A temperature-compensated surface acoustic wave resonator, filter and manufacturing method thereof

Abstract

The present application provides a temperature-compensated surface acoustic wave resonator, a filter and a manufacturing method thereof, wherein the surface acoustic wave resonator comprises a substrate, an interdigital transducer, a first load structure and a second load structure; the interdigital transducer comprises a plurality of long finger electrodes; the first load structure is arranged on a side of the insulating layer away from the long finger electrodes, and the orthographic projection of the first load structure on the substrate overlaps at least partially with the orthographic projection of the long finger electrodes on the substrate; the second load structure is arranged on a side of the first load structure away from the long finger electrodes, and the orthographic projection of the second load structure on the substrate overlaps at least partially with the orthographic projection of the long finger electrodes on the substrate; the second load structure comprises at least one hollow region. The present invention can suppress the lateral mode and improve the Q value by setting the first load structure; the present invention can improve the heat dissipation capacity of the resonator under the premise of miniaturization by setting the second load structure comprising at least one hollow region, thereby improving the power resistance capacity of the filter.

Description

Technical Field

[0001] The present application relates to the technical field of surface acoustic wave resonators, and in particular to a temperature compensated surface acoustic wave resonator, a filter and a manufacturing method thereof. Background Art

[0002] Surface acoustic wave (SAW) is a mechanical wave that processes electrical signals by propagating on the surface of a crystal. SAW filters use the characteristics of this acoustic wave to achieve signal filtering. However, temperature changes can affect the performance of SAW filters, resulting in frequency drift and unstable performance.

[0003] To solve this problem, the Temperature Compensated Surface Acoustic Wave Filter (TC-SAW) uses special design and technology to maintain stable performance at different temperatures. It usually includes a temperature sensor and compensation circuit to monitor and adjust the operating temperature of the filter to achieve temperature compensation.

[0004] Temperature-compensated surface acoustic wave filters are widely used in wireless communication devices due to their superior temperature stability, such as mobile phones, satellite communications, radars, etc. With the requirement of miniaturization, the reduction in the size of the filter has limited the area of ​​the resonator, and the reduction in size has also reduced the power handling capacity. Therefore, there is an urgent need for a temperature-compensated surface acoustic wave filter that can not only meet the miniaturization requirements of the filter but also improve the power handling capacity. Summary of the invention

[0005] The present application provides a temperature-compensated surface acoustic wave resonator, a filter and a manufacturing method thereof, which are used to solve the problem of reduced power handling capability caused by reducing the size of the filter.

[0006] In a first aspect, the present application provides a temperature compensated surface acoustic wave resonator, comprising:

[0007] substrate;

[0008] An interdigital transducer is disposed on a side surface of the substrate, the interdigital transducer comprises a plurality of long finger electrodes, the long finger electrodes comprise a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along a second direction and are arranged along the first direction; the first long finger electrode and the second long finger electrode are cross-arranged along the second direction;

[0009] at least one first load structure, disposed on a side of the long finger electrode away from the substrate, and an orthographic projection of the first load structure on the substrate at least partially overlaps with an orthographic projection of the long finger electrode on the substrate;

[0010] A second load structure is arranged on a side of the first load structure away from the long finger electrode, and the orthographic projection of the second load structure on the substrate at least partially overlaps with the orthographic projection of the long finger electrode on the substrate; the second load structure includes at least one hollow area;

[0011] The first direction intersects the second direction.

[0012] Preferably, the distance between the first load structure and the second load structure in the thickness direction is a first spacing L, and the value range of the first spacing L is: 0≤L≤λ, where λ is the wavelength of the surface acoustic wave. It can be understood that when L=0, the first load structure is in contact with the second load structure in the thickness direction; when 0<L≤λ, the first load structure is not in contact with the second load structure in the thickness direction.

[0013] Preferably, the shape of the hollow area includes a circle and a polygon, the polygon includes a regular polygon and an irregular polygon, and the regular polygon includes a triangle, a rectangle, and a rhombus.

[0014] Preferably, the maximum size of the hollow area along the first direction is a first size M, and the value range of the first size M is: λ≤M≤2λ; the maximum size of the hollow area along the second direction is a second size N, and the value range of the second size N is: 0.5λ≤N≤λ.

