CN115425941A - Resonator, filter and electronic device - Google Patents

Abstract

The application provides a resonator, a filter and electronic equipment, the resonator includes piezoelectric substrate, interdigital transducer and reflection configuration, and interdigital transducer includes first busbar, second busbar, a plurality of first electrode finger and a plurality of second electrode finger. The first electrode fingers are connected to the first bus bar and extend toward the second bus bar, and the second electrode fingers are connected to the second bus bar and extend toward the first bus bar. The interdigital transducer further includes at least one piston structure located on at least a portion of the first electrode finger, at least one of the piston structures located on the first electrode finger including two metal layers having different thicknesses, and at least one of the piston structures located on the second electrode finger including two metal layers having different thicknesses. Acoustic reflection is formed by changing the transmission speed of the acoustic wave signals on the piezoelectric substrate in the region where the two metal layers are located, so that the leakage of the acoustic wave signals is avoided, and the transverse mode of the resonator is further suppressed.

Description

Resonators, Filters and Electronics

technical field

The present application relates to the technical field of communication, and in particular to a resonator, a filter with the resonator, and an electronic device with the filter.

Background technique

Surface acoustic wave devices use the characteristics of acoustic-electric transducers to process acoustic signals propagating on the surface of piezoelectric substrates. Surface acoustic wave devices have the advantages of low cost, small size and multiple functions, so they have been widely used in radar, communication, navigation, identification and other fields. The surface acoustic wave device is mainly composed of multiple interdigital transducers (Interdigital Transducer, IDT) on the piezoelectric substrate, and the interdigital transducer can convert electrical signals into acoustic signals or convert acoustic signals into electrical signals. Wherein, the IDT includes two parallel bus bars and a plurality of electrode fingers vertically connected to the bus bars.

The high-order transverse mode (Transverse Mode) of the surface acoustic wave device will cause sound wave leakage, which will cause loss of sound energy and reduce the value of quality factor. In order to suppress the transverse mode of the surface acoustic wave device, dummy fingers are usually added to the bus bar or pistons are added to the ends of the electrode fingers to change the sound velocity distribution of the surface acoustic wave. However, the excitation of the transverse mode cannot be completely suppressed by adding a dummy finger or a piston at the end of the electrode finger.

Therefore, how to further suppress the excitation of the transverse mode to avoid surface acoustic wave leakage is an urgent problem to be solved by those skilled in the art.

Contents of the invention

In view of the above-mentioned deficiencies in the prior art, the purpose of this application is to provide a resonator, a filter with the resonator and an electronic device with the filter, which aim to solve the problem of surface acoustics in the prior art. Wave leakage leads to a problem that the quality factor value of the surface acoustic wave device decreases.

In order to solve the above technical problems, an embodiment of the present application provides a resonator, including a piezoelectric substrate, an interdigital transducer located on the piezoelectric substrate, and A reflective structure, the interdigital transducer comprising:

the first bus bar and the second bus bar arranged oppositely;

A plurality of first electrode fingers and a plurality of second electrode fingers, the plurality of first electrode fingers are connected to the first bus bar and extend toward the second bus bar, the plurality of second electrode fingers are connected to the second bus bar The second bus bar is connected to and extends toward the first bus bar, and a plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged in sequence;

At least one piston structure disposed on at least part of the first electrode fingers, the piston structure is at least located at the end of the first electrode finger facing away from the first bus bar, and disposed on at least part of the second electrode at least one piston structure on a finger, the piston structure is located at least at the end of the second electrode finger facing away from the second bus bar;

At least one of the piston structures on the first electrode finger includes two metal layers with different thicknesses, and at least one of the piston structures on the second electrode finger includes two metal layers with different thicknesses. Floor.

In summary, the resonator provided in the embodiment of the present application includes a piezoelectric substrate and an interdigital transducer located on the piezoelectric substrate, and the interdigital transducer includes a first bus bar, a second bus bar , a plurality of first electrode fingers and a plurality of second electrode fingers. The first electrode fingers are connected to the first bus bar and extend toward the second bus bar, and the second electrode fingers are connected to the second bus bar and extend toward the first bus bar. The IDT further includes at least one piston structure disposed on the first electrode finger and at least one piston structure disposed on the second electrode finger, and the piston structure disposed on the first electrode finger At least one of the piston structures includes two metal layers with different thicknesses, and at least one of the piston structures located on the second electrode finger includes two metal layers with different thicknesses. Therefore, the resonator of the present application can change the transmission speed of the acoustic wave signal on the piezoelectric substrate in the area where the two metal layers are located by arranging metal layers with different thicknesses on at least part of the electrode fingers, thereby forming acoustic reflection and avoiding Acoustic signal leakage confines the acoustic signal within the IDT, thereby improving suppression of transverse modes of the resonator.

In an exemplary embodiment, at least one of the piston structures on the first electrode finger includes two adjacent metal layers with different thicknesses, and the piston structure on the second electrode finger At least one of them includes two adjacent metal layers of different thicknesses. Alternatively, at least one of the piston structures located on the first electrode finger includes two metal layers with a predetermined distance apart and different thicknesses, and at least one of the piston structures located on the second electrode finger It includes two metal layers separated by a preset distance and having different thicknesses.

In an exemplary embodiment, a plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged in sequence along the extending direction of the first bus bar and the second bus bar to form an alternating region, The alternating regions include a first edge region, a second edge region, a middle region, a third edge region and a fourth edge region which are sequentially arranged in a direction from the first bus bar to the second bus bar.

In an exemplary embodiment, at least one piston structure disposed on at least part of the first electrode fingers and at least part of the second electrode fingers includes a first piston structure and a second piston structure arranged at intervals, and the first piston structure A piston structure includes a first metal layer and a second metal layer, and the second piston structure includes a third metal layer and a fourth metal layer. Wherein, the thickness of the first metal layer is different from the thickness of the second metal layer, and the thickness of the third metal layer is different from the thickness of the fourth metal layer; the third metal layer, the first metal layer The four metal layers, the first metal layer and the second metal layer are sequentially located in the first edge region, the second edge region, and the third edge region along the extending direction of the first electrode fingers. and the fourth edge region, and the second metal layer is located at the end of the first electrode finger facing away from the first bus bar. The third metal layer, the fourth metal layer, the first metal layer and the second metal layer are sequentially located in the fourth edge region, the first metal layer along the extending direction of the second electrode fingers. There are three edge regions, the second edge region and the first edge region, and the second metal layer is located at an end of the second electrode finger facing away from the second bus bar.

In an exemplary embodiment, at least one piston structure disposed on at least a part of the first electrode fingers and at least a part of the second electrode fingers includes a first piston structure and a second piston structure arranged at intervals, the first piston structure A piston structure includes a first metal layer, and the second piston structure includes a third metal layer and a fourth metal layer, wherein the thickness of the third metal layer is different from that of the fourth metal layer. The third metal layer, the fourth metal layer and the first metal layer are sequentially located in the first edge region, the second edge region and the first electrode finger along the extending direction of the first electrode finger. Three edge regions; the third metal layer, the fourth metal layer, and the first metal layer are located in the fourth edge region, the third edge region in sequence along the extending direction of the second electrode fingers and the second edge region.

In an exemplary embodiment, at least one piston structure disposed on at least a part of the first electrode fingers and at least a part of the second electrode fingers includes a first piston structure and a second piston structure arranged at intervals, the first piston structure A piston structure includes a second metal layer, the second piston structure includes a third metal layer and a fourth metal layer, wherein the thickness of the third metal layer is different from that of the fourth metal layer. The third metal layer, the fourth metal layer, and the second metal layer are sequentially located in the first edge region, the second edge region, and the first electrode finger along the extending direction of the first electrode finger. four edge regions, and the second metal layer is located at the end of the first electrode finger facing away from the first bus bar. The third metal layer, the fourth metal layer and the second metal layer are sequentially located in the fourth edge region, the third edge region and the first electrode finger along the extending direction of the second electrode finger. An edge region, and the second metal layer is located at the end of the second electrode finger facing away from the second bus bar.

In an exemplary embodiment, at least one piston structure disposed on at least part of the first electrode fingers and at least part of the second electrode fingers each includes a first piston structure including a first metal layer And a second metal layer, wherein the thickness of the first metal layer is different from the thickness of the second metal layer. The first metal layer and the second metal layer are located in the third edge area and the fourth edge area in sequence along the extending direction of the first electrode fingers, and the second metal layer is located in the The first electrode refers to the end facing away from the first bus bar. The first metal layer and the second metal layer are located in the second edge area and the first edge area in sequence along the extending direction of the second electrode fingers, and the second metal layer is located in the The second electrode refers to the end facing away from the second bus bar.

In an exemplary embodiment, the thickness of the metal layer located in the first edge area is greater than the thickness of the metal layer located in the second edge area, and the thickness of the metal layer located in the fourth edge area is greater than the thickness of the metal layer located in the second edge area. The thickness of the metal layer in the tri-edge area.

In an exemplary embodiment, the ratio of the length of the metal layer located in the first edge area to the length of the metal layer located in the second edge area is 0.8 to 1.2, and the ratio of the length of the metal layer located in the fourth edge area The ratio of the length to the length of the metal layer located in the third edge region is 0.8 to 1.2.

In an exemplary embodiment, the ratio of the width of the metal layer located in the first edge area to the width of the metal layer located in the second edge area is 0.8 to 1.2, and the ratio of the width of the metal layer located in the fourth edge area The ratio of the width to the width of the metal layer located in the third edge region is 0.8 to 1.2.

