Abstract: An exemplary pressure cavity is disclosed that is durable, stable, and biocompatible and configured in such a way that it constitutes pico to nanoliter-scale volume. The exemplary pressure cavity is hermetically sealed from the exterior environment while maintaining the ability to communicate with other devices. Micromachined, hermetically-sealed sensors are configured to receive power and return information through direct electrical contact with external electronics. The pressure cavity and sensor components disposed therein are hermetically sealed from ambient pressure in order to reduce drift and instability within the sensor. The sensor is designed for harsh and biological environments, e.g., intracorporeal implantation and in vivo use. Additionally, novel manufacturing methods are employed to construct the sensors.

Abstract: A pressure/vacuum sensor and method, comprising: driving a MEMS piezoresistive resonator (8) into resonant vibration, applying Joule heating to the resonator (8); and sensing a variable parameter that varies in response to the tendency of the resonant frequency (fo) to depend upon the temperature of the resonator (8), the temperature thereof depending upon the pressure. The variable parameter may be the resonant frequency of the resonator (8), or a change therein, or may be derived from a feedback loop, being for example a time integrated feedback signal (82) or a reading (94) of the sense current (22), the loop keeping the resonant frequency constant in opposition to the above mentioned tendency. A reference MEMS capacitive resonator (62) may be located in the vicinity of the resonator (8) for compensating purposes.

Abstract: A pressure sensor for sensing a fluid pressure comprising: a first chamber including a first conductive membrane, wherein a fluid is sealed within the first chamber at a reference pressure such that the first conductive membrane deflects from pressure differences between the reference and the fluid pressure; a second chamber including a second conductive membrane sealed from the fluid pressure, wherein the second membrane deflects in response to a change in temperature which the pressure sensor is exposed thereto; and a circuit in electrical communication with the first and second conductive membrane, the circuit being configured to obtain a first and second signal from the first and second conductive membranes respectively, the first and second signals being indicative of the deflection of the first and second conductive membranes, wherein the circuit adjusts the first signal by the second signal to generate an output signal indicative of the fluid pressure.

Abstract: A pressure sensor adapted to provide a high resolution at a low pressure and a high pressure of an operating range is provided. The pressure sensor includes a body having an interface sur ace, a membrane sealingly disposed in the cavity adjacent the interface surface, and a sensing element in communication with the membrane. A fuel cell system including the pressure sensor is also provided.

Abstract: A process transmitter for measuring a process variable in an industrial process comprises a sensor module, a heating device and transmitter circuitry. The sensor module has a sensor for sensing a process variable of an industrial process and generating a sensor signal. The heating device is connected to the sensor module for generating a heat pulse to influence generation of the sensor signal. The transmitter circuitry is connected to the sensor and the heating device. The transmitter circuitry verifies operation of the sensor by measuring a change in the sensor signal due to the heat pulse. In one embodiment of the invention, the heat pulse thermally expands a volume of a fill fluid within the process transmitter. In another embodiment, the heat pulse changes a physical property, such as dielectric, of a fill fluid within the process transmitter.

Abstract: A pressure transducer, particularly adapted to measure the pressure in a tire and to enable the tire to be filled includes a first housing, having an internal hollow. Positioned in the hollow of the first housing is a second housing, also having an internal hollow. The second housing is supported within the first housing so that a passageway for airflow exists between the housings. The second housing has a pressure port for monitoring the pressure of a tire. The first housing has an inlet port for receiving a source of pressure. The inlet port contains a valve which is selectively operated. The valve, when operated, permits air to flow into the hollow of the first housing and to flow about the periphery of the second housing to enter the pressure port associated with the second housing. The pressure port may, as indicated, be associated with a tire and the second housing contains a pressure sensing device which monitors the pressure in the tire via the pressure port.

