Surface acoustic wave resonator and filter

Abstract

The utility model provides a surface acoustic wave resonator and a filter, and relates to the technical field of semiconductor devices, at least one heat conduction layer is formed above a temperature compensation layer, so that heat generated by the surface acoustic wave resonator can be dissipated more easily through the at least one heat conduction layer, and the surface acoustic wave resonator is more compact. Therefore, the maximum power tolerance effect of the surface acoustic wave resonator is improved, and it is ensured that the surface acoustic wave resonator can be used in a high-power environment.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor devices, and more specifically to a surface acoustic wave resonator and a filter. Background Art

[0002] SAW (Surface Acoustic Wave) resonator is the abbreviation of surface acoustic wave resonator. It is a special filtering device made by using its piezoelectric effect and the physical characteristics of surface acoustic wave propagation. It is widely used in various fields, such as radio frequency. Among them, surface acoustic wave is an elastic wave with energy concentrated near the surface.

[0003] In current surface acoustic wave product designs, SAW resonators often cannot be used in higher power environments because their power tolerance is often greatly limited. Therefore, how to improve the power tolerance of SAW resonators is a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0004] In view of this, in order to solve the above problems, the utility model provides a surface acoustic wave resonator and a filter, and the technical solution is as follows:

[0005] A surface acoustic wave resonator, comprising:

[0006] substrate;

[0007] an interdigitated electrode located on one side of the substrate;

[0008] a temperature compensation layer located on a side of the interdigital electrode away from the substrate, wherein an orthographic projection of the temperature compensation layer on the plane where the substrate is located at least completely covers an orthographic projection of the interdigital electrode on the plane where the substrate is located;

[0009] A heat-conducting layer is located on a side of the temperature compensation layer away from the substrate; the orthographic projection of the heat-conducting layer on the plane where the substrate is located at least covers the orthographic projection of the interdigital electrodes on the plane where the substrate is located.

[0010] Preferably, in the above-mentioned surface acoustic wave resonator, the heat-conducting layer comprises a first heat-conducting layer;

[0011] The thickness of the first heat-conducting layer is greater than 40 nm.

[0012] Preferably, in the above surface acoustic wave resonator, the heat conducting layer further comprises:

[0013] A second heat-conducting layer is located on a side of the first heat-conducting layer facing away from the substrate.

[0014] Preferably, in the above-mentioned surface acoustic wave resonator, the thickness of the temperature compensation layer is in the range of 0.2λ-0.5λ, wherein λ represents the wavelength of the surface acoustic wave of the surface acoustic wave resonator.

[0015] Preferably, in the above-mentioned surface acoustic wave resonator, the interdigitated electrodes include bus bars, and the bus bars include a first bus bar and a second bus bar arranged opposite to each other in a first direction, and a first electrode finger located on the first bus bar and a second electrode finger located on the second bus bar; the first bus bar and the second bus bar have the same length extension direction and both extend along the second direction, the first direction and the second direction are parallel to the plane where the substrate is located, and the first direction and the second direction intersect.

[0016] Preferably, in the above-mentioned surface acoustic wave resonator, the surface acoustic wave resonator further comprises:

[0017] A plurality of first dummy electrode fingers are located on the first bus bar, and a plurality of second dummy electrode fingers are located on the second bus bar. The first dummy electrode fingers extend in a direction parallel to the first direction, and the second dummy electrode fingers extend in a direction parallel to the first direction.

[0018] Preferably, in the above-mentioned surface acoustic wave resonator, a reflection grating is located at at least one end of the interdigital electrode along the propagation direction of the main acoustic mode;

[0019] The orthographic projection of the heat-conducting layer on the plane where the substrate is located also covers the orthographic projection of the reflection grid on the plane where the substrate is located.

[0020] The present application also provides a filter, which includes the surface acoustic wave resonator described in any one of the above items.

