MEMS resonator

Abstract

The utility model provides an MEMS resonator which is provided with an anchoring part used for fixing, a resonance body used for vibrating and a connecting beam, the resonance body and the anchoring part are arranged in a spaced mode and arranged on the peripheral side of the anchoring part, the anchoring part is provided with a groove sunken towards the interior of the anchoring part, and the connecting beam is arranged in the groove. At least part of the connecting beam extends into the groove to be connected with the wall face of the groove so that the resonance body can be connected with the anchoring part. According to the MEMS resonator, the groove structure is formed in the anchoring part, the connecting beam is connected with the anchoring part at the groove, and at least part of the connecting beam penetrates into the groove, so that when the MEMS resonator vibrates, energy radiated from the connecting beam can be reflected back through the groove, anchor point loss is reduced, and the Q value is increased.

Description

Technical Field

[0001] The present application relates to the technical field of micromechanical resonators, and in particular to a MEMS resonator. Background Art

[0002] A micromechanical resonator (MEMS resonator) is a device based on a micromechanical structure. When the resonator is stimulated by an external physical signal and the driving signal frequency is equal to the system's natural frequency, the system's mechanical structure will resonate near its natural frequency, the system amplitude reaches its maximum, and the resulting resonant signal is converted into other physical signal outputs. Because the amplitude of a micromechanical resonator is the largest at its natural frequency and the energy conversion efficiency is the highest, a micromechanical resonator can achieve mechanical frequency selection through mechanical vibration. In the field of wireless communications, oscillators and filters based on micromechanical resonators are widely used.

[0003] The performance parameters of a micromechanical resonator include resonant frequency, quality factor (Q value), dynamic impedance, and frequency temperature coefficient. The Q value is the primary performance parameter used to measure the energy loss of a micromechanical resonator. A high Q value can improve the frequency selectivity of a micromechanical resonator while reducing dynamic impedance and phase noise, thereby improving the frequency stability of the micromechanical resonator. It is a core element in the practical application and commercialization of high-performance micromechanical resonators.

[0004] Among them, anchor point loss is one of the main factors affecting the Q value. However, the anchor point loss of existing resonators is relatively high, which makes it difficult to meet the requirements of high frequency and high Q. Utility Model Content

[0005] In view of this, the present application provides a MEMS resonator to reduce anchor point loss.

[0006] The present application provides a MEMS resonator comprising an anchor for fixing, a resonant body for vibrating, and a connecting beam. The resonant body is spaced apart from the anchor and disposed around the anchor. The anchor is provided with a groove recessed toward the interior of the anchor. At least a portion of the connecting beam extends into the groove and connects to the wall of the groove, thereby connecting the resonant body to the anchor.

[0007] In some embodiments, the groove is provided at a portion of the anchor member close to the resonant body, and the connecting beam is connected to a bottom wall of the groove.

[0008] In some embodiments, the connecting beam is a straight beam and / or a curved beam.

[0009] In some embodiments, if the connecting beam is the curved beam, the curved beam is configured as at least one of a folded beam, an arc beam, and a ring beam.

[0010] In some embodiments, the number of the connecting beams and the number of the grooves are both plural and connected in a one-to-one correspondence.

[0011] In some embodiments, the resonant body includes multiple vibration units, each of the vibration units includes a vibrator and at least one coupling beam, the first end of the coupling beam is connected to the vibrator of the same vibration unit, and the second end of the coupling beam is connected to the vibrator of another vibration unit or the second end of the coupling beam, so as to connect the multiple vibration units together in sequence and form a preset geometric shape, which is a stepped annular pattern, and the anchor is located on the inner side of the stepped annular pattern.

[0012] In some embodiments, the resonant body includes four vibration units, each of the vibration units includes a vibrator, one end of the connecting beam is connected to the vibrator, and the other end of the connecting beam extends into the groove to be connected to the wall of the groove at the groove, and the vibrator, the connecting beam and the anchor form a cross structure.

[0013] In some embodiments, a concave-convex structure is provided on the wall surface of the groove.