Abstract: A process transmitter for measuring a process variable in an industrial process comprises a gauge pressure sensor, an excitation source and transmitter circuitry. The gauge pressure sensor measures a pressure difference between a process fluid and a reference volume, and generates a pressure sensor signal representing the pressure difference. The excitation source generates a pressure pulse within the reference volume to influence generation of the pressure sensor signal. The transmitter circuitry is connected to the gauge pressure sensor to provide an output related to a change in the pressure sensor signal due to the pressure pulse.

Abstract: A method for fabricating a wireless pressure sensor includes providing a first substrate. A portion of the first substrate is controllably displaced to form a cavity. A conducting material is patterned on the first substrate to form a first capacitor plate and a first inductor. A second substrate is provided. A conducting material is patterned on the second substrate to form a second capacitor plate. The second substrate is attached to the first substrate to seal the cavity such that at least a portion of the second substrate is movable with respect to the first substrate within the cavity in response to a change in an external condition. A hermetically sealed capacitive pressure sensor may reside in the cavity between the first substrate and second substrate.

Abstract: A pressure sensor includes a first set of electrodes, a second set of electrodes, and a common electrode. The first and second sets of electrodes overlie an insulative surface, wherein the first set of electrodes represent sense capacitor bottom electrodes and the second set of electrodes represent reference capacitor bottom electrodes. The second set of electrodes is configured in an interleaved arrangement with the first set of electrodes, wherein the geometry of individual electrodes of the first set of electrodes substantially matches the geometry of individual electrodes of the second set of electrodes.

Abstract: Disclosed is a capacitive pressure probe for high temperature applications, such as for use in a gas turbine engine. The capacitive probe or pressure sensor of the present invention includes, inter alia, a sensor housing that defines an interior sensing chamber having a pressure port and an interior reference chamber positioned adjacent to a sensing electrode. The reference chamber is separated from the sensing chamber by a deflectable diaphragm made from Haynes 230 alloy, wherein the deflection of the diaphragm in response to an applied pressure in the sensing chamber corresponds to a change in capacitance value detected by the sensing electrode.

Abstract: A capacitance-type pressure sensor for measuring a change in a physical volume of a medium to be measured, by measuring two capacitances wherein the capacitances vary differently from each other in accordance with a change in the physical volume of the medium to be measured, provided with a function for measuring independent values for each capacitance and determining that there is an disconnect failure when at least one of these capacitance values falls below a capacitance value that indicates the normal operating range of the capacitance-type pressure sensor, to thereby provide a pressure sensor with higher reliability through performing the disconnect detection robustly.

Abstract: The present invention is directed at methods and apparatuses for facilitating the establishment of a reference pressure within a reference chamber of a pressure transducer. The transducer has a housing and a cover, the housing defining a reference chamber and an aperture. A meltable sealing material is disposed on at least one of the cover and the housing. The apparatus includes a pressure chamber that is rotatable between a first position and a second position, a pressure source that is connected to the pressure chamber, a guide that is attachable to the transducer near the aperture, and a heater for selectively heating the pressure chamber to a temperature sufficiently high to melt the sealing material. The cover is positioned in an internal space of the guide. The guide is attached to the transducer near the aperture.

Abstract: A diaphragm pressure measuring cell arrangement has a housing body at least partly made of sapphire material and a planar sapphire diaphragm with a peripheral edge joined by a first edge seal to the housing body to form a reference vacuum chamber. An outer surface of the diaphragm is exposed to a medium to be measured. A ceramic supporting body is attached to the back side of the housing body by sealing glass and includes a surface area overhanging that surrounds the housing body to form a first sealing surface. A tubular sensor casing incorporates the measuring cell for mounted the ceramic support body, the casing including an inside second surrounding sealing surface corresponding to the first sealing surface. A metal ring seal is between the sealing surfaces and a pressing member presses sealing surfaces together.

Abstract: In a pressure sensor including a pressure detecting element in an intermediate portion or at a deep side of a through hole formed in a protrusion, a body portion (a base portion and the protrusion) is made of ceramic or an insulative resin material and molded into a predetermined shape, and the pressure sensor is constituted as a molded interconnect device in which a conductive pattern is formed on a surface thereof. Accordingly, a smaller pressure sensor can be obtained.

