Abstract: The present invention is directed to a capacitor apparatus of the capacity variable type. This capacitor apparatus is manufactured by Micro Electro-Mechanical System technology, and comprises an insulating substrate (2) in which at least two capacitor electrodes (3), (4) are formed on one surface (2a) in the state where they are insulated each other, an actuator (5) formed by insulating material and having an external shape to bridge over the respective capacitor electrodes (3), (4), the actuator (5) being such that a conductor which respectively constitutes capacitors between the conductor (6) and these capacitor electrodes (3), (4), and drive means (7) for allowing this actuator (5) to undergo an operation to come into contact with one principal surface (2a) of the insulating substrate (2) or to become away therefrom.

Abstract: A detector assembly including a support element, a first capacitor plate and a second capacitor plate. The support element is configured to attach the detector assembly to a chamber wall that separates a lower pressure region and a higher pressure region. A surface of the second capacitor plate is spaced apart from a surface of the first capacitor plate to define a capacitor gap. The first capacitor plate is positioned to be inside the lower pressure region when the detector assembly is attached to the chamber wall. The second capacitor plate is supported by the support element through insulating couplings. The detector assembly also includes a means for reducing mechanical load on the insulating couplings between the second capacitor plate and the support element. The reduced mechanical load includes load caused by a pressure difference between the lower and higher pressure regions.

Abstract: The present invention is directed to a capacitor apparatus of the capacity variable type. This capacitor apparatus is manufactured by Micro Electro-Mechanical System technology, and comprises an insulating substrate (2) in which at least two capacitor electrodes (3), (4) are formed on one surface (2a) in the state where they are insulated each other, an actuator (5) formed by insulating material and having an external shape to bridge over the respective capacitor electrodes (3), (4), the actuator (5) being such that a conductor which respectively constitutes capacitors between the conductor (6) and these capacitor electrodes (3), (4), and drive means (7) for allowing this actuator (5) to undergo an operation to come into contact with one principal surface (2a) of the insulating substrate (2) or to become away therefrom.

Abstract: A sensor assembly includes a stainless steel tubular housing. Within the housing is a polyetheretherketone tube and a sensor. An optical fiber joins the sensor to a transmission cable and is fixedly positioned within the tube. A first end of the housing includes a pressure transmission device or bellows and the second end of the housing is crimped about the tube to fixedly position the tube and the sensor within the housing. The sensor assembly is positioned within a channel of a gasket to obtain pressure data from a combustion chamber. This abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A method for making a pressure sensor by providing a wafer including a base silicon layer, a buried sacrificial layer, and a top silicon layer. The top silicon layer is arranged over the buried sacrificial layer and the buried sacrificial layer is arranged over the base silicon layer. Etching vents through the top silicon layer to the buried sacrificial layer and removing a portion of the buried sacrificial layer. Depositing silicon to seal the vents and arranging a strain gauge or a capacitance contact on the wafer. A method for making a pressure sensor including providing a bulk wafer and depositing a sacrificial layer on the bulk wafer. Depositing silicon on the sacrificial layer and the bulk wafer to form an encapsulation layer. Etching vents through the encapsulation layer to the sacrificial layer and removing the sacrificial layer. Closing the vents with a silicon deposition and arranging a strain gauge or a capacitance contact on the encapsulation layer.

Abstract: A cover plate (130) which is a plate member made of sapphire is joined to a pressure sensor chip (110), to which a buffer member (120) is fixed, by using a coating solution prepared by adding titanium dioxide to an aqueous solution of boehmite (AlO(OH)) which is a hydroxymineral of aluminum.

Abstract: The object of the present invention is to propose an etch channel sealing structure characterized by excellent impermeability to moisture and resistance to temporal change of the diaphragm in the pressure sensor produced according to the sacrificial layer etching technique, and to provide a pressure sensor characterized by excellent productivity and durability. After a very small gap is formed by the sacrificial layer etching technique, silicon oxide film is deposited by the CVD technique or the like, thereby sealing the etch channel. Further, impermeable thin film of polysilicon or the like is formed to cover the oxide film. This allows an etch channel sealing structure to be simplified in the pressure sensor produced according to the sacrificial layer etching technique, and prevents entry of moisture into the cavity, thereby improving moisture resistance. Moreover, sealing material with small film stress reduces temporal deformation of the diaphragm.

