Tuning fork type piezoelectric vibrating reed and oscillator using same

Abstract

A tuning fork type piezoelectric vibrating reed includes a base portion and two vibrating arm portions extending from the base portion, a first main surface of each vibrating arm portion is provided with a first driving groove, a second main surface of each vibrating arm portion is provided with a second driving groove, and the first driving groove and the second driving groove are arranged in parallel. A small groove is formed in the first main face or the second main face of the vibrating arm part, the small groove, a first driving groove and a second driving groove are sequentially formed in the length direction of the vibrating arm part, inner wall driving electrodes are arranged on the inner walls of the first driving groove, the second driving groove and the small groove, and side wall driving electrodes are arranged on the side wall of the vibrating arm part. At least one plane driving electrode is arranged at the position, corresponding to the second driving groove, of the first main surface of the vibrating arm part, and at least one plane driving electrode is arranged at the position, corresponding to the first driving groove, of the second main surface of the vibrating arm part; and a plurality of width thumbnail parts are arranged at the positions, close to the vibrating arm part, of the base part. Energy dissipation caused by thermoelastic damping can be reduced, out-of-plane displacement is effectively reduced, and therefore the Q value is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piezoelectric vibration element, in particular to a tuning fork type piezoelectric vibration piece and an oscillator using the same. BACKGROUND

[0002] The tuning fork type piezoelectric vibration piece has good frequency temperature characteristics and is widely used as a frequency reference source for various electronic devices. However, with the miniaturization of devices, the temperature difference generated by the bending vibration of the existing tuning fork type piezoelectric vibration piece is difficult to eliminate, thus causing a significant reduction in Q value. SUMMARY

[0003] The purpose of the present application is to provide a tuning fork type piezoelectric vibration piece and an oscillator using the same, which can effectively improve the Q value and solve the above-mentioned problems existing in the prior art.

[0004] To solve the above technical problems, the present application adopts the following technical solutions:

[0005] In a first aspect, the present application provides a tuning fork type piezoelectric vibration piece, comprising a base and two vibration arm portions extending from one end of the base, the two vibration arm portions are symmetrically arranged, and the polarities of the drive electrodes at the corresponding positions are opposite; each first main surface of the vibration arm portion is provided with a first drive groove, and the second main surface of the vibration arm portion is provided with a second drive groove, the first main surface and the second main surface are two oppositely arranged surfaces, and the first main surface or the second main surface of the vibration arm portion is further provided with a small groove, the small groove, the first drive groove and the second drive groove are sequentially arranged along the length direction of the vibration arm portion, the length of the first drive groove is greater than the length of the second drive groove, and the length of the second drive groove is greater than the length of the small groove, the inner walls of the first drive groove, the second drive groove and the small groove are provided with inner wall drive electrodes, the side wall of the vibration arm portion is provided with a side wall drive electrode, and at least one piece of planar drive electrode is arranged at the position corresponding to the second drive groove of the first main surface of the vibration arm portion and the position corresponding to the first drive groove of the second main surface of the vibration arm portion along the width direction of the vibration arm portion, drive electrodes are arranged on both sides of the base, and a plurality of width reduction portions completely through in thickness are arranged on both sides of the base close to the vibration arm portion.

[0006] Further, the length of the first drive groove and the second drive groove accounts for 40%-70% of the length of the vibration arm portion, and the width of the first drive groove and the width of the second drive groove account for 35%-65% of the width of the vibration arm portion.

[0007] Further, the first driving groove and the second driving groove are integral grooves with a U-shaped cross section, and the depth of the first driving groove and the second driving groove accounts for no more than 80% of the thickness of the vibrating arm portion.

[0008] Further, along the length direction of the vibrating arm portion, the bottom of the first driving groove and the second driving groove is respectively provided with a partition beam, so that the first driving groove and the second driving groove are each divided into two grooves with a U-shaped cross section, and the depth of the first driving groove and the second driving groove accounts for no more than 85% of the thickness of the vibrating arm portion.

