Filter

Abstract

The utility model discloses a filter. The filter comprises a resonator and a heat dissipation structure, the resonator comprises a substrate and a transducer stacking structure arranged on one side of the substrate, and a cavity is formed between the substrate and the transducer stacking structure; the heat dissipation structure comprises at least one first heat dissipation structure and at least one second heat dissipation structure; the first heat dissipation structure is arranged in the substrate, and the heat conductivity of the first heat dissipation structure is greater than that of the substrate; the second heat dissipation structure is in contact with the transducer stacking structure; the thermal conductivity of the second heat dissipation structure is greater than air thermal conductivity. According to the technical scheme of the utility model, the heat dissipation structures are arranged in the filter, and the first heat dissipation structure is arranged in the substrate, so that the problem of device damage caused by heat accumulation in the cavity is avoided; meanwhile, the second heat dissipation structure is arranged to be in contact with the transducer stacking structure, so that the heat dissipation efficiency of the transducer stacking structure is further improved, the heat dissipation efficiency of the filter is improved, and the purpose of improving the power capacity of the filter is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a filter. Background Art

[0002] Thin film bulk acoustic wave resonators have the advantages of small size, high frequency, large power capacity and high sensitivity, and play an important role in communications, sensors and other fields.

[0003] A single filter includes multiple FBAW resonators. Heat energy is inevitably generated during the operation of the FBAW resonator. Due to the cavity structure in the FBAW resonator and the poor thermal conductivity of air, heat accumulates in the cavity, resulting in excessive temperature, which affects the working efficiency and life of the filter. Utility Model Content

[0004] The utility model provides a filter to solve the problem in the prior art that the heat dissipation efficiency of the filter is low, which easily leads to heat accumulation in the cavity, thereby affecting the working efficiency and life of the filter.

[0005] According to a filter provided by the utility model, the filter includes: a resonator and a heat dissipation structure;

[0006] The resonator includes a substrate and a transducer stack structure arranged on one side of the substrate, and a cavity is arranged between the substrate and the transducer stack structure;

[0007] The heat dissipation structure includes at least one first heat dissipation structure and at least one second heat dissipation structure;

[0008] The first heat dissipation structure is disposed in the substrate and the thermal conductivity of the first heat dissipation structure is greater than the thermal conductivity of the substrate;

[0009] The second heat dissipation structure is in contact with the transducer stacking structure; and the thermal conductivity of the second heat dissipation structure is greater than the thermal conductivity of air.

[0010] Optionally, the filter further comprises a circuit board;

[0011] The circuit board is arranged on a side of the transducer stack structure away from the substrate and is electrically connected to the transducer stack structure;

[0012] The second heat dissipation structure is also in contact with the circuit board.

[0013] Optionally, the transducer stack structure includes a piezoelectric layer, and the circuit board includes a circuit board body;

[0014] The second heat dissipation structure contacts the piezoelectric layer and penetrates the circuit board body.

[0015] Optionally, the heat dissipation structure further includes a third heat dissipation structure;

[0016] The third heat dissipation structure is arranged on a side of the substrate away from the transducer stack structure and the third heat dissipation structure is in contact with the second heat dissipation structure;

[0017] The thermal conductivity of the third heat dissipation structure is greater than the thermal conductivity of the substrate.

[0018] Optionally, along the thickness direction of the filter, the third heat dissipation structure covers the substrate.

[0019] Optionally, the substrate includes a first substrate portion, and along a thickness direction of the filter, the first substrate portion overlaps with the cavity;

[0020] The first heat dissipation structure is disposed in the first substrate section.

[0021] Optionally, along the thickness direction of the filter, the first heat dissipation structure penetrates the first substrate portion.

[0022] Optionally, the substrate includes a second substrate section, along the thickness direction of the filter, the second substrate section does not overlap with the cavity and the second substrate section is in contact with the transducer stack structure;

[0023] The first heat dissipation structure is disposed in the second substrate section.

[0024] Optionally, along the thickness direction of the filter, the first heat dissipation structure penetrates the second substrate portion.

