Abstract: The present invention relates to a method for increasing the efficiency of an energy transfer device (100) with which electrical energy is converted contactlessly into electrical energy with the aid of a magnetic field in order to electrically excite a rotor of an electrical machine, comprising the step of: arranging an additional electrically conductive material layer (13) on at least one active part (12, 19, 35, 45) of the energy transfer device (100), wherein an active part of the energy transfer device (100) is a part of the energy transfer device (100) which is at least partially exposed to the magnetic field used for energy transfer, and wherein the electrical conductivity of the additional material layer (13) is greater than the electrical conductivity of the at least one active part (12, 19, 35, 45). Moreover, the invention relates to an energy transfer device (100) and to a use of an electrically conductive material.

Abstract: Tooling (10) for making slots in a multistage disk (1) by electrochemical machining. The tooling comprises first and second rings (20) arranged coaxially about a disk axis and configured to act as cathodes, each ring having an inside periphery with a plurality of radial machining projections. The first and second rings (20) are rigidly secured relative to each other. A method of making slots in a multistage disk by electrochemical machining using such a tool.

Abstract: A device suitable for the electrochemical processing of an object is at least provided with a chamber that is to accommodate an electrolyte, a support for the object that is to be processed in the chamber, at least one set of electrodes located in the chamber such that during operation at least one electrode is located opposite each portion of a surface of said object that is to be processed. The device also includes a controller configured to provide an electric current between the object that is to be processed and the electrodes.

Abstract: A method of removing a metal detail from a dielectric material of an article may include placing the article in an electrolyte bath such that at least a portion of the metal detail is submerged. The metal detail may be coupled to a dielectric material. The method may further include positioning at least one cathode in the electrolyte bath in spaced relation to the metal detail, and passing electrical current through the metal detail. The method may additionally include deplating the metal detail from the dielectric material in response to passing the electrical current through the metal detail.

Abstract: A device suitable for the electrochemical processing of an object is at least provided with a chamber that is to accommodate an electrolyte, a support for the object that is to be processed in the chamber, at least one set of electrodes located in the chamber such that during operation at least one electrode is located opposite each portion of a surface of said object that is to be processed. The device also includes a controller configured to provide an electric current between the object that is to be processed and the electrodes.

Abstract: A feed control method for wire cutting electrochemical discharge machining is disclosed. The method determines whether a contact event has occurred using a wire electrode, based on variations in wire tension when being cut. A wire is cut with an ideal feed speed when the wire electrode is not in contact with a workpiece.

Abstract: In an apparatus and method for magnetic field assisted electrochemical discharge machining (ECDM), the magneto hydrodynamic (MHD) effect is utilized to improve the thickness of bubble film and the electrolyte circulation so as to enhance the machining accuracy and efficiency. Since charged ions in a magnetic field are induced by Lorenz force to move, and the electrolysis bubbles generated in the ECDM process are suffused with electrification ions on their surfaces, the electrolysis bubbles can be forced to move in the direction of the magnetic field without the need of mechanical disturbance. The present invention can be widely applied in the micro-machining of non-conductive brittle materials of different dimensions and shapes, comprising the forming of microchannels and microholes on a biochip, and in the micro-opto-electro-mechanical system (MOEMS) and various kinds of micro-machining fields. The machined surface is smooth and does not require a second time machining.

Abstract: Provided are an electrode, an electrolysis cell, and an electrochemical analyzer that improve the long-term stability of analysis data. A working electrode, a counter electrode, and reference electrode are disposed in an electrolysis cell. The working electrode is obtained by forming a lead wire in a composite material having platinum or a platinum alloy as a base material, in which a metal oxide is dispersed, or in a laminated material obtained by laminating a valve metal and platinum such that the cross sectional crystal texture in the thickness direction of the platinum is formed in layers and the thickness of each layer of the platinum is 5 micrometers or less. The metal oxide is selected from among zirconium oxide, tantalum oxide, and niobium oxide, and the metal oxide content of the platinum or the platinum alloy is 0.005 to 1 wt % in terms of the zirconium, tantalum, or niobium metal.