[0021] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0022] The utility model provides a surface acoustic wave resonator and filter. At least one heat-conducting layer is formed above a temperature compensation layer, so that the heat generated by the surface acoustic wave resonator can be more easily dissipated through the at least one heat-conducting layer, thereby improving the maximum power tolerance effect of the surface acoustic wave resonator and ensuring that the surface acoustic wave resonator can be used in a higher power environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 A schematic diagram of a top view of a surface acoustic wave resonator provided in an embodiment of the utility model;

[0025] Figure 2 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model;

[0026] Figure 3 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model;

[0027] Figure 4 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model;

[0028] Figure 5 A schematic diagram of the cross-sectional structure of a surface acoustic wave resonator provided in an embodiment of the utility model;

[0029] Figure 6 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model;

[0030] Figure 7 A schematic cross-sectional structure diagram of another surface acoustic wave resonator provided in an embodiment of the utility model;

[0031] Figure 8 A schematic cross-sectional structure diagram of another surface acoustic wave resonator provided in an embodiment of the utility model;

[0032] Fig. 9 A schematic diagram of the relationship between the thickness of the SiN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator provided in an embodiment of the utility model when the thickness of the AlN heat-conducting layer is 50 nm;

[0033] Fig.10 A schematic diagram of the relationship between the thickness of the AlN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.29λ provided in an embodiment of the utility model;

[0034] Fig.11 A schematic diagram of the relationship between the thickness of the AlN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.31λ provided in an embodiment of the utility model;

[0035] Fig.12 A schematic diagram of the relationship between the thickness of the AlN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.33λ provided in an embodiment of the utility model;

[0036] Fig.13A schematic diagram of the relationship between the thickness of the AlN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.35λ provided in an embodiment of the utility model;

[0037] Fig.14 A schematic diagram of the relationship between the thickness of the AlN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.37λ provided in an embodiment of the utility model;

[0038] Fig.15 A schematic diagram of the relationship between the thickness of the AlN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.39λ provided in an embodiment of the utility model;

[0039] Fig.16 A schematic diagram of the relationship between the thickness of the AlN heat-conducting layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.41λ provided in an embodiment of the utility model;

[0040] Fig.17 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model;

[0041] Fig.18 A schematic top view of the structure of another surface acoustic wave resonator provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0043] Surface acoustic wave resonators and filters are acoustic devices widely used in the field of radio frequency. They combine low insertion loss and good suppression performance, and are relatively small in size. They are used to filter out interference from different frequency signals, attenuate some frequency components, and only allow specified frequency components. They are the technical basis for the application of wireless spectrum as a non-renewable scarce resource. The specific principle can be simply understood as based on the piezoelectric properties of piezoelectric materials, using input and output transducers such as interdigital transducers to convert electrical signals into mechanical energy, and then convert them into electrical signals after processing, so as to amplify the required signals, filter out noise signals and improve signal quality. They are widely used in various wireless communication equipment.

[0044] At present, filters are mainly divided into SAW filters and BAW (Bulk Acoustic Wave) filters. Surface acoustic waves are an elastic wave that is generated and propagated on the surface of a piezoelectric substrate with piezoelectric properties, and whose amplitude decreases rapidly as the depth of the piezoelectric substrate increases. For SAW filters, their manufacturing cost is much lower than that of BAW filters. They are used in low-frequency bands, have low insertion loss and good suppression, and are temperature sensitive.

[0045] At the same time, it should be noted that SAW filters also have corresponding limitations. One of them is that they are easily affected by temperature changes. When the temperature rises, the stiffness of the substrate material tends to decrease and the sound speed will also decrease. It can also be said that the SAW filter has the defect of temperature drift, that is, the frequency will drift with the operating temperature. Therefore, based on the traditional SAW filter, the TC-SAW filter, that is, the temperature-compensated SAW filter, is produced accordingly. It mainly utilizes the temperature elastic properties of the temperature compensation layer (such as SiO2 layer) and the piezoelectric layer opposite to realize compensation for the temperature drift characteristics.

[0046] Among them, the design of the filter often uses the resonator as the basic unit, which can form the corresponding topology and amplify the specified frequency component signal.

