Patents Examined by Kourosh Cyrus Khosravi
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Patent number: 5530341Abstract: A trigger system for a digital oscilloscope operating in external clock mode. Every n pulses, the trigger system generates a trigger signal. The trigger system therefore provides a trigger every n samples of the input signal waveform.Type: GrantFiled: October 11, 1994Date of Patent: June 25, 1996Assignee: Tektronix, Inc.Inventors: Pavel R. Zivny, Edward E. Averill
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Patent number: 5530374Abstract: A marker is provided outside the probe arrangement region of the lower surface of a probe card. In identifying positions of probes, the marker is recognized by a camera before the distal end of a reference probe is recognized. The camera is then moved from the position of the marker based on information about the relative position stored in advance to recognize the distal end of the reference probe. The camera is moved complementarily to make a reference point in the view of the camera and the distal end of the reference probe align with each other. Furthermore, where the same operation is performed for another reference probe, a deviation of the probes in the .theta. direction is calculated as .theta. correction data.Type: GrantFiled: March 9, 1995Date of Patent: June 25, 1996Assignee: Tokyo Electron LimitedInventor: Masao Yamaguchi
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Patent number: 5528160Abstract: An improved structure for a spacing frame for interfacing a test head of an IC tester and an IC handler wherein the spacing frame can be changed in a short period of time without moving the test head of the IC tester or the IC handler. The spacing frame and the temperature chamber provide a unique structure which is capable of inserting and replacing the spacing frame within a vertical space in the chamber and locking the spacing frame in the predetermined position in the chamber.Type: GrantFiled: August 25, 1994Date of Patent: June 18, 1996Assignee: Advantest CorporationInventors: Keiichi Fukumoto, Noriyuki Igarashi
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Patent number: 5523701Abstract: Machine operating conditions can be monitored by analyzing, in either the time or frequency domain, the spectral components of the motor current. Changes in the electric background noise, induced by mechanical variations in the machine, are correlated to changes in the operating parameters of the machine.Type: GrantFiled: June 21, 1994Date of Patent: June 4, 1996Assignee: Martin Marietta Energy Systems, Inc.Inventors: Stephen F. Smith, Kimberly N. Castleberry
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Patent number: 5523677Abstract: A DC current sensor has a detecting core with a plurality of detecting core members adapted to be divided in a circumferential direction for receiving the lead wire. A pair of annular exciting cores on one of said detecting core members formed of saturable magnetic material has a core intersection inter-connected perpendicularly to the circumferential direction of said detecting core members, and are disposed oppositely in spaced relation with said detecting core members to magnetically saturate a portion thereof by a magnetic flux produced substantially in the perpendicular direction against a magnetic flux in the circumferential direction, produced by the DC current flowing through said lead wire being detected, and to interrupt a magnetic path by the magnetic flux in the circumferential direction periodically. Exciting coils are wound around the exciting cores in negative-phase excitation.Type: GrantFiled: October 12, 1994Date of Patent: June 4, 1996Assignee: Sumitomo Special Metals Co., Ltd.Inventors: Makoto Kawakami, Shigeru Yamaguchi
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Patent number: 5521511Abstract: A test method whereby a high current is supplied to a first pin of an integrated device to be tested, and the variation in the voltage drop between the first pin and a second pin on the device to be tested is determined; the two pins being connected to two pads in turn connected, inside the device to be tested, by a low-voltage-drop path. The variation in the voltage drop of the device to be tested is compared with the measured nominal variation of an undoubtedly sound device of the same type, to determine any excessive deviation indicative of deficiency. The supply current in fact results in power dissipation, local heating and, consequently, a variation in the resistance of the connecting wires or of the die attachment to the lead frame, the extent of which differs according to whether only one or both of the wires of a two-wire connection to be tested are present, and according to whether the die is attached properly, poorly or badly to the lead frame.Type: GrantFiled: April 26, 1994Date of Patent: May 28, 1996Assignee: SGS-Thomson Microelectronics S.r.L.Inventors: Adriano Lanzi, Giovanni Avenia, Elia Pagani
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Patent number: 5521525Abstract: The doping density profile and thus the process-related parameters which control the operation and performance of a semiconductor layer, such as that in metal-insulator-semiconductor (MIS) device are reliably determined by determining the difference in the measured and calculated band bendings of a semiconductor layer in accumulation mode. In addition, high and low frequency C-V measurements of the MIS device are performed in order to calculate a second band bending and to approximate the doping density profile of the semiconductor layer. Based upon the approximated doping density profile, an approximate band bending curve is generated. The difference between the approximate and second band bending curves is then compared to the difference between the measured and calculated band bendings of the semiconductor layer in accumulation to determine the variance therebetween.Type: GrantFiled: April 15, 1994Date of Patent: May 28, 1996Assignee: University of North CarolinaInventors: Edward H. Nicollian, Catherine E. Blat