[0025] Optionally, the filter further comprises a packaging layer, the packaging layer at least covers the lower surface and side surfaces of the substrate and covers the side surfaces of the transducer stack structure;

[0026] The second heat dissipation structure is in contact with the packaging layer;

[0027] The lower surface of the substrate includes a surface remote from the transducer stack structure.

[0028] The technical solution of the utility model is to set a heat dissipation structure in the filter, and set the first heat dissipation structure in the substrate. The thermal conductivity of the first heat dissipation structure is greater than the thermal conductivity of the substrate, so that the heat accumulated in the cavity can be quickly discharged, thereby avoiding the problem of heat accumulation in the cavity causing damage to the device; at the same time, the second heat dissipation structure is set to contact with the transducer stacking structure, further improving the heat dissipation efficiency of the transducer stacking structure, so that the heat of the transducer stacking structure is preferentially transmitted to the second heat dissipation structure or the substrate, thereby avoiding heat accumulation in the cavity, improving the heat dissipation efficiency of the filter, and achieving the purpose of increasing the power capacity of the filter.

[0029] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present utility model, nor are they intended to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a structural schematic diagram of a first filter provided according to an embodiment of the utility model;

[0032] Figure 2 is a structural schematic diagram of a second filter provided according to an embodiment of the utility model;

[0033] Figure 3 is a schematic structural diagram of a third filter provided according to an embodiment of the utility model;

[0034] Figure 4 is a schematic structural diagram of a fourth filter provided according to an embodiment of the utility model;

[0035] Figure 5 It is a structural schematic diagram of a fifth filter provided according to an embodiment of the utility model. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present utility model 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 numbers used in this way can be interchanged where appropriate, so that the embodiments of the utility model described herein can be implemented in an order other than those illustrated or described herein.

[0038] Figure 1 Schematic diagram of the structure of the first filter provided according to the embodiment of the utility model. Figure 1 As shown, the filter includes:

[0039] Resonator 1 and heat dissipation structure 2;

[0040] The resonator 1 includes a substrate 11 and a transducer stack structure 12 disposed on one side of the substrate 11, and a cavity 13 is disposed between the substrate 11 and the transducer stack structure 12;

[0041] The heat dissipation structure 2 includes at least one first heat dissipation structure 21 and at least one second heat dissipation structure 22;

[0042] The first heat dissipation structure 21 is disposed in the substrate 11 and the thermal conductivity of the first heat dissipation structure 21 is greater than the thermal conductivity of the substrate 11;

[0043] The second heat dissipation structure 22 is in contact with the transducer stack structure 12 ; the thermal conductivity of the second heat dissipation structure 22 is greater than the thermal conductivity of air.

[0044] The filter may include a plurality of resonators 1, and the resonator 1 may be an electronic component that generates a resonant frequency, such as a thin film bulk acoustic wave resonator 1, which is a device that converts energy into sound waves through the inverse piezoelectric effect of a piezoelectric film to form resonance. The resonator 1 includes a substrate 11 and a transducer stack structure 12, and the transducer stack structure 12 can be used as a piezoelectric film, and a cavity 13 is included between the substrate 11 and the transducer stack structure 12. During the operation of the resonator 1, an electrical signal is input to the transducer stack structure 12, and the transducer stack structure 12 converts the electrical signal into an acoustic signal due to the inverse piezoelectric effect. Since the acoustic structure of the resonator 1 is selective for acoustic signals of different frequencies, the acoustic signal that meets the condition of total reflection of the acoustic wave in the resonator 1 will resonate in the resonator 1, and the acoustic signal that does not meet the condition of the resonator 1 will be attenuated, thereby completing the frequency selection. However, heat is inevitably generated during the operation of the resonator 1. The heat mainly comes from the vibration of the transducer stack structure 12. Due to the limitations of the structure of the resonator 1, the heat of the transducer stack structure 12 is discharged through the substrate 11 on the one hand, and enters the cavity 13 on the other hand. Since the thermal conductivity of gas is lower than that of solid, the heat in the cavity 13 is easy to accumulate, thereby affecting the heat dissipation efficiency of the resonator 1. Therefore, a heat dissipation structure 2 is provided, which includes a first heat dissipation structure 21 and a second heat dissipation structure 22. The first heat dissipation structure 21 is provided in the substrate 11 and the thermal conductivity of the first heat dissipation structure 21 is greater than the thermal conductivity of the substrate 11. Since the first heat dissipation structure 21 is provided in the substrate 11 and a cavity 13 is included between the substrate 11 and the transducer stacking structure 12, the heat dissipation efficiency of the substrate 11 can be improved, thereby improving the efficiency of heat in the cavity 13 being exported from the substrate 11; similarly, a second heat dissipation structure 22 is provided, and the second heat dissipation structure 22 is in contact with the transducer stacking structure 12, so that the heat of the transducer stacking structure 12 is transferred to the second heat dissipation structure 22, thereby reducing the heat supplied to the cavity 13 and improving the heat dissipation performance of the resonator 1.

