International Business Machines Corporation

Robert A Martone

Chi Shih Chang

Thurston Bryce Youngs, Jr

Subahu Dhirubhai Desai

Ivan I Chobot

Keith K Ho

Phillip A Hartley

Roy T Mulcahy

Scott A Versprille

Robert J Haskins, Jr

Robert D Schoening

Debra A Gernhart

Louis J Shaffer

The present invention increases real estate by providing non-annular lands which do not completely encircle the through holes. The non-annular lands are non-annular, that is they do not extend 360.degree. around the through hole. Preferably the non-annular lands contact no more than one side of the through holes thereby providing real estate not otherwise available using conventional lands. The present invention also relates to a method for producing such Non-annular lands.

Non-annular lands

Disclosed is a design tool and a method of fabricating a multi-layer printed circuit board. The method utilizes the design tool. The knowledge base means has both (1) printed circuit board cross sectional geometric parameter to transmission line parameter data and (2) 'IF . . . THEN . . . ' production rules for lamination, registration, circuitization, testability, test tools, and test procedures. These tools relate to manufacturability, cost, test development, second level packaging and printed circuit board. The printed circuit board begins with the user entering the printed circuit board design parameters and performance parameters into the input/output interface. Next, the knowledge base production rules are applied to the printed circuit board design and performance parameters to generate a set of cross section designs meeting the user specified parameters. The printed circuit board is then built up in accordance with one of the generated cross section designs.

Method and apparatus for the cross-sectional design of multi-layer

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Endicott, NY, United States of America

Robert A Martone