Abstract: An fast steering mirror (30), such as a PMN actuated mirror, is positioned in a beam path (18) of a stage-based positioning system (40) to continuously move a laser beam (46) in a high speed prescribed pattern about a nominal target position (60) to spatially separate focused laser spots (48) generated at a high laser repetition rate and thereby create geometric features having dimensions greater than those of the focused laser spot (48). A series of laser spots (48) at a given repetition rate appear as a series of larger diameter laser spots at a lower pulse rate without beam quality problems associated with working out of focus.

Abstract: A tertiary positioner system (80) of this invention employs X- and Y-axis translation stages (86, 88), galvanometer-driven mirrors (64, 66), and a fast steering mirror (“FSM”) (120) to direct a laser beam (90) to target locations (121) on a workpiece (92). A positioning signal is received by a low-pass filter (103) that produces filtered position data for driving the X- and Y-axis translation stages. The actual positions of the X- and Y-axis translation stages are subtracted from the unfiltered positioning data to produce an X-Y position error signal for driving the galvanometer-driven X- and Y-axis mirrors. The actual mirror positions are subtracted from the actual positions of the X- and Y-axis translation stages to generate a positional error signal representing the difference between the commanded and actual positions of the laser beam. The positional error signal drives the FSM to rapidly correct any positional errors.

Abstract: An fast steering mirror (30), such as a PMN actuated mirror, is positioned in a beam path (18) of a stage-based positioning system (40) to continuously move a laser beam (46) in a high speed prescribed pattern about a nominal target position (60) to spatially separate focused laser spots (48) generated at a high laser repetition rate and thereby create geometric features having dimensions greater than those of the focused laser spot (48). A series of laser spots (48) at a given repetition rate appear as a series of larger diameter laser spots at a lower pulse rate without beam quality problems associated with working out of focus.

Abstract: The present invention preferably employs non-contact, small-displacement, capacitive sensors to determine Abbe errors due to the pitch, yaw, or roll of a near linear mechanical stage that are not indicated by an on-axis position indicator, such as a linear scale encoder or laser interferometer. The system is calibrated against a precise reference standard so the corrections depend only on sensing small changes in the sensor readings and not on absolute accuracy of the sensor readings. Although the present invention is preferred for use in split-axis positioning systems with inertially separated stages, the invention can be employed in typical split-axis or stacked stage systems to reduce their manufacturing costs.

Abstract: The present invention preferably employs non-contact, small-displacement, capacitive sensors to determine Abbe errors due to the pitch, yaw, or roll of a near linear mechanical stage that are not indicated by an on-axis position indicator, such as a linear scale encoder or laser interferometer. The system is calibrated against a precise reference standard so the corrections depend only on sensing small changes in the sensor readings and not on absolute accuracy of the sensor readings. Although the present invention is preferred for use in split-axis positioning systems with inertially separated stages, the invention can be employed in typical split-axis or stacked stage systems to reduce their manufacturing costs.

Abstract: A multi-rate, multi-head positioner (150) receives and processes unpanelized positioning commands to actuate slow stages (56, 58) and multiple fast stages (154) that are mounted on one of the slow stages to simultaneously position multiple tools (156) relative to target locations (162) on multiple associated workpieces (152). Each of the fast stages is coupled to a fast stage signal processor (172) that provides corrected position data to each fast stage positioner to compensate for fast stage nonlinearities and workpiece placement, offset, rotation, and dimensional variations among the multiple workpieces. When cutting blind via holes in etched circuit boards (ECBs), improved throughput and process yield are achieved by making half of the tools ultraviolet ("UV") lasers, which readily cut conductor and dielectric layers, and making the other half of the tools are infrared ("IR") lasers, which readily cut only dielectric layers.

