Metal recycling by membrane distillation.

Abstract

A method for recovering metal from a chemical bath (100) for chemically treating a structure with the metal, the method comprising the steps of providing a chemical composition comprising the metal from the chemical bath (100) to a membrane still (106), separating at least a portion of the metal in the membrane still (106), and reintroducing the separated metal into the chemical bath (100).

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for recovering metal from a chemical bath for the chemical treatment of structures with metal, and to a method of use.

[0002] In the context of increasing product functionality of component carriers carrying one or more electronic components, and increasing miniaturization of such components, as well as an increasing number of components mounted on component carriers such as printed circuit boards, increasingly powerful array-like components or packages are used with several components, which have multiple contacts or connections, with much smaller spacing between these contacts. Removal of heat generated by such components and the component carrier itself during operation is becoming an increasing challenge. At the same time, the component carrier should be mechanically robust and electrically reliable so that it can operate under harsh conditions.

[0003] During the manufacture of component carriers and other products using conventional manufacturing techniques, a significant amount of waste can be generated.

[0004] There may be a need to produce metal coated structures with reduced waste.

[0005] According to an exemplary embodiment of the present invention, a method for recovering metals (particularly heavy metals) from a chemical bath for chemically treating a structure (e.g., a component carrier structure) with the metal (particularly during the manufacture of the component carrier) is provided, the method comprising the steps of supplying a chemical composition comprising the metal from the chemical bath to a membrane distiller, separating at least a portion of the metal in the membrane distiller, and reintroducing the separated metal into the chemical bath.

[0006] According to another exemplary embodiment of the present invention, an apparatus for recovering metal from a chemical bath for chemically treating a structure (e.g., a component carrier structure) with the metal (e.g., during manufacturing of the component carrier) is provided, the apparatus comprising a supply section configured to supply a chemical composition including the metal from the chemical bath to a membrane distiller, a membrane distiller configured to separate at least a portion of the metal by membrane distillation, and a reintroduction section configured to reintroduce the separated metal into the chemical bath.

[0007] According to yet another exemplary embodiment of the present invention, membrane distillation is used (e.g., in a part carrier manufacturing plant) to separate metals from a chemical bath and to reintroduce the separated metals into the chemical bath, preferably in a controlled manner to keep the metal concentration in the chemical bath constant.

[0008] In the context of the present application, the term "structure" may in particular denote any object, in particular in the form of a plate, that is subjected to metal processing.

[0009] In the context of this application, the term "component carrier" may particularly denote any support structure on and / or within which one or more components can be stored to provide mechanical support and / or electrical connectivity. In other words, the component carrier may be configured as a mechanical and / or electronic carrier for the components. In particular, the component carrier may be one of a printed circuit board, an organic interposer, and an IC (integrated circuit) substrate. The component carrier may also be a hybrid board that combines different of the above types of component carriers.

[0010] In the context of this application, the term "component carrier structure" may specifically refer to a currently manufactured preform of a component carrier. In particular, the component carrier structure may comprise a plurality of, yet integrally connected, component carriers, or preforms thereof, that may be manufactured in a batch process prior to being singulated. In particular, the component carrier structure may be a panel (e.g., having dimensions of 18 inches (45.72 centimeters) by 24 inches (60.96 centimeters) or larger), or an array (e.g., of the six component carriers currently manufactured). For example, the manufactured component carrier may be a printed circuit board or an IC substrate.

[0011] In the context of this application, the term "component carrier manufacturing plant" may specifically denote a plant or factory where component carriers such as PCB or IC substrates are manufactured.

[0012] In the context of this application, the term "chemical bath" may particularly denote a chemical composition that is contained in a container and includes various chemicals, including metals (e.g., metals in elemental form and / or dissolved metals), and a solvent, such as water. One or more further chemicals, such as one or more additives, may be included in the chemical composition. The chemical bath may be configured to perform a predetermined chemical process, particularly in plating (e.g., of a component carrier structure). In such an embodiment, the chemical bath may also be denoted as a plating bath or plating section. For example, the chemical bath may be adapted for electroplating. Electroplating is a process in which an electric current is used to reduce dissolved metal cations to form a coherent thin metal coating on an electrode, particularly a component carrier structure. In one technique, the anode is made of the metal that is to be plated onto the (e.g., component carrier) structure. Both the anode and the (e.g., component carrier) structure may be immersed in an electrolyte solution that contains one or more dissolved metal salts, as well as other ions that allow the flow of electricity. A power supply supplies a direct current to the anode, oxidizing the metal atoms it contains and allowing them to dissolve in the solution. At the cathode, metal ions dissolved in the electrolyte solution are reduced at the interface of the solution and the cathode for deposition on the cathode, e.g., a component carrier structure. In other electroplating processes, non-consumable anodes may be used, and ions of the metal to be plated may be replenished and / or reintroduced into the chemical bath as they are removed from the solution.

[0013] In the context of the present application, the term "chemical fluid" may particularly denote a liquid and / or gaseous solvent or solvent composition, optionally containing solid particles and / or one or more additives.

[0014] In the context of this application, the term "membrane distillation" may specifically refer to a thermally driven separation process in which the separation is driven by a phase transition. A hydrophobic membrane may be provided as a barrier for the liquid and / or solid phase, allowing the vapor or gas phase (e.g., water vapor) to selectively pass through the pores of the membrane. The driving force for the separation process may be a vapor partial pressure difference, which may be induced by a temperature difference.

[0015] According to an exemplary embodiment of the present invention, a metal recirculation and / or metal control system for a plant (such as a part carrier manufacturing plant) is provided in which metals are separated from a chemical bath for treating a (e.g., part carrier) structure by membrane distillation. The separated metals can then be fed back into the chemical bath for use in the next iteration, cycle, or phase of chemical treatment of the (e.g., part carrier) structure in the chemical bath. By taking this measure, substantially the entire metal content can be maintained in a closed system, rather than a large amount of residual metal being disposed of. As a result, an exemplary embodiment of the present invention can ensure efficient use of metal resources and keep the ecological footprint small during the manufacture of products such as part carriers. Advantageously, it may be possible to control the metal recirculation and refeed of metals to the chemical bath to avoid undesired dilution of the chemical bath, preferably keeping the metal concentration in the chemical bath substantially constant. Advantageously, membrane distillation may be used as a concentration technique to concentrate and reintroduce metals, for example to avoid excess water resulting from washing processes, for example to keep the metal concentration in the chemical bath stable over time. Besides the recovery of valuable resources such as metals, the exemplary embodiments may contribute to the prevention of waste, since waste may be avoided as a result of the recovery of resources. For example, only solvents such as water may be removed by membrane distillation separation from the chemical bath, while other materials (such as acids and additives used for suitable plating) may all be recovered. Thus, significant amounts of hazardous waste may be avoided.

[0016] Another advantageous effect of the present invention is that the temperature in the chemical bath can be kept constant. Additives present in the chemical bath can be very sensitive to temperature fluctuations and can even be damaged above a certain temperature threshold (e.g., 40°C). Therefore, membrane distillation is an ideal tool, on the one hand, to recover metals (optionally including plating additives) and solvents (such as water), and on the other hand, to control the temperature of the chemical bath. Thus, the concentrated metal solution, once delivered to the chemical bath, can already be at the target temperature.

[0017] More specifically, exemplary embodiments of the present invention may ensure a significant reduction in chemical drag-out by implementing membrane distillation in the process of manufacturing structures such as component carriers. In particular, a membrane distillation process may be used to control the concentration of chemical baths, in particular electroplating solutions in the chemical baths. Advantageously, recovered metals (in particular electroplating substances) may be concentrated and returned to the chemical baths. However, products other than component carriers may also be treated in the mentioned manner. Examples are structures or products treated by, for example, gold plating, zinc plating, nickel plating, etc. In general, embodiments may refer to surface treatments, for example, electroplating and corresponding applications.

[0018] In the following further exemplary embodiments of the method and apparatus are described.

[0019] In one embodiment, the metal comprises at least one of the group consisting of gold, palladium, tin, silver, iron, nickel, cobalt, lead, iridium, zinc, and copper. The metal may be present in dissolved form and / or as elemental metal. In particular, any type of heavy metal that is processed in a surface metallization process (example for component carrier manufacturing) may be recovered by the exemplary embodiment. In the context of this application, the term "heavy metal" refers to a metal having a concentration of 5 g / cm 3Metals with greater density may be particularly noted. Specifically, heavy metals may include iron, copper, nickel, tin, silver, gold, palladium, and platinum. However, given their limited availability, recycling of gold and palladium may be most important.

[0020] In one embodiment, the method comprises a step of separating the solvent or chemical fluid, in particular water, from the metal in a membrane still and reintroducing the separated solvent or chemical fluid into a cleaning system. In addition to the concentration of metal on one side of the distillation membrane, the solvent (in particular water) accumulated on the opposite side can also be fed back into the manufacturing process, preferably into the cleaning system as a cleaning fluid. Advantageously, additionally separated chemical fluids such as water can also be recycled by membrane distillation and can for example be fed back into the cleaning system for a subsequent cleaning process. The above cleaning process can be carried out after a chemical treatment of a structure (in particular a component carrier structure) in a chemical bath. For example, a structure that can be provided with metal during the chemical treatment can be washed after the chemical treatment to remove excess amounts of metal, and then the cleaning fluid containing the removed metal can be fed into the chemical bath. This diluted solvent from the chemical bath can then be fed into a membrane still for separating the metal against the water. By retaining the solvent such as water also in the manufacturing process, resources can be used even more efficiently.

[0021] In one embodiment, the method comprises separating at least one further substance of the chemical composition in a membrane still, and in particular reintroducing the separated at least one further substance into the chemical bath. For example, the method comprises concentrating the at least one further substance before reintroducing the concentrated at least one further substance into the chemical bath. In particular, the at least one further substance comprises at least one of the group consisting of at least one plating additive, an acid, and a base. Recycling such substances used during the manufacturing process (e.g., for manufacturing the component carrier) can avoid waste, reduce the ecological footprint, and conserve resources.

[0022] In one embodiment, the method comprises a step of cleaning the chemically treated structure (particularly the component carrier structure) by means of a cleaning system, in particular using the reintroduced solvent. After a plating process that may be carried out on the structure (particularly the component carrier structure) in the chemical bath, excess metallic contaminants of the structure may be removed by a cleaning step. The required cleaning fluid may be returned from the distillation membrane.

[0023] In one embodiment, the method comprises a step of washing the structure (in particular the component carrier structure) with a washing fluid directly in or above the chemical bath. In particular, the washing fluid may be fed from a washing system to the chemical bath before, during and / or after the washing step. As a result, the chemical bath may be diluted with the washing fluid. The dilute solution of the chemical fluid with the dissolved metals may then be fed to a membrane still for metal reconcentration, and the reconcentrated dissolved metals may be fed back to the chemical bath.

[0024] In one embodiment, the method comprises reintroducing the separated solvent into the cleaning system at a flow rate in the range of 5 l / h to 50 l / h, in particular in the range of 10 l / h to 30 l / h. Thus, already relatively small flow rates may be sufficient to operate the cleaning system with the recovered fluid. These moderate flow rates reflect the fact that the focus of the exemplary embodiment of the invention may be to concentrate metals for the purpose of maintaining the chemical bath, with the recirculation of chemical fluids such as water being a by-product.

[0025] In one embodiment, the method comprises plating in a chemical bath a plate-shaped structure, in particular a panel for manufacturing a component carrier. The method may also comprise a step of cleaning the plate-shaped structure, in particular a panel for manufacturing a component carrier, in a cleaning system. In particular, the method may comprise plating and / or cleaning the plate-shaped structure in a horizontal or vertical orientation. Advantageously, it may be possible to implement membrane distillation in a horizontal plating line. According to such an embodiment, it may be advantageous to install a cleaning system above an initial cleaning cascade. This method may be used in particular when panels are plated in a horizontal plating line. Such an embodiment may refer to a scenario where there is limited space to install a cleaning system above the chemical bath. More generally, the exemplary embodiment of the invention is advantageously compatible with both horizontal or vertical alignment of plate-shaped structures during the plating and / or cleaning steps. This increases the freedom of design of the manufacturing architecture.

[0026] In one embodiment, the method comprises a step of supplying waste heat from a manufacturing plant, in particular a part carrier manufacturing plant, to the hot side of the membrane still, which may correspond to the recovered metal side. By taking this measure, the energy consumption of the recycling process may be reduced.

[0027] In one embodiment, the method comprises a step of supplying waste heat from an etching process and / or from a plating process of a manufacturing plant, in particular a part carrier manufacturing plant, to the hot side of the membrane still. In the etching stage of a manufacturing plant, a significant amount of waste heat may occur that is conventionally lost to the environment. By selectively redirecting such waste heat from the etching stage or any other suitable stage of the manufacturing process to the membrane still, energy efficiency may be improved. Correspondingly, during the manufacturing of a product (such as a part carrier), a plating process of a plating structure (such as a part carrier structure), for example a plating process carried out in a chemical bath, may also generate a significant amount of heat. Very advantageously, the chemical bath, if embodied as a plating stage, may be spatially very close to the membrane still, as a result of which the redirection of waste heat from plating to the membrane still may be energetically very efficient. However, it should be said that exemplary embodiments of the present invention may also be applied to manufacturing processes other than those for part carriers, for example for plating or surface metallization in any other suitable industrial field. In such a scenario, waste heat created in other manufacturing stages may also be applied to the membrane still for heating or preheating.

