SURFACE-MOUNTABLE PIEZOELECTRIC DEVICES INCLUDING EUTECTIC-BONDED PACKAGES

摘要

Piezoelectric devices are disclosed that are mountable on the surface of a printed circuit board or the like. An exemplary device comprises a piezoelectric vibrating piece enclosed and sealed within a package including at least a cover and a base-substrate formed of glass or piezoelectric material. The package includes frame-shaped metallic films formed in peripheral regions of inner main surfaces of the cover and/or the base substrate. The frame-shaped metallic films are used for sealing the package using a eutectic material (e.g., solder). At least one mounting terminal is provided on the outer (bottom) main surface of the base-substrate. At least one of the frame-shaped metallic films and mounting terminals includes a chromium foundation layer formed on the surface of the glass or piezoelectric material, a middle layer of NiW alloy formed on the surface of the chromium layer, and a gold layer formed on the surface of the middle layer.