Abstract: A resistance welding apparatus characterized by very low output impedance, and providing a substantially constant voltage source to low impedance (e.g., resistances on the order of 1-100 micro-ohms) materials-to-be-joined. The welding apparatus includes one or more primary and secondary winding pairs disposed about a high permeability core with the secondary coil(s) positioned between the primary coil(s) and the core. In a preferred form, the secondary coil(s) are capable of delivering more than 75,000 amperes of welding current. The welding apparatus is lighter, more cost efficient, and more energy efficient than conventional systems.

Abstract: A resistance welding apparatus characterized by very low output impedance, and providing a substantially constant voltage source to low impedance (e.g., resistances on the order of 1-100 micro-ohms) materials-to-be-joined. The welding apparatus includes one or more primary and secondary winding pairs disposed about a high permeability core with the secondary coil(s) positioned between the primary coil(s) and the core. In a preferred form, the secondary coil(s) are capable of delivering more than 75,000 amperes of welding current. The welding apparatus is lighter, more cost efficient, and more energy efficient than conventional systems.

Abstract: A thermosonic bonding apparatus including an ultrasonic transducer; a bonding tool including a high resistivity tip, and a low resistivity shaft extending from the tip; a tool support arm interconnecting the bonding tool and the ultrasonic transducer to vibrate the high resistivity bonding tool tip; and a voltage source connected to the bonding tool to locally heat the high resistivity bonding tool tip in a pulsed fashion.

Abstract: A modular igniter system which preferably provides either direct electrical connection between the metallized ends of the hot surface igniter and the socket contact, or indirect electrical connection by a short lead wire held in place on the hot surface element by an active metal braze.

Abstract: A computer controlled laser apparatus having multiple mirrors positioned along the locus of an ellipse having a first focus point at the center of an angle select mirror and a second focus point on a workpiece to be soldered. Such a geometrical configuration permits a computer to efficiently control the reflection of the laser beam onto the workpiece at different angles of incidence while maintaining a constant laser beam pathlength without requiring refocusing of the beam as it is moved from angle to angle.

Abstract: A method and apparatus for forming a spherical shape on the end of an aluminum wire using a relatively low voltage across an arc gap to heat the end. Because the voltage is below the minimum sparking potential, a high voltage impulse is superimposed on the electrode to ionize the gas therebetween and initiate the arc. The gap may be in a protective environment such as an inert gas to prevent the formation of additional oxide. The wire may then be used in an aluminum ball bond.

Abstract: A method and apparatus for providing high reliability ultrasonic bonds by monitoring the force required to separate the bonding tool from the wire after the bonding operation. This force which is required to break an incidental bond between the tool and the wire is related to the quality of the primary bond of the wire to a conductor terminal. The output of a transducer is proportional to the force and it may be coupled to a visual display, alarm, or computer for trend analysis.

Abstract: A platinum film resistor device and method for making the same. A layer of quartz, deposited upon an insulative substrate preferably silicon, is sputter etched at high power levels to produce etch pits in the surface thereof. A layer of platinum is then deposited over the quartz layer by first sputtering platinum at high power for a relatively short period of time and then completing the layer by continuing to sputter deposit platinum at a lower power. A second layer of quartz is deposited over the layer of platinum and the second layer of quartz masked and chemically etched away in the regions where portions of the platinum layer are to be removed. The exposed platinum and a portion of the second quartz layer are then sputter etched away leaving the platinum in a predetermined configuration. The platinum is then annealed, the second quartz layer removed above the lead bonding pads, and external leads attached. The device is particularly useful in temperature measuring application.