[0028] In one embodiment, the method comprises the step of supplying cooling energy to the cold side of the membrane still (which may correspond to the recovered solvent or water side) from a manufacturing plant (in particular a part carrier manufacturing plant). By taking this measure, the energy consumption of the recycle process can be reduced.

[0029] In one embodiment, the method comprises the step of supplying cooling energy to the cold side of the membrane still from a cold cleaning fluid supply (such as an industrial water supply) of a manufacturing plant (particularly a component carrier manufacturing plant). For example, the cleaning fluid is provided as part of an industrial water supply system in a component carrier factory, typically at a temperature in the range of 6° C. to 14° C., often in the range of 8° C. to 12° C. As such, the temperature of the water supply may be significantly below room or laboratory temperature. Thus, the fresh water supply may be used as a heat sink, which may efficiently cool the solvent side of the membrane still, only gently heating the fresh water by a few degrees Celsius, without adversely affecting the fresh water supply within the framework of the PCB factory.

[0030] In one embodiment, the method comprises concentrating metals in a membrane still, i.e. accumulating metals (e.g. dissolved and / or elemental) on one side of the membrane. It is then possible to reintroduce the concentrated metals back into the chemical bath. Such a metal concentration approach, when implemented in a PCB manufacturing environment, is a paradigm shift in membrane distillation. Typically, membrane distillation is used for large volumes of aqueous solutions when trying to recover water, etc. According to an exemplary embodiment of the invention, this logic is reversed and the concentration of metals is increased on the hot side of the distillation membrane, which is the main goal of the incorporation of membrane distillation in PCB manufacturing. By taking this measure, membrane distillation contributes to keeping the chemical bath and especially its metal concentrations within the target range, and in particular to preventing excessive dilution in the chemical bath.

[0031] In one embodiment, the method comprises controlling (especially regulating, for example, based on a measurement of the metal concentration in the chemical bath) the feeding and / or separating and / or reintroducing steps so that the concentration of the metal in the chemical bath remains constant. In particular, the device may comprise a control (such as a processor, a multiprocessor or a part of a processor) configured to control (especially regulate) the device (especially at least one of the feeding, the membrane still and the reintroduction). More particularly, said control may be configured to control or regulate the device so that the concentration of the metal in the chemical bath remains constant. Very advantageously, the metal recovery process may be carried out in a controlled manner for the maintenance of the chemical bath, in particular to avoid excessive dilution thereof. For example, the control may control the device so that the concentration of the metal dissolved in the chemical bath always remains at a target concentration. The operation of the membrane still may therefore be adjusted so that the amount of metal fed back from the membrane still to the chemical bath corresponds to the metal lost in the chemical bath so that the concentration of the metal in the chemical bath remains constant.

[0032] In one embodiment, the device comprises a user interface configured to allow a user to control the operation of the device, in particular to control the process of recovering metals from a chemical bath carried out by the device. For example, the user may select a manual or automatic operation mode of the device via the user interface. In particular, the user interface may be configured to operate a controller for controlling the process carried out by the device. This may allow automating the operation of the membrane distiller. A software-assisted controller may be implemented to allow a fully automated process control. Thus, software-assisted control of the membrane distillation may be realized. This may include one or more process control sensors, e.g., pressure sensors, flow rate sensors, etc. The software may receive information from the sensors and compare these values ​​with predefined reference values. If these two values ​​do not match, a behavior may be triggered, e.g., the flow rate is increased or decreased.

[0033] Details of user adjustable controls of an apparatus according to an exemplary embodiment of the invention, performed by a controller, such as a software-based processor, are described below.

[0034] Control components and sensors may be implemented for control of the process. Such implementations may enable pressure measurement, flow measurement, providing frequency inverters for pumps, conductivity measurement, pH measurement, providing level controls and / or level indicators, temperature measurement, providing valves (e.g. magnetic valves, motor valves, etc.), providing calorimeters, providing leak sensors, etc.

[0035] The device can be controlled in manual or automatic mode.

[0036] In manual mode, for example, pumps, valves, motor valves can be manually controlled (to be heated or cooled). In this mode of operation, set points can be prevented from being automatically adjusted. Manual mode may be used when testing adjustments (e.g., when changing modules, during maintenance, etc.). Safety parameters such as over-temperature may also be operational in manual mode and may lead to a safety shutdown of the device if thresholds are exceeded.

[0037] In automatic mode, the operation of the device can be carried out as follows: As long as the membrane still of the device is cold, the membrane may be bypassed by a bypass line. The feed circuit may be heated to a target temperature and the permeate circuit may be cooled to another target temperature. The pump may be operated with minimum power up to the target temperature, for example by using a frequency inverter, which may be controlled to a given flow in the parameter management. At the same time, the membrane may be preheated to the target temperature. The bypass valve may then be closed and the membrane flow-through may be induced. At the start, the membrane flow-through may be induced with a limited feed and permeate ratio (for example at a ratio of 1:6). When the parts of the device reach the target temperature, the pump performance may be gradually increased. The feed and permeate flows may be operated with maximum power specified in the parameters, for example the ratio may be changed to 1:10. The device may automatically switch between different operating modes depending on the relationship between the filling level and the flow rate. This may correspond to the need for wash water. The removal of the wash water may be indicated by a sensor in the permeate tank, which measures the filling level. The level at which the next operating mode should be changed may be specified in the setpoint (e.g., associated with the parameter sets "min", "setpoint", "max"). Even for absolute minimums, values ​​should be entered. If the system falls below the value, it may shut down (e.g., safety shut down to avoid pumps running dry, under-separation, etc.). Based on the level, the two pumps may adjust the flow rate. If more wash water is required (i.e., in a high utilization scenario), the level in the permeate tank may be reduced and the flow rates (feed and permeate) may be increased to generate more wash water.

[0038] When the system is operated in maximum operating mode for a certain period of time, i.e., water flushing is not required for an extended period of time (e.g., in a low fill scenario), an automatic change to standby mode may occur (i.e., a mode using minimum separation power). In the set point management, a time delay can be set to activate the standby mode.

[0039] In automatic mode, the system may be operated at a temperature value predefined in the parameter set. The feed temperature is the relevant parameter in this context, the temperature of the process fluid. The maximum value should not be exceeded (as this may destroy the process chemistry). Minimum and maximum values ​​for temperature can also be entered into the setpoint control. If the maximum value is exceeded, the system may shut down (as a safety shutdown to protect against overheating). In one embodiment, the temperature is not changed in standby mode. The system may always remain at the setpoint temperature in automatic operation at full capacity as well as in standby mode at minimum capacity.

[0040] The maximum allowable input and differential pressure on the modules may be constantly monitored. If these maximum values ​​are exceeded, the system may automatically shut down (in automatic mode and in manual operation), i.e. a safety shutdown may be performed. The feed and permeate conductivities may be constantly monitored. If there is a sudden drop in the feed conductivity value or a sudden rise in the permeate conductivity value, the device may go into a safety shutdown. Uneven changes in conductivity may indicate a membrane break or other critical problems in the process. The pH values ​​of the feed and permeate may also be constantly detected. Maximum and minimum limit values ​​can also be stored for the pH value in order to force an emergency shutdown of the system. The feed and permeate flows may be permanently monitored by flow measurements. If there is a significant deviation from the flows defined in the parameter set, the cause may be, for example, a broken pipe or an incorrectly switched valve. The device may return to an emergency shutdown. The device may stand on a drip cup. A leak sensor may be installed in the drip cup. If the leak sensor responds, an appropriate alarm may be issued so that the operator can check for leaks. If the alarm is not acknowledged for a defined period of time, the system goes into a safety shutdown.

[0041] In one embodiment, the membrane still is configured to provide the separated metals at the heatable or heated side of the membrane still or its membrane. Correspondingly, the membrane still may be configured to provide a chemical fluid or solvent, in particular water, separated from the metals in the membrane still at the coolable or cooled side of the membrane still or its membrane. Due to the temperature gradient applied across the membrane and according to the functional principle of membrane distillation, the metals will accumulate on the hotter side and the water will accumulate on the cooler side. The respective separated solvents may then be fed back to the chemical bath (i.e. metal solvent) or to the washing system (i.e. water).

[0042] In one embodiment, the device comprises a heating section configured to heat the metal side of the membrane distiller. For example, such a heating section may be a heating assembly. Even more preferably, the heating section may be configured to heat the metal side using waste heat of the manufacturing plant (particularly the part carriers). As a result, by using low-temperature waste heat as an energy source, energy efficiency may be increased.

[0043] In one embodiment, the apparatus includes a cooling section configured to cool the solvent side of the membrane distiller. For example, such a cooling section may be a cooling assembly. Even more preferably, the cooling section may be configured to cool the solvent side using waste cooling energy of the manufacturing plant (e.g., part carriers). Thus, the energy efficiency of the apparatus and method may be further improved by using a heat sink of the manufacturing equipment to cool the solvent side of the membrane distiller without the need to expend additional energy for cooling.

[0044] In one embodiment, the apparatus comprises a closed metal loop for circulating (molten and / or elemental) metals within a manufacturing plant, in particular a component carrier manufacturing plant, so that substantially no metal is lost, thereby reducing the efforts to dispose of metals that may occur in the past. Furthermore, metal resources consumed by the manufacturing plant can be used more efficiently.

[0045] In one embodiment, the device comprises a closed solvent loop for circulating the solvent in a manufacturing plant, in particular a part carrier manufacturing plant, so that the water circulation may be closed for cleaning applications, and thus the demand for cleaning water may be reduced.

[0046] In one embodiment, the method comprises a step of temporarily bypassing the membrane still for the flow of the chemical composition. In particular, said bypassing step may be performed if, until or as long as the temperature difference between the hot side and the cold side of the membrane still falls below a predefined threshold. Another challenge arising from the application of the membrane still is that the necessarily applied temperature gradient may not be immediately obtained at the beginning. Thus, metal dragout (to the water side) may occur as long as the temperature gradient has not yet been reached. To efficiently suppress this undesired dragout, it may be possible to implement a bypass function during the warm-up of the membrane still. Until the temperature difference between the hot side and the cold side of the membrane still is not large enough, the chemical composition from the chemical bath will not be fed to the membrane still for separation, but will be redirected or directed around the membrane still along the bypass line.

[0047] In one embodiment, the method comprises a step of temporarily reducing the ratio of the flow of the chemical composition to the membrane still and the flow of the solvent leaving the membrane still. In particular, said step of reducing the ratio may be performed if, until or as long as the temperature difference between the hot side and the cold side of the membrane still falls below a predefined threshold. The amount of chemical composition fed from the chemical bath to the membrane still may be reduced and / or the amount of water taken off at the cold side of the membrane may be increased until the temperature difference (and, consequently, the partial pressure difference) between the hot side and the cold side of the membrane still is large enough to perform membrane distillation without the unintentional migration of significant amounts of metals towards the water side. Descriptively, this may result in the adjustment of more favorable partial pressure conditions.

[0048] In one embodiment, the method comprises a step of preheating the membrane distiller before starting to supply the chemical composition to the membrane distiller. In particular, the preheating step without supplying the chemical composition to the membrane distiller may be performed if, until or as long as the temperature difference between the hot side and the cold side of the membrane distiller falls below a predefined threshold. For example, the membrane can be preheated simultaneously with the above-mentioned bypassing step to reduce the time until the proper functioning of the membrane distiller is ensured. This may result in a more rapid adjustment of the partial pressure value at the membrane of the membrane distiller.

[0049] In one embodiment, the chemical bath is or forms part of a plating unit that is configured to plate, in particular electrically plate, the structure (in particular the component carrier of the component carrier structure). During plating of gold, palladium or copper material, a chemical plating bath may be implemented to plate the structure with gold, palladium or copper material. Such plating process may result in contamination of the structure (and / or of the handling unit for handling such structure) with gold, palladium or copper in unwanted areas, and as a result, the excess gold, palladium or copper material may be removed by washing. The gold, palladium or copper may then be recovered from the chemical plating bath and / or from a washing system.

[0050] In one embodiment, the device comprises a cleaning system for cleaning a structure by treatment with a moist gas beam, in particular with a water-saturated moist air beam. More specifically, a water-saturated pressurized gas can be directed onto a surface of the structure (in particular onto a main surface of a plate-shaped structure, more specifically a component carrier structure) to remove chemicals from said surface and clean the structure. Descriptively, a pressurized gas with a large amount of water vapor can act as a gas knife and efficiently clean the surface of the structure, advantageously requiring a small amount of cleaning liquid (in particular water). At the same time, such a moist gas beam can efficiently clean the surface without the risk of solidified chemicals remaining attached to the surface of the structure due to the water content of the moist gas beam. More advantageously, the solvent in the form of the former moist gas beam in liquid form can be accumulated in a container or the like and can contain a relatively large amount of chemicals. The latter can be recycled, in particular by a membrane still.

