Packaging structure and filter

Abstract

The invention discloses a packaging structure and a filter, and the packaging structure comprises a device substrate, the device substrate is provided with a resonance unit, the resonance unit comprises a bottom electrode, a piezoelectric layer and a top electrode, the bottom electrode faces the device substrate, and the top surface of the top electrode is provided with a first cavity located in an effective resonance region; the sealing cover plate is bonded on the device substrate and faces the resonance unit, and the first cavity is sealed by the sealing cover plate; the first bonding structure is located between the sealing cover plate and the device substrate so that the sealing cover plate and the device substrate can be bonded, the first bonding structure comprises a first sealing ring surrounding the periphery of the resonance unit, and the first sealing ring enables a second cavity for containing the resonance unit to be formed between the sealing cover plate and the device substrate. The first cavity located in the effective resonance area is formed in the top surface of the top electrode, so that the requirements for the height of the second cavity and the thickness of the sealing cover plate are reduced, and the longitudinal size of the packaging structure is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a packaging structure and a filter. Background Art

[0002] With the development of wireless communication technology, traditional single-band, single-mode equipment can no longer meet the diverse requirements of communication systems. Currently, communication systems are increasingly moving towards multi-band, which requires communication terminals to be able to accept various frequency bands to meet the requirements of different communication service providers and different regions.

[0003] Among existing filters, bulk acoustic wave resonator (BAW) has become one of the most suitable filters for communication applications due to its higher quality factor Q and lower energy loss.

[0004] However, as the market demand for device miniaturization becomes increasingly strong, smaller package sizes have become the current trend, and with the advancement of technology, there seems to be a trend of further reduction. Summary of the Invention

[0005] The problem solved by the embodiments of the present invention is to provide a packaging structure and a filter, which are conducive to reducing the size of the packaging structure.

[0006] To solve the above problems, an embodiment of the present invention provides a packaging structure, comprising: a device substrate, wherein the device substrate has a resonance unit, the resonance unit comprising a bottom electrode, a piezoelectric layer, and a top electrode stacked in sequence, the bottom electrode facing the device substrate, and the top surface of the top electrode having a first cavity located in an effective resonance region; a sealing cover plate bonded to the device substrate and facing the resonance unit, the sealing cover plate sealing the first cavity; a first bonding structure located between the sealing cover plate and the device substrate to enable the sealing cover plate and the device substrate to be bonded, the first bonding structure comprising a first sealing ring surrounding the periphery of the resonance unit, the first sealing ring providing a second cavity between the sealing cover plate and the device substrate to accommodate the resonance unit.

[0007] Correspondingly, an embodiment of the present invention further provides a filter, comprising the packaging structure described in any embodiment of the present invention.

[0008] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0009] In the packaging structure provided by an embodiment of the present invention, a first cavity located in an effective resonance region is provided in the top surface of the top electrode. The first cavity can suppress acoustic wave leakage, and thus the sealing cover plate can seal the first cavity. Compared with suppressing acoustic wave leakage by spacing the sealing cover plate and the top electrode, the embodiment of the present invention is conducive to reducing the requirements for the height of the second cavity and the thickness of the sealing cover plate, thereby facilitating a reduction in the longitudinal dimension of the packaging structure.

[0010] In an optional solution, the packaging structure also includes: a first inductor, located on the first surface and the second surface of the cover plate, and the surface of the cover plate is used to provide a formation position for the inductor, so that the space of the packaging structure can be better utilized to increase the layout space of the inductor, which is beneficial to reducing the lateral size of the packaging structure.

[0011] In an optional solution, the packaging structure also includes: a second inductor, located on the fourth surface of the device substrate, and utilizing the surface of the device substrate facing away from the resonance unit to provide a formation position for the inductor, thereby enabling better utilization of the space of the packaging structure to increase the layout space of the inductor, thereby facilitating reduction of the lateral dimensions of the packaging structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural diagram of a packaging structure;

[0013] Figure 2 is a structural diagram of a first embodiment of the packaging structure of the present invention;

[0014] Figure 3 is a structural diagram of a second embodiment of the packaging structure of the present invention;

[0015] Figure 4 is a plan view of a first inductor in an embodiment of a packaging structure of the present invention;

[0016] Figure 5 is a structural diagram of a third embodiment of the packaging structure of the present invention;

[0017] Figure 6 is a structural diagram of a fourth embodiment of the packaging structure of the present invention;

[0018] Figure 7 1 is a schematic structural diagram of a fifth embodiment of the packaging structure of the present invention. DETAILED DESCRIPTION

[0019] As can be seen from the background art, the size of current packaging structures needs to be further reduced. The following will analyze the reasons why current packaging sizes are still relatively large, using a packaging structure.

[0020] Figure 1 It is a structural diagram of a packaging structure.

[0021] A packaging structure includes: a device substrate 20, on which a resonant unit 25 is provided; a sealing cover plate 30, bonded to the device substrate 20 and facing the resonant unit 25, the sealing cover plate 30 and the resonant unit 25 being spaced apart in the longitudinal direction, and having a groove (not shown) in the sealing cover plate 30, the groove corresponding to the position of the resonant unit 25; a sealing ring 50, located between the sealing cover plate 30 and the device substrate 20 and surrounding the periphery of the resonant unit 25, so as to achieve bonding between the sealing cover plate 30 and the device substrate 20 and to form a cavity 35 between the sealing cover plate 30 and the device substrate 20 for accommodating the resonant unit 25; a printed circuit board (PCB) 40, disposed on a side of the sealing cover plate 30 facing away from the device substrate 20 and electrically connected to the sealing cover plate 30, the PCB 40 having an inductor 45, the inductor 45 being electrically connected to the resonant unit 25.

[0022] To suppress acoustic wave leakage, the sealing cover 30 and the device substrate 20 cannot directly contact each other so as to form a cavity 35 therebetween. Therefore, there are currently certain requirements for the height of the cavity 35, making it difficult to further reduce the longitudinal dimension of the packaging structure.

[0023] At the same time, due to the thickness limitation of the sealing ring 50, in order to make the height of the cavity 35 meet the requirements, it is necessary to provide a groove in the sealing cover plate 30. The groove is used to increase the height of the cavity 35, making it difficult to further reduce the thickness of the sealing cover plate 30, thereby making it difficult to further reduce the longitudinal size of the packaging structure.

[0024] In order to solve the technical problem, an embodiment of the present invention provides a packaging structure, including: a device substrate, on which a resonance unit is provided, wherein the resonance unit includes a bottom electrode, a piezoelectric layer and a top electrode stacked in sequence, the bottom electrode faces the device substrate, and the top surface of the top electrode has a first cavity located in an effective resonance region; a sealing cover plate bonded to the device substrate and facing the resonance unit, the sealing cover plate sealing the first cavity; a first bonding structure located between the sealing cover plate and the device substrate to enable the sealing cover plate and the device substrate to be bonded, the first bonding structure including a first sealing ring surrounding the periphery of the resonance unit, the first sealing ring creating a second cavity between the sealing cover plate and the device substrate to accommodate the resonance unit.

