Surface acoustic wave filter packaging structure and preparation method thereof, and related equipment

Abstract

The present invention provides a surface acoustic wave filter packaging structure, a preparation method thereof, and related equipment, and relates to the field of semiconductor technology. The spacing area between the interdigitated electrodes and the carrier substrate in the first direction is the cavity area of ​​the surface acoustic wave filter; the pad structure contacts the substrate and the carrier substrate respectively in the first direction, and the interdigitated electrodes and the pad main body structure are located inside the area surrounded by the first wall structure. Therefore, during the preparation of the plastic sealing layer, the setting of at least the Nth wall structure will block the plastic sealing filler from entering the cavity area, thereby achieving effective protection of the working area of ​​the surface acoustic wave filter packaging structure. Compared with the existing technical solutions, the technical solution of the present application does not require additional materials and structures to form a closed cavity, and uses the pad structure as a barrier layer for the plastic sealing filler, thereby achieving the purpose of simplifying the process steps and reducing production costs.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a surface acoustic wave filter packaging structure, a preparation method thereof, and related equipment. Background Art

[0002] SAW (Surface Acoustic Wave) filters, short for surface acoustic wave filters, are specialized filtering devices that utilize the piezoelectric effect and the physical properties of surface acoustic wave propagation. They are widely used in various fields, such as radio frequency. Surface acoustic waves are elastic waves whose energy is concentrated near the surface.

[0003] The current surface acoustic wave filter packaging structure is to package the SAW filter into a CSP (Chip Scale Package). However, this technology requires additional materials and structures to form a sealed cavity. For example, an organic dry film is used to cover and protect the SAW filter to protect it from external contamination. This results in a complex process and high production cost. Summary of the Invention

[0004] In view of the above problems, this application provides a surface acoustic wave filter packaging structure and its preparation method, as well as related equipment, to achieve the purpose of simplifying the process steps and reducing production costs. The specific solution is as follows:

[0005] A first aspect of the present application provides a surface acoustic wave filter packaging structure, the surface acoustic wave filter packaging structure comprising: a surface acoustic wave filter and a carrier substrate;

[0006] The surface acoustic wave filter comprises a substrate, interdigitated electrodes and a pad structure; the substrate and the carrier substrate are arranged relative to each other in a first direction, and the first direction is perpendicular to the plane where the substrate is located;

[0007] The interdigitated electrodes and the pad structure are located on a side of the substrate facing the carrier substrate; the pad structure includes a pad main structure and N wall structures spaced from the inside out, where N is greater than or equal to 1 and is a positive integer; the interdigitated electrodes and the pad main structure are located inside an area enclosed by the first wall structure; wherein the pad structure contacts the substrate and the carrier substrate respectively in the first direction, and a gap is formed between the interdigitated electrodes and the carrier substrate in the first direction;

[0008] The surface acoustic wave filter packaging structure further includes a plastic packaging layer for packaging the surface acoustic wave filter, and the plastic packaging layer is in contact with the outer side wall of the Nth wall structure.

[0009] Preferably, in the above-mentioned surface acoustic wave filter packaging structure, the wall structure and the pad main body structure are an integrally formed structure.

[0010] Preferably, in the above-mentioned surface acoustic wave filter packaging structure, at least one of the N wall structures is electrically connected to the pad main body structure.

[0011] Preferably, in the above-mentioned surface acoustic wave filter packaging structure, the widths of the N wall structures gradually decrease from the outside to the inside.

[0012] Preferably, in the above-mentioned surface acoustic wave filter packaging structure, the surface acoustic wave filter packaging structure further comprises:

[0013] A bonding layer is located on a side of the carrier substrate facing the surface acoustic wave filter; the pad structure is in contact with the carrier substrate via a groove penetrating the bonding layer.

[0014] Preferably, in the above-mentioned surface acoustic wave filter packaging structure, the surface acoustic wave filter packaging structure further comprises:

[0015] a through hole penetrating the carrier substrate and an external lead structure;

[0016] The external lead structure is electrically connected to the pad main body structure through the through hole.

[0017] Preferably, in the above-mentioned surface acoustic wave filter packaging structure, the surface acoustic wave filter packaging structure further comprises:

[0018] A protective layer is located on a side of the carrier substrate away from the surface acoustic wave filter; the protective layer exposes a portion of the surface of the external lead structure.