[0051] In one embodiment, the cleaning system is configured to feed the solvent collected during cleaning of the structure by treatment with a wet gas beam to a chemical bath or to a membrane still. Said solvent, constituting the fluid residue of the described cleaning process using a wet gas knife, may have very high concentrations of chemicals (and in particular metal chemicals) that are to be recycled. It is then very suitable to feed this solvent to the chemical bath (or directly to the membrane still) for recycling metals, plating additives, acids, bases, etc.

[0052] In one embodiment, the device is configured to supply water from the membrane still to the scrubbing system. More specifically, water collected on the cold side of the membrane still may be supplied to the scrubbing system to provide the humidity required to generate the moist gas beam. Such recovery or re-injection of water to the scrubbing system using a gas knife may further reduce waste and may use resources more efficiently.

[0053] In one embodiment, the cleaning system includes at least one additional cleaning stage for cleaning the structure after cleaning by an initial cleaning stage configured to clean the structure by treatment with a moist gas beam. Thus, a multi-stage cleaning system may be provided, for example as described above, where the initial or first stage may be constituted by a moist gas beam directed towards the structure to be cleaned. The pre-cleaned structure may then be additionally cleaned or washed in one or more additional cleaning stages. For example, each of said additional cleaning stages may include a sprinkler system for spraying a cleaning liquid such as water onto the structure to be cleaned. Alternatively, any additional cleaning stage may be constituted by a further moist gas beam directed towards the structure to be additionally cleaned (as described above for the initial cleaning stage). Since the gas knife type initial cleaning stage provides a particularly high concentration of chemicals to be recirculated in a particularly small amount of residual solvent, and the liquid sprinkler type additional cleaning stage provides a significantly lower concentration of chemicals in a much larger amount of liquid residual solvent, it may be possible to use only the solvent output by the initial cleaning stage for recirculation.

[0054] In one embodiment, the membrane distiller includes a heatable side, a coolable side, and a gap between the heatable side and the coolable side, with a first membrane disposed in the heatable side and the gap, and a second membrane disposed between the gap and the coolable side. In this case, direct contact between the heatable side, where the chemical concentrate is concentrated, and the coolable side, where the separated solvent is concentrated, is avoided. This allows avoiding contamination of the separated solvent due to membrane leakage. In this configuration, it is also possible to control the dilution of the separated metals during rest of the membrane distiller due to osmotic pressure across the membrane. Any leakage of the separated metals in the gap can be evacuated from the gap. It is also possible to remove non-condensable gases that may be trapped inside the gap or in the membrane by applying a gentle vacuum to the gap. The first and second membranes are preferably hydrophobic PTFE membranes.

[0055] According to a further embodiment, the membrane still further comprises a heat exchanger thermally coupled to the heatable side. In this case, it is therefore possible to preheat the heatable side, thus increasing the temperature difference between the heatable and coolable sides, resulting in a more efficient functioning of the membrane still. In this context, the heat exchanger may allow the utilization of waste heat (otherwise not utilized) coming from another process and / or from a sub-process of the above-mentioned method.

[0056] According to a further embodiment, the heat exchanger comprises a channel for conducting a flow of hot distillate, the channel being separated from the heatable side by a thermally conductive material layer, preferably a polymer film. According to this embodiment, it is therefore possible to use the waste heat coming from the hot distillate during the manufacturing process to heat the heatable side. The thermally conductive material layer is impermeable and is preferably a polymer film, such as polyvinyl alcohol. It is also possible to use other sources of waste heat present during the manufacturing process.

[0057] According to a further embodiment, the membrane distiller has a further heatable side and a further gap. The coolable side is arranged between the gap and the further gap, and the further gap is arranged between the coolable side and the further heatable side. Thus, the described membrane distiller can be realized in a modular structure, which can be particularly advantageous for saving space by providing a compact assembly. It may also be possible to recover solvent from two heatable sides using a single coolable side.

[0058] According to a further embodiment, the supply comprises an evaporator. In particular, the supply may comprise an evaporator capable of carrying out a flash evaporation of the chemical composition to be fed to the membrane evaporator. The evaporator is therefore a flash evaporator. During evaporation, only a part of the solvent of the chemical composition present in the evaporator is evaporated.

[0059] In a further embodiment, the membrane distiller has a heatable side, a coolable side, a vapor side, a membrane, and a thermally conductive layer. The heatable side is disposed between the vapor side and the coolable side, the membrane is disposed between the heatable side and the coolable side, and the thermally conductive layer is disposed between the vapor side and the heatable side. In this embodiment, the device further comprises a vapor supply means for supplying vapor from the evaporator to the vapor side, and a condensate supply means for supplying the chemical composition in liquid form from the evaporator to the heatable side. In this particular configuration, the vapor generated by the evaporator may be used to heat the heatable side of the membrane distiller. The vapor may contain a solvent of the chemical composition. The vapor in the vapor side may condense due to thermal exchange with the heatable side at the thermally conductive layer and may be collected and reused as a solvent. The solvent in the chemical composition present on the heatable side may partially evaporate and the generated vapor may pass through the membrane, where the vapor may condense as a solvent and be collected for further use. The non-evaporated portion of the chemical composition may have a higher concentration of the metal elements to be recovered and may be collected and reused. The thermally conductive layer may preferably be a polymeric film.

[0060] According to another embodiment, the membrane distiller further comprises a further heatable side, a further coolable side, a further membrane and a further thermally conductive layer. The further heatable side is arranged between the coolable side and the further coolable side, the further membrane is arranged between the further heatable side and the further coolable side, and the further thermally conductive layer is arranged between the further heatable side and the coolable side. The device further comprises a further concentrate supply means for supplying the chemical composition in liquid form from the heatable side to the further heatable side, wherein during operation the pressure in the heatable side is greater than the further pressure in the further heatable side. It may therefore be possible to lay the membrane distiller in a modular manner, where the heatable and coolable sides spatially alternate with each other, and the pressure in the system decreases with the number of modules included in the system. By using a decreasing pressure along the modules, it is possible to reduce the temperature required for the solvent to evaporate and thus use the previous coolable side as a waste heat source for the next heatable side of the system. Thus, the overall efficiency, and in particular the energy efficiency of the membrane distiller, may be further increased.

[0061] In an embodiment, the component carrier manufactured may comprise a stack of at least one electrically insulating layer structure and / or at least one electrically conductive layer structure. For example, the component carrier may be a stack of the above-mentioned electrically insulating layer structure and the conductive layer structure, which is formed in particular by applying mechanical pressure and / or thermal energy. The above-mentioned stack may provide a plate-shaped component carrier, which may be very thin and compact while still offering a large mounting surface for further components. The term "layer structure" may in particular denote a continuous layer, a patterned layer, or a plurality of discontinuous islands in a common plane.

[0062] In one embodiment, the component carrier is shaped as a plate. This contributes to a compact design, yet the component carrier provides a large platform on which to place components. Furthermore, particularly for example embedded electronic components, bare dies can be conveniently embedded in thin plates, such as printed circuit boards, due to their small thickness.

[0063] In one embodiment, the component carrier is configured as one of the group consisting of a printed circuit board, a substrate (particularly an IC substrate), and an interposer.

[0064] In the context of this application, the term "printed circuit board" (PCB) may in particular denote a plate-shaped component carrier formed by laminating several conductive layer structures with several electrically insulating layer structures, for example by applying pressure and / or by supplying thermal energy. As a preferred material for PCB technology, the conductive layer structures are made of copper, whereas the electrically insulating layer structures may comprise resin and / or glass fibers, so-called prepreg or FR4 material. The various conductive layer structures may be connected to each other in the desired manner, for example by forming through-holes through the laminate by laser drilling or mechanical drilling, and filling them with a conductive material, in particular copper, to form vias as through-hole connections. In addition to one or more components that may be embedded in the printed circuit board, the printed circuit board is usually configured to store one or more components on one or both opposing faces of the plate-shaped printed circuit board. They may be connected to the respective main surfaces by soldering. The dielectric part of the PCB may be made of resin with reinforcing fibers (such as glass fibers).

[0065] In the context of the present application, the term "substrate" may in particular denote a small component carrier. A substrate may be a relatively small component carrier on which one or more components may be placed in relation to a PCB and which may act as a connection medium between one or more chips and further PCBs. For example, a substrate may have substantially the same size as the components (particularly electronic components) placed thereon (for example in the case of a chip-scale package (CSP)). More specifically, a substrate may be understood as a carrier for electrical connections or electrical networks and a component carrier comparable to a printed circuit board (PCB), but with a much higher density of connections arranged laterally and / or vertically. The lateral connections may for example be conductive tracks, whereas the vertical connections may for example be drilled holes. These lateral and / or vertical connections may be arranged in the substrate and used to provide electrical, thermal and / or mechanical connections of housed or unhoused components (such as bare dies), in particular IC chips, to a printed circuit board or an intermediate printed circuit board. The term "substrate" therefore also includes "IC substrates". The dielectric portion of the substrate may be composed of a resin having reinforcing particles (such as reinforcing spheres, especially glass spheres).

[0066] The substrate or interposer may include or consist of at least a layer of glass, silicon (Si), or a photosensitive or dry-etchable organic material such as an epoxy-based build-up material (such as an epoxy-based build-up film), or a polymeric compound such as a polyimide, polybenzoxazole, or benzocyclobutene functionalized polymer.

[0067] In one embodiment, the at least one electrical insulation layer structure comprises at least one of the group consisting of resin (reinforced or non-reinforced resin, such as epoxy resin or bismaleimide triazine resin), cyanate ester resin, polyphenylene derivative, glass (particularly glass fiber, laminated glass, glass-like material), prepreg material (such as FR-4 or FR-5), polyimide, polyamide, liquid crystal polymer (LCP), epoxy-based build-up film, polytetrafluoroethylene (PTFE, Teflon®), ceramic, and metal oxide. Reinforcement structures such as webs, fibers, or spheres made of glass (laminated glass) may also be used. Prepregs, especially FR4, are usually preferred for rigid PCBs, but other materials, especially epoxy-based build-up films or photosensitive dielectric materials, may also be used. For high frequency applications, high frequency materials such as polytetrafluoroethylene, liquid crystal polymers, and / or cyanate ester resins, low temperature co-fired ceramics (LTCC), or other low, very low, or ultra low DK materials may be implemented as electrically insulating layer structures in the component carrier.

[0068] In one embodiment, the at least one conductive layer structure comprises at least one of the group consisting of copper, aluminum, nickel, silver, gold, palladium, and tungsten. Copper is usually preferred, but other materials or coatings thereof are also possible, especially those coated with superconducting materials such as graphene.

[0069] At least one component that may be embedded in and / or surface mounted on the stack may be selected from the group consisting of an electrically non-conductive inlay (preferably comprising a ceramic inlay, aluminum nitride or aluminum oxide, etc.), a conductive inlay (such as a metal inlay, preferably comprising copper or aluminum), a heat transfer section (e.g., a heat tube), a light directing element (e.g., an optical waveguide or light conductor connection), an optical element (e.g., a lens), an electronic component, or a combination thereof. For example, the component may be an active electronic component, a passive electronic component, an electronic chip, a storage device (e.g., a DRAM or another data memory), a filter, an integrated circuit, a signal processing component, a power management component, an optoelectronic interface element, a light emitting diode, a photocoupler, a voltage converter (e.g., a DC / DC converter or an AC / DC converter), a cryptographic component, a transmitter and / or a receiver, an electromechanical transducer, a sensor, an actuator, a microelectromechanical system (MEMS), a microprocessor, a capacitor, a resistor, an inductance, a battery, a switch, a camera, an antenna, a logic chip, and an energy harvester. However, other components may also be embedded in the component carrier. For example, magnetic elements may be used as components. Such magnetic elements may be permanent magnetic elements (ferromagnetic, antiferromagnetic, multiferroic or ferrimagnetic elements, such as ferrite cores) or paramagnetic elements. However, the components may also be substrates, interposers or further component carriers, for example in a board-in-board configuration. The components may be surface mounted and / or embedded within the component carrier. Also other components may be used as components.

[0070] In one embodiment, the component carrier is a stacked component carrier, in which the component carrier is a composite of multiple layers that are stacked and connected together by application of pressure and / or heat.

[0071] After processing the internal layer structure of the component carrier, one or both opposing main surfaces of the processed layer structure can be covered symmetrically or asymmetrically (in particular by lamination) with one or more further electrically insulating and / or conductive layer structures, in other words the build-up can be continued until the desired number of layers is obtained.

[0072] After the formation of the stack of electrically insulating and conductive layer structures has been completed, it is possible to proceed with a surface treatment of the resulting layer structure or component carrier.

[0073] In particular, an electrically insulating solder resist may be applied to one or both opposing major surfaces of the layer stack or component carrier for surface treatment. For example, it is possible to form a solder resist or the like over the entire major surface, and then pattern the layer of solder resist to expose one or more conductive surface portions that are used to electrically couple the component carrier to electronic peripherals. Surface portions of the component carrier that remain covered with the solder resist may be effectively protected against oxidation or corrosion, particularly surface portions that contain copper.