[0014] In some embodiments, the anchor includes an anchoring area and a connecting area connected to each other, the anchoring area is connected to the substrate below for fixation, the connecting area is located between the anchoring area and the connecting beam and is used to connect the anchoring area and the connecting beam, the groove is arranged in the connecting area, and the connecting area, the resonant body, and the connecting beam are all arranged opposite to the cavity below.

[0015] In some embodiments, the thickness of the connection region is the same as the thickness of the connection beam.

[0016] The present application provides a MEMS resonator, which is formed by providing a groove structure on an anchor, and connecting a connecting beam to the anchor at the groove. The connecting beam at least partially penetrates into the groove, so that when the MEMS resonator vibrates, the energy radiated from the connecting beam can be reflected back through the groove, thereby reducing the anchor point loss and improving the Q value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of the first structure of the MEMS resonator provided by this application;

[0019] Figure 2 yes Figure 1 Schematic diagram of the amplified structure of the MEMS resonator A;

[0020] Figure 3 This is a second structural diagram of the MEMS resonator provided in this application. DETAILED DESCRIPTION

[0021] The following, in conjunction with the accompanying drawings, clearly and completely describes the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the description of this application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the relevant listed items. The terms "connected", "electrically connected", and "electrically connected" as used herein include any direct and indirect electrical or structural connection means. Therefore, if the text describes a first device as being coupled / connected / electrically connected to a second device, it means that the first device can be directly electrically / structurally connected to the second device, or indirectly electrically / structurally connected to the second device through other devices or connection means.

[0024] The present application provides a MEMS resonator comprising an anchor for fixing, a resonating body for vibrating, and a connecting beam. The resonating body is spaced apart from the anchor and disposed around the anchor. The anchor is provided with a groove recessed toward the interior of the anchor, and at least a portion of the connecting beam extends into the groove and connects to the wall of the groove, thereby connecting the resonating body to the anchor.

[0025] In the present application, a groove structure is provided on the anchor, and the connecting beam is connected to the anchor at the groove, so that the connecting beam at least partially extends into the groove, so that when the MEMS resonator vibrates, the energy radiated from the connecting beam can be reflected back through the groove, thereby reducing the anchor point loss and improving the Q value.

[0026] See also Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the first structure of the MEMS resonator provided by this application; Figure 2 yes Figure 1 Schematic diagram of the enlarged structure of the MEMS resonator A in FIG. The present application provides a MEMS resonator 10, which has an anchor 100 for fixing, a resonating body 200 for vibration, and a connecting beam 300. The resonating body 200 is spaced apart from the anchor 100 and is arranged on the circumferential side of the anchor 100, wherein the anchor 100 is provided with a groove 110 recessed toward the inside of the anchor 100, and at least part of the connecting beam 300 is connected to the wall of the groove 110 by extending into the groove 110 to connect the resonating body 200 to the anchor 100. It can be understood that the MEMS resonator 10 has a substrate provided below the anchor 100 and the resonating body 200 and used for supporting. The anchor 100 can be connected to the substrate below for fixing. The resonating body 200 is spaced apart from the substrate below to form a cavity to facilitate the vibration of the resonating body 200.

[0027] Specifically, the shape of the groove 110 can be square, triangular, hexagonal, or arc-shaped, etc. However, this is not limiting. In this embodiment, the square shape of the groove 110 is used as an example for description. The anchor 100 includes an anchoring region 120 and a connecting region 130, which are connected to each other. The anchoring region 120 can be connected to the underlying substrate for fixation. The connecting region 130 is located between the anchoring region 120 and the connecting beam 300 and is connected to both. The groove 110 is provided in the connecting region 130. In one embodiment, the groove 110 is provided in a portion of the anchor 100 close to the resonant body 200.

[0028] Optionally, the connection area 130 can be the same as the resonant body 200 and the connecting beam 300, and can be arranged opposite the cavity below. The cavity is used to provide a vibration space for the resonant body 200 and the connecting beam 300, so that the resonant body 200 and the connecting beam 300 can vibrate. Optionally, the connection area 130 can also be connected to the substrate below.

