A method of testing a semiconductor package is provided. The method includes forming a first metallization layer, wherein the first metallization layer includes a first conductive pad electrically connected to a charge measurement unit and a charge receiving unit; performing a first test against the charge measurement unit through the first conductive pad to determine whether breakdown occurs in the charge measurement unit; and in response to determining that no breakdown occurs in the charge measurement unit, forming a second dielectric layer over the first metallization layer, wherein a portion of the first conductive pad is exposed from the second dielectric layer.