[0074] With regard to surface treatment, it is also possible to selectively apply a surface finish to exposed conductive surface portions of the component carrier. Such a surface finish can be a conductive cover material on exposed conductive layer structures (especially copper-containing or copper-made, such as pads, conductive tracks, etc.) on the surface of the component carrier. If such exposed conductive layer structures are left unprotected, the exposed conductive component carrier material (especially copper) can oxidize and reduce the reliability of the component carrier. The surface finish can then be formed, for example, as an interface between the surface mount component and the component carrier. The surface finish has the function of protecting the exposed conductive layer structures (especially copper circuits) and enabling a joining process with one or more components, for example by soldering. Examples of materials suitable for the surface finish are organic solderability preservative (OSP), electroless nickel immersion gold (ENIG), gold (especially hard gold), chemical tin, nickel gold, nickel palladium, electroless nickel immersion palladium immersion gold (ENIPIG), etc.

[0075] The above-defined and further aspects of the invention are apparent from and will be elucidated with reference to the example embodiments described hereinafter. [Brief description of the drawings]

[0076] [Figure 1] FIG. 1 shows a schematic diagram of an apparatus for recovering gold from a chemical bath for chemically treating component carrier structures with gold in a component carrier manufacturing plant according to an exemplary embodiment of the present invention.

[0077] [Diagram 2] 1 illustrates a membrane still for an apparatus and method according to an exemplary embodiment of the present invention.

[0078] [Diagram 3] FIG. 1 shows a schematic diagram of an apparatus for recovering gold from a chemical bath for chemically treating component carrier structures with gold in a component carrier manufacturing plant according to an exemplary embodiment of the present invention.

[0079] [Figure 4] 1 shows a schematic diagram of an apparatus for recovering palladium from a chemical bath for chemically treating component carrier structures with palladium in a component carrier manufacturing plant according to an exemplary embodiment of the present invention.

[0080] [Diagram 5] 1 illustrates elements of a membrane still for an apparatus and for use in a method according to an exemplary embodiment of the present invention.

[0081] [Figure 6] FIG. 1 illustrates an apparatus for recovering metals from a chemical bath for chemically treating component carrier structures with metals in a component carrier manufacturing plant, according to another exemplary embodiment of the present invention, where the membrane still can be bypassed, preheated, and / or subject to varying feed / permeate ratios.

[0082] [Figure 7] According to yet another exemplary embodiment of the present invention, an apparatus for recovering metals from a chemical bath for chemically treating component carrier structures with metals in a component carrier manufacturing plant is shown, in which a multi-stage cleaning system includes an initial stage based on treating a plate-shaped component carrier structure with a moist gas beam, followed by a subsequent stage based on spraying a cleaning liquid onto the plate-shaped component carrier structure.

[0083] [Figure 8] 1 illustrates an apparatus for recovering metals from a chemical bath for chemically treating component carrier structures with metals in a component carrier manufacturing plant, according to yet another exemplary embodiment of the present invention implementing various multi-stage cleaning systems. [Figure 9] 1 illustrates an apparatus for recovering metals from a chemical bath for chemically treating component carrier structures with metals in a component carrier manufacturing plant, according to yet another exemplary embodiment of the present invention implementing various multi-stage cleaning systems.

[0084] [Figure 10] 1 shows an apparatus for recovering metal from a chemical bath for chemically treating component carrier structures with metal in a component carrier manufacturing plant according to yet another exemplary embodiment of the present invention.

[0085] [Figure 11] 1 shows a membrane still according to a further embodiment of the present invention.

[0086] [Figure 12] An apparatus for recovering metal from a chemical bath for chemically treating component carrier structures with metal in a component carrier manufacturing plant according to a further embodiment of the invention is shown, the apparatus comprising a supply with an evaporator.

[0087] [Figure 13] 1 shows a membrane still according to a further embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0088] The illustrations in the drawings are schematic and in different drawings similar or identical elements are given the same reference signs.

[0089] Before the exemplary embodiments are described in more detail with reference to the drawings, some basic considerations are summarized based on which the exemplary embodiments of the present invention have been developed.

[0090] Specifically, the following description focuses on the application of membrane distillation in terms of a manufacturing process for producing component carriers such as printed circuit boards (PCBs). However, it should be noted that the exemplary embodiments are not limited to such techniques, but may be broadly applied to the manufacture of other products or structures, particularly for the metallization of surfaces of such products or structures.

[0091] In conventional chemical wet processes, the products may be washed in a washing bath followed by a cascade of subsequent washing stages. Washing with conventional washing systems results on the one hand in the removal of the process liquid from the active bath and on the other hand in large amounts of waste water contaminated by the bath parts.

[0092] Traditionally, membrane distillation is often used to recover water from highly diluted solutions, e.g., to desalinate salt water. Due to the large flow rates to be processed, membrane distillation systems have been considered too costly, too large, and too energy consuming.

[0093] According to an exemplary embodiment of the present invention, membrane distillation may be implemented to recover metals from an outlet of a chemical bath used to process a component carrier structure, and the metals recovered by membrane distillation may be fed back into the chemical bath to prevent undesired metal depletion or dilution of the chemical bath.

[0094] In particular, exemplary embodiments of the present invention may use membrane distillation to separate small amounts of water from an active chemical bath. This concept according to exemplary embodiments of the present invention is a paradigm shift compared to conventional approaches (the latter intended to purify large amounts of slightly contaminated wash water). In contrast, exemplary embodiments of the present invention may adapt the cleaning process to run directly in or above the chemical bath. This allows membrane distillation to be implemented as a concentration technique to concentrate (particularly dissolved and / or elemental) metals to be recovered, since the chemical bath may be diluted by the contaminated wash fluids provided by the cleaning system. By separating an appropriate amount of chemical fluid or solvent (such as water) from the metal in the membrane still, the metal concentration in the chemical bath (e.g., a gold bath used to plate printed circuit boards) can be kept constant or sufficiently high. In particular, the concentration can be adjusted by the amount of dissolved metal to be recovered or by the addition of (particularly washing) water.

[0095] Corresponding adjustments that can be made according to exemplary embodiments of the present invention can lead to the fact that only a very small amount of water needs to be separated, instead of a large amount of highly diluted wash water that needs to be reprocessed. The combination of process adaptation and membrane distillation allows the technology to be operated very efficiently with low energy consumption (e.g. low temperature waste heat). That is, advantageously, the membrane distiller may be operated with a relatively small amount of heat.

[0096] According to an exemplary embodiment of the present invention, membrane distillation may be implemented in a part carrier manufacturing plant to concentrate heavy metals from a cleaning bath and to reintroduce the concentrated heavy metals into a chemical bath for processing. More specifically, the membrane distillation process may be used for energy-efficient processing of electroplating solutions. The cleaning process may be performed above the etching bath or on a separate water basin to dilute the bath. Thus, membrane distillation may be used to control the concentration of electroplating substances in the etching bath. On the one hand, the electroplating substances (including the metals in dissolved and / or elemental form) may be concentrated and returned to the chemical bath, while on the other hand, the chemical fluid or solvent such as water may be recycled for the next cleaning process. The cleaning process may be performed above the chemical bath (particularly the etching bath) or on a separate water basin to dilute the chemical bath. Advantageously, membrane distillation may be used to control the concentration of metals and / or other electroplating substances in the etching bath.

[0097] Advantageously, the described process control may make membrane distillation very efficient and therefore usable on an industrial scale. Furthermore, exemplary embodiments of the present invention may make it possible to close the water circulation in cleaning applications. In addition to this, the demand for cleaning water may be reduced due to at least partial recirculation of the cleaning fluid. Furthermore, energy efficiency may be improved, since low-temperature waste heat generated elsewhere in the part carrier manufacturing plant may be used as an energy source for heating the warm side of the membrane distiller.

[0098] Advantageously, the apparatus and method according to the exemplary embodiments of the present invention can be used for all processes that operate with a chemical bath followed by a washing section. Such embodiments can overcome the traditional problems of dragging out metals and / or other electroplating substances by implementing membrane distillation in industrial-scale production processes. Both the manufacturing effort and the environmental impact can be significantly reduced. Also, the process stability can be enhanced and resource consumption can be reduced. In addition, energy efficiency and workplace safety can be increased.

[0099] Specifically, exemplary embodiments of the present invention may reduce energy consumption and chemical demand, which may lead to cleaner and safer production. Furthermore, by using membrane distillation, the energy and operating effort of manufacturing part carriers may be reduced. Operators no longer need to add or replenish chemicals as frequently. Thus, operators come into contact with less harmful substances. This may significantly increase the safety of the manufacturing process.

[0100] Advantageously, membrane distillation may be used as a concentration technique to remove the excess of water coming from the washing process to keep the metal concentration in the chemical bath stable.

[0101] According to exemplary embodiments of the present invention, electroactive materials such as gold and / or palladium, which are traditionally lost with the cleaning fluid, can be partially or fully recovered or recycled. Such a process may involve concentration of the metal solvent in the effluent by membrane distillation, which can advantageously be carried out at relatively low temperatures. Thus, the described process is energy efficient and conserves resources in the process for manufacturing printed circuit boards.

[0102] 1 shows a schematic diagram of an apparatus 120 for recovering gold from a chemical bath 100 according to an exemplary embodiment of the invention. The chemical bath 100 is provided in a component carrier manufacturing plant 104 for electroplating gold onto component carrier structures, e.g. panels for manufacturing printed circuit boards (PCBs).

[0103] The illustrated apparatus 120 is configured to recover gold, as an example of a heavy metal, from a chemical bath 100, such as a plating bath. The chemical bath 100 may then be or form part of a plating unit configured to electroplating gold onto component carriers of a component carrier structure, which is still integrally connected to the panel level. During plating onto the component carrier structure, metal (gold in this example) from the chemical bath 100 is consumed by being deposited onto the component carrier structure. As also shown in FIG. 1 and as indicated by reference numeral 145, chemical fluids (such as water) and chemicals (such as plating metal) may be provided to the chemical bath 100 from a cleaning system 102 as gold-spiked cleaning water. In the context of a plating process, the chemical bath 100 (which serves as a metal source during plating onto the component carrier structure) may be used in combination with one or more cleaning baths of the cleaning system 102. The cleaning system 102 may be used to clean the component carrier structure and associated handling equipment after plating. During the cleaning or washing process or the like, a plating metal such as gold may be introduced into the washing fluid. More specifically, the component carrier structure may be electrolytically coated with gold in an electroplating bath constituting the chemical bath 100. Thereby, the component carrier structure as well as handling tools for handling the component carrier structure may become contaminated with gold. By means of the washing system 102, the handling tools and the component carrier structure may be cleaned. Advantageously, the component carrier structure previously plated with gold may be washed directly above the activated chemical bath 100 (i.e., the gold bath). The contaminated washing fluid that may flow into the chemical bath 100 may then be separated.

[0104] As shown, the chemical bath 100 is fluidly connected to a membrane still 106 via a supply 122, which is used and configured here to concentrate metals. The supply 122, which may include, for example, pumps and valves (not shown), may control fluid flow from the chemical bath 100 to the membrane still 106. More specifically, the supply 122 may be configured to supply a chemical fluid (such as water) containing a heavy metal (such as gold) from the chemical bath 100 to the membrane still 106. The solvent supplied by the supply 122 to the membrane still 106 may be a diluted chemical. The dilution may be the result of the supply of cleaning fluid to the chemical bath 100 and / or the consumption of metal material therein due to plating of the component carrier structure in the chemical bath 100.

[0105] The membrane still 106 is configured to separate heavy metals from the supplied chemical composition by membrane distillation. Descriptively, a vapor pressure gradient in the membrane still 106 may allow for separation of water from the rest of the chemical composition supplied to the membrane still 106 from the chemical bath 100. More specifically, due to the functionality of membrane distillation in combination with the formation of a temperature gradient between the left and right sides of the preferably hydrophobic membrane (see reference number 140 in FIG. 2) of the membrane still 106, gold (dissolved and / or elemental) may accumulate on the left side of the membrane still 106 in FIG. 1 and water may accumulate on the right side. Thus, gold may be concentrated by the membrane still 106. Descriptively, the hydrophobic membrane 140 allows mainly only water vapor to pass through the membrane 140, thereby removing water from the gold.

[0106] Furthermore, the apparatus 120 includes a reintroduction section 124 configured to reintroduce the separated gold into the chemical bath 100 (see loop 132 on the left side of FIG. 1 ) and to reintroduce the separated water again into the cleaning system 102 (see loop 130 on the right side of FIG. 1 ). As a result, a closed heavy metal loop 132 is thus provided for circulating the gold within the component carrier manufacturing plant 104, and a closed solvent loop 130 is thus provided for circulating the water within the component carrier manufacturing plant 104.

[0107] More specifically, the membrane still 106 is configured to provide the separated gold at a heated side 108 of the membrane 140. The warmer or heated side 108 is heated by a heating section 126. Advantageously, the heating section 126 is configured to heat the heated side 108 using waste heat generated elsewhere in the component carrier manufacturing plant 104. Preferably, waste heat from an etching process and / or from a plating process (e.g. an electroplating process for depositing copper on the component carrier structure) of the component carrier manufacturing plant 104 may be provided to heat the heated side 108 of the membrane still 106. As a result, an energy-efficient operation of the apparatus 120 is possible. Additionally or alternatively, the side 108 of the membrane 140 may be heated using an active heating source 142, such as an electric heating source.

