Packaging structure of bulk acoustic wave resonator and oscillator

Abstract

The invention relates to the field of semiconductor devices and provides a packaging structure of a bulk acoustic wave resonator and an oscillator. The packaging structure comprises a bulk acoustic wave resonator, a first substrate and a second substrate, the first substrate and the second substrate clamp the bulk acoustic wave resonator in a first direction, the packaging structure further comprises a connecting part electrically connected with an external element, and the connecting part is arranged in a central area of a first surface, away from the second substrate, of the first substrate. The central area is an area within a preset range with the geometric center of the first surface as the center. According to the bulk acoustic wave resonator, the connecting part electrically connected with the external element is arranged in the central area of the packaging structure, even if the external element is strained due to stress, the stress coupled to the packaging structure is small, and therefore the stability and reliability of the bulk acoustic wave resonator are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor devices, and in particular to a packaging structure of a bulk acoustic wave resonator and an oscillator. Background Art

[0002] In the field of chip packaging technology, welding processes are usually used to electrically connect chips. For example, a chip containing a bulk acoustic wave resonator is generally connected to the electrical connection layer of another chip through an electrical connection layer on the surface of the chip via solder balls to achieve the corresponding function.

[0003] Flip-Chip packaging is a common chip packaging process. Figure 1 As shown, chip D10 includes an acoustic device R10, a substrate 100 and a substrate 160. When a flip-chip packaging process is adopted, the acoustic device R10 is usually carried on the substrate 100, and the other substrate 160 serves as a cover to protect the acoustic device R10. The acoustic device R10 is electrically connected to the metal layers 201-1 and 201-2 of the chip 200 through the metal layers 161-1 and 161-2 arranged on the surface of the substrate 160 via the solder balls 171-1 and 171-2. The metal layers 161-1 and 161-2, the solder balls 171-1 and 171-2 and the metal layers 201-1 and 201-2 constitute the connection between the chip D10 and the chip 200.

[0004] In order to avoid electrical signal crosstalk between the connecting parts, avoid short circuits between the connecting parts caused by the manufacturing process, and to make the acoustic device R10 more mechanically stable, the interval between the electrical connecting parts is usually increased as much as possible, for example, Figure 1 As shown, a connection portion composed of a metal layer 161-1, a solder ball 171-1, and a metal layer 201-1 and a connection portion composed of a metal layer 161-2, a solder ball 171-2, and a metal layer 201-2 are respectively provided on both sides of the acoustic device R10.

[0005] This section is intended to provide a background or context to the embodiments of the present application as recited in the claims. No description herein is admitted to be prior art by inclusion in this section. Summary of the invention

[0006] The inventors found that the connection parts arranged on both sides of the acoustic device R10 have a large interval, which limits the overall freedom of the chip D10 and the chip 200. When the chip 200 is affected by the external environment and generates stress and deforms, the stress and deformation will be coupled to the chip D10 through the connection parts. Usually, the strain in the chip or substrate is bending strain, for example, Figure 2As shown, when the chip 200 bends downward, since the freedom of chip D10 is restricted by the connecting parts on both sides, the stress will be coupled to the chip D10 through the connecting parts, causing D10 to bend and deform together. When the deformation is large, the connecting parts will be damaged, thereby reducing the frequency stability and reliability of the bulk acoustic wave resonator R10 in the chip D10.

[0007] In order to solve at least one of the above problems or other similar problems, embodiments of the present application provide a packaging structure of a bulk acoustic wave resonator and an oscillator.

[0008] According to a first aspect of an embodiment of the present application, a packaging structure of a bulk acoustic wave resonator is provided, the packaging structure comprising a bulk acoustic wave resonator and a first substrate and a second substrate sandwiching the bulk acoustic wave resonator in a first direction, the packaging structure further comprising a connection portion electrically connected to an external element, the connection portion being arranged in a central area of ​​a first surface of the first substrate away from the second substrate, the central area being an area within a predetermined range centered on a geometric center of the first surface.

[0009] According to a second aspect of the embodiments of the present application, an oscillator is provided, comprising a packaging structure of the BAW resonator according to the embodiment of the first aspect; and an integrated circuit chip electrically coupled to the connection portion of the packaging structure.

[0010] One of the beneficial effects of the embodiments of the present application is that by arranging the connection portion electrically connected to the external element in the central area of ​​the packaging structure, even if the external element is strained due to stress, the stress coupled to the packaging structure is small, thereby improving the stability and reliability of the bulk acoustic wave resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 It is a schematic diagram of a chip packaging structure in the prior art.

[0013] Figure 2 yes Figure 1 A schematic diagram of the chip packaging structure generating strain is shown.

[0014] Figure 3 It is a schematic diagram of the chip packaging structure of an embodiment of the present application.

[0015] Figure 4 It is a schematic diagram of the central area of ​​an embodiment of the present application.

