Patent application number | Description | Published |
20080217728 | Fusion bonding process and structure for fabricating silicon-on-insulator (SOI) semiconductor devices - A method of fabricating a semiconductor-on-insulator device including: providing a first semiconductor wafer having an about 200 angstrom thick oxide layer thereover; etching the first semiconductor wafer to raise a pattern therein; doping the raised pattern of the first semiconductor wafer through the about 200 angstrom thick oxide layer; providing a second semiconductor wafer having an oxide thereover; and, bonding the first semiconductor wafer oxide to the second semiconductor wafer oxide at an elevated temperature. | 09-11-2008 |
20080276712 | Pressure transducer employing a micro-filter and emulating an infinite tube pressure transducer - A pressure transducer for measuring pressures in high temperature environments employs a tube which is terminated at one end by an acoustic micro-filter. The acoustic filter or micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. Mounted to the tube is a pressure transducer with a diaphragm flush with the inner wall of the tube. The tube is mounted in an aperture in a casing of a gas turbine operating at a high temperature. The hot gases propagate through the tube where the pressure of the gases are measured by the transducer coupled to the tube and where the acoustic filter operates to absorb acoustic waves impinging on it with little or no reflection, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation. | 11-13-2008 |
20090007680 | High pressure transducer having an H shaped cross-section - A high pressure transducer has an H shaped cross-section with a center arm of the H having a top and bottom surface with the top surface of the H accommodating four strain gauges. Two strain gauges are located at the center of the top portion of the center arm of the H and are positive strain gauges, while two strain gauges are located near the periphery of the center arm of the gauge. The bottom surface of the center arm of the gauge has an active area of a smaller diameter than the circular diameter of the center arm portion of the transducer. The smaller active area is surrounded by a thicker stepped area which surrounds an active area on the pressure side of the H shaped member. The surrounding stepped area enables one to position the two negative strain gauges on the opposite surface of the center arm and near the periphery to thereby cause the negative gauges to respond to a negative stresses and therefore to enable one to provide a full Wheatstone bridge which includes the two positive strain gauges located at the center of the center arm of the H and the two negative peripheral gauges. | 01-08-2009 |
20090007682 | High pressure transducer having an H shaped cross-section - A high pressure transducer has an H shaped cross-section with a center arm of the H having a top and bottom surface with the top surface of the H accommodating four strain gauges. Two strain gauges are located at the center of the top portion of the center arm of the H and are positive strain gauges, while two strain gauges are located near the periphery of the center arm of the gauge. The bottom surface of the center arm of the gauge has an active area of a smaller diameter than the circular diameter of the center arm portion of the transducer. The smaller active area is surrounded by a thicker stepped area which surrounds an active area on the pressure side of the H shaped member. The surrounding stepped area enables one to position the two negative strain gauges on the opposite surface of the center arm and near the periphery to thereby cause the negative gauges to respond to a negative stresses and therefore to enable one to provide a full Wheatstone bridge which includes the two positive strain gauges located at the center of the center arm of the H and the two negative peripheral gauges. | 01-08-2009 |
20090007684 | Joystick sensor apparatus - A joystick apparatus employs a hermetically sealed load cell having strain gauges placed on flexible beams formed on the load cell. All of the strain gauges are on the same surface of the load cell and therefore wiring is performed on a single side of the load cell. The strain gauges are enclosed in hermetically sealed cavity. The sensing diaphragm consists of a concentric thick inner and outer section joined by thinner diametrically opposed beam elements. The thin beam elements are compliant members which can deflect. Each beam includes strain gauges or sensor elements and the load cell is coupled to a joystick which when moved causes the beams to deflect to cause the sensor elements to produce an electrical output proportional to the force and direction of the joystick. The sensor can yield an output proportional to any angle over the 360° movement of the joystick to provide outputs proportional to the X and Y positions of said joystick. Thus, the joystick arrangement can resolve any angle or force into X and Y components for full directional control. | 01-08-2009 |
20090071250 | Beam accelerometer with limiting apparatus - An accelerometer includes a cantilever mass with a thin beam element between the mass and the fixed end of the accelerometer. The end of the mass is tapered. A limiting member has an aperture that is tapered corresponding to the taper at the end of the mass and positioned to surround the tapered end of the seismic mass. The beam accelerometer as well as the limiting member is placed in a cylindrical housing whereby the limiting member is moved along the taper of the seismic mass to adjust the spacing between the limiting member and the inner wall of the housing to thereby adjust the amount of movement of the seismic mass. In one embodiment the aperture of the tapered limited member also surrounds the seismic mass but the gap between the inner wall of the tapered limiting member and the outer wall of the seismic mass is adjusted to determine the amount of movement of the beam. In this manner, one can utilize a beam accelerometer arrangement of a cylindrical configuration within a housing and whereby the seismic mass has a taper and the taper coacts with a limiting member which has a corresponding taper to adjust the distance that the beam can move upon application of a force thereto. | 03-19-2009 |
20090078547 | Pressure switch employing silicon on insulator (SOI) technology - A pressure switch employs semiconductor silicon on insulator (SOI) technology and utilizes a first silicon wafer which has a deflecting diaphragm. Deposited on the wafer is at least one distinct metal contact. Secured to the semiconductor wafer is a glass wafer having a central aperture defining a deflecting region. Positioned on top of the glass wafer is another metal contact which is positioned to receive the two contacts deposited on the silicon wafer when a given pressure is applied to the silicon wafer. The metal contact on the silicon wafer is connected to a header pin, via apertures formed in the glass wafer, the apertures are filled with a conductive glass metal frit so that contact is made between the header pins and the metal contacts deposited on the silicon wafer. Operation is such that when a pressure is applied of a given magnitude the contact on the silicon wafer will contact the metal contact trace on the glass wafer and therefore a connection would be made between the first metal trace and the second metal trace to create a low impedance path between the two traces thereby connecting the first trace on the silicon wafer to the second trace on the glass wafer. This creates a high impedance or open circuit in a first state and when the pressure exceeds the threshold a slow impedance or short circuit in a second state. | 03-26-2009 |
20090114028 | Pressure transducer apparatus adapted to measure engine pressure parameters - A pressure header assembly has a closed front and back surface. The back surface has an aperture for accommodating a separate dual die pressure header. The dual die pressure header has an absolute and differential pressure sensor positioned thereon. A differential pressure port is located on a side surface of the pressure header assembly and is directed to a bore in the pressure header assembly. The bore contains an elongated tube which is positioned in the pressure header assembly and locked in place by means of a crush nut and locking nut assembly. One end of the tube is coupled to the differential pressure port, while the other end of the tube accommodates a differential pressure tube which is bent in an arcuate position and directed to the underside of the sensor of the differential sensor assembly mounted in the dual die pressure header. Suitable leads from the dual die pressure header assembly are directed to a terminal board which is mounted within a pressure transducer housing shell, which terminal board coacts with an outboard contact cap assembly forming the transducer. The pressure header assembly portion also contains extending tabs which have apertures for external mounting. | 05-07-2009 |
