Capacitive Sensor Patents (Class 73/514.32)
  • Patent number: 6938485
    Abstract: The invention relates to measuring devices used for the measuring of acceleration, and specifically to capacitive acceleration sensors. The capacitive acceleration sensor according to the present invention comprises a pair of electrodes composed of a movable electrode (4) and a stationary electrode (5), and, related to the pair of electrodes, an isolator protrusion having a special coating. The invention provides an improved, more durable sensor structure, which withstands wear caused by overload situations better than earlier structures.
    Type: Grant
    Filed: February 10, 2004
    Date of Patent: September 6, 2005
    Assignee: VTI Technologies Oy
    Inventors: Heikki Kuisma, Juha Lahdenperä, Risto Mutikainen
  • Patent number: 6938484
    Abstract: A high-sensitivity and low-noise micromachined capacitive lateral accelerometer device having an input axis and a monolithic, three-axis accelerometer utilizing the device are provided. The device includes at least one electrode having a side surface normal to the input axis. A relatively large proofmass has at least one side surface normal to the input axis and extends along a width of the proofmass. The proofmass is movable against acceleration relative to the at least one electrode due to inertial force along the input axis to obtain a capacitive variation between the at least one electrode and the proofmass. The side surfaces are spaced apart to define a narrow, high-aspect ratio sensing gap which extends along substantially the entire width of the proofmass. The proofmass forms a sense capacitor with the at least one electrode.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: September 6, 2005
    Assignee: The Regents of the University of Michigan
    Inventors: Khalil Najafi, Junseok Chae
  • Patent number: 6938486
    Abstract: A semiconductor mechanical sensor having a new structure in which a S/N ratio is improved. In the central portion of a silicon substrate 1, a recess portion 2 is formed which includes a beam structure. A weight is formed at the tip of the beam, and in the bottom surface of the weight in the bottom surface of the recess portion 2 facing the same, an electrode 5 is formed. An alternating current electric power is applied between the weight portion 4 and the electrode 5 so that static electricity is created and the weight is excited by the static electricity. In an axial direction which is perpendicular to the direction of the excitation of the weight, an electrode 6 is disposed to face one surface of the weight and a wall surface of the substrate which faces the same. A change in a capacitance between the facing electrodes is electrically detected, and therefore, a change in a physical force acting in the same direction is detected.
    Type: Grant
    Filed: July 27, 2004
    Date of Patent: September 6, 2005
    Assignee: Denso Corporation
    Inventors: Tetsuo Fujii, Masahito Imai
  • Patent number: 6938487
    Abstract: An inertia device is constructed by both suspension structure and micro-electroplating structure. The suspension structure may be manufactured by surface micromachining technique of sacrificial layer process or bulk micromachining technique incorporating with thin film process. One side of the suspension structure is arranged firmly to a supporting piece, so that another side of the suspension structure is in a suspension state. The suspension side of the suspension structure is made as micro-electroplating structure through the micro-electroplating process and functions as inertia mass for an inertia sensor. The size of the micro-electroplating structure may be changed through the micro-electroplating process, such that the inertia sensor may be adapted for sensing in different levels.
    Type: Grant
    Filed: October 28, 2003
    Date of Patent: September 6, 2005
    Assignee: Industrial Technology Research Institute
    Inventors: Yi-Ru Chen, Kai-Cheng Chang, Guang-Chyeng Fang, Ming-Hsiu Hsu, Pei-Fang Liang
  • Patent number: 6935176
    Abstract: A sensor chip (100) includes comb-toothed movable electrodes (24) displaceable in a Y-direction, and comb-toothed stationary electrodes (30, 31, 40, 41) arranged to confront those movable electrodes (24), on one face side of a semiconductor substrate (10). The sensor chip (100) detects acceleration on the basis of a capacity change accompanying an acceleration application in the Y-direction between the movable electrodes (24) and the stationary electrodes (30, 31, 41, 42). The stationary electrodes (30, 31, 41, 42) are individually disposed to confront each other on one and other sides of the direction taken along the Y-direction in the individual movable electrodes (24). The individual electrode pads (25a, 30a, 31a, 40a, 41a) and the circuit chip (200) are electrically connected by bump electrodes (300) so that one face of the substrate (10) confronts the circuit chip (200).
