CN117043395A

CN117043395A - Method for treating etching waste medium from circuit board and/or substrate manufacture

Info

Publication number: CN117043395A
Application number: CN202280017930.0A
Authority: CN
Inventors: 康斯坦丁·克恩; 安德烈亚斯·灿克尔; 海因茨·莫伊齐; 阿洛伊斯·雷德尔; 弗里德里希·格罗斯; 约兰塔·克洛采克; 马丁·施赖; 克里斯托夫·埃宾格尔
Original assignee: AT&S Austria Technologie und Systemtechnik AG
Current assignee: AT&S Austria Technologie und Systemtechnik AG
Priority date: 2021-03-02
Filing date: 2022-03-01
Publication date: 2023-11-10
Also published as: TWI823276B; JP2024507957A; TW202244009A; WO2022184688A1

Abstract

There is provided a method of treating an etching waste medium from circuit board and/or substrate manufacturing, the method comprising: i) Providing the etching waste medium as a medium (11) to be treated, in particular a medium (11) to be treated from an etching treatment (150), the medium (11) to be treated comprising a metal salt to be treated and an acid (15); ii) treating the medium (11) to be treated in an ion exchange treatment (145) such that the metal salt to be treated is exchanged by a metal salt and a medium (10) containing a metal salt is obtained from the medium (11) to be treated; thus a) flowing a first treatment cycle (170) through the ion exchange treatment (145), wherein the first treatment cycle (170) is a first closed loop producing substantially only elemental metal (50); and b) flowing a second treatment cycle (180) through the ion exchange treatment (140), wherein the second treatment cycle (180) is a second closed loop producing substantially only purified water (188) and/or lean metal salt concentrate (186 b).

Description

Method for treating etching waste medium from circuit board and/or substrate manufacture

Technical Field

The present invention relates to a method of treating an etching waste medium from the manufacture of circuit boards and/or substrates. Furthermore, the invention relates to a circuit board and/or substrate manufacturing plant configured to perform the method. Furthermore, the invention relates to a specific use of the ion exchange treatment.

The invention may thus be of relevance in the technical field of circuit board and/or substrate manufacturing. In particular, the invention may relate to the technical field of processing metal salt-containing media (particularly recovery metals) from circuit board and/or substrate manufacturing. Furthermore, the invention may relate to the technical field of recycling in the manufacture of circuit boards and/or substrates (in particular to the provision of waste water in the quality of the discharge).

Background

For the production of circuit boards and/or substrates, in principle a large amount of metals, in particular heavy metals (e.g. copper, nickel, gold, silver, palladium, tin, iron), is required. Thus, during the manufacturing process, the metal-containing residues and the metal-containing medium (in particular the solution) are present in different treatments, respectively.

The metal (salt) containing medium (and waste and residue concentrates to be treated, respectively) originates substantially from two different treatments in circuit board and/or substrate manufacturing: i) An etching process (e.g., etching copper foil) and ii) an electroplating process (e.g., copper plating). Furthermore, the metal (salt) -containing medium to be treated occurs during the rinse process from the etching process and from the electroplating process. These flushing water only contain low concentrations of metals, especially copper. Conversely, the metal (salt) -containing medium to be treated from the etching treatment and the electroplating treatment includes a relatively high concentration of metal.

The metal (salt) -containing medium to be treated from the etching treatment typically comprises a metal salt, wherein the metal is chemically bonded (e.g. copper chloride, wherein the chloride is derived from hydrochloric acid) to a salt of an acid (from the etching treatment). The metal (salt) -containing medium to be treated from the electroplating process also typically contains a metal salt, wherein the metal is chemically bonded to a salt of an electrolytic acid (e.g., copper sulfate, wherein the sulfate is derived from sulfuric acid). In addition, metal (salt) containing media from electroplating processes generally contain high concentrations of foreign metals, such as iron.

Methods for recovering metals from the described metal (-salt) -containing media are known per se. However, only the high purity form of the recycled metal (e.g., 99% to 99.99%, particularly about 99.9% purity) is significant for circuit board and/or substrate manufacturing. Such recovery may be performed, for example, by electrolysis. However, the above-mentioned metal (salt) containing media are highly unsuitable for this purpose, as the deposition of pure metals (e.g. copper) is hindered or complicated. High concentrations of acid, hydrogen peroxide (and foreign metals) can disable high quality electrolysis.

For this reason, waste concentrates produced from circuit boards and/or substrates are conventionally disposed in a cost-consuming, environmentally unfriendly and not durable manner, respectively.

Disclosure of Invention

It is an object of the present invention to enable cost-effective, environmentally friendly and durable treatment of waste media from circuit board and/or substrate manufacturing, especially from etching processes.

The object is solved by the subject matter according to the independent patent claims. Preferred embodiments are derived from the attached patent claims.

According to an exemplary embodiment of the present invention, a method of treating an etching (treatment) waste medium from circuit board and/or substrate manufacturing is provided. The method comprises the following steps:

i) Providing an etching waste medium as a medium to be treated (in particular from an etching process), wherein the medium to be treated comprises a metal salt and an acid to be treated,

ii) treating the medium to be treated in an ion exchange treatment such that the metal salt to be treated is exchanged by the metal salt and a medium containing the metal salt is obtained from the medium to be treated, thus

A first treatment cycle is flowed through the ion exchange treatment, wherein the first treatment cycle is a first (closed) loop that produces (substantially) only elemental metal (e.g., using an electrolytic treatment).

In particular, the method may further comprise flowing a second treatment cycle through the ion exchange treatment, wherein the second treatment cycle is a second (closed) loop that (substantially) only yields purified water and/or a lean metal salt concentrate (e.g. using a reverse osmosis treatment).

According to another exemplary embodiment of the present invention, there is provided a circuit board and/or substrate manufacturing factory, including:

i) An etching treatment module that produces an etching waste medium as a medium to be treated, wherein the medium to be treated includes a metal salt to be treated and an acid,

ii) an ion exchange treatment module configured to treat the medium to be treated such that the metal salt to be treated is exchanged by the metal salt, and the medium containing the metal salt is obtained from the medium to be treated,

iii) A first treatment cycle (e.g., implemented as a fluid delivery system via an electrolysis module) flowing through the ion exchange treatment module, wherein the first treatment cycle is a first closed loop that yields substantially only elemental metal, and

iv) a second treatment cycle (e.g., implemented as a fluid delivery system via a reverse osmosis module) flows through the ion exchange treatment, wherein the second treatment cycle is a second closed loop that yields substantially only purified water and/or lean metal salt concentrate.

According to yet another exemplary embodiment of the present invention, there is provided the use of an ion exchange process coupled to an electrolytic process in a first closed loop process cycle and to a membrane filtration process in a second closed loop process cycle to treat circuit board and/or substrate manufacturing etching wastewater such that (substantially) only elemental copper, purified water and/or a heavy metal salt depleted concentrate is produced.

According to a further exemplary embodiment of the present invention, a process control device for adjusting the above method and/or the above device is provided. The process control device includes:

i) For capturing at least one process parameter (and actual values, respectively) from a running process, in particular a database of a plurality of process parameters,

ii) a data model unit adapted to store at least one predetermined process parameter (and target values, respectively), in particular a plurality of predetermined process parameters, and iii) a computing device adapted to

a) Comparing the captured process parameters with predetermined process parameters (and a plurality of each other, respectively),

b) Determining a control operation based on the comparison result (e.g., actively compensating for a difference between an actual value and a target value), and c) performing a predetermined control operation (e.g., adjusting a flow rate, etc.).

According to yet another exemplary embodiment of the present invention, a computer program product for controlling a method of processing an etching waste medium from circuit board and/or substrate manufacturing is provided, which when executed by one person, controls a method (as described above) and/or an apparatus (as described above) and/or a process control apparatus (as described above).

In the context of the present application, the term "medium containing a metal salt" may particularly denote any (liquid) medium comprising a metal salt. Metal salts are compounds between a metal and an acid. Examples of such metals may include: copper, nickel, gold, silver, cobalt, cadmium, magnesium, sodium, palladium, tin. Examples of the acid may include: sulfuric acid, hydrochloric acid, nitrous acid, phosphoric acid; wherein the metal salt is present accordingly, such as for example a sulfate, chloride, nitrate or phosphate. Accordingly, the metal salt may be, for example, copper sulfate or copper chloride. This may be present as metal ions and salt ions in the medium containing the metal salt. In addition to the metal salt, the metal salt-containing medium may include, for example, an aqueous solution or an acidic solution in which the metal salt is dissolved. For example, the medium may include hydrochloric acid and/or sulfuric acid in addition to water. In one example, the metal salt-containing medium originates from the manufacture of circuit boards and/or substrates and may include corresponding residues. Furthermore, the medium containing the metal salt may be treated such that substantially only the metal salt is present. In one example, the metal salt-containing medium is (substantially) free of (undesired) foreign metals (e.g., iron). In another example, the metal salt-containing medium includes (residues of) the foreign metal. The term "medium to be treated" may denote a medium to be further treated in a subsequent treatment step. Thus, the medium to be treated may comprise a metal salt to be treated (e.g. the salt is to be exchanged by another salt), and the medium is obtained from the medium to be treated when the metal salt to be treated is exchanged by the metal salt. In one exemplary embodiment, the metal salt to be treated comprises copper chloride and the metal salt comprises copper sulfate.

In the context of the present application, the term "processing cycle" may particularly denote a large number of processing steps (and/or processing modules) connected in a cycle-like manner. In particular, the treatment cycle may be arranged such that the product of one first step is fed back to a second step, which is an upstream treatment with respect to the first step. More particularly, the product of the last step is fed back as input back to the first step. Such an embodiment may be referred to as a closed loop processing cycle. Preferably, the closed loop processing cycle is performed such that no waste is generated. This may be achieved, for example, using a third process cycle, wherein the strong acid from the etching process is separated in membrane dialysis and then fed back to the etch-back process via an enrichment step. In another embodiment, the first treatment cycle may only produce elemental metal as waste (e.g., by flowing an acidic medium through an ion exchange process, transporting fixed metal ions to an electrolytic process producing elemental metal, and feeding back a metal-depleted acidic medium), however, where elemental metal is a desired product that may be fed back to another manufacturing process. In another embodiment, the second treatment cycle may yield only purified water and metal-depleted (and therefore readily discharged) salt concentrate as waste, for example, by passing the additional acidic medium stream through an ion exchange process, through a reverse osmosis process, and back to the ion exchange process.