In an exemplary embodiment, the ratio of the thickness of the metal layer located in the first edge area to the thickness of the metal layer located in the second edge area is 1.2 to 5, and the ratio of the thickness of the metal layer located in the fourth edge area The ratio of the thickness to the thickness of the metal layer located in the third edge region is 1.2 to 5.

In an exemplary embodiment, the ratio of the length of the metal layer located in the first edge region to the length of the metal layer located in the second edge region is 1, and the ratio of the length of the metal layer located in the fourth edge region to The ratio of the lengths of the metal layers located in the third edge region is 1. The ratio of the width of the metal layer located in the first edge area to the width of the metal layer located in the second edge area is 1, and the width of the metal layer located in the fourth edge area is equal to the width of the metal layer located in the third edge area The ratio of the width of the metal layer is 1. The ratio of the thickness of the metal layer located in the first edge area to the thickness of the metal layer located in the second edge area is 2, the thickness of the metal layer located in the fourth edge area is the same as the thickness of the metal layer located in the third edge area The ratio of the thickness of the metal layer is 2.

In an exemplary embodiment, the sound velocity corresponding to the middle region is greater than the sound velocity corresponding to the first edge region and the sound velocity corresponding to the second edge region, and the sound velocity corresponding to the first edge region is different from that of the second edge region. The sound speeds corresponding to the edge regions are different. The sound velocity corresponding to the middle region is greater than the sound velocity corresponding to the third edge region and the sound velocity corresponding to the fourth edge region, and the sound velocity corresponding to the third edge region is different from the sound velocity corresponding to the fourth edge region.

In an exemplary embodiment, the sound velocity corresponding to the second edge region is greater than the sound velocity corresponding to the first edge region, and the sound velocity corresponding to the third edge region is greater than the sound velocity corresponding to the fourth edge region.

In an exemplary embodiment, the width of the metal layer on the first electrode finger is less than or equal to the width of the first electrode finger, and the width of the metal layer on the second electrode finger is less than or equal to the width of the second electrode finger. The width of the electrode fingers.

In an exemplary embodiment, the thickness of the metal layer on the first electrode finger is smaller than the thickness of the first electrode finger, and the thickness of the metal layer on the second electrode finger is smaller than the thickness of the second electrode finger .

In an exemplary embodiment, the IDT further includes a plurality of first dummy fingers and a plurality of second dummy fingers, and the first dummy fingers are arranged between the first electrode fingers and the second busbar. between the bars, and the first dummy finger is connected to the second bus bar; the second dummy finger is arranged between the second electrode finger and the first bus bar, and the second dummy The fingers are connected to the first bus bar.

In an exemplary embodiment, the resonator further includes a temperature compensation layer covering the IDT on the piezoelectric substrate.

Based on the same inventive concept, an embodiment of the present application also provides a resonator, including a piezoelectric substrate and an interdigital transducer located on the piezoelectric substrate, the interdigital transducer including:

the first bus bar and the second bus bar arranged oppositely;

A plurality of first electrode fingers and a plurality of second electrode fingers, the plurality of first electrode fingers are connected to the first bus bar and extend toward the second bus bar, the plurality of second electrode fingers are connected to the second bus bar The second bus bar is connected to and extends toward the first bus bar, and a plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged in sequence;

A plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged sequentially along the extending direction of the first bus bar and the second bus bar to form an alternating area, and the alternating area includes the At least two fifth edge regions, a middle region and at least two sixth edge regions arranged sequentially in a direction in which the first bus bar points to the second bus bar;

The sound velocity corresponding to the middle region is respectively greater than the sound velocity corresponding to the at least two fifth edge regions and the sound velocity corresponding to the at least two sixth edge regions;

The sound velocities corresponding to the at least two fifth edge regions arranged sequentially from the middle region to the direction of the first bus bar decrease successively;

The sound velocities corresponding to the at least two sixth edge regions arranged sequentially in a direction from the middle region to the second bus bar decrease successively.

In summary, the resonator provided in the embodiment of the present application includes a piezoelectric substrate and an interdigital transducer located on the piezoelectric substrate, and the interdigital transducer includes a first bus bar, a second bus bar strips, a plurality of first electrode fingers and a plurality of second electrode fingers. The first electrode fingers are connected to the first bus bar and extend toward the second bus bar, and the second electrode fingers are connected to the second bus bar and extend toward the first bus bar. A plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged in turn to form an alternating area, and the alternating area includes at least Two fifth edge regions, a middle region and at least two sixth edge regions. The sound velocities corresponding to the middle regions are respectively greater than the sound velocities corresponding to the at least two fifth edge regions and the sound velocities corresponding to the at least two sixth edge regions, so that acoustic reflection is formed on the piezoelectric substrate, avoiding Acoustic signal leakage confines the acoustic signal within the IDT, thereby improving suppression of transverse modes of the resonator.

Based on the same inventive concept, an embodiment of the present application further provides a filter, which at least includes a plurality of the above-mentioned resonators.

In summary, the filter includes a plurality of resonators, the resonators include a piezoelectric substrate and an interdigital transducer located on the piezoelectric substrate, and the interdigital transducer includes a first bus a bar, a second bus bar, a plurality of first electrode fingers and a plurality of second electrode fingers. The first electrode fingers are connected to the first bus bar and extend toward the second bus bar, and the second electrode fingers are connected to the second bus bar and extend toward the first bus bar. The IDT further includes at least one piston structure disposed on the first electrode finger and at least one piston structure disposed on the second electrode finger, and the piston structure disposed on the first electrode finger At least one of the piston structures includes two metal layers with different thicknesses, and at least one of the piston structures located on the second electrode finger includes two metal layers with different thicknesses. Thereby changing the transmission speed of the acoustic wave signal on the piezoelectric substrate in the region where the two metal layers are located, forming acoustic reflection, confining the acoustic wave signal in the interdigital transducer, avoiding the leakage of the acoustic wave signal, and further improving the suppression of the transverse modes of the resonator.

Based on the same inventive concept, an embodiment of the present application further provides an electronic device, including a substrate and the above-mentioned filter, where the filter is mounted on the substrate and electrically connected to the substrate.

In summary, the electronic device provided by the embodiment of the present application includes a substrate and a filter, and the filter includes a plurality of resonators, and the resonators include a piezoelectric substrate and an interdigital switch located on the piezoelectric substrate. The interdigital transducer includes a first bus bar, a second bus bar, a plurality of first electrode fingers and a plurality of second electrode fingers. The first electrode fingers are connected to the first bus bar and extend toward the second bus bar, and the second electrode fingers are connected to the second bus bar and extend toward the first bus bar. The IDT further includes at least one piston structure disposed on the first electrode finger and at least one piston structure disposed on the second electrode finger, and the piston structure disposed on the first electrode finger At least one of the piston structures includes two metal layers with different thicknesses, and at least one of the piston structures located on the second electrode finger includes two metal layers with different thicknesses. Therefore, the resonator of the present application can change the transmission speed of the acoustic wave signal on the piezoelectric substrate in the area where the two metal layers are located by arranging metal layers with different thicknesses on at least part of the electrode fingers, thereby forming acoustic reflection and avoiding Acoustic signal leakage confines the acoustic signal within the IDT, thereby improving suppression of transverse modes of the resonator.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

FIG. 1 is a schematic diagram of the layer structure of the first resonator disclosed in the embodiment of the present application;

Fig. 2 is the schematic diagram of the front view structure of the interdigital transducer of the resonator shown in Fig. 1;

FIG. 3 is a schematic diagram of the layer structure of the second resonator disclosed in the embodiment of the present application;

Fig. 4 is a front structural schematic view of the interdigital transducer of the resonator shown in Fig. 3;

FIG. 5 is a schematic diagram of the layer structure of the third resonator disclosed in the embodiment of the present application;

Fig. 6 is a front view structural schematic diagram of the interdigital transducer of the resonator shown in Fig. 5;

FIG. 7 is a schematic diagram of the layer structure of the fourth resonator disclosed in the embodiment of the present application;

Fig. 8 is a front structural schematic view of the interdigital transducer of the resonator shown in Fig. 7;

FIG. 9 is a schematic diagram of the admittance curve corresponding to the first preferred structural parameter of the interdigital transducer disclosed in the embodiment of the present application;

Fig. 10 is a schematic diagram of the admittance curve corresponding to the second preferred structural parameter of the interdigital transducer disclosed in the embodiment of the present application;

Fig. 11 is a schematic diagram of the admittance curve corresponding to the third preferred structural parameter of the interdigital transducer disclosed in the embodiment of the present application;

12 is a schematic diagram of an admittance curve corresponding to structural parameters of an IDT in the prior art;

Fig. 13 is a schematic diagram of the sound velocity distribution corresponding to each region in the resonator described in Fig. 1;

Fig. 14 is a schematic diagram of the sound velocity distribution corresponding to each region in the resonator described in Fig. 3;

Fig. 15 is a schematic diagram of the sound velocity distribution corresponding to each region in the resonator described in Fig. 5;

Fig. 16 is a schematic diagram of the sound velocity distribution corresponding to each region in the resonator described in Fig. 7;

Fig. 17 is a schematic diagram of the fifth layer structure of the resonator disclosed in the embodiment of the present application;

Fig. 18 is a front view structural schematic diagram of the interdigital transducer of the resonator shown in Fig. 17;

FIG. 19 is a schematic structural diagram of a sixth resonator disclosed in the embodiment of the present application;

FIG. 20 is a schematic structural diagram of a filter disclosed in an embodiment of the present application.