[0029] Alternatively, see Figure 1The middle area of ​​the anchoring area 120 is connected to the substrate below, and the connecting area 130 is arranged around the periphery of the anchoring area 120, and an arm-like structure extending outward is provided on the connecting area 130 to facilitate connection with the connecting beam 300. By setting the anchoring area 120 to be connected to the substrate, and the connecting area 130 to be connected to the connecting beam 300, the risk of vibration energy leaking to the substrate through the anchoring area 120 is reduced, and the Q value is improved.

[0030] In one embodiment, the groove 110 is located at the edge of the connection region 130, away from the anchor region 120 and close to the resonant body 200. Alternatively, the connection region 130 is located outside the anchor region 120 and is provided with an outwardly extending arm-like structure. By increasing its size, it increases impact resistance, thereby preventing material fatigue or fracture and extending the service life of the device. Alternatively, the thickness of the connection region 130 can be the same as that of the connecting beam 300 to simplify the manufacturing process.

[0031] In the existing MEMS resonator, there is no groove design at the connection between the anchor and the connecting beam, which leads to serious energy leakage when the existing MEMS resonator vibrates, thereby causing a significant decrease in the Q value. However, the present application sets a groove 110 on the anchor 100, and the connecting beam 300 is connected to the anchor 100 at the groove 110. When the MEMS resonator 10 is working, the resonant body 200 vibrates and drives the connecting beam 300 to vibrate. When part of the energy leaked from the connecting beam 300 is radiated from the side wall of the connecting beam 300 in the form of sound waves, the setting of the groove 110 can reflect the leaked energy back to the MEMS resonator 10, reducing energy loss due to sound wave leakage and other means, thereby reducing anchor point loss. Compared with the existing MEMS resonator, the Q value of the MEMS resonator 10 of the present application is improved by two to three orders of magnitude, that is, the MEMS resonator 10 provided by the present application can maintain a high Q value at high frequencies, while reducing the impedance and noise of the device.

[0032] It is understood that the connecting beam 300 extending into the groove 110 can be spaced apart from the inner wall of the groove 110. There should be at least enough space for the connecting beam 300 to deform when the resonant body 200 vibrates, thereby reducing the impact on the vibration.

[0033] In one embodiment, the groove 110 may surround the connecting beam 300 as much as possible, so that most of the connecting beam 300 extends into the groove, thereby reflecting back a large amount of sound waves radiated from the sidewall of the connecting beam 300 as much as possible.

[0034] In one embodiment, the connecting beam 300 is connected to the bottom wall of the groove 110. Figure 1The groove 110 is arranged at the end area of ​​the arm-like structure away from the anchoring area 120, that is, the groove 110 is arranged at the end of the connection area 130, and the connecting beam 300 extends into the groove 110 and is connected to the bottom wall of the groove 110 at the groove 110, so that most of the connecting beam 300 extends into the groove 110, so that the groove 110 can surround the connecting beam 300 as much as possible, so that the groove 110 can better ensure that the energy is reflected back and improve the Q value.

[0035] In one embodiment, the connecting beam 300 is a straight beam and / or a curved beam. Specifically, the connecting beam 300 can be a straight beam, or a curved beam, or a combination of straight and curved beams. In this embodiment, the connecting beam 300 is described as being composed of a straight beam and a curved beam. It will be appreciated that the curved beam configuration of the connecting beam 300 can further reduce anchor point loss and improve the Q factor.

[0036] In one embodiment, the connecting beam 300 is at least one of a folded beam, a curved beam, and a ring beam, and the folded beam, the curved beam, and the ring beam are all curved beams to further reduce the anchor loss and improve the Q value.

[0037] In one embodiment, see Figure 2 The connecting beam 300 is composed of an annular beam and a straight beam, which are connected to the middle area of ​​the annular beam to form a "Z"-shaped structure. The connecting beam 300, formed by the straight beam and the annular beam, forms a "Z"-shaped structure to reduce the air damping effect and energy loss during vibration. It also effectively disperses stress concentration during vibration transmission, reduces the risk of structural fatigue, and improves the durability and reliability of the MEMS resonator 10.

[0038] In the embodiment of the present application, the structure of the resonant body 200 may not be restricted too much. The resonant body 200 may be as follows: Figure 1 The structure shown is a multi-ring array structure, and can also be other shapes, such as Figure 3 The cross-shaped structure shown, or the cantilever beam structure and so on.

