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US 5,619,791 AGranted
Method for fabricating highly conductive vias
AssigneeLucent Technologies Inc.
InventorsVincent G. Lambrecht, Jr., Henry H. Law, Apurba Roy, John Thomson, Jr., Te-Sung Wu
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Abstract
The thickness uniformity of a plated metal layer inside a via hole can be enhanced by intersecting a conductive via with an insulating aperture before plating. The new via configuration improves the mass transfer of the plating. It is believed that the apertures lower the local solution ohmic resistance near the via holes. The method can be applied to the manufacture of a wide variety of circuit boards.
Claims6
A method for making conductive vias in an insulating substrate comprising the steps of:
- providing an insulating substrate having a pair of major surfaces;
- forming a plurality of via through-holes in said substrate between said major surfaces;
- applying a first coating of conductive material to said substrate within said via holes;
- forming one or more apertures in said substrate intersecting said conductively coated via holes so that the peripheries of the resulting composite apertures include both conductively coated via portions and insulating portions;
- and
- plating said conductively coated via portions with a second layer of conductor.
3 more elements
Dependencies are inferred from the claim text.