Multi-Layer Circuit Substrate and Method Having Improved Transmission Line Integrity and Increased Routing Density

A method of making an integrated circuit, comprising:

• providing a core comprising a dielectric layer with a pattern of large-diameter conductive vias extending therethrough from a top side to a bottom side thereof, wherein the large-diameter conductive vias include signal-bearing vias and voltage plane vias;
• laminating a first top insulating layer on the top side of the core;
• depositing a top transmission line reference plane metal layer on a top side of the first top insulating layer;
• laminating a second top insulating layer on a top side of the top transmission line reference plane metal layer;
• and
• forming a top signal layer on a top side of the second top insulating layer having conductive paths routed above the voltage plane vias, and wherein the depositing the top transmission line reference plane metal layer defines regions devoid of metal above the signal-bearing vias so that capacitive coupling between the tops of the signal-bearing vias and the top transmission line reference plane metal layer is substantially reduced.

An integrated circuit package, comprising:

• a core comprising a dielectric layer with a pattern of large-diameter conductive vias extending therethrough from a top side to a bottom side thereof, wherein the large-diameter conductive vias include signal-bearing vias and voltage plane vias;
• a plurality of signal layers having conductive paths routed above the voltage plane vias;
• a plurality of insulating layers disposed between the plurality of signal layers to insulate the signal layers from adjacent signal layers;
• at least one die electrically connected to at least one of the conductive paths or the signal-bearing vias;
• and
• at least one transmission line reference plane metal layer disposed between the core and at least one of the plurality of signal layers, wherein the top transmission line reference plane metal layer provides a reference plane for transmission lines formed by the conductive paths, and wherein the transmission line reference plane metal layer defines regions substantially devoid of metal around the profile of the signal-bearing vias projected to the transmission line reference plane metal layer so that capacitive coupling between the ends of the signal-bearing vias and the transmission line reference plane metal layer is substantially reduced.