20090116537 | Combined temperature and pressure transducer incorporating connector keyway alignment and an alignment method - A transducer sensor is positioned within a hollow of the body of a housing. The housing has an extending alignment pin, which pin coacts with a corresponding slot or aperture in the wall of a vessel whose pressure or temperature is to be monitored. The transducer body is associated with a connector where the alignment pin is placed and extends from the housing in a fixed relation to the connector. A suitable aperture or slot in the wall of the vessel to be monitored accommodates the extending pin whereby when the transducer is placed in the vessel aperture the connector associated with the transducer is always located in proper position. Positioned on the housing is a sliding nut which can move in a direction parallel to the central axis of the housing and either to the right or left. This sliding nut is rotatably positioned in the housing and coacts with threads formed in the aperture in the wall of the vessel to enable tightening of the transducer housing when placed in the wall and when the alignment pin is positioned within the corresponding slot or aperture. This assures a proper alignment so that an external connector which is not moveable or rotatable can be immediately connected to the transducer connector without further experimentation or adjustment. | 05-07-2009 |
20090126499 | Ultra miniature multi-hole probes having high frequency response - A pressure probe includes a longitudinal tubular housing symmetrically disposed about a central axis and having an ultra miniature conical front end and an opened back end. A plurality of aperture ports having an opening are disposed about the front end. A plurality of ultra small leadless transducers has a central active deflecting area in a semiconductor substrate, and a layer of oxide on a bottom surface. At least one sensor network is disposed within the active area on the oxide layer. A glass contact wafer is bonded to the non-deflecting portion of sensing network and has a number of apertures surrounding the active area suitable for interconnection with header. A header encloses each transducer and is of a shape and size to be positioned in an associated aperture port of the probe housing. At least one lead is coupled to a header pin extending from bottom of the aperture and directed through the bottom opening into the hollow of the probe housing. | 05-21-2009 |
20090139339 | Pressure transducer employing a micro-filter and emulating an infinite tube pressure transducer - A pressure transducer for measuring pressures in high temperature environments employs a tube which is terminated at one end by an acoustic micro-filter. The acoustic filter or micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. Mounted to the tube is a pressure transducer with a diaphragm flush with the inner wall of the tube. The tube is mounted in an aperture in a casing of a gas turbine operating at a high temperature. The hot gases propagate through the tube where the pressure of the gases are measured by the transducer coupled to the tube and where the acoustic filter operates to absorb acoustic waves impinging on it with little or no reflection, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation. | 06-04-2009 |
20090160069 | Leadless alignment of a semiconductor chip - There is disclosed a mounting technique for mounting a semiconductor chip of the leadless or so-called flip chip type to a header. The header has an insert made of glass or other suitable non-conductive material within the header hollow. Mounted into the glass insert are a series of conductive metal pins which are placed in areas so that when a chip is mounted in the header, the chip makes contact with these conductive pins and allows one to make outside connections. Also positioned in the header are a series of nonconductive guide pins. These pins are placed in suitable positions in the header to enable one to contact the outside surfaces of the chip when the chip is placed in the header. In this manner, the chip is constrained from movement from side to side or from rotation. However, due to the positioning of the nonconductive pins within the header, it is possible to move the chip up and down while mounting. | 06-25-2009 |
20090205433 | Low differential pressure transducer - A pressure transducer has an H-shaped header having a front and a back section. The front and back sections are of equal diameter and are circular. Each front and back section has a depression with a diaphragm covering the depression. Each diaphragm is of equal size and the depressions communicate one with the other via a central channel in the central arm of the H. A pressure sensor communicates with the channel, where the pressure sensor responds to a first pressure applied to the first diaphragm and a second pressure applied to the second diaphragm. The pressure sensor produces an output equal to the difference in pressure. The differential pressure inducer having both diaphragms of the same size and still enabling leads from the sensor to be brought out. | 08-20-2009 |
20090205434 | Low differential pressure transducer - A pressure transducer has an H-shaped cross-sectional header having a front and a back section. The front and back sections are of equal diameter and are circular. Each front and back section has a depression with an isolation diaphragm covering the depression. Each diaphragm is of equal size and the depressions communicate one with the other via a central channel in the central arm of the H. A pressure sensor communicates with the channel, where the pressure sensor responds to a first pressure applied to the first isolation diaphragm and a second pressure applied to the second isolation diaphragm. The pressure sensor produces an output equal to the difference in pressure. The differential pressure transducer having both diaphragms of the same size and still enabling leads from the sensor to be brought out. | 08-20-2009 |
20090260446 | Header for a differential pressure transducer - There is disclosed a header for a differential pressure transducer. The header has a cylindrical sensor housing section which has a front and a back surface. The front surface has a sensor accommodating recess. There is a plurality of terminal pins extending from the front surface and directed through the housing to extend from said back surface. The pins are arranged in a semi-circular pattern, said sensor housing having a stem aperture and cylindrical wall. A stem housing is positioned in the stem aperture and is brazed thereto. The stem housing has a stem passageway directed through the housing which communicates with a passageway in the cylindrical sensor housing. The cylindrical sensor recess contains a sensing device which receives a first input pressure on one diaphragm surface of the sensing device and a second input pressure on a second surface of the diaphragm to produce a differential output pressure. The header, as indicated, is rugged and simple to use and produce. | 10-22-2009 |
20090280002 | Method and system for determining gas turbine tip clearance - A system for sensing at least one physical characteristic associated with an engine including a turbine having a plurality of blades turning inside a casing, the system including: a pressure sensor coupled substantially adjacent to the casing and including at least one output; a port in the turbine casing for communicating a pressure indicative of a clearance between the blades and casing to the pressure sensor; a cooling cavity substantially surrounding the pressure sensor; and, an inlet for receiving fluid from the engine and feeding the fluid to the cooling cavity to cool the pressure sensor; wherein, the pressure sensor output is indicative of the clearance between the blades and casing. | 11-12-2009 |
20090294740 | Method and apparatus for preventing catastrophic contact failure in ultra high temperature piezoresistive sensors and transducers - A method to prevent the catastrophic failure of electrical contacts of silicon piezoresistive transducers located on a silicon wafer at temperatures above 600° C. comprising the steps of using a lead-free glass frit to surround the contacts and bonding the sensor wafer to a glass wafer employing a lead-free glass and utilizing a modified electrostatic bonding technique to join the silicon wafer to the lead-free glass wafer to form a high temperature SOI device. | 12-03-2009 |
20090301217 | Multiple axis load cell controller - There is disclosed a multiple axis load cell or controller in which axial and torsion measurements are decoupled while maximizing the outputs of both measurements. The active member of the load cell is a wheel with dual beams as the spokes. The wheel thus has four spokes or four beam members, each spoke is a pair of rectangular cross-section beams, orthogonal to each other. The beams have strain gages on the wide surfaces which measure the bending strain which is proportional to torsion or the axial input. There is an inner beam section and an outer beam section associated with each spoke and orthogonal to each other. The outer beams have the wide surface normal to the axis of the load cell. This beam section is more sensitive to the axial tension/compression input. The inner beam sections have their wide surface parallel to the axis of the load cell and are much less sensitive to bending but are sensitive to torsion. Therefore when a torsion or twisting motion is applied to the load cell, the inner beams with their wide surface parallel to the axis of the wheel are more sensitive and bend more. These beams experience bending as a result of the torsion input and have strain gages formed in a Wheatstone bridge arrangement to provide an output proportional to the torsion. The outer beams also have gages mounted thereon which are also wired in a Wheatstone bridge configuration and which Wheatstone bridge output of these gages are proportional to the axial force. | 12-10-2009 |
