Semiconductor package and fabrication method thereof

A fabrication method of a semiconductor package, comprising the steps of:

• disposing a plurality of interposers on a carrier through a plurality of conductive bumps, wherein each of the interposers has opposite first and second surfaces and a plurality of conductive through holes penetrating the first and second surfaces of the interposer, and each of the interposers is disposed on the carrier through the first surface of the interposer with the plurality of conductive bumps;
• forming an encapsulant on the carrier and being flush with the carrier at sides to encapsulate the interposers, wherein the second surfaces of the interposers and ends of the conductive through holes are exposed from the encapsulant;
• forming a redistribution layer on a surface of the encapsulant defined as a same side as the second surfaces and the second surfaces of the interposers, wherein the redistribution layer is in direct contact with the ends of the conductive through holes and electrically connected to the plurality of conductive through holes of each of the interposers;
• disposing and electrically connecting at least a semiconductor element to the redistribution layer;
• and
• performing a singulation process to form a plurality of semiconductor packages.