Resonator element, resonator, and oscillator

Abstract

A resonator element, a resonator, and an oscillator. The resonator element includes: a quartz substrate having a resonator portion including a resonator region and a support portion having a thickness larger than that of the resonator portion; and an excitation electrode disposed in the vibration region, the excitation electrode satisfying the relationship y < = 329.8 exp (-x / 76.7) + 4.0, where y [nm] is the plate thickness deviation in the vibration region of the quartz substrate and x [MHz] is the oscillation frequency.

Description

TECHNICAL FIELD

[0001] The present application relates to a vibration element, a vibrator, and an oscillator. BACKGROUND

[0002] In Patent Literature 1, as a problem to achieve a small piezoelectric vibration element of high frequency in which CI value is small and a parasitic of the vicinity is suppressed by a fundamental wave, a vibration element is disclosed which has a rectangular vibration portion, an L-shaped thick wall portion formed integrally with the vibration portion, and a slit provided on the thick wall portion.

[0003] Patent Literature 1: Japanese Patent Application Laid-Open No. 2014-7693

[0004] Communication devices require faster and larger capacity communication, and the requirements for vibration elements are also advancing to high frequency. On the other hand, as the frequency is higher, the CI value tends to increase and the required performance of the oscillator cannot be satisfied. Therefore, as in the piezoelectric vibration element of Patent Literature 1, only the arrangement of the vibration portion or the thick wall portion is studied, and there is a limit in achieving further high frequency or low CI value. SUMMARY

[0005] The vibration element has a quartz substrate having a vibration portion including a vibration region and a support portion having a thickness larger than the vibration portion, and an excitation electrode provided in the vibration region, and satisfies a relationship of y ≤ 329.8exp(-x / 76.7) + 4.0 when a plate thickness deviation in the vibration region of the quartz substrate is y [nm] and an oscillation frequency is x [MHz].

[0006] The vibrator has the above vibration element, and a container that houses the vibration element.

[0007] The oscillator has the above vibration element, an oscillation circuit that excites the vibration element, and a container that houses the vibration element and the oscillation circuit. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a perspective view showing the structure of the vibration element of the first embodiment.

[0009] Figure 2 is a view explaining the relationship between an AT-cut quartz substrate and crystal axes of quartz.

[0010] Figure 3 is a plan view of the vibration element shown in Figure 1

[0011] Figure 4 is a sectional view at A1-A1 line in Figure 3

[0012] ​​Figure 5 is a graph showing a relationship of an oscillation frequency and a plate thickness deviation in a vibration region.

[0013] Figure 6 is a plan view showing a structure of a vibration element of the second embodiment.

[0014] Figure 7 is a cross-sectional view at A2-A2 line in Figure 6

[0015] Figure 8 is a plan view showing a structure of a vibration element of the third embodiment.

[0016] Figure 9 is a cross-sectional view at A3-A3 line in Figure 8

[0017] Figure 10 is a plan view showing a structure of a vibration element of the fourth embodiment.

[0018] Figure 11 is a cross-sectional view at A4-A4 line in Figure 10

[0019] Figure 12 is a plan view showing a structure of a vibration element of the fifth embodiment.

[0020] Figure 13 is a cross-sectional view at A5-A5 line in Figure 12

[0021] Figure 14 is a plan view showing a structure of a vibration element of the sixth embodiment.

[0022] Figure 15 is a cross-sectional view at A6-A6 line in Figure 14

[0023] Figure 16 is a plan view showing a structure of a vibrator of the seventh embodiment.

[0024] Figure 17 is a cross-sectional view at A7-A7 line in Figure 16

[0025] Figure 18 is a plan view showing a structure of an oscillator of the eighth embodiment.

[0026] Figure 19 is a cross-sectional view at A8-A8 line in Figure 18 Explanation of Reference Signs

[0027]

[0028] ​​​​​​​1, 1a, 1b, 1c, 1d, 1e vibration element; 2 vibrator; 3 oscillator; 10 quartz substrate; 11 vibration portion; 12 support portion; 13 vibration region; 14 one face; 15 another face; 16 connecting portion; 17 connecting portion; 20 container; 21 lid; 22 recess; 23 accommodation space; 24 inner bottom face; 25 pedestal portion; 26 lower face; 27 upper face; 28 internal terminal; 29 external terminal; 31, 32 excitation electrode; 33, 34 pad electrode; 35, 36 lead electrode; 40 container; 41 lid; 42 recess; 43 accommodation space; 44 inner bottom face; 46 lower face; 47 upper face; 48 internal terminal; 49 external terminal; 50, 51, 52 joining member; 60, 61 joining wire; 70 oscillation circuit; 71 circuit terminal; Y approximate curve. DETAILED DESCRIPTION

[0029] 1. First Embodiment

[0030] Reference Figures 1 to 4 The vibration element 1 of the first embodiment will be described.