[0047] Based on the TC-SAW resonator, the ratio of the thickness of the SiO2 temperature compensation layer and the thickness of the piezoelectric layer is equal to the inverse of the ratio of the temperature adjustment coefficients of the two. Therefore, under normal circumstances, the thickness of the SiO2 temperature compensation layer in the TC-SAW resonator will be relatively thick. Although a relatively thick temperature compensation layer can achieve a better temperature compensation effect, the heat dissipation performance of the material selected for the temperature compensation layer is very poor. For example, the heat dissipation performance of the SiO2 temperature compensation layer is very poor, so the surface acoustic wave resonator often cannot be used in a higher power environment because its power tolerance is often greatly limited. Therefore, how to improve the power tolerance of the surface acoustic wave resonator is also a technical problem that technical personnel in this field need to solve urgently.

[0048] Based on this, an embodiment of the utility model provides a surface acoustic wave resonator and a filter. By forming at least one heat-conducting layer above the temperature compensation layer, the heat generated by the surface acoustic wave resonator can be more easily dissipated through the at least one heat-conducting layer, thereby improving the maximum power tolerance effect of the surface acoustic wave resonator and ensuring that the surface acoustic wave resonator can be used in a higher power environment.

[0049] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0050] refer to Figure 1 , Figure 1A schematic diagram of a top view of a surface acoustic wave resonator provided in an embodiment of the utility model, referring to Figure 2 , Figure 2 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model, referring to Figure 3 , Figure 3 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model. A surface acoustic wave resonator provided in an embodiment of the utility model includes:

[0051] The substrate 11 may be a piezoelectric substrate.

[0052] An interdigitated electrode 12 is located on one side of the substrate 11; wherein the interdigitated electrode 12 includes a bus bar, the bus bar includes a first bus bar 121 and a second bus bar 122 arranged opposite to each other in a first direction X, and a first electrode finger 123 located on the first bus bar 121 and a second electrode finger 124 located on the second bus bar 122; the first bus bar 121 and the second bus bar 122 have the same length extension direction, both extending along the second direction Y, the first direction X and the second direction Y are parallel to the plane where the substrate 11 is located, and the first direction X and the second direction Y intersect; Figure 1 As shown, the first direction X and the second direction Y are perpendicular to each other as an example; Figure 2 The first direction X and the second direction Y are not perpendicular but intersecting as an example. Figure 2 The interdigitated electrodes 12 shown are designed to be inclined; Figure 3 As shown, the virtual line formed by connecting the ends of the electrode fingers in the interdigitated electrode 12 is a broken line.

[0053] It should be noted that the improved solution in the technical solution of the utility model is applicable to Figure 1 The SAW resonator shown is also suitable for Figure 2 The SAW resonator shown is also suitable for Figure 3 The surface acoustic wave resonator shown in the following embodiments of the present utility model is only used as Figure 1 The surface acoustic wave resonator shown is used as an example for schematic explanation.

[0054] That is to say, in some special designs, the envelope formed by the connection lines at the ends of the bus bars or electrode fingers may be a surface acoustic wave resonator with a gradient structure such as an inclined or zigzag shape, which is suitable for the improved solution of the technical solution of the utility model.

[0055] The length extension directions of the first electrode fingers 123 and the second electrode fingers 124 are the same and are respectively parallel to the first direction X. The multiple first electrode fingers 123 on the first bus bar 121 are arranged at intervals in the second direction Y, and the multiple second electrode fingers 124 on the second bus bar 122 are arranged at intervals in the second direction Y. The multiple first electrode fingers 123 on the first bus bar 121 and the multiple second electrode fingers 124 on the second bus bar 122 are arranged crosswise in sequence in the second direction Y, and there are intervals between the multiple first electrode fingers 123 on the first bus bar 121 and the second bus bar 122, and there are intervals between the multiple second electrode fingers 124 on the second bus bar 122 and the first bus bar 121. At this time, the bus bars and the electrode fingers are distributed in a manner similar to crossing fingers to form so-called interdigitated electrodes. When the first bus bar 121 and the first electrode fingers 123 thereon are used as the transmitting end, the second bus bar 122 and the second electrode fingers 124 thereon are used as the receiving end. Conversely, when the first bus bar 121 and the first electrode fingers 123 thereon are used as the receiving end, the second bus bar 122 and the second electrode fingers 124 thereon are used as the transmitting end. The transmitting end is used to convert the electrical signal into an acoustic wave, and the acoustic wave mainly propagates on the surface of the substrate, and the receiving end is used to convert the received acoustic wave into an electrical signal output, thereby realizing filtering.

