Abstract: A process for forming a microelectromechanical system (MEMS) device by a deep reactive ion etching (DRIE) process during which a substrate overlying a cavity is etched to form trenches that breach the cavity to delineate suspended structures. A first general feature of the process is to define suspended structures with a DRIE process, such that the dimensions desired for the suspended structures are obtained. A second general feature is the proper location of specialized features, such as stiction bumps, vulnerable to erosion caused by the DRIE process. Yet another general feature is to control the environment surrounding suspended structures delineated by DRIE in order to obtain their desired dimensions. A significant problem identified and solved by the invention is the propensity for the DRIE process to etch certain suspended features at different rates.

Abstract: A multi-sensor module (10) includes a housing (12) with a plurality of vehicle operating condition sensors (S1-SN) mounted therein and a signal processing circuit (20, 26, 30) also mounted therein which receives sensor signals provided by the plurality of sensors (S1-SN). The signal processing circuit (20, 26, 30) is operable to produce at an output thereof (38) a time-division multiplexed signal representative of the various sensor signals according to a vehicle data bus communications protocol. The signal processing circuit output is connected to an electrical connector (36) adapted for connection to an existing vehicle data bus (18) which is further connected to a vehicle control computer (16). The signal processing circuit (20, 26, 30) is accordingly operable to broadcast on the vehicle data bus (18) sensor information provided by each of the sensors (S1-SN) mounted within the module (10).

Abstract: A bracket for supporting and aligning a circuit component, such as a voltage regulator, on a circuit board during assembly. The bracket frictionally engages the component to restrain the component's movement and raised dimples position the component so that a hole in the component is aligned with holes in the bracket. Proper alignment of the holes allows proper insertion of a fastener which clamps the bracket and component to a heat-dissipating surface. The design of the bracket overcomes the necessity of machining an allowance in the heat-dissipating surface as is required to accommodate the prior art bracket. The bracket also prevents the application of stresses at the junction between the component and its leads when the leads are inserted through holes in the circuit board.

Abstract: The invention relates to circuitry for protecting n-channel load driving devices from reverse voltage conditions and for inhibiting the flow of destructive currents through such devices under reverse voltage conditions. According to one embodiment of the invention, a circuit is provided for protecting an n-channel high side load driving device from negative battery and negative transient operating conditions.

Abstract: A soldering flux containing borneol, which is also referred to as bornyl alcohol. A method soldering using such a flux is also disclosed. Even minor proportions of borneol in the flux help reduce ionic residue from the flux after soldering. Larger proportions of borneol can give the flux tackiness for wave soldering operations. The flux preferably comprises borneol and an organic acid activator that volatilizes during soldering. The flux is applied as a solution of borneol and the organic acid activator in a solvent that substantially evaporates before soldering without leaving any measurable solvent residue.

Abstract: A rollover sensing apparatus and method are provided for predicting rollover or pitchover conditions of a vehicle. The apparatus and method sense angular roll rate, angular pitch rate, longitudinal acceleration, lateral acceleration, and vertical acceleration of the vehicle and produce output signals indicative thereof. A non-linear filter, such as an extended Kalman filter, estimates a current roll angle and a current pitch angle as a function of the sensed signals. A predictor predicts a future roll angle as a function of the estimated current roll angle and the sensed roll rate, and further predicts a future pitch angle as a function of the estimated current pitch angle and the sensed pitch rate. The predicted roll and pitch attitude angles are compared to a threshold value and a vehicle overturn condition signal is output to indicate a predicted vehicle rollover or pitchover condition.

Abstract: A method is provided for altering a play list of a Random Access Player without interrupting the generation of output by the Player. The method includes initiating a reproduction mode that activates the Random Access Player, commencing the generating of output by the Random Access Player and receiving play list requests while the Random Access Player is generating the output, and processing the received play list requests while the Random Access Player is generating the output such that the play list is altered without interrupting the generation of output by the player.