20090313797 | Mounting apparatus and method for accurately positioning and aligning a leadless semiconductor chip on an associated header - There is disclosed a method and apparatus for mounting a leadless semiconductor chip on a header. The semiconductor chip has contacts on a surface and the chip is of a specified geometric shape. The header has a contact surface for receiving the chip with the contact surface of the header containing header contact pins, which pins have to contact the contacts on the semiconductor chip. The header has a guide pin extending from the contact surface and there is a guide plate which has an aperture adapted to be placed over the guide pin, the guide plate further has a chip accommodating aperture of the same geometric shape as the chip. The guide plate, when placed over the guide pin enables the chip to be placed in the chip accommodating aperture so that the contacts of the header pin are properly and accurately aligned with respect to the contacts on the semiconductor chip. | 12-24-2009 |
20090314094 | COMPACT ABSOLUTE AND GAGE PRESSURE TRANSDUCER - A compact absolute and gage pressure transducer consists of two sensors made from the same silicon wafer and selected to be adjacent to each other on the wafer. The transducer contains a common header which has a first input port for receiving a first pressure and a second input port for receiving a second pressure. The second input port is directed through a reference tube into the hollow of the housing to apply the pressure from the reference tube to the common sensor arrangement. The first input port is directed from another surface of the housing to direct that pressure to both sensor devices. One sensor device operates as a gage sensor which produces an output proportional to the difference between one input pressure and the other input pressure while the other sensor on the same chip produces an absolute output. The sensor chip is associated with a sensor header, which header is positioned in the housing and which header is fabricated from glass. Positioned on the header is a guide plate also fabricated from glass. The header has extending therefrom an alignment pin, while the guide plate has an aperture which accommodates the alignment pin. The guide plate also has a central aperture which conforms to the size of the sensor chip. In this manner, once the alignment or guide plate is positioned within the alignment pin, the exact position of the sensor chip is determined. This enables contact areas from the sensor chip to make conductive contact with terminal pins associated with the glass header. These terminal pins are then directed to a connector or other device associated with the header. | 12-24-2009 |
20100016990 | Microelectromechanical system (MEMS) employing wireless transmission for providing sensory signals - A medical system employs wireless transmission and provides sensory signals to a user of a prosthetic or other medical device. A series of pressure, force or strain sensors are placed upon various areas of the prosthetic device. The sensors are strategically placed according to anticipated functions of the prosthetic device and the sensors may be placed in clusters, where each cluster may include more than one sensor. The prosthetic device is normally operated by a biometric controller. The biometric controller is controlled by the handicapped user via muscles or other devices to enable the prosthetic device to perform various desired functions. During performing of such functions, the sensors will respond and produce outputs according to applied pressure or strain. These voltage outputs are transmitted by a transmitter to a remote receiver which is located on the body or person of the handicapped user. The receiver demodulates the transmitted signal to provide output signals proportional to the sensor signals as transmitted. These output signals are then directed to electrodes, probes or terminal pads imbedded in the body of the handicapped user by a physician or suitable technician. The imbedded probes or electrodes receive the sensor signals from the receiver and operate to stimulate the nerves so that a user can receive signals indicative of the force applied to given areas of the prosthetic device. In this manner the user can better control prosthetic device operation. | 01-21-2010 |
20100018319 | APPARATUS AND METHOD FOR ELIMINATING VARYING PRESSURE FLUCTUATIONS IN A PRESSURE TRANSDUCER - 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. In this manner, the pump ripple cannot cause resonance which would result in pressure amplification and which pressure amplification would destroy the sensor. | 01-28-2010 |
20100063749 | GAS DENSITY TRANSDUCER WITH A MICROPROCESSOR EXECUTING AN ALGORITHM SOLVING VAN DER WAALS EQUATION - A gas density transducer including: a piezoresistive bridge sensor operative to provide an output indicative of an applied pressure, a computing processor having multiple inputs and at least one output, with the output of the bridge sensor coupled to an input of the processor; a temperature sensor coupled to an input of the processor for providing at an output a signal indicative of a temperature of the bridge sensor, the output of the temperature sensor coupled to an input of the processor; and, at least one memory accessible by the processor and having stored therein: compensation coefficients for compensating the output of the bridge sensor for temperature variation; an algorithm for solving Van der Waal's equation; and, code for providing at an output of the processor a signal indicative of a gas density when the bridge is subjected to a gas containing environment. | 03-11-2010 |
20100083764 | Redundant self compensating leadless pressure sensor - 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. | 04-08-2010 |
20100083767 | Dual purpose pressure sensor - A pressure transducer, particularly adapted to measure the pressure in a tire and to enable the tire to be filled includes a first housing, having an internal hollow. Positioned in the hollow of the first housing is a second housing, also having an internal hollow. The second housing is supported within the first housing so that a passageway for airflow exists between the housings. The second housing has a pressure port for monitoring the pressure of a tire. The first housing has an inlet port for receiving a source of pressure. The inlet port contains a valve which is selectively operated. The valve, when operated, permits air to flow into the hollow of the first housing and to flow about the periphery of the second housing to enter the pressure port associated with the second housing. The pressure port may, as indicated, be associated with a tire and the second housing contains a pressure sensing device which monitors the pressure in the tire via the pressure port. In this manner, the pressure in the tire can be monitored while additional air can be added through the valve which air flows around the second housing to enter the tire or other device coupled to the pressure transducer. | 04-08-2010 |
20100107771 | SENSOR ARRAY FOR A HIGH TEMPERATURE PRESSURE TRANSDUCER EMPLOYING A METAL DIAPHRAGM - A sensor array for a pressure transducer having a diaphragm with an active region, and capable of deflecting when a force is applied to the diaphragm. The 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 dielectrically isolated from the substrate. | 05-06-2010 |
20100107773 | METHOD AND APPARATUS FOR PREVENTING CATASTROPHIC CONTACT FAILURE IN ULTRA HIGH TEMPERATURE PIEZORESISTIVE SENSORS AND TRANSDUCERS - A piezoresistive sensor device and a method for making a piezoresistive device are disclosed. The sensor device comprises a silicon wafer having piezoresistive elements and contacts in electrical communication with the elements. The sensor device further comprises a contact glass coupled to the silicon wafer and having apertures aligned with the contacts. The sensor device also comprises a non-conductive frit for mounting the contact glass to a header glass, and a conductive non-lead glass frit disposed in the apertures and in electrical communication with the contacts. The method for making a piezoresistive sensor device, comprises bonding a contact glass to a silicon wafer such that apertures in the glass line up with contacts on the wafer, and filling the apertures with a non-lead glass frit such that the frit is in electrical communication with the contacts. The use of a lead free glass frit prevents catastrophic failure of the piezoresistive sensor and associated transducer in ultra high temperature applications. | 05-06-2010 |
20100107774 | ULTRA-MINIATURE MULTI-HOLE PROBES HAVING HIGH FREQUENCY, HIGH TEMPERATURE RESPONSES - 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. | 05-06-2010 |
20100122581 | Flexible transducer structures - 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. | 05-20-2010 |
20100125426 | High temperature transducer using SOI electronics - There is disclosed a high temperature pressure sensing system which includes a SOI Wheatstone bridge including piezoresistors. The bridge provides an output which is applied to an analog to digital converter also fabricated using SOI technology. The output of the analog to digital converter is applied to microprocessor, which microprocessor processes the data or output of the bridge to produce a digital output indicative of bridge value. The microprocessor also receives an output from another analog to digital converter indicative of the temperature of the bridge as monitored by a span resistor coupled to the bridge. The microprocessor has a separate memory coupled thereto which is also fabricated from SOI technology and which memory stores various data indicative of the microprocessor also enabling the microprocessor test and system test to be performed. | 05-20-2010 |
