Abstract: A pressure detecting apparatus has a pressure detecting device that converts a strain caused by a stress exerted thereto to an electrical signal, and outputs the converted electrical signal. The apparatus has a housing base including a housing recess that houses the pressure detecting device therein, and a connecting material interposed between the pressure detecting device and the housing recess. The connecting material connects the pressure detecting device and the housing recess with a tensile elongation percentage of about 400% or higher. The pressure detecting apparatus facilitates preventing thermal stress from adversely affecting the detection performance thereof, and produces excellent thermal response.

Abstract: A pressure sensor (30) for sensing a fluid pressure in harsh environments such as the air pressure in a tire, by using a first wafer substrate (32) with a front side and an opposing back side, a chamber (58) partially defined by a flexible membrane (50) formed on the front side and at least one hole (33) etched from the back side to the chamber (58); a second wafer (31) on the back side of the first wafer (32) to seal the at least one hole (33); wherein, the chamber (58) containing a fluid at a reference pressure, such that the flexible membrane (50) deflects due to pressure differentials between the reference pressure and the fluid pressure; and, associated circuitry (34) for converting the deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure; wherein, the second wafer (31) is wafer bonded to the first wafer substrate (32). Wafer bonding offers an effective non-adhesive solution.

Abstract: A high temperature pressure sensing system (transducer) including: a pressure sensing piezoresistive sensor formed by a silicon-on-insulator (SOI) process; a SOI amplifier circuit operatively coupled to the piezoresistive sensor; a SOI gain controller circuit including a plurality of resistances that when selectively coupled to the amplifier adjust a gain of the amplifier; a plurality of off-chip contacts corresponding to the resistances, respectively, for electrically activating the corresponding resistances and using a metallization layer for the SOI sensor and SOI ASIC suitable for high temperature interconnections (bonding); wherein the piezoresistive sensor, amplifier circuit and gain control circuit are suitable for use in environments having a temperature greater than 175 degrees C. and reaching between 250° C. and 300° C., and wherein the entire transducer has a high immunity to nuclear radiation.

Abstract: A pressure sensor includes a hollow cylindrical stem, a sensor chip, and a wiring board. The hollow cylindrical stem has a pressure-sensitive flexible diaphragm at a first axial end thereof and an opening at a second axial end thereof, the opening for transmitting pressure into the stem. The sensor chip is provided on the diaphragm for outputting an electrical signal in proportion to the deformation of the diaphragm. The wiring board electrically connects the sensor chip to an external circuit. The wiring board is located around the sensor chip on the first axial end of the stem.

Abstract: A silicon-based hydrogen pressure sensor module incorporates a low temperature cofired ceramic (LTCC) substrate that shields the cavity formed by the silicon membrane and cell body from hydrogen permeation. A bossed container filled with an oil material is mounted on the substrate and houses a sensor cell. The oil material may be impregnated with a hydrogen getter material.

Abstract: An apparatus for measuring the differential pressure of fluid in filter. The apparatus comprises a housing defining a pressure chamber. A differential pressure gauge divides the pressure chamber into first and second fluid chambers. The differential pressure gauge is arranged to measure a differential pressure between fluid in the first chamber and fluid in the second chamber. The differential pressure gauge has a variable output.

Abstract: A pressure sensor (30) for sensing fluid pressure in harsh environments such as the air pressure in a tire by providing a chamber (58) partially defined by a flexible membrane (50). The flexible membrane (50) is at least partially formed from conductive material, and the chamber (58) contains a fluid at a reference pressure. The flexible membrane (50) deflects from any pressure difference between the reference pressure and the fluid pressure. A conductive layer (36) within the chamber spaced from the flexible membrane (50) and, associated circuitry (34) incorporating the flexible membrane (50) and the conductive layer (36). The conductive layer (36) and the flexible membrane (50) form capacitor electrodes and the deflection of the flexible membrane (50) changes the capacitance which the associated circuitry (34) converts into an output signal indicative of the fluid pressure.

