CN115395920A - MEMS resonator and vibrating arm assembly thereof - Google Patents

Abstract

The application discloses an MEMS resonator and a vibrating arm component thereof; the MEMS resonator vibrating arm assembly comprises an anchor and a vibrating arm; the vibrating arm is provided with a fixed end and a free end at intervals in the length direction; the fixed end is connected with the anchoring piece, the vibrating arm is configured to be close to a root area of the fixed end and close to a head area of the free end, and the mass of the head area is larger than that of the root area. This application is through following the arm that shakes the arm length direction divide into the root region that is close to the stiff end and the head region that is close to the free end, makes the regional quality of head be greater than the quality of root region to utilize this mass distribution characteristic to reduce the influence of technology deviation to resonant frequency.

Description

MEMS resonator and vibrating arm assembly thereof

Technical Field

The application relates to the technical field of micro-electro-mechanical systems, in particular to an MEMS resonator and a vibrating arm assembly thereof.

Background

Micro-Electro-Mechanical systems (MEMS), also called Micro-Electro-Mechanical systems, microsystems, micromachines, etc., refer to high-tech devices with dimensions of a few millimeters or even smaller. The micro-electro-mechanical system is a micro device or system integrating micro sensors, micro actuators, micro mechanical structures, micro power supplies, micro energy sources, signal processing and control circuits, high-performance electronic integrated devices, interfaces, and communication.

Microelectromechanical Systems (MEMS) devices are currently being developed for a wide variety of applications. One example of such a device is a MEMS resonator, which may be used in timing circuits of electronic devices. MEMS resonator systems typically include a plurality of electrodes to drive the MEMS resonator. When a bias voltage is applied to the drive electrode, charge accumulates on the electrode, which creates an electrostatic force between the electrode and the opposing charge accumulated on the MEMS resonator. By applying a time-varying voltage signal to the drive electrode, typically in combination with a DC voltage, a time-varying electrostatic force may be generated, which causes the MEMS resonator to oscillate.

Since the MEMS resonator has no uniform microstructure processing process, even if the processing process flow and the standard are different for the same type of product, the MEMS resonator often has a large deviation of the resonant frequency due to the processing deviation.

Disclosure of Invention

The technical problem that this application mainly solved provides a MEMS syntonizer and arm subassembly shakes thereof to solve among the prior art MEMS syntonizer and lead to resonant frequency to produce the problem of great deviation because of the processing deviation.

In order to solve the technical problem, the application adopts a technical scheme that:

a MEMS resonator horn assembly is provided comprising:

an anchoring member;

the vibration arm is provided with a fixed end and a free end at intervals in the length direction; the fixed end is connected with the anchoring piece, the vibrating arm is configured to be close to a root area of the fixed end and close to a head area of the free end, and the mass of the head area is larger than that of the root area.

Wherein the vibrating arm has a width changing section, and the width of the vibrating arm gradually increases in a direction from the fixed end to the free end in at least part of the width changing section.

Wherein the length of the gradually increasing width part of the vibrating arm is not less than one tenth of the total length of the vibrating arm.

Wherein the width variation section is located within the root region and the head region, or the width variation section is located only within the head region.

Wherein the width change section is arranged in a wedge shape or a disc shape.

The vibrating arm is provided with a fixed end, a vibrating arm and a vibrating arm, wherein the vibrating arm is also provided with a constant width section which is positioned on one side of the variable width section towards the fixed end and is connected with the variable width section; in the constant width section, the width of the vibrating arm is kept constant along the length direction of the vibrating arm.

The MEMS resonator vibration arm assembly further comprises a coupling beam, the anchoring piece and the vibration arm are arranged at intervals in the width direction of the vibration arm, and the fixed end is connected with the anchoring piece through the coupling beam.

The number of the vibrating arms is at least two, and the at least two vibrating arms are connected with each other along the length direction of the vibrating arms and/or are spaced from each other along the width direction of the vibrating arms; wherein the at least two vibrating arms are connected with the same anchor.

