Package carrier and manufacturing method thereof

A method for manufacturing a package carrier, comprising:

• providing a substrate comprising a core layer, two first copper foil layers, and two second copper foil layers, wherein the two first copper foil layers are disposed on two opposite surfaces of the core layer and are located between the core layer and the two second copper foil layers;
• respectively forming two photoresist layers on the two second copper foil layers of the substrate, wherein the two photoresist layers have a plurality of openings respectively, and the plurality of openings expose a portion of the two second copper foil layers;
• bonding a plurality of metal balls to the two second copper foil layers exposed by the plurality of openings;
• forming two first insulation protective layers respectively on the two photoresist layers, wherein the two first insulation protective layers have a plurality of first openings respectively, and the plurality of first openings respectively expose the plurality of metal balls;
• forming a plurality of connection pads in the plurality of first openings of the two first insulation protective layers and extending onto the two first insulation protective layers, wherein the plurality of connection pads respectively cover the plurality of metal balls, and there is an arc-shaped contact surface between each of the plurality of connection pads and the corresponding metal ball;
• forming two build-up circuit structures respectively on the two first insulation protective layers, wherein the plurality of connection pads are electrically connected to the two build-up circuit structures;
• and
• removing the substrate and the photoresist layer to expose the two first insulation protective layers and the plurality of metal balls, wherein the plurality of metal balls and the corresponding connection pads respectively define a plurality of bump structures, and a plurality of top surfaces of the bump structures are on a same plane.