Patent ID: 8653722

Claim:
A method for manufacturing a quartz-crystal device, comprising the steps of: preparing an AT-cut quartz-crystal wafer including a plurality of frames, the frame having an AT-cut vibrating piece having a first principal surface and a second principal surface, and an outer frame which surrounds the AT-cut vibrating piece for supporting the AT-cut vibrating piece thereof; preparing a quartz-crystal lid wafer having a plurality of lids having a first surface, which is bonded to the first principal surface of the outer frame; preparing a quartz-crystal base wafer having a plurality of bases having a second surface, which is bonded to the second principal surface of the outer frame; and bonding the AT-cut quartz-crystal wafer, the quartz-crystal base wafer and the quartz-crystal lid wafer; wherein the respective AT-cut quartz-crystal wafer, the quartz-crystal base wafer and the quartz-crystal lid wafer are in a size between three to four inches, and during the preparing steps, the quartz-crystal base wafer and the quartz-crystal lid wafer are cut at an angle between 24°00′ or more and 32°28′ or less from crystallographic Z-axis.