Abstract: An integrated circuit device is provided which comprises a substrate, a conductive line configured to experience a pressure, and a magnetic tunnel junction (“MTJ”) core formed between the substrate and the current line. The conductive line is configured to move in response to the pressure, and carries a current which generates a magnetic field. The MTJ core has a resistance value which varies based on the magnetic field. The resistance of the MTJ core therefore varies with respect to changes in the pressure. The MTJ core is configured to produce an electrical output signal which varies as a function of the pressure.

Abstract: This invention aims to realize reduction in size without impairing measurement accuracy or connection reliability in a semiconductor pressure sensor in which a glass substrate is adhered to a rear-surface side of a pressure-sensitive chip in which piezoresistive pressure-sensitive gauges have been formed on a front surface of a diaphragm formed of a silicon single crystal to form a space between a rear surface of the diaphragm and the glass substrate, for measuring a pressure applied to the front surface of the diaphragm with reference to a pressure of the first space as a standard pressure. In order to achieve this object, the semiconductor pressure sensor includes resinous projections formed on pressure-sensitive gauge electrodes disposed on a front surface of the pressure-sensitive chip or on wiring from the pressure-sensitive gauge electrodes and bumps formed so as to partially or entirely cover the resinous projections.

Abstract: A bioinformation detection device, comprising a three-layer structure having a base, an elastic body, and a cover body, wherein a closed space is formed by a load applied to the structure, a strain detection element is sealed in the closed space, and an air pressure variation caused by bioinformation is converted into an electric signal and taken out, whereby the detail bioinformation can be accurately provided for a long time.

Abstract: Microfluidic devices having wall structures comprised of sintered glass frit and further including a glass, glass-ceramic or ceramic membrane structure sealed by a sintered seal to said wall structures, such that a fluid passage or chamber is defined at least in part by the wall structures and said membrane structure. This allows for changes in pressure within the fluid passage or chamber to cause deflections of the membrane structure, providing for direct measurement of pressure within the device. The microfluidic device may have both floors and walls of sintered frit, or may have only walls of sintered frit, with planar floor-like substrate structures, thicker than the membrane structure defining the vertical boundaries of the internal passages. The device may include multiple fluid passages or chambers each defined at least in part by a membrane structure. Multiple membrane structures may be used in a single device, and one single membrane structure may be used for multiple passages or chamber.

Abstract: A manufacturing method of a pressure sensor that includes a pressure detector having a bottomed cylindrical member with a bottom including a thin-wall portion and a strain detecting mechanism provided on one side of the bottom for detecting a strain of the bottom and a pressure-introducing joint for introducing the fluid to be measured into the bottomed cylindrical member is provided. The method includes: first welding for butt-welding an end of the cylindrical portion of the bottomed cylindrical member and an end of the pressure-introducing joint; and second welding for welding the pressure-introducing joint in parallel to a first weld bead formed by the first welding.

Abstract: A weight part (12) is supported by a beam part (26) in a slim piece shape supported by a frame-shaped support part (10), and the beam part (26) is provided with a piezoresistance element (20) as a transducing element that transduces a mechanical variation to an electrical variation, so that a mechanical variation of the weight part (12) is transmitted to the piezoresistance element (20) via the beam part (26). Then, the beam part (26) is constructed by stacking the silicon nitride film (16) and a resin film (18) such as a polyimide film.

Abstract: A displacement transducer includes a load cell structure having a thick outer peripheral area, a thick inner central area and two symmetrical thin beams. The two beams are disposed along a common diameter of the structure and joins the outer peripheral area and the inner central area. At least one strain gauge is placed on a surface of one beam and at least one strain gauge is placed on a surface of the second beam. A top diaphragm cover member is secured to a top surface of the outer peripheral area and covers the two beams.