In the context of the present application, the term "foreign metal" may particularly denote a metal that is present (in dissolved form) in the medium containing the metal salt but (for some applications) is not desired to be present. Examples of such foreign metals (and their ions, respectively) may include, depending on the application: iron (fe3+, fe2+), lead (pb2+), tin (sn2+), molybdenum (Mo 3+), nickel (ni2+), cobalt (co2+), indium (in3+), cadmium (cd2+), zinc (zn2+), chromium (cr3+), sodium (na+), palladium (pd2+). In one embodiment, the medium containing the metal salt should be treated so that the metal in the metal salt is present in elemental form and can be recycled. Foreign metals may cause interference or failure of the process (e.g., by electrolysis), so removal of foreign metals in advance may be suggested. In one exemplary embodiment, the metal salt-containing medium is derived from an electroplating process, and elemental copper should be obtained from the metal salt copper sulfate. Due to the electroplating process, the metal salt-containing medium may include foreign metals, particularly iron. The foreign metal may be present as a salt of the foreign metal (e.g., iron sulfate). This can severely interfere with the electrolysis of the copper sulfate (inhibiting copper deposition at the cathode). At lower (residual) concentrations, the foreign metals may be oxidized during the recovery process while the metals are reduced (separately deposited).

In the context of the present application, the term "medium containing a foreign metal and a metal salt" may particularly denote a medium comprising a metal salt (as described above) and a foreign metal (as described above). In one embodiment, the medium containing the foreign metal and metal salt is derived from the plating. In particular, the medium containing the foreign metal and metal salt is a highly acidic medium (e.g. pH < 1). This may be due to the fact that the medium containing the foreign metal and metal salt comprises a strong acid, such as sulfuric acid, in high concentration (e.g. in the range of 100 to 200 g/L).

In the context of the present application, the term "treatment" may particularly denote that the medium to be treated, in particular a medium having at least one undesired characteristic, is treated in one or more treatment steps such that the treated medium, in particular a medium no longer comprising the undesired characteristic, is present. For example, the medium to be treated may be a medium containing metal salts, wherein at least one metal salt is undesirable. Accordingly, the medium to be treated may be treated (e.g. by membrane dialysis and chemical reaction) such that a metal salt-containing medium is present as the treated medium, which (substantially) no longer comprises undesired metal salts.

In the context of the present application, the term "partial flow" may particularly denote that the medium (in particular the liquid medium) in the (manufacturing) process is carried out in a certain (desired) process direction. In other words, the medium flow in the (manufacturing) process can be controlled in a desired manner. The term "partial flow" may especially relate to the fact that the respective (manufacturing) process comprises at least two such flows (from different process steps). Each single stream (of the preferred liquid medium) in the same (manufacturing) process and the same plant may be represented as a partial stream, respectively. The partial flow may be a controlled flow of (in particular) the produced waste medium. At least two (and in particular three or more) of the at least partial streams may be combined into a total stream. In one embodiment, the first partial stream includes treated metal salt-containing medium (e.g., including copper sulfate and hydrochloric acid) and an etch-treated waste stream from circuit board and/or substrate fabrication, respectively, while the second partial stream includes treated metal salt-containing medium (e.g., including copper sulfate, iron sulfate, and sulfuric acid) and an electroplating-treated waste stream from circuit board and/or substrate fabrication, respectively. In one example, these may be combined into one total stream, which is then processed, for example, to recover the metal of the metal salt in elemental form.

In the context of the present application, the term "circuit board and/or substrate manufacturing" may particularly denote a process for manufacturing circuit boards and/or substrates, which is performed in a factory, such as a circuit board factory. The term "circuit board" may particularly relate to a Printed Circuit Board (PCB), whereas the term "substrate" may be, for example, a substrate for a semiconductor chip, such as an integrated circuit or an organic interposer, in accordance with the present application. The manufacture of circuit boards and/or substrates generally comprises an etching process in which the metal is removed by etching so that the desired metal structure is obtained, and an electroplating process in which the metal is provided by electroplating. Starting materials for circuit board and/or substrate fabrication include essentially metals and electrically insulating materials, typically organic materials, such as resins. The processed products may be finished circuit boards and substrates, respectively, or may be intermediate products.

In the context of the present application, the term "etching process" may particularly denote a process of circuit board and/or substrate manufacture, which includes etching metal, in particular copper, to provide the desired metallic (conductive) structure. According to an exemplary embodiment, the process may be performed as follows: the photoresist protects the copper paths that should not be etched away, whereas the etched away copper areas should not be covered by photoresist. First, the entire copper layer is coated with photoresist for this purpose. Then, the photoresist is developed by ultraviolet light through the mask. The mask passes uv light only where the photoresist should remain (i.e., where the desired conductor trace should be provided). During the development process, the resist (and polymer, respectively) cross-links at the locations exposed to ultraviolet light. After development, the unexposed (and undeveloped) photoresist can be easily washed away. Subsequently, the panel (and the respective component carrier preform) is etched. The photoresist protects the conductor trace and copper not covered by the photoresist is etched/removed. When the etching process is completed, the photoresist is removed and stripped (photoresist is crosslinked and solid), respectively, and conductor traces are left. The stripped photoresist may be later precipitated by ferric chloride.

In the context of the present application, the term "electroplating process" may particularly denote a process in which electroplating is performed in the manufacture of circuit boards and/or substrates. Electroplating may refer to the electrochemical deposition of metal deposits on a device. For example, when the device is used as a circuit board and/or substrate, metal precipitates (e.g., copper) may be used thereon as the conductive layer structure and the conductor trace, respectively. In addition, for example, the holes (through holes) may be electrically conductive by laterally plating or by completely filling them by electroplating. In one example, an electrical current is applied to the electrolyzer. At the positive electrode (anode) the metal (e.g. copper or nickel) to be placed is positioned, and at the negative electrode (cathode) the object to be coated (e.g. circuit board) is positioned. By means of an electric current, metal ions are deposited on the object by reduction. In one example, the treatment may be implemented as a series of electrolytic baths. The electroplating process may be performed continuously or discontinuously (in a batch mode). Typically, a significant amount of the medium containing the metal salt is obtained as a waste concentrate ("exudate") in this process. This generally involves foreign metals and high acid contents, which makes recycling of the metal (metal salt) conventionally impossible in an economical manner, because of the process.

In the context of the present application, the term "reaction cell" may particularly denote any reactor capable of recovering the metal of the metal salt in elemental and high purity form from the medium containing the metal salt. The term "recovery" may particularly denote the separation and isolation of the elemental metal from the medium containing the metal salt (for reuse purposes), respectively. An example of a reaction cell may be an electrolytic cell. The term "electrolysis" may particularly denote the use of an electric current to effect a chemical redox reaction. Thus, the electrolytic cell may comprise: a direct voltage source for providing an electrical current is coupled to the cathode (negative electrode) and the anode (positive electrode). The voltage source may cause electron starvation in the anode and electron excess in the cathode. In one embodiment, a medium containing a metal salt is added to an electrolytic cell that includes copper as a metal and iron as a foreign metal. Copper has a higher redox potential (more noble and rare) and is therefore reduced and deposited at the cathode, respectively. Conversely, iron is oxidized at the anode. In one exemplary embodiment, the reaction cell preferably includes a plurality (e.g., twenty) of electrolysis modules, wherein elemental metal (e.g., copper) is deposited at the cathode. In the reaction, oxidation of the foreign metal (of the electrolyte) occurs, the chemistry of which is less noble than the metal to be deposited. In one example, recovery may be achieved through a series of electrolytic baths. Recovery may be performed continuously or discontinuously (batch wise).

In the context of the present application, the term "ion exchange treatment" may particularly denote any treatment suitable for exchanging ions of a liquid medium. The term "ion exchanger" may encompass materials (respectively and devices) in which dissolved ions may be replaced by other ions of the same charge (positive or negative) (see further detailed description below).

In the context of the present application, the term "dialysis" may particularly denote a concentration-driven membrane treatment for removing molecules (in particular ions) from a solution. In one embodiment, the medium containing the metal salt is provided via a first feed (dialysate feed) on a first side of the membrane and the additional medium (e.g., water) is provided via a second feed (diffusion feed) on a second (opposite the first) side of the membrane. The membrane may be semipermeable and allow anions (e.g. chloride) to pass through (the anionic membrane) but not cations (e.g. cu2+). Thus, cations are enriched in the medium containing the metal salt as dialysate, while anions are enriched in the other medium as diffusion fluid. In the case of chloride anions, the diffusion liquid becomes highly acidic, so the term "acid dialysis" may also be used.

For membrane dialysis described below, the same membrane or (preferably) different membranes may be used, respectively. The anionic membrane may be functionalized, for example, with bromine (Br-), wherein the support material may be, for example, PET or PVC. In some cases, the metal salt-containing solution may include hydrogen peroxide (H2O 2). In this case, an oxidation-resistant film based on, for example, polyetheretherketone (PEEK) may be preferably used.

In the context of the present application, the term "regeneration" may particularly denote a transition of the (selective) ion exchanger from a first operating state to a second operating state. In particular, in the first operating state, metals (in particular cations) are adsorbed at the ion exchanger (and respectively at the ion exchange resin). Further particularly, in the second operating state, the metal is substantially desorbed. Thus, in the second operating state, the ion exchanger is operable to be loaded again and may accordingly assume the first operating state again. Advantageously, regeneration may be repeated multiple times. In one example, the regeneration is performed by a regeneration medium, in particular a regeneration acid, such as sulfuric acid and/or hydrochloric acid. In the regeneration process, the regeneration medium may desorb the adsorbed metal. The purified regeneration medium can be reused. In another example, the regeneration medium need not be purified, such that the concentration of metal in the regeneration medium increases with each (regeneration) cycle through the ion exchanger. Thus, in this document, "regeneration" may also be enrichment of the metal to be recovered.