[0025] In the packaging structure provided by an embodiment of the present invention, a first cavity located in an effective resonance region is provided in the top surface of the top electrode. The first cavity can suppress acoustic wave leakage, and thus the sealing cover plate can seal the first cavity. Compared with suppressing acoustic wave leakage by spacing the sealing cover plate and the top electrode, the embodiment of the present invention is conducive to reducing the requirements for the height of the second cavity and the thickness of the sealing cover plate, thereby facilitating a reduction in the longitudinal dimension of the packaging structure.

[0026] In order to make the above-mentioned objects, features and advantages of the embodiments of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] Figure 2 It is a structural diagram of an embodiment of the packaging structure of the present invention.

[0028] The packaging structure of the embodiment of the present invention includes: a device substrate 100, on which a resonator unit 120 is provided, wherein the resonator unit 120 includes a bottom electrode 121, a piezoelectric layer 122, and a top electrode 123 stacked in sequence, wherein the bottom electrode 121 faces the device substrate 100, and the top surface of the top electrode 123 has a first cavity 124 located in an effective resonant region (not labeled); a sealing cover plate 190 bonded to the device substrate 100 and facing the resonator unit 120, wherein the sealing cover plate 190 seals the first cavity 124; a first bonding structure 130 located between the sealing cover plate 190 and the device substrate 100 to achieve bonding between the sealing cover plate 190 and the device substrate 100, wherein the first bonding structure 130 includes a first sealing ring 135 surrounding the periphery of the resonator unit 120, wherein the first sealing ring 135 creates a second cavity 100V between the sealing cover plate 190 and the device substrate 100 to accommodate the resonator unit 120.

[0029] The device substrate 100 is used to provide a process platform for preparing the resonance unit 120 .

[0030] In this embodiment, the device substrate 100 is a first semiconductor substrate, so that the resonance unit 120 can be manufactured based on a CMOS process, thereby facilitating improved reliability and efficiency in manufacturing the resonance unit 120. It is understood that in other embodiments, the device substrate can also be made of other suitable materials.

[0031] For example, the material of the first semiconductor substrate may include silicon, germanium, silicon germanium, silicon carbide, gallium arsenide or indium gallium. The semiconductor substrate may also include other types of multi-layer structure substrates such as a silicon-on-insulator substrate or a germanium-on-insulator substrate.

[0032] In this embodiment, the device substrate 100 includes a third surface 100A located on one side of the resonant unit 120 and a fourth surface 100B opposite to the third surface 100A.

[0033] In this embodiment, the resonance unit 120 is a bulk acoustic wave resonator, and the resonance unit 120 includes a bottom electrode 121 , a piezoelectric layer 122 , and a top electrode 123 stacked in sequence.

[0034] The bottom electrode 121 , the piezoelectric layer 122 and the top electrode 123 are used to form a piezoelectric acoustic resonance stack, which is used to achieve mutual conversion between electrical signals and acoustic signals, so that the resonance unit 120 can filter the signal.

[0035] The BAW resonator may include a reflective array bulk acoustic wave resonator (BAW-SMR), a film bulk acoustic wave (FBAR) resonator, or an air gap film bulk acoustic wave resonator.

[0036] In one embodiment, the resonance unit 120 is an FBAR resonator, which has excellent characteristics such as small size, high resonance frequency, high Q value, large power capacity, and good roll-off effect.

[0037] The material of either the bottom electrode 121 or the top electrode 123 may include a conductive material such as a metal, a metal silicide, a metal nitride, a metal oxide, or conductive carbon, for example, Mo, Al, Cu, Ag, Au, Ni, Co, TiAl, TiN, or TaN. In this embodiment, the material of both the bottom electrode 121 and the top electrode 123 is Mo.

[0038] During operation of the BAW resonator, a radio frequency voltage is applied to the bottom electrode 121 and the top electrode 123 to excite BAW in the piezoelectric layer 122 , thereby achieving resonance.

[0039] The material of the piezoelectric layer 122 can be a piezoelectric crystal, a piezoelectric ceramic, or a piezoelectric polymer. The piezoelectric crystal can be aluminum nitride, lead zirconate titanate, a quartz crystal, lithium gallate, lithium germanate, titanium germanate, lithium niobate, or lithium tantalate. The piezoelectric polymer can be polyvinylidene fluoride, a vinylidene fluoride-trifluoroethylene copolymer, nylon-11, or a vinylidene cyanide-vinyl acetate alternating copolymer. In this embodiment, the material of the piezoelectric layer 122 is aluminum nitride.

[0040] The packaging structure further includes: an acoustic reflection structure 140 located above or inside the device substrate 100 , and the acoustic reflection structure 140 is located at the bottom of the resonance unit 120 .

[0041] The sound reflection structure 140 is located at the bottom of the resonance unit 120. The sound reflection structure 140 is used to reflect the energy of the sound wave, thereby suppressing the leakage of the sound wave and further improving the quality factor Q of the resonator.

[0042] The fact that the sound reflection structure 140 is located at the bottom of the resonance unit 120 means that the sound reflection structure 140 is located at a side of the bottom electrode 121 away from the piezoelectric layer 122 .

[0043] The acoustic reflection structure 140 may be of at least one of the following types: a fifth cavity within the third surface 100A of the device substrate 100 , a back cavity extending through the device substrate 100 , or a Bragg reflection layer on the third surface 100A of the device substrate 100 .

[0044] In this embodiment, the resonance unit 120 is an FBAR resonator, and therefore, the sound reflection structure 140 is a fifth cavity.

[0045] The top surface of the top electrode 123 has a first cavity 124 located in an effective resonance region (not marked). The first cavity 124 can suppress the leakage of sound waves, so the sealing cover plate 190 can seal the first cavity 124. Compared with suppressing the leakage of sound waves by spacing the sealing cover plate and the top electrode, this embodiment reduces the requirements for the longitudinal distance between the sealing cover plate 190 and the resonance unit 120, which is conducive to reducing the requirements for the height of the second cavity 100V and the thickness of the sealing cover plate, and further helps to reduce the longitudinal size of the packaging structure.

[0046] Moreover, the first cavity 124 is at least located in the effective resonance region, so that it can effectively suppress the leakage of sound waves, thereby reducing energy loss and improving the quality factor Q of the resonance unit 120.

[0047] It should be noted that the device substrate 100 includes an effective resonance region and an inactive region. The region on the acoustic reflective structure 140 where the bottom electrode 121 and the top electrode 123 overlap is the effective resonance region, while the remaining region is the inactive region. In other words, the region where the acoustic reflective structure 140, the bottom electrode 121, and the top electrode 123 overlap is the effective resonance region.

