Package substrate and fabricating method thereof

A method of fabricating a package substrate, comprising:

• providing a core layer defined with a first side and a second side opposing the first side, and having at least one conductive pillar communicating the first side and the second side, and forming a first wiring layer and a second wiring layer on the first side and the second side, respectively, wherein the first wiring layer and the second wiring layer are electrically connected to the at least one conductive pillar;
• forming a plurality of dielectric layers on the core layer, wherein each of the dielectric layers has at least one recess exposing the first wiring layer or the second wiring layer;
• forming a first conductive layer on a surface of the at least one recess, and electrically connecting the first conductive layer to the first wiring layer or the second wiring layer;
• forming a colloid on the first conductive layer to fill the at least one recess;
• and
• forming a second conductive layer on the colloid to cover the colloid.