[0019] Preferably, in the above-mentioned surface acoustic wave filter packaging structure, the interdigitated electrodes include a first bus bar and a second bus bar arranged opposite to each other in the second direction, and a first electrode finger located on the first bus bar and a second electrode finger located on the second bus bar;

[0020] The first bus bar and the second bus bar have the same length extension direction, both extending along a third direction. The second direction and the third direction are parallel to the plane where the substrate is located, and the second direction and the third direction intersect.

[0021] A second aspect of the present application provides a method for preparing a surface acoustic wave filter packaging structure, the method comprising:

[0022] A surface acoustic wave filter is provided, comprising a substrate, interdigitated electrodes, and a pad structure; the pad structure comprises a pad main structure and N wall structures sequentially arranged from the inside out, where N is greater than or equal to 1 and is a positive integer; the interdigitated electrodes and the pad main structure are located within an area enclosed by the first wall structure;

[0023] The surface acoustic wave filter is fixed on a carrier substrate; the substrate and the carrier substrate are arranged relative to each other in a first direction, the first direction being perpendicular to the plane of the substrate; the interdigitated electrodes and the pad structure are located on a side of the substrate facing the carrier substrate; the pad structure is in contact with the substrate and the carrier substrate respectively in the first direction, and there is a gap between the interdigitated electrodes and the carrier substrate in the first direction;

[0024] A plastic packaging layer is formed for packaging the surface acoustic wave filter, and the plastic packaging layer is in contact with the outer side wall of the Nth surrounding wall structure.

[0025] Preferably, in the method for preparing the surface acoustic wave filter packaging structure, the wall structure and the pad main body structure are formed in the same process, and the wall structure and the pad main body structure are an integrally formed structure.

[0026] Preferably, in the above-mentioned method for preparing a surface acoustic wave filter packaging structure, before fixing the surface acoustic wave filter on the carrier substrate, the method for preparing the surface acoustic wave filter packaging structure further comprises:

[0027] A bonding layer is formed on one side surface of the carrier substrate; after the surface acoustic wave filter is fixed on the carrier substrate, the pad structure contacts the carrier substrate through a groove penetrating the bonding layer.

[0028] Preferably, in the above-mentioned method for preparing a surface acoustic wave filter packaging structure, the method for preparing a surface acoustic wave filter packaging structure further comprises:

[0029] Processing the carrier substrate to form a through hole penetrating the carrier substrate;

[0030] An external lead structure is formed; the external lead structure is electrically connected to the pad main body structure through the through hole.

[0031] Preferably, in the above-mentioned method for preparing a surface acoustic wave filter packaging structure, the method for preparing a surface acoustic wave filter packaging structure further comprises:

[0032] A protective layer is formed on a side of the carrier substrate away from the surface acoustic wave filter; the protective layer exposes a portion of the surface of the external lead structure.

[0033] A third aspect of the present application provides a radio frequency device, which includes any of the above-mentioned surface acoustic wave filter packaging structures.

[0034] A fourth aspect of the present application provides a vehicle-mounted device, which includes any of the above-mentioned surface acoustic wave filter packaging structures.

[0035] A fifth aspect of the present application provides a vehicle-mounted device, which includes the radio frequency device described above.

[0036] By means of the above technical solution, the present application provides a surface acoustic wave filter packaging structure and its preparation method, and related equipment, wherein there is a gap between the interdigitated electrode and the carrier substrate in the first direction, and this gap area is the cavity area of ​​the surface acoustic wave filter; the pad structure contacts the substrate and the carrier substrate respectively in the first direction, and the pad structure includes a pad main body structure and N wall structures arranged in sequence from the inside to the outside, and the interdigitated electrode and the pad main body structure are located inside the area surrounded by the first wall structure. Therefore, during the preparation of the plastic sealing layer, the setting of at least the Nth wall structure will block the plastic sealing filler from entering the cavity area, thereby achieving effective protection of the working area of ​​the surface acoustic wave filter packaging structure. Compared with the existing technical solutions, the technical solution of the present application does not require additional materials and structures to form a closed cavity, and uses the pad structure as a barrier layer for the plastic sealing filler, thereby achieving the purpose of simplifying the process steps and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.

