Vibrating pieces and vibrating devices

Abstract

To provide a vibrating element that can reduce vibration leakage and improve the Q value. [Solution] A vibrating piece comprising a base, two vibrating arms extending from the base, a protrusion projecting from the side of a groin connecting the two vibrating arms, and at least one support portion fixed to a container via a connecting member, wherein, in a plan view, when a virtual center line passing through the midpoints of the two vibrating arms is assumed, the volume of the protrusion in one region divided by the virtual center line is greater than the volume of the protrusion in the other region divided by the virtual center line, and at least one support portion is located in the one region.

Description

Technical Field

[0001] The present invention relates to a vibrating reed and a vibration device.

Background Art

[0002] Vibration devices in which a vibrating reed is housed in a package are known.

[0003] For example, Patent Document 1 describes a tuning-fork type piezoelectric vibrating reed including: a base portion; a plurality of leg portions protruding from one end surface of the base portion; and an L-shaped joint portion protruding from a position on the other end surface of the base portion that faces an intermediate position between the plurality of leg portions in the width direction of the one end surface of the base portion. Plating bumps are respectively formed on the short side portion and the long side portion of the joint portion, and the short side portion and the long side portion are each bonded to an electrode pad of a base via the plating bump. The tuning-fork type piezoelectric vibrating reed is formed by wet-etching a quartz base plate, which is a quartz piece made of an anisotropic material.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] Demands for frequency stability for the above-described tuning-fork type piezoelectric vibrating reeds have been increasing, and there is a need to reduce vibration leakage and improve the Q factor.

Means for Solving the Problem

[0006] One aspect of the vibrating reed according to the present invention is: a base portion, two vibrating arms extending from the base portion, and a protruding portion protruding from a side surface of a crotch portion connecting the two vibrating arms, At least one support portion fixed to the container via a connecting member, Includes, In a plan view, assuming a virtual center line passing through the midpoints of the two aforementioned vibrating arms, The volume of the protrusion in one region divided by the virtual center line is greater than the volume of the protrusion in the other region divided by the virtual center line. At least one of the support portions is located in the one region.

[0007] One aspect of the vibration device according to the present invention is: The vibrating piece and, The container in which the vibrating piece is housed, The joining member is positioned between at least one of the support portions and the container, Includes. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic plan view showing the vibrating piece according to the first embodiment. [Figure 2] A schematic plan view showing the manufacturing process of a vibrating element according to the first embodiment. [Figure 3] A schematic plan view showing a vibrating piece according to a first modified example of the first embodiment. [Figure 4] A schematic plan view showing a vibrating piece according to a second modified example of the first embodiment. [Figure 5] A schematic plan view showing a vibrating piece according to a third modified example of the first embodiment. [Figure 6] A schematic plan view showing the vibrating piece according to the second embodiment. [Figure 7] A schematic plan view showing a vibrating piece according to a modified example of the second embodiment. [Figure 8] A schematic cross-sectional view showing a vibration device according to the third embodiment. [Figure 9] A schematic plan view showing a vibration device according to the third embodiment. [Figure 10] A schematic cross-sectional view showing the vibration device according to the fourth embodiment. [Figure 11] SEM image of a tuning-fork type crystal vibrating piece. [Figure 12] Figure showing a model of a tuning-fork type crystal vibrating piece. [Figure 13] Table showing the Q value of the model of a tuning-fork type crystal vibrating piece and the actually measured values of the Q value of the tuning-fork type crystal vibrating piece. [Figure 14] Figure showing displacement vectors in the model of a tuning-fork type crystal vibrating piece. [Figure 15] Figure showing displacement vectors near the crotch portion in the model of a tuning-fork type crystal vibrating piece. [Figure 16] Figure showing dimensions in the model of a tuning-fork type crystal vibrating piece. [Figure 17] Table showing Q_vibration leakage when the supporting position and the size of the supporting portion are changed. [Figure 18] Figure showing displacement vectors for the model of a tuning-fork type crystal vibrating piece. [Figure 19] Graph showing Q_vibration leakage when the diameter of the supporting portion is changed. [Figure 20] Figure showing displacement vectors in the model of a tuning-fork type crystal vibrating piece. [Figure 21] Figure showing displacement vectors in the model of a tuning-fork type crystal vibrating piece. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. In addition, not all of the configurations described below are necessarily essential constituent requirements of the present invention.

[0010] 1. First Embodiment 1.1. Vibrating Piece First, a vibrating piece according to the first embodiment will be described with reference to the drawings. Figure 1 is a plan view schematically showing the vibrating piece 100 according to the first embodiment. In Figure 1, an X-axis, a Y-axis, and a Z-axis are illustrated as three mutually orthogonal axes.

[0011] As shown in Figure 1, the vibrating element 100 includes, for example, a quartz substrate 10, a first electrode 80, and a second electrode 82.

[0012] The quartz substrate 10 is, for example, a Z-cut quartz plate. The vibrating element 100 is, for example, a tuning fork-shaped quartz vibrating element. In the illustrated example, the quartz substrate 10 has a flat plate shape that extends in the XY plane defined by the X and Y axes and has thickness in the Z axis direction. The X, Y, and Z axes correspond to the electrical axis, mechanical axis, and optical axis, which are the crystal axes of the quartz, respectively.

[0013] The quartz crystals that make up the quartz substrate 10 have excellent properties such as a low coefficient of thermal expansion, corrosion resistance, and chemical stability. Vibrating elements using quartz crystals are widely used as reference frequency sources and oscillator sources in electronic equipment due to their temperature stability and high Q factor during resonance. The Q factor (Quality Factor) is an important indicator for evaluating the performance of oscillators and resonant circuits. The Q factor is a dimensionless quantity that indicates the efficiency of vibration and resonance, and is defined as shown in equation (1) below.