[0045] It is understandable that, during the device preparation process, the material of the substrate 11 generally contains silicon, and the thermal conductivity of the first heat dissipation structure 21 is set to be greater than the thermal conductivity of the substrate 11, so that the thermal conductivity of the first heat dissipation structure 21 is greater than the thermal conductivity of the silicon material, ensuring the structural stability of the substrate 11 while improving the thermal conductivity of the substrate 11. In some embodiments, the material of the first heat dissipation structure 21 may be a metal material, and the embedded thickness may be 300μm-450μm. The first heat dissipation structure 21 may include multiple, arrayed in the substrate 11, and the distance between the array first heat dissipation structures 21 may be 1μm-100μm. The specific material may be metal such as molybdenum, gold or copper. The thermal conductivity of the second heat dissipation structure 22 is set to be greater than the thermal conductivity of the air, so that the heat of the transducer stack structure 12 is preferably discharged from the second heat dissipation structure 22 instead of being derived from the cavity 13. In some embodiments, the thermal conductivity of the second heat dissipation structure 22 may be greater than the thermal conductivity of the substrate 11, so that the first heat dissipation structure 21 and the second heat dissipation structure 22 are both higher than the thermal conductivity of the resonator 1 itself, thereby improving the thermal conductivity of the resonator 1. The material of the second heat dissipation structure 22 may be the same as or different from the material of the first heat dissipation structure 21 , and this is not limited in the embodiment of the present invention.

[0046] The technical solution of the embodiment of the utility model is to set a heat dissipation structure in the filter, and set the first heat dissipation structure in the substrate. The thermal conductivity of the first heat dissipation structure is greater than the thermal conductivity of the substrate, so that the heat accumulated in the cavity can be quickly discharged, thereby avoiding the problem of heat accumulation in the cavity causing damage to the device; at the same time, the second heat dissipation structure is set to contact with the transducer stacking structure, further improving the heat dissipation efficiency of the transducer stacking structure, so that the heat of the transducer stacking structure is preferentially transmitted to the second heat dissipation structure or the substrate 11, thereby avoiding the accumulation of heat in the cavity, improving the heat dissipation efficiency of the filter, and achieving the purpose of increasing the power capacity of the filter.

[0047] Optional, continue to refer to Figure 1 As shown, the filter also includes a circuit board 3;

[0048] The circuit board 3 is arranged on a side of the transducer stack structure 12 away from the substrate 11 and is electrically connected to the transducer stack structure 12;

[0049] The second heat dissipation structure 22 is also in contact with the circuit board 3 .

[0050] The circuit board 3 may be a structure for transmitting electrical signals to the transducer stack structure 12, and the circuit board 3 is arranged on the side of the transducer stack structure 12 away from the substrate 11. The circuit board 3 and the transducer stack structure 12 may be connected through a pad 30, and the transducer stack structure 12 may include an upper electrode layer 121 and a lower electrode layer 123. The circuit board 3 is respectively connected to the upper electrode layer 121 and the lower electrode layer 123 through the pad 30 to realize the transmission of electrical signals to the transducer stack structure 12.

