MEMS resonator

Abstract

We provide MEMS resonators that are highly efficient and offer a high degree of design freedom. [Solution] The MEMS resonator includes a parallelogram pantograph, vibrators connected to the vertices of the pantograph, and electrodes arranged opposite each vibrator to form a capacitance element together with the vibrator. Voltages that are 180° out of phase with each other are applied to the electrodes arranged opposite the vibrators on extensions of different diagonal lines of the pantograph. At least two MEMS resonators may be connected so as to share one vibrator.

Description

[Technical Field]

[0001] The present invention relates to a MEMS resonator, and more particularly to a MEMS resonator that can be made smaller and more efficient. [Background technology]

[0002] In recent years, highly reliable and miniaturizable MEMS resonators have been put to practical use as an alternative to conventional quartz crystal resonators. One example of a MEMS resonator has a structure with cross-shaped beams extending in four directions from a connection point, and a ring-shaped vibrator at the end of each beam. The vibrators repeatedly expand and contract simultaneously, causing the entire MEMS resonator to vibrate at a predetermined resonant frequency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-134376

[0004] [overview] However, in conventional MEMS resonators, in order for the entire MEMS resonator to resonate efficiently at a specified resonant frequency, the length of the beam connecting the vibrators had to be set to an integer multiple of half the resonant wavelength. Furthermore, because the four vibrators expand and contract simultaneously, the beam connecting the vibrators repeatedly compresses and stretches, consuming energy. Another problem was that feedthrough occurs due to parasitic capacitance with the package and wiring, making it difficult to see changes in the resonator's capacitance.

[0005] Therefore, an object of the present disclosure is to provide a highly efficient MEMS resonator with a high degree of freedom in design.

[0006] One aspect of the present disclosure is A parallelogram pantograph, Vibrators connected to the apexes of the pantograph, The MEMS resonator includes electrodes arranged opposite each of the vibrators and constituting a capacitance element together with the vibrators.

[0007] Another aspect of the present disclosure is This is a MEMS resonator in which voltages with a phase difference of 180° are applied to the electrodes arranged opposite to each other on vibrators on the extensions of different diagonals of a parallelogram pantograph. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view of a MEMS resonator according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line IIA-IIB in FIG. [Figure 3] 4 shows the driving voltage of the MEMS resonator according to the first embodiment of the present invention. [Figure 4] FIG. 2 is a plan view illustrating the operation of the MEMS resonator according to the first embodiment of the present invention. [Figure 5] FIG. 10 is a plan view of a MEMS resonator according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along line IVA-IVB in FIG. 5. [Figure 7] FIG. 10 is a plan view of a MEMS resonator according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a plan view of a MEMS resonator according to a fourth embodiment of the present invention. [Figure 9] FIG. 10 is a plan view of a MEMS resonator according to a fifth embodiment of the present invention. [Figure 10] FIG. 10 is a plan view of a MEMS resonator according to a sixth embodiment of the present invention. [Figure 11] FIG. 13 is a plan view showing an application example of the MEMS resonator according to the seventh embodiment of the present invention. [Figure 12] FIG. 13 is a plan view of a MEMS resonator according to an eighth embodiment of the present invention. [Figure 13] 10 is a diagram showing a modified example of the pantograph of the MEMS resonator according to the first to eighth embodiments of the present invention.

[0009] [Detailed explanation] <First Embodiment> FIG. 1 is a plan view of a MEMS resonator generally designated by 100 according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line IIA-IIB in FIG.

[0010] The MEMS resonator 100 includes a square pantograph 10. Beams 20 are provided at the four vertices of the pantograph 10 on extensions of the diagonals of the square, and ring-shaped vibrators 30A to 30D are connected to the ends of the beams. Furthermore, arc-shaped external electrodes 40A to 40D are provided around the vibrators 30A to 30D so as to surround the vibrators 30A to 30D at a fixed distance. The vibrators 30A to 30D and the external electrodes 40A to 40D form capacitance elements.