Abstract: Described herein is the sense element assembly for a capacitive pressure sensor and method for creating same that has increased sensitivity without additional size. The sense element assembly and method includes fabricating an off-centered elliptically shaped center electrode, at least one elliptical annular-like electrode around the center electrode, a ground electrode and a method for fusing the layers together to optimize sensitivity.

Abstract: A process device for coupling to an industrial process for use in monitoring or controlling the process includes a device housing configured to physically couple to the industrial process. A process variable sensor is configured to measure a process variable and measurement circuitry coupled to the process variable sensor provides an output related to the sensed process variable. A piezoelectric transducer provides an electrical output related to pressure pulsations in the industrial process. Electrical circuitry in the housing includes an input configured to receive the electrical output from the piezoelectric sensor.

Abstract: The present invention relates to a capacitance type pressure measurement apparatus by using a diaphragm, and more specifically to an apparatus for measuring pressure by using a diaphragm capable of measuring pressure of atmospheric pressure or less as well as pressure of atmospheric pressure or more without having a getter pump by fixedly mounting a pressure variable container on a sensor housing having a diaphragm mounted therein.

Abstract: The present invention provides a diaphragm attaching structure of an electrostatic capacity type pressure gauge which can achieve an improvement of a measuring precision by inhibiting a poor weld and a heat strain from being generated while restricting an increase of a cost with an easy manufacturing.

Abstract: A capacitance manometer comprises: a flexible diaphragm including a first electrode structure; an electrode structure including second and third spaced-apart electrode structures secured relative to the diaphragm so as to establish a capacitance between the first electrode structure and the second electrode structure and a capacitance between the first electrode structure and the third spaced-apart electrode structure, wherein the capacitances between the first electrode structure and each of the second and third electrode structures change with changes in differential pressure placed on opposite sides of the flexible diaphragm; and a thick film dielectric material disposed between the first electrode and each of the second and third spaced-apart electrode structures so as to increase the gain in capacitance of the manometer without decreasing the distance between the first electrode structure and each of the second and third electrode structures and without increasing the stroke of the flexible diaphragm, wh

Abstract: A physical quantity sensor includes two substrates and a movable electrode that is disposed between the two substrates and is bonded to the two substrates. In the physical quantity sensor, the movable electrode has an elastically deformable diaphragm and one of the two substrates is an electrode substrate having a detection electrode on a detection surface opposite to the diaphragm to detect capacitance between the diaphragm and the detection electrode. In the physical quantity sensor, in a range between a room temperature and a bonding temperature when the two substrates and the movable electrode are bonded, coefficients of thermal expansion of the two substrates are smaller than that of the movable electrode and in a temperature range where the physical quantity sensor is used, a coefficient of thermal expansion of the movable electrode is between a first and second substrates.

Abstract: A capacitive pressure sensor for an industrial process transmitters comprises a housing, a sensing diaphragm, an electrode and a fill fluid. The housing includes an interior cavity and a channel extending from an exterior of the housing to the cavity. The sensing diaphragm is disposed within the interior cavity opposite the electrode. The fill fluid occupies the interior cavity such that a pressure from the channel is conveyed to the sensing diaphragm to adjust a capacitance between the electrode and the sensing diaphragm. The fill fluid has a dielectric constant higher than about 3.5. In various embodiments, the pressure sensor has a diameter less than approximately 3.175 centimeters (˜1.25 inches), the electrode has a diameter less than approximately 1 cm (˜0.4 inches), the pressure sensor has a capacitance of approximately 5 to approximately 10 pico-farads, and the fill fluid is comprised of hydraulic fluid having a liquid additive.

Abstract: A protecting casing for a transducer has an outer casing, an inner casing, a circuit board and a connector. The inner casing is detachably mounted in the outer casing and has a mounting hole and a cap detachably mounted on the inner casing to cover the mounting hole in a watertight manner. The circuit board is detachably mounted in the inner casing and has a surface, a circuit formed on the surface and a plug with terminals extends out of the inner casing. The connector is detachably mounted to the outer casing and is electrically connected between the circuit board and an external functional accessory component. Within such an arrangement to facilitate maintenance, assembly of the transducer, and effectively avoid intrusion of water, foreign object and the like.