Abstract: A flow through pressure transducer for use in harsh environments like oil well cement slurry mixing process. A thin cylindrical sensor sleeve is protected from fluid wear and corrosion by a molded elastomeric sleeve provided on its internal diameter that prevents fluid from reaching the sensor sleeve. Pressure is transmitted to the sensor sleeve through the elastomeric sleeve. The sensor sleeve is mounted in such a way that the fluid pressure only exerts hoop stresses on the sensor sleeve. Two dual strain gauges are mounted on the outside of the sensor sleeve in spaced apart relationship for measuring hoop stress and an additional strain gauge is mounted 90 degrees to the stress direction for temperature compensation. The body or spool of the transducer surrounds and protects the sensor sleeve and prevents leakage in the event of sleeve failure. The spool is held in between transducer outer flanges by threaded fasteners.

Abstract: A pressure measurement device with protection from long-term loads and pressure shocks. The novel device includes a diaphragm adapted to deform in response to a pressure applied thereto, and a retractable support adapted to support the diaphragm during periods of non-operation. A strain gauge is attached to the diaphragm for measuring the deformation and the retractable support is designed to minimize stress on the strain gauge during periods of non-operation. The support is retracted during periods of operation to allow the diaphragm and strain gauge to function normally in response to the applied pressure. The diaphragm is disposed within a housing to form a first cavity, which is coupled to media to be measured, and a second cavity, which is set at a reference pressure. In an illustrative embodiment, the retractable support is a threaded plug inserted into the second cavity.

Abstract: A pressure transmitter comprises a metal wall separating a process pressure chamber from an electronics compartment. The metal wall has a stepped bore with a bore shelf facing the process pressure chamber. A metal header has a stepped outer rim with a header shelf that contacts the bore shelf. The metal header includes at least one electrical feedthrough with a glass-to-metal seal adjacent the stepped outer rim. A welded seal seals the stepped outer rim to the stepped bore.

Abstract: A method for making a pressure transducer comprising: forming a recess in a diaphragm, the diaphragm having a thinned region that deflects responsively to pressure being applied thereto; depositing a glass frit in the recess; embedding a plurality of strain gages in the glass frit; and, wire bonding the strain gages into a Wheatstone bridge configuration.

Abstract: A method for compensation for influences, which interfere with the measurement accuracy, in measurement devices of the vibration type, comprising a measurement tube through which a fluid medium can flow and which is caused to oscillate mechanically, acting as an oscillation body, by an excitation unit, whose oscillation behavior, which changes as a function of the flowrate and/or the viscosity and/or the density of the fluid medium, is detected by at least one oscillation sensor in order to determine the flowrate, wherein the material strain in the measurement tube is detected by means of at least one sensor, from which an indicator value for the influence causing the material strain is calculated in order to correct the measurement signal, by signal processing, from the indicator value obtained in this way.

Abstract: A pressure sensor is composed of a pressure housing having a pressure chamber inside and a pressure sensitive element arranged in the pressure chamber, and a joint housing having a fluid passage for leading fluid into the pressure housing, wherein the pressure housing and the joint housing are jointed by brazing with an insulating member interposed at a joint section therebetween. A stress relieving member is interposed at least either between the metal housing and the insulating member or between the joint housing and the insulating member, so that the insulating member can be relieved of a stress which is caused by the braze jointing to act on the insulating member.

Abstract: A pressure sensor assembly comprised of a single and dual layer diaphragm with integrated force sensing flexure, such as a cantilever beam. Strain gages are positioned on the force sensing beam. The pressure forces the diaphragm to deflect. The deflection is constrained by the beam, which is compelled to bend. The bending induces strains in strain gages located on the beam. The strain gages are connected in a Wheatstone bridge configuration. When a voltage is applied to the bridge, the strain gages provide an electrical output signal proportional to the pressure. Composite diaphragm—beam pressure sensors convert pressure more efficiently and improve sensor performance.

Abstract: A hermetically sealed displacement sensor has strain gauges placed on thin flexible triangular shaped beams of a load beam cell. The strain gauges are enclosed in a hermetically sealed cavity which cavity is sealed by means of a cover plate placed over the load beam cell. The thin beams are connected together by a center hub and basically form two constant moment beams. There is a top isolation diaphragm member which is convoluted and to which a force is applied which applied force is transmitted to the thin flexible beams. The beams deflect and the sensors produce an output proportional to strain. The sensors on each beam are two in number wherein one sensor is placed in a longitudinal direction with respect to the beam while the other sensor is in a transverse position. The sensors may be wired to form a full Wheatstone bridge or half bridges may be employed. The electrical output from the strain gauge bridge is proportional to the deflection of the center of the sensor.