[0009] Further, the length of the planar driving electrode on the first main surface of the vibrating arm portion is the same as the length of the second driving groove, and the length of the planar driving electrode on the second main surface of the vibrating arm portion is the same as the length of the first driving groove.

[0010] Further, along the width direction of the vibrating arm portion, the first main surface of the vibrating arm portion is provided with three planar driving electrodes with alternating polarities, and the second main surface of the vibrating arm portion is provided with three planar driving electrodes with alternating polarities; the polarity of the side wall driving electrode of the vibrating arm portion is the same as the polarities of the two side planar driving electrodes of the three planar driving electrodes on the first main surface of the vibrating arm portion, the two side planar driving electrodes of the three planar driving electrodes on the second main surface of the vibrating arm portion, and the two side driving electrodes of the base portion, and is opposite to the polarities of the inner wall driving electrode of the first driving groove, the inner wall driving electrode of the second driving groove, and the inner wall driving electrode of the small groove.

[0011] Further, the side wall driving electrode of the vibrating arm portion, the two side planar driving electrodes of the three planar driving electrodes on the first main surface of the vibrating arm portion, and the two side planar driving electrodes of the three planar driving electrodes on the second main surface of the vibrating arm portion are all non-segmented electrodes, and the middle planar driving electrode of the three planar driving electrodes on the first main surface of the vibrating arm portion and the middle planar driving electrode of the three planar driving electrodes on the second main surface of the vibrating arm portion are all rectangular electrodes.

[0012] Further, the application further comprises a weight applying part, two weight applying parts with the same shape are respectively connected to the ends of the two vibration arm parts and symmetrically arranged, the polarities of the driving electrodes at the corresponding positions of the two weight applying parts are opposite, the width of the weight applying part is greater than the width of the vibration arm part, a width transition area is arranged at the position of the weight applying part close to the vibration arm part, a metal with a preset thickness is arranged at the end of the weight applying part, at least one of the first main surface and the second main surface of the weight applying part is provided with a driving electrode, the polarity of the driving electrode of the weight applying part is opposite to the polarity of the inner wall driving electrode of the first driving groove and the polarity of the inner wall driving electrode of the second driving groove.

[0013] Further, the width transition part is arranged in a zigzag parallel arrangement with the same interval.

[0014] In the second aspect, the application further provides an oscillator comprising the tuning fork type piezoelectric vibration piece.

[0015] Compared with the prior art, the application has the following beneficial technical effects:

[0016] In the tuning fork type piezoelectric vibration piece and the oscillator using the piezoelectric vibration piece, when the piezoelectric vibration piece is in bending vibration, the distance of heat transfer from the compressed surface to the elongated surface is lengthened, that is, the heat conduction path is lengthened, the energy dissipation caused by the thermoelastic damping can be reduced, the out-of-plane displacement can be effectively reduced, and the Q value can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 It is a perspective view of the tuning fork type piezoelectric vibration piece of the embodiment 1 of the application.

[0019] Figure 2 It is a perspective view of the tuning fork type piezoelectric vibration piece of the embodiment 1 of the application.

[0020] Figure 3 It is a sectional view of the vibration arm part of the tuning fork type piezoelectric vibration piece of the embodiment 1 of the application.

[0021] Figure 4 It is a structural view of the first main surface of the tuning fork type piezoelectric vibration piece of the embodiment 1 of the application.

[0022] Figure 5 It is a structural view of the second main surface of the tuning fork type piezoelectric vibration piece of the embodiment 1 of the application.

[0023] Figure 6 FIG. 2 is a schematic view of a cross-sectional structure of a vibration arm portion of a tuning fork type piezoelectric vibration piece according to Embodiment 2 of the present application.

