen and ammonia are removed from the etching chamber 1
0 is added directly to the processing etchant. This addition is supplied, for example, through a porous membrane tube placed inside or by source lines 101 and 102, respectively. In this way, the corresponding depletion of cuprous ions produced in the oxidation of the etched copper metal and cupric ions in the working etching solution is wholly or partly oxidized to the desired Cu ⁺² state, And an appropriate operating pH is maintained in the etching solution for processing. Alternatively, or in addition to the direct supply of oxygen and ammonia to the liquid in the etching chamber, at least a part of the etching liquid for processing (other than the portion extracted as the waste etching liquid) is removed from the etching chamber 10. It can be withdrawn periodically, optionally treated with oxygen and / or ammonia in another withdrawal vessel and returned to the working etching bath of the etching chamber 10.

When the system is operated as described above, it is processed through the waste etching liquid withdrawn from the etching chamber 10, that is, the waste etching liquid storage tank 20, the electrolytic cell 30, and the fresh etching liquid storage tank. The etchant returning to 10 does not necessarily have to be treated with oxygen or ammonia before returning to the etching chamber 10. That is, the cupric ion and / or ammonia deficiency present in the waste etching liquid treated in this way should be easily handled in the process of the processing etching liquid, a part of which is part of the treated waste etching liquid. You can Nevertheless, it is still desirable to treat the waste etchant with oxygen and / or ammonia after electrolysis and at a point before it returns to the etching chamber 10 for mixing with the working etchant. sell. For this purpose, a convenient location for such processing is in the fresh etchant reservoir 40. There, fresh etchant can optionally be mixed with ammonia and / or oxygen (indicated by 42 in the figure). In fact, the means for making these additions may be to deliver the electrolyzed gas (oxygen, ammonia) directly into the fresh etchant contained in the fresh etchant reservoir 40 (eg via line 43), or Alternatively or additionally, oxygen and / or ammonia may be added to the fresh etching storage container 40 by other alternative means (eg, porous tube 42).

Alternatively or in addition to the above, the fresh etchant from the electrolysis process may contain oxygen and oxygen in a separate bath before it is fed to the fresh etchant reservoir 40 or after leaving the reservoir 40. And / or can be treated with ammonia. In any case, especially if a fresh etchant is done after leaving its storage,
Using the same location, oxygen and / or ammonia can be sent to the portion of the etching liquid for processing that has been withdrawn from the etching chamber 10 for processing, and a facility for returning this to the etching chamber can be prepared as described above.

As described above, all or part of the mixed gas generated in the electrolysis process can be directly sent to the etching chamber 10 to supply oxygen and / or ammonia to the etching liquid for processing.

As mentioned above, copper nitrate and / or ammonium nitrate or complexes thereof may form as a result of the electrolytic treatment of the waste etchant, and chloride-containing etch rate enhancing additives may be added to the alkaline ammoniacal etchant for processing. The trend seems to be more pronounced when used inside. These nitrates will eventually saturate in the etching chamber 10 (or other equipment) if accumulation is allowed throughout the entire process of etching and regeneration and if the overall system is substantially closed. Precipitation occurs above the level, which creates the problem of obstructing and / or blocking the equipment containing the etchant, as well as the need to interrupt the operation to remove the solids due to the accumulation of solids. In a preferred embodiment of the invention, means are provided for eliminating or at least reducing the content of these nitrates in one or more stages of the overall system.

Preferably, the means for removing these nitrates is crystallization and further crystallization of a part of the etching liquid for processing which is withdrawn from the etching chamber 10 at least periodically. For this purpose, the crystallization tank 60 is used to bring the portion of the etching liquid for processing, which is withdrawn from the etching chamber 10 through the line 64, to a temperature at which the solubility of nitrate is reduced as compared with that in the etching liquid for processing. Cool down
This causes at least some of the nitrate in the crystallizer to precipitate as a solid. The etching solution, which is now reduced in nitrate content after being treated in this way, is returned to the etching chamber 10 as a processing etching solution through the line 65 and mixed with the etching solution having a temperature higher than that of the crystallization tank to solubilize the nitrate. Increase, thereby eliminating nitrate precipitation in the etching chamber 10. The crystallizer 60 is of any capacity, efficiency and cooling coil area, as long as it is sufficient to cause the required temperature drop for the amount of etchant required to withdraw from the etching chamber 10 and keep the nitrate below saturation. It can be of any suitable type or construction.

Alternatively, or in addition to the above,
Nitrate removal can be accomplished by treatment of other solutions in the process, such as waste etchant or fresh etchant withdrawn from each reservoir for such treatment.

