Abstract: Strain gauge apparatus comprises two strain sensitive piezoresistors R.sub.r1 and R.sub.t1, two op-amps, three predetermined value resistances, R.sub.a, R.sub.b, and R.sub.c, and voltage source supplying V.sub.dc. Said elements are connected to produce an output signal of the form V.sub.dc (R.sub.c /R.sub.a l ) (R.sub.r1 / R.sub.t1 -R.sub.a /R.sub.b).

Abstract: Each sensor consists of a spinel substrate in the form of a beam or a diaphragm which carries a pattern of a plurality of doped silicon piezoresistive resistors. The latter are formed from layers of doped silicon, each of which layers has been epitaxially grown on a corresponding surface of the spinel substrate. The spinel minimizes the occurrence of leakage currents with respect to the resistors, while cooperating with the silicon to provide a high degree of stress transmission to the resistors. The beam form of sensor is shown as the sensor member of a differential fluid pressure to electric signal transducer, wherein the sensor is deflected and strained in accordance with the differential pressure to be sensed.

Abstract: A semiconductor pressure transducer includes a base member fabricated from n-type silicon. The base member has a central depression defining an active area and located on a bottom surface; diffused in the top surface, is at least one contact area which is directed from the active region towards the periphery of said base member. A piezoresistive sensor is located on said top surface and in contact with said contact area within said active region. A layer of epitaxial material surrounds the active region and has an aperture on the surface which is in communication with the contact area outside said active region. The epitaxial layer is polished at a top surface and a housing is coupled to the region by means of a suitable bond. Alternate methods of fabricating the transducer are shown employing both polycrystalline and monocrystalline epitaxial layers.

Abstract: A strain gauge element having an elastic beam with field effect transistors deposited on one surface arranged in a Wheatstone bridge so that deformation of the beam produces a proportional imbalance signal across the bridge, and means for applying a gate biasing voltage to the transistors with at least one such voltage being adjustable so that the bridge can be electrically balanced for a null or no load condition.

Abstract: A piezo-electric transducer element is disclosed which is formed by selected etchings from boron doped silicon. The transducer includes a diaphragm and a spring lever adapted to bias the transducer element into a state of strain so that a vibration of the diaphragm is transmitted to the transducer element. The transducer element is particularly suitable for use in a telephone microphone.

Abstract: A semiconductor pressure transducer comprising a disc-shaped pressure-responsive diaphragm; a pair of radial strain gauge units having a piezoresistance effect, formed by injecting an impurity in the radial direction in the surface of the diaphragm; and a pair of tangential strain gauge units having a piezoresistance effect, formed by injecting an impurity in the tangential direction in the surface of the diaphragm, wherein the distance from the pair of the radial strain gauge units to the center of the circular diaphragm is greater than the distance from the pair of the tangential strain gauge units to the center of the circular diaphragm.

Abstract: A semiconductor transducer comprising an improved strain-yielding body yielding a strain in response to the impartation of a force or displacement, and a semiconductor strain gauge bonded to the strain-yielding body. The improved strain-yielding body is made of an iron-nickel-cobalt alloy containing 28.2 to 31.0% by weight of nickel and 15.0 to 19.5% by weight of cobalt. This iron-nickel-cobalt alloy is initially heated up to a temperature above 600.degree. C. for the purpose of standard heat treatment for removing its internal strain. After the standard heat treatment, the iron-nickel-cobalt alloy is subjected to cold working at a working rate of more than and including 60%, and is then subjected to heat treatment at a temperature between 350.degree. C. and 600.degree. C. The heat-treated iron-nickel-cobalt alloy is shaped into the predetermined form of the strain-yielding body.

Abstract: A probe for measuring the amplitude of high frequency pressure pulses in a high or low temperature fluid environment comprising a hollow housing structure having an open end covered by a flexible metallic diaphragm member. A transducer is located in the housing and is forcibly maintained in direct engagement with the diaphragm member. Pressure pulses in the high or low temperature fluid medium deflect the diaphragm member, which is in contact with the transducer, causing it to produce electrical signals representative of the pressure pulses impinging against the diaphragm member. These electrical signals are transmitted to electronic recording and analyzing equipment to provide an accurate reading of the sensed pressure pulses.

Abstract: A method and apparatus for shaping semiconducting crystals for utilization in force and pressure measuring devices by chip removing machining of at least one surface portion of the crystal member. The shaping is effected by mounting the crystal member to be shaped and a ground cutting tool with respect to one another and rotating and contacting the tool and crystal member with respect to one another so as to remove a surface portion from the crystal. In this manner, many individual crystals can be shaped in an identical manner with high accuracy and with substantially no wear of the cutting tool.

Abstract: The leakage current in metal oxide varistor bodies is found to vary as a function of applied pressure in the 0.5 kbar to 10 kbar range.A pressure sensing device is conditioned by first prestressing a metal oxide varistor to a pressure above the range of measurement and then releasing the prestress pressure. Upon application of subsequent pressures equal or less than the prestress pressure, the leakage current in the device is found to vary as a function of pressure.

Abstract: A semiconductor transducer comprises a semiconductor strain gauge composed of a mono-crystalline semiconducting material and a strain sensing region formed in a first main surface of the mono-crystalline semiconducting material, and a strain measuring member coupled to the semiconductor strain gauge through an alloy material. An electrical insulating layer is attached to a second main surface of the mono-crystalline semiconducting material which is coupled to the strain measuring member through the alloy material. The insulating layer is extended to a side surface of the mono-crystalline semiconducting material thereby to cover the same side.

Abstract: The pressure transducer includes a semiconductor cantilever beam, a diaphragm, a spacer, and a back plate. The diaphragm, spacer, and back plate are bonded together at their peripheries to form a cup. The ends of the beam are bonded, respectively, to the supported periphery of the diaphragm and to an intermediate deflecting portion thereof, whereby pressure forces within the cup are transmitted by the diaphragm to the beam. Piezoresistive elements are diffused into the surface of the beam to produce an electric signal in accordance with the strain produced in the beam as the result of the pressure forces. In one embodiment, the beam is a flat plate. In another embodiment, the beam includes a portion at the mounting end that is massive relative to the stress sensitive portion of the beam. The juncture of the massive mounting portion and the stress sensitive portion is an abrupt step, whereby a precise fulcrum for the stress sensitive beam portion is provided.

Abstract: A semiconductor transducer chip is flip-chip bonded to a semiconductor interface chip, which is mounted on the ceramic package. Thermal coupling between the package and the transducer chip is minimized by the small contact area between the transducer chip and interface chip. Micron size spacing between the spring membrane in the transducer chip and the interface chip produces squeeze film damping of the spring membrane.

Abstract: Semiconductor material stress sensors are provided where the sensing resistors therein have good electrical stability while being sufficiently protected without degrading sensor performance. This is accomplished through control of the locations of the maximum concentrations of the resistor dopant. The mounting of semiconductor stress sensors on mounts of a different material type in a manner minimizing offset temperature shifts is disclosed.