In other words, according to one embodiment, the metal concentration increases while the acid concentration decreases. The regenerated acid, which already contains desorbed metal ions, is reused until the acid concentration obtained is too low to release metal ions from the resin. Then, the acid concentration decreases because the protons (h+) of the acid remain on the resin.

In the context of the present application, the term "valuable material recycling" may particularly denote that a plurality of valuable materials (substances required for the manufacturing process, such as main components and/or starting materials/raw materials) are constantly (and respectively continuously) recovered within the manufacturing process (and the industrial plant). In particular, multiple valuable materials from a single process step are processed and/or recycled to be supplied again to the single process step. The valuable material leaves the treatment step as a component of the waste medium and as an occurring residue, respectively, but can be fed back after treatment internal to the treatment. Valuable materials may include, for example, heavy metals such as copper, nickel, gold, and the like. These may occur in different processing steps within the medium containing the metal salt. The residues that occur can be carried out in partial streams (the flow of the medium can be controlled in particular) and can be treated jointly at least in part, so that valuable materials can be recovered. From the partial streams which are fed back to the individual process steps finally (in particular by processing the total stream), the separated streams can be separated, which in turn can be fed back to the individual process steps and/or can be supplied to the partial streams via, for example, an enrichment (and respectively concentration adjustment) process.

In the context of the present application, the term "medium in emission quality" may particularly denote a (liquid) medium which may be allowed to enter a wastewater treatment plant and/or aquatic environment according to legal standards and boundary values. In one example, the medium in the supply mass (essentially) does not comprise the main components of the circuit board/substrate manufacturing, but consists only of water, (non-heavy metal) salts and (possibly) organic materials. In a preferred embodiment, the medium in the supply mass no longer (substantially) comprises heavy metals. The medium in the supply mass may comprise organic residues which may be removed, for example, by means of activated carbon filters, in a wastewater treatment plant or, for example, in a sewage treatment plant.

In an exemplary embodiment, the medium in the emission mass comprises an emission mass in a wastewater treatment plant. The concentration of heavy metals may be 15mg/L or less, in particular the concentration of copper may be 0.5mg/L or less (thus within legal boundary values of, for example, the australian republic of china), the medium in the quality of the emissions may be purified (for example, in a wastewater treatment plant inside the treatment), so that the medium may be supplied to the aquatic environment. This purification may be independent of heavy metals but is related to organic residues. These can be simply removed, for example by means of an activated carbon filter. For example, after purification, CSB (chemical oxygen demand) in the discharge quality medium may be below 300mg/L, in particular below 75mg/L (further in particular below 65 mg/L), as a measure of the concentration of organic compounds. If oxygen is the oxidant, the CSB value may dictate the amount of oxygen (in mg/L) required for oxidation of the oxidizable material. For example, according to law, the boundary value is 75mg/L in Austria. The CSB boundary value of a sewage treatment plant may vary widely, for example 300mg/L.

In the context of the present application, the term "process control device" may particularly denote each device (or devices) adapted to perform process control, wherein the process is (at least partly) related to circuit board and/or substrate manufacturing. In particular, the process control means are adapted to (at least partially) control and regulate, respectively, the valuable material circulation, wherein the produced residues are fed back such that essentially no (heavy metal and/or acid) waste occurs. For this purpose, the process control device may comprise, inter alia, a database (unit) and a data model unit, wherein the former stores the captured process data and the latter stores the expected desired process data. The process control device may be coupled with a plurality of sensors and measuring devices in such a way that the actual parameters of the different process stations are determined. Further, the process control means may include a calculation means that compares the captured parameter with the desired parameter, and based thereon determines and performs the control operation. In a preferred embodiment, the process control means comprise an Algorism (AI) by which the control and regulation of the process can be continuously improved, respectively.

In the context of the present application, the term "substantially" may be interpreted as including negligible residues and/or contaminations, which may no longer be excluded by an acceptable worker. In one embodiment, these negligible residues and contaminations are (intentionally) undesirable, respectively, but can no longer be removed with reasonable effort. For example, a medium with an emission quality may be substantially free of heavy metals, which may mean that negligible residues and contamination may be present (e.g., in the lower percentage range, in the per-thousandth range, or in the parts per million (ppm) range), respectively. Those skilled in the art understand that although these residues and/or contaminations are undesirable, they still cannot be separated in a manner with acceptable technical effort. In particular, the term "emission quality" may mean "substantially" free of heavy metals, as the heavy metal concentration consists only of residues/pollution, and is so low as to allow emission in an aqueous environment.

In the context of the present application, the term "(printed circuit board" (PCB) may particularly denote a substantially plate-like component carrier (which may be flexible, rigid or semi-flexible) which is formed by laminating a plurality of electrically conductive layer structures with a plurality of electrically insulating layer structures, for example by applying pressure and/or by supplying thermal energy. As a preferred material for PCB technology, the electrically conductive layer structure is made of copper, whereas the electrically insulating layer structure may comprise resin and/or glass fibres, so-called prepreg or FR4 material. The different conductive layer structures can be connected to each other in a desired manner by forming through holes through the laminate, for example by laser drilling or mechanical drilling, and by filling them with a conductive material, in particular copper, wherein the through holes are thereby formed as connections through the openings. In addition to one or more components that may be embedded in a printed circuit board, the printed circuit board is typically configured to receive one or more components on one or both opposing surfaces of the board-like printed circuit board. They may be attached to the respective main surfaces by welding. These components may also be embedded. The dielectric portion of the PCB may include a resin (e.g., fiberglass or glass spheres) having a reinforcing structure. In an embodiment, the system comprises an output unit configured to provide: output data indicative of the designed test specimen meeting the compliance conditions and/or the performance of the component carrier. At the output unit, a data set may be provided that describes the created or designed specimen and may include all information or instructions necessary to manufacture the specimen.

In the context of the present application, the term "substrate" may particularly denote a small component carrier having substantially the same dimensions as the components, in particular electronic components, to be mounted thereon, such as in a Chip Scale Package (CSP). In particular, the substrate may represent a carrier for an electrical connection or an electrical network, or may also represent a component carrier comparable to a Printed Circuit Board (PCB), but with a significantly higher density of connections arranged laterally and/or vertically. For example, the lateral connection is a conductive path, while the vertical connection may be, for example, a borehole. These lateral and/or vertical connections are arranged in the substrate and may be used to provide electrical and/or mechanical connection of packaged or unpackaged components (e.g. dies), in particular IC chips, with a printed circuit board or an intermediate printed circuit board. Thus, the term "substrate" also includes "IC substrate". The dielectric portion of the substrate may comprise a resin (e.g. reinforcing spheres, particularly glass spheres) with reinforcing particles. In an embodiment, the compliance input unit is configured to receive compliance input data indicative of user-defined compliance conditions. Therefore, user requirements that can be freely defined can be considered in designing the sample. This increases the flexibility of sample design.

The substrate or interposer may be composed of at least one glass layer (silicon (Si)) or an organic layer that is photo-structured or dry-etchable. As the organic material/organic layer, for example, an epoxy-based build-up material (for example, an epoxy-based build-up film) or a polymer compound such as polyimide, polybenzoxazole, or benzocyclobutene functionalized polymer can be used.

In an embodiment, the component carrier is a laminate type component carrier. In such an embodiment, the component carrier is a composite material made of a multi-layer structure that is stacked and connected to each other by applying pressure and/or heat.

In an embodiment, the at least one conductive layer structure comprises at least one of the group consisting of copper, aluminum, nickel, silver, gold, palladium, magnesium, and tungsten. Although copper is typically preferred, other materials and forms of their coatings are also possible, particularly coated with a superconducting material, such as graphene.

In the context of the present application, the term "heavy metal" may particularly denote metals having a density of more than 5.0g/cm3 (or more than 4.5g/cm 3). This includes, for example, copper, nickel, cobalt, gold, silver, palladium, tungsten, tin, zinc, iron, lead, chromium, rhodium, cadmium, and the like. According to this definition, for example, aluminum, silicon, sodium, potassium, calcium, magnesium, etc., are not denoted heavy metals.

According to one exemplary embodiment, the invention may be based on the idea that if an ion exchange process is integrated between two closed loop process cycles, wherein the first process cycle only yields elemental metal and the second process cycle only yields purified water and/or a lean metal salt concentrate, a metal salt-containing etching waste medium of circuit board and/or substrate manufacture can be economically, ecologically and durably treated in an efficient and robust manner (within a valuable material cycle).

It is known that waste and waste concentrates (metal-rich salts and acids) from circuit board and/or substrate manufacturing are treated in a cost-effective, non-ecological and non-durable manner. The waste from the etching process is typically highly acidic and is therefore destined to be carefully treated as a special waste. Thus, recovery in a high quality manner (which is mandatory for recovery) seems not to be possible in a cost-effective manner.

It has now surprisingly been found that it is possible to economically recover, in particular elemental metal, from a waste medium containing metal salts. After treatment, costs and effort can be saved and the recovered material can be fed back to different treatment steps. For example, elemental copper may be fed directly back to the electroplating process, while the separated acid may be fed to the etching process. In a preferred embodiment, the recovery can be performed continuously, so that the waste produced from the different treatment steps can be permanently treated and the recovery can be provided directly to the individual treatment steps.

Advantageously, the guiding and treatment of the flow is performed such that the high acid concentration does not interfere, but the acid itself is kept in the valuable material cycle as part of the treatment process and fed back. Since these treatments may be water consuming, the purified water may advantageously be fed back into the different treatments.

While the metal salt-containing media traditionally from circuit board and/or substrate fabrication (where due to high concentrations of extraneous metals and acids) are considered waste products that require careful handling, a complete comparative description thereof is now presented in which it is possible to economically and efficiently feed back metals and acids in one and the same production process.