[0031] In addition, in the following drawings other than Figure 2 , Figure 5 , Figure 18 and Figure 19 , the X axis, the Y' axis, and the Z' axis are illustrated as three axes orthogonal to each other. Furthermore, the length direction of the vibration element 1 is referred to as the "X direction" as the direction along the X axis, the thickness direction of the vibration element 1 is referred to as the "Y' direction" as the direction along the Y' axis, and the direction perpendicular to the X axis and the Y' axis is referred to as the "Z' direction" as the direction along the Z' axis. In addition, the arrow side of each axis is referred to as the "positive side", and the side opposite to the arrow is referred to as the "negative side".

[0032] As shown in Figure 1 , the vibration element 1 of the present embodiment has a quartz substrate 10 having a vibration portion 11 including a vibration region 13 and a support portion 12 having a larger thickness than the vibration portion 11, and excitation electrodes 31, 32 disposed in the vibration region 13.

[0033] The quartz substrate 10 is a plate-shaped substrate. Here, quartz as a material of the quartz substrate 10 belongs to the trigonal system, as shown in Figure 2 , has crystal axes X, Y, Z perpendicular to each other. The X axis, the Y axis, and the Z axis are respectively referred to as the electric axis, the mechanical axis, and the optical axis. The quartz substrate 10 of the present embodiment is a "rotated Y-cut quartz substrate" cut along a plane after rotating the XZ face around the X axis by a prescribed angle θ, and for example, a substrate in the case of cutting along a plane after rotating θ = 35° 15' is referred to as an "AT-cut quartz substrate". By using such a quartz substrate 10, the vibration element 1 having excellent temperature characteristics is obtained.

[0034] However, as the quartz substrate 10, as long as the thickness shear vibration can be excited, it is not limited to the AT-cut quartz substrate, and for example, a BT-cut quartz substrate can also be used.

[0035] Further, hereinafter, the Y axis and the Z axis which are rotated around the X axis in correspondence with the angle Θ are set as a Y' axis and a Z' axis. That is, the quartz substrate 10 has a thickness in the Y' direction and has an extension in the XZ' plane direction.

[0036] The quartz substrate 10 has an elongated shape in which the X direction is a long side and the Z' direction is a short side when viewed from above. Further, the quartz substrate 10 takes the negative X direction as a front end side and takes the positive X direction as a base end side.

[0037] As shown in Figs. 1 and 2, the quartz substrate 10 has a vibration portion 11 including a region in which vibration energy is enclosed, that is, a vibration region 13, and a support portion 12 which is integrated with the vibration portion 11 and has a thickness larger than that of the vibration portion 11. Figure 1 Figure 3 As shown in Figs. 1 and 2, the quartz substrate 10 has a vibration portion 11 including a region in which vibration energy is enclosed, that is, a vibration region 13, and a support portion 12 which is integrated with the vibration portion 11 and has a thickness larger than that of the vibration portion 11.

[0038] The vibration portion 11 is biased toward the negative side of the X direction and the negative side of the Z' direction with respect to the center of the quartz substrate 10, and a part of the outer edge thereof is exposed from the support portion 12. That is, a part of the outer edge of the vibration portion 11 constitutes a part of the outer edge of the quartz substrate 10. When the vibration element 1 is viewed from above, the area of the vibration portion 11 is preferably 1 / 2 or less of the area of the quartz substrate 10. Thereby, the support portion 12 which has high mechanical strength can be formed to be sufficiently wide, and thus the rigidity of the vibration portion 11 can be sufficiently ensured.

[0039] The support portion 12 protrudes on the one face 14 side of the vibration portion 11 than the vibration portion 11. Specifically, as shown in Figs. 1 and 2, the main face of the positive Y' direction side of the support portion 12 is provided to protrude toward the positive Y' direction side than the main face of the positive Y' direction side of the vibration portion 11, that is, the one face 14. On the other hand, the main face of the negative Y' direction side of the support portion 12 is provided on the same plane as the main face of the negative Y' direction side of the vibration portion 11, that is, the other face 15. Figure 1 Figure 3 Figure 4 The support portion 12 has a support portion 12 connected to the outer edge of the positive X direction side of the vibration portion 11 and a support portion 12 connected to the outer edge of the positive Z' direction side of the vibration portion 11. Therefore, the support portion 12 has a configuration in which it is curved along the vibration portion 11 when viewed from above, and has a substantially L shape. Therefore, it is possible to reduce the mass of the front end side of the vibration element 1 while maintaining the rigidity of the vibration portion 11 of the vibration element 1. Further, it is possible to achieve miniaturization of the vibration element 1.

