Shipley Company LLC

Other

Oleh B Dutkewych

Michael Gulla

John J Bladon

Leonard R Levy

Charles A Gaputis

James G Shelnut

Charles R Shipley

David Merricks

Disclosed are methods for depositing a copper seed layer on a substrate having a conductive layer. Such methods are particularly suitable for depositing a copper seed layer on a substrate having small apertures, and preferably very small apertures.

Seed layer deposition

A catalytic adsorbate suspended in an aqueous solution comprising reduced catalytic metal on an organic suspending agent where the reduced catalytic metal has a maximum dimension not exceeding 500 angstroms. The catalytic adsorbate is useful for the electroless metal deposition of substrates that are non-catalytic to electroless metal deposition.

Catalytic metal of reduced particle size

An electroless copper deposit having an elongation capability of at least 10 percent as determined by a mechanical bulge test on a foil having a thickness of between 1.5 and 2.0 mils.

Ductile electroless copper

A catalytic adsorbate suspended in an aqueous solution comprising reduced catalytic metal on an organic suspending agent where the reduced catalytic metal has a maximum dimension not exceeding 500 angstroms and the organic suspending agent is one capable of complexing with ions of the catalytic metal. The catalytic adsorbate is useful for the electroless metal deposition of substrates that are non-catalytic to electroless metal deposition.

A structure having a catalytic surface plated with an autocatalytic electroless alloy of copper, a metal selected from nickel, cobalt, mixtures thereof and phosphorous.

Electroless alloy plating

This invention is directed to an etchant and to a process for its use. The etchant comprises sulfuric acid activated with hydrogen peroxide or the synergistic combination of hydrogen peroxide and molybdenum. The etchant is characterized by a source of phosphate ions as an inhibitor against attack on tin, especially immersion tin, as well as several other metals such as nickel and alloys of nickel such as gold alloys. The etchant is especially useful for etching copper and its alloys in the presence of a tin etch resist, and therefore, provides a new procedure for the fabrication of printed circuit boards using immersion tin as an etch resist.

Etchant and process

This invention is directed to an etchant and to a process for its use. The etchant comprises a synergistic combination of hydrogen peroxide and molybdenum as oxidants in acidic solution. The combination of oxidants provides for sustained etching at an exalted rate. The etchant is useful for etching metals, especially copper and its alloys, and is particularly useful in the manufacture of printed circuit boards.

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Harvard, MA, United States of America

Oleh B Dutkewych