Abstract: A fiber optic differential pressure sensor. In a described embodiment, a differential pressure sensor system for use in a subterranean well includes a fluid property sensing housing having a flow passage formed therethrough. A differential pressure sensor has an optical fiber extending in a wall having a first side and a second side, each of the first and second sides being exposed to pressure in the flow passage.

Abstract: A stress sensor in which the direction and magnitude of a stress being applied to a post (6) bonded to or integrated with the surface of an insulating board (3) can be grasped from variation in the resistance of a plurality of resistor elements (8) being stimulated by application of the stress while suppressing variation in the shape of each resistor (2). The resistor element (8) comprises a resistor (4) formed, by screen print, between a pair of electrodes for the resistor element, i.e. circuit pattern electrodes (1), arranged on the surface of the insulating board (3). The electrode is connected, through a conductor (9), with a board terminal part (5) arranged at one end of the insulating board (3). The electrode (1) and the conductor (9) or a print accuracy adjusting member (7) have a constant height from the surface of the insulating board (3).

Abstract: A method and media-isolated absolute pressure sensor apparatus includes a first sensor (101) to measure a pressure difference between an isolated media (P1) and a second media (Pa). A second sensor (103) measures an absolute (relative to vacuum) pressure of the second media (Pa). Each sensor (101, 103) has its own offset and slope response. An equalizer (217, 219) matches the slopes of the sensors (101, 103), wherein a summing circuit (225) can add the substantially same slope outputs to provide an output signal (227) indicative of an absolute pressure measurement of the isolated media (P1). Offset and temperature compensation of each sensor can also be provided.

Abstract: A pressure transducer and method for measuring pressure of a fluid flow in a tube include use of a sensing tube through which the pressurized flow passes. The sensing tube deforms outward in response to the pressurized flow within. Deformation measuring devices, such as strain gages, measure the outward deformation and allow computation of the pressure of the flowing fluid. A housing surrounds the sensing tube to relieve stresses on the sensing tube, to prevent damage to the sensing tube, and to contain any rupture of the sensing tube. The sensing tube may have a round, rectangular, or other shape cross-section. The pressure transducer allows continuous and non-invasive measurement of pressure inside a tube. In addition, a flow restriction such as an orifice may be provided in the sensing tube to enable a flow rate to be determined from the pressure drop across the flow restriction.

Abstract: A first end of each hollow stem includes a diaphragm and a strain gauge, and a second end of each stem includes an opening. A housing includes a plurality of stem receiving through holes, each of which receives the corresponding stem. An O-ring is arranged in each through hole such that the O-ring is placed adjacent an end surface of the second end of the stem, which is axially inwardly spaced from a surface of the side of the housing. When the stems and the housing are integrally installed over the device under test, each O-ring seals between the end surface of the second end of the corresponding stem and the device under test.

Abstract: It is an object to provide a method of adjusting a pressure sensor, in which adjustment of a diaphragm portion and adjustment of an amplification circuit connected to the diaphragm portion are simplified. A flexible circuit board having the amplification circuit mounted thereon is connected to a diaphragm member having the diaphragm portion formed with gauge resistances, and offset, span and temperature-compensating adjustment resistances, and adjustment of the adjustment resistances formed on the diaphragm member is performed in this state. The adjustment on the side of the diaphragm member including the amplification circuit accommodates adjustment deviation on the amplification circuit, and hence adjustment of the whole pressure sensor can be achieved by a single adjustment process. The adjustment process thus simplified can reduce manufacturing costs.