Exemplary embodiments of the invention

According to an exemplary embodiment, the metal in the metal salt and the metal in the metal salt to be treated are the same metal. The metal is in particular at least one of the group consisting of: copper, nickel, cobalt, tin, cadmium, magnesium, sodium, silver, gold. Thus, the industrially relevant metals are recovered efficiently rather than being exhausted cost-effectively.

According to another exemplary embodiment, the salt of the metal salt (e.g., copper sulfate) and the salt of the metal salt to be treated (e.g., copper chloride) are different salts. The salt comprises at least two of chloride, sulfate, nitrate and phosphate. This may have the following advantages: the various metal salts to be treated can be converted into the desired metal salts within the treatment in a flexible manner.

According to an illustrative example, copper in the form of copper chloride (as metal salt to be treated) and hydrochloric acid as acid emerge from the etching treatment as medium to be treated. The high content of chloride ions promotes uncontrolled formation of chlorine gas during the recovery process, such as electrolysis. In addition, chloride ions can co-deposit on the electrolytic electrode, thereby negatively affecting the purity of the deposited copper.

According to another exemplary embodiment, the first processing cycle further comprises:

i) A further acid different from the acid (in particular, the further acid comprises at least one of the group consisting of: sulfuric acid (H2 SO 4), hydrochloric acid (HCl), nitrous acid (HNO 3), phosphoric acid (H3 PO 4)) flows through the ion exchange process such that additional acid removes metal from the ion exchange process (e.g., desorbs metal ions from the ion exchange resin) to provide a metal salt-containing medium (e.g., a copper sulfate rich medium) (additional acid may also be referred to as a regeneration medium (which includes/consists of additional acid)),

ii) feeding the medium containing the metal salt to an elemental metal recovery process to obtain elemental metal and additional acid from the medium containing the metal salt (e.g. by electrolysis), and

iii) The (lean) additional acid (metal has been removed as elemental metal) is fed back to the ion exchange process (as regeneration medium).

In this way, the acidic medium (additional acid) flows in the closed loop of the first treatment cycle. The acid of the acidic medium does not have to be discharged in a cost-effective manner, but remains in the valuable material cycle. Thus, the waste product of the first treatment cycle is (essentially) only elemental metal, which is in fact a valuable recycled material.

The additional acid/acidic medium may also be referred to as the "regeneration medium" of the ion exchange process. Such regeneration medium may comprise a high acid concentration, in particular not less than 100g/L, further in particular not less than 200g/L, further in particular not less than 250g/L (e.g.sulfuric acid).

In one example, where the metal is copper, the medium to be treated comprises copper chloride, and the additional acid comprises sulfuric acid, the following reaction may occur:

CuCl ₂ in the medium to be treated>2Cl ^- (in a Metal-lean acid Medium) +Cu ²⁺ (immobilization) then

Cu ²⁺ (fixing) +H ₂ SO ₄ In other acids)>CuSO ₄ (in a Medium containing Metal salts) +2H ⁺ (fixation).

During the regeneration treatment, cu ²⁺ The ions are thus surrounded by two H' s ⁺ Ion exchange to obtain H ₂ SO ₄ And CuSO ₄ Can be directly used for electrolysis (metal-rich electrolyte).

In addition to the described examples of exchanging copper chloride for copper sulfate, the following salt exchange reactions (with the corresponding acids, respectively) can also take place, for example (both directions may be possible, depending on the educts):

According to a further embodiment, the elemental metal recovery process comprises an electrolytic process wherein the medium containing the metal salt resembles a metal-rich electrolyte entering the electrolytic process and wherein the additional acid resembles a metal-lean electrolyte exiting the electrolytic process. This may provide the advantage of providing a medium suitable for electrolysis without additional effort. Elemental metal may be recovered by electrolysis to a purity of about 99.999%, which may be necessary to return it to the manufacturing process.

According to a further embodiment, a metal salt-containing medium is applied as the metal-rich electrolyte, alone or in combination with other metal salt-containing mediums from circuit board and/or substrate manufacturing. The processing (and adjusting the composition, respectively) of such streams (or total streams) may include at least one of the following features:

i) The organic component is filtered from the medium (electrolyte) containing the metal salt through a filter, preferably an activated carbon filter.

ii) separating (oxidized) foreign metals, in particular iron, from the medium containing metal salts (electrolyte) by means of a further ion exchanger. This may have the advantage that the medium containing the metal salt is purified as an electrolyte, whereas the foreign metal is obtained as a raw material for further processing steps.

iii) Separating the acid, in particular sulfuric acid, from the medium (electrolyte) containing the metal salt. This enables selective adjustment (readjustment) wherein the separated substances are at least partially reused internally in the process.

According to another embodiment, the elemental metal is recovered from the medium containing the metal salt in the reaction cell (in particular by electrolysis). Elemental metal (e.g., copper) of the metal salt-containing medium should be recovered in the reaction cell in (high) purity form for re-supply to the process of manufacturing the circuit board and/or substrate. In particular, the elemental metal obtained is fed back to the electroplating process.

According to a further embodiment, the second processing cycle further comprises:

i) The medium to be treated is passed through an ion exchange treatment, wherein the medium to be treated is separated into a metal and a metal-depleted (hydrochloric acid) acidic medium, the metal then remaining in the ion exchange treatment (e.g. being adsorbed by an ion exchange resin),

ii) treating the metal acid depleted medium in a water treatment process such that purified water is obtained and purified water according to at least one of the group comprising:

a) Purified water is fed back to the ion exchange treatment,

b) The purified water is fed back to further circuit board and/or substrate manufacturing processes (e.g. membrane dialysis, dilution treatment, rinse water treatment processes etc.),

c) The purified water is discharged as water in the discharge mass.

This may provide the advantage that the highly acidic medium (which is typically discharged in a cost-consuming and non-environmentally friendly manner) is treated to purified water in an efficient manner. Since the described treatment may be very water-consuming, it may be highly desirable to continuously recycle the treated water.

The medium (water) in the discharge mass no longer (substantially) comprises the main components of the circuit board/substrate manufacture (in particular free of heavy metals), but consists only of water, salts and organic materials.

According to another embodiment, the water treatment process comprises a membrane filtration process, in particular a reverse osmosis process, wherein the permeate comprises purified water, and wherein the concentrate comprises a salt concentrate. This may provide the advantage that established industrial processes can be directly carried out to yield purified water that can be recycled internally within the process.

The term "membrane filtration" may refer herein to an established water purification process that uses a partially permeable membrane to separate ions, undesirable molecules, and larger particles from water. Examples of membrane filtration may include microfiltration, nanofiltration and reverse osmosis. In reverse osmosis, applied pressure may be used to overcome osmotic pressure. Reverse osmosis can therefore remove a variety of dissolved and suspended chemicals and biological substances (mainly bacteria) from water. Reverse osmosis treatment can yield two products: permeate (purified water) and concentrate (salt concentrate, in particular metal salts).

According to a further embodiment, the second processing cycle further comprises: the salt concentrate is returned to the ion exchange process such that the metals in the salt concentrate remain in the ion exchange process, thereby providing a metal depleted salt concentrate.

Salt concentrates are in particular metal salt concentrates, which still comprise (heavy) metal from the etching process. Thus, the metal salt concentrate may not be suitable for being discharged. As a result, and in order to further increase the yield of elemental metal, the salt concentrate is transported (preferably diluted, in particular with purified water and/or flushing water) back to the ion exchange treatment. The metal can now be removed again from the diluted metal salt concentrate (e.g. adsorbed by the ion exchange resin), in particular after several cycles (e.g. three, seven, etc.) in the second treatment cycle, the metal salt concentrate has become a lean metal salt concentrate.

According to a further embodiment, the metal-depleted salt concentrate is (substantially) free of heavy metals (in particular comprising only salts and optionally water/organics) and can be discharged in a low cost and environmentally friendly manner.

According to a further embodiment, the method further comprises: a base (e.g., sodium hydroxide) is added to the metal-depleted acid medium, wherein the base and acid of the metal-depleted acid medium form a salt (e.g., sodium chloride) of a salt concentrate. This may provide the advantage of neutralizing strong acids in a cost-effective manner.

According to a further embodiment, the ion exchange treatment comprises the application of an ion exchanger, in particular wherein the ion exchanger comprises an ion exchange resin. The ion exchanger may be implemented, for example, as a column filled with ion exchange material, or as a membrane through which a solution flows. The ions to be exchanged are bound and adsorbed, respectively, on the ion exchange material. In one example, the ion exchanger comprises a selective ion exchange resin, further particularly a bifunctional ion exchange resin.

In one embodiment, the support material of the ion exchange resin of the ion exchanger comprises polystyrene. In particular, it comprises two functional groups (bifunctional ion exchange resins), for example i) a phosphonic acid residue, and ii) a sulfonic acid residue. The first acid group includes a higher pKs value than the second acid group. Acids with higher pKs values are weaker acids and pyrolyze more marginally than acids with lower pKs values (strong acids). Thus, the foreign metal can be more easily desorbed by the resin during the regeneration process.

According to one embodiment, it has surprisingly been demonstrated that the precise use of a specific ion exchange resin with two functional groups enables (benefit) desorption of metals, in particular iron.

In the illustrative example, the ion exchanger is constructed with two stages. The first ion exchanger (upstream) may comprise a strongly acidic ion exchange resin to adsorb most of the metals. The second ion exchanger (downstream) may comprise a weakly acidic ion exchange resin that adsorbs the remaining metals, particularly to the extent that the metal-depleted acidic medium has emission quality (from a heavy metal content perspective).

In an illustrative example, a strongly acidic ion exchange resin may adsorb (any) cations applied to the resin. Thus, the initial ion exchange resin may not be a selective ion exchange resin. However, strongly acidic ion exchange resins can have significantly increased adsorption capacities, which can be considered advantageous. This lack of selectivity works well in cases where the amount of (different) cations is not significant. The weakly acidic ion exchange resin can selectively adsorb residual amounts of copper. In a subsequent treatment step, the pH may be increased. Otherwise, sodium ions may be introduced during the treatment, which further contaminates the electrolyte (and the capacity of the initial ion exchange resin may also decrease, as sodium may adsorb onto the resin).

