Abstract: A gage pressure transducer comprising a first pressure sensing assembly exposed to a main pressure and a second pressure sensing assembly exposed to a reference pressure. The pressure sensing assemblies comprise half-bridge sensors and means for using an alignment glass plate with each sensor which reduces the amount of oil required for operation, which consequently reduces the back pressures caused by large volumes of oil. The pressure sensor assemblies are hermetically sealed using glass frits, therefore enabling the gage pressure transducer to robustly and accurately measure pressure in harsh environments.

Abstract: The present disclosure relates generally to pressure sensors, and more particularly, to methods and apparatus for compensating pressure sensors for stress, temperature and/or other induced offsets and/or errors. In one illustrative embodiment, a pressure sensor may include a pressure sensing die mounted to a substrate of a pressure sensor package. The pressure sensor die may include on-board compensation. In some instances, the on-board compensation may include an on-board heating element and an on-board zener diode trim network, both situated on or in the pressure sensing die. The zener diode trim network may include one or more zener diodes and one or more resistive elements, where the zener diodes can be selectively activated to “trim” the resistive network to compensate for one or more offsets and/or errors of the pressure sensor.

Abstract: There are provided embodiments of a sensing device that comprise a sensing element, a substrate, and a bonding element, each being selected for environments that utilize caustic working fluids such as automotive fuel. Material for use as the bonding element can form molecular bonds with ceramics and glass. In one embodiment, the sensing device comprises a receptacle or cavity, in which are located the sensing element and the bonding element. This configuration facilitates the formation of bonds between the bonding element and each of the sensing element and a peripheral wall of the cavity. Such bonds are configured in a tensile bonding area and a shear bonding area, the combination of which is useful to secure the sensing element in the cavity. The sensing device can further comprise a seal such as an o-ring disposed in annular relation to the substrate to seal the sensing device to a peripheral device such as a fluid fitting, which may be found in a fuel system of an automobile.

Abstract: An implantable intraocular pressure sensor system has a sealed geometric shape with an internal pressure at a first value. A strain gauge wire is embedded in a surface of the sealed geometric shape. When the surface is deflected by intraocular pressure, a measured resistance of the strain gauge wire indicates the intraocular pressure. The system also has a processor coupled to a power source and memory. The processor is configured to read the measured resistance and write values corresponding to intraocular pressure to the memory.

Abstract: A MEMS differential pressure sensing element is provided by two separate silicon dies attached to opposite sides of a silicon or glass spacer, the sides of which are recessed and the recesses formed therein at least partially evacuated. The dies are attached to the spacer using silicon-to-silicon bonding provided in part by silicon oxide layers if a silicon spacer is used. The dies can be also attached to the spacer using anodic bonding if a glass spacer is used. Conductive vias extend through the layers and provide electrical connections between Wheatstone bridge circuits formed from piezoresistors in the silicon dies.

Abstract: A MEMS device, including: a substrate having a first principal plane and a second principal plane opposite to the first principal plane; a through hole formed in the substrate; and a vibrating film formed over the first principal plane so as to cover the through hole. The first principal plane and the second principal plane are both a (110) crystal face; and the through hole has a substantially rhombic shape on the second principal plane.

Abstract: A pressure transducer is provided that has a transducer body with a rim, a diaphragm that deflects in response to pressure and a sensor bonded to the diaphragm at the rim and at a center of the diaphragm. The sensor detects deflection of the metal diaphragm. The sensor and diaphragm are made of different materials. A thermal expansion difference between the sensor and the diaphragm is accommodated by flexures in the sensor that accept relative motion in a radial direction of the metal diaphragm with little effect on a sensitivity of the silicon structure to motion in an axial direction of the diaphragm.

Abstract: A diaphragm structure for a MEMS device includes a through-hole formed so as to penetrate from an upper surface to a bottom surface of a substrate; and a vibrating electrode film formed on the upper surface of the substrate so as to cover the through-hole. An opening shape of the through-hole in the upper surface of the substrate is substantially hexagonal.

