Hughes Aircraft Company

Nordson Corporation

Other

Joseph E Donner

William H Hill

Horatio Quinones

Thomas L Ratledge

Christopher L Giusti

Yuriy Suhinin

Michael Gorman

Alan Ray Lewis

William M Fries

Wayne P Jensen

Methods and systems of accurately dispensing a viscous fluid onto a substrate. In an embodiment, a method includes using an electronic flow meter device to produce electrical flow meter output signals and performing a responsive control function in a closed loop manner by adjusting at least one dispensing parameter to correct for a difference between an output data set and a reference data set. In another embodiment, a system includes a control operatively coupled to a gas flow meter device and to a weigh scale allowing for a density of an amount of viscous material to be determined. In another embodiment, a method includes using a control coupled to both a gas flow meter device and a weigh scale and performing a responsive control function in a closed loop manner by adjusting at least one dispensing parameter using gas flow meter output signals and weigh scale output signals.

Flow metering for dispense monitoring and control

A non-contact jetting dispenser, viscous fluid dispensing system and method. The system includes a viscous fluid dispenser for dispensing the viscous fluid. The system further includes a viscous fluid supply container adapted to hold the viscous fluid. A flow path is provided for the viscous fluid between the viscous fluid supply container and an outlet of the viscous fluid dispenser. An electronic flow meter device is used to produce electrical output signals proportional to the flow rate of the fluid flowing through the flow path. A control is operatively coupled to the electronic flow meter for continuously receiving and processing the electrical output signals and performing a responsive control function in a closed loop manner.

Dispenser and method of dispensing and controlling with a flow meter

Improved ultrasonic wire bonders, and improvements to ultrasonic wire bonding transducers that are used with such ultrasonic wire bonders. The improvements to the ultrasonic wire bonding transducer includes driver-node mounting of the transducer and a clamping arrangement for a bonding tool in the transducer. The driver-node mounting of the transducer is achieved by mounting it in the ultrasonic bonder such that a 3/4--wavelength distance is created between a mounting bracket of the transducer and a distal end of the transducer at which the bonding tool is disposed. As a result, vibrational problems caused by the transducer not being located at the node are eliminated. The driver-node mounting aspect of the present invention provides a shorter overall transducer and concentrates the mass at the driver end for less tool impact, and reduces manufacturing variables related to achieving a one-half wavelength distance between the driver node and the transducer node. The mounting arrangement is achieved by using a set screw, and more particularly a soft point set screw, opposite a drilled-out back wall of the transducer. The set screw directly secures the bonding tool or engages a clamping shoe that radially secures the bonding tool to the end of the transducer. As a consequence, rigid clamping of the bonding tool is achieved. Therefore, the clamping force exerted on the bonding tool is in line with the direction of ultrasonic motion imparted to the bonding tool. The present clamping arrangement improves the transfer of ultrasonic energy that excites the bonding tool into transverse (flexural) vibration.

Ultrasonic wire bonder and transducer improvements

An AC line voltage compensation method and controller for use with an AC welding system that is adapted to weld an article. Welding parameters are provided by an operator that are suitable for welding the article. A desired heating percentage is also input by the operator that is determinative of an RMS output voltage supplied by the AC welding system. The AC line voltage supplied to the AC welding system is measured by means of a voltmeter. The difference between the measured AC line voltage and a desired nominal AC line voltage is determined. The time at which heat is applied to the article is adjusted as a function of the measured difference to maintain the RMS output voltage supplied at the output of the AC welding system at a relatively constant level for all AC line voltages supplied to the AC welding system. More specifically, gain adjustment which provides for improved line voltage compensation, and which is controlled by means of a user programmed digital control panel, has been added to a line voltage compensation computational algorithm employed in an AC resistance welding controller. The use of the user programmed gain factor allows an operator to adjust the amount of compensation for a specific welding setup. The user adjusts the gain factor to modify a mathematically calculated term for line voltage compensation. The computed gain factor is used to set a variable time delay, after which an SCR is turned on. The variable time delay determines the phase angle of the AC pulse applied during each weld.

Line voltage compensation for AC resistance welding systems and the like

Voltage stored in a capacitor bank (12) of a capacitor discharge welding apparatus is modified in accordance with the magnitude of output energy actually delivered to the weld. After empirically determining capacitor bank voltage and output energy emloyed in the making of an acceptable weld, energy delivered to subsequent welds is monitored (50,56). An efficiency factor based upon stored voltage and delivered energy of the prior weld is determined. Based upon this efficiency factor and the output energy delivered during the prior weld, a new value of capacitor voltage is calculated for use in a subsequent weld. Regulation of the voltage on the capacitor bank (12) is determined by a feedback circuit which senses capacitor bank voltage, compares it to a set point, and shuts down a boost charging circuit when capacitor voltage has reached a predetermined amount.

Welding control

A parallel-gap welder applies a precisely controlled force to the weld head (40) by means of a solenoid (60) having a plunger (72) aligned with the axis of the welding electrodes (50,52). To precisely control the amount of force applied by the solenoid a load cell (80) is interposed between the weld head (40) and the solenoid plunger (72) to provide a feedback force signal (158) indicative of the force applied by the solenoid. The feedback force signal is used to control current through the solenoid coil (68) and thereby servo the applied force to a force command input. The solenoid plunger (72) and load cell (80) are axially aligned with the axis of the electrodes (50,52) and solenoid force is applied through a universal joint (76,78) connection to assure an in-line driving force on the electrodes.

Pressure welding with closed loop force control

A force limiting weld head (11) which includes a supporting structure (13), a pressure barrel (15) and an output member (17) mounted for movement on the supporting structure, a fixed electrode (19) mounted on the supporting structure, a movable electrode (21) driven by the output member, a coupling (23) for drivingly coupling the pressure barrel and the output member. The coupling includes a variable-volume chamber (89) and a piston (77) responsive to overtravel for varying the volume of the chamber.

Force limiting weld head

An adjustable heater bar arrangement (8) for integrated circuit attachment and removal apparatus including a base plate having four slots (14) in which heater bars (12) are slidably mounted and held in position by clamping screws (18). By directing the slots (14) at an appropriate angle, inward and outward movement of the heater bars (12) is accompanied by lateral movement of each heater bar (12), such that the device (8) may be adjusted to accommodate large and small sized ICs (13A, 13B), as well as lot-to-lot variations between ICs (13A, 13B). For example, to accommodate a square IC (13A, 13B), each slot (14) extends outward at an acute angle of 45 degrees, respectively, with reference to the sides of a substantially rectangular base plate (10).

Adjustable heater collet

Apparatus for gripping and removing integrated circuits, including four heatable jaws movable into gripping relation with soldered integrated circuit leads. The heatable jaws are mounted to respective leveler plates, each of which is suspended from a base member by a pivotable gripper arm and three flexure arms. Individual air cylinders are selectively actuable to pivot the gripper arms and thereby achieve inward motion and gripping action of the jaws. A second embodiment employs a cam follower mechanism rather than air cylinders to actuate similarly-mounted jaw elements.

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Vista, CA, United States of America

Joseph E Donner