Patent ID: 8580126
Filing Date: 2013-11-12
Classification: H01L,H03H,Y10T

Abstract:
1. A method for manufacturing a piezoelectric vibrating piece, comprising: on each surface of a piezoelectric wafer, forming a respective metal film; on the piezoelectric wafer, forming a through-groove that defines outer edges of a piezoelectric substrate, the piezoelectric substrate including a first main surface, a second main surface, and respective peripheral regions extending from each main surface to respective edges; forming a film of resist on the metal film on at least one main surface of the piezoelectric substrate; exposing the resist through a photomask that defines a resist pattern for a first mesa step in at least one peripheral region on the main surface, thereby forming the resist pattern; using the resist as an etch-protectant, etching the metal film to form a metal-film pattern; using the metal-film pattern as an etch-protective film, etching the piezoelectric substrate a first depth to form a first mesa step and denuded edges of the metal film, the first mesa step being inboard of the respective outer edge; further using the resist as an etch-protectant, edge-etching the denuded edges of the metal film under the resist a defined distance to produce corresponding denuded regions of the piezoelectric substrate; and using the metal-film pattern as an etch-protectant, etching the denuded regions of the piezoelectric substrate a second depth to form a second mesa step located inboard of the first mesa step, such that the piezoelectric substrate becomes step-wise thinner from the main surfaces to the second mesa step to the first mesa step.