Package substrate, package structure including the same, and their fabrication methods

A method for fabricating a package structure, comprising the steps of:

• (A) providing a carrier;
• (B) forming a metal wiring layer on the carrier, and patterning the metal wiring layer to form a first metal wire;
• (C) forming a first dielectric material layer on the carrier while enabling the first metal wire to be exposed;
• (D) forming a metal pillar on the first dielectric material layer, so that the metal pillar is electrically connected to the first metal wire;
• (E) forming a molding compound layer on the first dielectric material layer while enabling an upper surface of the metal pillar to be exposed;
• (F) forming a flexible material layer on the molding compound layer while enabling the upper surface of the metal pillar to be exposed, wherein the flexible material layer has a surface area larger than that of the molding compound layer so that the flexible material layer has an extension part extending from the molding compound layer without covering the first metal wire;
• (G) forming a second metal wire on the flexible material layer and on the upper surface of the metal pillar, so that the second metal wire is connected to the metal pillar;
• (H) forming a protective layer to cover the flexible material layer and the second metal wire, and forming an opening to expose the second metal wire;
• and
• (I) electrically connecting an integrated-circuit chip to the first metal wire.