Patent ID: 8183749
Filing Date: 2012-05-22
Classification: H01L,Y10T

Abstract:
1. An electronic device obtained by removing entirely, with an etching solution, a substrate from a multilayer board having a laminate to become the electronic device, wherein the laminate has a top surface, a side face, and a bottom surface and the laminate includes a multilayer structure in which a piezoelectric film is interposed between a pair of electrode films, both the top surface and the side face being wholly covered by a protecting film, the bottom surface being exposed from the protecting film, and the laminate comprises a first thin film and a second thin film, the first thin film having an oxide film disposed on a side of the bottom surface of the laminate, the oxide film being in contact with at least one electrode film, wherein the at least one electrode film is distinct from the oxide film, the second thin film being the piezoelectric film located on a top surface side of the first thin film, the second thin film being formed of a material having lower resistance to dissolution in the etching solution than the first thin film, and an outer edge of the second thin film is located inside an outer edge of at least a portion of the first thin film, wherein the outer edge of at least a portion of the first thin film has a length that extends beyond the outer edge of the second thin film and the length is not less than 10 times the total thickness of the oxide film.