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Patent number: 5517105Abstract: A digital oscilloscope of the type that processes (30) the digital waveform values of the waveform record using interpolation and/or decimation (81) to produce a main trace record (91) and first (92) and second (93) zoomed trace records, and uses those records to produce (40) a main trace display (65) and first (61) and second (62) zoomed trace displays is improved by providing (94) a first zoom box (63) encompassing that portion of the main trace (65) display shown in the first zoomed trace (61) display and a second zoom box (64) encompassing that portion of the main trace (65) display shown in the second zoomed trace (62) display.Type: GrantFiled: October 25, 1994Date of Patent: May 14, 1996Assignee: Tektronix, Inc.Inventor: Benton Holzwarth
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Patent number: 5517125Abstract: A reusable carrier (10) for temporarily holding an integrated circuit (12) during burn-in and electrical test includes a base (14) and a lid (16) attached to the base (14) by hinges (18). A flexible substrate (19) is attached to the base (14) with a suitable adhesive. Alignment posts (20) have tapered surfaces (22) that engage corners (24) of the integrated circuit (12) to position the integrated circuit (12) precisely on upper surface (26) of the substrate (19). A spring-loaded latch (28) engages projection (30) in aperture (32) of the base (14) to hold the lid (16) closed over the integrated circuit (12). Electrically conductive traces (34) on the surface (26) have contact bumps which engage contact pads on the underside of the circuit (12) to connect the integrated circuit (12) to peripheral contact pads (38) around edges (40) of the substrate (19).Type: GrantFiled: July 9, 1993Date of Patent: May 14, 1996Assignee: AEHR Test Systems, Inc.Inventors: Rhea Posedel, Larry Lape, James Wrenn
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Patent number: 5512839Abstract: The test probe for electrical measuring instruments, particularly for voltmeters, is characterized by an automatic holding device that automatically holds the test probe in a socket-outlet jack of any given design, which device comprises a contact spring at least partially adjacent to a contact pin and bilaterally bulging toward the tip of the contact pin. This results in a universally utilizable test probe that will hold automatically in any jack format of different socket-outlets, shock-hazard protection being ensured at all times.Type: GrantFiled: April 7, 1994Date of Patent: April 30, 1996Assignee: MDM Elektrosystem AGInventor: Edoardo De Monaco
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Patent number: 5510724Abstract: A loader section for supplying semiconductor wafers is arranged at one end of a linear first convey path for a convey unit. Burn-in test sections, probe test sections, a laser repair section, a deposition repair section, a marking section, a baking section, and visual test sections are arranged on both the sides of the first convey path. In the burn-in test section arranged in the loader section, each semiconductor wafer picked up from a cassette is pre-aligned. The pre-aligned semiconductor wafers are loaded/unloaded into/from the respective test sections and the repair section by the convey unit in accordance with a predetermined test procedure, thereby performing a plurality of test items and repair steps by an inline scheme. Each burn-in test section includes a probe card having conductive projections which are brought into contact with all of many semiconductor chips formed on each semiconductor wafer at once.Type: GrantFiled: May 31, 1994Date of Patent: April 23, 1996Assignee: Tokyo Electron LimitedInventors: Taketoshi Itoyama, Yuichi Abe, Masao Yamaguchi
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Patent number: 5510705Abstract: Apparatus is disclosed for use in the testing of the electromagnetic compatibility (EMC) and electrostatic discharge (ESD) performance of an electrical unit. The apparatus comprises a cable tray positioned adjacent the unit, the cable tray having arranged upon it cabling which is representative of the normal cable installation for the unit and in which the cabling is connected to the unit. A cable tray base plate may also be provided. The cable tray is pivotally, and detachably, mounted to the base plate such that the orientation of the cable tray with respect to the base plate is adjustable.Type: GrantFiled: June 28, 1995Date of Patent: April 23, 1996Assignee: GPT LimitedInventor: Michael D. Langrish
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Patent number: 5510709Abstract: An eddy current surface inspection array probe and method for detecting cracks and flaws in aircraft skin metal immediately surrounding rivets, without requiring rivet removal or manual scanning. The array probe includes a circular array of small sense coils positioned beneath a much larger drive coil encased in ferrite. The sense coils are differentially connected in pairs such that the signals from two sense coils located on opposite sides of the rivet (180.degree. apart) subtract to produce a resultant output signal. During operation, the probe is positioned concentrically over the rivet and data acquired from all sense coil pairs. If no cracks or other defects are present, all sense coil pairs produce a null (zero) signal. If a crack exists, some sense coil pairs (the exact number depending on the crack length, number of sense coils, and sense coil spacing) produce a non-zero signal.Type: GrantFiled: April 19, 1995Date of Patent: April 23, 1996Assignee: General Electric CompanyInventors: Donna C. Hurley, Robert S. Gilmore, John D. Young
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Patent number: 5508618Abstract: In combination, a gas turbine engine ignition system exciter, an igniter, a conductor that connects the exciter to the igniter to form a discharge circuit, and a current pulse detector for detecting current pulses in the circuit, the detector comprising a wire disposed in close proximity to a current carrying element in the circuit so that a sense current is induced in the wire across a coreless gap; the detector further comprising a signal conditioning circuit for converting the sense current to an output that indicates occurrence of a spark discharge.Type: GrantFiled: July 15, 1993Date of Patent: April 16, 1996Assignee: Simmonds Precision Engine SystemsInventor: David N. Owens
