Abstract: A high density IC layout is achieved by providing conductive feedthroughs through an IC chip directly to input/output locations within the circuitry, inward from the periphery of the chip or alternately at the periphery of the chip. The chip can thus be mounted to a substrate face up, allowing for visual inspection and simplified mounting techniques. To provide a high density 3-D stack, substrates with chips mounted thereon are stacked together, with substrate feedthroughs connecting to selected chip feedthrough via the substrate routing, and successive layers electrically connected by contact springs. Chips mounted on a single substrate can also be used in a 2-D configuration, without substrate feedthroughs.

Abstract: A power down logic control circuit employing a diode and a capacitor to develop a voltage from a main power supply which normally holds a transistor in an "off" state. Upon disconnection of the main supply, the transistor switches "on" and activates a second transistor. Upon activation, the second transistor produces an inhibit signal to tri-state memory control circuitry and thereby preserve the memory data during transition to standby memory power provided by a lithium battery.