[0015] Preferably, the remaining portion of the second load structure after removing the hollow area is a metal wire, the line width of the metal wire is a third dimension Q, and the value range of the third dimension Q is: 0.5λ≤Q≤λ.

[0016] Preferably, along the first direction, the size of the second load structure is greater than or equal to the size of the effective aperture area; along the second direction, the size of the second load structure is greater than or equal to the size of the effective aperture area.

[0017] Preferably, along the second direction, the first long finger electrode includes a first end portion close to a side of the second long finger electrode and a second end portion away from a side of the second long finger electrode;

[0018] An orthographic projection of at least a portion of the first load structure on the substrate overlaps with an orthographic projection of the first end on the substrate;

[0019] The second long finger electrode comprises a third end portion close to a side of the first long finger electrode and a fourth end portion away from a side of the first long finger electrode;

[0020] An orthographic projection of at least a portion of the first load structure on the substrate overlaps with an orthographic projection of the third end on the substrate.

[0021] Preferably, the IDT further comprises a bus bar, and the bus bar comprises a first bus bar and a second bus bar;

[0022] The first bus bar and the second bus bar both extend along the second direction and are arranged opposite to each other along the first direction;

[0023] The second end of the first long finger electrode is connected to the first bus bar;

[0024] The fourth end of the second long finger electrode is connected to the second bus bar.

[0025] Preferably, the first long finger electrode and the second long finger electrode have the same length extending along the second direction.

[0026] Preferably, the temperature-compensated surface acoustic wave resonator further comprises a temperature compensation layer; the temperature compensation layer is arranged on a side of the interdigital transducer away from the substrate.

[0027] Preferably, the temperature-compensated surface acoustic wave resonator further includes a reflection grating region, which is located at least on one side of the long finger electrode along the first direction; the reflection grating region includes a plurality of reflection gratings, which extend along the second direction, and the plurality of reflection gratings are arranged along the first direction.

[0028] Preferably, at least part of the orthographic projection of the first load structure on the substrate overlaps with the orthographic projection of the reflective grating region on the substrate, and at least part of the orthographic projection of the second load structure on the substrate overlaps with the orthographic projection of the reflective grating region on the substrate.

[0029] Preferably, along the first direction, ends of the first load structure and the second load structure are both aligned with a boundary of the reflective grating region away from the interdigital transducer.

[0030] In a second aspect, the present application further provides a temperature-compensated surface acoustic wave filter, comprising the temperature-compensated surface acoustic wave resonator described in any one of the first aspects.

[0031] In a third aspect, the present application also provides a method for manufacturing a temperature compensated surface acoustic wave resonator, comprising:

[0032] Providing a substrate, wherein the substrate is a piezoelectric substrate, and the material used includes lithium niobate or lithium tantalate;

[0033] An interdigital transducer is manufactured on one side surface of the substrate, and the processes used include coating, exposure, development, evaporation, and demolding; the interdigital transducer includes a bus bar and a plurality of long finger electrodes, and the long finger electrodes include a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along the second direction and are arranged along the first direction; the first long finger electrode and the second long finger electrode are arranged crosswise along the first direction; the material used for the long finger electrode includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, and aluminum, and a combination thereof;

[0034] A first load structure is fabricated on a side of the long finger electrode away from the substrate; an orthographic projection of the first load structure on the substrate at least partially overlaps with an orthographic projection of the long finger electrode on the substrate;

[0035] A second load structure is fabricated on a side of the first load structure away from the long finger electrode; the orthographic projection of the second load structure on the substrate at least partially overlaps with the orthographic projection of the long finger electrode on the substrate; the second load structure includes at least one hollow area;

[0036] A temperature compensation layer is formed on a surface of the IDT away from the long finger electrode, wherein the temperature compensation layer covers the first load structure, the second load structure, the IDT and at least a portion of the surface of the substrate;

[0037] The first direction intersects the second direction.

