A notched quartz tuning fork resonator

Abstract

The application discloses a recessed quartz tuning fork resonator, which comprises a quartz tuning fork, a first electrode assembly and a second electrode assembly; the first electrode assembly and the second electrode assembly are arranged in a central symmetry about the center of the quartz tuning fork; the front surface and the back surface of each tuning fork arm of the quartz tuning fork are provided with a recess extending along the long axis of the tuning fork arm; a first positive electrode sheet is arranged in one recess of one of the tuning fork arms and covers the groove bottom and the groove wall of the recess; a sixth positive electrode sheet is arranged in the other recess of one of the tuning fork arms and covers the groove bottom and the groove wall of the recess, and the sixth positive electrode sheet is connected with the first positive electrode sheet through a seventh positive electrode sheet and has an area equal to that of the first positive electrode sheet; and the vibration mode of the quartz tuning fork is an anti-phase bending vibration mode. According to the application, the groove bottom and the groove wall of the recess of the tuning fork arm are covered with the electrode sheets, the area of the electrode sheets on the tuning fork arm is increased, the impedance is reduced, and the sensitivity is improved.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, and specifically relates to a grooved quartz tuning fork resonator. Background Technology

[0002] Sensor technology, as one of the pillars of modern information technology, is now playing a significant role in aerospace, resource exploration, transportation and communication, medical electronics, biological research, and daily life. With the continuous development of modern measurement and control technology, various fields are placing higher demands on sensor detection systems. Among existing sensors, temperature sensors are widely used, serving not only as important thermal sensors but also as key components in modern measurement and control systems.

[0003] Thickness-shear quartz crystal temperature sensors employ a resonator based on the thickness-shear vibration mode as the sensor's sensitive element. A quartz crystal with a specific cutting direction is fabricated into a wafer, and metal electrodes are deposited on both sides of the wafer using vacuum deposition or vacuum sputtering. When an excitation voltage is applied to the electrodes, the oscillator vibrates using the inverse piezoelectric effect, simultaneously generating alternating charges on the electrodes. These charges are replenished through electrodes connected to an external circuit to supply the energy required for this electro-mechanical constant-amplitude oscillation. When the quartz oscillator is subjected to static pressure, the vibration frequency changes linearly with the applied pressure. The resonator structure is typically square or circular. In practical applications, the quartz wafer is often beveled to form a lens shape to enhance the energy trapping effect.

[0004] However, the resonator output of the thickness shear mode quartz crystal temperature sensor is high-frequency, has high power consumption, relatively narrow temperature measurement range, poor sensitivity, and weak anti-interference ability. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a grooved quartz tuning fork resonator. The technical problem to be solved by this invention is achieved through the following technical solution:

[0006] A grooved quartz tuning fork resonator includes: a quartz tuning fork, a first electrode assembly, and a second electrode assembly;

[0007] The first electrode assembly and the second electrode assembly are arranged in a centrally symmetrical manner about the center of the quartz tuning fork;

[0008] Each tuning fork arm of the quartz tuning fork has a groove extending along the long axis of the tuning fork arm on both the front and back sides.

[0009] The first electrode assembly includes: a first positive electrode plate, a second positive electrode plate, a third positive electrode plate, a fourth positive electrode plate, a fifth positive electrode plate, a sixth positive electrode plate, and a seventh positive electrode plate;

[0010] The first positive electrode sheet is located in a groove of one of the tuning fork arms and covers the groove bottom and groove wall;

[0011] The second positive electrode sheet is arranged on the quartz tuning fork, one end of which is connected with the first positive electrode sheet;

[0012] The third positive electrode sheet is arranged on the quartz tuning fork, two ends of which are respectively connected with the fourth positive electrode sheet and the fifth positive electrode sheet;

[0013] The fourth positive electrode sheet is located on the outer side wall of the other tuning fork arm and connected with the other end of the second positive electrode sheet;

[0014] The fifth positive electrode sheet is located on the inner side wall of the other tuning fork arm;

[0015] The sixth positive electrode sheet is located in another groove of one of the tuning fork arms and covers the groove bottom and groove wall, connected with the first positive electrode sheet through the seventh positive electrode sheet, and has an area equal to that of the first positive electrode sheet;

[0016] The vibration mode of the quartz tuning fork is an anti-phase bending vibration mode.