Explanation of reference signs:

Q1-first edge area; Q2-second edge area; C-middle area; Q3-third edge area; Q4-fourth edge area; 1-interdigital transducer; 7-piezoelectric substrate; 8- Substrate; 9-temperature compensation layer; 10-first bus bar; 20-second bus bar; 40-first electrode finger; 50-second electrode finger; 60-piston structure; 80-first piston structure; 81 - first metal layer; 82 - second metal layer; 90 - second piston structure; 91 - third metal layer; 92 - fourth metal layer; 101 - resonator; 102 - resonator; 103 - resonator; 104 -resonator; 105-resonator; 106-resonator; 130-first false finger; 140-second false finger; 200-filter; IN-input end; OUT-output end; Bl-series branch; B2 -Parallel branch; GND-ground connection.

Detailed ways

In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Preferred embodiments of the application are shown in the accompanying drawings. However, the present application can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the application more thorough and comprehensive.

The following descriptions of the various embodiments refer to the accompanying drawings to illustrate specific embodiments that the present application can be used to implement. The serial numbers assigned to components in this document, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any sequence or technical meaning. The "connection" and "connection" mentioned in this application all include direct and indirect connection (connection) unless otherwise specified. The directional terms mentioned in this application, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", etc., only is to refer to the direction of the attached drawings. Therefore, the direction terms used are for better and clearer description and understanding of the present application, rather than indicating or implying that the referred device or element must have a specific orientation, and must have a specific orientation. construction and operation, therefore should not be construed as limiting the application.

In the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Ground connection, or integral connection; can be mechanical connection; can be directly connected, can also be indirectly connected through an intermediary, and can be internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations. It should be noted that the terms "first" and "second" in the specification and claims of the present application and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the term "comprising", "may include", "comprises", or "may include" used in this application indicates the existence of the corresponding disclosed functions, operations, elements, etc., and does not limit other one or more more Functions, operations, components, etc. In addition, the term "comprises" or "comprises" means that there are corresponding features, numbers, steps, operations, elements, components or combinations thereof disclosed in the specification, and does not exclude the existence or addition of one or more other features, numbers, steps, Operations, elements, components, or combinations thereof, are intended to cover non-exclusive inclusions. It should also be understood that the meaning of "at least one" described herein is one or more, such as one, two or three, etc., and the meaning of "multiple" is at least two, such as two or three etc., unless expressly and specifically defined otherwise.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terminology used herein in the description of the application is only for the purpose of describing specific embodiments, and is not intended to limit the application.

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of the layer structure of the first type of resonator disclosed in the embodiment of the present application. As shown in Figure 1, the resonator 101 provided by the embodiment of the present application may at least include a piezoelectric substrate 7, a plurality of interdigital transducers 1 located on one side of the piezoelectric substrate 7, and a plurality of interdigital transducers 1 arranged on the interdigital reflective structures on opposite sides of the transducer 1 .

Specifically, when the interdigital transducer 1 receives an alternating electric signal and generates an alternating electric field corresponding to the alternating electric signal, the action of the piezoelectric substrate 7 on the alternating electric field deformed below. Since the electric field strength of the alternating electric field changes, the degree of deformation of the piezoelectric substrate 7 changes with time, and then an acoustic wave signal is generated on the surface of the piezoelectric substrate 7, and the spread on the surface of the piezoelectric substrate 7. The deformation of the piezoelectric substrate 7 under the action of the alternating electric field is called the Converse Piezoelectricity Effect.

The acoustic wave signal propagates on the piezoelectric substrate 7 to another area where the IDT 1 is located. The acoustic wave signal causes the piezoelectric substrate 7 in this area to deform, and the piezoelectric substrate 7 will generate equal amounts of positive and negative charges on its opposite surface to resist deformation, so as to exchange between the fingers. An electrical signal is formed on the energy device 1. The phenomenon that the deformed piezoelectric substrate 7 generates positive and negative charges is called positive piezoelectric effect (Positive Piezoelectric Effect).

Please refer to FIG. 2 . FIG. 2 is a front view structural diagram of the IDT of the resonator shown in FIG. 1 . In the embodiment of the present application, each of the interdigital transducers 1 includes a first bus bar 10, a second bus bar 20, a plurality of first electrode fingers 40 and A plurality of second electrode fingers 50 . The first bus bar 10 is arranged opposite to the second bus bar 20, the plurality of first electrode fingers 40 are connected to the first bus bar 10 and extend toward the second bus bar 20, and the plurality of electrode fingers 40 are connected to the first bus bar 10 and extend toward the second bus bar 20. The second electrode fingers 50 are connected to the second bus bar 20 and extend toward the first bus bar 10 , and the plurality of first electrode fingers 40 and the plurality of second electrode fingers 50 are alternately arranged in sequence.

In the embodiment of the present application, the interdigital transducer 1 further includes a plurality of piston structures 60 . At least one piston structure 60 is provided on the surface of at least part of the first electrode finger 40 facing away from the piezoelectric substrate 7, and the piston structure 60 is at least located on the surface of the first electrode finger 40 facing away from the first electrode finger 40. An end of a bus bar 10 . At least one piston structure 60 is provided on the surface of at least part of the second electrode fingers 50 facing away from the piezoelectric substrate 7, and the piston structure 60 is at least located on the surface of the second electrode fingers 50 facing away from the first electrode finger 50. Two ends of the bus bar 20 .

In an exemplary embodiment, at least one of the piston structures 60 on the first electrode finger 40 includes two metal layers with different thicknesses, and the piston structure 60 on the second electrode finger 50 At least one of them includes two metal layers of different thicknesses.

In an exemplary embodiment, at least one piston structure 60 may be provided on the surface of part of the first electrode fingers 40 facing away from the piezoelectric substrate 7 and part of the second electrode fingers 50 facing away from the piezoelectric substrate 7. At least one piston structure 60 is provided on the surface of the piezoelectric substrate 7 . It is also possible that at least one piston structure 60 is provided on the surface of each of the first electrode fingers 40 facing away from the piezoelectric substrate 7 and each of the second electrode fingers 50 is facing away from the piezoelectric substrate. At least one piston structure 60 is provided on the surface of the sheet 7, which is not specifically limited in the present application.

It can be understood that by arranging at least two metal layers with different thicknesses on the first electrode fingers 40 and at least two metal layers with different thicknesses on the second electrode fingers 50, in the generation of acoustic signals, The area forms a "potential well" area, which can confine the acoustic wave energy to the area where the IDT 1 is located, and suppress the excitation of the transverse mode.

In an exemplary embodiment, at least one of the piston structures 60 located on the first electrode finger 40 includes two adjacent metal layers with different thicknesses, and all the piston structures located on the second electrode finger 50 At least one of the piston structures 60 includes two adjacent metal layers with different thicknesses. Alternatively, at least one of the piston structures 60 located on the first electrode finger 40 includes two metal layers with a predetermined distance apart and different thicknesses, and the piston structure 60 located on the second electrode finger 50 At least one of them includes two metal layers separated by a preset distance and having different thicknesses. This application does not specifically limit this.

In other embodiments of the present application, the piston structure 60 can also be arranged on the surface of the first electrode finger 40 facing the piezoelectric substrate 7 and the surface of the second electrode finger 50 facing the piezoelectric substrate. The surface of the sheet 7 is not specifically limited in this application.

In an exemplary embodiment, the size of the first bus bar 10 is the same as that of the second bus bar 20 , that is, the length, width, and height of the first bus bar 10 are the same as the length of the second bus bar 20 Same width and height. The size of the first electrode finger 40 is the same as that of the second electrode finger 50 , that is, the length, width, and height of the first electrode finger 40 are the same as the length, width, and height of the second electrode finger 50 .

In an exemplary embodiment, in the structure of the IDT 1 , along the direction in which the electrode fingers are alternately arranged, the duty cycle of the electrode fingers located on both sides is smaller than that of the electrode fingers located in the middle. Wherein, duty cycle=width of electrode fingers/distance between centerlines of two adjacent electrode fingers.

In an exemplary embodiment, the first bus bar 10 and the second bus bar 20 are arranged in parallel to each other, and the first electrode fingers 40 are connected to the first bus bar 10 and the second bus bar respectively. 20 , the second electrode fingers 50 are perpendicular to the first bus bar 10 and the second bus bar 20 respectively.

In an exemplary embodiment, the number of the first electrode fingers 40 may be 2 to 20, for example, 2, 6, 11, 16, 20, or other numbers. In the description, the number of the first electrode fingers 40 is 6 as an example for illustration. The number of the second electrode fingers 50 can be 2 to 20, for example, 2, 5, 11, 15, 20, or other numbers. In the embodiment of the present application, the first The number of electrode fingers 40 is 5 as an example for description.

In an exemplary embodiment, the material of the piezoelectric substrate 7 may be aluminum nitride, zinc oxide, lead zirconate titanate (PZT) or a rare earth element doped material of a certain atomic ratio of the above materials. The piezoelectric substrate 7 can also be a single crystal piezoelectric material, for example, single crystal aluminum nitride, lithium niobate, lithium tantalate, quartz, etc., which is not specifically limited in this application.

In an exemplary embodiment, the material of the interdigital transducer 1 and the metal layer may be a single metal material or a composite or alloy material of different metals. The material of the IDT 1 and the metal layer can be one of molybdenum, tungsten, ruthenium, gold, magnesium, aluminum, copper, chromium, titanium, osmium, iridium or a composite of the above metals or an alloy thereof, etc. Or, this application does not specifically limit it.

In the embodiment of the present application, the resonator 101 further includes reflective structures arranged on opposite sides of the IDT, that is, in the longitudinal direction of the first bus bar 10 and the second bus bar 20 Both ends are provided with the reflective structure. It can be understood that, by arranging the reflective structures on both sides of the IDT 1, the acoustic wave signal can be reflected, thereby confining the acoustic wave signal between the two reflective structures, so as to improve the The quality factor value of the resonator 101 and the performance of the resonator 101 are improved.