Abstract: A method and system for measuring the distribution of pressure forces over a selected area includes a sensor having an array of pressure sensing capacitance nodes formed by intersecting rows and columns, where measured capacitance of a node is compared to a fixed value of reference capacitance placed on each row that can be measured as if it was another node.

Abstract: Embodiments of the present disclosure are directed to a package having pressure sensor including a first substrate having a fixed electrode bonded to a second substrate having a movable electrode disposed at a predetermined interval from the fixed electrode, a support substrate with an opening for storing the second substrate, and a resin layer for fixing the pressure sensor and the support substrate. The pressure sensor may be packaged on the support substrate via the first substrate and a bonding member in a state where the second substrate is fit within the opening. The package for the pressure sensor may be sufficiently thin to be employed for the use on a minimum area.

Abstract: A pressure sensor for sensing a fluid pressure comprising: a first chamber including a first conductive membrane, wherein a fluid is sealed within the first chamber at a reference pressure such that the first conductive membrane deflects from pressure differences between the reference and the fluid pressure; a second chamber including a second conductive membrane sealed from the fluid pressure, wherein the second membrane deflects in response to a change in temperature which the pressure sensor is exposed thereto; and a circuit in electrical communication with the first and second conductive membrane, the circuit being configured to obtain a first and second signal from the first and second conductive membranes respectively, the first and second signals being indicative of the deflection of the first and second conductive membranes, wherein the circuit adjusts the first signal by the second signal to generate an output signal indicative of the fluid pressure.

Abstract: A high pressure transducer has an H shaped cross-section with a center arm of the H having a top and bottom surface with the top surface of the H accommodating four strain gauges. Two strain gauges are located at the center of the top portion of the center arm of the H and are positive strain gauges, while two strain gauges are located near the periphery of the center arm of the gauge. The bottom surface of the center arm of the gauge has an active area of a smaller diameter than the circular diameter of the center arm portion of the transducer. The smaller active area is surrounded by a thicker stepped area which surrounds an active area on the pressure side of the H shaped member.

Abstract: Methods and devices based on a microelectromechanical capacitive sensor are disclosed. In one embodiment, a method for fabricating an electromechanical capacitive device includes forming a housing of the electromechanical capacitive device using a non-conductive material and applying a conductive material on one or more areas on the housing to form one or more pairs of conductor plates.

Abstract: A diaphragm pressure measuring cell arrangement has a housing body at least partly made of sapphire material and a planar sapphire diaphragm with a peripheral edge joined by a first edge seal to the housing body to form a reference vacuum chamber. An outer surface of the diaphragm is exposed to a medium to be measured. A ceramic supporting body is attached to the back side of the housing body by sealing glass and includes a surface area overhanging that surrounds the housing body to form a first sealing surface. A tubular sensor casing incorporates the measuring cell for mounted the ceramic support body, the casing including an inside second surrounding sealing surface corresponding to the first sealing surface. A metal ring seal is between the sealing surfaces and a pressing member presses sealing surfaces together.

Abstract: A capacitance sensing circuit for a membrane pressure sensor is provided. The sensing circuit has a controller, two switches in signal communication with the controller, a charge amplifier and a charge injector. The charge amplifier is connected to the switches via a sensor capacitor Cs and a reference capacitor Cr. The sensor and reference capacitors are arranged in parallel with one another and a parasitic capacitance Cp to ground. The charge injector and amplifier are arranged in parallel connection between the capacitors and the controller. The controller is configured to determine a charge imbalance indicative of a pressure difference between membranes of the pressure sensor.

