Abstract: In one aspect, the invention provides a coating process system including a continuous conveyor, a first end defining a loading station for loading work pieces to the conveyor, and a second end defining an unloading station for unloading work pieces from the conveyor. A series of workstations is configured to render coated work pieces and arranged at a first level to extend between the first and second ends. A cure oven is arranged at a second level above the first level, the conveyor making a plurality of runs between the first and second ends at different sub-levels within the second level. A first post-oven run of the conveyor extends from an outlet of the cure oven to the unloading station. A second post-oven run of the conveyor extends from the unloading station to the loading station.

Abstract: Provided herein are apparatuses, systems, and methods for the electrodeposition of nano- or microlaminate coatings, which have improved heat, wear, and corrosion resistance, on a plurality of workpieces.

Abstract: A protruding portion is formed on a rear side of a side plate, namely a side surface forming guide passage. The protruding portion is intended to prevent a thrust metal from being put to the guide passage with the left and right ends being in the wrong position. Accordingly, a height of the protruding portion is smaller than a depth of the oil ditch of the thrust metal, the width of the protruding portion is smaller than the width of the oil ditch. Also, regarding to the formation position of the protruding portion, when the thrust metal is truly set to guide passage, the center of the protruding portion approximately accords with the center of the oil ditch of the thrust metal.

Abstract: Provided is a substrate carrier device for electroplating of a solar cell which simultaneously plates both surfaces of a wafer.

Abstract: A panel frame carrier, comprises: a frame body; a transverse first rail assembly arranged at a front side of the frame body; a transverse second rail assembly arranged at a rear side of the frame body; a transformed rail arranged on a support plate; a longitudinal carrying assembly provided for supporting a support plate to drive the longitudinal displacement of the support plate; a panel frame including a sliding platform moveably disposed on the any rails mentioned above; a first moving member provided for pushing the panel frame from the first moving member to the transformed rail; and a second moving member provided for pushing the panel frame from the panel frame to the second moving member; whereby the panel frame is transmitted from an end of the first rail assembly through the transformed rail to the second rail assembly and vice versa.

Abstract: Apparatus for the electrolytic treatment of the product L using a treatment agent is used to make the treatment of a plate-shaped product more uniform. This apparatus includes devices 40, 42 for retaining the product L in the apparatus, one or more flow devices 10, which each include at least one nozzle 15 and are disposed situated opposite the product L, one or more counter electrodes 30, which are inert relative to the treatment agent and are disposed parallel to at least one treatment surface, eccentric motor means for generating a relative movement 44 between the product L, on the side, and the flow devices 10 and/or the counter electrodes 30, on the other side, in at least one direction parallel to a treatment surface. The product L can be immersed in the treatment agent during treatment.

Abstract: Embodiments of a closed-contact electroplating cup assembly that may be rapidly cleaned while an electroplating system is on-line are disclosed. One disclosed embodiment comprises a cup assembly and a cone assembly, wherein the cup assembly comprises a cup bottom comprising an opening, a seal surrounding the opening, an electrical contact structure comprising a plurality of electrical contacts disposed around the opening, and an interior cup side that is tapered inwardly in along an axial direction of the cup from a cup top toward the cup bottom.

Abstract: A method and apparatus for plating parts like lug nuts or other metal parts that have both an easily plated outside surface as well as a recessed cavity. The invention works in combination with a standard multi-station plating process. Also, a method and apparatus for preventing areas of electrode contact on a part from being non-plated. The present invention drains and plates a part containing a cavity by moving the part from a position where the cavity is facing around 45 degrees down to a position where the cavity is facing around 45 degrees up and then back down at various times during the process. The moving is generally initiated when the rack moving along a track above the fluid tanks encounters a roller. The roller causes a depression bar to activate a mechanical mechanism that shifts the position of the part. Other embodiments of the present invention can also rotate the part on an electrode finger as a roller on the track is encountered by the rack to avoid non-plated regions on the part.

Abstract: Methods, apparatuses, and various apparatus components, such as base plates, lipseals, and contact ring assemblies are provided for reducing contamination of the contact area in the apparatuses. Contamination may happen during removal of semiconductor wafers from apparatuses after the electroplating process. In certain embodiments, a base plate with a hydrophobic coating, such as polyamide-imide (PAI) and sometimes polytetrafluoroethylene (PTFE), are used. Further, contact tips of the contact ring assembly may be positioned further away from the sealing lip of the lipseal. In certain embodiments, a portion of the contact ring assembly and/or the lipseal also include hydrophobic coatings.

