Package structure and manufacturing method thereof

Abstract

The embodiment of the invention provides a packaging structure and a manufacturing method thereof. The packaging structure comprises a device region and a non-device region, the device area comprises at least one resonator, and comprises a substrate, a reflection structure, a first electrode layer, a piezoelectric layer, a second electrode layer and a first frequency repairing structure which are stacked in sequence; the non-device area comprises a second frequency repairing structure arranged on the side, away from the substrate, of the second electrode layer and a bonding pad structure arranged on the side, away from the substrate, of the first electrode layer or the second electrode layer, the second frequency repairing structure and the bonding pad structure are arranged adjacently, and the bonding pad structure is at least partially embedded into the second frequency repairing structure; the dielectric structure is arranged on the side, away from the substrate, of the second frequency repairing structure, and at least part of the surface, away from the substrate, of the bonding pad structure is exposed out of the dielectric structure; wherein in the non-device area, the orthographic projection of the second frequency correction structure on the substrate is located within the sum of the orthographic projection ranges of the medium structure and the bonding pad structure on the substrate.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of packaging technology, including but not limited to a packaging structure and a manufacturing method thereof. Background Art

[0002] The wafer level package (WLP) structure can improve the stability and reliability of the product. In the WLP structure, an Under Bump Metallization (UBM) layer is usually formed between the formation of the pad and the formation of the bump to improve the bonding strength between the pad and the bump. However, a variety of alkaline solutions may be used in the process of forming the UBM layer, which can damage the product, resulting in degradation of the product's electrical performance and reduced reliability.

[0003] Therefore, there is an urgent need to improve the packaging structure. Summary of the invention

[0004] In view of this, an embodiment of the present disclosure provides a packaging structure and a manufacturing method thereof.

[0005] In a first aspect, an embodiment of the present disclosure provides a packaging structure, the packaging structure comprising: a device region and a non-device region provided on one side of a substrate, the non-device region provided on at least one side of the device region; the device region comprising at least one resonator, the at least one resonator comprising: the substrate, a reflection structure, a first electrode layer, a piezoelectric layer, a second electrode layer and a first frequency-correcting structure stacked in sequence; the non-device region comprising: a second frequency-correcting structure provided on a side of the second electrode layer away from the substrate, and a pad structure provided on a side of the first electrode layer or the second electrode layer away from the substrate, the second frequency-correcting structure and the pad structure being provided adjacently, the pad structure being at least partially embedded in the second frequency-correcting structure; a dielectric structure provided on a side of the second frequency-correcting structure away from the substrate, the dielectric structure exposing at least a portion of the surface of the pad structure away from the substrate; wherein, in the non-device region, the orthographic projection of the second frequency-correcting structure on the substrate is within the sum of the orthographic projection ranges of the dielectric structure and the pad structure on the substrate.

[0006] In some embodiments, the non-device area surrounds the device area, and the device area and the non-device area together form a chip area; the packaging structure further includes: a cutting road area provided on one side of the substrate and surrounding the chip area.

[0007] In some embodiments, in the non-device area, the second frequency-modified structure has a first opening exposing the first electrode layer or the second electrode layer, the pad structure is in contact with the first electrode layer or the second electrode layer through the first opening, and the size of the pad structure along the stacking direction is larger than the size of the second frequency-modified structure along the stacking direction; the size of the pad structure along a direction parallel to the substrate is larger than or equal to the size of the first opening along a direction parallel to the substrate.

[0008] In some embodiments, a sidewall of the dielectric structure and a sidewall of the pad structure are in contact, and an orthographic projection of the dielectric structure on the substrate and an orthographic projection of the pad structure on the substrate do not have an overlapping area.

[0009] In some embodiments, the dielectric structure covers a portion of the surface of the pad structure away from the substrate, and an orthographic projection of the dielectric structure on the substrate and an orthographic projection of the pad structure on the substrate have an overlapping area.

[0010] In some embodiments, the dimension of the dielectric structure near the cutting path region in the non-device area along the direction parallel to the substrate is L1, the dimension of the overlapping area between the second frequency trimming structure near the cutting path region in the non-device area and the pad structure along the direction parallel to the substrate is L2, and the dimension of the second frequency trimming structure near the cutting path region in the non-device area along the direction parallel to the substrate is L3; wherein, 25μm≤L3≤33μm; and / or, 0μm≤L2≤L3-23μm; and / or, 25μm≤L1≤L3+2μm; and / or, L3≤L1+L2≤L3+2μm.

[0011] In some embodiments, in the non-device area, there is a second opening between adjacent pad structures to expose the second electrode layer, the second frequency trimming structure is in contact with the second electrode layer through the second opening, and the second frequency trimming structure includes a first portion in contact with the second electrode layer and a second portion in contact with the side wall of the pad structure.

[0012] In some embodiments, the dielectric structure covers the first part and the second part of the second frequency trimming structure; the orthographic projection of the second frequency trimming structure on the substrate coincides with the orthographic projection of the dielectric structure on the substrate; or, the orthographic projection of the second frequency trimming structure on the substrate is within the range of the orthographic projection of the dielectric structure on the substrate.

[0013] In some embodiments, the second frequency trimming structure also includes a third portion that contacts a portion of the surface of the pad structure away from the substrate; the dielectric structure covers the first portion, the second portion, and the third portion of the second frequency trimming structure; and the orthographic projection of the second frequency trimming structure on the substrate is within the orthographic projection range of the dielectric structure on the substrate.

[0014] In some embodiments, the dimension of the overlapping area between the dielectric structure and the pad structure near the cutting path area in the non-device area along the direction parallel to the substrate is L4, and the dimension of the overlapping area between the second frequency trimming structure and the pad structure near the cutting path area in the non-device area along the direction parallel to the substrate is L5; wherein, 0μm<L4-L5; and / or, 2μm≤L5.

[0015] In some embodiments, the sidewalls of a portion of the second frequency trimming structure in the non-device area close to the cutting line area and the sidewalls of the dielectric structure are aligned along the stacking direction; or, the sidewalls of a portion of the second frequency trimming structure in the non-device area close to the cutting line area are covered by the dielectric structure.

[0016] In some embodiments, the non-device area also includes: a connecting layer arranged on the side of the pad structure away from the substrate, the connecting layer exposing a portion of the surface of the pad structure away from the substrate; a conductive column arranged on the side of the connecting layer away from the pad structure; and a bump arranged on the side of the conductive column away from the connecting layer, the bump being used to lead out an electrical signal from the first electrode layer or the second electrode layer.

[0017] In some embodiments, an angle between a sidewall of the second frequency trimming structure and the substrate is less than 90 degrees.

[0018] In some embodiments, the packaging structure further includes: a cover plate disposed on a side of the dielectric structure away from the substrate, a cavity is formed between the substrate, the dielectric structure and the cover plate, the resonator is disposed in the cavity and there is a gap between the first frequency modification structure and the cover plate.

[0019] In a second aspect, an embodiment of the present disclosure provides a method for manufacturing a packaging structure, the packaging structure comprising: a device area and a non-device area arranged on one side of a substrate, the non-device area being arranged on at least one side of the device area; the manufacturing method comprising: forming a reflective structure, a first electrode layer, a piezoelectric layer, and a second electrode layer stacked in sequence on the substrate; forming a frequency trimming structure and a pad structure on a side of the second electrode layer away from the substrate; the frequency trimming structure comprising a first frequency trimming structure arranged in the device area and a second frequency trimming structure arranged in the non-device area, the second frequency trimming structure being in contact with the second electrode layer; the pad structure being arranged in the non-device area, the pad structure being in contact with the first electrode layer or the second electrode layer The layers are in contact with each other, in the non-device area, the second frequency trimming structure and the pad structure are adjacently arranged, and the pad structure is at least partially embedded in the second frequency trimming structure; the device area includes at least one resonator, and the at least one resonator includes the substrate, the reflection structure, the first electrode layer, the piezoelectric layer, the second electrode layer and the first frequency trimming structure which are stacked in sequence; a dielectric structure is formed on the side of the second frequency trimming structure away from the substrate, and the dielectric structure exposes at least a portion of the surface of the pad structure away from the substrate; wherein, in the non-device area, the orthographic projection of the second frequency trimming structure on the substrate is within the sum of the orthographic projection ranges of the dielectric structure and the pad structure on the substrate.