[0016] Figure 5 is another schematic diagram of the central area of ​​an embodiment of the present application.

[0017] Figure 6 It is a schematic diagram of the chip packaging structure of the embodiment of the present application being subjected to stress and generating strain.

[0018] Figure 7 It is a schematic diagram of an implementation of a packaging structure of a BAW resonator according to an embodiment of the present application.

[0019] Figure 8 is included Figure 7 A schematic diagram of a chip packaging structure of a BAW resonator packaging structure is shown.

[0020] Fig. 9 yes Figure 7 A top view of the packaging structure of a BAW resonator is shown.

[0021] Fig.10 It is a schematic diagram of an implementation of a packaging structure of a BAW resonator according to an embodiment of the present application.

[0022] Fig.11 yes Fig.10 A top view of the packaging structure of a BAW resonator is shown.

[0023] Fig.12 It is a top view of an implementation of a packaging structure of a bulk acoustic wave resonator according to an embodiment of the present application.

[0024] Fig.13 It is a top view of another implementation of the packaging structure of the BAW resonator according to the embodiment of the present application.

[0025] Fig.14 It is a top view of another implementation of the packaging structure of the BAW resonator according to the embodiment of the present application.

[0026] Fig.15 It is a top view of another implementation of the packaging structure of the BAW resonator according to the embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application more clear, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not intended to limit the present application.

[0028] In the embodiments of the present application, the terms "first", "second", "upper", "lower", etc. are used to distinguish different elements in terms of title, but do not indicate the spatial arrangement or time order of these elements, etc., and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having", etc. refer to the presence of the stated features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.

[0029] In the embodiments of the present application, the singular forms "a", "the", etc. include plural forms and should be broadly understood as "a kind" or "a type" rather than being limited to the meaning of "one"; in addition, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. In addition, the term "according to" should be understood as "at least in part according to...", and the term "based on" should be understood as "at least in part based on...", unless the context clearly indicates otherwise.

[0030] Embodiments of the first aspect

[0031] An embodiment of a first aspect of the present application provides a packaging structure of a bulk acoustic wave resonator, which can be applied to a chip packaging structure. Figure 3 is a schematic diagram of a chip packaging structure according to an embodiment of the present application, Figure 4 is a schematic diagram of the central area of ​​an embodiment of the present application, Figure 5 is another schematic diagram of the central area of ​​an embodiment of the present application.

[0032] like Figure 3 As shown, the chip packaging structure 3 may include a packaging structure 30 of a bulk acoustic wave resonator (hereinafter sometimes referred to as "packaging structure 30") and a chip 40. For example, the chip 40 may be an integrated circuit chip. The chip 40, for example, includes conductive layers 401 and 402. The conductive part 50, for example, includes a first conductive part 501 and a second conductive part 502. The packaging structure 30 is electrically connected to the conductive layers 401 and 402 of the chip 40 through the first conductive part 501 and the second conductive part 502. The conductive part 50 is, for example, a solder ball, a copper pillar bump, etc., which is not limited in the embodiments of the present application.

[0033] In at least one embodiment, Figure 3As shown, the package structure 30 includes a BAW resonator 300, a first substrate 310, a second substrate 320 and a connection portion 330. The first substrate 310 and the second substrate 320 sandwich the BAW resonator 300 in a first direction z. The connection portion 330 is used to electrically connect to an external element. For example, the connection portion 330 can be electrically connected to the chip 40 through a conductive portion 50. In addition, in the embodiment of the present application, the first direction z, the second direction x and the third direction y are perpendicular to each other. In addition, the size of each part in the first direction z is recorded as "thickness", the size of each part in the second direction x is recorded as "length", and the size of each part in the third direction y is recorded as "width".

[0034] In at least one embodiment, the connection portion 330 is disposed on the first surface 310a of the first substrate 310 away from the second substrate 320, and the connection portion 330 is located in the central area of ​​the first surface 310a, and the central area is, for example, an area within a predetermined range centered on the geometric center of the first surface 310a. The range covered by the central area can be set according to the size of the BAW resonator 300, or according to actual needs, for example, according to the environmental conditions (for example, temperature, humidity, pressure, etc.) during actual application, and the embodiments of the present application are not limited to this.

[0035] In at least one embodiment, the maximum size of the projection of the central area on the first surface may be less than 30% of the maximum size of the first surface, or the minimum size of the projection of the central area on the first surface may be less than 50% of the minimum size of the first surface. In addition, the shape of the central area may be any shape, for example, the projection of the central area on the first surface may be a rectangle or a circle, which is not limited in the embodiments of the present application.

[0036] For example, Figure 4 As shown, the projection C0 of the central area on the first surface 310a (hereinafter referred to as "central area C0") can be a circular area with the center O of the first surface 310a as the origin, and the diameter of the circular area is D0. The first surface 310a is, for example, a rectangle, and the lengths of two adjacent sides are L0 and W0 respectively, and L0 is greater than or equal to W0. For example, the diameter D0 of the central area C0 is less than or equal to 30% of L0, for example, D0 is not greater than 300 microns, or D0 is less than or equal to 20% of L0, for example, D0 is not greater than 200 microns.

