Patent ID: 7755445

Claim:
A multi-layered high speed printed circuit board (PCB) for interconnecting one or more electronic elements, the multi-layered printed circuit board comprising: at least one, first dielectric system further comprising; at least one dielectric layer, and at least one electrical signal line overlying on a first surface of said at least one dielectric layer, and at least one backside open trench on a second opposing surface of said at least one dielectric layer, wherein said at least one backside open trench is located under, and aligned with the at least one electrical signal line; and at least one prepreg layer located under said second surface; and at least one, second dielectric system comprising; at least one other dielectric layer at least one ground/power plane overlying on a first surface of said at least one other dielectric layer, and at least one other backside open trench on a second opposing surface of said at least one other dielectric layer; and at least one other prepreg layer located under said second surface of the at least one other dielectric layer; wherein one or more of said first and second dielectric systems are stacked alternately, such that in a stack, the at least one first dielectric system overlies said ground/power plane of said at least one second dielectric system wherein, said at least one electrical signal line aligned with said at least one backside open trench and, said at least one ground/power plane provide a microstrip type transmission line, and the at least second dielectric system overlies a second one of the at least one first dielectric system wherein, a second one of at least one electrical signal line aligned with said at least one backside open trench located in the second one of the at least one first dielectric system, stacked between said at least one ground/power plane and a second one of a ground/power plane provide a stripline type transmission line, and wherein the shape of said at least one, and said at least one other backside open trenches in the at least one first and at least one second dielectric systems is the one selected from a group consisting of a circle, a cylinder, a sphere, a trapezoid and a square.