20100139408 | Low pass filter semiconductor structures for use in transducers for measuring low dynamic pressures in the presence of high static pressures - A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives a high and very low frequency static pressure attendant with a high frequency low dynamic pressure at one end, the filter operates to filter said high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives said filtered static pressure at the other port where said transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is found between a silicon wafer and a glass cover wafer, an input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure. | 06-10-2010 |
20100140723 | NANOTUBE AND GRAPHENE SEMICONDUCTOR STRUCTURES WITH VARYING ELECTRICAL PROPERTIES - Nanotube and graphene transducers are disclosed. A transducer according to the present invention can include a substrate, a plurality of semiconductive structures, one or more metal pads, and a circuit. The semiconductive structures can be nanotubes or graphene located entirely on a surface of the substrate, such that each of the semiconductive structures is supported along its entire length by the substrate. An electrical property of the semiconductive structures can change when a force is applied to the substrate. The metal pads can secure at least one of the semiconductive structures to the substrate. The circuit can be coupled to at least some of the semiconductive structures to provide an output responsive to the change in the electrical property of the semiconductive structures, so as to indicate the applied force. | 06-10-2010 |
20100147082 | COMBINED WET-WET DIFFERENTIAL AND GAGE TRANSDUCER EMPLOYING A COMMON HOUSING - A combined wet-wet differential transducer and a gage pressure transducer are located in the same housing. A semiconductor chip which is formed from a single substrate, has located thereon an absolute or gage sensor chip on one section and a delta or differential sensor chip on a second section. Each sensor chip has a Wheatstone bridge arrangement comprising piezoresistors and responsive to an applied pressure. The absolute or gage chip, as well as the differential or delta chip are placed in a header having a front section and a back section. Each section has an outer surface with a central section joining the front and back sections to form an H shaped header. The front section outer surface has a depression of a given area with a first flexible isolation diaphragm covering the depression. The back section outer surface has a second depression of a given area with a second flexible isolation diaphragm covering the second depression, where the first and second diaphragms are relatively of the same size and area. A channel positioned within the central area and extending and communicating with the first and second depressions. The header described above, has a first sensor chip indicative of an absolute or gage sensor and a second sensor chip indicative of a differential sensor. Both sensors, as indicated, receive a first pressure at a corresponding diaphragm surface. The housing which contains the above noted header has a tube which communicates with the bottom diaphragm side of the differential chip section. The top side of the both the differential chip section and the absolute chip section receives the same pressure via a pressure port in the header. The differential portion of the chip receives a pressure via a curved tube which is directed to the second isolation diaphragm and which pressure propagates from the diaphragm through the channel and therefore applies that pressure to the underside of the differential sensor section. | 06-17-2010 |
20100175481 | APPARATUS FOR MEASURING MULTIPLE PRESSURES WITHIN DIFFERENT PRESSURE RANGES - There is disclosed apparatus for measuring multiple pressures within different pressure ranges. The apparatus contains multiple pressure sensors which are positioned on a housing, where each pressure sensor is adapted to measure pressure within a different pressure range. The housing has an input port which is constructed to communicate with different output ports, where the output ports communicate with each different pressure sensor utilized in a different pressure range. The input port has a stepped or keyed aperture which is adapted to receive different pressure adapters to assure that, for example, only a high pressure will be applied to the high pressure sensor during high pressure measurements. By selecting another adapter, a mid-range pressure and a high pressure will be applied to the pressure sensors during the measurement of a mid-range pressure. By receiving a different adapter, a low pressure will be applied to all the pressure sensors during low pressure measurement. In this manner, one is assured that the pressure sensors are operated without damage to the diaphragms during all pressure measurements. It is of course noted that while three pressure ranges are indicated, there can be more than three or at least two pressure ranges can be accommodated within the common housing. As indicated, the common housing has an input port which consists of contiguous varying diameter sections to enable the selective insertion of various adapter members as indicated where each adapter member can only be inserted within the input port to a desired position, where at that position, the pressure applied to the input port will be directed to the proper sensor. | 07-15-2010 |
20100175482 | PRESSURE TRANSDUCER EMPLOYING A MICRO-FILTER AND EMULATING AN INFINITE TUBE PRESSURE TRANSDUCER - It is an objective of the present invention to provide a pressure transducer assembly for measuring pressures in high temperature environments that employs an elongated tube which is terminated at one end by an acoustic micro-filter. The micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. To improve the absorption of acoustic waves, the elongated tube may be tapered and/or mounted to a support block and further convoluted to reduce the overall size and mass of the device. A pressure transducer with a diaphragm flush may be mounted to the elongated tube and extend through to the inner wall of the tube. Hot gases propagate through the elongated tube and their corresponding pressures are measured by the transducer. The acoustic filter operates to absorb acoustic waves resultant from the hot gases, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation. | 07-15-2010 |
20100185403 | High temperature,high bandwidth pressure acquisition system - 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. This module houses electronics which digitally converts the data from the sensors and then compensates the data for temperature effects. The advantage of the system is that each individual sensor does not have any compensation and it can be made very small to operate at very high temperatures without any loss of accuracy. Thus, a large number of sensors can be utilized in a very small volume, even under extreme environmental conditions. It is noted that the Acquisition and Compensation electronics module can be located remotely in a safe environment outside of the wind tunnel and therefore respond extremely accurately to the pressure and temperatures subjected by the model in the wind tunnel. | 07-22-2010 |
20100193908 | FUSION BONDING PROCESS AND STRUCTURE FOR FABRICATING SILICON-ON-INSULATION (SOI) SEMICONDUCTOR DEVICES - A method of fabricating a semiconductor-on-insulator device including: providing a first semiconductor wafer having an about 500 angstrom thick oxide layer thereover; etching the first semiconductor wafer to raise a pattern therein; doping the raised pattern of the first semiconductor wafer through the about 500 angstrom thick oxide layer; providing a second semiconductor wafer having an oxide thereover; and, bonding the first semiconductor wafer oxide to the second semiconductor wafer oxide at an elevated temperature. | 08-05-2010 |
20100199775 | Method for temperature compensation of a piezoresistive gaged metal diaphragm - There is described a temperature compensation scheme for a pressure sensitive metal diaphragm transducer. The transducer employs a Wheatstone bridge fabricated from p-type piezoresistors. The Wheatstone bridge is glassed directly onto the metal diaphragm. As the temperature of operation increases, the diaphragm exhibits a temperature variation of the Modulus of Elasticity. The Modulus of the metal diaphragm decreases with increasing temperature. Because of this, the same pressure applied to the metal diaphragm causes it to deflect further, which in turns causes increased strain applied to the bridge. Because of this effect, the sensitivity of the transducer increases with increasing temperature. A resistor is now placed in series with the Wheatstone bridge. The resistor is in series with the biasing voltage and because the TCS of the diaphragm is of an opposite sign, the series resistor has an even higher TCR in series with the bridge. In this manner, the bridge voltage is made to decrease with increasing temperature. Due to the fact that the bridge voltage decreases with increasing temperature the change in voltage compensates for the change in the Modulus of the metal diaphragm and therefore provides an accurate output at all temperatures. | 08-12-2010 |