[0024] Reference Signs: 10, tuning fork type piezoelectric vibration piece; 11, base portion; 12a, 12b, width-reduced portion; 11a, 11b, driving electrode of base portion; 11c, 11d, electrode pattern; 20a, 20b, vibration arm portion; 21a, 21b, small groove; 22a, 22b, first driving groove; 23a, 23b, second driving groove; 241, 251, middle one of three planar driving electrodes; 242, 243, 252, 253, side wall driving electrode of vibration arm portion; 31, 41, weight portion; 31c, 41c, driving electrode of weight portion. DETAILED DESCRIPTION

[0025] Embodiments of the present application are described in detail below with reference to the accompanying drawings. In the description of the present application, identical or similar components or components having identical or similar functions are denoted by the same reference numerals throughout the several drawings, and description thereof is not repeated. The embodiments described below are exemplary only, and are merely for the purpose of explaining the present application, and should not be construed in a limiting sense of the present application.

[0026] In the description of the present application, it should be understood that the terms "length", "width", "inner", "outer", and the like indicate the positional or spatial relationship based on the positional or spatial relationship shown in the drawings, and are merely for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application. In addition, the terms "first", "second" are for the purpose of description only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "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 explicitly specified and limited.

[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the 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.

[0028] The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] Embodiment 1

[0030] As shown in the figure, the tuning fork type piezoelectric vibration piece of the embodiment 1 of the present application comprises a base and two vibration arm parts extending from one end of the base, the two vibration arm parts are symmetrically arranged, and the polarities of the driving electrodes at the corresponding positions are opposite. Figures 1 to 5

[0031] Wherein, for each vibration arm part, the first main surface of the vibration arm part is provided with a first driving groove, the inner wall of the first driving groove is provided with an inner wall driving electrode, the second main surface of the vibration arm part is provided with a second driving groove, the inner wall of the second driving groove is provided with an inner wall driving electrode, along the length direction of the vibration arm part, the first driving groove and the second driving groove are staggered, and the length of the driving groove close to the base is greater than or equal to the length of the driving groove away from the base, the side wall of the vibration arm part is provided with a side wall driving electrode, along the width direction of the vibration arm part, at least one piece of planar driving electrode is arranged on the first main surface of the vibration arm part corresponding to the position of the second driving groove, and at least one piece of planar driving electrode is arranged on the second main surface of the vibration arm part corresponding to the position of the first driving groove.

[0032] And the first main surface and the second main surface are two opposite surfaces.

[0033] When the tuning fork type piezoelectric vibration piece of the embodiment 1 bends and vibrates, the distance of heat transfer from the compressed surface to the elongated surface becomes longer, that is, the heat conduction path becomes longer, which can reduce the energy dissipation caused by thermoelastic damping and effectively reduce the out-of-plane displacement, thereby improving the Q value and helping the miniaturization of the device.

[0034] As shown in the figure, the first driving groove of the first main surface of the vibration arm part is an integral groove, and the first driving groove is the driving groove close to the base, that is, as shown in the figure, the cross-sectional shape of the first driving groove on the vibration arm part is U-shaped; the second driving groove of the second main surface of the vibration arm part is also an integral groove, and the second driving groove is the driving groove away from the base, that is, as shown in the figure, the cross-sectional shape of the second driving groove on the vibration arm part is inverted U-shaped; the length of the first driving groove is greater than or equal to the length of the second driving groove. Figure 1 Figure 3 Figure 3

[0035] In the embodiment 1, by setting the U-shaped driving groove, when the vibration arm part bends and vibrates between the first main surface and the second main surface, the compressed surface and the elongated surface can be blocked from directly transferring heat, the distance of heat transfer becomes longer, the thermoelastic damping is reduced, and the electric field efficiency is effectively improved.

[0036] ​​​​The depth of the first driving slot and the depth of the second driving slot account for no more than 80% of the thickness of the vibrating arm part, the length of the first driving slot and the length of the second driving slot account for 40%-70% of the length of the vibrating arm part, the width of the first driving slot and the width of the second driving slot account for 35%-65% of the width of the vibrating arm part. In this way, a large enough electric field driving force can be generated to drive the vibrating arm part to perform alternating bending vibration, and meanwhile, the crystal impedance value is prevented from being too large to affect the performance of the device.

[0037] Preferably, the depth of the first driving slot is the same as the depth of the second driving slot, and the width of the first driving slot is the same as the width of the second driving slot.