The application provides a MEMS resonator on another aspect, which comprises a driving electrode, a sensing electrode and the MEMS resonator vibrating arm component; the driving electrode and the induction electrode are opposite at intervals, and the vibrating arm is located between the driving electrode and the induction electrode.

The driving electrode and the induction electrode are respectively arranged with the surface clearance of the vibrating arm.

The beneficial effect of this application is: different from the prior art, the vibration arm is divided into the root area close to the fixed end and the head area close to the free end along the length direction of the vibration arm, so that the mass of the head area is greater than that of the root area, and the influence of process deviation on the resonance frequency is reduced by utilizing the mass distribution characteristic.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a MEMS resonator arm assembly in a first embodiment provided herein;

FIG. 2 is a schematic structural diagram of a MEMS resonator arm assembly in a second embodiment provided herein;

FIG. 3 is a schematic structural diagram of a MEMS resonator arm assembly in a third embodiment provided by the present application;

FIG. 4 is a schematic structural diagram of a MEMS resonator arm assembly in a fourth embodiment provided by the present application;

FIG. 5 is a schematic structural diagram of a MEMS resonator arm assembly in a fifth embodiment provided herein;

FIG. 6 is a schematic structural diagram of a MEMS resonator arm assembly in a sixth embodiment provided herein;

FIG. 7 is a schematic structural diagram of a MEMS resonator arm assembly in a seventh embodiment provided herein;

FIG. 8 is a schematic structural diagram of a MEMS resonator arm assembly in an eighth embodiment provided by the present application;

FIG. 9 is a schematic diagram of a MEMS resonator arm assembly according to a ninth embodiment of the present application;

FIG. 10 is a schematic diagram of a MEMS resonator in a tenth embodiment provided herein;

fig. 11 is a schematic structural diagram of a MEMS resonator in an eleventh embodiment provided by the present application;

fig. 12 is a schematic structural diagram of a MEMS resonator in a twelfth embodiment provided in the present application;

fig. 13 is a schematic structural diagram of a MEMS resonator in a thirteenth embodiment provided by the present application;

FIG. 14 is a schematic diagram of a MEMS resonator in a fourteenth embodiment provided herein;

FIG. 15 is a schematic diagram of a MEMS resonator in a fifteenth embodiment provided herein;

fig. 16 is a schematic structural diagram of a MEMS resonator in a sixteenth embodiment provided in the present application;

FIG. 17 is a schematic diagram of a MEMS resonator according to a seventeenth embodiment provided herein;

fig. 18 is a schematic structural diagram of a MEMS resonator in an eighteenth embodiment provided by the present application;

FIG. 19 is a table of process variation versus frequency for a MEMS resonator horn assembly as provided herein.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first", "second" and "third" in the embodiments of the present application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of the feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise. In the embodiment of the present application, all directional indicators (such as up, down, left, right, front, rear \8230;) are used only to explain the relative positional relationship between the components, the motion situation, etc. at a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly. The terms "comprising" and "having" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a MEMS resonator arm assembly according to a first embodiment of the present disclosure. The present application provides a MEMS resonator horn assembly 100 that includes an anchor 110 and a horn 130.

In the present embodiment, the vibrating arm 130 is disposed in an elongated shape, and has a fixed end 131 and a free end 132 spaced apart from each other along the length of the vibrating arm 130. Fixed end 131 is connected to anchor 110 to form a pivot point 133. The horn 130 is able to swing about a pivot point 133. MEMS resonator arm assembly 100 is secured to a substrate (not shown) by anchor 110.

The horn 130 is configured as a root region 134 near the fixed end 131 and a head region 135 near the free end, wherein the mass of the head region 135 is larger than the mass of the root region 134.

Specifically, the arm 130 is divided into a root region 134 near the fixed end 131 and a head region 135 near the free end 132 with a midpoint in the longitudinal direction of the arm 130 as a boundary point, and the mass of the head region 135 is greater than that of the root region 134. Therefore, the influence of the process deviation caused by the nonlinear characteristic of the process deviation is counteracted by utilizing the quality distribution characteristic, and the influence of the process deviation on the resonant frequency is reduced.