[0038] A temperature-compensated surface acoustic wave resonator provided in an embodiment of the present invention comprises a substrate, an interdigital transducer, a first load structure and a second load structure; the interdigital transducer comprises a plurality of long finger electrodes, the long finger electrodes comprise a first long finger electrode and a second long finger electrode cross-arranged along a second direction, the first long finger electrode and the second long finger electrode both extend along the second direction and are arranged along the first direction; the interdigital transducer is arranged on a surface of one side of the substrate; an insulating layer is arranged on one side of the long finger electrode; the first load structure is arranged on a side of the insulating layer away from the long finger electrode, and an orthographic projection of the first load structure on the substrate at least partially overlaps with an orthographic projection of the long finger electrode on the substrate; the second load structure is arranged on a side of the first load structure away from the long finger electrode, and an orthographic projection of the second load structure on the substrate at least partially overlaps with an orthographic projection of the long finger electrode on the substrate; the second load structure comprises at least one hollow area. The present invention can increase the force of the long finger electrode on the piezoelectric substrate by setting the first load structure, thereby changing the propagation speed of the surface acoustic wave, so that the sound speed of the surface acoustic wave in the area where the first load structure is set is less than the sound speed of the area where the first load structure is not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator. The present invention increases the heat conduction channel by setting the second load structure including at least one hollow area, and can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 is a top view of the temperature-compensated surface acoustic wave resonator provided in Example 1 of the present application;

[0041] Figure 2 is a top view of a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application;

[0042] Figure 3 is a top view of a temperature-compensated surface acoustic wave resonator provided in Embodiment 3 of the present application;

[0043] Figure 4 It is a cross-sectional view of a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application.

[0044] Explanation of symbols:

[0045] 1. Substrate; 2. Interdigital transducer; 21. Long finger electrode; 211. First long finger electrode; 212. Second long finger electrode; 22. Bus bar; 221. First bus bar; 222. Second bus bar; 3. First load structure; 4. Second load structure; 41. Hollow area; 42. Metal wire; 5. Reflective grid area; 6. Temperature compensation layer; L. First spacing; M. First size; N. Second size; Q. Third size; X. First direction; Y. Second direction. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0047] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0048] like Figure 1-Figure 4 As shown, in a first aspect, an embodiment of the present invention provides a temperature compensated surface acoustic wave resonator, comprising:

[0049] Substrate 1; the substrate 1 is a piezoelectric substrate, and the material used includes lithium niobate or lithium tantalate;

[0050] An interdigital transducer 2 is disposed on a side surface of the substrate 1, the interdigital transducer 2 includes a plurality of long finger electrodes 21, the long finger electrodes 21 include a first long finger electrode 211 and a second long finger electrode 212; the first long finger electrode 211 and the second long finger electrode 212 both extend along a second direction Y and are arranged along a first direction X; the first long finger electrode 211 and the second long finger electrode 212 are cross-arranged along the second direction Y; the material used for the long finger electrode 21 includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, and aluminum, and a combination thereof;

[0051] at least one first load structure 3, arranged on a side of the long finger electrode 21 away from the substrate 1, and the orthographic projection of the first load structure 3 on the substrate 1 at least partially overlaps with the orthographic projection of the long finger electrode 21 on the substrate 1; the material of the first load structure 3 includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, aluminum and a combination thereof;

[0052] The second load structure 4 is arranged on a side of the first load structure 3 away from the long finger electrode 21, and the orthographic projection of the second load structure 4 on the substrate 1 at least partially overlaps with the orthographic projection of the long finger electrode 21 on the substrate 1; the second load structure 4 includes at least one hollow area 41; the material used for the second load structure 4 includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, aluminum and a combination thereof;

[0053] The first direction X and the second direction Y intersect.

[0054] By setting the first load structure 3, the present invention can increase the force of the long finger electrode 21 on the piezoelectric substrate 1, thereby changing the propagation speed of the surface acoustic wave, so that the sound speed of the surface acoustic wave in the area where the first load structure 3 is set is less than the sound speed of the area where the first load structure 3 is not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator. By setting the second load structure 4 including at least one hollow area 41, the present invention increases the heat conduction channel, can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0055] Preferably, the distance between the first load structure 3 and the second load structure 4 along the thickness direction is a first spacing L, and the value range of the first spacing L is: 0≤L≤λ, where λ is the wavelength of the surface acoustic wave. It can be understood that when L=0, the first load structure 3 and the second load structure 4 are in contact along the thickness direction, and when 0<L≤λ, the first load structure 3 and the second load structure 4 are not in contact along the thickness direction. The first load structure 3 and the second load structure 4 are simple to set and have a large degree of freedom in setting, and the setting method is flexible.