[0108] Correspondingly, the membrane still 106 is configured to provide the water, which has been separated from the gold in the membrane still 106, at a cooler or cooled side 110 of the membrane still 106. A cooling section 128 is provided and configured to cool the cooled side 110 of the membrane still 106. Preferably, the cooling section 128 is configured to cool the cooled side 110 using waste cooling energy of the component carrier manufacturing plant 104. Advantageously, the cooling energy may be provided to the cold side 110 of the membrane still 106 from a cold cleaning fluid source of the component carrier manufacturing plant 104. For example, the cleaning water source may provide cleaning water at a relatively low temperature, for example 8° C. or 12° C., to the various consumers of the component carrier manufacturing plant 104. After cooling the cold side 110, the slightly warmed cleaning water may still be used in the various consumers of the component carrier manufacturing plant 104, for example by the cleaning system 102. Cooling the cold side 110 also promotes energy efficient operation of the device 120. Additionally or alternatively, the side 110 of the membrane 140 can be cooled using an active cooling source 144, such as one or more cooling assemblies.

[0109] As already mentioned, a closed solvent loop 130 is provided for circulating the solvent within the component carrier manufacturing plant 104. The solvent, e.g. water, is separated from the gold in the membrane still 106 and reintroduced into the cleaning system 102 for use in a subsequent cleaning process to clean the component carrier structures treated in the chemical bath 100. Thus, the chemically treated component carrier structures may be cleaned by the cleaning system 102 using the reintroduced water. For example, the separated water may be pumped back into the cleaning system 102 at a flow rate of 15 l / h, which may be sufficient for a PCB manufacturing process.

[0110] Very advantageously, a control 134 is provided that is configured to control, or even regulate, one or more of the supply 122, the membrane distiller 106, the reintroduction 124, the chemical bath 100, and the cleaning system 102 so that the concentration of gold in the chemical bath 100 remains constant. Thus, membrane distillation may be used in the part carrier manufacturing plant 104 to separate gold from the chemical bath 100, and to reintroduce the separated metal into the chemical bath 100 in a controlled manner so as to keep the gold concentration in the chemical bath 100 constant. The system of Figure 1 may advantageously be used only for the maintenance of the chemical bath 100.

[0111] The apparatus 120 includes a user interface 150 (e.g., a graphic user interface (GUI)) configured to allow a user to control the operation of the apparatus 120, in particular to control the process of recovering metals from the chemical bath 100 performed by the apparatus 120. The user interface 150 may be configured to operate the controller 134 (which may be a processor, a part of a processor, or multiple processors) to control the process performed by the apparatus 120. Such a control architecture may allow automation of the operation of the membrane distiller 106 by a software-assisted controller 134, which may allow fully automated process control. With the user interface 150 and controller 134 configured according to an embodiment of the invention, software-assisted process control for a membrane distillation plant may be possible. For example, the user interface 150 may have an input (e.g., a keypad, a joystick, a touch screen, and / or a voice recognition system) through which a user can input control commands to control the controller 134. Additionally, the user interface 150 may have an output (e.g., a liquid crystal display, a touch screen, etc.) to output the results of the operation of the apparatus 120.

[0112] In conventional membrane distillation plants, operation and fault handling are adjusted and performed manually by technicians. Manual intervention is essential in such conventional systems, especially when the system is started. Errors often occur due to the widely fluctuating temperatures, especially during heating or cooling of the membrane distiller.

[0113] In order to obtain a stable controller concept, the functionality of the user interface 150 according to an exemplary embodiment of the invention may be limited to the most important functions, which makes it possible to achieve a high degree of automation when operating the device 120 under the control of the control unit 134. Both the start and the stop of the device 120 may be performed in automatic mode, i.e. controlled only by the control unit 134. Both the standby operation and the emergency stop of the device 120 may be selectively specified by the user via the user interface 150 or automatically by the control unit 134. Advantageously, an error storage may be implemented, which preferably allows to output corresponding message texts and behavior specifications. Both the activation and the deactivation of the cleaning process may be specified by the user via the user interface 150 or automatically by the control unit 134.

[0114] The user interface 150, which is to be operated by an operator, may also allow the setting of all the functions of the device 120, such as parameter adjustment and / or adjustment of the control of the device 120. Preferably, a controller concept may be implemented, which is able to handle variations in thermal and cooling management. For example, a cascade control using several controllers and different guide types may be provided. Due to its high degree of automation, the corresponding device 120 may be user-friendly and allow stable process management by the control unit 134. The membrane distillation process may be significantly improved with respect to the operation of the device 120, making it possible to operate the plant by the user without the assistance of a specialist.

[0115] In this manner, in the embodiment of Figure 1, membrane distillation may be used to control the concentration of gold in chemical bath 100 during the gold plating process. Thus, water from chemical bath 100 may be partially separated and purified using membrane distillation. The separation is driven by the difference in partial vapor pressure of water on either side of membrane 140. As water is continuously removed from chemical bath 100, the concentration of gold increases and a highly concentrated gold solution is fed back to chemical bath 100. By this procedure, it is possible to keep the gold concentration in chemical bath 100 constant.

[0116] Advantages of the implementation of membrane distillation in the apparatus 120 are its ability to efficiently recycle metals and aqueous solvent, its suitable match to the PCB manufacturing process (also taking into account the required gold concentration), the advantageously high robustness of the distillation membrane 140 against carryover during PCB processing compared to other separation techniques, and the unique implementation of membrane distillation to concentrate gold.

[0117] In addition to or as an alternative to recycling gold, apparatus 120 may also be used to recycle other metals, such as copper and / or palladium, during the component carrier manufacturing process. A significant advantage of apparatus 120 is its ability to keep heavy metals in a closed loop during the manufacturing of component carriers.

[0118] 1, operation of the apparatus 120 may include recovery of at least one additional substance (i.e., a substance other than a metal) and / or additional recovery, for example, using the membrane still 106, and reintroducing the concentrated additional substance into the chemical bath 100. For example, such additional substances to be recycled may be plating additives, acids, bases, etc. This may allow for further reduction in waste and may allow for more efficient use of resources.

[0119] FIG. 2 illustrates a membrane still 106 for an apparatus 120 and for a method according to an exemplary embodiment of the invention.

[0120] Figure 2 shows that between the heated side 108 (feeding the metals to be recovered) and the cooled side 110 of the hydrophobic membrane 140 of the membrane distiller 106, the vapor 146 moves in substantially only one direction across the membrane 140. Thus, membrane distillation is implemented as a heat-driven separation or concentration process, where the feed (on the heated side 108) and the permeate or condensate (on the cooled side 110) are separated by the hydrophobic membrane 140. The driving force for the separation is the vapor pressure difference, i.e. the temperature difference of the feed and the permeate. Evaporation can occur already at relatively low temperatures, for example 80°C. The implementation of the membrane distiller 106 of Figure 2 in the device 120 of Figure 1 can close the water circulation and reduce the amount of gold required in the system.

[0121] FIG. 3 shows a schematic diagram of an apparatus 120 for recovering gold from a chemical bath 100 for chemically treating component carrier structures with gold in a component carrier manufacturing plant 104 according to an exemplary embodiment of the invention.

[0122] 3 shows a process flow 160 during PCB manufacturing. Before a preceding manufacturing stage 162 and after a subsequent manufacturing stage 164, gold plating of component carrier structures is accomplished in a chemical bath 100, followed by cleaning of contaminated component carrier structures by a cleaning system 102. Within the process flow 160, a membrane still 106 is used to separate the solvent (such as water) provided from the chemical bath 100, including the cleaning fluid from the cleaning system 102, into gold and water. The concentrated gold is redirected to the chemical bath 100 for use in a subsequent plating process. The separated water is redirected to the cleaning system 102 for use in a subsequent cleaning process.

[0123] Advantageously, the component carrier structure is washed after treatment by electroplating or in an etching bath, i.e. after treatment in the chemical bath 100. This can be done directly above (or even in) the chemical bath 100 or above a separate water basin. Washing brings about the need to concentrate the electroplating or etching bath or the washing water needs to be treated in such a way that, on the one hand, the electroplating substances are concentrated and can be returned to the chemical bath 100, and, on the other hand, the washing water needs to be freed of the electroplating substances and can be recycled as water.

[0124] FIG. 4 shows a schematic diagram of an apparatus 120 for recovering palladium from a chemical bath 100 (not shown in FIG. 4) for chemically treating a component carrier structure with palladium in a component carrier manufacturing plant 104, according to an exemplary embodiment of the present invention.

[0125] During the manufacture of the component carrier in the manufacturing process 190, various manufacturing stages 180, 182, 184 are carried out. After palladium plating in a chemical bath (not shown in FIG. 4 but carried out, for example, in one of the manufacturing stages shown in FIG. 4), the component carrier structure is treated in a conductor bath 192 and then in a selector bath 194. Two cleaning systems 102, in which cleaning of the palladium-treated component carrier structure may be carried out, are implemented in between. The palladium-contaminated cleaning fluid from the cleaning system 102 is fed to a membrane distillation section 106 for separation of palladium with respect to the water. The recovered clean water is again led to the cleaning system 102 in a closed-loop water circulation. See reference number 130. The recovered palladium is led to a palladium precipitation section 196 for precipitation of palladium. To precipitate palladium in an efficient manner, palladium may be concentrated in the membrane distillation section 106 to 50 mg / l or more. The recovered palladium may then be reused for palladium plating of component carrier structures or, more generally, the recovered palladium may be reintroduced into the manufacturing process, for example after being conditioned in conditioning section 198.

[0126] FIG. 5 illustrates elements of a membrane still 106 for an apparatus 120 and method according to an exemplary embodiment of the invention.

[0127] 5 illustrates that the membrane distiller 106 according to an exemplary embodiment of the present invention can be used with a single membrane block 166, a stacked membrane block 168, or even larger modules 170 with multiple stacked membrane blocks 168. Thus, the recovery system according to an exemplary embodiment of the present invention is suitably scalable.

[0128] 6 shows an apparatus 120 for recovering metals from a chemical bath 100 (such as a plating bath) for chemically treating component carrier structures (such as panels for producing printed circuit boards, PCBs) with metals in a component carrier manufacturing plant according to another exemplary embodiment of the invention. According to FIG. 6, the membrane still 106 may be temporarily bypassed, preheated and / or subject to a varying feed / permeate ratio to suppress undesired switch-on effects (such as chemical leakage).

[0129] Specifically, if the temperature difference between the hot side 108 and the cold side 110 of the membrane still 106 falls below a predefined threshold, it may be possible to temporarily bypass the membrane still 106 with respect to the flow of the chemical composition from the chemical bath 100. If the temperature difference is too small, the partial pressure difference between the hot side 108 and the cold side 110 may also be too small, and as a result the membrane still will not operate properly. Specifically, it may occur that metals (which would be collected on the hot side 108) migrate to the water on the cold side 110. This may result in an undesired carryover of chemicals within the apparatus 120. To suppress such undesired artifacts, the chemical composition pumped by the pump 152 from the chemical bath 100 may be directed by a fluid valve 151 (e.g., a three-way valve) towards the bypass path 133, thereby bypassing the chemical composition with respect to the membrane still 106. After an appropriate temperature difference (and therefore an appropriate partial pressure) is established between the hot side 108 and the cold side 110 (which may be detected by corresponding sensors, e.g., temperature and / or pressure sensors, not shown), the fluid valve 151 may be switched (e.g., by rotating 90° counterclockwise) so that the chemical composition from the chemical bath 100 is introduced into the membrane still 106 for separation, as described above with reference to Figure 1. Reference numeral 155 denotes an evaporator and reference numeral 156 denotes a condenser of the membrane still 106.

[0130] To avoid chemical leakage and / or other undesirable phenomena due to insufficient temperature difference between the hot side 108 and the cold side 110, it may also be possible to temporarily reduce the ratio of the flow of the chemical composition from the chemical bath 100 to the membrane distiller 106 on the one hand and the flow of the separated solvent (particularly water) leaving the cold side 110 on the other hand. Descriptively, a smaller amount of the chemical composition may be fed to the membrane distiller 106 and a larger amount of water may be removed from the membrane distiller 106. This may be achieved by adjusting the pumping action of the pump 152 which pumps the chemical composition between the chemical bath 100 and the membrane distillation section 106 and of a further pump 154 ​​which pumps the solvent (mainly water) from the cold side 110 to the cleaning system 102 for use as a cleaning fluid. The pump 152 (and / or another pump downstream of the membrane distillation section 106, not shown) may pump the separated metal solvent from the hot side 108 to the chemical bath 100. After a sufficient temperature profile is established between the hot side 108 and the cold side 110, the amount of chemical composition transferred may again be increased and / or the amount of water removed may again be decreased.

[0131] Although not shown in Figure 6, three additional heat exchangers may be implemented in the process. One heat exchanger may be used to cool and heat the membrane distiller 106. The other two heat exchangers may be used to keep the temperature constant.