Abstract: A capacitative pressure sensor (30) for harsh environments such as vehicle tires. The sensor has two opposing electrodes (36 and 50). One electrode is a membrane (50) that extends between fluid at a reference pressure and fluid at the pressure to be sensed. In use, the flexible membrane (50) deflects due to pressure differentials between the reference pressure and the fluid pressure. Associated circuitry converts the deflection into a signal indicative of the pressure to be sensed. The membrane is a laminate at least partially formed from a transition metal nitride because transition metal nitrides are a metal ceramics with high yield strength and metallic bonding that makes it suitable for use in extreme environments. They can also readily include an oxidizing component such as aluminium so that the membrane form a passivating surface oxide layer to protect it from oxidative failure.

Abstract: Introduced is a method for the production of a diaphragm vacuum measuring cell, wherein on the one side of the diaphragm (2) at a spacing a first housing plate (1) is disposed sealing in the margin region with a joining means (3), and that on the other side of the diaphragm (2) at a spacing a second housing plate (4) is disposed sealing in the margin region with a joining means (3), and that the second housing plate (4) has an opening at which a connection means (5) is disposed sealing with joining means (3) for the connection of the measuring cell (8) with the medium to be measured, wherein the diaphragm (2) and the two housing plates (1, 4) are comprised of a metal oxide.

Abstract: A pressure sensor for sensing a fluid pressure comprising: a first chamber including a first conductive membrane, wherein a fluid is sealed within the first chamber at a reference pressure such that the first conductive membrane deflects from pressure differences between the reference and the fluid pressure; a second chamber including a second conductive membrane sealed from the fluid pressure, wherein the second membrane deflects in response to a change in temperature which the pressure sensor is exposed thereto; and a circuit in electrical communication with the first and second conductive membrane, the circuit being configured to obtain a first and second signal from the first and second conductive membranes respectively, the first and second signals being indicative of the deflection of the first and second conductive membranes, wherein the circuit adjusts the first signal by the second signal to generate an output signal indicative of the fluid pressure.

Abstract: A sensor including a carrier having two channels, a capacitive sensing element disposed on the carrier, and a cover is provided. The capacitive sensing element has a membrane, and a first chamber is formed between the membrane and the carrier. The cover is disposed on the carrier for covering the capacitive sensing element. A second chamber is formed between the membrane and the cover. The first chamber and the second chamber are located at two sides of the membrane, and the channels are respectively communicated with the first chamber and the second chamber.

Abstract: An electrostatic capacitance diaphragm type pressure sensor which includes a stationary electrode and a diagraph that are arranged to oppose each other, and in which the diaphragm is deformed by an external force and a pressure is obtained from an electrostatic capacitance between the stationary electrode and diaphragm which changes in accordance with deformation of the diaphragm, includes an outer case which surrounds the main body of the sensor, a heater arranged on the inner surface of the outer case, a temperature sensor to measure the temperature inside the outer case, and a temperature adjustment circuit which compares a temperature signal obtained by the temperature sensor with a predetermined value and outputs a drive signal to drive the heater on the basis of the comparison result.

Abstract: A method and apparatus for monitoring the pressure of a fluid within a rigid vessel are disclosed. A preferred method comprises monitoring the capacitance of a capacitor comprising a deformable resilient solid dielectric separating first and second conductive elements, the capacitor being exposed to said pressurised fluid such that the distance between the conductive elements and thus the capacitance of the capacitor changes with compression or relaxation of the dielectric in response to changes in fluid pressure.

Abstract: The invention provides for a capacitance sensing circuit for a pressure sensor. The pressure sensor includes a sensor membrane and a compensation membrane. The circuit includes a controller arranged in signal communication with a charge amplifier, a charge injector and two switches. The charge amplifier is connected to the switches via a sensor capacitor in parallel with a reference capacitor in parallel with a parasitic capacitance to ground. The charge injector and charge amplifier are arranged in parallel connection between the capacitors and the controller. The controller operates the circuit to determine a charge imbalance indicative of a pressure difference between the sensor and compensation membranes.

