Kavlico Corporation

Custom Sensors & Technologies, Inc.

Horst Obermeier

Robert D Hunter

Peter H Seesink

Omar Abed

Calin Miclaus

Saleh U Ahmed

Dan Rodriguez

Described herein is a method for integrating MEMS with submicron semiconductor electrical circuits such as CMOS to provide more complex signal processing, on-chip calibration and integration with RF technologies. A MEMS sensor is provided having an upper layer, an insulating layer into which a cavity has been formed and a handle layer. The upper layer acts as both the substrate of the semiconductor electrical circuit and as the active MEMS element. The remainder of the circuitry is fabricated either in or on the upper layer. In a preferred method of the present invention a first wafer assembly and a second wafer assembly are fabricated such that a MEMS sensor and the substrate of at least one semiconductive electrical circuit is formed.

Cointegrated MEMS sensor and method

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

Reliable piezo-resistive pressure sensor

A pre-stressed capacitive pressure transducer is disclosed which is capable of withstanding an applied high pressure. The transducer incorporates a pre-stress mechanism comprising upper and lower pre-stress members which are welded together to apply a compressive force to the transducer sealing means. The compressive force serves to improve the transducer seal resistance to high pressure damage. The pre-stress mechanism may also be adapted to provide additional overpressure protection by bottoming out against the transducer input flange. A method of forming such a pre-stressed transducer is also disclosed. The pre-stress mechanism and method can be easily adapted to meet the requirements of a wide variety of transducers without requiring modification of the transducer internal design parameters.

Pre-stressed pressure transducer and method of forming same

A stable pressure transducer system is disclosed. The transducer system includes a variable capacitor having conductive plates with one of the conductive plates being associated with a diaphragm variable under pressure changes to vary the capacitance of the variable capacitor. The system also includes a reference capacitor. Circuitry for applying signals to the pressure variable and the fixed reference capacitor is used to obtain outputs from each of the capacitors with the output from the variable capacitor varying in amplitude with its capacitance. Circuitry for differentially combining the outputs from the variable and fixed capacitors provides an output voltage indicating the pressure applied to the diaphragm. In order to stabilize the output of the transducer, an isolating capacitor having a capacitance value at least several times greater than the capacitance of the variable and reference capacitors is coupled in series with one or both of the variable and reference capacitors. Preferably two isolation capacitors are used, one in series with each of said variable and reference capacitors on either side thereof. However, in some cases a single isolating capacitor between a common output point of the variable and fixed capacitors and ground may be effective.

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Huellhorst, Germany

Horst Obermeier