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: August 30, 2005
    Assignee: Denso Corporation
    Inventors: Keisuke Goto, Tameharu Ohta
  • Patent number: 6935175
    Abstract: A Micro Electro-Mechanical System (MEMS) acceleration sensing device, formed of a an elongated sensing element of substantially uniform thickness suspended for motion relative to a rotational axis offset between first and second ends thereof such that a first portion of the sensing element between the rotational axis and the first end is longer than a shorter second portion between the rotational axis and the second end; a stationary silicon substrate spaced away from the sensing element; a capacitor formed by a surface of the substrate and each of the first and second portions of the sensing element; and a valley formed in the substrate surface opposite from the first longer portion of the sensing element and spaced away from the rotational axis a distance substantially the same as the distance between the rotational axis and the second end of the sensing element.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: August 30, 2005
    Assignee: Honeywell International, Inc.
    Inventors: Mark H. Eskridge, David L. Malametz
  • Patent number: 6928876
    Abstract: A dual capacitance accelerometer system includes two flexure plates coupled to the housing and defining a respective parallel flex axes. A fixed plate is adjacent to and in substantially parallel relation to the two flexure plates and is also coupled to the housing. The fixed plate and one of the flexure plates define a first distance and the fixed plate and the other flexure plate define a second distance. The first and second distances vary in response to acceleration forces acting upon the flexure plates.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: August 16, 2005
    Assignee: The Boeing Company
    Inventor: Ray F. Campbell
  • Patent number: 6928872
    Abstract: An integrated gyroscope, including an acceleration sensor formed by: a driving assembly; a sensitive mass extending in at least one first and second directions and being moved by the driving assembly in the first direction; and by a capacitive sensing electrode, facing the sensitive mass. The acceleration sensor has an rotation axis parallel to the second direction, and the sensitive mass is sensitive to forces acting in a third direction perpendicular to the other directions. The capacitive sensing electrode is formed by a conductive material region extending underneath the sensitive mass and spaced therefrom by an air gap.
    Type: Grant
    Filed: May 21, 2003
    Date of Patent: August 16, 2005
    Assignee: STMicroelectronics S.r.l.
    Inventors: Guido Spinola Durante, Sarah Zerbini, Angelo Merassi
  • Patent number: 6923061
    Abstract: A physical quantity sensor for detecting physical quantity includes a substrate having an opening; a beam protruding in the opening of the substrate and supported on the substrate; and a fixed electrode supported on the substrate. The beam is movable in a vertical direction of the substrate so that the physical quantity in the vertical direction is detectable. The sensor can be minimized, and has excellent output characteristics. Further, a manufacturing cost of the sensor is small.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: August 2, 2005
    Assignee: Denso Corporation
    Inventor: Koichi Tsubaki
  • Patent number: 6923062
    Abstract: For a sensor whose sensor structure is implemented in a micromechanical structural component and which has parts which are movable in relation to the stationary substrate of the structural component, and which also includes an unsupported a seismic mass, a spring system having at least one spring, the seismic mass being connected to the substrate through the spring system, and an overload protection to limit the deflection of the spring system and the seismic mass in at least one direction, and an arrangement for detecting the deflections of the spring system and the seismic mass, whereby the impact forces may be reduced to prevent conchoidal breaks and resulting incipient damage to the sensor structure, as well as formation of particles. To that end, at least one two-dimensional stop for at least one moving part of the sensor structure is provided as overload protection.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: August 2, 2005
    Assignee: Robert Bosch GmbH
    Inventors: Jochen Franz, Oliver Kohn, Frank Henning, Matthias Maute
  • Patent number: 6923060
    Abstract: A capacitive-type acceleration sensor includes a sensor chip that forms a moving electrode and a fixed electrode. The electrodes face each other while maintaining a detection gap. The sensor chip is joined to a circuit chip integrally. The circuit chip is mounted on a package via a resin adhesive. The adhesive is mixed with a filler of a material having a Young's modulus higher than that of the resin.
    Type: Grant
    Filed: August 1, 2003
    Date of Patent: August 2, 2005
    Assignee: Denso Corporation
    Inventors: Takashi Katsumata, Toshiya Ikezawa, Tomohito Kunda
  • Patent number: 6912902
    Abstract: A low cost, pendulous, capacitive-sensing Micro Electro-Mechanical Systems (MEMS) accelerometer is provided. The accelerometer includes a pendulous proof mass, one or more securing pads, and one or more flexures coupled with the pendulous proof mass and the one or more securing pads. The flexures flex linearly with respect to motion of the pendulous proof mass. First and second capacitor plates are positioned relative to the pendulous proof mass for detecting motion of the proof mass according to a sensed difference in capacitance. One or more strain isolation beams are connected between the one or more flexures and the pendulous proof mass or the securing pads. The strain isolation beams protect the flexures from mechanical strain.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: July 5, 2005
    Assignee: Honeywell International Inc.