Abstract: A surface mount circuit device (110), such as a flip chip, of the type which is attached to a conductor pattern (126) with solder bump connections (120). The solder bump connections (120) are formed by reflowing solder on shaped input/output pads (112) on the device (110), with the shape of the pads (112) being tailored to favorably affect optimal distribution, shape and height of the solder bump connections (120) following reflow soldering of the device (110) to the conductor pattern (126). The solder bump connections (120) are preferably characterized by a shape that increases the stand-off height of the device (110). The shaped solder bump connections (120) also promote stress relief during thermal cycling, improve mechanical bonding, allow better penetration of cleaning solutions, and improve flow of encapsulation materials between the device (110) and its substrate (122).

Abstract: A method for forming a ruthenium-based thick-film resistor having copper terminations, in which the thick-film resistor is fired in a non-oxidizing atmosphere so as not to oxidize the copper terminations yet without reducing the thick-film resistor to metallic ruthenium. A ruthenium-based thick-film resistor ink having a matrix material and an organic vehicle is deposited on a copper layer that will form the terminations for the thick-film resistor formed by firing the ink. The organic vehicle of the ink is then burned out at a temperature of less than 350° C. in an oxidizing atmosphere, such as air. Thereafter, the ink is fired in a non-oxidizing atmosphere (e.g., nitrogen) at a temperature sufficient to sinter the matrix material and yield a ruthenium-based thick-film resistor with copper terminations formed by the copper layer.

Abstract: A method and assembly (10) for conducting heat from a semiconductor device, such as a power flip chip (12). The assembly (10) is generally constructed to dissipate heat from the chip (12) when mounted to a flexible substrate (16). Heat is conducted from the chip (12) with a heat-conductive member (26) brought into thermal contact with the surface of the chip (12) opposite solder bump connections (18) that attach the chip (12) to the substrate (16). A biasing member (30) biases the substrate (16) against the chip (12) so as to maintain thermal contact between the chip (12) and the heat-conductive member (26). A thermally-conductive lubricant (32) is preferably provided between the surface of the chip (12) and the heat-conductive member (26) in order to promote thermal contact while also decoupling any lateral mechanical strains that may arise as a result of different thermal expansions and movement between the chip (12), substrate (26) and heat-conductive member (26).

Abstract: An overmolded electronic assembly (10) and method for forming the assembly (1) that entails enclosing a circuit board (12) having one or more circuit devices (16) mounted to its surface. The assembly (10) includes a heat-conductive member (18) in thermal contact with one or more of the circuit devices (16) mounted to the circuit board (12). An overmolded body (22) encloses the circuit board (12) and the circuit devices (16) with the heat-conductive member (18), such that the overmolded body (22) and heat-conductive member (18) form a moisture-impermeable seal around the circuit board (12) and circuit devices (16). The overmolded body (22) also includes a connector housing (28) integrally-formed in its outer surface. The method for manufacturing the overmolded electronic assembly (10) generally entails supporting the circuit board (12) with the heat-conductive member (18) such that the heat-conductive member (18) thermally contacts the circuit devices (16).

Abstract: In a preferred embodiment, a compact, low-cost, rotary control knob assembly, including: an indicator portion having disposed thereon indicia representing selectable settings of the control knob assembly; a knob portion disposed over the indicator portion, such that the indicia are contained within a perimeter-defined area of the knob portion; and an indicator opening defined through the knob portion, which indicator opening is selectively alignable with ones of the indicia by rotation of the knob portion with respect to the indicator portion.

Abstract: A method for forming a solder bump pad (22), and more particularly converting a wire bond pad (12) of a surface-mount IC device (10) to a flip chip solder bump pad (22), such that the IC device (10) can be flip-chip mounted to a substrate. The process generally entails an aluminum wire bond pad (12) on a substrate, with at least a portion of the wire bond pad (12) being exposed through a dielectric layer (16) on the substrate. A nickel layer (24) is then deposited on the portion of the wire bond pad (12) exposed through the dielectric layer (16). The nickel layer (24) is selectively deposited on the exposed portion of the wire bond pad (12) without use of a masking operation, such as by an electroless deposition technique. The nickel layer (24) completely overlies the aluminum wire bond pad (12), and therefore protects the bond pad (12) from oxidation due to exposure. Thereafter, the solder bump pad (22) is formed by depositing a solderable material on the nickel layer (24).