[0051] Specifically, since the circuit board 3 also generates heat during operation, the second heat dissipation structure 22 is arranged in contact with the circuit board 3 so that the second heat dissipation structure 22 can also conduct heat generated in the circuit board 3, thereby improving the heat dissipation efficiency of the circuit board 3.

[0052] In some embodiments, the transducer stack structure 12 includes a piezoelectric layer 122, and the circuit board 3 includes a circuit board body; the second heat dissipation structure 22 contacts the piezoelectric layer 122 and penetrates the circuit board body. The piezoelectric layer 122 can be arranged between the upper electrode layer 121 and the lower electrode layer 123, and the circuit board 3 is electrically connected to the upper electrode layer 121 and the lower electrode layer 123 respectively. When the second heat dissipation structure 22 is a metal material with a large thermal conductivity, the second heat dissipation structure 22 cannot be connected to the upper electrode layer 121 and the lower electrode layer 123 to avoid electrical conduction. At this time, only the piezoelectric layer 122 is in contact with the second heat dissipation structure 22 to conduct the heat of the transducer stack structure 12.

[0053] Exemplarily, the piezoelectric layer 122 may include an upper surface, a lower surface and a side surface, the upper electrode layer 121 is arranged on the upper surface, the lower electrode layer 123 is arranged on the lower surface, and the side surface is in contact with the second heat dissipation structure 22, so that the heat of the piezoelectric layer 122 can be discharged through the side surface. Since the circuit board 3 is arranged on the side of the piezoelectric layer 122 away from the substrate 11, the second heat dissipation structure 22 can extend to the circuit board body along the thickness direction of the resonator 1 and penetrate the circuit board body, so that the second heat dissipation structure 22 is used for heat dissipation of the circuit board 3 and the transducer stack structure 12 at the same time.

[0054] In some embodiments, Figure 2 is a schematic diagram of the structure of a second filter provided according to an embodiment of the utility model, such as Figure 2 As shown, the second heat dissipation structure 22 extends to the side of the substrate 11 along the thickness direction of the resonator 1 and is arranged between the resonators 1, so that the second heat dissipation structure 22 is in contact with the adjacent circuit board 3, the piezoelectric layer 122 and the substrate 11 at the same time, further improving the heat dissipation performance of the filter.

[0055] The technical solution of the embodiment of the utility model makes the second heat dissipation structure contact with the circuit board so that the second heat dissipation structure plays the function of dissipating heat for the circuit board, further improving the heat dissipation characteristics of the filter and achieving the purpose of increasing the power capacity of the filter.

[0056] Optional, continue to refer to Figure 1 As shown, the heat dissipation structure 2 also includes a third heat dissipation structure 23;

[0057] The third heat dissipation structure 23 is disposed on a side of the substrate 11 away from the transducer stack structure 12 and the third heat dissipation structure 23 is in contact with the second heat dissipation structure 22;

[0058] The thermal conductivity of the third heat dissipation structure 23 is greater than the thermal conductivity of the substrate 11 .

[0059] Among them, the thermal conductivity of the third heat dissipation structure 23 is greater than the thermal conductivity of air, and the third heat dissipation structure 23 is in contact with the second heat dissipation structure 22, so that the heat in the second heat dissipation structure 22 can be transferred to the third heat dissipation structure 23, thereby increasing the heat dissipation area. At the same time, the third heat dissipation structure 23 is arranged on the side of the substrate 11 away from the transducer stacking structure 12, so that the third heat dissipation structure 23 can also extract the heat in the substrate 11, thereby further improving the heat dissipation efficiency of the resonator 1.

[0060] It is understandable that the third heat dissipation structure 23 may be made of the same material as or different from the second heat dissipation structure 22. Preferably, the third heat dissipation structure 23 is made of the same material as the second heat dissipation structure 22, so that the resonator 1 can be manufactured in one piece after packaging, simplifying the manufacturing process.