[0014] Q=ω0 / Δω ···(1)

[0015] Note that ω0 is the resonant frequency, and Δω is the full width at half maximum (FWHM) of the resonant peak. A high Q factor means less energy loss and a sharper resonance. This means that in oscillators and filter circuits, the selectivity is high and they are very sensitive to specific frequencies. A low Q factor means greater energy loss and a broader resonance. This means that the vibrations dampen quickly, resulting in high responsiveness but low selectivity.

[0016] The crystal substrate 10 includes, for example, a base portion 20, a first vibrating arm 30, a second vibrating arm 32, a constricted portion 40, a support beam 50, a support portion 60, and a protrusion 70.

[0017] The base 20 supports the first vibrating arm 30 and the second vibrating arm 32. The base 20 is positioned between the vibrating arms 30, 32 and the constricted portion 40. In plan view, the shape of the base 20 is, for example, approximately rectangular. In the illustrated example, "in plan view" refers to the view from the Z-axis direction.

[0018] The first vibrating arm 30 and the second vibrating arm 32 are connected to the base 20. The vibrating arms 30 and 32 extend from the base 20. The vibrating arms 30 and 32 extend, for example, from the side surface 22 of the base 20 in the -Y axis direction. The base 20 has a groin portion 24 that connects the first vibrating arm 30 and the second vibrating arm 32. The side surface 22 constitutes the groin portion 24. The vibrating arms 30 and 32 flex and vibrate at a predetermined frequency when a voltage is applied between the first electrode 80 and the second electrode 82.

[0019] The first vibrating arm 30 and the second vibrating arm 32 each have, for example, a wide portion 34 at the end opposite to the base 20, which has a wide width in the X-axis direction. The wide portion 34 allows for an increase in the mass of the vibrating arms 30 and 32, thereby enabling miniaturization of the vibrating piece 100.

[0020] Grooves 36 are formed in the first vibrating arm 30 and the second vibrating arm 32. The grooves 36 are formed on the front and back surfaces of the crystal substrate 10. In the illustrated example, the front surface of the crystal substrate 10 is the surface facing the +Z axis direction. The back surface of the crystal substrate 10 is the surface facing the -Z axis direction. Due to the grooves 36, the vibrating arms 30 and 32 have a substantially H-shaped cross-section. The grooves 36 can reduce the CI (Crystal Impedance) value of the vibrating piece 100.

[0021] The constricted portion 40 is connected to the base portion 20. The constricted portion 40 is connected to the base portion 20 on the opposite side from the vibrating arms 30 and 32. The constricted portion 40 is positioned between the base portion 20 and the support beam 50. The width W2 of the constricted portion 40 in the X-axis direction is smaller than the width W1 of the base portion 20 in the X-axis direction.

[0022] The support beam 50 is connected to the constricted portion 40. The support beam 50 is positioned on the opposite side of the base 20 from the vibrating arms 30 and 32. The support beam 50 has, for example, a connecting portion 52 connected to the constricted portion 40, a first beam portion 54 extending from the connecting portion 52 in the +X-axis direction, and a second beam portion 56 extending from the connecting portion 52 in the -X-axis direction. The connecting portion 52 is located between the first beam portion 54 and the second beam portion 56. In the illustrated example, the width of the support beam 50 in the X-axis direction is set to be greater than the width of the base 20 in the X-axis direction, but this is not limited to this configuration. Although not shown in the illustration, the width of the support beam 50 in the X-axis direction may be equal to or less than the width of the base 20 in the X-axis direction.

[0023] In a plan view, the support portion 60 overlaps with the joining member, which will be described later. The support portion 60 is fixed to the container as a package via the joining member. In a plan view, the support portion 60 is the part that overlaps with the contact surface of the crystal substrate 10 with the joining member. In the example shown in Figure 1, the shape of the support portion 60 is circular. Although not shown in the figure, in a plan view, the shape of the support portion 60 may be elliptical or polygonal.

[0024] Two support members 60 are provided. Of the two support members 60, the first support member 60a is provided on the first beam 54. The first beam 54 has, for example, the first support member 60a. Of the two support members 60, the second support member 60b is provided on the second beam 56. The second beam 56 has, for example, the second support member 60b. In the illustrated example, in plan view... The area of ​​the first support portion 60a and the area of ​​the second support portion 60b are the same. In a plan view, the diameters of the support portions 60a and 60b are, for example, 40 μm or more and 80 μm or less, preferably 50 μm or more and 70 μm or less. The diameters of the support portions 60a and 60b are measured, for example, by a laser microscope or SEM (Scanning Electron Microscope).

[0025] The "diameter of the support portion 60" refers to the diameter of the support portion 60 if it is a circle in a plan view, and the diameter of the smallest inclusion circle if the support portion 60 is not a circle. For example, the diameter of the support portion 60 is the diameter of the smallest circle that contains the polygon if it is a polygon in a plan view, and the diameter of the smallest circle that contains the ellipse if it is an ellipse.

[0026] The first support portion 60a is located in the first region 102, which is one of the regions divided by the virtual center line C in a plan view. The second support portion 60b is located in the second region 104, which is the other region divided by the virtual center line C in a plan view. The virtual center line C is a virtual line that passes through the midpoint between the first vibrating arm 30 and the second vibrating arm 32 in a plan view. The distance between the virtual center line C and the first vibrating arm 30 is the same as the distance between the virtual center line C and the second vibrating arm 32. In the illustrated example, the virtual center line C is parallel to the Y axis. The first region 102 is the region in the +X axis direction of the virtual center line C. The second region 104 is the region in the -X axis direction of the virtual center line C.

[0027] The distance L1 between the center of the first support portion 60a and the virtual center line C is smaller than the distance L2 between the center of the second support portion 60b and the virtual center line C. Distance L1 is, for example, 50 μm or more and 120 μm or less, preferably 60 μm or more and 115 μm or less. Distance L2 is, for example, 150 μm or more and 250 μm or less, preferably 200 μm or more and 230 μm or less. Distances L1 and L2 are measured, for example, by a laser microscope or SEM.

