Abstract: A thermal accelerometer device that provides a compensation for sensitivity variations over temperature. The thermal accelerometer includes signal conditioning circuitry operative to receive analog signals representing a differential temperature is indicative of a sensed acceleration. The signal conditioning circuitry includes serially connected A-to-D and D-to-A converters, which implement a temperature dependent function and process the received signals to provide a compensation for sensitivity variations over a range of ambient temperature. To provide a ratiometric compensation for variations in power supply voltage, a buffered voltage proportional to the supply voltage is provided as a reference voltage to the D-to-A converter. The thermal accelerometer includes a self-test circuit for verifying the integrity of a heater, temperature sensors, and circuitry included within the device.

Abstract: An acceleration sensor chip package includes an acceleration sensor chip formed of a frame portion with an opening portion, a movable structure, a detection element, and an electrode pad. The movable structure has a beam portion and a movable portion supported on the beam portion to be movable. The acceleration sensor chip package further includes a re-wiring layer with a wiring portion having one end connected to the electrode pad; an outer terminal connected to the other end of the wiring portion; a first sealing portion for sealing the electrode pad and the re-wiring layer; and a substrate for sealing the opening portion of the frame portion.

Abstract: The piezo-resistance type triaxial acceleration sensor includes a frame section, a mass section disposed in the frame section, beam elements which flexibly support the mass section, and piezo-resistors for the X, Y and Z axes formed on the beam elements. The length of the Z-axis piezo-resistors is longer than the length of the X-axis piezo-resistors and the Y-axis piezo-resistors, so as to decrease the sensitivity.

Abstract: An acceleration sensing device includes a movable sensing member, a frame member and a supporting member. The supporting member is coupled between the movable sensing member and the frame member so as to support the movable sensing member. The acceleration sensing device further includes a covering member disposed above the movable sensing member, with a gap between the covering member and the movable sensing member. The acceleration sensing device still further includes internal electrodes, interconnection films, external electrodes and a resin film. The internal electrodes are arranged around the covering member. The interconnection films are disposed on the frame member so as to be coupled to the internal electrodes. The external electrodes are disposed on the interconnection films. The resin film is disposed on the frame member so as to seal the covering member. Also, there is provided a manufacturing method of the acceleration sensing device.

Abstract: A semiconductor acceleration sensor in which a reduction in size can be achieved when electrodes are formed in a chip main body and acceleration can be measured with good sensitivity. The semiconductor acceleration sensor comprises a weight section, flexible sections which support the weight section and have measurement elements P, and a chip main body which has a front surface having chip electrodes electrically connected with the measurement elements, and support the flexible sections, wherein an additional weight, which has an inclined face which surrounds a bonding section and decreases its size toward the bonding section, is bonded on the front surface of the weight section.

Abstract: In one aspect, a microelectromechanical device and method of producing the device includes an accelerometer with a thinned flexure structure. In another embodiment, the device and method of producing the device includes an accelerometer and a pressure sensor integrated on a single chip.

Abstract: A semiconductor acceleration sensor is disclosed which has a small difference in acceleration detection sensitivity among X, Y, and Z axes and a high detection sensitivity. The acceleration sensor has a mass portion in its center, a support frame surrounding the mass portion, and a plurality of flexible arms connecting the mass portion and the support frame. The flexible arm has wider portions on both ends and a narrower portion between the wider portions. Piezo resistors are restrictedly provided within a top surface region of the wider portion of the flexible arm, and through holes connecting metal wires and the piezo resistors are disposed on the mass portion/support frame. The plurality of flexible arms are symmetric with respect to the center of the mass portion, and each of the flexible arms is symmetric with respect to the center line of the flexible arm.

Abstract: The present invention provides a semiconductor acceleration sensor wherein a semiconductor element is prevented from being damaged even when at least part of a weight is disposed in an internal space of a semiconductor sensor element and the mass of a weight is accordingly increased. An inner peripheral surface of a support portion 9 is constituted by four trapezoidal inclined surfaces 13 of a substantially identical shape which are annularly combined so as to define an outer peripheral surface of a frust-pyramidal space. A weight 3 is so constructed as to have an abutting portion including a linear portion 3d which abuts against the inclined surfaces 13 constituting the inner peripheral surface of the support portion 9 when the weight 3 makes a maximum displacement in a direction where a diaphragm portion 11 is located. The abutting portion 3d has a circular outline shape as seen from a side where a weight fixing portion 7 is located.

