HIGH DENSITY INTERCONNECTS IN AN EMBEDDED TRACE SUBSTRATE (ETS) COMPRISING A CORE LAYER

A substrate that includes a first substrate portion, a second substrate portion and a second dielectric layer. The first substrate portion includes a core layer having a first core surface, and a plurality of core substrate interconnects, wherein the plurality of core substrate interconnects includes a plurality of surface core substrate interconnects formed over the first surface of core layer. The second substrate portion includes a first dielectric layer having a first dielectric surface, the first dielectric surface facing the first core surface of the core layer, and a plurality of substrate interconnects, wherein the plurality of substrate interconnects includes a plurality of interconnects formed over the first dielectric surface. The second dielectric layer is formed between the first substrate portion and the second substrate portion such that the plurality of surface core substrate interconnects and the plurality of substrate interconnects are located in the second dielectric layer.