Abstract: A semiconductor wafer test system for carrying out a burn-in test on a semiconductor wafer including multiple semiconductor devices thereon. A metal interconnect is connected to the gate electrode of each of those devices. A power supply applies an ac voltage of predetermined amplitude to a conductive plate, which creates an ac electric field to be placed on the devices. The ac field should have an intensity at least equal to a minimum value required for the burn-in test and less than a critical value, below which no breakdown occurs in the gate oxide film of each device. By changing the amount of time for which the devices are exposed to the ac field, the burn-in period can be changed freely. In addition, forward and reverse fields are both placed on the gate oxide film of each device. Thus, failures can be screened out very effectively.

Abstract: A testing apparatus and method for testing conductivity of electric pathways formed on a substrate, each pathway including a first wiring and a second wiring partially overlapping each other. The apparatus includes a first electric signal applier for applying a first electric signal having an electric parameter changing with time to an input portion of the first wiring, a first electrode facing a first portion of the second wiring, a second electrode facing a second portion of the second wiring, a second electric signal applier for applying to the second a electrode a second electric signal changing its electric parameter in the phase reverse to that of the first electric signal, and a monitor for monitoring the signal transmitted to the first electrode through its capacitive coupling.

Abstract: A system and method for detecting a location of an open circuit is disclosed. The open circuit is in a circuit of semiconductor device. The semiconductor device has a surface. The method and system include supplying alternating power to the semiconductor device and sensing a time-varying signal that is related to the alternating power. The method and system also include determining where the signal is substantially changed.

Abstract: Non-destructive EMI susceptibility testing involves near-field injection of very high levels of instantaneous energy and low average power through localized injection of signals of very high field strength and low duty cycle. An electric field injector and a magnetic field injector are scanned, each in turn, over the equipment under test. For each injector, the amplitude and frequency of the induced localized electric or magnetic field, respectively, is varied such that the susceptibility locations, magnitudes, and frequencies can be identified and mapped. This approach localizes which section or subcircuit of the equipment under test is susceptible, the frequencies and field strengths of susceptibility, and whether susceptibility problems are created by magnetic fields, electric fields, or both.

Abstract: A device and method are provided for locating faults in a paired line. The fault locating device has a transmitting unit connectable to the conductors of a paired line containing the fault. The device also has a portable receiving unit to track the path of the paired line. The transmitting unit contains circuits for creating and transmitting a locator signal and a carrier signal including synchronization through the conductors toward the receiving unit. The receiving unit contains a pickup coil positioned proximal to the paired line, inducing induced locator and carrier signals in the pickup coil. The receiving unit also contains circuits for processing the induced locator and carrier signals and for producing a synchronization signal used to detect and segregate a component of the induced locator signal which is indicative of a fault. The presence or absence of the indicative component is communicated to an operator by means of an audible or visual fault indicator.

Abstract: A manufacturing defect analyzer for printed circuit boards which can detect open circuit faults between leads of components and the printed circuit board. The manufacturing defect analyzer can operate in an inductive coupling mode or a capacitive coupling mode. The same sensors are used in each mode, allowing different leads on the same part to be tested using either technique. A method is also disclosed whereby the device is used to rapidly and accurately detect manufacturing defects.

Abstract: The apparatus and method operate by first generating a set of amplitudes for a constant current pulse. Each amplitude in the set is associated with one conductor on the reference printed circuit board and represents the amplitude which generates a determined voltage rise in that one conductor that is within a set range of a desired voltage rise for that one conductor. Each determined voltage rise representing the difference between a first voltage drop reading and a subsequent voltage drop reading taken across each conductor while the constant current pulse is applied. Once the set of amplitudes is generated, the apparatus and method generate a set of test voltage rises.

Abstract: Apparatus for identifying faults within electrical power cables is provided. The apparatus allows a user to detect faults in cables regardless of the cable environment's noise content. Circuitry may be included for filtering the received test signal based on an understanding of a generic urban noise environment. The apparatus can provide the user with the size and direction of the test signal at a particular testing location.

Abstract: A novel apparatus for determining the location of an inoperative bulb in a series circuit of decorative Christmas tree type light bulbs is provided which comprises a housing member having an opening adapted to accommodate the physical insertion therein of each of the light bulbs to be tested while in said series circuit. An elongated electromagnetic radiation shield is fixedly secured within said opening and along the inner peripheral surface thereof and an elongated electro-magnetic radiation receptor is fixedly secured along the inner peripheral surface of said shield and insulated therefrom and adapted to intercept electromagnetic radiation which is radiated from a light bulb inserted therein. A battery operated audio amplifier is mounted within said housing and has an input terminal and an output terminal. An energizable signal indicator is fixedly secured to said housing.

