JP2014011724A - Crystal oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystal oscillator which uses a face-shear mode and hardly leaks vibrations thereof.SOLUTION: A first support part 11 extends from a first side surface 13c and a second support part 12 extends from a second side surface 13d. The first support part 11 is connected to a part of the first side surface 13c from the center in a width direction W to a third side surface 13e side, which includes an end on the third side surface 13e side. The second support part 12 is connected to a part of the second side surface 13d from the center in a width direction W to a fourth side surface 13f side, which includes an end on the fourth side surface 13f side.

Description

  The present invention relates to a crystal resonator.

  Conventionally, a piezoelectric vibrator is used in an oscillation circuit of an electronic device. For example, Patent Literature 1 discloses a piezoelectric vibrator including a piezoelectric vibration element made of piezoelectric ceramics as a piezoelectric vibrator. However, if a piezoelectric vibrator including a piezoelectric vibration element made of piezoelectric ceramics is used, for example, it is difficult to realize a highly accurate oscillation circuit. In order to realize a highly accurate oscillation circuit, it is preferable to use a crystal resonator including a crystal resonator element.

  By the way, some crystal resonators use various vibration modes. For example, a crystal resonator using a contour sliding vibration mode is known (see, for example, Patent Document 2). Such a crystal resonator includes a crystal resonator element that vibrates in a contour sliding vibration mode.

  In general, a quartz-crystal vibrating element that vibrates in a contour sliding vibration mode does not have a portion serving as a node. Accordingly, there is a problem that vibration leaks from the support portion in the crystal resonator element that vibrates in the contour sliding vibration mode. In Patent Document 2, in order to suppress the leakage of vibration, it has been proposed that the shape of the support portion extending from the center of the two opposing sides of the rectangular vibration portion is a meandering shape.

JP-A-8-139561 JP 2008-166903 A

  However, in the crystal resonator described in Patent Document 2, the leaked vibration is only attenuated by the support portion, and the vibration leakage itself is not substantially suppressed.

  A main object of the present invention is to provide a crystal resonator that uses a contour sliding vibration mode and that is unlikely to leak vibration.

  The crystal resonator according to the present invention includes a vibrating portion, first and second electrodes, a first support portion, and a second support portion. The vibration part is made of crystal. The vibration part is a rectangular plate-like vibration part that vibrates in a sliding manner. The vibration unit has first and second side surfaces, and third and fourth side surfaces. The first and second side surfaces extend along the width direction and the thickness direction. The third and fourth side surfaces extend along the length direction and the thickness direction. The dimension along the length direction of the third and fourth side surfaces is longer than the dimension along the width direction of the first and second side surfaces. The first and second electrodes are provided in the vibration part. The first support portion extends from the first side surface. The second support portion extends from the second side surface. The first support portion is a portion on the third side surface side from the center in the width direction of the first side surface, and is connected to a portion including the end portion on the third side surface side. The second support portion is a portion on the fourth side surface side from the center in the width direction of the second side surface, and is connected to a portion including the end portion on the fourth side surface side.

  In a specific aspect of the crystal resonator according to the present invention, the entire first support portion is provided on the third side surface side from the center in the width direction of the first side surface. The entire second support portion is provided on the fourth side surface side from the center in the width direction of the second side surface.

  In another specific aspect of the crystal resonator according to the present invention, the connection portion with the first side surface of the first support portion and the connection portion with the second side surface of the second support portion are respectively It extends along the length direction.

  In another specific aspect of the crystal resonator according to the present invention, the first and second electrodes are opposed to each other in the thickness direction via the vibrating portion.

  In still another specific aspect of the crystal unit according to the present invention, the vibration unit is configured by a rotating Y-cut crystal plate.

  In still another specific aspect of the crystal resonator according to the present invention, the vibration portion and the first and second support portions are configured by a single crystal plate.

  According to the present invention, it is possible to provide a crystal resonator that uses a contour sliding vibration mode and that is less likely to leak vibration.