Abstract: An absolute-pressure type of pressure sensor is provided. The sensor has a pressure detecting device having a metal diaphragm. Strain gauges are disposed on one surface of the diaphragm, whose other surface is formed to receive fluid to be detected. The sensor comprises a lid, relay board, two seal rings, and input/output terminal. The lid provides a reference pressure space. The relay board is electrically connected to the gauge and composed of laminated ceramic members having both of through holes formed to pass through both sides thereof and a protrusion formed outwardly. The two seal rings are located to face the two sides of the board, respectively. The one seal ring air-tightly connects the relay board and the diaphragm. The other seal ring air-tightly connects the relay board and the lid. The terminal is electrically connected to the relay board and mounted on the protrusion of the relay board.

Abstract: A port fitting (102) is formed with a closed, pedestal end forming a diaphragm (102a) on which a strain gauge sensor is mounted. A support member (106) is received on the pedestal end and is formed with a flat end wall (106a) having an aperture (106d) aligned with the sensor. A circuit assembly (108) is bonded to the flat end wall and the sensor wire bonded to the electronic circuit. A cover member (114) placed on the support member, is provided with a cavity for a metal shield member (118) fitted inside the cover member before assembly. The shield member is formed with spring members (118b) extending outside the perimeter of the cover member. The cover member is formed with circular cavities (114d) extending in an axial direction to provide seating for contact spring members (117), making electronic contact to the sensor electronics and protruding beyond the body of the cover member. The cover member is also fitted with a circular elastomer gasket member (116), providing an environmental seal.

Abstract: A semiconductor sensor chip is interposed between a sensor case and a housing. A first pressure is introduced from the sensor case and applied to a rear surface of the sensor chip, while a second pressure is introduced from the housing and applied to a front surface of the sensor chip. The sensor chip detects a pressure difference between the first and the second pressures and converts it into an electrical signal. The sensor chip is hermetically mounted in a depressed portion formed in the sensor case by charging a sealing material from holes formed around the depressed portion. The charging holes are positioned between terminals electrically connecting the sensor chip to an outside circuit to avoid enlarging the pressure sensor size by forming the charging holes.

Abstract: The step of comparing the pushing pressure developing when the pusher of a test hand presses an IC placed on the socket with the allowable press force calculated from the combined spring constant for the socket and IC, and the step of controlling the operation of the test hand at a pressure equal to or lower than the allowable press force on the basis of the result of the comparison are provided.

Abstract: An acoustic system has an acoustic sensor and a processing circuit. The acoustic sensor includes a base, a microphone having a microphone diaphragm supported by the base, and a hot-wire anemometer having a set of hot-wire extending members supported by the base. The set of hot-wire extending members defines a plane which is substantially parallel to the microphone diaphragm. The processing circuit receives a sound and wind pressure signal from the microphone and a wind velocity signal from the hot-wire anemometer, and provides an output signal based on the sound and wind pressure signal from the microphone and the wind velocity signal from the hot-wire anemometer (e.g., accurate sound with wind noise removed). The configuration of the hot-wire extending members defining a plane which is substantially parallel to the microphone diaphragm can be easily implemented in a MEMS device making the configuration suitable for miniaturized applications.

Abstract: A first end of each hollow stem includes a diaphragm and a strain gauge, and a second end of each stem includes an opening. A housing includes a plurality of stem receiving through holes, each of which receives the corresponding stem. An O-ring is arranged in each through hole such that the O-ring is placed adjacent an end surface of the second end of the stem, which is axially inwardly spaced from a surface of the side of the housing. When the stems and the housing are integrally installed over the device under test, each O-ring seals between the end surface of the second end of the corresponding stem and the device under test.

Abstract: An absolute-pressure type of pressure sensor is provided. The sensor has a pressure detecting device having a metal diaphragm. Strain gauges are disposed on one surface of the diaphragm, whose other surface is formed to receive fluid to be detected. The sensor comprises a lid, relay board, two seal rings, and input/output terminal. The lid provides a reference pressure space. The relay board is electrically connected to the gauge and composed of laminated ceramic members having both of through holes formed to pass through both sides thereof and a protrusion formed outwardly. The two seal rings are located to face the two sides of the board, respectively. The one seal ring air-tightly connects the relay board and the diaphragm. The other seal ring air-tightly connects the relay board and the lid. The terminal is electrically connected to the relay board and mounted on the protrusion of the relay board.