[0056] refer to Figure 4 , Figure 4 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model, referring to Figure 5 , Figure 5 A schematic diagram of the cross-sectional structure of a surface acoustic wave resonator provided by an embodiment of the utility model is shown in FIG. Figure 4 and Figure 5 As shown, the surface acoustic wave resonator provided by the embodiment of the utility model further includes:

[0057] The temperature compensation layer 13 is located on the side of the interdigital electrode 12 away from the substrate 11 , and the orthographic projection of the temperature compensation layer 13 on the plane where the substrate 11 is located at least completely covers the orthographic projection of the interdigital electrode 12 on the plane where the substrate 11 is located.

[0058] Optionally, the material of the temperature compensation layer 13 can be SiO2 material, and the thickness of the temperature compensation layer 13 is greater than the thickness of the underlying metal layer. It can also be understood that the thickness of the temperature compensation layer 13 is greater than the thickness of the interdigitated electrode 12. The thickness range of the temperature compensation layer 13 is 0.2λ-0.5λ, where λ represents the wavelength of the surface acoustic wave of the surface acoustic wave resonator.

[0059] That is to say, in the embodiment of the utility model, for the TC-SAW resonator, a temperature compensation layer 13 is deposited in the aperture area of ​​the surface acoustic wave resonator (i.e., the area where the forked electrode 12 is located), and the surface of the temperature compensation layer 13 facing away from the substrate 11 is polished and flat. The temperature compensation layer 13 has a dense structure and is used to compensate for the negative temperature effect of the surface acoustic wave resonator. Especially on certain cut-angle substrates (such as 128°YXLiNb03), the temperature compensation layer 13 of SiO2 material can effectively suppress the lateral shear wave mode excited by the electrode fingers.

[0060] It should be noted that in order to better reflect the hierarchical relationship of the film layer, Figure 4 In the example, the case where the coverage area of ​​the temperature compensation layer 13 is different from the coverage area of ​​the substrate 11 is used for explanation. In some optional embodiments, the coverage area of ​​the temperature compensation layer 13 and the coverage area of ​​the substrate 11 may be the same.

[0061] refer to Figure 6 , Figure 6 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model, referring to Figure 7 , Figure 7 A schematic cross-sectional structure diagram of another surface acoustic wave resonator provided in an embodiment of the utility model is shown in FIG. Figure 6 and Figure 7 As shown, the surface acoustic wave resonator provided by the embodiment of the utility model further includes:

[0062] At least one heat-conducting layer 14 is located on a side of the temperature compensation layer 13 facing away from the substrate 11 .

[0063] The orthographic projection of the heat-conducting layer 14 on the plane where the substrate 11 is located at least covers the orthographic projection of the interdigital electrodes 12 on the plane where the substrate 11 is located.

[0064] It should be noted that in order to better reflect the hierarchical relationship of the film layer, Figure 6 The example in which the coverage area of ​​the temperature compensation layer 13, the coverage area of ​​the substrate 11 and the coverage area of ​​the heat conducting layer 14 are different is used for explanation. In some optional embodiments, the coverage area of ​​the temperature compensation layer 13, the coverage area of ​​the substrate 11 and the coverage area of ​​the heat conducting layer 14 may also be the same.

[0065] Specifically, in the embodiment of the present invention, the orthographic projection of the heat conducting layer 14 on the plane where the substrate 11 is located at least completely covers the entire area where the interdigital electrodes 12 are located. Figure 7As shown, the heat-conducting layer 14 is a thin layer structure covering the temperature compensation layer 13. The heat generated by the surface acoustic wave resonator can be more easily dissipated through the at least one layer of heat-conducting layer 14, thereby improving the maximum power tolerance effect of the surface acoustic wave resonator and ensuring that the surface acoustic wave resonator can be used in a higher power environment.