[0132] Additionally or alternatively, if the temperature difference between the hot side 108 and the cold side 110 of the membrane still 106 is still below a predefined threshold, it may be possible to preheat the membrane still 106 before starting to supply the chemical composition to the membrane still 106. To this end, a heating section 126 may be implemented on the evaporator side of the membrane still 106. The preheating step may increase the temperature difference between the hot side 108 and the cold side 110, thereby inhibiting carryover.

[0133] By the means described, improved mixing of the permeate and the feed can be advantageously achieved during the process of membrane distillation. Membrane distillation is a thermally driven separation process, which requires a defined temperature difference between the two main volumetric streams (i.e., feed and permeate). To achieve this temperature difference, the permeate circuit should be cooled before entering the condenser 156, while the feed circuit should be preheated.

[0134] During this warm-up phase, the feed (i.e., solvent from the chemical bath 100) and the permeate (i.e., solvent such as water) may be prone to chemical leakage. This problem may severely limit the potential applications of membrane distillation in wet chemical processes. The process or chemical bath 100 may be diluted during start-up, and as a result, the membrane distillation may then need to run for a significant amount of time (e.g., several hours) to reach the target concentration. This may severely limit the use of membrane distillation at a sufficiently high and constant throughput in production processes that are to be carried out on an industrial scale.

[0135] To overcome this difficulty, in an exemplary embodiment the start-up time may be reduced and therefore the mixing of phases with one or more of the following process modifications: In one embodiment, the feed and permeate ratio may be modified, for example set to 1:6 (i.e. 1 part feed and 6 parts permeate). This measure may already significantly reduce mixing. In other embodiments (which may also be combined with the previously described embodiments), it may be possible to disconnect the membrane during the start-up phase. More specifically, the membrane distiller 106 may be bypassed by a bypass line 133 during the heating phase. This allows heating or cooling of the feed and permeate circuits without touching the membrane. In addition, the membrane itself may be preheated by the heating section 126. With the described process management modifications, the start-up time may be reduced, which makes the device 120 ready for use faster. In addition, dilution effects may be effectively suppressed.

[0136] Thus, improved process control (in terms of hydraulics and parameters) can be achieved. Pre-heating of the membrane modules can also be advantageous, which advantageously significantly reduces undesired mixing of feed and permeate. In addition, these measures can allow the membrane distillation to be directly integrated and operated in the production process, which prevents production downtime due to dilution of the process bath caused by the membrane distillation process.

[0137] FIG. 7 shows an apparatus 120 for recovering metal from a chemical bath 100 for chemically treating component carrier structures 135 (e.g., plate-shaped panels for producing printed circuit boards) with metal in a component carrier manufacturing plant, according to yet another exemplary embodiment of the present invention.

[0138] In the embodiment shown, a multi-stage cleaning system 102 is provided that includes an initial stage 157 based on treating the plate-shaped component carrier structure 135 with a moist gas beam, followed by subsequent stages 158, 159, etc., that perform additional cleaning based on spraying a liquid, such as water, onto the plate-shaped component carrier structure 135. With reference to FIG. 7, the component carrier structure 135 may be oriented horizontally (rather than vertically) during plating and / or cleaning. This may be advantageous, especially when only limited space is available. Thus, an exemplary embodiment of the present invention may implement membrane distillation in a horizontal plating line.

[0139] As shown, the initial stage 157 of the cleaning system 102 for cleaning the horizontally oriented component carrier structure 135 may be configured for treatment with a moist gas beam 139, more precisely with a water-saturated moist air beam directed onto one or both of the main surfaces of the component carrier structure 135. Descriptively, the initial stage 157 may form a gas knife 137. Pressurized gas will clean the surface of the component carrier structure 135. The water saturation of the gas beam 139 will prevent chemicals from solidifying on the surface of the component carrier structure 135, so that contamination of the component carrier structure 135 can be avoided. Aqueous contaminant solvent 167 that falls from the component carrier structure 135 during cleaning of the component carrier structure 135 by treatment with a moist gas beam can be collected, for example, in a container 141. Said solvent 167, which may contain a significant amount of chemicals to be recycled, may be fed to the chemical bath 100 and then to the membrane still 106 (or directly to the membrane still 106). As illustrated by reference numeral 138, in the membrane distiller 106, the water separated based on the solvent 167 may be supplied again to the initial stage 157 as the main component of the moisture content of the wet gas beam 139 to be produced for cleaning.

[0140] As also shown in Fig. 7, the cleaning system 102 includes one or more additional cleaning stages 158, 159... for cleaning the component carrier structure 135 after cleaning by the initial cleaning stage 157. The one or more additional cleaning stages 158, 159, etc. may be configured to clean the component carrier structure 135 using a sprayer 139 (or any other cleaning device) or a process with a further moist gas beam (as in the initial cleaning stage 157). Since the residues of the additional cleaning stages 158, 159, etc. contain chemicals that would normally be recirculated in significantly smaller quantities, such residues may be fed to the drain 143. Alternatively, they may also be fed to the chemical bath 100.

[0141] 8 and 9, two possibilities are described how to implement membrane distillation, for example in a horizontal plating line, where panels for producing printed circuit boards are oriented horizontally during plating. It may be preferable to place a membrane distiller 106 between the chemical bath 100 and the first cleaning cascade of the cleaning system 102.

[0142] FIG. 8 shows an apparatus 120 for recovering metal from a chemical bath 100 for chemically treating component carrier structures with metal in a component carrier manufacturing plant according to yet another exemplary embodiment of the present invention, implementing a (e.g., triple) cascaded multi-stage cleaning system 102. FIG. 8 shows an initial stage 157 of the cleaning system 102 above additional stages 158, 159, etc. of the cleaning system 102. FIG. 9 shows an apparatus 120 for recovering metal from a chemical bath 100 for chemically treating component carrier structures with metal in a component carrier manufacturing plant according to yet another exemplary embodiment of the present invention, implementing a (e.g., quadruple) cascaded multi-stage cleaning system 102. In the embodiment of FIG. 9, it may be possible to implement the initial stage 157 of the cleaning system 102 directly above the chemical bath 100 (as may also be done for a vertical plating line).

[0143] Very advantageously, the initial stage 157 of the cleaning system 102 may be based on an air knife, see reference 137. The air knife uses pressure to remove remaining process liquid. While dry air may be used by the air knife, a preferred embodiment of the invention may use saturated air to clean the panel surface. If saturated air is used, the remaining process liquid may be sufficiently removed from the surface of the component carrier structure, whereas dry pressurized air may result in undesirable residues on the panel surface as the surface dries. The amount of moisture present in the saturated air may be provided by membrane distillation, see reference 138.

[0144] Advantageously, the embodiments of Figures 8 and 9, in combination with membrane distillation, allow for a significant reduction in chemical carryover during horizontal wet chemical processes.

[0145] Traditionally, horizontal wet chemical processes use washing systems that require very large amounts of fresh water to prevent carryover of chemicals to subsequent baths or to remove contaminants from the product. Large amounts of wastewater need to be treated intensively, which involves large labor and consumes energy. High dilution of chemicals with wash water usually makes recovery difficult or even impossible.

[0146] In contrast, the exemplary embodiment of Fig. 8 and Fig. 9 implements a cascaded cleaning system 102 in which the first stage 157 is separated from the rest of the cascaded system. In the first stage 157, air knives 137 may be installed above and below the movement of the component carrier structures, which use air jets to remove chemicals from the component carrier structures. In the supply air pipe, the humidity of the air may be increased to preferably at least 50%, for example 99%, by using a water sprayer. This may avoid dried chemical residues on the cleaned structures, thereby suppressing quality issues. Compressed air may be generated with little effort by a side channel compressor. Air recirculation may be realized to significantly reduce the effects of air balance in the cleaning system 102. In addition, this may save a large amount of water during humidification. The diluted chemical concentrates that accumulate in the first stage 157 of the cleaning system 102 are returned to the active module, i.e., the chemical bath 100.

[0147] The slightly diluted chemical bath 100 is concentrated and returned to the desired concentration by membrane distillation. The resulting wash water may be returned directly to the water sprayer.

[0148] Advantageously, the membrane distillation plant may be operated primarily using low temperature waste heat from the process.

[0149] The remaining cascades of the cleaning system 102 may be embodied as sprinklers. In these cascades, the amount of fresh water required can be significantly reduced, since the cleaned structures can hardly be contaminated.

[0150] Losses of unused chemicals due to carryover in the cleaning system 102 can be significantly reduced by the embodiments of Figures 8 and 9. Large amounts of fresh water and waste water can be saved. Production efficiency can be increased, as well as conserving resources, since previously unusable low-temperature waste heat can be used. Fluctuations in process parameters can be reduced, since fewer bath modifications are required.

[0151] 10 shows an apparatus 120 for recovering metal from a chemical bath 100 for chemically treating component carrier structures with metal in a component carrier manufacturing plant, according to yet another exemplary embodiment of the present invention. The embodiment of FIG. 10 is similar to the embodiment of FIG. 6, however, supplementary explanations specifically relating to the embodiment of FIG. 10 are provided below.

[0152] Descriptively, the membrane distillation has three channels 200, 202, and 204. In the embodiment shown, two pumps for the circuit may be implemented: pump 206 for channel 204 (permeate and wash water) and pump 208 for channel 202 (feed).

[0153] Next, the circulation of the permeate according to the channel 204 is described. From the permeate tank 210, the permeate may be pumped into the condenser 156 corresponding to the cooled side 110. The permeate stream can additionally pass through a heat exchanger 212, which may also be thermally coupled to an external cooling source 220. After leaving the condenser 156, the permeate stream passes through another heat exchanger 214, in which the permeate is heated. Descriptively, said permeate stream can indirectly become a kind of feed. The hot permeate stream may then heat the evaporator 155 corresponding to the heated side 108. This means that the permeate stream may be used for cooling and heating. The permeate may then be pumped again into the permeate tank 210, thereby closing the channel 204.

[0154] In the following, the feed flow according to channel 202 is described. As soon as a sufficient temperature gradient is reached, the feed from chemical bath 100 is led in a closed loop via membrane still 106 to heat exchanger 216. Before that, membrane still 106 may be completely bypassed (see bypass path 133).

[0155] Next, the channel 200 is described. The channel 200 is not a separate flow path since it is connected to the permeate flow. In the embodiment shown, the wash water comes from a permeate tank 210 that is continuously filled with water separated from the membrane still 106. In addition, the wash water can also be drained directly into the chemical bath 100, for example, if it is desired to dilute the chemical bath 100. Figure 10 shows a further heat exchanger 222 that is disposed in the channel 200 and that may be thermally coupled to an external heat source 224.

[0156] Figure 11 shows a membrane still according to an exemplary embodiment of the device of the present invention. In Figure 11, a membrane still 1106 is shown. The membrane still 1106 includes a heat exchanger 1112, a heatable side 1108, an air gap 1122, and a coolable side 1110. The heat exchanger 1112 is a channel through which hot distillate hD flows in the direction shown by the left arrow. The hot distillate hD is an uncontaminated distillate that has been used, for example, to wash parts during the manufacturing process of the structure.

[0157] The polymeric film layer 1128 is disposed between the channel 1112 and the heatable side 1108. The polymeric film 1128 is impermeable and thermally conductive such that the channel 1112 is thermally coupled to the heatable side 1108, and thus provides heat to heat the chemical composition cC flowing through the heatable side 1108. As a result, the solvent present in the chemical composition cC is partially evaporated.

[0158] A first membrane 1126, for example a PTFE membrane, separates the heatable side 1108 from the cavity 1122. A second membrane 1130, which may also be a PTFE membrane, separates the cavity 1122 from the coolable side 1110.

[0159] In this way, the vapor can therefore pass from the heatable side 1108 through the first membrane 1126, the gap 1122, and the second membrane 1130 and condense on the side of the second membrane 1130 that is directed towards the coolable side 1110. The vapor on the coolable side 1110 condenses as a low-temperature distillate cD, which is then recovered as a distillate for further use. The chemical composition cC now has a higher concentration of metal elements. This concentrated chemical solution is recovered and reused.

[0160] According to the embodiment of FIG. 11, the membrane distiller 1106 further comprises an additional cavity 1124, an additional heatable side 1118, an additional heat exchanger 1120, a third membrane 1134, a fourth membrane 1138, and an additional polymeric film layer 1136.

[0161] A third membrane 1134 separates the further cavity 1124 from the coolable side 1110. A fourth membrane 1138 separates the further cavity 1124 from the further heatable side 1118.

[0162] The further cavity 1124 , the further heatable side 1118 and the further heat exchanger 1120 are arranged in a mirror image with respect to the cavity 1122 , the heatable side 1108 and the heat exchanger 1112 with respect to the coolable side 1110 .

[0163] Thus, the membrane still 1106 according to FIG. 11 is laid out in a modular manner, in which a single coolable side 1110 is used to condense distillate vapors provided by two heatable sides 1108 and 1118.

[0164] FIG. 12 shows an apparatus 1200 for recovering metal from a chemical bath for chemically treating component carrier structures with metal in a component carrier manufacturing plant.

[0165] The apparatus 1200 of FIG. 12 includes a membrane still 1206 , a supply section 1202 having an evaporator 1212 , and a distillate collection section 1246 having a condenser 1236 .