In summary, the resonator 101 provided in the embodiment of the present application includes the piezoelectric substrate 7 and the IDT 1 . The IDT 1 includes a first bus bar 10 , a second bus bar 20 , a plurality of first electrode fingers 40 and a plurality of second electrode fingers 50 . At least one piston structure 60 is disposed on the first electrode finger 40 , and the piston structure 60 is at least located at an end of the first electrode finger 40 facing away from the first bus bar 10 . At least one piston structure 60 is disposed on the second electrode finger 50 , and the piston structure 60 is at least located at an end of the second electrode finger 50 facing away from the second bus bar 20 . At least one of the piston structures 60 located on the first electrode finger 40 includes two metal layers with different thicknesses, and at least one of the piston structures 60 located on the second electrode finger 50 includes two metal layers with different thicknesses. two metal layers. Therefore, at least one piston structure 60 including two metal layers is provided on the first electrode finger 40 and the second electrode finger 50, and the two metal layers are different, thereby changing the area where the two metal layers are located. The transmission speed of the acoustic wave signal on the piezoelectric substrate 7 in the interior forms an acoustic reflection, therefore, not only avoiding the leakage of the acoustic wave signal, but also confining the acoustic wave signal in the described interdigital transducer, thereby improving the response to the resonance The suppression of the transverse mode of the resonator 101 reduces the loss of acoustic energy, increases the value of the quality factor and improves the performance of the resonator 101.

In the embodiment of the present application, please refer to FIG. 2 , a plurality of the first electrode fingers 40 and a plurality of the second electrode fingers 50 extend along the extension of the first bus bar 10 and the second bus bar 20 The directions are alternately arranged in order to form an alternating area, and the alternating area includes the first edge area Q1, the second edge area Q2, the middle area C, The third edge area Q3 and the fourth edge area Q4.

It can be understood that the part of the first electrode fingers 40 overlaps with the part of the second electrode fingers 50 along the length direction of the first bus bar 10 , and the overlapping parts of a plurality of the first electrode fingers 40 The portion overlapping with the plurality of second electrode fingers 50 forms an alternating area.

In an exemplary embodiment, the length direction of the first edge region Q1, the length direction of the second edge region Q2, the length direction of the middle region C, the length direction of the third edge region Q3 and the The length direction of the fourth edge region Q4 is parallel to the length directions of the first bus bar 10 and the second bus bar 20 .

In an exemplary embodiment, gap regions are respectively formed between the first edge region Q1 and the first bus bar 10 and between the fourth edge region Q4 and the second bus bar 20 .

In the embodiment of the present application, referring to FIG. 2 , at least one piston structure 60 disposed on at least part of the first electrode fingers 40 and at least part of the second electrode fingers 50 includes first piston structures 80 arranged at intervals. As with the second piston structure 90 , the first piston structure 80 includes a first metal layer 81 and a second metal layer 82 , and the second piston structure 90 includes a third metal layer 91 and a fourth metal layer 92 . The thickness of the first metal layer 81 is different from that of the second metal layer 82 , and the thickness of the third metal layer 91 is different from that of the fourth metal layer 92 .

In the embodiment of the present application, the third metal layer 91 , the fourth metal layer 92 , the first metal layer 81 and the second metal layer 82 are along the extending direction of the first electrode fingers 40 Located in the first edge region Q1, the second edge region Q2, the third edge region Q3 and the fourth edge region Q4 in sequence, and the second metal layer 82 is located in the first electrode finger 40 facing away from the end of the first bus bar 10 .

In the embodiment of the present application, the third metal layer 91 , the fourth metal layer 92 , the first metal layer 81 and the second metal layer 82 are along the extending direction of the second electrode fingers 50 sequentially located in the fourth edge region Q4, the third edge region Q3, the second edge region Q2 and the first edge region Q1, and the second metal layer 82 is located in the second electrode finger 50 opposite to the end of the second bus bar 20 .

In an exemplary embodiment, the first metal layers 81 on the plurality of first electrode fingers 40 and the fourth metal layers 92 on the plurality of second electrode fingers 50 are alternately arranged side by side and located at In the third edge region Q3, the second metal layers 82 on the plurality of first electrode fingers 40 and the third metal layers 91 on the plurality of second electrode fingers 50 are alternately arranged side by side And located in the fourth edge area Q4. The third metal layers 91 on the plurality of first electrode fingers 40 and the second metal layers 82 on the plurality of second electrode fingers 50 are alternately arranged side by side and located in the first edge region Q1 Inside, the fourth metal layers 92 on the plurality of first electrode fingers 40 and the first metal layers 81 on the plurality of second electrode fingers 50 are alternately arranged side by side and located at the second edge In area Q2.

In an exemplary embodiment, the third metal layer 91 is disposed adjacent to the fourth metal layer 92 , and the first metal layer 81 is disposed adjacent to the second metal layer 82 . Alternatively, the third metal layer 91 is separated from the fourth metal layer 92 by a preset distance, and the first metal layer 81 is separated from the second metal layer 82 by a preset distance.

In an exemplary embodiment, the material of the metal layer and the material of the IDT may be the same or different, the material of the first metal layer 81 and the second metal layer 82 may be the same or different, and the third Materials of the metal layer 91 and the fourth metal layer 92 may be the same or different.

In an exemplary embodiment, the metal layer may be fabricated by processes such as glue coating, exposure, development, metal deposition, and wet stripping. The first metal layer 81 and the second metal layer 82 can be prepared integrally, the third metal layer 91 and the fourth metal layer 92 can be prepared integrally, and metal layer structures with different thicknesses are formed by etching process .

Please refer to FIG. 3 and FIG. 4 , FIG. 3 is a schematic diagram of the layer structure of the second resonator disclosed in the embodiment of the present application, and FIG. 4 is a schematic diagram of the front view structure of the IDT of the resonator shown in FIG. 3 . The difference between the second type of resonator 102 and the first type of resonator 101 is that the first piston structure 80 of the IDT 1 of the second type of resonator 102 only includes the first metal layer 81 and does not include the second metal layer. Layer 82. For the description of the similarities between the second type of resonator 102 and the first type of resonator 101 , please refer to the description of the first type of resonator 101 , which will not be repeated here.

In the embodiment of the present application, at least one piston structure 60 disposed on at least part of the first electrode fingers 40 and at least part of the second electrode fingers 50 includes first piston structures 80 and second piston structures arranged at intervals. 90 , the first piston structure 80 includes a first metal layer 81 , and the second piston structure 90 includes a third metal layer 91 and a fourth metal layer 92 . Wherein, the third metal layer 91 and the fourth metal layer 92 have different thicknesses.

In the embodiment of the present application, the third metal layer 91 , the fourth metal layer 92 and the first metal layer 81 are sequentially located in the first edge region along the extending direction of the first electrode fingers 40 Q1, the second edge area Q2 and the third edge area Q3. The third metal layer 91 , the fourth metal layer 92 and the first metal layer 81 are sequentially located in the fourth edge region Q4 and the third edge along the extending direction of the second electrode fingers 50 . area Q3 and the second edge area Q2.

In an exemplary embodiment, the first metal layers 81 on the plurality of first electrode fingers 40 and the fourth metal layers 92 on the plurality of second electrode fingers 50 are alternately arranged side by side and located at In the third edge area Q3, the third metal layers 91 on the plurality of second electrode fingers 50 are arranged side by side and at intervals and located in the fourth edge area Q4. The third metal layer 91 on the plurality of first electrode fingers 40 is arranged side by side at intervals and located in the first edge region Q1, and the fourth metal layer 92 on the plurality of first electrode fingers 40 The first metal layers 81 on the plurality of second electrode fingers 50 are arranged side by side, alternately and at intervals, and are located in the second edge region Q2.

Please refer to FIG. 5 and FIG. 6. FIG. 5 is a schematic diagram of the layer structure of the third type of resonator disclosed in the embodiment of the present application, and FIG. 6 is a schematic diagram of the front view structure of the IDT of the resonator shown in FIG. 5 . The difference between the third type of resonator 103 and the first type of resonator 101 is that the first piston structure 80 of the IDT 1 of the third type of resonator 103 only includes the second metal layer 82 and does not include the first metal layer. Layer 81. For the description of the similarities between the third type of resonator 103 and the first type of resonator 101 , please refer to the description of the first type of resonator 101 , which will not be repeated here.

In the embodiment of the present application, at least one piston structure 60 disposed on at least part of the first electrode fingers 40 and at least part of the second electrode fingers 50 includes first piston structures 80 and second piston structures arranged at intervals. 90 , the first piston structure 80 includes a second metal layer 82 , and the second piston structure 90 includes a third metal layer 91 and a fourth metal layer 92 . Wherein, the third metal layer 91 and the fourth metal layer 92 have different thicknesses.

In the embodiment of the present application, the third metal layer 91 , the fourth metal layer 92 and the second metal layer 82 are sequentially located in the first edge region along the extending direction of the first electrode fingers 40 Q1 , the second edge area Q2 and the fourth edge area Q4 , and the second metal layer 82 is located at the end of the first electrode finger 40 facing away from the first bus bar 10 .

In the embodiment of the present application, the third metal layer 91 , the fourth metal layer 92 and the second metal layer 82 are sequentially located in the fourth edge region along the extending direction of the second electrode fingers 50 Q4 , the third edge area Q3 and the first edge area Q1 , and the second metal layer 82 is located at the end of the second electrode finger 50 facing away from the second bus bar 20 .