[0011] The beams 20, vibrators 30A to 30D, and external electrodes 40A to 40D are arranged at positions that are four-fold rotationally symmetric with respect to the central axis O in the Z-axis direction of the square pantograph 10. That is, the vibrators 30A to 30D are connected equidistantly from each vertex of the square by beams 20 that are arranged on extensions of the diagonals of the square. The pantograph 10, beams 20, vibrators 30A to 30D, and external electrodes 40A to 40D are formed by etching a substrate 50 made of, for example, silicon.

[0012] A recess 120 is provided in the substrate 50, and the pantograph 10, beam 20, and vibrators 30A to 30D are held in midair above the recess 120 by anchors 130, and the external electrodes 40A to 40D are held in midair above the recess 120 by anchors 130, 140. Insulating isolation joints (IJ) 135, 145 made of, for example, silicon oxide are inserted in the middle of the anchors 130, 140, and provide electrical insulation between the substrate 50 and the pantograph 10, beam 20, and vibrators 30A to 30D, and between the substrate 50 and the external electrodes 40A to 40D.

[0013] As shown in FIG. 2, the surface of the substrate 50 is covered with a surface oxide film 150 made of, for example, silicon oxide. Electrodes 160, 170, 180, 190, and 197 are provided on the surface oxide film 150. The electrode 160 is connected to the external electrode 40A via a wiring layer 165. The electrode 170 is connected to the pantograph 10, the beam 20, and the vibrators 30A to 30D via a wiring layer 175. The electrode 180 is connected to the external electrode 40B via a wiring layer 185. The electrode 190 is connected to the external electrode 40D via a wiring layer 195. The electrode 197 is connected to the external electrode 40C via a wiring layer 199. The electrodes 160, 170, 180, 190, and 197 and the wiring layers 165, 175, 185, 195, and 199 are made of, for example, copper. Note that the surface oxide film 150 is omitted from FIG. 1.

[0014] Next, the operation of the MEMS resonator 100 shown in Fig. 1 will be described with reference to Figs. 3 and 4. Fig. 3 shows voltages applied to the external electrodes 40A and 40B from the electrodes 160 and 180 of the MEMS resonator 100 in Fig. 1, where A indicates the voltage applied to the external electrode 40A and B indicates the voltage applied to the external electrode 40B. A constant voltage of 18V is applied to the pantograph 10, the beam 20, and the vibrators 30A to 30D from the electrode 170. The electrodes 190 and 197 are used as detection electrodes.

[0015] 3, AC voltages of opposite phases are applied to adjacent external electrodes 40A and 40B rotated 90° and ranging from 0 V to ±0.1 V. As a result, for example, if vibrator 30B is fixed at 18 V, +0.1 V is applied to external electrode 40A, and −0.1 V is applied to external electrode 40B, a large electrostatic attractive force is generated by the capacitance element formed by external electrode 40B and vibrator 30B, and vibrator 30B is pulled toward external electrode 40B and expands. As a result, pantograph 10 contracts in the X direction and extends in the Y direction via beam 20, promoting the contraction of 30A and 30C.

[0016] 4 shows the deformation of pantograph 10 in this state, with vibrator 30B pushing and deforming pantograph 10 in the 30B direction. As a result, vibrator 30A is pushed out in the 30A direction via beam 20. When the applied voltage is reversed, vibrator 30A is pulled by external electrode 40A, and pantograph 10 deforms accordingly.

[0017] In this way, by applying voltages of opposite phases to the adjacent external electrodes 40A and 40B, it is possible to vibrate the vibrators 30A and 30B at a predetermined resonant frequency. Although a sine wave is used in Fig. 3, waves of other waveforms such as a square wave or a triangular wave may also be used (the same applies to the following embodiments).

[0018] In particular, deformation of the pantograph 10 suppresses deformation of the beam 20 as in the conventional case, and energy consumption due to deformation of the beam 20 can be prevented.