Abstract: A method and apparatus for detecting the location of an incipient fault in an insulated power which includes the application of an excitation voltage to a power line to produce a partial discharge signal pulse at a fault along the power line. The surface of the power line is scanned with two axially spaced sensors disposed adjacent the surface of the power line, the sensors detecting the partial discharge signal pulse to produce discrete detected pulses. These detected pulses are combined to produce a combined signal having all amplitude level which reaches an extreme value when the fault is located equidistantly between the sensors. The sensors are moved along the power line until the fault is located substantially equidistantly between the sensors as indicated by the extreme amplitude level of the combined signal.

Abstract: Disclosed is a system that determines whether input and output leads of semiconductor components are present and properly soldered to a printed circuit board. The system includes a signal source which is connected to a wiring trace on the printed circuit board, which is soldered to the lead being tested. A capacitive test probe is placed on top of the component and connected to a capacitance measuring device. The signal source signal is capacitively coupled through the lead of the integrated circuit package being tested to the capacitive test probe, so if a predetermined capacitance is measured by the capacitance measuring device, the lead is connected to the circuit assembly. As the capacitances being measured are small, the capacitive test probe may include an amplifier, a shield or a buffer circuit to reduce stray capacitance.

Abstract: The present invention provides an electro-optical element arranged to face a liquid crystal base plate, an electric source to impress an electric voltage between them, a source of light for irradiating light on the electro-optical element, a light detector to receive the reflected light from the electro-optical element, and a mounting device for fixing the liquid crystal base plate in a fixed position. The mounting device has a highly flat surface, groove thereon and vacuum attaches the liquid crystal base plate on the surface of the base platform. Light irradiates a reflective layer located on the lower surface of an electro-optical element which is in close proximity to the liquid crystal display base plate. A voltage is applied across the electro-optical element and the light reflected by the electro-optical element are measured. The optical characteristics of the electro-optical element is measured.

Abstract: A probe for measurement of an electrically conductive surface covered by an insulating cover layer has a pair of electrically conductive pads for capacitive coupling to the conductive surface. The pads may be formed by photolithography as part of a disk of a metallic layer disposed on a substrate of low dielectric material such as fibrous glass in an epoxy binder, the pads being separated by a relatively narrow gap. Included within the probe is an electrically insulating holder for supporting the substrate and the pads, the holder being configured to facilitate manual manipulation of the probe. The probe connects with a signal analyzer which provides a test signal coupled to the pads via a coaxial transmission line. During a sliding of the pads along the cover layer, electrical characteristics of a signal coupled capacitively via the pads to the conductive surface are analyzed by the analyzer to provide information on electrical continuity and resistivity of the surface.

Abstract: Disclosed is a system for testing continuity that determines whether input and output leads of semiconductor components are present and properly soldered to a printed circuit board. The system includes a signal source stimulus which is connected to a wiring trace on the printed circuit board, which is soldered to the lead being tested. A capacitive test probe is placed on top of the component. The stimulus signal is capacitively coupled through the lead of the integrated circuit package being tested to the capacitive test probe, so if a predetermined signal level is detected by the capacitance test probe, the lead is connected to the circuit assembly. As the capacitances involved are small, the capacitive test probe includes an amplifier, a shield or guard and a buffer circuit to reduce stray fields pick up effects.

Abstract: A method and apparatus for verifying the condition of an electrical insulator which is placed between two live conducting elements which are separated by the insulator. The insulator has a continuous electrically insulating core that may be covered with other types of insulating material. The insulator may also be a lightening arrester consisting of stacked insulating discs. An electric field detecting apparatus is positioned at a plurality of locations along the insulator to measure the intensity of an electric field created along the insulator. At each location a detected signal value of the electric field is stored within the apparatus and all of these signals are analyzed to detect deviations from expected values of the electric field and indicative of a fault(s) along the insulator.

