Piezoelectric Properties Patents (Class 427/100)
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Patent number: 5112642Abstract: The thickness and rate of growth of a deposited film is monitored using a piezoelectric crystal sensor such as an AT-cut plano-convex crystal. The frequencies of the fundamental frequency and another resonance mode are measured prior to deposition, and the change of these two frequencies is monitored during deposition. The areal mass density of the deposited material is determined from these two resonance frequencies for the uncoated quartz crystal and for the crystal during deposition. A frequency generator provides accurate sweeps of frequency which are applied to the crystal, and the crystal response is supplied to a phase detector to identify the positions of the resonance frequencies. The acoustic impedance ratio Z of the deposited material relative to the fresh crystal is computed from the resonance frequencies for the coated and uncoated crystal, by applying the modal equations for AT-cut plano-convex quartz crystal and Lu-Lewis relation.Type: GrantFiled: March 30, 1990Date of Patent: May 12, 1992Assignee: Leybold Inficon, Inc.Inventor: Abdul Wajid
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Patent number: 5091820Abstract: A ceramic piezoelectric, includes a thick core formed of a sintered ceramic material, and a pair of electrodes formed on opposing end faces of the core, wherein the electrodes are a reduced form of the ceramic material of the core. The electrodes may also be a reduced layer of an oxide formed on the ceramic material of the core.Type: GrantFiled: November 3, 1989Date of Patent: February 25, 1992Assignee: TDK CorporationInventors: Shouichi Iwaya, Munemitsu Hamada, Hitoshi Masumura
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Patent number: 5078834Abstract: A method and arrangement for providing damping of undesired modes of piezoelectric vibrators is disclosed that eliminates the tedious and often inaccurate methods of known mass-loading techniques. Instead, the arrangement relies on physically altering a controlled amount of the piezoelectric material located at a predetermined point to effect the selective damping needed to minimize the undesired responses and to minimally interfere with the desired mode of operation.Type: GrantFiled: May 4, 1989Date of Patent: January 7, 1992Assignee: Motorola, Inc.Inventor: Robert S. Witte
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Patent number: 5064684Abstract: The invention generally is accomplished by a casting of a liquid metallo-organic ceramic precursor solution to form a layer on a substrate. This layer is then heated to a low temperature to create an amorphous layer. Then a selected area is heated to a high temperature by localized heating to create a patterned area of polycrystalline ceramic having electro-optic properties.Type: GrantFiled: August 2, 1989Date of Patent: November 12, 1991Assignee: Eastman Kodak CompanyInventors: Jose M. Mir, John A. Agostinelli
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Patent number: 5028455Abstract: A method to produce thin films suitable for fabricating ferroelectric thin films. The method provides for selection of the predetermined amounts of lead, lanthanum, zirconium, and titanium precursors which are soluble in different solvents. Dissolving predetermined amounts of the precursors in their respective solvents in proportions such that hydrolyze reaction rate for each metal precursor will be approximately equal. The precursors and solvents are mixed, and water is added to begin a hydrolysis reaction. After the hydrolysis the solution is heated to drive off the excess water and solvent to promote the formation of a sol-gel. The sol-gel is then applied to a thin substrate and sintered to produce the ferroelectric film.Type: GrantFiled: May 9, 1990Date of Patent: July 2, 1991Assignee: National Semiconductor CorporationInventors: William D. Miller, Leo N. Chapin, Joseph T. Evans, Jr.
