Piezoelectric device and method for fabricating the same

A method for fabricating a piezoelectric device, comprising:

• preparing a piezoelectric wafer that includes a plurality of piezoelectric vibrating pieces, the piezoelectric vibrating piece including a vibrator, a framing portion, and a connecting portion, the vibrator vibrating at a predetermined vibration frequency, the framing portion surrounding the vibrator, the connecting portion connecting the vibrator and the framing portion;
• preparing a base wafer that includes a plurality of rectangular base plates;
• preparing a lid wafer that includes a plurality of lid plates;
• forming first metal films on predetermined regions on both principal surfaces of the base wafer;
• bonding the base wafer and the piezoelectric wafer such that the piezoelectric vibrating pieces are placed on one principal surfaces of the respective base plates;
• bonding the lid wafer on the piezoelectric wafer to seal the vibrator;
• plating an electroless plating film on a surface of the metal film formed on another principal surface of the base wafer by electroless plating;
• removing a part of the electroless plating film by laser or dicing;
• and
• dicing the base wafer and the lid wafer including the boundary between the adjacent base plates, wherein
• the metal film formed on the other principal surface of the base wafer is disposed across at least a part of the boundary.

A surface mount type piezoelectric device, comprising:

• a piezoelectric vibrating piece that includes a vibrator vibrating at a predetermined vibration frequency;
• a base plate in a rectangular shape that has one principal surface where the piezoelectric vibrating piece being to be placed;
• and
• a lid plate that seals the vibrator, wherein
• the base plate has another principal surface that includes a pair of mounting terminals to mount the piezoelectric device,
• the mounting terminal includes:
• a first region formed of a metal film and an electroless plating film, the electroless plating film being formed on a surface of the metal film, and
• a second region where the metal film and the electroless plating film are not formed, and the second region is sandwiched by the first region that includes the metal film and the electroless plating film, the second region being parallel to a short side or a long side of the base plate, the second region extending from an outer periphery of the mounting terminal toward an inside of the mounting terminal.