Abstract: A device which includes an acceleration sensor for outputting small differential voltages VIP and VIN using resistance changes, and an output amplifier for amplifying the voltage difference. The output amplifier includes an offset-voltage adjustment circuit and an instrumentation amplifier. The instrumentation amplifier includes a first Op-amp having inputs connected to VIP and offset-voltage input terminals, a second Op-amp having inputs connected to VIN and VCOM input terminals, and a third Op-amp having inputs connected to outputs of the first and second Op-amps via resistors. The reference voltage VCOM of the instrumentation amplifier output is also applied to the second Op-amp.

Abstract: An acceleration sensor comprises an acceleration sensor element having a mass portion in the center, a thick frame surrounding the mass portion and a plurality of elastic support arms bridging the mass portion and the thick frame, and an upper regulation plate covering the acceleration sensor element and fixed on the thick frame with adhesive. The mass portion has, on the mass portion upper surface, connection portions connecting the mass portion with each of the arms, wired areas having lead wires on it and non-wired areas. The non-wired areas have a major area of the upper surface of the mass portion and are lower than the wired areas. The upper regulation plate has a first gap with the wired areas and a second gap with the non-wired areas, of which length is more than the sum of the first gap length, a lead wire thickness and 0.1 ?m (preferably 1.0 ?m).

Abstract: A semiconductor acceleration sensor comprises: a frame having an opening inside thereof; flexible beams extending from the frame to the inside of the opening of the frame; a weight suspended from and supported by the beams so that the weight can freely move; piezoresistors to be mounted on the beams and to vary the resistance values in response to accelerations which work on the piezoresistors. The frame comprises damper plate portions, each of which covers a part of the opening spanning from a corner portion of two neighboring sides of the frame on the side of the opening to the inside of the opening, and each of which serves serve as a stopper to limit movement of the weight. The weight has corner portions which face the corner portions, respectively, and each of which is chamfered to have a shape of arc or a polygonal line consisting of at least three sides as seen in plan view.

Abstract: A miniaturized micromachined (MEMS) accelerometer-based sensor suitable for use in biological applications, such as a middle ear implant, is provided. An encapsulation layer is deposited on top of an accelerometer proof mass and flexure prior to release of the proof mass and flexure. The encapsulation layer protects the proof mass and flexure from subsequent processing steps, such as dicing and packaging, which enables fabrication of finished devices having reduced size. Surfaces within the accelerometer may be passivated after releasing the proof mass and flexure. Remote piezoresistive sensing is performed in order to provide low noise and reduced sensor head size.

Abstract: An accelerometer includes: a sensor chip including a weight portion for detecting a force imparted from outside, a frame portion that surrounds the weight portion, a beam portion that is deflectable and flexibly supports the weight portion, and a sensor element whose electric resistance varies depending on an amount by which the beam portion deflects; and a spacer provided at a position on a surface of a mounting substrate which position corresponds to the central portion of the weight portion. The sensor chip is mounted on the mounting substrate with a bottom surface of the frame portion being fixed at a predetermined position on the mounting substrate by an adhesive portion. The spacer has a thickness greater than that of the adhesive portion and may be formed by an adhesive concurrently with the adhesive portion, with a gap being maintained between the bottom surface of the weight portion and the spacer.

Abstract: There is provided a compact, high-sensitivity acceleration sensor. The acceleration sensor includes a weight 8, a pedestal 9 arranged around the periphery of the weight 8, a support frame 3 formed to have a width narrower than the width of the pedestal 9 all around its perimeter, a mass 2 attached to the weight 8 to retain the weight 8 inside the support frame 3, beams 4 connecting the support frame 3 and the mass 2 and overlapping the pedestal 9 near their ends on the side of the support frame 3, and a peripheral interlayer 12 arranged between the support frame 3 and the pedestal 9 to create a predetermined clearance between the pedestal 9 and the parts of the beams 4 that overlap the pedestal 9.

Abstract: A microstructure includes a mass; a base member in which the mass is movably contained. The mass includes a surface, which is exposed out of the base member, and a stopper wire, which is arranged above the surface of the mass so as to inhibit over move of the mass.