Abstract: A semiconductor pressure sensor is not influenced by a charged object in a fluid to be measured or an electric field from the outside, so satisfactory sensitivity and accuracy can be ensured. The semiconductor pressure sensor is provided with a diaphragm 4 that responds to the pressure of the fluid to be measured. The diaphragm includes a silicon substrate with piezoresistive elements, which together constitute a bridge circuit, being embedded therein, and a shield film for electromagnetic shielding formed on a surface of the silicon substrate at a side thereof at which the fluid to be measured is in contact with the silicon substrate. The shield film is electrically connected to the silicon substrate so as to have the same potential as that of the silicon substrate.

Abstract: A pressure sensor includes a housing with which terminals are insert-molded, a sensing element mounted on the housing and electrically connected to the terminals, an electrically insulating protective member for covering the terminals and the sensing element. The protective member has a triple-layer structure. The first protective member for covering the terminals has high elasticity to prevent bubbles from being produced in the protective member. The second protective member for covering the sensing element has low elasticity to reduce stress applied to the sensing element. The third protective member having higher acid resistance covers the second protective member so that the sensor has high acid resistance without sacrificing the sensor characteristics.

Abstract: A physical quantity sensor according to the invention includes a first member, a second member, a sensing member, a temperature detector, a correcting circuit, and a heat conduction path thermally connecting the sensing member and the temperature detector. The sensing member is interposed in contact between the first and the second members and configured to generate an electrical signal as a function of a physical quantity applied thereto through one of the first and the second members. The temperature detector detects a temperature of the sensing member. The correcting circuit corrects the electrical signal generated by the sensing member using the temperature detected by the temperature detector and outputs the corrected electrical signal. The heat conduction path is formed through the second member such that the second member has a thermal resistance along the path less than that of the first member in an application direction of the physical quantity.

Abstract: A pressure sensor includes a sensor chip having a pressure receiving surface formed on one surface of the sensor chip, a first case having one end portion at which the sensor chip is provided, a second case attached to the one end portion of the first case to cover the sensor chip. The second case is provided with a pressure introducing passage for introducing the pressure to the sensor chip, and a wiring board is provided at the one end portion of the first case to have a surface facing toward the pressure introducing passage. In the pressure sensor, the sensor chip is electrically connected with the surface of the wiring board through bumps by a flip-chip bonding such that the pressure receiving surface faces the surface of the wiring board, and an insulating member is provided to seal a connection portion of the bumps.

Abstract: In manufacturing a pressure sensor a recess that will form part of the sensor cavity is formed in a lower silicon substrate. An SOI-wafer having a monocrystalline silicon layer on top of a substrate is bonded to the lower silicon substrate closing the recess and forming the cavity. The supporting substrate of the SOI-wafer is then etched away, the portion of the monocrystalline layer located above the recess forming the sensor diaphragm. The oxide layer of the SOI-wafer here acts as an “ideal” etch stop in the case where the substrate wafer is removed by dry (plasma) or wet etching using e.g. KOH. This is due to high etch selectivity between silicon and oxide for some etch processes and it results in a diaphragm having a very accurately defined and uniform thickness. The cavity is evacuated by forming a opening to the cavity and then sealing the cavity by closing the opening using LPCVD. Sensor paths for sensing the deflection of the diaphragm are applied on the outer or inner surface of the diaphragm.

Abstract: A pressure sensor includes a semiconductor substrate and a pedestal member such as a glass pedestal. The semiconductor substrate has a diaphragm for detecting a pressure and a thick portion positioned around the diaphragm. The pedestal member has one surface bonded to the thick portion of the semiconductor substrate and the other surface opposite to the one surface. In the pressure sensor, the pedestal member has a through hole through which pressure is introduced to the diaphragm. The through hole penetrates through the pedestal member from an opening of the other surface to the one surface of the pedestal member, and the through hole has a hole diameter that becomes smaller from the one surface toward the other surface of the pedestal member. Accordingly, it can effectively restrict foreign materials such as dusts from being introduced into the through hole of the pressure sensor.

Abstract: A pressure sensor (30) for harsh environments such as vehicle tires, formed from a wafer substrate (32) with a recess, a flexible membrane (50) covering the recess to define a chamber (58) containing a fluid at a reference pressure. In use, the flexible membrane (50) deflects due to pressure differentials between the reference pressure and the fluid pressure. Associated circuitry (34) converts the deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure. An apertured guard (54) over the membrane formed using lithographically masked etching and deposition techniques protects the delicate MEMS structures. Forming the guard in situ by depositing material offers greater time efficiency and accuracy than producing a guard separately and securing it over the membrane. Semiconductor etching and deposition techniques allow highly intricate surface details. The apertures in the guard can be made smaller to exclude more particles from contacting the membrane.