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Patent number: 4963390Abstract: An improved process to deposit transparent, crystalline, ferroelectric films from metallo-organic solutions on platinum, glass, quartz, and sapphire substrates is disclosed. The use of this process results in a significant improvement in the transparency of perovskite, ferroelectric lead titanate (PT), lead zirconate titanate (PZT) and doped-PZT films (e.g. films doped with lanthanum, PLZT).Type: GrantFiled: October 5, 1988Date of Patent: October 16, 1990Assignee: The Aerospace CorporationInventors: Russell A. Lipeles, Dianne J. Coleman
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Patent number: 4951370Abstract: An intelligent multiprobe tip comprising a mounting member comprised essentially of piezoelectric material wherein, through appropriately locating metalized areas, the characteristics of the piezoelectric material are employed to insulate selected regions from each other while providing an appropriate force-induced output signal responsive to the contact of an attached tip with a movable work piece.Type: GrantFiled: September 1, 1989Date of Patent: August 28, 1990Assignee: Texas Instruments IncorporatedInventor: Lee R. Reid
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Patent number: 4918567Abstract: A new type of corona discharging apparatus. The apparatus revealed is equipped with a pair of thin electrodes which are edge-to-edge parallelly arranged, and bewteen them is an air gap. It is characteristic of this apparatus that the equipped electrodes are allowed to reciprocate along a definite path within a desired distance. By using the apparatus, corona discharge on polymer film can be performed, either in a still or moving state, for a considerable length of time without causing dielectric breakdown. One of the practical applications of this invention is poling of stretched PVDF (polyvinylidene flouride) films to gain high piezolelectric activity with high production yield.Type: GrantFiled: December 8, 1988Date of Patent: April 17, 1990Assignee: Industrial Technology Research InstituteInventor: Chiu-Fong Liaw
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Patent number: 4912822Abstract: An integrated scanning tunneling microscope and an integrated piezoelectric transducer and methods for making both. The device consists of one or two arm piezoelectric bimorph cantilevers formed by micromachining using standard integrated circuit processing steps. These cantilevers are attached to the substrate at one area and are free to move under the influence of piezoelectric forces which are caused by the application of appropriate voltages generated by control circuitry and applied to pairs of electrodes formed as an integral part of the bimorph cantilever structure. The electric fields caused by the control voltages cause the piezoelectric bimorphs to move in any desired fashion within ranges determined by the design. The bimorph cantilevers have tips with very sharp points formed thereon which are moved by the action of the control circuit and the piezoelectric bimorphs so to stay within a very small distance of a conducting surface.Type: GrantFiled: May 8, 1989Date of Patent: April 3, 1990Assignee: Stanford UniversityInventors: Mark Zdeblick, Thomas R. Albrecht
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Patent number: 4890369Abstract: A method of manufacturing surface acoustic wave devices includes providing a dielectric substrate with a plurality of channels which open onto a substrate surface region and each of which accommodates a metallic electrode, the electrodes being recessed below the substrate surface region by an actual distance which at least equals a desired distance at which the electrodes have a minimum acoustic reflectivity, testing the performance of the device to ascertain at least the acoustic reflectivity of the electrodes, and etching at least the dielectric substrate, when it is ascertained during the testing that the acoustic electrode reflectivity is excessive, at least at the substrate surface region to a predetermined etching depth. The use of this method results in a device having reduced post-etching acoustic electrode reflectivity as a result of the thus obtained reduction in the difference between the actual and desired distances.Type: GrantFiled: October 28, 1988Date of Patent: January 2, 1990Assignee: United Technologies CorporationInventor: William J. Tanski
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Patent number: 4890370Abstract: A manufacturing method for an integrated resonator is disclosed wherein a mass of O.sup.+ ions are implanted into a silicon monocrystal substrate from one side thereof, a buried SiO.sub.2 layer is formed by annealing the ion implanted substrate, an SiO.sub.2 layer is formed on the surface of the substrate by oxidizing it, at least one slit is formed on the SiO.sub.2 layer for etching a predetermined area of the silicon monocrystal layer sandwich between two SiO.sub.2 layers to form a cavity and, a piezo-electric resonator is formed on an area of the surfacial SiO.sub.2 layer corresponding to the cavity in the substrate.Type: GrantFiled: October 7, 1988Date of Patent: January 2, 1990Assignee: Murata Manufacturing Co., Ltd.Inventors: Susumu Fukuda, Hisashi Ariyoshi, Toru Kasanami
