Abstract: Apparatus for testing integrated circuit packages has a test circuit, a socket for receiving a standard circuit representing the packages being tested, and a special contact assembly for coupling to the packages being tested. Two sets of contacts in the assembly are permanently connected to the socket and the test circuit respectively, and one set is movable to connect with the other set or to terminals of a package being tested. A handler inserts the packages one at a time into the contact assembly and moves the movable set of contacts into circuit engagement with the package, and then the package is tested by the test circuit. The handler removes the package from the contact assembly and allows the movable set of contacts to engage the other set so that the standard circuit can be tested to verify that the test circuit is functioning correctly.

Abstract: A wide range oxygen sensor is provided which operates partially in the diffusion limited current mode to provide an output which is proportional to the oxygen partial pressure in a gas mixture which is sensed, such as the exhaust gas of an automotive internal combustion engine. The wide range oxygen sensor is constructed to have a planar structure with a single solid electrolyte layer that is shared by electrochemical storage, pumping and reference cells and which is deposited using known thermal deposition techniques. As a result, the wide range oxygen sensor of the present invention is characterized as being relatively low cost and readily producible under mass production conditions. Moreover, the wide range oxygen sensor is capable of rapidly and accurately sensing the exhaust gas oxygen partial pressure while the engine is operating in either the fuel-rich or fuel-lean condition to enable the evaluation of the air-to-fuel ratio of the precombustion fuel mixture.

Abstract: A semiconductor magnetoresistive sensor and a method for its assembly is specifically provided. The preferred assembly method of this invention is compatible with automated semiconductor chip placement and packaging technology, so as to alleviate the previous requirement that the semiconductor sensing element be separately packaged. The sensor leads are substantially embedded within a powdered metal permanent magnet body. An exposed terminal end of each lead is available for electrical and adhesive contact to a subsequently attached magnetoresistive semiconductor sensing element, using conventional semiconductor placement and packaging techniques. The powdered metal magnetic body is preferably formed by utilizing powder metal compaction techniques, wherein the powder metal is compacted around the interior electrical leads.

Abstract: A semiconductor film is provided characterized by having high carrier mobility and carrier density. The semiconductor film is doped with the rare-earth element erbium so as to improve its temperature stability. The semiconductor film is thereby particularly suited for use as a magnetic field sensing device, such as a Hall effect sensor or magnetoresistor. The semiconductor film is formed from a narrow-gap Group III-V compound, preferably indium antimonide, which is n-doped with the erbium to provide an electron density sufficient to increase temperature stability. In particular, the semiconductor film is characterized by a nini-structure which is generated using a slab-doping technique. The slab-doping process encompasses the growing of alternating layers of doped and undoped layers of the Group III-V compound, with the doped layers being substantially thinner than the undoped layers, and preferably as thin as one atomic plane.

Abstract: An accelerometer is provided which is suitably rugged for use in on-board automotive safety control and navigational systems. The preferred thick film accelerometer is formed from an alumina substrate having an integrally formed U-shaped flexure member which surrounds an intermediate support member. A mass is provided on the unsupported end of the U-shaped flexure member. Deflection is maximum at the unsupported end of the U-shaped flexure member, while strain is maximum at the supported end of the flexure member. Four piezoresistors for detecting the strain within the flexure member corresponding to the acceleration in the direction perpendicular to the plane of the support member are provided on the U-shaped flexure member adjacent its supported ends. The four piezoresistors form a Wheatstone bridge, whose analog output voltage is conditioned and amplified to provide the output signal. The signal conditioning and amplifying circuitry are preferably located on the support member.

Abstract: A film having a unique asymmetrical hysteresis, a method of making, and a method of using such a film in and/or as a device. An example describes a distinctive ferroelectric device as an infrared detector that operates at generally ambient conditions.

Abstract: A carrier frame has cells with inwardly extending thin flexible tabs. Pressure sensor housings are molded into the frame cells such that only the tips of the tabs penetrate the housing wall and after processing the housings are readily pushed out of the frame. A lead frame is insert molded at the same time. During molding the cells of the frame are open ended and after molding a reinforcing tie bar is attached across the open side of the frame to close the cells. A flange is bent up on the opposite side to lend rigidity to the frame. Preformed code flags are provided in the frame and selectively bent out for coding.