Abstract: An ultra miniature high temperature capacitive inductive pressure transducer is fabricated by MEMS techniques. The transducer consists of two separated pieces of silicon which form the plates of the capacitor, one of which plate is micromachined in such a way to allow a controlled deflection with pressure. The gap between the two capacitive plates is determined by an extending rim on one of the two plates. The two pieces of silicon are subsequently fusion bonded, leading a very small gap between the two plates. An inductor is formed on the top surface of one of the pieces of silicon by sputtering metal in a spiral like fashion on the back side of the non-micromachined plate.

Abstract: The present invention is directed to a capacitor apparatus of the capacity variable type. This capacitor apparatus is manufactured by Micro Electro-Mechanical System technology, and comprises an insulating substrate (2) in which at least two capacitor electrodes (3), (4) are formed on one surface (2a) in the state where they are insulated each other, an actuator (5) formed by insulating material and having an external shape to bridge over the respective capacitor electrodes (3), (4), the actuator (5) being such that a conductor which respectively constitutes capacitors between the conductor (6) and these capacitor electrodes (3), (4), and drive means (7) for allowing this actuator (5) to undergo an operation to come into contact with one principal surface (2a) of the insulating substrate (2) or to become away therefrom.

Abstract: A device and method for signaling differential pressure change occurring during leak testing of an evaporative emission control space in a motor vehicle fuel system. A casing has sensing ports one of which is communicated to a reference pressure, such as atmospheric pressure, and another of which is communicated to sense pressure in the evaporative emission control space. As difference between the reference pressure and the pressure in the control space changes, the net magnetic flux acting on a magnetoresistive sensor changes. The sensor is electrically connected to the vehicle electrical system for signaling the differential pressure. The device may be used for both positive and negative pressure leak testing.

Abstract: A thermal pressure sensor monitors pressure by measuring effects caused by variations of thermal conductivity between a member and a substrate to which the member is adhered by stiction. The interface between the member and the substrate behaves as an extremely narrow gap. In a preferred embodiment the member is a bridge extending between a pair of cantilever arms. Two pressure sensors may be combined in a Wheatstone bridge configuration. A method for fabricating a pressure sensor according to the invention comprises forming a layer of oxide on a substrate, depositing a layer of material on the oxide layer, forming the member from the layer of material, removing the oxide layer and then bringing the member into contact with the substrate. The portion of the substrate under the member may be patterned with plateaus and valleys.

Abstract: The present invention provides a variable capacity condenser having fewer components. A variable capacity condenser according to the present invention comprises a dielectric substance, two electrodes, and a flexible electrode. The dielectric substance has two end faces. The two electrodes are disposed on one end face of the dielectric substance. The flexible electrode faces the other end face of the dielectric substance. The flexible electrode is pressible by a pressing member to vary a distance between at least a portion of the flexible electrode and the other end face of the dielectric substance.

Abstract: An electret formed by micro-machining technology on a support surface, including a self-powered electret sound transducer, preferably in the form of a microphone, formed by micro-machining technology. Each microphone is manufactured as a two-piece unit, comprising a microphone membrane unit and a microphone back plate, at least one of which includes an electret formed by micro-machining technology. When juxtaposed, the two units form a microphone that can produce a signal without the need for external biasing, thereby reducing system volume and complexity. The electret material used is a thin film of spin-on polytetrafluoroethylene (PTFE). An electron gun preferably is used for charge implantation. The electret has a saturated charged density in the range of about 2×10−5 C/m2 to about 8×10−4 C/m2. Thermal annealing is used to stabilize the implanted charge. An open circuit sensitivity of about 0.5 mV/Pa has been achieved for a hybrid microphone package.

Abstract: A diaphragm-type semiconductor device includes a semiconductor substrate, a surface of which is substantially flat, a diaphragm, which covers a circular pressure reference space located on the surface, and a circular electrode layer, a middle part of which is embedded in the diaphragm. The electrode layer is larger than the space and is coaxial with the space. Therefore, internal stress is balanced between inner and outer sides of the diaphragm, and a step formed at the outer edge of the top electrode layer is separated from the diaphragm. The device also includes a step adjuster around the space on the surface. Therefore, another step formed at the outer edge of the space disappears, and a new step is formed separately from the diaphragm at the outer edge of the step adjuster. With this structure, the diaphragm has a desired flatness.