[0056] Preferably, the shape of the hollow area 41 includes a circle and a polygon. Figure 1 As shown, in the first embodiment, the second load structure 4 is surrounded by a closed rectangle, and a hollow area 41 is formed inside the rectangle. The routing of the hollow area 41 intersects with the multiple long finger electrodes 21 of the interdigital transducer 2, and is neither perpendicular nor parallel, and the shape of the hollow area 41 is divided into a triangle and a rhombus. Among them, the part where the hollow area 41 is connected to the edge of the rectangle is cut by the edge of the rectangle to form a triangle. Figure 2 As shown, in the second embodiment, the routing of the hollow area 41 is parallel or perpendicular to the multiple long finger electrodes 21 of the interdigital transducer 2, and the hollow area 41 is divided into multiple rectangular hollow areas. Figure 3As shown, in the third embodiment, the routing of the hollow area 41 is divided into a plurality of sub-rectangles along the width direction, and the configuration inside each sub-rectangle is a bent shape, dividing the sub-rectangle into a plurality of triangular hollow areas. Exemplarily, the shape of the hollow area 41 can also be a circle, an ellipse, a regular polygon or an irregular polygon, etc. It can be understood that, as Figure 1-Figure 3 The embodiments shown are only some of the embodiments shown in the present invention, and are not intended to limit the present invention. It should be noted that the embodiments of the present invention do not limit the number, area, and shape of the hollow regions 41, which can enhance the power handling capability of the filter on the one hand, and can diversify the settings of the temperature-compensated surface acoustic wave filter on the other hand.

[0057] Preferably, the maximum size of the hollow area 41 along the first direction X is a first size M, and the value range of the first size M is: λ≤M≤2λ; the maximum size of the hollow area 41 along the second direction Y is a second size N, and the value range of the second size N is: 0.5λ≤N≤λ. This setting increases the heat conduction channel, can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0058] Preferably, the remaining portion of the second load structure 4 after removing the hollow area 41 is a metal wire 42, and the line width of the metal wire 42 is a third dimension Q, and the value range of the third dimension Q is: 0.5λ≤Q≤λ. This setting increases the heat conduction channel, and can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0059] Preferably, along the first direction X, the size of the second load structure 4 is greater than or equal to the size of the effective aperture area; along the second direction Y, the size of the second load structure 4 is greater than or equal to the size of the effective aperture area. This arrangement increases the heat conduction channel, and can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0060] Preferably, along the second direction Y, the first long finger electrode 211 includes a first end close to the second long finger electrode 212 and a second end away from the second long finger electrode 212; the second long finger electrode 212 includes a third end close to the first long finger electrode 211 and a fourth end away from the first long finger electrode 211;

[0061] At least a portion of the orthographic projection of the first load structure 3 on the substrate 1 overlaps with the orthographic projection of the first end on the substrate 1; at least a portion of the orthographic projection of the first load structure 3 on the substrate 1 overlaps with the orthographic projection of the third end on the substrate 1. Figure 2As shown, in Embodiment 2, a part of the orthographic projection of the first end and the third end on the substrate 1 overlaps with the orthographic projection of the first load structure 3 on the substrate 1; Figure 1 and Figure 3 As shown, in the first and third embodiments, all of the orthographic projections of the first end and the third end on the substrate 1 overlap with the orthographic projections of the first load structure 3 on the substrate 1. The present invention can increase the force of the long finger electrode 21 on the piezoelectric substrate 1 by setting the first load structure 3, thereby changing the propagation speed of the surface acoustic wave, so that the sound speed of the surface acoustic wave in the area where the first load structure 3 is set is smaller than the sound speed of the area where the first load structure 3 is not set, thereby suppressing the lateral mode and improving the Q value of the temperature compensated surface acoustic wave resonator.