[0020] In some embodiments, the manufacturing method further includes: forming a connecting material layer covering the dielectric structure and the pad structure in the non-device area; etching the connecting material layer to form a connecting layer exposing a portion of the surface of the pad structure away from the substrate; forming a conductive column on a side of the connecting layer away from the pad structure in the non-device area; forming a bump on a side of the conductive column away from the connecting layer in the non-device area, the bump being used to lead out an electrical signal from the first electrode layer or the second electrode layer.

[0021] The embodiment of the present disclosure provides a packaging structure and a manufacturing method thereof. In the embodiment of the present disclosure, at least one resonator is provided in the device region of the packaging structure, and a second frequency-correcting structure and a pad structure are provided in the non-device region of the packaging structure. The second frequency-correcting structure is in contact with the second electrode layer, and the pad structure is in contact with the first electrode layer or the second electrode layer, and the pad structure is at least partially embedded in the second frequency-correcting structure. A dielectric structure is also provided in the non-device region, and the dielectric structure covers the second frequency-correcting structure and exposes at least part of the surface of the pad structure; in the non-device region, the orthographic projection of the second frequency-correcting structure on the substrate is within the sum of the orthographic projection ranges of the dielectric structure and the pad structure on the substrate. In this way, the surface of the second frequency-correcting structure in the non-device region is covered by the dielectric structure or the second frequency-correcting structure in the non-device region is covered by the dielectric structure and the pad structure, that is, the second frequency-correcting structure in the non-device region is protected by the dielectric structure or the second frequency-correcting structure in the non-device region is protected by the dielectric structure and the pad structure, effectively preventing the second frequency-correcting structure and the second electrode layer, the piezoelectric layer and the first electrode layer arranged below the second frequency-correcting structure from being damaged by the alkaline solution used in the subsequent process, thereby improving the yield and reliability of the packaging structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A partial cross-sectional view of a package structure provided for some examples;

[0023] Figure 2 A top view of each region in the packaging structure provided by an embodiment of the present disclosure;

[0024] Figure 3 A partial cross-sectional view of a chip region provided for an embodiment of the present disclosure;

[0025] Figure 4 A partial cross-sectional view of a packaging structure provided for some embodiments of the present disclosure;

[0026] Figure 5 Figures (a), (b), (c) and (d) are partial cross-sectional views of a second frequency trimming structure, a pad structure and a dielectric structure in a packaging structure provided in some embodiments of the present disclosure;

[0027] Figure 6 A partial cross-sectional view of a packaging structure provided in some other embodiments of the present disclosure;

[0028] Figure 7 Figures (a) and (b) are partial cross-sectional views of a second frequency trimming structure, a pad structure, and a dielectric structure in a packaging structure provided in some other embodiments of the present disclosure;

[0029] Figure 8 A schematic diagram of a process for manufacturing a packaging structure provided by an embodiment of the present disclosure;

[0030] Fig. 9 Figures (a), (b), (c) and (d) are cross-sectional views of the packaging structure provided by the embodiment of the present disclosure during the manufacturing process. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present disclosure and the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0032] In the following description, a large number of specific details are given to provide a more thorough understanding of the present disclosure. However, it is obvious to those skilled in the art that the present disclosure can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present disclosure, some technical features known in the art are not described; that is, all features of actual embodiments are not described here, and well-known functions and structures are not described in detail.

[0033] In the drawings, the sizes of layers, regions, elements and their relative sizes may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0034] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present disclosure necessarily has the first element, component, region, layer or part.

[0035] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0036] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be a limitation of the present disclosure. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0037] In order to thoroughly understand the present disclosure, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present disclosure. The preferred embodiments of the present disclosure are described in detail below, but in addition to these detailed descriptions, the present disclosure may also have other implementations.

[0038] refer to Figure 1 , Figure 1 A partial cross-sectional view of the package structure is provided for some examples. Figure 1 As shown, the packaging structure 100 may include: a frequency-correcting layer 102 having an opening, wherein the frequency-correcting layer 102 has an opening exposing a portion of the surface of the lower electrode layer or the upper electrode layer of the resonator; a pad layer 104 is provided in the opening of the frequency-correcting layer 102, wherein the pad layer 104 is in contact with the portion of the surface of the lower electrode layer or the upper electrode layer exposed by the frequency-correcting layer 102, and the pad layer 104 is used to lead out the electrical signal of the lower electrode layer or the upper electrode layer; and a dielectric layer 106 is provided on a side of the frequency-correcting layer 102 away from the upper electrode layer, wherein the dielectric layer 106 covers a portion of the surface of the frequency-correcting layer 102 away from the upper electrode layer. There is a gap (such as Figure 1 The gap may expose a portion of the surface of the frequency trimming layer 102 away from the upper electrode layer.

[0039] Here, the subsequent electrical signal extraction of the pad layer 104 may include the following steps: forming a metallization material layer under the solder ball that covers the surface of the pad layer 104 away from the upper electrode layer, the surface of the dielectric layer 106 away from the upper electrode layer, and the surface of the frequency correction layer 102 exposed by the covering gap; etching the metallization material layer under the solder ball to form a metallization layer under the solder ball 108 covering a portion of the surface of the pad layer 104; and sequentially forming a copper pillar 110 and a solder ball 112 on the metallization layer under the solder ball 108.

[0040] In the above technical solution, a variety of alkaline liquids may be used in the process of forming the metallization layer under the solder ball. The alkaline liquid will flow down along the gap between the pad layer and the dielectric layer, causing damage to the frequency repair layer in the packaging structure, such as cracks in the frequency repair layer; further, in more serious cases, the alkaline liquid will even continue to corrode the upper electrode layer along the cracks in the frequency repair layer, or the alkaline liquid will corrode and destroy the frequency repair layer until the upper electrode layer and / or lower electrode layer of the resonator are exposed. The corrosion and destruction of the upper electrode layer or the lower electrode layer by the alkaline liquid will not only cause the electrical performance of the resonator to deteriorate, but also cause pollution to the alkaline liquid. The corrosion and destruction of the frequency repair layer or the piezoelectric layer by the alkaline liquid will reduce the reliability of the resonator and also cause pollution to the alkaline liquid.

[0041] In view of this, an embodiment of the present disclosure provides a packaging structure and a manufacturing method thereof.

[0042] Before introducing the embodiments of the present disclosure, various directions that may be involved in the following are defined. In the plane where the substrate is located, intersecting X-direction and Y-direction are defined, and the direction perpendicular to the substrate is defined as Z-direction. In some embodiments, the X-direction and the Y-direction may be perpendicular to each other, so that the X-direction, the Y-direction, and the Z-direction are perpendicular to each other. In other embodiments, the X-direction and the Y-direction may not be perpendicular to each other. The following will be described by taking the X-direction, the Y-direction, and the Z-direction as an example in which the X-direction, the Y-direction, and the Z-direction are perpendicular to each other.

[0043] refer to Figure 2 , Figure 3 and Figure 4 , Figure 2 A top view of each region in the packaging structure provided by an embodiment of the present disclosure, Figure 3 A partial cross-sectional view of a chip region provided in an embodiment of the present disclosure, Figure 4 A partial cross-sectional view of a packaging structure provided by some embodiments of the present disclosure. Figure 2 As shown, the embodiment of the present disclosure provides a packaging structure 200, which includes: a chip area 204 (such as Figure 2 The substrate 202 may include a plurality of chip regions 204, and the chip regions 204 are used to form chips.

[0044] Here, the chip regions 204 on the substrate 202 may be arranged in an array along the X direction and the Y direction, and any adjacent chip regions 204 along the X direction or along the Y direction may be separated by the saw road region 206. Figure 2 The arrangement of the chip region 204 is merely used for illustrative purposes, and the present disclosure has no particular limitation on the arrangement of the chip region 204 .

[0045] In some embodiments, the chip region 204 may be in a circular, square, or other shapes. Figure 2 The shape, number and arrangement of the chip region 204 are merely illustrative and do not constitute a limitation on the protection scope of the present disclosure.

[0046] Here, a blade may be used to cut the substrate along the scribe line region 206 to obtain individual chips, wherein the scribe line region 206 may be regarded as a boundary of the chip.

[0047] In some embodiments, the material of the substrate 202 may include a single semiconductor material, such as silicon (Si) or germanium (Ge), III-V compound semiconductor materials, II-VI compound semiconductor materials, and organic semiconductor materials, or other semiconductor materials known in the art.