[0040] The support portion 12 has a support portion 12 connected to the outer edge of the positive X direction side of the vibration portion 11 and a support portion 12 connected to the outer edge of the positive Z' direction side of the vibration portion 11. Therefore, the support portion 12 has a configuration in which it is curved along the vibration portion 11 when viewed from above, and has a substantially L shape. Therefore, it is possible to reduce the mass of the front end side of the vibration element 1 while maintaining the rigidity of the vibration portion 11 of the vibration element 1. Further, it is possible to achieve miniaturization of the vibration element 1.

[0041] ​​​The support portion 12 has a connecting portion 16 that connects between the support portion 12 and the vibration portion 11, is provided continuously with the outer edge on the positive side in the Z' direction of the vibration portion 11, and has an inclined portion with a thickness that gradually increases toward the positive Z' direction, and a connecting portion 17 that is provided continuously with the outer edge on the positive side in the X direction of the vibration portion 11, and has an inclined portion with a thickness that gradually increases toward the positive X direction. In addition, the support portion 12 on the connecting portion 17 side becomes a mounting portion, and is fixed to a container or the like using a conductive adhesive or the like.

[0042] A pair of excitation electrodes 31, 32, a pair of pad electrodes 33, 34, and a pair of lead-out electrodes 35, 36 are formed on the quartz substrate 10.

[0043] The excitation electrodes 31, 32 are disposed in the vibration region 13 of the vibration portion 11. The excitation electrode 31 is disposed on one face 14 of the vibration portion 11. On the other hand, the excitation electrode 32 is disposed on the other face 15 of the vibration portion 11 so as to oppose the excitation electrode 31. The excitation electrodes 31, 32 are each a substantially rectangular shape with the X direction as the long side and the Z' direction as the short side.

[0044] The pad electrodes 33, 34 are disposed on the base end portion on the connecting portion 17 side of the support portion 12. The pad electrode 33 is disposed on the one face 14 side of the vibration portion 11. On the other hand, the pad electrode 34 is disposed on the other face 15 side of the vibration portion 11 so as to oppose the pad electrode 33.

[0045] The lead-out electrodes 35, 36 are disposed on the vibration portion 11 and the support portion 12. The lead-out electrode 35 electrically connects the excitation electrode 31 and the pad electrode 33. On the other hand, the lead-out electrode 36 electrically connects the excitation electrode 32 and the pad electrode 34. The lead-out electrodes 35, 36 are disposed so as not to overlap with each other across the quartz substrate 10. Thus, the electrostatic capacitance between the lead-out electrodes 35, 36 can be suppressed.

[0046] Next, in order to achieve further high frequency and low CI value, reference is made to Figure 5 The relationship between the oscillation frequency of the vibration element 1 and the plate thickness deviation in the vibration region 13 is described.

[0047] Figure 5 is a graph in which the plate thickness deviation in the vibration region 13 in which the CI value with respect to the oscillation frequency of the vibration element 1 satisfies a prescribed value is actually measured and plotted, and is a graph showing an approximate curve Y calculated by the least squares method from the three plots.

[0048] When the plate thickness deviation in the vibration region 13 of the quartz substrate 10 is y [nm] and the oscillation frequency is x [MHz], the approximate curve Y satisfies the relationship of y ≤ 329.8 exp(-x / 76.7) + 4.0. In addition, regarding the plate thickness in the vibration region 13 of the quartz substrate 10, the region where the drive electrodes 31, 32 are arranged is measured at an interval of 1.6 μm using a spectroscopic interference laser displacement meter, and the standard deviation Σ of the values is taken as the plate thickness.

[0049] According to Figure 5 , the vibration element 1 having a low CI value can be obtained by setting the plate thickness deviation in the vibration region 13 to the value of the approximate curve Y at each oscillation frequency.

[0050] Further, when the plate thickness deviation in the vibration region 13 is set to 12 nm or less, the vibration element 1 having a low CI value at an oscillation frequency of 285 MHz or less can be obtained.