Abstract: A pressure sensor includes a pressure detecting chamber sectionally formed by a diaphragm for receiving measured pressure and a semiconductor chip having a diaphragm as a pressure-sensitive portion is equipped in the pressure detecting chamber. Electrically insulating pressure transmitting liquid for transmitting the measured pressure received by the diaphragm to the semiconductor chip is sealingly filled in the pressure detecting chamber. Also, an electrical circuit for signal processing is equipped around the pressure-sensitive portion at the surface site of the semiconductor chip. The electrical circuit is coated by protection film. Electrical conducting film set to ground potential is formed as the uppermost layer of the semiconductor chip on the surface of the protection film.

Abstract: A sensor, in accordance with aspects of the present technique, is provided. The sensor comprises a membrane formed of gallium nitride. The membrane is disposed on a substrate, which is wet-etched to form a closed cavity. The membrane exhibits both a capacitive response and a piezo-response to an external stimulus. The sensor further includes a circuit for measuring at least one of the capacitive response or the piezo-response. In certain aspects, the sensor may be operable to measure external stimuli, such as, pressure, force and mechanical vibration.

Abstract: A pressure sensing device produces an output proportional to applied pressure irrespective of vibration/acceleration of the device, which device also provides an output proportional only to vibration/acceleration of the device irrespective of the pressure.

Abstract: A semiconductor pressure sensor is intended to achieve reduction in size and cost by decreasing the number of terminals and the number of pads. In the semiconductor pressure sensor, in a first mode in which correction data is input to a memory, a voltage input change-over switch and an input/output change-over switch are operated by an input signal from a switch change-over terminal in such a manner that a voltage input terminal and an input/output terminal are connected to a digital circuit, whereas in a second mode in which an electric signal corrected and amplified is output, the voltage input change-over switch is connected to a semiconductor sensor chip by means of an input signal from the switch change-over terminal, and the input/output terminal is connected to a correction and amplification circuit.

Abstract: A pressure sensor mainly includes a sensor chip, a circuit chip, and a substrate. The sensor chip is configured to generate an electrical signal representative of a pressure being sensed and includes a sensing area and a plurality of contact pads. The circuit chip includes a circuit configured to process the electrical signal and a plurality of contact pads. The substrate includes a resin sheet having an opening and a plurality of conductors within the resin sheet. The substrate is joined to both the sensor chip and circuit chip so that the sensing area of the sensor chip is to be exposed to the pressure being sensed through the opening of the resin sheet, the contact pads of the sensor chip and circuit chip are electrically connected to the conductors of the substrate, and all the contact pads and conductors are hermetically embedded in the resin sheet of the substrate.

Abstract: A gas pressure sensor 100 is disclosed as including a housing 10 to which a pressure is adapted to be introduced, a stem 20 communicating with the housing to admit the pressure thereto and having a diaphragm 22 deformable in response to the pressure, a sensor 24 associated with the diaphragm to produce an electric signal depending on a deformation of the diaphragm, and a substrate 30 that responds to the electric signal to generate an output signal that is outputted through a terminal 50. A chip capacitor 33 is connected between the terminal 50 and the substrate 30 and includes a first electrode 36, which admits a noise passing through the terminal 50 to be inputted to the substrate 30, and a second electrode 37 electrically connected to the housing 10, thereby enhancing improved resistance to noise.

Abstract: An absolute or relative pressure sensor formed of a monolithic plastic body (2) includes a carrier body (3) and a membrane (4). A printed circuit including wire strain gauges and comprised of a polymer paste is disposed on the membrane (4). The membrane (4) is shaped so as to be very soft affording high pressure sensitivity, while the circuit includes electric terminals (7) which may be embedded in the monolithic body (2) during manufacture to eliminate subsequent mounting of these terminals in simplifying production and reducing cost. By connecting the membrane (4) to an element embedded in the monolithic body (2), membrane elasticity may be adjusted to provide the pressure sensor with a desired sensitivity for a specific application. The embedded element is preferably formed as a core of the membrane which is completely surrounded by the plastic monolithic body (2) using a vacuum container (8).

