Piezoelectric thin film device
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsAkira Yamada, Chisako Maeda, Toshio Umemura, Fusaoki Uchikawa, Koichiro Misu, Shusou Wadaka, Takahide Ishikawa
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Abstract
A piezoelectric thin film device which is composed mainly of a substrate, a piezoelectric thin film formed on the substrate, and thin film electrodes formed on both the upper and lower surfaces of the thin film. The thin film is resonated by applying an AC voltage across the electrodes. A substrate removed section is formed by partially or entirely removing the substrate below the thin film and opened to both the front and rear surfaces of the substrate through openings so as to relieve the pressure variation in the substrate removed section below a resonant structure.
Claims9
A piezoelectric thin film device, comprising:
- a substrate having a top surface and a bottom surface;
- a piezoelectric thin film formed on the top surface of said substrate;
- and
- thin film electrodes formed on the upper and lower surfaces of said piezoelectric thin film,
- wherein an alternating voltage is applied across said thin film electrodes to resonance said portion of said piezoelectric thin film,
- wherein a portion of said substrate under said piezoelectric thin film is partially or entirely removed to form a recess, said recess being opened to air at the top surface of said substrate, and
- wherein said device further includes at least one bridge supported at one end thereof on at least said piezoelectric thin film, said thin film electrode, or an insulating film formed between said substrate and said piezoelectric thin film and the other end thereof on at least a portion of said substrate outside said recess, wherein said portion to be resonated is supported by said bridge.
Dependencies are inferred from the claim text.