[0039] Specifically, see Figure 1 , the resonant body 200 includes a plurality of vibration units 210. Each vibration unit 210 includes a vibrator 211 and at least one coupling beam 212. The first end of the coupling beam 212 is connected to the vibrator 211 of the same vibration unit 210; the second end of the coupling beam 212 is connected to the vibrator 211 of another vibration unit 210 or the second end of the coupling beam 212, so as to connect the plurality of vibration units 210 together in sequence and form a preset geometric shape. The preset geometric shape is a stepped annular pattern. The anchor 100 is located on the inner side of the stepped annular pattern. For example, see Figure 1The resonant body 200 includes twelve vibration units 210. Each vibration unit 210 specifically includes a coupling beam 212 and a vibrator 211. The first end of the coupling beam 212 is connected to the vibrator 211 of the same vibration unit 210, and the second end of the coupling beam 212 is connected to the vibrator 211 of another vibration unit 210. The coupling beam 212 is arranged perpendicular to the coupling beam 212 of the other vibration unit 210, so that the twelve vibration units 210 are sequentially connected together to form a cross-step ring shape. However, the number of vibration units 210 in the resonant body 200 is not limited to this, and may also be eight, ten, fourteen, or eighteen.

[0040] In the present application, by connecting multiple vibration units 210 together in sequence and forming a stepped ring pattern, the number of vibration units 210 in the resonant body 200 can be increased as much as possible within a limited area, so as to effectively increase the sensing area of ​​the electrodes (such as driving electrodes and sensing electrodes) in the MEMS resonator 10, reduce impedance, and thus help enhance the sensing signal of the device to achieve higher frequency output.

[0041] It is understood that the number of connecting beams 300 and anchors 100 may also vary depending on the structure of the resonant body 200. For example, there may be one anchor 100 and four connecting beams 300. Four arm-like structures extend outward from the connecting region 130 of the anchor 100. Each arm-like structure has a groove 110 at the end thereof and is connected to the coupling beam 212 in the resonant body 200 via a connecting beam 300. It should be noted that there may be one or more anchors 100, and the locations where they connect to the connecting beams 300 are all groove 110 structures. Optionally, there may be multiple connecting beams 300 and grooves 110, and they are connected one-to-one. However, the present invention is not limited thereto. There may be multiple connecting beams 300, wherein some connecting beams 300 are connected to corresponding grooves 110, while other connecting beams 300 are directly connected to other areas of the anchor 100.

[0042] In one embodiment, the vibrator 211 and the coupling beam 212 in the same resonant body 200 are integrated into one structure. By matching the sizes of the vibrator 211 and the coupling beam 212, the deformation of the coupling beam 212 is reduced, and energy transfer between the two vibrators 211 is achieved through the coupling beam 212.

[0043] In one embodiment, the vibrator 211 is a ring-shaped body with a through hole or a solid plate-shaped body. In this embodiment, the vibrator 211 is a ring-shaped body with a through hole, and the resonant body 200 is a multi-ring array structure. In addition, the solid plate-shaped body includes, but is not limited to, a solid circular body, a solid rectangular body, a solid elliptical body, a solid rounded rectangular body, or any other solid body of any shape.

[0044] In one embodiment, see Figure 2 The gap between the resonant body 200 and the walls b1 and b2 on both sides of the groove 110 in the anchor 100 is small, and the depth of the groove 110 is almost equal to the length of the connecting beam 300 (for example, the depth of the groove 110 is slightly less than the length of the connecting beam 300). This allows the connecting beam 300 to be placed as much as possible within the groove 110, so that the resonant body 200 has sufficient vibration space while being able to reflect a large amount of sound waves radiated by the connecting beam 300 back into the interior of the device, thereby reducing anchor point loss and improving Q value. The extending direction of the connecting beam 300 from one end connected to the resonant body 200 to the other end connected to the anchor 100 is defined as the length direction of the connecting beam 300.

[0045] In other words, the gap between the anchor 100 and the resonant body 200 should be large enough to ensure sufficient vibration space for the resonant body 200, and the gap should be as small as possible. Of course, the present invention is not limited thereto. The depth of the groove 110 can be less than the length of the connecting beam 300. Only a small portion of the connecting beam 300 extends into the groove 110, and one end is connected to the groove 110.