    Inventors: David L. Malametz, Stephen F. Becka, Robert D. Horning
  • Patent number: 6904805
    Abstract: An accelerometer is limited to a very small displacement range, and within that range, is useful for detecting motion and change of rate of motion by optical, magnetic, or electrical means. A unique spring suspends a planar mass that is very sensitive to motion of an object in which the accelerometer is held. In one embodiment, an optical detector detects the motion of the mass by the intensity of reflected radiation. In another embodiment, a Hall-effect sensor detects the motion of the mass by a current generated by the motion of the mass in an electric field. The accelerometer may be used in a variety of automotive, appliance, and industrial applications.
    Type: Grant
    Filed: June 3, 2003
    Date of Patent: June 14, 2005
    Assignee: Cherry Corporation
    Inventors: Peter D. Joseph, Erik W. Linske, Kenneth A. Albrecht
  • Patent number: 6906394
    Abstract: A method of manufacturing a semiconductor device is provided. The device is manufactured with use of an SOI (Silicon On Insulator) substrate having a first silicon layer, an oxide layer, and a second silicon layer laminated in this order. After forming a trench reaching the oxide layer from the second silicon layer, dry etching is performed, thus allowing the oxide layer located at the trench bottom to be charged at first. This charging forces etching ions to impinge upon part of the second silicon layer located laterally to the trench bottom. Such part is removed, forming a movable section. For example, ions to neutralize the electric charges are administered into the trench, so that the electric charges are removed from charged movable electrodes and their charged surrounding regions. Removing the electric charges prevents the movable section to stick to its surrounding portions.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: June 14, 2005
    Assignee: Denso Corporation
    Inventors: Hiroshi Muto, Tsuyoshi Fukada, Kenichi Ao, Minekazu Sakai, Yukihiro Takeuchi, Kazuhiko Kano, Junji Oohara
  • Patent number: 6904804
    Abstract: A device for acceleration measurement, in which measuring signals from a two-dimensional sensor from measuring different directions are combined (gated) with one another and then jointly evaluated in an evaluation circuit. This evaluation is carried out, for example, using a threshold-value discriminator, in order to perform a plausibility check for a crash detection.
    Type: Grant
    Filed: April 9, 2002
    Date of Patent: June 14, 2005
    Assignee: Robert Bosch GmbH
    Inventor: Arno Schaumann
  • Patent number: 6901801
    Abstract: A capacitance acceleration derivative detector includes a housing, and a first plate fixed within the housing. A second plate is also fixed within the housing and spaced apart from and in parallel relation to the first plate. A flexure plate is disposed between and in substantially parallel relation to the first and second plates. The flexure plate is coupled to the housing along at least an edge. The flexure plate and first plate define a first distance and the flexure plate and the second plate define a second distance. The first and second distances vary in response to acceleration forces acting upon the flexure plate. The flexure plate and the first fixed plate generate a first charge displacement capacitance signal, and the second fixed plate and the flexure plate generate a second charge displacement capacitance signal.
    Type: Grant
    Filed: July 28, 2003
    Date of Patent: June 7, 2005
    Assignee: The Boeing Company
    Inventors: Ray F. Campbell, Joan D. Wada
  • Patent number: 6898974
    Abstract: A semiconductor dynamic quantity sensor includes a supporting portion, an adhesive, and a sensor chip. The adhesive is located on a surface of the supporting portion. The sensor chip is located on the adhesive. The sensor chip and the supporting portion have been bonded together by heating the adhesive. The adhesive has a deformation factor of 0.5% or smaller at the temperature at which the adhesive is heated for bonding the sensor chip and the supporting portion together in order to reduce the stress caused by the hardening shrinkage of the adhesive.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: May 31, 2005
    Assignee: Denso Corporation
    Inventors: Masaaki Tanaka, Toshiya Ikezawa, Takashige Saitou
  • Patent number: 6892577
    Abstract: In a movable space, a boundary (CN1) between a ceiling surface and a wall surface of a cap (CA) has a curved plane. When stress is exerted on the cap (CA), this stress is dispersed accordingly around the boundary (CN1) having a high probability of generation of a crack. Therefore, generation of a crack in the cap (CN) is unlikely.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: May 17, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Teruaki Nagahara
  • Patent number: 6895321
    Abstract: An accelerometer system includes a rigid plate system coupled to an inertial platform. A first flexure plate defines a first flex axis and is adjacent to the rigid plate system a first distance from the spin axis. The first flexure plate generates a first frequency signal in response to acceleration of the first flexure plate. A second flexure plate defines a second flex axis and is adjacent to the rigid plate system a second distance from the spin axis. The second flexure plate generates a second frequency signal in response to acceleration of the second flexure plate. A controller including receives the first frequency signal and the second frequency signal and generates an angular acceleration signal from a difference of the first frequency signal and the second frequency signal. The controller also generates a linear acceleration signal in response to an average of the first frequency signal and the second frequency signal.
