1. A manufacturing method of a package substrate, comprising:(a) forming a patterned first dielectric layer on a carrier, such that the first dielectric layer has a plurality of openings;
(b) forming a first wiring layer on a first surface of the first dielectric layer facing away from the carrier, a wall surface facing at least one of the openings, and the carrier in at least one of the openings;
(c) forming a first conductive pillar layer on a portion of the first wiring layer that is on the first surface;
(d) forming a second dielectric layer on the first surface, the first wiring layer, and the openings, wherein the first conductive pillar layer is exposed from the second dielectric layer;
(e) forming a second wiring layer on the exposed first conductive pillar layer and the second dielectric layer;
(f) forming an electrical pad layer on the second wiring layer; and
(g) forming a third dielectric layer on the second dielectric layer and the second wiring layer, wherein the electrical pad layer is exposed from the third dielectric layer.