[0048] It should also be noted that Figure 2 FIG. 1 schematically shows one resonance unit 120. In other embodiments, the number of resonance units on the device substrate may be multiple according to actual needs.

[0049] In this embodiment, the sealing cover plate 190 is stacked and bonded on the device substrate 100 . The sealing cover plate 190 is used as a cap structure to protect the device substrate 100 and various components such as the resonant unit 120 located on the device substrate 100 .

[0050] As an example, the top surface of the top electrode 123 includes a first cavity 124 located in an effective resonance region (not shown), which reduces the requirements for the height of the second cavity 100V and the thickness of the sealing cover plate 190. Therefore, the sealing cover plate 190 is a planar cover plate. In other words, the sealing cover plate 190 does not have a groove facing the resonance unit 120.

[0051] Since there is no need to form a groove in the sealing cover plate 190 , the process steps of forming the packaging structure are simplified.

[0052] The sealing cover plate 190 seals the first cavity 124 , thereby significantly reducing the distance between the sealing cover plate 190 and the device substrate 100 , thereby further reducing the longitudinal dimension of the package structure.

[0053] The sealing cover plate 190 may be made of a semiconductor substrate, a quartz substrate, a glass substrate, or a ceramic substrate (eg, a ceramic material such as alumina).

[0054] As an example, the sealing cover plate 190 is a second semiconductor substrate so that interconnection can be achieved using a semiconductor manufacturing process.

[0055] For example, the material of the second semiconductor substrate may include silicon, germanium, silicon germanium, silicon carbide, gallium arsenide, or indium gallium. The semiconductor substrate may also include other types of multilayer structure substrates such as a silicon-on-insulator substrate or a germanium-on-insulator substrate.

[0056] As an example, the sealing cover plate 190 may be a capping chip (Die) or a capping wafer (Wafer).

[0057] In this embodiment, the sealing cover plate 190 includes a first surface 190A facing the device substrate 100 and a second surface 190B opposite to the first surface 190A.

[0058] The first bonding structure 130 is used to achieve bonding between the sealing cover plate 190 and the device substrate 100 .

[0059] The first bonding structure 130 includes a first sealing ring 135 surrounding the periphery of the resonant unit 120. The first sealing ring 135 creates a closed second cavity 100V between the sealing cover plate 190 and the device substrate 100, thereby sealing various components such as the resonant unit 120 in the space enclosed by the sealing cover plate 190, the device substrate 100 and the first sealing ring 135, thereby protecting the various components located in the second cavity 100V.

[0060] It should be noted that the first sealing ring 135 is located at the edge of the sealing cover plate 190 and the device substrate 100 , thereby increasing the lateral dimension of the second cavity 100V in a direction parallel to the surface of the device substrate 100 as much as possible.

[0061] In this embodiment, the first bonding structure 130 is a metal bonding structure, so that the sealing cover plate 190 and the device substrate 100 can be bonded by metal bonding, and the metal bonding has better firmness.

[0062] Correspondingly, the first bonding structure 130 includes: a first bonding layer (not labeled), located on the device substrate 100; a second bonding layer (not labeled), located on the sealing cover plate 190, the second bonding layer and the first bonding layer are stacked and bonded, and the second bonding layer and the first bonding layer stacked and bonded in the longitudinal direction form the first bonding structure 130.

[0063] As an example, the material of the first bonding structure 130 includes gold or gold-tin, so that the sealing cover plate 190 and the device substrate 100 are bonded by a gold-gold bonding process.

[0064] It should be noted that, in other embodiments, the first bonding structure may be made of other metal materials. In other embodiments, the first bonding structure may be made of other suitable conductive materials to achieve interconnection.

[0065] Continue to refer Figure 2 In this embodiment, the first bonding structure 130 also includes a first connector 132 and a second connector 131, which are located in the second cavity 100V, one end of the first connector 132 is electrically connected to the bottom electrode 121, and one end of the second connector 131 is electrically connected to the top electrode 123.

[0066] Specifically, one end of the first connector 132 facing the third surface 100A is electrically connected to the bottom electrode 121 , and one end of the second connector 131 facing the third surface 100A is electrically connected to the top electrode 123 .

[0067] In this embodiment, the materials of the first connector 132 and the second connector 131 are both metal materials. On the one hand, the first connector 132 and the second connector 131 can have conductive properties so that interconnection can be achieved through the first connector 132 and the second connector 131. On the other hand, the first connector 132 and the second connector 131 can have a bonding function and can also play a supporting role inside the second cavity 100V.

[0068] Specifically, the materials of the first connecting member 132 and the second connecting member 131 are the same as the material of the first sealing ring 135 .

[0069] In this embodiment, the packaging structure further includes: a first top electrode connection pad 123P located on the device substrate 100 , and the first top electrode connection pad 123P is electrically connected to the top electrode 123 .

[0070] By setting a first top electrode connection pad 123P on the side of the bottom electrode 121, the electrical properties of the top electrode 123 are led to the surface of the device substrate 100, which facilitates the electrical connection between the top electrode 123 and other components. In addition, the space of the second cavity 100V can be used to set the second connecting member 131, thereby reducing the height requirement of the second cavity 100V.

[0071] For example, when the bottom electrode 121 is formed on the device substrate 100 , the first top electrode connection pad 123P may be formed on the device substrate 100 at the same time, and the first top electrode connection pad 123P is isolated from the bottom electrode 121 .

[0072] Accordingly, in this embodiment, one end of the second connecting member 131 facing the third surface 100A is connected to the first top electrode connecting pad 123P.

[0073] In this embodiment, the bottom electrode 121 has a portion extending outward relative to the first top electrode connection pad 123P and the piezoelectric layer 122 . Therefore, the first connecting member 132 is connected to the extended portion of the bottom electrode 121 .

[0074] In this embodiment, the packaging structure further includes: a first conductive column 152 , which passes through the sealing cover plate 190 and is electrically connected to the other end of the first connector 132 ; and a second conductive column 151 , which passes through the sealing cover plate 190 and is electrically connected to the other end of the second connector 131 .

[0075] The first connector 132 is electrically led to the second surface 190B of the sealing cover plate 190 via the first conductive pillar 152, thereby achieving interconnection on the second surface 190B of the sealing cover plate 190. Similarly, the second connector 131 is electrically led to the second surface 190B of the sealing cover plate 190 via the second conductive pillar 151.

[0076] It is understood that, in other embodiments, the electrical properties of the bottom electrode and the top electrode may also be led out to the fourth surface of the device substrate.

[0077] The first conductive pillar 152 may be made of a conductive material such as copper, aluminum, cobalt, tungsten, or titanium, and the second conductive pillar 151 may be made of a conductive material such as copper, aluminum, cobalt, tungsten, or titanium. As an example, both the first conductive pillar 152 and the second conductive pillar 151 may be made of copper.

[0078] Continue to refer Figure 2 In this embodiment, the packaging structure further includes: a redistribution layer (RDL) 160, located on the second surface 190B of the sealing cover 190, and the redistribution layer 160 includes contact pads 161 electrically connected to the first conductive pillars 152 and the second conductive pillars 151.