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: May 17, 2005
    Assignee: The Boeing Company
    Inventors: Ray F. Campbell, Joan D. Wada, John P. Raab
  • Patent number: 6892576
    Abstract: Accelerometer offset is reduced by forming mass support structures within an inner periphery of the mass, affixing the mass support structures to the substrate by at least one anchor positioned near the mass' center of mass, and affixing the sensing fingers proximate to the anchor. The mass support structures can be affixed to the substrate using a single anchor or multiple anchors that are positioned close together. The sensing fingers can be affixed to the substrate or to the mass support structures. The mass is typically suspended from within its periphery but toward its outer periphery.
    Type: Grant
    Filed: July 18, 2003
    Date of Patent: May 17, 2005
    Assignee: Analog Devices, Inc.
    Inventors: Howard R. Samuels, David C. Hollocher, Michael Judy, Thor Juneau
  • Patent number: 6886405
    Abstract: A capacitive acceleration sensor includes a non-single-crystal-silicon-based substrate, a polysilicon beam structure having a movable section that includes a movable electrode, a polysilicon supporter positioned on the non-single-crystal-silicon-based substrate for fixing the beam structure and forming a distance between the beam structure and the non-single-crystal-silicon-based substrate, a stationary electrode positioned on the non-single-crystal-silicon-based substrate and opposite to the movable section of the beam structure, and a thin film transistor (TFT) control circuit positioned on the non-single-crystal-silicon-based substrate. The stationary electrode and the movable electrode constitute a plate capacitor, and the TFT control circuit is electrically connected to the plate capacitor.
    Type: Grant
    Filed: August 21, 2003
    Date of Patent: May 3, 2005
    Assignee: AU Optronics Corp.
    Inventor: Chien-Sheng Yang
  • Patent number: 6877382
    Abstract: A detector providing an electrical signal in response to the pressures encountered in sensing breath inhalation in respirators. The detector uses a capacitive pressure sensor formed by a flexible conductive diaphragm separated from fixed electrodes by a layer of dielectric film. Deflection of the diaphragm by pressure introduces a low permittivity space in the sensor resulting in a substantial change in capacitance. The change in capacitance modifies the frequency of an oscillator. A frequency responsive circuit provides balancing electrostatic force feedback voltage to the diaphragm. The force feedback stiffens the diaphragm and maintains it in a high capacitance, high sensitivity state. This feedback reduces sensitivity to changes in the diaphragm mechanical properties. Signal filtering reduces the effects of long term drift and environmental factors.
    Type: Grant
    Filed: October 20, 2003
    Date of Patent: April 12, 2005
    Inventor: Robert D Gourlay
  • Patent number: 6868726
    Abstract: A position-sense interface with improved transfer characteristics. Electrical position detection circuitry, which may be substantially time-multiplexed or frequency-multiplexed, comprises a differential charge integrator with input-sensed output-driven common mode feedback. By placing sense capacitors in the feedback loop of said differential charge integrator with input-sensed output-driven common mode feedback, improved position sensing linearity is attained. In some embodiments of the invention, a compensating charge is applied to the sense capacitors in a fashion that minimizes the output common mode shift of the opamp. The magnitude of the compensating charge may be preset at a substantially constant level, or derived by a feedback loop that measures the shift in output common mode voltage in response to an excitation signal and adjusts the magnitude of the compensating charge to drive said shift towards zero.
    Type: Grant
    Filed: January 18, 2001
    Date of Patent: March 22, 2005
    Assignee: Analog Devices IMI, Inc.
    Inventors: Mark A. Lemkin, Thor N. Juneau, William A. Clark, Allen W. Roessig
  • Patent number: 6868727
    Abstract: A semiconductor mechanical sensor having a new structure in which a S/N ratio is improved. In the central portion of a silicon substrate 1, a recess portion 2 is formed which includes a beam structure. A weight is formed at the tip of the beam, and in the bottom surface of the weight in the bottom surface of the recess portion 2 facing the same, an electrode 5 is formed. An alternating current electric power is applied between the weight portion 4 and the electrode 5 so that static electricity is created and the weight is excited by the static electricity. In an axial direction which is perpendicular to the direction of the excitation of the weight, an electrode 6 is disposed to face one surface of the weight and a wall surface of the substrate which faces the same. A change in a capacitance between the facing electrodes is electrically detected, and therefore, a change in a physical force acting in the same direction is detected.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: March 22, 2005
    Assignee: DENSO Corporation
    Inventors: Tetsuo Fujii, Masahito Imai
  • Patent number: 6865944
    Abstract: A micro-electromechanical systems (MEMS) device is described which includes a substrate having at least one anchor, a proof mass having either of at least one deceleration extension extending from the proof mass or at least one deceleration indentation formed in the proof mass, a motor drive comb, and a motor sense comb. The MEMS device further includes a plurality of suspensions configured to suspend the proof mass over the substrate and between the motor drive comb and the motor sense comb, and the suspensions are anchored to the substrate. The MEMS device also includes a body attached to the substrate and at least one deceleration beam extending from the body. The deceleration extensions are configured to engage either deceleration beams or deceleration indentations and slow or stop the proof mass before it contacts either of the motor drive comb or the motor sense comb.
