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US 4,808,967 AGranted
Circuit board material
AssigneeOhmega Electronics, Inc.
InventorsJames M. Rice, Bruce P. Mahler
Life of this patent
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AssigneeOhmega Electronics, Inc.
InventorsJames M. Rice, Bruce P. Mahler
Estimating the term…
A multilayered circuit board material is disclosed. The material includes an insulating material support layer, an electrical resistance material layer adhering to the support layer, and a conductive material layer adhering to the resistance material layer and in intimate contact with that layer. The electrical resistance material layer is formed from electroplated nickel-phosphorous containing up to about 30% by weight of phosphorous; however, no appreciable amounts of sulfur are present within at least the top about ten atomic layers of the electrical resistance material layer. As a result, the stability of the electrical resistance material layer is significantly increased. In addition, the electroplating bath does not contain chloride salts resulting in decreased pitting in the electrical resistance material layer.
A printed circuit board material in the form of a multilayer stock comprising:
A composition for an electrical resistance material layer in a multilayered printed circuit board comprising electroplated nickel-phosphorous containing up to about 30 percent by weight of phosphorus and wherein at least the top about ten atomic layers are sulfur free.
In a multilayered printed circuit board material having an insulating support layer, an electrical resistance material layer and a conductive material layer, wherein the electrical resistance material layer comprises electroplated nickel-phosphorous containing up to about 30 percent by weight of phosphorus, the improvement wherein the surface of the electrical resistance layer is substantially pit free and continuous at a magnification of 400.times..
Dependencies are inferred from the claim text.