[0028] The protrusion 70 protrudes from the side surface 22 of the base 20. Specifically, the protrusion 70 protrudes from the side surface 22 of the groin portion 24 of the base 20. In the illustrated example, the protrusion 70 protrudes from the side surface 22 in the -Y axis direction. At least a portion of the protrusion 70 is located between the first vibration arm 30 and the second vibration arm 32. The length of the protrusion 70 in the Y axis direction is, for example, smaller than the length of the base 20 in the Y axis direction. The width of the protrusion 70 in the X axis direction is, for example, smaller than the width of the constricted portion 40 in the X axis direction. The protrusion 70 is an anisotropic convex shape formed by the anisotropy of the quartz when the quartz plate constituting the quartz substrate 10 is wet-etched.

[0029] The protrusion 70 is arranged, for example, across a first region 102 and a second region 104. The volume of the protrusion 70 in the first region 102 is greater than the volume of the protrusion 70 in the second region 104. In plan view, the area of ​​the protrusion 70 in the first region 102 is greater than the area of ​​the protrusion 70 in the second region 104. Because the quartz substrate 10 has the protrusion 70, it is asymmetric with respect to the virtual center line C.

[0030] Although not shown in the diagram, the convex portion 70 may be located only in the first region 102 and not in the second region 104. In this case, the volume of the convex portion 70 in the second region 104 is zero.

[0031] The first electrode 80 and the second electrode 82 are arranged on the quartz substrate 10. Specifically, electrodes 80 and 82 are arranged on the front, back, and side surfaces of the quartz substrate 10. For convenience, in Figure 1, the first electrode 80 is shown in gray and the second electrode 82 is shown as a small black dot pattern. In the illustrated example, electrodes 80 and 82 are arranged on the base 20, vibrating arms 30 and 32, constricted portion 40, support beam 50, and support portion 60. The first support portion 60a overlaps with the first electrode 80 in a plan view. The first electrode 80 is arranged, for example, on the front and back surfaces of the first support portion 60a. In a plan view, the support portion 60b overlaps with the second electrode 82. The second electrode 82 is positioned, for example, on the front and back surfaces of the second support portion 60b. Electrodes 80 and 82 are also positioned in the wide portion 34 and the groove 36.

[0032] The first electrode 80 and the second electrode 82 are separated from each other. Electrodes 80 and 82 are composed of laminates, for example, a chromium (Cr) layer and a gold (Au) layer stacked from the quartz substrate 10 side. Electrodes 80 and 82 are electrodes for applying voltage to the vibrating arms 30 and 32.

[0033] 1.2. Manufacturing method Next, the manufacturing method of the vibrating element 100 according to the first embodiment will be described with reference to the drawings. Figure 2 is a schematic plan view showing the manufacturing process of the vibrating element 100 according to the first embodiment.

[0034] As shown in Figure 2, a quartz substrate 10 is formed by wet etching a quartz matrix. As the etching solution, for example, a liquid mainly composed of fluoride is used. Wet etching using a liquid mainly composed of fluoride is suitable for mass production in terms of efficiency and cost. Examples of liquids mainly composed of fluoride include hydrofluoric acid (HF) and a mixture of HF and ammonium fluoride (NH4F). Specifically, a mask layer is formed on the quartz matrix, and the quartz substrate 10 is formed by wet etching the quartz matrix using the mask layer as a mask.

[0035] Due to the anisotropy of the quartz crystal, the reactivity between the fluoride contained in the etching solution and the quartz substrate differs depending on the crystal plane of the quartz substrate. Therefore, differences in etching speed occur depending on the crystal plane of the quartz. As a result, an anisotropic convex shape of the protrusion 70 is formed on the groove 24. Although not shown in the figures, anisotropic convex shapes may also be formed on the sides of the groove 36 and the constricted portion 40 by wet etching.

[0036] Next, as shown in Figure 1, a first electrode 80 and a second electrode 82 are formed on the quartz substrate 10. The electrodes 80 and 82 are formed, for example, by sputtering, vacuum deposition, or CVD (Chemical Vapor Deposition).

[0037] The vibrating element 100 can be manufactured through the above process.

[0038] 1.3. Effects The vibrating piece 100 includes a base 20, two vibrating arms 30 and 32 extending from the base 20, a protrusion 70 projecting from the side surface 22 of a groin portion 24 connecting the two vibrating arms 30 and 32, and at least one support portion 60 fixed to the container via a connecting member. In a plan view, assuming a virtual center line C passing through the midpoints of the two vibrating arms 30 and 32, the volume of the protrusion 70 in the first region 102, which is one region divided by the virtual center line C, is larger than the volume of the protrusion 70 in the second region 104, which is the other region divided by the virtual center line C, and at least one support portion 60 is located in the first region 102.

[0039] Therefore, in the vibrating piece 100, as shown in "5. Experimental Example" described later, the support part 60 can be positioned in a part where the vibration caused by the vibrating arms 30 and 32 has little effect. This reduces vibration leakage and improves the Q value.

[0040] In the vibrating piece 100, at least one support portion 60 is provided in two locations, the first support portion 60a of the two support portions 60 is located in the first region 102, and the second support portion 60b of the two support portions 60 is located in the second region 104, with the center of the first support portion 60a and the virtual center line C The distance L1 between the two is smaller than the distance L2 between the center of the second support 60b and the virtual center line C. This arrangement makes it more difficult for vibrations to be transmitted to the support, and the Q value of the vibrating piece 100 can be improved. Furthermore, because there are two support 60s, the impact resistance and stability can be improved compared to when there is only one support 60.

[0041] The vibrating piece 100 includes a support beam 50 positioned on the opposite side of the vibrating arms 30 and 32 of the base 20, and the first support portion 60a and the second support portion 60b are positioned on the support beam 50. Therefore, the vibrating piece 100 can reduce the vibration of the vibrating arms 30 and 32 transmitted to the support portions 60a and 60b.