[0038] Figure 1 A schematic structural diagram of a surface acoustic wave filter packaging structure provided by an embodiment of the present invention;

[0039] Figure 2 A schematic structural diagram of another surface acoustic wave filter packaging structure provided by an embodiment of the present invention;

[0040] Figure 3 A schematic structural diagram of an interdigital electrode provided by an embodiment of the present invention;

[0041] Figure 4 A schematic structural diagram of another surface acoustic wave filter packaging structure provided by an embodiment of the present invention;

[0042] Figure 5A schematic structural diagram of another surface acoustic wave filter packaging structure provided by an embodiment of the present invention;

[0043] Figure 6 A schematic flow chart of a method for preparing a surface acoustic wave filter packaging structure provided by an embodiment of the present invention;

[0044] Figure 7 An embodiment of the present invention provides a Figure 6 One of the partial structural schematic diagrams corresponding to the preparation method shown;

[0045] Figure 8 An embodiment of the present invention provides a Figure 6 The second schematic diagram of the partial structure corresponding to the preparation method shown;

[0046] Figure 9 An embodiment of the present invention provides a Figure 6 The third schematic diagram of the partial structure corresponding to the preparation method shown;

[0047] Figure 10 An embodiment of the present invention provides a Figure 6 The fourth schematic diagram of the partial structure corresponding to the preparation method shown;

[0048] Figure 11 An embodiment of the present invention provides a Figure 6 The fifth schematic diagram of the partial structure corresponding to the preparation method shown;

[0049] Figure 12 An embodiment of the present invention provides a Figure 6 The sixth schematic diagram of the partial structure corresponding to the preparation method shown. DETAILED DESCRIPTION

[0050] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation methods of the present application are only used to explain the specific embodiments of the present application and are not intended to limit the present application. It is known to those skilled in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0051] It should be noted that the directional words appearing in the present invention are based on the relative position relationship shown in the drawings and cannot be used as an absolute limitation to the present application.

[0052] In conjunction with the content recorded in the background technology, surface acoustic wave resonators and filters are acoustic devices widely used in the radio frequency field. They combine low insertion loss and good suppression performance, and are relatively small in size. They are used to filter out interference from heterodyne signals, attenuate some frequency components, and only allow specified frequency components. They are the technical basis for the application of wireless spectrum as a non-renewable scarce resource.

[0053] Its specific principle can be simply understood as based on the piezoelectric properties of piezoelectric materials, using input and output transducer devices such as interdigital transducers to convert electrical signals into mechanical energy, and then converting them back into electrical signals after processing, in order to amplify the required signals, filter out noise signals and improve signal quality. It is widely used in various wireless communication equipment.

[0054] Currently, filters are primarily categorized as SAW filters and BAW (Bulk Acoustic Wave) filters. Surface acoustic waves (SAWs) are elastic waves that originate and propagate on the surface of a piezoelectric substrate, with their amplitude decreasing rapidly with depth. SAW filters are less expensive to manufacture than BAW filters and are primarily used in low-frequency bands. They offer low insertion loss, good rejection, and high temperature sensitivity.

[0055] The current SAW filter packaging structure is to package the SAW filter into a CSP. However, this technology requires additional materials and structures to form a sealed cavity to protect the SAW filter from external contamination, resulting in complex processes and high production costs. For example, the use of organic dry film to cover and protect the SAW filter, and the additional gold ball bonding process also reduces production efficiency.

[0056] Based on this, embodiments of the present invention provide a surface acoustic wave filter packaging structure, a method for manufacturing the same, and related equipment, thereby simplifying the process steps and reducing production costs. To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0057] refer to Figure 1 , Figure 1 A schematic diagram of a surface acoustic wave filter packaging structure provided by an embodiment of the present invention, referring to Figure 2 , Figure 2 A schematic structural diagram of another surface acoustic wave filter packaging structure provided by an embodiment of the present invention. The surface acoustic wave filter packaging structure provided by an embodiment of the present invention comprises: a surface acoustic wave filter 11 and a carrier substrate 12.

[0058] The surface acoustic wave filter includes a substrate 13 , interdigitated electrodes 14 and a pad structure 15 ; the substrate 13 and the carrier substrate 12 are arranged opposite to each other in a first direction X, and the first direction X is perpendicular to the plane where the substrate 13 is located.

[0059] The interdigitated electrodes 14 and the pad structure 15 are located on the side of the substrate 13 facing the carrier substrate 12; the pad structure 15 includes a pad main body structure 151 and N wall structures 152 arranged in sequence from the inside to the outside, N ≥ 1, and N is a positive integer; the interdigitated electrodes 14 and the pad main body structure 151 are located inside the area surrounded by the first wall structure 152; wherein, the pad structure 15 is in contact with the substrate 13 and the carrier substrate 12 in the first direction X, respectively, and there is a gap between the interdigitated electrodes 14 and the carrier substrate 12 in the first direction X. It should be noted that, Figure 1 In the following, N=2 is taken as an example for explanation.

