Patent ID: 7780281

Claim:
An ink cartridge used for an electronic device unit including an antenna, the ink cartridge comprising: an ink cartridge casing including a container that accommodates ink; and a liquid sensor including a semiconductor device that detects and manages information relating to the ink accommodated in the container, the semiconductor device comprising: a semiconductor substrate that includes an active element formation face on which an active element is formed; detection electrodes exposed in the container and embedded in the ink cartridge casing, detecting the ink by being wet in the ink, the detection electrodes being formed above the active element formation face; an antenna transmitting and receiving information to or from the antenna of the electronic device unit, the antenna being formed above the active element formation face; a storage circuit storing information relating to the ink; and a control circuit controlling the detection electrodes, the antenna, and the storage circuit wherein the detection electrodes protrude from the semiconductor substrate, and the semiconductor substrate is disposed so that the detection electrodes are only exposed to an inside of the container; wherein the semiconductor substrate is disposed so that faces of the detection electrodes on which the ink touches are formed at the same plane as that of a face of a wall of the ink cartridge casing, wherein said face of the wall touches the ink.