Tuning fork resonator element and tuning fork resonator

1. A tuning fork resonator element having a base portion, first and second resonating arms extending from the base portion in a first direction along and substantially parallel to a longitudinal axis of each of the first and second resonating arms, and a support frame sandwiching the first and second resonating arms and being connected to the base portion, the tuning fork resonator element comprising:

a first excitation electrode formed in an area close to a connection portion with the base portion and the support frame, the first excitation electrode being connected to a mount electrode with a conductive adhesive;

a second excitation electrode formed in an area sandwiching the first and second resonating arms of the support frame and in an area positioned farther than the first and second resonating arms in the first direction, the second excitation electrode being connected to a mount electrode with the conductive adhesive;

a pair of cut portions of the support frame formed on side surfaces of the support frame that are opposite to surfaces of the support frame opposing respective ones of the first and second resonating arms, the pair of cut portions being disposed along a length of the support frame between the base portion and a distal end of the support frame;

a cut portion of the base portion formed on both sides of the base portion in a width direction of the base portion; and

a fin made by anisotropic etching is formed in the cut portion of the base portion to disconnect the first excitation electrode and the second excitation electrode;

wherein the first and second excitation electrodes each extend through electrode films on a front surface and a back surface of the base portion to the resonating arm; and

wherein the electrode films on the front surface and the back surface of the base portion are connected through an electrode film of a side surface of the base portion, the electrode film on the side surface of the base portion being cut in the cut portion of the base portion.

2. The tuning fork resonator element according to claim 1 , wherein:

a substrate of the tuning fork resonator element is formed of quartz crystal including crystal axes having an X axis, a Y axis and a Z axis;

the first direction is a direction closest to a direction of the Y axis among the crystal axes; and

the width direction is a direction closest to a ±X axis direction among the crystal axes and a fin on a +X axis side is longer than a fin on a −X axis side.

3. The tuning fork resonator element according to claim 1 , wherein a space between the first and second resonating arms is longer than a width of the cut portion of the base portion.

4. The tuning fork resonator element according to claim 1 , wherein:

a groove, a groove electrode formed in the groove and a side surface electrode are formed in each of the first and second resonating arms.

5. A tuning fork resonator, comprising:

a tuning fork resonator element having a base portion, first and second resonating arms extending from the base portion in a first direction along and substantially parallel to a longitudinal axis of each of the first and second resonating arms, and a support frame sandwiching the first and second resonating arms and being connected to the base portion, the tuning fork resonator element including:

a first excitation electrode formed in an area close to a connection portion with the base portion and the support frame, the first excitation electrode being connected to a mount electrode with a conductive adhesive;

a second excitation electrode formed in an area sandwiching the first and second resonating arms of the support frame and in an area positioned farther than the first and second resonating arms in the first direction, the second excitation electrode being connected to a mount electrode with the conductive adhesive; and

a pair of cut portions of the support frame formed on side surfaces of the support frame that are opposite to surfaces of the support frame opposing respective ones of the first and second resonating arms, the pair of cut portions being disposed along a length of the support frame between the base portion and a distal end of the support frame;

a cut portion of the base portion formed on both sides of the base portion in a width direction of the base portion;

a fin made by anisotropic etching is formed in the cut portion of the base portion to disconnect the first excitation electrode and the second excitation electrode;

a base having the mount electrode formed thereon and having a seal hole;

a package frame closing part of the seal hole and being layered on the base;

a sealing member for sealing the seal hole; and

a lid for sealing the package frame;

wherein the first and second excitation electrodes each extend through electrode films on a front surface and a back surface of the base portion to the resonating arm; and

wherein the electrode films on the front surface and the back surface of the base portion are connected through an electrode film of a side surface of the base portion, the electrode film on the side surface of the base portion being cut in the cut portion of the base portion.

6. The tuning fork resonator according to claim 5 , wherein:

a substrate of the tuning fork resonator is formed of quartz crystal including crystal axes having an X axis, a Y axis and a Z axis;

the first direction is a direction closest to a direction of the Y axis among the crystal axes;

the width direction is a direction closest to a ±X axis direction among the crystal axes and a fin on a +X axis side is longer than a fin on a −X axis side.

7. The tuning fork resonator according to claim 5 , wherein a space between the first and second resonating arms is longer than a width of the cut portion of the base portion.

8. The tuning fork resonator according to claim 5 , wherein:

a groove, a groove electrode formed in the groove and a side surface electrode are formed in the first and second resonating arms.

9. The tuning fork resonator element according to claim 1 , wherein the width direction of the base is substantially perpendicular to the longitudinal axis of the first and second resonating arms.

10. The tuning fork resonator element according to claim 5 , wherein the width direction of the base is substantially perpendicular to the longitudinal axis of the first and second resonating arms.