Abstract: A method for dielectrically isolating a semiconductor integrated circuit is provided. Each integrated circuit is substantially surrounded by silicon oxide sidewalls which have been appropriately doped to be of an opposite conductivity type as the surrounding substrate. The doped silicon oxide sidewalls are formed prior to the growth of epitaxial silicon within the sidewalls. Upon deposition of the epitaxial silicon the dopant within the oxide sidewalls diffuses into the adjacent epitaxial silicon, thereby resulting in a heavily doped, low resistivity region of epitaxial silicon adjacent to and along the entire length of the oxide sidewall. This heavily doped region results in the substantial elimination of charge-depleting parasitic currents along the sidewalls during use of the integrated circuit. In addition, the heavily doped, low resistivity epitaxial region provides an electrically conductive contact to a buried layer within an integrated circuit having such a buried layer.

Abstract: A method for dielectrically isolating a semiconductor integrated circuit is provided. Each integrated circuit is substantially surrounded by silicon oxide sidewalls which have been appropriately doped to be of an opposite conductivity type as the surrounding substrate. The doped silicon oxide sidewalls are formed prior to the growth of epitaxial silicon within the sidewalls. Upon deposition of the epitaxial silicon the dopant within the oxide sidewalls diffuses into the adjacent epitaxial silicon, thereby resulting in a heavily doped, low resistivity region of epitaxial silicon adjacent to and along the entire length of the oxide sidewall. This heavily doped region results in the substantial elimination of charge-depleting parasitic currents along the sidewalls during use of the integrated circuit. In addition, the heavily doped, low resistivity epitaxial region provides an electrically conductive contact to a buried layer within an integrated circuit having such a buried layer.

Abstract: A magnetic field sensing device in the form of a sensor unit which reduces the effective air gap between the sensing device and its exciter is provided by packaging the sensing device in the manner that provides protection from the environment while simultaneously minimizing the distance between the sensing device and its exterior surface adjacent its exciter. The present invention is particularly suitable for automotive applications, such as magnetic field sensing devices for detecting the wheel speed for an electronic anti-lock braking system.

Abstract: An airflow sensor formed on a silicon chip comprises a silicon base covered with an insulating polyimide layer, a lineal resistance heater on the chip energized with current pulses to propagate thermal waves, and a thermistor on the chip downstream of the heater to detect the arrival of each thermal wave. Circuitry determines flow rate as a function of the measured propagation time of the thermal wave. The thermistor may be replaced by a bridge of four resistive elements of which only one or two are sensitive to the thermal wave. The thermistor material is platinum, polycrystalline silicon or amorphous silicon which exhibit high temperature coefficients of resistance.

Abstract: A microaccelerometer package is provided for use in on-board automotive safety control and navigational systems. The microaccelerometer package is constructed so as to minimize the influence of extraneous mechanical stress and vibrational resonance on the micromachined accelerometer. The microaccelerometer package includes a rigid housing in which there is a cavity for receiving the micromachined accelerometer unit and the signal-processing circuitry. The lower surface of the cavity is interrupted by a recess projecting below the plane of the lower surface. The micromachined accelerometer unit is secured within the recess so as to be below the plane of the lower surface. The signal-processing circuitry is supported by a substrate which is secured to the lower surface of the cavity.

Abstract: A microaccelerometer is provided for use in on-board automotive safety control and navigational systems. The microaccelerometer includes a central support body which is supported upon a backing chip, a peripheral proof mass which circumscribes the central support body, and at least one pair of microbridges, each of which are attached to both the central support body and the peripheral proof mass. The pair of microbridges extend outwardly in opposite directions from the central support body such that a longitudinal axis through each of the microbridges forms a common axis through the central support body. The microbridges are attached to the peripheral proof mass at the end opposite the central support body so as to suspend the peripheral proof mass circumferentially about the central support body and above the backing chip.

Abstract: A microaccelerometer is provided which has a silicon substrate bonded to a silicon capping plate and silicon back plate, wherein the bonds between the three silicon wafers are characterized by a relatively low residual stress level over a wide temperature range. The bonds are formed by means of an appropriate adhesive at a relatively low temperature without degradation to the microaccelerometer. The bonds between the silicon wafers also provide stress relief during use and packaging of the microaccelerometer. With this invention, the damping distance for the proof mass of the microaccelerometer is accurately controllable and stop means are provided for preventing excessive deflection of the proof mass in a direction perpendicular to the plane of the microaccelerometer.