In an exemplary embodiment, the fourth metal layers 92 on the plurality of second electrode fingers 50 are arranged side by side at intervals and located in the third edge region Q3, and the plurality of first electrode fingers 40 The second metal layer 82 and the third metal layer 91 on the plurality of second electrode fingers 50 are alternately arranged side by side and located in the fourth edge region Q4 . The third metal layers 91 on the plurality of first electrode fingers 40 and the second metal layers 82 on the plurality of second electrode fingers 50 are alternately arranged side by side and located in the first edge region Q1 Inside, the fourth metal layers 92 on the plurality of first electrode fingers 40 are arranged side by side at intervals and located in the second edge region Q2.

Please refer to FIG. 7 and FIG. 8 , FIG. 7 is a schematic diagram of the layer structure of the fourth resonator disclosed in the embodiment of the present application, and FIG. 8 is a schematic diagram of the front view structure of the interdigital transducer of the resonator shown in FIG. 7 . The difference between the fourth type of resonator 104 and the first type of resonator 101 is that the IDT 1 of the fourth type of resonator 104 only includes the first piston structure 80 and does not include the second piston structure 90 . For the description of the similarities between the fourth type of resonator 104 and the first type of resonator 101 , please refer to the description of the first type of resonator 101 , which will not be repeated here.

In the embodiment of the present application, at least one piston structure 60 disposed on at least part of the first electrode fingers 40 and at least part of the second electrode fingers 50 includes a first piston structure 80, and the first piston structure 80 It includes a first metal layer 81 and a second metal layer 82 . Wherein, the thickness of the first metal layer 81 is different from the thickness of the second metal layer 82 .

In the embodiment of the present application, the first metal layer 81 and the second metal layer 82 are sequentially located in the third edge region Q3 and the fourth edge region along the extending direction of the first electrode fingers 40 Q4, and the second metal layer 82 is located at the end of the first electrode finger 40 facing away from the first bus bar 10 . The first metal layer 81 and the second metal layer 82 are sequentially located in the second edge region Q2 and the first edge region Q1 along the extending direction of the second electrode finger 50 , and the second The metal layer 82 is located at the end of the second electrode finger 50 facing away from the second bus bar 20 .

In an exemplary embodiment, the first metal layers 81 on the plurality of first electrode fingers 40 are alternately arranged side by side and located in the third edge region Q3, and the first metal layers 81 on the plurality of first electrode fingers 40 The second metal layers 82 are arranged side by side at intervals and located in the fourth edge region Q4. The second metal layers 82 on the plurality of second electrode fingers 50 are arranged side by side at intervals and located in the first edge region Q1, and the first metal layers 81 on the plurality of second electrode fingers 50 arranged side by side at intervals and located in the second edge region Q2.

Please refer to FIG. 1 , FIG. 3 , FIG. 5 and FIG. 7 . In the embodiment of the present application, the thickness of the metal layer located in the first edge region Q1 is greater than the thickness of the metal layer located in the second edge region Q2 . The thickness of the metal layer in the fourth edge region Q4 is greater than the thickness of the metal layer in the third edge region Q3.

In an exemplary embodiment, the thickness of the second metal layer 82 is greater than that of the first metal layer 81 , and the thickness of the third metal layer 91 is greater than that of the fourth metal layer 92 .

In an exemplary embodiment, the thickness of the metal layer located in the first edge area Q1 and the thickness of the metal layer located in the fourth edge area Q4 may be equal or different; the thickness of the metal layer located in the second edge area Q2 The thickness of the metal layer and the thickness of the metal layer located in the third edge region Q3 may be equal or different, which is not limited in this embodiment of the present application.

Please refer to FIG. 2 , FIG. 4 , FIG. 6 and FIG. 8 , in the embodiment of the present application, the ratio of the length of the metal layer located in the first edge region Q1 to the length of the metal layer located in the second edge region Q2 is 0.8 to 1.2; the ratio of the length of the metal layer located in the fourth edge region Q4 to the length of the metal layer located in the third edge region Q3 is 0.8 to 1.2.

In the embodiment of the present application, the ratio of the length of the second metal layer 82 to the length of the first metal layer 81 is 0.8 to 1.2, for example, 0.8, 0.9, 1, 1.1, 1.2, or other values. The application is not specifically limited to this. The ratio of the length of the third metal layer 91 to the length of the fourth metal layer 92 is 0.8 to 1.2, for example, 0.8, 0.9, 1, 1.1, 1.2, or other values, which is not specifically limited in the present application.

In an exemplary embodiment, the second metal layer 82 has the same length as the third metal layer 91 , and the first metal layer 81 has the same length as the fourth metal layer 92 .

In an exemplary embodiment, the length of the metal layer located in the first edge area Q1 and the length of the metal layer located in the fourth edge area Q4 may be equal or different; the length of the metal layer located in the second edge area Q2 The length of the metal layer and the length of the metal layer located in the third edge region Q3 may be equal or different, which is not limited in this embodiment of the present application.

In the embodiment of the present application, the ratio of the width of the metal layer located in the first edge region Q1 to the width of the metal layer located in the second edge region Q2 is 0.8 to 1.2; The ratio of the width of the metal layer to the width of the metal layer located in the third edge region Q3 is 0.8 to 1.2.

In the embodiment of the present application, the ratio of the width of the second metal layer 82 to the width of the first metal layer 81 is 0.8 to 1.2, for example, 0.8, 0.9, 1, 1.1, 1.2, or other values. The application is not specifically limited to this. The ratio of the width of the third metal layer 91 to the width of the fourth metal layer 92 is 0.8 to 1.2, for example, 0.8, 0.9, 1, 1.1, 1.2, or other values, which is not specifically limited in the present application.

In an exemplary embodiment, the second metal layer 82 has the same width as the third metal layer 91 , and the first metal layer 81 has the same width as the fourth metal layer 92 .

In an exemplary embodiment, the width of the metal layer located in the first edge area Q1 and the width of the metal layer located in the fourth edge area Q4 may be equal or different; the width of the metal layer located in the second edge area Q2 The width of the metal layer and the width of the metal layer located in the third edge region Q3 may be equal or different, which is not limited in this embodiment of the present application.

In the embodiment of the present application, the ratio of the thickness of the metal layer located in the first edge area to the thickness of the metal layer located in the second edge area is 1.2 to 5; the ratio of the thickness of the metal layer located in the fourth edge area The ratio of the thickness to the thickness of the metal layer located in the third edge region is 1.2 to 5.

In the embodiment of the present application, the ratio of the thickness of the second metal layer 82 to the thickness of the first metal layer 81 is 1.2 to 5, for example, 1.2, 2, 3.2, 4.3, 5, or other values. The application is not specifically limited to this. The ratio of the thickness of the third metal layer 91 to the thickness of the fourth metal layer 92 is 1.2 to 5, for example, 1.2, 2, 3, 3.2, 4.3, 5, or other values, which are not specified in this application. limit.

It can be understood that there must be a certain thickness difference between the second metal layer 82 and the first metal layer 81, and there must be a certain thickness difference between the third metal layer 91 and the fourth metal layer 92, and The gap should not be too large. The thickness of the second metal layer 82 needs to be greater than the thickness of the first metal layer 81, the thickness of the third metal layer 91 is greater than the thickness of the fourth metal layer 92, and the ratio of the two should not be too large; If the ratio is too large, although it also has the effect of suppressing the transverse mode, it will cause the quality factor value of the antiharmonic point to be too low. When the ratio of the thickness of the second metal layer 82 to the thickness of the first metal layer 81 is 1.2 to 5, the ratio of the thickness of the third metal layer 91 to the thickness of the fourth metal layer 92 is From 1.2 to 5, a better transverse mode suppression effect can be obtained, and the quality factor value can be effectively improved.

In an exemplary embodiment, the second metal layer 82 has the same thickness as the third metal layer 91 , and the first metal layer 81 has the same thickness as the fourth metal layer 92 .

In an exemplary embodiment, the thickness of the metal layer located in the first edge area Q1 and the thickness of the metal layer located in the fourth edge area Q4 may be equal or different; the thickness of the metal layer located in the second edge area Q2 The thickness of the metal layer and the thickness of the metal layer located in the third edge region Q3 may be equal or different, which is not limited in this embodiment of the present application.

In the embodiment of the present application, the ratio of the length of the metal layer located in the first edge area to the length of the metal layer located in the second edge area is 1, and the length of the metal layer located in the fourth edge area is equal to The ratio of the lengths of the metal layers located in the third edge region is 1.

In the embodiment of the present application, the ratio of the width of the metal layer located in the first edge region to the width of the metal layer located in the second edge region is 1, and the ratio of the width of the metal layer located in the fourth edge region to The ratio of the width of the metal layer located in the third edge region is 1.

In the embodiment of the present application, the ratio of the thickness of the metal layer located in the first edge area to the thickness of the metal layer located in the second edge area is 2, and the thickness of the metal layer located in the fourth edge area is equal to The thickness ratio of the metal layer located in the third edge region is 2.

In the embodiment of the present application, the ratio of the length of the second metal layer 82 to the length of the first metal layer 81 is 1, the length of the third metal layer 91 to the length of the fourth metal layer 92 The ratio is 1. The ratio of the width of the second metal layer 82 to the width of the first metal layer 81 is 1, and the ratio of the width of the third metal layer 91 to the width of the fourth metal layer 92 is 1. The ratio of the thickness of the second metal layer 82 to the thickness of the first metal layer 81 is 2, and the ratio of the thickness of the third metal layer 91 to the thickness of the fourth metal layer 92 is 2.

In an exemplary embodiment, the length, thickness and width of the metal layer located in the first edge region Q1 may be equal to or different from the length, thickness and width of the metal layer located in the fourth edge region Q4 respectively. The length, thickness and width of the metal layer located in the second edge region Q2 and the length, thickness and width of the metal layer located in the third edge region Q3 may be equal or different, and this application implements Examples are not limited.