[0037] For example, Figure 5As shown, the central area C0 may be a rectangular area centered at the center O of the first surface 310a, the lengths of the two adjacent sides are L1 and W1 respectively, L1 is greater than or equal to W1, the first surface 310a is, for example, a rectangle, the lengths of the two adjacent sides are L0 and W0 respectively, L0 is greater than or equal to W0, for example, the length L1 of the central area C0 is less than or equal to 30% of L0, for example, L1 is not greater than 300 microns, or W1 is less than or equal to 50% of W0, for example, W1 is not greater than 300 microns. In addition, the angle between the edge of the rectangular central area C0 and the edge of the first surface 310a is less than or equal to 90°, for example, the angle between the edge of the central area C0 and the edge of the first surface 310a is equal to 0° or 90°, that is, the rectangular central area C0 and the rectangular first surface 310a are non-rotated relative to each other, for example, as Figure 5 As shown, the edge of the central area C0 is parallel or perpendicular to the edge of the first surface 310a, for example, the edge of the side length L1 of the central area C0 is parallel to the edge of the side length L0 of the first surface 310a, or the edge of the side length L1 of the central area C0 may also be parallel to the edge of the side length W0 of the first surface 310a; in addition, the angle between the edge of the central area C0 and the edge of the first surface 310a may also be between 0° and 90°, that is, the rectangular central area C0 may also be rotated relative to the rectangular first surface 310a by a predetermined angle, for example, the predetermined angle may be set according to the distribution of the connecting portion 330 on the first surface 310a.

[0038] In the embodiment of the present application, since the connection portion 330 is located at the center of the first surface 310a of the first substrate 310, even if strain occurs, the stress on the BAW resonator 300 coupled to the inside of the packaging structure 30 is small, thereby improving the stability and reliability of the BAW resonator 300.

[0039] Figure 6 It is a schematic diagram of the chip packaging structure of the embodiment of the present application being subjected to stress and generating strain.

[0040] For example, Figure 6 As shown, when the chip 40 is subjected to stress and deforms downward, since the connecting portion 330 is located at the center of the first surface 310a, the strain of the chip 40 has a smaller effect on the connecting portion 330. Therefore, the stress transmitted to the packaging structure 30 of the BAW resonator through the connecting portion 330 is smaller, so that the impact on the internal BAW resonator 300 is also smaller, thereby improving the stability and reliability of the BAW resonator 300.

[0041] The packaging structure of the BAW resonator according to the embodiment of the present application is described in detail below.

[0042] Figure 7is a schematic diagram of an implementation of a packaging structure of a bulk acoustic wave resonator according to an embodiment of the present application, Figure 8 is included Figure 7 A schematic diagram of a chip packaging structure of a BAW resonator packaging structure is shown.

[0043] In at least one embodiment, Figure 7 As shown, the BAW resonator 300 includes a first electrode 301, a second electrode 302 and a piezoelectric film 303. The first electrode 301, the piezoelectric film 303 and the second electrode 302 are stacked in sequence in a first direction z. Sometimes, the structure composed of the first electrode 301, the piezoelectric film 303 and the second electrode 302 is also called a "sandwich structure". Figure 7 In the direction shown, the first electrode 301 is located on the upper side of the second electrode 302, so the first electrode 301 is sometimes called a "top electrode" and the second electrode 302 is sometimes called a "bottom electrode", but the embodiments of the present application are not limited to this.

[0044] like Figure 7 As shown, the connection portion 330 includes a first connection portion 331 and a second connection portion 332, the first connection portion 331 is electrically connected to the first electrode 301, and the second connection portion 332 is electrically connected to the second electrode 302. Fig. 9 As shown, the first connection portion 331 and the second connection portion 332 are symmetrical about the geometric center O of the first surface 310 a . This is beneficial to the stability of the BAW resonator 300 when it is packaged.

[0045] For example, Figure 8 As shown, when the packaging structure 30 including the BAW resonator 300 is packaged with the chip 40 using a flip-chip packaging process, since the first connection portion 331 and the second connection portion 332 are located at the center of the packaging structure 30 and are symmetrical relative to the geometric center of the first surface, the packaging structure 30 can be stably fixed on the chip 40.

[0046] In addition, if Figure 8 As shown, the conductive layers 401 and 402 of the chip 40 may be located at the center of the surface 40a of the chip 40, thereby further ensuring the stability of the package structure 30. However, the embodiment of the present application is not limited thereto, and the conductive layers 401 and 402 of the chip 40 may be located at any area of ​​the surface 40a of the chip 40. For example, when there are multiple package structures 30 packaged with the chip 40, the multiple package structures 30 may be evenly distributed on the surface 40a of the chip 40, and the package position of the package structure 30 may also be set according to actual needs.

