A 3D IC package is provided. The 3D IC package includes: a first IC die comprising a first substrate at a back side of the first IC die; a second IC die stacked at the back side of the first IC die and facing the first substrate; a TSV through the first substrate and electrically connecting the first IC die and the second IC die, the TSV having a TSV cell including a TSV cell boundary surrounding the TSV; and a protection module fabricated in the first substrate, wherein the protection module is electrically connected to the TSV, and the protection module is within the TSV cell.