Electrical isolating structure for conductors in a substrate

Abstract

A substrate has a first dielectric layer; a first conductive layer on the first dielectric layer; a second dielectric layer on the first conductive layer; an elongated signal conductor embedded within the second dielectric layer; a second conductive layer on the second dielectric layer; a first conductive groove and second conductive groove through the second conductive layer, the second dielectric layer, the first conductive layer and into the first dielectric layer and extending continuously along the length of and on opposing sides of the signal conductor, the grooves having conductive side walls providing an electrical connection between the first conductive layer and the second conductive layer; first and second conductive end walls joining the first groove and second groove; and at least one insulating area through at least one of the first and second conductive layers to provide conductor access.