[0079] Specifically, the contact pad 161 is connected to the top of the first conductive pillar 152 and the top of the second conductive pillar 151 respectively.

[0080] The rewiring layer 160 is used to realize circuit redistribution. For example, the rewiring layer 160 facilitates the electrical connection of the bottom electrode 121 and the top electrode 123 to a suitable position on the second surface 190B.

[0081] In this embodiment, the material of the redistribution layer 160 is aluminum. In other embodiments, the redistribution layer may also be made of other applicable conductive materials.

[0082] In this embodiment, the packaging structure also includes: a circuit substrate 180, which is located on the side of the sealing cover 190 facing away from the device substrate 100 and is arranged opposite to the contact pad 161; a conductive bump 170, which is located between the redistribution layer 160 and the circuit substrate 180 to electrically connect the circuit substrate 180 to the redistribution layer 160.

[0083] The circuit substrate 180 is used to support the sealing cover plate 190 and the device substrate 100 , and to achieve signal transmission with the devices on the device substrate 100 .

[0084] It should be noted that the circuit substrate 180 may also be provided with a device for cooperating with the resonant unit 120 , such as an inductor.

[0085] In some embodiments, the circuit substrate 180 may include multiple inductor layers, and each inductor layer may include one or more inductors.

[0086] As an example, the circuit substrate 180 is a printed circuit board (PCB).

[0087] The conductive bumps 170 serve as external connection ports, so that the bottom electrode 121 and the top electrode 123 can be connected to an external circuit (eg, a circuit substrate 180 ) through the external connection ports.

[0088] It should be noted that Figure 2 Only two conductive bumps 170 are shown to respectively electrically connect the first conductive pillar 152 and the second conductive pillar 151. In other embodiments, when there are other devices that need to be connected to external circuits, the layout of the redistribution layer 160 may be changed accordingly, and the number of the conductive bumps is not limited to two.

[0089] As an example, the conductive bump 170 is a solder ball.

[0090] The material of the conductive bump 170 may include one or more of tin, silver, copper, zinc, indium, gold, and copper. As an example, the material of the conductive bump 170 is tin.

[0091] Figure 3 It is a structural diagram of the second embodiment of the packaging structure of the present invention.

[0092] The similarities between this embodiment and the first embodiment are not described in detail here. The main difference between this embodiment and the first embodiment is that the packaging structure further includes a first inductor 265 .

[0093] The inductor can form a resonant circuit with the resonant unit to achieve accurate filtering of the signal.

[0094] Combined with reference Figure 4 , Figure 4 2 is a plan view of a first inductor in an embodiment of a packaging structure of the present invention. As an example, the first inductor 265 is a conductive coil (eg, a spiral conductive coil).

[0095] It is understood that the shape of the inductor is not limited to Figure 4 In other embodiments, the inductor may have other shapes, such as a circular spiral, a square spiral, a hexagonal spiral, an octagonal spiral, or a trapezoidal spiral.

[0096] Specifically, the packaging structure includes a cover plate 295 or multiple stacked and bonded cover plates 295, bonded to the device substrate 200 and facing the resonance unit (not marked), and the cover plate 295 closest to the device substrate 200 serves as a sealing cover plate 290. The cover plate 295 includes a first surface 290A facing the device substrate 200 and a second surface 290B opposite to the first surface 290A.

[0097] The packaging structure further includes a first inductor 265 located on the first surface 290A and the second surface 290B. The first inductor 265 is electrically connected to the resonance unit, and the first inductor 265 located on the first surface 290A of the sealing cover plate 290 is spaced apart from the resonance unit.

[0098] By utilizing the surface of cover plate 295 to provide a location for the inductor, the package structure's space can be better utilized to increase the inductor's layout space, thereby facilitating a reduction in the package's lateral dimensions. For example, inductors are typically conductive coils with a large area, which affects the package's lateral dimensions. Therefore, fully utilizing the space on cover plate 295 can help reduce the package's lateral dimensions. The lateral dimensions refer to the dimensions perpendicular to the stacking direction of the device substrate 200 and the sealing cover plate 290.

[0099] Moreover, using the surface of the cover plate 295 to provide a location for forming the inductor can reduce the need to set the inductor in the circuit substrate (for example, it is beneficial to reduce the size or number of the inductor in the circuit substrate), thereby improving the problem of the inductor occupying too much space on the circuit substrate, and even eliminating the need to prepare the inductor in the circuit substrate, thereby helping to reduce the size of the circuit substrate (for example, thickness or area) and correspondingly reducing the size of the packaging structure.

[0100] In addition, the first inductor 265 located on the first surface 290A of the sealing cover plate 290 is spaced apart from the resonance unit to reduce the impact on the normal performance of the resonance unit.

[0101] It should also be noted that one or more first inductors 265 may be disposed on the same surface of the cover plate 295 .

[0102] Correspondingly, when a plurality of first inductors 265 are disposed on the same surface of the cover plate 295 , the first inductors 265 can not only provide self-inductance, but also achieve mutual inductance between adjacent first inductors 265 , thereby further enhancing the inductance effect.

[0103] As an example, the first inductor 265 has a serrated surface, and among the two first inductors 265 adjacent to each other in the longitudinal direction, the teeth 265A of one first inductor 265 and the tooth grooves 265B of the other first inductor 265 are arranged opposite to each other in the vertical direction, thereby further enhancing the mutual inductance between the adjacent first inductors 265.

[0104] In other embodiments, the surface of the first inductor may also be a plane.

[0105] like Figure 3 As shown, in this embodiment, the number of the cover plate 295 is one, that is, the cover plate 295 is the sealing cover plate 290 .

[0106] In this embodiment, the first bonding structure 230 includes a first sealing ring 235 and a third connecting member 233. The first sealing ring creates a second cavity (not labeled) between the sealing cover plate 290 and the device substrate 200 to accommodate the resonant unit. The third connecting member 233 is located in the second cavity. One end of the third connecting member 233 is electrically connected to the electrode (not labeled) of the resonant unit, and the other end is electrically connected to the first inductor 265 on the first surface 290A.

[0107] Since the first inductor 265 is formed on the sealing cover plate 290 and the resonance unit is formed on the device substrate 200 , the third connector 233 is used to achieve electrical connection between the resonance unit and the first inductor 265 .

[0108] One end of the third connecting member 233 is electrically connected to an electrode (not shown) of the resonance unit, thereby achieving electrical connection with the resonance unit.

[0109] Specifically, according to actual needs, one end of the third connector 233 can be electrically connected to the bottom electrode (not marked), or one end of the third connector 233 can also be electrically connected to the top electrode (not marked), or a third connector 233 electrically connected to the bottom electrode and the top electrode respectively can be provided, so that one end of the third connector 233 is electrically connected to the bottom electrode and the top electrode respectively.

