A method of fabricating a capacitive micromechanical electrical system (MEMS) pressure sensor includes the steps of forming a backing wafer, forming a diaphragm wafer that includes a diaphragm configured to deflect from an applied force and a pressure cavity configured to produce on the diaphragm the applied force which is indicative of a system pressure; fusing the diaphragm wafer to the backing wafer thereby forming a base wafer, forming a top wafer, joining the top wafer to the base wafer, thereby forming a detector wafer. The diaphragm defines a first capacitor surface and the top wafer defines a second capacitor surface. A void separates the second capacitor surface from the first capacitor surface by a separation distance which is a capacitor gap. A capacitive MEMS pressure sensor is also disclosed.

Embodiments in accordance with the present disclosure are directed to sensor apparatuses utilizing a one-piece thermal isolated fitting (TIF) tube and methods of assembling the same. In a particular embodiment, a sensor apparatus includes a one-piece thermal isolated fitting (TIF) tube that includes a cylindrical shaped body portion and a flange at one end of the TIF tube. In this example embodiment, the flange has a top surface that is facing away from the cylindrical shaped body portion and an underside surface that is facing towards the cylindrical shaped body portion.

A die attachment to a support is disclosed. In an embodiment, a semiconductor package includes a support and a die attached to the support by an adhesive on a backside of the die, wherein the die includes a capacitive pressure sensor integrated on a CMOS read-out circuit, and wherein the adhesive covers only a part of the backside of the die.

A differential MEMS pressure sensor includes a topping wafer with a top side and a bottom side, a diaphragm wafer having a top side connected to the bottom side of the topping wafer and a bottom side, and a backing wafer having a top side connected to the bottom side of the diaphragm wafer and a bottom side. The topping wafer includes a first cavity formed in the bottom side of the topping wafer. The diaphragm wafer includes a diaphragm, a second cavity formed in the bottom side of the diaphragm wafer underneath the diaphragm, an outer portion surrounding the diaphragm, and a trench formed in the top side of the diaphragm wafer and positioned in the outer portion surrounding the diaphragm.

A device (1) for performing ultrasonic examinations and pressure measurements comprises an ultrasonic transducer (60), a pressure sensor (50), a housing (10) to accommodate the ultrasonic transducer (60) and the pressure sensor (50), a support plate (40) arranged in the housing (10) and a flexible membrane (21) arranged on the end face of the housing. A sealed chamber (47) for receiving a liquid medium is formed between the membrane (21) and the support plate (40), and the ultrasonic transducer (60) and the pressure sensor (50) are arranged on the support plate (40) in such a way that a first transmission surface of the ultrasonic transducer (60) and a second transmission surface of the pressure sensor (50) are directed towards the chamber (47).

A method for manufacturing a micromechanical sensor, in particular a pressure difference sensor, including creating a functional layer on a substrate; creating at least one rear side trench area proceeding from a rear side of a substrate, for exposing the functional layer for a sensor diaphragm; creating at least one front side trench area for forming at least one supporting structure, in particular an energy storage structure, preferably in the form of a spring structure, in the substrate as a mounting for the sensor diaphragm; and at least partially filling at least a front side trench area with a gel.

A diaphragm-based sensor includes a deflectable diaphragm, a base layer opposite the diaphragm, and a corrugated wall extending between the diaphragm and the base layer. The diaphragm is suspended over a cavity enclosed by the diaphragm, the base layer and the corrugated wall. The diaphragm includes a first electrode and the base layer includes a second electrode such that a capacitance between the first and second electrodes changes when the diaphragm is deflected relative to the cavity.

A pressure sensing element, including a substrate, a device layer coupled to the substrate, a diaphragm being part of the device layer, and a plurality of piezoresistors coupled to the diaphragm. A plurality of bond pads is disposed on the device layer, and an electrical field shield is bonded to the top of device layer and at least one of the bond pads. At least one stress adjustor is part of the electrical field shield, where the stress adjustor is a cut-out constructed and arranged to reduce thermal hysteresis of the pressure sensing element caused by stress relaxation of the electrical field shield during a cooling and heating cycle. The stress adjustor may be a thin film deposited on top of the electrical field shield, which may apply residual stress to the piezoresistors. The pressure sensing element may include a cavity integrally formed as part of the substrate.

A pressure sensing element, including a substrate, a device layer coupled to the substrate, a diaphragm being part of the device layer, and a plurality of piezoresistors coupled to the diaphragm. A plurality of bond pads is disposed on the device layer, and an electrical field shield is bonded to the top of device layer and at least one of the bond pads. At least one stress adjustor is part of the electrical field shield, where the stress adjustor is a cut-out constructed and arranged to reduce thermal hysteresis of the pressure sensing element caused by stress relaxation of the electrical field shield during a cooling and heating cycle. The stress adjustor may be a thin film deposited on top of the electrical field shield, which may apply residual stress to the piezoresistors. The pressure sensing element may include a cavity integrally formed as part of the substrate.

In an embodiment, a semiconductor package includes a support and a stack of two or more semiconductor dies, the stack including an upper die and further including a lower die attached to the support by adhesive on a backside of the lower die, wherein the adhesive covers only part of the backside of the lower die, and wherein the adhesive has a plurality of non-contiguous regions on the backside of the lower die.