According to another embodiment, the ion exchange treatment comprises application of liquid/liquid extraction. In a preferred embodiment, liquid/liquid extraction may be performed using a hydrocarbon diluent with a high flash point as the extraction medium (hydrocarbon ion exchange medium). Such hydrocarbon diluents can form water insoluble complexes with various metal cations, such as copper. In the ion exchange treatment, the following reactions may occur: 2RH (org) +Cu ²⁺ (aq)->R ₂ Cu(org)+2H ⁺ (aq)。

The hydrocarbon diluent can thus act like an ion exchange resin in that it reversibly absorbs cations (particularly copper) through ion exchange reactions. In addition, cations are also exchanged by two h+ ions.

In one embodiment, the concentrated and deacidified media (e.g., copper chloride-containing) stream to be treated is extracted with a high flash point hydrocarbon diluent (ion). The two liquids are immiscible with each other but during the ion extraction/exchange process the two liquids may be in intimate contact with each other, for example by mixing (in the ion exchange process/system). By mixing, the two immiscible liquids are brought into intimate contact with each other in such a way that ion exchange (transfer) occurs at the liquid/liquid interface. Thus, cations (copper) will be present in the high flash point hydrocarbon diluent medium, while anions (e.g., chloride) will remain in the newly obtained metal-depleted acidic medium. Since the two media are immiscible, they separate after a period of time. This may be accomplished, for example, using a sedimentation tank (which may be part of the ion exchange process). The (cationic-rich) high flash point hydrocarbon diluent may then be further regenerated ("stripped") with additional acid (especially sulfuric acid), thereby enabling the production of a metal salt-containing medium (electrolyte with, for example, copper sulfate). Since the metal salt-containing medium and the (cation-lean) high flash point hydrocarbon diluent are also mutually immiscible, the metal salt (copper sulfate) can be easily separated, while the high flash point hydrocarbon diluent (hydrocarbon extraction medium) can be reused in a similar manner to the ion exchange resin. An illustrative example of a high flash point hydrocarbon diluent (hydrocarbon extraction medium) may be a mixture of 5-nonyl-Liu Quanwo (5-onyl-salicylaldoxime) and 2-hydroxy-5-nonylacetophenone oxime (2-hydroxy-5-nonylacetophenone oxime) in a 1:1 ratio.

According to a further embodiment, it is provided that the medium to be treated is integrated into a third treatment cycle, which is a third (closed) loop and produces (substantially) no waste. In this way, acidic waste from the etching process can be recovered efficiently in the same circuit board/substrate manufacturing.

According to a further embodiment, the third processing cycle further comprises:

i) Removing acid from the medium to be treated by membrane dialysis to provide an acid-depleted (less acidic) medium to be treated and an acidic diffusion liquid (in particular, further acid-enriching the acidic diffusion liquid in an acid-enriching treatment to obtain an acid-enriched diffusion liquid), and

ii) feeding back the acidic diffusion liquid and/or the acid-enriched diffusion liquid to the etching process to (again) produce the medium to be treated.

Therefore, no acidic waste is produced (difficult and costly to discharge). Instead, the acid from the etching process is separated from the medium to be processed and may be fed back to the etching process.

The acidic diffusion solution (after the membrane dialysis step for the process) for comprising only very low concentrations of metal salts (along with the further separation stream of the other process) may be enriched (e.g. using gas adsorption) with acid before being transported again to the etching process. Alternatively, the acidic diffusion liquid may be supplied to a central processing (e.g., rinse water). Although the acid may be reused in the circuit board and/or substrate manufacturing process, the metal salts are enriched (e.g., via rinse water treatment) and may be recycled again. In another embodiment, the acid is used as a regenerating acid to produce ferric chloride FeCl3.

According to a further embodiment, providing a medium to be treated comprises: hydrogen peroxide (H2O 2) elimination treatment was performed. The medium to be treated may contain an oxidizing agent, such as hydrogen peroxide from an etching process. These oxidants can attack membranes of membrane dialysis and/or ion exchange resins. The reduction and/or elimination of the oxidizing agent may be performed chemically, thermally, electrically or catalytically. Hydrogen peroxide elimination may include the following chemical reactions: 2H2O2- >2H2O+O2. For example, thermal decomposition occurs at about 50-60 ℃. The catalytic reaction may be carried out using, for example, ferric chloride (FeCl 3) as a catalyst, using an activated carbon filter, or an enzyme called catalase may be used to induce the elimination reaction. Upon application of an electric potential (voltage), electrolytic decomposition may occur. In addition, any reducing agent such as sodium bisulphite may be used to chemically eliminate hydrogen peroxide.

According to another embodiment, the process is performed continuously. This may have the following advantages: continuous enrichment of the medium to be treated takes place and the ion exchangers can each be regenerated particularly effectively.

According to another embodiment, the method further comprises diluting the medium to be treated prior to the ion exchange treatment, in particular in a mixing reactor. The acid-depleted medium to be treated may still comprise a relatively high acid concentration. Thus, a further dilution step may be advantageous/necessary. Dilution may also include dilution with (treated) rinse water and/or purified water from circuit board and/or substrate manufacturing. By diluting the acid-depleted medium, the pH can be increased, which can further increase the retention capacity of the ion exchange treatment. Thus, the ion exchange process can extract/adsorb more copper ions.

According to a further embodiment, about 40% HCl may be saved during the described process.

According to a further embodiment, the output stream (produced product, waste) may be hydrochloric acid (about 10%), water in the effluent quality, reverse osmosis concentrate (especially lean metal salts) and 99.999% pure copper.

The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment.

Drawings

Fig. 1 shows an overview of a partial flow of manufacturing a circuit board and/or substrate according to an embodiment of the invention.

Fig. 2-4 illustrate a method of processing an etching waste medium from an etching process for circuit board and/or substrate fabrication in accordance with an embodiment of the present invention.

Fig. 5 illustrates a process control apparatus for regulating at least a portion of the above-described methods (respectively, the factory) in accordance with an embodiment of the present invention.

The illustrations in the figures are schematic. In different drawings, similar or identical elements are provided with the same reference numerals.

Detailed Description

Fig. 1 shows an overview of flows 1 to 7 in the manufacture of circuit boards and/or substrates, for example in a factory 60, according to an embodiment of the invention. The method for manufacturing circuit boards and/or substrates is operated such that the generated process residues 11, 21, 31 are guided and fed back (respectively recovered) in three main partial streams 1, 2, 3 (and in particular at least partly as total stream 4) and three main separate streams 5, 6, 7 (which in particular comprise acid residues), such that in the (shown) operating state of the manufacturing method, only one medium 350 in the discharge (supply) quality (and/or the lean metal salt concentrate 186 b) takes place as waste (in other words: essentially the only waste leaving the manufacturing process). In other words, the medium 350 and/or the lean metal salt concentrate 186b in the exhaust mass no longer (substantially) comprises the main components of the circuit board/substrate manufacturing (in particular free of heavy metals), but consists only of (no more than) water, salt and organic matter. In the (shown) operating state, only water 352 and energy (essentially) have to be supplied to the manufacturing process (the acid residues present are (essentially) fed back into the valuable material circulation). Thus, essentially only such main components (in particular heavy metals, such as copper) are supplied to the manufacturing process, which makes the manufacturing process an integral part of the finished printed circuit board and/or substrate. In principle, 95% or more, in particular 98% or more, of heavy metal residues (e.g. copper residues) can be fed back in the described valuable material cycles. In an exemplary embodiment of the valuable material recycle, at least 80% (in particular at least 85%, further in particular at least 90%) of the separated hydrochloric acid is fed back and at least 70% (in particular at least 75%, further in particular at least 80%, more in particular at least 90%, further in particular at least 95%) of the desired sulfuric acid is produced internally by the process. Therefore, the main component is not (substantially) added to the manufacturing process, which makes the manufacturing method wasteful. In fact, such wastage does not occur in principle (substantially).

The process residues 11, 21, 31 and waste concentrate that occur can be represented respectively as metal salt-containing media to be treated and in an exemplary embodiment comprise: copper, copper sulfate, copper chloride, iron, nickel, gold, hydrochloric acid, sulfuric acid. The metal salt-containing media 11, 21 and 31 to be treated are treated in the respective treatment processes 100, 200, 300, respectively, and then supplied as part streams 1, 2, 3 to the recovery process 400, the part streams 1, 2, 3 comprising the treated metal salt-containing media 10, 20, 30, respectively. After treatment, the recovered elemental metal 50 is ultimately supplied again to the manufacturing process (arrows 52 and 54). In the following, a main overview of part of the flows 1 to 7 in the circulation of valuable materials is given. Hereinafter, a detailed description of the process of forming the central aspect of this document is provided.

The first partial flow 1 comprises a metal salt-containing medium 10 from a first process of an etching process 150 of circuit board and/or substrate manufacturing, which is processed in a first process procedure 100. The first process 100 can be seen as a main aspect of this document. The first treated metal salt-containing medium 10 (which does not substantially include the metal salt to be treated) is obtained from the medium to be treated 11 of the etching process 150 as an etching waste medium. The medium 11 to be treated comprises a metal salt to be treated (e.g. copper chloride) and an acid, such as hydrochloric acid. The process 100 includes removal of the acid 15 by membrane dialysis 110, 120 (preferably multiple stages) and ion exchange treatment 145 (particularly multiple stages). In the multi-stage membrane dialysis 110, 120, a first acid-containing diffusion liquid 116 is present. The second acidic diffusion 126 may be provided directly back (preferentially enriched) to the etching process 150.