Abstract: A method of fluid sealing a workpiece is provided. The method includes providing a force to cause a ring to form a barrier to fluid entry with the workpiece and preventing fluid from crossing the barrier to fluid entry by forming a pressure differential across the barrier.

Abstract: A tending module for a series of electrolysis cells designed for the manufacture of aluminum by igneous electrolysis, each cell including a series of anodes provided with a metal rod designed to fix and electrically connect the anodes to a metal anode frame. The tending module includes a frame to be fixed to a mobile component, and at least one anode handling unit connected to the frame. The module also includes, integral with the anode handling unit, an activator that can exert at least one force or impulse on the anode rod, with a force such that, although the stem is firmly maintained in contact against the anode frame, the contact surfaces are moved in relation to each other by an amount sufficient for electrical contact to be improved. Advantageously, the activator is a jack or an impulse generator integral with the anode clamp.

Abstract: A centrifugal workpiece processor for processing semiconductor wafers and similar workpieces includes a head which holds and spins the workpiece. The head includes a rotor having a gas system. Gas is sprayed or jetted from inlets in the rotor to create a rotational gas flow. The rotational gas flow causes pressure conditions which hold the edges of a first side of the workpiece against contact pins or surfaces on the rotor. The rotor and the workpiece rotate together. Guide pins adjacent to a perimeter may help to align the workpiece with the rotor. An angled surface helps to deflect spent process liquid away from the workpiece. The head is moveable into multiple different engagement positions with a bowl. Spray nozzles in the bowl spray a process liquid onto the second side of the workpiece, as the workpiece is spinning, to process the workpiece. A moving end point detector may be used to detect an end point of processing.

Abstract: Embodiments of a closed-contact electroplating cup assembly that may be rapidly cleaned while an electroplating system is on-line are disclosed. One disclosed embodiment comprises a cup assembly and a cone assembly, wherein the cup assembly comprises a cup bottom comprising an opening, a seal surrounding the opening, an electrical contact structure comprising a plurality of electrical contacts disposed around the opening, and an interior cup side that is tapered inwardly in along an axial direction of the cup from a cup top toward the cup bottom.

Abstract: In one embodiment, a substrate holder comprises a base supporting a substrate that includes a surface having a peripheral region. A cover may be assembled with the base and includes at least one opening exposing only a portion of the surface therethrough. A seal assembly substantially seals a region between the cover and base and further adjacent to the peripheral region of the substrate. An electrode includes at least one contact portion positioned within the region and extending over at least a portion of the peripheral region of the substrate. A compliant member comprises a polymeric material and may be positioned within the region between the at least one contact portion and either the peripheral region of the substrate or the cover. In other embodiments, an electroplating system is disclosed that may employ such a substrate holder.

Abstract: A plating apparatus can form a plated film having a uniform thickness over the entire surface of a substrate without a change of members. The plating apparatus includes a substrate holder, a cathode contact for contacting a conductive film formed on the substrate so that the conductive film serves as a cathode, a ring-shaped seal member for covering the cathode contact and bringing its inner circumferential portion into contact with the peripheral portion of the substrate to seal the peripheral portion of the substrate, an anode disposed so as to face the conductive film formed on the substrate, and an auxiliary cathode disposed with respect to the seal member such that at least part of the auxiliary cathode is exposed on a surface of the seal member. Plating is carried out by bringing the conductive film, the anode and the auxiliary cathode into contact with a plating solution.

Abstract: A process employing a rack having an article carrier that is movably supported on a frame and mechanically coupled for translating movement from a motor to the article carrier to effect movement of an article during processing to provide more uniform surface treatment, reducing or eliminating the need for shielding.

Abstract: A substrate holding and transporting assembly is disclosed. The substrate holding and transporting assembly includes a base plate and a pair of clamps connected to the base plate in a spaced apart orientation, the spaced apart orientation of the pair of clamps enable support of a substrate with at least two independent points. The substrate holding and transporting assembly also includes an electrode assembly connected to the base plate at a location that is substantially between the pair of clamps. The electrode assembly defined to impart an electrical contact to the substrate when present and held by the pair of clamps.

