Patent ID: 6498557
Filing Date: 2002-12-24
Classification: H01F

Abstract:
A micro-coil device comprising:a first silicon wafer having a trench defining an inductive cavity, said trench having metal formed therein; a second silicon wafer having at least one hole therein for providing a non metallic path for magnetic flux to exit said inductive cavity without passing through either said first or said second silicon wafer; a first metal formed on said first wafer and having a first pad connected thereto; and a second metal formed on said second wafer and having a second pad connected thereto; wherein said first and second wafers are proximate to each other and connected at one end to form a first coil situated between said first and second wafers and having at least one turn, said coil being formed around an inductive cavity having a diameter that is equal to or less than a thickness of said first wafer; said device including a third metal formed on said first wafer; and a fourth metal formed on said second wafer; wherein said third and fourth metals being first and second electrodes of a capacitor said coil and capacitor being interconnected to form a resonant circuit; said device further including a second coil situated between said first and second wafers wherein said second coil is inductively coupled to the first coil and one of said first and second coils is connected to an external circuit.