Abstract: In a piezo resistance type semiconductor device, a detecting sensitivity and output linearity are improved without increasing a forming region of a diaphragm. In a piezo resistance type semiconductor device having: a diaphragm; a supporting frame which is connected to an external periphery of the diaphragm, supports the diaphragm, and is formed relatively thicker than the diaphragm; and piezo resistance type stress detectors (4a, 4b) each for detecting a stress caused when the detector is distorted by deformation of the diaphragm by application of an acceleration or a pressure in the direction perpendicular to the diaphragm, at least a part of the diaphragm is cut off in a position where it is come into contact with the piezo resistance type stress detector and a groove is formed.

Abstract: A device for measuring pressure, e.g., for measuring high pressure, including a pressure transducer that is arranged in a housing and includes sensor elements and a sensor diaphragm on a first side, and on a second side opposite the first side is provided with a cutout that extends from the second side to the sensor diaphragm. The pressure transducer is formed as a semiconductor pressure transducer and, with an edge area of the second side surrounding the cutout, is directly soldered onto a support part, provided with a first pressure-channel section, with the aid of a solder layer in such a manner that the first pressure-channel section and the cutout are interconnected.

Abstract: An inexpensive and simple pressure sensor having good static pressure characteristics is provided. In a pressure sensor including a base having a hole to which a pressure is applied and performing electrical and mechanical insulation, and a sensor having a diaphragm connected to the hole and a strain gauge for converting a strain occurring in the diaphragm to an electric signal, the sensor being mounted to the base, the base is formed with such a thickness that the strain at the time of applying a static pressure does not change.

Abstract: An ultra high temperature hermetically protected transducer includes a sensor chip having an active area upon which is deposited piezoresistive sensing elements. The elements are located on the top surface of the silicon wafer chip and have leads and terminals extending from the active area of the chip. The active area is surrounded with an extending rim or frame. The active area is coated with an oxide layer which passivates the piezoresistive sensing network. The chip is then attached to a glass pedestal, which is larger in size than the sensor chip. The glass pedestal has a through hole or aperture at each corner. The entire composite structure is then mounted onto a high temperature header with the metallized regions of the header being exposed to the holes in the glass pedestal; a high temperature lead is then bonded directly to the metallized contact area of the sensor chip at one end. The leads are of sufficient length to extend into the through holes in the glass pedestal.

Abstract: A pressure sensor (30) for sensing fluid pressure in harsh environments such as the air pressure in a tire by providing a chamber (58) partially defined by a flexible membrane (50). The flexible membrane (50) is at least partially formed from conductive material, and the chamber (58) contains a fluid at a reference pressure. The flexible membrane (50) deflects from any pressure difference between the reference pressure and the fluid pressure. A conductive layer (36) within the chamber spaced from the flexible membrane (50) and, associated circuitry (34) incorporating the flexible membrane (50) and the conductive layer (36). The conductive layer (36) and the flexible membrane (50) form capacitor electrodes and the deflection of the flexible membrane (50) changes the capacitance which the associated circuitry (34) converts into an output signal indicative of the fluid pressure.

Abstract: A technique for manufacturing an integrated pressure sensor includes a number of steps. Initially, a substrate with conductive electrical traces located on first and second sides of the substrate is provided. A plurality of compensation circuits are positioned in an array on the first side of the substrate in electrical contact with one or more of the conductive electrical traces on the first side of the substrate. A plurality of pressure sensors are positioned on the second side of the substrate in electrical contact with one or more of the conductive electrical traces on the second side of the substrate. Each one of the sensors is associated with one of the compensation circuits to form a plurality of pressure sensor-compensation circuit pairs. The substrate includes conductive vias to electrically connect each of the sensor-compensation circuit pairs. Each of the compensation circuits provides temperature compensation for an associated one of the sensors.

Abstract: A pressure sensor is provided with a semiconductor device that is capable of detecting a pressure, a terminal that is connected to the semiconductor device by a bonding wire, a housing having an accommodation space for the semiconductor device, the bonding wire, and the terminal, a diaphragm for sealing the accommodation space, and working fluid that is sealed in the accommodation space and transmits a pressure applied to the diaphragm to the semiconductor device. The working fluid is silicone-based oil, and the terminal and the housing are sealed by fluorine-based adhesive.