[0019] Although the case where voltages of opposite phases are applied between adjacent external electrodes 40A and 40B has been described here, voltages of opposite phases may also be applied between external electrodes 40A, 40C and external electrodes 40B, 40D (external electrodes 40A, 40C are at the same potential, and external electrodes 40B, 40D are also at the same potential).

[0020] 1, when electrodes 190 and 197 are used as detection electrodes, a differential amplifier is connected to detect a signal via, for example, capacitance-to-voltage conversion circuits (C / V) connected to electrodes 190 and 197, respectively. In MEMS resonator 100, as described above, an AC voltage for resonating vibrator 30A is applied to electrode 160. As a result, a capacitance change due to vibration of vibrator 30C is input to one input terminal of the differential amplifier via the capacitance-to-voltage conversion circuit (C / V) connected to electrode 197 (not shown). On the other hand, a capacitance change due to vibration of vibrator 30D is input to the other input terminal of the differential amplifier via the capacitance-to-voltage conversion circuit (C / V) connected to electrode 190 (not shown).

[0021] Here, a portion of the AC voltage is superimposed on electrode 197 due to parasitic capacitance C1 between electrode 160 and electrode 197. This phenomenon is called feedthrough, and makes it difficult to see the change in capacitance due to the vibration of vibrator 30C. Similarly, feedthrough also occurs due to parasitic capacitance C2 between electrode 160 and electrode 190, and a portion of the AC voltage is superimposed on electrode 190, making it difficult to see the change in capacitance due to the vibration of vibrator 30D.

[0022] In MEMS resonator 100 according to the first embodiment of the present invention, vibrators 30C and 30D vibrate in opposite phases, whereas the two feedthroughs described above are superimposed in the same phase on electrodes 197 and 190. Therefore, at the output of the differential amplifier, signals due to the vibration of vibrators 30C and 30D are amplified, while feedthrough signals are canceled out and reduced. In particular, when C1=C2, the feedthrough signals are completely canceled out.

[0023] As described above, in the MEMS resonator 100 according to the first embodiment of the present invention, the occurrence of feedthrough can be suppressed and detection sensitivity can be improved by using the pantograph 10. Note that, for simplicity, the description has been given ignoring the application of AC voltage to the vibrator 30B, but the feedthrough is also similarly canceled out for the input signal to the vibrator 30B.

[0024] <Embodiment 2> Fig. 5 is a plan view of a MEMS resonator according to a second embodiment of the present invention, generally designated 200, and Fig. 6 is a cross-sectional view taken along line VIA-VIB in Fig. 1. In Figs. 5 and 6, the same reference numerals as in Figs. 1 and 2 indicate the same or corresponding parts. In Fig. 5, the lid 250 is omitted to make the structure easier to understand.

[0025] In the MEMS resonator 200 according to the second embodiment, circular internal electrodes 60A-60D are further provided inside the ring-shaped vibrators 30A-30D. Bumps 210 for connection to the wiring layer 230 (see FIG. 6) of the lid 250 are provided on the internal electrodes 60A-60D and the wiring layers 165, 185, 195, and 199. The bumps 210 are made of, for example, Au—Au, AlGe, Cu—Cu, or AuSn. The other structures and operations are similar to those of the MEMS resonator 100.

[0026] In the MEMS resonator 200, similarly to the MEMS resonator 100, voltages of opposite phases are applied between adjacent external electrodes 40A to 40D, and voltages of opposite phases are also applied between the external electrodes 40A to 40D and the internal electrodes 60A to 60D.

[0027] Specifically, a voltage shown in A of FIG. 3 is applied to the external electrodes 40B, 40D and the internal electrodes 60A, 60C, and a voltage shown in B of FIG. 3, which is in the opposite phase to the voltage shown in A of FIG. 3, is applied to the external electrodes 40A, 40C and the internal electrodes 60B, 60D.

