1506322 Semi-conductor diode oscillators and mixers THOMSON-CSF 19 Jan 1976 [22 Jan 1975] 02037/76 Heading H3T [Also in Division H1] A circuit for radiating or receiving microwave radiation has a semi-conductor negative resistance or non-linear diode such as a Gunn or varactor diode 14, Fig. 1a located above an electrically conductive substrate 11, 12 and surrounded by a dielectric resonator 16 positioned on the substrate. An insulator 13 between conductive plates 11, 12 provides a #/4 trap and a wire 15 in a cavity 17 provides a half dipole coupling between the diode 14 and a GaAs dielectric resonator 16. The diode can be operated as an oscillator such that the circuit transmits microwave radiation or as a non-linear mixer element of a receiver circuit providing an IF from mixing of the received radiation with a local microwave radiation. In a further embodiment (Fig. 2, not shown) the dielectric resonator (26) is provided by a droplet of low melting point glass in which the coupling wire (25) and microwave diode (24) are enclosed. In a still further embodiment, Fig. 3a, made as an integrated circuit a silicon resonator 31 has two sections of a dipole 37, 38 metal vapour deposited on a silicon oxide insulator layer 39. Diffused zones 32, 33 form the microwave diode. Cavities 35 and 36 locate the two sections 37, 38 of the dipole and a cavity 34 gives the diode a mesa structure. The circuit is mounted on two concentric metal discs 310, 311 which are insulated by an insulator 312 to form a #/4 trap. In a modification of this (Fig. 4, not shown) only one dipole section (41) is provided.

PURPOSE:To prevent the contamination of a decomposition liquid and to increase the concn. thereof by decomposing a solid sample consisting of a thin film or thin sheet in a hermetic vessel consisting of a fluororesin, etc. CONSTITUTION:A device 10 for dissolving the thin film or thin sheet is constituted of a dissolving vessel 1 consisting of a fluororesin or synthetic quartz and having a cover body 2 and a heating vessel 7 provided with a plate heater 6 for heating. The dissolving liquid 5 consisting of a hydrofluoric acid is contained at about 1ml into the base of the vessel 1. A semiconductor substrate 3 formed with the thin film 4 consisting of an oxide film having, for example, about 5,000Angstrom thickness on the surface is installed in the vessel 1 in such a manner that the bottom thereof is dipped in the liquid 5. The vessel 1 is then contained into a heating vessel 7 and is heated to evaporate the liquid 5 by a heater 6 by which the film 4 is decomposed and a decomposition liquid 8 is formed. The liquid 8 is then taken out of the vessel 7 and is allowed to cool. The contamination of the liquid 8 is prevented in the above-mentioned manner and the liquid 8 having the high concn. is obtd.

1,116,169. Digital light measurement. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 2 Nov., 1966 [11 Nov., 1965; 16 Dec., 1965; 24 Dec., 1965; 18 Feb., 1966], No. 49213/66. Heading G4H. [Also in Divisions G1 and H1] In a Gunn effect oscillator or amplifier apparatus including a semi-conductor element adapted to exhibit negative resistance when an electric field in excess of a certain critical value is applied, light is employed to produce a photocurrent which is superimposed on the current already present in the element to control its operation. The light may be applied directly to the element or to a separate light sensitive device connected in circuit with the element. In a Gunn effect oscillator adapted to oscillate when biased by an electric field exceeding a critical value U k , the oscillations may be initiated or stopped by means of the photocurrent which causes the actual bias U applied to the element to rise above or fall below U k , the photo-current being a function of the light intensity E. Consequently, by employing a number of Gunn elements biased to different extents above U k , the intensity of the light may be determined by noting which of the elements cease to oscillate. The elements preferably have the same oscillating frequency and are parts of the same semi-conductor body, although different frequencies and materials may be used. The invention may also be used to demodulate light of modulated intensity providing the period of the modulation is greater than the period of the oscillations but not more than twice this period. If the photo-current is produced by a separate light-sensitive device, this may be a photo-diode, photo-transistor or photo-resistor. In Gunn effect amplifier apparatus, the invention provides means to modify the gain or the frequency at which maximum gain is exhibited. The light employed may be a laser beam.

