Package structure and method of forming the same

A method, comprising:

• providing a composite wafer with a first surface and a second surface opposite to each other, wherein the composite wafer comprises a plurality of seal rings dividing the composite wafer into a plurality of packages;
• forming a conductive layer on the first surface of the composite wafer, wherein the conductive layer comprises:
• a first conductive feature electrically connected to the composite wafer;
• and
• a second conductive feature formed between the first conductive feature and a corresponding seal ring;
• forming a plurality of through holes in the composite wafer to respectively penetrate through the first and second surfaces of the composite wafer;
• respectively bonding a plurality of dies onto the plurality of packages at the first surface by the first conductive feature;
• and
• forming an underfill to laterally encapsulate the first conductive feature, wherein the second conductive feature separates the underfill from the plurality of through hole.

A method, comprising:

• providing a composite wafer with a first surface and a second surface opposite to each other, wherein the composite wafer comprises a plurality of seal rings divided the composite wafer into a plurality of packages;
• forming a plurality of conductive features on the first surface of the composite wafer;
• forming a plurality of through holes in the composite wafer to respectively penetrate through the first and second surfaces of the composite wafer;
• performing a joint process to respectively joint a plurality of contacts of a plurality of dies onto the plurality of conductive features and form a plurality of connectors bonding the plurality of dies and the plurality of packages;
• after the joint process, forming a plurality of dam structures between the plurality of connectors and the plurality of seal rings;
• and
• forming an underfill to laterally encapsulate the plurality of connectors, wherein the plurality of dam structures separate the underfill from the plurality of through hole.