Abstract: An acceleration sensor in a connecting portion connects a displacing section to a fixed section and a weight is connected to the displacing section from below. A pedestal is disposed adjacent to the weight and is connected to the fixed section by a pedestal joint layer so a displacement of the displacing section can be detected. The weight has a peripheral portion of its upper surface opposite a control surface on a lower surface of the fixed section to come into contact therewith upon a given magnitude of acceleration of the weight. A weight joint layer made of the same material as that of the pedestal joint layer joins the weight and the displacing section.

Abstract: An acceleration sensor in which a regulation plate is fixed with adhesive onto a support frame of a sensor chip of the sensor to limit the movement of a mass portion of the sensor chip within a predetermined gap range. In the acceleration sensor, the adhesion area of the adhesive can be controlled to a predetermined value to prevent a variation of the sensitivity due to the variation of the adhesion area. The sensor chip comprises the mass portion, the frame surrounding the mass portion and having on an upper surface of the frame a plurality of the recesses to fill adhesive into, elastic support arms bridging the mass portion and the frame, and strain gauges formed on the elastic support arms. The regulation plate is fixed with paste onto the frame with the predetermined gap with an upper surface of the mass portion. The paste contains hard plastic balls, of a diameter larger than the predetermined gap, mixed with adhesive. The adhesive is preferably of silicon-rubber resin.

Abstract: An acceleration sensor is disclosed that has a structure in which elastic support arms are not broken even if subjected to an impact that may be caused during a usual handling. The acceleration sensor comprises a mass portion, a mass portion top plate fixed onto the mass portion, a rectangular thick support frame surrounding the mass portion, a frame top plate fixed onto the frame, and four elastic support arms hanging the mass portion in the center of the frame and bridging the mass portion top plate and the frame top plate. There are provided lateral grooves just below the support arms on side surfaces of the mass portion and on inner side surfaces of the frame. Due to the grooves, the mass portion top plate and the frame top plate have their portions bonded to the mass portion/the frame and their portions protruding toward the support arms. Cross sections on boundaries between the bonded portions and the protruding portions are larger than those connecting the protruding portions to the support arms.

Abstract: A method of manufacturing a monolithic silicon acceleration sensor is disclosed. The monolithic silicon acceleration sensor includes one or more sensor cells, each sensor cell having an inertial mass positioned by beam members fixed to a silicon support structure. According to the method, a sandwiched etch-stop layer is formed. First sections of the inertia mass and beam members are also formed. In addition, a second section of the inertial mass is formed. Further, an inertial mass positioned by beam members fixed to a silicon support structure is formed. Also, a first cover plate structure is bonded to a first surface of the silicon support structure.

Abstract: A semiconductor acceleration sensor comprises: a frame having an opening inside thereof; flexible beams extending from the frame to the inside of the opening of the frame; a weight suspended from and supported by the beams so that the weight can freely move; piezoresistors to be mounted on the beams and to vary the resistance values in response to accelerations which work on the piezoresistors. The frame comprises damper plate portions, each of which covers a part of the opening spanning from a corner portion of two neighboring sides of the frame on the side of the opening to the inside of the opening, and each of which serves serve as a stopper to limit movement of the weight. The weight has corner portions which face the corner portions, respectively, and each of which is chamfered to have a shape of arc or a polygonal line consisting of at least three sides as seen in plan view.

Abstract: The present invention easily achieves an accurate control structure for limiting displacement of a weight. An SOI substrate with a trilaminar structure including a silicon layer, a silicon oxide layer, and a silicon layer is prepared, and slits are opened by applying induced coupling plasma etching which can selectively remove only silicon from the upper side. Then, the same etching is applied from the lower side to form grooves, whereby the lower silicon layer is separated into a weight and a pedestal. Next, the structure is immersed in an etchant which can selectively remove only silicon oxide, whereby the vicinities of exposed portions of the silicon oxide layer are removed to form joint layers. A glass substrate is joined to the bottom surface of the pedestal. Piezo resistor elements are formed on the upper surface of the silicon layer to detect bending. The degree of freedom of upward displacements of the weight is accurately set based on the thickness of the joint layer.

