Trw Limited

Northrop Grumman Systems Corporation

Ryan S Berkely

Mary C Massey

Steven F VanLiew

Brian E Parrish

William E McMullen

Steven Park

For qualification testing in product development, a test assembly contains a surrogate circuit board ( ) and surrogate electronic modules ( ) supported thereon. The terminals ( ) of the modules are joined to respective bonding pads ( ) on the circuit board to form bonded joints. The modules terminals and the wiring of the associated bonding pads is configured to produce at least one test series circuit ( ) associated with each module that includes the bonded joints. A tester ( ) supported on the circuit board monitors the test series circuit and produces a persistent indication ( ) should a break or interruption occur in a bonded joint or any other portion of the test series circuit. This allows indications of transient breaks that occurred when the test assembly was being subjected to stresses, such as those induced by temperature excursions, mechanical vibration, and/or mechanical shock to be preserved and recorded at a later time.

On-circuit board continuity tester

A novel captivated jackscrew structure is characterized by the formation of both an internal cavity ( ) within one of the two bodies that are to be connected together and an access passage ( ). One end of the cavity, located at one end of the body is open. The small diameter access passage extends through the other end of the body into the cavity's other end. A standard machine screw ( ) is installed head ( ) first and captured within the cavity, with the screw shaft ( ) protruding from the end of the body ( ). A barrier ( ) is provided to prevent withdrawal of the machine screw head, but permit the screw head and shaft to move a limited distance axially within the cavity. A backstop ( ), resembling an inverted cup with a hole in the bottom lies in inverted position in the cavity over the screw's head.

Captivated jackscrew design

Large size multi-chip module packages are fitted with a new lid (,) formed of a Kovar&trade; (,) framed sheet of Alumina (,) no less than 0.04 inches thick to form a new &ldquo;postless&rdquo; MCM package,(FIG.,and FIG.,) that is tolerant of differential pressures of at least one atmosphere and is reworkable. The rigidity of the Alumina sheet avoids the problem of excess deflection found in the prior lids for the package. It also permits elimination of internal lid support posts, freeing internal area within the MCM package that may be used to seat additional electronic circuitry and/or components.

Postless large multichip module with ceramic lid for space applications

A reworkable multi-chip module contains a large multi-chip module package (2) with an opening at the top to permit access to an internal region for semiconductor devices, the opening being at least four square inches area with the length or width dimension being at least two inches. The opening is sealed with a stiff closure (1) of sufficient rigidity to withstand at least one atmosphere of differential pressure without significant deflection, is removable in a single piece and may be reinstalled. The closure includes a panel of electrically non-conductive material (3) and a metal flange (5) borders the periphery of the panel to support the panel on the top of the module package.

Ceramic lid for large multi-chip modules

A multi-chip module or other electronic semiconductor component (1) contains a multi-layer substrate (9) whose bottom surface, the bottom of the bottom layer (15) of that substrate, serves as the bonding surface for bonding the multi-chip module or component to a printed wiring board (8) using a thermally sensitive adhesive, such as a thermally sensitive adhesive or solder. The bottom layer (15) of that multi-layer substrate integrally includes a plurality of electrical heaters (16-28), arranged side by side. When energized with appropriate current, the heater generates sufficient heat to weaken the adhesive bond, allowing the MCM to be pulled away from the printed wiring board and removed, without weakening the bonding of the multiple layers of the laminate substrate or weakening the MCM component's bond to that substrate.

Growing community of inventors

Long Beach, CA, United States of America

Ryan S Berkely