[0042] The vibrating piece 100 includes a constricted portion 40 between the base 20 and the support beam 50, which is narrower than the base 20. The constricted portion 40 allows the vibrating piece 100 to further reduce the vibration of the vibrating arms 30 and 32 transmitted to the support portions 60a and 60b.

[0043] In the vibrating piece 100, the distance between the center of at least one support portion 60 and the virtual center line C is between 50 μm and 120 μm. Specifically, the distance L1 between the center of the first support portion 60a and the virtual center line C is between 50 μm and 120 μm. Therefore, the vibrating piece 100 can further improve the Q value, as shown in "5. Experimental Examples" described later.

[0044] 1.4. Variations of the vibrating piece 1.4.1. First Variation Next, a vibrating piece according to the first modified example of the first embodiment will be described with reference to the drawings. Figure 3 is a schematic plan view showing a vibrating piece 110 according to the first modified example of the first embodiment. For convenience, the electrodes 80 and 82 are omitted from the illustration in Figure 3.

[0045] The following describes the differences between the vibrating piece 110 according to the first modified example of the first embodiment and the example of the vibrating piece 100 according to the first embodiment described above, while similar points will be simplified or omitted from the explanation. The same applies to the vibrating pieces according to the second and third modified examples of the first embodiment described later.

[0046] In the vibrating piece 100 described above, as shown in Figure 1, the area of ​​the first support portion 60a and the area of ​​the second support portion 60b were the same in a plan view.

[0047] In contrast, in the vibrating piece 110, as shown in Figure 3, in a plan view, the area of ​​the second support portion 60b is smaller than the area of ​​the first support portion 60a. In a plan view, the diameter D1 of the first support portion 60a is, for example, 40 μm or more and 80 μm or less, preferably 50 μm or more and 70 μm or less. In a plan view, the diameter D2 of the second support portion 60b is, for example, 0.1 μm or more and 40 μm or less, preferably 0.5 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less.

[0048] In the vibrating element 110, the area of ​​the second support portion 60b is smaller than the area of ​​the first support portion 60a when viewed from above. Therefore, the vibrating element 110 can achieve a higher Q-factor, as shown in "5. Experimental Example" described later.

[0049] In the vibrating element 110, the diameter D2 of the second support portion 60b is 10 μm or less in a plan view. Therefore, the Q value can be further improved in the vibrating element 110, as shown in "5. Experimental Example" described later.

[0050] 1.4.2. Second Variation Next, a vibrating piece relating to a second modified example of the first embodiment will be described with reference to the drawings. Figure 4 is a schematic plan view showing a vibrating piece 120 according to a second modified example of the first embodiment. For convenience, the electrodes 80 and 82 are omitted from the illustration in Figure 4.

[0051] In the vibrating piece 100 described above, as shown in Figure 1, only one first support portion 60a was provided.

[0052] In contrast, in the vibrating piece 120, as shown in Figure 4, multiple first support parts 60a are arranged. Multiple joining members for joining the first support parts 60a to the container are arranged in a number corresponding to the number of first support parts 60a. The number of first support parts 60a is not particularly limited, but in the illustrated example, three first support parts 60a are arranged. Only one second support part 60b is arranged. The diameter of the first support part 60a is, for example, smaller than the diameter of the second support part 60b. Note that the diameter of the first support part 60a may be the same as the diameter of the second support part 60b.

[0053] In the vibrating element 120, multiple first support parts 60a are arranged. Therefore, when the vibrating element 120 is joined to a container, the bonding strength between the vibrating element 120 and the container can be increased.

[0054] 1.4.3. Third Variation Next, a vibrating piece according to a third modified example of the first embodiment will be described with reference to the drawings. Figure 5 is a schematic plan view showing a vibrating piece 130 according to a third modified example of the first embodiment. For convenience, the electrodes 80 and 82 are omitted from the illustration in Figure 5.

[0055] In the vibrating piece 100 described above, the support portion 60 was positioned on the support beam 50, as shown in Figure 1.

[0056] In contrast, in the vibrating piece 130, as shown in Figure 5, the support portion 60 is located on the base portion 20. The vibrating piece 130 does not include the constricted portion 40 and the support beam 50.

[0057] In the vibrating piece 130, at least one support portion 60 is located on the base portion 20. Therefore, the vibrating piece 130 does not need to have a constricted portion 40 and a support beam 50, thus enabling miniaturization.

[0058] 2. Second Embodiment 2.1. Vibrating piece Next, the vibrating piece according to the second embodiment will be described with reference to the drawings. Figure 6 is a schematic plan view showing the vibrating piece 200 according to the second embodiment. For convenience, the electrodes 80 and 82 are omitted from the illustration in Figure 6.

[0059] The following describes the differences between the vibrating piece 200 according to the second embodiment and the example of the vibrating piece 100 according to the first embodiment described above, while similar points will be simplified or omitted from the explanation.

[0060] In the vibrating piece 100 described above, two support parts 60 were arranged, as shown in Figure 1.

[0061] In contrast, the vibrating element 200 has only one support portion 60, as shown in Figure 6. The support portion 60 is located in the first region 102. Although not shown, the first electrode 80 is located on the back surface of the support portion 60. The second electrode 82 is located on the front surface of the support portion 60. The support portion 60 is located between the first electrode 80 and the second electrode 82.

[0062] In the vibrating piece 200, only one support portion 60 is provided. Therefore, in the vibrating piece 200, compared to the case where two support portions 60 are provided, the support portion 60 is responsible for the vibration of the vibrating arms 30 and 32. The impact can be reduced, and vibrations are less likely to be transmitted to the outside through the support part 60, thus improving the Q value.

[0063] 2.2. Variations of the vibrating piece Next, a vibrating piece according to a modified example of the second embodiment will be described with reference to the drawings. Figure 7 is a schematic plan view showing a vibrating piece 210 according to a modified example of the second embodiment. For convenience, the first electrode 80 and the second electrode 82 are omitted from the illustration in Figure 7.