Abstract: A miniaturized micromachined (MEMS) accelerometer-based sensor suitable for use in biological applications, such as a middle ear implant, is provided. An encapsulation layer is deposited on top of an accelerometer proof mass and flexure prior to release of the proof mass and flexure. The encapsulation layer protects the proof mass and flexure from subsequent processing steps, such as dicing and packaging, which enables fabrication of finished devices having reduced size. Surfaces within the accelerometer may be passivated after releasing the proof mass and flexure. Remote piezoresistive sensing is performed in order to provide low noise and reduced sensor head size.

Abstract: The present invention easily achieves an accurate control structure for limiting displacement of a weight. An SOI substrate with a trilaminar structure including a silicon layer, a silicon oxide layer, and a silicon layer is prepared, and slits are opened by applying induced coupling plasma etching which can selectively remove only silicon from the upper side. Then, the same etching is applied from the lower side to form grooves, whereby the lower silicon layer is separated into a weight and a pedestal. Next, the structure is immersed in an etchant which can selectively remove only silicon oxide, whereby the vicinities of exposed portions of the silicon oxide layer are removed to form joint layers. A glass substrate is joined to the bottom surface of the pedestal. Piezo resistor elements are formed on the upper surface of the silicon layer to detect bending. The degree of freedom of upward displacements of the weight is accurately set based on the thickness of the joint layer.

Abstract: An ultra-small and slim semiconductor acceleration sensor with high sensitivity is provided. The acceleration sensor has a mass portion formed at a center part of a silicon semiconductor substrate, a frame formed on an edge part of the substrate, thin elastic support arms which are provided on top surfaces of the mass portion and the frame and connect the mass portion and the frame, and strain gauges constituted by a plurality of pairs of piezoresistors formed on top surfaces of the elastic support arms. A distance between a pair of Z-axis strain gauges provided on the top surface of the elastic support arm is made longer by 0.4L to 1.2L or shorter by 1.0L to 1.8L than a distance between a pair of X-axis strain gauges, whereby output of the Z-axis strain gauge is made at the same level as output of the X-axis strain gauge.

Abstract: An acceleration sensor in which a regulation plate is fixed with adhesive onto a support frame of a sensor chip of the sensor to limit the movement of a mass portion of the sensor chip within a predetermined gap range. In the acceleration sensor, the adhesion area of the adhesive can be controlled to a predetermined value to prevent a variation of the sensitivity due to the variation of the adhesion area. The sensor chip comprises the mass portion, the frame surrounding the mass portion and having on an upper surface of the frame a plurality of the recesses to fill adhesive into, elastic support arms bridging the mass portion and the frame, and strain gauges formed on the elastic support arms. The regulation plate is fixed with paste onto the frame with the predetermined gap with an upper surface of the mass portion. The paste contains hard plastic balls, of a diameter larger than the predetermined gap, mixed with adhesive. The adhesive is preferably of silicon-rubber resin.

Abstract: An acceleration sensor is disclosed that has a structure in which elastic support arms are not broken even if subjected to an impact that may be caused during a usual handling. The acceleration sensor comprises a mass portion, a mass portion top plate fixed onto the mass portion, a rectangular thick support frame surrounding the mass portion, a frame top plate fixed onto the frame, and four elastic support arms hanging the mass portion in the center of the frame and bridging the mass portion top plate and the frame top plate. There are provided lateral grooves just below the support arms on side surfaces of the mass portion and on inner side surfaces of the frame. Due to the grooves, the mass portion top plate and the frame top plate have their portions bonded to the mass portion/the frame and their portions protruding toward the support arms. Cross sections on boundaries between the bonded portions and the protruding portions are larger than those connecting the protruding portions to the support arms.

Abstract: An accelerometer comprises a housing including a mass-supporting frame and a mass supported on the frame by a pair of outer spring member aligned along a first axis. The mass may comprise an outer mass connected to the pair of outer spring members and an inner mass connected to the outer mass by a number of inner spring members, the inner spring members aligned along one or more axes, which form a plane which the axis of the outer spring members also may be aligned. Also provided is means for detecting rotation of the mass and translation of the inner mass.