[0110] As an example, one end of the third connecting member 233 facing the third surface is electrically connected to the top electrode.

[0111] In this embodiment, the third connector 233 is located on the first surface 290A and connected to the sidewall of the first inductor 265. In other embodiments, the third connector may also be located on the top surface of the first inductor.

[0112] The material of the third connecting member 233 includes gold or gold-tin, so that the sealing cover plate 290 and the device substrate 200 are bonded by a gold-gold bonding process.

[0113] As an example, the first sealing ring 235 and the third connecting member 233 are made of the same material.

[0114] Accordingly, in this embodiment, the packaging structure further includes: a second top electrode connection pad 265P located on the device substrate 100 , and the second top electrode connection pad 265P is electrically connected to the top electrode (not labeled).

[0115] By setting a second top electrode connection pad 265P on the side of the bottom electrode, the electrical properties of the top electrode 123 are led to the surface of the device substrate 100, which facilitates the electrical connection between the top electrode and other components. The space in the second cavity can also be used to set the third connecting member 233 to reduce the height requirement of the second cavity.

[0116] Specifically, one end of the third connecting member 233 facing the third surface is connected to the top of the second top electrode connection pad 265P.

[0117] It should be noted that the first bonding structure 230 further includes a first connector 232 and a second connector 231 located in the second cavity. For a detailed description of the first sealing ring 235, the first connector 232, the second connector 231, and the second cavity, please refer to the relevant description in the first embodiment and will not be repeated here.

[0118] In this embodiment, the packaging structure further includes: a third conductive column 253, which passes through the sealing cover 290, and one end of the third conductive column 253 facing the first surface 290A is electrically connected to the third connecting member 233 or the first inductor 265 on the first surface 290A, and the other end is electrically connected to the first inductor 265 on the second surface 290B.

[0119] The first inductor 265 is located on two opposite surfaces of the cover plate 295 (i.e., the sealing cover plate 290), and the third conductive column 253 is used to electrically connect the first inductors 265 located on the two opposite surfaces, thereby reducing the complexity of achieving electrical connection between the first inductors 265.

[0120] The material of the third conductive pillars 253 may include conductive materials such as copper, aluminum, cobalt, tungsten or titanium. As an example, the material of the third conductive pillars 253 is copper.

[0121] It should be noted that, in other embodiments, the first inductors on the two oppositely disposed surfaces of the cover plate may also be electrically connected in other ways, for example, by an interconnection layer disposed inside the cover plate.

[0122] In this embodiment, the package structure further includes a redistribution layer 260 located on the first surface 290A and the second surface 290B. The redistribution layer 260 includes a contact pad 261 and a first inductor 265 .

[0123] Using the redistribution layer process to fabricate the inductor simplifies the manufacturing process steps. In addition, the inductor made from the redistribution layer is a planar inductor, and the thickness of a single redistribution layer is generally small, thus helping to reduce the thickness of the package structure.

[0124] In some other embodiments, the first inductor 265 may also be located in the gaps of the redistribution layer 260 .

[0125] In this embodiment, the third connector 233 and the second connector 231 are the same connector, thereby reducing the area occupied by the connector. Accordingly, the third conductive pillar 253 and the second conductive pillar 251 are the same conductive pillar, and the second top electrode connection pad 265P and the first top electrode connection pad 223P are the same connection pad.

[0126] In other embodiments, the third connector and the first connector may also be different connectors separate from each other. Accordingly, the third conductive column and the second conductive column are different conductive columns separate from each other, and the second top electrode connection pad and the first top electrode connection pad are different connection pads separate from each other.

[0127] Figure 5 It is a structural diagram of the third embodiment of the packaging structure of the present invention.

[0128] The similarities between this embodiment and the previous embodiment are not repeated here. The main difference between this embodiment and the previous embodiment is that the packaging structure includes multiple stacked and bonded cover plates 395, wherein the cover plate 395 closest to the device substrate 300 serves as the sealing cover plate 390.

[0129] By using a plurality of stacked cover plates 395 , the layout space of the first inductor 365 can be further increased by adjusting the number of the cover plates 395 , thereby further reducing the lateral size of the package structure.

[0130] like Figure 5 As shown, as an example, the number of the cover plates 395 is two. In other embodiments, the number of the cover plates can be more than two according to requirements.

[0131] In this embodiment, the first inductor 365 on each cover plate 395 is electrically connected to the resonance unit.

[0132] In this embodiment, the packaging structure further includes: a second bonding structure 370 located between adjacent cover plates 395 to enable bonding between adjacent cover plates 395 .

[0133] The second bonding structure 370 includes a second sealing ring 375 , and the second sealing ring 375 defines a third cavity 395V between adjacent cover plates 395 .

[0134] The second sealing ring 375 defines a third cavity 395V between adjacent cover plates 395 , thereby sealing various components such as the first inductor 365 in the third cavity 395V, thereby protecting the various components located in the third cavity 395V.

[0135] It should be noted that the second sealing ring 375 is located at the edge of the cover plate 395, so as to increase the lateral dimension of the third cavity 395V in a direction parallel to the surface of the cover plate 395 as much as possible, so as to provide sufficient space for arranging various components such as the first inductor 365 in the third cavity 395V.

[0136] For example, the position of the second sealing ring 375 corresponds to the position of the first sealing ring 335. Here, corresponding positions refer to: the projections on the same projection plane have overlapping parts.

[0137] In this embodiment, the type of the second bonding structure 370 includes a metal bonding structure, so that the bonding between the cover plates 395 can be achieved by metal bonding, and the metal bonding has better firmness.

[0138] Correspondingly, the second bonding structure 370 includes: a third bonding layer (not labeled), located on the fourth surface (not labeled) of one of the cover plates 395; a fourth bonding layer (not labeled), located on the third surface (not labeled) of the other cover plate 395, the third bonding layer and the fourth bonding layer are stacked and bonded, and the third bonding layer and the fourth bonding layer stacked and bonded in the longitudinal direction form the second bonding structure 370.

[0139] As an example, the material of the second bonding structure 370 includes gold or gold-tin, so that adjacent cover plates 395 are bonded by a gold-gold bonding process.

[0140] It should be noted that, in other embodiments, the second bonding structure may be made of other metal materials. In other embodiments, the second bonding structure may be made of other suitable conductive materials to achieve interconnection.

[0141] In this embodiment, the second bonding structure 370 further includes a fourth connector 373 located within the third cavity 395V. The fourth connector 373 is electrically connected to the first inductor 365 on the adjacent cover plate 395. In other words, one end of the fourth connector 373 is electrically connected to the first inductor 365 on the fourth surface, and the other end is electrically connected to the first inductor 365 on the third surface.

[0142] like Figure 5 As shown, as an example, the fourth connector 373 is located on the top of the first inductor 365 and connected to the top of the first inductor 365. In other embodiments, the fourth connector may also be located on the cover and connected to the side wall of the first inductor.