[0062] Preferably, the IDT 2 further includes a bus bar 22, and the bus bar 22 includes a first bus bar 221 and a second bus bar 222; the first bus bar 221 and the second bus bar 222 both extend along the second direction Y and are arranged opposite to each other along the first direction X; the second end of the first long finger electrode 211 is connected to the first bus bar 221; and the fourth end of the second long finger electrode 212 is connected to the second bus bar 222. The bus bar 22 can receive an AC signal, and when an AC signal of a certain frequency is applied to the bus bar 22, a surface acoustic wave can be generated in the temperature compensated surface acoustic wave resonator.

[0063] Preferably, the first long finger electrode 211 and the second long finger electrode 212 have the same length extending along the second direction Y. This simplifies the arrangement so that the overall structure has symmetry and consistency, and is easy to design and maintain. It can also further enhance the suppression of lateral modes.

[0064] Preferably, the temperature-compensated surface acoustic wave resonator further includes a temperature compensation layer 6; the temperature compensation layer 6 is arranged on the side of the interdigital transducer 2 away from the substrate 1. Exemplarily, the material of the temperature compensation layer 6 can be silicon dioxide or silicon nitride. The provision of the temperature compensation layer 6 can prevent temperature changes from affecting the resonant frequency of the temperature-compensated surface acoustic wave resonator, thereby improving the temperature stability and reliability of the resonator. It should be noted that in order to enable the resonator to have better temperature stability, a material with a positive temperature coefficient can be used to compensate for the adverse effects of the piezoelectric material. This temperature-compensated surface acoustic wave resonator can reduce the adverse effects of temperature drift.

[0065] Preferably, the temperature-compensated surface acoustic wave resonator further comprises a reflection grating region 5, which is located at least on one side of the long finger electrode 21 along the first direction X; the reflection grating region 5 comprises a plurality of reflection gratings, which extend along the second direction Y, and the plurality of reflection gratings are arranged along the first direction X. The reflection gratings can be used to reflect surface acoustic waves and prevent surface acoustic wave leakage. Adding reflection gratings can enhance the selectivity of the filter, expand the bandwidth of the filter, reduce the size of the filter, and improve the stability of the filter.

[0066] Preferably, at least a portion of the orthographic projection of the first load structure 3 on the substrate 1 overlaps with the orthographic projection of the reflective grating area 5 on the substrate 1, and at least a portion of the orthographic projection of the second load structure 4 on the substrate 1 overlaps with the orthographic projection of the reflective grating area 5 on the substrate 1. It can be understood that along the first direction X, both the first load structure 3 and the second load structure 4 can extend to the reflective grating area 5. For example, Figure 2 As shown, in the second embodiment, the second load structure 4 extends to the reflection grating area 5; in the third embodiment, the first load structure 3 and the second load structure 4 both extend to the reflection grating area 5. Such a design is simple in setting on the one hand, and can further enhance the power handling capability of the filter and the suppression effect on the lateral mode on the other hand.

[0067] Preferably, along the first direction X, the ends of the first load structure 3 and the second load structure 4 are aligned with the boundary of the reflection grating area 5 away from the interdigital transducer 2. In the third embodiment, along the first direction X, the ends of the first load structure 3 and the second load structure 4 are aligned with the boundary of the reflection grating area 5, that is, the first load structure 3 and the second load structure 4 extend to the boundary of the reflection grating area 5. Such a design can further enhance the power resistance capability of the filter and the suppression effect on the lateral mode.

[0068] In the second aspect, based on the same inventive concept, an embodiment of the present invention further provides a temperature-compensated surface acoustic wave filter, including the temperature-compensated surface acoustic wave resonator described in any embodiment of the first aspect. The temperature-compensated surface acoustic wave filter can increase the force of the long finger electrode 21 on the piezoelectric substrate 1 by setting the first load structure 3, thereby changing the propagation speed of the surface acoustic wave, so that the sound velocity of the surface acoustic wave in the area where the first load structure 3 is set is less than the sound velocity of the area where the first load structure 3 is not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator. The present invention increases the heat conduction channel by setting the second load structure 4 including at least one hollow area 41, which can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0069] In a third aspect, based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a temperature compensated surface acoustic wave resonator, comprising:

[0070] Providing a substrate 1, wherein the substrate 1 is a piezoelectric substrate, and the material used includes lithium niobate or lithium tantalate;

[0071] An interdigital transducer 2 is manufactured on one side surface of the substrate 1, and the processes used include coating, exposure, development, evaporation, and demolding; the interdigital transducer 2 includes a bus bar 22 and a plurality of long finger electrodes 21, and the long finger electrodes 21 include a first long finger electrode 211 and a second long finger electrode 212; the first long finger electrode 211 and the second long finger electrode 212 both extend along the second direction Y and are arranged along the first direction X; the first long finger electrode 211 and the second long finger electrode 212 are arranged crosswise along the first direction X; the material used for the long finger electrode 21 includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, and aluminum, and a combination thereof;

[0072] A first load structure 3 is fabricated on a side of the long finger electrode 21 away from the substrate 1; the orthographic projection of the first load structure 3 on the substrate 1 at least partially overlaps with the orthographic projection of the long finger electrode 21 on the substrate 1;

[0073] A second load structure 4 is fabricated on a side of the first load structure 3 away from the long finger electrode 21; the orthographic projection of the second load structure 4 on the substrate 1 at least partially overlaps with the orthographic projection of the long finger electrode 21 on the substrate 1; the second load structure 4 includes at least one hollow region 41;

[0074] A temperature compensation layer 6 is formed on a surface of the IDT 2 away from the long finger electrode 21, and the temperature compensation layer 6 covers at least a portion of the surface of the first load structure 3, the second load structure 4, the IDT 2 and the substrate 1;

[0075] The first direction X and the second direction Y intersect.

[0076] The manufacturing method described in this embodiment can be used to manufacture the temperature-compensated surface acoustic wave resonator described in the above embodiment. The method can increase the force of the long finger electrode 21 on the piezoelectric substrate 1 by setting the first load structure 3, thereby changing the propagation speed of the surface acoustic wave, so that the sound speed of the surface acoustic wave in the area where the first load structure 3 is set is less than the sound speed of the area where the first load structure 3 is not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator; by setting the second load structure 4 including at least one hollow area 41, the heat conduction channel is increased, and the heat dissipation capacity of the resonator can be improved under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0077] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A temperature-compensated surface acoustic wave resonator, characterized in that: include: Substrate (1); An interdigital transducer (2) is arranged on a side surface of the substrate (1), the interdigital transducer (2) comprising a plurality of long finger electrodes (21), the long finger electrodes (21) comprising a first long finger electrode (211) and a second long finger electrode (212); the first long finger electrode (211) and the second long finger electrode (212) both extend along a second direction (Y) and are arranged along a first direction (X); the first long finger electrode (211) and the second long finger electrode (212) are arranged crosswise along the second direction (Y); at least one first load structure (3) arranged on a side of the long finger electrode (21) away from the substrate (1), and an orthographic projection of the first load structure (3) on the substrate (1) at least partially overlaps with an orthographic projection of the long finger electrode (21) on the substrate (1); A second load structure (4) is arranged on a side of the first load structure (3) away from the long finger electrode (21), and an orthographic projection of the second load structure (4) on the substrate (1) at least partially overlaps with an orthographic projection of the long finger electrode (21) on the substrate (1); the second load structure (4) comprises at least one hollow region (41); A reflection grating region (5), along the first direction (X), ends of the first load structure (3) and the second load structure (4) are both aligned with a boundary of the reflection grating region (5) away from the interdigital transducer (2); The first direction (X) intersects the second direction (Y).

2. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The distance between the first load structure (3) and the second load structure (4) along the thickness direction is a first spacing L, and the value range of the first spacing L is: 0≤L≤λ, where λ is the wavelength of the surface acoustic wave.

3. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The shape of the hollow area (41) includes a circle and a polygon.

4. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The maximum size of the hollow area (41) along the first direction (X) is a first size M, and the value range of the first size M is: λ≤M≤2λ; the maximum size of the hollow area (41) along the second direction (Y) is a second size N, and the value range of the second size N is: 0.5λ≤N≤λ, wherein λ is the wavelength of the surface acoustic wave.

5. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The remaining portion of the second load structure (4) after removing the hollow area (41) is a metal wire (42), the line width of the metal wire (42) is a third dimension Q, and the value range of the third dimension Q is: 0.5λ≤Q≤λ, where λ is the wavelength of the surface acoustic wave.

6. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Along the first direction (X), the size of the second load structure (4) is greater than or equal to the size of the effective aperture area; along the second direction (Y), the size of the second load structure (4) is greater than or equal to the size of the effective aperture area.

7. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Along the second direction (Y), the first long finger electrode (211) comprises a first end portion close to a side of the second long finger electrode (212) and a second end portion away from a side of the second long finger electrode (212); An orthographic projection of at least part of the first load structure (3) on the substrate (1) overlaps with an orthographic projection of the first end on the substrate (1); The second long finger electrode (212) comprises a third end portion close to a side of the first long finger electrode (211) and a fourth end portion far from a side of the first long finger electrode (211); An orthographic projection of at least part of the first load structure (3) on the substrate (1) overlaps with an orthographic projection of the third end on the substrate (1).

8. The temperature-compensated surface acoustic wave resonator according to claim 7, characterized in that: The interdigital transducer (2) further comprises a bus bar (22), wherein the bus bar (22) comprises a first bus bar (221) and a second bus bar (222); The first bus bar (221) and the second bus bar (222) both extend along the second direction (Y) and are arranged opposite to each other along the first direction (X); The second end of the first long finger electrode (211) is connected to the first bus bar (221); The fourth end of the second long finger electrode (212) is connected to the second bus bar (222).

9. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The first long finger electrode (211) and the second long finger electrode (212) have the same length extending along the second direction (Y).

10. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Also includes a temperature compensation layer (6); The temperature compensation layer (6) is arranged on a side of the interdigital transducer (2) away from the substrate (1).

11. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Along the first direction (X), the reflective grid region (5) is located at least on one side of the long finger electrode (21); The reflection grating area (5) comprises a plurality of reflection gratings, the reflection gratings extend along the second direction (Y), and the plurality of reflection gratings are arranged along the first direction (X).

12. The temperature-compensated surface acoustic wave resonator according to claim 11, characterized in that: At least part of the orthographic projection of the first load structure (3) on the substrate (1) overlaps with the orthographic projection of the reflective grating area (5) on the substrate (1), and at least part of the orthographic projection of the second load structure (4) on the substrate (1) overlaps with the orthographic projection of the reflective grating area (5) on the substrate (1).

13. A temperature-compensated surface acoustic wave filter, characterized in that: The invention comprises the temperature-compensated surface acoustic wave resonator according to any one of claims 1 to 12.

14. A method for manufacturing a temperature-compensated surface acoustic wave resonator, applied to the temperature-compensated surface acoustic wave resonator as claimed in claim 1, characterized in that: include: Providing a substrate (1); An interdigital transducer (2) is fabricated on a surface of one side of the substrate (1); the interdigital transducer (2) comprises a bus bar (22) and a plurality of long finger electrodes (21), the long finger electrodes (21) comprising a first long finger electrode (211) and a second long finger electrode (212); the first long finger electrode (211) and the second long finger electrode (212) both extend along a second direction (Y) and are arranged along a first direction (X); the first long finger electrode (211) and the second long finger electrode (212) are arranged crosswise along the first direction (X); A first load structure (3) is fabricated on a side of the long finger electrode (21) away from the substrate (1); an orthographic projection of the first load structure (3) on the substrate (1) at least partially overlaps with an orthographic projection of the long finger electrode (21) on the substrate (1); A second load structure (4) is fabricated on a side of the first load structure (3) away from the long finger electrode (21); an orthographic projection of the second load structure (4) on the substrate (1) at least partially overlaps with an orthographic projection of the long finger electrode (21) on the substrate (1); and the second load structure (4) comprises at least one hollow region (41); A temperature compensation layer (6) is formed on a surface of the interdigital transducer (2) away from the long finger electrode (21), wherein the temperature compensation layer (6) covers at least a portion of the surface of the first load structure (3), the second load structure (4), the interdigital transducer (2) and the substrate (1); The first direction (X) intersects the second direction (Y).

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