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Patent number: 4828886Abstract: In a method of applying small quantities of melted solder from a nozzle to surfaces to be wetted, which are then solidified, the solder is caused to melt by heating and is propelled by means of a piezoelectric transducer used as a pressure generator from a delivery nozzle in the form of droplets onto the area to be wetted.Type: GrantFiled: November 4, 1987Date of Patent: May 9, 1989Assignee: U.S. Philips CorporationInventor: Hartmann Hieber
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Patent number: 4820586Abstract: A pyroelectric and isotropic piezoelectric polymeric film, the film being formed from a blend of polyvinylidene fluoride and at least one polymer miscible therewith, and prepared by forming the film, heating it to a temperature sufficient to render the film substantially amorphous, cooling at a rate and to a temperature sufficient to prevent crystallization, and polarizing the film to render same .beta.-crystalline and pyroelectric and isotropically piezoelectric.Type: GrantFiled: October 26, 1987Date of Patent: April 11, 1989Assignee: Minnesota Mining and Manufacturing CompanyInventors: Dennis L. Krueger, Neil W. Loeding, Claudia I. Poser
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Patent number: 4792463Abstract: Method of producing a ferroelectric thin film by chemical vapor deposition, by providing a gaseous mixture containing oxygen and a gaseous raw material containing (A) alkyl lead and or alkyl bismuth together with an alcoholate of titanium, zirconium, silicon, germanium or niobium, (B) alkyl lead and alkyl germanium, or (C) alkyl bismuth and alkyl lead, and reacting the oxygen and gaseous raw material to oxidize the components of (A), (B) or (C), to form the thin film on the substrate.Type: GrantFiled: September 3, 1986Date of Patent: December 20, 1988Assignees: Masaru Okada, Horiba, Ltd.Inventors: Masaru Okada, Katsuhiko Tomita
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Patent number: 4784915Abstract: A polymer piezoelectric film comprising a poled film of a vinylidene fluoride copolymer having a high molecular weight as defined by an inherent viscosity within a specific range comprising 40 to 90 mol. % of vinylidene fluoride and 10 to 60 mol. % of trifluoroethylene. Such a high molecular weight vinylidene fluoride copolymer can give a preferable state of molecular arrangement during film formation, particularly preferably formation by casting, to provide a film excellent in piezoelectric characteristic and secondary processing characteristic.Type: GrantFiled: August 15, 1984Date of Patent: November 15, 1988Assignee: Kureha Kagaku Kogyo Kabushiki KaishaInventors: Teruo Sakagami, Kenichi Nakamura, Naohiro Murayama
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Patent number: 4783821Abstract: A miniature diaphragm pressure transducer. A thin diaphragm of silicon nitride has an upper face covered by a zinc-oxide piezoelectric film encapsulated in chemical vapor deposited silicon dioxide. A series of annular, basically concentric, polysilicon electrodes are provided in the silicon dioxide between the piezoelectric film and the diaphragm and in contact with the piezoelectric film. A series of annular, basically concentric, aluminum electrodes are on the opposite side of the piezoelectric film from the polysilicon electrodes and are aligned with the polysilicon electrodes; they lie over the silicon dioxide, and are in contact with the piezoelectric film.Type: GrantFiled: November 25, 1987Date of Patent: November 8, 1988Assignee: The Regents of The University of CaliforniaInventors: Richard S. Muller, Eun S. Kim
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Patent number: 4761298Abstract: The frequency of a piezoelectric resonator is precisely adjusted using monomolecular layer(s) of a thermally stable, low stress, uniform insulating film deposited on the active area of the resonator. The method is particularly suitable for precisely adjusting the frequencies of high frequency (i.e., very thin) resonators, and the frequencies of lateral field resonators, without degrading stability.Type: GrantFiled: May 6, 1987Date of Patent: August 2, 1988Assignee: The United States of America as represented by the Secretary of the ArmyInventor: John R. Vig