[0051] Further, when the plate thickness deviation in the vibration region 13 is set to 5 nm or less, the vibration element 1 having a low CI value at an oscillation frequency of 492 MHz or less can be obtained.

[0052] Further, when the plate thickness deviation in the vibration region 13 is set to 4 nm or less, the vibration element 1 having a low CI value at an oscillation frequency of 700 MHz or less can be obtained.

[0053] That is, the vibration element 1 having a low CI value can be obtained by setting the plate thickness deviation in the vibration region 13 to the value of the approximate curve Y or less at each oscillation frequency.

[0054] As described above, the vibration element 1 of the present embodiment satisfies the relationship of y ≤ 329.8 exp(-x / 76.7) + 4.0 when the plate thickness deviation in the vibration region 13 of the quartz substrate 10 is y [nm] and the oscillation frequency is x [MHz], and thus a low CI value can be achieved even at a high frequency. Therefore, the required performance of an oscillator used for a communication device for high-speed large-capacity communication can be satisfied.

[0055] 2. Second Embodiment

[0056] Next, the vibration element 1a of the second embodiment will be described with reference to Figure 6 and Figure 7 .

[0057] The vibration element 1a of the present embodiment is the same as the vibration element 1 of the first embodiment except for the configuration of the quartz substrate 10a. Further, the description will be made focusing on the difference from the above-described first embodiment, the same reference numerals are attached to the same matters and the description thereof will be omitted.

[0058] As described above, the vibration element 1a of the present embodiment satisfies the relationship of y ≤ 329.8 exp(-x / 76.7) + 4.0 when the plate thickness deviation in the vibration region 13 of the quartz substrate 10a is y [nm] and the oscillation frequency is x [MHz], and thus a low CI value can be achieved even at a high frequency. Therefore, the required performance of an oscillator used for a communication device for high-speed large-capacity communication can be satisfied.Figure 6 and Figure 7 As shown in FIG. 1, the vibration element 1a has a quartz substrate 10a having a vibration portion 11 including a vibration region 13 and a support portion 12a having a larger thickness than the vibration portion 11, and drive electrodes 31, 32 disposed in the vibration region 13.

[0059] The support portion 12a protrudes from the vibration portion 11 on one surface 14 side and also protrudes from the vibration portion 11 on the back side of the one surface 14, i.e., the other surface 15 side. That is, the vibration portion 11 is formed by etching the vibration portion 11 from both the one surface 14 and the other surface 15, and thus, the etching amount of the single surface can be reduced, and a vibration element 1a having a small plate thickness deviation of the vibration region 13 can be obtained.

[0060] The support portion 12a has a connecting portion 16a connecting between the support portion 12a and the vibration portion 11, which is continuously provided with the outer edge on the positive side of the Z' direction of the vibration portion 11, and has a sloped portion in which the thickness gradually increases toward the positive Z' direction, a connecting portion 17a which is continuously provided with the outer edge on the positive side of the X direction of the vibration portion 11, and has a sloped portion in which the thickness gradually increases toward the positive X direction, and a connecting portion 18a which is continuously provided with the outer edge on the negative side of the Z' direction of the vibration portion 11, and has a sloped portion in which the thickness gradually increases toward the negative Z' direction.

[0061] The outer edge on the positive side of the X direction, the outer edge on the positive side of the Z' direction, and the outer edge on the negative side of the Z' direction of the vibration portion 11 are connected to the support portion 12a, and a part of the outer edge of the vibration portion 11, i.e., the outer edge on the negative side of the X direction constitutes a part of the outer edge of the quartz substrate 10a. Thus, the rigidity of the vibration portion 11 of the vibration element 1a is further improved.

[0062] In the present embodiment, the support portion 12a is connected to three outer edges of the vibration portion 11, but as in the first embodiment, the support portion 12a can be connected to two outer edges of the vibration portion 11.

[0063] By adopting such a structure, the vibration element 1a has a low CI value at a high frequency, can reduce the plate thickness deviation of the vibration region 13, and can obtain a vibration element 1a in which the rigidity of the vibration portion 11 is further improved.

[0064] 3. Third Embodiment

[0065] Next, the vibration element 1b of the third embodiment will be described with reference to Figure 8 and Figure 9 The vibration element 1b of the third embodiment will be described.