[0047] In at least one embodiment, Figure 7As shown, the first electrode 301 has a first lead portion 3011, and the second electrode 302 has a second lead portion 3021. The first lead portion 3011 and the second lead portion 3021 are arranged on the second surface 320a of the second substrate 320a, and the second surface 320a is opposite to the first substrate 310. The package structure 30 also includes a wiring layer 340 arranged on the first substrate 310, and the first lead portion 3011 and the second lead portion 3021 are electrically connected to the first connection portion 331 and the second connection portion 332 through the wiring layer 340. Figure 7 As shown, the wiring layer 340 includes, for example, a metal layer 341 disposed on the third surface 310 b of the first substrate 310 and a conductive via 342 penetrating the first substrate 310 along the first direction z, and the third surface is opposite to the second substrate 320 .

[0048] In at least one embodiment, Figure 7 As shown, the metal layer 341 includes a first metal layer 3411 and a second metal layer 3412, and the first metal layer 3411 and the second metal layer 3412 are electrically connected to the first lead-out portion 3011 and the second lead-out portion 3021, respectively, for example, by bonding. The conductive via 342 includes, for example, a first conductive via 3421 and a second conductive via 3422, and the first conductive via 3421 and the second conductive via 3422 are, for example, filled with a conductor material 342b, and the first conductive via 3421 and the second conductive via 3422 are electrically connected to the first metal layer 3411 and the second metal layer 3412, respectively, so that the first metal layer 3411 is electrically connected to the first connection portion 331 through the first conductive via 3421, and the second metal layer 3412 is electrically connected to the second connection portion 332 through the second conductive via 3422.

[0049] Fig. 9 yes Figure 7 A top view of the packaging structure of a BAW resonator is shown.

[0050] In at least one embodiment, projections of the first conductive via and the second conductive via on the first surface are located outside the central area.

[0051] For example, Fig. 9As shown, the projections of the first conductive hole 3421 and the second conductive hole 3422 on the first surface 310a are located outside the central area C0, the first connecting portion 331 is electrically connected to the first conductive hole 3421 through the first extending portion 3311, the second connecting portion 332 is electrically connected to the second conductive hole 3422 through the second extending portion 3321, and the first extending portion 3311 and the second extending portion 3321 extend within the first surface 310a, for example, the first extending portion 3311 and the second extending portion 3321 extend along the second direction x within the first surface 310a. In addition, the widths of the first extending portion 3311 and the first connecting portion 331 may be the same or different, and the widths of the second extending portion 3321 and the second connecting portion 332 may be the same or different, for example, Fig. 9 As shown, the width of the first extension portion 3311 is smaller than the width of the first connection portion 331, and the width of the second extension portion 3321 is smaller than the width of the second connection portion 332. In addition, in order to reduce the contact resistance with the conductive hole, the ends of the first extension portion 3311 and the second extension portion 3321 can be enlarged, for example, as Fig. 9 As shown, the width of the end 3311a of the first extension portion 3311 connected to the first conductive hole 3421 is larger than the width of the connection between the first extension portion 3311 and the first connection portion 331, and the width of the end 3321a of the second extension portion 3321 connected to the second conductive hole 3422 is larger than the width of the connection between the second extension portion 3321 and the second connection portion 332.

[0052] In addition, projections of the first conductive via and the second conductive via may also be located in the central area of ​​the first surface.

[0053] Fig.10 is a schematic diagram of an implementation of a packaging structure of a bulk acoustic wave resonator according to an embodiment of the present application, Fig.11 yes Fig.10 A top view of the packaging structure of a BAW resonator is shown.

[0054] In at least one embodiment, Fig.11 As shown, the projections of the first conductive hole 3421 and the second conductive hole 3422 on the first surface 310a may also be located in the central area C0. Fig.11 As shown, the projection of the first conductive via 3421 on the first surface 310a may also overlap with the projection of the first connecting portion 331 on the first surface 310a, and the projection of the second conductive via 3422 on the first surface 310a may also overlap with the projection of the second connecting portion 332 on the first surface 310a.

[0055] In at least one embodiment, Fig.10As shown, the metal layer 341 includes a first metal layer 3411 and a second metal layer 3412, the first metal layer 3411 includes a first bonding portion 3411a and a third extension portion 3411b, the first bonding portion 3411a is bonded to the first lead-out portion 3011, and the third extension portion 3411b connects the first bonding portion 3411a and the first conductive hole 3421, the second metal layer 3412 includes a second bonding portion 3412a and a fourth extension portion 3412b, the second bonding portion 3412a is bonded to the second lead-out portion 3021, and the fourth extension portion 3412b connects the second bonding portion 3412a and the second conductive hole 3422.

