Apogee Semiconductor, Inc.

Other

David A Grant

Mark Hamlyn

Abhijeet Ghoshal

Expansion compensating structures are formed in redistribution layers of a wafer-level chip-scale integrated circuit package (WLCSP) or other IC package having a low-expansion substrate. The structures include micromechanical actuators designed and oriented to move solder bumps attached to them in the same direction and distance as a function of temperature as do pads to which they may be connected on a higher-expansion substrate such as a printed circuit board. Expansion compensated IC packages incorporating these expansion compensating structures are provided, as well as expansion compensated assemblies containing one or more of these IC packages. Methods of fabricating expansion compensated IC packages requiring minimal changes to existing commercial WLCSP fabrication processes are also provided. These devices and methods will result in assemblies having improved board-level reliability during thermal cycling, and allow the use of larger IC die sizes in WLCSP technology.

Integrated circuit packages having stress-relieving features

CMOS output stages, electrostatic discharge (ESD) protection circuits and input bus-keeper functions are provided that block dc and ac leakage paths within inactive powered-down integrated circuits used in redundant high-reliability system configurations employing cold-sparing to provide backup circuitry. These circuits and methods avoid both undesirable power consumption in a cold-spared backup unit and loading of connected active units when powered down, without compromising performance or functionality of the backup unit when in its active powered state. Inputs and outputs using an analog majority voting principle to implement in-circuit redundancy for on-chip fault tolerance are also provided, incorporating the low-leakage principles of the invention for low power dissipation when powered down. Such on-chip redundancy can harden an IC against various faults, such as single-event effects in high-radiation environments, while maintaining the other advantages in a cold-sparing system.

Circuits and methods for enabling redundancy in an electronic system employing cold-sparing

An integrated circuit for use in high-reliability electronic systems contains one or more digital majority voters with corresponding disagreement detectors connected to the same input signals producing a majority value output and an error signal that is active when not all input signals agree. Internal error signals from multiple majority voter/disagreement detectors as well as external error inputs may be combined using disjunctive error logic to produce an 'error detected' output indication. Cold-sparing and hot-plugging are supported by providing cold-sparable electrostatic discharge protection circuits and power-on reset circuitry controlling cold-sparable output stages. Internal modular redundancy provides immunity to single-event transients as well as enhanced reliability. Redundant electronic systems using the majority voter with error detection are also provided, as are fault notification systems that use the disjunctive error logic and external error input feedthrough capabilities of serially-connected integrated circuits to produce an error indication for a plurality of subsystems.

Majority voter with error detection

Systems and methods for fault-tolerant threshold circuits used in converting an analog input to a single-bit digital output employ N-modular redundancy of either inverting or non-inverting threshold circuits whose inputs are connected to a single input, and apply majority voting of their outputs to provide correction of transient or permanent faults in up to floor[(N&#x2212;1)/2] of the individual threshold circuits. Using summation to perform analog majority voting averages the N threshold circuit outputs and provides resilience to single-event transients, but may exhibit an output characteristic having intermediate voltage levels. A digital majority voter having N inputs connected to the outputs of N threshold circuits restores well-defined logic levels and clean hysteresis for Schmitt trigger threshold circuits. A single point of failure at the digital majority voter may be eliminated using an analog majority voter to sum the outputs of three or more redundant digital majority voters.

Modular redundant threshold circuit and method

The normal procedure for determining top-dead-center (T.D.C.) of a reciprocating engine involves slowly rotating the crankshaft of the engine until the maximum uppermost position (T.D.C.) of the piston in the cylinder has been attained and then inserting a linear gauge in the cylinder to make an appropriate measurement of this position. This method requires access to the piston crown and necessitates the disturbance of cylinder head components. The procedure disclosed obviates the deficiencies of the prior art by determining piston position from measurements taken externally of the engine, in particular by monitoring the speed of the engine, preferably using the flywheel of the engine, on a freely decelerating engine in a non-firing mode. The successive minimum speeds attained by the flywheel during a reciprocating cycle correspond to the two opposite extremities of movement of the piston in the cylinder of interest and thus accurate determination of T.D.C. and/or B.D.C. conditions is possible.

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Edinburgh, United Kingdom

David A Grant