Measurement Specialties, Incorporated

James Hoffman

David Eric Wagner

Ya-Mei Chen

Gerald Lopopolo

Natasha V Kachenko

Kaspar L Jenni

A sensor assembly includes a sensor and an overload stop disposed on a surface of the sensor. The sensor has a resilient central region and an outer region surrounding the central region. The overload stop includes a center stop disposed on the central region and a peripheral stop disposed on the outer region.

Sensor assembly having an overload stop

The sensor assembly comprises a sensor die comprising first and second members. The first member accommodates an actuation element on a second surface of the first member and in contact with a diaphragm that is integral with the first member. The second member is bonded to a first surface of the first member opposite the second surface, and sensing elements are positioned adjacent the diaphragm along the first surface and interposed between the first and second members. The second member also includes a recessed section that forms a cavity adjacent the diaphragm to accommodate and/or limit diaphragm deflection. An internal electrical connection is made between first and second member electrical contacts disposed along the interface between the first and second members to avoid external wires. The second member further includes external electrical terminals to facilitate an electrical surface connection with the sensor assembly without the need for external wires.

Sensor assemblies with integrated electrical connections and diaphragm overload protection

Sensor devices comprise a sensor die having a first membrane between a first outside surface and a buried cavity, and a second membrane between the buried cavity and a recessed section of the sensor die forming a backside cavity, wherein the first and second membranes oriented vertically adjacent one another. The sensor die comprises first and second members that are attached together, the buried cavity is formed between the members, and the first member comprises the first diaphragm and the second member comprises the second diaphragm. The membranes are configured to enable sensing over different ranges. Electrical sensing elements are in the sensor die for measuring movement of each of the first and second sensing membranes over the different ranges. Electrical contacts connected with sensing elements are exposed along a sensor die surface for providing an output signal for monitoring by an external device.

Sensor assemblies with multirange construction

A differential pressure sensor includes one or more semiconductor dies which are thinned at portions of the die to create a chamber defining a sensitive diaphragm, having piezoresistive elements defined at a surface of the diaphragm. A first diaphragm is in fluid communication with a first fluid on an upper surface of the first diaphragm and is in fluid communication with a second fluid on a lower surface of the first diaphragm. A second diaphragm is in fluid communication with ambient pressure at an upper and a lower surface of the second diaphragm. The piezoresistive elements corresponding to the second diaphragm are electrically connected to the piezoresistive elements of the first diaphragm so as to compensate the output of the second diaphragm with respect to the output of the first diaphragm.

Method and apparatus for correction of pressure sensors

A differential pressure sensor may provide a common mode corrected differential pressure reading. The differential pressure sensor may include two pressure sensing diaphragms. The pressure sensor may be configured so that the first diaphragm measures the differential pressure between two sections of a fluid. The pressure sensor may also be configured so that the second diaphragm measures the common mode error experienced by the die at the time the differential pressure is read by the first diaphragm. Electrical connectors may be configured so that the differential pressure outputs a common mode error corrected differential pressure reading based on the readings of the first and second diaphragm.

Differential pressure sensor incorporating common mode error compensation

A differential pressure sensor includes a pressure sensing die comprising a semiconductor die, having a thinned portion forming a diaphragm. The diaphragm includes piezo-resistive elements that exhibit varying resistance based on force exerted on the diaphragm. A first support structure is bonded to a first surface of the semiconductor die, having an aperture defined through the support structure such that a first surface of the diaphragm is exposed through the aperture. A second support structure is bonded to the opposite side of the semiconductor die having an aperture aligned with the opposing side of the diaphragm. Electrical components in electrical communication with the piezo-resistive elements are arranged outside the region defined by the bond between the first and second support structures and the semiconductor die. An oil-filled volume may be defined between the semiconductor die and a harsh medium which transmits a fluid pressure to the die without the harsh medium contacting the die.

Differential pressure sensing die

An electronic pressure-sensing device is isolated from corrosive, conductive gasses and fluids by a corrosion resistant metal diaphragm welded to a pressure port. The pressure-sensing device is attached to a support structure with a hole that provides a path from the diaphragm area to the pressure-sensing device. A fill fluid is sealed behind the diaphragm and fills the hole through the support structure to the electronic pressure-sensing device. In this design, any hostile chemical applied is completely isolated from the electronic sensor and associated adhesive seals by the metal diaphragm.

Isolation technique for pressure sensing structure

A strain-sensing device comprises a metal, glass, ceramic, or plastic cell that has formed within it a diaphragm characterized by a thin layer of material bounded by a thick layer of material. A silicon strain gauge, either junction isolated or dielectric isolated, is attached directly to the diaphragm. The strain gauge has at least one sensing element that is aligned such that applied pressure to the diaphragm induces a strain in the sensing element. The silicon strain gauge has a triangular shape that is optimizes the performance and reliability of the sensor with the added benefit of making it more affordable as well.

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Santa Clara, CA, United States of America

James Hoffman