[0048] Still Figure 2 As shown, the chip area 204 may include a device area 208 and a non-device area 210 disposed on at least one side of the device area 208; wherein at least one resonator is disposed in the device area 208, and a related structure for leading out electrical signals from the resonator is disposed in the non-device area 210.

[0049] Combination Figure 2 and Figure 3 As shown, the package structure 200 provided in the embodiment of the present disclosure may include a device region 208, in which at least one resonator 212 (eg, Figure 3 The resonator 212 includes: a substrate 202, a reflective structure 214, a first electrode layer 216, a piezoelectric layer 218, a second electrode layer 220 and a first frequency-modifying structure 222, which are stacked in sequence.

[0050] Here, the reflective structure 214 can be used to reflect the acoustic wave signal. When the acoustic wave signal generated by the piezoelectric layer 218 propagates toward the reflective structure 214, the acoustic wave signal can be totally reflected at the interface where the first electrode layer 216 and the reflective structure 214 are in contact, so that the acoustic wave signal is reflected back to the piezoelectric layer 218. In this way, the energy of the acoustic wave signal generated by the piezoelectric layer 218 can be confined in the piezoelectric layer 218, reducing the energy loss of the acoustic wave signal and improving the quality of the acoustic wave signal transmitted by the resonator 212.

[0051] In some embodiments, the reflective structure 214 may include an air cavity. In this case, the resonator 212 may include a film bulk acoustic resonator (FBAR).

[0052] In some other embodiments, the reflection structure 214 may include a Bragg reflection structure, wherein the Bragg reflection structure includes two dielectric materials with different acoustic impedances stacked together. In this case, the resonator 212 may include a solid mounted resonator (SMR).

[0053] Here, the first electrode layer 216 may also be referred to as a lower electrode layer, and the second electrode layer 220 may also be referred to as an upper electrode layer, and an electrical signal may be applied to the resonator 212 through the upper electrode layer and the lower electrode layer. In some embodiments, the materials of the first electrode layer 216 and the second electrode layer 220 may be the same or different, including a conductive metal or a conductive material composed of an alloy of a conductive metal, and the conductive metal may be, for example, aluminum (Al), molybdenum (Mo), ruthenium (Ru), or platinum (Pt).

[0054] Here, the piezoelectric layer 218 can be used to generate vibration according to the inverse piezoelectric property, convert the electrical signal loaded on the first electrode layer 216 and the second electrode layer 220 into an acoustic wave signal, and realize the conversion of electrical energy into mechanical energy. In some embodiments, the material of the piezoelectric layer 218 may include a material having piezoelectric properties. For example, aluminum nitride, scandium-doped aluminum nitride, zinc oxide, lithium tantalate, lead zirconate titanate, or barium titanate, etc.

[0055] Here, the first frequency trimming structure 222 can serve as a protective layer to reduce oxidation caused by exposure of the second electrode layer 220 to the external environment, protect the second electrode layer 220, the piezoelectric layer 218 and the first electrode layer 216 disposed below the first frequency trimming structure 222, and maintain the stability of the resonator 212; and the resonant frequency of the resonator 212 can also be adjusted by controlling the size (i.e., thickness) of the first frequency trimming structure 222 along the Z direction.

[0056] It should be noted that due to the problem of coating uniformity on the entire surface of the wafer, it may be necessary to use a frequency correction structure to gradually adjust the frequency to a consistent level, and the frequency correction structure can provide a certain capacity for process errors to prevent resonators with high frequencies from being unable to function normally.

[0057] Combination Figure 2 , Figure 3 and Figure 4 As shown, the package structure 200 provided in the embodiment of the present disclosure may include a non-device area 210, and the non-device area 210 may include: a second frequency trimming structure 224 disposed on a side of the second electrode layer 220 away from the substrate 202, that is, the second frequency trimming structure 224 is disposed on the top surface of the second electrode layer 220. Figure 3 As shown, in the non-device region 210, the second frequency trimming structure 224 can also be disposed on the top surface of the piezoelectric layer 218. The non-device region 210 can also include: a pad structure 226 disposed on the side of the first electrode layer 216 or the second electrode layer 220 away from the substrate 202, that is, the pad structure 226 is in contact with the top surface of the first electrode layer 216, or the pad structure 226 is in contact with the top surface of the second electrode layer 220. The second frequency trimming structure 224 and the pad structure 226 are arranged adjacent to each other, and the pad structure 226 is at least partially embedded in the second frequency trimming structure 224; the dielectric structure 228 is arranged on the side of the second frequency trimming structure 224 away from the substrate 202 (that is, on the top surface of the second frequency trimming structure 224), and the dielectric structure 228 exposes at least a portion of the surface of the pad structure 226 away from the substrate 202 (that is, at least a portion of the top surface of the pad structure 226); wherein, in the non-device area 210, the orthographic projection of the second frequency trimming structure 224 on the XY plane is located within the sum of the orthographic projection ranges of the dielectric structure 228 and the pad structure 226 on the XY plane, that is, the orthographic projection range of the second frequency trimming structure 224 on the XY plane is smaller than the sum of the orthographic projection ranges of the dielectric structure 228 and the pad structure 226 on the XY plane.

[0058] Here, the first frequency trimming structure 222 in the device region 208 and the second frequency trimming structure 224 in the non-device region 210 together form a frequency trimming structure, and the first frequency trimming structure 222 and the second frequency trimming structure 224 can be formed in the same process, and the difference between the first frequency trimming structure 222 and the second frequency trimming structure 224 is that they are arranged at different positions in the chip region 204. The first frequency trimming structure 222 and the second frequency trimming structure 224 both have a bottom surface close to the substrate 202 and a top surface away from the substrate 202; wherein, in the device region 208, the bottom surface of the first frequency trimming structure 222 at least contacts the second electrode layer 220; and in the non-device region 210, the bottom surface of the second frequency trimming structure 224 at least contacts the second electrode layer 220 and the top surface of the piezoelectric layer 218.

[0059] Here, the pad structure 226 has a bottom surface close to the substrate 202 and a top surface away from the substrate 202. The bottom surface of the pad structure 226 is in contact with the first electrode layer 216 or the second electrode layer 220. When the pad structure 226 is in contact with the first electrode layer 216, it is used to lead out the electrical signal of the first electrode layer 216; when the pad structure 226 is in contact with the second electrode layer 220, it is used to lead out the electrical signal of the second electrode layer 220. The second frequency-correcting structure 224 and the pad structure 226 are arranged adjacent to each other, which can also be regarded as the pad structure 226 being in contact with the first electrode layer 216 or the second electrode layer 220 through the first opening in the second frequency-correcting structure 224, that is, the pad structure 226 is at least partially embedded in the second frequency-correcting structure 224. In other words, the adjacent arrangement of the second trimming structure 224 and the pad structure 226 can also be regarded as the second trimming structure 224 contacting the second electrode layer 220 through the second opening between the adjacent pad structures 226 , that is, the second trimming structure 224 is at least partially embedded between the adjacent pad structures 226 .

[0060] Here, the dielectric structure 228 has a bottom surface close to the substrate 202 and a top surface far from the substrate 202 , and the bottom surface of the dielectric structure 228 is in contact with the top surface of the second frequency trimming structure 224 .

[0061] In the embodiment of the present disclosure, in the non-device area 210, the orthographic projection of the second frequency trimming structure 224 on the XY plane is within the sum of the orthographic projection ranges of the dielectric structure 228 and the pad structure 226 on the XY plane. In other words, the top surface of the second frequency trimming structure 224 in the non-device area 210 is covered by the dielectric structure 228 or the top surface of the second frequency trimming structure 224 in the non-device area 210 is covered by the dielectric structure 228 and the pad structure 226, that is, the second frequency trimming structure 224 in the non-device area 210 is protected by the dielectric structure 228 or the second frequency trimming structure 224 in the non-device area 210 is protected by the dielectric structure 228 and the pad structure 226, effectively preventing the second frequency trimming structure 224 and the second electrode layer 220, the piezoelectric layer 218 and the first electrode layer 216 disposed below the second frequency trimming structure 224 from being damaged by the alkaline solution used in the subsequent process, thereby improving the yield and reliability of the packaging structure 200. In the embodiment of the present disclosure, on the one hand, the second frequency trimming structure 224 and the piezoelectric layer 218 disposed below the second frequency trimming structure 224 can be prevented from being damaged by the alkaline solution used in the subsequent process, thereby improving the reliability of the resonator; on the other hand, the first electrode layer 216 and the second electrode layer 220 can be prevented from being damaged by the alkaline solution used in the subsequent process, thereby improving the electrical performance of the resonator.