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: March 15, 2005
    Assignee: Honeywell International Inc.
    Inventors: Max C. Glenn, Mark W. Weber, William P. Platt
  • Patent number: 6867601
    Abstract: A sensor unit having capacitance element electrodes and a displacement electrode being opposite thereto is disposed on a substrate. A detective button is supported onto the substrate in such a manner that the detective button is positioned above the sensor unit to define a specified space between the supporting member for supporting the detective button and the displacement electrode.
    Type: Grant
    Filed: July 9, 2003
    Date of Patent: March 15, 2005
    Assignee: Nitta Corporation
    Inventor: Hideo Morimoto
  • Patent number: 6862795
    Abstract: A method of manufacturing a monolithic silicon acceleration sensor is disclosed. The monolithic silicon acceleration sensor includes one or more sensor cells, each sensor cell having an inertial mass positioned by beam members fixed to a silicon support structure. According to the method, a sandwiched etch-stop layer is formed. First sections of the inertia mass and beam members are also formed. In addition, a second section of the inertial mass is formed. Further, an inertial mass positioned by beam members fixed to a silicon support structure is formed. Also, a first cover plate structure is bonded to a first surface of the silicon support structure.
    Type: Grant
    Filed: June 17, 2002
    Date of Patent: March 8, 2005
    Assignee: VTY Holding Oy
    Inventor: Geoffrey L. Mahon
  • Patent number: 6854330
    Abstract: An accelerometer includes a housing with a chamber, a member with a stored static charge, and a pair of electrodes connected to the housing. The member is connected to the housing and extends at least partially across the chamber. The pair of electrodes are each spaced from and on substantially opposing sides of the member from each other and are at least partially in alignment with each other. The member is movable with respect to the pair of electrodes or one of the pair of electrodes is movable with respect to the member.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: February 15, 2005
    Assignee: Nth Tech Corporation
    Inventor: Michael D. Potter
  • Patent number: 6848306
    Abstract: A semiconductor dynamic sensor such as an acceleration sensor is composed of a sensor chip having electrodes movable in response to acceleration applied thereto and a circuit chip having a circuit for processing signals fed from the sensor chip. The sensor chip and the circuit chip are contained and held in a packaging case. The sensor chip and the circuit chip are fixedly connected via an adhesive film. The sensor chip is correctly positioned on the circuit chip without creating misalignment relative to a sensing axis, because the adhesive film from which an adhesive material does not flow out under heat is used. A semiconductor wafer including plural sensor chips is first made and the adhesive film is stuck to one surface of the wafer, and then individual sensor chips are separated by dicing. The sensor chip is connected to the circuit chip via the adhesive film.
    Type: Grant
    Filed: April 4, 2001
    Date of Patent: February 1, 2005
    Assignee: Denso Corporation
    Inventor: Tomohito Kunda
  • Patent number: 6848309
    Abstract: In a capacitive type dynamic quantity sensor, a width of a beam in a beam portion extending in a direction that is perpendicular to a predetermined deformation direction and a gap disposed between a movable electrode and the fixed electrode in the predetermined deformation direction are approximately identical. Accordingly, manufacturing error is prevented from affecting the sensitivity of the capacitive type dynamic quantity sensor. For example, a manufacturing tolerance error of ±2.5% is allowed as a result of designing the width of the beam and the gap to be identical in length.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: February 1, 2005
    Assignee: Denso Corporation
    Inventor: Minekazu Sakai
  • Patent number: 6848310
    Abstract: A capacitive dynamic quantity sensor includes a semiconductor substrate, a weight, a movable electrode, and two fixed electrodes. The weight is movably supported by the semiconductor substrate. The movable electrode is integrated with the weight. The fixed electrodes are stationarily supported by the semiconductor substrate. The fixed electrodes face the movable electrode to provide a narrow gap and a wide gap and form a detection part having a capacitance. The weight and the movable electrode are displaced relative to the fixed electrodes in response to a dynamic quantity to be detected such that one of the gaps increases while the other decreases. The dynamic quantity is detected on the basis of the variation in the capacitance. One of wide gap electrode surfaces, which define the wide gap, is smaller than narrow gap electrode surfaces, which define the narrow gap, to improve sensor sensitivity.
