1. A packaging substrate, comprising:
a substrate body having a plurality of conductive pads disposed on a surface thereof;
an insulating protective layer formed on the surface of the substrate body and having openings for the conductive pads to
be exposed therefrom; and
conductive pillars disposed on end surfaces of the conductive pads exposed from the openings and having first ends, opposite
second ends, and side surfaces adjacent to the first ends and the second ends, the first ends being closer than the second
ends from the conductive pads, and the first ends having a width bigger than a width of the second ends, wherein the side
surfaces are arc concave toward centers of the conductive pillars.