[0062] Furthermore, if the top surface of the second frequency trimming structure 224 is not protected, when an alkaline solution is used in a subsequent process, the alkaline solution will not only corrode the second frequency trimming structure 224, but also pollute the alkaline solution. Thus, the polluting of the alkaline solution will reduce the number of times the alkaline solution can be reused. Therefore, in the embodiment of the present disclosure, the alkaline solution is prevented from reacting with the second frequency trimming structure 224, the piezoelectric layer 218, the first electrode layer 216, or the second electrode layer 220, so that the alkaline solution can be prevented from being contaminated, thereby increasing the number of times the alkaline solution can be reused.

[0063] like Figure 3 As shown, in some embodiments, the packaging structure 200 further includes: a cover plate 238 disposed on a side of the dielectric structure 228 away from the substrate 202, a cavity is formed between the substrate 202, the dielectric structure 228 and the cover plate 238, the resonator 212 is disposed in the cavity, and a gap is provided between the first frequency trimming structure 222 and the cover plate 238. Here, the dielectric structure 228 can be used as a side plate to support the cover plate 238 and form a space surrounding the resonator 212 together with the cover plate 238.

[0064] Here, the material of the dielectric structure 228 may include but is not limited to polyamic acid ester, epoxy resin or polyimide.

[0065] Here, the material of the cover plate 238 may be formed of a non-substrate and non-wafer material. Exemplarily, the material of the cover plate 238 may include, but is not limited to, a dry film, a photoresist film, a photosensitive polymer, an SU8 film, a resin (e.g., an epoxy resin), or a polyimide film, etc. Among them, the SU8 film is an organic polymer colloid formed by dissolving bisphenol A epoxy resin in γ-butyrolactone, and is named because an average of 8 epoxy resins are contained in one molecule.

[0066] like Figure 4 As shown, in some embodiments, the size of the dielectric structure 228 along the Z direction is greater than the size of the pad structure 226 along the Z direction, and the size of the pad structure 226 along the Z direction is greater than the size of the second frequency trimming structure 224 along the Z direction. Exemplarily, the thickness of the dielectric structure 228 may be 21 μm, the thickness of the pad structure 226 may be 2 μm, and the thickness of the second frequency trimming structure 224 may be 0.2 μm.

[0067] In some embodiments, the materials of the first frequency trimming structure 222 and the second frequency trimming structure 224 may include but are not limited to aluminum nitride (AlN), silicon nitride (Si 3 N 4 ) or zinc oxide (ZnO).

[0068] In some embodiments, the material of the pad structure 226 may include but is not limited to gold (Au), aluminum (Al), titanium (Ti), copper (Cu), etc.

[0069] like Figure 4 As shown, in some embodiments, in the non-device area of ​​the packaging structure 200, the second frequency trimming structure 224 has a first opening 230 exposing the first electrode layer 216 or the second electrode layer 220, the pad structure 226 is in contact with the first electrode layer 216 or the second electrode layer 220 through the first opening 230, and the size of the pad structure 226 along the Z direction is larger than the size of the second frequency trimming structure 224 along the Z direction; the size of the pad structure 226 along the X direction is larger than or equal to the size of the first opening 230 along the X direction.

[0070] Here, the size of the pad structure 226 along the X direction may be the same as the size of the first opening 230 along the X direction, and at this time, the sidewall of the pad structure 226 is in contact with the sidewall of the second frequency trimming structure 224, and the pad structure 226 is completely embedded in the second frequency trimming structure 224. In other words, there is no overlapping area between the orthographic projection of the pad structure 226 on the XY plane and the orthographic projection of the second frequency trimming structure 224 on the XY plane. Figure 5 Figures (a) and (c) illustrate that the size of the pad structure along the X direction is the same as the size of the first opening along the X direction.

[0071] Here, the size of the pad structure 226 along the X direction may be greater than the size of the first opening 230 along the X direction. At this time, the sidewall of the pad structure 226 is in contact with the sidewall of the second frequency trimming structure 224, and the pad structure 226 covers a portion of the top surface of the second frequency trimming structure 224, and the pad structure 226 is partially embedded in the second frequency trimming structure 224. In other words, the orthographic projection of the pad structure 226 on the XY plane and the orthographic projection of the second frequency trimming structure 224 on the XY plane have an overlapping area. Figure 5 Figures (b) and (d) illustrate that the size of the pad structure along the X direction is larger than the size of the first opening along the X direction.

[0072] refer to Figure 5 As shown in (a) and (b), in some embodiments, the sidewalls of the dielectric structure 228a (or, the dielectric structure 228b) and the sidewalls of the pad structure 226a (or, the pad structure 226b) are in contact, that is, there is no gap between the dielectric structure 228a (or, the dielectric structure 228b) and the pad structure 226a (or, the pad structure 226b), and there is no overlapping area between the orthographic projection of the dielectric structure 228a (or, the dielectric structure 228b) on the XY plane and the orthographic projection of the pad structure 226a (or, the pad structure 226b) on the XY plane. Figure 5 FIG. (a) shows that the top surface of the second frequency trimming structure 224a is covered by the dielectric structure 228a, and there is no overlapping area between the orthographic projection of the second frequency trimming structure 224a on the XY plane and the orthographic projection of the pad structure 226a on the XY plane. Figure 5 FIG. (b) shows that the top surface of the second frequency trimming structure 224b is covered by the dielectric structure 228b and the pad structure 226b, and there is an overlapping area between the orthographic projection of the second frequency trimming structure 224b and the orthographic projection of the pad structure 226b on the XY plane.

[0073] refer to Figure 5 As shown in Figures (c) and (d), in some embodiments, the dielectric structure 228c (or, the dielectric structure 228d) covers a portion of the top surface of the pad structure 226c (or, the pad structure 226d), that is, there is no gap between the dielectric structure 228c (or, the dielectric structure 228d) and the pad structure 226c (or, the pad structure 226d), and there is an overlapping area between the orthographic projection of the dielectric structure 228c (or, the dielectric structure 228d) on the XY plane and the orthographic projection of the pad structure 226c (or, the pad structure 226d) on the XY plane. Figure 5 The middle figure (c) shows that the top surface of the second frequency trimming structure 224c is covered by the dielectric structure 228c, and there is no overlapping area between the orthographic projection of the second frequency trimming structure 224c on the XY plane and the orthographic projection of the pad structure 226c on the XY plane. Figure 5 The middle figure (d) shows that the top surface of the second frequency trimming structure 224d is covered by the dielectric structure 228d and the pad structure 226d, and there is an overlapping area between the orthographic projection of the second frequency trimming structure 224d on the XY plane and the orthographic projection of the pad structure 226d on the XY plane.

[0074] Further, if there is no overlapping area between the orthographic projections of the dielectric structure and the pad structure on the XY plane, then in the case of errors in the process of forming the dielectric structure and / or the pad structure, a gap may appear between the dielectric structure and the pad structure, and the gap may expose part of the surface of the second frequency-correcting structure. In this way, the second frequency-correcting structure and the second electrode layer, the piezoelectric layer and the first electrode layer disposed below the second frequency-correcting structure may be damaged by the alkaline solution used in the subsequent process. In other words, the second frequency-correcting structure, the second electrode layer, the piezoelectric layer and the first electrode layer are all at risk of being damaged by the alkaline solution. If there is an overlapping area between the orthographic projections of the dielectric structure and the pad structure on the XY plane, then even in the case of errors in the process of forming the dielectric structure and / or the pad structure, the second frequency-correcting structure will not be exposed. In this way, the top surface of the second frequency-correcting structure can be better protected to prevent the second frequency-correcting structure and the second electrode layer, the piezoelectric layer and the first electrode layer disposed below the second frequency-correcting structure from being damaged by the alkaline solution used in the subsequent process.

