Piezoelectric vibration element having conductive etch stop, piezoelectric vibrator, and piezoelectric oscillator

1 . A piezoelectric vibration element comprising:

a piezoelectric piece having a first principal surface and a second principal surface;

a via electrode penetrating the piezoelectric piece from the first principal surface to the second principal surface thereof;

a conductive etch stop film covering the via electrode on the second principal surface; and

a wiring electrode covering at least part of an outer edge of the conductive etch stop film on the second principal surface.

2 . The piezoelectric vibration element according to claim 1 , wherein a material of the conductive etch stop film is nickel, copper or platinum.

3 . The piezoelectric vibration element according to claim 1 , wherein a thickness of the conductive etch stop film is 0.03 μm to 0.2 μm.

4 . The piezoelectric vibration element according to claim 1 , further comprising:

a protective electrode covering at least a portion of the wiring electrode.

5 . The piezoelectric vibration element according to claim 4 , wherein a material of the protective electrode is identical to a material of the wiring electrode.

6 . The piezoelectric vibration element according to claim 4 , wherein a thickness of the protective electrode is at least twice as large as a thickness of the wiring electrode.

7 . The piezoelectric vibration element according to claim 6 , wherein the thickness of the protective electrode is 0.3 μm to 1.0 μm.

8 . The piezoelectric vibration element according to claim 1 , further comprising:

a protective electrode covering an entirety of the wiring electrode.

9 . The piezoelectric vibration element according to claim 8 , wherein a material of the protective electrode is identical to a material of the wiring electrode.

10 . The piezoelectric vibration element according to claim 8 , wherein a thickness of the protective electrode is at least twice as large as a thickness of the wiring electrode.

11 . The piezoelectric vibration element according to claim 10 , wherein the thickness of the protective electrode is 0.3 μm to 1.0 μm.

12 . The piezoelectric vibration element according to claim 1 , wherein a material of the wiring electrode is aluminum.

13 . The piezoelectric vibration element according to claim 1 , further comprising:

a first excitation electrode provided to the first principal surface; and

a second excitation electrode provided to the second principal surface, wherein

the wiring electrode is electrically connected to the second excitation electrode.

14 . The piezoelectric vibration element according to claim 13 , wherein the wiring electrode and the second excitation electrode are integrally formed.

15 . The piezoelectric vibration element according to claim 13 , wherein a material of the first excitation electrode is identical to a material of the second excitation electrode.

16 . A piezoelectric vibrator comprising:

the piezoelectric vibration element according to claim 1 ; and

a support substrate supporting the piezoelectric vibration element so that the piezoelectric vibration element can vibrate.

17 . The piezoelectric vibrator according to claim 16 , further comprising:

a bonding layer bonding the piezoelectric vibration element and the support substrate.

18 . The piezoelectric vibrator according to claim 17 , wherein

a material of the bonding layer is silicon dioxide, and

the bonding layer bonds the second principal surface and the support substrate.

19 . A piezoelectric oscillator comprising:

the piezoelectric vibrator according to claim 16 ; and

a lid body attached to the support substrate so as to define a space therebetween for accommodating the piezoelectric vibration element.