Abstract: A beam of light is projected through an electrolyte to a SOI substrate to scan the surface of the SOI substrate. When the light passes through a pinhole in a buried oxide layer, the light excites a semiconductor layer beneath the buried oxides. An ammeter measures electric charges derived by this light excitation to indicate the presence of pinholes in the buried oxide.

Abstract: An inductive displacement sensor comprises a magnetically conductive housing, a coil located within the conductive housing, and a solenoid plunger movable within the coil. A ring-shaped air gap is formed between the solenoid plunger and the conductive housing. A short-circuit ring surrounds the solenoid plunger and is located on the outside of the conductive housing and in front of the ring-shaped air gap. An electronic unit is connected to the coil that measures the displacement-dependent inductance of the coil.

Abstract: A test head structure for a semiconductor test system which makes the replacement of pin cards in the test head easy. The test head is formed of a performance board for mounting a semiconductor device to be tested on; a mother board for functioning as an interface for achieving electric connection between the performance board and pin cards; and a back board for supporting and positioning the pin cards in combination with a housing of the test head. The back board is provided in parallel with an upper surface of the housing of the test head by being fixed inside of the housing, wherein the upper surface of the back board is directly attached to the lower surface of the mother board. Pin cards can be accessed to the test head through the bottom of the test head to be connected to or disconnected from the back board through connectors provided on the lower surface of the back board.

Abstract: A magnetic sensor includes a DC power source, a multivibrator circuit composed of two CMOS inverters, a resistor, and a capacitor, each of the CMOS inverters being composed of a pMOS transistor and an nMOS transistor connected in series, and a magneto-impedance element. In a transition state attributable to switching operations of the CMOS inverters, a sharp pulse current is caused to flow through the magneto-impedance element so as to excite the magneto-impedance element sufficiently causing the skin effect, whereas in a steady state, the flow of the current is stopped by the CMOS inverters so as to reduce power consumption.

Abstract: A test head is used in an electrical characteristic test of a plurality of integrated circuits formed on a semiconductor wafer. The test head includes a probe holder in a frame form for holding a plurality of first probes and supporting bodies in a plate form for supporting a plurality of second probes. The probe holder is disposed on a base plate such that the first probes are brought into contact with pads disposed at a portion corresponding to the edge portion defining an opening formed in the base plate. The supporting bodies are attached to the base plate with the direction of their thickness oriented in the lengthwise direction of the opening in the base plate in order that the second probes are brought into contact with pads existing at the boundary portions of a plurality of integrated circuits to be tested at a time and disposed at the portions corresponding to the adjoining sides of the integrated circuits.

Abstract: A personal computer card which includes four tone generators connected to a radio frequency synthesizer which, in turn, is connected to a 400 MHz hcal rubber coated antenna. Each of the four tone generators may be programmed to generate any one of twenty Interrange Instrumentation Group standard decoder tones which are used for testing the flight termination receivers and decoder in certain weapons systems such as a missile. The standard decoder tones generated by each of the four tone generators are supplied to the radio frequency synthesizer. The radio frequency synthesizer frequency modulates the IRIG tones onto a carrier signal in the flight termination band which is in a range from 400 MHz to 440 MHz. The modulated radio frequency signal is then supplied to the antenna for transmission to the weapons system being tested.

Abstract: A method for determining the depletion layer minority carrier lifetime .tau..sub.o in a depletion layer of a semiconductor wafer includes the following. A depletion layer is induced on a surface of the wafer. The wafer is heated to a temperature T.sub.1. A surface photovoltage is induced on the surface of the wafer with modulated light. A surface photovoltage .DELTA.V.sub.o1 is measured at a selected point of the wafer, at T.sub.1 and at a low light modulation frequency where the surface photovoltage is substantially independent of frequency. A surface photovoltage .DELTA.V.sub.1 is measured at the selected point, at T.sub.1 and at a higher light modulation frequency .omega. which is within a frequency range where the surface photovoltage is inversely proportional to frequency. A surface photovoltage response time .tau..sub.max1 is determined by the relationship: .tau..sub.max1 =.omega..sub.1.sup.-1 [(.DELTA.V.sub.o1 /.DELTA.V.sub.1).sup.2 -1].sup.1/2. The wafer is heated to a temperature T.sub.

