Honeywell G.m.b.h.

Other

Maxim Integrated Products, Inc.

Wisconsin Alumni Research Foundation

Honeywell International Inc.

David W Burns

Janusz Bryzek

Steven Saeed Nasiri

Henry Guckel

William R Herb

Sean S Cahill

J David Zook

Thomas George Stratton

James Kevin Carney

Robert D Horning

Max C Glenn

G Benjamin Hocker

Deidrich J Saathoff

Scott A McPherson

Akintunde I Akinwande

James D Zook

Amir R Mirza

Daniel W Youngner

Richard H Frische

James B Starr

An optically coupled resonator includes a resonator body having at least one resonator sidewall and a laterally offset photodiode formed in a semiconductor substrate adjacent to the resonator body. The resonator is driven by an electric field generated between the laterally offset photodiode and the resonator body when an incident light strikes the photodiode. A device including an optically coupled resonator and a method of operating an optically coupled resonator are also disclosed.

Optically coupled resonator

A process for fabricating an optically coupled resonant pressure sensor includes the steps of forming a sensor die including at least one optically coupled resonator from a first semiconductor substrate and forming a cap die including a fiber hole from a second semiconductor substrate. The sensor die and the cap die are aligned and bonded to form a resonant pressure sensor capsule. The fiber hole in the cap die is aligned with at least one resonator on the sensor die. Also disclosed is an optically coupled resonant pressure sensor formed from steps thereof.

Optically coupled resonant pressure sensor and process

A method for determining a resonant frequency of an optically coupled resonator includes modulating an incident light and striking a laterally offset photodiode with the modulated incident light. An electric field is generated between the laterally offset photodiode and the resonator in response to the modulated incident light, and the resonator is driven with a driving component of the generated electric field. A reflected light from the resonator is sensed, and the resonant frequency of the resonator is determined based on the reflected light. A system for determining a resonant frequency of an optically coupled resonator and a method of sensing an applied stimulus are also disclosed.

Optical and electronic interface for optically coupled resonators

An optically coupled resonant pressure sensor includes a deformable diaphragm and an optically coupled resonator fixedly attached to the deformable diaphragm. The resonator includes a resonator body and a laterally offset photodiode adjacent to the resonator body. The resonator is driven by an electric field generated between the laterally offset photodiode and the resonator body when an incident light strikes the photodiode. Pressure applied to one side of the deformable diaphragm causes a shift in a resonant frequency of the resonator. Also disclosed are a method and system for determining pressure.

Optically coupled resonant pressure sensor

A process to form a laterally offset photodiode for an optically coupled resonator includes implanting a semiconductor substrate to form the laterally offset photodiode adjacent to the resonator. The resonator masks the implanting underneath the resonator when the semiconductor substrate is implanted. Also disclosed is an optically coupled resonator, a process for fabricating an optically coupled resonator, and a device including an optically coupled resonator having a laterally offset photodiode.

Optically coupled sealed-cavity resonator and process

A sensor device for detecting vibration, including a laser light, a first optical fiber for transmitting the laser light, an oscillator to receive the transmitted laser light and reflect the light as a frequency modulated light; a second optical fiber to transmit the frequency modulated light; and a frequency modulated discriminator for receiving the frequency modulated light from the second optical fiber and producing a signal responsive of vibration of the oscillator. In a preferred embodiment, the frequency modulated discriminator further includes a frequency meter for determining the average number of cycles per unit time to provide a second signal responsive of the temperature of the oscillator. The optical fibers may be a pair of different fibers positioned for transmitting the laser light and the frequency modulated light respectively, or the same fiber positioned for transmitting both the laser light and the frequency modulated light.

Fiber-optic vibration sensor based on frequency modulation of light-excited oscillators

A multi-material resonant thin film beam for a micromechanical sensor having a zero temperature coefficient of frequency (TCF) which is the resonant frequency shift with temperature change. One of the materials may be polysilicon and the other material may be silicon nitride or silicon oxide. Each material has a different thermal coefficient of expansion. The proportion of the various materials is adjusted and the specific geometries are determined so that the TCF is zero. One embodiment is a microbeam composed of two polysilicon thin films with a silicon nitride thin film inserted between the polysilicon films. The thickness of the silicon nitride film may be adjusted to trim the TCF to zero. The film of nitride instead may be placed on one side of a polysilicon film to form a beam. Dual or multiple beam resonators likewise may be made with several materials. The nitride may be placed in the shank areas which join and secure the ends of the beams. Such zero TCF beams may be incorporated in microsensor structures for measuring pressure, temperature, strain and other parameters.

Zero TCF thin film resonator

A hermetic media interface for a sensor package is disclosed. Preferably, the hermetic media interface is incorporated into a pressure sensor package for interfacing directly to fluid and/or gaseous media. In one embodiment, the pressure sensor package includes a semiconductor die and a pressure port that are housed in a pre-molded plastic package. A eutectic solder is coupled between the semiconductor die and the pressure port to solder the same to the semiconductor die. The semiconductor die may be metallized to enhance solderability. In an alternative embodiment, the pressure port is made from one or more plastic materials and the pressure port is attached to the semiconductor die with an adhesive. An integral stress-isolation region may optionally be incorporated on the semiconductor die.

Hermetic packaging for semiconductor pressure sensors

A chip-scale sensor package is described. In one embodiment, the chip-scale sensor package includes a semiconductor substrate having a sensor region, and a semiconductor cap having a recess. The semiconductor cap is bonded to the semiconductor substrate with a thermocompression bond to form a cavity therebetween. The semiconductor substrate is bonded to the semiconductor cap using different types of materials. The semiconductor substrate and/or the semiconductor cap may optionally include a semiconductor device such as an electronically trimmable integrated circuit fabricated thereon. In addition, the semiconductor substrate may optionally include an integral stress isolation flexible region for isolation of the sensor region.