[0017] In an embodiment of the present application, one end of the second positive electrode sheet is connected with the first positive electrode sheet near the end of the base of the quartz tuning fork, and the other end extends towards the other tuning fork arm to the edge of the base and is connected with the fourth positive electrode sheet.

[0018] In an embodiment of the present application, one end of the third positive electrode sheet is located at the connection between the other tuning fork arm and the base and is connected with the fifth positive electrode sheet, and the other end extends away from the first positive electrode sheet to the edge of the base and is connected with the fourth positive electrode sheet.

[0019] In an embodiment of the present application, one end of the seventh positive electrode sheet is connected with the first positive electrode sheet away from the end of the base, and the other end is connected with the sixth positive electrode sheet away from the end of the base.

[0020] In an embodiment of the present application, the first electrode assembly further comprises an eighth positive electrode sheet;

[0021] The eighth positive electrode sheet is located on the same side of the quartz tuning fork as the sixth positive electrode sheet and is connected with the sixth positive electrode sheet near the end of the base.

[0022] In one embodiment of the present application, the fourth positive electrode sheet extends to the outer sidewall of the base.

[0023] In one embodiment of the present application, the thermal sensitive cut type of the quartz tuning fork is (xylt) 47°, -10°.

[0024] In one embodiment of the present application, the length of each tuning fork arm of the quartz tuning fork is 3 mm, the width of each tuning fork arm is 0.38 mm, and the thickness of the quartz tuning fork is 0.13 mm; the total length of the quartz tuning fork is 5 mm; and the total width of the quartz tuning fork is 1 mm.

[0025] The present application has the following beneficial effects:

[0026] In the present application, the first electrode assembly and the second electrode assembly are symmetrically arranged, so that the electrode sheet areas on the two tuning fork arms of the quartz tuning fork are equal. Under the excitation of an external alternating electric signal, two electric fields of equal size and opposite directions are generated. Under the action of the inverse piezoelectric effect, two forces of equal size and opposite directions are generated on the two tuning fork arms. Therefore, the two tuning fork arms are in an anti-phase bending vibration mode, have a high quality factor, prevent the occurrence of cross interference and frequency hopping phenomenon caused by mode coupling, and improve the anti-interference ability of the resonator and the stability and reliability of the sensor. Meanwhile, the groove bottom and groove wall of the tuning fork arm are covered with electrode sheets, which increases the area of the electrode sheets on the tuning fork arm, reduces the impedance, and improves the sensitivity.

[0027] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1a FIG. 1 is a structural schematic view of the front side of a groove type quartz tuning fork resonator according to an embodiment of the present application;

[0029] Figure 1b FIG. 2 is a structural schematic view of the back side of a groove type quartz tuning fork resonator according to an embodiment of the present application;

[0030] Figure 2 FIG. 3 is a structural schematic view of a quartz tuning fork according to an embodiment of the present application;

[0031] Figure 3 FIG. 4 is an electrode connection schematic view of a groove type quartz tuning fork resonator according to an embodiment of the present application;

[0032] Figure 4 FIG. 5 is an electric field schematic view of the electrodes of a groove type quartz tuning fork resonator according to an embodiment of the present application;

[0033] Figure 5 FIG. 6 is an anti-phase bending vibration mode schematic view of a groove type quartz tuning fork resonator according to an embodiment of the present application.

[0034] Figure 6 A schematic diagram of the influence of meshing on the sixth-order vibration mode resonance frequency in finite element analysis of the quartz tuning fork provided for the embodiment of the present application;

[0035] Figure 7 A schematic diagram of the influence of the width of the quartz tuning fork on the frequency provided for the embodiment of the present application;

[0036] Figure 8 A schematic diagram of the influence of the width of the tuning fork arm of the quartz tuning fork on the frequency provided for the embodiment of the present application;

[0037] Figure 9 A schematic diagram of the influence of the length of the base of the quartz tuning fork on the frequency provided for the embodiment of the present application;

[0038] Figure 10 A schematic diagram of the influence of the length of the tuning fork arm of the quartz tuning fork on the frequency provided for the embodiment of the present application;

[0039] Figure 11 A schematic diagram of the influence of the thickness of the quartz tuning fork on the frequency provided for the embodiment of the present application.