[0066] The vibration element 1b of this embodiment is the same as the vibration element 1 of the first embodiment except for the configuration of the quartz substrate 10b. The same components as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

[0067] As shown in FIG. 1B, the vibration element 1b has a quartz substrate 10b having a vibration portion 11 including a vibration region 13 and a support portion 12b having a larger thickness than the vibration portion 11, and drive electrodes 31, 32 disposed in the vibration region 13. Figure 8 Figure 9 As shown in FIG. 1B, the vibration element 1b has a quartz substrate 10b having a vibration portion 11 including a vibration region 13 and a support portion 12b having a larger thickness than the vibration portion 11, and drive electrodes 31, 32 disposed in the vibration region 13.

[0068] The support portion 12b includes a first support portion 121 disposed along one outer edge of the vibration portion 11, i.e., the positive Z' side outer edge, and a second support portion 122 disposed along the other outer edge of the vibration portion 11, i.e., the negative Z' side outer edge, opposite the one outer edge. The first support portion 121 protrudes from the vibration portion 11 on the side of one face 14, and the second support portion 122 protrudes from the vibration portion 11 on the side of the other face 15 opposite one face 14. That is, the support portion 12b is formed by etching the vibration portion 11 from both faces, and thus the etching amount of each face can be reduced, and a vibration element 1b having a small plate thickness deviation of the vibration region 13 can be obtained.

[0069] The first support portion 121 and the vibration portion 11 are connected by a connecting portion 16b continuously provided with the outer edge 111 of the vibration portion 11 on the positive Z' side and having a sloped portion in which the thickness gradually increases toward the positive Z' direction. In addition, the support portion 12b and the vibration portion 11 are connected by a connecting portion 17b continuously provided with the outer edge of the vibration portion 11 on the positive X' side and having a sloped portion in which the thickness gradually increases toward the positive X' direction. The second support portion 122 and the vibration portion 11 are connected by a connecting portion 18b continuously provided with the outer edge 112 of the vibration portion 11 on the negative Z' side and having a sloped portion in which the thickness gradually increases toward the negative Z' direction. Thus, the vibration region 13 of the vibration portion 11 can be enlarged.

[0070] Only a portion of the outer edge of the vibration portion 11, i.e., the outer edge on the negative X' side, constitutes a portion of the outer edge of the quartz substrate 10b. Thus, the rigidity of the vibration portion 11 of the vibration element 1b is further improved.

[0071] By adopting such a configuration, the vibration element 1b has a low CI value at high frequencies, the plate thickness deviation of the vibration region 13 can be reduced, the vibration region 13 of the vibration portion 11 can be enlarged, and a vibration element 1b having further improved rigidity of the vibration portion 11 can be obtained.

[0072] 4. Fourth Embodiment ​

[0073] Next, the vibration element 1c of the fourth embodiment will be described with reference to Figure 10 and Figure 11 The vibration element 1c of the fourth embodiment will be described.

[0074] The vibration element 1c of the present embodiment is the same as the vibration element 1 of the first embodiment except for the configuration of the quartz substrate 10c. Further, the same reference numerals are attached to the same matters and the description thereof is omitted, focusing on the difference from the first embodiment described above.

[0075] As shown in Figure 10 and Figure 11 , the vibration element 1c has a quartz substrate 10c having a vibration portion 11 including a vibration region 13 and a support portion 12c having a larger thickness than the vibration portion 11, and drive electrodes 31, 32 disposed in the vibration region 13.

[0076] The support portion 12c protrudes on the one surface 14 side of the vibration portion 11.

[0077] Further, the support portion 12c has a connecting portion 16c connecting between the support portion 12c and the vibration portion 11, which is continuously provided with the outer edge on the positive side of the Z' direction of the vibration portion 11, and has a slope portion having a thickness gradually increasing toward the positive Z' direction, a connecting portion 17c which is continuously provided with the outer edge on the positive side of the X direction of the vibration portion 11, and has a slope portion having a thickness gradually increasing toward the positive X direction, and a connecting portion 18c which is continuously provided with the outer edge on the negative side of the X direction of the vibration portion 11, and has a slope portion having a thickness gradually increasing toward the negative X direction.

[0078] The outer edge on the positive side of the Z' direction, the outer edge on the positive side of the X direction, and the outer edge on the negative side of the X direction of the vibration portion 11 are connected to the support portion 12c, and a part of the outer edge of the vibration portion 11, that is, the outer edge on the negative side of the Z' direction constitutes a part of the outer edge of the quartz substrate 10c. Therefore, the rigidity of the vibration portion 11 of the vibration element 1c is further improved.

[0079] In the present embodiment, the vibration portion 11 is formed by etching from the one surface 14 side, but it can also be formed by etching from the other surface 15 side at the same time as in the second and third embodiments.