Alternatively, the ratio of the root region 134 to the head region 135 along the length of the horn 130 may be 1/6, 1/5, 1/4, or 1/3, and is not particularly limited herein.

Optionally, the root region 134 and the head region 135 are each made of a different material, so that the mass of the head region 135 is greater than the mass of the root region 134.

Optionally, the root region 134 and the head region 135 each have a different thickness, such that the mass of the head region 135 is greater than the mass of the root region 134.

Optionally, the horn 130 has a width varying section 136. In this embodiment, the width of the vibrating arm 130 gradually increases in a direction from the fixed end 131 to the free end 132 in at least a portion of the width varying section 136, so that the mass of the head region 135 is greater than that of the root region 134.

The length of the gradually increasing width portion of the vibrating arm 130 is not less than one tenth of the total length of the vibrating arm 130. Specifically, in the process of manufacturing the vibrating arm 130, the length of the gradually increasing width portion of the vibrating arm 130 may be one tenth, one eighth, one fifth or one third of the total length of the vibrating arm 130, and is not particularly limited herein.

Referring to fig. 1 and 2, fig. 2 is a schematic structural diagram of a MEMS resonator arm assembly according to a second embodiment of the present disclosure. The width variation 136 of the horn 130 in the MEMS resonator horn assembly 100 is located in the root region 134 and the head region 135, or the width variation 136 is located only in the head region 135.

Specifically, in the first embodiment, the width-varying section 136 is located within the root region 134 and the head region 135. The horn 130 in the width varying section 136 is spread from the root region 134 to the head region 135. In plan projection, the vibrating arm 130 in the width varying section 136 is in the shape of a planar cone. In the width varying section 136, the width of the arm 130 is smallest at the side of the root region 134 near the fixed end 131, and the width of the arm 130 is largest at the side of the head region 135 near the free end 132.

Specifically, in the second embodiment, the width varying section 136 is located only in the head region 135. The horn 130 within the width variation section 136 is "trumpet" shaped. The vibrating arm 130 in the width variation section 136 is equivalent to a weight, so that the mass of the head region 135 of the vibrating arm 130 is obviously increased, and the mass of the head region 135 of the vibrating arm 130 is larger than that of the root region 134, thereby reducing the influence of the process deviation on the resonant frequency by using the mass distribution characteristic.

Optionally, the width-changing section 136 is in a wedge-shaped arrangement or a disc-shaped arrangement. Referring to fig. 2 and 3, fig. 3 is a schematic structural diagram of a MEMS resonator arm assembly according to a third embodiment of the present disclosure. Specifically, in the second embodiment, the vibrating arm 130 in the width varying section 136 has a "trumpet" shape, i.e., a wedge-shaped configuration. In the third embodiment, the vibrating arm 130 in the width varying section 136 has a "disk" shape, i.e., a disk-shaped arrangement. When the width variation section 136 is only located in the head region 135, the head region 135 of the vibrating arm 130 is equivalent to adding a balancing weight by arranging the width variation section 136 in a wedge shape or a disc shape, so that the mass of the head region 135 of the vibrating arm 130 is larger than that of the root region 134, and the influence of the process deviation on the resonant frequency is reduced by using the mass distribution characteristic. Alternatively, in other embodiments, when the width varying section 136 is located only in the head region 135, the vibrating arm 130 within the width varying section 136 may be any other irregular shape.

Optionally, the horn 130 of the MEMS resonator horn assembly 100 further has a constant width segment 137. In the present embodiment, the constant width section 137 is located on the side of the variable width section 136 facing the fixed end 131, and is connected to the variable width section 136. In the constant width section 137, the width of the horn 130 is kept constant along the length direction of the horn 130. In other embodiments, the constant width segments 137 and the varying width segments 136 may be arranged alternately, so long as the mass of the head region 135 of the horn 130 is ensured to be greater than the mass of the root region 134.

Alternatively, in other embodiments, the constant width section 137 may not be provided, and the vibrating arm 130 is entirely located within the variable width section 136.