[0060] The surface acoustic wave filter packaging structure further includes a plastic packaging layer 16 for packaging the surface acoustic wave filter 11 . The plastic packaging layer 16 is in contact with the outer sidewall of the Nth wall structure 152 .

[0061] Specifically, in the embodiment of the present invention, the substrate 13 is a piezoelectric substrate, and the material of the substrate 13 includes but is not limited to lithium niobate, niobium tantalate, etc. The material of the carrier substrate 12 is an insulating material, including but not limited to ceramic, glass, silicon, or other organic materials such as resin, Polymid, etc. Figure 3 , Figure 3 A schematic diagram of the structure of an interdigitated electrode provided in an embodiment of the present invention. The interdigitated electrode 14 includes a first bus bar 141 and a second bus bar 142 arranged opposite each other in a second direction Y, as well as first electrode fingers 143 located on the first bus bar 141 and second electrode fingers 144 located on the second bus bar 142. The first bus bar 141 and the second bus bar 142 extend in the same direction, both extending along a third direction Z. The second direction Y and the third direction Z are parallel to the plane of the substrate 13 and intersect with each other.

[0062] In the embodiment of the present invention, the second direction Y is perpendicular to the third direction Z. The first electrode fingers 143 and the second electrode fingers 144 have the same length extension direction, which is parallel to the second direction Y. The multiple first electrode fingers 143 on the first bus bar 141 are arranged at intervals in the third direction Z, and the multiple second electrode fingers 144 on the second bus bar 142 are arranged at intervals in the third direction Z. The multiple first electrode fingers 143 on the first bus bar 141 and the multiple second electrode fingers 144 on the second bus bar 142 are arranged in sequence in the third direction Z. There are intervals between the multiple first electrode fingers 143 on the first bus bar 141 and the second bus bar 142, and there are intervals between the multiple second electrode fingers 144 on the second bus bar 142 and the first bus bar 141. In this case, the bus bars and the electrode fingers are arranged in a manner similar to crossing fingers, forming a so-called interdigitated electrode. When the first bus bar 141 and its first electrode fingers 143 function as the transmitter, the second bus bar 142 and its second electrode fingers 144 function as the receiver. Conversely, when the first bus bar 141 and its first electrode fingers 143 function as the receiver, the second bus bar 142 and its second electrode fingers 144 function as the transmitter. The transmitter converts electrical signals into acoustic waves, which primarily propagate along the substrate surface. The receiver converts the received acoustic waves into electrical signals for output, thereby achieving filtering.

[0063] like Figure 1 As shown, there is a gap between the interdigitated electrode 14 and the carrier substrate 12 in the first direction X, and this gap area is the cavity area of ​​the surface acoustic wave filter 11; the pad structure 15 includes a pad main body structure 151 and N wall structures 152 arranged in sequence from the inside to the outside, and the wall structure 152 forms a closed figure. The interdigitated electrode 14 and the pad main body structure 151 are located inside the area surrounded by the first wall structure 152. Since the pad structure 15 contacts the substrate 13 and the carrier substrate 12 respectively in the first direction X, the setting of at least the Nth wall structure 152 during the preparation of the plastic encapsulation layer 16 will prevent the plastic encapsulation filler from entering the cavity area, and the setting of N wall structures 152 can also achieve N-fold protection of the working area of ​​the surface acoustic wave filter packaging structure, thereby achieving effective protection of the working area of ​​the surface acoustic wave filter packaging structure. Compared with the existing technical solutions, the technical solution of the present application does not require additional materials and structures to form a closed cavity, and uses the pad structure 15 as a barrier layer for the plastic encapsulation filler, thereby simplifying the process steps and reducing production costs.

[0064] Optionally, the material of the pad structure 15 includes but is not limited to Al material, that is, the material of the pad main body structure 151 includes but is not limited to Al material, and the material of the wall structure 152 includes but is not limited to Al material.

[0065] In an optional embodiment of the present invention, reference Figure 4 , Figure 4 This is a schematic structural diagram of another surface acoustic wave filter packaging structure provided by an embodiment of the present invention. The wall structure 152 and the pad main body structure 151 are integrally formed.