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Patent number: 4749900Abstract: The invention relates to a multi-layered piezoelectric acoustic transducer for generating layers of the same piezoelectric material are provided such tool alternate layers have different crystallographic orientations and different piezoelectric coupling coefficients. The layers may be provided so that alternate layers have crystallographic orientations which provide maximum electro-acoustic coupling and layers which provide minimum electro-acoustic coupling.Type: GrantFiled: November 17, 1986Date of Patent: June 7, 1988Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Babur B. Hadimioglu, Butrus T. Khuri-Yakub, Calvin F. Quate
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Patent number: 4711808Abstract: There are disclosed a novel PVF.sub.2 film of beta phase crystalline structure, predominantly, and a method for making it. The beta phase is achieved by first exposing a surface of an insulating polymeric support to an A.C. corona discharge treatment, and then casting molten PVF.sub.2 onto that exposed surface while chilling the cast PVF.sub.2.Type: GrantFiled: February 19, 1986Date of Patent: December 8, 1987Assignee: Eastman Kodak CompanyInventors: Michael A. Marcus, John E. Benson
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Patent number: 4704306Abstract: The invention relates to a mask for use in forming a thin film on a workpiece on which the thin film is to be formed, the mask comprising a member which flexes so that the center part of the mask projects toward the workpiece in the temperature range in which the thin film is formed.Type: GrantFiled: January 31, 1986Date of Patent: November 3, 1987Assignee: Murata Manufacturing Co., Ltd.Inventor: Takeshi Nakamura
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Patent number: 4686111Abstract: Passivated and low scatter acoustic wave devices comprise surface acoustic wave (SAW) and shallow bulk acoustic wave (SBAW) devices having transducers composed of oxidizable metal and layers of metal oxide on conventional acoustic wave substrates. Passivated transducers are achieved by forming a layer of oxide on an existing transducer. The method may be used to passivate a device packaged in a non-oxidizable package with oxidizable wire leads, thus combining complete protection with efficient manufacturing operations. Low scatter SAW transducers are achieved by forming the transducer and the interstitial insulating layer from a single layer of oxidizable metal by means of masking and oxidation operations.Type: GrantFiled: February 13, 1984Date of Patent: August 11, 1987Assignee: Motorola, Inc.Inventors: Frederick Y. Cho, Fred S. Hickernell
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Patent number: 4682130Abstract: Digital structures of a surface wave filter are manufactured in a photolithographic method with a lift-off or with an etching technique. The surface wave filter comprises at least one resonator structure, this resonator structure having auxiliary coatings of the substrate surface allocated to it. These auxiliary coatings are continuations of existing, neighboring pads which compensate during an exposure step associated with manufacture of the digital structures.Type: GrantFiled: December 27, 1985Date of Patent: July 21, 1987Assignee: Siemens AktiengesellschaftInventors: Wolf-Eckhart Bulst, Gertrud Lindemann, Peter Zibis
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Patent number: 4679014Abstract: A surface wave filter is provided with digital structures formed of strip-shaped coatings which are photolithographically produced. The digital structures have groups allocated to them which are also formed of strip-shaped coatings and which follow a respective digital structure. By use of such groups, which do not produce interfering reflections, a level exposure during formation of the digital structures is achieved.Type: GrantFiled: January 16, 1986Date of Patent: July 7, 1987Assignee: Siemens AktiengesellschaftInventors: Wolf-Eckhart Bulst, Mira Erthel, Peter Zibis
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Patent number: 4676993Abstract: A dual-coupled resonator crystal is fine-tuned by frequency balancing the input and output resonators and thereafter plating a coupling adjust spot on the grounded side shadowing the unelectroded region of the front side of the crystal to produce a change in synchronous peak separation frequency. Thereafter, the front side electrodes are sequentially plated to bring plateback and synchronous peak separation frequency to their target values. Interim adjustments in synchronous peak separation frequency may be made during the tuning process to compensate for misalignment of the plating elements.Type: GrantFiled: April 11, 1986Date of Patent: June 30, 1987Assignee: General Electric CompanyInventors: Gerald E. Roberts, Samuel Toliver, Robert J. Crescenzi