Abstract: A pressure sensor for sensing a pressure level of a medium. The pressure sensor includes a rigid substrate having a medium contacting side and a pressure sensitive resistor mounted on the medium contacting side. The resistor exhibits a change in resistance in response to pressure changes on the resistor above a predetermined threshold. Other embodiments of the invention are shown using a wheatstone bridge with pressure sensitive resistors and resistors that are insensitive to pressure changes.

Abstract: Pressure sensor methods and systems are disclosed. In general, two micromachined die and a diaphragm for a pressure sensor can be provided. The two micromachined die can be embedded in a glass adhesive on a surface of the diaphragm, such that the glass adhesive possesses a large size relative to the two micromachined die. The large size of the glass adhesive creates a large planar target for placement of the two micromachined die upon the diaphragm, thereby providing a size difference between the glass adhesive and the two micromachined die thereby creates an optimum strain transfer, while maintaining stability for the pressure sensor.

Abstract: The semiconductor pressure sensor includes a substrate (20). The sensor includes a diaphragm (26) implemented in the substrate (26) and being displaceable by a pressure medium acting on a side of the substrate (26). The sensor includes sensor circuitry (22, 23) implemented on the opposite side of the substrate in coincidence with the diaphragm (26) for detecting displacement of the diaphragm (26) for pressure.

Abstract: Various sensors use an electro-active device (11) electrically connected to a detector circuit. The electro-active device (11) comprises an electro-active structure in the form of a continuous electro-active member (12) curving in a helix around a minor axis (13) which is in itself curved for example in a helix around a major axis (14). On activation by relative displacement of the ends (16) of the device (11), the electro-active structure twists around the minor axis due to the fact that the minor axis (13) is curved. The continuous member (12) has a bender construction of a plurality of layers (21) and (22) including at least one layer of electro-active material so that concomitantly with the twisting the continuous member (12) bends generating an electrical signal detected by the detector circuit. The electro-active device (11) is advantageous as a sensing element in a sensor because it has a large displacement, high sensitivity and low compliance.

Abstract: A method for providing location information. In the method a demand of providing location information of a terminal of a second user is accepted from a terminal of a first user. An approval of the location information provided to a terminal of the second user is requested, which depends on a request of providing the location information. A reply for approving providing the location information is received from the second terminal. Map information of the first and the second user which includes each other's location information is then generated, the location information which was provided from the first and second user's terminal is synthesized, and map data chosen based on the location information from the data base, when providing the location information, is approved. The generated map information is displayed at least on the first user's terminal.

Abstract: In general, a dielectric polymer substrate provided and an antenna formed upon the dielectric polymer substrate. A piezoelectric polymer layer (e.g., a polyvinylidene fluoride (PVDF) piezoelectric film) can be formed above the dielectric polymer substrate. Additionally, an interdigital (IDT) layer can be configured upon the PVDF piezoelectric layer, thereby permitting the piezoelectric polymer layer and the IDT layer to detect pressure data and transmit the data to a receiver via the antenna.

Abstract: A pressure sensor for detecting a pressure such as a brake oil pressure in an automobile is composed of a cylindrical stem, a sensor chip and a circuit board for processing an electrical signal from the sensor chip. The cylindrical stem includes a thin diaphragm formed at an axial end and an opening formed at the other axial end. The sensor chip is mounted on the diaphragm, and the circuit board is mounted on a flat side surface formed on the outer periphery of the cylindrical stem so that the circuit board is positioned perpendicularly to the sensor chip, thereby reducing a size of the pressure sensor in the radial direction of the stem. The pressure to be detected is introduced into the cylindrical stem from its opening, and the pressure is detected by the sensor chip mounted on the diaphragm.

Abstract: A pressure sensor includes a semiconductor substrate having a diaphragm in which an electrical circuit including a gauge resistance is formed, an insulation film provided on a surface of the semiconductor substrate, an Al film provided on the insulation film and electrically connected to the electrical circuit through a conductor hole of the insulation film, an Au film provided on the Al film through a Ti film, a first protective film which covers the Al film and has an opening portion from which a portion of the Au film is exposed. In the pressure sensor, a second protective film made of polyimideamide or polyimide covers at least the surface of the Au film exposed from the first protective film, and a vicinity of the opening portion of the first protective film. Therefore, corrosion resistance of the Al film can be prevented while the pressure sensor has a reduced component number.