[0038] As shown in FIG. 1, the inner wall of the first driving slot and the inner wall of the second driving slot are provided with inner wall driving electrodes. Figure 3

[0039] As shown in FIG. 1, the inner wall of the first driving slot and the inner wall of the second driving slot are provided with inner wall driving electrodes. Figure 4 As shown in FIG. 1, the inner wall of the first driving slot and the inner wall of the second driving slot are provided with inner wall driving electrodes. Figure 5 As shown in FIG. 1, the inner wall of the first driving slot and the inner wall of the second driving slot are provided with inner wall driving electrodes.

[0040] Optionally, among the three planar driving electrodes, the two side planar driving electrodes are non-segmented electrodes, and the middle planar driving electrode is a rectangular electrode, and the polarities of the three planar driving electrodes are alternately changed, that is, the polarities of the two side planar driving electrodes are opposite to the polarity of the middle planar driving electrode.

[0041] Specifically, the polarities of the two side planar driving electrodes of the three planar driving electrodes on the first main surface of the vibrating arm part are the same as the polarity of the two side planar driving electrodes of the three planar driving electrodes on the second main surface of the vibrating arm part and the polarity of the side wall driving electrode of the vibrating arm part; the polarity of the middle planar driving electrode of the three planar driving electrodes on the first main surface of the vibrating arm part is the same as the polarity of the middle planar driving electrode of the three planar driving electrodes on the second main surface of the vibrating arm part, the polarity of the inner wall driving electrode of the first driving slot on the first main surface of the vibrating arm part, and the polarity of the inner wall driving electrode of the second driving slot on the second main surface of the vibrating arm part.

[0042] In addition, the side wall driving electrode of the vibrating arm part is also a non-segmented electrode, as shown in FIG. 1, the two side planar driving electrodes can be integrated with the corresponding side wall driving electrode. Figure 3

[0043] In this embodiment 1, by arranging the three planar driving electrodes, the electric field efficiency can be further improved, and when the same voltage is applied, a better driving effect can be generated.

[0044] ​​Preferably, the length of the planar driving electrode of the first main surface of the vibrating arm part is the same as the length of the second driving groove, and the length of the planar driving electrode of the second main surface of the vibrating arm part is the same as the length of the first driving groove.

[0045] It should be noted that in other embodiments of the present application, the planar driving electrode of the first main surface of the vibrating arm part and the planar driving electrode of the second main surface of the vibrating arm part can also be in other forms; for example, two planar driving electrodes, at this time, the polarities of the two planar driving electrodes can be set to be the same and opposite to the polarity of the sidewall driving electrode of the vibrating arm part; for another example, four planar driving electrodes or more planar driving electrodes, at this time, the number of planar driving electrodes is large, and the polarities of the planar driving electrodes located in the middle can be set to be the same and opposite to the polarities of the planar driving electrodes on both sides, and the same as the polarity of the sidewall driving electrode of the vibrating arm part.

[0046] In the embodiment 1, as shown in Figure 1 , the first main surface of the vibrating arm part is further provided with a small groove, the small groove is located at the root of the vibrating arm part close to the base part, and the rear end side of the small groove is the same distance from the root of the vibrating arm part to the end of the base part.

[0047] As shown in Figure 4 , the inner wall of the small groove is provided with an inner wall driving electrode, and the polarity of the inner wall driving electrode of the small groove is the same as the polarity of the inner wall driving electrode of the first driving groove and the polarity of the inner wall driving electrode of the second driving groove.

[0048] In the embodiment 1, by providing the small groove, the direct transfer of heat is blocked, the heat conduction path is increased, and the Q value is improved. Moreover, the small groove can effectively reduce the local stress generated by bending at the root of the vibrating arm part, and prevent the vibrating arm part from breaking due to stress.

[0049] It should be noted that in the embodiment 1, the small groove is located on the first main surface; in other embodiments, the small groove can also be located on the second main surface, which is not limited in the present application.

[0050] Preferably, when the small groove is located on the first main surface of the vibrating arm part, the depth of the small groove is the same as the depth of the first driving groove, and when the small groove is located on the second main surface of the vibrating arm part, the depth of the small groove is the same as the depth of the second driving groove, which can reduce the number of etching groove parts and simplify the process.