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Patent number: 4657775Abstract: Semiconductor piezoresistive devices can be obtained by the plasma CVD method, i.e., exposing a substrate to a plasma atmosphere produced from silicon hydride gas containing boron hydride to deposit on the substrate a thin film of crystalline silicon as a piezoresistive material. In accordance with this method, it is possible to form piezoresistive devices into IC's and also to impart excellent properties thereto.Type: GrantFiled: December 30, 1985Date of Patent: April 14, 1987Assignee: Kabushiki Kaisha Nagano Keiki SeisakushoInventors: Hisanori Shioiri, Mitsuhiro Kiuchi, Mineo Takayama, Toshio Homma, Hiroshi Nagasaka, Yoshikazu Kaneko
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Patent number: 4638536Abstract: A resonator having a desired frequency is made from a quartz crystal resonator plate by a method including the steps of:(A) etching the quartz crystal resonator plate to a frequency slightly higher than the desired frequency,(B) vacuum desposting metallic electrodes onto the active area of the resonator plate to lower the frequency to a frequency that very closely approaches the desired frequency, and(C) treating the plate with the deposited electrodes with UV-ozone to oxidize the electrodes in a slow, precisely controlled manner to the desired frequency.Type: GrantFiled: January 17, 1986Date of Patent: January 27, 1987Assignee: The United States of America as represented by the Secretary of the ArmyInventor: John R. Vig
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Patent number: 4632856Abstract: There is disclosed a laminate comprising alternating polymer sheets and metal layers between the polymer sheets, the laminate being substantially free of adhesive. Each polymer sheet of the laminate has a thickness not exceeding about 25 .mu.m, and the resistivity of the metal layer is from 1 to about 4 ohms/square. Such laminates are useful in making capacitors and piezoelectric multimorphs.A method of making such laminates is also disclosed, wherein a plurality of metal-coated polymer sheets are compressed, in the absence of an adhesive, under pressure sufficient to reduce the thickness of each of the polymeric film layers to a value that is no larger than about 25 .mu.m.Type: GrantFiled: February 6, 1985Date of Patent: December 30, 1986Inventors: Michael A. Marcus, Edward D. Morrison
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Patent number: 4631197Abstract: A method and apparatus is disclosed to allow the frequency adjustment of a crystal resonator sealed in a housing. The housing includes a transparent area which has plating material deposited thereon. The plating material is vaporized by a laser beam which sprays onto the crystal resonator thereby adjusting the operating frequency. The laser beam is scanned over the transparent area until an effective amount of plating material has been vaporized to adjust the frequency of the crystal resonator.Type: GrantFiled: July 17, 1985Date of Patent: December 23, 1986Assignee: Motorola, Inc.Inventors: Jeffrey A. DeFreese, Theodore E. Lind
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Patent number: 4627379Abstract: A system for plating resonator electrodes or the like by the vapor deposition process employs one or more shutters between the deposition material source and a plating mask. At least one of the shutters has a pair of apertures aligned with different apertures in the plating mark. In one embodiment comprising a two shutter, four position system, the two shutters may be positioned such that either, both or neither of the resonators can be plated. Because each shutter is either ON or OFF, a simple binary analogy for control of the shutters results.Type: GrantFiled: November 29, 1984Date of Patent: December 9, 1986Assignee: General Electric CompanyInventors: Gerald E. Roberts, Samuel Toliver
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Patent number: 4615848Abstract: A pyroelectric and isotropic piezoelectric polymeric film, the film being formed from a blend of polyvinylidene fluoride and at least one polymer miscible therewith at a temperature above the melting point of the polyvinylidene fluoride, and a process for preparing the film comprising forming the film, heating it to a temperature sufficient to render the film substantially amorphous, cooling at a rate and to a temperature sufficient to prevent crystallization, and polarizing the film to render same pyroelectric and isotropically piezoelectric.Type: GrantFiled: February 15, 1985Date of Patent: October 7, 1986Assignee: Minnesota Mining and Manufacturing CompanyInventors: Dennis L. Krueger, Neil W. Loeding, Claudia I. Poser
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Patent number: 4606871Abstract: A pyroelectric and isotropic piezoelectric polymeric film, the film being formed from a blend of polyvinylidene fluoride and at least one polymer miscible therewith at a temperature above the melting point of the polyvinylidene fluoride, and a process for preparing the film comprising forming the film, heating it to a temperature sufficient to render the film substantially amorphous, cooling at a rate and to a temperature sufficient to prevent crystallization, and polarizing the film to render same pyroelectric and isotropically piezoelectric.Type: GrantFiled: May 1, 1984Date of Patent: August 19, 1986Assignee: Minnesota Mining and Manufacturing CompanyInventors: Dennis L. Krueger, Neil W. Loeding, Claudia I. Poser