Abstract: A pressure sensor includes a substrate having a top metallized pad formed on the top surface and a bottom metallized pad formed on the bottom surface. These pads are divided into segments for connection with piezoresistors. A sensing piezoresistor is formed on the substrate's top surface in order to respond to a pressure of interest. A reference piezoresistor is formed on the substrate's bottom surface to respond to a reference pressure. A conductive strip is joined between the two piezoresistors for conducting heat and electricity therebetween. A temperature measuring resistor can also be positioned on the substrate. The substrate and sensors can be positioned in a housing having electrical contacts in communication with the sensors for providing voltages in response to changing pressure differentials and temperatures.

Abstract: A pressure sensor system for measuring the pressure of a corrosive media includes a silicon plate forming a diaphragm and a glass plate or ring bonded to said silicon plate with an opening over the diaphragm. The diaphragm has resistive areas of different orientations to provide first resistive areas which have increased resistance with diaphragm deflection, and other areas which have decreased or little change in resistance with diaphragm deflection. The resistive areas may be formed by doping the silicon plate. The resistive areas have broad doped connectors extending outward to areas beyond the seal between the glass plate or ring, to wire bond areas on the silicon plate. Accordingly, the wire bond pads are not exposed to the corrosive media.

Abstract: A pressure sensing system formed in a monolithic semiconductor substrate. The pressure sensing system comprises a pressure sensing device formed on the monolithic semiconductor substrate. Pressure sensing device is adapted to be disposed in an environment for developing an electrical pressure signal corresponding to the pressure in the environment. The system includes driver circuitry formed in the monolithic semiconductor substrate. The driver circuitry is responsive to input electrical signal for generating an output pressure signal. A conductive interconnect structure formed in the monolithic semiconductor substrate to electrically connects the pressure sensing device to the driver circuitry such that electrical pressure signals developed by the pressure sensing device are provided as input electrical signals to the driver circuitry.

Abstract: A multi-channel pressure sensor module (10) for integration in a hydraulic/electrical control unit of a vehicular braking system is shown. A body or manifold (16) mounts a plurality of strain gauge sense element assemblies (12) each having a port for connection to a fluid pressure source to be monitored. An electronic module assembly (14) has a contact printed circuit board (24) and a sense element printed circuit board (22) sandwiching a spacer/support member (20) and electrically coupled together by a flexible circuit board (26). The spacer/support member (20) is formed with pockets (20e, 20f) for receipt of discrete electronic components and to provide access to wire bond pads (22c) and sense element openings (22b). First and second sets of guide posts (20c, 20d) extend from the spacer/support member for alignment of the circuit boards as well as the electronic module assembly on the base.

Abstract: A pressure sensor module is provided with an isolation platform which isolates stress. The pressure sensor module includes a base structure and a cantilever member formed in the base structure by an isolation gap. A pressure sensing element is located on the cantilever member such that the cantilever member provides stress isolation to the pressure sensing element.

Abstract: A piezoresistive strain concentrator that converts mechanical movement into electrical output and a process for fabricating the concentrator are provided. The device includes a strain sensing structure composed of a piezoresistive strain sensitive element that spans a gap in a substrate. The strain sensing structure is supported on a strain concentrating structure also spanning the gap that has vertical walls extending to a cross-section at the base of the gap, both structures being etched from the substrate. The structure of the strain-concentrating support for the strain sensitive element is fabricated by deep reactive ion etch (DRIE). The strain sensing structure has an increased sensitivity, a low gage factor and an increased resistance to buckling and fracture compared to previous strain gage structures. Several of the strain sensing structures can be connected in a sequence in a bridge circuit.

Abstract: A semiconductor pressure sensor includes a semiconductor substrate having a diaphragm for receiving pressure and a bridge circuit for detecting a distortion of the diaphragm corresponding to the pressure. The bridge circuit includes a pair of first gauge resistors and a pair of second gauge resistors. The first gauge resistors are disposed on a center of the diaphragm, and the second gauge resistors are disposed on a periphery of the diaphragm. Each first gauge resistor has a first resistance, which is larger than a second resistance of each second gauge resistor. The TNO property of the sensor is improved, so that the sensor has high detection accuracy.

