Hughes Aircraft Company

Hughes Electronics Corporation

Other

Choice Products, Inc.

Louis E Gates, Jr

Albert Kamensky

Trueman R Betts

William W Milroy

Don C Devendorf

Ronald I Wolfson

Joseph P Smalanskas

Michael D Runyan

Charles A Finnila

Douglas A Hubbard

Donald B Mertens

James H Cliborn

Richard K Cochran

Richard M Port

Jose A Martinez

James H LeCourt

A method of manufacturing an environmentally robust electronic module for aircraft avionics or other military or commercial electronic systems. The method produces a sealed chip-on-board electronic module and comprises the following steps. A printed wiring board is provided having an electrical interconnection circuit printed thereon. Bare integrated circuit chips directly mounted and wirebonded to the printed wiring board. Solderable components are then mounted and conductively connected to the printed wiring board to produce a chip-on-board electronic module. The chip-on-board electronic module is then passivated with silicon nitride to produce a sealed chip-on-board electronic module. The electronic module is passivated by applying a coating of silicon nitride using a plasma enhanced chemical vapor deposition process at a temperature near room temperature so that no stress is induced in the integrated circuit chips or wirebonds of the electronic module. The silicon nitride coating typically has a thickness on the order of one-half micron. After passivation, the sealed chip-on-board electronic module is encapsulated or a cover is disposed thereon.

Method of constructing a sealed chip-on-board electronic module

A heater assembly and a method for securing and removing an object, such as a ceramic package to and from a surface, such as the surface of circuit module or printed wiring board, for example. The heater assembly includes a heater element such as a foil (film or wire) element, embedded or sandwiched between two layers of adhesive, such as thermoplastic adhesive. The layers of adhesive may contain a dielectric filler material with relatively high thermal conductivity to enhance heat transfer capabilities through the heater assembly. Two heater electrodes protrude from the heater assembly and are not encapsulated by the layers of adhesive and are accessible so that voltage may be applied to the heater element. During use, the heater assembly is disposed between the base of the object and the surface to which it is to be secured. A predetermined low voltage is applied to exposed heater electrodes to activate the heater element, whereupon heat generated by the heater element softens the layers of adhesive. When the voltage is removed, the layers of adhesive solidify and bond the object firmly to the surface. When bonding a ceramic package to a circuit board, for example, the use of layers of adhesive containing dielectric filler material having a relatively high thermal conductivity enhances heat transfer from the package to the circuit board, or to a heat sink upon which it typically mounted. If the object needs to be removed for repair or replacement, voltage is reapplied to the heater electrodes, whereupon the layers of adhesive soften and the object is removed.

Adhesive heater and method for securing an object to a surface

An integrated circuit chip bonding system comprising a multi-layer film adhesive for mounting an integrated circuit chip to a printed circuit substrate having a metallized grounding pad disposed thereon that is connected to a circuit ground of the integrated circuit chip. The multi-layer film adhesive comprises a lower film layer that is a dielectric insulator, and an upper film layer that is disposed in contact with the chip. The length and width dimensions of the upper film layer are slightly larger than the dimensions of the integrated circuit chip, and the dimensions of the lower film layer are slightly larger than the dimensions of the upper film layer. Conductive adhesive is used to electrically connect the upper film layer to the circuit ground by way of the metallized pad.

Multi-layer film adhesive for electrically isolating and grounding an

Methods for making low cost, high density circuits for multichip modules using a two-layer interconnect pattern. The circuit is comprised of parallel line segments on each side of the dielectric film, orthogonal to each other to form a mesh or grid when viewed through the film. Line segments are interrupted, as required, to form signal lines connected to each other with metalized vias at appropriately selected intersections of the grid through the dielectric film. Power and ground lines are placed between the signal lines to prevent crosstalk between long parallel line segments. Power and ground lines are also appropriately connected at intersections to form co-connected mesh planes in the two surfaces. The novelty of the invention also resides in the methods of constructing the circuit, wherein circuit patterns on each side and vias are formed simultaneously in a single set of plating operations. Virtually no subtractive etching is required, making the methods environmentally friendly and very low cost. Line feature sizes approach 25 microns or smaller, with line pitch of 50 microns or smaller. Fabricated circuits can accommodate wire-, TAB-, or flip-chip-mounted components, and passive components by adhesive bonding or soldering. Because all lines are formed with additive copper, total circuit resistance is low, typically forty percent lower circuit resistance than signal lines 15 made with aluminum conductors.

Orthogonal grid circuit interconnect method

Two or more integrated circuit or memory chips (64-66, 104, 106-108, 116-118, 122-126) are stacked on a circuit substrate (72, 100) or a printed-wiring board in such a manner that the planes of the chips lie horizontally, rather than vertically, on the substrate or wiring board. The chips are preferably interconnected along all of their edges (68) and thence, preferably by ribbon bonds, to the substrate or wiring board. The thus assembled arrangement is hermetically sealed by coatings of passivation and encapsulant. Such chips (25) are oversized, as distinguished from chips conventionally diced from wafers. Specifically, each chip is larger than an individual wafer circuit (18, 20), that is, each wafer portion (24) which is selected to be formed into a chip has a size that is larger than the individual wafer circuit which it incorporates, thus overlapping adjacent circuits.