[0143] In this embodiment, each cover plate 395 includes a third conductive post 353. The third conductive post 353 is located in each cover plate 395 and passes through the corresponding cover plate 395. One end of the third conductive post 353 is electrically connected to the first inductor 365 on the first surface, and the other end is electrically connected to the first inductor 365 on the second surface, thereby electrically connecting the first inductors 365 on both surfaces of the same cover plate 395.

[0144] The fourth connector 373 is used to electrically connect the first inductors 365 on adjacent cover plates 395, and the third conductive column 353 is used to electrically connect the first inductors 365 on two surfaces of the same cover plate 395. Therefore, through the fourth connector 373 and the third conductive column 353, electrical connection can be achieved between multiple first inductors 365 in the longitudinal direction, meeting actual electrical connection requirements.

[0145] As an example, the fourth connecting member 373 and the third conductive column 353 are used to connect the first inductors 365 on each of the cover plates 395 in series.

[0146] In this embodiment, the first bonding structure 330 also includes a first connecting member 332 and a second connecting member 331, which are located in the second cavity 300V, one end of the first connecting member 332 is electrically connected to the bottom electrode (not marked), and one end of the second connecting member 331 is electrically connected to the top electrode (not marked).

[0147] The second bonding structure 370 further includes a fifth connector 372 and a sixth connector 371 , which are located in the third cavity 395V. The fifth connector 372 corresponds to the position of the first connector 332 , and the sixth connector 371 corresponds to the position of the second connector 331 .

[0148] Correspondingly, the packaging structure also includes: a first conductive column 352, which is respectively located in each of the cover plates 395 and passes through the corresponding cover plate 395, and the first conductive column 352 corresponds to the position of the first connector 332 and the fifth connector 372, so that the first connector 332 and the fifth connector 372 are electrically connected through the first conductive column 352; a second conductive column 351, which is respectively located in each of the cover plates 395 and passes through the corresponding cover plate 395, and the second conductive column 351 corresponds to the position of the second connection 331 and the sixth connection 371, so that the second connection 331 and the sixth connection 371 are electrically connected through the second conductive column 351.

[0149] Here, the corresponding positions refer to that the projections on the same projection plane have overlapping parts.

[0150] The first connector 332 , the first conductive pillar 352 , and the fifth connector 372 are stacked in a longitudinal direction, thereby electrically leading the bottom electrode to the second surface of the cover plate 395 farthest from the device substrate 300 .

[0151] The second connection 331 , the second conductive pillar 351 and the sixth connection member 371 are stacked vertically, thereby electrically leading the top electrode to the second surface of the cover plate 395 farthest from the device substrate 300 .

[0152] It should be noted that the first bonding structure 330 further includes a third connector 333 , one end of which is connected to the second top electrode connection pad 365P of the top electrode, and the other end is electrically connected to the first inductor 365 on the first surface.

[0153] like Figure 5 As shown, as an example, the second top electrode connection pad 365P and the first top electrode connection pad 323P are separated from each other, and accordingly, the third connecting member 333 and the second connecting member 331 are separated from each other, and the third conductive column 353 and the second conductive column 351 are separated from each other.

[0154] In this embodiment, the packaging structure further includes: a redistribution layer 360 located on the second surface of the cover plate 395 farthest from the device substrate 300 , and the redistribution layer 360 includes contact pads 361 electrically connected to the first conductive pillars 352 and the second conductive pillars 351 .

[0155] Specifically, the package structure includes a redistribution layer 360 located on the first surface and the second surface, and the redistribution layer 360 includes a first inductor 365. In other words, the first inductor 365 on each cover plate 395 can be prepared by the redistribution layer 360.

[0156] Figure 6 1 is a schematic structural diagram of a fourth embodiment of the packaging structure of the present invention.

[0157] The similarities between this embodiment and the previous embodiment are not repeated here. The main difference between this embodiment and the previous embodiment is that the packaging structure further includes a second inductor 601 located on the fourth surface 600B of the device substrate 600, and the second inductor 601 is electrically connected to the resonant unit (not labeled) on the device substrate 600.

[0158] For the description of the second inductor 601 , reference may be made to the related description of the first inductor in the aforementioned embodiment, which will not be repeated here.

[0159] The surface of the device substrate 600 facing away from the resonant unit is used to provide a location for the inductor, thereby better utilizing the space of the package structure to increase the layout space for the inductor, thereby facilitating a reduction in the lateral dimensions of the package structure. Furthermore, placing the second inductor 601 on a side facing away from the resonant unit helps minimize the impact on the resonant unit.

[0160] It should be noted that, with the redistribution layer on the cover plate 395 as the first redistribution layer, the packaging structure may further include: a second redistribution layer located on the fourth surface 600B of the device substrate 600 , wherein the second redistribution layer includes the second inductor 601 .

[0161] Using the redistribution layer process to fabricate the inductor simplifies the manufacturing process steps. In addition, the inductor made from the redistribution layer is a planar inductor, and the thickness of a single redistribution layer is generally small, thus helping to reduce the thickness of the package structure.

[0162] In some other embodiments, when a second redistribution layer is provided on the fourth surface, the second inductor may also be located in gaps in the second redistribution layer.

[0163] In this embodiment, the packaging structure further includes: a fourth conductive column 693 passing through the device substrate 600 , one end of the fourth conductive column 693 being electrically connected to the second inductor 601 on the fourth surface 600B, and the other end being electrically connected to the resonant unit.

[0164] The resonant unit is arranged on the third surface 600A of the device substrate 600, and the second inductor 601 is arranged on the fourth surface 600B of the device substrate 600. The third surface 600A and the fourth surface 600B are arranged opposite to each other. Therefore, the fourth conductive column 693 that passes through the device substrate 600 is used to reduce the complexity of achieving electrical connection between the resonant unit and the second inductor 601.

[0165] The material of the fourth conductive pillar 693 may include conductive materials such as copper, aluminum, cobalt, tungsten or titanium. As an example, the material of the fourth conductive pillar 693 is copper.

[0166] As an example, one end of the fourth conductive pillar 693 facing the third surface 600B is connected to the second top electrode connection pad 665P.

[0167] It should be noted that, in other embodiments, according to actual needs, the end of the fourth conductive column facing the third surface may also be connected to other top electrode connection pads electrically connected to the top electrode.

[0168] It should also be noted that, in other embodiments, the packaging structure may not have the fourth conductive pillar. For example, the electrical connection between the second inductor and the resonant unit may be achieved through an interconnection layer inside the device substrate.

[0169] Figure 7 1 is a schematic structural diagram of a fifth embodiment of the packaging structure of the present invention.

[0170] The similarities between this embodiment and the previous embodiment are not repeated here. The main difference between this embodiment and the previous embodiment is that the packaging structure includes multiple device substrates 400 that are stacked and bonded, and the device substrate 400 seals the first cavity (not labeled) of the resonant unit (not labeled) on another adjacent device substrate 400.