    Type: Grant
    Filed: July 9, 2003
    Date of Patent: February 1, 2005
    Assignee: Denso Corporation
    Inventor: Keisuke Goto
  • Patent number: 6845670
    Abstract: A transducer is provided herein which comprises an unbalanced proof mass (51), and which is adapted to sense acceleration in at least two mutually orthogonal directions. The proof mass (51) has first (65) and second (67) opposing sides that are of unequal mass.
    Type: Grant
    Filed: July 8, 2003
    Date of Patent: January 25, 2005
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Andrew C. McNeil, Gary Li, Daniel N. Koury, Jr.
  • Patent number: 6840106
    Abstract: A self-test structure is placed in the middle of a sensing structure that utilizes a movable mass. The sensing structure has portions aligned in two directions that are orthogonal to each other. The self-test structure is an actuator made up of individual sensing patterns. The individual sensing patterns are aligned along a line that is diagonal to the two directions, thereby reducing the number of individual sensing patterns required for the actuator that is used for self-test. The reduced number of sensing patterns results in more mass for the movable mass, thereby improving sensitivity of the sensing structure.
    Type: Grant
    Filed: August 14, 2003
    Date of Patent: January 11, 2005
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Andrew C. McNeil
  • Patent number: 6841992
    Abstract: A Micro Electro-Mechanical System (MEMS) acceleration sensing device, formed of a sensing element having first and second substantially planar and parallel spaced apart opposing surfaces and being suspended for pendulous motion about a hinge axis oriented along a minor axis of the sensing element; and one or more substrates each having a face spaced from one of the opposing surfaces of the sensing element, each of the substrates having pluralities of electrodes arranged substantially crosswise to the hinge axis of the sensing element symmetrically to a longitudinal axis of the sensing device and forming respective first and second capacitors with the moveable sensing element. Each of the one or more substrates optionally including a clearance relief for extending the rotational range of motion of the sensing element.
    Type: Grant
    Filed: February 18, 2003
    Date of Patent: January 11, 2005
    Assignee: Honeywell International, Inc.
    Inventors: Aiwu Yue, Ronald B. Leonardson
  • Patent number: 6838385
    Abstract: This invention provides a method for manufacturing an electric capacitance type acceleration sensor capable of achieving high productivity in which a semiconductor manufacturing process is used.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: January 4, 2005
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Nobuo Ozawa
  • Publication number: 20040255674
    Abstract: A control unit in a vehicle with a processor and a sensor is proposed, whereby the processor is capable of being connected with the sensor, whereby the processor includes means for generating at least one clock pulse for the at least one sensor, whereby the sensor uses the clock pulse for a sensor operation, preferably sensor measurement and sensor signal processing.
    Type: Application
    Filed: April 19, 2004
    Publication date: December 23, 2004
    Inventors: Eckard Steiger, Hartmut Schumacher
  • Patent number: 6829937
    Abstract: A monolithic silicon acceleration sensor capable of detecting acceleration along multiple orthogonal axes of acceleration is disclosed. The monolithic silicon acceleration sensor is micromachined from silicon to form one or more sensor cells, each sensor cell having an inertial mass positioned by beam members fixed to a silicon support structure. Movement of the inertial mass due to acceleration is detected by either a differential capacitance measurement between opposing surfaces of the inertial mass and electrically conductive layers on a top and a bottom cover plate structure, or by a resistance measurement of piezoresistive elements fixed to the positioning beam members. Embodiments of the invention are capable of detecting acceleration in a plane, along two orthogonal axes of acceleration, or along three orthogonal axis of acceleration.
    Type: Grant
    Filed: June 17, 2002
    Date of Patent: December 14, 2004
    Assignee: VTI Holding Oy
    Inventor: Geoffrey L. Mahon
  • Publication number: 20040237652
    Abstract: In a semiconductor acceleration sensor (S1), above one side of a first silicon substrate (10) made of a semiconductor and serving as a fixed electrode (11), a moving electrode (20) made of a semiconductor and displaceable in the thickness direction of the first silicon substrate (10) is disposed apart from and facing the first silicon substrate (10). An applied acceleration is detected on the basis of capacitance changes between the moving electrode (20) and the face of the first silicon substrate (10) accompanying displacement of the moving electrode (20). A space and an electrically insulative insulating layer (13) having a relative permittivity larger than that of air are interposed between the moving electrode (20) and the face of the first silicon substrate (10), side by side in the direction in which the moving electrode (20) and the first silicon substrate (10) are apart.