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Patent number: 5508632Abstract: In a method of simulating hot carrier deterioration of an MOS transistor,.DELTA.I.sub.D /I.sub.D =(.DELTA.I.sub.D /I.sub.D).sub.f .multidot.(W.multidot.B).sup.-n .multidot.I.sub.SUB.sup.mn .multidot.I.sub.D.sup.(1-m)n .multidot.t.sup.n.DELTA.I.sub.D /I.sub.D =(.DELTA.I.sub.D /I.sub.D).sub.f .multidot.B.sup.-n .multidot.W.sup.-mn .multidot.I.sub.G.sup.mn .multidot.t.sup.nis used in the simulation for a P-MOS transistor, where B is a constant, W is a gate width, I.sub.SUB is a substrate current, I.sub.D is a drain current, t is a time, I.sub.G is a gate current, n is represented by a function g=(V.sub.G, V.sub.D), and V.sub.G and V.sub.D represent a gate voltage and a drain voltage, respectively.Type: GrantFiled: June 17, 1994Date of Patent: April 16, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Satoshi Shimizu, Motoaki Tanizawa
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Patent number: 5508606Abstract: Direct current can be measured by passing a conductor carrying the current through the core of a toroidal transformer having a bias winding and a sensing winding. A pulse generator send pulses of magnetization current through the sensing winding so that the magnetization current produces a magnetic flux in the core which opposes a magnetic flux produced by the direct current carried by the conductor. A sensing circuit, connected to the sensing winding, detects the level of current through that winding to produce a measurement of the direct current carried by the conductor. A constant direct current is applied through the bias winding to increase the magnetic flux produced by the direct current carried by the conductor. Biasing the magnetic flux enables even small currents flowing through the conductor to be measured. Another version of the current sensor uses two transformers to measure direct current flowing in either direction in the conductor and provides an indication of that current's polarity.Type: GrantFiled: April 25, 1994Date of Patent: April 16, 1996Assignee: Eaton CorporationInventor: Lawrence J. Ryczek
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Patent number: 5508627Abstract: An improved non-contact electrical measurement system, method, probe assembly, and probe tip. A probe tip having a photoemissive coating deposited thereon is provided and disposed substantially adjacent a measurement site of a test sample. The photoemissive coating of the probe tip is illuminated by a light source, and electrical measurements are made upon the probe tip to determine the electrical characteristics of the measurement site.Type: GrantFiled: May 11, 1994Date of Patent: April 16, 1996Inventor: Joseph M. Patterson
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Patent number: 5506510Abstract: A probe fixture for an automatic circuit board tester has a high density array of probe pads. The array of probe pads are sized and spaced apart to ensure contact with all of the test points on the device under test (DUT). The width of the pads is made smaller than the known minimum separation of the test points, and the separation of the pads is made smaller than the known width of the test points. The pads are connected to remote contacts of the fixture. A multiplexer unit may be provided to connect the desired test circuits to different probe pads of the fixture. Using the multiplexer unit, a controller of the tester can individually test the relative connection status of each of the probes of the fixture. By comparing to the known test point layout of the DUT, the controller then determines which of the probe pads is in contact with which of the test points and proceeds with the desired test functions accordingly.Type: GrantFiled: May 18, 1994Date of Patent: April 9, 1996Assignee: GenRad, Inc.Inventor: Steven M. Blumenau
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Patent number: 5506515Abstract: A probe suitable for low-loss microwave frequency operation has a tip assembly including a semi-rigid coaxial cable having a Teflon.TM. dielectric for temperature stability and a freely-suspended end. On this end a semicylindrical recess is formed defining a shelf along which an inner finger and outer pair of fingers are mounted, each made of resilient conductive material, so as to form a coplanar transmission line. Cantilevered portions of the fingers extend past the end of the cable to form an air-dielectric transmission path of uniform and stable characteristic despite exposure to numerous contact cycles and to provide suitable means for probing nonplanar device pads while also offering good visibility of device pads generally.Type: GrantFiled: July 20, 1994Date of Patent: April 9, 1996Assignee: Cascade Microtech, Inc.Inventors: Edward M. Godshalk, Jeffrey A. Williams, Jeremy N. Burr
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Patent number: 5504436Abstract: A testing socket apparatus is provided for testing a plurality of different kinds of semiconductors without deformation of their leads. The testing socket apparatus includes a movable base which is movable up and down above a base and a loading portion which is substantially centrally provided on the movable base and on which the semiconductor device is loaded. A tip end of each of testers extends upwardly from a periphery of the loading portion. The tip end of each of the testers is brought into contact with an outer surface of the associated lead by lowering the movable base. The testers may be provided through guide holes formed in the movable base or may be biased toward the loading portion. Also, each of the testers may be formed substantially in L-shape to provide a pivot point at its corner whereby movement about the pivot point brings the testers into contact with the outer surface of the leads.Type: GrantFiled: April 19, 1994Date of Patent: April 2, 1996Assignee: Sony CorporationInventor: Masumi Okutsu