[0080] By adopting such a structure, the vibration element 1c has a low CI value at a high frequency, and a vibration element 1c having further improved rigidity of the vibration portion 11 can be obtained.

[0081] 5. Fifth Embodiment

[0082] Next, the vibration element 1c of the fourth embodiment will be described with reference to Figure 12 and Figure 13The vibration element 1d of the fifth embodiment will be described.

[0083] The vibration element 1d in this embodiment is the same as the vibration element 1 in the first embodiment, except that the structure of the quartz substrate 10d is different. Furthermore, the description will focus on the differences from the first embodiment described above, and identical items will be labeled with the same reference numerals and their descriptions will be omitted.

[0084] like Figure 12 and Figure 13 As shown, the vibration element 1d includes: a quartz substrate 10d having a vibration portion 11 including a vibration region 13 and a support portion 12d with a thickness greater than that of the vibration portion 11; and excitation electrodes 31 and 32, which are disposed in the vibration region 13.

[0085] The support portion 12d protrudes beyond the vibrating portion 11 on one side 14 of the vibrating portion 11.

[0086] Furthermore, the support portion 12d has a connecting portion 17d, which connects the support portion 12d and the vibration portion 11. It is continuously provided with the outer edge of the positive X-direction side of the vibration portion 11 and has an inclined portion with a thickness that gradually increases in the positive X-direction.

[0087] The outer edge of the vibrating part 11 on the positive side in the X direction is connected to the support part 12d. A portion of the outer edge of the vibrating part 11, namely the outer edge on the positive side in the Z' direction, the outer edge on the negative side in the X direction, and the outer edge on the negative side in the Z' direction, constitutes a portion of the outer edge of the quartz substrate 10d. Therefore, the vibration region 13 of the vibrating part 11 can be expanded.

[0088] In addition, in this embodiment, the vibration part 11 is formed by etching from one side of surface 14. However, as in the second and third embodiments, the vibration part 11 can also be formed by etching from the other side of surface 15 at the same time.

[0089] By adopting such a structure, the vibrating element 1d has a low CI value at high frequencies, and a vibrating element 1d with a wider vibration region 13 of the vibrating part 11 can be obtained.

[0090] 6. Sixth Implementation Method

[0091] Next, refer to Figure 14 and Figure 15 The vibration element 1e of the sixth embodiment will be described.

[0092] The vibration element 1e of the present embodiment is the same as the vibration element 1 of the first embodiment except for the configuration of the quartz substrate 10e. In addition, the same reference numerals are attached to the same matters and the description thereof is omitted, with the focus on the differences from the first embodiment.

[0093] As shown in Figure 14 and Figure 15 , the vibration element 1e has a quartz substrate 10e having a vibration portion 11 including a vibration region 13 and a support portion 12e having a larger thickness than the vibration portion 11, and drive electrodes 31, 32 disposed in the vibration region 13.

[0094] The support portion 12e protrudes on the one face 14 side of the vibration portion 11.

[0095] In addition, the support portion 12e surrounds the vibration portion 11 in plan view. That is, the support portion 12e has a connecting portion 16e connecting between the support portion 12e and the vibration portion 11, which is continuously provided with the outer edge on the positive side of the Z' direction of the vibration portion 11, and has a slope portion having a thickness gradually increasing toward the positive Z' direction, a connecting portion 17e which is continuously provided with the outer edge on the positive side of the X direction of the vibration portion 11, and has a slope portion having a thickness gradually increasing toward the positive X direction, a connecting portion 18e which is continuously provided with the outer edge on the negative side of the X direction of the vibration portion 11, and has a slope portion having a thickness gradually increasing toward the negative X direction, and a connecting portion 19e which is continuously provided with the outer edge on the negative side of the Z' direction of the vibration portion 11, and has a slope portion having a thickness gradually increasing toward the negative Z' direction. Thus, the rigidity of the vibration portion 11 of the vibration element 1e is further improved.

[0096] In addition, in the present embodiment, the vibration portion 11 is formed by etching from the one face 14 side, but it can also be formed by etching from the other face 15 side at the same time as in the second and third embodiments.

[0097] By adopting such a structure, the vibration element 1e has a low CI value at a high frequency, and a vibration element 1e having further improved rigidity of the vibration portion 11 can be obtained.

[0098] 7. Seventh Embodiment

[0099] Next, the vibrator 2 of the seventh embodiment will be described with reference to Figure 16 and Figure 17 In the present description, the vibrator 2 having the above vibration element 1 is exemplified as an example. In addition, in Figure 16 , the state in which the cover 21 is removed is illustrated in order to facilitate the description of the internal structure of the vibrator 2.