[0028] 6, the internal electrodes 60A to 60D are formed as a structure connected to the bottom surface of the recess 120 in the process of etching the recess 120 in the substrate 50. The internal electrode 60A is insulated from the substrate 50 by a ring-shaped isolation joint (IJ) 137, and is connected to the wiring layer 230 of the lid 250 via the wiring layer 177 and bumps 210, and a predetermined voltage is applied to it. The same applies to the other internal electrodes 60B, etc.

[0029] In this way, by providing the internal electrodes 60A to 60D in addition to the external electrodes 40A to 40D, the vibrators 30A to 30D can be vibrated more efficiently.

[0030] Here, the internal electrodes 60A to 60D are circular, but they may be ring-shaped. Also, although the isolation joint (IJ) 137 is used to insulate the internal electrodes 60A to 60D from the substrate 50, an SOI substrate may be used as the substrate 50, and the internal electrodes 60A to 60D may be insulated from the substrate by an insulating layer (insulator) of the SOI substrate.

[0031] <Third Embodiment> Fig. 7 is a plan view of a MEMS resonator according to a third embodiment of the present invention, generally designated 300. In Fig. 7, the same reference numerals as in Figs. 1 and 2 indicate the same or corresponding parts, and the substrate 50, recess 120, anchors 130, 140, etc. are omitted.

[0032] In the MEMS resonator 300 according to the third embodiment, vibrators 30A to 30D are directly connected to the four vertices of the pantograph 10 without using beams.

[0033] In the MEMS resonator 300 according to the third embodiment, the length of the beam is not limited to an integral multiple of half the resonant wavelength as in conventional MEMS resonators, and therefore it is possible to eliminate the beam as shown in FIG.

[0034] In this way, by directly connecting the vibrators 30A to 30D and the pantograph 10, the vibration efficiency is improved and the resonator can be made smaller.

[0035] <Fourth Embodiment> Fig. 8 is a plan view of a MEMS resonator according to a fourth embodiment of the present invention, generally designated 400. In Fig. 8, the same reference numerals as in Figs. 1 and 2 indicate the same or corresponding parts, and the substrate 50, recess 120, anchors 130, 140, etc. are omitted.

[0036] In the MEMS resonator 400 according to the fourth embodiment, arc-shaped beam extensions 25A-25D are provided along the vibrators 30A-30D at the ends of the beams extending from the four vertices of the pantograph 10. Furthermore, the beam extensions 25A-25D and the vibrators 30A-30D are connected by a plurality of connection portions 27A-27D. It is preferable that the intervals between the vibrators 30A-30D and the beam extensions 25A-25D are constant.

[0037] Beam extension portions 25A to 25D and connection portions 27A to 27D are formed by etching substrate 50, similar to pantograph 10, and are held in the air above recess 120. Other structures and operations are the same as those of MEMS resonator 100.

[0038] By providing beam extension portions 25A-25D and connection portions 27A-27D in this manner, when vibrators 30A-30D contract, for example, vibrators 30A-30D themselves are less likely to deform because vibrators 30A-30D are connected to beam extension portions 25A-25D via multiple connection portions 27A-27D. As a result, the contraction of vibrators 30A-30D acts as a translational motion, pulling on beam 20, and vibrations can be efficiently transmitted to pantograph 10.

[0039] 8, five connecting portions 27A to 27D are provided for each beam extension portion 25A to 25D, but the number is not limited to five as long as the vibrators 30A to 30D and the beam extension portion 25A to 25D are connected at multiple locations. Note that the multiple connecting portions 27A to 27D are preferably provided at equal intervals between the vibrators 30A to 30D and the beam extension portion 25A to 25D.

[0040] <Fifth Embodiment> Fig. 9 is a plan view of a MEMS resonator according to a fifth embodiment of the present invention, generally designated 500. In Fig. 9, the same reference numerals as in Fig. 7 indicate the same or corresponding parts, and the substrate 50, recess 120, anchors 130, 140, etc. are omitted.