Abstract: A tunable pressure transducer assembly that comprises a sensing element disposed within a housing, wherein the sensing element is adapted to output a signal substantially indicative of an applied pressure, and a filter assembly also disposed within the housing. The filter assembly comprises a cap and a tube, wherein the cap is spaced from the sensing element within the housing such that it encloses a set volume around the sensing element, and wherein the tube controls access of the applied pressure to the set volume. The filter assembly is operative to substantially reduce high frequency pressure ripples and allow static and quasi-static pressures to pass through to the sensing element, and may be manipulated to tune the pressure transducer assembly to achieve a desired dampening frequency. The filter assembly therefore enables one pressure transducer assembly outline to accurately measure pressure in various systems.

Abstract: Embodiments of an ultra miniature pressure probe are disclosed. The pressure probe can include a probe body, a plurality of transducer ports, and a plurality of transducers. The probe body can be a longitudinal tubular body having a front conical end. The transducer ports can be disposed about the front end of the body. The transducers can be leadless SOI transducers, each having an active deflection area associated with a semiconductor substrate. Each transducer can be in communication with a header for supporting the transducer. The header can have a thickness substantially less than the probe diameter and can comprise a flange about an edge of the header. Each of the plurality of transducer ports can define an aperture and a counter-bore, wherein each transducer is positionable in an associated transducer port with the flange of the header of the transducer being welded to the counter-bore of the transducer port.

Abstract: A pressure sensing device package including a circuit substrate, a pressure sensing device, a molding compound, and a flexible protection layer is provided. The circuit substrate has an opening. The pressure sensing device is flip chip bonded to the circuit substrate and has a sensing region facing toward the opening. The molding compound encapsulates the pressure sensing device but exposes the sensing region. The flexible protection layer is disposed on the sensing region and exposed by the opening of the circuit substrate.

Abstract: A pressure sensor, comprising: a monocrystalline membrane body, which includes a measuring membrane and an edge region surrounding the measuring membrane. The edge region has a greater material thickness than the measuring membrane and the edge region has a first mounting surface, whose surface normal is given by a first principal crystal axis. A monocrystalline substrate, which, with respect to crystal structure, comprises the same semiconductor material as the membrane body, the substrate has a second mounting surface, whose surface normal extends parallel to the first principal crystal axis. The membrane body is tightly connected to the substrate by joining the first mounting surface to the second mounting surface. The orientations of other principal crystal axes of the membrane body and the substrate are, in each case, oriented parallel relative to one another.

Abstract: There is provided a fluid transducer. The transducer housing includes a nose section, a middle section, and a rear section, with the nose section defining a through bore. A sensor is disposed in the nose section and is in fluid communication with the through bore. An electronic module is disposed in the middle section and is in electrical communication with the sensor. A cap is coupled to the real section of the transducer housing, with the cap configured to seal the rear section of the transducer housing. A conductor-insulator assembly is coupled to an outer surface of the transducer housing and the conductor of the conductor-insulator assembly is coupled to the electronic module. In one embodiment the conductor-insulator assembly is annular in shape, with an inside diameter corresponding to the outer surface of the transducer housing.

Abstract: A pressure guiding bump is configured on the center of a pressure gauge to obtain a single “conductivity-pressure” curve feature which is independent from any position wherever a pressure is applied on the guiding bump. When a pressure is applied, the guiding bump guides the pressure against a fixed deformable area to be deformed, whatever the pressure is, the deformed area is nearly a same area. The pressure gauge is extraordinarily adequate to be designed in a weighing machine with parallel connection in between them.

Abstract: An electrical contact device comprising a first contact assemblage having multiple contact pads disposed in a row which are allocated to different connection types, and having a second contact assemblage having multiple contact pads disposed in a row in accordance with a predetermined sequence, which are allocated to different connection types and having bonding wire connections that electrically connect at least some of the contact pads of the first contact assemblage to contact pads of the second contact assemblage.