[0040] BRIEF DESCRIPTION OF DRAWINGS

[0041] 10 - first tuning fork arm; 11 - first positive electrode piece; 12 - second positive electrode piece; 13 - third positive electrode piece; 14 - fourth positive electrode piece; 15 - fifth positive electrode piece; 16 - sixth positive electrode piece; 17 - seventh positive electrode piece; 18 - eighth positive electrode piece; 20 - second tuning fork arm; 21 - first negative electrode piece; 22 - second negative electrode piece; 23 - third negative electrode piece; 24 - fourth negative electrode piece; 25 - fifth negative electrode piece; 26 - sixth negative electrode piece; 27 - seventh negative electrode piece; 28 - eighth negative electrode piece; 30 - groove; 40 - base. DETAILED DESCRIPTION

[0042] The present application will be further described below in conjunction with specific embodiments, but the embodiments of the present application are not limited thereto.

[0043] Embodiment One

[0044] As shown in Figure 1a , Figure 1b and Figure 2 , a groove type quartz tuning fork resonator comprises a quartz tuning fork, a first electrode assembly and a second electrode assembly.

[0045] The first electrode assembly and the second electrode assembly are centrally symmetrically arranged about the center of the quartz tuning fork; the quartz tuning fork comprises a base 40 and two tuning fork arms arranged on the base 40, one of which is a first tuning fork arm 10 and the other is a second tuning fork arm 20. The first electrode assembly and the second electrode assembly are centrally symmetric about the symmetry axis between the two tuning fork arms. The front surface and the back surface of each tuning fork arm of the quartz tuning fork are provided with a groove 30 extending along the long axis of the tuning fork arm;

[0046] The first electrode assembly comprises a first positive electrode sheet 11, a second positive electrode sheet 12, a third positive electrode sheet 13, a fourth positive electrode sheet 14, a fifth positive electrode sheet 15, a sixth positive electrode sheet 16 and a seventh positive electrode sheet 17.

[0047] The first positive electrode sheet 11 is attached in one groove 30 of the first tuning fork arm 10 and covers the groove bottom and the groove wall of the groove 30; in the embodiment, the first positive electrode sheet 11 is taken as an example located on the front surface of the quartz tuning fork, that is, the first positive electrode sheet 11 is taken as an example located in the groove 30 on the front surface of the first tuning fork arm 10.

[0048] The second positive electrode sheet 12 is arranged on the quartz tuning fork, one end of the second positive electrode sheet 12 is connected with the first positive electrode sheet 11; preferably, the second positive electrode sheet 12 is located on the same surface of the quartz tuning fork as the first positive electrode sheet 11. In the embodiment, correspondingly, the second positive electrode sheet 12 is attached on the front surface of the quartz tuning fork.

[0049] The third positive electrode sheet 13 is arranged on the quartz tuning fork, both ends of the third positive electrode sheet 13 are respectively connected with the fourth positive electrode sheet 14 and the fifth positive electrode sheet 15; preferably, the third positive electrode sheet 13 is located on the same surface of the quartz tuning fork as the second positive electrode sheet 12, and in the embodiment, the third positive electrode sheet 13 is correspondingly attached on the front surface.

[0050] The fourth positive electrode sheet 14 is attached on the outer side wall of the second tuning fork arm 20, and the fourth positive electrode sheet 14 is connected with the other end of the second electrode;

[0051] The fifth positive electrode sheet 15 is attached on the inner side wall of the second tuning fork arm 20;

[0052] The sixth positive electrode sheet 16 is located in the other groove 30 of the first tuning fork arm 10 and covers the groove bottom and the groove wall of the groove 30, the sixth positive electrode sheet 16 is connected with the first positive electrode sheet 11 through the seventh positive electrode sheet 17, and the area of the sixth positive electrode sheet 16 is equal to that of the first positive electrode sheet 11; the first positive electrode sheet 11 and the sixth positive electrode sheet 16 are respectively located in the two grooves 30 of the first tuning fork arm 10, and correspondingly, in the embodiment, the sixth positive electrode sheet 16 is located on the back surface of the quartz tuning fork, that is, the sixth positive electrode sheet 16 is located in the groove 30 on the back surface.

[0053] The vibration mode of the quartz tuning fork is an anti-phase bending vibration mode.

[0054] In the embodiment, the second electrode assembly comprises: a first negative electrode sheet 21, a second negative electrode sheet 22, a third negative electrode sheet 23, a fourth negative electrode sheet 24, a fifth negative electrode sheet 25, a sixth negative electrode sheet 26, and a seventh negative electrode sheet 27.

