Abstract: The object of the invention is to provide a method and apparatus for treating membrane-containing material with electrical fields, in vitro, and with an added treating substance. With the method, a plurality of electrodes are arrayed around the material to be treated and are connected to outputs of an electrode selection apparatus. Inputs of the electrode selection apparatus are connected to outputs of a pulse sequence generator. A treating substance is added to the membrane-containing material. Electrical pulses are applied to the electrode selection apparatus and are routed through the electrode selection apparatus in a predetermined, computer-controlled sequence to selected electrodes in the array of electrodes, whereby the membrane-containing material is treated with the added treating substance and with electrical fields. The routing of applied pulses through the electrode selection apparatus to selected electrodes can be done in an enormous number of ways.

Abstract: An apparatus and method for plating a workpiece. The apparatus comprises, generally, an anode, a cathode, and a selective anode shield/material flow assembly. In use, both the anode and the cathode are immersed in a solution, and the cathode is used to support the workpiece. During an electroplating process, the anode and the cathode generate an electric field emanating from the anode towards the cathode, to generate a corresponding current to deposit an electroplating material on the workpiece. The selective shield/material flow assembly is located between the anode and the cathode, and forms a multitude of adjustable openings. These opening have sizes that are adjustable during the electroplating process for selectively and controllably adjusting the amount of electric flux passing through the selective shield/material flow assembly and the distribution of the electroplating material on the workpiece. The selective shield/material flow assembly can also be used with an electroless plating system.

Abstract: A method and apparatus are provided for the electroplating of a substrate such as a semiconductor wafer which provides a uniform electroplated surface and minimizes bum-through of a seed layer used on the substrate to initiate electroplating. The method and apparatus of the invention uses a specially defined multistep electroplating process wherein, in one aspect, a voltage below a predetermined threshold voltage is applied to the anode and cathode for a first time period followed by applying a current to the anode and cathode for a second time period the current producing a voltage below the predetermined threshold voltage. In another aspect of the invention, a current is applied to the anode and cathode substrate which current is preprogrammed to ramp up to a current value from a first current value which current produces a voltage below a predetermined threshold voltage.

Abstract: A method of electrochemically machining an electrically conductive workpiece in an electrolyte by applying electrical pulses between the workpiece and an electrically conductive electrode, one or more machining pulses alternating with passivation voltage pulses for depositing passivation layers on the workpiece. The amplitude of the passivation voltage pulses is adjusted during an adjustment procedure in which the amplitude of the passivation voltage pulses is increased gradually from zero to the voltage at which the workpiece starts to dissolve in the electrolyte. After each voltage increase the resistance of the gap between the electrode and the workpiece is measured. The voltage value for the highest gap resistance is stored in a memory and used during further machining. The time span of the passivation voltage pulses may be divided into time slices and for each time slice the voltage is adjusted for maximum gap resistance during that time slice.

Abstract: A method of removing a metal skin from a through-hole surface of a copper-Invar-copper (CIC) laminate without causing differential etchback of the laminate. The metal skin includes debris deposited on the through-hole surface as the through hole is being formed by laser or mechanical drilling of a substrate that includes the laminate as an inner plane. Removing the metal skin combines electrochemical polishing (ECP) with ultrasonics. ECP dissolves the metal skin in an acid solution, while ultrasonics agitates and circulates the acid solution to sweep the metal skin out of the through hole. ECP is activated when a pulse power supply is turned on and generates a periodic voltage pulse from a pulse power supply whose positive terminal is coupled to the laminate and whose negative terminal is coupled to a conductive cathode. After the metal skin is removed, the laminate is differentially etched such that the copper is etched at a faster rate than the Invar.

Abstract: The present invention relates to a novel process for coating objects by means of direct current, in which process an adjustable DC voltage is pulse-modulated with an adjustable AC voltage. The process is useful for electrochemical coating of objects with resinous coating material. Preferably, the pulse modulation of the DC voltage is limited to certain time intervals during the coating process and the pulse modulation is connected and disconnected with an adjustable duty ratio.

Abstract: The circuit arrangement and method for supplying pulsed current to electrolytic cells according to the invention are used in electroplating systems. To supply current to each electrolytic cell, there are provided two galvanic rectifiers 5, 32 and one change-over switch 12 with respectively two individual switches 23, 24, one output of the rectifiers being connected via a first electric line 33 with the one terminal of the electrolytic cell, the respective other outputs of the rectifiers being connected each via a second electric line 34, 35 with the inputs of the change-over switches, and the output 18 of the change-over switch being connected with the other terminal of the electrolytic cell, a capacitor 20, 21 being respectively connected, in addition, between the first electric line and the second electric lines. Periodic pulse sequences are generated by alternate opening and closing said separate switches.

Abstract: In an electrolytic water producing apparatus, an anode and a cathode in an electrolytic cell are periodically switched to reduce degradation thereof. The concentration of hypochlorous acid formed in the strong acidic liquid is measured through a concentration sensor, and a concentration variation pattern varying in a sawteeth pattern according to the switching of the anode and cathode is taken into a control device. A control pattern inversely corresponding to the sawteeth pattern is calculated by the controlling device. Electrolytic current or voltage to be supplied to the electrodes may be controlled according to the control pattern, or supply quantities of raw water or a chloride solution may be controlled by a flow rate controlling valve and a metering pump. Thus, although the polarities of the electrodes are switched, the strong acidic liquid containing hypochlorous acid with a constant concentration can be obtained.