[0041] In MEMS resonator 500 according to the fifth embodiment, vibrators 530A to 530D are directly connected to the four vertices of pantograph 10 without using beams, and vibrators 530A to 530D have a circular shape instead of a ring shape. Other structures and operations are the same as those of MEMS resonator 300 shown in FIG.

[0042] Such vibrators 530A to 530D can be formed as a structure connected to the bottom surface of recess 120, similar to internal electrodes 60A to 60D in Figure 5, and in such a structure, anchor 130 that holds vibrators 530A to 530D and pantograph 10 can be omitted.

[0043] <Sixth Embodiment> Fig. 10 is a plan view of a MEMS resonator according to a sixth embodiment of the present invention, generally designated 600. In Fig. 10, the same reference numerals as in Fig. 1 indicate the same or corresponding parts, and the substrate 50, recess 120, anchors 130, 140, etc. are omitted.

[0044] In the MEMS resonator 600 according to the fifth embodiment, instead of the vibrators 30B and 30D and the external electrodes 40B and 40D of the MEMS resonator 100 according to the first embodiment, comb-tooth vibrators 630B and 630D and external electrodes 640B and 640D are used, which are arranged opposite to each other. That is, a capacitance element is formed by the comb-tooth external electrode 640B arranged in parallel and the comb-tooth vibrator 630B arranged parallel to be sandwiched therebetween (the external electrode 640D and the vibrator 630D also have the same structure). The comb-tooth vibrators 630B and 630D and the external electrodes 640B and 640D are supported in midair above a recess 120 formed in the substrate 50. Other structures and operations are the same as those of the MEMS resonator 100 shown in FIG.

[0045] In the MEMS resonator 600, voltages of opposite phases are applied to the external electrodes 40A and 40C and the external electrodes 640B and 640D within a range of ±0.1 V centered around 18 V. As a result, when, for example, +0.1 V is applied to the external electrodes 40A and 40C and −0.1 V is applied to the external electrodes 640B and 640D, a large electrostatic attractive force is generated by the comb-tooth-shaped capacitance elements formed by the external electrode 640B and the vibrator 630B, and the external electrode 640D and the vibrator 630D, and the vibrators 630B and 630D are pulled toward the external electrodes 640B and 640D. As a result, the pantograph 10 is also pulled via the beam 20. Furthermore, the vibrators 30A and 30C are pulled inward via the beam 20.

[0046] In this way, it is possible to configure a MEMS resonator using capacitance elements consisting of comb-shaped external electrodes and a vibrator. In Figure 10, two capacitance elements have a comb-shaped structure, but it is also possible for all capacitance elements to have a comb-shaped structure.

[0047] <Seventh Embodiment> Fig. 11 is a plan view showing an application example of a MEMS resonator according to a seventh embodiment of the present invention, generally designated 700. In Fig. 11, the same reference numerals as in Fig. 1 indicate the same or corresponding parts, and the substrate 50, recess 120, anchors 130, 140, etc. are omitted.

[0048] 1 further includes a beam 720 branched from the beam 20, and a DC voltage circuit 750 including a switching unit 770. The beam 720 and the switching unit 770 can be formed by etching the substrate 50. The beam 720 is formed so as to be continuous with the beam 20 and held in the air, for example, and the switching unit 770 is formed from a counter electrode held in the air, for example.

[0049] As with the MEMS resonator 100, applying voltages of opposite phases to adjacent external electrodes 40A and 40B causes the vibrator 30A to repeatedly expand and contract. When the vibrator 30A expands and the vibrator 30B contracts, the pantograph 10 deforms as shown in FIG. 4, turning the switching unit 770 on (for example, bringing the opposing electrodes into contact). Conversely, when the vibrator 30A contracts and the vibrator 30B expands, the pantograph 10 deforms so as to be pulled toward the vibrator 30A, turning the switching unit 770 off (for example, separating the opposing electrodes).

