Abstract:
A physical quantity sensor includes a pair of physical quantity sensor chips that are inclined with respect to the bottom of an exterior mold package whose side surfaces are each inclined in a thickness direction by an angle ranging from 0° to 5° and are formed in proximity to the outer ends of the physical quantity sensor chips. It is possible to realize the inclination of stages without using molds, wherein absorption devices are used to absorb prescribed portions related to stages, which rotate about axial lines and are thus inclined with respect to a prescribed base. In manufacturing, a thin metal plate having a plurality of lead frames is placed on a base delimited by a clamp; then, intersecting points of intermediate portions formed between the lead frames are subjected to pressing so as to realize the inclination of stages.
Abstract:
The present invention discloses a micro-electro-mechanical system (MEMS) device, comprising: a mass including a main body and two capacitor plates located at the two sides of the main body and connected with the main body, the two capacitor plates being at different elevation levels; an upper electrode located above one of the two capacitor plates, forming one capacitor therewith; and a lower electrode located below the other of the two capacitor plates, forming another capacitor therewith, wherein the upper and lower electrodes are misaligned with each other in a horizontal direction.
Abstract:
The present invention provides an angular velocity sensor in which higher sensitivity for sensors is available even with a smaller base portion. The angular velocity sensor includes a fixed portion fixed to the top surface of a sensor element supporting portion of a casing, an upper detection arm and a lower detection arm, each of them being connected to the fixed portion on sides opposite to each other and extending along a plane parallel to the top surface of the sensor element supporting portion, and a pair of upper vibration arms connected to the fixed portion in such a manner as to form a pair of arms with the upper detection arm in between and extending in a direction parallel to the extending direction of the upper detection arm.
Abstract:
A micro-electromechanical device includes a semiconductor substrate, in which a first microstructure and a second microstructure of reference are integrated. The first microstructure and the second microstructure are arranged in the substrate so as to undergo equal strains as a result of thermal expansions of the substrate. Furthermore, the first microstructure is provided with movable parts and fixed parts with respect to the substrate, while the second microstructure has a shape that is substantially symmetrical to the first microstructure but is fixed with respect to the substrate. By subtracting the changes in electrical characteristics of the second microstructure from those of the first, variations in electrical characteristics of the first microstructure caused by changes in thermal expansion or contraction can be compensated for.
Abstract:
A micromechanical device having a substrate wafer has at least one first cavity and one second cavity, the cavities being hermetically separated from each other, the first cavity having a different internal atmospheric pressure than the second cavity. The cavities are capped by a thin film cap. A method is for manufacturing a micromechanical device which has a thin film cap having cavities of different internal atmospheric pressures.
Abstract:
A method of forming a thick polysilicon layer for a MEMS inertial sensor includes forming a first amorphous polysilicon film on a substrate in an elevated temperature environment for a period of time such that a portion of the amorphous polysilicon film undergoes crystallization and grain growth at least near the substrate. The method also includes forming an oxide layer on the first amorphous polysilicon film, annealing the first amorphous polysilicon film in an environment of about 1100° C. or greater to produce a crystalline film, and removing the oxide layer. Lastly, the method includes forming a second amorphous polysilicon film on a surface of the crystalline polysilicon film in an elevated temperature environment for a period of time such that a portion of the second amorphous polysilicon film undergoes crystallization and grain growth at least near the surface of the crystalline polysilicon film.
Abstract:
A method for making a subsurface electrical contact on a micro-electrical-mechanical-systems (MEMS) device. The contact is formed by depositing a layer of polycrystalline silicon onto a surface within a cavity buried under a device silicon layer. The polycrystalline silicon layer is deposited in the cavity through holes etched through the device silicon and reseals the cavity during the polycrystalline silicon deposition step. The polycrystalline silicon layer can then be masked and etched, or etched back to expose the device layer of the micromachined device. Through the layer of polycrystalline silicon, a center hub of the device may be electrically contacted.
Abstract:
A method of assembling a three dimensional micromachined structure comprising the steps of defining a cavity in a holder wafer having a thick upper layer, providing a plurality of fingers in the thick upper layer extending from the holder wafer into the cavity, and disposing an out-of-plane wafer into the cavity in the holder wafer in engagement with the fingers to hold the out-of-plane wafer in place in an out-of-plane position with respect to the holder wafer. The invention also includes an apparatus made according to any combination of the above method steps and/or the structure of the apparatus which is fabricated from any combination of those method steps.
Abstract:
In a displacement detection device having an IC chip for a regulation plate, silicon broken pieces might drop from loose chippings during assembling or using the device and affect properties of the displacement detection device. By setting an angle of grinding traces on an IC chip wafer of chip with a vertical line on side ridges of the IC chip to less than 45 degrees, more preferably 10 to 45 degrees, the chippings including loose chippings can be reduced on the side ridges of the IC chip. Using of an IC chip having loose chippings on side ridges for a regulation plate can be avoided, and a highly reliable displacement detection device can be provided.
Abstract:
A method for making a subsurface electrical contact on a micro-electrical-mechanical-systems (MEMS) device. The contact is formed by depositing a layer of polycrystalline silicon onto a surface within a cavity buried under a device silicon layer. The polycrystalline silicon layer is deposited in the cavity through holes etched through the device silicon and reseals the cavity during the polycrystalline silicon deposition step. The polycrystalline silicon layer can then be masked and etched, or etched back to expose the device layer of the micromachined device. Through the layer of polycrystalline silicon, a center hub of the device may be electrically contacted.