[0166] In the vaporizer 1212 of the supply 1202, a chemical composition 1232 is present, which is made up of a solvent 1232 and of metallic elements. The chemical composition 1232 is provided by a chemical bath for chemically treating the component carrier structure.

[0167] The membrane still 1206 has a vapor side 1204, a heatable side 1208, and a coolable side 1210. A thin thermally conductive layer 1226, preferably a polymeric film, is disposed between the vapor side 1204 and the heatable side 1208. The thermally conductive layer 1226 is impermeable. A membrane 1222, preferably a hydrophobic PTFE membrane, is disposed between the heatable side 1208 and the coolable side 1210.

[0168] The evaporator 1212 evaporates a portion of the solvent 1238 present in the chemical composition 1232. The evaporator 1212 can be a flash evaporator.

[0169] Steam is supplied to the steam side 1204 via a steam supply means 1214, and a chemical composition 1232 is supplied to the heatable side 1208 via a concentrate supply means 1216. According to embodiments described herein, the steam supply means is realized using or includes a tube.

[0170] Chemical composition 1232 on heatable side 1208 is heated by the vapor present in vapor side 1204. The vapor present in vapor side 1204 thereby cools and condenses on thermally conductive layer 1226. The resulting condensate is collected inside condenser 1236 as solvent 1238.

[0171] A portion of the solvent 1238 present in the chemical composition 1232 on the heatable side 1208 evaporates due to the temperature increase caused by heat exchange with the vapor on the vapor side 1204. The vapor on the heatable side 1208 is filtered by the membrane 1222 and directed to the coolable side 1210.

[0172] The coolable side 1210 is thermally coupled to a further heatable side 1218 via a further thermally conductive layer 1228, where the chemical composition 1232 emerging from the heatable side 1208 is pumped through a further concentrate supply means 1230. There is also a further coolable side 1220. A further membrane 1224 is disposed between the further heatable side 1218 and the further coolable side 1220. According to the embodiments described herein, the further concentrate supply means 1230 is realised using or comprises a tube.

[0173] The chemical composition 1232 on the further heatable side 1218 is heated by the vapor present on the coolable side 1210, resulting in some of the solvent 1238 in the chemical composition 1232 being evaporated and the vapor on the coolable side 1210 being cooled and condensing on the further thermally conductive layer 1228. The condensate is collected inside the condenser 1236 as the solvent 1238.

[0174] A further membrane 1224 filters vapor generated during heating of the chemical composition 1232 and directs it to the further heatable side 1218. Vapor reaching the second coolable side condenses and is collected in a condenser 1236 as solvent 1238.

[0175] The concentrated chemical composition 1232 is collected as a concentrate at the end of the further heatable side 1218 and recycled via a concentrate collection means 1234 for reuse.

[0176] The condenser 1236 cools the solvent 128 collected from the vapor side 1204, the coolable side 1210, and the further coolable side 1220. The condenser 1236 also collects remaining uncondensed vapor present at the further coolable side 1220 via further vapor conducting means 1240. The vapor collected in the condenser 1236 is then condensed and recycled as solvent 1238. The recycled solvent is fed into the system via solvent feeding means 1244.

[0177] 12 shows a modular structure of a membrane distillation system 1206, in which heat generated by partial evaporation of the chemical composition 1232 is used to heat it in the membrane still 1206. Additionally, vapor pressure generated in a previous stage of the membrane still 1206 is used to heat the chemical composition 1232 in a further stage of the membrane still 1206. In this configuration, the use of decreasing vapor pressure across the stages is also advantageous, due to which the evaporation point for the solvent 1238 in the chemical composition 1232 decreases along the stages.

[0178] FIG. 13 shows a membrane still 1306 installed in a modular fashion.

[0179] Each module includes a vapor side, a heatable side, and a coolable side, with a thermally conductive layer disposed between the vapor side and the heatable side, and a membrane disposed between the heatable side and the coolable side.

[0180] 13, the first module includes a vapor side 1304, a heatable side 1308, a coolable side 1310, a thermally conductive layer 1312, and a membrane 1340. The thermally conductive layer 1312 is disposed between the vapor side 1304 and the heatable side 1308. The membrane 1340 is disposed between the heatable side 1308 and the coolable side 1310.

[0181] Vaporized hot solvent is supplied to the vapor side 1304 via vapor supplies 1350,1352 and chemical concentrate is provided to the heatable side 1308 via chemical concentrate supplies 1360,1362.

[0182] The evaporated hot solvent on the vapor side 1304 heats the chemical composition on the heatable side 1308 and condenses on the thermally conductive layer 1312 due to the heat exchange effect at the thermally conductive layer 1312. The condensate is collected and recycled outside the membrane still.

[0183] On the other hand, due to the heat exchange at the thermally conductive layer 1312, the solvent present in the chemical concentrate at the heatable side 1360 partially evaporates. The evaporated solvent is filtered through the membrane 1340 and condenses at the coolable side 1310 where it is collected via the solvent collecting means 1374, 1370. The chemical composition at the heatable side 1308 at the end of the process has a higher concentration of the metallic elements to be recovered and is collected via the chemical concentrate collecting means for further use.

[0184] 13, the second module includes a further heatable side 1318, a further vapor side 1314, a further membrane 1342, and a further thermally conductive layer 1322. The coolable side 1310 serves as the further coolable side for the second module. Further vapor supply means 1350, 1354 supply the evaporated hot solvent from the evaporator, and further chemical condensate supply means 1360, 1364 supply the chemical condensate to the further heatable side 1318.

[0185] 13, the second module is mirrored relative to the first with respect to coolable side 1310. Thus, coolable side 1310 is used to concentrate chemical compositions in the two heatable sides, namely, heatable side 1308 and further heatable side 1318.

[0186] The third module of the membrane distiller 1306 of Figure 13 further includes a third heatable side 1328, a third coolable side 1320, a third membrane 1344, and a third thermally conductive layer 1332. The further vapor side 1314 serves as a third vapor side for the third module. A third chemical concentrate supply means 1360, 1366 supplies chemical concentrate to the third heatable side 1328. Further solvent collection means 1372, 1374 collects solvent from the third coolable side 1328.

[0187] The third module is mirrored relative to the second one with respect to the second vapor side 1314 .

[0188] Finally, a fourth heatable side 1338 and a fourth membrane 1346 that are part of the fourth module are also shown in FIG. 13 along with a fourth chemical concentrate supply means 1360, 1360 that supplies chemical concentrate to the fourth heatable side 1338.

[0189] For purposes of the present invention, the term "heatable side" as used in connection with the described apparatus is equivalent to the term "hot side" as used in connection with the described method, and correspondingly, the term "coolable side" is equivalent to the term "cold side."

[0190] It should be noted that the term "comprising" does not exclude other elements or steps, and that "a" or "an" does not exclude a plurality. Also, elements described in association with different embodiments may be combined.

[0191] It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims.

[0192] The implementation of the invention is not limited to the preferred embodiment shown in the drawings and described above, instead many variations are possible using the solutions shown and the principles according to the invention, even in the case of radically different embodiments. [Other possible items] [Item 1] 1. A method for recovering metal from a chemical bath (100) for chemically treating a structure with metal, comprising: providing a metal-containing chemical composition from the chemical bath (100) to a membrane still (106); separating at least a portion of the metals in the membrane still (106); and reintroducing said separated metals into said chemical bath (100). A method for providing the above. [Item 2] 2. The method of claim 1, wherein the metal comprises at least one of the group consisting of gold, palladium, tin, silver, iron, nickel, cobalt, lead, iridium, zinc, and copper. [Item 3] separating the solvent, in particular the water, from the metal in the membrane still (106); and reintroducing said separated solvent into the cleaning system (102). 3. The method according to item 1 or 2, comprising: [Item 4] 4. The method according to claim 3, comprising a step of cleaning the structure chemically treated in the chemical bath (100) by means of the cleaning system (102), in particular using the reintroduced solvent. [Item 5] 5. The method according to any of items 1 to 4, comprising a step of cleaning the structure with a cleaning fluid in a cleaning system (102) directly in or above said chemical bath (100). [Item 6] 6. The method according to items 1 to 5, comprising a step of plating in said chemical bath (100) plate-shaped structures, in particular panels for producing component carriers. [Item 7] 7. The method according to items 1 to 6, comprising a step of cleaning plate-shaped structures, in particular panels for manufacturing component carriers, in a cleaning system (102). [Item 8] 8. The method according to item 6 or 7, comprising plating and / or cleaning the plate-shaped structure horizontally or vertically. [Item 9] 9. The method according to any one of items 1 to 8, comprising supplying waste heat generated during the manufacturing process to the hot side (108) of the membrane distiller (106). [Item 10] 10. The method of claim 9, comprising supplying the hot side (108) of the membrane still (106) with waste heat from an etching process and / or from a plating process carried out during the manufacturing process. [Item 11] 11. The method according to any one of items 1 to 10, comprising the step of supplying a cold side (110) of the membrane distiller (106) with cooling energy generated during the production process. [Item 12] 12. The method of claim 11, comprising providing cooling energy to the cold side (110) of the membrane still (106) from a cold cleaning fluid source used during the manufacturing process. [Item 13] 13. The method according to any of the preceding claims, comprising concentrating the metal in the membrane still (106) and reintroducing the concentrated metal into the chemical bath (100). [Item 14] 14. The method according to any of the preceding claims, comprising separating at least one further substance of the chemical composition in the membrane still (106) and in particular reintroducing the separated at least one further substance into the chemical bath (100). [Item 15] 15. The method of claim 14, wherein the at least one further substance comprises at least one of the group consisting of at least one plating additive, an acid, and a base. [Item 16] 16. The method according to any of the preceding claims, comprising controlling at least one of the steps of providing, separating and reintroducing such that the concentration of the metal in the chemical bath (100) remains constant over time. [Item 17] 17. The method according to any of the preceding claims, comprising a step of chemically treating said structure in said chemical bath (100) by plating said structure with said metal. [Item 18] 18. The method according to any of the preceding claims, in particular comprising temporarily redirecting the flow of the chemical composition to bypass the membrane still (106) as long as a temperature difference between a hot side (108) and a cold side (110) of the membrane still (106) is below a predefined threshold. [Item 19] 19. The method according to any of items 3 to 18, comprising reducing the ratio of the flow of the chemical composition into the membrane still (106) and the flow of the solvent away from the membrane still (106), in particular as long as the temperature difference between the hot side (108) and the cold side (110) of the membrane still (106) is below a predefined threshold. [Item 20] 20. The method according to any of the preceding claims, comprising pre-heating the membrane still (106) before starting to supply the chemical composition to the membrane still (106), in particular as long as the temperature difference between the hot side (108) and the cold side (110) of the membrane still (106) is below a predefined threshold. [Item 21] 21. The method according to any of items 1 to 20, wherein treating the structure with a metal comprises treating a component carrier structure with a metal during manufacturing of the component carrier. [Item 22] 22. The method according to any one of items 1 to 21, further comprising recovering at least one of the group consisting of at least one plating additive, an acid, and a base from the chemical composition. [Item 23] 1. An apparatus (120) for recovering metal from a chemical bath (100) for chemically treating a structure with metal, comprising: a supply (122) configured to supply a metal-containing chemical composition from the chemical bath (100) to the membrane still (106); the membrane still (106) configured to separate at least a portion of the metals by membrane distillation; and a reintroduction portion (124) configured to reintroduce the separated metal into the chemical bath (100); An apparatus (120) comprising: [Item 24] 24. The apparatus (120) of claim 23, wherein the membrane still (106) is configured to provide the separated metals at a heatable side (108) of the membrane still (106). [Item 25] 25. The apparatus (120) according to claim 23 or 24, wherein the membrane still (106) is configured to provide the solvent, in particular water, separated from the metal in the membrane still (106) on a coolable side (110) of the membrane still (106). [Item 26] 26. The apparatus (120) according to any one of items 23 to 25, comprising a heating section (126) configured to heat the metal side of the membrane still (106) to which the separated metal is provided. [Item 27] 27. The apparatus (120) of claim 26, wherein the heating section (126) is configured to heat the metal side surface using waste heat obtained during a manufacturing process. [Item 28] 28. The apparatus (120) according to any one of items 25 to 27, comprising a cooling section (128) configured to cool a solvent side of the membrane distiller (106) to which the separated solvent is provided. [Item 29] 29. The apparatus (120) of claim 28, wherein the cooling section (128) is configured to cool the solvent side using cooling energy obtained during the manufacturing process. [Item 30] 30. The apparatus (120) according to any one of items 23 to 29, comprising a closed metal loop (132) including the chemical bath (100), the supply section (122), the membrane still (106), and the reintroduction section (124) for circulating metal during a manufacturing process. [Item 31] 31. The apparatus (120) according to any of items 23 to 30, comprising a closed solvent loop (130) comprising the chemical bath (100), the supply (122), the membrane still (106), and a cleaning system (102) for circulating a solvent during a manufacturing process. [Item 32] 32. An apparatus (120) according to any of items 23 to 31, wherein the chemical bath (100) is or forms part of a plating unit adapted to plate structures, in particular to plate electrically. [Item 33] 33. The apparatus (120) according to any of items 23 to 32, comprising a control unit (134) configured to control, in particular adjust, the apparatus (120), in particular at least one of the supply unit (122), the membrane still (106) and the reintroduction unit (124), in such a way that the concentration of the metal in the chemical bath (100) remains constant. [Item 34] 34. The apparatus (120) according to any of items 23 to 33, comprising a user interface (150) configured to enable a user to control the operation of the apparatus (120), in particular to control the process of recovering metal from the chemical bath (100) carried out by the apparatus (120). [Item 35] 35. The apparatus (120) according to items 33 and 34, wherein the user interface (150) is configured to operate the control unit (134) for controlling the process performed by the apparatus (120). [Item 36] 36. An apparatus (120) according to any of items 23 to 35, comprising a cleaning system (102) for cleaning a structure by treatment with a moist gas beam, in particular with a water-saturated moist air beam. [Item 37] Item 37. The apparatus (120) of item 36, wherein the cleaning system (102) is configured to supply the solvent collected during cleaning of the structure by the treatment with the moist gas beam to the chemical bath (100) or to the membrane still (106). [Item 38] Item 38. The apparatus (120) according to item 36 or 37, configured to supply water from the membrane still (106) to the cleaning system (102) to generate the humid gas beam. [Item 39] Item 39. The apparatus (120) according to any of items 36 to 38, wherein the cleaning system (102) comprises at least one additional cleaning stage (158, 159) for cleaning the structure after cleaning by an initial cleaning stage (157) configured to clean the structure by the treatment with the moist gas beam. [Item 40] 40. The apparatus (120) according to any one of items 23 to 39, wherein the apparatus (120) is configured to treat a component carrier structure with a metal during manufacturing of the component carrier. [Item 41] 41. The apparatus (120) according to any one of items 23 to 40, wherein the membrane distiller (1106) comprises a heatable side (1108), a coolable side (1110), and a gap (1122) between the heatable side (1108) and the coolable side (1110), wherein a first membrane (1126) is disposed between the heatable side (1108) and the gap (1122), and a second membrane (1130) is disposed between the gap (1122) and the coolable side (1110). [Item 42] 42. The apparatus (120) of claim 41, wherein the membrane distiller (1106) further comprises a heat exchanger (1112) thermally coupled to the heatable side (1108). [Item 43] Item 43. The apparatus (120) according to item 42, wherein the heat exchanger (1112) comprises a channel (1112) for conducting a flow of hot distillate (hD), wherein the channel (1112) is separated from the heatable side (1108) by a layer of thermally conductive material (1128), preferably a polymer film (1128). [Item 44] The membrane distiller (106) comprises: Further heatable sides (1118), Further voids (1124), Where: the coolable side surface (1110) is disposed between the gap (1122) and a further gap (1124); A further air gap (1124) is disposed between the coolable side (1110) and the further heatable side (1118). 44. The device (120) according to any one of Items 41 to 43, comprising: [Item 45] Item 45. The apparatus (1200) according to any one of items 23 to 44, wherein the supply section (1202) includes an evaporator (1212). [Item 46] The membrane distiller (1206) comprises: a heatable side (1208), a coolable side (1210), a vapor side (1204), a membrane (1222), and a thermally conductive layer (1226). Where: the heatable side (1208) is disposed between the vapor side (1204) and the coolable side (1210); the membrane (1222) is disposed between the heatable side (1208) and the coolable side (1210); the thermally conductive layer (1226) is disposed between the vapor side (1204) and the heatable side (1208); The device (1200) comprises: a steam supply means (1214) for supplying steam from the evaporator (1212) to the steam side (1204); and a concentrate supply means (1216) for supplying said chemical composition (1232) in liquid form from said evaporator (1212) to said heatable side (1208); Further comprising Item 46. The apparatus (1200) according to item 45, comprising: [Item 47] The membrane distiller (1206) comprises: Further heatable sides (1218), Further coolable sides (1220); a further membrane (1224), and Additional thermally conductive layer (1228) Where: the further heatable side (1218) is disposed between the coolable side (1210) and the further coolable side (1220); the further membrane (1224) is disposed between the further heatable side (1218) and the further coolable side (1220); the further thermally conductive layer (1228) is disposed between the further heatable side (1218) and the coolable side (1210); The device (1200) comprises: a further concentrate supply means (1230) for supplying said chemical composition in liquid form from said heatable side (1208) to said further heatable side (1218); Here, during operation, the pressure on the heatable side (1208) is greater than the further pressure on the further heatable side (1218). Further comprising Item 47. The apparatus (1200) of item 46, further comprising: [Item 48] A method using membrane distillation in a plant (104) for carrying out a manufacturing process for separating metals from a chemical bath (100) and for reintroducing the separated metals into the chemical bath (100), preferably in a controlled manner so as to keep the metal concentration in the chemical bath (100) constant.

