Semiconductor package

A method of manufacturing a semiconductor package comprising:

• forming a plurality of via holes penetrating through an insulating layer to expose a portion of a redistribution conductor;
• forming a preliminary seed layer extending along an upper surface of the insulating layer and an inner surface of each of the plurality of via holes;
• forming a first photoresist layer on the preliminary seed layer, the first photoresist layer exposes first partial surfaces of the preliminary seed layer within each of the plurality of via holes;
• forming under-bump metal (UBM) vias in the plurality of via holes, respectively;
• forming a second photoresist layer by removing a partial region of the first photoresist layer, the second photoresist layer exposes second partial surfaces of the preliminary seed layer on the insulating layer;
• forming UBM pads covering the UBM vias and the second partial surfaces of the preliminary seed layer, each of the UBM pads has an exposed surface on a side facing away from a corresponding one of the UBM vias;
• removing the second photoresist layer and a partial region of the preliminary seed layer;
• and
• attaching a solder ball on the UBM pads, the solder ball is contacting the exposed surfaces of the UBM pads, and the solder ball extends between the exposed surfaces of at least two UBM pads, of the UBM pads, that are provided within a perimeter of the solder ball.

A method of manufacturing a semiconductor package comprising:

• forming at least two via holes penetrating through an insulating layer;
• forming a preliminary seed layer extending along an inner surface of each of the at least two via holes;
• forming a first photoresist layer on the preliminary seed layer, the first photoresist layer exposes first partial surfaces of the preliminary seed layer within each of the at least two via holes;
• forming at least two under-bump metal (UBM) vias in the at least two via holes, respectively;
• forming a second photoresist layer by removing a partial region of the first photoresist layer, the second photoresist layer exposes second partial surfaces of the preliminary seed layer on the insulating layer;
• forming at least two UBM pads on the at least two UBM vias, respectively, each of the at least two UBM pads has an exposed surface convexly protruding away from a corresponding one of the at least two UBM vias;
• removing the second photoresist layer and a partial region of the preliminary seed layer;
• and
• attaching one solder ball on the at least two UBM pads, the one solder ball is contacting the exposed surfaces of the at least two UBM pads.