[0171] By using a plurality of stacked device substrates 400 , the layout space of the second inductor 401 can be further increased by adjusting the number of the device substrates 400 , thereby further reducing the lateral size of the package structure.

[0172] It should be noted that, since the top surface of the top electrode has a first cavity located in the effective resonance zone, the device substrate 400 can be fitted with the top electrode on another adjacent device substrate 400, thereby sealing the first cavity of the resonance unit on the other adjacent device substrate 400. This reduces the requirements for the longitudinal distance between adjacent device substrates 400, thereby facilitating reduction of the longitudinal dimensions of the packaging structure.

[0173] like Figure 7 As shown, as an example, the number of the device substrates 400 is two. In other embodiments, the number of the device substrates can be more than two according to requirements.

[0174] Correspondingly, the sealing cover plate 490 is bonded to the topmost device substrate 400 .

[0175] In this embodiment, the packaging structure also includes: a third bonding structure 480, which is located between adjacent device substrates 400 to enable the adjacent device substrates 400 to be bonded, and the third bonding structure 480 includes a third sealing ring 485, and the third sealing ring 485 enables a fourth cavity 400V for accommodating the resonance unit to be provided between adjacent device substrates 400.

[0176] Correspondingly, the second inductor 401 located between adjacent device substrates 400 is located in the fourth cavity 400V.

[0177] The third sealing ring 485 allows a fourth cavity 400V for accommodating the resonance unit to be provided between adjacent device substrates 400 , thereby sealing various components such as the resonance unit in the fourth cavity 400V, thereby protecting the various components located in the fourth cavity 400V.

[0178] It should be noted that the third sealing ring 485 is located at the edge of the device substrate 400, thereby increasing the lateral dimension of the fourth cavity 400V parallel to the surface of the device substrate 400 as much as possible, thereby providing sufficient space for arranging various components such as the second inductor.

[0179] In this embodiment, the third bonding structure 480 includes a metal bonding structure, so that bonding between adjacent device substrates 400 can be achieved by metal bonding, and the metal bonding has better firmness.

[0180] Correspondingly, the third bonding structure 480 includes: a fifth bonding layer (not marked), located on one of the device substrates 400; a sixth bonding layer (not marked), located on the other device substrate 400, the sixth bonding layer and the fifth bonding layer are stacked and bonded, and the sixth bonding layer and the fifth bonding layer stacked and bonded vertically form the third bonding structure 480.

[0181] As an example, the material of the third bonding structure 480 includes gold or gold-tin, so that the adjacent device substrates 400 are bonded through a gold-gold bonding process.

[0182] It should be noted that, in other embodiments, the third bonding structure may be made of other metal materials. In other embodiments, the third bonding structure may be made of other suitable conductive materials to achieve interconnection.

[0183] In this embodiment, the third bonding structure further includes: a seventh connector 483, wherein one end of the seventh connector 483 facing the fourth surface 400B is electrically connected to the second inductor 401 on the fourth surface 400B, and one end facing the third surface 400A is electrically connected to the second inductor 401 on another fourth surface 400B through the fourth conductive column 493.

[0184] There are multiple device substrates 400, adjacent device substrates 400 are spaced apart in the longitudinal direction, and the second inductor 401 is located on the fourth surface 400B of the device substrate 400. Therefore, by providing the seventh connecting member 483 between adjacent device substrates 400, the second inductors 401 located on different device substrates 400 can be electrically connected.

[0185] In this embodiment, one end of the seventh connector 483 facing the third surface 400A is connected to the second top electrode connection pad 465P, thereby being electrically connected to the second inductor 401 on the other fourth surface 400B through the second top electrode connection pad 465P and the fourth conductive column 493 .

[0186] It should be noted that the first bonding structure 430 also includes a first connector 432 and a second connector 431. Therefore, the third bonding structure 480 also includes: an eighth connector 482, corresponding to the position of the first connector 432, and the end of the eighth connector 482 facing the third surface 400A is electrically connected to the bottom electrode; a ninth connector 481, corresponding to the position of the second connector 431, and the end of the ninth connector 481 facing the third surface 400A is electrically connected to the top electrode.

[0187] Specifically, one end of the ninth connecting member 481 facing the third surface 400A is electrically connected to the first top electrode connection pad 423P.

[0188] Moreover, the packaging structure also includes: a fifth conductive column 492, which passes through the device substrate 400 and is located between the first connector 432 and the eighth connector 482, and the end of the fifth conductive column 492 facing the third surface 400A is electrically connected to the first connector 432, and the other end facing the fourth surface 400B is electrically connected to the eighth connector 482; a sixth conductive column 491, which passes through the device substrate 400 and is located between the second connector 431 and the ninth connector 481, and the end of the sixth conductive column 491 facing the third surface 400A is electrically connected to the second connector 431, and the other end facing the fourth surface 400B is electrically connected to the ninth connector 481.

[0189] Through the eighth connector 482 and the fifth conductive pillar 492 , the top electrode on each device substrate 400 is electrically led out to the second surface of the cover farthest from the device substrate 400 along the direction from the device substrate 400 to the sealing cover 490 .

[0190] Through the ninth connector 481 and the sixth conductive pillar 491 , the top electrode on each device substrate 400 is electrically led out to the second surface of the cover farthest from the device substrate 400 along the direction from the device substrate 400 to the sealing cover 490 .

[0191] The material of the fifth conductive pillar 492 may include a conductive material such as copper, aluminum, cobalt, tungsten, or titanium, and the material of the sixth conductive pillar 491 may include a conductive material such as copper, aluminum, cobalt, tungsten, or titanium. As an example, the material of the fifth conductive pillar 492 and the sixth conductive pillar 491 are both copper.

[0192] It should be noted that, for the detailed description of the remaining embodiments of the present invention, reference may be made to the relevant contents of the first embodiment, and no further details will be given.

[0193] Correspondingly, an embodiment of the present invention further provides a filter, comprising the packaging structure provided by any of the aforementioned embodiments.

[0194] The packaging structure provided by any of the aforementioned embodiments has a relatively small size, which is correspondingly beneficial for reducing the size of the filter.

[0195] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A packaging structure, characterized in that: include: A device substrate having a resonance unit thereon, the resonance unit comprising a bottom electrode, a piezoelectric layer, and a top electrode stacked in sequence, the bottom electrode facing the device substrate, and a top surface of the top electrode having a first cavity located in an effective resonance region; a sealing cover plate, bonded to the device substrate and facing the resonant unit, wherein the sealing cover plate seals the first cavity; A first bonding structure is located between the sealing cover plate and the device substrate to bond the sealing cover plate and the device substrate. The first bonding structure includes a first sealing ring surrounding the periphery of the resonance unit. The first sealing ring creates a second cavity between the sealing cover plate and the device substrate to accommodate the resonance unit.

