Texas Instruments Corporation

Interplex Nas, Inc.

Christopher M Sullivan

Raymond A Frechette

David W West

Donald Charles Abbott

Robert A Sabo

Robert M Fritzsche

Steve Smith

Christopher Machado

John E Cotugno

A metal processing method includes etching to remove material from a thin metal part. A pattern of etch resistant material is used to prevent etching of the metal in desired locations. The etch resistant material is intentionally applied to unclean surfaces so that an adhesion between the etch resistant material and the metal will fail during the etching process. An edge is formed during etching at the boundaries of the pattern of the etch resistant material. These edges are rounded where the adhesion fails. A shaver foil is produced using the described metal processing method including a face side, a cutter side and a plurality of whisker holes. A face edge is formed where an etched profile of the whisker hole meets the face side and a cutter edge is formed where the etched profile of the whisker hole meets the cutter side. The face edge is rounded using the aforementioned process and the cutter edge is sharp using a conventional etch resistant material application method.

Method for forming an etched soft edge metal foil and the product thereof

A method for the fabrication of a double-sided electrical interconnection flexible circuit () particularly useful as a substrate for an area array integrated circuit package. A copper matrix with studs () is pressed through a dielectric film () having a copper layer on the opposite surface, thereby forming an intermediate structure for a flex circuit with self-aligned solid copper vias in a one step process. The contacts are reinforced by plating both surfaces with a layer of copper, and conventional processes are used to complete the circuit patterning.

Method of fabricating flexible circuits for integrated circuit interconnections

A double sided electrical connection flexible circuit particularly useful as a substrate for an area array integrated package, and the method of fabricating the structure is described. A circuit having interconnections on one surface and solder ball contact pads on the second surface are interconnected by copper plated from a single surface in order to avoid entrapment of air pockets. In one embodiment, the conductive vias are formed from a copper film which extends from the solder ball contact pads, which may be indented, providing a well for solder balls in the contact pad.

Flex circuit substrate for an integrated circuit package

The invention is a method which deliberately applies exaggerated features (22,32) on the photo-image used to pattern the lead frame for etching. The resulting etched leads (20,25,29) will have a flat to concave shape at the end of the lead tips (23,26,30), which can be used to 'self-center' wire bond paths, eliminating the slung wire tendency altogether, provided the wire path crosses the lead tip within the concave shape region.

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Acushnet, MA, United States of America

Christopher M Sullivan