A semiconductor package includes a substrate, a semiconductor die mounted on the substrate, and a heatsink over the semiconductor die. The heatsink includes a roof portion and at least one connecting portion extending between the roof portion and the substrate. The at least one connecting portion includes a connection lead mounted on a connection pad of the substrate. The connection pad includes a first portion and a second portion spaced apart from each other, which are configured to electrically couple to different voltage signals, respectively, for detecting heatsink floating.