Abstract: A process for bonding a flip chip (20), of the type having an active face provided with conductive bumps, to a substrate (22) so that its active face is oriented toward the substrate (22). The flip chip (20) is coupled through a vacuum to the distended end (32) of an ultrasonic horn (30) and then lowered onto the substrate (22) so that the bumps (20b) align with a bonding pattern on the substrate (22). A bias force is applied through the ultrasonic horn (30) to the backside of the flip chip (20), in a direction normal to the substrate (22) so that minimal lateral displacement of the flip chip (20) and the substrate (22) results. The ultrasonic horn (30) is then activated while the bias force is applied such that the ultrasonic energy is isothermally transferred in a direction normal to and across the flip chip (20) to the substrate (22) for creating a diffusion bond therebetween.

Abstract: A footprint, and method for forming the footprint, of the type for mounting a surface mount component having a heatsink which defines a first registration edge thereon. The substrate pad is positioned on the substrate for registrated engagement with the heatsink. The substrate pad has an area substantially larger than the area of the heatsink to improve the dissipation of thermal energy. The substrate pad includes notches for defining registration edges which are juxtaposed with corresponding registration edges on the heatsink when the electronic component is in proper alignment with the substrate pad. Surface tension forces produced by melting solder interposed between the heatsink and the substrate pad act upon the registration edges to maintain proper alignment of the component with the substrate pad.

Abstract: A process for bonding a flip chip (20), of the type having an active face provided with conductive bumps, to a substrate (22) so that its active face is oriented toward the substrate (22). The flip chip (20) is coupled through a vacuum to the distended end (32) of an ultrasonic horn (30) and then lowered onto the substrate (22) so that the bumps (20b) align with a bonding pattern on the substrate (22). A bias force is applied through the ultrasonic horn (30) to the backside of the flip chip (20), in a direction normal to the substrate (22) so that minimal lateral displacement of the flip chip (20) and the substrate (22) results. The ultrasonic horn (30) is then activated while the bias force is applied such that the ultrasonic energy is isothermally transferred in a direction normal to and across the flip chip (20) to the substrate (22) for creating a diffusion bond therebetween.

Abstract: A four wheel steering strategy determines when the rear tire longitudinal slip becomes greater than the front tire longitudinal slip, either due to braking or acceleration, such that the rear tire slip angles must be increased to maintain vehicle balance with respect to the level of understeer/oversteer. The out-of-phase rear steering angle is reduced or the in-phase rear steering angle is increased to increase the rear tire slip angles and thereby correct vehicle balance. Three embodiments are disclosed which use estimated tire longitudinal slips, wheel speeds, and engine throttle information, respectively. The required inputs for the various embodiments can be obtained from independent sensors or preferably are available from other vehicle systems such as an anti-lock braking system, a traction control system or an engine management system. Advantageously, the present invention operates without requiring expensive sensors such as yaw sensors which are currently not feasible for mass market use.

Abstract: The method and system provide a means of inspecting die sets by scanning the core die and the cavity die separately. A special software technique is used to transform both data scans to the same coordinate system or frame in an orientation which simulates die closure. Then methods are used to determined the exact shape of the interior of the die set when closed.

Abstract: A method of time-aligning sequential gas concentrations, generated by a non-plug flow real time emissions analyzer, with corresponding plug flow inputs from an emissions source includes selecting a sequence of known plug flow test gas pulses representative of the emissions source, feeding the known plug flow test gas pulses into the analyzer, saving a sequence of blurred test pulses generated by the analyzer, determining a mathematical relationship between the known plug flow test gas pulses and the blurred test pulses, configuring a filter such that the filter corresponds to the mathematical relationship, inputting a subset of the blurred test pulses into the filter, recording a sequence of deconvoluted test pulses generated by the filter, comparing the deconvoluted test pulses with a subset of the known plug flow test gas pulses to generate difference errors, adjusting the filter to minimize the plurality of difference errors, repeating the first inputting step, the first recording step, the comparing step,

Abstract: In an apparatus for cleaning a workpiece with abrasive CO.sub.2 particles, a CO.sub.2 nozzle receives and expels liquid CO.sub.2 through at least one orifice sized for at least partially converting the liquid into CO.sub.2 particles. The CO.sub.2 particles are injected into a converging-diverging nozzle at a location adjacent to the throat section thereof. Pressurized air is directed into the converging section of the nozzle upstream from the throat section. The pressurized air accelerates the CO.sub.2 particles which are focused by the diverging section of the nozzle for impacting the pressure-sensitive surface of the workpiece to be cleaned.