Abstract: In a control device of a plasma processing system, a communication unit is configured to receive processing information related to a carrier of a next processing lot. A determination unit is configured to determine whether the processing information received by the communication unit has pre-treatment information related to one of the plasma processing devices. When it is determined that the processing information has the pre-treatment information by the determination unit, a generation unit is configured to generate an object for declaring execution of the pre-treatment for the carrier of a next processing lot if a desired condition of transferring of the carrier is satisfied. In addition, if the object is generated by the generation unit, a process executing control unit is configured to start the pre-treatment for the target object in the carrier of a next processing lot without any notification that the carrier reaches a destination plasma processing device.

Abstract: A production apparatus is provided for producing a near field optical head that includes, during its production process, a substrate, at least one protuberance extending from a surface of the substrate, an electrically conductive shielding film covering the protuberance and the substrate, and a parent film, as a mother material for an air bearing, covering the shielding film. The production apparatus has an etchant for etching the parent film and a container for storing the etchant and for containing the substrate, the shielding film, and the parent film so that the substrate, the shielding film, and the parent film are immersed in the etchant. At least one electrode is fixedly mounted in the container so as to be immersed in the etchant. A measuring device measures an electrical characteristic between the electrode and the shielding film.

Abstract: Methods for removing coatings from metal components, such as metal components used in aircraft and other aerospace vehicles and the oil industry. The method may include removing an outer layer of a coating with a first stripping operation, removing an inner layer of the coating with a second stripping operation, and specifying an aqueous bath for either the first stripping process based upon an element in the outer layer or the second stripping process based upon an element in the inner layer.

Abstract: In a method for setting the distance between an electrode and a workpiece in electrochemical metal working, the electrode is moved by an oscillating drive system, in which an acceleration signal of the oscillating drive system is picked up, the acceleration signal is divided into individual sections, characteristic magnitudes of the individual sections of the acceleration signal are determined, the characteristic magnitudes of the individual sections are compared to one another and the distance of the electrode from the workpiece is adjusted in response to a deviation of the characteristic magnitudes from the specified values. A device for carrying out the method includes an electrode, that is connected to a drive axis, an oscillating motion being able to be transferred to the electrode via the drive axis. A sensor is situated on the drive axis which picks up acceleration signals.

Abstract: Versatile methods of refining a first and a second layer of a workpiece are discussed. New refining methods and refining apparatus are disclosed. The new refining methods can help improve yield and appreciably change the cost of manufacture for refining of workpieces. The methods can be applied to workpieces having extremely close tolerances such as semiconductor wafers. New methods of control are also discussed. Methods use controllers, processors, computers, and processor readable memory devices are discussed. Use of stored information is to make changes in process control are discussed. Use of process models are discussed for refining. Determining a changed process control with stored information from first and second layers of a workpiece is disclosed. A changed process control can make an appreciable changes to the cost of manufacture of a workpiece.

Abstract: Apparatus and methods for removing coatings from metal components, such as metal components used in aircraft and other aerospace vehicles and the oil industry, as well as aqueous bath compositions. The metal component may be DC coupled with a counter electrode and immersed in an aqueous bath that includes an active oxygen source and a ligand in a composition effective to remove the coating. The aqueous bath may include hydrogen peroxide as the active oxygen source and may be maintained in a specific pH range if the temperature of the aqueous bath is controlled. In an alternative embodiment, the composition of the aqueous bath may include a non-peroxide active oxygen source, such as sodium perborate, and be maintained in a different specific pH range. An oxygen sensor may be provided to periodically monitor the concentration of active oxygen in the aqueous bath.

Abstract: The invention relates to electrochemical machining of metals and alloys and, more particularly, to high-precision dimensional electrochemical machining. The invention may be used for forming a regular nanometric and micrometric layers on an intricately shaped surface. Disclosed is a method of electrochemical machining in neutral electrolytes using current pulses which are synchronized with oscillation phases corresponding to the electrolyte pressure maximum in the interelectrode gap, wherein the oscillation mode of the machining electrode and electrode approach speed are set in a specific way for a predetermined frequency and amplitude, characterized in that the electrode approach speed is set in a way that the maximum value Pmax (t) of the electrolyte pressure at the interelectrode gap does not exceed an acceptable maximum value Pmax of the electrolyte pressure at the interelectrode gap.

Abstract: Conventional electrochemical machining process requires fixed shaped tool cathodes, which makes retooling time consuming and expensive. Flexible tool cathodes include elastically deformable cathodes that can deform in two or three dimensions and can adapt to the contour of the workpiece while the workpiece is moving relative to the flexible tool cathode. That is, the flexible tool cathode can perform tracing. Certain flexible tool cathodes can be also used for special configurations such corners and edges. The flexible tool cathodes can be used to polish, finish, or shape the workpiece through electrochemical processes.