Stacked chip assembly and manufacturing method therefor

A structure integrity monitoring apparatus and method for use with certain structures such as air-frame structures. A meandering transmission line (22) or serpentine coaxial cable is adhered to a dielectric substrate (20). The dielectric substrate may be a composite panel of the air-frame structure. A microwave signal is introduced at one end of the transmission line (22) or coaxial cable and absorbed at the other end by an appropriate signal absorbing device. For use of the meandering transmission line (22), generally two conductors (22, 24) are affixed on opposite sides of the dielectric substrate (20). In this manner, an electric field created by the two conductors (22, 24) by the microwave signals propagating through them is confined within the dielectric substrate (20). As the signals travel down the transmission conductors (22, 24), they will be reflected at crossover points along the way creating a signature reflection wave. If the dielectric substrate is flawed, a perturbation in the electric field caused by the flaw will create a reflection of the microwave signal at the flaw area. When this reflection signal is compared with the signature signal, it can be determined where and if a flaw is present.

Detection and ranging of material flaws using microwave transmission

The hermetic package (10) has an interior recess (46) for receipt of a semiconductor chip. The recess is square and set at 45.degree. with respect to the rectangular exterior of the package. The ceramic layers which make up the package carry conductive planes thereof with the interior opening stepped to provide connection points. The lowest layer having a chip opening therein may be left out of the assembly to provide a shallower chip opening recess.

Hermetic package for integrated circuit chips

A diaphragm test probe for establishing a detachable electrical connection to the pads on an integrated circuit chip. Leads are electrically connected to a plurality of conductive contacts which are affixed to a flexible diaphragm. The conductive contacts are arranged to match the pattern of the pads on the integrated circuit chip and are aligned with these pads using visual sighting. After alignment, fluidic pressure is applied to the flexible diaphragm, causing it to flex and, in turn, the conductive contacts to make electrical contact with the pads on the integrated circuit. A plurality of sets of conductive contacts may be affixed to a single flexible diaphragm so as to allow multiple chip testing without realignment of the test probe.

Diaphragm test probe

The electronic package (10) is comprised of a plurality of support plates (12-24), each of which has a plenum therein and preferably webs extending into the plenum for fluid flow control and heat transfer. A wafer (104) is mounted in a recess (100) in the support plate (12) so that fluid in the plenum (52) directly cools the wafer. Electrical connection is by flexible cable (108) to an exterior printed wiring board (40). The package may have any selected number of support plates, and each support plate may carry one full-sized wafer for compact packaging.

Stacked wafer electronic package

A flame extinguishing device for use with an ornamental lamp having a base, a chimney, and a wick which provides a lamp flame, includes a plate coupled inside of the chimney below the flame. The plate has a hole in the center thereof surrounding the flame but below the flame. As the plate is lifted above the flame, a low pressure area is formed below the plate. The pressure differential between the bottom of the plate and the top of the plate causes combustion by-products above the flame to flow downward through the hole. As the combustion by-products flow past the flame, oxygen is temporarily prevented from reaching the flame, thus extinguishing it. Therefore, extinguishing the flame is a simple matter of lifting the chimney an inch or so. The plate may include side holes which prevent the flame from being extinguished when the chimney and plate are placed on the lamp when the flame is burning.

Flame-extinguishing device

A food warming oven has a wire rack frame surrounded by an insulation fabric cover which acts to retain heat within the oven, yet breathes to prevent moisture buildup in the heat retention volume. A flame producing device is disposed within the oven to provided a flame heat source. A heat distribution plate is disposed above the flame to insure a uniform heat distribution throughout the heat retention volume. A retention apparatus insures that the heat source is reliably and securely retained with the oven.

Portable warming oven

A microelectronic package for the protection, housing, cooling and interconnection of a microelectronic chip. The package is made of a plurality of ceramic layers, each of which carries a particular electrically conductive pattern and which have interior openings therein so as to provide recesses in which the chip and discrete capacitors can be located and connected.

Microelectronic package

A flat pack or a platform type ceramic-metal package for housing large scale integrated (LSI) circuit wafers or hybrid circuits comprises a rectangular, square or circular, flat ceramic base metallized with a pattern of radial leads from the central portion of the package to its periphery. The leads pass out underneath a ceramic ring frame hermetically sealed to the base. The outside of the ring frame is metallized. Alternatively, flat-headed metal pins may be passed through the base. Hermetically brazed to the frame is a Kovar ring or sleeve. The electronic device is bonded inside the ring frame to the package base. Electrical connections from wafer or hybrid circuit pads to lead pads or pins within the ring frame are made by conventional wire bonding techniques. A ceramic lid with rim and the outer portion of its upper surface metallized is attached to the package by soldering to the Kovar ring.

Growing community of inventors

Westlake Village, CA, United States of America

Louis E Gates, Jr