Abstract: A sensor and method for fabricating a sensor is disclosed that in one embodiment bonds an etched semiconductor substrate wafer to an etched device wafer comprising a silicon on insulator wafer to create a suspended structure, the flexure of which is determined by an embedded sensing element to measure absolute pressure. Interconnect channels embedded in the sensor facilitate streamlined packaging of the device while accommodating interconnectivity with other devices.

Abstract: A novel flexible transducer structure is suitable for attaching to curved surface such as the leading edge of an aircraft wing. The structure comprises a thin flexible sheet of an insulating material with a leadless transducer secured to the sheet. The sheet is then placed over the curved surface and assumes the curvature of the surface. The transducer secured to the sheet provides an output of pressure according the pressure exerted on the sheet. The sheet basically is fabricated from a thin material such as Kapton and is flexible so as to assume the curvature of the surface with the transducer being exposed to pressure applied to the curved surface. The sensor in conjunction with the flexible sheet allows pressure to be measured without disturbing the air flow patterns of the measuring surfaces and because of its construction, is moisture resistant over a large variety of atmospheric conditions.

Abstract: A general pressure sensor for an automobile comprising a sensor shell, a silicon piezoresistive sensitive core, a sensor core seat, a signal conditioning circuit, and an automobile electric device interface is disclosed. The silicon piezoresistive sensitive core, the sensor core seat and the signal conditioning circuit are disposed in the inner cavity of the sensor housing. The sensor housing is installed to the automobile electric device interface, and the silicon piezoresistive sensitive core comprises a silicon piezoresistive sensitive element and a glass ring sheet. The silicon piezoresistive sensitive element is welded and fixed to a surface of the glass ring sheet. An insulation oxidation layer is formed on one surface of the glass ring sheet and the silicon piezoresistive sensitive element. The other surface of the glass ring sheet is hermetically fixed to the ring-shape recession surface provided on the sensor core seat.

Abstract: There is disclosed an internally switched multiple range transducer. The transducer employs a plurality of individual pressure sensors or Wheatstone bridges fabricated from semiconductor materials and utilizing piezoresistors. Each sensor is designed to accommodate accurately a given pressure range, therefore, each sensor is selected to provide an output when an applied pressure is within its accommodated range. As soon as the pressure exceeds the range, then another sensor is employed to produce an output. Each of the sensors, or each separate transducer, is coupled to a switch or other device to enable the selection of one of the plurality of sensors to operate within its given pressure range when the applied pressure is in that range. In this manner one obtains pressure measurements with a high degree of accuracy across a relatively large pressure range.

Abstract: A system for measuring a multiplicity of pressures as those experienced by a model in a wind tunnel is depicted. The system includes individual sensor devices which are connected to an Acquisition and Compensation electronics module. The individual sensor or transducer devices are semiconductor piezoresistive devices and are connected to the Acquisition and Compensation electronics module by means of a cable in a first embodiment. In an alternate embodiment the system uses connectors which connect each of the individual sensor devices to the Acquisition and Compensation electronics module via a mating connector located therein. The connectors may also include a memory which stores compensation coefficients associated with each of the various sensor devices. In this manner as described, the transducers which are small devices are connected via electrical lines or cables to the central Acquisition and Compensation electronics modules.

Abstract: An apparatus structure and measurement method are provided to retain high precision and high reliability of a semiconductor mechanical quantity measuring apparatus which senses a mechanical quantity and transmits measured information wirelessly. As to a silicon substrate of the semiconductor mechanical quantity measuring apparatus, for example, a ratio of a substrate thickness to a substrate length along a measurement direction is set small, and a ratio of a substrate thickness to a substrate length along a direction perpendicular to the measurement direction is set small. The apparatus upper surface is covered with a protective member. It is possible to measure a strain along a particular direction and realize mechanical quantity measurement with less error and high precision. An impact resistance and environment resistance of the apparatus itself can be improved.

