Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – With rotor
Patent
1990-12-18
1993-12-21
Nguyen, Vinh
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
With rotor
324 96, 324 731, G01R 3122
Patent
active
052724344
ABSTRACT:
Electro-optical in-circuit testing, especially of large circuits such as those assembled on printed circuit boards, is achieved in an automatic test system by disposing an electro-optical sensor in proximity to the circuit conductors, applying test signals to the circuit under test, and measuring an optical property of the sensor at selected regions thereof corresponding to internal nodes, i.e. test points, of the circuit. The sensor may be an optical probe, having a lens and a layer of electro-optical material which is adapted to be applied to the circuit. The electro-optical material may be either a polymer film or a crystal, the latter requiring a flexible coupling medium on the face applied to the circuit under test. The electro-optical material is provided with a reflective coating on one surface to facilitate a polarimetric measurement made transverse to the plane of the material. Another type of optical probe has a layer of electro-optical material with electrodes on the surface opposite the surface applied to the circuit under test. A polarimetric measurement is made by suitably biasing the electrodes and detecting light that passes through the material parallel to its surfaces. In another type of optical probe, the electro-optical material is coated on both surfaces, one coating being highly reflective and the other being semi-transparent. An interferometric measurement is provided by this type of sensor. Moreover, the polymer film may be applied directly to the printed circuit board during manufacture, in which case the lens is brought into contact with the electro-optical material during circuit testing.
REFERENCES:
patent: 3449583 (1969-06-01), Eden
patent: 3934199 (1976-01-01), Channin
patent: 3990770 (1976-11-01), Carl et al.
patent: 4105298 (1978-08-01), Levine et al.
patent: 4147979 (1979-04-01), Baues et al.
patent: 4242635 (1980-12-01), Burns
patent: 4269481 (1981-05-01), Yeh et al.
patent: 4333051 (1982-06-01), Goodman
patent: 4355278 (1982-10-01), Burns et al.
patent: 4446425 (1984-05-01), Valdmanis et al.
patent: 4603293 (1986-07-01), Mourou et al.
patent: 4618819 (1986-10-01), Mourou et al.
patent: 4642560 (1987-02-01), Morille et al.
patent: 4681449 (1987-07-01), Bloom et al.
patent: 4779961 (1988-10-01), DeMartino
patent: 4841234 (1989-06-01), Aoshima et al.
patent: 4870356 (1989-09-01), Tingley
patent: 4877298 (1989-10-01), Teng et al.
patent: 4891579 (1990-01-01), Aoshima et al.
patent: 4891584 (1990-01-01), Kamieniecki et al.
patent: 4906922 (1990-03-01), Takahashi et al.
patent: 4910454 (1990-03-01), Williamson
patent: 4920310 (1990-04-01), Aoshima et al.
patent: 4923288 (1990-05-01), Allen et al.
patent: 4999577 (1991-03-01), Beha et al.
patent: 5090824 (1992-02-01), Nelson et al.
John Hiatt; "A Method of Detecting Hot Spots on Semiconductors Using Liquid Crystal"; IEEE/Proc. IRPS; 1981; pp. 130-133.
Giannini et al.; "Liquid Crystal Technique for Field Detection in Microwave Integrated Circuitry"; Alta Freg. (Italy), vol. 46, No. 4; Apr. 1977.
Zhu, Z. H. et al., "New measurement technique: CW electro-optic probing of electric fields," Applied Physics Letters, vol. 49, No. 8, pp. 432-434, 1986.
A. Hurty et al., "How the Active Matrix LCD Works," Macworld, Nov. 1989, p. 147.
IEEE Journal of Quantum Electronics, vol. QE-19, No. 4, Apr. 1983, pp. 664-667, US; J. A. Valdmanis et al.: "Subpicoseond electrical sampling".
Herts Stevenage, "Noncontact Electro-Optic Sampling With a GaAs Injection Laser", Aug. 14, 1986, vol. 22, No. 17, pp. 918-919.
Meyrueix Paul
Tremblay Gerard
Vernhes Jean P.
Nguyen Vinh
Schlumberger Technologies Inc.
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