Abstract: A microfabricated device includes a substrate having a device layer and substantially filled, isolating trenches; a doped region of material formed by photolithographically defining a region for selective doping of said device layer, selectively doping said region, and thermally diffusing said dopant; circuits on said device layer formed using a substantially standard circuit technology; and at least one structure trench in the substrate which completes the definition of electrically isolated micromechanical structural elements.

Abstract: An accelerometer has a substrate with a cavity therein, a heater extending over the cavity, and a pair of temperature sensitive elements each spaced apart from the heater a distance of 75-400 microns also extending over the cavity. On passing an electrical current through the heater a symmetrical temperature distribution is set up on both sides of the heater. On acceleration, this distribution moves and by measuring the temperature as sensed by the pair of temperature sensitive elements the acceleration that caused the shift can be calculated.

Abstract: A monolithic silicon acceleration sensor capable of detecting acceleration along multiple orthogonal axes of acceleration is disclosed. The monolithic silicon acceleration sensor is micromachined from silicon to form one or more sensor cells, each sensor cell having an inertial mass positioned by beam members fixed to a silicon support structure. Movement of the inertial mass due to acceleration is detected by either a differential capacitance measurement between opposing surfaces of the inertial mass and electrically conductive layers on a top and a bottom cover plate structure, or by a resistance measurement of piezoresistive elements fixed to the positioning beam members. Embodiments of the invention are capable of detecting acceleration in a plane, along two orthogonal axes of acceleration, or along three orthogonal axis of acceleration.

Abstract: The present invention is a method of making an acceleration sensor chip. The sensor chip is prepared from a SOI wafer having a silicon substrate, a SiO2 layer and a silicon thin film. A dopant is ion implanted at a position corresponding to a semiconductor strain gauge on the silicon thin film to form a diffusion resistor, and for forming devices necessary for circuit construction on said silicon thin film. A protective film is provided on the entire surface of the wafer, and a plurality of through holes penetrating the silicon thin film are formed by patterning and etching to make a weight part and a beam part connected to a support frame part on the periphery. The SiO2 layer under the weight part and the beam part is removed by wet etching to form the through holes, while leaving the protective film in place. The protective film is removed and a resist coated over the entire surface of the wafer. A slit for dividing the chip is formed part way through the wafer by dicing.

Abstract: A micromechanical device includes a single crystal micromechanical structure where at least a portion of the micromechanical structure is capable of performing a mechanical motion. An epitaxial layer covers at least a portion of the micromechanical structure. In one embodiment, the micromechanical structure and the epitaxial layer are formed of different materials.

Abstract: An ultra-small and slim semiconductor acceleration sensor with high sensitivity is provided. The acceleration sensor has a mass portion formed at a center part of a silicon semiconductor substrate, a frame formed on an edge part of the substrate, thin elastic support arms which are provided on top surfaces of the mass portion and the frame and connect the mass portion and the frame, and strain gauges constituted by a plurality of pairs of piezoresistors formed on top surfaces of the elastic support arms. A distance between a pair of Z-axis strain gauges provided on the top surface of the elastic support arm is made longer by 0.4L to 1.2L or shorter by 1.0L to 1.8L than a distance between a pair of X-axis strain gauges, whereby output of the Z-axis strain gauge is made at the same level as output of the X-axis strain gauge.

Abstract: A microminiature and thin semiconductor acceleration sensor with high sensitivity is provided. The acceleration sensor has a mass portion formed in a center part of a silicon semiconductor substrate, a frame formed at a perimeter portion of the substrate, thin elastic support arms, which are provided at upper part of the mass portion and the frame and connect the mass portion and the frame, and a plurality of pairs of piezoresistors disposed on top surface sides of the elastic support arms. At least one of the mass portion and the thick frame has a cross section vertical to a respective top surface, spreading in width from the respective top surface toward a respective bottom surface. Since a side length of the mass portion and/or a width of the frame at a site, where the elastic support arms each is connected, are made short, the elastic support arm is made long, hereby the sensitivity of the sensor is enhanced.

Abstract: A microelectricalmechanical system (MEMS) digital isolator may be created in which an actuator such as an electrostatic motor drives a beam against a predefined force set, for example, by another electrostatic motor. When the threshold of the opposing force is overcome, motion of the beam may be sensed by a sensor also attached to the beam. The beam itself is electrically isolated between the locations of the actuator and the sensor. The structure may be incorporated into integrated circuits to provide on-chip isolation.