Abstract: A capacitive fluid pressure transducer (10′) has a sensing element (12) received in an electrically conductive cup-shaped shield member (24) which is crimped onto the base of an electrical connector (20′). A conditioning circuit (14) is received in a circuit chamber formed between the sensor element and the connector and is provided with a tab carrying a conductive trace for electrical connection of the shield member with the circuit. The shield member is received in an electrically insulating sleeve (28) which in turn is received in a cavity formed in a metallic, high strength hexport housing so that the shield member is electrically isolated from the hexport housing.

Abstract: A pressure-measuring device with monitoring for diaphragm fracture comprises a housing with a passage whose two openings at the end faces of the housing are closed by a first deformation body and a second deformation body. The passage is completely filled with a transmission liquid in order to transmit the process pressure from the first deformation body to the second deformation body. The device has components for monitoring a material property of the transmission liquid. A change in the material property indicates contamination by the process medium and thus a fracture of the first deformation body. The material property monitored is preferably the relative dielectric constant.

Abstract: The present invention discloses a relaxor material lead iron tungstate which has been synthesized in doped and undoped conditions by single and two step heat treatment. The relaxor material is seen to exhibit almost negligible hysteresis and a transducer made thereby shows pressure measurement capability over a wide range from 0.5 MPa to 415 MPa with accuracy of ±0.05%.

Abstract: A method for making capacitive silicon pressure sensors and pressure switches with high long-term stability involves fabrication by wafer bonding of a silicon substrate wafer with another silicon wafer where a highly boron-doped diaphragm is defined by a self-aligned doping process through a window defined on an insulating layer. The long-term stability of the device is secured by anisotropically etching the window, e.g. by reactive ion etching, so as to create vertical window walls. The flatness of the diaphragm can be secured by the provision of an insulating film on the backside of the substrate wafer that compensates the stress on the silicon diaphragm created by the insulating layer present between the two wafers. The cavity formed by the window may contain gas or it may be evacuated in which case the fabrication method may also involve a process step facilitating the evacuation of the cavity and sealing the same using metal employed for making electrical connections.

Abstract: A capacitive pressure sensor includes a first substrate (1), a first flat electrode (1a) formed on the first substrate (1), a pressure-sensing frame (4) surrounding the first flat electrode (1a) provided on the first substrate (1), second substrates (2, 3) connected to the pressure-sensing frame (4) opposedly to the first substrate (1) and forming a capacitance chamber (7) together with the first substrate (1) and the pressure-sensing frame (4), a stage (5) provided on the second substrates (2, 3) in the capacitance chamber (7), separated from the pressure-sensing frame (4), and opposed to and separated from the first flat electrode (1a), and a second flat electrode (2a) provided on the stage (5) and opposed to the first flat electrode (1a), wherein the pressure-sensing frame (4) deforms elastically according to a pressure applied to the first and second substrates (1, 2, 3).

Abstract: The present invention relates to an electret condenser microphone including the vibratory diaphragm which is comprised of an electret film into which an electric charge is charged; a conductive film formed on one side of the electret film and a polar ring disposed at a peripheral edge of the underside of the conductive film. Also, this microphone includes a vibratory diaphragm support member which is disposed on the vibratory diaphragm and has a concave groove and a concave portion. On the vibratory diaphragm support member is attached an integrated circuit serving to receive and amplify a transformed electrical signal from the vibratory diaphragm.

Abstract: A sensor, in particular a humidity sensor, comprises a measuring layer (4), the dielectric properties of which depend on a parameter to be measured, e.g. of the humidity of the environmental air. Electrodes (2, 3) are arranged on a substrate (1) side by side for capacitively measuring the measuring layer (1). A protective layer (8) of a non-oxidizing material, in particular a layer of silicon oxide or gold, is arranged between the electrodes (2, 3) and the measuring layer (4). This layer prevents an oxidation of the electrodes (2, 3) and increases the live time and reliability of the sensor.