[0050] By using the MEMS resonator 700, the voltage of the DC voltage circuit 750 can be turned on and off in accordance with the vibration frequency of the vibrator, and the DC voltage can be converted into an AC voltage of a predetermined frequency.

[0051] <Embodiment 8> 12 is a plan view showing an application example of a MEMS resonator according to an eighth embodiment of the present invention, the whole of which is denoted by 800. In the MEMS resonator 800, for example, the MEMS resonators 100 according to the first embodiment are connected together to form the MEMS resonator (MEMS resonator connection structure) 800 as a whole.

[0052] Specifically, the MEMS resonators 100 are connected in the X-axis direction and the Y-axis direction so that adjacent MEMS resonators 100 share an oscillator, as shown in Fig. 12. Note that external electrodes, anchors, etc. are omitted from Fig. 12.

[0053] In the MEMS resonator 800 of FIG. 12, voltages of opposite phases are applied to the vibrators at coordinates (2,0), (0,2), (2,2), (4,2), and (2,4) and to the vibrators at coordinates (1,1), (3,1), (1,3), and (3,3). For example, if the former vibrators expand and the latter vibrators contract, all pantographs are deformed so as to be pulled in the X-axis direction as shown in FIG. 3. If the applied voltage is reversed by 180°, the pantographs are deformed so as to be pulled in the Y-axis direction. By alternately expanding and contracting the former and latter vibrators, the MEMS resonator 800 can be vibrated at a constant vibration frequency.

[0054] In the MEMS resonator 800 according to the eighth embodiment, a larger resonance signal can be obtained by connecting a plurality of MEMS resonators and resonating them. In particular, since there is no limit to the length of the beam connecting the vibrator and the pantograph, the MEMS resonator 800 can be miniaturized. Note that it is also possible to connect the MEMS resonators 200, 300, 400, 500, and 600 according to the other embodiments in a similar manner.

[0055] Although the embodiments of the present invention have been described with reference to a square pantograph, the shape of the pantograph may also be a rhombus, rectangle, or parallelogram. When the pantograph has these shapes, it is preferable that the vibrators are arranged equidistant from each vertex on the extension of the diagonal line. The essence of the shape of the pantograph is that it deforms in opposite phases in the two axial directions, as shown in Figure 4. As long as this condition is met, the shape may be other than a rectangle with a uniform thickness, as shown in Figure 13, for example.

[0056] In the embodiment of the present invention, an example has been shown in which capacitance elements each consisting of vibrators 30A-30D and external electrodes 40A-40D are used to drive a MEMS resonator, but some capacitance elements may also be used to detect the resonance frequency.Furthermore, the same capacitance element may be used for both driving and detection, for example, by switching over time.

[0057] <Additional Notes> The present disclosure provides: A parallelogram pantograph, Vibrators connected to the apexes of the pantograph, The MEMS resonator includes electrodes arranged opposite each of the vibrators and constituting a capacitance element together with the vibrators. In this MEMS resonator, the deformation of the pantograph prevents the energy consumption caused by the deformation of the beam as in conventional structures, and allows for efficient resonance. Furthermore, since there is no limit to the length of the beam as in conventional structures, the MEMS resonator can be made smaller.

[0058] The present disclosure relates to a MEMS resonator in which voltages that are 180 degrees out of phase with each other are applied to electrodes arranged opposite to vibrators on extensions of different diagonals of a parallelogram pantograph. In this way, by applying voltages of opposite phases to the opposing electrodes of adjacent vibrators, the adjacent vibrators can be alternately expanded and contracted, resulting in highly efficient resonance.

[0059] In the present disclosure, the parallelogram is preferably a square or a rectangle, as this simplifies the fabrication and placement of the pantograph.

[0060] In the present disclosure, the pantograph and the vibrator are connected by beams arranged on the extensions of the diagonals of a parallelogram. In this case, the length of the beams is not limited to an integer multiple of half the resonant wavelength as in conventional structures.