[0064] The following describes the differences between the vibrating piece 210 according to a modified example of the second embodiment and the example of the vibrating piece 200 according to the second embodiment described above, while similar points will be simplified or omitted from the explanation.

[0065] In the vibrating piece 200 described above, the support portion 60 was positioned on the support beam 50, as shown in Figure 6.

[0066] In contrast, in the vibrating piece 210, as shown in Figure 7, the support portion 60 is located on the base portion 20. The vibrating piece 210 does not include the constricted portion 40 and the support beam 50.

[0067] In the vibrating element 210, the support portion 60 is located on the base portion 20. Therefore, the vibrating element 210 does not require a constricted portion 40 and a support beam 50, thus enabling miniaturization.

[0068] 3. Third Embodiment Next, the vibration device according to the third embodiment will be described with reference to the drawings. Figure 8 is a schematic cross-sectional view showing the vibration device 300 according to the third embodiment. Figure 9 is a schematic plan view showing the vibration device 300 according to the third embodiment.

[0069] The vibration device 300 includes, for example, a vibrating piece 100, a container 310, and a connecting member 320, as shown in Figures 8 and 9. For convenience, the vibrating piece 100 is shown in a simplified form in Figure 8.

[0070] The container 310 houses the vibrating piece 100 and the connecting member 320. The container 310 includes, for example, a base 312, a first connection terminal 314, a second connection terminal 316, and a lid 318.

[0071] The base 312 is made of a ceramic material such as alumina. A recess 313 with an opening on its upper surface is formed in the base 312. The vibrating piece 100 is housed in the space formed by the recess 313. The space of the recess 313 is airtight and under reduced pressure, preferably closer to a vacuum. This reduces viscous resistance and improves the vibration characteristics of the vibrating piece 100. The space of the recess 313 may be filled with an atmosphere of an inert gas such as nitrogen or argon. In the example shown in Figure 8, the recess 313 has a first recess 313a with an opening on the upper surface of the base 312, and a second recess 313b formed on the bottom surface of the first recess 313a. The opening width of the second recess 313b is smaller than the opening width of the first recess 313a. The vibrating piece 100 is placed in the second recess 313b. Although not shown in the diagram, the second recess 313b may not be formed, and the vibrating piece 100 may be placed in the first recess 313a.

[0072] The first connection terminal 314 and the second connection terminal 316 are located on the base 312. Specifically, the connection terminals 314 and 316 are located on the bottom surface of the second recess 313b. In the example shown in Figure 9, the connection terminals 314 and 316 are aligned in the X-axis direction. First connection terminal 314 In a plan view, the first support portion 60a overlaps with the second support portion 60b. The second connecting terminal 316 overlaps with the second support portion 60b in a plan view.

[0073] The first connection terminal 314 and the second connection terminal 316 are electrically isolated from each other. The connection terminals 314 and the second connection terminal 316 are spaced apart from each other. The first connection terminal 314 may be electrically connected to a first external terminal (not shown) located on the outer bottom surface of the container 310. The second connection terminal 316 may be electrically connected to a second external terminal (not shown) located on the outer bottom surface of the container 310. The connection terminals 314 and 316 are made of a laminate formed by stacking nickel (Ni) layers and gold (Au) layers from the base 312 side, for example.

[0074] The lid 318 is joined to the base 312, as shown in Figure 8. The joining of the lid 318 to the base 312 is performed, for example, by placing a seal ring (not shown) on the base 312, placing the lid 318 on the seal ring, and welding the seal ring to the base 312 using a resistance welding machine. The joining of the base 312 to the lid 318 is not particularly limited and may be done using an adhesive or by seam welding.

[0075] The material of the lid 318 is, for example, a metal such as Kovar, or a light-transmitting glass. The lid 318 seals the opening of the recess 313. The shape of the lid 318 is, for example, plate-like.

[0076] The joining member 320 is positioned between the support portion 60 and the container 310. Two joining members 320 are provided. Of the two joining members 320, the first joining member 320a is positioned on the first connection terminal 314. The first joining member 320a is positioned between the first support portion 60a and the container 310. Of the two joining members 320, the second joining member 320b is positioned on the second connection terminal 316. The second joining member 320b is positioned between the second support portion 60b and the container 310. The joining member 320 is, for example, a metal bump made of gold or a conductive adhesive such as silver paste.

[0077] The vibrating element 100 is mounted in the container 310. The first support portion 60a is fixed to the container 310 via the first connecting member 320a. The first electrode 80 is electrically connected to the first connection terminal 314 via the first connecting member 320a. The second support portion 60b is fixed to the container 310 via the second connecting member 320b. The second electrode 82 is electrically connected to the second connection terminal 316 via the second connecting member 320b.

[0078] Although not shown in the figures, the container 310 may also house a circuit element for driving the vibrating piece 100. The circuit element is electrically connected to the electrodes 80 and 82 of the vibrating piece 100. For example, the vibrating piece 100 may be placed in the first recess 313a and the circuit element may be placed in the second recess 313b. Alternatively, the circuit element may be placed outside the container 310.

[0079] Furthermore, the circuit element may have an oscillation circuit that causes the vibrating element 100 to oscillate. In this case, the vibration device 300 functions as an oscillator. The vibration device 300 may also be used as a device other than an oscillator or vibrator, such as an acceleration sensor or an angular velocity sensor. The vibration device 300 may be built into computers, printers, smartphones, tablet devices, watches, televisions, head-mounted displays, video cameras, digital still cameras, car navigation systems, electronic game devices, various medical devices, various measuring instruments, various mobile devices, etc.

[0080] The vibration device 300 includes a vibrating piece 100, a container 310 housing the vibrating piece 100, and a connecting member 320, of which two connecting members 320 are arranged, and the first connecting member 320a of the two connecting members 320 is positioned between the first support 60a and the container 310, and the two Of the two joining members 320, the second joining member 320b is positioned between the second support portion 60b and the container 310. Therefore, the Q value can be improved in the vibration device 300. Furthermore, because two joining members 320 are provided, impact resistance and stability can be improved compared to the case where only one joining member 320 is provided. In addition, the aforementioned vibrating pieces 110, 120, and 130 may be provided instead of the vibrating piece 100.