Abstract: A method for manufacturing a blisk for a gas turbine, in particular an aircraft gas turbine, includes generating blade profiles from an outer contour of a forged disk by milling and/or electrochemical machining. A robot-controlled, mechanical rework is performed of blade areas, in areas of the leading and trailing edges, the annulus, the fillet, the platform and the blade tip. A specified contour according to the engineering drawing of the blisk blade areas is referenced and an actual contour is determined by visualization. A difference between the specified contour and the actual contour is then calculated. The blade areas are then finish-machined and polished in a special processing machine according to a program prepared on the basis of the calculated difference.

Abstract: The present invention relates to a device and a method for the electrochemical machining of at least one workpiece with a conductor and first storing element for an electrolyte, wherein at least one measuring unit for measuring at least one property of the electrolyte is arranged on the conductor.

Abstract: A method and system are provided for the shaping and polishing of the surface of a material selected from the group consisting of electrically semi-conductive materials and conductive materials. An electrically non-conductive polishing lap incorporates a conductive electrode such that, when the polishing lap is placed on the material's surface, the electrode is placed in spaced-apart juxtaposition with respect to the material's surface. A liquid electrolyte is disposed between the material's surface and the electrode. The electrolyte has an electrochemical stability constant such that cathodic material deposition on the electrode is not supported when a current flows through the electrode, the electrolyte and the material. As the polishing lap and the material surface experience relative movement, current flows through the electrode based on (i) adherence to Faraday's Law, and (ii) a pre-processing profile of the surface and a desired post-processing profile of the surface.

Abstract: The invention relates to a method, an apparatus and a computer program for electrochemical machining where a removal of cathode depositions is performed in a fully automated way by means of an application of optimal pulses of a suitable polarity.

Abstract: The present invention provides panels for a microchannel heat exchanger core wherein the panels may have greater than about 36 fins per inch of the panel. The microchannels of the panels may have an aspect ratio of at least about 10. Panels are also provided having microchannels and fins on one side of the panel or on opposite sides of the panel. Methods are also provided for machining the panels of the present invention.

Abstract: Plasma process uniformity is controlled by maintaining near an optimum value an impedance of a ground return path for VHF source power from an overhead electrode through a workpiece support. A feedback control loop controls a variable reactance element of a reactive circuit that provides isolation between the VHF source power and a lower frequency bias power match circuit.

Abstract: A method and apparatus for local polishing and deposition control in a process cell is generally provided. In one embodiment, an apparatus for electrochemically processing a substrate is provided that selectively polishes discrete conductive portions of a substrate by controlling an electrical bias profile across a processing area, thereby controlling processing rates between two or more conductive portions of the substrate.

Abstract: According to the plasma treatment on an object accommodated in the processing room, the plasma treatment is carried out as follows. The discharge detecting sensor detects a signal of potential change caused with change in plasma discharge. Receiving the signal, the signal recording section temporarily records the signal as signal data indicating potential change. Referencing the signal data, the signal analysis section extracts index data. The index data shows a condition of plasma discharge, for example, as a count value for discharge-start waves, a count value for abnormal discharge, a count value for feeble arc discharge. The device control section judges a condition of plasma discharge by monitoring the index data and carries out the retry process, the accumulative plasma process, and the maintenance judgment process for performing plasma treatment operations properly.

Abstract: The invention is a method of electrochemical etching of a non-conductive insulator. The method entails inducing a current in the insulator by exciting electrons into the conduction band by supplying the needed energy through irradiation of the insulator. Alternatively, electrons may be supplied externally from an electron gun. The insulator is subject to an electrical bias, and the induced or supplied electrons then create a current in the insulator that effects the etch rated.

Abstract: An electro-thinning apparatus for removing excess metal from the surface metal layer of the substrate is provided. The apparatus includes an electrolysis bath, a transportation system, an anode roller, a cathode roller, and at least one shielding plate. The electrolysis bath contains an electrolysis liquid. The transportation system is disposed in the electrolysis bath for moving a substrate from an upstream end to a downstream end. The anode roller is disposed relative to the electrolysis bath and located upstream to the transportation system. The cathode roller is located above the transportation system and located downstream to the anode roller. The at least one shielding plate is located downstream to the cathode roller. During electrolysis, the anode roller contacts a surface metal layer of the substrate while the cathode roller is partly immersed in the electrolysis liquid and away from the surface metal layer of the substrate during electrolysis.