[0055] The first positive electrode sheet 11 and the first negative electrode sheet 21 are the same in shape and are centrally symmetric, and correspondingly, the first negative electrode sheet 21 is attached to the concave groove 30 on the opposite side of the second tuning fork arm 20 and covers the groove bottom and groove wall of the concave groove 30; in the embodiment, taking the front side of the quartz tuning fork as an example, the first negative electrode sheet 21 is located on the back side of the quartz tuning fork.

[0056] The second positive electrode sheet 12 and the second negative electrode sheet 22 are the same in shape and are centrally symmetric, and correspondingly, the second negative electrode sheet 22 is arranged on the quartz tuning fork, one end of the second negative electrode sheet 22 is connected with the first negative electrode sheet 21; preferably, the second negative electrode sheet 22 and the first negative electrode sheet 21 are located on the same side of the quartz tuning fork. In the embodiment, correspondingly, the second negative electrode sheet 22 is attached to the back side of the quartz tuning fork.

[0057] The third positive electrode sheet 13 and the third negative electrode sheet 23 are the same in shape and are centrally symmetric, and correspondingly, the third negative electrode sheet 23 is arranged on the quartz tuning fork, both ends of the third negative electrode sheet 23 are connected with the fourth negative electrode sheet 24 and the fifth negative electrode sheet 25 respectively; preferably, the third negative electrode sheet 23 and the second negative electrode sheet 22 are located on the same side of the quartz tuning fork, and in the embodiment, correspondingly, the third negative electrode sheet 23 is attached to the back side.

[0058] The fourth positive electrode sheet 14 and the fourth negative electrode sheet 24 are the same in shape and are centrally symmetric, and correspondingly, the fourth negative electrode sheet 24 is attached to the outer side wall of the first tuning fork arm 10, and the fourth negative electrode sheet 24 is connected with the other end of the second negative electrode sheet 22.

[0059] The fifth positive electrode sheet 15 and the fifth negative electrode sheet 25 are the same in shape and are centrally symmetric, and correspondingly, the fifth negative electrode sheet 25 is attached to the inner side wall of the first tuning fork arm 10.

[0060] The sixth positive electrode sheet 16 and the sixth negative electrode sheet 26 are the same shape and are centrally symmetrically arranged, and correspondingly, the sixth negative electrode sheet 26 is located in the other groove 30 of the second tuning fork arm 20 and covers the groove bottom and groove wall of the groove 30, the sixth negative electrode sheet 26 is connected with the first negative electrode sheet 21 through the seventh negative electrode sheet 27, and the area of the sixth negative electrode sheet 26 is equal to that of the first negative electrode sheet 21; the first negative electrode sheet 21 and the sixth negative electrode sheet 26 are respectively located in the two grooves 30 of the second tuning fork arm 20, and correspondingly, in this embodiment, the sixth negative electrode sheet 26 is located on the front surface of the quartz tuning fork, that is, the sixth negative electrode sheet 26 is located in the groove 30 on the front surface.

[0061] In this embodiment, the quartz tuning fork resonator is used as a thermal element of a temperature sensor, and the change of the external temperature is converted into the mechanical strain of the quartz tuning fork resonator through the mechanical structure, and further converted into the change of the resonant frequency, and the change of the temperature is characterized by detecting the change of the resonant frequency.

[0062] The first positive electrode sheet 11, the sixth positive electrode sheet 16, the fourth negative electrode sheet 24 and the fifth negative electrode sheet 25 are located on the first tuning fork arm 10, and the first negative electrode sheet 21, the sixth negative electrode sheet 26, the fourth positive electrode sheet 14 and the fifth positive electrode sheet 15 are located on the second tuning fork arm 20, the cross section at the groove 30 position of each tuning fork arm is H-shaped, and the electrode distribution and electric field distribution of the two tuning fork arms are as shown in Figure 3 and Figure 4 Due to the symmetry, the electric field can be divided into an electric field component Ex along the x direction and an electric field component Ez along the z direction. On both sides of the groove 30 of the quartz tuning fork arm, the size of Ex is equal and the direction is opposite, and through the coupling effect of the corresponding piezoelectric strain constant d'21, two forces with equal size and opposite direction are generated on the two tuning fork arms under the action of the inverse piezoelectric effect, therefore, the two tuning fork arms are in the anti-phase bending vibration mode, as shown in Figure 5 The two tuning fork arms are in the anti-phase bending vibration mode, that is, the two tuning fork arms bend towards each other at the same time and bend away from each other at the same time. The two tuning fork arms are in the anti-phase bending vibration mode, that is, the two tuning fork arms bend towards each other at the same time and bend away from each other at the same time.