Alternatively, the width of the vibrating arm 130 continuously decreases in a direction from the fixed end 131 to the free end 132 in a portion of the width varying section 136. The length of the continuously decreasing width portion of the horn 130 is not greater than one-half of the total length of the horn 130. Specifically, in the process of manufacturing the horn 130, the length of the continuously reduced width portion of the horn 130 may be one half, one quarter, one eighth, or one tenth of the total length of the horn 130, and is not particularly limited herein.

With continued reference to fig. 1, the mems resonator arm assembly 100 further includes, but is not limited to, a coupling beam 120. In the present embodiment, the anchor 110 and the vibration arm 130 are spaced apart from each other in the width direction of the vibration arm 130, and the fixed end 131 is connected to the anchor 110 via the coupling beam 120. Specifically, the vibration arm 130 is connected to one end of the coupling beam 120 through the fixed end 131, the anchor 110 is connected to the other end of the coupling beam 120, and the vibration arm 130 is not in contact with the anchor 110. In operation, the horn 130 oscillates in its entirety about the pivot point 133.

Referring to fig. 4 to 6, fig. 4 is a schematic structural diagram of a MEMS resonator arm assembly according to a fourth embodiment of the present disclosure; FIG. 5 is a schematic structural diagram of a MEMS resonator arm assembly in a fifth embodiment provided herein; fig. 6 is a schematic structural diagram of a MEMS resonator horn assembly in a sixth embodiment provided in the present application. The present application provides a MEMS resonator horn assembly 100. The MEMS resonator horn assembly 100 includes at least two horns 130. In this embodiment, the at least two vibration arms 130 are connected to each other along a length direction of the vibration arms 130, and/or spaced apart from each other along a width direction of the vibration arms 130, and connected to the same anchor 110.

Specifically, the two vibrating arms 130 are a first vibrating arm 1301 and a second vibrating arm 1302 respectively. The fixed end 131 of the first vibrating arm 1301 is connected to one end of the coupling beam 120, and the fixed end 131 of the second vibrating arm 1302 is connected to the other end of the coupling beam 120. The anchor 110 is disposed between the first vibrating arm 1301 and the second vibrating arm 1302, and the anchor 110 is disposed at a distance from both the first vibrating arm 1301 and the second vibrating arm 1302. The first vibrating arm 1301, the anchor 110 and the second vibrating arm 1302 are all located on the same side of the coupling beam 120. In operation, first boom 1301 and second boom 1302 oscillate about respective pivot points 133 in a direction toward and away from anchor 110.

Alternatively, in other embodiments, first boom 1301 and second boom 1302 oscillate about respective pivot points 133 crosswise in directions toward and away from anchor 110, respectively.

Alternatively, in other embodiments, second horn arms 1302 are connected to each other along the length of first horn arm 1301.

Optionally, the vibrating arm 130, the coupling beam 120, and the anchor 110 are integrally formed as a structure.

Referring to fig. 7 to 9, fig. 7 is a schematic structural diagram of a MEMS resonator arm assembly according to a seventh embodiment of the present disclosure; FIG. 8 is a schematic structural diagram of a MEMS resonator arm assembly in an eighth embodiment provided by the present application; fig. 9 is a schematic structural diagram of a MEMS resonator arm assembly in a ninth embodiment provided in the present application.

In these embodiments, the MEMS resonator arm assembly 100 has four vibrating arms 130, and the four vibrating arms 130 are a first vibrating arm 1301, a second vibrating arm 1302, a third vibrating arm 1303, and a fourth vibrating arm 1304. The fixed end 131 of the first vibrating arm 1301 is connected to one end of the coupling beam 120, and the second vibrating arms 1302 are spaced apart from each other in the width direction of the first vibrating arm 1301. The fixed end 131 of the second vibrating arm 1302 is connected to the other end of the coupling beam 120, and the first vibrating arm 1301 and the second vibrating arm 1302 are disposed on the first surface 121 of the coupling beam 120. The third vibrating arms 1303 are connected to each other along a length direction of the first vibrating arm 1301, the fourth vibrating arms 1304 are disposed at intervals along a width direction of the third vibrating arms 1303, and the third vibrating arms 1303 and the fourth vibrating arms 1304 are disposed on the second surface 122 of the coupling beam 120. The first surface 121 and the second surface 122 are disposed opposite to each other. The MEMS resonator arm assembly 100 is generally "H" shaped.

