Method of making circuitized substrate

A method of making a circuitized substrate, said method comprising:

• forming a first sub-composite including a first dielectric layer of a partially cured dielectric material and having first and second electrically conductive layers positioned on opposite sides thereof, said second electrically conductive layer including a plurality of openings therein, said forming including bonding said first dielectric layer of said partially cured dielectric material and said first and second electrically conductive layers together at a temperature not sufficient to fully cure said partially cured dielectric material;
• forming a second sub-composite including a second dielectric layer having a third electrically conductive layer positioned thereon;
• aligning said first and second sub-composites such that said second electrically conductive layer of said first sub-composite including said plurality of openings therein faces said second dielectric layer of said second sub-composite;
• bonding said first and second sub-composites together using pressure and heat sufficient to substantially fully cure said partially cured dielectric material of said first dielectric layer and also to cause said dielectric material to substantially fill said plurality of openings within said second electrically conductive layer;
• and
• forming conductive openings within said bonded first and second sub-composites to provide electrical connections between selected ones of said first, second, and third conductive layers.