Patents

Anthony F. Bernhardt and Vincent Malba
Attachment Method for Stacked Integrated Circuit (IC) Chips
U.S. Patent 5,933,712
August 3, 1999
A method for connecting stacked integrated circuit (IC) chips, such as DRAM memory chips. Pads on the individual chips are rerouted to the side of the chip. When the chips are stacked on top of each other, the side-located pads can be used to form interconnections to other chips or to a circuit board. The side pads are connected to metal lines on a flexible plastic tape (flex) using anisotropically conductive adhesive (ACA). The metal lines on the flex are likewise connected to other pads on chips and/or to pads on a circuit board. In the case of a stack of DRAM chips, pads to corresponding address lines on the various chips may be connected to the same metal line on the flex to form an address bus. This method has the advantage of reducing the number of connections to circuit boards required by busing. The flex can accommodate dimensional variation in the alignment of chips in the stack. The bonding of the ACA is accomplished at low temperature and is otherwise simpler and less expensive than solder bonding; chips can be bonded to the ACA all at once if the sides of the chips are substantially coplanar, as in the case for stacks of identical chips such as DRAM.

Thomas C. Kuklo
Concentric Ring Flywheel without Expansion Separators
U.S. Patent 5,941,132
August 24, 1999
A concentric ring flywheel configured to eliminate the need for differential expansion separators between its adjacent rings. In this configuration, a circumferential step is formed on an outer surface of an inner concentric ring and a matching circumferential step is formed on the inner surface of an adjacent outer concentric ring. During operation, the circumferential steps allow the rings to differentially expand without forming gaps that then need expansion separators to take them up.

David J. Erskine
Multichannel Heterodyning for Wideband Interferometry, Correlation, and Signal Processing
U.S. Patent 5,943,132
August 24, 1999
A method for processing a high-bandwidth signal by coherently subdividing it into many narrow-bandwidth channels for individual processing, in parallel, at lower frequencies. Phase and amplitude information about the original frequencies is preserved. This multichannel heterodyning can be used to interfere, correlate, autocorrelate, delay, filter, record, and synthesize waveforms as well as combinations of these processes. This invention allows the use of inexpensive, low-bandwidth and low-frequency signal processing components to manipulate signals of much higher bandwidth and frequency. Furthermore, signal comparisons can be performed using reference frequencies that may slowly drift. Not requiring stabilization of this drift reduces device costs.

Robert J. Deri, Eugene D. Brooks III, Ronald E. Haigh, and Anthony J. DeGroot
Massively Parallel Processor Networks with Optical Express Channels
U.S. Patent 5,943,150
August 24, 1999
An optical method for separating and routing local and express channel data. Nodes in a network are interconnected with fiber-optic cables that carry both express channel traffic and local channel traffic. Express channel traffic is placed on, or filtered from, the fiber-optic cable at a light frequency (color) different from that of the local channel traffic. On its light carrier, the express channel traffic skips over local nodes one by one by reflecting off mirrors selectively placed at each local node. The local-channel-traffic light carriers, on the other hand, pass through the mirrors. A single fiber-optic cable can thus be threaded throughout a three-dimensional matrix of nodes with the x, y, and z directions of propagation color-encoded for local or express channel traffic. This frequency division multiple access eliminates the bucket-brigade latencies that would result if express traffic had to hop between every local node to reach its ultimate destination.

Abraham P. Lee, Peter A. Krulevitch, and M. Allen Northrup
Micromachined Electrical Cauterizer
U.S. Patent 5,944,717
August 31, 1999
A micromachined electrical cauterizer, in which microstructures are combined with microelectrodes for highly localized electrocauterization. The microcauterizer is fabricated by bulk-etching silicon to form knife edges, then aligning parallel microelectrodes adjacent to the knife edges. While most of the microelectrode lines are electrically insulated from the atmosphere by depositing and patterning silicon dioxide on the electric feedthrough portions, a window is opened in the silicon dioxide to expose the microelectrodes. This helps reduce power loss and assists in focusing the power locally for more efficient and safer procedures.

Awards