[0063] It should be noted that, compared with the surface electrode attached to the front surface and the back surface of the tuning fork arm, in this embodiment, the groove 30 is arranged on the tuning fork arm, and the electrode sheet covers the groove bottom and groove wall of the groove 30, the area of the surface electrode sheet of the tuning fork arm is increased, the impedance is reduced, the elastic compliance constant of the quartz tuning fork arm is reduced, and therefore the nominal frequency of the tuning fork arm is maintained unchanged after the length of the tuning fork arm is shortened, and the sensitivity of the temperature sensor based on the quartz tuning fork resonator is improved.

[0064] The groove 30 can be a rectangular slot structure.

[0065] Further, one end of the second positive electrode tab 12 is connected to the end of the first positive electrode tab 11 close to the base 40, and the other end of the second positive electrode tab 12 extends to the edge of the base 40 of the quartz tuning fork towards the second tuning fork arm 20 and is connected to the fourth positive electrode tab 14. The fourth positive electrode tab 14 extends from the outer side wall of the second tuning fork arm 20 to the outer side wall of the base 40.

[0066] Correspondingly, one end of the second negative electrode tab 22 is connected to the end of the first negative electrode tab 21 close to the base 40, and the other end of the second negative electrode tab 22 extends to the edge of the base 40 of the quartz tuning fork towards the first tuning fork arm 10 and is connected to the fourth positive electrode tab 14. The fourth negative electrode tab 24 extends from the outer side wall of the first tuning fork arm 10 to the outer side wall of the base 40.

[0067] Further, one end of the third positive electrode tab 13 is located at the connection between the second tuning fork arm 20 and the base 40 and is connected to the fifth positive electrode tab 15, and the other end of the third positive electrode tab 13 extends away from the first positive electrode tab 11 to the edge of the base 40 and is connected to the fourth positive electrode tab 14.

[0068] Correspondingly, one end of the third negative electrode tab 23 is located at the connection between the first tuning fork arm 10 and the base 40 and is connected to the fifth negative electrode tab 25, and the other end of the third negative electrode tab 23 extends away from the first negative electrode tab 21 to the edge of the base 40 and is connected to the fourth negative electrode tab 24.

[0069] Further, one end of the seventh positive electrode tab 17 is connected to the end of the first positive electrode tab 11 away from the base 40, and the other end of the seventh positive electrode tab 17 is connected to the end of the sixth positive electrode tab 16 away from the base 40. The seventh positive electrode tab 17 is attached to the first tuning fork arm 10, one end of the seventh positive electrode tab 17 is located on the front face of the first tuning fork arm 10, and the other end extends to the back face through the outer side wall of the first tuning fork arm 10. There is a gap between the seventh positive electrode tab 17 and the fourth negative electrode tab 24.

[0070] Correspondingly, one end of the seventh negative electrode tab 27 is connected to the end of the first negative electrode tab 21 away from the base 40, and the other end of the seventh negative electrode tab 27 is connected to the end of the sixth negative electrode tab 26 away from the base 40. The seventh negative electrode tab 27 is attached to the second tuning fork arm 20, one end of the seventh negative electrode tab 27 is located on the front face of the second tuning fork arm 20, and the other end extends to the back face through the outer side wall of the second tuning fork arm 20. There is a gap between the seventh negative electrode tab 27 and the fourth positive electrode tab 14.

[0071] Further, the first electrode assembly further comprises: an eighth positive electrode tab 18;

[0072] The eighth positive electrode sheet 18 is located on the same side (the reverse side) of the quartz tuning fork as the sixth positive electrode sheet 16, and the eighth positive electrode sheet 18 is connected to the sixth positive electrode sheet 16 near the end of the base 40. There is a gap between the eighth positive electrode sheet 18 and the third negative electrode sheet 23.

[0073] Correspondingly, the second electrode assembly further comprises: an eighth negative electrode sheet 28;

[0074] The eighth negative electrode sheet 28 is located on the same side (the front side) of the quartz tuning fork as the sixth negative electrode sheet 26, and the eighth negative electrode sheet 28 is connected to the sixth negative electrode sheet 26 near the end of the base 40. There is a gap between the eighth negative electrode sheet 28 and the third positive electrode sheet 13.