Abstract: A sensor system, e.g., a pressure sensor system, includes a substrate having at least one trench on a first side. The trench is provided for forming a first diaphragm region on a second side opposite from the first side. In addition, a second diaphragm region and a cavern are integrated into the material of the first diaphragm region.

Abstract: A device (20) comprising a pressure measurement surface (28) functionally attached to a proof body (22) and a rigid component (30), functionally attached to the proof body (22), the measurement surface (28) forming a surface of the rigid component (30). In addition, the device comprises a support (38), functionally separated from the proof body (22), of generally annular shape, housing the rigid component (30) and a flexible mass (40) radially inserted between the support (38) and the rigid component (30) such that the contour of the measurement surface (28) is bounded by the flexible mass (40), this flexible mass (40) adhering to the support (38) and to the rigid component (30).

Abstract: A pressure sensor including a pressure-sensor element having a monolithic body of semiconductor material, and a first main face and a second main face acting on which is a stress resulting from a pressure, the value of which is to be determined; and a package enclosing the pressure-sensor element. The package has an inner chamber containing liquid material, and the pressure-sensor element is arranged within the inner chamber in such a manner that the first and second main faces are both in contact with the liquid material. In particular, the liquid material is a silicone gel.

Abstract: A pressure sensor for sensing a pressure of a fluid includes a monolithic metal including substrate having a substantially planar top side, wherein the metallic comprising substrate includes s a relatively thick boss near a center of the substrate and a thinned sensing portion that is elastically deformable and pressure-sensitive positioned radially outward from the boss. At least one dielectric layer is on the top side of the substrate. A plurality of piezoresistors are on the dielectric layer, wherein the piezoresistors are positioned over the thinned diaphragm portion. At least one overglaze layer is over the conductor layer that provides apertures for electrically contacting the plurality of piezoresistors. A sensing system includes a housing including at least a first port for coupling to a fluid for measurement of a pressure of the fluid and at least one sensor in the housing including a pressure sensor according to an embodiment of the invention.

Abstract: There is provided a semiconductor pressure sensor which improves the sensor sensitivity and is excellent in the withstand pressure characteristic and the temperature characteristic. In the semiconductor pressure sensor in which a diaphragm is formed by a cavity provided on one of top and bottom surfaces of a silicon substrate and a plurality of piezoresistors is disposed in the diaphragm edge, a recess which has a larger area than the planar shape of the diaphragm and whose entire edge is located outward from the diaphragm edge in plan view is provided in a protective film which covers the entire surface of the silicon substrate on the diaphragm side. The protective film located on the diaphragm is preferably formed of SiO2.

Abstract: A relative pressure sensor for registering pressure of a medium relative to surrounding atmospheric pressure includes: a pressure measuring cell having a measuring membrane and a platform, wherein pressure of the medium can act on a first side of the measuring membrane facing away from the platform, and wherein the platform has a reference air opening, through which surrounding atmospheric pressure can act on a second side of the measuring membrane facing the platform. A support body, through which a reference air duct extends between a first surface section and a second surface section of the support body is provided, wherein the pressure measuring cell is affixed to the support body with a pressure resistant, bonded adhesive.

Abstract: A very robust sensor element for an absolute-pressure measurement is described, which is suitable for high temperatures and able to be miniaturized to a large extent. The micromechanical pressure-sensor element includes a sensor diaphragm having a rear-side pressure connection and at least one dielectrically insulated piezo resistor for signal acquisition. Furthermore, the pressure-sensor element has a front-side reference volume, which is sealed by a cap structure spanning the sensor diaphragm. The cap structure is realized as thin-film structure.

Abstract: A pressure transducer comprising a corrosion resistant metal diaphragm, having an active region, and capable of deflecting when a force is applied to the diaphragm; and a piezoresistive silicon-on-insulator sensor array disposed on a single substrate, the substrate secured to the diaphragm, the sensor array having a first outer sensor near an edge of the diaphragm at a first location and on the active region, a second outer sensor near an edge of the diaphragm at a second location and on the active region, and at least one center sensor substantially overlying a center of the diaphragm, the sensors connected in a bridge array to provide an output voltage proportional to the force applied to the diaphragm. The sensors are dielectrically isolated from the substrate.

