Package substrate with metallization layer(s) that includes an additional metal pad layer to facilitate reduced via size for reduced bump pitch, and related integrated circuit (ic) packages and fabrication methods

A method of fabricating a package substrate, comprising:

• forming a first metallization layer extending in a first direction, comprising:
• forming a first metal layer adjacent to a first surface;
• forming a plurality of first metal interconnects in the first metal layer;
• forming a first metal pad layer adjacent to the first metal layer;
• forming a plurality of first metal pads in the first metal pad layer and each in contact with a first metal interconnect of the plurality of first metal interconnects;
• disposing a first insulating layer on the plurality of first metal pads and the first surface adjacent to the plurality of first metal interconnects;
• and
• forming a plurality of first vias in the first insulating layer and each in contact with a first metal pad of the plurality of first metal pads, the plurality of first vias adjacent to a second surface opposite the first surface in a second direction orthogonal to the first direction.

An integrated circuit (IC) package, comprising:

• a package substrate, comprising:
• a first metallization layer extending in a first direction, the first metallization layer comprising:
• a first surface and a second surface opposite the first surface in a second direction orthogonal to the first direction;
• a first metal layer adjacent to the first surface, the first metal layer comprising a plurality of first metal interconnects;
• and
• a first insulating layer, comprising:
• a first metal pad layer, comprising:
• a plurality of first metal pads each in contact with a first metal interconnect of the plurality of first metal interconnects;
• and
• a plurality of first vias adjacent to the second surface and each in contact with a first metal pad of the plurality of first metal pads;
• and
• a die comprising a plurality of die interconnects each coupled to a first metal interconnect of the plurality of first metal interconnects.