[0046] In one embodiment, a concave-convex structure is provided on the wall surface of the groove 110 to increase the energy exchange between the resonant body 200 and the anchor 100 and further improve the Q value.

[0047] See also Figure 3 , Figure 3 This is a second structural diagram of the MEMS resonator 10 provided in this application. It should be noted that, Figure 3 and Figure 1 The difference is that: the resonant body 200 includes four vibration units 210, each vibration unit 210 includes a vibrator 211, one end of the connecting beam 300 is connected to the vibrator 211, and the other end of the connecting beam 300 extends into the groove 110 to be connected to the wall of the groove 110 at the groove 110, and the vibrator 211, the connecting beam 300 and the anchor 100 form a cross structure.

[0048] In another embodiment, the resonant body 200 and the connecting beam 300 are substantially cantilever beam structures.

[0049] The present application provides a MEMS resonator 10, which is provided with a groove 110 on an anchor 100, and a connecting beam 300 is connected to the anchor 100 at the groove 110. When the MEMS resonator 10 is in operation, the resonant body 200 vibrates, driving the connecting beam 300 to vibrate. When some energy leaks from the connecting beam 300, such as radiating from the sidewalls of the connecting beam 300 in the form of sound waves, the provision of the groove 110 can reflect the leaked energy back into the MEMS resonator 10, reducing energy loss due to sound wave leakage and other means, thereby reducing anchor point loss. Compared with existing MEMS resonators 10, the Q value of the MEMS resonator 10 of the present application is improved by two to three orders of magnitude. That is, the MEMS resonator 10 provided by the present application can maintain a high Q value at high frequencies, reducing the impedance and noise of the device.

[0050] The above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, such as the mutual combination of technical features between the embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A MEMS resonator, comprising an anchor for fixing, a resonant body for vibrating, and a connecting beam, wherein the resonant body is spaced apart from the anchor and disposed on the peripheral side of the anchor, wherein: The anchor is provided with a groove recessed toward the inside of the anchor, and at least part of the connecting beam is connected to the wall of the groove by extending into the groove, so as to connect the resonant body to the anchor.

2. The MEMS resonator according to claim 1, wherein The groove is provided at a position of the anchoring member close to the resonant body, and the connecting beam is connected to the bottom wall of the groove.

3. The MEMS resonator according to claim 1, wherein: The connecting beam is a straight beam and / or a curved beam.

4. The MEMS resonator according to claim 3, wherein: If the connecting beam is the curved beam, the curved beam is configured as at least one of a folded beam, an arc beam and a ring beam.

5. The MEMS resonator according to claim 1, wherein: The number of the connecting beams and the number of the grooves are both plural and connected in a one-to-one correspondence.

6. The MEMS resonator according to claim 1, wherein: The resonant body includes multiple vibration units, each of which includes a vibrator and at least one coupling beam. The first end of the coupling beam is connected to the vibrator of the same vibration unit, and the second end of the coupling beam is connected to the vibrator of another vibration unit or the second end of the coupling beam, so as to connect the multiple vibration units together in sequence and form a preset geometric shape, which is a stepped annular pattern. The anchor is located on the inner side of the stepped annular pattern.

7. The MEMS resonator according to claim 1, wherein: The resonant body includes four vibration units, each of which includes a vibrator. One end of the connecting beam is connected to the vibrator, and the other end of the connecting beam extends into the groove to be connected to the wall of the groove at the groove. The vibrator, the connecting beam and the anchor form a cross structure.

8. The MEMS resonator according to claim 1, wherein: A concave-convex structure is arranged on the wall surface of the groove.

9. The MEMS resonator according to claim 1, wherein: The anchoring member includes an anchoring area and a connecting area connected to each other, the anchoring area is connected to the base below for fixation, the connecting area is located between the anchoring area and the connecting beam and is used to connect the anchoring area and the connecting beam, the groove is arranged in the connecting area, and the connecting area, the resonant body, and the connecting beam are all arranged opposite to the cavity below.

10. The MEMS resonator according to claim 9, wherein: The thickness of the connecting area is the same as the thickness of the connecting beam.

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