Abstract: A non-intrusive electrical cable tester determines the nature and location of a discontinuity in a cable through application of an oscillating signal to one end of the cable. The frequency of the oscillating signal is varied in increments until a minimum, close to zero voltage is measured at a signal injection point which is indicative of a minimum impedance at that point. The frequency of the test signal at which the minimum impedance occurs is then employed to determine the distance to the discontinuity by employing a formula which relates this distance to the signal frequency and the velocity factor of the cable. A numerically controlled oscillator is provided to generate the oscillating signal, and a microcontroller automatically controls operation of the cable tester to make the desired measurements and display the results. The device is contained in a portable housing which may be hand held to facilitate convenient use of the device in difficult to access locations.

Abstract: A magnetic field sensing structure for sensing magnetic field changes provided therein having a pair of pole structures with a gap space between them that each include permeable material and end in substantially a common surface. A plurality of field sensing structures is positioned successively in the gap space to be supported between the pole structures with each having an end thereof substantially the common surface. These sensing structures are formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic, electrically conductive layer positioned between them. They are electrically connected to one another adjacent the common surface, and may be electrically connected to one of the pole structures.

Abstract: A current sensor for sensing alternating current in a current-carrying conductor includes a substantially C-shaped magnetic core having first and second ends with a gap therebetween. A current sensing element, which includes a microresonant element, is positioned proximate the gap between the first and second ends of the magnetic core such that the element oscillates when exposed to an alternating magnetic field. A biasing coil is attached to the micro-resonant element for carrying a bias current. The micro-resonant element resonates, or vibrates, at a standard oscillating frequency when no current is present in the biasing coil, and resonates at a modified oscillating frequency when current is present in both the biasing coil and the current-carrying conductor. The magnitude of current in the current-carrying conductor is determined as a multiple of the product of a ratio of the standard oscillating frequency and the modified oscillating frequency, and the bias current.

Abstract: A magnetic detecting apparatus is capable of performing accurate waveform processing without being affected by noise signals or the like, the level shifting circuit thereof having a fixed voltage shift so as to be free of varying amplitudes of analog signals. Waveform shaping circuitry for turning an analog signal detected from a giant magnetoresistive element into a pulse signal includes: the level shifting circuit for generating an amplified voltage (V1) of analog signals and a voltage (V2) which is higher than the voltage (V1) and a voltage (V3) which is lower than the voltage (V1); a circuit which alternately retains the minimum value of the voltage (V2) and the maximum value of the voltage (V3) as a reference voltage; and a comparator circuit which compares a voltage resulting from adding a hysteresis to the voltage (V1) with the reference voltage and issues a pulse signal.

Abstract: A circuit (10) is disclosed for enabling voltage to be sensed across a power transistor (12) of the type which has first and second active regions, such as source (85) and drain (76) regions of an MOS transistor (12), or emitter and collector regions of a bipolar transistor (42), in a semiconductor substrate (72), with the first region (76) located along a first lateral extent in the substrate (72) to have ends at terminal locations (D1,S1) of the first lateral extent and the second region located along a second lateral extent in the substrate (72) to have ends at terminal locations (D2,S2) of the second lateral extent. The circuit (10) includes a first conductive line (20) connected to the first region at said terminal locations (D1,D2) of the first lateral extent, and a first voltage sensing connection (22) to a midpoint of the first conductive line (20).

Abstract: A sensing method continuously scans an array of sensing elements and determines positions by converting array peak amplitude information to a time based function. An array of magneto resistive elements responds to a relatively moving magnetic field. The process of scanning the magneto resistive elements is independent of the relatively moving magnetic field. Instead of using only one voltage source to power both the driving logic circuitry and the sensing element array, a separate voltage source for powering the sensing element array is used in conjunction with the solid switch array, thus excluding unwanted noise that originates in the driving logic circuitry.