Crystal element and crystal device
Provided are a crystal element and a crystal device that have an improved DLD characteristic. The crystal element includes a crystal piece and a pair of electrodes. Each of the electrodes is positioned on a corresponding one of both surfaces of the crystal piece and includes a conductive layer having a gold content of 90% or more in mass ratio. The crystal element has the DLD characteristic in which a portion in a positive direction (+) and a portion in an opposite direction (−) are mixed.
1 . A crystal element comprising:
a crystal piece; and
a pair of electrodes, each of the electrodes being positioned on a corresponding one of both surfaces of the crystal piece and comprising a conductive layer having a gold content of 90% or more in mass ratio, wherein
the crystal element has a drive level dependency (DLD) characteristic in which a portion in a positive direction (+) and a portion in an opposite direction (−) are mixed; and wherein a crystal impedance of the crystal element is less than 30 Ω.
2 . The crystal element according to claim 1 , further comprising a base layer between the conductive layer and the crystal piece.
3 . The crystal element according to claim 1 , wherein a resonance frequency of the crystal element is 40 MHz or more and 400 MHz or less.
4 . The crystal element according to claim 1 , wherein a thickness of the conductive layer is 50 nm or more and 600 nm or less.
5 . The crystal element according to claim 1 , wherein the pair of electrodes is positioned at an identical position in plan view.
6 . A crystal device comprising the crystal element according to claim 1 .
7 . A crystal element comprising:
a crystal piece; and
a pair of electrodes, each of the electrodes being positioned on a corresponding one of both surfaces of the crystal piece and comprising a conductive layer having a gold content of 90% or more in mass ratio, wherein
the crystal element has a drive level dependency (DLD) characteristic in which a portion in a positive direction (+) and a portion in an opposite direction (−) are mixed and wherein a product value of a thickness (mm) of the conductive layer and a resonance frequency (MHz) of the crystal element is 0.017272 or more and 0.019684 or less.
8 . The crystal element according to claim 7 , further comprising a base layer between the conductive layer and the crystal piece.
9 . The crystal element according to claim 7 , wherein a resonance frequency of the crystal element is 40 MHz or more and 400 MHz or less.
10 . The crystal element according to claim 7 , wherein a thickness of the conductive layer is 50 nm or more and 600 nm or less.
11 . The crystal element according to claim 7 , wherein the pair of electrodes is positioned at an identical position in plan view.
12 . A crystal device comprising the crystal element according to claim 7 .
13 . A crystal element comprising:
a crystal piece; and
an electrode comprising:
a base layer positioned on both surfaces of the crystal piece at an identical position in plan view on the respective surfaces; and
a conductive layer positioned on the base layer and having a gold content of 90% or more in mass ratio, wherein
a product value of a thickness (mm) of the conductive layer and a resonance frequency (MHz) of the crystal element is 0.017272 or more and 0.019684 or less.
14 . The crystal element according to claim 13 , wherein the product value is 0.017933 or more and 0.018363 or less.
15 . The crystal element according to claim 13 , wherein the resonance frequency is 76.8 MHz.
16 . A crystal device comprising the crystal element according to claim 13 .