Abstract: A method for fabricating a sensor is disclosed that in one embodiment bonds a first device wafer to an etched second device wafer to create a suspended structure, the flexure of which is determined by an embedded sensing element that is in electrical communication with an outer surface of the sensor through an interconnect embedded in a device layer of the first device wafer. In one embodiment the suspended structure is enclosed by a cap and the sensor is configured to measure absolute pressure.

Abstract: Pressure sensors having a topside boss and a cavity formed using deep reactive-ion etching (DRIE) or plasma etching. Since the boss is formed on the topside, the boss is aligned to other features on the topside of the pressure sensor, such as a Wheatstone bridge or other circuit elements. Also, since the boss is formed as part of the diaphragm, the boss has a reduced mass and is less susceptible to the effects of gravity and acceleration. These pressure sensors may also have a cavity formed using a DRIE or plasma etch. Use of these etches result in a cavity having edges that are substantially orthogonal to the diaphragm, such that pressure sensor die area is reduced. The use of these etches also permits the use of p-doped wafers, which are compatible with conventional CMOS technologies.

Abstract: There is disclosed a flat planar pressure transducer which comprises a planar insulative substrate of a rectangular configuration. Disposed on the substrate is an array of conductive areas which extend from a contact terminal area of said substrate to an end of the substrate. There is a leadless sensor module positioned at said contact terminal area, with the contacts of said leadless sensor contacting contact terminals of said contact terminal area. The leadless sensor is enclosed by an enclosure which is coupled to the substrate and surrounds the sensor. The enclosure has a screen positioned on the top surface to prevent particles from entering or damaging the leadless sensor. The above-noted structure forms a very flat, compact pressure transducer which can be utilized in lieu of flex circuit type devices and provides greater mechanical stability as well as a more accurate output.

Abstract: A diaphragm made of a polysilicon film is provided above a first main surface of a silicon substrate. Four gauge resistors are provided on the top face of the diaphragm. A through hole for exposing the bottom face of the diaphragm is formed in the silicon substrate. An anchor portion for mounting the diaphragm on the silicon substrate is provided between the diaphragm and the silicon substrate in a manner surrounding circumferentially an opening end of the through hole located at the side facing the first main surface. Accordingly, a semiconductor pressure sensor having a diaphragm of reduced and less varied thickness can be obtained.

Abstract: A single pressure sensing capsule has a reference pressure ported to the rear side of a silicon sensing die. The front side of the silicon sensing die receives a main pressure at another port. The silicon sensing die contains a full Wheatstone bridge on one of the surfaces and within the active area designated as the diaphragm area. Thus, the difference of the main and reference pressure results in the sensor providing an output equivalent to the differential pressure, namely the main pressure minus the reference pressure which is the stress induced in a sensing diaphragm. In any event, the reference pressure or main pressure may be derived from a pump pressure which is being monitored. The pump pressure output is subjected to a pump ripple or a sinusoidally varying pressure. In order to compensate for pump ripple, one employs a coiled tube. The tube length is selected to suppress the pump ripple as applied to the sensor die.

Abstract: A micromechanical sensor element (1) is provided, which has a sealed diaphragm (2) affixed in a frame (3), exhibits high sensitivity at high overload resistance and has a small size, and which allows a piezoresistive measured-value acquisition. To this end, at least one carrier element (4), which is connected to the frame (3) via at least one connection link (5), is formed in the region of the diaphragm (2). Furthermore, piezoresistors (6) for detecting a deformation are situated in the region of the connection link (5).

Abstract: A sensor system, in particular a pressure sensor system, having a substrate having a main extension plane, the substrate having at least one trench on a first side, and the trench being provided to produce a diaphragm area on a second side of the substrate diametrically opposite to the first side perpendicularly to the main extension plane, and a decoupling element further being integrated in the material of the diaphragm area.