Abstract: A pressure sensor (e.g., a condenser microphone) includes a plate having a fixed electrode, a diaphragm having a moving electrode positioned opposite to the fixed electrode, and a support, wherein the diaphragm is subjected to displacement due to pressure variations applied thereto, and the support has a first interior wall forming a first cavity, in which the end portions of the plate are fixed, and a second interior wall, in which a step portion is formed in the thickness direction of the diaphragm in relation to the first interior wall and which forms a second cavity whose cross-sectional area is larger than the cross-sectional area of the first cavity in the plane direction of the diaphragm. The first and second cavities can be redesigned to communicate with each other via a passage, whereby it is possible to improve both of low-frequency characteristics and high-frequency characteristics in the pressure sensor.

Abstract: A temperature compensating pressure sensor comprises a substrate having sealed channels on which is deposited a CMOS layer; a conductive layer and a passivation layer deposited on the CMOS layer; a conductive active membrane spaced from the conductive layer to form an active chamber, the conductive active membrane having a corrugated cross section; a conductive reference membrane spaced from the conductive layer to form a reference chamber; and a cap which covers the membranes, said cap exposing the active membrane to an outside fluid pressure. The active membrane deflects due to differential stresses so that an active capacitance is developed between the active membrane and the conductive layer depending on the electrical permittivity e of the fluid, with the reference membrane providing a temperature compensating reference capacitance.

Abstract: A temperature compensating pressure sensor arrangement includes a capacitive pressure sensor having a substrate carrying CMOS layers. A conductive membrane is arranged on the substrate and defines a reference chamber such that capacitance changes resulting from displacement of the conductive membrane can be converted to pressure change values. A cap covers the conductive membrane and has openings to permit pressure changes to be detected by the conductive membrane. A capacitive temperature sensor is operatively arranged with respect to the capacitive pressure sensor and has a conductive membrane arranged on the substrate and defines a reference chamber such that capacitance changes resulting from displacement of the conductive membrane can be converted to temperature change values. The conductive member defining openings and cap covers and seals the conductive membrane from an external environment.

Abstract: This invention relates generally to a micromachined acoustic transducer that has a scalable array of sealed cavities and perforated members forming capacitive cells that convert the electrical signal to acoustic signal or vice versa. It also relates to the method and more particularly to a micromachined acoustic transducer which includes a plurality of micromachined membranes and perforated members forming capacitive cells and more particularly to an acoustic transducer in which the capacitive cells are connected in a scalable array whereby electrical signals are applied to the said array and converted to acoustic signals. The transducer can either be used as an acoustic actuator or a microphone.

Abstract: The present invention relates to a temperature-compensated pressure sensor assembly for fitting within the valve stem of a vehicle tire. The assembly includes a substrate assembly defining a plurality of holes. A pressure sensor is mounted to the substrate assembly. The pressure sensor includes a first deflectable membrane defining a first chamber and a first cap mounted to the membrane to form a second chamber. A temperature compensation sensor is mounted to the substrate assembly. The temperature compensation sensor includes a second deflectable membrane mounted to the substrate assembly to define a third chamber and a second cap mounted to the other membrane to form a fourth chamber.

Abstract: A transmitter for use in an industrial process control system, includes a process coupling configured to couple to a process fluid. A sensor housing has a cavity formed therein which is in fluidic communication with the process fluid. A diaphragm in the cavity isolates a portion of the cavity from the process fluid and moves in response to pressure applied by the process fluid. A first electrode in the isolated portion of the cavity is configured to form a first capacitance with the diaphragm and a second electrode in the isolated portion of the cavity configured to form a second capacitance with the diaphragm. Measurement circuitry coupled to the first and second capacitance measures a pressure of the process fluid based upon at least one of the first capacitance and second capacitance. The measurement circuitry further configured to measure vibrations in the process fluid based upon at least one of the first capacitance and second capacitance.

Abstract: A capacitive pressure sensing device comprising, a base member, a diaphragm member deflectable under an external pressure, a cantilever member disposed between the base member and the diaphragm member and supported on a support structure, wherein the base member and the cantilever member form a capacitor structure of the device and wherein deflection of the diaphragm member beyond a threshold value causes the cantilever member to deflect to cause a capacitive change in the capacitor structure.