[0066] Specifically, in the embodiment of the present invention, the wall structure 152 and the pad main structure 151 are set to an integrally formed structure to improve the overall stability of the pad structure 15 and avoid the problem of the wall structure 152 and / or the pad main structure 151 tilting.

[0067] In an optional embodiment of the present invention, at least one of the N wall structures 152 is electrically connected to the pad main structure 151 .

[0068] Specifically, in the embodiment of the present invention, at least one of the N wall structures 152 is electrically connected to the pad main structure 151. Obviously, the wall structure 152 electrically connected to the pad main structure 151 can also serve as an electrical connection point between the surface acoustic wave filter 11 and external components, thereby reducing the difficulty of electrical connection between the surface acoustic wave filter 11 and external components, and can be applicable to various layout designs.

[0069] It should be noted that if Figure 2 As shown, four pad main body structures 151 are illustrated, wherein the pad main body structures 151 at the upper left corner and the lower right corner are not connected to the wall structure 152 and are independent of each other, and the pad main body structures 151 at the lower left corner and the upper right corner are an integrated structure with the wall structure 152. Figure 2 The pad main body structure 151 at the lower left corner and the upper right corner is not illustrated.

[0070] It should be further explained that the layout of the pad main structure 151 and the wall structure 152 may also include other variations. Figure 2In terms of the orientation shown, the two pad main structures 151 on the left are not connected to the wall structure 152 and are independent of each other, and the two pad main structures 151 on the right are an integral structure with the wall structure 152; or, the two pad main structures 151 on the top are not connected to the wall structure 152 and are independent of each other, and the two pad main structures 151 on the bottom are an integral structure with the wall structure 152; or, one of the four pad main structures 151 is not connected to the wall structure 152 and is independent of each other, and the remaining three pad main structures 151 are an integral structure with the wall structure 152; or, three of the four pad main structures 151 are not connected to the wall structure 152 and are independent of each other, and the remaining one pad main structure 151 is an integral structure with the wall structure 152; and so on.

[0071] In an optional embodiment of the present invention, reference Figure 5 , Figure 5 A schematic diagram of another surface acoustic wave filter packaging structure provided by an embodiment of the present invention. The width of the N wall structures 152 gradually decreases from the outside to the inside. Figure 5 As shown, there is a relationship of L1>L2.

[0072] Specifically, in the embodiment of the present invention, the width of the wall structure 152 ranges from 10 μm to 15 μm; for example, the width of the wall structure 152 is 10 μm, 13.5 μm, or 15 μm. Because the plastic encapsulation filler will first impact the Nth wall structure 152, to prevent the Nth wall structure 152 from tilting or collapsing, the width of the Nth wall structure 152 is set to be relatively wide, forming a structure in which the widths of the N wall structures 152 gradually decrease from the outside to the inside. This improves the stability of the Nth wall structure 152, thereby effectively protecting the working area of ​​the surface acoustic wave filter packaging structure to the greatest extent possible.

[0073] In an optional embodiment of the present invention, Figure 1 、 Figure 4 as well as Figure 5 As shown, the surface acoustic wave filter packaging structure provided by the embodiment of the present invention further includes:

[0074] A bonding layer 17 is located on the side of the carrier substrate 12 facing the surface acoustic wave filter 11 ; the pad structure 15 is in contact with the carrier substrate 12 via a groove penetrating the bonding layer 17 .

[0075] The surface acoustic wave filter packaging structure provided by the embodiment of the present invention further includes: a through hole penetrating the carrier substrate 12, and an external lead structure 18. The external lead structure 18 is electrically connected to the pad main body structure 151 through the through hole.

[0076] The SAW filter packaging structure provided by the embodiment of the present invention further includes: a protective layer 19 located on a side of the carrier substrate 12 away from the SAW filter 11 ; the protective layer 19 exposes a portion of the surface of the external lead structure 18 .

[0077] It should be noted that the external lead structure 18 is also referred to as an RDL (Re Distribution Layer) structure in the field.

[0078] Specifically, in an embodiment of the present invention, a bonding layer 17 is provided to achieve bonding between the surface acoustic wave filter 11 and the carrier substrate 12, and the pad structure 15 is contacted with the carrier substrate 12 through a groove penetrating the bonding layer 17. This can increase the contact area between the pad structure 15 and the bonding layer 17, thereby improving the bonding stability of the surface acoustic wave filter packaging structure, and directly using a through-hole process to form the electrical connection of the RDL. Compared with the gold ball bonding process of the prior art, the process steps are simplified, the production cost is reduced, and the production efficiency is improved.