[0061] The present disclosure also provides a MEMS resonator in which the end of the beam is provided with a beam extension that is aligned with the vibrator, and the beam extension and the vibrator are connected by multiple connectors. In this structure, contraction of the vibrator pulls the beam as a translational motion, enabling efficient transmission of vibration to the pantograph.

[0062] In the present disclosure, the pantograph and the vibrator may be directly connected, and in this structure, the vibration of the vibrator can be efficiently transmitted to the pantograph.

[0063] In the present disclosure, the electrode may be an arc-shaped external electrode provided on the outside of the vibrator.

[0064] In the present disclosure, the electrode may be a circular internal electrode provided inside the vibrator.

[0065] In the present disclosure, the capacitance element may be configured with a ring-shaped vibrator and an arc-shaped electrode.

[0066] In the present disclosure, the capacitance element may be configured with a comb-tooth shaped vibrator and a comb-tooth shaped electrode that are arranged opposite each other.

[0067] The present disclosure may also be a MEMS resonator that includes a switching unit connected to one vertex of the pantograph and a DC voltage circuit connected to the switching unit, and that opens and closes the switching unit by vibrating the vibrator. In such a MEMS resonator, the voltage of the DC voltage circuit can be turned on and off in accordance with the vibration frequency of the vibrator, and the DC voltage can be converted into an AC voltage of a predetermined frequency.

[0068] The present disclosure also provides a MEMS resonator connection structure in which at least two of the above-described MEMS resonators are connected to share one oscillator. By connecting and resonating multiple MEMS resonators, it is possible to obtain a larger resonance signal. [Industrial Applicability]

[0069] The MEMS resonator according to the present invention can be applied to resonators, filters, temperature sensors, pressure sensors, mass sensors, and the like. [Explanation of symbols]

[0070] 10 Pantograph 20 beams 30A~30D vibrator 40A~40D external electrode 50 boards 60A~60D Internal electrode 100 MEMS resonators 120 recess 130, 140 Anchor 135, 145 Isolation Joint (IJ) 150 oxide film 160, 170, 180 electrodes 165, 175, 185 wiring layer

Claims

1. A parallelogram pantograph, vibrators connected to the vertices of the pantograph; an electrode disposed opposite each of the vibrators and constituting a capacitance element together with the vibrators;

2. 2. The MEMS resonator according to claim 1, wherein voltages that are 180 degrees out of phase with each other are applied to the electrodes that are arranged opposite to the vibrators on the extensions of different diagonals of the parallelogram pantograph.

3. The MEMS resonator of claim 1 , wherein the parallelogram is a square or a rectangle.

4. The MEMS resonator according to claim 1 , wherein the pantograph and the vibrator are connected by a beam disposed on an extension of a diagonal line of the parallelogram.

5. The MEMS resonator according to claim 4 , further comprising a beam extension portion at an end of the beam that is aligned with the vibrator, the beam extension portion and the vibrator being connected by a plurality of connection portions.

6. The MEMS resonator according to claim 1 , wherein the pantograph and the vibrator are directly connected to each other.

7. The MEMS resonator according to claim 1 , wherein the electrode is an arc-shaped external electrode provided on the outside of the vibrator.

8. The MEMS resonator according to claim 1 , wherein the electrode is a circular internal electrode provided inside the vibrator.

9. The MEMS resonator according to claim 1 , wherein the capacitance element is composed of the ring-shaped vibrator and the arc-shaped electrode.

10. The MEMS resonator according to claim 1 , wherein the capacitance element is formed by the comb-teeth-shaped vibrator and the comb-teeth-shaped electrode, which are arranged opposite to each other.

11. 2. The MEMS resonator according to claim 1, further comprising: a switching unit connected to one vertex of the pantograph; and a DC voltage circuit connected to the switching unit, wherein the vibrator is vibrated to open and close the switching unit.

12. The MEMS resonator connection structure according to claim 1 , wherein at least two MEMS resonators are connected to share one vibrator.

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