Piezoelectric resonator, manufacturing method thereof and lid for piezoelectric resonator

Abstract

A piezoelectric resonator includes a piezoelectric resonator element having a resonating arm and a metal film that is formed on the resonating arm; a package including a bottom part on which the piezoelectric resonator element is fixed and a frame wall that surrounds the bottom part, and having an opening above the bottom part; and a lid including a frame in which a through hole is provided and an optically transparent part that has an upper face and a lower face of the frame and is disposed at the through hole, the through hole penetrating a front face and a back face, the lower face of the optically transparent part being disposed so as to oppose the metal film, and the lid closing the opening of the package such that the lid overlaps with the bottom part and the frame wall, the through hole having a curved inner wall face whose curved face is coupled with at least one of the front face and the back face at least one opening edge of the front face and the back face and a vertical inner wall face that is provided vertical to the front face and the back face and in a part of a thickness direction of the frame, and the optically transparent part being provided so as to contact closely with at least a part of the vertical inner wall face and at least a part of the curved inner wall face.