Abstract: An integrated microsensor includes a bowed micromachined membrane coupled to a substrate to define a microcavity therebetween. An integrated strain sensor is coupled to the micromachined membrane to generate a signal responsive to (deformation of the membrane and hence responsive to the pressure of the fluid in the microcavity. A frame is coupled to the peripheral edge of the membrane to assist in enlarging the microcavity. The membrane is composed of a nitride of B, Al, Ga, In, Tl or combinations thereof, or more particularly of p-type GaN where the frame is comprised of n-type GaN. The membrane and frame are fabricated using a photoelectrochemical etching technique. The fabrication of the integrated strain sensor creates stresses across the membrane. The strain sensor comprises an integrated circuit strain-FET. The strain-FET comprises an AlGaN/GaN heterostructure having an AlGaN/GaN interface where deformation of the membrane is coupled as strain to the AlGaN/GaN piezoelectric interface.

Abstract: A pressure sensor device is described that has a diaphragm acted upon by a working medium, on a first side, and a sensor chip, which is disposed on a second side of the diaphragm that is remote from the working medium. There is formed in the sensor chip a measuring bridge having four sensor elements, which form two pairs disposed parallel, and the pairs are disposed at right angles to one another. The sensor elements are disposed such that they are closely spaced apart from one another in the edge region of the sensor chip that faces toward the central point of the diaphragm.

Abstract: The invention provides a simple, non-invasive means for measuring pressure of fluid in fluid-containing, resilient tubing by measuring the force to mechanically compress the tubing to a predetermined distance. In the apparatus of the invention, first and second opposed members are moved together to a predetermined distance to compress the fluid-containing, resilient tubing therebetween. Measuring means connected to at least one of the members is used to measure the force exerted by the fluid-containing, resilient tubing against the members when the members are at the predetermined distance from one another, wherein the measuring means has been pre-calibrated at the predetermined distance, to correspond to fluid pressure within the fluid-containing, resilient tubing. An important application of the invention is the provision of a convenient, non-intrusive, low-cost device for field measurement of pressure in drip irrigation systems, without installing special fittings or puncturing the tubing.

Abstract: An absolute micromachined silicon pressure sensor provides the resistive or piezoresistive strain gauges, conductive traces, wirebond pads and other electrical components on a micromachined silicon die in a location that is isolated from the sensed fluid. This protects the electronic components from the corrosive effects of the sensed fluid. A hermetic cover is provided on the backside of the silicon die and is directly bonded thereto to create a hermetically sealed volume of gas or vacuum.

Abstract: A diaphragm that distorts according to pressure applied thereon and a signal processor circuit are formed on a semiconductor substrate having an (110)-surface-orientation. Stain gauges converting the diaphragm distortion into an electric signal and forming a bridge circuit are formed on the diaphragm. The electric signal from the bridge circuit is processed by the signal processor circuit. A pair of transistors constituting an input circuit of an amplifier in the signal processor circuit are positioned on the substrate to equalize their source-drain current directions. Thermal stress influence on the sensor outputs is minimized since sensor components are formed on the substrate having the (110)-surface orientation, and thereby the pressure applied to the diaphragm is accurately detected.

Abstract: A sensor operable at temperatures in excess of 400° C. is described. The sensor of the present invention operates without fluid fill, is non-porous, non-contaminating, and has no exterior exposed metallic components. The sensor includes a non-porous, impermeable sensing diaphragm that may be positioned in direct contact with fluids in an ultra-pure environment. The non-porous surface may be comprised of a layer of single crystal sapphire that is glassed to a backing plate. The sensor of the present invention is suitable for use in a chemically inert pressure transducer module for sensing pressures and/or temperatures in process fluids and may be molded directly into the high temperature plastic housing of the pressure transducer module.