Please refer to Figures 9 to 11, Figure 9 is a schematic diagram of the admittance curve corresponding to the first preferred structural parameter of the IDT disclosed in the embodiment of the present application, and Figure 10 is a schematic diagram of the admittance curve of the IDT disclosed in the embodiment of the present application A schematic diagram of the admittance curve corresponding to the second preferred structural parameter, and FIG. 11 is a schematic diagram of the admittance curve corresponding to the third preferred structural parameter of the interdigital transducer disclosed in the embodiment of the present application.

In the embodiment of the present application, the length of the metal layer is adjusted while controlling the width and thickness of the metal layer. The first preferred structural parameter corresponds to: the ratio of the length of the second metal layer 82 to the length of the first metal layer 81 is 1, the length of the third metal layer 91 to the length of the fourth metal layer 92 The ratio of the lengths is 1. As can be seen from FIG. 9, when the structural parameter of the IDT 1 is the first optimal structural parameter, the admittance curve between the resonance point and the anti-resonance point is smooth, there is no clutter, and the admittance is real. The upper curve has no sharper peak between the resonance point and the anti-resonance point, so that the transverse mode can be well suppressed.

In the embodiment of the present application, the width of the metal layer is adjusted under the condition that the length and thickness of the metal layer are kept constant. The second preferred structural parameter corresponds to: the ratio of the width of the second metal layer 82 to the width of the first metal layer 81 is 1, the width of the third metal layer 91 to the width of the fourth metal layer 92 The width ratio is 1. As can be seen from FIG. 10, when the structural parameter of the IDT 1 is the second optimal structural parameter, the admittance curve between the resonance point and the anti-resonance point is smooth, there is no clutter, and the admittance is real. The upper curve has no sharper peak between the resonance point and the anti-resonance point, so that the transverse mode can be well suppressed.

In the embodiment of the present application, the thickness of the metal layer is adjusted under the condition that the length and width of the metal layer are kept constant. The third preferred structural parameter corresponds to: the ratio of the thickness of the second metal layer 82 to the thickness of the first metal layer 81 is 2, the thickness of the third metal layer 91 to the thickness of the fourth metal layer 92 The thickness ratio is 2. Please refer to Figure 11 and Figure 12 together, Figure 12 is a schematic diagram of the admittance curve corresponding to the structural parameters of the prior art IDT, the structural parameters of the prior art IDT and the third preferred structural parameter The difference is that the prior art piston structure has only one metal layer. As can be seen from FIG. 11, when the structural parameter of the IDT 1 is the third preferred structural parameter, the admittance curve between the resonance point and the anti-resonance point is smooth, there is no clutter, and the admittance is real. The upper curve has no sharper peak between the resonance point and the anti-resonance point, so that the transverse mode can be well suppressed. It can be seen from Fig. 12 that there is clutter between the resonance point and the anti-resonance point of the IDT in the prior art, and the real part curve of the admittance has a relatively sharp peak at the resonance point, thereby causing the transverse mode the excitation.

Please refer to Figure 13 to Figure 16, Figure 13 is a schematic diagram of the sound velocity distribution corresponding to each region in the resonator described in Figure 1, Figure 14 is a schematic diagram of the sound velocity distribution corresponding to each region in the resonator described in Figure 3, Figure 15 is a diagram FIG. 16 is a schematic diagram of the sound velocity distribution corresponding to each region in the resonator described in FIG. 7 .

In the embodiment of the present application, the sound velocity corresponding to the middle region C is greater than the sound velocity corresponding to the first edge region Q1 and the sound velocity corresponding to the second edge region Q2, and the sound velocity corresponding to the first edge region Q1 is the same as The sound velocities corresponding to the second edge regions Q2 are different. The sound velocity corresponding to the middle region C is greater than the sound velocity corresponding to the third edge region Q3 and the sound velocity corresponding to the fourth edge region Q4, and the sound velocity corresponding to the third edge region Q3 is the same as the sound velocity corresponding to the fourth edge region Q4 The corresponding speed of sound is different.

In the embodiment of the present application, the sound velocity corresponding to the second edge region Q2 is greater than the sound velocity corresponding to the first edge region Q1, and the sound velocity corresponding to the third edge region Q3 is greater than the sound velocity corresponding to the fourth edge region Q4. .

It can be understood that the greater the thickness of the metal layer, the lower the corresponding sound velocity in the edge region.

In an exemplary embodiment, the sound velocity corresponding to the first edge region Q1 is equal to the sound velocity corresponding to the fourth edge region Q4, and the sound velocity corresponding to the second edge region Q2 is equal to the sound velocity corresponding to the third edge region Q3 corresponds to the same speed of sound.

In the embodiment of the present application, please refer to FIG. 2 , FIG. 4 , FIG. 6 and FIG. 8 , the width of the metal layer on the first electrode finger 40 is less than or equal to the width of the first electrode finger, and the second The width of the metal layer on the electrode finger 50 is smaller than or equal to the width of the second electrode finger.

In the embodiment of the present application, the width of the third metal layer 91 and the width of the fourth metal layer 92 on the first electrode finger 40 are less than or equal to the width of the first electrode finger 40, the The width of the first metal layer 81 and the width of the second metal layer 82 on the first electrode finger 40 are smaller than or equal to the width of the first electrode finger 40 .

In the embodiment of the present application, the width of the third metal layer 91 and the width of the fourth metal layer 92 on the second electrode finger 50 are less than or equal to the width of the second electrode finger 50, the The width of the first metal layer 81 and the width of the second metal layer 82 on the second electrode finger 50 are less than or equal to the width of the second electrode finger 50 .

In the embodiment of the present application, please refer to FIG. 1 , FIG. 3 , FIG. 5 and FIG. 7 , the thickness of the metal layer on the first electrode finger 40 is smaller than the thickness of the first electrode finger; the second electrode finger The thickness of the metal layer on 50 is smaller than the thickness of the second electrode finger.

In the embodiment of the present application, the thickness of the third metal layer 91 and the thickness of the fourth metal layer 92 on the first electrode finger 40 are smaller than the thickness of the first electrode finger 40 , and the first The thicknesses of the first metal layer 81 and the second metal layer 82 on the electrode fingers 40 are smaller than the thickness of the first electrode fingers 40 .

In the embodiment of the present application, the thickness of the third metal layer 91 and the thickness of the fourth metal layer 92 on the second electrode finger 50 are smaller than the thickness of the second electrode finger 50 , and the second The thicknesses of the first metal layer 81 and the second metal layer 82 on the electrode fingers 50 are smaller than the thickness of the second electrode fingers 50 .

In the embodiment of the present application, please refer to Fig. 17 and Fig. 18, Fig. 17 is a schematic diagram of the fifth layer structure of the resonator disclosed in the embodiment of the present application, and Fig. 18 is the interdigital transducer of the resonator shown in Fig. 17 Schematic diagram of the front view structure. The difference between the fifth type of resonator 105 and the first type of resonator 101 is that the IDT 1 of the fifth type of resonator 105 further includes a plurality of first dummy fingers 130 and a plurality of second dummy fingers 140 . For the description of the similarities between the fifth type resonator 105 and the first type resonator 101 , please refer to the description of the first type resonator 101 , which will not be repeated here.

In the embodiment of the present application, the interdigital transducer 1 further includes a plurality of first dummy fingers 130 and a plurality of second dummy fingers 140, and the first dummy fingers 130 are arranged between the first electrode fingers 40 and the second dummy fingers 140. between the second bus bars 20 , and the first dummy finger 130 is connected to the second bus bars 20 . The second dummy finger 140 is disposed between the second electrode fingers 50 and the first bus bar 10 , and the second dummy finger 140 is connected to the first bus bar 10 .

It can be understood that, setting the first dummy finger 130 and the second dummy finger 140 on the interdigital transducer 1 can be located where the first dummy finger 130 and the second dummy finger 140 are located. The region further forms a low-velocity region, which can further suppress the transverse mode of the resonator 101 .

In an exemplary embodiment, a plurality of the first electrode fingers 40 and a plurality of the second dummy fingers 140 are arranged alternately and alternately along the length direction of the first bus bar 10 , and the second dummy fingers The length of 140 is smaller than the length of the first electrode finger 40 , and the width and height of the second dummy finger 140 are equal to the width and height of the first electrode finger 40 . The plurality of second electrode fingers 50 and the plurality of first dummy fingers 130 are arranged alternately and alternately along the length direction of the second bus bar 20 , and the length of the first dummy fingers 130 is shorter than that of the first dummy fingers 130 . The length of the two electrode fingers 50 , the width and height of the first dummy finger 130 are equal to the width and height of the second electrode fingers 50 .

In an exemplary embodiment, the first dummy fingers 130 are arranged parallel to the first electrode fingers 40 , and the number of the first dummy fingers 130 is the same as the number of the first electrode fingers 40 . The second dummy fingers 140 are arranged parallel to the second electrode fingers 50 , and the number of the second dummy fingers 140 is the same as the number of the second electrode fingers 50 . The length, width, and height of the first dummy finger 130 are equal to the length, width, and height of the second dummy finger 140 .

In the implementation manner of this application, please refer to FIG. 1 , FIG. 3 , FIG. 5 , FIG. 7 and FIG. 16 . The resonator 101 also includes a temperature compensation layer 9 , and the temperature compensation layer 9 covers the IDT 1 on the piezoelectric substrate 7 . The temperature compensation layer 9 is used to adjust the temperature frequency coefficient of the resonator 101 to avoid changes in the resonant frequency of the resonator due to temperature changes.

