Abstract: Static neutralization of a charged object is provided by applying an alternating voltage having a complex waveform, hereinafter referred to as a “multi-frequency voltage”, to an ionizing electrode in an ionizing cell. When the multi-frequency voltage, measured between the ionizing electrode and a reference electrode available from the ionizing cell, equals or exceeds the corona onset voltage threshold of the ionizing cell, the multi-frequency voltage generates a mix of positively and negatively charged ions, sometimes collectively referred to as a “bipolar ion cloud”. The bipolar ion cloud oscillates between the ionizing electrode and the reference electrode. The multi-frequency voltage also redistributes these ions into separate regions according to their negative or positive ion potential when the multi-frequency voltage creates a polarizing electrical field of sufficient strength.

Abstract: A low maintenance AC gas-flow driven static neutralizer, comprising at least one emitter and at least one reference electrode; a power supply having an output electrically coupled to the emitter(s) and a reference terminal electrically coupled to the reference electrode(s) with the power supply disposed to produce an output waveform that creates ions by corona discharge and to produce an electrical field when this output waveform is applied to the emitter(s); a gas flow source disposed to produce a gas flow across a first region that includes these generated ions and the emitter(s), the gas flow including a flow velocity; and wherein, during a first time duration, the output waveform decreases an electrical force created by the electrical field, enabling the gas flow to carry away from the emitter(s) a contamination particle that may be located within a second region surrounding the emitter(s), and to minimize a likelihood of the contamination particle from accumulating on the emitter(s).

Abstract: An apparatus and method for monitoring the output of an ionizing blower. A measuring channel captures a portion of the air ion stream, and measures balance plus air ion current. Since the measurement channel is isolated from extraneous electrostatic fields, measurements contain less analytical noise. Air flow through the measurement chamber is created by the inherent pressure difference between the high pressure and low pressure sides of an air mover. Two electrodes inside the measurement chamber are combined with a power supply, a low current amplifier, and a controller. The controller also makes adjustments to the ionizing blower.

Abstract: Ions for neutralizing electrostatic charge on an object are generated and delivered in a stream of gas flowing through a dielectric channel that surrounds a loop of conductive filament which forms an ionizing electrode. The loop is formed within a single plane, or within multiple planes, and is supported within the channel with a plane of the loop substantially aligned with flow of gas through the channel. A region of minimum field intensity within the bounded region of the loop electrode is oriented in alignment with substantially maximum velocity of gas flow through a cross section of the dielectric channel.

Abstract: A module for generating ions in a flowing air stream includes a support structure having a central region adapted to pass a flowing air stream therethrough, and including a plurality of supports for positioning a filamentary ion-generating electrode in a polygonal configuration within the central region. The supports and filament are relatively moveable to wipe the surface of the filament at each support for removing accumulated contaminants on the filament.

Abstract: A corona discharge static neutralizing device includes a wire electrode retained in tension between spaced ends of a resilient support member that is positioned within a flowing air stream. Another electrode aligned with and spaced from the wire electrode promotes a flowing ion stream, when connected to receive an ionizing difference of potential, that flows in skew orientation relative to the flowing air stream. Multiple wire electrodes are supported in tension on a resilient support member along with another electrode disposed on the support member intermediate the wire electrodes and in substantially the same plane therewith.

Abstract: An air ion collimator is added to ionizers with integrated fans that are used to remove static charge. Three mechanisms minimize air ion losses through recombination. Hence, the collimator increases the air ions that are available for charge removal. First, reducing turbulence slows air ion mixing. Second, air entrainment into fast moving air ion zones further slows the rate of air ion losses by dilution. The rate of recombination reaction slows with decreasing ion density. Third, vanes within the collimator delay mixing. In addition to conserving air ions, the collimator directs more ions to the target. Air ions lost to grounding are reduced. Again, more air ions are available to remove static charge from the target.

Abstract: A module for generating ions in a flowing air stream includes a support structure having a central region adapted to pass a flowing air stream therethrough, and including a plurality of supports for positioning a filamentary ion-generating electrode in a polygonal configuration within the central region. The supports and filament are relatively moveable to wipe the surface of the filament at each support for removing accumulated contaminants on the filament.

Abstract: Static neutralization of a charged object is provided by applying an alternating voltage having a complex waveform, hereinafter referred to as a “multi-frequency voltage”, to an ionizing electrode in an ionizing cell. When the multi-frequency voltage, measured between the ionizing electrode and a reference electrode available from the ionizing cell, equals or exceeds the corona onset voltage threshold of the ionizing cell, the multi-frequency voltage generates a mix of positively and negatively charged ions, sometimes collectively referred to as a “bipolar ion cloud”. The bipolar ion cloud oscillates between the ionizing electrode and the reference electrode. The multi-frequency voltage also redistributes these ions into separate regions according to their negative or positive ion potential when the multi-frequency voltage creates a polarizing electrical field of sufficient strength.

Abstract: An air ionizing module and method for generating ions of one and opposite polarities within a flowing stream of air or other gas includes a thin-filament electrode mounted within the flowing stream in regions thereof of maximum flow velocity. The thin-filament electrode is mounted in a multi-sided polygonal configuration to receive high ionizing voltage of alternating one and opposite polarities to form an intense stream of ions toward an electrically-isolated reference electrode positioned upstream of the filament electrode. Another reference electrode positioned within the flowing stream downstream of the filament electrode receives a bias voltage of selected polarity to control the quantities of generated ions of positive and negative polarities in an outlet stream of the ions and flowing gas.