Abstract: A capacitor industrial process control transmitter includes a three-phase excitation circuit to charge a sensing capacitor and a compensation capacitor of the transmitter and transfer charges to an integrator. The sensing capacitor is charged during the first phase. During the second phase, the voltage to the sensing capacitor is reversed, and the charge on the sensing capacitor is pumped to the integrator. Also, the compensation capacitor is charged with the reversed voltage during the second phase. During the third phase, the voltage to the compensation capacitor is changed, and the charge on the compensation capacitor is pumped to the integrator.

Abstract: A process transmitter for measuring a process pressure includes a pressure sensor in a sensor housing. An isolation diaphragm which isolates fill fluid from process fluid is spaced apart from a process fluid seal. The spacing reduces deformation of the isolation diaphragm due to a mounting force.

Abstract: A pressure measuring device with a housing (21, 53) and a pressure measuring cell is provided, the pressure measuring cell being protected from interference, in particular independently of its installation position in the housing (21, 53), and comprising: a housing (21, 53), a pressure measuring cell, which has at least one pressure-sensitive measuring diaphragm (3, 35, 37), on the outer side of which a pressure (P, P1, P2) acts during operation, which has a transducer for converting a pressure-dependent deflection of the measuring diaphragm (3, 35, 37) into an electrical measured variable and which has free outer circumferential surfaces, which are provided with an electrically conductive coating (31, 61), and an electronic circuit (13, 49) for converting the electrical measured variable into a measuring signal.

Abstract: The invention relates to a novel micro relay for switching electric currents, in which a movable contact piece 1 moves parallel to the substrate.

Abstract: A new type of high-Q variable capacitor includes a substrate, a first electrically conductive layer fixed to the substrate, a dielectric layer fixed to a portion of the electrically conductive layer, and a second electrically conductive layer having an anchor portion and a free portion. The anchor portion is fixed to the dielectric layer and the free portion is initially fixed to the dielectric layer, but is released from the dielectric layer to become separated from the dielectric layer, and wherein an inherent stress profile in the second electrically conductive layer biases the free portion away from the a dielectric layer. When a bias voltage is applied between the first electrically conductive layer and the second electrically conductive layer, electrostatic forces in the free portion bend the free portion towards the first electrically conductive layer, thereby increasing the capacitance of the capacitor.

Abstract: A varactor includes a first capacitor plate, a second capacitor plate, at least one fixed charge holder, and a control electrode. The second capacitor plate is spaced from and movable towards and away from the first capacitor plate. At least one fixed charge holder with an imbedded charge is on at least a portion of the second capacitor plate. The control electrode is spaced from the second capacitor plate. Applying a bias to the control electrode moves the second capacitor plate towards or away from the first capacitor plate depending on the polarity of the applied bias.

Abstract: A diaphragm 30 and basic body 20 of a pressure sensor 10 are interconnected via a joint F. A groove 26 is provided in the basic body 20 in order to reduce the stress concentration in the region of the joint F.

Abstract: A structure and method is disclosed for dissipating electrostatic charges comprising an underlying dielectric layer disposed over capacitor plates of sensor circuitry, and a conductive layer and passivation layers disposed over the underlying dielectric layer wherein the conductive layer diffuses electrostatic charges at the surface of the integrated circuit.

Abstract: A micromechanical component placed on a substrate face includes at least one cell. A counter-electrode of a cell capacitor is placed under a cavity. The counter-electrode can be made from a first part of a lower conductive layer. An optionally circular membrane used as an electrode of the capacitor is placed above the cavity. The membrane is homogeneous, has a substantially uniform thickness, and can be part of an upper conductive layer preferably supported by a second part of the lower conductive layer. A caustic channel used to remove the sacrificial coating in order to form the cavity is laterally connected thereto. The channel has a vertical dimension equal to the vertical dimension of the cavity. A closure is adjacent to the channel and disposed outside the membrane. The component can be used as a pressure sensor, and can have several cells each adjacent to six other cells. A process for fabricating a micromechanical component is also provided.

Abstract: This invention discloses a method for electronically decreasing the sensitivity of thin film movable micromachined layers to vibrations, accelerations, or rotations that would result in part or all of the movable layer being displaced in the direction of the film thickness. In addition, the disclosed method can also be used to remove some of the curvature introduced into thin film movable structures due to vertical stress gradients. Electronic stiffening is achieved by using position sensing and force feedback at one or more points on the movable micromachined structure. Precise servo control of Z axis height makes it possible to dramatically decrease the spacing between the movable MEMS layer or layers and fixed electrodes, which can lead to a dramatic increase in sensitivity and/or actuation force.