Abstract: In a vehicular warning system for sensing the approach of severe weather, a pressure sensor generates a first signal representative of the barometric pressure. A computer, coupled to the pressure sensor through the electrical system of the vehicle, generates a second signal responsive to the first signal changing in a time series pattern correlated with a known time series pattern representative of a severe weather system. The computer is coupled through the electrical system of the vehicle to the horn and/or lights for generating warning signals responsive to receiving the second signal, but only when the vehicle is not in the operating mode.

Abstract: A method and system for calculating the effective fuel economy of a fuel-consuming engine in a vehicle are disclosed. The effective fuel economy is calculated taking into consideration the chemical energy contained in the fuel and the change in kinetic energy of the vehicle (42). The effective fuel economy is also calculated by further considering the change in potential energy of the vehicle (60). The chemical energy contained in the fuel is determined by sensing the mass flow rate of fuel (52). The kinetic energy (56) is determined by sensing the change in the speed of the vehicle and the mass of the vehicle (50). The potential energy (58) is determined by sensing the change in elevation of the vehicle (50). The effective fuel economy is displayed to the operator of the vehicle (64).

Abstract: A piezoelectric fluid control valve (10) and fluid control method using a polymorph (48) with a characteristic that as a potential difference is applied thereto, the polymorph is deflected. The valve includes a supply port (14) for introducing fluid and a chamber (16) defined within the valve body. An outlet port (18) is in fluid communication with the chamber and a device controlled thereby, such as an anti-lock brake system. A relief port (78) returns fluid to a source thereof. Upper and lower metering elements (100, 116) are supported within the chamber. A cantilevered spring valve (128, 130) is positionable within metering orifices defined within the metering elements (100, 110). The polymorph is positioned between and in operative communication therewith. An electrical circuit (56) is connected to the polymorph, the circuit providing the potential difference thereto, which is regulated in accordance with an input signal delivered to the circuit.

Abstract: A method for determining the testing profile for accelerated laboratory sinusoidal vibrational testing of a product, includes the steps of (i) selecting the type and rate for the frequency sweep, (ii) developing a simplified composite Power Spectral Density function PSD.sub.j representing expected field vibration levels, (iii) developing the acceleration force function G.sub.T (f) corresponding to the PSD function, (iv) determining the stress response curve H(f) for the product, (v) selecting the number of frequency sweeps N.sub.w based on the testing equipment, the testing time available, and the range of acceleration forces required for implementing G.sub.T (f) from the relationship ##EQU1## (vi) recalculating the acceleration forces G.sub.u, and then (vii) testing the product using the selected variables to validate the required performance lifetime for the product when no test failures are observed over all of the N.sub.w test sweeps.

Abstract: Method and system for modifying a linear control algorithm which controls an automotive HVAC (heating, ventilation and air conditioning) system using fuzzy logic. The control algorithm responds to signals generated by various climate control sensors to produce a desired vehicle air temperature as set by an operator of the vehicle. Fuzzy linear control achieves the following three functions: (1) calibration blending, (2) target set point adjustment, and (3) non-linear offset compensation. Fuzzy logic calculations are performed based on fuzzy rules and membership functions to provide nonlinear compensation and to allow the control to be expressed in the same heuristic terms that an occupant could use in describing the level of comfort.

Abstract: An apparatus and method for cleaning a workpiece with abrasive CO.sub.2 snow operates with a nozzle for creating and expelling the snow. The nozzle includes an upstream section for receiving CO.sub.2 in a gaseous form, and having a first contour shaped for subsonic flow of the CO.sub.2. The nozzle also includes a downstream section for directing the flow of the CO.sub.2 and the snow toward the workpiece, with the downstream section having a second contour shaped for supersonic flow of the CO.sub.2. The nozzle includes a throat section, interposed between the upstream and downstream sections, for changing the CO.sub.2 from the gaseous phase along a constant entropy line to a gas and snow mixture within the downstream section at a speed of at least Mach 1.0. In this manner, additional kinetic energy is imparted to the snow by delaying the conversion into the solid phase until the gaseous CO.sub.2 reaches supersonic speeds.

