Abstract: A progressive stopper for a pressure sensing element is able to redistribute and reduce the stress of a diaphragm exposed to high pressure via multi-step contacts, such as at least dual contacts, where the diaphragm (designed for detecting pressure within a defined pressure range) is enabled to withstand much higher pressures above of the defined pressure range, such that the progressive stopper prevents catastrophic failure of the diaphragm. The progressive stopper is created to redistribute and reduce stress on the diaphragm significantly and effectively. The progressive stopper does not limit the output of the pressure sensing element such that the pressure sensing element is able to maintain the output voltage above the maximum output voltage of the defined pressure range when the diaphragm is exposed to high pressures with reduced stresses and strains.

Abstract: 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.

Abstract: 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.

Abstract: A pressure sensing element includes a supporting substrate including a cavity. A device layer is bonded to the supporting substrate, with a diaphragm of the device layer covering the cavity in a sealed manner. A plurality of piezoresistors is coupled to the diaphragm. A plurality of metal stress equalizers is disposed on the device layer such that each stress equalizer is generally adjacent to, but separated from, a corresponding piezoresistor. A plurality of metal bond pads is disposed on the device layer. The plurality of stress equalizers are constructed and arranged to reduce thermal hysteresis of the pressure sensing element caused by stress relaxation of the metal bond pads during a cooling and heating cycle of the pressure sensing element.

Abstract: A pressure sensing element includes a supporting substrate including a cavity. A device layer is bonded to the supporting substrate, with a diaphragm of the device layer covering the cavity in a sealed manner. A plurality of piezoresistors is coupled to the diaphragm. A plurality of metal stress equalizers is disposed on the device layer such that each stress equalizer is generally adjacent to, but separated from, a corresponding piezoresistor. A plurality of metal bond pads is disposed on the device layer. The plurality of stress equalizers are constructed and arranged to reduce thermal hysteresis of the pressure sensing element caused by stress relaxation of the metal bond pads during a cooling and heating cycle of the pressure sensing element.

Abstract: A MEMS pressure sensing element and integrated circuit (IC) are mounted on a circuit board. The sensing element and IC can be either stacked or unstacked. Bond wires connect the IC to the circuit board. Other bond wires connect the sensing element to the IC. A cap covers the sensing element and IC. The cap is attached to the circuit board and has a small hole in it, through which viscous gel is inserted. The gel encapsulates the MEMS sensing element, IC and bond wires in the cap. The hole also allows pressurized fluid to enter the cap and exert force on the MEMS pressure sensing element after encapsulation in the gel. Chip capacitors can also be mounted on the circuit board, outside the cap. Electrical signals are generated, which represent pressure applied to the MEMS pressure sensing element through the hole and gel.

Abstract: A pressure sensor includes a pressure sensing element in fluid communication with a port and an oil separator in the port. The oil separator is configured to reduce an amount of oil-vapor residue that reaches the pressure sensing element by elongating a path of fluid from an opening of the port to the pressure sensing element and by creating additional surface area within the port upon which oil-vapor residue may be deposited. There is also a cover, which has holes, and that is configured to prevent the oil separator from falling out of the port. The oil separator may include circular discs having cut-out portions. The cut-out portions on adjacent circular discs may be rotated relative to one another about a longitudinal axis of the oil separator. The cut-out portions may have a semi-circular shape.

Abstract: An automotive electronic device includes a pocket, which houses electronic components, bond wires connecting the electronic components, and a protective gel to encapsulate the electronic components and bond wires. A pocket cover has fins that protrude into the gel to reduce vibration of the gel and reduce vibration fatigue failure of the bond wires. The fins may: divide the gel into a plurality of cells; reduce the width of cells perpendicular to the bond wires; protrude deeper into the gel than the bond wires; and/or have differing shapes and/or depths.

Abstract: An improved microelectromechanical system (MEMS) pressure sensing device has an extended shallow polygon cavity on a top side of a silicon supporting substrate. A buried silicon dioxide layer is formed between the top side of the supporting substrate and a bottom side of a device layer. Piezoresistors and bond pads are formed and located on a top side of the device layer and produce measureable voltage changes responsive to a fluid pressure applied to the device layer. The purpose of the extend shallow polygon cavity is to improve the sensitivity or increase the span while keep a low pressure nonlinearity during shrinking the die size of the MEMS pressure sensing device die with corner metal bond pads having a keep-out distance to prevent a wire bonder from breaking the thin diaphragm.

Abstract: A pressure sensor device with a MEMS piezoresistive pressure sensing element attached to an in-circuit ceramic board comprises a monolithic ceramic circuit board formed by firing multiple layers of ceramic together. The bottom side of the circuit board has a cavity, which extends through layers of material from the ceramic circuit board is formed. A ceramic diaphragm, which is one of the layers, has a peripheral edge. The diaphragm's thickness enables the diaphragm bounded by the edge to deflect responsive to applied pressure. A MEMS piezoresistive pressure sensing element attached to the top side of the ceramic circuit board generates an output signal responsive to deflection of the ceramic diaphragm. A conduit carrying a pressurized fluid (liquid or gas) can be attached directly to the ceramic circuit board using a seal on the bottom of the ceramic circuit board, which surrounds the opening of the cavity through the bottom.

