Apparatus and method for electroless surface finishing on glass

A substrate package, comprising:

• a substrate comprising:
• a glass core;
• a dielectric layer located on the glass core, the dielectric layer having an upper surface that is characterized by surface variations of less than plus or minus 5 microns;
• a conductive pillar located within the dielectric layer and oriented substantially perpendicular to the upper surface;
• a conductive dome, the conductive dome comprising nickel and attached to the conductive pillar, the conductive dome having a radius that exceeds a radius of the conductive pillar;
• a solder resist layer located on the upper surface;
• an opening in the solder resist layer that is substantially centered on the conductive dome;
• a solder material located in the opening in the solder resist layer and electrically connected to the conductive dome;
• and
• an integrated circuit die attached to the substrate via the solder material.

A method, comprising:

• fabricating a substrate having a dielectric layer comprising a conductive layer having a plurality of conductive contacts on a first surface;
• locating a pillar on at least one conductive contact of the plurality of conductive contacts;
• overlaying the dielectric layer above the first surface of the substrate;
• planarizing the dielectric layer to less than a plus or minus 5-micron surface variation;
• performing an electroless nickel electroless palladium immersion gold (ENEPIG) deposit on the at least one conductive contact;
• depositing and patterning solder resist over the planarized dielectric layer;
• and
• depositing solder material in an opening in the solder resist.