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AssigneeInternational Business Machines Corporation
InventorsEdmond Otto Fey, Raymond Thomas Galasco, Thomas Richard Miller, Anita Sargent
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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.
The method of making a printed wiring board without the formation of slivers, comprising the steps of:
The method of manufacturing a printed wiring board having a circuitized metal electrodeposit on both sides thereof, comprising the steps of
A circuit trace deposited on a printed wiring board or a multilayer wiring board comprising a conductive copper having a rectangular or a trapezoidal cross-sectional shape and having a layer of a more noble metal deposited thereon and conforming to the surface thereof.
Dependencies are inferred from the claim text.