[0056] For example, a recess 310c is formed on one side of the first substrate 310 opposite to the second substrate 320, and the recess 310c and the second substrate 320 form a cavity for accommodating the BAW resonator 300, and the third extension portion 3411b and the fourth extension portion 3412b extend along the wall surface of the recess 310c. Fig.10 As shown, the cross-sectional shape of the recess 310c is a trapezoid, but the embodiment of the present application does not limit the cross-sectional shape of the recess 310c. For example, the cross-sectional shape of the recess 310c may also be a rectangle or a semicircle.

[0057] In at least one embodiment, the BAW resonator 300 further includes an acoustic reflection structure 304 disposed on the second substrate 320 , and the second electrode 302 covers a surface of the acoustic reflection structure 304 close to the first substrate 310 .

[0058] For example, Figure 7 As shown, the BAW resonator 300 is, for example, a film bulk acoustic resonator (FBAR), and the acoustic reflection structure 304 is a cavity structure surrounded by a recess formed in the second substrate 320 and the second electrode 302 .

[0059] Or, if Fig.10 As shown, the BAW resonator 300 is, for example, a solid-state mounted resonator (SMR), and the acoustic reflection structure 304 is a Bragg reflection structure formed on the second surface 320 a of the second substrate 320 .

[0060] In at least one embodiment, Fig. 9 and Fig.11 As shown, the projection of the connection portion 330 on the first surface 310a is within the projection range of the sound reflection structure 304 on the first surface 310a. For example, the projections of the first connection portion 331 and the second connection portion 332 on the first surface 310a are within the projection range of the sound reflection structure 304 on the first surface 310a.

[0061] Furthermore, the projection of the connecting portion 330 on the first surface 310a may be located within the projection range of the effective area of ​​the acoustic reflection structure 304 on the first surface 310a. Thus, the stability of the resonator can be further ensured. The effective area of ​​the acoustic reflection structure 304 is, for example, an area where the acoustic reflection structure 304 and the effective acoustic area of ​​the "sandwich structure" overlap in the first direction z, for example, Figure 7 As shown, the effective acoustic area of ​​the "sandwich structure" is, for example, the area covered by the first electrode 301, the effective area R of the sound reflection structure 304 is, for example, the portion of the sound reflection structure 304 that overlaps with the first electrode 301 in the first direction z, and the projection of the connecting portion 330 on the first surface 310a is, for example, located within the range of the projection of the effective area R of the sound reflection structure 304 on the first surface 310a.

[0062] In at least one embodiment, the BAW resonator packaging structure 30 may include a plurality of BAW resonators 300. For example, a plurality of BAW resonators 300 may be sandwiched between a first substrate 310 and a second substrate 320. The connection portion 330 of each BAW resonator 300 is located in a central region C0 of a first surface 310a of the first substrate 310.

[0063] The packaging structure 30 of the BAW resonator includes two BAW resonators as an example for description. In addition, in order to distinguish the two BAW resonators, the two BAW resonators are respectively labeled as 300-1 and 300-2, and similar labels represent components of the same BAW resonator. For example, the connection part of the BAW resonator 300-1 is labeled as 330-1, and the connection part of the BAW resonator 300-2 is labeled as 330-2, etc., which will not be described one by one below.

[0064] Fig.12 is a top view of an implementation of a packaging structure of a bulk acoustic wave resonator according to an embodiment of the present application, Fig.13 is a top view of another embodiment of the packaging structure of the BAW resonator of the embodiment of the present application, Fig.14 It is a top view of another implementation of the packaging structure of the BAW resonator according to the embodiment of the present application.

[0065] like Figure 12 to Figure 14 As shown, the BAW resonator 300-1 ( Figure 12 to Figure 14 ) of the connection portion 330-1 (for example, Figure 12 to Figure 14 The first connection portion 331-1, the second connection portion 332-1) and the BAW resonator 300-2 ( Figure 12 to Figure 14 ) of the connection portion 330-2 (for example, Figure 12 to Figure 14The first connection portion 331-2 and the second connection portion 332-2 indicated in the figure are both located in the central area C0 of the first substrate 310. In addition, the first connection portion 331-1 and the second connection portion 332-1 are symmetrical about the geometric center O of the first surface 310a, and the first connection portion 331-2 and the second connection portion 332-2 are symmetrical about the geometric center O of the first surface 310a.

[0066] In addition, the symmetry axis of the figure formed by the projections of the connection portions 330 of the plurality of BAW resonators 300 on the first surface 310 a coincides with the symmetry axis of the projection of the connection portion 330 of each BAW resonator 300 on the first surface 310 a .

[0067] For example, Figure 12 to Figure 14 As shown, the symmetry axes of the first connection part 331-1 and the second connection part 332-1 are M1 and M2, the symmetry axes of the first connection part 331-2 and the second connection part 332-2 are M1 and M2, and the symmetry axes of the figure formed by the first connection part 331-1, the second connection part 332-1, the first connection part 331-2, and the second connection part 332-2 are also M1 and M2.