[0079] The protective layer 19 is mainly used to protect the surface area of ​​the exposed external lead structure 18 and a partial area of ​​the carrier substrate 12 , and a few electrical connection points are exposed according to actual needs.

[0080] Optionally, the material of the external lead structure 18 includes but is not limited to Cu material.

[0081] Based on the above embodiment of the present invention, another embodiment of the present invention further provides a method for preparing a surface acoustic wave filter packaging structure, referring to Figure 6 , Figure 6 A schematic flow chart of a method for preparing a surface acoustic wave filter packaging structure provided by an embodiment of the present invention. The method for preparing a surface acoustic wave filter packaging structure provided by an embodiment of the present invention comprises:

[0082] S101: If Figure 7 As shown, a surface acoustic wave filter 11 is provided, which includes a substrate 13, an interdigitated electrode 14 and a pad structure 15; the pad structure 15 includes a pad main structure 151 and N wall structures 152 arranged in sequence from the inside to the outside, N ≥ 1, and N is a positive integer; the interdigitated electrode 14 and the pad main structure 151 are located inside the area enclosed by the first wall structure 152.

[0083] Specifically, in the embodiment of the present invention, the wall structure 152 and the pad main body structure 151 are formed in the same process. Optionally, the wall structure 152 and the pad main body structure 151 are an integrally formed structure.

[0084] S102: Figure 8 and Figure 9 As shown, the surface acoustic wave filter 11 is fixed on a carrier substrate 12; the substrate 13 and the carrier substrate 12 are arranged relative to each other in a first direction X, and the first direction X is perpendicular to the plane where the substrate 13 is located; the interdigitated electrodes 14 and the pad structure 15 are located on the side of the substrate 13 facing the carrier substrate 12; the pad structure 15 is in contact with the substrate 13 and the carrier substrate 12 respectively in the first direction X, and there is a gap between the interdigitated electrodes 14 and the carrier substrate 12 in the first direction X.

[0085] Specifically, in the embodiment of the present invention, Figure 8 As shown, before fixing the surface acoustic wave filter 11 on the carrier substrate 12, the method for preparing the surface acoustic wave filter packaging structure further includes:

[0086] A bonding layer 17 is formed on one side surface of the carrier substrate 12. Figure 9 As shown, after the surface acoustic wave filter 11 is fixed on the carrier substrate 12 , the pad structure 15 contacts the carrier substrate 12 through the groove penetrating the bonding layer 17 .

[0087] S103: If Figure 10 As shown, a plastic packaging layer 16 is formed to package the surface acoustic wave filter 11 , and the plastic packaging layer 16 contacts the outer side wall of the Nth wall structure 152 .

[0088] Optionally, the method for preparing the surface acoustic wave filter packaging structure provided in the embodiment of the present invention further includes:

[0089] like Figure 11 As shown, the carrier substrate 12 is processed to form a through hole 20 penetrating the carrier substrate 12 .

[0090] like Figure 12 As shown, an external lead structure 18 is formed; the external lead structure 18 is electrically connected to the pad main body structure 151 through the through hole 20.

[0091] like Figure 1 As shown, a protection layer 19 is formed on the side of the carrier substrate 12 away from the surface acoustic wave filter 11 ; the protection layer 19 exposes a portion of the surface of the external lead structure 18 .

[0092] From the above description, it can be seen that in the surface acoustic wave filter packaging structure prepared in the embodiment of the present invention, there is a gap between the interdigitated electrode 14 and the carrier substrate 12 in the first direction X, and this gap area is the cavity area of ​​the surface acoustic wave filter 11; the pad structure 15 includes a pad main body structure 151 and N wall structures 152 arranged in sequence from the inside to the outside, and the wall structure 152 forms a closed figure. The interdigitated electrodes 14 and the pad main body structure 151 are located inside the area enclosed by the first wall structure 152. Since the pad structure 15 contacts the substrate 13 and the carrier substrate 12 respectively in the first direction X, the setting of at least the Nth wall structure 152 during the preparation of the plastic packaging layer 16 will prevent the plastic packaging filler from entering the cavity area, and the setting of N wall structures 152 can also achieve N-fold protection of the working area of ​​the surface acoustic wave filter packaging structure, thereby achieving effective protection of the working area of ​​the surface acoustic wave filter packaging structure. Compared with the existing technical solutions, the technical solution of the present application does not require additional materials and structures to form a closed cavity, and uses the pad structure as a barrier layer for the plastic encapsulation filler, thereby simplifying the process steps and reducing production costs.