Abstract: Method and apparatus for generating positive and negative ions include electrodes that are spaced apart by a gap and that are supplied alternating ionizing voltage at a frequency which causes the generated ions to move within the gap between electrodes and exhibit a resident time in transit that accumulates the ions substantially within the central region of the gap. An electrostatic field, or a flowing stream of air or other gas passing through the gap, transports the generated ions from within the gap. Self-balancing of generated positive and negative ions is accomplished using capacitive coupling of the ionizing voltage to at least one of the electrodes disposed about the gap.

Abstract: An improvement for a self-balancing shielded bipolar ionizer (U.S. Pat. No. 6,002,573), which uses pressurized air or nitrogen to increase performance, extend the operating distance range, and reduce cleaning frequency. An air assist assembly is inserted into the ion generation cavity, which directs pressurized air or nitrogen past the electrodes. In applications where little natural airflow exists, air assist technology is particularly useful. Ions are blown toward the target. This directs the ions to where they are needed, and delivers ions faster. Useful operating distances are increased. Faster delivery minimizes ion losses due to recombination. Furthermore, pure pressurized air protects the electrodes from impurities in the environmental air. Less chemical growth affects electrode performance. Hence, the ionizer exhibits more stable performance, plus the need for electrode cleaning is minimized.

Abstract: Apparatus and method for generating and controlling flows of positive and negative air ions includes interposing isolated sets of electrodes in a flowing air stream to separately produce positive and negative ions. The rates of separated production of positive and negative ions are sensed to control ionizing voltages applied to electrodes that produce the ions. Variations from a balance condition of substantially equal amounts of positive and negative ions flowing in the air stream are also sensed to alter bias voltage applied to a grid electrode through which the air stream and ions flow.

Abstract: An ionizer bar includes upper and lower housings having aerodynamically-shaped exterior surfaces to support laminar air flow over the structure. The upper housing forms an upper interior chamber for electrical circuitry isolated from a lower chamber within the lower housing that confines fluid under pressure therein. Outlets spaced along the length of the structure include ionizing electrodes that are disposed within fluid conduits and that are connected to a source of ionizing voltage mounted in the upper chamber. Fluid passages at the outlets release fluid under pressure within the lower chamber around associated ionizing electrodes mounted at the outlets.

Abstract: Concentrations of positive and negative ions that are generated in the ambient air at a selected location are controlled in time-varying manner. Apparatus for generating air ions includes controllable high voltage sources and electrodes connected to the sources adapted to generate positive ions and negative ions in ambient air near the electrodes. Control circuitry is coupled to the high voltage sources to control the voltage levels at the electrodes for altering the quantities of positive ions and/or negative ions that are generated in time-varying manner within the ambient air about the electrodes. The control circuitry may control the voltage sources to generate a simulated ion signature of variations in ion concentrations as detected at a selected geographic location.

Abstract: Concentrations of positive and negative ions that are generated in the ambient air at a selected location are controlled in time-varying manner. Apparatus for generating air ions includes controllable high voltage sources and electrodes connected to the sources adapted to generate positive ions and negative ions in ambient air near the electrodes. Control circuitry is coupled to the high voltage sources to control the voltage levels at the electrodes for altering the quantities of positive ions and/or negative ions that are generated in time-varying manner within the ambient air about the electrodes. The control circuitry may control the voltage sources to generate a simulated ion signature of variations in ion concentrations as detected at a selected geographic location.

Abstract: An enclosure for transporting semiconductor wafers includes a pair of sensors that are responsive to electrostatic fields mounted on conductive grounded plates in facing orientations on opposite sides of a position within the enclosure at which a semiconductor wafer is to be located. Electronic circuitry within the enclosure in communication with the sensors supplies monitoring signals to remote circuitry external to the enclosure that isolates sources of contaminants and provides remote balance and gain adjustments. Calibration of the balance and gain adjustments uses a grounded plate for zero balance reference, and uses a plate of insulating material that is charged to a known potential for referencing gain adjustments to produce related outputs.

Abstract: Apparatus and method and system for measuring and controlling electrostatic charge on objects such as semiconductor substrates include a cassette having an inner structure with supporting slots and electrically conductive regions, and having isolated conductive outer walls for supporting objects in the slots, and include a charge monitor connected to the conductive regions and the conductive walls for sensing charge applicable to one or more objects carrying static charge positioned within the cassette. Charge neutralization is controlled in response to sensed charge attaining a selected level.

Abstract: Air ionization apparatus includes a plurality of air ionizing electrodes connected to a source of high ionizing voltages, and includes a bias source connected to supply bias voltage to a reference electrode positioned near the air ionizing electrodes to alter the field gradients thereabout to selectively enhance production of positive or negative air ions in response to levels and polarity of bias voltage supplied to the reference electrode.

Abstract: Simultaneous neutralization and monitoring of charge on a moving dielectric material is achieved with ionizing devices that supply ions in proximity to the material to thereby substantially neutralize charge on the material, and with circuitry that senses the ion currents flowing from the ionizing devices to the material. A controller can be utilized to control the ionizing devices and/or calculate various parameters (such as charge densities on the web, efficiency, etc.) based on the sensed ion currents.