Abstract: A circuit tracer for determinating the location of a conductor, such as a wire, which is either an open or closed circuit, and which may lie underground. The tracer includes a transmitter which is connected to the conductor, a hand-held probe, and a receiver which is connected to the probe. The probe has three different sensors: an electric field sensor, primarily for locating the terminus of an open-ended conductor or for distinguishing such a wire in a bundled cable of wires; a differential electric field sensor, for determining the direction to and location of an open-ended conductor located above ground; and an inductive sensor for determining the direction to and location of a current-carrying conductor, including an open-ended conductor lying below ground. A switch selectively provides the output from one of the sensors to the receiver unit, which determines the magnitude of any signal based upon the direction the probe is pointing.

Abstract: A nondestructive noninvasive device and method for testing printed circuit boards (PCBs) through the utilization of a liquid crystal material which visually images the electric fields of the PCBs. Circuit faults resulting in a change of current flow in a PCB produce recognizable changes in observed electric fields. The present invention may be used in a stand-alone mode or as a supplement to other testing techniques.

Abstract: Selected test points of conductors on the substrate of a printed circuit board are tested by positioning the circuit board adjacent an array of electrodes or by utilizing a set of conductors in or on the substrate as an array of electrodes. An electric potential is set up by applying an inhomogeneous electric field to the array of electrodes or to the conductors to be tested, and signals denoting the characteristics of the electric potential are generated. Such signals are evaluated by a suitable circuit, for example, by comparing them with reference signals which are indicative of passable or non-defective conductors, i.e., of conductors which are devoid of open and/or short circuits, or by comparing the generated signals with each other. Test probes are utilized to apply an electric field to the conductors to be tested and/or to transmit signals to the evaluating circuit.

Abstract: The voltage potential and E-Field occurring at the site of a circuit discontinuity is detected by capacitively coupling and actuating an annunciator responsive to an above threshold energy level.

Abstract: A detector (42) is provided for testing a string of lamps (12) that are connected to a wire (14) in a series configuration. The detector (42) has a probe (44) disposed on the end thereof with a cavity (56) formed therein. The cavity (56) is operable to be disposed around the socket (30) of lamp (12). The electrodes (34) and (36) disposed in the interior of the socket (30) are disposed parallel to two electrodes (60) and (62) that are embedded in the probe (44). A detector circuit is provided for detecting the presence of an AC signal capacitively coupled from one of the electrodes (34) and (36) to one of the capacitive plates (60) and (62), respectively. A large DC signal will be present for a defective bulb having at least one of the electrodes (34) or (36) connected to one side of an AC supply (18).

Abstract: Breaks in the bare neutral conductor of an underground electric cable can be located by applying an alternating signal across the neutral conductor and a phase conductor at one end of the cable. The neutral and phase conductors are connected together at the other end of the cable. The electrical potential of the alternative signal is measured at a series of spaced apart points on the earth's surface along the cable's path. The potential between points over a cable section with an open in the neutral conductor will be about two orders of magnitude greater than the potential between points above good cable section.

Abstract: The control apparatus has an antenna (10) for the reception of electromagnetic radiation emitted from the alternating current transmission line. The antenna (10) is connected to an amplifying device (20) the signal output (22) of which is connected to an oscilloscope (30) in such a manner that the output signals of the amplifying device (20) effect both vertical and horizontal deflection of the image spot on the image screen of the oscilloscope (30). The amplifying device (20) is constructed for the amplification of a broad frequency range extending from below the line frequency to at least 20 kHz, wherein the amplification in the frequency range below about 10 kHz is reduced. The whole frequency spectrum of the output signals of the amplifier device (20) is fed to the oscilloscope (30).

Abstract: A method and apparatus for detecting defective insulators in an insulating column supporting an electrical conductor in a power line. The column is made of a plurality of serially connected insulator members. Voltage present on the conductor supported by the column generates an electric field about it. The presence of faulty insulators within the column causes field redistribution and discontinuities in it. A specially configured electric field probe is provided to measure at predetermined distance and locations, this electric field. A displacement device is provided whereby to displace the probe along an axis substantially parallel along the length of the column to automatically obtain measurements. Means to analyze the measurements are provided and allow to identify the defective insulators whose positions correspond to the locations of the discontinuities in the electric field surrounding the column. The main advantage of this method is that no electrical contact need to be made to the insulators.

Abstract: A method is provided for utilizing a nonintrusive, noncontacting electric field sensing device to detect faults in high voltage transmission line insulators. The electric field surrounding an unfaulted insulator is mapped using a spherical dipole to obtain a characteristic reference curve. The field of a suspect insulator is then mapped to obtain a test curve which is compared with the reference curve to determine the existence of and location of a fault.