[0075] Wherein, there is a gap between the positive electrode sheet and the negative electrode sheet.

[0076] Further, the thermal sensitive cut type of the quartz tuning fork is (xylt) 47°, -10°. The quartz tuning fork resonator temperature sensor utilizes the anisotropy of the quartz crystal to sense the external temperature, converts the change of the external temperature into the change of the resonant frequency, detects the change of the temperature by detecting the shift of the resonator resonant frequency. The double-turn thermal sensitive cut type of the embodiment can avoid redundant vibration modes while maintaining sufficient piezoelectric activity, optimize the anti-phase bending vibration mode, and obtain good frequency-temperature characteristics, thereby improving the sensitivity and accuracy of the quartz crystal temperature sensor.

[0077] In the embodiment, by designing the structure of the quartz tuning fork and setting the driving electrode, the quartz tuning fork resonator works in the ideal vibration mode to obtain a single vibration mode and a high quality factor, which can avoid the influence of mutual interference between vibration modes on the sensor and improve the stability and reliability of the sensor.

[0078] Further, each tuning fork arm of the quartz tuning fork has a length of 3 mm, a width of 0.38 mm, and a thickness of 0.13 mm; the total length of the quartz tuning fork is 5 mm; and the total width of the quartz tuning fork is 1 mm.

[0079] The structure of the quartz tuning fork is analyzed by finite element analysis, such as Figure 1a and Figure 1b Figure 6 ​As shown, the resonant frequency tends to be stable after 0.1 mm, but too fine mesh needs to spend a very long time for calculation and the final results gap is small. To get accurate simulation results, 0.1 mm is selected as the mesh size of finite element analysis. Such mesh size contains 398847 nodes and 228177 units. The fixed end of the base 40 of the quartz tuning fork is set as a constraint condition to simulate the actual tuning fork resonator. Considering the electromechanical coupling of the quartz crystal, to realize the force-electric coupling of the electrode and the quartz tuning fork, the load and ground electrodes are defined, and the electrode is defined to deform to generate ultrasonic waves when an electric field is applied. Therefore, two groups of electrodes are created, one group of electrodes is defined as the load electrode to provide a stable sinusoidal voltage wave, and the other group is defined as the ground electrode. Modal analysis and harmonic response analysis are used to determine the structural vibration characteristics of the quartz tuning fork.

[0080] Thus, in the fifth order vibration mode, the quartz tuning fork is in a stable bending vibration state, and the tuning fork arms vibrate in the width direction in opposite phases. This order of vibration mode meets the working condition of the tuning fork.

[0081] Figure 7 The influence of the width of the quartz tuning fork on the frequency. As the width increases, the frequency of the working state remains basically unchanged, and the frequency of the working state is closer and closer to the frequency of the next order and further and further away from the frequency of the previous order. Therefore, 1.0 mm is selected as the width of the quartz tuning fork to optimize the structure of the quartz tuning fork resonator.

[0082] See Figure 8 , Figure 8 The influence of the width of the tuning fork arm on the frequency. As the width of the tuning fork increases, the frequency of the bending vibration state is closer and closer to the frequency of the next order and further and further away from the frequency of the previous order. In order to take into account these two cases, 0.38 mm, which has the largest average value, is selected as the width of each tuning fork arm of the quartz tuning fork resonator.

[0083] See Figure 9 , Figure 9 The influence of the length of the base 40 on the frequency. As the length of the base 40 increases, it has little effect on the frequency of the bending vibration state, while the frequency of the next order gradually approaches the bending vibration state and the frequency of the previous order gradually moves away from the bending vibration state. Similarly, in order to take into account the two vibration states, 2 mm is selected as the length of the base 40.

[0084] See Figure 10 , Figure 10 The influence of the length of the tuning fork arm on the frequency. As the length of the tuning fork increases, the vibration frequencies of the fourth, fifth and sixth modes all decrease sharply. Too high or too low frequency will affect the temperature sensitivity of the quartz tuning fork resonator, so 3 mm is selected as the length of the tuning fork arm.