Abstract: Method for process control of electro-processes is provided. In one embodiment, the method includes processing a conductive layer formed on a wafer using a target endpoint, detecting breakthrough of the conductive layer to expose portions of an underlying layer, and adjusting the target endpoint in response to the detected breakthrough. In another embodiment, the target endpoint is adjusted relative to an amount of underlying layer exposed through the conductive layer.

Abstract: In a method for setting the distance between an electrode and a workpiece in electrochemical metal working, the electrode is moved by an oscillating drive system, in which an acceleration signal of the oscillating drive system is picked up, the acceleration signal is divided into individual sections, characteristic magnitudes of the individual sections of the acceleration signal are determined, the characteristic magnitudes of the individual sections are compared to one another and the distance of the electrode from the workpiece is adjusted in response to a deviation of the characteristic magnitudes from the specified values. A device for carrying out the method includes an electrode, that is connected to a drive axis, an oscillating motion being able to be transferred to the electrode via the drive axis. A sensor is situated on the drive axis which picks up acceleration signals.

Abstract: A method and apparatus for electropolishing a conductive surface of a semiconductor wafer. The apparatus includes a polisher having at least one first electrode and at least one second electrode separated from one another by an isolation region. A moving mechanism rotates the wafer while the conductive surface of the wafer is moved linearly and parallel to a first direction, which varies an exposure of the relative surface areas of the conductive surface to the at least one first electrode and the at least one second electrode.

Abstract: Method and apparatus for process control of electro-processes. The method includes electro-processing a wafer by the application of two or more biases and determining an amount of charge removed as a result of each bias, separately. In one embodiment, an endpoint is determined for each bias when the amount of charge removed for a bias substantially equals a respective target charge calculated for the bias.

Abstract: A method and an apparatus for electroerosive material machining of a workpiece with an elongated tool electrode are described. The tool electrode is guided in an electrode guide, in which an oval void is embodied. The wire segment located in the void is exposed to a magnetic field, as a result of which the wire segment can be deflected laterally. The lateral deflection is converted into an axial motion of the wire segment located in the region of the workpiece, in order to create an optimal work gap between the workpiece and the free end part of the wire segment.

Abstract: An electrolytic processing apparatus can detect the end point of electrolytic processing stably with high precision and with a relatively simple construction. The electrolytic processing apparatus includes: a processing electrode which can come close to or into contact with a processing object; a feeding electrode for feeding electricity to the processing object; a fluid supply section for supplying fluid between the processing object and at least one of the processing electrode and the feeding electrode; a processing power source for applying a voltage between the processing electrode and the feeding electrode; a drive section for causing relative movement between the processing object and at least one of the processing electrode and the feeding electrode; and an eddy current sensor for detecting the thickness of the processing object from a change in eddy current loss. The sensor is disposed not in contact with (or separately) by an insulator from the processing electrode and/or the feeding electrode.

Abstract: An electrode (10) is provided for electrochemical reduction of a workpiece (20) that is to be treated. The electrode (10) has a predefined contour and contains an electrically conductive material. The electrically conductive material of the predefined contour forms an electrode core (12). The outside of the electrode core (12) is covered with an insulation layer (13). The insulation layer (13) is porous and is made of an electrically non-conductive material.

Abstract: The present invention replaces all or a portion of substrate processing by chemical-mechanical polishing with electrolytic processing using deionized water, ultrapure water or the like. An electrolytic processing apparatus comprises: a chemical-mechanical polishing section for chemically-mechanically polishing a surface of a substrate; an electrolytic processing section having a processing electrode and a feeding electrode, and also having an ion exchanger provided at least either between the substrate and the processing electrode or between the substrate and the feeding electrode, for electrolytically processing a surface of a workpiece under existence of a solution by applying a voltage between the processing electrode and the feeding electrode; and a top ring capable of freely moving between the chemical-mechanical polishing section and the processing electrode section.