Abstract: In order to do multiple synchronized calibrations, chip capacitors are mounted outside of each of multiple caps on a circuit board. Each cap confines a MEMS pressure sensing element, an ASIC and bond wires to form multiple first-level pressure sensor packages. After calibrations, each singulated pressure sensor package can be installed in a pre-formed plastic housing having connector pins or overmolded with connector pins to form a MEMS pressure sensor. Gel encapsulates the MEMS pressure sensing element, ASIC and bond wires inside each cap to prevent contamination. The volume of gel can be reduced by a cap having an orifice through which the gel is dispensed into the cap. The cap is also used to isolate thermal stresses transferred over from epoxy or overmold in the second-level packaging. The cap, which when made of metal, reduces electromagnetic interference (EMI) or acts as an electrostatic discharge (ESD) shield.

Abstract: Suspending a microelectromechanical system (MEMS) pressure sensing element inside a cavity using spring-like corrugations or serpentine crenellations, reduces thermally-mismatched mechanical stress on the sensing element. Overlaying the spring-like structures and the sensing element with a gel further reduces thermally-mismatched stress and vibrational dynamic stress.

Abstract: The voltage output span and sensitivity from a MEMS pressure sensor are increased and pressure nonlinearity is reduced by thinning a diaphragm and forming the diaphragm to include anchors that are not connected to or joined to diaphragm-stiffening beams or thickened regions of the diaphragm.

Abstract: An improved microelectromechanical system (MEMS) pressure sensing device has an extended shallow polygon cavity on a top side of a silicon supporting substrate. A buried silicon dioxide layer is formed between the top side of the supporting substrate and a bottom side of a device layer. Piezoresistors and bond pads are formed and located on a top side of the device layer and produce measureable voltage changes responsive to a fluid pressure applied to the device layer. The purpose of the extend shallow polygon cavity is to improve the sensitivity or increase the span while keep a low pressure nonlinearity during shrinking the die size of the MEMS pressure sensing device die with corner metal bond pads having a keep-out distance to prevent a wire bonder from breaking the thin diaphragm.

Abstract: Electrical and mechanical noise in a microelectromechanical system (MEMS) pressure sensor are reduced by the symmetrical distribution of bond pads, conductive vias and interconnects and by the elimination of bond wires used in the prior art to connect a MEMS pressure sensing element to an application specific integrated circuit (ASIC). The bond wires are eliminated by using conductive vias to connect an ASIC to a MEMS pressure sensing element. Extraneous electrical noise is suppressed by conductive rings that surround output signal bond pads and a conductive loop that surrounds the conductive rings and bond pads. The conductive rings and loop are connected to a fixed voltage or ground potential.

Abstract: In a microelectromechanical system (MEMS) pressure sensor, thin and fragile bond wires that are used in the prior art to connect a MEMS pressure sensing element to an application specific integrated circuit (ASIC) for the input and output signals between these two chips are replaced by stacking the ASIC on the MEMS pressure sensing element and connecting each other using conductive vias formed in the ASIC. Gel used to protect the bond wires, ASIC and MEMS pressure sensing element can be eliminated if bond wires are no longer used. Stacking the ASIC on the MEMS pressure sensing element and connecting them using conductive vias enables a reduction in the size and cost of a housing in which the devices are placed and protected.

Abstract: The voltage output span and sensitivity from a MEMS pressure sensor are increased and pressure nonlinearity is reduced by thinning a diaphragm and forming the diaphragm to include anchors that are not connected to or joined to diaphragm-stiffening beams or thickened regions of the diaphragm.

Abstract: A pressure sensor includes a pressure sensing-element in fluid communication with a port and an oil separator in the port. The oil separator is configured to reduce an amount of oil-vapor residue that reaches the pressure sensing element by elongating a path of fluid from an opening of the port to the pressure sensing element and by creating additional surface area within the port upon which oil-vapor residue -may be deposited. There is also a cover, which has holes, and that is configured to prevent the oil separator from felling out of the port. The oil separator may include circular discs having cut-out portions. The cut-out portions on adjacent circular discs may he rotated relative to one another about a longitudinal axis of the oil separator. The cut-out portions may have a semi-circular shape.

Abstract: The voltages output from a low-pressure MEMS sensor are increased by increasing the sensitivity of the sensor. Sensitivity is increased by thinning the diaphragm of the low pressure sensor device. Nonlinearity increased by thinning the diaphragm is reduced by simultaneously creating a cross stiffener on the top side of the diaphragm. An over-etch of the top side further increases sensitivity.

Abstract: Suspending a microelectromechanical system (MEMS) pressure sensing element inside a cavity using spring-like corrugations or serpentine crenellations, reduces thermally-mismatched mechanical stress on the sensing element. Overlaying the spring-like structures and the sensing element with a gel further reduces thermally-mismatched stress and vibrational dynamic stress.