20100200779 | Pressure transducers employing radiation hardened electronics - There is disclosed a transducer employing radiation hardened electronics. Essentially a sensor assembly is positioned in a front section of a housing where the sensor assembly is coupled to an electronic module via terminals which connect the sensor to the module. The electronic module assembly is surrounded by an internal tungsten housing which is formed from a first tungsten “U” shaped cross-sectional member coupled to a second tungsten “U” shaped cross-sectional enclosure. The two members are coupled together and totally surround the electronic assembly. The members as held together are positioned within the housing by outer shell members to form a complete housing assembly whereby the electronic assembly and its associated terminal pins are totally surrounded by the tungsten holder section and the tungsten enclosure section. | 08-12-2010 |
20100251825 | COMBINED WET-WET DIFFERENTIAL AND GAGE TRANSDUCER EMPLOYING A COMMON HOUSING - A combined wet-wet differential transducer and a gage pressure transducer located in the same housing, comprising a semiconductor chip which comprises a gage sensor chip on one section and a differential sensor chip on a second section. Each sensor chip has a Wheatstone bridge comprising piezoresistors and is responsive to an applied pressure. The gage chip and the differential chip are placed in a header having a front section and a back section adapted to receive a first and second pressure, respectively. The sensors are in communication with first and second pressure ports such that the absolute sensor provides an output indicative of a pressure applied to a first port and the differential sensor provides an output indicative of the pressure difference between the first and second pressure ports. | 10-07-2010 |
20100257936 | Internally switched multiple range transducer - 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. | 10-14-2010 |
20100257937 | Leadless oil filled pressure transducer - An oil filled pressure transducer which exhibits reduced backpressure and utilizes a smaller volume of oil employs a glass pre-form which has a plurality of pin accommodating apertures and has an oil tube accommodating aperture. There are a plurality of contact pins inserted into the pin accommodating apertures and which extend from the top to the bottom surfaces of the pre-form. There is an oil fill tube inserted into the oil tube accommodating aperture, which oil fill tube extends from the bottom to the top surface of the pre-form with one end of the tube extending above the top surface of the pre-form. There is a glass alignment plate which has an alignment aperture for encircling the extended oil fill tube and has a sensor accommodating shaped aperture located at a predetermined position from said alignment aperture. When the glass alignment plate is being accommodated on the top surface of the pre-form by inserting the alignment aperture about the oil tube, the position of a sensor module is accurately determined based on the position of the sensor accommodating aperture. A sensor module is now placed in the shaped aperture of the alignment plate and makes contact with the pins to enable the sensor contacts to contact the pins. A header surrounds the sensor as positioned on the glass pre-form and a diaphragm is then placed to cover the top surface of the header to create a space between the top surface and the sensor. This space contains oil which is placed in the space by the oil fill tube. Due to the presence of the glass alignment plate, which has a given thickness, the volume of oil now required is much less than the volume required in the prior art, thus substantially reducing backpressure and further assuring that the sensor device is always properly aligned with respect to the pins. | 10-14-2010 |
20100257938 | Flat planner pressure transducer - 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. | 10-14-2010 |
20100275696 | Torque insensitive header assembly - There is disclosed a high pressure sensing header which is relatively insensitive to mounting torque. Essentially the header consists of an outer torque isolating shell which has a “C” shaped cross section with the cylindrical shell surrounding an inner “H” section header. The inner “H” section header has a thick diaphragm and is surrounded by the torque isolating shell which is secured to the “H” section header at a peripheral flange of the “H” section header. In this manner when the header is installed, the installation force is absorbed by the outer shell and there is no installation force or torque exhibited by the inner “H” section which will respond only to stress due to pressure. The torque isolating shell also contains a top surface which has a counterbore which can accommodate a crush ring, and when the unit is installed, the crush ring is forced or crushed against an installation wall to enable the inner header to receive pressure without experiencing any significant installation force. | 11-04-2010 |
20100310207 | OPTICAL MICROMACHINED PRESSURE SENSOR - It is an objective of the present invention to provide a highly sensitive optical pressure sensor that uses a Mach-Zehnder Interferometer to measure pressure. The pressure sensor comprises a deflectable diaphragm including a substantially central boss and channel and an optical waveguide having a first arm and a second arm, wherein the first arm is substantially aligned with an edge of the boss and the second arm is substantially aligned with an edge of the channel, and further wherein the first and second arms contain a periodic array of etched holes to improve the overall sensitivity of the pressure sensor. The pressure sensor further comprises a light source coupled to the optical waveguide for introducing light to the waveguide and a light detector coupled to the waveguide for detecting changes in the intensity of light. The change in light intensity is then correlated to an applied pressure. | 12-09-2010 |
20100326199 | LOW DIFFERENTIAL PRESSURE TRANSDUCER - It is an object of the present invention to provide a pressure transducer having a header wherein the header is comprised of a first section and a second section that are offset from each other. Each first and second section has a flexible diaphragm adapted to receive a first and second pressure, respectively. A central channel connects the diaphragms and a pressure sensor, located within the central channel, communicates with the channel and produces an output equal to the difference between the first and second pressures. The resultant device is a low differential pressure transducer which enables one to bring leads from the sensor out while having diaphragms of substantially the same size and diameter, therefore enabling the diaphragms to exhibit the same back pressure and be equally compliant. | 12-30-2010 |
20100332179 | Wireless interface for a plurality of transducers - A wireless interface system can interface with any one of a plurality of transducers of different types, such as pressure sensors, temperature sensors, current probes and so on. In the system, all such transducers employ identical connectors with a common connecting scheme. In this manner, any transducer can be connected to a wireless interface which has the same input connection scheme. When the wireless interface is connected to the transducer, a rechargeable battery, which is associated with the wireless interface, is activated. The wireless interface then determines the type of transducer being utilized and provides sufficient circuitry as well as determining the requirements of the connected transducer. In this manner, the wireless interface, besides recognizing and determining the type of transducer, can determine the range of the sensor, and depending on the type and range of the sensor, can provide specific circuitry to be activated to supply power and to read data from the sensor via common output pins. | 12-30-2010 |
20110061467 | LOW PASS FILTER SEMICONDUCTOR STRUCTURES FOR USE IN TRANSDUCERS FOR MEASURING LOW DYNAMIC PRESSURES IN THE PRESENCE OF HIGH STATIC PRESSURES - A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives a high and very low frequency static pressure attendant with a high frequency low dynamic pressure at one end, the filter operates to filter said high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives said filtered static pressure at the other port where said transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is found between a silicon wafer and a glass cover wafer, an input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure. | 03-17-2011 |
20110107840 | Enhanced Static-Dynamic Pressure Transducer Suitable for Use in Gas Turbines and Other Compressor Applications - A filter assembly for use with a static-dynamic piezoresistive pressure transducer that measures low amplitude, dynamic pressure perturbations superimposed on top of a high static pressure through the implementation of a low-pass mechanical filter assembly is disclosed. The filter assembly may comprise a dual lumen reference tube and a removable filter subassembly further comprising a porous metal filter and narrow diameter tube. The transducer, which may be capable of operating at ultra-high temperatures and in harsh environments, may comprise of a static piezoresistive pressure sensor, which measures the large pressures on the order of 200 psi and greater, and an ultrasensitive, dynamic piezoresistive pressure sensor which may capture small, high frequency pressure oscillations on the order of a few psi or less. The filter assembly may transmit static pressure to the back of the dynamic pressure sensor to cancel out the static pressure present at the front of the sensor while keeping dynamic pressure from reaching the back of the sensor. In this manner, the filter assembly enables the transducer to accurately read dynamic pressure in the presence of high static pressure without rupturing the thin diaphragm of the dynamic pressure sensor. | 05-12-2011 |
