Abstract: An electromechanical sensor is provided which comprises: first semiconductor wafer including a first stop surface residing in a first shallow recessed region of the first wafer; a second semiconductor wafer; wherein the first and second semiconductor wafers are laminated together such that the first recessed region of the first wafer and the second wafer define a first chamber in which the first stop surface and the second wafer are disposed close enough together such that the first stop surface restrains the second wafer from deflecting beyond the first stop surface; and an apparatus for measuring deflection of the second wafer.

Abstract: An electromechanical sensor is provided which comprises: a first silicon wafer which defines a resonant element; wherein the resonant element is doped with approximately the same impurity concentration as a background dopant concentration of the first wafer; and a second single crystal wafer which defines a device for coupling mechanical stress from the second wafer to the resonant element; wherein the first and second wafers are fusion bonded together.

Abstract: A pressure measurement apparatus is provided which comprises: a housing formed from a thermoplastic material and defining a chamber, the housing including an upper wall region and a lower wall region and first and second opposed side-wall regions disposed between the upper and lower wall regions, the upper wall region including first and second vent ports formed therein; a semiconductor pressure transducer mounted within the chamber, the pressure transducer including a first surface in communication with the first vent port and including a second surface in communication with the second vent port; at least one first pin terminal extending through the first side-wall region, the at least one first pin terminal including a short segment within the chamber and an elongated segment outside the chamber; and at least one second pin terminal extending through the second side-wall region, the at least one second pin terminal including a short segment within the chamber and an elongated segment outside the chamber.

Abstract: A glass header structure for a pressure transducer employs a cylindrical member fabricated from a borosilicate glass having a thermal expansion coefficient which matches silicon. The glass header has a central aperture which extends from the top to the bottom surface. Positioned about the central aperture are four smaller apertures located at 90 degree intervals and each containing an elongated terminal pin. The pins are of a nail head configuration with a flat top head of a larger diameter than the diameter of the apertures and of the main pin body. Affixed to the flat top surfaces of the terminal pins by means of ball bonding are wires which connect to the terminal areas of a semiconductor pressure transducer which is mounted over the central aperture of the header.

Abstract: A high temperature transducer consists of a first section having a base layer of monocrystalline silicon which layer is coated with an oxide. A thin layer of a high temperature glass is sputtered on the oxide layer of the base layer. A second section is formed by diffusing a wafer of N type silicon to form a p+ layer. The first and second sections are bonded together by an anodic bond where the p+ layer is secured to the glass layer to form a composite structure. The N type material is then removed and piezoresistive deivces are formed in the p+ layer. This structure provides a high temperature transducer which exhibits stable operating parameters over a wide operating range.

Abstract: A transducer employs two separate pressure input ports. Each port is associated with a separate metal diaphragm behind which diaphragm is secured a transducer structure having a cup-shaped silicon pressure diaphragm which is retained within a hollow of the transducer which is oil filled. One transducer structure is a half bridge array and monitors the main pressure applied to the positive port. A full bridge is formed by two resistors associated with the positive port and two resistors in an array associated with the other port which is the negative port. The resistors in the array at the negative port are selected to be larger in magnitude than those at the positive port and exhibit a greater sensitivity per unit of applied pressure.

Abstract: There is disclosed a medical transducer apparatus which employs composite planar members each of which is fabricated from a highly insulative material. The members are positioned in congruency and a first member which may be a composite member has a diaphragm area located on the surface thereof to which a piezoresistive gage is bonded. The gage is surrounded by an aperture in another member to enable leads from the gage to be directed to an interconnection and circuit board also fabricated from an insulator material. The structure provides isolation to the patient in regard to the biasing source used for the gage array and also provides isolation based on external voltage which serves to protect the transducer during operation.

Abstract: A transducer housing consists of a first and a second section. The first section contains an internal hollow into which a transistor header is mounted. The header, as mounted in the first section, is firmly secured within the section by means of a locking ring or other arrangement. Located in the internal hollow of the first section is a printed circuit board which has a plurality of apertures on the surface thereof each of which communicates with an extending tubular post on the opposite surface. Leads from the header are directed through the apertures in the printed circuit board and extend into the tubular posts. The second housing section is emplaced on the first section and contains a series of hollow metal tubular connectors or posts.

Abstract: A transducer structure is disclosed which comprises a single crystal semiconductor diaphragm dielectrically isolated by a layer of silicon dioxide from a single crystal gage configuration. The methods depicted employ high dose oxygen which is ion implanted into a monocrystalline wafer to form a buried layer of silicon dioxide with the top surface of the wafer being monocrystalline silicon. An additional layer of silicon is epitaxially grown on the top surface of the wafer to enable the etching or formation of a desired gage pattern.

Abstract: A pressure transducer employs a tubular glass structure of a "D" shaped cross section, with the arcuate section of the "D" shaped configuration being substantially thicker than the base section. A sensor array is positioned on the underside of the base section while a pressure conducting fluid is directed through the tubular member to provide deflection of the base to cause the sensor array to provide an output indicative of pressure variations in the fluid medium. The sensor array as positioned on the underside of the base is both electrically and mechanically isolated from the pressure conducting medium.