[0051] In the embodiment 1, as shown in Figure 1 , a plurality of width reduction parts with a thickness completely through are arranged at the position close to the vibrating arm part of the base part, and the width reduction parts on both sides of the base part are symmetrically arranged.

[0052] Specifically, the width reduction parts on each side of the base part are arranged in a zigzag shape in parallel and have the same spacing.

[0053] In this embodiment 1, by setting the width reduction part, the displacement change caused by vibration is difficult to be transmitted from the vibration arm part to the base part, the energy transmission will be intercepted, the vibration leakage from the vibration arm part to the base part can be effectively reduced, and the Q value is further improved.

[0054] It should be noted that in this embodiment 1, the width reduction part on each side of the base part is three; in other embodiments, the width reduction part on each side of the base part can be two, four or other number, which is not limited in the present application.

[0055] As shown in Figure 4 , Figure 5 , the driving electrodes are also provided on both sides of the base part, and the polarity of the driving electrode on each side of the base part is opposite to the polarity of the inner wall driving electrode of the first driving slot of the first major surface of the corresponding vibration arm part and the polarity of the inner wall driving electrode of the second driving slot of the second major surface.

[0056] In this embodiment 1, as shown in Figure 1 , the tuning fork type piezoelectric vibration piece also includes two weight applying parts with the same shape at the ends of the two vibration arm parts, the two weight applying parts are symmetrically arranged, and the polarities of the driving electrodes at the corresponding positions are opposite. Specifically, the width of the weight applying part is slightly larger than the width of the vibration arm part, and the position of the weight applying part close to the vibration arm part is provided with a width transition area, which is in a straight line connection.

[0057] In this embodiment 1, by setting the weight applying part, the resonant frequency of the vibration piece can be effectively reduced, and the coarse adjustment of the resonant frequency can be realized.

[0058] Preferably, the end of the weight applying part is provided with a metal with a predetermined thickness, which can realize the fine adjustment of the resonant frequency.

[0059] As shown in Figure 4 , Figure 5 , at least one of the first major surface and the second major surface of the weight applying part is provided with a driving electrode, and the polarity of the driving electrode of the weight applying part is opposite to the polarity of the inner wall driving electrode of the first driving slot of the first major surface of the corresponding vibration arm part and the polarity of the inner wall driving electrode of the second driving slot of the second major surface.

[0060] In this embodiment 1, each driving electrode uses a metal with good conductivity, and the electrode is adhered to the piezoelectric vibration piece by sputtering, with a thickness of 50-200 nm.

[0061] The electrode polarity of the first major surface of the tuning fork type piezoelectric vibration piece of this embodiment 1 is shown in Figure 4 , and the electrode polarity of the second major surface is shown in Figure 5 , different patterns represent different electrode polarities.

[0062] For the first polarity, as shown in Figure 4As shown, the driving electrode 11a of the base 11 is connected to the inner wall driving electrode of the small groove 21b of the vibrating arm 20b, the inner wall driving electrode of the first driving groove 22b, and the planar driving electrode 251 in the middle of the first main surface through the electrode pattern 11c. At the same time, the driving electrode 11a of the base 11 is connected to the driving electrode 31c of the weighting part 31 through the side wall driving electrode 252 of the vibrating arm 20a. Meanwhile, the driving electrode 31c of the weighting part 31 is connected to the side wall driving electrode 253 of the vibrating arm 20a.

[0063] Correspondingly, for the second type of polarity, such as Figure 4 As shown, the driving electrode 11b of the base 11 is connected to the driving electrode 41c of the weighting part 41 via the side wall driving electrode 242 of the vibrating arm 20b. Simultaneously, the driving electrode 41c of the weighting part 41 is connected to the inner wall driving electrode of the small groove 21a of the vibrating arm 20a, the inner wall driving electrode of the first driving groove 22a, and the planar driving electrode 241 in the middle of the first main surface via the side wall driving electrode 243 of the vibrating arm 20b. Meanwhile, as... Figure 5 As shown, the driving electrode 11b of the base 11 is connected to the planar driving electrode 241 in the middle of the second main surface of the vibrating arm 20a and the inner wall driving electrode of the second driving groove 23b through the electrode pattern 11d.