20110113890 | TORQUE INSENSITIVE HEADER ASSEMBLY - There is disclosed a high pressure sensing header which is relatively insensitive to mounting torque. The header comprises an outer torque isolating shell which surround an inner “H” section header. The inner “H” section header has a thick diaphragm and is surrounded by the torque isolating shell which is secured to the “H” section header at a peripheral flange of the “H” section header. In this manner when the header is installed, the installation force is absorbed by the outer shell and there is no installation force or torque exhibited by the inner “H” section which will respond only to stress due to pressure. The torque isolating shell also contains a top surface which has a counterbore that accommodates a crush ring. When the unit is installed, the crush ring is crushed against an installation wall to enable the inner header to receive pressure without experiencing significant installation force. | 05-19-2011 |
20110118997 | HIGH TEMPERATURE TRANSDUCER USING SOI ELECTRONICS - There is disclosed a high temperature pressure sensing system which includes a SOI Wheatstone bridge including piezoresistors. The bridge provides an output which is applied to an analog to digital converter also fabricated using SOI technology. The output of the analog to digital converter is applied to microprocessor, which microprocessor processes the data or output of the bridge to produce a digital output indicative of bridge value. The microprocessor also receives an output from another analog to digital converter indicative of the temperature of the bridge as monitored by a span resistor coupled to the bridge. The microprocessor has a separate memory coupled thereto which is also fabricated from SOI technology and which memory stores various data indicative of the microprocessor also enabling the microprocessor test and system test to be performed. | 05-19-2011 |
20110126633 | LEADLESS OIL FILLED PRESSURE TRANSDUCER - An oil-filled pressure transducer having reduced back pressure, comprising an alignment plate having a sensor accommodating aperture, a sensor module inserted into the sensor accommodating aperture, a header surrounding the alignment plate, the header having a protruding top surface, and a diaphragm disposed on the protruding top surface to create a relatively small oil accommodating region between the diaphragm and the sensor. This configuration reduces the oil volume required for operation, which ultimately reduces the back pressure applied against the diaphragm. | 06-02-2011 |
20110126634 | FLAT PLANAR PRESSURE TRANSDUCER - 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. | 06-02-2011 |
20110159617 | DUAL LAYER COLOR-CENTER PATTERNED LIGHT SOURCE - A method of fabricating a color laser, comprising growing a first thin layer of ionic crystal on a substrate. The crystal can comprise many types of ionic crystals, such as sodium chloride or potassium chloride. A second thin layer of a different type of ionic crystal can be deposited above the first ionic crystal layer, such as lithium fluoride or sodium fluoride. An inert metal layer can be deposited between the first and second layers of ionic crystal and above the second layer of ionic crystal. When the first and second ionic crystal layers are radiated with gamma rays, they form color centers at the spots radiated. Because of the difference in crystalline properties of the two different ionic crystal centers, their color centers have different wavelengths. Each of the ionic crystal layers emit light at different characteristic wavelengths when illuminated at their unique absorption frequencies, and can be made to lase separately. | 06-30-2011 |
20110169497 | SHUNT CALIBRATION FOR ELECTRONIC PRESSURE SWITCHES - Disclosed herein is an electronic switch that comprises a pressure sensitive bridge array adapted to monitor pressure and activate an indicator when the monitored pressure exceeds a predetermined value indicative of a dangerous condition. The electronic switch further comprises a monitoring circuit adapted to test the overall operability of the pressure sensitive bridge array and its accompanying electronics control circuitry. | 07-14-2011 |
20110185818 | APPARATUS AND METHOD FOR ELIMINATING VARYING PRESSURE FLUCTUATIONS IN A PRESSURE TRANSDUCER - 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 difference between the main and reference pressure results in the sensor providing an differential pressure output. 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, a coiled tube or an adjustable dampening chamber comprising a spiral inlet tube and a volume cavity can be used. The tube length is selected to suppress the pump ripple as applied to the sensor die. In this manner, the pump ripple cannot cause resonance which would result in pressure amplification and which pressure amplification would destroy the sensor. | 08-04-2011 |
20110188994 | METHOD AND SYSTEM FOR DETERMINING GAS TURBINE TIP CLEARANCE - A system for sensing at least one physical characteristic associated with an engine including a turbine having a plurality of blades turning inside a casing, the system including: a pressure sensor coupled substantially adjacent to the casing and including at least one output; a port in the turbine casing for communicating a pressure indicative of a clearance between the blades and casing to the pressure sensor; a cooling cavity substantially surrounding the pressure sensor; and, an inlet for receiving fluid from the engine and feeding the fluid to the cooling cavity to cool the pressure sensor; wherein, the pressure sensor output is indicative of the clearance between the blades and casing. | 08-04-2011 |
20110203381 | CORROSION-RESISTANT HIGH TEMPERATURE PRESSURE TRANSDUCER EMPLOYING A METAL DIAPHRAGM - 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. | 08-25-2011 |
20110235678 | LEADLESS MEDIA PROTECTED FAST RESPONSE RTD SENSOR AND METHOD FOR MAKING THE SAME - The RTD device of the present invention is comprised of a semiconductor substrate and a substantially thin conductive metal layer disposed upon the semiconductor substrate, wherein the conductive metal has a substantially linear temperature-resistance relationship. The conductive layer is etched into a convoluted RTD pattern, which consequently increases the overall resistance and minimizes the overall mass of the RTD assembly. A contact glass cover and a conductive metal-glass frit are placed over the RTD assembly to hermetically seal the RTD. The resultant structure can be “upside-down” mounted onto a header or a flat shim so that the bottom surface of the semiconductor substrate is exposed to the external environment, thus shielding the RTD from external forces. The resultant structure is a low mass, highly conductive, leadless, and hermetically sealed RTD that accurately measures the temperature of liquids and gases and maintains fast response time in high temperatures and harsh environments. | 09-29-2011 |
20110239772 | DIFFERENTIAL TEMPERATURE AND ACCELERATION COMPENSATED PRESSURE TRANSDUCER - A dual diaphragm pressure transducer, or sensor, with compensation for non-pressure effects is disclosed. The pressure sensor can include two pressure transducers located on separate portions of a chip. The first pressure transducer can be a differential pressure transducer, which produces a signal proportional to one or more applied pressures and includes other non-pressure effects. The second pressure transducer can be sealed in a hermetic chamber and thus can produce a signal proportional only to non-pressure effects. The signals can be combined to produce a signal proportional to the applied pressures with no non-pressure effects. The first and second pressure transducers can be physically and/or electrically isolated to improve sealing between the two pressure transducers and prevent pressure leaks therebetween. | 10-06-2011 |
20110239783 | TWO OR THREE-AXIS SHEAR LOAD CELL - A two or three axis load cell capable of measuring axial and one or more shear forces is disclosed. The load cell can comprise a force collector connected by one or more connecting rods to one or more cross pieces. The load cell can comprise a single cross piece and can measure an axial force applied to the load cell and at least one component of shear force applied to the load cell. In other embodiments, the load cell can comprise two cross pieces, disposed at disparate angles, to enable the measurement of an axial force and both components of shear force applied to the force collector. The cross pieces are equipped with a means, such as piezoresistive elements to measure their deflection due to the applied forces on the force collector. The connecting rods can be fitted with additional piezoresistors to measure the axial forces on the force collector. | 10-06-2011 |
20110275192 | FUSION BONDING PROCESS AND STRUCTURE FOR FABRICATING SILICON-ON-INSULATION (SOI) SEMICONDUCTOR DEVICES - A method of fabricating a semiconductor-on-insulator device including: providing a first semiconductor wafer having an about 500 angstrom thick oxide layer thereover; etching the first semiconductor wafer to raise a pattern therein; doping the raised pattern of the first semiconductor wafer through the about 500 angstrom thick oxide layer; providing a second semiconductor wafer having an oxide thereover; and, bonding the first semiconductor wafer oxide to the second semiconductor wafer oxide at an elevated temperature. | 11-10-2011 |
