US Patent 7355264 Integrated passive devices with high Q inductors

The specification describes flip bonded dual substrate inductors wherein a portion of the inductor is constructed on a base IPD substrate, a mating portion of the inductor is constructed on a cover (second) substrate. The cover substrate is then flip bonded to the base substrate, thus mating the two portions of the inductor. Using this approach, a two level inductor can be constructed without using a multilevel substrate. Using two two-level substrates yields a four-level flip bonded dual substrate inductor.