Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Making electrical device
Reexamination Certificate
2008-05-27
2008-05-27
Huff, Mark F. (Department: 1795)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Making electrical device
C430S313000, C430S315000
Reexamination Certificate
active
07378227
ABSTRACT:
A PWB or multilayer board with circuit traces is treated by a process that serves to reduce the incident of failure of the board. The process includes the steps of applying a thin commoning layer of copper onto a catalyzed surface of the board substrate and the circuit lines. A photoresist is then applied over the commoning layer after which the photoresist is removed only from the commoning material over the circuit lines. A thin layer of a more noble metal, such as nickel, is electrodeposited over the exposed conductive layer. This is followed by a gold layer electrodeposited over the nickel in close registry therewith. The process provides the traces with a conforming nickel/gold layer that extends down the side of the traces. This reduces the tendency of a subsequent copper etch step from undercutting the nickel/gold, thereby causing slivers that could cause short circuiting between adjacent circuit patterns.
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Fey Edmond Otto
Galasco Raymond Thomas
Miller Thomas Richard
Sargent Anita
Driggs, Hogg, Daugherty & Del Zoppo
Huff Mark F.
International Business Machines - Corporation
Lucas James A.
Sullivan Caleen O
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