In steady state operation, the apparatus is designed to maintain a relatively constant volume of processing etchant of relatively constant composition in the etching chamber 10, and can be readily automated to achieve this end. You can That is, certain process and composition parameters can be measured and suitable control / logic circuits that can operate in response can be used. As shown in the preferred embodiment of FIG. 1, the control unit 100 is mainly used to provide information on the specific gravity of the working etchant in the etching chamber 10 and a corresponding measure of the depletion of the active ingredient in the working bath. To understand as. Optionally, the control unit 100 understands, as additional information, information regarding the amount and specific gravity of the waste etching liquid extracted from the etching chamber 10 via the line 15 to determine the amount of copper and the active component of the copper etched by the processing etching liquid. Can be used to indicate exhaustion.

Control unit 1 for non-renewable additives
The information provided in 00 can be used to activate the hump transfer member (pump 12 shown in FIG. 1) into the etching chamber 10 with an appropriate amount of fresh additive, if desired.
Control unit 1 for major regenerative active ingredients of the device
00 is used to activate the transfer member which picks up an appropriate amount of fresh etchant from the fresh etchant reservoir 40 to replenish the working etchant. At the same time, a substantially equal volume of the etching liquid for processing (as waste etching liquid) is withdrawn from the etching chamber 10 into the waste etching storage tank 20 by overflow or pumping.

A portion of the waste etchant in reservoir 20 can spill into electrolyzer 30 and then into fresh etch reservoir 40 (and heat if necessary) to pit. The waste etchant in the electrolytic cell 30 is monitored by specific gravity and / or ampere hours and / or residence time to determine the time at which a sufficient amount of etched copper has been removed therefrom and deposited on the cathode in the form of metallic copper. can do. The information is understood by the controller 200. The controller 200 responsively operates the moving member that humps the thus treated solution into the fresh etching solution storage tank to reactivate the electrolytic cell from the waste etching solution storage tank 20 (through the pump 26) with a large amount of the waste etching solution. See

Additional controls can be used in this device. The most notable control is the control that understands the information from the pH and dissolved oxygen readings and activates and regulates the addition of ammonia (eg anhydrous ammonia) and oxygen in response.

Also, of course, various storage tanks (eg storage tanks for waste etching solution and / or fresh etching solution).
Can be equipped with a stirrer if desired or necessary,
And / or a member for extracting and circulating the liquid may be provided as a stirring means or a means for keeping the movement of the solution.

[0033]

In general, the apparatus of the present invention provides that the addition of the replenished etchant from the fresh etchant reservoir 40 corresponds to the withdrawal of the waste etchant and the regeneration of the waste etchant. It is best operated as a triggering supply and discharge system. However, an important feature of the present invention is that regeneration is continued and independent of the etching process, fresh etchant is stored and retained in the reservoir 40, and waste etchant is correspondingly retained in the reservoir 20. It is in the point of being extracted from. The use of both waste etchant and fresh etchant reservoirs allows the apparatus of the present invention to be substantially free of limitations in this regard due to capacity and / or flow limited processes (eg electrolysis of waste etchant). Are arranged to be able to respond to even periodic refill and withdrawal requests.

[Brief description of drawings]

FIG. 1 is an explanatory diagram outlining a preferred embodiment of the apparatus and method of the present invention.

[Explanation of symbols]

 10 etching chamber 20 waste etching liquid storage tank 30 electrolysis tank 40 fresh etching liquid storage tank 60 crystallizing tank 100 control unit

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Claims (15)