[0075] refer to Figure 5As shown in (b), in some embodiments, the size of the dielectric structure 228b near the cutting path area in the non-device area along the X direction is L1; the size of the overlapping area between the second frequency trimming structure 224b and the pad structure 226b near the cutting path area in the non-device area along the X direction is L2, that is, the size of the portion of the second frequency trimming structure 224b covered by the pad structure 226b along the X direction is L2; ​​the size of the second frequency trimming structure 224b near the cutting path area in the non-device area along the X direction is L3; wherein, 25μm≤L3≤33μm; and / or, 0μm≤L2≤L3-23μm; and / or, 25μm≤L1≤L3+2μm; and / or, L3≤L1+L2≤L3+2μm.

[0076] Here, the value of L2 can be adjusted. On the premise of satisfying the resonator arrangement in the packaging structure, the larger the value of L2 is, the greater the exposure offset redundancy of the bump formed in the subsequent process.

[0077] In some embodiments, the angle between the sidewall of the second frequency trimming structure 224 and the substrate 202 is less than 90 degrees, that is, the angle between the sidewall of the second frequency trimming structure 224 and the substrate 202 may also be an acute angle. Figure 4 It is shown that the angle between the sidewall of the second frequency trimming structure 224 and the substrate 202 is 90 degrees, that is, the sidewall of the second frequency trimming structure 224 and the substrate are perpendicular to each other. Figure 4 The sidewall of the second frequency trimming structure 224 is only used for exemplary description and does not constitute a limitation on the protection scope of the present disclosure.

[0078] Here, setting the angle between the sidewall of the second frequency trimming structure 224 and the substrate 202 to an acute angle is more conducive to enhancing the contact interface bonding force between the sidewall of the second frequency trimming structure 224 and the pad structure 226 .

[0079] In some embodiments, the sidewall of the second frequency trimming structure 224 may be an inclined plane. In other embodiments, the sidewall of the second frequency trimming structure 224 may also be an inclined curved surface. In still other embodiments, the sidewall of the second frequency trimming structure 224 may also be a segmented inclined surface. Further, in the case where the sidewall of the second frequency trimming structure 224 is a segmented inclined surface, the angle between the portion of the inclined surface of the second frequency trimming structure 224 closest to the substrate 202 and the substrate 202 ranges from 50 to 70 degrees.

[0080] like Figure 4As shown, in some embodiments, the non-device area of ​​the packaging structure 200 may also include: a connection layer 232 (for example, a UBM layer) disposed on the side of the pad structure 226 away from the substrate, that is, the connection layer 232 is disposed on the top surface of the pad structure 226, and the connection layer 232 exposes a portion of the top surface of the pad structure 226; a conductive column 234 disposed on the side of the connection layer 232 away from the pad structure 226, that is, the conductive column 234 is disposed on the top surface of the connection layer 232; a bump 236 (for example, a solder ball) disposed on the side of the conductive column 234 away from the connection layer 232, that is, the bump 236 is disposed on the top surface of the conductive column 234, and the bump 236 is used to lead out the electrical signal of the first electrode layer 216 or the second electrode layer 220.

[0081] Here, the connection layer 232 can be used to improve the bonding force between the pad structure 226 and the conductive pillar 234 and the bump 236. Since the top surface of the second frequency trimming structure 224 is protected by the dielectric structure 228 or the top surface of the second frequency trimming structure 224 is protected by the dielectric structure 228 and the pad structure 226, even if an alkaline solution is used in the process of forming the connection layer 232, the alkaline solution will not damage the second frequency trimming structure 224 and the second electrode layer 220, the piezoelectric layer 218 and the first electrode layer 216 disposed below the second frequency trimming structure 224, thereby improving the yield and reliability of the packaging structure 200.

[0082] refer to Figure 5 As shown in FIG. (a), in some embodiments, the sidewalls of the portion of the second frequency trimming structure 224a near the cutting path region in the non-device region 210 and the sidewalls of the dielectric structure 228a are aligned along the Z direction, that is, the sidewalls of the portion of the second frequency trimming structure 224a near the cutting path region in the non-device region 210 are exposed. Here, an alkaline solution is used in the process of forming the connection layer, and a small amount of the alkaline solution may flow down along the sidewalls of the dielectric structure 228a and the sidewalls of the second frequency trimming structure 224a near the cutting path region in the non-device region (such as Figure 5 If the sidewall of the second frequency trimming structure 224a is exposed, the sidewall of the second frequency trimming structure 224a may come into contact with the alkaline solution and be corroded by the alkaline solution. The alkaline solution will not only damage the second frequency trimming structure 224a, but also cause the alkaline solution itself to be contaminated, thereby reducing the number of times the alkaline solution can be reused. Figure 5 Figures (b), (c) and (d) also illustrate that the sidewalls of a portion of the second frequency trimming structure near the cutting line area in the non-device area and the sidewalls of the dielectric structure are aligned along the Z direction.

[0083] refer to Figure 4As shown, in other embodiments, the sidewalls of the part of the second frequency trimming structure 224 near the cutting path area in the non-device area are covered by the dielectric structure 228, that is, the sidewalls of the part of the second frequency trimming structure 224 near the cutting path area in the non-device area are not exposed. Here, even if an alkaline solution is used in the process of forming the connection layer, a small amount of the alkaline solution flows down along the sidewalls of the dielectric structure 228 near the cutting path area in the non-device area, and the alkaline solution will not contact the second frequency trimming structure 224 to cause damage to the second frequency trimming structure 224, and the number of times the alkaline solution can be reused can also be increased.

[0084] refer to Figure 6 , Figure 6 A partial cross-sectional view of a packaging structure provided by some other embodiments of the present disclosure. Figure 6 As shown, the packaging structure 300 may include: a second frequency trimming structure 324 disposed on a side of the second electrode layer away from the substrate, that is, the second frequency trimming structure 324 is disposed on the top surface of the second electrode layer, and a pad structure 326 disposed on the top surface of the first electrode layer or the top surface of the second electrode layer, the second frequency trimming structure 324 and the pad structure 326 are disposed adjacent to each other, and the pad structure 326 is at least partially embedded in the second frequency trimming structure 324; a dielectric structure 328 disposed on the top surface of the second frequency trimming structure 324, the dielectric structure 328 exposes at least a portion of the top surface of the pad structure 326; wherein, in the non-device area, the orthographic projection of the second frequency trimming structure 324 on the XY plane is within the sum of the orthographic projection ranges of the dielectric structure 328 and the pad structure 326 on the XY plane, that is, the orthographic projection range of the second frequency trimming structure 324 on the XY plane is smaller than the sum of the orthographic projection ranges of the dielectric structure 328 and the pad structure 326 on the XY plane.

[0085] Here, the first frequency-modifying structure in the device region and the second frequency-modifying structure 324 in the non-device region together form a frequency-modifying structure, and the first frequency-modifying structure and the second frequency-modifying structure 324 can be formed in the same process, and the difference between the first frequency-modifying structure and the second frequency-modifying structure 324 is that they are arranged at different positions in the chip region. The first frequency-modifying structure and the second frequency-modifying structure 324 both have a bottom surface close to the substrate and a top surface away from the substrate; wherein, in the device region, the bottom surface of the first frequency-modifying structure at least contacts the top surface of the second electrode layer; in the non-device region, the bottom surface of the second frequency-modifying structure 324 at least contacts the top surfaces of the second electrode layer and the piezoelectric layer.

[0086] Here, the pad structure 326 has a bottom surface close to the substrate and a top surface away from the substrate. The bottom surface of the pad structure 326 is in contact with the first electrode layer or the second electrode layer. When the pad structure 326 is in contact with the first electrode layer, it is used to draw out the electrical signal of the first electrode layer; when the pad structure 326 is in contact with the second electrode layer, it is used to draw out the electrical signal of the second electrode layer. When the second frequency-correcting structure 324 and the pad structure 326 are arranged adjacent to each other, it can also be regarded as the second frequency-correcting structure 324 being in contact with the second electrode layer through the second opening between the adjacent pad structures 326, that is, the second frequency-correcting structure 324 is at least partially embedded between the adjacent pad structures 326.

[0087] Here, the dielectric structure 328 has a bottom surface close to the substrate and a top surface away from the substrate. The bottom surface of the dielectric structure 328 is in contact with the top surface of the second frequency trimming structure 324, or the bottom surface of the dielectric structure 328 is in contact with the top surface of the second frequency trimming structure 324 and the top surface of the pad structure 326 at the same time.

