International Business Machines Corporation

Other

International Flex Technologies, Inc.

Allan Robert Knoll

Kim Joseph Blackwell

Luis Jesus Matienzo

Pei C Chen

Frank Daniel Egitto

George Joseph Matarese

Richard D Weale

David J Bajkowski

Daniel P Labzentis

Francesco F Marconi

Stephen E Deliman

Suryadevara Vijayakumar Babu

Joseph G Hoffarth

Walter E Mlynko

John F Rembetski

Kenneth D Mack

Disclosed is a method of producing a flexible circuit board having gold selectively plated on only desired elements of the conductive circuits. These desired elements typically are attachment sites, such as wire bond pads or ball grid array pads, for semiconductor chips. This method eliminates the requirement to buss all circuits to a common plating contact by using a background seed metal for plating continuity. This method also provides a means to alleviate the requirement for precise registration or alignment when multiple photoresist layers are employed in order to selectively plate only a portion of the metallic elements present on the flexible circuit board. The defect of resist lifting followed by nickel/gold underplating is eliminated by conditioning the intermediate photoresist to survive the nickel/gold plating bath.

Method of producing flex circuit with selectively plated gold

The adhesion of chromium-copper layer to polyimide has been greatly improved by a method which provides controlled reduction, rather than total elimination, of water content in the polyimide. The electronic packaging device which incorporates the flexible circuit prepared by the method exhibits greatly improved reliability. It is believed that the invention can be used to improve the adhesion between other organic materials having moisture affinity and materials comprising in-organics or between two organic materials.

High adhesion performance roll sputtered strike layer

A method for attaching adherent metal components, particularly a copper film, on at least one surface of a polyimide substrate is provided. The method comprises the steps of: exposing at least one surface of the polyimide substrate to a reactive gas plasma that provides a level of ion bombardment of the polyimide surface sufficient to disrupt at least a portion of the imide groups on the surface and to form reactive carboxylate groups, carbonyl groups and other carbon-oxygen functional groups on the surface; and then depositing a metal film onto the chemically-modified surface without intervening exposure to air. The present invention also provides a copper-coated polyimide product comprising a polyimide substrate having a substantially smooth and chemically-modified surface and a copper film directly attached to the surface, i.e., the product is free of a polymeric adhesive layer or tie coat between the surface of the polyimide substrate and the copper film.

Method of forming adherent metal components on a polyimide substrate

A metallic layer is coated onto a polyimide substrate by sputtering a layer of chromium followed by a layer of copper whereby the rate of deposition of the chromium is about 4 angstroms/second or less.

Process for coating a substrate with metallic layer

A method for vapor phase depositing a thin seed layer of, for example, chromium and copper onto the side walls of through holes in thin film substrates of, for example, polyimide is disclosed. This method is useful in fabricating devices such as a thin film semiconductor chip carrier in which a semiconductor chip mounted on one major surface of the chip carrier is electrically connected to a ground plane and/or a power conductor on the other major surface of the chip carrier via one or more metallized through holes.

Method for metallizing through holes in thin film substrates, and

Electronic package including lower water content polyimide film

A copper layer is coated onto an organic polymeric substrate in the presence of a gas containing nitrogen and a noble gas.

Process for creating organic polymeric substrate with copper

A plasma etching process is disclosed wherein the substrate to be etched is first exposed to an etchant gas containing a volatile organohalide. When the etch rate is stabilized, the organohalide in the etchant gas is replaced by oxygen whereby the etch rate of the substrate is immediately increased to a substantially higher value. When the above is repeatedly done a substantially higher average etch rate is obtained.

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Endicott, NY, United States of America

Allan Robert Knoll