[0068] In addition, the above description is made by taking the case where two BAW resonators 300 are included as an example. When the BAW resonator packaging structure 30 includes other numbers of BAW resonators 300 , the connection parts of the BAW resonators 300 may also satisfy the above symmetry condition.

[0069] Fig.15 It is a top view of another implementation of the packaging structure of the BAW resonator according to the embodiment of the present application.

[0070] For example, three bulk acoustic wave resonators 300 may be sandwiched between the first substrate 310 and the second substrate 320. Fig.15 As shown, the first connection portion 331-1 and the second connection portion 332-1 are symmetrical about the geometric center O of the first surface 310a, the first connection portion 331-2 and the second connection portion 332-2 are symmetrical about the geometric center O, and the first connection portion 331-3 and the second connection portion 332-3 are symmetrical about the geometric center O. In addition, the connection portions 331-1, 332-1, 331-2, 332-2, 331-3, and 332-3 are all located in the central area C0 of the first surface 310a of the first substrate 310.

[0071] In addition, if Fig.15As shown, the axes of symmetry of the first connection part 331-1 and the second connection part 332-1 are M1 and M2, the axes of symmetry of the first connection part 331-2 and the second connection part 332-2 are M3 and M4, the axes of symmetry of the first connection part 331-3 and the second connection part 332-3 are M5 and M6, and the axes of symmetry of the figure formed by the connection parts 331-1, 332-1, 331-2, 332-2, 331-3, and 332-3 are M1, M2, M3, M4, M5, and M6.

[0072] In addition, each connecting portion can be of any shape, for example Figures 11 to 13 As shown, each connection portion 331-1, 332-1, 331-2, 332-2 is rectangular; Fig.14 As shown, each connection portion 331-1, 332-1, 331-2, 332-2 is fan-shaped; Fig.15 As shown, each connection portion 331-1, 332-1, 331-2, 332-2, 331-3, 332-3 may also be circular.

[0073] In at least one embodiment, the maximum size of the figure formed by the projection of the connection portion 330 on the first surface 310a is more than 5 times the size of the smallest gap in the figure. In addition, the maximum size of the figure formed by the projection of the connection portion 330 on the first surface 310a may also be more than 2.5 times the size of the smallest gap in the figure formed by the projection of the conductive portion 50 on the first surface 310a. In this way, the effects of reducing stress coupling, ensuring the firmness of welding, and avoiding adhesion of adjacent conductive portions (such as solder balls) can be achieved.

[0074] For example, Fig.11 As shown, L10 is defined as the minimum gap of the connecting portion 330, that is, the gap width between the second connecting portion 332 and the first connecting portion 331; L11 is defined as the maximum size of the figure formed by the projection of the connecting portion 330 on the first surface 310a, that is, the distance from the left edge of the second connecting portion 332 to the right edge of the first connecting portion 331; W10 is defined as the width of the minimum gap of the conductive portion 50, that is, the edge gap between the first conductive portion 501 and the second conductive portion 502, L10 is, for example, 5 microns to 100 microns, L11 is, for example, 50 microns to 500 microns, and W10 is, for example, 10 microns to 200 microns.

[0075] For example, Fig.12As shown, a transverse "H"-shaped gap is formed between the first connection portion 331-1, the second connection portion 332-1, the first connection portion 331-2, and the second connection portion 332-2 (hereinafter sometimes referred to as "connection portion 331-1, connection portion 332-1, connection portion 331-2, connection portion 332-2" or collectively referred to as "connection portion 330"), and L20 is defined as the minimum gap of the connection portion 330, that is, the minimum width of the "H"-shaped gap; L21 is defined as the minimum width of the connection portion 330 at The maximum size of the figure formed by the projection of the first surface 310a, that is, the overall maximum height of the connecting part community, that is, the distance from the upper edge of the connecting part 331-2 to the lower edge of the connecting part 332-2; W20 is defined as the width of the minimum gap of the conductive part 50, that is, the edge spacing between the first wire part 501-1 and the second conductive part 502-1, L20 is, for example, 5 microns to 100 microns, L21 is, for example, 80 microns to 800 microns, and W20 is, for example, 10 microns to 200 microns.

[0076] For example, Fig.13 As shown, a "cross"-shaped gap is formed between the first connecting portion 331-1, the second connecting portion 332-1, the first connecting portion 331-2, and the second connecting portion 332-2, and L30 is defined as the minimum gap of the connecting portion 330, that is, the minimum width of the "cross"-shaped gap; L31 is defined as the maximum size of the figure formed by the projection of the connecting portion 330 on the first surface 310a, that is, the longer diagonal length of the rectangle composed of the above-mentioned connecting portion community. In addition, when the figure composed of the connecting portion community is a square, L31 is the diagonal length of the square; W30 is defined as the width of the minimum gap of the conductive portion 50, that is, the edge spacing between two adjacent conductive portions, such as the edge gap between the second conductive portion 332-1 and the second conductive portion 332-2; L30 is, for example, 5 microns to 100 microns, L31 is, for example, 70 microns to 700 microns, and W30 is, for example, 10 microns to 200 microns.