[0088] In the embodiment of the present disclosure, in the non-device area, the orthographic projection of the second frequency trimming structure 324 on the XY plane is within the orthographic projection range of the dielectric structure 328 on the XY plane, that is, the orthographic projection range of the second frequency trimming structure 324 on the XY plane is smaller than the orthographic projection range of the dielectric structure 328 on the XY plane. In other words, the top surface of the second frequency trimming structure 324 in the non-device area is covered by the dielectric structure 328, that is, the second frequency trimming structure 324 in the non-device area is protected by the dielectric structure 328, effectively preventing the second frequency trimming structure 324 and the second electrode layer, the piezoelectric layer and the first electrode layer disposed below the second frequency trimming structure 324 from being damaged by the alkaline solution used in the subsequent process, thereby improving the yield and reliability of the packaging structure 300. In the embodiment of the present disclosure, on the one hand, the second frequency trimming structure 324 and the piezoelectric layer disposed below the second frequency trimming structure 324 can be prevented from being damaged by the alkaline solution used in the subsequent process, thereby improving the reliability of the resonator; on the other hand, the first electrode layer and the second electrode layer can be prevented from being damaged by the alkaline solution used in the subsequent process, thereby improving the electrical performance of the resonator.

[0089] Furthermore, if the top surface of the second frequency trimming structure 324 is not protected, when an alkaline liquid is used in a subsequent process, the alkaline liquid will corrode the second frequency trimming structure 324 and contaminate the alkaline liquid. Thus, contamination of the alkaline liquid will reduce the number of times the alkaline liquid can be reused. Therefore, in the embodiment of the present disclosure, the alkaline liquid is prevented from reacting with the second frequency trimming structure 324, the piezoelectric layer, the first electrode layer, or the second electrode layer, so that contamination of the alkaline liquid can be avoided, thereby increasing the number of times the alkaline liquid can be reused.

[0090] Here, the materials of the first frequency trimming structure, the second frequency trimming structure, the pad structure and the dielectric structure can refer to the relevant text description in the above embodiments, which will not be repeated here.

[0091] like Figure 6 As shown, in some embodiments, in the non-device area of ​​the packaging structure 300, there is a second opening 330 exposing the second electrode layer between adjacent pad structures 326, and the second frequency trimming structure 324 is in contact with the second electrode layer through the second opening 330. The second frequency trimming structure 324 includes a first portion 338 in contact with the second electrode layer and a second portion 340 in contact with the side wall of the pad structure 326.

[0092] Here, the second frequency trimming structure 324 includes a first portion 338 covering between adjacent pad structures 326 and a second portion 340 covering the sidewalls of the pad structures 326. At this time, all of the pad structures 326 are embedded in the second frequency trimming structure 324.

[0093] Here, the second trimming structure 324 may include a first portion 338 covering between adjacent pad structures 326, a second portion 340 covering the sidewalls of the pad structure 326, and a third portion 342 covering a portion of the top surface of the pad structure 326. At this time, the pad structure 326 is partially embedded in the second trimming structure 324. In other words, the orthographic projection of the pad structure 326 on the XY plane and the orthographic projection of the second trimming structure 324 on the XY plane have an overlapping area. Figure 6 It is illustrated that there is an overlapping area between the orthographic projection of the pad structure 326 on the XY plane and the orthographic projection of the second frequency correction structure 324 on the XY plane.

[0094] Figure 7 Figures (a) and (b) are partial cross-sectional views of the second frequency trimming structure, the pad structure, and the dielectric structure in the packaging structure provided in some other embodiments of the present disclosure. Figure 7 As shown in FIG. (a), in some embodiments, the dielectric structure 328a covers the first portion 338a and the second portion 340a of the second frequency trimming structure 324a; the orthographic projection of the second frequency trimming structure 324a on the XY plane coincides with the orthographic projection of the dielectric structure 328a on the XY plane, that is, there is no overlapping area between the orthographic projection of the dielectric structure 328a (or, the second frequency trimming structure 324a) on the XY plane and the orthographic projection of the pad structure 326a on the XY plane. Here, there is no gap between the dielectric structure 328a and the pad structure 326a, and the surface of the second frequency trimming structure 324a is covered by the dielectric structure 328a. At this time, there is no overlapping area between the orthographic projection of the pad structure 326a on the XY plane and the orthographic projection of the second frequency trimming structure 324a on the XY plane.

[0095] refer to Figure 7As shown in the middle (b) figure, the dielectric structure 328b covers the first part 338b and the second part 340b of the second frequency-correcting structure 324b; the orthographic projection of the second frequency-correcting structure 324b on the XY plane is within the orthographic projection range of the dielectric structure 328b on the XY plane, that is, the orthographic projection range of the second frequency-correcting structure 324b on the XY plane is smaller than the orthographic projection range of the dielectric structure 328b on the XY plane, that is, there is an overlapping area between the orthographic projection of the dielectric structure 328b on the XY plane and the orthographic projection of the pad structure 326b on the XY plane. Here, there is no gap between the dielectric structure 328b and the pad structure 326b, and the surface of the second frequency-correcting structure 324b is covered by the dielectric structure 328b. At this time, there is no overlapping area between the orthographic projection of the pad structure 326b on the XY plane and the orthographic projection of the second frequency-correcting structure 324b on the XY plane.

[0096] Still Figure 6 As shown, in some embodiments, the second frequency trimming structure 324 further includes a third portion 342 that contacts a portion of the top surface of the pad structure 326; the dielectric structure 328 covers the first portion 338, the second portion 340, and the third portion 342 of the second frequency trimming structure 324; the orthographic projection of the second frequency trimming structure 324 on XY is within the orthographic projection range of the dielectric structure 328 on XY, that is, the orthographic projection range of the second frequency trimming structure 324 on XY is smaller than the orthographic projection range of the dielectric structure 328 on XY. The dielectric structure 328 covers the sidewall of the third portion 342 of the second frequency trimming structure 324, that is, the orthographic projection of the dielectric structure 328 on the XY plane and the orthographic projection of the pad structure 326 on the XY plane have an overlapping area. Here, there is no gap between the dielectric structure 328 and the pad structure 326, and the surface of the second frequency trimming structure 324 is covered by the dielectric structure 328.

[0097] Further, if there is no overlapping area between the orthographic projections of the dielectric structure and the pad structure on the XY plane, then in the case where there is an error in the process of forming the dielectric structure and / or the pad structure, a gap may appear between the dielectric structure and the pad structure, and the gap may expose part of the surface of the second frequency correction structure. In this way, the second frequency correction structure and the second electrode layer, the piezoelectric layer and the first electrode layer disposed below the second frequency correction structure may be damaged by the alkaline solution used in the subsequent process. If there is an overlapping area between the orthographic projections of the dielectric structure and the pad structure on the XY plane, then even if there is an error in the process of forming the dielectric structure and / or the pad structure, the second frequency correction structure will not be exposed. In this way, the top surface of the second frequency correction structure can be better protected to prevent the second frequency correction structure and the second electrode layer, the piezoelectric layer and the first electrode layer disposed below the second frequency correction structure from being damaged by the alkaline solution used in the subsequent process.

[0098] like Figure 6As shown, in some embodiments, the non-device area of ​​the packaging structure 300 may also include: a connection layer 332 (for example, a UBM layer) disposed on the side of the pad structure 326 away from the substrate, that is, the connection layer 332 is disposed on the top surface of the pad structure 326, and the connection layer 332 exposes a portion of the top surface of the pad structure 326 away from the substrate; a conductive column 334 disposed on the side of the connection layer 332 away from the pad structure 326, that is, the conductive column 334 is disposed on the top surface of the connection layer 332; a bump 336 (for example, a solder ball) disposed on the side of the conductive column 334 away from the connection layer, that is, the bump 336 is disposed on the top surface of the conductive column 334, and the bump 336 is used to lead out the electrical signal of the first electrode layer or the second electrode layer.

[0099] Here, the connection layer 332 can be used to improve the bonding force between the pad structure 326 and the conductive pillar 334 and the bump 336. Since the top surface of the second frequency trimming structure 324 is protected by the dielectric structure 328, even if an alkaline solution is used in the process of forming the connection layer 332, the alkaline solution will not damage the second frequency trimming structure 324 and the second electrode layer, the piezoelectric layer and the first electrode layer disposed below the second frequency trimming structure 324, thereby improving the yield and reliability of the packaging structure 300.