Abstract: Pillars are formed on a substrate at the same time as electrical circuit components are formed thereon and of the same materials used to form the circuit, the pillars serving to maintain standoff of an integrated circuit chip during bonding of solder bumps on the chip underside to the formed substrate circuit. The pillars are provided without extra materials and steps, under the existing alignment requirements for providing the circuit components, during the applying of a series of discontinuous layers, e.g., by screen printing, onto the substrate to form the circuit, by also applying portions of the series of layers as stacked layers in spaced island areas to form the pillars at otherwise unused substrate sites.

Abstract: A package for a magnetic field sensitive element, such as a magnetoresistor, includes at least two planar layers of a relatively stiff ferromagnetic material which is also electrically conductive. The layers have opposed edges which are in closely spaced relation to form a narrow gap therebetween. A terminal tab is integral with and extends from each layer. A magnetic field sensitive element is on a surface of at least one of the layers and preferably extends across the gap to be on both layers. The magnetic field sensitive element has a pair of contacts each of which is electrically connected to a separate one of the layers. A permanent magnet is mounted on and insulated from the surface of the layers opposite the magnetic field sensitive element. A protective layer of an insulating material may cover the magnetic field sensitive element and the layers with the terminal tabs extending therefrom.

Abstract: A pressure sensor assembly is provided containing a substrate having signal conditioning circuitry disposed on both surfaces of the substrate, with the critical pressure sensing element disposed on one surface of the substrate and the laser trimmable resistors disposed on the other surface of the substrate. The preferred ported housing of this invention seals the one side of the substrate containing the pressure sensing element thereby forming a pressurizable chamber, while allowing the signal conditioning circuitry and resistors on the other surface exposed for calibration by laser trimming of the resistors. This eliminates the requirement for a separate housing for the critical pressure sensing element. In addition, when the preferred ported housing is mounted to the pressure sensing side of the substrate for formation of the sealed pressure chamber, the through-holes which electrically interconnect the signal processing circuitry on both sides of the substrate are also concurrently sealed.

Abstract: A semiconductor magnetoresistive sensor and a method for its assembly is specifically provided. The preferred assembly method of this invention is compatible with automated semiconductor chip placement and packaging technology, so as to alleviate the previous requirement that the semiconductor sensing element be separately packaged. The sensor leads are substantially embedded within a powdered metal permanent magnet body. An exposed terminal end of each lead is available for electrical and adhesive contact to a subsequently attached magnetoresistive semiconductor sensing element, using conventional semiconductor placement and packaging techniques. The powdered metal magnetic body is preferably formed by utilizing powder metal compaction techniques, wherein the powder metal is compacted around the interior electrical leads.

Abstract: A magnetic field sensor, such as a magnetoresistor, includes a strip of a layer of a high electron mobility semiconductor whose electrical characteristics vary when a magnetic field is applied thereto on the surface of a body (substrate) of an insulating layer. Conductive contacts are on the strip at the ends thereof and conductive shorting bars are on and spaced along the strip to divide the strip into active regions. The body is mounted on a permanent magnet assembly which includes a magnet and a layer of a ferromagnetic material with the ferromagnetic material extending over the strip. The ferromagnetic layer is in close proximity to only the strip and, more preferably, to only the active regions of the strip so as to confine the magnetic field to the strip.

Abstract: A magnetic field sensor, such as a magnetoresistor, having improved electron mobility comprises a substrate of an insulating semiconductor material, such as gallium arsenide or indium phosphide, having on a surface thereof a narrow strip of a thin active film. The active film has a thin first layer of undoped or lightly doped high electron mobility semiconductor material, such as indium antimonide or indium arsenide, on the substrate surface, and a second layer of the semiconductor material, which may be thicker than the first layer, on the first layer. The second layer is at least partially doped n-type conductivity so as to have a high electron density. The second layer may be entirely of the n-type conductivity semiconductor material or a superlattice of alternating layers of n-type conductivity and intrinsic semiconductor materials or a superlattice of intrinsic semiconductor material and a ternary or quaternary alloy of the semiconductor material which is at least partially of n-type conductivity.