[0077] For example, Fig.14As shown, the first connection part 331-1, the second connection part 332-1, the first connection part 331-2, and the second connection part 332-2 (hereinafter sometimes referred to as "connection part 331-1, connection part 332-1, connection part 331-2, connection part 332-2" or collectively referred to as "connection part 330") together form a circle, and a "cross"-shaped gap is formed between the connection parts 331-1, the connection parts 332-1, the connection parts 331-2, and the connection parts 332-2. L40 is defined as the minimum gap of the connection part 330, that is, The minimum width of the "X"-shaped gap; L41 is defined as the maximum size of the figure formed by the projection of the connecting portion 330 on the first surface 310a, that is, the diameter of the circle formed by the above-mentioned connecting portion community; W40 is defined as the width of the minimum gap of the conductive portion 50, that is, the edge spacing between two adjacent conductive portions, such as the edge gap between the second conductive portion 502-1 and the second conductive portion 502-2; L40 is, for example, 5 microns to 100 microns, L41 is, for example, 70 microns to 700 microns, and W40 is, for example, 10 microns to 200 microns.

[0078] For example, Fig.15 As shown, the first connection part 331-1, the second connection part 332-1, the first connection part 331-2, the second connection part 332-2, the first connection part 331-3 and the second connection part 332-3 together form a rough hexagon, and L50 is defined as the minimum gap of the connection part 330, for example, the gap width between the first connection part 331-1 and the first connection part 331-2; L51 is defined as the maximum size of the figure formed by the projection of the connection part 330 on the first surface 310a, that is, the distance from the left edge of the connection part 332-1 to the right edge of the connection part 331-1; W50 is defined as the width of the minimum gap of the conductive part 50, that is, the edge spacing between two adjacent conductive parts, for example, the edge gap between the first conductive part 501-1 and the first conductive part 501-2; L50 is, for example, 5 microns to 150 microns, L51 is, for example, 70 microns to 1050 microns, and W50 is, for example, 10 microns to 300 microns.

[0079] In addition, the embodiments of the present application do not limit the constituent materials of each part, which can be selected according to actual needs. For details, please refer to the relevant technology.

[0080] It can be seen from the embodiments of the first aspect of the present application that by arranging the connection portion electrically connected to the external element in the central area of ​​the packaging structure, even if the external element is strained due to stress, the stress coupled to the packaging structure is small, thereby improving the stability and reliability of the bulk acoustic wave resonator.

[0081] Embodiments of the second aspect

[0082] An embodiment of the second aspect of the present application provides an oscillator, which includes the packaging structure of the BAW resonator described in the embodiment of the first aspect. Since the structure and features of the packaging structure of the BAW resonator have been described in detail in the embodiment of the first aspect, its content is incorporated herein and the description is omitted here.

[0083] In addition, the oscillator further includes an integrated circuit chip electrically coupled to the connection portion of the packaging structure of the BAW resonator, and the integrated circuit chip controls, for example, the voltage applied to the BAW resonator. In addition, the implementation of the integrated circuit chip can refer to the implementation of the chip 40 described in the embodiment of the first aspect, and can also refer to related technologies, which are not limited in the embodiments of the present application.

[0084] In addition, the oscillator of the embodiment of the present application may also include other electronic devices as needed, for example, it may also include capacitors, inductors, resistors, etc. The selection of these electronic devices can refer to relevant technologies, and the embodiment of the present application does not limit this.

[0085] In addition, the embodiment of the present application further provides an electronic device, which includes the oscillator described above, and its contents are incorporated herein, and the description is omitted here. The embodiment of the present application does not limit the application scenario of the electronic device, and the details can be referred to the relevant technology.

[0086] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A packaging structure of a bulk acoustic wave resonator, characterized in that: The packaging structure includes a BAW resonator and a first substrate and a second substrate sandwiching the BAW resonator in a first direction. The packaging structure also includes a connection portion electrically connected to an external element, wherein the connection portion is disposed in a central region of a first surface of the first substrate away from the second substrate, and the central region is a region within a predetermined range centered on a geometric center of the first surface.

2. The packaging structure according to claim 1, characterized in that: The BAW resonator includes a first electrode, a piezoelectric film, and a second electrode sequentially stacked in the first direction. The connection portion includes a first connection portion electrically connected to the first electrode and a second connection portion electrically connected to the second electrode.

3. The packaging structure according to claim 2, characterized in that: The first connection portion and the second connection portion are symmetrical about the geometric center of the first surface.