[0061] In some embodiments, along the thickness direction y of the filter, the third heat dissipation structure 23 covers the substrate 11. The third heat dissipation structure 23 covers the substrate 11 so that along the thickness direction y of the filter, the third heat dissipation structure 23 is in full contact with the substrate 11, increasing the heat conduction area from the substrate 11 to the third heat dissipation structure 23, and further improving the heat conduction effect of the third heat dissipation structure 23.

[0062] Exemplarily, the substrate 11 includes an upper surface, a lower surface and a side surface. The upper surface of the substrate 11 is connected to the transducer stacking structure 12 and forms a cavity 13 between the substrate 11 and the transducer stacking structure 12; the lower surface of the substrate 11 contacts the third heat dissipation structure 23 and completely covers the lower surface of the substrate 11; the side surface of the substrate 11 contacts the second heat dissipation structure 22 and contacts the side surface of the piezoelectric layer 122 and penetrates the circuit board 3; the first heat dissipation structure 21 penetrates the substrate 11. Such a configuration allows the heat path when the transducer stacking structure 12 generates heat to be as follows: 1. Transmitted to the second heat dissipation structure 22 and the third heat dissipation structure 23 through the piezoelectric layer 122 and dissipated; 2. Transmitted to the first heat dissipation structure 21 and the third heat dissipation structure 23 through the substrate 11 and dissipated; 3. The heat in the cavity 13 is exported to the third heat dissipation structure 23 through the first heat dissipation structure 21 and dissipated. At the same time, the heat of the circuit board 3 can also be dissipated through the second heat dissipation structure 22 and the third heat dissipation structure 23. Such a configuration allows the heat dissipation path to be included between the filters, optimizes the heat dissipation structure 2, and ensures the normal operation of the filter.

[0063] The technical solution of the embodiment of the utility model further increases the heat dissipation area of ​​a single resonator by setting a third heat dissipation structure, so that the heat in the substrate and the heat of the second heat dissipation structure are quickly discharged, thereby improving the heat dissipation efficiency of the filter.

[0064] Optional, Figure 3is a schematic diagram of the structure of the third filter provided according to an embodiment of the utility model, referring to Figure 3 and Figure 1 As shown, the substrate 11 includes a first substrate portion 111, and along the thickness direction y of the filter, the first substrate portion 111 overlaps with the cavity 13;

[0065] The first heat dissipation structure 21 is disposed in the first substrate portion 111 .

[0066] The first substrate portion 111 may be used to form a cavity 13 with the transducer stack structure 12 .

[0067] Specifically, the cavity 13 is formed by surrounding the first substrate sub-portion 111 and the transducer stacking structure 12, and the first substrate sub-portion 111 overlaps the cavity 13. The first heat dissipation structure 21 is arranged in the first substrate sub-portion 111 to be closer to the cavity 13 and to more efficiently extract the heat in the cavity 13. The first heat dissipation structure 21 may include a plurality of first heat dissipation structures 21, which may extend along a first direction and be arranged along a second direction in the first substrate sub-portion 111, wherein the first direction is the thickness direction y of the filter, and the second direction is perpendicular to the first direction.

[0068] In some embodiments, along the thickness direction y of the filter, the first heat dissipation structure 21 penetrates the first substrate subdivision 111. When the first heat dissipation structure 21 penetrates the first substrate subdivision 111, it means that the first heat dissipation structure 21 is directly connected to the cavity 13, and the heat in the cavity 13 can be extracted by the first heat dissipation structure 21. Since the thermal conductivity of the substrate 11 is smaller than that of the first heat dissipation structure 21, the first heat dissipation structure 21 can extract the heat in the cavity 13 faster to avoid heat accumulation. At the same time, the first heat dissipation structure 21 penetrates the first substrate subdivision 111, which means that the first heat dissipation structure 21 is also directly connected to the outside world, so that the heat in the first heat dissipation structure 21 can be directly conducted to the outside world, which is more efficient than conducting it to the outside world through the substrate 11.

[0069] The technical solution of the embodiment of the utility model arranges the first heat dissipation structure in the first substrate section so that the position of the first heat dissipation structure is closer to the cavity, thereby improving the efficiency of heat extraction in the cavity and avoiding heat accumulation in the cavity.