Abstract: A pressure sensor is formed by sandwiching a pressure-sensitive dielectric membrane between and in contact with a pair of electrodes. As pressure is applied, the dielectric constant of the pressure-sensitive membrane changes while the distance of separation between the pair of electrodes remains constant. This change in the dielectric constant is detected by a circuit as a change in the electrostatic capacitance between the electrodes to measure the applied pressure. Since the pressure-sensitive dielectric membrane is not required to undergo any elastic deformation for measuring the pressure, the pressure sensor can be made extremely thin.

Abstract: A pressure detecting apparatus has a single-crystal semiconductor sensor chip disposed on a metallic diaphragm through a low melting point glass. The sensor chip has a planar shape selected from a circular shape, a first polygonal shape having more than five sides and having interior angles all less than 180°, and a second polygonal shape having a ratio of a circumscribed circle diameter relative to an inscribed circle diameter being less than 1.2. Four strain gauge resistors are disposed on X, Y axes passing through a center point O of the sensor chip in parallel with <110> directions. Accordingly, thermal stress is reduced not to adversely affect a detection error and simultaneously high sensitivity is provided.

Abstract: A leadless sensor of the type employing a p+ rim which surrounds contact areas, each contact area defined by a metallized portion surrounded by a p+ semiconductor material, which p+ semiconductor materials or fingers are coupled to an active sensor array. The leadless sensor is bonded to a first glass cover member having two slotted apertures which communicate with the active regions of the sensor area on the underside and a top glass contact member which has two slotted regions which communicate with the piezoresistive sensors on the top side of the semiconductor wafer. The glass contact member has a series of corner through holes which are congruent with the contact terminals associated with the semiconductor sensor and which through holes are filled with a glass metal frit to enable contact to be made to the contact terminals of the semiconductor sensor.

Abstract: A semiconductor sensor chip mounted on a thin diaphragm of a cylindrical metallic stem via an insulation layer is hermetically contained in a housing of a pressure sensor. The sensor chip includes a strain gage for outputting an electrical signal according to distortion of the diaphragm caused by pressure to be measured. A shield layer is interposed between the insulation layer and the sensor chip, and the shield layer is grounded. Influence of outside noises on the sensor outputs is eliminated or suppressed by the grounded shield layer even if the outside noises are in a high frequency region.

Abstract: A strain gauge based sensor for use in relatively high pressure applications has a diaphram frame with an active diaphragm portion having a high t/D ratio, or t2/A ratio, and an annular groove provided in at least a portion of a periphery of the diaphram frame which alters the strain field on the surface of the active diaphram, causing the radial stresses to be primarily bending stresses and minimizing shear stresses, thus bringing the &egr;t/&egr;c ratio closer to one and increasing the linearity of the output of strain gauges affixed to the top of the diaphram.

Abstract: In a flowmeter for measuring fluid flow, fluid passes through a primary element (20) in which the pressure on respective sides of the restriction (2a) acts on respective sides of the diaphragm (11) mounted in a diaphragm housing (3). The diaphragm, in turn, acts on a measuring element (17) provided with strain gauges (27) connected to a measuring bridge (5). The signals from the measuring bridge (5) can be used to indicate the flow through the orifice plate, for example, on an indicating instrument (7), or otherwise to record changes in the flow or control the flow to a desired value by means of a control system.

Abstract: It is an object to provide a method of adjusting a pressure sensor, in which adjustment of a diaphragm portion and adjustment of an amplification circuit connected to the diaphragm portion are simplified. A flexible circuit board having the amplification circuit mounted thereon is connected to a diaphragm member having the diaphragm portion formed with gauge resistances, and offset, span and temperature-compensating adjustment resistances, and adjustment of the adjustment resistances formed on the diaphragm member is performed in this state. The adjustment on the side of the diaphragm member including the amplification circuit accommodates adjustment deviation on the amplification circuit, and hence adjustment of the whole pressure sensor can be achieved by a single adjustment process. The adjustment process thus simplified can reduce manufacturing costs.