1 is a schematic cross-sectional view of a crystal resonator according to a first embodiment of the present invention. 1 is a schematic plan view of a crystal resonator according to a first embodiment of the present invention. 6 is a schematic plan view of a crystal resonator according to a second embodiment of the present invention. FIG. FIG. 4 is a displacement diagram of a crystal resonator element in the crystal resonator according to the first embodiment of the invention. It is a displacement figure of the crystal oscillation element in the crystal oscillator concerning a 2nd embodiment of the present invention. It is a displacement figure of the crystal oscillation element in the crystal oscillator concerning the 1st comparative example. It is a displacement figure of the crystal oscillation element in the crystal oscillator concerning the 2nd comparative example. It is a displacement figure of the crystal oscillation element in the crystal oscillator concerning the 3rd comparative example. Ratio of the dimension along the length direction L of the vibration part in the crystal unit according to the first embodiment of the present invention along the width direction W ((dimension along the length direction L of the vibration part)) / (Dimension along the width direction W of the vibration part)) and a graph representing the relationship between the electromechanical coupling coefficient and the CI (Crystal Impedance) value. Ratio of the dimension along the length direction L of the vibration part in the crystal unit according to the second embodiment of the present invention along the width direction W ((dimension along the length direction L of the vibration part) / (Dimension along the width direction W of the vibration part)) and a graph representing the relationship between the electromechanical coupling coefficient and the CI (Crystal Impedance) value.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described. A ratio of dimensions of an object drawn in a drawing may be different from a ratio of dimensions of an actual object. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

  FIG. 1 is a schematic cross-sectional view of a crystal resonator 1 according to a first embodiment of the present invention. FIG. 2 is a schematic plan view of the crystal unit 1 according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, the crystal unit 1 includes a crystal resonator element 10 and a substrate 20. The crystal resonator element 10 is mounted on the substrate 20 via, for example, a conductive adhesive layer 21. The substrate 20 is not particularly limited. The substrate 20 may be made of, for example, a resin or ceramics.

  The crystal resonator element 10 includes a vibrating part 13, a first support part 11, and a second support part 12. In this embodiment, the vibration part 13 and the 1st and 2nd support parts 11 and 12 are comprised by the single crystal plate. Specifically, in the present embodiment, the vibrating portion 13 and the first and second support portions 11 and 12 are configured by a single rotated Y-cut quartz plate. In detail, the rotated Y-cut quartz plate refers to a quartz plate having Euler angles (φ, θ, ψ) of (0 °, 38 °, 0 °).

  The vibrating unit 13 vibrates in a sliding manner. That is, the crystal unit 1 is a crystal unit that uses the contour sliding vibration mode.

  The vibrating part 13 has a rectangular plate shape. That is, the vibration part 13 is provided in the plate shape whose shape in planar view is a rectangle. The vibration unit 13 includes a first main surface 13a, a second main surface 13b, a first side surface 13c, a second side surface 13d, a third side surface 13e, and a fourth side surface 13f. The first main surface 13a and the second main surface 13b are parallel to each other. The first main surface 13a and the second main surface 13b extend along the width direction W and the length direction L, respectively. The first side surface 13c and the second side surface 13d are parallel to each other. The first side surface 13c and the second side surface 13d extend along the width direction W and the thickness direction T, respectively. The third side surface 13e and the fourth side surface 13f are parallel to each other. The third side surface 13e and the fourth side surface 13f extend along the length direction L and the thickness direction T, respectively. The dimension along the length direction L of the third side surface 13e and the fourth side surface 13f is longer than the dimension along the width direction W of the first side surface 13c and the second side surface 13d. The dimension along the length direction L of the third side surface 13e and the fourth side surface 13f is 1.45 times to 1.65 times the dimension along the width direction W of the first side surface 13c and the second side surface 13d. It is preferably double, and more preferably 1.50 times to 1.60 times.

  Note that at least a part of the corners and ridges of the vibrating part 13 may be chamfered or rounded.