Abstract: A problem during electrolytic treatment of printed circuit boards having a very thin basic metallization is that the treatment yields irregular results in various regions on the surface of the printed circuit board. In overcoming this problem the invention provides a device for electrolytically treating an at least superficially electrically conducting work piece having at least two substantially opposing side edges. The device comprises current supply devices for the work piece, said current supply devices each comprising contact strips located on the opposing side edges which are capable of electrically contacting the work piece at the substantially opposing side edges.

Abstract: The invention provides an improved contact ring and an improved workpiece support, each of which is useful alone or jointly with the other in a workpiece holder for electrochemically treating microelectronic workpieces. Several embodiments of the invention provide a composite contact ring having a dielectric base carrying a conductor which delivers electric power to a microelectronic workpiece. The dielectric base may be rigid and define a plurality of rigid fingers, each of which carries a separate electrical contact of the conductor. Such a contact ring is expected to have a long service life and enhance uniformity of electrochemical treatment. Several embodiments of the invention provide a workpiece support which induces a control the flexure of a microelectronic workpiece without damaging the workpiece. This controlled flexure can ensure more uniform contact between the workpiece and a contact assembly despite variations in the workpiece and/or the contact assembly.

Abstract: A system and method increase yield from semiconductor wafer electroplating. The aspects include a semiconductor wafer, the semiconductor wafer comprising a plurality of die areas. A plating ring for holding the semiconductor wafer in position during electroplating is also included, the plating ring substantially surrounding a circumference of the semiconductor wafer and having a width that varies in order to avoid overlap near edge die areas of the semiconductor wafer.

Abstract: A system for use in manufacturing semiconductor devices, is provided. The system includes an electrochemical processing tool and an image sensor. The electrochemical processing tool includes an electrode located at a central region of a platen. The electrode is adapted for contacting a wafer workpiece during certain processing of the wafer workpiece using the tool. At least part of the electrode is viewable from above the platen when the electrochemical processing tool is operably assembled. The image sensor is capable of capturing an image of the viewable part of the electrode. The image sensor is positioned above the platen. The image sensor is adapted to be aimed at the electrode when an image of the electrode is to be taken with the image sensor.

Abstract: Contact assemblies for electrochemical processing of microelectronic workpieces. The contact assembly (400) can comprise a support member (410) that includes an inner wall (412) which defines an opening (414) configured to receive the workpiece and a plurality of contacts (420). The individual contacts (420) include a conductor (440) and a cover (430). The conductor (440) can comprise a proximal section (435) projecting inwardly into the opening (414) relative to the support member (410), a distal section (436) extending from the proximal section (435), and an inert exterior (444) at least at the distal section (436). The cover (430) comprises a dielectric element that covers at least the proximal section of the conductor, but does not cover at least a portion of the distal section of the core. The exposed portion of the distal section of the core, accordingly, defines a conductive contact site for contacting a conductive layer (e.g., a seed layer) on the workpiece.

Abstract: A contact ring for an electrochemical plating system is provided. The contact ring includes an annular substrate supporting member, a plurality of radially positioned conductive substrate contact pins extending from the substrate supporting member, an annular conductive thief element attached to the substrate supporting member, and at least one source of electrical power in electrical communication with the contact pins and the conductive thief element.

Abstract: On a fixture for electro-chemical machining for the production of long, curved cavities (11) in a component (12), the working electrode (3) of the electro-chemical machining tool (1) is connected to a guide body (1a) which moveably rests against the inner walls of the respective cavity by means of power-actuated guide elements (2), with the guide body being connected to a flexurally soft and torsionally stiff guide linkage (5) coupled to a feed and rotary drive. Control of the movement of the guide body is accomplished in dependence of at least one wall thickness measured with a measuring device (13, 14) during feed movement.

Abstract: The present invention provides improvements in methods for the manufacture of stents. Specifically, the invention provides methods wherein stents are placed on jigs of various designs which facilitate manufacture, stents carried by the jigs are immersed in liquid baths which contain an electrolyte, the stents are urged into contact with their associated electrodes while current is applied to those electrodes, and wherein the positions of contact between the stents and their respective electrodes are altered during processing without removing the stents from the jig. The method is applicable for electropolishing and electro-plating.

