A component carrier has formed therein a water sensor, having a first patterned conductor piece formed in a metal layer of the component carrier and a bridge being an amount of water-soluble conductive glue filling an electrically insulating gap between the patterned conductor piece and another conductor in the carrier. This forms a conductive path between the patterned conductor piece and the another conductor. A sensing circuit is coupled to detect changes in impedance of the path. In another embodiment, a discrete component has a pair of terminals with a bridge being an amount of water-soluble conductive glue filling the electrically insulating gap between the terminals to form a conductive path whose impedance changes in response to coming into contact with a sufficient amount of water. Other embodiments are also described and claimed.