Abstract: A hybrid transducer employing a ceramic substrate having on a surface a suitable geometry for defining an active or clamped area, a semiconductor strain gage is positioned on said substrate within said active area and connections are made to said gage by conductors printed on said substrate by thick or thin film techniques. Thick film printing techniques or thin film deposition techniques are employed to print the conductors, terminal areas, compensating resistors and stop members.

Abstract: A bridge array employing piezoresistive sensors responsive to the longitudinal piezoresistive effect generally exhibits a positive nonlinearity over a pressure range, while a bridge array employing piezoresistive sensors employing the transverse piezoresistive effect exhibits a negative nonlinearity over the pressure range. A composite pressure transducer is provided by interconnecting a longitudinal and transverse bridge array in a common composite configuration. The resulting transducer exhibits linear operation over the pressure range due to the cancellation of said nonlinearities from the connected arrays.

Abstract: A pressure transducer employing a semiconductor diaphragm having a convoluted central section surrounded by a rigid peripheral section. The convolutions are a series of concentric grooves formed as squares producing a square nonplanar diaphragm in the preferred embodiment. The convolutions are formed on the semiconductor wafer by an anisotropic etch. Piezoresistive devices are diffused into the diaphragm in the peripheral region to form a bridge array. The transducer structure thus formed is capable of producing a linear and large magnitude voltage signal in response to a relatively small applied pressure or force.

Abstract: A transducer structure is disclosed which comprises a single crystal semiconductor diaphragm dielectrically isolated by a layer of silicon dioxide from a single crystal gage configuration. The methods depicted employ high dose oxygen which is ion implanted into a monocrystalline wafer to form a buried layer of silicon dioxide with the top surface of the wafer being monocrystalline silicon. An additional layer of silicon is epitaxially grown on the top of the wafer to enable the etching or formation of a desired gage pattern.

Abstract: There is disclosed a spreading resistance piezoresistive transducer which employs a planar diaphragm member fabricated from a semiconductor material and having deposited on a surface thereof at least three contact areas. A first contact area is located central to the diaphragm with a second area near the periphery of the diaphragm. A third contact is of a larger area and is positioned between the first and second contacts. A source of biasing potential is applied between the first and second contacts to cause current flow indicative of the spreading resistance between the contacts. The value of the spreading resistance varies in accordance with a force applied to the diaphragm.

Abstract: There is disclosed a rectangular diaphragm employing a quasi rectangular active area. The diaphragm as configured has an aspect ratio which is the length to width ratio of greater than 3:1. The active area of the diaphragm, which is the area which most readily deflects upon application of a force to the diaphragm, is formed by an anisotropic etching technique to provide steep vertical sidewalls. The diaphragm structure thus described exhibits as a response to an applied force or pressure, a maximum longitudinal stress and a minimum transverse stress and can accommodate piezoresistive elements located within the active area of the diaphragm.

Abstract: Compensating apparatus for a shear gage transducer employing a piezoresistor. The shear gage transducer or sensor is of a cross-shaped planar configuration where a lack of symmetry in structure or in fabrication undesirably provides offsets at the output terminals associated with the horizontal cross arm. The compensating apparatus includes a series chain of resistors positioned between selected terminals of said sensor to provide a desired null output voltage over a temperature operating range. Further embodiments depict a shear sensor having a unique contact configuration to enable resistive compensation of undesired offsets.

Abstract: A housing comprises a first top cylindrical section having an internal hollow which is manifested by three concentric sections, each of a larger diameter to give the sidewall of the housing a step-like cross section. A transducer assembly is positioned within the hollow of the top section and bonded to the inner wall. An annular ring is positioned in the hollow within the second section and accommodates small diameter wires directed from said transducer assembly through the aperture and bonded to metallized land areas on the undersurface of the annular member. The metallized areas also contain a separate conductive post which is directed from the land areas. A second bottom housing accommodates tubular conductive members which are aligned with the post member. When the second housing is emplaced within the first housing the posts are positioned within the tubular conductor members where they are welded to the tubular members to form a permanent assembly.

Abstract: There is disclosed a semiconductor pressure transducer which employs a piezoresistive array fabricated on the surface of a thin substrate member and having the piezoresistors coupled to metallic contacts via ion implanted terminal leads.

Abstract: A monocrystalline silicon substrate has formed on a surface a grating pattern manifested by a series of parallel grooves, a layer of dielectric is thermally grown on said surface to replicate said pattern on an opposite surface of said dielectric and a layer of silicon deposited on said opposite surface of said dielectric is single crystal silicon determined by said grating. The structure formed enables the deposited single crystal layer to be selectively treated to provide at least one piezoresistive sensing element to thereby provide a transducer having both the force collector or substrate and the sensing elements of single crystal silicon and dielectrically isolated by means of said dielectric layer.