In operation, first boom 1301 and second boom 1302 oscillate about respective pivot points 133 in a direction toward and away from anchor 110 simultaneously; third horn arm 1303 and fourth horn arm 1304 oscillate about their respective pivot points 133 in a direction toward and away from anchor 110.

Optionally, in other embodiments, the MEMS resonator horn assembly 100 has more than four horns 130. The number of the vibrating arms 130 may be set according to actual conditions, and is not particularly limited herein.

Referring to fig. 10 to 12, fig. 10 is a schematic structural diagram of a MEMS resonator according to a tenth embodiment of the present disclosure; FIG. 11 is a schematic diagram of a MEMS resonator in an eleventh embodiment provided herein; fig. 12 is a schematic structural diagram of a MEMS resonator in a twelfth embodiment provided in the present application.

The present application further provides a MEMS resonator 10 comprising a MEMS resonator horn assembly 100, a drive electrode 140, and a sense electrode 150. The driving electrode 140 and the sensing electrode 150 are spaced apart from each other, and the vibrating arm 130 is located between the driving electrode 140 and the sensing electrode 150. Preferably, the driving electrode 140 and the sensing electrode 150 are spaced apart from the surface of the horn 130, respectively.

In the present embodiment, the driving electrode 140 is located on one side of the vibrating arm 130 along the width direction of the vibrating arm 130, and the sensing electrode 150 is located on one side of the vibrating arm 130 away from the driving electrode 140.

The sensing electrode 150 is located on the same side of the horn 130 as the anchor 110 in the width direction of the horn 130. When the vibrating arm 130 is at rest, the vibrating arm 130 is disposed between the driving electrode 140 and the sensing electrode 150.

Specifically, the driving electrode 140 and the sensing electrode 150 have width variation sections respectively matched with the partial width variation sections 136 of the vibrating arm 130. When the width of the width change section 136 of the vibrating arm 130 is continuously increased, the width change sections of the driving electrode 140 and the sensing electrode 150 are continuously decreased by half of the continuously increased width of the width change section 136 of the vibrating arm 130; when the width of the width-changing section 136 of the vibrating arm 130 is continuously decreased, the width-changing sections of the driving electrode 140 and the sensing electrode 150 are continuously increased by half of the continuously decreased width of the width-changing section 136 of the vibrating arm 130.

In use, after power is applied to the driving electrode 140, the vibrating arm 130 swings toward the driving electrode 140. Applying a time varying signal to the drive electrodes 140 at a given frequency, for example, applying a DC and/or AC voltage between the horn 130 and the drive electrodes 140, causes the horn 130 to oscillate in a tuning fork manner, which in turn causes the average capacitance between the sense electrodes 150 and the horn 130 to vary at a substantially constant frequency. Thus, sensing electrode 150 can measure capacitance and the resulting signal can then be used to generate a timing signal.

Optionally, drive electrode 140 and sense electrode 150 each have an anchor 160. In this embodiment, the driving electrode 140 and the sensing electrode 150 are fixed to the substrate by their respective anchors 160.

Referring to fig. 13 to 15, fig. 13 is a schematic structural diagram of a MEMS resonator according to a thirteenth embodiment of the present application; FIG. 14 is a schematic diagram of a MEMS resonator in a fourteenth embodiment provided herein; fig. 15 is a schematic structural diagram of a MEMS resonator in a fifteenth embodiment provided by the present application.

In these embodiments, the MEMS resonator 10 comprises a first drive electrode 141 and a second drive electrode 142. The first driving electrode 141 is located on one side of the first vibrating arm 1301, which is far away from the second vibrating arm 1302, along the width direction of the first vibrating arm 1301; the second driving electrode 142 is located on the side of the second vibrating arm 1302 far from the first vibrating arm 1301 along the width direction of the second vibrating arm 1302; the sensing electrode 150 is located between the first vibrating arm 1301 and the second vibrating arm 1302, and is not in contact with the first vibrating arm 1301, the second vibrating arm 1302, and the anchor 110.