[0066] Optionally, in another embodiment of the present invention, as Figure 7 As shown, the heat-conducting layer 14 provided in the embodiment of the present invention includes a first heat-conducting layer 14a.

[0067] Specifically, in the embodiment of the utility model, the thermal conductive layer 14 only includes one thermal conductive layer structure, and the first thermal conductive layer 14a includes but is not limited to AlN thermal conductive layer, Si thermal conductive layer, SiC thermal conductive layer, diamond thermal conductive layer, quartz thermal conductive layer, sapphire thermal conductive layer or SiN thermal conductive layer.

[0068] Optionally, in another embodiment of the present invention, refer to Figure 8 , Figure 8 This is a schematic diagram of a cross-sectional structure of another surface acoustic wave resonator provided in an embodiment of the utility model. The heat conducting layer 14 provided in an embodiment of the utility model further includes:

[0069] The second heat conducting layer 14 b is located on a side of the first heat conducting layer 14 a away from the substrate 11 .

[0070] Specifically, in the embodiment of the present invention, the second thermal conductive layer 14b includes but is not limited to a SiN thermal conductive layer, and the SiN thermal conductive layer also has a good passivation effect. When the first thermal conductive layer 14a is an AlN thermal conductive layer, the AlN material has strong water absorption and is easy to absorb water molecules in the air to affect the device performance and quality. Therefore, in the embodiment of the present invention, a SiN thermal conductive layer is further formed, which can have both passivation effect and thermal conductivity effect.

[0071] Optionally, in another embodiment of the present invention, the thickness of the first heat conducting layer 14a is greater than 40 nm.

[0072] Specifically, in the embodiment of the present invention, the first heat-conducting layer 14a is an AlN heat-conducting layer for example. The thickness range of the second heat-conducting layer 14b is a SiN heat-conducting layer and is not limited in the embodiment of the present invention. Fig. 9 , Fig. 9 A schematic diagram of the relationship between the thickness of the SiN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator is provided for an embodiment of the utility model when the thickness of the AlN thermal conductive layer is 50 nm, wherein the horizontal axis is the thickness of the SiN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in ° C.

[0073] based on Fig. 9 It can be seen from the results that no matter how the thickness of the SiN thermal conductive layer changes, the maximum temperature of the surface acoustic wave resonator is stable near a certain value, and the variation range is very small. In other words, the influence of the thickness of the SiN thermal conductive layer on the maximum temperature of the surface acoustic wave resonator can be ignored. Therefore, in the embodiment of the utility model, the thickness range of the SiN thermal conductive layer is not limited and can be determined according to actual conditions.

[0074] refer to Fig.10 , Fig.10 A schematic diagram of the relationship between the thickness of the AlN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.29λ is provided for an embodiment of the utility model, wherein the horizontal axis is the thickness of the AlN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in °C.

[0075] refer to Fig.11 , Fig.11 A schematic diagram of the relationship between the thickness of the AlN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.31λ is provided for an embodiment of the utility model, wherein the horizontal axis is the thickness of the AlN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in °C.

[0076] refer to Fig.12 , Fig.12 A schematic diagram of the relationship between the thickness of the AlN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.33λ is provided for an embodiment of the utility model, wherein the horizontal axis is the thickness of the AlN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in °C.

[0077] refer to Fig.13 , Fig.13 A schematic diagram of the relationship between the thickness of the AlN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.35λ is provided for an embodiment of the utility model, wherein the horizontal axis is the thickness of the AlN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in °C.

[0078] refer to Fig.14 , Fig.14 A schematic diagram of the relationship between the thickness of the AlN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.37λ is provided for an embodiment of the utility model, wherein the horizontal axis is the thickness of the AlN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in °C.