Abstract: A micro-deformable piezoresistive material is provided, including a hard plastic body, a micro-deformable rough texture surface, and a plurality of conductive particles. The micro-deformable rough texture surface is formed on a side of the hard plastic body, wherein the maximum deformation of the rough texture surface is far less than the thickness of the hard plastic body. Additionally, the conductive particles are evenly dispersed in the plastic body.

Abstract: A pressure sensor includes a housing, a pressure input orifice opened on a pipe sleeve formed on the housing, a diaphragm that seals the pressure input orifice and has one face as a pressure receiving face, a force transmitting unit connected to a central area of the other face of the diaphragm in the housing, and a pressure sensitive element whose detection direction of a force is a detection axis. A displacement direction and the detection axis of the force transmitting unit are roughly orthogonal to the pressure receiving face. One end and the other end of the pressure sensitive element are respectively fixed to the housing and the force transmitting unit with an adhesive therebetween, and the adhesive is an inorganic adhesive.

Abstract: There is disclosed flat planar pressure transducer which comprises a planar insulative substrate of a rectangular configuration. Disposed on the substrate is an array of conductive areas which extend from a contact terminal area of said substrate to an end of the substrate. There is a leadless sensor module positioned at said contact terminal area, with the contacts of said leadless sensor contacting contact terminals of said contact terminal area. The leadless sensor is enclosed by an enclosure which is coupled to the substrate and surrounds the sensor. The enclosure has a screen positioned on the top surface to prevent particles from entering or damaging the leadless sensor. The above-noted structure forms a very flat, compact pressure transducer which can be utilized in lieu of flex circuit type devices and provides greater mechanical stability as well as a more accurate output.

Abstract: Pressure non-linearity in a low pressure sensor device formed from a silicon diaphragm with an embedded piezoresistive transducer is reduced by using a shallow boss or thin stiffener on an ultra-thin diaphragm while the pressure sensitivity of the device is increased with corner trenches.

Abstract: There is disclosed a redundant pressure sensing chip which includes first and second redundant devices. Each pressure sensing device produces an output proportional to applied pressure irrespective of vibration/acceleration of the device. Each device also provides an output proportional to pressure and because of the nature of the devices, thermal effects as well as acceleration and the vibration are canceled. Based on chip operation and subtracting the signals from the two diaphragms, acceleration/vibration is canceled but also the effects of absolute pressure and differential pressure is also canceled. Therefore the chip can be used as a redundant absolute pressure sensor as well as a differential pressure sensor.

Abstract: A pressure sensor module of the invention includes a pressure sensor and a laminar substrate. Electrodes are arranged in the vicinity of a diaphragm portion of the pressure sensor. In the laminar substrate, a plurality of substrates are laminated, and the laminar substrate incorporates the pressure sensor. One face of the diaphragm portion is exposed by a space portion. According to the invention, it is possible to provide a pressure sensor module which facilitates smaller and thinner sizes, and which enables high-density packaging.

Abstract: A push-button switch test device having a flexible tab fixedly attached to a pushing member. The flexible tab is made of a flexible material and includes a deformation sensitive resistor mounted on a surface. The push-button switch test device may be used to test a push-button by imposing a known force on the flexible tab while receiving a signal level across the deformation sensitive resistor. As the known force pushes on the flexible tab, the signal level indicates when the push-button has engaged. The force may then be reversed to permit sensing of the disengagement of the switch. Configurations of a plurality of push-button switch test devices may be arranged in a test frame that mirrors a configuration of push-button switches.

Abstract: A fluid dynamic polymer-based contact sensor measures ambient pressure based on the resistivity changes across the sensor under different ambient pressures. The pressure sensor may applied to airfoil structures such as wind turbine blades without impacting the blade structure and fluid dynamic characteristics. The sensor may also be applied to fluid measurements. The pressure measurements are used to measure blade performance with high fidelity. The pressure measurements are transmitted to processing to determine blade characteristics and environment including flow separation, stagnation point, angle of attack, lift and drag and wind speed. Further processing of the pressure distribution may identify wind shear, up-flow and yaw error.