Abstract: An optical scanner and a fabricating method thereof are provided. The optical scanner includes a base substrate, a frame, a H-shaped stage, supporters, and a stage driving structure. An interconnection layer having a predetermined pattern is formed on the base substrate. The frame has a rectangular frame shape which is formed on the base substrate. The H-shaped stage has a central area that performs a seesaw motion in the frame with respect to a uniaxial central axis and is positioned on the uniaxial central axis, and four extended areas that extend from two sides of the central area through which the uniaxial central axis passes, parallel the uniaxial central axis. The supporters have support beams that are positioned on the uniaxial central axis and connected to the frame and torsion bars that extend from the support beams and are connected to the central area of the stage.

Abstract: An improved vacuum variable capacitor can include one or more characteristics that provide advantages over previous vacuum variable capacitors. In particular, the vacuum variable capacitor can be constructed so as to enable the capacitance to be adjusted more easily, reduce parasitic electrical characteristics that degrade the performance of the vacuum variable capacitor, increase the strength of the capacitor plates of the vacuum variable capacitor, reduce the size of the vacuum variable capacitor, and/or make the shape of the vacuum variable capacitor more easily integrated into a system of which the vacuum variable capacitor is part.

Abstract: A process for detecting the point of touching of a tactile surface. A high frequency signal is sequentially supplied to four corners of a plate having a capacitive surface. This is accomplished by supplying one diagonal with the others being idle. The output voltages are measured at the four corners for all the various possible positions of touching. Relations between voltages are established from these measurements obtained for each diagonal. During touching, the relations obtained are compared with those stored in order to locate the point of touching.

Abstract: In order to avoid short-circuits between the electrodes, the pressure sensor comprises: a substrate (11) made of ceramic material, on one surface of which an electrode (13) and a glass layer (14) formed from an original glass frit are disposed; a diaphragm (12) made of ceramic material, which is permanently joined and pressure-sealed to the substrate by means of the original glass frit acting as a spacer (17) holding the diaphragm and the substrate from each other to form a cavity (16), and which on the cavity side is provided with an electrode (15); and leads (18, 19) which extend inwards and/or through the diaphragm (12) to the electrodes (13, 15) in the region of the spacer (17). The differential pressure sensor is formed in a mirror-inverted arrangement in relation to the centre plane of the substrate, so that it carries two pressure sensors. These are pressure-linked by a hole (41) filled with oil and connecting the two cavities and leading through the substrate and outwards.

Abstract: Embodiments of the invention include a sensor such as a capacitive sensor with improved scratch resistance. The sensor has a substrate and a layer of sensing elements formed thereon that are formed from materials having a greater mechanical firmness than conventional aluminum or other soft metal materials. Sensor interconnects also are made of such materials. The increased mechanical firmness of the sensing elements and interconnects improves the scratch and mechanical resistance thereof by reducing scratches, mechanical stress and cracks by reducing the deformation and consequently the bridge and/or gap effects of the sensing element material. Such effects plague conventional electronic devices, integrated circuits and sensors. Alternatively, the inventive sensor includes, e.g., a dielectric region operably coupled to the sensing elements and interconnects, thus forming a capacitive sensor or other electronic devices.

Abstract: A variable capacitor includes a stator, a conductive rotor, and a spring-action portion. The rotor electrode projects from the rotor, and a protrusion extends from the rotor as far as the rotor electrode, wherein the protrusion is formed on the rotor in a region other than that where the rotor electrode is formed. The spring-action portion applies a spring force on the rotor so as to press the rotor against the stator. The spring-action portion is formed on a cover around an adjustment hole formed in the cover. The cover allows the rotor to rotate relative to the stator, and the adjustment hole permits the introduction of a tool for rotating the rotor by inserting the tool therethrough. The radial position of the protrusion is selected so as to substantially fall on a circular trajectory which, as the rotor rotates, is swept out on the rotor by a section of the spring-action portion, which section is in contact with the rotor.