Abstract: A contact ring for use in electroplating of a substrate material is constructed such that fluid (e.g., electrolyte) is allowed to flow radially away from the axis of a toroidal support ring, thus preventing the trapping of fluids between the substrate and the toroidal support ring. The contact ring is constructed with a series of openings arranged about the circumference of the ring and wherein an electrical contact is placed in the path of each opening so any fluid passing through the opening also passes around the associated electrical contact. Further, the electrical contacts are also placed such that a substrate (e.g., a semiconductor wafer) can be placed inside the support ring so as to electrically contact the electrical contacts. The toroidal support ring has an aerodynamically streamlined cross-section at the openings, such that fluid flows through the openings with reduced aerodynamic drag.

Abstract: Embodiments of the invention may further provide a contact ring for an electrochemical plating system. The contact generally includes a substrate receiving member having a substrate support surface formed thereon, a plurality of electrical contact pins extending from the substrate support surface, a first seal positioned on the substrate support surface radially inward of the plurality of electrical contacts, and a second seal positioned radially outward of the plurality of electrical contacts. Additionally, the contact ring generally includes a fluid inlet configured to supply a fluid to a volume between the first seal and the second seal.

Abstract: An apparatus for securing a substrate in an electrochemical deposition system is provided. The apparatus generally includes a substrate support member adapted to receive the substrate and a thrust plate assembly adapted to exert a downward force on the substrate. For some embodiments, a first sealing member adapted to engage a plating surface of the substrate may be attached to the substrate support member. The apparatus may also include a second sealing member adapted to engage a non-plating surface of the substrate or a surface of the substrate support member to prevent the flow of plating fluid to a non-plating surface of the substrate. The apparatus may also include electrical contacts to electrically contact the plating or non-plating surface of the substrate.

Abstract: An apparatus for providing an electrical bias to a substrate in a processing system is described. The apparatus generally includes a conductive annular body defining a central opening. The conductive annular body may have a substrate seating surface adapted to receive the substrate and a plurality of scallops formed on a surface opposing the substrate seating surface. A plurality of electrical contacts may be formed on the substrate seating surface opposite the plurality of scallops. The electrical contacts may be adapted to engage a plating surface of the substrate.

Abstract: Contact assemblies for electrochemical processing of microelectronic workpieces. The contact assemblies can comprise a support member that includes an inner wall which defines an opening configured to receive the workpiece and a plurality of contacts. The individual contacts include a conductor and a cover. The conductor can comprise a proximal section projecting inwardly into the opening relative to the support member, a distal section extending from the proximal section, and an inert exterior at least at the distal section. The cover comprises a dielectric element that covers at least the proximal section of the conductor, but does not cover at least a portion of the distal section of the core. The exposed portion of the distal section of the core, accordingly, defines a conductive contact site for contacting a conductive layer (e.g., a seed layer) on the workpiece.

Abstract: Contact assemblies, electroplating machines with contact assemblies, and methods for making contact assemblies that are used in the fabrication of microelectronic workpieces. The contact assemblies can be wet-contact assemblies or dry-contact assemblies. A contact assembly for use in an electroplating system can comprise a support member and a contact system coupled to the support member. The support member, for example, can be a ring or another structure that has an inner wall defining an opening configured to allow the workpiece to move through the support member along an access path. In one embodiment, the support member is a conductive ring having a plurality of posts depending from the ring that are spaced apart from one another by gaps. The contact system can be coupled to the posts of the support member. The contact system can have a plurality of contact members projecting inwardly into the opening relative to the support member and transversely with respect to the access path.

Abstract: Contact assemblies, electroplating machines with contact assemblies, and methods for making contact assemblies that are used in the fabrication of microelectronic workpieces. The contact assemblies can be wet-contact assemblies or dry-contact assemblies. A contact assembly for use in an electroplating system can comprise a support member and a contact system coupled to the support member. The support member, for example, can be a ring or another structure that has an inner wall defining an opening configured to allow the workpiece to move through the support member along an access path. In one embodiment, the support member is a conductive ring having a plurality of posts depending from the ring that are spaced apart from one another by gaps. The contact system can be coupled to the posts of the support member. The contact system can have a plurality of contact members projecting inwardly into the opening relative to the support member and transversely with respect to the access path.