In an exemplary embodiment, the temperature compensation layer 9 may have a positive temperature coefficient to compensate for the negative temperature coefficient of the piezoelectric substrate 7 . The material of the temperature compensation layer 9 includes, but is not limited to, silicon dioxide, fluorine-containing silicon dioxide, silicon nitride-based silicon-containing dielectric films, and the like.

In an exemplary embodiment, the resonator 101 may further include a passivation layer (not shown) and/or a frequency modulation layer (not shown), and the passivation layer and/or the frequency modulation layer are located at the temperature The side of the compensation layer 9 facing away from the piezoelectric substrate 7, the materials of the passivation layer and the frequency modulation layer include but not limited to silicon nitride (Si3N4) and the like.

In an exemplary embodiment, the resonator 101 may be a temperature compensated surface acoustic wave filter (Temperature Compensated SAW, TC-SAW).

In an exemplary embodiment, the interdigital transducer 1 can also be applied to a transversely excited film bulk acoustic resonator (X-Film Bulk Acoustic Resonator, X-BAR). Please refer to FIG. 19 . FIG. 19 is a schematic structural diagram of a sixth resonator disclosed in an embodiment of the present application. The difference between the sixth type of resonator 106 and the first type of resonator 101 is that the IDT 1 of the sixth type of resonator 106 also includes a substrate. The resonator 106 includes a substrate 8, a piezoelectric substrate 7, and an interdigital transducer 1 stacked in sequence. A cavity is formed on the substrate 8, and the cavity penetrates from the upper surface of the substrate 8 to the lower surface. , the upper surface is the surface on which the piezoelectric substrate 7 is provided. For the description of the similarities between the sixth type of resonator 106 and the first type of resonator 101 , please refer to the description of the first type of resonator 101 , which will not be repeated here.

In an exemplary embodiment, the structure of the lateral excitation film bulk acoustic resonator (X-Film Bulk Acoustic Resonator, X-BAR) may also be: a window is formed on the substrate, and the opening direction of the window is provided with a piezoelectric substrate On the surface of the sheet 7, the piezoelectric substrate 7 is covered on the window.

In another embodiment of the present application, the alternating regions include at least two fifth edge regions, a middle region and at least two fifth edge regions arranged in sequence from the first bus bar 10 to the second bus bar 20. Six edge regions.

The speed of sound corresponding to the middle region is respectively greater than the speed of sound corresponding to the at least two fifth edge regions, and the speed of sound corresponding to the at least two sixth edge regions;

The sound velocities corresponding to the at least two fifth edge regions arranged sequentially from the middle region to the direction of the first bus bar 10 decrease successively;

The sound velocities corresponding to the at least two sixth edge regions arranged sequentially in a direction from the middle region to the second bus bar 20 decrease successively.

In an exemplary embodiment, at least two fifth edge regions and at least two sixth edge regions are respectively provided with metal layers, and by controlling the thickness relationship and width relationship between the metal layers, the intermediate The sound velocities corresponding to the at least two fifth edge regions that are arranged in sequence pointing to the direction of the first bus bar 10 decrease in sequence, and the sound velocities corresponding to the at least two fifth edge regions that are arranged in sequence from the middle region to the direction of the second bus bar 20 The effect that the speed of sound corresponding to the at least two sixth edge regions decreases sequentially.

Based on the same inventive concept, please refer to FIG. 20 , which is a schematic structural diagram of a filter disclosed in an embodiment of the present application. The embodiment of the present application further provides a filter 200, the filter 200 at least includes a plurality of the above-mentioned resonators 101 .

In the implementation manner of the present application, the filter may further include at least an input terminal IN, an output terminal OUT, a series branch B1 and at least one parallel branch B2. Wherein, the series branch B1 is connected between the input terminal IN and the output terminal OUT, one end of the parallel branch B2 is connected to the series branch B1, and the other end is connected to the ground terminal GND; At least two resonators 101 connected in series are arranged in the series branch B1, and the resonators 101 connected in parallel are arranged in each parallel branch B2.

In the implementation manner of the present application, the filter 200 includes the first type of resonator 101 as an example for illustration. The filter 200 may also include a second type of resonator 102, a third type of resonator 103, a fourth type of resonator 104, a fifth type of resonator 105, and a sixth type of resonator 106, which is not specifically limited in this application . Since the resonator has been introduced in detail in the embodiments shown in FIGS. 1 to 19 , details are not repeated here.

To sum up, the filter 200 provided by the embodiment of the present application includes a plurality of resonators 101 , and the resonators 101 include a piezoelectric substrate 7 and an IDT 1 . The IDT 1 includes a first bus bar 10 , a second bus bar 20 , a plurality of first electrode fingers 40 and a plurality of second electrode fingers 50 . At least one piston structure 60 is disposed on the first electrode finger 40 , and the piston structure 60 is at least located at an end of the first electrode finger 40 facing away from the first bus bar 10 . At least one piston structure 60 is disposed on the second electrode finger 50 , and the piston structure 60 is at least located at an end of the second electrode finger 50 facing away from the second bus bar 20 . At least one of the piston structures 60 located on the first electrode finger 40 includes two metal layers with different thicknesses, and at least one of the piston structures 60 located on the second electrode finger 50 includes two metal layers with different thicknesses. two metal layers. Therefore, at least one piston structure 60 including two metal layers is provided on the first electrode finger 40 and the second electrode finger 50, and the two metal layers are different, thereby changing the area where the two metal layers are located. The transmission speed of the acoustic wave signal on the piezoelectric substrate 7 in the interior forms an acoustic reflection; thereby avoiding the leakage of the acoustic wave signal, the acoustic wave signal is limited in the described interdigital transducer, thereby improving the performance of the resonator 101 The suppression of the transverse mode; the acoustic energy loss is reduced, the quality factor value is improved and the performance of the resonator 101 is improved.

Based on the same inventive concept, an embodiment of the present application further provides an electronic device, including a substrate and the above-mentioned filter 200 , where the filter 200 is flip-chip mounted on the substrate and electrically connected to the substrate.

In an exemplary embodiment, the substrate may be a Printed Circuit Board (PCB).

In an exemplary embodiment, the electronic equipment includes, but is not limited to: LED panels, tablet computers, notebook computers, navigators, mobile phones and electronic watches, etc., any electronic equipment or components with PCBA board components, and this application does not make any Specific restrictions.

Understandably, the electronic device may also include electronic devices such as personal digital assistants (Personal Digital Assistant, PDA) and/or music player functions, such as mobile phones, tablet computers, wearable electronic devices with wireless communication functions (such as smart watch), etc. The aforementioned electronic equipment may also be other electronic devices, such as a laptop computer (Laptop) with a touch-sensitive surface (eg, a touch panel). In some embodiments, the electronic device can have a communication function, that is, it can pass 2G (second-generation mobile phone communication technical specification), 3G (third-generation mobile phone communication technical specification), 4G (fourth-generation mobile phone communication technical specification) , 5G (fifth-generation mobile phone communication technology specification) or W-LAN (wireless local area network) or communication methods that may appear in the future to establish communication with the network. For the sake of brevity, this embodiment of the present application does not make further limitations.

Since the resonator and the filter 200 have been introduced in detail in the embodiments shown in FIGS. 1 to 20 , details are not repeated here.

To sum up, the electronic device provided by the embodiment of the present application includes a filter 200 , the filter includes a plurality of resonators 101 , and the resonators 101 include a piezoelectric substrate 7 and an IDT 1 . The IDT 1 includes a first bus bar 10 , a second bus bar 20 , a plurality of first electrode fingers 40 and a plurality of second electrode fingers 50 . At least one piston structure 60 is disposed on the first electrode finger 40 , and the piston structure 60 is at least located at an end of the first electrode finger 40 facing away from the first bus bar 10 . At least one piston structure 60 is disposed on the second electrode finger 50 , and the piston structure 60 is at least located at an end of the second electrode finger 50 facing away from the second bus bar 20 . At least one of the piston structures 60 located on the first electrode finger 40 includes two metal layers with different thicknesses, and at least one of the piston structures 60 located on the second electrode finger 50 includes two metal layers with different thicknesses. two metal layers. Therefore, at least one piston structure 60 including two metal layers is provided on the first electrode finger 40 and the second electrode finger 50, and the two metal layers are different, thereby changing the area where the two metal layers are located. The transmission speed of the acoustic wave signal on the piezoelectric substrate 7 in the interior forms an acoustic reflection; thereby avoiding the leakage of the acoustic wave signal, the acoustic wave signal is limited in the described interdigital transducer, thereby improving the performance of the resonator 101 The suppression of the transverse mode; the acoustic energy loss is reduced, the quality factor value is improved and the performance of the resonator 101 is improved.

In the description of this specification, reference to the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific examples" or "some examples" etc. The specific features, structures, materials or features described in the manner or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes based on the above descriptions, and all these improvements and changes should belong to the protection scope of the appended claims of the present application. Those skilled in the art can understand that all or part of the methods for implementing the above embodiments, and equivalent changes made according to the claims of the present application, still belong to the scope covered by the present application.

