Processes of making pad-less interconnect for electrical coreless substrate

A process comprising:

• providing a mounting substrate, wherein the mounting substrate includes a central core, a center metallic substrate layer embedded in the central core, and a metallic substrate layer adjacent the center metallic substrate layer;
• forming a first dielectric layer on the metallic substrate layer, wherein the first dielectric layer has a die side adjacent the metallic substrate layer and an opposing land side;
• forming a recess through the first dielectric layer to expose a fraction of the metallic substrate layer;
• forming at least one surface finish layer in the recess and upon the metallic substrate layer, wherein the at least one surface finish layer is planar to the first dielectric layer die side;
• forming an electrically conductive first plug within the recess in contact with the at least one surface finish layer;
• forming an electrically conductive subsequent plug disposed proximate the first dielectric layer land side, wherein the electrically conductive subsequent plug is electrically coupled to the electrically conductive first plug, and disposed directly above the electrically conductive first plug;
• separating the center metallic substrate layer and central core from the metallic substrate layer;
• removing the metallic substrate layer;
• and
• forming an electrical connector in contact with the at least one surface finish layer, after removing the metallic substrate layer.

A process comprising:

• providing a mounting substrate, wherein the mounting substrate includes a central core, a center metallic substrate layer embedded in the central core, and a metallic substrate layer adjacent the center metallic substrate layer;
• forming a first dielectric layer on the metallic substrate layer, wherein the first dielectric layer has a die side adjacent the metallic substrate layer and an opposing land side;
• forming a recess through the first dielectric layer to expose a fraction of the metallic substrate layer;
• forming an in situ surface finish first layer on the fraction of the metallic substrate layer that is exposed through the recess, wherein the surface finish first layer is planar to the first dielectric layer die side;
• forming an in situ surface finish second layer on the surface finish first layer;
• forming an electrically conductive first plug within the recess in contact with the surface finish second layer and coupled to the metallic substrate layer;
• forming an electrically conductive second plug in contact with the electrically conductive first plug;
• forming an electrically conductive subsequent plug that is coupled to the electrically conductive second plug;
• separating the center metallic substrate layer and central core from the metallic substrate layer;
• removing the metallic substrate layer;
• and
• forming an electrical connector electrically in contact with the surface finish first layer and coupled to the electrically conductive first plug proximate the first dielectric layer die side, after removing the metallic substrate layer.

A process comprising:

• providing a mounting substrate, wherein the mounting substrate includes a central core, a center metallic substrate layer embedded in the central core, and a metallic substrate layer adjacent the center metallic substrate layer;
• forming a first dielectric layer on the metallic substrate layer, wherein the first dielectric layer has a die side adjacent the metallic substrate layer and an opposing land side;
• forming a recess through the first dielectric layer to expose a fraction of the metallic substrate layer by laser ablation to achieve a characteristic dimension;
• forming at least one surface finish layer in the recess and upon the metallic substrate layer, wherein the at least one surface finish first layer is planar to the first dielectric layer die side;
• forming an electrically conductive first plug within the recess in contact with the at least one surface finish layer;
• forming an electrically conductive second plug disposed on the land side and in contact with the electrically conductive first plug;
• forming an electrically conductive subsequent plug disposed on the land side, wherein the electrically conductive subsequent plug is electrically coupled to the electrically conductive second plug, and disposed directly above the electrically conductive second plug;
• separating the center metallic substrate layer and central core from the metallic substrate layer;
• removing the metallic substrate layer;
• and
• forming an electrical connector in contact with the at least one surface finish layer, wherein forming the electrical connector is carried out within the characteristic dimension, after removing the metallic substrate layer.