Abstract: Methods and apparatus for providing closed-loop control over an electrochemical etching process during porous semiconductor fabrication enhance the quality of the porous semiconductor materials, especially those contained structural variations (such as porosity or morphology variations) along the thickness of said porous semiconductors. Such enhancement of the control over the electrochemical etching process is highly desired for many applications of porous semiconductor materials.

Abstract: Methods and apparatuses for detecting characteristics of a microelectronic substrate. A method in accordance with an embodiment of the invention includes positioning the microelectronic substrate proximate to and spaced apart from the first and second spaced apart electrodes, contacting the microelectronic substrate with a polishing surface of a polishing medium, removing conductive material from the microelectronic substrate by moving the substrate and/or the electrodes relative to each other while passing a variable electrical signal through the electrodes and the substrate, and detecting a change in the variable electrical signal or a supplemental electrical signal passing through the microelectronic substrate. The rate at which material is removed from the microelectronic substrate can be changed based at least in part on the change in the electrical signal.

Abstract: Apparatus and method for making a metrological scale by electrochemical machining of a scale substrate using a tool having at least one feature. The method has the steps of passing an electrolyte solution between the tool and the scale substrate and forming an electrical connection between the scale substrate and the tool. Electrochemical dissolution of the scale substrate occurs adjacent to the feature of the tool to produce at least one scale marking. This is suitable for making linear, rotary and two dimensional scales.

Abstract: A composite electrolytic processing method makes it possible to remove a conductive film without leaving it in an electrically-insulated state on an underlying barrier film, thereby exposing the barrier film. The electrochemical mechanical polishing method includes: applying a voltage between a first electrode connected to one pole of a power source and a second electrode, connected to the other pole of the power source, for feeding electricity to a conductive film of a polishing object; filling an electrolytic liquid into a space between the first electrode and the conductive film of the polishing object; and pressing and rubbing the conductive film against a polishing surface of a polishing pad to polish the conductive film in such a manner that a barrier film underlying the conductive film becomes gradually exposed from the center toward the periphery of the polishing object.

Abstract: The invention provides a method of determining at least one electrochemical characteristic of a chemical-mechanical or electrochemical-mechanical polishing system comprising application of a potential between a polishing substrate and an electrode to generate a current, and determining the at least one electrochemical characteristic by analysis of the current as a function of time.

Abstract: Methods of refining using a plurality of refining elements are discussed. A refining apparatus having refining elements that can be smaller than the workpiece being refined are disclosed. New refining methods, refining apparatus, and refining elements disclosed. Methods of refining using frictional refining, chemical refining, tribochemical refining, and electrochemical refining and combinations thereof are disclosed. A refining apparatus having magnetically responsive refining elements that can be smaller than the workpiece being refined are disclosed. The refining apparatus can supply a parallel refining motion to the refining element(s) for example through magnetic coupling forces. The refining apparatus can supply multiple different parallel refining motions to multiple different refining elements for example solely through magnetic coupling forces to improve refining quality and versatility. A refining chamber can be used. New methods of control are refining disclosed.

Abstract: A method of forming a perforate membrane (1) is disclosed for use in a liquid transport device. The membrane has at least plural nozzles (10) formed therethrough. Each of those nozzles has a throat portion (12) opening at opposite end through opposite surface (2?) of the perforate membrane and a smoothly curved outwardly diverging portion (11) extending from the first end of the throat portion to the first surface (2) of the perforate membrane. Laser energy is applied selectively to the first surface (2) of the membrane in the form of a pulsed, focused beam to form the nozzles (10) and thereafter the first surface (2) of the membrane and the surface of the diverging portion (11) of the nozzles (10) are electro-polished to remove surface imperfections. The electro-polishing is controlled so as to remove material from the surface of the diverging portion (11) of the nozzles to a depth less than the length of the throat portion (12).

Abstract: Controlled-potential electroplating provides an effective method of electroplating metals onto the surfaces of high aspect ratio recessed features of integrated circuit devices. Methods are provided to mitigate corrosion of a metal seed layer on recessed features due to contact of the seed layer with an electrolyte solution. The potential can also be controlled to provide conformal plating over the seed layer and bottom-up filling of the recessed features. For each of these processes, a constant cathodic voltage, pulsed cathodic voltage, or ramped cathodic voltage can be used. An apparatus for controlled-potential electroplating includes a reference electrode placed near the surface to be plated and at least one cathode sense lead to measure the potential at points on the circumference of the integrated circuit structure.