[0064] Example 2

[0065] like Figure 6 As shown, the difference between the tuning fork piezoelectric vibrator of Embodiment 2 and Embodiment 1 is that, along the length direction of the vibrating arm, a partition beam is provided at the bottom of the first driving groove on the first main surface of the vibrating arm, dividing the first driving groove into two grooves. Preferably, the width, length, and depth of the two grooves are exactly the same, that is, the cross-sectional shape of the first driving groove on the vibrating arm is ш-shaped. At the same time, along the length direction of the vibrating arm, a partition beam is also provided at the bottom of the second driving groove on the second main surface of the vibrating arm, dividing the second driving groove into two grooves. Preferably, the width, length, and depth of the two grooves are exactly the same, that is, the cross-sectional shape of the second driving groove on the vibrating arm is inverted ш-shaped.

[0066] In this embodiment 2, the depth of the first driving groove and the depth of the second driving groove account for no more than 85% of the thickness of the vibrating arm. The sum of the lengths of the first driving groove and the second driving groove accounts for 40%-70% of the length of the vibrating arm. The widths of the first driving groove and the second driving groove account for 35%-65% of the width of the vibrating arm. With this setting, a sufficiently large electric field driving force can be generated to drive the vibrating arm to perform alternating bending vibration, while preventing the crystal impedance value from being too large and affecting the device performance.

[0067] like Figure 6As shown, the inner wall of the first driving groove and the inner wall of the second driving groove are provided with inner wall driving electrodes, and no driving electrode is arranged on the partition beam.

[0068] Compared with the embodiment 1, by arranging the ш-shaped driving groove, the rigidity of the vibration arm part can be enhanced, and the fracture can be avoided.

[0069] In other embodiments of the present application, the groove form of the first driving groove of the first main surface of the vibration arm part and the groove form of the second driving groove of the second main surface of the vibration arm part can be different, for example, when the first driving groove is a U-shaped groove, the second driving groove can be a U-shaped groove, but also can be a ш-shaped groove or other form of groove.

[0070] Embodiment 3

[0071] The oscillator of the embodiment 3 of the present application comprises the tuning fork type piezoelectric vibration piece, the piezoelectric vibration piece is received in the internal space of the package and is vacuum packaged, and has certain air tightness. The oscillator of the embodiment 3 has good performance.

[0072] In the tuning fork type piezoelectric vibration piece and the oscillator using the piezoelectric vibration piece of the present application, when the piezoelectric vibration piece bends and vibrates, the distance of heat transfer from the compressed surface to the elongated surface is lengthened, that is, the heat conduction path is lengthened, the energy dissipation caused by the thermoelastic damping can be reduced, the out-of-plane displacement can be effectively reduced, and the Q value can be improved.

[0073] The above-described embodiments are only used to describe the preferred modes of the present application, and do not limit the scope of the present application, and various modifications and improvements of the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope determined by the claims of the present application.

Claims

1. A tuning fork type piezoelectric vibrator, characterized in that, The device includes a base and two vibrating arms extending from one end of the base. The two vibrating arms are symmetrically arranged, and the driving electrodes at corresponding positions have opposite polarities. Each vibrating arm has a first driving groove on its first main surface and a second driving groove on its second main surface. The first and second main surfaces are opposite to each other. Each vibrating arm also has a small groove on its first or second main surface. The small groove, the first driving groove, and the second driving groove are sequentially arranged along the length of the vibrating arm. The length of the first driving groove is greater than the length of the second driving groove. The length of the moving groove is greater than the length of the small groove. The inner walls of the first driving groove, the second driving groove, and the small groove are all provided with inner wall driving electrodes. The side walls of the vibrating arm are provided with side wall driving electrodes. Along the width direction of the vibrating arm, at least one planar driving electrode is provided on the first main surface of the vibrating arm corresponding to the position of the second driving groove and on the second main surface of the vibrating arm corresponding to the position of the first driving groove. Driving electrodes are provided on both sides of the base. The base is provided with multiple width reduction portions that are completely through in thickness near the position of the vibrating arm. The width reduction portions are symmetrically arranged on both sides of the base.