Abstract: A method and circuit for actively controlling the transition resistance of a multiplex communication signal line having a known termination resistance and characterized by digital signals defined by dominant and recessive states between a voltage source and a ground potential. The digital signal is sensed at the node when it moves through a transition band defined between the dominant and recessive states. The effective terminator resistance at the node along the signal line is reduced only responsive to the digital signal level being within the transition band, whereby the transition time for the signal to travel through the transition band is reduced by reducing the effective resistance and therefore the effective RC time constant at the node.

Abstract: A CO.sub.2 nozzle expels liquid CO.sub.2 under pressure through an orifice therein for converting the liquid into CO.sub.2 snow. The CO.sub.2 nozzle is contained within an elongated mixing cavity within a body which is coupled to an exhaust nozzle for directing the CO.sub.2 snow toward the workpiece. The CO.sub.2 nozzle includes several wings for creating aerodynamic turbulence within the elongated mixing cavity for enhancing the coagulation of the CO.sub.2 snow into larger CO.sub.2 snow particles or CO.sub.2 snowflakes.

Abstract: A circuit for sensing the loss of a signal ground in an automotive electronic system having a source of electrical power and both a signal ground and a power ground, includes a first sensor coupled to the power ground and between the signal ground and the source of electrical power for generating a first signal responsive to the voltage on the signal ground differing from the voltage on the power ground by more than a first predetermined limit. A latching semiconductor switch is coupled to the first sensor and between the signal ground and the power ground for latching the electrical coupling of the signal ground to the power ground responsive to receiving the first signal.

Abstract: An apparatus for determining a number of cylinders to operate in a variable displacement engine includes a signal representative of air charge temperature, a signal representative of barometric pressure, a desired mass air flow evaluator, a maximum mass air flow evaluator, a desired exhaust gas recirculation flow evaluator, a maximum exhaust gas recirculation flow evaluator, and a controller. The controller compares the desired mass air flow to the maximum mass air flow, generating a mass air flow error signal if desired mass air flow error exceeds maximum mass air flow error. The controller also compares the desired exhaust gas recirculation flow to the maximum exhaust gas recirculation flow, generating an exhaust gas recirculation flow error signal if desired exhaust gas recirculation flow exceeds maximum exhaust gas recirculation flow.

Abstract: A single-point impact sensor has a fully differential capacitive sense element for providing a capacitive difference which is proportional to the acceleration of the vehicle. The capacitive difference is converted into a digital pulse train signal which is pulse density modulated with variations in the capacitance. The pulse density of the pulse train is evaluated according to a hierarchy of counters and timers to determine if it is indicative of an activation worthy event. In one embodiment, a non-volatile programmable memory is provided to control the operation of the impact sensor.

Abstract: A method for differentially etching an N-sided polygon aperture through a first major surface of a <100> silicon wafer along the <111> planes begins with depositing a mask and defining therein a first intermediate polygon aperture having at least 4N+2 sides, where N is a positive integer. At least one side is generally parallel to the <110> plane, and the intersection of a second side and a third side of the first intermediate polygon is located generally along a major crystal axis perpendicular to the <110> plane. The included angle between the second and third sides expands during anisotropic etching to form one of the N sides of the polygon located along the major axis perpendicular to the <110> plane.

Abstract: Circular reference features such as drilled holes are located in an area of a part such as a cylinder head, the surface of which is laser scanned to obtain scan data. The scan data provides height values of the part. Differences in height values are used to determine the points on scan lines which are boundary points of the circular holes. A first algorithm is used to estimate the contour and radius of each hole. A second algorithm provides a correction factor for the radius of each hole. The circular reference features are used for registering the part relative to a reference datum. Methods are provided that allow the accurate determination of the location of such reference features to within 0.01 mm. (0.0004 in.) from the scan data. The method may be utilized to create modified scan data to machine the part. The method may be utilized iteratively from different views of the part to obtain data which represents the part.