Abstract: Method and apparatus for process control of electro-processes. The method includes electro-processing a wafer by the application of two or more biases and determining an amount of charge removed as a result of each bias, separately. In one embodiment, an endpoint is determined for each bias when the amount of charge removed for a bias substantially equals a respective target charge calculated for the bias.

Abstract: In an electrochemical reactor used for electrochemical treatment of a substrate, for example, for electroplating or electropolishing the substrate, one or more of the surface area of a field-shaping shield, the shield's distance between the anode and cathode, and the shield's angular orientation is varied during electrochemical treatment to screen the applied field and to compensate for potential drop along the radius of a wafer. The shield establishes an inverse potential drop in the electrolytic fluid to overcome the resistance of a thin film of conductive metal on the wafer.

Abstract: A polishing method and polishing apparatus able to easily flatten an initial unevenness with an excellent efficiency of removal of excess copper film and suppress damage to a lower interlayer insulation film, and a plating method and plating apparatus able to deposit a flat copper film. The polishing method comprises the steps of measuring thickness equivalent data of a film on a wafer, making a cathode member smaller than the surface face a region thereof, interposing an electrolytic solution between the surface and the cathode member, applying a voltage using the cathode member as a cathode and the film an anode, performing electrolytic polishing by electrolytic elution or anodic oxidation and chelation and removal of a chelate film in the same region preferentially from projecting portions of the film until removing the target amount of film obtained from the thickness equivalent data, and repeating steps of moving the cathode member to another region to flattening the regions over the entire surface.

Abstract: The present invention alleviates workloads in chemical-mechanical polishing (CMP) by replacing all or a portion of the substrate processing by means of chemical-mechanical polishing with electrolytic processing using deionized water, ultrapure water or the like and enables processing insuring the higher flatness with the higher efficiency.

Abstract: A polishing method and polishing apparatus able to easily flatten an initial unevenness with an excellent efficiency of removal of excess copper film and suppress damage to a lower interlayer insulation film, and a plating method and plating apparatus able to deposit a flat copper film. The polishing method comprises the steps of measuring thickness equivalent data of a film on a wafer, making a cathode member smaller than the surface face a region thereof, interposing an electrolytic solution between the surface and the cathode member, applying a voltage using the cathode member as a cathode and the film an anode, performing electrolytic polishing by electrolytic elution or anodic oxidation and chelation and removal of a chelate film in the same region preferentially from projecting portions of the film until removing the target amount of film obtained from the thickness equivalent data, and repeating steps of moving the cathode member to another region to flattening the regions over the entire surface.

Abstract: A method for determining an end point of a planarization process for removing metal from a surface of a substrate submerged in an electrolytic solution or slurry. A first electrode is provided which is operable to contact the surface of the substrate, such as a working electrode of a potentiostat system. A second electrode is provided which is operable to contact the electrolytic solution, such as a reference electrode of the potentiostat system. The first electrode is contacted to the surface of the substrate and an electrochemical property is measured, such as the electrochemical potential between the first and second electrodes, where the electrochemical property is indicative of an electrochemical characteristic of the substrate-slurry system. The planarization process is preferably stopped when a substantial change in the electrochemical potential of the system is measured.

Abstract: An electrochemical planarization apparatus for planarizing a metallized surface on a workpiece includes a polishing pad and a platen. The platen is formed of conductive material, is disposed proximate to the polishing pad and is configured to have a negative charge during at least a portion of a planarization process. At least one electrical conductor is positioned within the platen. The electrical conductor has a first end connected to a power source. A workpiece carrier is configured to carry a workpiece and press the workpiece against the polishing pad. The power source applies a positive charge to the workpiece via the electrical conductor so that an electric potential difference between the metallized surface of the workpiece and the platen is created to remove at least a portion of the metallized surface from the workpiece.

Abstract: For an electromechanical machining of a work piece there is an optimal pulse duration for the machining pulses corresponding to the maximum copying accuracy. Such an optimal pulse duration corresponds to a certain value of the gap. By alternating the machining pulses with measurement pulses it is possible to obtain an accurate information about the gap dimensions on-line during the electrochemical machining process. The process control means (20) are used to automate the electromechanical machining, while keeping it in the optimal mode. For this purpose the process control means (20) comprise the pulse control unit (26) to establish the pulse duration of the voltage pulses to be applied across the gap (4).