Abstract: An analog signal processing system for determining airbag deployment includes a first low pass filter receiving a conditioned analog accelerometer signal and providing an analog acceleration signal therefrom. A first comparator/latch circuit receives the analog acceleration signal and provides a first signal to a logic circuit. The analog acceleration signal is further provided to a first integrator which converts the signal to a first velocity signal and provides the first velocity signal to a second comparator/latch circuit which provides a second logic level signal to the logic circuit. A second low pass filter receives the analog acceleration signal and provides a low frequency analog acceleration signal to a third comparator/latch circuit which provides a third signal to the logic circuit.

Abstract: A soldering flux containing borneol, which is also referred to as bornyl alcohol. A method soldering using such a flux is also disclosed. Even minor proportions of borneol in the flux help reduce ionic residue from the flux after soldering. Larger proportions of borneol can give the flux tackiness for wave soldering operations. The flux preferably comprises borneol and an organic acid activator that volatilizes during soldering. The flux is applied as a solution of borneol and the organic acid activator in a solvent that substantially evaporates before soldering without leaving any measurable solvent residue.

Abstract: An improved pressure-based weight estimation system that includes an adaptive technique for reliably and accurately determining the vacant, or unoccupied, seat pressure. The vacant seat pressure is initially determined by a factory calibration procedure, and is thereafter suitably updated by an adaptive learning algorithm based on temperature, time, and the measured pressure. If the seat temperature is within a normal range, and the measured pressure remains at least a predetermined amount below the calibrated vacant seat pressure for at least a predetermined time, a fraction of the difference between the measured and calibrated values is subtracted from the calibrated value to form a new calibration value. The predetermined difference amount determines the sensitivity of the control, and the predetermined time prevents adaptive correction of the calibration value due to transient pressure conditions.

Abstract: An improved method of operation for a microprocessor-based controller wherein a frequency limited counter can be used to generate low frequency PWM signals having on and/or off periods that exceed the period of the microprocessor's free-running counter. The improved method of operation involves comparing the requested PWM period (on or off) to the counter period, and determining if multiple counter periods are required to generate the requested PWM period. If multiple counter periods are required, the controller configures the PWM output port to maintain its current logic level until the requested period has timed out. In this way, the microprocessor can accurately generate the requested low frequency PWM output signals without requiring any hardware modifications.

Abstract: A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor and converts the differential voltage to current. First and second current sourcing circuits, each including a plurality of current sourcing branches, receives the current and provides current attenuation by switching in and out transistor-based current sourcing branches. The rectifier and differential to single-ended conversion circuit converts the variably attenuated currents to a voltage output.

Abstract: An amplifier circuit (14') for canceling variations in an amplifier feedback signal includes compensation circuitry (50) defining a replica of the feedback current therethrough. The replicated feedback current is drawn from a circuit node (N1) which directs the feedback signal to a differential pair (Q1, Q2) of the amplifier circuit 14', whereby any biasing effects on the differential pair (Q1, Q2) due to changes in the feedback signal resulting from changes in a gate drive output voltage (V.sub.GD) of the amplifier circuit (14') are eliminated. Accordingly, the gate drive output voltage (V.sub.GD) may be used to control an ignition coil (L1) drive transistor (16) whereby any changes in gate drive voltage (V.sub.GD) will not cause the coil current (I.sub.L) to deviate from its target coil current limit value.

Abstract: A motion sensor having a sensing ring and electrodes formed on or in a surface region of a substrate, such as a silicon chip. The sensing ring is supported above the substrate by a number of spring members extending radially from a hub, so that the ring has an axis of rotation through the hub. The electrodes are formed to closely surround the ring, with some of the electrodes being adapted to induce vibration in the ring, while others detect angular and radial deflections of the ring. Finally, the spring members are substantially S-shaped with substantially C-shaped first and second portions having different radii of curvature. Configuring the spring members to have two portions of different radii of curvature substantially produces in the sensing ring the elliptical vibration mode shape of an ideal ring.