[Claims] 1. A method of etching copper metal and regenerating the etching solution with a processing alkaline ammoniacal etching solution containing a halogen-free cupric acid and an ammonium salt and having a pH in the range of 8.0 to 10.0. Then, the following steps are performed: (a) etching copper metal with the alkaline ammoniacal etching solution for processing in the etching chamber; (b) etching ability compared to the desired etching capacity and concentration of the etching solution for processing. At least a portion of the processing alkaline ammoniacal etching solution is removed from the etching chamber as a waste etching solution having a reduced concentration and an increased copper concentration that has been etched, and the waste etching solution is transferred to a collection container to accumulate the solution. c) Withdraw at least a part of the waste etching liquid from the waste etching liquid collection container, And to remove the concentration of the etched copper by electrolyzing a waste etching solution into the electrolytic cell having a cathode and depositing the etched copper as copper metal on the cathode; (d) the waste etching treated in step (c). The liquid is withdrawn as a fresh etching liquid having a reduced concentration of etched copper as compared to the etched copper in the waste etching liquid and transferred to a collecting container to accumulate the fresh etching liquid; (e) this fresh etching liquid At least a portion of the solution is transferred to the etching chamber as a working alkaline ammoniacal etching solution; and (f) the fresh etching solution and / or the working alkaline ammoniacal etching solution is added to the working alkaline ammoniacal etching solution. Sufficient oxygen and alkaline alkali ammonia for processing to maintain the desired level of cupric ion Wherein the consisting of various steps; provide sufficient ammonia to maintain the pH of the etching solution in the range of 8-10. 2. The method according to claim 1, wherein the supply of oxygen and ammonia in step (f) is carried out only to the working alkaline ammoniacal etching liquid. 3. The method of claim 1 wherein the oxygen and ammonia feeds of step (f) are provided to both the fresh etchant and the working alkaline ammoniacal etchant. 4. The method of claim 1, wherein the oxygen and ammonia feed of step (f) uses oxygen and ammonia generated at least in part in the electrolysis of step (c). 5. Nitrate is formed during the electrolysis of step (c),
The method of claim 1, wherein at least a portion of said nitrate is at least periodically removed from the working alkaline ammoniacal etchant and / or fresh etchant and / or waste etchant. 6. The method of claim 5, wherein the nitrate is removed by crystallization and precipitation of the nitrate from the etchant. 7. A part of the etching liquid for processing is extracted from the etching chamber separately from the part to be extracted as the waste etching liquid, and the other extraction member is subjected to low temperature treatment to separate the precipitated nitrate from the other extraction part, 7. The method according to claim 6, wherein the nitrate is removed from the working alkaline ammoniacal etching solution by returning the separated another extracted portion to the etching chamber. 8. A volume measuring portion of a processing alkaline ammoniacal etching liquid extracted as a waste etching liquid from the etching chamber is a volume measuring portion of a fresh etching liquid transferred to the etching chamber as a processing alkaline ammonia etching liquid. The method of claim 1 which substantially corresponds. 9. The method according to claim 8, wherein a part of the etching liquid for processing is withdrawn from the etching chamber as a waste etching liquid, and a fresh etching liquid is moved to the etching chamber as an alkaline liquid for processing. .. 10. An apparatus for etching copper metal with a processing alkaline ammoniacal etching solution having a pH in the range of 8.0 to 10.0 and containing non-halogen cupric and ammonium salts, and regenerating the etching solution. Therefore, the following elements are provided: (a) an etching chamber for etching a copper-containing substrate with a processing alkaline ammoniacal etching solution; (b) etching compared to a desired etching capacity and concentration of the processing etching solution. (C) A member for collecting at least a part of the etching liquid for processing as a waste etching liquid into the waste etching liquid collecting container; d) including an anode and a cathode, by depositing copper etched from an etching solution in the form of a metal on the cathode. An electrolytic bath adapted to be removed; (e) a member for extracting at least a part of the waste etching liquid from the waste etching liquid collection container into the electrolytic bath; (f) comparing the etched copper concentration in the waste etching liquid (G) A member for discharging at least a part of the waste etching liquid from the electrolytic cell as a fresh etching liquid to a fresh etching liquid collecting device; h) a member for moving the fresh etching liquid to the etching chamber as a processing etching liquid; and (i) at least a part of the fresh etching liquid or the processing etching liquid, with a second copper having a desired concentration in the processing etching liquid. A member for replenishing ions and a sufficient amount of oxygen and ammonia for maintaining a pH in the range of 8 to 10; And devices. 11. The apparatus of claim 10, further comprising a member for introducing an etch rate enhancing additive into the processing etchant to make up for the etch rate enhancing additive consumed in the etching. 12. A member for treating at least a part of one or more of a processing etching solution, a waste etching solution and a fresh etching solution to remove at least a part of the precipitating nitrate present therein. 11. The apparatus of claim 10 including. 13. The apparatus of claim 12, wherein the processing member for removing at least a portion of the precipitating nitrate comprises a crystallization member. 14. A member for detecting a predetermined increased concentration of etched copper in a working etching liquid and transferring a fresh etching liquid to the etching chamber as the working etching liquid, and at least a part of the working etching liquid. 11. The apparatus of claim 10, further comprising a control member for actuating a member that draws from the etching chamber as waste etchant. 15. A member for detecting a predetermined increase of etched copper in a waste etching solution in an electrolytic cell to extract at least a part of the waste etching solution as a fresh etching solution from the electrolytic cell and at least the waste etching solution. 11. The apparatus of claim 10, further comprising a control member for actuating a member that draws a portion of the waste etching collection container into the electrolytic cell.