In the ion exchange process 145, a metal salt (e.g., copper chloride) to be treated is exchanged with a metal salt (e.g., copper sulfate) to obtain a metal salt-containing medium 10 (e.g., copper sulfate) from a medium 11 (e.g., copper chloride) to be treated. The metal salt-containing medium 10 is fed as a first partial stream 1 to an elemental metal recovery process 400 (see below). In addition, a lean metal acid medium 136 (e.g., hydrochloric acid) is produced during the ion exchange process 145. The lean metal acid medium 136 may (at least partially) flow as a first separated stream 5 to the rinse water treatment process 300 (see description below). Another portion of the metal-depleted acid medium 136, particularly after being supplied by a base (e.g., sodium chloride) 187, flows through a membrane filtration process that is implemented as a reverse osmosis process 185. Reverse osmosis process 185 produces i) permeate (e.g., purified water 188) that is returned to ion exchange process 145 (via mixing reactor 140) or another circuit board manufacturing process of manufacturing plant 60. In addition, purified water 188 may be used as water in discharge quality 350 (i.e., including only water, as well as small amounts of salts and organics). Reverse osmosis treatment 185 further yields ii) a salt concentrate 186a of salts and metal residues. The salt concentrate 186a can be diluted 189 and again passed through the ion exchange process 145. Thus, the diluted salt concentrate 186a becomes a metal (particularly heavy metal) depleted salt concentrate 186b (i.e., comprising only salt and small amounts of organics) that can be discharged in concentrated or diluted form. Thus, treating the waste medium 11 from the etching process 150 yields only purified water 188 (in the effluent quality 350) and/or lean metal salt concentrate 186b. All other produced products may be recycled within the circuit board and/or substrate manufacturing process.

The second partial flow 2 comprises a metal salt-containing medium 20 from a second process of an electroplating process 250 of circuit board and/or substrate manufacturing. The second treated metal salt-containing medium 20 (which does not substantially include iron) is obtained from the iron and metal salt-containing medium 21 from the electroplating process 250. Process 200 includes separating iron from the iron and metal salt containing medium 21 by an ion exchanger. In the regeneration treatment of the ion exchanger, a second acid-containing diffusion liquid occurs, which can be supplied to the rinse water treatment process 300 as a second separation stream 6.

The third partial flow 3 comprises a third treated metal salt-containing medium 30 from a rinsing water and a rinsing water mixture 31 of the circuit board and/or substrate manufacturing, respectively. The third treated metal salt-containing medium 30 is obtained in a third treatment process 300 using an ion exchanger, wherein the metal salts in the treated metal salt-containing medium 30 are enriched compared to the rinse water mixture 31. The additions described herein illustrate that the rinse water process 300 may also be implemented in the ion exchange process 145 or coupled with the ion exchange process 145. In this case, (a mixture of) flushing water 31 is mixed with the medium 12 to be treated in the mixing reactor 140 and both are subjected to an ion exchange treatment 145 and a first treatment cycle 170 (and optionally also to a second treatment cycle 180), respectively.

The partial streams 1, 2, 3 may be (at least partially) combined (see step 405) into the total stream 4 or may be treated separately. The process 400 includes recovering 400 elemental metal 50 (e.g., elemental copper) from a metal salt-containing medium 50 in a (electrolytic) reaction cell. Adjusting (continuously) the composition of the metal salt containing medium 40 as an electrolyte includes separating the acid by membrane dialysis, wherein a third acid containing diffusion liquid 446 is present. Alternatively, the diffusion liquid 446 may be used for regeneration of the ion exchanger to treat the rinse water (see third separated stream 7).

Another possibility is that no acid is removed from the electrolyte 10 at all. Conversely, the used electrolyte 175 may be used as a regenerant. As the acid concentration during electrolysis 400 will increase and the copper ion concentration will decrease, the electrolyte 175 used will be strongly acidic, which enables better desorption of copper ions from the ion exchange process 145. Furthermore, copper that has not yet been deposited will remain in the process cycle. Thus, the acid concentration in the electrolyte 10 may be increased to further use it as a regenerant. In addition, by not using further membrane dialysis, water and energy can be saved.

Metals, particularly copper, are also retained in the valuable material cycle and can therefore be almost completely removed from the metal salt-containing medium. This has the advantage that further processing steps of membrane dialysis can be saved. The resulting high purity metal 50 is in turn suitable for feedback to an etching process (see arrow 52) and/or to an electroplating process 250 (see arrow 54).

The first separated stream 5 originates from the first process 100 and includes an acidic diffusion liquid 136. The second separation stream 6 originates from the second treatment process 200 and includes a second acid-containing diffusion liquid 236. The third separated stream 7 originates from the treatment of the total stream 4 and comprises a third acid-containing diffusion liquid 446. The separate streams 5, 6, 7 each comprise a low concentration of metal salt (e.g. copper sulphate) and each comprise a lower concentration of metal salt than in the third partial stream 3. The separate streams 5, 6, 7 are (at least partly) combined into the medium 31 to be treated, respectively a mixture of flushing water (total separate stream). Further flushing water of the production method can also be introduced here. The medium 31 to be treated is treated by the third treatment process 300 as described above to significantly increase the concentration of the recovery 400.

It should be noted here that the described rinse water treatment process 300 can also be implemented in the ion exchange process 145 or coupled with the ion exchange process 145 (see above).

Fig. 2 shows in detail an exemplary embodiment of a method of treating an etching waste medium from circuit board and/or substrate fabrication. An etching waste medium is provided as a medium to be treated 11 from an etching process 150 and includes a metal salt (e.g., copper chloride) and an acid 15 (e.g., hydrochloric acid) to be treated. The medium 11 to be treated may comprise high concentrations of hydrogen peroxide from the etching solution, which may interfere with subsequent treatments and damage the membranes of the membrane dialysis 110, 120. Thus, the hydrogen peroxide concentration is reduced or hydrogen peroxide is removed within the hydrogen peroxide abatement process 160, for example, catalytic decomposition, thermal decomposition, chemical decomposition, or electrical decomposition. After hydrogen peroxide elimination 160, the medium 11 to be treated flows through the two stages 110, 120 of membrane dialysis (see fig. 3 and 4 for a detailed description).

The membrane dialysis 110, 120 is supplied by desalted water 352, which desalted water 352 may be introduced (from the outside) into the process and/or may include purified water 188, which purified water 188 will be produced later in the process and may be fed back. During membrane dialysis 110, 120, the acid 15 is substantially removed from the medium to be treated 11 to obtain a medium to be treated 12 that is less acidic. The acid 15 is now part of the acidic diffusion solution 126 (acid concentration of about 10%) which may be fed back to the etching process 150. Because the etching process 150 may employ an etching medium having an acid concentration of about 30%, the acidic diffusion solution 126 is optionally enriched in the acid enrichment process 128. The enriched acidic medium 129 can then be fed back to the etching process 150. Thus, the etching process 150, the hydrogen peroxide elimination 160, and the membrane dialysis 110, 120 (and optionally the acid enrichment process 128) may form a third process cycle 190 configured as a third closed loop that (substantially) does not yield waste (because the acid 15 is transported within the closed loop cycle).

The less acidic medium 12 to be treated is introduced into a mixing reactor 140 where it can be mixed with other metal salt media. For example, the rinse water 31 may be mixed with the less acidic medium 12 to be treated, wherein the rinse water 31 comprises small amounts of metal salts (e.g., copper sulfate) from different treatments of the circuit board manufacturing process. Furthermore, the mixing reactor 31 serves to dilute the less acidic medium 12 to be treated (in particular if it still contains a significant acid concentration). For example, dilution may be performed using rising water 31, external water 352, or purified water 188 fed back. From the mixing reactor 140, the (mixed) medium 12 to be treated is supplied to an ion exchange treatment 145.

The ion exchange process 145 may include an ion exchanger (e.g., an ion exchanger with ion exchange resin) or a liquid-liquid ion exchange process. When the diluting medium 12 to be treated is caused to flow through the ion exchange process 145, metal ions (e.g., copper ions) will remain (at least partially) in the ion exchange process 145, e.g., copper ions are adsorbed by the ion exchange resin. After flowing through ion exchange process 145 (where the metal remains), a metal-depleted acid medium 136 is obtained. Even though the medium 136 is strongly depleted by metal, it may still include heavy metals (as well as copper). Thus, the lean metal acid medium 136 is not of effluent quality and further flows into the water purification treatment 185.

The ion exchange process 145 is integrated in a first process cycle 170 configured as a first closed loop. Thus, additional acid (e.g., sulfuric acid) 175, other than acid 15, flows through ion exchange process 145 such that additional acid 175 removes metals from ion exchange process 145 (e.g., desorbs copper ions from the ion exchange resin by exchanging them with h+ ions) to provide metal salt-containing medium 10. The additional acid 175 may also be considered to include additional acid 175/regeneration medium consisting of additional acid 175. In the exemplary embodiment depicted, the metal (copper) from ion exchange process 145 and the salt from the additional acid (sulfate) result in a medium 10 containing a metal salt (copper sulfate). The metal salt-containing medium 10 is fed to an elemental metal recovery process 400 (see above) to obtain elemental metal 50 (e.g., elemental copper after electrolysis) from the metal salt-containing medium 10 and to obtain additional acid 175 again (regeneration medium). Then, for a closed loop, additional acid 175 is sent back to the ion exchange process 145 to remove the (fixed) metal again.

In one example, the additional acid 175 may still include copper, such as copper sulfate. The additional acid 175 thus includes an electrolyte in which the copper concentration is too low to achieve the desired copper deposition rate. Furthermore, the acid concentration is increasing during electrolysis 400. Thus, the additional acid 175 has a low pH value and is well suited for recovering copper adsorbed on the ion exchange process 145.

As described above, the elemental metal recovery process 400 preferably comprises an electrolytic process in which the metal salt-containing medium 10 resembles a metal-rich electrolyte that enters the electrolytic process. After elemental metal 50 is obtained, the metal-depleted electrolyte exits the electrolytic process, which essentially includes additional acid 175.