[0100] like Figure 6 As shown, in some embodiments, the size of the overlapping area between the dielectric structure 328 and the pad structure 326 near the cutting line area in the non-device area along the X direction is L4; the size of the overlapping area between the second frequency trimming structure 324 and the pad structure 326 near the cutting line area in the non-device area along the X direction is L5, that is, the size of the part of the pad structure 326 covered by the second frequency trimming structure 324 along the X direction is L5; the size of the distance between the dielectric structure 328 and the connection layer 332 along the X direction is L6; wherein, 0μm<L4-L5; and / or, 2μm≤L5; and / or, 0μm≤L6. Optionally, 5μm≤L6.

[0101] refer to Figure 7 As shown in FIG. (a), in some embodiments, the sidewalls of the portion of the second frequency trimming structure 324a near the cutting path region in the non-device region and the sidewalls of the dielectric structure 328a are aligned along the Z direction, that is, the sidewalls of the portion of the second frequency trimming structure 324a near the cutting path region in the non-device region are exposed. Here, an alkaline solution is used in the process of forming the connection layer, and a small amount of the alkaline solution may flow down along the sidewalls of the dielectric structure 328a and the second frequency trimming structure 324a near the cutting path region in the non-device region (such as Figure 7If the sidewall of the second frequency trimming structure 324a is exposed, the sidewall of the second frequency trimming structure 324a may come into contact with the alkaline solution and be corroded by the alkaline solution. The alkaline solution will not only damage the second frequency trimming structure 324a, but also cause the alkaline solution itself to be contaminated, thereby reducing the number of times the alkaline solution can be reused. Figure 7 FIG. (b) also shows that the sidewalls of a portion of the second frequency trimming structure 324b and the sidewalls of the dielectric structure 328b in the non-device region near the scribe line region are aligned along the Z direction.

[0102] refer to Figure 6 As shown, in other embodiments, the sidewalls of the part of the second frequency trimming structure 324 near the cutting path area in the non-device area are covered by the dielectric structure 328, that is, the sidewalls of the part of the second frequency trimming structure 324 near the cutting path area in the non-device area are not exposed. Here, even if an alkaline solution is used in the process of forming the connection layer, a small amount of the alkaline solution flows down along the sidewalls of the dielectric structure 328 near the cutting path area in the non-device area, and the alkaline solution will not contact the second frequency trimming structure 324, causing damage to the second frequency trimming structure 324, and at the same time, the number of times the alkaline solution can be reused can be increased.

[0103] refer to Figure 8 , Figure 8 Schematic diagram of a process for manufacturing a packaging structure provided by an embodiment of the present disclosure. Figure 8 As shown, an embodiment of the present disclosure provides a method for manufacturing a packaging structure, the packaging structure comprising: a device region and a non-device region arranged on one side of a substrate, the non-device region being arranged on at least one side of the device region; the manufacturing method comprises:

[0104] Step S810: forming a reflective structure, a first electrode layer, a piezoelectric layer and a second electrode layer stacked in sequence on a substrate;

[0105] Step S820: forming a frequency-modifying structure and a pad structure on a side of the second electrode layer away from the substrate; the frequency-modifying structure includes a first frequency-modifying structure arranged in the device area and a second frequency-modifying structure arranged in the non-device area, and the second frequency-modifying structure is in contact with the second electrode layer; the pad structure is arranged in the non-device area, the pad structure is in contact with the first electrode layer or the second electrode layer, the second frequency-modifying structure and the pad structure are arranged adjacent to each other in the non-device area, and the pad structure is at least partially embedded in the second frequency-modifying structure; the device area includes at least one resonator, and the at least one resonator includes a substrate, a reflective structure, a first electrode layer, a piezoelectric layer, a second electrode layer and a first frequency-modifying structure which are sequentially stacked;

[0106] Step S830: forming a dielectric structure on a side of the second frequency trimming structure away from the substrate, wherein the dielectric structure exposes at least a portion of the surface of the pad structure away from the substrate; wherein, in the non-device area, the orthographic projection of the second frequency trimming structure on the substrate is within the sum of the orthographic projection ranges of the dielectric structure and the pad structure on the substrate.

[0107] Here, in step S810, a reflective structure, a first electrode layer, a piezoelectric layer and a second electrode layer are sequentially stacked on a substrate. The substrate, the reflective structure, the first electrode layer, the piezoelectric layer and the second electrode layer in the device region together form a resonator.

[0108] Here, in step S820, a frequency trimming structure and a pad structure are formed on the side of the second electrode layer away from the substrate, and the frequency trimming structure may include a first frequency trimming structure disposed in the device region and a second frequency trimming structure disposed in the non-device region. Figure 4 and Figure 5 As shown, in some embodiments, a frequency trimming structure may be formed first on the side of the second electrode layer away from the substrate, and then a pad structure may be formed. Figure 6 and Figure 7 As shown, in some other embodiments, a pad structure may be formed first on the side of the second electrode layer away from the substrate, and then the frequency trimming structure may be formed.

[0109] Fig. 9 Figures (a), (b), (c) and (d) are cross-sectional schematic diagrams of the packaging structure provided by the embodiment of the present disclosure during the manufacturing process. Fig. 9 , explains in detail how to form Figure 4 The package structure shown.

[0110] like Fig. 9 As shown in FIG. (a), a frequency-modifying material layer is formed on the top surface of the second electrode layer; the frequency-modifying material layer is etched to form a first frequency-modifying structure in the device region and a second frequency-modifying structure in the non-device region. In the non-device region, the second frequency-modifying structure 424 has a first opening 430 exposing the first electrode layer or the second electrode layer.

[0111] like Fig. 9 As shown in FIG. 5( b ), a pad material layer is formed to cover the second frequency trimming structure 424 and the second electrode layer exposed by the first opening 430 ; the pad material layer is etched to form a pad structure 426 , and the pad structure 426 contacts the first electrode layer or the second electrode layer through the first opening 430 .

[0112] In some embodiments, the size of the pad structure 426 along the X direction is 110 μm, and the distance between adjacent pad structures 426 is 70 μm.

[0113] like Fig. 9As shown in FIG. 5( c ), a dielectric material layer is formed to cover the second frequency trimming structure 424 and the pad structure 426 ; the dielectric material layer is etched to form a dielectric structure 428 , and the dielectric structure 428 is in contact with the second frequency trimming structure 424 , or the dielectric structure 428 is in contact with the second frequency trimming structure 424 and the pad structure 426 at the same time.

[0114] In some embodiments, the dimension of the dielectric structure 428 along the X direction is 80 μm, and the distance between adjacent dielectric structures 428 is 100 μm.

[0115] like Fig. 9 As shown in Figure (d), in some embodiments, the manufacturing method further includes: forming a connection material layer covering the dielectric structure 428 and the pad structure 426 in the non-device area; etching the connection material layer to form a connection layer 432 that exposes a portion of the surface of the pad structure 426 away from the substrate. At this time, since the pad structure 426 and the dielectric structure 428 jointly cover the top surface of the second frequency trimming structure 424, even if an alkaline solution is used to remove part of the connection material layer, the alkaline solution will not contact the second frequency trimming structure 424. A conductive column 434 is formed on the top surface of the connection layer 432 in the non-device area; a bump 436 is formed on the top surface of the conductive column 434 in the non-device area, and the bump 436 is used to lead out the electrical signal of the first electrode layer or the second electrode layer.

[0116] The embodiment of the present disclosure provides a packaging structure and a manufacturing method thereof. In the embodiment of the present disclosure, at least one resonator is provided in the device region of the packaging structure, and a second frequency-correcting structure and a pad structure are provided in the non-device region of the packaging structure. The second frequency-correcting structure is in contact with the second electrode layer, and the pad structure is in contact with the first electrode layer or the second electrode layer, and the pad structure is at least partially embedded in the second frequency-correcting structure. A dielectric structure is also provided in the non-device region, and the dielectric structure covers the second frequency-correcting structure and exposes at least part of the surface of the pad structure; in the non-device region, the orthographic projection of the second frequency-correcting structure on the substrate is within the sum of the orthographic projection ranges of the dielectric structure and the pad structure on the substrate. In this way, the surface of the second frequency-correcting structure in the non-device region is covered by the dielectric structure or the second frequency-correcting structure in the non-device region is covered by the dielectric structure and the pad structure, that is, the second frequency-correcting structure in the non-device region is protected by the dielectric structure or the second frequency-correcting structure in the non-device region is protected by the dielectric structure and the pad structure, effectively preventing the second frequency-correcting structure and the second electrode layer, the piezoelectric layer and the first electrode layer arranged below the second frequency-correcting structure from being damaged by the alkaline solution used in the subsequent process, thereby improving the yield and reliability of the packaging structure.