4. The packaging structure according to claim 2, characterized in that: The first electrode has a first lead portion, and the second electrode has a second lead portion, The first lead portion and the second lead portion are disposed on a second surface of the second substrate opposite to the first substrate, The packaging structure further includes a wiring layer disposed on the first substrate, and the first lead-out portion and the second lead-out portion are electrically connected to the first connecting portion and the second connecting portion respectively through the wiring layer.

5. The packaging structure according to claim 4, characterized in that: The wiring layer includes a metal layer disposed on a third surface of the first substrate opposite to the second substrate and a conductive via penetrating the first substrate along the first direction.

6. The packaging structure according to claim 5, characterized in that: The metal layer includes a first metal layer and a second metal layer electrically connected to the first lead-out portion and the second lead-out portion, respectively. The conductive vias include a first conductive via and a second conductive via electrically connected to the first metal layer and the second metal layer, respectively. The first metal layer is electrically connected to the first connection portion through the first conductive via, and the second metal layer is electrically connected to the second connection portion through the second conductive via.

7. The packaging structure according to claim 6, characterized in that: The projections of the first conductive hole and the second conductive hole on the first surface are located outside the central area, The first connecting portion is electrically connected to the first conductive hole through the first extending portion, and the second connecting portion is electrically connected to the second conductive hole through the second extending portion. The first extension portion and the second extension portion extend on the first surface of the first substrate.

8. The packaging structure according to claim 6, characterized in that: The projections of the first conductive hole and the second conductive hole on the first surface are located in the central area, The projection of the first conductive via on the first surface overlaps with the projection of the first connecting portion on the first surface, and the projection of the second conductive via on the first surface overlaps with the projection of the second connecting portion on the first surface.

9. The packaging structure according to claim 8, characterized in that: The first metal layer includes a first bonding portion bonded to the first lead portion, and a third extending portion connecting the first bonding portion and the first conductive hole. The second metal layer includes a second bonding portion bonded to the second lead portion, and a fourth extending portion connecting the second bonding portion and the second conductive via.

10. The packaging structure according to claim 2, characterized in that: The BAW resonator further includes an acoustic reflection structure disposed on the second substrate, and the second electrode covers a surface of the acoustic reflection structure close to the first substrate.

11. The packaging structure according to claim 10, characterized in that: The acoustic reflection structure is a cavity structure surrounded by a recess formed in the second substrate and the second electrode, or the acoustic reflection structure is a Bragg reflection structure formed on a second surface of the second substrate opposite to the first substrate.

12. The packaging structure according to claim 10, characterized in that: The projection of the connecting portion on the first surface is located within the range of the projection of the sound reflection structure on the first surface.

13. The packaging structure according to claim 12, characterized in that: The projection of the connecting portion on the first surface is located within the range of the projection of the effective area of ​​the sound reflection structure on the first surface.

14. The packaging structure according to claim 1, characterized in that: The maximum dimension of the projection of the central area on the first surface is less than 30% of the maximum dimension of the first surface, or the minimum dimension of the projection of the central area on the first surface is less than 50% of the minimum dimension of the first surface.

15. The packaging structure according to claim 14, characterized in that: The projection of the central area on the first surface is a rectangle or a circle.

16. The packaging structure according to claim 15, characterized in that: The first surface is rectangular, The projection of the central area on the first surface is a rectangle, and an angle between a side of the projection of the central area and a side of the first surface is less than or equal to 90°.

17. The packaging structure according to claim 1, characterized in that: The maximum size of a figure formed by the projection of the connecting portion on the first surface is more than 5 times the size of the smallest gap in the figure.

18. The packaging structure according to claim 17, characterized in that: The packaging structure is connected to an external circuit via a conductive portion connected to the connecting portion. The maximum size of a figure formed by the projection of the connecting portion on the first surface is at least 2.5 times the size of a minimum gap in a figure formed by the projection of the conductive portion on the first surface.

19. The packaging structure according to claim 17, characterized in that: The shape of the gap in the figure formed by the projection of the connecting portion on the first surface is H-shaped or cross-shaped.

20. The packaging structure according to claim 17, characterized in that: The maximum size of a pattern formed by the projection of the connecting portion on the first surface ranges from 50 micrometers to 1050 micrometers, and the size of a minimum gap in the pattern ranges from 5 micrometers to 150 micrometers.

21. The packaging structure according to claim 18, characterized in that: The maximum size of a figure formed by the projection of the connecting portion on the first surface ranges from 50 micrometers to 1050 micrometers, and the minimum size of a gap in a figure formed by the projection of the conductive portion on the first surface ranges from 10 micrometers to 300 micrometers.

22. The packaging structure according to any one of claims 1 to 21, characterized in that: A plurality of the BAW resonators are sandwiched between the first substrate and the second substrate, The connection portion of each BAW resonator is located in the central region.

23. An oscillator, characterized in that: The oscillator comprises: The packaging structure of the BAW resonator according to any one of claims 1 to 22; and An integrated circuit chip is electrically coupled to the connection portion of the package structure.

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