Chip-scale packaged pressure sensor

A rigid encapsulation package for semiconductor sensors, actuators, and devices is described. In one embodiment, a semiconductor pressure sensor includes a sensor element having a deformable diaphragm for measurement of pressure, and a cap that includes a recess. The cap is attached to the sensor element to form a cavity therebetween. The pressure sensor further includes a leadframe, interconnecting bond wires, a pressure port that is coupled to the sensor element, and a nominally rigid material formed over the sensor element, cap, leadframe, and bond wires. The material may include one or more of the following: epoxy, RTV, resins, and gel. The sensor element may include a built-in stress isolation flexible region. A second pressure port may optionally be attached to the housing for providing differential or gage pressure measurements.

Rigid encapsulation package for semiconductor devices

A sensor device for detecting vibration, including a light source for providing a laser light, a first optical fiber connected to the source for transmitting the laser light, an oscillator positioned to receive the transmitted laser light and adapted to reflect the light as a frequency modulated light; a second optical fiber positioned to capture the frequency modulated light to transmit the frequency modulated light; and a frequency modulated discriminator for receiving the frequency modulated light from the second optical fiber and producing a signal responsive of vibration of the oscillator. In a preferred embodiment, the frequency modulated discriminator further includes a frequency meter for determining the average number of cycles per unit time to provide a second signal responsive of the temperature of the oscillator. The optical fibers may be a pair of different fibers positioned for transmitting the laser light and the frequency modulated light respectively, or the same fiber positioned for transmitting both the laser light and the frequency modulated light. In this latter embodiment, the device further includes a beam splitter to direct the frequency modulated light to the discriminator. The preferred oscillator includes a microchip having a microbeam mounted on a thin silicon cantilever such that deflection of the beam perpendicular to the plane of the microchip changes the tension in the microbeam to change its resonant frequency. Also preferred is a microbeam including a thin metal deposit to create a bimorph structure.

A semiconductor pressure sensor compatible with fluid and gaseous media applications is described. The semiconductor pressure sensor includes a sensor capsule having a semiconductor die and a silicon cap that is bonded to the semiconductor die. The semiconductor die includes a diaphragm that incorporates piezoresistive sensors thereon, and a stress isolation mechanism for isolating the diaphragm from packaging and mounting stresses. The silicon cap includes a cavity for allowing the diaphragm to deflect. The semiconductor pressure sensor further includes a pressure port that is hermetically attached to the semiconductor die. The sensor capsule and pressure port may be incorporated into a plastic housing. In one embodiment, the silicon cap is bonded to the semiconductor die to form an integral pressure reference. In an alternative embodiment, a second pressure port is provided for allowing gage or differential pressure measurements. A technique for incorporating the piezoresistive sensors is also described. An ASIC may be optionally attached to the silicon cap, and/or active electronic circuitry may be fabricated on the semiconductor die or silicon cap. Additional coatings may be optionally applied to the pressure port and semiconductor die for enhancing chemical resistance.

Compensated semiconductor pressure sensor

A stress-isolated integrated circuit includes a semiconductor die (24) having first and second surfaces (28, 32) and a semi-circumferential trench (44) formed into the first surface of the die to define a stress-isolated region (48). At least some of the active IC components are located in the stress-isolated region. A cavity (46) is formed into the second surface of the die, the cavity being sized so that the trench opens into the cavity to create a cantilevered stress-isolated region extending from the remainder of the die. The second surface of the die is secured to a lead frame (36), the lead frame having bond wires (42) secured to bond pads (26) on the die. A molding compound (54) encapsulates the die, the cap, the bond wires and a portion of the lead frame to create a molded IC device (20). The invention helps to improve performance characteristics and component variables of analog and mixed-signal integrated circuits by isolating critical portions of the integrated circuits from detrimental packaging and molding stresses.

Stress isolated integrated circuit and method for making

The present invention is a semiconductor pressure sensor. In one embodiment, the semiconductor pressure sensor includes a diaphragm having a first thickness and at least cone raised boss that is coupled to a first side of the diaphragm. The at least one raised boss increases the diaphragm thickness in the region occupied by the at least one raised boss to a second thickness. A plurality of piezoresistors are disposed on a second side of the diaphragm in regions of the first thickness. In another embodiment, a semiconductor pressure sensor diaphragm includes at least one raised boss disposed along a central axis on a first side of the diaphragm. At least two raised bridge regions are disposed along the central axis, interconnecting the at least one raised boss and a diaphragm edge. Each raised bridge region is narrower than the raised boss. A plurality of piezoresistors are disposed on the raised bridge regions of the diaphragm along the central axis.

Piezoresistive pressure sensor with sculpted diaphragm

A micromechnical sensor having a polysilicon beam that is an integral part of the diaphragm resulting in a frequency of the beam that is a direct result of the pressure applied to the external surface of the diaphragm. Fabrication of this resonant microbeam sensor has no backside wafer processing, and involves a process and layout independent of wafer thickness for high yield and robustness. Both the diaphragm and resonant beam are formed from polysilicon. The sensor may have more than one resonant beam. The sensor beam or beams may be driven and sensed by electrical or optical mechanisms. For stress isolation, the sensor may be situated on a cantilevered single crystal silicon paddle. The sensor may be recessed on the isolating die for non-interfering interfacing with optical or electrical devices. The sensor die may be circular for ease in mounting with fiber optic components.

Growing community of inventors

Minneapolis, MN, United States of America

David W Burns