949,740. Apparatus for microradiography. PHILIPS ELECTRICAL INDUSTRIES Ltd. June 26, 1962 [June 29, 1961], No. 24534/62. Heading H5R. In a device for taking X-ray photographs of a thin layer of material supported on or close to the surface of a film, the support is such that the film and the material are jointly movable relative to the X-ray beam. The device is intended for use in microradiography, and the X-ray tube has a thin beryllium window 5 permeable to soft X-rays. A housing 17 is joined to the wall 2 of the X-ray tube. The film and specimen are supported on the end wall of a carrier 6 housed in a sleeve 9, and held therein by a rubber ring 14. The photographic film is glued on to the end wall 7, and before the ring 14 is fitted, a ring 16 carrying a thin film of the specimen is inserted. This is clamped between carrier 6 and ring 14 by the pressure of a spring 12. Carrier 6 can be rotated by means of a spindle portion 11, which passes through a further sleeve 22 and terminates in a pulley 25 which is belt-driven from a motor 27. Rotation of the film and specimen together obviates spurious interfering contrast effects due to difference of intensity across the beam. The construction also permits ready removal of the carrier 6 from the housing 17 in order to change the specimen and the film.

995, 252. Liquid level control and indication. HALKERGERHUTTE G.m.b.H. Dec. 21, 1961 [Dec. 24, 1960], No. 45887/61. Heading G1H. [Also in Division G4] A liquid level indicating and/or controlling device comprises a transparent gauge tube 1 connected to the container and containing a float 2 of opaque material when the liquid is transparent and of transparent material when the liquid is opaque and two housings 3,4 at opposite sides of the tube respectively containing a semi-conductor photosensitive means 5 and a convex lens 8 which brings light rays 9 to a focus on the means 5. The photosensitive means may be a germanium photo-diode or a silicon photo-cell. In operation the opaque float interrupts the light rays or, in the case of a transparent float, allows them to pass, when it reaches the level of the housings whereby in each case the means 5 transmits an electrical pulse to an amplifying relay. Housings can be located at desired high and low levels and the relay arranged to stop or start a filling pump and to operate acoustic or visual signals. A number of housings may be arranged on the gauge tube so that switching operations for control and/ or indication may occur at selected levels. The housings may be provided with cooling fins.

1,009,271. Semi-conductor circuit. ASSOCIATED FIRE ALARMS Ltd., and B.J.L. WHITE. March 2, 1964 [March 4, 1963], No. 8549/63, Heading H3T. [Also in Division G1] The voltage at a point 17 between an ionization gauge 10 responsive to the amount of smoke in the atmosphere, and a resistor 11, which may be a second ionization chamber closed to the atmosphere, is applied to the modulator of a field effect transistor 14 fed from an LT source 16, and when as a result of smoke the voltage drops below that at point 18 current through transistor 14 ceases and point 20 which is set to become positive with respect to point 19 eventually renders transistors TR1 and TR2 conductive, diode D3 making the arrangement bi-stable. The larger current drawn from the source by the transistors actuates a relay in the supply lead. Capacitor C ensures that transistor TR1 does not conduct immediately on reset. A number of such circuits may be connected to a single LT power source, and the relay may be responsive to the total current drawn. Transistor 14 may be coupled to point 17 by a capacitor to make the circuit responsive only to rapid changes. Component values are exemplified.

PURPOSE:To judge a peeling point of a thin film from a base material while enabling accurate measurement of a peeling load by determining a testing point with an optical monitor to apply a peeling load to a plane indenter after it is bonded on a thin film sample. CONSTITUTION:An optical image of a base material sample 17 formed with an optical monitor 30 is taken with a TV camera 33 to be stored into an image memory 35 and projected onto a CRT 36 to determine a testing position of a thin film on the surface of the sample 17. Then, the thin film is bonded on a plane indenter 7 by putting an adhesive on the plane indenter 7. A load is generated with a load current feeder 13 so as to lift the indenter 7. In this manner, a tensile load is applied continuously to the thin film to measure a load as peeling load at which a peeling occurs between the thin film and the base material 17. This enables accurate measurement of a peeling load of the thin film sample thereby accomplishing an evaluation of the strength of the thin film accurately.