[0085] Please refer to Figure 11 , Figure 11 The influence of the thickness of the quartz tuning fork on the frequency. With the increase of the thickness of the tuning fork, the frequency of the bending vibration state is not greatly affected, but the frequency of the previous order vibration state is rapidly close to the frequency of the bending vibration state, and the frequency of the later order vibration state is gradually away from the frequency of the bending vibration state. In order to avoid the coupling of the frequency of the previous order vibration state and the frequency of the bending vibration state, and to affect the accuracy, 0.13mm is selected as the thickness of the quartz tuning fork.

[0086] The quartz tuning fork of the embodiment has a small volume, and the quartz tuning fork resonator ensures the sensitivity and accuracy of the temperature sensor through the arrangement of the groove 30 and the electrode sheet under a small structural size.

[0087] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0088] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0089] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0090] In the present application, unless specifically stated and limited otherwise, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the first feature is lower than the second feature in horizontal height.

[0091] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and integrate different embodiments or examples described in the present application.

[0092] The above is a further detailed description of the present application in combination with specific preferred embodiments, and cannot be considered as limiting the specific implementation of the present application to these descriptions. For those skilled in the art, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope of the present application.

Claims

1. A grooved quartz tuning fork resonator, characterized in that, include: Quartz tuning fork, first electrode assembly, and second electrode assembly; The first electrode assembly and the second electrode assembly are arranged in a centrally symmetrical manner about the center of the quartz tuning fork; The quartz tuning fork includes a base (40) and two tuning fork arms disposed on the base (40). Each tuning fork arm of the quartz tuning fork has a groove (30) extending along the long axis of the tuning fork arm on both the front and back surfaces. The first electrode assembly includes: a first positive electrode plate (11), a second positive electrode plate (12), a third positive electrode plate (13), a fourth positive electrode plate (14), a fifth positive electrode plate (15), a sixth positive electrode plate (16), and a seventh positive electrode plate (17); The first positive electrode plate (11) is located in a groove (30) of one of the tuning fork arms and covers the bottom and wall of the groove (30); The second positive electrode plate (12) is disposed on the quartz tuning fork, and one end is connected to the first positive electrode plate (11); one end of the second positive electrode plate (12) is connected to the end of the first positive electrode plate (11) near the base (40) of the quartz tuning fork, and the other end extends toward the other tuning fork arm to the edge of the base (40) and is connected to the fourth positive electrode plate (14); The third positive electrode plate (13) is disposed on the quartz tuning fork, and its two ends are respectively connected to the fourth positive electrode plate (14) and the fifth positive electrode plate (15); one end of the third positive electrode plate (13) is located at the connection between the other tuning fork arm and the base (40) and is connected to the fifth positive electrode plate (15), and the other end extends away from the first positive electrode plate (11) to the edge of the base (40) and is connected to the fourth positive electrode plate (14); The fourth positive electrode plate (14) is located on the outer wall of another tuning fork arm and is connected to the other end of the second positive electrode plate (12); The fifth positive electrode plate (15) is located on the inner wall of the other tuning fork arm; The sixth positive electrode plate (16) is located in another groove (30) of one of the tuning fork arms and covers the bottom and wall of the groove (30). It is connected to the first positive electrode plate (11) through the seventh positive electrode plate (17) and has the same area as the first positive electrode plate (11). One end of the seventh positive electrode plate (17) is connected to the end of the first positive electrode plate (11) away from the base (40), and the other end is connected to the end of the sixth positive electrode plate (16) away from the base (40). The vibration mode of the quartz tuning fork is an anti-phase bending vibration mode.

2. The grooved quartz tuning fork resonator according to claim 1, characterized in that, The first electrode assembly further includes: an eighth positive electrode sheet (18); The eighth positive electrode plate (18) is located on the same side of the quartz tuning fork as the sixth positive electrode plate (16), and is connected to the end of the sixth positive electrode plate (16) near the base (40).

3. A grooved quartz tuning fork resonator according to claim 1, characterized in that, The fourth positive electrode plate (14) extends to the outer wall of the base (40).

4. A grooved quartz tuning fork resonator according to claim 1, characterized in that, The thermal cut of the quartz tuning fork is (xylt) 47°, -10°.

5. A grooved quartz tuning fork resonator according to claim 1, characterized in that, The length of each tuning fork arm of the quartz tuning fork is 3mm, the width of each tuning fork arm is 0.38mm, and the thickness of the quartz tuning fork is 0.13mm; the total length of the quartz tuning fork is 5mm; and the total width of the quartz tuning fork is 1mm.

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