Patent US 5,546,321

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.