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Patent number: 4567059Abstract: An electroconductive paste consists essentially of 100 parts by weight of zinc in finely divided form, from about 0.01 to 10.00 parts by weight of a glass frit such as, typically, that of PbO-B.sub.2 O.sub.3 -SiO.sub.2 composition, and a vehicle such as alpha-terpineol containing ethylcellulose as an organic binder, for pasting the mixture of the zinc powder and the glass frit. The paste may contain an additive or additives such as the oxides of some metallic elements. By being baked on ceramic bodies at a temperature above the melting point of zinc, the paste forms conductors or electrodes of ceramic capacitors, varistors or the like. The capacitors or varistors having their conductors or electrodes thus prepared from the zinc paste are approximately equivalent in electrical and mechanical properties to those having their conductors or electrodes fabricated from a conventional silver paste.Type: GrantFiled: July 5, 1983Date of Patent: January 28, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Nobutatsu Yamaoka, Kazuo Sasazawa
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Patent number: 4557880Abstract: Film with piezoelectric and pyroelectric properties is obtained by extruding PVDF, stretching the extrudate and applying a corona discharge, preferably at the place where stretching occurs. The PVDF may be homopolymer, but copolymers of at least 50 mole % of vinylidene fluoride with tetrafluoroethylene and/or trifluoroethylene may be used.Type: GrantFiled: March 14, 1983Date of Patent: December 10, 1985Assignee: British TelecommunicationsInventor: Philippos Pantelis
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Patent number: 4527082Abstract: A method for the fabrication of surface acoustic wave devices by the selective removal of one of the phases of a metallic eutectic, solidified as a thin film having a lamellar morphology, forms a first spaced array of metallic elements. Removal is by line-heater or laser beam. This then provides a self-aligned structure for the formation of a second array of metallic elements interdigitated with the elements of the first array.Type: GrantFiled: September 12, 1983Date of Patent: July 2, 1985Assignee: General Electric CompanyInventor: Harvey E. Cline
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Patent number: 4521322Abstract: The invention relates to piezoelectric or pyroelectric polymer materials. It provides a process for manufacturing these materials comprising pressing polymer pellets while heating, dipping the obtained sheets in water, stretching the sheets, electrically polarizing the sheets by applying between the two faces of the sheets an electric orientation field, irradiating the sheets to obtain crosslinking and reheating the sheets.Type: GrantFiled: October 20, 1983Date of Patent: June 4, 1985Assignee: Thomson-CSFInventors: Dominique Broussoux, Hugues Facoetti, Francois Micheron, Lucien Monnerie
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Patent number: 4484382Abstract: Each resonant frequency of a coupling resonator is measured at a plurality of each different temperatures. From these values the first order temperature coefficient .alpha. is calculated. According to the value of .alpha., it is accurately adjusted and finally the resonant frequency of a fundamental vibration is also adjusted to a nominal frequency.Type: GrantFiled: March 30, 1982Date of Patent: November 27, 1984Assignee: Seiko Instruments & Electronics Ltd.Inventor: Hirofumi Kawashima
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Patent number: 4482833Abstract: A transducer with thin films of gold having a high degree of orientation on surfaces previously yielding only unoriented gold has a layer of glass over the surface of the substrate material followed by a layer of oriented gold over the layer of glass. The added layer of piezoelectric material over the layer of oriented gold provides piezoelectric material having good orientation due to the oriented gold. Addition of a top conductive electrode forms a transducer wherein the piezoelectric material has a high degree of orientation.Type: GrantFiled: January 4, 1984Date of Patent: November 13, 1984Assignee: Westinghouse Electric Corp.Inventors: Robert W. Weinert, Donald H. Watt
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Patent number: 4477952Abstract: An improved crystal is provided with an aluminum baseplate, a nickel plating on the aluminum baseplate, and a silver plating on the nickel plating. The nickel is plated on the aluminum baseplate before the aluminum has oxidized to provide high yields of stable crystals.Type: GrantFiled: April 4, 1983Date of Patent: October 23, 1984Assignee: General Electric CompanyInventors: Robert J. Crescenzi, John U. Daniels, Jr., Gerald E. Roberts
