Sealed mask ROM wafer with 5 mm magnetic resonant coupling for long-term digital data preservation

A mask ROM wafer with magnetic resonant coupling is developed that enables us contact-less power delivery and communication of 5 mm distance using an on-chip coil. Since all circuit components are sealed by the passivation layer of the wafer surface and no wire bonding is necessary, the circuit is protected from chemical damages such as humidity and expected to have an extremely long lifetime. The magnetic resonant coupling between the on-chip coil of 5 mm diameter and a reader´s coil on the FR4 surface achieves Q=50.2 at f_o=954MHz and delivers 1.8 V × 4 mA power to supply the read-out circuits including 4 MByte mask ROM in 0.18 μm technology.