[0079] refer to Fig.15 , Fig.15A schematic diagram of the relationship between the thickness of the AlN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.39λ is provided for an embodiment of the utility model, wherein the horizontal axis is the thickness of the AlN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in °C.

[0080] refer to Fig.16 , Fig.16 A schematic diagram of the relationship between the thickness of the AlN thermal conductive layer and the maximum temperature of the surface acoustic wave resonator when the thickness of the temperature compensation layer is 0.41λ is provided for an embodiment of the utility model, wherein the horizontal axis is the thickness of the AlN thermal conductive layer, in nm; the vertical axis is the maximum temperature of the surface acoustic wave resonator, in °C.

[0081] Since the thickness of the temperature compensation layer 13 in the TC-SAW resonator needs to be determined according to the wavelength and the thickness of the piezoelectric layer, Figure 10-Figure 16 It can be seen from the results that, under different thicknesses of the temperature compensation layer 13, the applicant found that when the thickness of the AlN thermal conductive layer is greater than 40nm, the maximum temperature drop of the surface acoustic wave resonator will enter a relatively gentle range, and is less than 280°C. That is to say, when the thickness of the AlN thermal conductive layer is less than 40nm, the maximum temperature of the surface acoustic wave resonator will change very quickly every time the thickness of the AlN thermal conductive layer is thickened a little, which means that the effect of increasing the maximum power tolerance of the surface acoustic wave resonator by thickening the thickness of the AlN thermal conductive layer will be very obvious. When the thickness of the AlN thermal conductive layer is greater than 40nm, the effect of increasing the maximum power tolerance of the surface acoustic wave resonator is not very obvious when the thickness of the AlN thermal conductive layer is further thickened. Therefore, in the embodiment of the utility model, the thickness range of the first thermal conductive layer 14a is set to a thickness range greater than 40nm.

[0082] Optionally, in another embodiment of the present invention, refer to Fig.17 , Fig.17 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model. The surface acoustic wave resonator provided in an embodiment of the utility model further includes:

[0083] A plurality of first dummy electrode fingers 125 are located on the first bus bar 121, and a plurality of second dummy electrode fingers 126 are located on the second bus bar 122, wherein the length extension direction of the dummy electrode fingers is parallel to the first direction X, the plurality of first dummy electrode fingers 125 and the plurality of first electrode fingers 123 on the first bus bar 121 are arranged in sequence and spaced apart in the second direction Y, the plurality of second dummy electrode fingers 126 and the plurality of second electrode fingers 124 on the second bus bar 122 are arranged in sequence and spaced apart in the second direction Y, and in the first direction X, the first electrode fingers 123 on the first bus bar 121 and the second dummy electrode fingers 126 on the second bus bar 122 are arranged opposite to each other, and there is a gap between them, and the first dummy electrode fingers 125 on the first bus bar 121 and the second electrode fingers 124 on the second bus bar 122 are arranged opposite to each other, and there is also a gap between them.

[0084] That is to say, in the embodiment of the present utility model, the interdigital electrode 12 can be an interdigital electrode without dummy electrode fingers, or can be an interdigital electrode without dummy electrode fingers. Figure 3 and Fig.17 The interdigitated electrodes with dummy electrode fingers shown in the figure, when the interdigitated electrodes 12 are provided with dummy electrode fingers, the provision of the dummy electrode fingers can also play the effect of suppressing clutter and improving the quality factor of the surface acoustic wave resonator.

[0085] Optionally, in another embodiment of the present invention, refer to Fig.18 , Fig.18 A schematic diagram of a top view of another surface acoustic wave resonator provided in an embodiment of the utility model. The surface acoustic wave resonator provided in an embodiment of the utility model further includes:

[0086] The reflection grating 15 is located at at least one end of the interdigital electrode 12 along the second direction Y. It should be noted that in the embodiment of the utility model, the reflection grating 15 is provided at both ends of the interdigital electrode 12 along the second direction Y. It should be noted that the second direction Y can also be understood as the propagation direction of the main acoustic mode of the surface acoustic wave resonator.