    Type: Application
    Filed: June 1, 2004
    Publication date: December 2, 2004
    Applicant: DENSO CORPORATION
    Inventor: Minekazu Sakai
  • Publication number: 20040237650
    Abstract: A capacitive acceleration sensor includes a non-single-crystal-silicon-based substrate, a polysilicon beam structure having a movable section that includes a movable electrode, a polysilicon supporter positioned on the non-single-crystal-silicon-based substrate for fixing the beam structure and forming a distance between the beam structure and the non-single-crystal-silicon-based substrate, a stationary electrode positioned on the non-single-crystal-silicon-based substrate and opposite to the movable section of the beam structure, and a thin film transistor (TFT) control circuit positioned on the non-single-crystal-silicon-based substrate. The stationary electrode and the movable electrode constitute a plate capacitor, and the TFT control circuit is electrically connected to the plate capacitor.
    Type: Application
    Filed: August 21, 2003
    Publication date: December 2, 2004
    Inventor: Chien-Sheng Yang
  • Publication number: 20040237651
    Abstract: A sensor element includes a pair of differential capacitors having capacitances C1 and C2 causing a complementary capacitance change in response to an applied acceleration. An additional capacitor is connected to either capacitor to generate a capacitance difference between the capacitance C1 and the composite capacitance C2+C3. This enables to adjust an input LPFout of a correcting circuit correcting the offset level of the sensor output Gout in such a manner that a correction amount in the correcting circuit becomes large and accordingly deviates sufficiently from a reference level Vref. In case of failure in which the input of the correcting circuit is fixed to the reference level Vref, the sensor output Gout surely deviates from the reference level Vref by an amount equivalent to the correction in the correcting circuit.
    Type: Application
    Filed: March 25, 2004
    Publication date: December 2, 2004
    Applicant: DENSO CORPORATION
    Inventor: Akihisa Furuichi
  • Publication number: 20040231421
    Abstract: A capacitance type physical quantity sensor detects physical quantity. The sensor includes a movable portion including a movable electrode and a fixed portion including a fixed electrode. The fixed electrode includes a detection surface facing a detection surface of the movable electrode. The movable electrode is movable toward the fixed electrode in accordance with the physical quantity so that a distance between the detection surfaces is changeable. At least one of the movable and the fixed electrodes includes a groove. The groove is disposed on a top or a bottom of the one of the movable and the fixed electrodes, has a predetermined depth from the top or the bottom, and extends from the detection surface to an opposite surface.
    Type: Application
    Filed: April 29, 2004
    Publication date: November 25, 2004
    Inventors: Tetsuo Yoshioka, Akihiko Teshigahara, Junji Ohara, Yukihiro Takeuchi, Toshimasa Yamamoto, Kazuhiko Kano
  • Publication number: 20040231420
    Abstract: A monolithic integrated 3-axis accelerometer chip includes a single crystal substrate, the substrate including at least one single crystal membrane layer portion. A single sensor microstructure made from the single crystal membrane senses acceleration in each of the three orthogonal directions. At least one electronic circuit can also be disposed on the chip, such as a circuit for driving, detecting, controlling and signal processing.
    Type: Application
    Filed: February 24, 2004
    Publication date: November 25, 2004
    Inventors: Huikai Xie, Gary K. Fedder, Zhiyu Pan, William Frey
  • Publication number: 20040226376
    Abstract: A sensor chip (100) includes comb-toothed movable electrodes (24) displaceable in a Y-direction, and comb-toothed stationary electrodes (30, 31, 40, 41) arranged to confront those movable electrodes (24), on one face side of a semiconductor substrate (10). The sensor chip (100) detects acceleration on the basis of a capacity change accompanying an acceleration application in the Y-direction between the movable electrodes (24) and the stationary electrodes (30, 31, 41, 42). The stationary electrodes (30, 31, 41, 42) are individually disposed to confront each other on one and other sides of the direction taken along the Y-direction in the individual movable electrodes (24). The individual electrode pads (25a, 30a, 31a, 40a, 41a) and the circuit chip (200) are electrically connected by bump electrodes (300) so that one face of the substrate (10) confronts the circuit chip (200).
    Type: Application
    Filed: April 29, 2004
    Publication date: November 18, 2004
    Inventors: Keisuke Goto, Tameharu Ohta
  • Publication number: 20040226375
    Abstract: A moving member having a plurality of moving electrodes is supported by support members at both ends thereof on a substrate surface in such a way that it can be subjected to displacement in a two-dimensional plane. A plurality of fixed electrodes are arranged to face the plurality of moving electrodes respectively, thus forming different facing areas therebetween when an input acceleration is zero. The facing areas formed between pairs of the electrodes facing each other are varied in response to the displacement of the moving member, whereby a capacitance caused by one pair of the electrodes whose facing area is relatively small is used to detect a relatively small input acceleration, and a capacitance caused by the other pair of the electrodes whose facing area is relatively large is used to detect a relatively large input acceleration.
