| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric vibration device which improves hermetic sealing performance of a package and facilitates the characteristic improvements.SOLUTION: In a surface mounted crystal oscillator, a crystal diaphragm 2 is housed in a base and is hermetically sealed by a lid and an IC 4 for an oscillation circuit is mounted. The base has a cavity C opening at the lower side. A step part 111 is formed into a rectangular peripheral shape in the cavity so as to be spaced a given depth dimension away from the opening of the cavity C. The lid is joined to the upper surface of the step part by a brazing material 31. A lower portion (the opening side) 11a of a side wall part 11 is formed so as to be thinner than the step part, and external terminals 14 are formed at four corners of a base bottom surface. |