Abstract: A micromechanical inertial sensor is provided having a reduced pickoff Q, while maintaining a high motor Q. The micromechanical inertial sensor includes a pair of proof masses and aligned pickoff plates. Each pickoff plate is spaced from the respective proof mass by a gap that varies in response to out-of-plane movement of the proof mass. The micromechanical inertial sensor also includes at least one voltage source for providing charge to the pickoff plates. By measuring the movement of charge in each electrical circuit that includes a pickoff plate as the gap between the pickoff plate and the respective proof mass varies, a measurement of the rotation of the micromechanical inertial sensor about an input axis may be obtained. The micromechanical inertial sensor further includes resistive elements disposed in series between the voltage source and each pickoff plate to increase the pickoff resonance damping of the micromechanical inertial sensor.

Abstract: A micromachined accelerometer for measuring acceleration in a direction parallel with the plane of the accelerometer substrate. The accelerometer has a strain-isolation pedestal, a flexure attached to the pedestal, and a proof mass attached to the flexure. The pedestal is wider than the flexure and does not bend when the device is under acceleration. The pedestal serves to isolate the flexure from substrate strain which may be caused by device packaging or temperature variations. Preferably, the joint between the pedestal and flexure, and the joint between the flexure and proof mass are smoothed to prevent stress concentration. The joints have a radius of curvature of at least 1 micron. A piezoresistor is located in one sidewall of the flexure. Alternatively, two piezoresistors are located on the flexure, with one on each sidewall. In this embodiment, a center-tap connection is provided to the point where the two piezoresistors are connected.

Abstract: A sensor chip has a support frame part, and sensor structure including at least one displaceable weight part, and a beam part for connecting the weight part to the support frame part, the sensor structure is formed on a silicon substrate through an insulating layer, the insulating layer between the sensor structure and the silicon substrate is removed, the beam part is formed of two parallel beams, the weight part is connected to the support frame part by two parallel beams, and at least two semiconductor strain gauges are formed on the surface of the two respective parallel beams.

Abstract: A sensor chip has a support frame part, and sensor structure including at least one displaceable weight part, and a beam part for connecting the weight part to the support frame part, the sensor structure is formed on a silicon substrate through an insulating layer, the insulating layer between the sensor structure and the silicon substrate is removed, the beam part is formed of two parallel beams, the weight part is connected to the support frame part by two parallel beams, and at least two semiconductor strain gauges are formed on the surface of the two respective parallel beams.

Abstract: An acceleration sensor module capable of performing sensitivity adjustment in a minimum arrangement without containing an amplifier includes an acceleration sensor and a trimmable resistor which are mounted on a printed wiring board. At least one terminal of the acceleration sensor and at least one terminal of the trimmable resistor are connected to at least one external connection terminal of the printed circuit board through printed wiring.

Abstract: A sensor chip has a support frame part, and sensor structure including at least one displaceable weight part, and a beam part for connecting the weight part to the support frame part, the sensor structure is formed on a silicon substrate through an insulating layer, the insulating layer between the sensor structure and the silicon substrate is removed, the beam part is formed of two parallel beams, the weight part is connected to the support frame part by two parallel beams, and at least two semiconductor strain gauges are formed on the surface of the two respective parallel beams.

Abstract: A sensor chip has a support frame part, and sensor structure including at least one displaceable weight part, and a beam part for connecting the weight part to the support frame part, the sensor structure is formed on a silicon substrate through an insulating layer, the insulating layer between the sensor structure and the silicon substrate is removed, the beam part is formed of two parallel beams, the weight part is connected to the support frame part by two parallel beams, and at least two semiconductor strain gauges are formed on the surface of the two respective parallel beams.

Abstract: A sensor chip has a support frame part, and sensor structure including at least one displaceable weight part, and a beam part for connecting the weight part to the support frame part, the sensor structure is formed on a silicon substrate through an insulating layer, the insulating layer between the sensor structure and the silicon substrate is removed, the beam part is formed of two parallel beams, the weight part is connected to the support frame part by two parallel beams, and at least two semiconductor strain gauges are formed on the surface of the two respective parallel beams.