Abstract: Method and apparatus for measuring the pressure of a fluid medium, by immersing within the fluid medium an electrical resistor having a resistance varying with temperature; applying electrical current through the electrical resistor to heat it to a predetermined temperature above that of the fluid medium; and measuring the rate of change in resistance of the electrical resistor to produce a measurement of the rate of thermal heat dissipation, varying with the density of the fluid medium in which the electrical resistor is immersed, and thereby a measurement of the pressure of the fluid medium.

Abstract: In manufacturing a pressure sensor a recess that will form part of the sensor cavity is formed in a lower silicon substrate. An SOI-wafer having a monocrystalline silicon layer on top of a substrate is bonded to the lower silicon substrate closing the recess and forming the cavity. The supporting substrate of the SOI-wafer is then etched away, the portion of the monocrystalline layer located above the recess forming the sensor diaphragm. The oxide layer of the SOI-wafer here acts as an “ideal” etch stop in the case where the substrate wafer is removed by dry (plasma) or wet etching using e.g. KOH. This is due to high etch selectivity between silicon and oxide for some etch processes and it results in a diaphragm having a very accurately defined and uniform thickness. The cavity is evacuated by forming a opening to the cavity and then sealing the cavity by closing the opening using LPCVD. Sensor paths for sensing the deflection of the diaphragm are applied on the outer or inner surface of the diaphragm.

Abstract: A microelectronic pressure sensor comprises a resonator (23) made on the basis of a crystalline material and secured to the inside of a package (24) made use of a cap (27) and a baseplate (26) for assembling one to the other. The cap (27) and the baseplate (26) are made completely or almost completely out of the same material as the resonator (23), and the pressure (Pe) to be detected is applied all around the package.

Abstract: A pressure gauge is arranged to function on the outside of a measuring element. The measuring element has a central cavity and is constituted by at least to parts, which are tightly joined for creation of the cavity. The measuring element has sensor organs for determining the mechanical state of stress of the measuring element during pressure influence. The two parts of the measuring element are manufactured with planar techniques, preferably by silicon or quarts with the cavity running in the longitudinal direction. The central cavity has a considerably greater height than width. The sensor organs have form of piezo-resistive elements arranged near an outer surface of the measuring element.

Abstract: The invention is intended to provide a small and highly reliable pressure sensor, which has a smaller number of components and can be produced by using a mold for resin molding in common. A sensor unit (11) is molded with resin and includes a semiconductor chip (1) for converting the change in pressure of a medium introduced through an introduction hole for measurement into an electric signal. A lead member (12) has one end exposed in a connector (23) and is electrically connected to the semiconductor chip (1) in the sensor unit (11) beforehand. Pressure is applied to the semiconductor chip (1) through a pipe (22). An outer case (21) is integrally formed of synthetic resin by insert molding of the sensor unit (11), the lead member (12) and the pipe (22).

Abstract: A new and versatile ultra-miniature pressure sensor comprises a very thin diaphragm of approximately one micron or less, e.g., 0.2 microns. In some embodiments, the diaphragm has a radius of 20 microns and the pressure sensor can detect signals at or near 0.1 Atm with 1% accuracy. The diaphragm is formed by epitaxial growth of silicon or by bonding and etching. A plurality of high sensitivity piezoresistive strain gauges measure strain of the diaphragm. Less than 0.1 microns thick, the piezoresistive strain gauges are embedded in the diaphragm by ion implantation or formed thereon by epitaxial growth. The ability to form ultra-thin piezoresistive layers on very thin diaphragms enables the miniaturization of the pressure sensor as well as any device that employs it.

Abstract: The present invention is related to a semiconductor pressure sensor device employed for an application of a micro pressure and includes a thin part constituting a diaphragm, a thick part surrounding the thin part, a strain gage element formed on a surface of the diaphragm in a side of the one main surface, for detecting a pressure, a semiconductor sensor substrate having a first concave part formed by the thin part and the thick part, having an opening part in the other main surface, and whose bottom part corresponds to the thin part, and a support member comprising a second concave part and the support member is fixed on the thick part of the semiconductor sensor substrate in a side of the other main surface so that an opening part of the second concave part faces with the opening part of the first concave part and has a positional relationship to be included in the opening part of the first concave part in a plane view.