  The vibrating part 13 is provided with a first electrode 15 and a second electrode 16. The first electrode 15 is provided on the first main surface 13a. The second electrode 16 is provided on the second main surface 13b. An electric field is applied to the vibrating portion 13 by the first electrode 15 and the second electrode 16. The first electrode 15 and the second electrode 16 are opposed to the vibrating portion 13, more specifically, at least the central portion of the vibrating portion 13 in the thickness direction T.

  The arrangement and shape of the first electrode 15 and the second electrode 16 are not particularly limited as long as the electric field can be applied to the vibrating part 13 so that the vibrating part 13 vibrates in a sliding manner.

  A first support part 11 and a second support part 12 are connected to the vibration part 13. The quartz resonator element 10 includes a portion of the first support portion 11 opposite to the portion connected to the vibration portion 13 and a portion of the second support portion 12 opposite to the portion connected to the vibration portion 13. And is supported in the part.

  The first support portion 11 extends along the length direction L from the first side surface 13 c of the vibration portion 13. As shown in FIG. 2, the first support portion 11 is a portion on the third side surface 13e side from the center in the width direction W of the first side surface 13c, and has an end portion on the third side surface 13e side. Connected to the part containing. The 1st support part 11 is connected to the corner | angular part comprised by the 1st side surface 13c and the 3rd side surface 13e. The entire first support portion 11 is provided on the third side surface 13e side from the center in the width direction W of the first side surface 13c.

  The second support portion 12 extends along the length direction L from the second side surface 13 d of the vibration portion 13. As shown in FIG. 2, the second support portion 12 is a portion on the fourth side surface 13f side from the center in the width direction W of the second side surface 13d, and an end portion on the fourth side surface 14f side. Connected to the part containing. The second support portion 12 is connected to a corner portion constituted by the second side surface 13d and the fourth side surface 13f. The entire second support portion 12 is provided on the fourth side surface 13f side from the center in the width direction W of the second side surface 13d.

  In the present embodiment, as described above, the entire first support portion 11 is provided on the third side surface 13e side from the center in the width direction W of the first side surface 13c. The entire second support portion 12 is provided on the fourth side surface 13f side from the center in the width direction W of the second side surface 13d. However, the present invention is not limited to this configuration. In this invention, the connection part with the 1st side surface of a 1st support part is provided in the 3rd side surface side from the center in the width direction of a 1st side surface, and it is 2nd of the 2nd support part. The connection part with this side surface should just be provided in the 4th side surface side from the center in the width direction of a 2nd side surface. FIG. 3 is a schematic cross-sectional view of a crystal resonator 1a according to a second embodiment of the present invention. As shown in FIG. 3, the portion of the first support portion 11 excluding the connection portion with the first side surface 13c extends from the center in the width direction W of the first side surface 13c to the fourth side surface 13f side. Also good. Moreover, the part except the connection part with the 2nd side surface 13d of the 2nd support part 12 may have reached the 3rd side surface 13e side from the center in the width direction W of the 2nd side surface 13d.

  As described above, in the first and second embodiments, the first support portion 11 is a portion on the third side surface 13e side from the center in the width direction W of the first side surface 13c, and the third side It is connected to the part including the end on the side surface 13e side. The second support portion 12 is connected to a portion on the fourth side surface 13f side from the center in the width direction W of the second side surface 13d and including an end portion on the fourth side surface 14f side. Yes. For this reason, it can suppress that the vibration in the vibration part 13 leaks to the 1st and 2nd support parts 11 and 12. FIG.

  FIG. 4 is a displacement diagram of the crystal resonator element 10 in the crystal unit 1 according to the first embodiment. FIG. 5 is a displacement diagram of the crystal resonator element 10 in the crystal resonator 1a according to the second embodiment. FIG. 6 is a displacement diagram of the crystal resonator element in the crystal resonator according to the first comparative example. FIG. 7 is a displacement diagram of the crystal resonator element in the crystal resonator according to the second comparative example. FIG. 8 is a displacement diagram of the crystal resonator element in the crystal resonator according to the third comparative example.