Abstract: Embodiments of the invention generally provide an electrochemical plating cell having an electrolyte container assembly configured to hold a plating solution therein, a head assembly positioned above the electrolyte container, the head assembly being configured to support a substrate during an electrochemical plating process, and an anode assembly positioned in a lower portion of the electrolyte container. The anode assembly generally includes a copper member having a substantially planar upper surface, at least one groove formed into the substantially planar upper surface, each of the at least one grooves originating in a central portion of the substantially planar anode surface and terminating at a position proximate a perimeter of the substantially planar upper surface, and at least one fluid outlet positioned at a perimeter of the substantially planar upper anode surface.

Abstract: An apparatus for electroplating a workpiece is disclosed in which the apparatus includes a workpiece holding structure. The workpiece holding structure includes a workpiece support having at least one surface that is disposed to engage a front side of the workpiece and at least one electrical contact disposed for contact with at least one corresponding electrical contact on a back-side of the workpiece. The workpiece includes one or more electrically conductive paths between the at least one corresponding electrical contact and a front-side of the workpiece to facilitate electroplating of the front-side surface.

Abstract: Embodiments of the invention generally provide an electrochemical plating cell having an electrolyte container assembly configured to hold a plating solution therein, a head assembly positioned above the electrolyte container, the head assembly being configured to support a substrate during an electrochemical plating process, and an anode assembly positioned in a lower portion of the electrolyte container. The anode assembly generally includes a copper member having a substantially planar upper surface, at least one groove formed into the substantially planar upper surface, each of the at least one grooves originating in a central portion of the substantially planar anode surface and terminating at a position proximate a perimeter of the substantially planar upper surface, and at least one fluid outlet positioned at a perimeter of the substantially planar upper anode surface.

Abstract: An apparatus for electroplating a workpiece is disclosed in which the apparatus includes a workpiece holding structure. The workpiece holding structure includes a workpiece support having at least one surface that is disposed to engage a front side of the workpiece and at least one electrical contact disposed for contact with at least one corresponding electrical contact on a back-side of the workpiece. The workpiece includes one or more electrically conductive paths between the at least one corresponding electrical contact and a front-side of the workpiece to facilitate electroplating of the front-side surface.

Abstract: A wafer chuck for holding a wafer during electropolishing and/or electroplating of the wafer includes a top section, a bottom section, and a spring member. In accordance with one aspect of the present invention, the top section and the bottom section are configured to receive the wafer for processing. The spring member is disposed on the bottom section and configured to apply an electric charge to the wafer. In accordance with another aspect of the present invention, the spring member contacts a portion of the outer perimeter of the wafer. In one alternative configuration of the present invention, the wafer chuck further includes a seal member to seal the spring member from the electrolyte solution used in the electropolishing and/or electroplating process.

Abstract: A cathode current control system employing a current thief for use in electroplating a wafer is set forth. The current thief comprises a plurality of conductive segments disposed to substantially surround a peripheral region of the wafer. A first plurality of resistance devices are used, each associated with a respective one of the plurality of conductive segments. The resistance devices are used to regulate current through the respective conductive finger during electroplating of the wafer. Various constructions are used for the current thief and further conductive elements, such as fingers, may also be employed in the system. As with the conductive segments, current through the fingers may also be individually controlled. In accordance with one embodiment of the overall system, selection of the resistance of each respective resistance devices is automatically controlled in accordance with predetermined programming.

Abstract: The invention relates to a transverse conveyor for electrodes used in the production of metals. This transverse conveyor consists of a transfer device, located below the electrodes to be transferred and which device moves back and forth on a horizontal plane, as well as of lifters used for lifting the electrodes. The transfer device consists of a frame, on which there is a moving transfer bar, which is designed to cover the frame at all stages of its movement.

Abstract: A semiconductor workpiece holder used in electroplating systems for plating metal layers onto a semiconductor workpieces, and is of particular advantage in connection with plating copper onto semiconductor materials. The workpiece holder includes electrode assemblies which have a contact part which connects to a distal end of an electrode shaft and bears against the workpiece and conducts current therebetween. The contact part is preferably made from a corrosion resistant material, such as platinum. The electrode assembly also preferably includes a dielectric layer which covers the distal end of the electrode shaft and seals against the contact part to prevent plating liquid from corroding the joint between these parts.