Abstract: An electronic detector configuration enables the accurate determination of pressure differences in scenarios in which conventional detectors and detector systems introduce inherent thermal inequalities at the interface with their immediate environs. A preferred embodiment of the present invention accurately measures snow water equivalent (SWE) while eliminating the need for fluid-filled pillows that contain environmentally hazardous fluids. By matching the thermal conductivity of)surrounding soil to a detector configuration having an inherently low specific heat, it minimizes effects of differences in thermal conductivity at the snow/soil interface that cause SWE pressure sensor measurement errors. Further, it minimizes thermal effects by keeping soil moisture under the configuration approximately the same as that of surrounding soil.

Abstract: A port fitting (12, 42) is formed with a closed, pedestal end forming a diaphragm (12a, 42b) on which a strain gauge sensor (22) is mounted. A support member (16, 44) is received on the pedestal end and is formed with a flat end wall (16a, 44a) having an aperture (16c, 44c) aligned with the sensor. A portion of a flexible circuit assembly (24a, 58a) is bonded to the flat end wall. An electronics chamber is formed in a connector (18, 46) which is inverted and maintained at a selected height adjacent to the flat end wall of the support member to facilitate soldering of the flexible circuit to terminals (20, 48) in the connector and electronic components to the flexible circuit. The port fitting, when assembled to the support member, is also maintained at the selected height adjacent to the inverted connector to facilitate wire bonding the sensor to the bonded portion of the flexible circuit.

Abstract: A pressure sensor, particularly for use in extruders of plastic materials, having an outer enclosure containing a supporting element for a semiconductor chip which is provided with a strain-gauge on one of opposite faces of the chip, a covering element in order to close the enclosure, a mechanical transmission element accommodated in the covering element, directed toward the semiconductor chip and in contact with the chip, the semiconductor chip being accommodated so as to float in the supporting element.

Abstract: A strain gage system for determining state of charge in a battery having a pressure vessel includes a strain gage bridge system mounted on a first cylindrical portion of the pressure vessel. The bridge system has a plurality of active strain gages and no inactive or dummy gages. An electrical output of the strain gage bridge is correlated to a state of charge of the battery.

Abstract: The step of comparing the pushing pressure developing when the pusher of a test hand presses an IC placed on the socket with the allowable press force calculated from the combined spring constant for the socket and IC, and the step of controlling the operation of the test hand at a pressure equal to or lower than the allowable press force on the basis of the result of the comparison are provided.

Abstract: A diaphragm that distorts according to pressure applied thereon and a signal processor circuit are formed on a semiconductor substrate having an (110)-surface-orientation. Stain gauges converting the diaphragm distortion into an electric signal and forming a bridge circuit are formed on the diaphragm. The electric signal from the bridge circuit is processed by the signal processor circuit. A pair of transistors constituting an input circuit of an amplifier in the signal processor circuit are positioned on the substrate to equalize their source-drain current directions. Thermal stress influence on the sensor outputs is minimized since sensor components are formed on the substrate having the (110)-surface orientation, and thereby the pressure applied to the diaphragm is accurately detected.

Abstract: In order to compensate non-linearity in the zero drift of the bridge at very low temperatures, a strain gauge in at least one of the arms of the bridge is in series with a resistor, e.g., a connection lead, of resistance that is much less than that of the strain gauge, and a compensation circuit is connected in parallel with the resistor. The compensation circuit includes a resistive element, e.g., a platinum probe, whose resistance varies as a function of temperature in such a manner as to influence, in the very low temperature range, the resistance of the parallel circuit of which it forms a part, and to do so in a manner that is sensitive to temperature and that increases with decreasing temperature.

Abstract: A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Abstract: A good quality passive-state film is formed on a gas-contact face of a diaphragm of a pressure detector using a sensor chip to prevent corrosion on, or water content emission from, or catalytic action at a gas-contact face, thereby improving production quality in a semiconductor manufacturing process and providing high accuracy pressure detection. The passive-state film is formed on the gas-contact face of the diaphragm when the diaphragm is mounted on a diaphragm base. The diaphragm base is then fixedly secured to a sensor base in which a sensor chip is housed and a pressure transmitting medium is sealed in a gap between the sensor base and the diaphragm base.