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Patent number: 4454639Abstract: A method for adjusting the frequency of a piezoelectic resonator such as a quartz crystal is disclosed. The resonator is placed within its enclosure facing a metallic surface. The atmosphere within the enclosure is made suitable for supporting a glow discharge. An electrical potential is then established between the resonator electrode and the metallic surface causing mass to sputter between the electrode and to the metallic surface to vary the characteristics of the resonator.Type: GrantFiled: June 3, 1982Date of Patent: June 19, 1984Assignee: Motorola, Inc.Inventors: Lawrence N. Dworsky, Douglas H. Weisman, Loi Q. Ninh
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Patent number: 4448805Abstract: In devices comprising closely spaced metallized regions deposited upon a dielectric substrate, in particular acoustic wave devices, electric fields may arise between the regions due to pyroelectic effects or acquired static charges during production or subsequently. These fields can cause damage by arcing or cracking of the substrate. The present method overcomes this problem by providing resistive links between such regions so that the fields do not arise. Preferably the links are of metallizing formed simultaneously with the metallized regions. Application to a SAW convolver is described in which the links are strips of metallizing (7,8,9).Type: GrantFiled: July 8, 1982Date of Patent: May 15, 1984Assignee: National Research Development CorporationInventor: Meirion F. Lewis
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Patent number: 4435441Abstract: The adjustment of the resonant frequency of a surface acoustical wave (SAW) evice is achieved utilizing the elastic deformation which occurs in a polymer when the polymer is energized. A film or patch of a polymer coating is applied to the substrate of the SAW device before sealing. The device is then subjected to an elevated temperature, to precure the polymer, and sealed. After being sealed with an appropriate transparent material, the device is subjected to a polymer-energizing media such as a light beam, high temperature or an electron beam. The applied polymer patch is energized resulting in elastic deformation of the patch. The polymer deformation results in a change in the elastic stiffness of the piezoelectric medium and thereby a change in the resonant frequency of the device.Type: GrantFiled: December 30, 1982Date of Patent: March 6, 1984Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Elio Mariani, Arthur Ballato
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Patent number: 4428808Abstract: A method for depositing thin films of gold having a high degree of orientation on surfaces previously yielding only unoriented gold by sputtering a layer of glass over the surface of the material followed by depositing a layer of oriented gold over the layer of glass. The additional step of depositing a layer of piezoelectric material over the layer of oriented gold is included to provide piezoelectric material having good orientation due to the oriented gold. A transducer is described having a layer of glass deposited over a material which previously provided unoriented gold followed by a layer of gold, a layer of piezoelectric material and a top conductive electrode to form a transducer wherein the piezoelectric material has a high degree of orientation.Type: GrantFiled: April 1, 1981Date of Patent: January 31, 1984Assignee: Westinghouse Electric Corp.Inventors: Robert W. Weinert, Donald H. Watt
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Patent number: 4427515Abstract: A surface acoustic wave device, a method for manufacturing the same and a manufacturing equipment therefor are disclosed. In the surface acoustic wave device having functional elements such as input and output interdigital electrodes of Al, Al-Si alloy or Al-Cu-Si alloy thin film strips and a grating type reflector, arranged on a piezoelectric substrate and any other bus conductors arranged on the same substrate, at least a portion of the functional elements and the bus conductors having a high frequency metal strip having a line width of no more than 2 .mu.m, at least the metal strip having the width of no more than 2 .mu.m has a film thickness of no less than 0.25 .mu.Type: GrantFiled: April 23, 1981Date of Patent: January 24, 1984Assignee: Hitachi, Ltd.Inventors: Akitsuna Yuhara, Shinya Iida, Hideo Abe, Kiyoharu Kishimoto, Katashi Hazama
