Piezoelectric vibrating piece and piezoelectric vibrator
To increase the strength of mounting at the time of mounting a piezoelectric vibrating piece on a package. In a piezoelectric vibrating piece having a pair of support arm portions which are provided with mount electrodes outside a pair of vibrating arm portions, concave portions to which a conductive adhesive used for mounting to the package can penetrate are formed in side end surfaces on the inner sides in a width direction of the respective support arm portions near the mount electrodes.
1. A piezoelectric vibrating piece comprising:
a pair of vibrating arm portions at an interval in a width direction orthogonal to a thickness direction and extending in a longitudinal direction orthogonal to the thickness direction and the width direction, each of the vibrating arm portions having tip end sides in the longitudinal direction that comprise vibrating free ends and fixed base end sides;
a base portion extending in the width direction to outer sides of the pair of vibrating arm portions, to which respective base end sides of the pair of vibrating arm portions are integrally connected and fixed;
a pair of support arm portions connected to the base portion outside the pair of vibrating arm portions and extending from the base portion to a same side as the pair of vibrating arm portions, the support arm portions having first and second opposing surfaces in the thickness direction and first and second opposing surfaces in the width direction; and
a pair of mount electrodes on a first surface of the opposing surfaces in the thickness direction of the respective support arm portions,
wherein the pair of mount electrodes are bonded to respective electrode pads on a package side housing the piezoelectric vibrating piece through a conductive bonding material, and
wherein concave portions extend into the pair of mount electrodes from the first surface toward the second surface of the opposing surfaces in the thickness direction in proximity to the mount electrodes, and a length of at least one concave portion in the longitudinal direction is less than a length of the mount electrode in the longitudinal direction, and the conductive adhesive overlies the mount electrodes and the concave portions.
2. The piezoelectric vibrating piece according to claim 1 , wherein the at least one concave portion is in the first surface in the width direction of each support arm portion.
3. The piezoelectric vibrating piece according to claim 2 , wherein the first surface in the width direction is on a vibrating arm portion side of each support arm portion.
4. A piezoelectric vibrator in which the piezoelectric vibrating piece according to claim 1 is housed in a hermetically sealed cavity of a package,
wherein the two mount electrodes are respectively bonded to the two electrode pads through the conductive adhesive to thereby mount the piezoelectric vibrating piece on the package so that bonded portions are set as support fixing points and that other portions float from the package.