[0100] As shown in Figure 16 andFigure 17 As shown, the vibrator 2 has the vibration element 1, a container 20 that houses the vibration element 1, and a lid 21 that forms a housing space 23 with the container 20.

[0101] The container 20 has a recess 22 that is open to the lid 21 side, and the lid 21 that closes the opening of the recess 22 is joined to the upper surface 27. By closing the recess 22 of the container 20 with the lid 21, the housing space 23 that houses the vibration element 1 is formed. The housing space 23 can be in a reduced pressure or vacuum state, or can be sealed with an inert gas such as nitrogen (N), helium (He), argon (Ar), or the like.

[0102] As a material for the container 20, various ceramics such as alumina can be used without particular limitation. Also, as a material for the lid 21, a member having a linear expansion coefficient similar to that of the material for the container 20 can be used without particular limitation. Also, the joining of the container 20 and the lid 21 is not particularly limited, and can be performed via an adhesive, or by seam welding or the like.

[0103] An internal terminal 28 is formed on the inner bottom surface 24 of the container 20, and the internal terminal 28 is formed on a pedestal portion 25 that protrudes from the inner bottom surface 24 toward the lid 21. Also, a plurality of external terminals 29 are formed on the lower surface 26 of the container 20. The internal terminal 28 on the inner bottom surface 24 is electrically connected to the external terminal 29 via a through electrode not shown that is formed in the container 20, and the internal terminal 28 on the pedestal portion 25 is electrically connected to the external terminal 29 via a through electrode not shown that is formed in the container 20.

[0104] The vibration element 1 housed in the housing space 23 has one face 14 of the vibration portion 11 facing the inner bottom surface 24 of the container 20, and is fixed to the container 20 at the support portion 12 by a joining member 50 that is a conductive adhesive. The joining member 50 is provided so as to be in contact with the internal terminal 28 and the pad electrode 33. Thus, the internal terminal 28 and the pad electrode 33 are electrically connected via the joining member 50. By supporting the vibration element 1 at one or a point using the joining member 50, stress that occurs in the vibration element 1 due to a difference in thermal expansion rate between the container 20 and the quartz substrate 10, for example, can be suppressed.

[0105] The pad electrode 34 of the vibration element 1 is electrically connected to the internal terminal 28 via a wire 60. As described above, the pad electrode 34 is arranged in opposition to the pad electrode 33, and thus is located directly above the joining member 50 in a state in which the vibration element 1 is fixed to the container 20. Thus, leakage of ultrasonic vibrations applied to the pad electrode 34 at the time of wire bonding can be suppressed, and connection of the wire 60 and the pad electrode 34 can be performed more reliably.

[0106] By adopting such a structure, the oscillator 2 has a high-frequency and low-CI value vibration element 1, thus, it is possible to obtain an oscillator 2 with a high-frequency and low-CI value.

[0107] Furthermore, in the seventh embodiment, various ceramics are described as constituent materials of the container 20 and the lid 21, but it is not limited to these; a semiconductor substrate may also be used.

[0108] 8. Implementation Method 8

[0109] Next, refer to Figure 18 and Figure 19 The oscillator 3 of the eighth embodiment will be described. Furthermore, in this description, an oscillator 3 equipped with an oscillator 2 having the aforementioned vibrating element 1 will be given as an example. Figure 18 In the diagram, to facilitate explanation of the internal structure of the oscillator 3, the state with cover 41 removed is shown. Furthermore, in... Figure 19 In the above, the cross-sectional structure of oscillator 2 is as described. Figure 17 The explanation is provided in the text, therefore, the illustration is omitted.

[0110] like Figure 18 and Figure 19 As shown, the oscillator 3 has: an oscillator 2 having a vibrating element 1; an oscillating circuit 70 that excites the vibrating element 1; a container 40 that houses the oscillator 2 and the oscillating circuit 70; and a cover 41 that forms a storage space 43 with the container 40.

[0111] The container 40 has a recess 42 that opens toward the lid 41, and the lid 41, which closes the opening of the recess 42, is joined on the upper surface 47. By closing the recess 42 of the container 40 with the lid 41, a storage space 43 for accommodating the oscillator 2 and the oscillation circuit 70 is formed.