20110283803 | INTERNALLY SWITCHED MULTIPLE RANGE TRANSDUCERS - 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. | 11-24-2011 |
20110296924 | PRESSURE TRANSDUCER EMPLOYING A MICRO-FILTER AND EMULATING AN INFINITE TUBE PRESSURE TRANSDUCER - A pressure transducer assembly for measuring pressures in high temperature environments employing an elongated tube which is terminated at one end by an acoustic micro-filter. The micro-filter is operative to absorb acoustic waves impinging on it with limited or no reflection. To improve the absorption of acoustic waves, the elongated tube may be tapered and/or mounted to a support block and further convoluted to reduce the overall size and mass of the device. A pressure transducer with a diaphragm flush may be mounted to the elongated tube and extend through to the inner wall of the tube. Hot gases propagate through the elongated tube and their corresponding pressures are measured by the transducer. The acoustic filter operates to absorb acoustic waves resultant from the hot gases, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation. | 12-08-2011 |
20120029847 | HIGH TEMPERATURE, HIGH BANDWIDTH PRESSURE ACQUISITION SYSTEM - 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 electronics module. The sensors may be connected to the electronics module via a cable in a first embodiment. In an alternate embodiment, the sensors may be connected to the electronics module via a mating connector located therebetween. A memory component which stores compensation coefficients associated with each of the sensors may also be included in the system to correct errors associated with each sensor. The advantage of the various embodiments is that each sensor does not have any compensation stored thereon and thus, the sensors can be made very small to operate at very high temperatures without any loss of accuracy. | 02-02-2012 |
20120060618 | TORQUE INSENSITIVE HEADER ASSEMBLY - There is disclosed a high pressure sensing header which is relatively insensitive to mounting torque. The header generally includes an outer torque isolating shell which has a “C” shaped cross section with the cylindrical shell surrounding an inner “H” section header. The inner “H” section header has a thick diaphragm and is at least partially surrounded by the torque isolating shell. In this manner, when the header is installed, the installation force is absorbed by the outer shell and there is relatively no installation force or torque exhibited by the inner “H” section which will respond only to stress due to pressure. | 03-15-2012 |
20120073377 | ENHANCED STATIC-DYNAMIC PRESSURE TRANSDUCER SUITABLE FOR USE IN GAS TURBINES AND OTHER COMPRESSOR APPLICATIONS - A transducer comprising a filter assembly that measures low amplitude, dynamic pressure perturbations superimposed on top of a high static pressure through the implementation of a low-pass mechanical filter assembly. The filter assembly may comprise a dual lumen reference tube and a removable filter subassembly further comprising a porous metal filter and narrow diameter tube. The transducer, which may be capable of operating at ultra-high temperatures and in harsh environments, may comprise of a static piezoresistive pressure sensor, which measures the large pressures on the order of 200 psi and greater, and an ultrasensitive, dynamic piezoresistive pressure sensor which may capture small, high frequency pressure oscillations on the order of a few psi. The filter assembly may transmit static pressure to the back of the dynamic pressure sensor to cancel out the static pressure present at the front of the sensor while removing dynamic pressure. | 03-29-2012 |
20120152026 | GAGE PRESSURE TRANSDUCER AND METHOD FOR MAKING THE SAME - 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. | 06-21-2012 |
20120200425 | WIRELESS INTERFACE FOR A PLURALITY OF TRANSDUCERS - A wireless interface system that interfaces with any one of a plurality of transducers of different types, such as pressure sensors, temperature sensors, and current probes. The transducers employ identical connectors with a common connecting scheme. In this manner, any transducer can be connected to a wireless interface which has the same input connection scheme. When the wireless interface is connected to the transducer, a rechargeable battery, which is associated with the wireless interface, is activated. The wireless interface then determines the type of transducer being utilized and provides sufficient circuitry as well as determining the requirements of the connected transducer. In this manner, the wireless interface, besides recognizing and determining the type of transducer, can determine the range of the sensor and can provide specific circuitry to be activated to supply power and to read data from the sensor via common output pins. | 08-09-2012 |
20120216391 | LEADLESS OIL FILLED PRESSURE TRANSDUCER - An oil-filled pressure transducer having reduced back pressure, comprising an alignment plate having a sensor accommodating aperture, a sensor module inserted into the sensor accommodating aperture, a header surrounding the alignment plate, the header having a protruding top surface, and a diaphragm disposed on the protruding top surface to create a relatively small oil accommodating region between the diaphragm and the sensor. This configuration reduces the oil volume required for operation, which ultimately reduces the back pressure applied against the diaphragm. | 08-30-2012 |
20120234098 | GAGE PRESSURE TRANSDUCER AND METHOD FOR MAKING THE SAME - 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. | 09-20-2012 |
20120247219 | PRESSURE TRANSDUCER UTILIZING NON-LEAD CONTAINING FRIT - A piezoresistive sensor device and method for making the same are disclosed. The device comprises a silicon wafer having piezoresistive elements and contacts in electrical communication with the elements. The device further comprises a contact glass coupled to the silicon wafer and having apertures aligned with the contacts. The device also comprises a non-conductive frit for mounting the contact glass to a header glass, and a conductive non-lead glass frit disposed in the apertures and in electrical communication with the contacts. The method for making the device comprises bonding a contact glass to a silicon wafer such that apertures in the glass line up with contacts on the wafer, and filling the apertures with a non-lead glass frit such that the frit is in electrical communication with the contacts. The use of a lead free glass frit prevents catastrophic failure of the device in ultra high temperature applications. | 10-04-2012 |
20120291560 | CORROSION-RESISTANT HIGH TEMPERATURE PRESSURE TRANSDUCER EMPLOYING A METAL DIAPHRAGM - 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. | 11-22-2012 |
20120318068 | TORQUE INSENSITIVE HEADER ASSEMBLY - There is disclosed a high pressure sensing header which is relatively insensitive to mounting torque. The header comprises an outer torque isolating shell which surrounds an inner “H” section header. The inner “H” section header has a thick diaphragm and is surrounded by the torque isolating shell which is secured to the “H” section header at a peripheral flange of the “H” section header. In this manner when the header is installed, the installation force is absorbed by the outer shell and there is no installation force or torque exhibited by the inner “H” section which will respond only to stress due to pressure. The torque isolating shell also contains a top surface which has a counterbore that accommodates a crush ring. When the unit is installed, the crush ring is crushed against an installation wall to enable the inner header to receive pressure without experiencing significant installation force. | 12-20-2012 |
20130091940 | Method and System for Determining Gas Turbine Tip Clearance - A system for sensing at least one physical characteristic associated with an engine including a turbine having a plurality of blades turning inside a casing, the system including: a pressure sensor coupled substantially adjacent to the casing and including at least one output; a port in the turbine casing for communicating a pressure indicative of a clearance between the blades and casing to the pressure sensor; a cooling cavity substantially surrounding the pressure sensor; and, an inlet for receiving fluid from the engine and feeding the fluid to the cooling cavity to cool the pressure sensor; wherein, the pressure sensor output is indicative of the clearance between the blades and casing. | 04-18-2013 |
20130098159 | LOW PASS FILTER SEMICONDUCTOR STRUCTURES FOR USE IN TRANSDUCERS FOR MEASURING LOW DYNAMIC PRESSURES IN THE PRESENCE OF HIGH STATIC PRESSURES - A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. In one embodiment, a method comprises receiving, at a filter, a pressure, wherein the pressure includes a static pressure component and a dynamic pressure component; filtering, by the filter, at least the dynamic pressure component of the pressure; outputting, from the filter, a filtered pressure; receiving, at a first surface of a diaphragm, the pressure; receiving, at a second surface of the diaphragm, the filtered pressure, wherein the second surface of the diaphragm is operatively coupled to the filter; and measuring, at a sensor operatively coupled to the diaphragm, a difference between the pressure and the filtered pressure. | 04-25-2013 |
