Package substrate and method for fabricating the same

A package substrate and a method for fabricating the same. The package substrate includes a substrate body having a first surface and a second surface opposite to the first surface; a first circuit layer formed on the first surface and having first conductive pads and first holes penetrating through the first conductive pads; a first dielectric layer formed on the first surface and the first circuit layer; a second circuit layer formed on the first dielectric layer and having second conductive pads; a third circuit layer formed on the second surface and having third conductive pads and third holes penetrating through the third conductive pads; a second dielectric layer formed on the second surface and the third circuit layer; a fourth circuit layer formed on the second dielectric layer and having fourth conductive pads; through holes penetrating through the first and second surfaces, and the first and second dielectric layers; and conductive vias penetrating through the through holes and the first and third holes and electrically connected to the first, second, third and fourth conductive pads.