The ion exchange process 145 is further integrated in a second process cycle 180 configured as a second closed loop. The second treatment cycle 180 includes a water purification treatment 185 through which the lean metal acid medium 136 flows. From the treatment, purified water 188 is obtained, which purified water 188 may be fed back (through the mixing reactor 140) to the ion exchange treatment 145 within the second treatment cycle 180. Additionally or alternatively, the purified water 188 is fed back to another circuit board and/or substrate manufacturing process (e.g., membrane dialysis 110, 120, rinse water treatment process 300) or is discharged as water in the discharge quality 350. In one embodiment, a strong base 187 (e.g., sodium hydroxide) is added to the metal-lean acid medium 136. Base 187 and the acid (hydrochloric acid) of lean metal acid medium 136 then form a salt (e.g., sodium chloride).

Preferably, water treatment process 185 comprises a reverse osmosis treatment, wherein permeate 185a comprises purified water 188 and concentrate 185b comprises salt concentrate 186a. As described above, the salt concentrate 186a includes a high salt concentration (e.g., sodium chloride) from the acid 15 and heavy metals (still from the etching process 150). The salt concentrate 186a is returned to the ion exchange process 145 within the second process cycle 180 such that the (heavy) metal of the salt concentrate 186a remains in the ion exchange process 145 in the same manner as the metal from the medium 12 to be treated (e.g., adsorbed by the ion exchange resin). This provides a lean metal salt concentrate 186b that can be discarded as a concentrate or in diluted form. The lean metal salt concentrate 186b is substantially free of heavy metals (and includes only salts and optionally water and organics). The salt concentrate 186a can be diluted in a dilution process 189 and returned to the ion exchange process 145 as a separate stream. The salt concentrate 186a can be diluted in the mixing reactor 140 (e.g., with rinse water 31, external water 352, purified water 188) and/or mixed with the medium 12 to be treated. Additionally or alternatively, the salt concentrate 186a can be at least partially diluted with purified water 188 and returned to the ion exchange treatment 145 as a unified stream. The treatment may be carried out continuously or batchwise.

Fig. 3 shows an example of providing a less acidic medium 12 to be treated using membrane dialysis 110, 120 according to an exemplary embodiment of the present invention. In the following embodiments, copper is mainly used as an illustrative example. However, the same applies to other metals, such as: nickel, cobalt, rhodium, tin, cadmium, magnesium, sodium, silver, gold. They may form metal salts with acids (e.g., hydrochloric acid, sulfuric acid, nitrous acid, phosphoric acid). According to an exemplary embodiment, from the etching process 150, copper in the medium 11 to be treated is present in the form of copper chloride (as metal salt to be treated), and hydrochloric acid is present in the form of acid 15. The high content of chloride ions promotes uncontrolled formation of chlorine gas during recovery, e.g., electrolysis. In addition, chloride ions can co-deposit on the electrodes, which can negatively impact the purity of the deposited copper. Thus, in the first treatment process 100, copper chloride is converted to copper sulfate, while the free acid (free acid) 15 is separated. The medium 11 containing metal salts to be treated is collected in an overflow launder of the etching process 150 and provided to the first membrane dialysis 110 as dialysis liquid 11. Further, desalted water is supplied to the membrane dialysis 110 via the first diffusion liquid feed 113. The membrane 112 may comprise, for example, a wound membrane or a sheet membrane. Membrane 112 is semipermeable and allows anions (e.g., chloride) to pass through (an anionic membrane) while cations (e.g., cu2+) cannot. The membrane dialysis 110 comprises a throughput in the range of 0.5 to 5L/hm2, in particular 1 to 2L/hm 2. For the membrane dialysis described below, the same membrane or (preferably) different membranes may be used, respectively (e.g. treated (etched) according to the source of the corresponding metal salt containing solution). The anionic membrane may be functionalized, for example with bromine (Br-), wherein the support material may be, for example, PET or PVC. In some cases, the metal salt-containing solution may include hydrogen peroxide (H2O 2). In this case, an oxidation-resistant film based on, for example, polyetheretherketone (PEEK) may be preferably used.

The first portion of acid 15a is removed from the medium 11 to be treated by a first membrane dialysis 110 to obtain a first dialysate 115 having a first concentration of metal salts to be treated, and a first diffusion liquid 116 comprising the first portion of acid 15 a. The first diffusion liquid 116 also includes a second concentration of metal salt to be treated (which is lower than the first concentration). This is due to the fact that some cations still pass through the membrane 112, especially when the cations form complexes and aggregates (e.g., copper-chloride complexes), respectively. Without wishing to be bound by any particular theory, it is presently assumed that this aggregate formation may occur as the concentration of cations in the solution increases.

Subsequently, the first diffusion liquid 116 is subjected to a second membrane dialysis 120. The first diffusion liquid 116 is supplied to the second membrane dialysis 120 as a dialysate feed. As the second diffusion feed 123, desalted water was used. The second part of the acid 15b is removed from the first diffusion liquid 116 to obtain a second dialysis liquid 125 with a third concentration of the metal salt to be treated, which is lower than the second concentration, and a second (acidic) diffusion liquid 126 comprising the second part of the acid 15 b. The first diffusion liquid 116 also includes a second concentration of the metal salt to be treated. The second diffusion liquid 126 includes a fourth concentration of the metal salt to be treated that is lower than the third concentration. The cation concentration of the metal salt to be treated in the first diffusion liquid 116 is significantly lower than the cation concentration in the dialysate feed 11. Thus, it is assumed that substantially no aggregates are formed anymore and that only a negligible amount of cations diffuse through the membranes 112, 122. For this reason, preferably exactly two membrane dialysis phases 110, 120 are performed. Thus, in an advantageous manner, a high concentration of metal salts can be obtained, while the amount of liquid used does not become too high.

The second diffusion liquid 126, which includes only a negligible amount of the metal salt to be treated but has a high acid concentration, is collected in the etching treatment collection tank and then supplied again to the etching treatment 150 of the circuit board and/or the manufacturing substrate. In particular, the second diffusion liquid 126 is first treated. The first dialysate 115 and the second dialysate 125 are combined to provide the enriched, less acidic (or substantially acid-free) metal salt-containing medium 12 to be treated.

Fig. 4 again shows an example of providing a less acidic medium 12 to be treated using membrane dialysis 110, 120 according to an exemplary embodiment of the invention and ion exchange treatment 145 as detailed in fig. 2. Further, a first processing cycle 170, a second processing cycle 180, and a third processing cycle 190 are shown (see description of fig. 2 for details).

Fig. 5 illustrates a process control apparatus 600 for regulating (and separately controlling) at least a portion of the above-described methods (and plants 60, respectively) in accordance with an embodiment of the present invention. In the illustrated example, the process control apparatus 600 is implemented in a first process 100 for providing a first metal salt-containing medium 10 from an etching process 150 from circuit board and/or substrate manufacturing. In this manner, the process control device 600 may also be implemented in further (above-described) processes (and methods, respectively).

The process control apparatus 600 includes: i) A database 610 for capturing at least one process parameter 611 from a running (in an operational state) process, in the example shown the first process 100. In the exemplary embodiment, process parameters (values and/or ranges) 611 are shown captured at all processing steps (e.g., by sensors) and supplied to database 610. Thus, the process parameters constitute "actual" values (e.g., HCl concentration, copper concentration, pressure differential, etc.). The process control apparatus 600 further includes: ii) a data model unit 620 adapted to store at least one predetermined processing parameter 621 (value and/or range). In the illustrated example, a plurality of processing parameters according to one or more data models are provided in the data model unit 620 for different processing steps. Thus, these predetermined processing parameters 621 constitute "target" values. The process control apparatus 600 further includes: iii) A computing means 630 (e.g. a single (separate) unit or a plurality of units) adapted to a) compare the captured process parameter 611 (a plurality of these parameters, respectively) with the predetermined process parameter 621 (a plurality of these parameters, respectively) (e.g. compare an "actual" value with a "target" value), b) determine a control operation 631 based on the comparison (e.g. actively balancing the difference between the "actual" value and the "target" value), and c) perform the determined control operation 631 (e.g. adjusting the flow rate).

According to an exemplary embodiment of the (software-based) process control device 600, the database 610 collects data from the running process (process parameters 611), accesses the values from the previous process steps (process parameters 611), respectively, and thus saves (all) "actual" values. The data model and the plurality of data models (which are stored in the data model unit 620, e.g. also in the form of a database) depending on each other, include, among other things, "target" values (and "target" -ranges), optionally also their relationships and variables (e.g. the data model 621 as reference value/reference model for verifying the "actual" value 611). The computing device 630 compares the "actual" value with the "target" value (performing the computing steps in conjunction with the "actual" value 611, respectively, based on the data model 621) and then sets the action (control operation 631) to correspond to the comparison result (e.g., the "actual" value corresponds to the "target" value, the "actual" value deviates from the "target" value, the "actual" value meets certain criteria, etc.). The determined control operation 631 may comprise (at least part of) the method steps described above.

According to an exemplary embodiment, the computing device 630 includes a self-learning Algorithm (AI) 625 (e.g., implemented by a neural network) for comparison and/or for determination. The self-learning algorithm 625 is adapted to automatically perform the determined control operation 631 and/or provide it to the user for verification. Furthermore, based on the comparison, the self-learning algorithm 625 is adapted to determine new predetermined processing parameters 622 and to automatically provide them to the data model unit 620 and/or to provide them to the user for verification. Preferably, the self-learning algorithm 625 is adapted to take the user-verified results as a basis for learning. According to an exemplary embodiment, the computing unit 630 includes a self-learning algorithm 625 that sets actions that are implemented directly in the system or provided to the operator for verification (control operation 631). In addition, the operator's decision at the time of verification may in turn form the basis for learning artificial intelligence functions. Furthermore, based on the captured "actual" values 611, the AI can create and suggest new "target" values/ranges 621, respectively, that are incorporated into the data model in an automated or operator-controlled manner.

