Patent ID: 8365371

Claim:
A method for manufacturing a piezoelectric vibrating device having a base and at least a pair of vibrating arms extending from the base, the vibrating arms defining a first groove regions, the method comprising: forming a metal film on both surfaces of a piezoelectric wafer, the wafer having a thickness; on the metal film, forming a layer of photoresist and exposing the photoresist to pattern the layer of photoresist, the pattern including a profile outline of the piezoelectric vibrating device; performing a first metal-film-etching step to etch the metal film according to the pattern in the layer of photoresist, including etching outside the profile outline; performing a first piezoelectric-etching step to etch the wafer outside the profile outline but not completely through the thickness of the wafer; after the first piezoelectric-etching step, exposing the photoresist to pattern the layer of photoresist, the pattern including the profile outline and first groove regions to be formed in the arms; performing a second metal-film-etching step to etch the metal film according to the pattern in the layer of photoresist; and performing a second piezoelectric-etching step to etch the wafer outside the profile outline and in the first groove regions, the etching outside the profile outline being completely through remaining thickness of the wafer, and the etching in the first groove regions being partly through the thickness, thereby forming the piezoelectric vibrating device.