Specifically, the first driving electrode 141 has a width change section matched with a partial width change section 136 of the first vibrating arm 1301, and when the width change section 136 of the first vibrating arm 1301 continuously increases, the width change section of the first driving electrode 141 continuously decreases by half of the continuously increasing width of the width change section 136 of the first vibrating arm 1301; the second driving electrode 142 has a width change section matched with a part of the width change section 136 of the second vibrating arm 1302, and when the width change section 136 of the second vibrating arm 1302 continuously increases, the width change section of the second driving electrode 142 continuously decreases by half of the continuously increasing width of the width change section 136 of the second vibrating arm 1302; the sensing electrode 150 has a width change section which is matched with the partial width change section 136 of the first vibrating arm 1301 and the partial width change section 136 of the second vibrating arm 1302, and when the width change section 136 of the first vibrating arm 1301 and the width change section 136 of the second vibrating arm 1302 both have continuously increased widths, the width change section of the sensing electrode 150 continuously decreases the sum of half of the continuously increased width of the width change section 136 of the first vibrating arm 1301 and half of the continuously increased width of the width change section 136 of the second vibrating arm 1302.

When a voltage is established between the first drive electrode 141 and the first horn 1301, the resulting electrostatic force causes the first horn 1301 to swing about the pivot point 133 toward the first drive electrode 141 and then toward the sense electrode 150. Similarly, when a voltage is established between the second drive electrode 142 and the second horn 1302, the resulting electrostatic force causes the second horn 1302 to swing about the pivot point 133 toward the second drive electrode 142 and then toward the sense electrode 150.

Referring to fig. 16 to 18, fig. 16 is a schematic structural diagram of a MEMS resonator according to a sixteenth embodiment of the present application; FIG. 17 is a schematic diagram of a MEMS resonator according to a seventeenth embodiment provided herein; fig. 18 is a schematic structural diagram of a MEMS resonator in an eighteenth embodiment provided in the present application.

In these embodiments, MEMS resonator arm assembly 100 includes two drive electrodes 140 and two sense electrodes 150. The first driving electrode 141 is located on one side of the first vibrating arm 1301 away from the second vibrating arm 1302 along the width direction of the first vibrating arm 1301, and the length of the first driving electrode 141 is greater than or equal to the sum of the lengths of the first vibrating arm 1301 and the third vibrating arm 1303; the second driving electrode 142 is located on a side of the second vibrating arm 1302 far from the first vibrating arm 1301 in the width direction of the second vibrating arm 1302, and the length of the second driving electrode 142 is greater than or equal to the sum of the lengths of the second vibrating arm 1302 and the fourth vibrating arm 1304. The first induction electrode 151 is located between the first vibrating arm 1301 and the second vibrating arm 1302, and is not in contact with the first vibrating arm 1301, the second vibrating arm 1302 and the anchor 110; the second sensing electrode 152 is located between the third vibrating arm 1303 and the fourth vibrating arm 1304, and is not in contact with the third vibrating arm 1303, the fourth vibrating arm 1304, and the anchor 110. Specifically, the first sensing electrode 151 is located at one side of the first surface 121 of the coupling beam 120, and the second sensing electrode 152 is located at one side of the second surface 122 of the coupling beam 120.

Optionally, both ends of the first driving electrode 141 are respectively provided with a width change section matched with the partial width change section 136 of the first vibrating arm 1301 and the partial width change section 136 of the third vibrating arm 1303; the two ends of the second driving electrode 142 are respectively provided with a width change section matched with the partial width change section 136 of the second vibrating arm 1302 and the partial width change section 136 of the fourth vibrating arm 1304; the first sensing electrode 151 has a width change section which is matched with the partial width change section 136 of the first vibrating arm 1301 and the partial width change section 136 of the second vibrating arm 1302; the second sensing electrode 152 has a width variation section that is matched with the partial width variation section 136 of the third vibrating arm 1303 and the partial width variation section 136 of the fourth vibrating arm 1304.

