1. US20100301954 - Piezoelectric resonator with control film to increase a degree of vacuum inside the package

Provided are: a piezoelectric oscillation piece which has a pair of oscillation arms disposed in parallel with each other with base ends of the oscillation arms fixed to a base of the piezoelectric oscillation piece and with weight metal films formed at the tips of the oscillation arms; a base substrate on the upper surface of which the piezoelectric oscillation piece is mounted; a lid substrate joined with the base substrate such that the mounted piezoelectric oscillation piece can be accommodated in a cavity; and a control film disposed in the vicinity of the pair of the oscillation arms as viewed in the plan view and formed at least on either of the substrates in such a manner as to extend from the base end side to the tip side in the longitudinal direction of the oscillation arms for increasing the degree of vacuum inside the cavity by heating. The control film is locally deposited on the side surfaces of the oscillation arms in the vicinity of the control film by heating.