[0112] There are no particular limitations on the material used to construct the container 40; various ceramics such as alumina can be used. Similarly, there are no particular limitations on the material used to construct the lid 41. Furthermore, there are no particular limitations on the joining method between the container 40 and the lid 41; for example, they can be joined using an adhesive or by seam welding.

[0113] A plurality of internal terminals 48 are formed on the inner bottom surface 44 of the container 40. Additionally, a plurality of external terminals 49 are formed on the lower surface 46 of the container 40. Among the internal terminals 48 on the inner bottom surface 44, those disposed around the oscillation circuit 70 (viewed from above) are electrically connected to the external terminals 49 via wiring or through electrodes (not shown) formed in the container 40. Furthermore, internal terminals 48 disposed at positions overlapping with the oscillator 2 (viewed from above) are electrically connected to internal terminals 48 disposed around the oscillation circuit 70 via wiring (not shown).

[0114] The vibrator 2 housed in the housing space 43 is fixed to the container 40 at the external terminal 29 by a conductive adhesive or a solder or the like as a joining member 51. The external terminal 29 and the internal terminal 48 are electrically connected via the joining member 51.

[0115] The oscillation circuit 70 housed in the housing space 43 is fixed to the container 40 by an adhesive or the like as a joining member 52. A plurality of circuit terminals 71 are provided on the side of the cover 41 of the oscillation circuit 70, and the circuit terminals 71 are electrically connected to the internal terminals 48 arranged around the oscillation circuit 70 via the bonding wires 61. Some of the circuit terminals 71 are electrically connected to the external terminals 29 of the vibrator 2 via the internal terminals 48, and thus the vibration element 1 can be excited. In addition, some of the circuit terminals 71 are electrically connected to the external terminals 49 via the internal terminals 48, and thus power can be input from the external terminals 49, and the oscillation frequency output from the oscillation circuit 70 can be output from the external terminals 49.

[0116] By adopting such a structure, the oscillator 3 has the vibration element 1 having a high frequency and a low CI value, and thus an oscillator 3 having a high frequency and excellent oscillation characteristics can be obtained.

[0117] In addition, in the eighth embodiment, the vibrator 2 having the vibration element 1 housed in the container 20 is fixed to the container 40, but a configuration in which the vibration element 1 itself is mounted to the container 40 can also be adopted. In addition, although not shown, as the container 40, a semiconductor substrate formed with the oscillation circuit 70 can also be used. By mounting the vibration element 1 on this semiconductor substrate, a space for the oscillation circuit 70 in the housing space 43 is not required, and the oscillator 3 can be made smaller.

Claims

1. A vibrating element, comprising: A quartz substrate having a vibrating portion including a vibration region and a support portion with a thickness greater than the vibrating portion; and An excitation electrode is disposed in the vibration region. When the thickness deviation of the quartz substrate in the vibration region is y [nm] and the oscillation frequency is x [MHz], the relationship y ≤ 329.8exp(-x / 76.7) + 4.0 is satisfied.

2. The vibration element according to claim 1, wherein, The plate thickness deviation is below 12nm, and the oscillation frequency is below 285MHz.

3. The vibration element according to claim 1, wherein, The plate thickness deviation is less than 5 nm, and the oscillation frequency is less than 492 MHz.

4. The vibration element according to claim 1, wherein, The plate thickness deviation is less than 4 nm, and the oscillation frequency is less than 700 MHz.

5. The vibrating element according to any one of claims 1 to 4, wherein, The support portion protrudes beyond the vibrating portion on one side of the vibrating portion.

6. The vibration element according to claim 5, wherein, The support portion also protrudes beyond the vibrating portion on the back side of one surface, i.e., on the other surface side.

7. The vibrating element according to any one of claims 1 to 4, wherein, The support portion includes: A first support portion, which is disposed along one outer edge of the vibrating portion; and The second support portion is configured relative to the vibrating portion along another outer edge on the opposite side of the first outer edge. The first support portion protrudes beyond one side of the vibrating portion. The second support portion protrudes beyond the vibrating portion on the other side of the back side of one surface.

8. The vibrating element according to any one of claims 1 to 4, wherein, A portion of the outer edge of the vibrating part constitutes a portion of the outer edge of the quartz substrate.

9. The vibrating element according to any one of claims 1 to 4, wherein, The support surrounds the vibrating part when viewed from above.

10. An oscillator having: The vibrating element according to any one of claims 1 to 4; and A container that houses the vibrating element.

11. An oscillator having: The vibrating element according to any one of claims 1 to 4; An oscillating circuit that excites the vibrating element; and A container that houses the vibrating element and the oscillation circuit.

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