In one particular embodiment, the following process parameters 611 are monitored and measured separately (hereinafter, exemplary measurement methods are separately specified) and captured in database 610:

i) A fill level; by means of the ultrasonic wave measurement,

ii) a volumetric flow; by means of the flow meter,

iii) H2O2 concentration; through the use of the oxidation-reduction potential,

iv) acid concentration; pH (along line) or titration (sample extraction),

v) organic concentration; photometry (along the line) or cyclic voltammetry (sample extraction),

vi) chloride concentration; titration (sampling of a sample),

vii) iron/copper concentration; photometric or densitometry (along lines) or titration (sample extraction),

viii) temperature; a temperature sensor (along the line),

ix) a membrane dialysis pressure difference between the diffusion fluid and the dialysate; pressure sensor (along line).

In the particular embodiment, after comparing (and evaluating, data analysis) the determined (measured) process parameters 611 and the process parameters 621 predetermined by the computing device 630, for example, the following control operations 631 (and actions, respectively) are determined and performed (and triggered, respectively) by the computing device 630:

i) Chlorine formation (e.g., via a gas sensor); control operation: the electrolysis is turned off and the anode is turned off,

ii) peroxide overload; control operation: the ion exchanger for treating the washing water is not loaded,

iii) The liquid level is too low; control operation: the pump is turned off and,

iv) the iron concentration in the electrolyte is too high; control operation: the ion exchange resin is switched on and turned on,

v) the acid concentration in the electrolyte is too high; control operation: switching on membrane dialysis or pumping out the electrolytic cell,

vi) low copper concentration in the electrolyte; control operation: pumping out the electrolytic cell and delivering the electrolyte to a pre-treatment tank of the flushing water,

vii) the pressure difference in membrane dialysis is too high; control operation: the volumetric flow (flow rate) is adjusted,

viii) copper concentration in the ion exchanger permeate for treating the rinse water; control operation: the regeneration is carried out,

ix) the concentration of iron in the ion exchanger permeate for removing iron from the electroplating wastewater; control operation: the regeneration is carried out,

x) the concentration of chloride in the dialysate is too high; control operation: the volumetric flow (flow rate) is adjusted.

Reference numerals

1,2,3 first, second and third partial flows

Total flow rate

5,6,7 first, second and third separate streams

40 Medium containing metal salt, electrolyte

50 elemental metal (copper)

52 Metal feedback of etching process

54 metal feedback of the electroplating process

60 factory for manufacturing printed Circuit Board

100 treatment of Metal salt-containing (waste) Medium 10 from etching treatment in printed Circuit Board manufacturing Process Metal salt-containing Medium, metal-rich electrolyte

11 Medium to be treated

12 acid-free Medium to be treated

15 acid(s)

15a first partial acid

15b second partial acid

110 first Membrane dialysis

112 first film

113 first feed

115 first dialysate

116 first diffusion liquid

120 second Membrane dialysis

122 second film

123 second feed

125 second dialysate

126 second diffusion liquid, acid diffusion liquid

128 acid enrichment treatment

129 acid-rich, acid-rich diffusion liquid

136 lean metal acid medium (first separated stream)

140 mixing/dilution reactor

145 ion exchange treatment

150 etching treatment

160 peroxide elimination treatment

170 first process shield ring

175 other acids, regeneration medium, lean metal electrolyte

180 second treatment of the shield ring

185 membrane filtration treatment, reverse osmosis treatment

185a penetration

185b concentrated solution

186a concentrated salt

186b lean metal salt concentrate

187 alkali, sodium hydroxide

188 purified water

189 additional dilution treatment

190 third treatment cycle

200 treatment of metal salts and extraneous metal-containing media in electroplating processes during printed circuit board manufacture

20 Medium containing metal salt

21 Medium containing iron and Metal salts

231 for processing circuit board (Fu ferrite)

236 acid-containing diffusion liquid, second separation stream

250 electroplating treatment

300 treatment of a medium containing a metal salt with flushing water in the manufacture of printed circuit boards

30 flushing water medium containing metallic salt

31 Medium to be treated, total separation flow

32 additional flushing water

350 waste medium, water with discharge quality

352 water supply

400 recovery of elemental metal from a metal salt-containing medium in a printed circuit board manufacturing process

405 providing, combining, enriching

431 for further circuit board processing (Fu ferrite)

446 by acid diffusion (third separation stream)

500 further circuit board treatment, photoresist (ferric chloride) treatment

600 process control device

610 database

611 processing parameters, actual values

620 data model unit

621 predetermined process parameters, target values

622 new predetermined processing parameters

625 self-learning algorithm

630 computing device

631, determined control operations.

Claims

1. A method of processing an etching waste medium from circuit board and/or substrate fabrication, the method comprising:

providing the etching waste medium as a medium (11) to be treated, in particular a medium (11) to be treated from an etching treatment (150), wherein the medium (11) to be treated comprises a metal to be treated;

treating the medium (11) to be treated in an ion exchange treatment (145) such that the metal salt to be treated is exchanged by a metal salt, and a medium (10) containing a metal salt is obtained from the medium (11) to be treated; accordingly, it is

Flowing a first treatment cycle (170) through the ion exchange process (145), wherein the first treatment cycle (170) is a first closed loop that yields substantially only elemental metal (50); and is also provided with

Flowing a second treatment cycle (180) through the ion exchange treatment (145), wherein the second treatment cycle (180) is a second closed loop producing substantially only purified water (188) and/or lean metal salt concentrate (186 b).

2. The method according to claim 1,

wherein the metal in the metal salt and the metal in the metal salt to be treated are the same metal, and

wherein the metal is at least one of the group consisting of copper, nickel, cobalt, tin, cadmium, magnesium, sodium, silver, gold; and/or

Wherein the salt of the metal salt and the salt of the metal salt to be treated are different salts, and

wherein the salt comprises at least two of the group consisting of chloride, sulfate, nitrate, phosphate.

3. The method according to claim 1 or 2,

wherein the first processing cycle (170) further comprises:

flowing a further acid (175) different from the acid (15) through the ion exchange treatment (145), in particular as a regeneration medium, such that the further acid (175) removes the metal from the ion exchange treatment (145) to provide the metal salt containing medium (10);

Delivering the metal salt-containing medium (10) to an elemental metal recovery process (400) to obtain the elemental metal (50) and the additional acid (175) from the metal salt-containing medium (10); and is also provided with

The further acid (175) is fed back to the ion exchange process (145).

4. A method according to claim 3,

wherein the elemental metal recovery process (400) comprises an electrolytic process,

wherein the medium (10) containing metal salt is similar to the metal-rich electrolyte entering the electrolytic treatment, and

wherein the additional acid (175) is similar to the lean metal electrolyte exiting the electrolytic treatment.

5. The method of claim 1, wherein the second processing cycle (180) further comprises:

flowing the medium (11) to be treated through the ion exchange process (145), wherein the medium (11) to be treated is separated into the metal and metal-depleted acid medium (136), and then the metal remains in the ion exchange process (145);

-treating the metal acid depleted medium (136) in a water treatment process (185) such that the purified water (188) is obtained; and is also provided with

Feeding back the purified water (188) to the ion exchange process (145), and/or feeding back the purified water (188) to a further circuit board and/or substrate manufacturing process (110, 120, 140, 300), and/or

The purified water (188) is discharged as water having a discharge quality (350).

6. The method of claim 5, wherein the water treatment process (185) comprises a membrane filtration process,

wherein the permeate (185 a) comprises the purified water (188), and

wherein the concentrate (185 b) comprises a salt concentrate (186 a).

7. The method of claim 6, wherein the second processing cycle (180) further comprises:

feeding back the salt concentrate (186 a) to the ion exchange process (145) such that metal of the salt concentrate (186 a) remains in the ion exchange process (145); thereby providing the lean metal salt concentrate (186 b).

8. The method of claim 7, wherein the lean metal salt concentrate (186 b) is substantially free of heavy metals.

9. The method of claim 5, wherein the method further comprises:

adding a base (187) to the metal-depleted acid medium (136),

wherein the base (187) and the acid of the metal-depleted acid medium (136) form a salt of the salt concentrate (186 a).

10. The method of claim 1, wherein the ion exchange process (145) comprises:

applying an ion exchanger with an ion exchange resin; and/or

Liquid/liquid extraction is applied using a hydrocarbyl ion exchange medium.

11. A method according to claim 1, wherein the method comprises,

wherein the provision of the medium (11) to be treated is integrated in a third treatment cycle (190), which is a third closed loop and produces substantially no waste.

12. The method of claim 11, wherein the third processing cycle (190) comprises:

removing the acid (15) from the medium (11) to be treated by membrane dialysis (110, 120) to provide an acid-free medium (12) to be treated and an acid diffusion liquid (126),

further acid enriching the acid diffusion liquid (126) in an acid enrichment treatment (128) in particular to obtain an acid enriched diffusion liquid (129); and

-feeding back the acidic diffusion liquid (126) and/or the acid-enriched diffusion liquid (129) to the etching process (150) for producing the medium (11) to be treated.

13. The method according to claim 1, wherein providing the medium (11) to be treated comprises:

hydrogen peroxide, H2O2 elimination processing (160) is performed.

14. A circuit board and/or substrate manufacturing plant (60), comprising:

an etching treatment module (150) that produces an etching waste medium as a medium (11) to be treated, wherein the medium (11) to be treated comprises a metal salt to be treated and an acid (15);

an ion exchange processing module (145) configured to process the medium (11) to be processed such that the metal salt to be processed is exchanged by the metal salt, and a medium (10) containing the metal salt is obtained from the medium (11) to be processed;

A first treatment cycle (170) flowing through the ion exchange treatment module (145), wherein the first treatment cycle (170) is a first closed loop producing substantially only elemental metal (50); and

a second treatment cycle (180) flows through the ion exchange treatment (145), wherein the second treatment cycle (180) is a second closed loop producing substantially only purified water (188) and/or lean metal salt concentrate (186 b).

15. A method of processing an etching waste medium from circuit board and/or substrate fabrication, the method comprising: an etching wastewater (11) from circuit board and/or substrate manufacturing is treated using an ion exchange process (145) coupled to an electrolytic process (400) in a first closed loop process cycle (170) and to a membrane filtration (185) in a second closed loop process cycle (180) such that substantially only elemental copper (50), purified water (188), and a heavy metal salt-depleted concentrate (186 b) are produced.