The present disclosure provides a semiconductor package includes a contact pad, a device external to the contact pad and a solder bump on the contact pad. The device has a conductive contact pad corresponding to the contact pad. The solder bump connects the contact pad with the conductive contact pad. The solder bump comprises a height from a top of the solder bump to the contact pad; and a width which is a widest dimension of the solder bump in a direction perpendicular to the height. A junction portion of the solder bump in proximity to the contact pad comprises an hourglass shape.