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Patent number: 4419379Abstract: A crystal plating device and method of plating crystals in which a crystal to be plated and thereby set at a desired frequency is placed in an external removable holder or slug for insertion into a chamber of a plating device. The device is connected to a vacuum pump which is activated after the slug is loaded. Spring loaded filament posts carry a filament of precious metal such as gold or silver. The crystal is oscillated at a predetermined frequency prior to energizing the filament to evaporate or atomize the metal which plates the crystal and sets its frequency identical to that of the oscillator.The slug is externally loaded and can carry different size crystals. It is fitted with masks to accurately direct the deposit of the metal upon either or both sides of the crystal. After plating the slug is easily removed from the plating device.Type: GrantFiled: April 19, 1982Date of Patent: December 6, 1983Assignee: Emkay Manufacturing CompanyInventor: Alan Kaplan
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Patent number: 4414243Abstract: A method is described for the fabrication of surface acoustic wave devices by the selective removal of one of the phases of a metallic eutectic solidified as a thin film having a lamellar morphology to form a first spaced array of metallic elements which then provides a self-aligned structure for the formation of a second array of metallic elements interdigitated with the elements of the first array.Type: GrantFiled: July 6, 1982Date of Patent: November 8, 1983Assignee: General Electric CompanyInventor: Harvey E. Cline
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Patent number: 4407852Abstract: This invention relates to electrets which comprise a film of plasma polymerized dielectric material having a volumetric space charge.Type: GrantFiled: October 16, 1980Date of Patent: October 4, 1983Inventors: Slawomir W. Sapieha, Michael R. Wertheimer
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Patent number: 4406059Abstract: A mechanical and electrical connection for a piezoelectric member of polyic material such as polyvinylidene fluoride, and method for forming such a connection. To form the connection, the piezoelectric member is first masked to prevent a preselected portion of its surface from being coated during subsequent coating operations. An electrically conductive member such as a lead wire or a solderable terminal is then attached to the nonmasked area of the piezoelectric member with adhesive such as epoxy. The masked piezoelectric member, the electrically conductive member, and (incidentally) the mask are then coated with a conductive coating such as sputtered gold to electrically connect the conductive member to the piezoelectric member. The mask can now be removed from the piezoelectric member if desired, although it can be left in place as a convenient vise.Type: GrantFiled: April 22, 1981Date of Patent: September 27, 1983Assignee: The United States of America as represented by the Secretary of the NavyInventors: William R. Scott, Philip Bloomfield, William T. Weist, Karen M. McMahon
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Patent number: 4397884Abstract: The invention relates to piezoelectric resonators formed from a block of a crystalline material. During finishing of such resonators, some of the faces thereof, the distances between which define the frequency, are subjected to abrasive operations which alter the surface state of the network, with surface cracks, dislocations and fragmentations. The invention provides a process for implanting light ions on these faces (He, Li, Be) after finishing, by creating therein a layer of vitreous protection silica from the crystallized quartz.Type: GrantFiled: November 19, 1981Date of Patent: August 9, 1983Assignee: Compagnie d'Electronique et de Piezo-ElectriciteInventor: Georges Dube
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Patent number: 4393093Abstract: The piezoelectric and pyroelectric activity of vinylidene fluoride polymers is enhanced by treating the polymers with a glow discharge at a reduced pressure. The treatment is believed to convert a portion of the .alpha. phase crystal content of the polymers to the .gamma. phase. Piezoelectric and pyroelectric elements are formed by metallizing a film of the treated polymer and poling the metallized film.Type: GrantFiled: June 12, 1981Date of Patent: July 12, 1983Assignee: Pennwalt CorporationInventor: Oliver S. Sprout, Jr.
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Patent number: 4389445Abstract: A data recording sheet in which data signals are stored in a polarizable macromolecular material sheet layer with polarization different locally in the direction of the surfaces of said sheet layer. The sheet layer causes pyroelectric or piezo-electric polarization through polarization operation, and the data signals thus stored are reproduced in a pyroelectric or piezo-electric mode. The polarizable macromolecular material sheet layer is laminated through a thin intermediate electrode layer on a macromolecular substrate layer whose Young's modulus is greater than that of the sheet layer.Type: GrantFiled: July 9, 1979Date of Patent: June 21, 1983Assignee: Kureha Kagaku Kogyo Kabushiki KaishaInventors: Masafumi Yoshida, Kenichi Nakamura