Airtight package, piezoelectric device, and piezoelectric oscillator

摘要

An airtight package has an insulating base having an opening approximately in the center and a recessed portion penetrating the insulating base in a thickness direction on a circumferential surface of the insulating base. The airtight package also has a lid sealed against the insulating base so as to block the opening. The lid is bonded to the insulating base in a manner that an edge of the lid overlaps the recessed portion exposed on an opening-side surface of the insulating base.