Abstract: A sensor apparatus includes pressure and temperature sensors for measuring the pressure and temperature of high-pressure fluid media within a vessel. The pressure sensor is disposed in a sensor cavity that is coupled to a measurement port, and the leads of a temperature sensor that is disposed in the measurement port pass through the body of the sensor apparatus to a termination cavity that is physically isolated from the sensor cavity.

Abstract: A capacitive sensor (10) producing an output signal (VOUT) that is insensitive to stray capacitance (CS) caused by environmental and aging conditions. The sensor includes a sensing electrode (11) that exhibits a total capacitance that is responsive to both the measured process variable and to stray capacitance (CT=CA+CS). The sensor also includes a reference electrode (19) that exhibits a stray capacitance (CS?) essentially the same as that of the sensing electrode, but that is insensitive to the process variable. Balancing circuitry (29) provides an output signal that is responsive to the measured process variable and insensitive to the stray capacitance (VOUT=CT?CS?). The reference electrode is manufactured of the same materials and dimensions as the sensing electrode and may be mounted in the sensor body proximate the sensing electrode.

Abstract: A capacitance detecting apparatus which can detect the change in minute capacitance of a measuring object with high sensitivity comprises a signal generator, a differential amplifying circuit, and a detecting unit. The signal generator generates a probe signal w(t) to be applied to one end of the measuring object. The differential amplifying circuit amplifies differentially a response signal v1(t) developed at the other end of the measuring object in response to the application of the probe signal w(t) and the probe signal w(t). The detecting unit detects capacitance change of the measuring object based on the amplified signal v(t) from the differential amplifying circuit.

Abstract: A pressure-sensor package mainly includes a pressure sensor, a support substrate, and a resin layer. The pressure sensor includes a glass substrate having a fixed electrode, and a silicon substrate having a diaphragm that is disposed apart from the fixed electrode by a predetermined distance. The support substrate is a silicon/glass composite substrate on which the pressure sensor is mounted such that the support substrate and the diaphragm face each other. The resin layer fixes the pressure sensor and the support substrate together. The pressure sensor is mounted on a mounting area of the support substrate with a joint member therebetween. Accordingly, even if a gap between the support substrate and the diaphragm has a size of about several micrometers, the pressure-sensor package is capable of performing pressure detection with high sensitivity.

Abstract: A pressure sensor includes a gold-silicon eutectic crystal layer interposed between the contact layer and the silicon substrate. Because the contact layer and the silicon substrate are electrically connected to each other by using a gold-silicon eutectic reaction at the time of bonding the silicon substrate and the glass substrate, a contact resistance between the contact layer and the silicon substrate can be stabilized, and a Q value of the sensor can be stabilized. In addition, since the contact layer and the silicon substrate are bonded to each other by the gold-silicon eutectic reaction, the bonding strength is sufficient.

Abstract: A capacitive pressure sensor includes a substrate assembly. The substrate assembly includes a conductive layer and defines a plurality of channels terminating in closed ends. A conductive membrane is mounted to the substrate assembly so that a sealed reference chamber including the channels is defined by the conductive membrane and the substrate assembly. A cap is mounted relative to the substrate assembly and defines one or more apertures so that an antechamber is defined by the cap and the conductive membrane. Differential pressure between the reference chamber and antechamber can cause deflection of the conductive membrane which, in turn, varies the capacitance between the conductive membrane and conductive layer.

Abstract: A system and method are described for maintaining power dissipation substantially constant across the sensor interface board of a capacitance pressure transducer. A shorted diaphragm level detector detects a shorting of the diaphragm onto one or more reference electrodes. A power dissipating resistor is placed near the oscillator that drives the capacitance detecting circuit in the capacitance pressure transducer. The resistor is switched across a power supply when the shorting is detected, causing current to flow through the resistor so that power can be added in an amount sufficient to maintain power dissipation by the oscillator substantially constant when the diaphragm shorts.