  In the first comparative example shown in FIG. 6, the second comparative example shown in FIG. 7, and the third comparative example shown in FIG. 8, the first and second support portions 111 and 112 are rectangular plate-shaped, respectively. The vibration part 113 is connected to the center part of the side surface on the long side. In the second comparative example shown in FIG. 7, each of the first and second vibrating portions 111 and 112 is provided with portions 111 a and 112 a having an annular shape in plan view. In the third comparative example shown in FIG. 8, the first and second support portions 111 and 112 are provided in a meandering shape in plan view.

  From the results shown in FIGS. 4 to 5, the first support portion 11 is a portion on the third side surface 13e side from the center in the width direction W of the first side surface 13c, and is an end on the third side surface 13e side. The second support portion 12 is a portion on the fourth side surface 13f side from the center in the width direction W of the second side surface 13d, and is an end on the fourth side surface 14f side. It can be seen that vibration leakage from the vibration part 13 to the first and second support parts 11 and 12 can be suppressed when connected to a part including the part.

  FIG. 9 shows a ratio of dimensions along the length direction L of the vibrating part in the quartz crystal resonator according to the first embodiment of the present invention ((in the length direction L of the vibrating part). It is a graph showing the relationship between the dimension along (width dimension W along the width direction W): L / W), an electromechanical coupling coefficient, and CI (Crystal Impedance) value. FIG. 10 shows a ratio of dimensions along the length direction L of the vibrating part in the quartz crystal resonator according to the second embodiment of the present invention ((in the length direction L of the vibrating part). It is a graph showing the relationship between the dimension along (width dimension W along the width direction W): L / W), an electromechanical coupling coefficient, and CI (Crystal Impedance) value.

  From the results shown in FIG. 9 and FIG. 10, it can be seen that in the first embodiment, the electromechanical coupling coefficient (k) increases at various L / Ws. From this, it is understood that a large electromechanical coupling coefficient can be realized at various L / Ws by adopting the quartz crystal resonator element 10 having the shape as in the first embodiment. On the other hand, from the results shown in FIGS. 9 and 10, it can be seen that the CI value can be reduced in various L / Ws in the second embodiment. Therefore, by adopting the crystal resonator element 10 having the shape as in the second embodiment, a crystal resonator having a small CI value and small vibration leakage can be realized.

DESCRIPTION OF SYMBOLS 1, 1a ... Crystal oscillator 10 ... Crystal oscillator element 11 ... 1st support part 12 ... 2nd support part 13 ... Vibration part 13a ... 1st main surface 13b ... 2nd main surface 13c ... 1st side surface 13d ... second side surface 13e ... third side surface 13f ... fourth side surface 15 ... first electrode 16 ... second electrode 20 ... substrate 21 ... conductive adhesive layer

Claims (6)

A rectangular plate-shaped vibrating portion made of crystal and oscillating in a sliding manner, wherein the first and second side surfaces extend along the width direction and the thickness direction, and extend along the length direction and the thickness direction. And a vibrating portion having third and fourth side surfaces having a dimension along the length direction longer than a dimension along the width direction of the second side surface,
First and second electrodes provided in the vibrating section;
A first support portion extending from the first side surface;
A second support portion extending from the second side surface;
With
The first support portion is a portion on the third side surface side from the center in the width direction of the first side surface, and is connected to a portion including an end portion on the third side surface side,
The second support part is connected to a part on the fourth side face side from the center in the width direction of the second side face and connected to a part including the end part on the fourth side face side. Vibrator. The entirety of the first support portion is provided on the third side surface side from the center in the width direction of the first side surface,
2. The crystal resonator according to claim 1, wherein the entire second support portion is provided on the fourth side surface side from the center in the width direction of the second side surface.   The connection part with the said 1st side surface of the said 1st support part, and the connection part with the said 2nd side surface of the said 2nd support part each extend along a length direction. Or the crystal resonator of 2.   4. The crystal resonator according to claim 1, wherein the first and second electrodes are opposed to each other in the thickness direction via the vibrating portion.   The crystal unit according to any one of claims 1 to 4, wherein the vibration unit is formed of a rotating Y-cut quartz plate.   The crystal unit according to claim 1, wherein the vibration unit and the first and second support units are configured by a single crystal plate.

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