[0081] In the vibration device 300, the joining member 320 may be a metal bump. If the joining member 320 is a metal bump, the joining strength can be increased.

[0082] In the vibration device 300, the joining member 320 may be a conductive adhesive. If the joining member 320 is a conductive adhesive, it has higher elasticity compared to, for example, a metal bump, and can absorb stress. Therefore, the effect of stress on the support part 60 can be reduced.

[0083] 4. Fourth Embodiment Next, a vibration device according to the fourth embodiment will be described with reference to the drawings. Figure 10 is a schematic cross-sectional view showing the vibration device 400 according to the fourth embodiment.

[0084] The following describes the differences between the vibration device 400 according to the fourth embodiment and the example of the vibration device 300 according to the third embodiment described above, while similar points will be simplified or omitted.

[0085] The vibration device 300 described above included a vibrating element 100, as shown in Figure 8.

[0086] In contrast, the vibration device 400 includes a vibrating element 200, as shown in Figure 10. For convenience, the vibrating element 200 is shown in a simplified form in Figure 10.

[0087] In the vibration device 400, only one connecting member 320 is provided. The back side of the support portion 60 is connected to the first connection terminal 314 via the connecting member 320. Specifically, the first electrode 80, which is located on the back side of the support portion 60, is connected to the first connection terminal 314 via the connecting member 320.

[0088] The vibration device 400 includes a conductive wire 410. The surface side of the support portion 60 is joined to the second connection terminal 316 via the conductive wire 410. Specifically, the second electrode 82, located on the surface of the support portion 60, is joined to the second connection terminal 316 via the conductive wire 410. The conductive wire 410 is made of a metal such as gold or copper. In the illustrated example, the second connection terminal 316 is located on the bottom surface of the first recess 313a formed in the base 312.

[0089] The vibration device 400 includes a vibrating piece 200, a container 310 in which the vibrating piece 200 is housed, and a connecting member 320 positioned between the support 60 and the container 310. Therefore, the vibration device 400 can improve the Q value.

[0090] In the vibration device 400, at least one support portion 60 is provided, and the container 310 has a first connection terminal 314 and a second connection terminal 316 that are electrically isolated from each other. One side of the support portion 60 is joined to the first connection terminal 314 via a joining member 320, and the other side of the support portion 60 is connected to the second connection terminal 316 via a conductive wire 410. Therefore, in the vibration device 400, the influence of the joining member 320 on the vibration of the vibrating arms 30 and 32 can be reduced compared to the case where two joining members 320 are provided, and the Q value can be improved.

[0091] 5. Experimental Examples 5.1. First Experimental Example Figure 11 is an SEM image of a tuning fork-shaped quartz vibrator fabricated by wet etching a quartz substrate with a liquid mainly composed of fluoride. As shown in Figure 11, an anisotropic convex shape was observed in the tuning fork-shaped quartz vibrator.

[0092] Next, the fabricated tuning fork-shaped quartz crystal vibrator was measured with a laser microscope, a 3D model was created, and a simulation was performed using the finite element method. Figure 12 shows 3D model M1, which reproduces a tuning fork-shaped quartz crystal vibrator considering anisotropic convex shape, and 3D model M2, which reproduces a tuning fork-shaped quartz crystal vibrator without considering anisotropic convex shape.

[0093] The Q values ​​for models M1 and M2 were calculated. The Q value is determined by the sum of various loss mechanisms. In the case of a tuning fork-type vibrator vibrating in a vacuum and in its fundamental mode, the two main factors determining the Q value are thermoelastic loss and support loss due to the interaction between the vibrating arm and the support (hereinafter also referred to as "vibration leakage"). The overall Q value is expressed as the sum of the reciprocals of each independent loss, as shown in equation (2) below.

[0094] 1 / (Q_Total) = 1 / (Q_Thermoelastic Loss) + 1 / (Q_Vibration Leakage) ... (2)

[0095] Models M1 and M2 are models with the same material constants, support position, potential, and mesh count. Each loss was calculated by simulation, and the total Q value (Q_Total) was determined based on equation (2). Furthermore, the Q value of the actually fabricated tuning fork-type quartz vibrator shown in Figure 11 was measured as an actual value.

[0096] Figure 13 is a table showing the Q values ​​of models M1 and M2 obtained by simulation, and the measured Q values ​​of the fabricated tuning fork-type quartz crystal vibrator. As shown in Figure 13, model M1, which takes anisotropic convex shape into account, had a Q_Total closer to the measured value than model M2, which does not take anisotropic convex shape into account. This experimental example shows that model M1, which takes anisotropic convex shape into account, can reproduce a shape close to that of the actually fabricated tuning fork-type quartz crystal vibrator.

[0097] 5.2. Second Experimental Example Figure 14 shows the displacement vectors in model M1 as determined by simulation. Figure 15 shows the displacement vectors near the hip joint in model M1 and model M2 as determined by simulation. In Figures 14 and 15, the direction of the arrows indicates the direction of displacement of the vibrating piece in the fundamental mode. The grayscale indicates the magnitude of the displacement.

[0098] In Model M2, as shown in Figure 15, the vibrations generated at the base are in opposite phase with respect to the virtual centerline C. The vibrations cancel each other out along the virtual centerline C through the constricted section, dramatically reducing the stress transmitted to the support.