2. The tuning fork type piezoelectric vibrator according to claim 1, characterized in that, The length of the first drive groove and the second drive groove accounts for 40%-70% of the length of the vibrating arm, and the width of the first drive groove and the width of the second drive groove account for 35%-65% of the width of the vibrating arm.

3. The tuning fork type piezoelectric vibrator according to claim 1, characterized in that, Both the first drive groove and the second drive groove are integral grooves with a U-shaped cross-section. The depth of the first drive groove and the second drive groove is no more than 80% of the thickness of the vibrating arm. The depth of the small groove is the same as the depth of the corresponding first drive groove or second drive groove.

4. The tuning fork type piezoelectric vibrator according to claim 1, characterized in that, Along the length of the vibrating arm, the bottom of the first drive groove and the second drive groove are respectively provided with a partition beam, which divides the first drive groove and the second drive groove into two grooves with a cross-sectional shape of ш. The depth of the first drive groove and the second drive groove is no more than 85% of the thickness of the vibrating arm. The depth of the small groove is the same as the depth of the corresponding first drive groove or second drive groove.

5. The tuning fork type piezoelectric vibrator according to claim 1, characterized in that, The length of the planar driving electrode on the first main surface of the vibrating arm is the same as the length of the second driving groove, and the length of the planar driving electrode on the second main surface of the vibrating arm is the same as the length of the first driving groove.

6. The tuning fork type piezoelectric vibrator according to claim 1, characterized in that, Along the width direction of the vibrating arm, three planar driving electrodes with alternating polarities are provided on the first main surface of the vibrating arm, and three planar driving electrodes with alternating polarities are provided on the second main surface of the vibrating arm. The polarity of the side wall driving electrodes of the vibrating arm is the same as the polarity of the two planar driving electrodes on both sides of the three planar driving electrodes on the first main surface of the vibrating arm, the two planar driving electrodes on both sides of the three planar driving electrodes on the second main surface of the vibrating arm, and the polarity of the two side driving electrodes of the base, and is opposite to the polarity of the inner wall driving electrodes of the first driving groove, the inner wall driving electrodes of the second driving groove, and the inner wall driving electrodes of the small groove.

7. The tuning fork type piezoelectric vibrator according to claim 6, characterized in that, The side wall driving electrodes of the vibrating arm, the two planar driving electrodes on both sides of the three planar driving electrodes on the first main surface of the vibrating arm, and the two planar driving electrodes on both sides of the three planar driving electrodes on the second main surface of the vibrating arm are all non-segmented electrodes. The middle planar driving electrode of the three planar driving electrodes on the first main surface of the vibrating arm and the middle planar driving electrode of the three planar driving electrodes on the second main surface of the vibrating arm are all rectangular electrodes.

8. The tuning fork type piezoelectric vibrator according to claim 1, characterized in that, It also includes a weighting part, two weighting parts of the same shape are respectively connected to the ends of the two vibrating arms and are symmetrically arranged. The driving electrodes of the two weighting parts have opposite polarities at corresponding positions. The width of the weighting part is greater than the width of the vibrating arm. A width transition area is provided at the position of the weighting part near the vibrating arm. A metal of a preset thickness is provided at the end of the weighting part. At least one of the first main surface and the second main surface of the weighting part is provided with a driving electrode. The polarity of the driving electrode of the weighting part is opposite to the polarity of the driving electrode on the inner wall of the first driving groove and the polarity of the driving electrode on the inner wall of the second driving groove.

9. The tuning fork type piezoelectric vibrator according to any one of claims 1-8, characterized in that, The width reduction portions are arranged in parallel in a zigzag pattern with equal spacing.

10. An oscillator, characterized in that, Includes the tuning fork type piezoelectric vibrator as described in any one of claims 1-9.

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