[0070] Optional, Figure 4 is a schematic diagram of the structure of a fourth filter provided according to an embodiment of the utility model, such as Figure 4 As shown, the substrate 11 includes a second substrate portion 112. Along the thickness direction y of the filter, the second substrate portion 112 does not overlap with the cavity 13 and the second substrate portion 112 is in contact with the transducer stack structure 12.

[0071] The first heat dissipation structure 21 is disposed in the second substrate portion 112 .

[0072] The second substrate sub-portion 112 may be a portion of the substrate 11 in contact with the transducer stacking structure 12. The first substrate sub-portion 111 and the transducer stacking structure 12 are separated by the cavity 13, and there is no separation between the second substrate sub-portion 112 and the transducer stacking structure 12, and they are in direct contact. The first heat dissipation structure 21 is disposed in the second substrate sub-portion 112, so that the first heat dissipation structure 21 is closer to the transducer stacking structure 12, and the heat in the transducer stacking structure 12 is extracted with higher efficiency.

[0073] Specifically, the first heat dissipation structure 21 may include multiple ones. In the second substrate section 112, the first heat dissipation structures 21 may extend along a first direction and be arranged along a second direction. The first direction is the thickness direction y of the filter, and the second direction is perpendicular to the first direction.

[0074] In some embodiments, along the thickness direction y of the filter, the first heat dissipation structure 21 penetrates the second substrate subdivision 112. When the first heat dissipation structure 21 penetrates the second substrate subdivision 112, it means that the first heat dissipation structure 21 is in direct contact with the transducer stacking structure 12, and the heat in the transducer stacking structure 12 can be directly extracted by the first heat dissipation structure 21. Since the thermal conductivity of the substrate 11 is smaller than that of the first heat dissipation structure 21, the first heat dissipation structure 21 can extract the heat in the transducer stacking structure 12 faster, dispersing the heat entering the cavity 13, and indirectly avoiding the accumulation of heat in the cavity 13. At the same time, the first heat dissipation structure 21 penetrates the second substrate subdivision 112, which means that the first heat dissipation structure 21 is also directly connected to the outside world, so that the heat in the first heat dissipation structure 21 can be directly conducted to the outside world, which is more efficient than conducting to the outside world through the substrate 11.

[0075] The technical solution of the embodiment of the utility model, by arranging the first heat dissipation structure in the second substrate section, makes the position of the first heat dissipation structure closer to the transducer stacking structure, thereby improving the efficiency of heat extraction in a single resonator and improving the working performance of the filter.

[0076] Optional, Figure 5 is a schematic diagram of the structure of a fifth filter provided according to an embodiment of the utility model, such as Figure 5 As shown, the filter further includes a packaging layer 4, which covers at least the lower surface and side surfaces of the substrate 11 and the side surfaces of the transducer stack structure 12;

[0077] The second heat dissipation structure 22 is in contact with the packaging layer 4;

[0078] The lower surface of the substrate 11 includes a surface away from the transducer stack structure 12 .

[0079] The purpose of the packaging layer 4 is to protect each resonator 1 in the filter from being corroded by water vapor and improve the reliability of the filter. The second heat dissipation structure 22 is in contact with the packaging layer 4 so that the heat of the packaging layer 4 can also be discharged through the second heat dissipation structure 22, thereby ensuring airtightness and improving heat dissipation.

[0080] The lower surface of the substrate 11 may be a surface away from the transducer stack structure 12, and the lower surface does not contact the transducer stack structure 12. The side surface of the substrate 11 may be a surface connected to the lower surface.

[0081] Among them, in the transducer stack structure 12 , the upper electrode layer 121 and the lower electrode layer 123 are in contact with the upper surface and the lower surface of the piezoelectric layer 122 respectively, and the side surface of the transducer stack structure 12 connects the upper surface and the lower surface of the piezoelectric layer 122 .