Referring to fig. 19, fig. 19 is a table showing process variation versus frequency variation for the MEMS resonator arm assembly according to the present disclosure. The process deviation 0 is used as a comparison standard, and when the process deviation is between-0.5 um and 0.5um, the frequency variation amplitude and the frequency variation rate (percentage) in the first, fourth and seventh embodiments are all smaller than the frequency variation in the prior art.

For example, at a process variation of 0, the prior art frequency reference is 525.2Khz, and when the process variation is 0.5um, the prior art frequency reference is raised to 571.2Khz, the frequency change rate is about 8.7%; when the process variation is 0, the frequency reference of the first embodiment is 521.8Khz, and when the process variation is 0.5um, the frequency reference of the first embodiment is increased to 563.5Khz, and the frequency change rate is about 7.9%; the frequency reference of example four was 524.6Khz at a process variation of 0, and increased to 562.5Khz at a process variation of 0.5um, with a frequency change rate of about 7.2%; the frequency reference for example seven was 525.1Khz at a process variation of 0, and increased to 563.6Khz at a process variation of 0.5um, with a frequency change rate of about 7.3%. Therefore, the frequency change amplitude and the frequency change rate (percentage) in the first, fourth and seventh embodiments are smaller than the frequency change in the prior art.

Because the overall mass of the vibrating arm 130 is non-uniformly distributed, the influence of the process deviation caused by the nonlinear characteristic of the process deviation is counteracted by utilizing the mass distribution characteristic, and the influence of the process deviation on the resonant frequency is reduced.

The present application utilizes this mass distribution feature to reduce the effect of process variations on resonant frequency by dividing the horn 130 into a root region 134 near the fixed end 131 and a head region 135 near the free end 132 along the length of the horn 130 such that the mass of the head region 135 is greater than the mass of the root region 134.

The above description is only a part of the embodiments of the present application, and not intended to limit the scope of the present application, and all equivalent devices or equivalent processes performed by the contents of the specification and the drawings, or applied directly or indirectly to other related technical fields, are all included in the scope of the present application.

Claims (10)

1. A MEMS resonator horn assembly comprising:

an anchoring member;

the vibration arm is provided with a fixed end and a free end at intervals in the length direction; the fixed end is connected with the anchoring piece, the vibrating arm is configured to be close to a root area of the fixed end and close to a head area of the free end, and the mass of the head area is larger than that of the root area.

2. The MEMS resonator horn assembly of claim 1 wherein the horn arm has a width varying section, the width of the horn arm increasing in a direction from the fixed end to the free end over at least a portion of the width varying section.

3. The MEMS resonator horn assembly of claim 2 wherein the length of the gradually increasing width portion of the horn is not less than one tenth of the total length of the horn.

4. The MEMS resonator horn assembly of claim 2 wherein the width varying section is located in the root region and the head region or the width varying section is located only in the head region.

5. The MEMS resonator horn assembly of claim 2 wherein the width varying section is in a wedge or disc configuration.

6. The MEMS resonator horn assembly of claim 2 wherein the horn further has a constant width section on a side of the varying width section toward the fixed end and connected to the varying width section; in the constant width section, the width of the vibrating arm is kept constant along the length direction of the vibrating arm.

7. The MEMS resonator arm assembly of claim 1, further comprising a coupling beam, wherein the anchor and the arm are spaced apart along a width of the arm, and wherein the fixed end is connected to the anchor through the coupling beam.

8. The MEMS resonator arm assembly of claim 1, wherein the number of the arms is at least two, and the at least two arms are connected to each other along a length direction of the arms and/or spaced apart from each other along a width direction of the arms; wherein the at least two vibrating arms are connected with the same anchor.

9. A MEMS resonator comprising a drive electrode, a sense electrode, and a MEMS resonator horn assembly of any one of claims 1 to 8; the driving electrode and the induction electrode are opposite at intervals, and the vibrating arm is located between the driving electrode and the induction electrode.

10. The MEMS resonator of claim 9, wherein the driving electrode and the sensing electrode are spaced apart from a surface of the horn.

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