[0099] On the other hand, the displacement vector in model M1, which is closer to the actual structure, differed significantly from the displacement vector in model M2. This is because the presence of anisotropic convex shape causes slight differences in the mass and center of gravity of the two vibrating arms, and more vibration is transmitted through the anisotropic convex shape at the joint to the side with the larger volume of the anisotropic convex shape. In model M1, since the vibration amounts of the two vibrating arms are different, the difference in vibration amounts between the two vibrating arms could not be completely canceled out, and a moment was generated at the base. The center of the moment was located at a position offset from the virtual center line C. Due to the generation of a moment at the base, the center of the support beam was shifted through the constricted section to the side with the larger volume of the anisotropic convex shape. As shown in Figure 15, a clockwise moment was generated. The vibrations leaking to the support are transmitted from the support to the package, worsening the vibration leakage Q value as a support loss.

[0100] This experimental example revealed that in the realistic model M1, a moment caused by the vibration of the vibrating arm is generated around a position shifted from the virtual center line C towards the side with a larger volume of the anisotropic convex shape.

[0101] 5.3. Third Experimental Example In Model M1, which considers anisotropic convex shape, the optimal support position for minimizing support loss was investigated. To reduce support loss, it is desirable to position the support in a location where vibration is less likely to be transmitted and stress is less likely to be applied. In other words, it is effective to position the support as close as possible to the vibration center where the displacement is smallest.

[0102] Figure 16 shows the dimensions of Model M1, taking into account the anisotropic convex shape. Figure 16 also shows a magnified view of the area near the crotch. As shown in Figure 16, the total length of Model M1 is 1180 μm, and the width of Model M1 is 520 μm. The length of the anisotropic convex shape in the crotch is 82 μm, and the width of the anisotropic convex shape in the crotch is 97 μm. The thickness of the quartz substrate of Model M1 is 130 μm.

[0103] Figure 17 is a table showing the Q vibration leakage when the support position and size of the support are changed.

[0104] Level 1 is a model in which the first support part S1 and the second support part S2 are arranged symmetrically with respect to the virtual center line C. The first support part S1 is the support part on the side with a larger volume of the anisotropic convex shape of the crotch. The second support part S2 is the support part on the side with a smaller volume of the anisotropic convex shape of the crotch. The distance between the first support part S1 and the virtual center line C, and the distance between the second support part S2 and the virtual center line C are both set to 200 μm. The diameter of the first support part S1 and the diameter of the second support part S2 are both set to 60 μm.

[0105] Level 2 is the same as Level 1, except that the distance between the first support part S1 and the virtual center line C is set to 110 μm.

[0106] Level 3 is the same as Level 1, except that the distance between the second support part S2 and the virtual center line C is set to 110 μm.

[0107] Level 4 is the same as Level 1, except that the distance between the first support part S1 and the virtual center line C is 110 μm, and the diameter of the second support part S2 is 20 μm.

[0108] As shown in Figure 17, Level 2 showed improved Q_vibration leakage compared to Level 1. As shown in Figure 18, in Model M1, the displacement amount was 10% within the entire vibrating piece. -9 The region where the displacement is mm, that is, the range where the vibration center is extremely small, was between 50 μm and 120 μm from the virtual center line C. In Level 2, the first support part S1 was positioned in this range, so the first support part S1 was closer to the vibration center, which reduced the support loss and improved Q_vibration leakage. On the other hand, as shown in Figure 17, Q_vibration leakage worsened in Level 3 compared to Level 2.

[0109] This experiment demonstrated that the Q-value can be improved by bringing the support portion on the side with the larger volume of the anisotropic convex shape closer to the virtual centerline C.

[0110] Level 4 showed a significant improvement in Q_vibration leakage compared to Level 1, and also showed an improvement in Q_vibration leakage compared to Level 2.

[0111] Here, a more detailed examination of Level 4 was conducted. Figure 19 is a graph showing the Q_vibration leakage when the diameter of the second support part S2 is changed at Level 4. Figure 19 also shows an expanded graph for the range of the second support part S2 diameter from 10 μm to 60 μm.

[0112] As shown in Figure 19, the smaller the diameter of the second support portion S2, the more the Q_vibration leakage tends to improve. Specifically, the Q_vibration leakage dramatically improved when the diameter was 10 μm. It was found that setting the diameter of the support portion on the side with the smaller volume of the anisotropic convex shape to 10 μm or less can particularly improve the Q_vibration leakage.

[0113] Reducing the diameter of the second support part S2 results in a configuration closer to a so-called single-point support, thus reducing the influence from the support part and improving Q_dynamic leakage. Figure 20 shows the displacement vector in a model assuming a single-point support.

[0114] Figure 21 shows the displacement vector in a model without a constricted section and support beams.

[0115] The embodiments and variations described above are examples only and are not limited thereto. For example, each embodiment and each variation can be combined as appropriate.

[0116] The present invention includes configurations substantially identical to those described in the embodiments, for example, configurations with the same function, method, and results, or configurations with the same purpose and effect. Furthermore, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as those described in the embodiments. Finally, the present invention includes configurations that add known technology to the configurations described in the embodiments.

[0117] The following can be derived from the embodiments and modifications described above.

[0118] One aspect of the vibrating element is, The base and, Two vibrating arms extending from the base, A protrusion extending from the side of the groin connecting the two aforementioned vibrating arms, At least one support portion fixed to the container via a connecting member, Includes, In a plan view, assuming a virtual center line passing through the midpoints of the two aforementioned vibrating arms, The volume of the protrusion in one region divided by the virtual center line is greater than the volume of the protrusion in the other region divided by the virtual center line. At least one of the support portions is located in the one region.

[0119] This vibrating element can reduce vibration leakage and improve the Q factor.

[0120] In one embodiment of a vibrating element, At least one of the support parts is arranged in pairs. The first of the two support parts is positioned in one of the regions. The second of the two support parts is positioned in the other region. The distance between the first support and the virtual centerline may be smaller than the distance between the second support and the virtual centerline.

[0121] This vibrating element can improve shock resistance and stability.

[0122] In one embodiment of a vibrating element, Includes a support beam positioned on the opposite side of the base from the vibrating arm, The first support and the second support may be arranged on the support beam.

[0123] This vibrating element can reduce the vibration of the vibrating arm transmitted to the first and second support parts.

