Radio frequency IC tag and bolt with an IC tag

摘要

A radio frequency IC tag 1 includes an antenna substrate 3 accommodated on a bottom portion of an outer casing 2 and an antenna radiation portion 4 mounted on a surface of the antenna substrate 3. These parts are encapsulated by a sealing agent 7. An IC chip 5 is disposed at a substantial center on a backside of the antenna substrate 3. A ground pattern connected to an electrode terminal of the IC chip 5 is formed in an area, on which the IC chip 5 is not mounted. A through electrode 6 passes through the antenna substrate 3 from its back surface to above its front surface at a position slightly offset from the center thereof. The through electrode 6 is then connected to the antenna radiation portion 4 on the front surface and to the electrode terminal of the IC chip on the back surface.