Piezoelectric vibrator and sensor

Patent metadata

Field	Value
Publication number	US-11031539-B2
Application number	US-201615773157-A
Country	US
Kind code	B2
Filing date	Nov 4, 2016
Priority date	Nov 5, 2015
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

To provide a vibrator made of a piezoelectric crystal having a larger electromechanical coupling coefficient and a more satisfactory frequency-temperature characteristic than those of quartz, a vibrating piece (101) is made of a Ca3Ta(Ga1-xAlx)3Si2O14 single crystal (0<x≤1). In the single crystal, letting θ be a rotation angle from an X-Z plane about an X-axis serving as a rotation axis, 18x+17.5≤θ≤24x+24.5 is set. In addition, the vibrating piece (101) is made of a Ca3Nb(Ga1-xAlx)3Si2O14 single crystal (0<x≤1). In the single crystal of this arrangement, letting θ be a rotation angle from an X-Z plane about an X-axis serving as a rotation axis, 25x+23.083≤θ≤32x+26.167 is set.

First claim

The invention claimed is:

1. A piezoelectric vibrator comprising at least one vibrating piece made of a Ca 3 Ta(Ga 1-x Al x ) 3 Si 2 O 14 single crystal (0<x≤1),
wherein in the single crystal, letting θ be a rotation angle from an X-Z plane about an X-axis serving as a rotation axis, 18x+17.5≤θ≤24x+24.5 is set.

2. The piezoelectric vibrator according to claim 1 , wherein 20x+20.16≤θ≤21x+22.083 is set.

3. A piezoelectric vibrator comprising at least one vibrating piece made of a Ca 3 Nb(Ga 1-x Al x ) 3 Si 2 O 14 single crystal (0<x≤1),
wherein in the single crystal, letting θ be a rotation angle from an X-Z plane about an X-axis serving as a rotation axis, 25x+23.083≤θ≤32x+26.167 is set.

4. The piezoelectric vibrator according to claim 3 , wherein 27.6x+24.367≤θ≤27.8x+25.783 is set.

5. A piezoelectric vibrator comprising at least one vibrating piece made of a Ca 3 (Ta 1-y Nb y )(Ga 1-x Al x ) 3 Si 2 O 14 single crystal (0<x≤1, 0≤y≤1),
wherein in the single crystal, letting θ be a rotation angle from an X-Z plane about an X-axis serving as a rotation axis, {18+(25−18)y}x+17.5+(23.083−17.5)y≤θ≤{24+( 32 −24)y}x+24.5+(26.167−24.5)y is set.

6. The piezoelectric vibrator according to claim 5 , wherein {20+(27.6−20)y}x+20.16+(24.367−20.16)y≤θ≤{21+(27.8−21)y}x+22.083+(25.783−22.083)y is set.

7. The piezoelectric vibrator according to claim 1 , further comprising:
an electrode provided on the vibrating piece;
a connection terminal connected to the electrode; and
a hermetic container storing the vibrating piece and filled with an inert gas.

8. A sensor using a piezoelectric vibrator described in claim 1 , comprising:
a measurement region provided on a vibrating piece and brought into contact with a measurement target substance; and
measurement means for detecting a mass of the substance that is in contact with the measurement region based on a change in a resonance frequency of the vibrator caused by the contact of the substance with respect to the measurement region.

9. The piezoelectric vibrator according to claim 2 , further comprising:
an electrode provided on the vibrating piece;
a connection terminal connected to the electrode; and
a hermetic container storing the vibrating piece and filled with an inert gas.

10. The piezoelectric vibrator according to claim 3 , further comprising:
an electrode provided on the vibrating piece;
a connection terminal connected to the electrode; and
a hermetic container storing the vibrating piece and filled with an inert gas.

11. The piezoelectric vibrator according to claim 4 , further comprising:
an electrode provided on the vibrating piece;
a connection terminal connected to the electrode; and
a hermetic container storing the vibrating piece and filled with an inert gas.

12. The piezoelectric vibrator according to claim 5 , further comprising:
an electrode provided on the vibrating piece;
a connection terminal connected to the electrode; and
a hermetic container storing the vibrating piece and filled with an inert gas.

13. The piezoelectric vibrator according to claim 6 , further comprising:
an electrode provided on the vibrating piece;
a connection terminal connected to the electrode; and
a hermetic container storing the vibrating piece and filled with an inert gas.

14. A sensor using a piezoelectric vibrator described in claim 2 , comprising:
a measurement region provided on a vibrating piece and brought into contact with a measurement target substance; and
measurement means for detecting a mass of the substance that is in contact with the measurement region based on a change in a resonance frequency of the vibrator caused by the contact of the substance with respect to the measurement region.

15. A sensor using a piezoelectric vibrator described in claim 3 , comprising:
a measurement region provided on a vibrating piece and brought into contact with a measurement target substance; and
measurement means for detecting a mass of the substance that is in contact with the measurement region based on a change in a resonance frequency of the vibrator caused by the contact of the substance with respect to the measurement region.

16. A sensor using a piezoelectric vibrator described in claim 4 , comprising:
a measurement region provided on a vibrating piece and brought into contact with a measurement target substance; and
measurement means for detecting a mass of the substance that is in contact with the measurement region based on a change in a resonance frequency of the vibrator caused by the contact of the substance with respect to the measurement region.

17. A sensor using a piezoelectric vibrator described in claim 5 , comprising:
a measurement region provided on a vibrating piece and brought into contact with a measurement target substance; and
measurement means for detecting a mass of the substance that is in contact with the measurement region based on a change in a resonance frequency of the vibrator caused by the contact of the substance with respect to the measurement region.

18. A sensor using a piezoelectric vibrator described in claim 6 , comprising:
a measurement region provided on a vibrating piece and brought into contact with a measurement target substance; and
measurement means for detecting a mass of the substance that is in contact with the measurement region based on a change in a resonance frequency of the vibrator caused by the contact of the substance with respect to the measurement region.

Assignees

• Piezo Studio Inc
• Univ Tohoku

Inventors

• Yoshikawa Akira
• Ohashi Yuji
• Yokota Yuui
• Kamada Kei
• Ito Masatoshi
• Inoue Kenji
• Amano Hiroyuki

Classifications

• H03H9/02039

  consisting of a material from the crystal group 32, e.g. langasite, langatate, langanite · CPC title

• H03H2003/0407

  Temperature coefficient · CPC title

• H03H3/04

  for obtaining desired frequency or temperature coefficient · CPC title

• G01N29/036

  by measuring frequency or resonance of acoustic waves · CPC title

• H03H9/02102 Primary

  of temperature influence (cutting angles H03H9/02015) · CPC title