Abstract: A sensor chip having a support frame part and sensor structure including at least one displaceable weight part, and a beam part for connecting the weight part to the support frame part. The sensor structure is formed on a silicon substrate through an insulating layer and the insulating layer between the sensor structure and the silicon substrate is removed. The beam part is formed of two parallel beams and the weight part is connected to the support frame part by two parallel beams. At least two semiconductor strain gauges are formed on the surface of the two respective parallel beams. The semiconductor chip may be contained in a package having a main surface for mounting the semiconductor sensor chip formed at a predetermined angle with respect to the surface of a printed circuit board for mounting the package. The main surface is provided with a plurality of terminals along two opposite sides thereof for connecting with input/output terminals of the semiconductor sensor chip.

Abstract: A method and apparatus for enclosing a sensing device, such as an accelerometer, for reducing outside forces and strains on the sensing device. The cover includes two parts that bond to each other thereby forming a clamshell-type cover. The sensing device can float within the cover, is bonded to bonding points on one of the cover parts or is held in place by a pressure fit of the two cover parts on the sensing device.

Abstract: A semiconductor physical quantity sensor has a beam connecting a movable portion and a support substrate for displacing the movable portion in a displacement direction. The beam has a rectangular frame shape with a hollow portion and is surrounded by a groove. The groove has opposing intervals at both sides of the beam in the displacement direction, and the opposing intervals are equal to an interval of the hollow portion in the displacement direction. Accordingly, etching rates at the groove and the hollow portion become approximately equal to each other, reducing processing variation of the beam.

Abstract: An acceleration sensor made available without using a high-level semiconductor technology or a micro-machining technology. The sensor detects an acceleration with a high precision, yet the manufacturing cost is inexpensive. In the sensor, a silicon substrate (1) is used only for a portion with which a strain is caused by an acceleration, while an auxiliary substrate (4A,4B), a cap (8A,8B) and a mass substance (6A,6B) are formed of glass material. Joining of the silicon substrate (1) to the mass substance (6A,6B) and the auxiliary substrate (4A,4B), and the auxiliary substrate (4A,4B) to the cap (8A,8B) are made by direct bonding.

Abstract: A drive line vibration sensor includes a housing having a strain gage attached to the drive line component, and an actuator disposed within the housing. In operation, the actuator exerts a force upon the strain gage proportional to acceleration experienced by the actuator. As the actuator is preferably a sphere manufactured of a low friction material, the friction between the actuator, strain gage, and the housing are minimized to improve the vibration sensor sensitivity. In another embodiment, the actuator is a pendulum attached to the housing by a pivot point having low friction bearings to reduce the effect of radial acceleration upon the measurement of longitudinal acceleration. A recording device is preferably in communication with the controller to record the pressure applied to the strain gage to provide an inexpensive diagnostic and maintenance system which can record the overall operation of a drive line under actual operational conditions.

Abstract: A high strength, high frequency acceleration transducer is used for measuring the acceleration of an impacted machine or structure. The acceleration transducer includes a diaphragm, the diaphragm including one or more strain gages for producing an output signal indicative of the transducer flexure. The diaphragm is securely clamped or held over part of its surface, and is free to deflect over other parts, for example, the remainder of its surface—the diaphragm can be clamped or held along its circumference with its middle free to flex, or alternatively the diaphragm can be clamped or held along its center with the outside portion of the diaphragm free to flex. The diaphragm preferably includes one or more holes positioned relative to the strain gages to concentrate the strains locally within the diaphragm towards the strain gages.

Abstract: A gravity-type horizontal shift sensing apparatus being mounted on and moved along with an object for efficiently sensing and measuring any difference in angle of inclination of the object when the object moves. The apparatus includes two intersected rocking arms rotatably disposed between close-up inner cover and inner seat, and a weight suspended from the rocking arms. The rocking arm each is provided at one end outside the inner cover and the inner seat with a toothed wheel and an optical wheel associated with the toothed wheel. The toothed wheel meshes with a gear sideward projected from a wheel mounted to one side of the rocking arm. The wheel each also has an optical wheel associated therewith. Outer peripheries of the optical wheels on the rocking arms and the wheels respectively pass between two sensing elements mounted at two sides of recesses formed on the circuit board.