[0124] In one embodiment of a vibrating element, A constricted portion, smaller in width than the base, may be included between the base and the support beam.

[0125] This vibrating element makes it possible to further reduce the vibration of the vibrating arm transmitted to the first support and the second support.

[0126] In one embodiment of a vibrating element, At least one of the support members may be located on the base.

[0127] This vibrating element allows for miniaturization.

[0128] In one embodiment of a vibrating element, The distance between the center of at least one of the support parts and the virtual center line may be 50 μm or more and 120 μm or less.

[0129] This vibrating element allows for a further improvement in the Q factor.

[0130] In one embodiment of a vibrating element, The distance between the center of the first support portion and the virtual center line may be 50 μm or more and 120 μm or less.

[0131] This vibrating element allows for a further improvement in the Q factor.

[0132] In one embodiment of a vibrating element, In a plan view, the area of ​​the second support portion may be smaller than the area of ​​the first support portion.

[0133] This vibrating element allows for a further improvement in the Q factor.

[0134] In one embodiment of a vibrating element, In a plan view, the diameter of the second support portion may be 10 μm or less.

[0135] This vibrating element allows for a further improvement in the Q factor.

[0136] In one embodiment of a vibrating element, Multiple first support members may be provided.

[0137] This vibrating element can increase the bonding strength with the container.

[0138] One embodiment of a vibration device is, One embodiment of the vibrating piece, The container in which the vibrating piece is housed, The joining member is positioned between at least one of the support portions and the container, Includes.

[0139] This vibration device can reduce vibration leakage and improve the Q factor.

[0140] In one form of a vibration device, At least one of the support members is provided, The container has a first connection terminal and a second connection terminal that are electrically isolated from each other. One side of the support portion is joined to the first connecting terminal via the joining member. The other side of the support portion may be connected to the second connection terminal via a conductive wire.

[0141] This vibration device makes it possible to reduce the influence of the connecting member on the vibration of the vibrating arm.

[0142] One embodiment of a vibration device is, One embodiment of the vibrating piece, The container in which the vibrating piece is housed, The aforementioned joining member, Includes, The aforementioned joining members are arranged in pairs, The first of the two connecting members is positioned between the first support and the container. The second of the two connecting members is positioned between the second support and the container.

[0143] This vibration device can improve shock resistance and stability.

[0144] In one form of a vibration device, The aforementioned joining member may be a metal bump.

[0145] This vibration device allows for increased joint strength.

[0146] In one form of a vibration device, The joining member may be a conductive adhesive.

[0147] This vibration device allows stress to be absorbed in the joint members. [Explanation of Symbols]

[0148] 10...Crystal substrate, 20...Base, 22...Side, 24...Hip, 30...First vibrating arm, 32...Second vibrating arm, 34...Wide section, 36...Groove, 40...Constricted section, 50...Support beam, 52...Connection section, 54...First beam section, 56...Second beam section, 60...Support section, 60a...First support section, 60b...Second support section, 70...Convex section, 80...First electrode, 82...Second electrode, 100...Vibrating piece, 102...First region, 104...First 2 regions, 110, 120, 130, 200, 210… vibrating piece, 300… vibrating device, 310… container, 312… base, 313… recess, 313a… first recess, 313b… second recess, 314… first connection terminal, 316… second connection terminal, 318… lid, 320… joining member, 320a… first joining member, 320b… second joining member, 400… vibrating device, 410… conductive wire

Claims

1. The base and, Two vibrating arms extending from the base, A protrusion extending from the side of the groin connecting the two aforementioned vibrating arms, At least one support portion fixed to the container via a connecting member, Includes, In a plan view, assuming a virtual center line passing through the midpoints of the two aforementioned vibrating arms, The volume of the protrusion in one region divided by the virtual center line is greater than the volume of the protrusion in the other region divided by the virtual center line. At least one of the support portions is a vibrating piece positioned in the one region.

2. In claim 1, At least one of the support parts is arranged in pairs. The first of the two support parts is positioned in one of the regions. The second of the two support parts is positioned in the other region. A vibrating piece in which the distance between the first support and the virtual center line is smaller than the distance between the second support and the virtual center line.

3. In claim 2, Includes a support beam positioned on the opposite side of the base from the vibrating arm, The first support portion and the second support portion are vibrating pieces arranged on the support beam.

4. In claim 3, A vibrating piece having a constricted portion between the base and the support beam that is narrower than the base.

5. In claim 1 or 2, At least one of the support parts is a vibrating piece disposed on the base.

6. In claim 1, A vibrating piece in which the distance between the center of at least one of the support parts and the virtual center line is 50 μm or more and 120 μm or less.

7. In claim 2, A vibrating piece in which the distance between the center of the first support and the virtual center line is 50 μm or more and 120 μm or less.

8. In claim 2, In a plan view, the area of ​​the second support portion is smaller than the area of ​​the first support portion, wherein the vibrating piece.

9. In claim 8, In a plan view, the diameter of the second support portion is 10 μm or less, in the vibrating piece.

10. In claim 2, The first support portion comprises multiple vibrating pieces.

11. The vibrating piece according to claim 1, The container in which the vibrating piece is housed, The joining member is positioned between at least one of the support portions and the container, A vibration device, including

12. In claim 11, At least one of the support members is provided, The container has a first connection terminal and a second connection terminal that are electrically isolated from each other. One side of the support portion is joined to the first connecting terminal via the joining member. The other side of the support portion is connected to the second connection terminal via a conductive wire, forming a vibration device.

13. The vibrating piece according to claim 2, The container in which the vibrating piece is housed, The aforementioned joining member, Includes, The aforementioned joining members are arranged in pairs, The first of the two connecting members is positioned between the first support and the container. The second of the two connecting members is a vibration device positioned between the second support and the container.

14. In claim 11 or 13, The aforementioned joining member is a metal bump, which is a vibration device.

15. In claim 11 or 13, The aforementioned joining member is a conductive adhesive, in the vibration device.

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