Abstract: The invention relates to a device for at least partly removing a deposit created in the electrolytic refining or electrowinning of metal from the surface of the mother plate used as an electrode in the refining or electrowinning process, said device comprising at least one member for removing the deposit and at least one member for controlling the removal member with respect to the deposit to be removed. According to the invention, the device comprises at least one gripping element that is used for creating a mechanical contact between the deposit and the removal member, said gripping element being connected to a control member, to which there are coupled both the shaft part of the gripping element and the deposit removal member.

Abstract: A lift and rotate assembly for use in a workpiece processing station. The lift and rotate assembly includes a body having a slim profile and pins located on opposite sides for mounting the assembly onto a tool frame. The lift and rotate assembly is removably and pivotally mounted to an exposed outer surface of the frame. The lift and rotate assembly has a body, a process head movably connected to the body, and control components mounted within the body and configured to move the process head relative to the body. The lift and rotate assembly in one embodiment is positionable in a forward, operating position with the body adjacent to the frame, and in a tilted, service position with the body tilted away from the frame.

Abstract: The present cup-type plating apparatus improves a conventional cup-type plating apparatus and prevents the surface of a wafer due to a mist of the plating solutions from being contaminated. A plating solution is supplied to a wafer which is placed on a wafer support provided along an opening at the top of a plating tank from a solution-supply port provided at the bottom of the plating tank by an upward-moving stream; the plating solution is made to flow out of a solution-outlet port provided for the plating tank; and plating is performed while the plating solution is brought into contact with a surface of the placed wafer, which is to be plated, wherein the solution-outlet port has a solution-outlet path in which the discharged plating solution is isolated from the outer space.

Abstract: An electroplating apparatus for wheel disk comprises an electrolytic cell containing electrolytic bath, a cathode plate, an auxiliary anode, at least one anode plate and a driving mechanism. Part of the auxiliary anode is provided with an insulating shielding, one end of the insulating shielding passes through the center hole of the disk wheel. Part of the auxiliary anode is exposed on both sides of the wheel disk. Therefore, the auxiliary anode forms a dual anodes scheme with the anode plate to provide complete and smooth plating. The wheel disk is rotated by the driving mechanism to prevent tip-discharging.

Abstract: A method for multilayered coating, whereby hurdles for the item that is to be treated are guided for galvanic dip coating (2) through in a separate circuit. Downstream from the tank, the hurdles are changed over (12) and the item that is to be treated is guided in another hurdle for electrophoretic coating through a tank (4) in another separate circuit.

Abstract: An electrical contact element for electrically connecting an electric device and providing current transmission in an electric device wherein the electrical contact element comprises a metallic body, and wherein at least one contact surface, present on the body, is completely or partially coated with a friction-reducing layer. The friction-reducing layer comprises a metal salt.

Abstract: An apparatus for electroplating a workpiece is disclosed in which the apparatus includes a workpiece holding structure. The workpiece holding structure includes a workpiece support having at least one surface that is disposed to engage a front side of the workpiece and at least one electrical contact disposed for contact with at least one corresponding electrical contact on a back-side of the workpiece. The workpiece includes one or more electrically conductive paths between the at least one corresponding electrical contact and a front-side of the workpiece to facilitate electroplating of the front-side surface.

Abstract: A plating clamp assembly for use with a plating system including a plating bath and an article transport assembly to selectively engage an article to be plated as the article is moved through the plating bath by the article transport assembly to coat at least a selected portion of the surface of the article with material without creating faults on the selected portion of the surface of the article.

Abstract: A wafer plating system horizontally transporting vertically oriented wafers into one or more process cells. The wafer processing system includes a carrier rotatable from a substantially horizontal orientation to a substantially vertical orientation. A cathode assembly secures the wafer onto the carrier and electrically couples the wafer to a power supply.

Abstract: The invention concerns a motorized device for adjusting the interelectrodic gap in mercury cathode electrolysis cells, mainly consisting of a frame, to which a number of anodes are suspended, movable in the vertical direction by means of a single jackscrew driven by a gear motor acting on double levers. The jackscrew with the motor and the lever system are fixed to a main frame, supported on the cell bottom by means of supports positioned on adjustable columns, while the above mentioned movable frame (also called sub-frame) carrying the anodes, is connected to the lever arms by means of four hinged supports. The shifting of the movable frame and, consequently, of the anodes can be controlled by a centralized and computerized system (which is not part of the invention) as a function of voltage and current variation measurements.