[0082] Exemplarily, the packaging layer 4 covers the lower surface and side surfaces of the substrate 11 and covers the side surfaces of the transducer stack structure 12, thereby improving the airtightness of the single resonator 1, so that the lower surface and side surfaces of the substrate 11 and the side surfaces covering the transducer stack structure 12 are not corroded by water vapor, thereby ensuring the airtightness of the cavity 13.

[0083] In some embodiments, the filter includes a circuit board 3, which is arranged on the side of the transducer stack structure 12 away from the substrate 11. Along the thickness direction of the filter, the packaging layer 4 covers the lower surface of the substrate 11 and extends to the surface of the circuit board 3, thereby enclosing the resonator 1 in the space surrounded by the circuit board 3 and the packaging layer 4, further improving the reliability of the filter.

[0084] In some embodiments, the packaging layer 4 includes a fixing glue 41 and a sub-packaging layer 42. The fixing glue 41 is arranged between the sub-packaging layer 42 and the resonator 1 to fix the sub-packaging layer 42 and ensure the airtightness of the sub-packaging layer 42. The fixing glue 41 can be thermoplastic polypropylene glue, and the sub-packaging layer 42 can be packaging black glue to isolate the outside world from the resonator 1 and improve the reliability of the filter.

[0085] The technical solution of the embodiment of the utility model ensures the air tightness of the filter and increases the heat dissipation efficiency by providing a packaging layer and contacting the second heat dissipation structure with the packaging layer, thereby improving the reliability of the filter as a whole.

[0086] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A filter, characterized in that: include: Resonator and heat dissipation structure; The resonator comprises a substrate and a transducer stack structure arranged on one side of the substrate, and a cavity is arranged between the substrate and the transducer stack structure; The heat dissipation structure includes at least one first heat dissipation structure and at least one second heat dissipation structure; The first heat dissipation structure is disposed in the substrate and the thermal conductivity of the first heat dissipation structure is greater than the thermal conductivity of the substrate; The second heat dissipation structure is in contact with the transducer stack structure; The thermal conductivity of the second heat dissipation structure is greater than the thermal conductivity of air.

2. The filter according to claim 1, characterized in that The filter also includes a circuit board; The circuit board is arranged on a side of the transducer stack structure away from the substrate and is electrically connected to the transducer stack structure; The second heat dissipation structure is also in contact with the circuit board.

3. The filter according to claim 2, characterized in that The transducer stack structure includes a piezoelectric layer, and the circuit board includes a circuit board body; The second heat dissipation structure contacts the piezoelectric layer and penetrates the circuit board body.

4. The filter according to claim 1, characterized in that The heat dissipation structure further includes a third heat dissipation structure; The third heat dissipation structure is arranged on a side of the substrate away from the transducer stack structure and the third heat dissipation structure is in contact with the second heat dissipation structure; The thermal conductivity of the third heat dissipation structure is greater than the thermal conductivity of the substrate.

5. The filter according to claim 4, characterized in that Along the thickness direction of the filter, the third heat dissipation structure covers the substrate.

6. The filter according to claim 1, characterized in that The substrate comprises a first substrate section, and along a thickness direction of the filter, the first substrate section overlaps with the cavity; The first heat dissipation structure is disposed in the first substrate section.

7. The filter according to claim 6, characterized in that Along the thickness direction of the filter, the first heat dissipation structure penetrates the first substrate section.

8. The filter according to claim 1, characterized in that The substrate comprises a second substrate section, along the thickness direction of the filter, the second substrate section does not overlap with the cavity and the second substrate section contacts with the transducer stack structure; The first heat dissipation structure is disposed in the second substrate section.

9. The filter according to claim 8, characterized in that Along the thickness direction of the filter, the first heat dissipation structure penetrates the second substrate section.

10. The filter according to claim 1, characterized in that The filter further comprises a packaging layer, wherein the packaging layer at least covers the lower surface and the side surface of the substrate and covers the side surface of the transducer stack structure; The second heat dissipation structure is in contact with the packaging layer; The lower surface of the substrate includes a surface away from the transducer stack structure.

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