[0087] Specifically, in the embodiment of the utility model, a reflection grating 15 can be set at at least one end of the interdigitated electrode 12 along the second direction Y to reflect the sound waves back to the resonance area, allowing the sound waves to continue to resonate in the resonance area, thereby forming a better resonance effect and mode, and improving the transmission performance of the surface acoustic wave resonator.

[0088] When the surface acoustic wave resonator provided by the embodiment of the utility model includes a reflection grating 15, as Fig.18As shown, the orthographic projection of the temperature compensation layer 13 on the plane where the substrate 11 is located also completely covers the orthographic projection of the reflective grating 15 on the plane where the substrate 11 is located, and the orthographic projection of the heat conducting layer 14 on the plane where the substrate 11 is located also completely covers the orthographic projection of the reflective grating 15 on the plane where the substrate 11 is located. In other words, the orthographic projection of the heat conducting layer 14 on the plane where the substrate 11 is located needs to completely cover any metal area thereunder.

[0089] Optionally, based on the above embodiments of the present invention, a filter is further provided in another embodiment of the present invention. The filter includes the surface acoustic wave resonator described in the above embodiments.

[0090] This filter has the same effect as the surface acoustic wave resonator in the above-mentioned embodiment.

[0091] The surface acoustic wave resonator and filter provided by the utility model are introduced in detail above. The principle and implementation mode of the utility model are explained in this article by using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model. At the same time, for the general technicians in this field, according to the idea of ​​the utility model, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the utility model.

[0092] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0093] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device that includes a series of elements is inherent to the elements, or also includes elements inherent to these processes, methods, articles or devices. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0094] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surface acoustic wave resonator, characterized in that: The surface acoustic wave resonator comprises: substrate; an interdigitated electrode located on one side of the substrate; a temperature compensation layer located on a side of the interdigital electrode away from the substrate, wherein an orthographic projection of the temperature compensation layer on the plane where the substrate is located at least completely covers an orthographic projection of the interdigital electrode on the plane where the substrate is located; A heat-conducting layer is located on a side of the temperature compensation layer away from the substrate; the orthographic projection of the heat-conducting layer on the plane where the substrate is located at least covers the orthographic projection of the interdigital electrodes on the plane where the substrate is located.

2. The surface acoustic wave resonator according to claim 1, characterized in that: The heat-conducting layer comprises a first heat-conducting layer; The thickness of the first heat-conducting layer is greater than 40 nm.

3. The surface acoustic wave resonator according to claim 2, characterized in that: The heat conducting layer further comprises: A second heat-conducting layer is located on a side of the first heat-conducting layer facing away from the substrate.

4. The surface acoustic wave resonator according to claim 1, characterized in that: The temperature compensation layer has a thickness ranging from 0.2λ to 0.5λ, wherein λ represents the wavelength of the surface acoustic wave of the surface acoustic wave resonator.

5. The surface acoustic wave resonator according to claim 1, characterized in that: The interdigitated electrode includes a bus bar, which includes a first bus bar and a second bus bar arranged opposite to each other in a first direction, and a first electrode finger located on the first bus bar and a second electrode finger located on the second bus bar; the first bus bar and the second bus bar have the same length extension direction and both extend along the second direction, the first direction and the second direction are parallel to the plane where the substrate is located, and the first direction and the second direction intersect.

6. The surface acoustic wave resonator according to claim 5, characterized in that: The surface acoustic wave resonator further comprises: A plurality of first dummy electrode fingers are located on the first bus bar, and a plurality of second dummy electrode fingers are located on the second bus bar. The first dummy electrode fingers extend in a direction parallel to the first direction, and the second dummy electrode fingers extend in a direction parallel to the first direction.

7. The surface acoustic wave resonator according to claim 1, characterized in that: A reflection grating located at at least one end of the interdigitated electrode along the propagation direction of the main acoustic mode; The orthographic projection of the heat-conducting layer on the plane where the substrate is located also covers the orthographic projection of the reflection grid on the plane where the substrate is located.

8. A filter, characterized in that: The filter comprises the surface acoustic wave resonator according to any one of claims 1 to 7.

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