    Type: Application
    Filed: March 1, 2004
    Publication date: November 18, 2004
    Inventor: Tamito Suzuki
  • Publication number: 20040226377
    Abstract: An inertial detecting device for detecting a change in capacitance of a sensor element caused by inertial force includes a displaceable unit. The displaceable unit includes a movable mass member which is displaceable in the direction of an inertial force and is supported in a space by a pair of beams fixed on the substrate. At least one pair of detection units for detecting the displacement of the displaceable unit are provided on the substrate. The detection unit includes a drive unit and a pair of sensing electrodes which are disposed opposite to the displaceable unit. Any gap can be freely set between the sensing electrode and the movable mass member, thereby changing the sensitivity of the detecting device in a wide range.
    Type: Application
    Filed: May 14, 2004
    Publication date: November 18, 2004
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahiro Tsugai
  • Publication number: 20040226374
    Abstract: The invention relates to measuring devices used for the measuring of acceleration, and specifically to capacitive acceleration sensors. The capacitive acceleration sensor according to the present invention comprises a pair of electrodes composed of a movable electrode (4) and a stationary electrode (5), and, related to the pair of electrodes, an isolator protrusion having a special coating. The invention provides an improved, more durable sensor structure, which withstands wear caused by overload situations better than earlier structures.
    Type: Application
    Filed: February 10, 2004
    Publication date: November 18, 2004
    Inventors: Heikki Kuisma, Juha Lahdenpera, Risto Mutikainen
  • Publication number: 20040221650
    Abstract: The invention relates to measuring devices used in the measuring of acceleration and, more specifically, to capacitive acceleration sensors. The capacitive acceleration sensor according to the present invention contains a movable electrode (5) supported at an axis of rotation (7). The capacitance change in the pair of electrodes of the acceleration sensor, according to the present invention, is enhanced. The acceleration sensor structure, according to the present invention, enables improving the capacitance sensitivity of the pair of electrodes based on rotational motion and measuring acceleration with good performance in capacitive acceleration sensor designs.
    Type: Application
    Filed: February 10, 2004
    Publication date: November 11, 2004
    Inventor: Tuomo Lehtonen
  • Publication number: 20040216523
    Abstract: The invention relates to measuring devices used in the measurement of acceleration and, more specifically, to capacitive acceleration sensors. The capacitive acceleration sensor according to the present invention contains a movable electrode (5) of the acceleration sensor supported at an axis of rotation (7). Several pairs of electrodes are utilized in the acceleration sensor according to the present invention. Advantages of symmetry are achieved with the acceleration sensor structure according to the present invention, and it enables reliable and efficient measuring of acceleration, in particular in small capacitive acceleration sensor designs.
    Type: Application
    Filed: February 10, 2004
    Publication date: November 4, 2004
    Inventor: Tuomo Lehtonen
  • Patent number: 6810735
    Abstract: A sensing apparatus comprises a sensing unit and a supporting unit. The sensing unit detects a direction and an amount of physical quantity applied thereto. The sensing unit has a detection reference axis along which the direction and the amount of the physical quantity are detected. The supporting unit stationarily supports the sensing unit. The sensing unit is inclined relative to the supporting unit by a predetermined angle so that a difference in angle between the detection reference axis and the direction of the physical quantity actually applied to the sensing unit when detecting the direction and the amount of the physical quantity is reduced.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: November 2, 2004
    Assignee: Pioneer Corporation
    Inventors: Hitoshi Kaneko, Tatsuya Okamoto, Isao Endo
  • Patent number: 6810736
    Abstract: A semiconductor dynamic sensor such as an acceleration sensor is composed of a sensor chip for detecting a dynamic force applied thereto and a circuit chip for processing output signals from the sensor chip. The sensor chip is supported on the circuit chip, and both chips are mounted on a package case. To suppress thermal stress transfer from the package case to the sensor chip through the circuit chip, an adhesive film having an elasticity modulus lower than 10 MPa is interposed between the circuit chip and the package case. Characteristics of the sensor chip are kept stable by suppressing the thermal stress transfer from the package case.
    Type: Grant
    Filed: March 5, 2003
    Date of Patent: November 2, 2004
    Assignee: Denso Corporation
    Inventors: Toshiya Ikezawa, Takashige Saitou, Masaaki Tanaka