Abstract: A semiconductor package (10) including a pressure sensor die (14) has an interconnect layer (22) formed over a first major surface of the pressure sensor die (14). An encapsulant (18) encapsulates a second major surface and sides of the pressure sensor die (14). A cavity (32) extends through the interconnect layer (22) to the first major surface of the pressure sensor die (14). The interconnect layer (22) allows for the assembly of a low-profile package.

Abstract: A high temperature pressure transducer is fabricated from silicon carbide. A wafer of silicon carbide has reduced or active areas which act as deflecting diaphragms. Positioned on the reduced or active area is a silicon carbide sensor. The sensor is secured to the silicon carbide wafer by a glass bond. The pressure transducer is fabricated by first epitaxially growing a layer of highly N-doped 3C silicon carbide on a first silicon wafer or substrate. A second wafer of silicon carbide is selected to be a carrier wafer. The carrier wafer is etched preferentially to produce the deflecting members or reduced areas which serve as diaphragms. The 3C material on the silicon slice is patterned appropriately to provide a series of individual piezoresistors which then may be interconnected to form a Wheatstone bridge.

Abstract: There is disclosed flat planar pressure transducer which comprises a planar insulative substrate of a rectangular configuration. Disposed on the substrate is an array of conductive areas which extend from a contact terminal area of said substrate to an end of the substrate. There is a leadless sensor module positioned at said contact terminal area, with the contacts of said leadless sensor contacting contact terminals of said contact terminal area. The leadless sensor is enclosed by an enclosure which is coupled to the substrate and surrounds the sensor. The enclosure has a screen positioned on the top surface to prevent particles from entering or damaging the leadless sensor. The above-noted structure forms a very flat, compact pressure transducer which can be utilized in lieu of flex circuit type devices and provides greater mechanical stability as well as a more accurate output.

Abstract: A micro semiconductor-type pressure sensor and a manufacturing method thereof are provided. The micro semi-conductor-type pressure sensor is implemented by etching a cavity-formation region of a substrate to form a plurality of trenches, oxidizing the plurality of trenches through a thermal oxidation process to form a cavity-formation oxide layer, forming a membrane-formation material layer on upper portions of the cavity-formation oxide layer and the substrate, forming a plurality of etching holes in the membrane-formation material layer, removing the cavity-formation oxide layer through the plurality of etching holes to form a cavity buried in the substrate, forming a membrane reinforcing layer on an upper portion of the membrane-formation material layer to form a membrane for closing the cavity, and forming sensitive films made of a piezoresisive material on an upper portion of the membrane.

Abstract: A diaphragm made of a polysilicon film is provided above a first main surface of a silicon substrate. Four gauge resistors are provided on the top face of the diaphragm. A through hole for exposing the bottom face of the diaphragm is formed in the silicon substrate. An anchor portion for mounting the diaphragm on the silicon substrate is provided between the diaphragm and the silicon substrate in a manner surrounding circumferentially an opening end of the through hole located at the side facing the first main surface. Accordingly, a semiconductor pressure sensor having a diaphragm of reduced and less varied thickness can be obtained.

Abstract: A pressure sensor is described with sensing elements electrically and physically isolated from a pressurized medium. An absolute pressure sensor has a reference cavity, which can be at a vacuum or zero pressure, enclosing the sensing elements. The reference cavity is formed by bonding a recessed cap wafer with a gauge wafer having a micromachined diaphragm. Sensing elements are disposed on a first side of the diaphragm. The pressurized medium accesses a second side of the diaphragm opposite to the first side where the sensing elements are disposed. A spacer wafer may be used for structural support and stress relief of the gauge wafer. In one embodiment, vertical through-wafer conductive vias are used to bring out electrical connections from the sensing elements to outside the reference cavity. In an alternative embodiment, peripheral bond pads on the gauge wafer are used to bring out electrical connections from the sensing elements to outside the reference cavity.