[0117] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present disclosure. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present disclosure, the size of the serial number of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure. The serial numbers of the embodiments of the present disclosure are for description only and do not represent the advantages and disadvantages of the embodiments.

[0118] The above description is only a preferred embodiment of the present disclosure, and does not limit the patent scope of the present disclosure. All equivalent structural changes made by using the contents of the present disclosure and the drawings under the inventive concept of the present disclosure, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present disclosure.

Claims

1. A packaging structure, characterized in that: The packaging structure comprises: a device region and a non-device region arranged on one side of the substrate, wherein the non-device region is arranged on at least one side of the device region; The device region includes at least one resonator, and the at least one resonator includes: the substrate, the reflection structure, the first electrode layer, the piezoelectric layer, the second electrode layer and the first frequency modification structure which are stacked in sequence; The non-device area includes: a second frequency trimming structure provided on a side of the second electrode layer away from the substrate, and a pad structure provided on a side of the first electrode layer or the second electrode layer away from the substrate, the second frequency trimming structure and the pad structure are arranged adjacent to each other, and the pad structure is at least partially embedded in the second frequency trimming structure; A dielectric structure is arranged on a side of the second frequency trimming structure away from the substrate, the dielectric structure exposing at least a portion of the surface of the pad structure away from the substrate; wherein, in the non-device area, the orthographic projection of the second frequency trimming structure on the substrate is within the sum of the orthographic projection ranges of the dielectric structure and the pad structure on the substrate.

2. The packaging structure according to claim 1, characterized in that: The non-device area surrounds the device area, and the device area and the non-device area together form a chip area; The packaging structure further includes: a scribe line region disposed on one side of the substrate and surrounding the chip region.

3. The packaging structure according to claim 2, characterized in that: In the non-device area, the second frequency-modifying structure has a first opening exposing the first electrode layer or the second electrode layer, the pad structure is in contact with the first electrode layer or the second electrode layer through the first opening, and the size of the pad structure along the stacking direction is larger than the size of the second frequency-modifying structure along the stacking direction; the size of the pad structure along a direction parallel to the substrate is larger than or equal to the size of the first opening along a direction parallel to the substrate.

4. The packaging structure according to claim 3, characterized in that: The sidewall of the dielectric structure is in contact with the sidewall of the pad structure, and there is no overlapping area between the orthographic projection of the dielectric structure on the substrate and the orthographic projection of the pad structure on the substrate.

5. The packaging structure according to claim 3, characterized in that: The dielectric structure covers a portion of the surface of the pad structure away from the substrate, and an orthographic projection of the dielectric structure on the substrate and an orthographic projection of the pad structure on the substrate have an overlapping area.

6. The packaging structure according to claim 3, characterized in that: The dimension of the dielectric structure near the cutting path area in the non-device area along the direction parallel to the substrate is L1, the dimension of the overlapping area between the second frequency trimming structure near the cutting path area in the non-device area and the pad structure along the direction parallel to the substrate is L2, and the dimension of the second frequency trimming structure near the cutting path area in the non-device area along the direction parallel to the substrate is L3; wherein, 25μm≤L3≤33μm; and / or, 0μm≤L2≤L3-23μm; and / or, 25μm≤L1≤L3+2μm; and / or, L3≤L1+L2≤L3+2μm.

7. The packaging structure according to claim 2, characterized in that: In the non-device area, there is a second opening between adjacent pad structures to expose the second electrode layer, the second frequency trimming structure is in contact with the second electrode layer through the second opening, and the second frequency trimming structure includes a first portion in contact with the second electrode layer and a second portion in contact with the side wall of the pad structure.

8. The packaging structure according to claim 7, characterized in that: The dielectric structure covers the first part and the second part of the second frequency-modifying structure; the orthographic projection of the second frequency-modifying structure on the substrate coincides with the orthographic projection of the dielectric structure on the substrate; Alternatively, the orthographic projection of the second frequency correction structure on the substrate is located within the orthographic projection range of the dielectric structure on the substrate.

9. The packaging structure according to claim 7, characterized in that: The second frequency trimming structure also includes a third part that contacts a portion of the surface of the pad structure away from the substrate; the dielectric structure covers the first part, the second part and the third part of the second frequency trimming structure; and the orthographic projection of the second frequency trimming structure on the substrate is within the orthographic projection range of the dielectric structure on the substrate.

10. The packaging structure according to claim 7, characterized in that: The dimension of the overlapping area between the dielectric structure and the pad structure near the cutting path area in the non-device area along the direction parallel to the substrate is L4, and the dimension of the overlapping area between the second frequency-modifying structure and the pad structure near the cutting path area in the non-device area along the direction parallel to the substrate is L5; wherein, 0μm<L4-L5; and / or, 2μm≤L5.

11. The packaging structure according to any one of claims 2 to 10, characterized in that: The sidewall of the second frequency trimming structure in the non-device area close to the scribe line area and the sidewall of the dielectric structure are aligned along the stacking direction; or, A portion of the sidewall of the second frequency trimming structure in the non-device area close to the scribe line area is covered by the dielectric structure.

12. The packaging structure according to claim 11, characterized in that: The non-device area also includes: A connection layer provided on a side of the pad structure away from the substrate, the connection layer exposing a portion of the surface of the pad structure away from the substrate; A conductive column disposed on a side of the connection layer away from the pad structure; A bump is provided on a side of the conductive column away from the connecting layer, and the bump is used to lead out an electrical signal of the first electrode layer or the second electrode layer.

13. The packaging structure according to claim 1, characterized in that: An angle between a sidewall of the second frequency trimming structure and the substrate is less than 90 degrees.

14. The packaging structure according to claim 1, characterized in that: The packaging structure further includes: A cover plate is arranged on a side of the dielectric structure away from the substrate, a cavity is formed between the substrate, the dielectric structure and the cover plate, the resonator is arranged in the cavity and a gap is provided between the first frequency trimming structure and the cover plate.

15. A method for manufacturing a packaging structure, characterized in that: The packaging structure comprises: a device region and a non-device region arranged on one side of a substrate, wherein the non-device region is arranged on at least one side of the device region; and the manufacturing method comprises: Forming a reflective structure, a first electrode layer, a piezoelectric layer, and a second electrode layer stacked in sequence on the substrate; A frequency-modifying structure and a pad structure are formed on the side of the second electrode layer away from the substrate; the frequency-modifying structure includes a first frequency-modifying structure arranged in the device area and a second frequency-modifying structure arranged in the non-device area, and the second frequency-modifying structure is in contact with the second electrode layer; the pad structure is arranged in the non-device area, and the pad structure is in contact with the first electrode layer or the second electrode layer, and the second frequency-modifying structure and the pad structure are arranged adjacent to each other in the non-device area, and the pad structure is at least partially embedded in the second frequency-modifying structure; the device area includes at least one resonator, and the at least one resonator includes the substrate, the reflective structure, the first electrode layer, the piezoelectric layer, the second electrode layer, and the first frequency-modifying structure, which are sequentially stacked; A dielectric structure is formed on a side of the second frequency trimming structure away from the substrate, and the dielectric structure exposes at least a portion of the surface of the pad structure away from the substrate; wherein, in the non-device area, the orthographic projection of the second frequency trimming structure on the substrate is within the sum of the orthographic projection ranges of the dielectric structure and the pad structure on the substrate.

16. The manufacturing method according to claim 15, characterized in that: The manufacturing method further comprises: forming a connection material layer covering the dielectric structure and the pad structure in the non-device area; Etching the connection material layer to form a connection layer exposing a portion of the surface of the pad structure away from the substrate; Forming a conductive column on a side of the connection layer away from the pad structure in the non-device area; A bump is formed on a side of the conductive column away from the connection layer in the non-device region, and the bump is used to lead out an electrical signal from the first electrode layer or the second electrode layer.

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