Claims

1. 1. A method for recovering metal from a chemical bath for chemically treating a structure with a metal, comprising the steps of: providing a chemical composition comprising a metal from the chemical bath to a membrane still; separating at least a portion of the metals in the membrane still; and reintroducing said separated metal into said chemical bath. Equipped with The method further comprises: separating a solvent or chemical fluid from the metal in the membrane still; and reintroducing the separated solvent or chemical fluid into a cleaning system; a cleaning process is carried out after the chemical treatment of the structure in the chemical bath; method.

2. The method of claim 1 , wherein the metal comprises at least one of the group consisting of gold, palladium, tin, silver, iron, nickel, cobalt, lead, iridium, zinc, and copper.

3. A method as described in claim 1 or 2, comprising a step of cleaning the chemically treated structure in the chemical bath by the cleaning system.

4. The method described in claim 3, wherein the structure is chemically treated in the chemical bath using the reintroduced solvent by the cleaning system.

5. The following features: plating a plate-shaped structure in said chemical bath; cleaning said plate-shaped structure in said cleaning system. The method according to any one of claims 1 to 4, comprising at least one of:

6. 6. The method of claim 5, comprising plating and / or cleaning the plate-shaped structures horizontally or vertically.

7. 7. The method of claim 1, comprising supplying the hot side of the membrane still with waste heat generated during the manufacturing process.

8. 8. The method of claim 7, comprising supplying the hot side of the membrane still with waste heat from an etching process and / or from a plating process carried out during the manufacturing process.

9. 9. The method of claim 1, further comprising the step of supplying the cold side of the membrane still with refrigeration energy generated during the production process.

10. 10. The method of claim 9, comprising providing cooling energy to the cold side of the membrane still from a cold cleaning fluid source used during the manufacturing process.

11. 11. The method according to any one of claims 1 to 10, comprising separating at least one further substance of the chemical composition in the membrane still and reintroducing the separated at least one further substance into the chemical bath.

12. The method of claim 11 , wherein the at least one additional substance comprises at least one of the group consisting of at least one plating additive, an acid, and a base.

13. concentrating the metal in the membrane still and reintroducing the concentrated metal into the chemical bath; controlling at least one of the steps of providing, separating, and reintroducing such that a concentration of the metal in the chemical bath remains constant over time; chemically treating said structure in said chemical bath by plating said structure with said metal; temporarily redirecting the flow of the chemical composition to bypass the membrane still so long as a temperature differential between the hot side and the cold side of the membrane still is below a predefined threshold; pre-heating the membrane still prior to beginning to supply the chemical composition to the membrane still as long as the temperature differential between the hot side and the cold side of the membrane still is below the predefined threshold; additionally recovering at least one of the group consisting of at least one plating additive, an acid, and a base from the chemical composition; Cleaning the structure with a cleaning fluid in the cleaning system, either directly in or above the chemical bath. The method according to any one of claims 1 to 12, comprising at least one of:

14. A method described in any one of claims 3 to 13, comprising a step of reducing the ratio of the flow of the chemical composition to the membrane distiller and the flow of solvent away from the membrane distiller so long as the temperature difference between the hot side and the cold side of the membrane distiller is below a predefined threshold.

15. The method of claim 5, wherein the step of plating a plate-shaped structure in the chemical bath includes a step of treating the structure of the component carrier as the plate-shaped structure using the metal during manufacturing of a component carrier.

16. 1. An apparatus for recovering metal from a chemical bath for the chemical treatment of a structure with metal, comprising: a supply configured to supply a chemical composition comprising a metal from the chemical bath to a membrane still; the membrane still configured to separate at least a portion of the metals by membrane distillation; and a reintroduction section configured to reintroduce the separated metal into the chemical bath. Equipped with The membrane still is configured to provide a chemical fluid or solvent separated from the metal in the membrane still at a coolable side of the membrane still; the reintroduction portion is further configured to reintroduce the separated solvent or chemical fluid into the cleaning system; the cleaning system is configured such that a cleaning process is performed after the chemical treatment of the structure in the chemical bath. Device.

17. The following features: the membrane still configured to provide the separated metals at a heatable side of the membrane still; the apparatus is configured to treat a component carrier structure with the metal during manufacturing of the component carrier; a closed metal loop including the chemical bath, the feed, the membrane still, and the reintroduction for circulating the metal during a manufacturing process; a closed solvent loop for circulating the solvent during the manufacturing process, the closed solvent loop including the chemical bath, the supply, the membrane still, and a cleaning system for cleaning the structure; The chemical bath is or forms part of a plating unit configured to plate the structure.

17. The apparatus of claim 16, comprising at least one of:

18. 18. The device according to claim 16 or 17, wherein the solvent is water.

19. 19. The apparatus of any one of claims 16 to 18, comprising a heating section configured to heat a metal side of the membrane still to which the separated metal is provided.

20. 20. The apparatus of claim 19, wherein the heating portion is configured to heat the metal side surface using waste heat obtained during a manufacturing process.

21. 21. The apparatus of any one of claims 18 to 20, comprising a cooling section configured to cool a solvent side of the membrane still to which the separated solvent is provided.

22. 22. The apparatus of claim 21, wherein the cooling section is configured to cool the solvent side using cooling energy available during a manufacturing process.

23. The following features: a controller configured to control the apparatus such that a concentration of the metal in the chemical bath remains constant; a user interface configured to enable a user to control the operation of the device; The apparatus according to any one of claims 16 to 22, comprising at least one of:

24. 24. The apparatus of claim 23, wherein the user interface is configured to operate the control unit to control a process performed by the apparatus.

25. An apparatus as claimed in any one of claims 16 to 24, comprising a cleaning system for cleaning the structure by treatment with a gas beam containing moisture.

26. An apparatus for recovering metal from a chemical bath for chemically treating a structure with the metal, comprising: a supply configured to supply a chemical composition comprising a metal from the chemical bath to a membrane still; the membrane still configured to separate at least a portion of the metals by membrane distillation; a reintroduction portion configured to reintroduce the separated metal into the chemical bath; and CLEANING SYSTEM FOR CLEANING SUCH STRUCTURE BY TREATMENT WITH A GAS BEAM CONTAINING MOISTURE - Patent application An apparatus comprising:

27. The following features: the cleaning system is configured to supply a solvent collected during cleaning of the structure by the treatment with the moist gas beam to the chemical bath or to the membrane still; the apparatus is configured to supply water from the membrane still to the cleaning system to generate the humidified gas beam; The cleaning system includes at least one additional cleaning stage for cleaning the structure after cleaning with an initial cleaning stage configured to clean the structure by the treatment with the moist gas beam.

27. The apparatus of claim 25 or 26, comprising at least one of:

28. 28. The apparatus of any one of claims 16 to 27, wherein the membrane distiller has a heatable side, a coolable side, and a gap between the heatable side and the coolable side, wherein a first membrane is disposed between the heatable side and the gap, and a second membrane is disposed between the gap and the coolable side.

29. 30. The apparatus of claim 28, wherein the membrane distiller further comprises a heat exchanger thermally coupled to the heatable side.

30. 30. The apparatus of claim 29, wherein the heat exchanger has a channel for conducting a flow of hot distillate (hD), the channel being separated from the heatable side by a layer of thermally conductive material.

31. The membrane distiller comprises: Further heatable sides, a further void; Where: the coolable side surface is disposed between the gap and the further gap; the further gap is disposed between the coolable side and the further heatable side. Apparatus according to any one of claims 28 to 30.

32. Apparatus according to any one of claims 16 to 31, wherein the supply comprises an evaporator.

33. The membrane distiller comprises: Heatable side, coolable side, vapor side, membrane, and thermally conductive layer having the heatable side is disposed between the vapor side and the coolable side; the membrane is disposed between the heatable side and the coolable side; the thermally conductive layer is disposed between the vapor side and the heatable side; The apparatus comprises: steam supply means for supplying steam from the evaporator to the steam side; and a concentrate supply means for supplying said chemical composition in liquid form from said evaporator to said heatable side; 33. The apparatus of claim 32, further comprising:

34. The membrane distiller comprises: Further heatable sides, Further cooling aspects, Further membranes, and Additional thermally conductive layer Further comprising: the further heatable side is disposed between the coolable side and the further coolable side; the further membrane is disposed between the further heatable side and the further coolable side; the further thermally conductive layer is disposed between the further heatable side and the coolable side; The apparatus comprises: a further concentrate supply means for supplying said chemical composition in liquid form from said heatable side to said further heatable side; During operation, the pressure on the heatable side is greater than the further pressure on the further heatable side.

34. The apparatus of claim 33.

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