Claims (21)

1. A resonator comprising a piezoelectric substrate, an interdigital transducer positioned on the piezoelectric substrate and reflective structures arranged on opposite sides of the interdigital transducer, characterized in that the Interdigital transducers include: the first bus bar and the second bus bar arranged oppositely; A plurality of first electrode fingers and a plurality of second electrode fingers, the plurality of first electrode fingers are connected to the first bus bar and extend toward the second bus bar, the plurality of second electrode fingers are connected to the second bus bar The second bus bar is connected to and extends toward the first bus bar, and a plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged in sequence; At least one piston structure disposed on at least part of the first electrode fingers, the piston structure is at least located at the end of the first electrode finger facing away from the first bus bar, and disposed on at least part of the second electrode at least one piston structure on a finger, the piston structure is located at least at the end of the second electrode finger facing away from the second bus bar; At least one of the piston structures on the first electrode finger includes two metal layers with different thicknesses, and at least one of the piston structures on the second electrode finger includes two metal layers with different thicknesses. Floor. 2. The resonator according to claim 1, wherein at least one of the piston structures located on the first electrode finger comprises two adjacent metal layers with different thicknesses, located on the first electrode finger At least one of the piston structures on the two electrode fingers includes two adjacent metal layers with different thicknesses; or, At least one of the piston structures on the first electrode finger includes two metal layers with different thicknesses separated by a predetermined distance, and at least one of the piston structures on the second electrode finger includes a spacer Two metal layers with preset distances and different thicknesses. 3. The resonator according to claim 2, wherein a plurality of the first electrode fingers and a plurality of the second electrode fingers extend along the extension of the first bus bar and the second bus bar The directions are alternately arranged in order to form an alternating area, and the alternating area includes a first edge area, a second edge area, a middle area, and a third edge area arranged in sequence from the first bus bar to the direction of the second bus bar and the fourth edge region. 4. The resonator according to claim 3, wherein at least one piston structure disposed on at least part of the first electrode fingers and at least part of the second electrode fingers includes first piston structures arranged at intervals With the second piston structure, the first piston structure includes a first metal layer and a second metal layer, and the second piston structure includes a third metal layer and a fourth metal layer, wherein the thickness of the first metal layer is Different from the thickness of the second metal layer, the thickness of the third metal layer is different from the thickness of the fourth metal layer; the third metal layer, the fourth metal layer, the first metal layer and the second metal layer is sequentially located in the first edge region, the second edge region, the third edge region and the fourth edge region along the extending direction of the first electrode fingers, and the The second metal layer is located at the end of the first electrode finger facing away from the first bus bar; The third metal layer, the fourth metal layer, the first metal layer and the second metal layer are sequentially located in the fourth edge region, the first metal layer along the extending direction of the second electrode fingers. There are three edge regions, the second edge region and the first edge region, and the second metal layer is located at an end of the second electrode finger facing away from the second bus bar. 5. The resonator according to claim 3, wherein at least one piston structure disposed on at least part of the first electrode fingers and at least part of the second electrode fingers includes first piston structures arranged at intervals And a second piston structure, the first piston structure includes a first metal layer, the second piston structure includes a third metal layer and a fourth metal layer, wherein the third metal layer and the fourth metal layer different thicknesses; The third metal layer, the fourth metal layer and the first metal layer are sequentially located in the first edge region, the second edge region and the first electrode finger along the extending direction of the first electrode finger. Three edge regions; the third metal layer, the fourth metal layer, and the first metal layer are located in the fourth edge region, the third edge region in sequence along the extending direction of the second electrode fingers and the second edge region. 6. The resonator according to claim 3, wherein at least one piston structure disposed on at least part of the first electrode fingers and at least part of the second electrode fingers includes first piston structures arranged at intervals And a second piston structure, the first piston structure includes a second metal layer, the second piston structure includes a third metal layer and a fourth metal layer, wherein the third metal layer and the fourth metal layer different thicknesses; The third metal layer, the fourth metal layer, and the second metal layer are sequentially located in the first edge region, the second edge region, and the first electrode finger along the extending direction of the first electrode finger. Four edge regions, and the second metal layer is located at the end of the first electrode finger facing away from the first bus bar; The third metal layer, the fourth metal layer and the second metal layer are sequentially located in the fourth edge region, the third edge region and the first electrode finger along the extending direction of the second electrode finger. An edge region, and the second metal layer is located at the end of the second electrode finger facing away from the second bus bar. 7. The resonator according to claim 3, wherein at least one piston structure disposed on at least part of the first electrode fingers and at least part of the second electrode fingers comprises a first piston structure, the The first piston structure includes a first metal layer and a second metal layer, wherein the thickness of the first metal layer is different from the thickness of the second metal layer; The first metal layer and the second metal layer are located in the third edge area and the fourth edge area in sequence along the extending direction of the first electrode fingers, and the second metal layer is located in the The first electrode finger faces away from the end of the first bus bar; the first metal layer and the second metal layer are sequentially located in the second edge region and the second metal layer along the extending direction of the second electrode finger. The first edge region, and the second metal layer is located at the end of the second electrode finger facing away from the second bus bar. 8. The resonator according to any one of claims 4-7, wherein the thickness of the metal layer located in the first edge region is greater than the thickness of the metal layer located in the second edge region, and the thickness of the metal layer located in the second edge region is The thickness of the metal layer in the fourth edge region is greater than the thickness of the metal layer in the third edge region. 9. The resonator according to any one of claims 4-7, wherein the ratio of the length of the metal layer located in the first edge region to the length of the metal layer located in the second edge region is 0.8 to 1.2; the ratio of the length of the metal layer located in the fourth edge region to the length of the metal layer located in the third edge region is 0.8 to 1.2. 10. The resonator according to any one of claims 4-7, wherein the ratio of the width of the metal layer located in the first edge region to the width of the metal layer located in the second edge region is 0.8 to 1.2; the ratio of the width of the metal layer located in the fourth edge region to the width of the metal layer located in the third edge region is 0.8 to 1.2. 11. The resonator according to any one of claims 4-7, wherein the ratio of the thickness of the metal layer located in the first edge region to the thickness of the metal layer located in the second edge region is 1.2 to 5; the ratio of the thickness of the metal layer at the fourth edge region to the thickness of the metal layer at the third edge region is 1.2 to 5. 12. The resonator according to any one of claims 4-7, wherein the ratio of the length of the metal layer located in the first edge region to the length of the metal layer located in the second edge region is 1 ; The ratio of the length of the metal layer located in the fourth edge region to the length of the metal layer located in the third edge region is 1; The ratio of the width of the metal layer located in the first edge region to the width of the metal layer located in the second edge region is 1; the ratio of the width of the metal layer located in the fourth edge region to the width of the metal layer located in the third edge region The ratio of the width of the metal layer is 1; The ratio of the thickness of the metal layer located in the first edge area to the thickness of the metal layer located in the second edge area is 2; the thickness of the metal layer located in the fourth edge area is the same as that located in the third edge area The ratio of the thickness of the metal layer is 2. 13. The resonator according to any one of claims 3-7, wherein the sound velocity corresponding to the middle region is greater than the sound velocity corresponding to the first edge region and the sound velocity corresponding to the second edge region, and The speed of sound corresponding to the first edge region is different from the speed of sound corresponding to the second edge region; The sound velocity corresponding to the middle region is greater than the sound velocity corresponding to the third edge region and the sound velocity corresponding to the fourth edge region, and the sound velocity corresponding to the third edge region is different from the sound velocity corresponding to the fourth edge region. 14. The resonator according to claim 13, wherein the sound velocity corresponding to the second edge region is greater than the sound velocity corresponding to the first edge region, and the sound velocity corresponding to the third edge region is greater than the fourth edge region The speed of sound corresponding to the region. 15. The resonator according to any one of claims 1-7, wherein the width of the metal layer on the first electrode finger is less than or equal to the width of the first electrode finger; the second electrode The width of the metal layer on the finger is less than or equal to the width of the second electrode finger. 16. The resonator according to any one of claims 1-7, wherein the thickness of the metal layer on the first electrode fingers is smaller than the thickness of the first electrode fingers; The thickness of the metal layer is smaller than the thickness of the second electrode finger. 17. The resonator according to any one of claims 1-7, wherein the IDT further comprises a plurality of first dummy fingers and a plurality of second dummy fingers, the first dummy fingers It is arranged between the first electrode finger and the second bus bar, and the first dummy finger is connected to the second bus bar; the second dummy finger is arranged between the second electrode finger and the second bus bar. between the first bus bars, and the second dummy fingers are connected to the first bus bars. 18. The resonator according to any one of claims 1-7, characterized in that, the resonator further comprises a temperature compensation layer, and the temperature compensation layer covers the interdigital transducer on the pressure on the electrical substrate. 19. A resonator comprising a piezoelectric substrate and an interdigital transducer located on the piezoelectric substrate, characterized in that the interdigital transducer comprises: the first bus bar and the second bus bar arranged oppositely; A plurality of first electrode fingers and a plurality of second electrode fingers, the plurality of first electrode fingers are connected to the first bus bar and extend toward the second bus bar, the plurality of second electrode fingers are connected to the second bus bar The second bus bar is connected to and extends toward the first bus bar, and a plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged in sequence; A plurality of the first electrode fingers and a plurality of the second electrode fingers are alternately arranged sequentially along the extending direction of the first bus bar and the second bus bar to form an alternating area, and the alternating area includes the At least two fifth edge regions, a middle region and at least two sixth edge regions arranged sequentially in a direction in which the first bus bar points to the second bus bar; The sound velocity corresponding to the middle region is respectively greater than the sound velocity corresponding to the at least two fifth edge regions and the sound velocity corresponding to the at least two sixth edge regions; The sound velocities corresponding to the at least two fifth edge regions arranged sequentially from the middle region to the direction of the first bus bar decrease successively; The sound velocities corresponding to the at least two sixth edge regions arranged sequentially in a direction from the middle region to the second bus bar decrease successively. 20. A filter, characterized by comprising at least a plurality of resonators according to any one of claims 1-19. 21. An electronic device, characterized by comprising a substrate and the filter according to claim 20, the filter being mounted on the substrate and electrically connected to the substrate.

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