Abstract: A multi-rate positioner system (50) receives unpanelized positioning commands from a database subsystem (64), profiles the commands (72) into a half-sine positioning signal, and further processes the signal into a low-frequency positioning signal (LFP) and a high-frequency positioning signal (HFP) for actuating respective slow (56, 58) and fast (54) positioners to target locations on a workpiece (62). The slow and fast positioners move without necessarily stopping in response to a stream of positioning command data while coordinating their individually moving positions to produce temporarily stationary tool positions (140) over target locations defined by the database. The multi-rate positioning system reduces the fast positioner movement range requirement while providing significantly increased tool processing throughput.

Abstract: A multi-rate positioner system (50) receives unpanelized positioning commands from a database storage subsystem (64), profiles the commands (72) into a half-sine positioning signal, and further processes the signal into a low-frequency positioning signal (LFP) and a high-frequency positioning signal (HFP) for actuating respective slow (56, 58) and fast (54) positioners to target locations on a workpiece (62). The slow and fast positioners move without necessarily stopping in response to a stream of positioning command data while coordinating their individually moving positions to produce temporarily stationary tool positions (140) over target locations defined by the database. The multi-rate positioning system reduces the fast positioner movement range requirement while providing significantly increased tool processing throughput.

Abstract: A collecting and treating tank which holds liquid and in which a vertically movable cover floats on the liquid or on a gas layer above the liquid, comprising a tank having a vertical cylindrical circular wall, a bottom at and joined to the wall, and a circular cover which fits loosely inside the circular wall so that it is vertically displaceable with change in liquid and/or gas volume beneath the cover; and a plurality of cover guides, spaced radially around the cover edge, which are adapted to maintain the cover periphery spaced from the tank wall; said cover guides being faced with a solid polymeric layer which is slippery and has a low coefficient of friction so that the cover is readily displaceable vertically solely with change in volume of liquid, gas or both beneath the cover.

Abstract: Apparatus comprising a freeze exchanger in which an aqueous mixture is indirectly cooled by a cooling fluid to produce an aqueous mixture containing ice; a centrifuge; a conduit for feeding an ice slurry from the freeze exchanger to the centrifuge; a heater; a conduit for feeding ice from the centrifuge to the heater to melt the ice; a water treatment apparatus; a conduit for feeding the water from the heater to the water treatment apparatus to condition the water for contact with a reverse osmosis membrane; a reverse osmosis apparatus; and a conduit for feeding the conditioned water to the reverse osmosis apparatus in which the water is purified by reverse osmosis.

Abstract: A falling film freeze exchanger, heat exchanger or crystallizer having a plurality of spaced apart vertical tubes secured in, and penetrating, an upper circular tube sheet and a lower circular tube sheet; each tube having a top end and a bottom end; a circular cylindrical shell around the tube sheets and connected thereto; the shell having a heat exchange fluid inlet and a heat exchange fluid outlet for circulating heat exchange fluid around the tubes between the tube sheets; a header surrounding and joined to the upper part of the shell and extending above the top tube sheet and above the top end of the tubes; means to deliver a liquid process feed stream into the header; and wiper means, adapted to rotate about a vertical axis, in contact with the top ends of the tubes.

Abstract: Falling film heat exchanger includes circular areas for evenly distributing feed liquid and/or heat exchange liquid to the tube interior and/or exterior surfaces. The circular areas may be defined by a liquid porous material, slots in an O-ring or vertical slots in the holes through and to which the tubes are joined.

Abstract: This disclosure relates to a heat pump including a plurality of interconnected elements, each of said elements comprising a piston body having an evaporator section at one end thereof and a condenser section at the other end thereof, each condenser section being connected to a vapor condenser. Each element has its evaporator section connected by a vapor bridge to the condenser of an adjacent element. Each piston body contains a working fluid having a liquid phase and a vapor phase, the liquid phase forming a liquid piston which oscillates during operation and the pistons of the elements oscillating with a phase displacement. The evaporator sections are located in relatively warm areas and the condensers are located in another cooler area. Portions of the liquid in the evaporator sections vaporize and the vapor is heated, and the heated vapor is condensed in the condensers thereby transferring heat from the warm areas to the cooler areas.