2. The packaging structure according to claim 1, wherein: The first bonding structure further includes a first connector and a second connector, which are located in the second cavity, one end of the first connector is electrically connected to the bottom electrode, and one end of the second connector is electrically connected to the top electrode; The packaging structure further includes: a first conductive pillar, which passes through the sealing cover and is electrically connected to the other end of the first connector; and a second conductive pillar, which passes through the sealing cover and is electrically connected to the other end of the second connector.

3. The packaging structure according to claim 2, wherein: The sealing cover plate includes a first surface facing the device substrate and a second surface opposite to the first surface; The packaging structure further includes a redistribution layer located on the second surface of the sealing cover plate, wherein the redistribution layer includes contact pads electrically connected to the first conductive pillars and the second conductive pillars.

4. The packaging structure according to claim 1, wherein: The packaging structure includes one or multiple cover plates bonded together, bonded to the device substrate and facing the resonant unit, with the cover plate closest to the device substrate serving as a sealing cover plate. The cover plate includes a first surface facing the device substrate and a second surface opposite to the first surface. The packaging structure further includes: a first inductor located on the first surface and the second surface, the first inductor being electrically connected to the resonance unit, and the first inductor located on the first surface of the sealing cover is spaced apart from the resonance unit.

5. The packaging structure according to claim 4, wherein: The first bonding structure further includes a third connector located in the second cavity, wherein one end of the third connector is electrically connected to the electrode of the resonant unit, and the other end of the third connector is electrically connected to the first inductor on the first surface; The packaging structure further includes: a third conductive column passing through the sealing cover plate, wherein one end of the third conductive column facing the first surface is electrically connected to the third connector or the first inductor on the first surface, and the other end is electrically connected to the first inductor on the second surface.

6. The packaging structure according to claim 5, wherein: The packaging structure includes a plurality of cover plates that are stacked and bonded; The packaging structure further includes: a second bonding structure located between adjacent cover plates to enable bonding between adjacent cover plates; The second bonding structure includes: a second sealing ring, which defines a third cavity between adjacent cover plates; and a fourth connector located in the third cavity, which electrically connects the first inductors on adjacent cover plates.

7. The packaging structure according to claim 6, wherein: The third conductive column is respectively located in each of the cover plates and passes through the corresponding cover plate. One end of the third conductive column is electrically connected to the first inductor on the first surface, and the other end is electrically connected to the first inductor on the second surface.

8. The packaging structure according to claim 6, wherein: The first bonding structure further includes a first connector and a second connector, which are located in the second cavity, one end of the first connector is electrically connected to the bottom electrode, and one end of the second connector is electrically connected to the top electrode; The second bonding structure further includes a fifth connecting member and a sixth connecting member, which are located in the third cavity, wherein the fifth connecting member corresponds to the position of the first connecting member, and the sixth connecting member corresponds to the position of the second connecting member; The packaging structure also includes: a first conductive column, which is respectively located in each of the cover plates and passes through the corresponding cover plate, and the first conductive column corresponds to the position of the first connector and the fifth connector, so that the first connector and the fifth connector are electrically connected through the first conductive column; a second conductive column, which is respectively located in each of the cover plates and passes through the corresponding cover plate, and the second conductive column corresponds to the position of the second connector and the sixth connector, so that the second connector and the sixth connector are electrically connected through the second conductive column.

9. The packaging structure according to claim 8, wherein: The packaging structure further includes a redistribution layer located on the second surface of the cover plate farthest from the device substrate, the redistribution layer including contact pads electrically connected to the first conductive pillars and the second conductive pillars.

10. The packaging structure according to claim 4, wherein: The first inductor has a sawtooth surface, and among the two first inductors adjacent to each other in the longitudinal direction, the teeth of one first inductor are arranged vertically opposite to the tooth grooves of the other first inductor.

11. The packaging structure according to claim 1, wherein: The packaging structure further includes: an acoustic reflection structure located above or inside the device substrate, and the acoustic reflection structure is located at the bottom of the resonance unit.

12. The packaging structure according to claim 3 or 9, wherein: The package structure further includes a redistribution layer on the first surface and the second surface, the redistribution layer including a first inductor.

13. The packaging structure according to any one of claims 1 to 11, wherein: The device substrate includes a third surface located on one side of the resonant unit and a fourth surface opposite to the third surface; The packaging structure further includes: a second inductor located on the fourth surface of the device substrate, and the second inductor is electrically connected to the resonance unit on the device substrate.

14. The packaging structure according to claim 13, wherein: The packaging structure further includes: a fourth conductive column passing through the device substrate, wherein one end of the fourth conductive column is electrically connected to the second inductor on the fourth surface, and the other end of the fourth conductive column is electrically connected to the resonance unit.

15. The packaging structure according to claim 14, wherein: The packaging structure includes a plurality of device substrates that are stacked and bonded, and the device substrate seals a first cavity of a resonance unit on another adjacent device substrate; The sealing cover plate is bonded to the topmost device substrate; The packaging structure further includes: a third bonding structure located between adjacent device substrates to enable bonding of the adjacent device substrates, the third bonding structure including a third sealing ring, the third sealing ring providing a fourth cavity between the adjacent device substrates for accommodating the resonant unit; The second inductor located between adjacent device substrates is located in the fourth cavity.

16. The packaging structure according to claim 15, wherein: The third bonding structure further includes: a seventh connector, wherein one end of the seventh connector facing the fourth surface is electrically connected to the second inductor on the fourth surface, and one end of the seventh connector facing the third surface is electrically connected to the second inductor on another fourth surface through the fourth conductive column.

17. The packaging structure according to claim 15, wherein: The first bonding structure further includes a first connector and a second connector, which are located in the second cavity, one end of the first connector is electrically connected to the bottom electrode, and one end of the second connector is electrically connected to the top electrode; The third bonding structure further includes: an eighth connector, corresponding to the position of the first connector, and having one end of the eighth connector facing the third surface electrically connected to the bottom electrode; a ninth connector, corresponding to the position of the second connector, and having one end of the ninth connector facing the third surface electrically connected to the top electrode; The packaging structure also includes: a fifth conductive column, which passes through the device substrate and is located between the first connector and the eighth connector, wherein one end of the fifth conductive column facing the third surface is electrically connected to the first connector, and one end facing the fourth surface is electrically connected to the other end of the eighth connector; a sixth conductive column, which passes through the device substrate and is located between the second connector and the ninth connector, wherein one end of the sixth conductive column facing the third surface is electrically connected to the second connector, and one end facing the fourth surface is electrically connected to the other end of the ninth connector.

18. The packaging structure according to claim 3 or 9, wherein: The packaging structure further includes: a circuit substrate, located on a side of the sealing cover plate facing away from the device substrate and arranged opposite to the contact pad; The conductive bump is located between the redistribution layer and the circuit substrate to electrically connect the circuit substrate to the redistribution layer.

19. A filter, characterized in that: The package structure comprises the package structure according to any one of claims 1 to 18.

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