20130112992 | HIGH TEMPERATURE TRANSDUCER USING SOI, SILICON CARBIDE OR GALLIUM NITRIDE ELECTRONICS - There is disclosed a high temperature pressure sensing system which includes a SOI, silicon carbide, or gallium nitride Wheatstone bridge including piezoresistors. The bridge provides an output which is applied to an analog to digital converter also fabricated using SOI, silicon carbide, or gallium nitride materials. The output of the analog to digital converter is applied to microprocessor, which microprocessor processes the data or output of the bridge to produce a digital output indicative of bridge value. The microprocessor also receives an output from another analog to digital converter indicative of the temperature of the bridge as monitored by a span resistor coupled to the bridge. The microprocessor has a separate memory coupled thereto which is also fabricated from SOI, silicon carbide, or gallium nitride materials and which memory stores various data indicative of the microprocessor also enabling the microprocessor test and system test to be performed. | 05-09-2013 |
20130298700 | Pressure Transducer Utilizing Non-Lead Containing Frit - A piezoresistive sensor device and a method for making a piezoresistive device are disclosed. The sensor device comprises a silicon wafer having piezoresistive elements and contacts in electrical communication with the elements. The sensor device further comprises a contact glass coupled to the silicon wafer and having apertures aligned with the contacts. The sensor device also comprises a non-conductive frit for mounting the contact glass to a header glass, and a conductive non-lead glass frit disposed in the apertures and in electrical communication with the contacts. The method for making a piezoresistive sensor device, comprises bonding a contact glass to a silicon wafer such that apertures in the glass line up with contacts on the wafer, and filling the apertures with a non-lead glass frit such that the frit is in electrical communication with the contacts. The use of a lead free glass frit prevents catastrophic failure of the piezoresistive sensor and associated transducer in ultra high temperature applications. | 11-14-2013 |
20130312532 | CORROSION-RESISTANT HIGH TEMPERATURE PRESSURE TRANSDUCER EMPLOYING A METAL DIAPHRAGM - 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. | 11-28-2013 |
20130327150 | METHOD OF JOINING A PRESSURE SENSOR HEADER WITH AN ASSOCIATED TRANSDUCER ELEMENT - A pressure transducer assembly including: a pressure sensor header; a transducer assembly member; and a joining arrangement disposed at an interface of the header and the transducer assembly member, for joining the header with the transducer assembly member, the joining arrangement including: a recessed female joining element formed in one of the header and the transducer assembly member; and a protruding male joining element formed on the other of the header and the transducer assembly member, the male joining element received in the female joining element. | 12-12-2013 |
20140041457 | Apparatus and Method for Eliminating Varying Pressure Fluctuations in a Pressure Transducer - A differential pressure transducer employing a coiled tube to eliminate varying pressure fluctuations is provided. In one embodiment, a method comprises receiving, at an inlet tube of a dampening chamber, a main pressure, wherein the main pressure includes a static pressure component and a dynamic pressure component; filtering, by the inlet tube, at least a portion of the dynamic pressure component of the main pressure; outputting, from the inlet tube, a first filtered main pressure; receiving, at a volume cavity of the dampening chamber, the first filtered main pressure, wherein the volume cavity is operatively coupled to the inlet tube; filtering, by the volume cavity, at least a portion of the dynamic pressure component of the first filtered main pressure; outputting, from the volume cavity, a second filtered main pressure; and wherein the dampening chamber is tuned to a predetermined resonance frequency. | 02-13-2014 |
20140053652 | Gage Pressure Transducer and Method for Making the Same - A method, device and system for a gage pressure transducer including the making thereof are provided. In one embodiment, a method comprises receiving, at a first diaphragm, a first pressure, wherein the first diaphragm is composed of metal; transferring, from the first diaphragm, to a first sensor, the first pressure using a first oil region, wherein the first oil region is disposed between the first diaphragm and the first sensor; receiving, at the first sensor, the first pressure; measuring, by the first sensor, the first pressure to generate a first pressure signal; and outputting, from the first sensor, to a first header pin, the first pressure signal, wherein the first header pin is electrically coupled to the first sensor using a first conductive glass frit. | 02-27-2014 |
20140067288 | High Temperature, High Bandwidth Pressure Acquisition System - A method, device and system are provided for measuring multiple pressures under severe conditions. In one embodiment, a method comprises receiving, by a processor, from a first sensor, a first pressure signal; receiving, by the processor, from a second sensor, a second pressure signal; receiving, by the processor, from a first memory, a first correction coefficient for the first sensor; receiving, by the processor, from a second memory, a second correction coefficient for the second sensor; modifying, by the processor, the first pressure signal using the first correction coefficient to generate a first corrected pressure signal; modifying, by the processor, the second pressure signal using the second correction coefficient to generate a second corrected pressure signal; and outputting, by the processor, the first corrected pressure signal and the second corrected pressure signal. | 03-06-2014 |
20140090477 | INTERNALLY SWITCHED MULTIPLE RANGE TRANSDUCERS - Systems and methods for an internally switched multiple range transducer are provided. In one embodiment, a method comprises receiving, at a first sensor, a pressure, wherein the first sensor is associated with a first pressure range; measuring, at the first sensor, the pressure to generate a first pressure signal; in response to determining that the first pressure signal is not associated with the first pressure range, activating a second sensor, wherein the second sensor is associated with a second pressure range that is different from the first pressure range; and measuring, at the second sensor, the pressure to generate a second pressure signal. | 04-03-2014 |
20140123771 | PRESSURE TRANSDUCER UTILIZING NON-LEAD CONTAINING FRIT - A piezoresistive sensor device and a method for making a piezoresistive device are disclosed. In one example, a method may comprise receiving, by a sensor device having a contact, a pressure; measuring, by the sensor device, the pressure to generate a pressure signal; outputting, by the sensor device, to the contact, the pressure signal; and receiving, by a header pin, from the contact, the pressure signal, wherein the header pin and the contact are electrically coupled using a conductive, non-lead containing frit and are aligned using a contact cover that is coupled to the sensor device using a non-conductive, non-lead containing frit. | 05-08-2014 |
20140130611 | PRESSURE TRANSDUCER STRUCTURES SUITABLE FOR CURVED SURFACES - A flexible transducer structure suitable for attaching to a curved surface such as the leading edge of an aircraft wing is provided. In one example embodiment, a method may include receiving, at a sensor disposed on a flexible sheet, a pressure, wherein the sensor is electrically coupled to a conductive trace disposed on the flexible sheet; measuring, by the sensor, the pressure to generate a pressure signal; outputting, by the sensor, to the conductive trace, the pressure signal, wherein the conductive trace extends away from the sensor on the flexible sheet; and wherein the flexible sheet is adaptable to conform to a contour of a curved surface. | 05-15-2014 |
20140165735 | MATCHING BACK PRESSURES ON DIFFERENTIAL OIL-FILLED DIAPHRAGMS - Exemplary embodiments of the present invention provide a differential pressure transducer that comprises first and second diaphragms of different configurations, i.e., different diameters and/or thicknesses. The pressure transducer provides more versatility over prior art designs as the diaphragms can be of different configurations yet still maintain substantially similar back pressures. Therefore, the errors commonly associated with back pressures are eliminated because the back pressures from the diaphragms ultimately cancel out in the sensor's differential pressure measurement. | 06-19-2014 |
20140331775 | LOW PASS FILTER SEMICONDUCTOR STRUCTURES FOR USE IN TRANSDUCERS FOR MEASURING LOW DYNAMIC PRESSURES IN THE PRESENCE OF HIGH STATIC PRESSURES - A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. In one embodiment, a method comprises receiving, at a filter having a plurality of apertures, a pressure, wherein the pressure includes a static pressure component and a dynamic pressure component; filtering, by the plurality of apertures, at least a portion of the dynamic pressure component of the pressure, wherein a diameter of each of the plurality of apertures is such that the plurality of apertures filters at least the portion of the dynamic pressure component of the pressure; outputting, from the filter, a filtered pressure; and wherein the filtered pressure is used to determine the dynamic pressure component of the pressure. | 11-13-2014 |