[0093] Based on the above embodiment of the present invention, another embodiment of the present invention further provides a radio frequency device, which includes the surface acoustic wave filter packaging structure described in the above embodiment.

[0094] Based on the above embodiments of the present invention, another embodiment of the present invention further provides a vehicle-mounted device, which includes the surface acoustic wave filter packaging structure described in the above embodiments.

[0095] Alternatively, the vehicle-mounted device includes the radio frequency device described in the above embodiment.

[0096] The above is a detailed introduction to a surface acoustic wave filter packaging structure, a preparation method thereof, and related equipment provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

[0097] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0098] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that the process, method, article, or apparatus comprising a series of elements inherent to the elements, or also including elements inherent to these processes, methods, articles, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0099] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surface acoustic wave filter packaging structure, characterized in that: The surface acoustic wave filter packaging structure includes: a surface acoustic wave filter and a carrier substrate; The surface acoustic wave filter comprises a substrate, interdigitated electrodes and a pad structure; the substrate and the carrier substrate are arranged relative to each other in a first direction, and the first direction is perpendicular to the plane where the substrate is located; The interdigitated electrodes and the pad structure are located on a side of the substrate facing the carrier substrate; the pad structure includes a pad main structure and N wall structures arranged in sequence from the inside to the outside, N ≥ 1, and N is a positive integer; the interdigitated electrodes and the pad main structure are located inside the area surrounded by the first wall structure; wherein at least one of the N wall structures is electrically connected to the pad main structure, the pad structure is in contact with the substrate and the carrier substrate respectively in the first direction, and there is a gap between the interdigitated electrodes and the carrier substrate in the first direction; The surface acoustic wave filter packaging structure further includes a plastic packaging layer for packaging the surface acoustic wave filter, and the plastic packaging layer is in contact with the outer side wall of the Nth wall structure.

2. The surface acoustic wave filter packaging structure according to claim 1, wherein: The wall structure and the pad main body structure are an integrally formed structure.

3. The surface acoustic wave filter packaging structure according to any one of claims 1 to 2, characterized in that: The widths of the N wall structures gradually decrease from the outside to the inside.

4. The surface acoustic wave filter packaging structure according to claim 1, wherein: The surface acoustic wave filter packaging structure further includes: A bonding layer is located on a side of the carrier substrate facing the surface acoustic wave filter; the pad structure is in contact with the carrier substrate via a groove penetrating the bonding layer.

5. The surface acoustic wave filter packaging structure according to claim 1, wherein: The surface acoustic wave filter packaging structure further includes: a through hole penetrating the carrier substrate and an external lead structure; The external lead structure is electrically connected to the pad main body structure through the through hole.

6. The surface acoustic wave filter packaging structure according to claim 5, characterized in that: The surface acoustic wave filter packaging structure further includes: A protective layer is located on a side of the carrier substrate away from the surface acoustic wave filter; the protective layer exposes a portion of the surface of the external lead structure.

7. The surface acoustic wave filter packaging structure according to claim 1, wherein: The interdigitated electrodes include a first bus bar and a second bus bar disposed opposite to each other in a second direction, and a first electrode finger located on the first bus bar and a second electrode finger located on the second bus bar; The first bus bar and the second bus bar have the same length extension direction, both extending along a third direction. The second direction and the third direction are parallel to the plane where the substrate is located, and the second direction and the third direction intersect.

8. A method for preparing a surface acoustic wave filter packaging structure, characterized in that: The preparation method of the surface acoustic wave filter packaging structure comprises: A surface acoustic wave filter is provided, comprising a substrate, interdigitated electrodes, and a pad structure; the pad structure comprises a pad main structure and N wall structures arranged sequentially from the inside to the outside, N ≥ 1, and N is a positive integer; the interdigitated electrodes and the pad main structure are located inside an area surrounded by the first wall structure; at least one of the N wall structures is electrically connected to the pad main structure, The surface acoustic wave filter is fixed on a carrier substrate; the substrate and the carrier substrate are arranged relative to each other in a first direction, the first direction being perpendicular to the plane of the substrate; the interdigitated electrodes and the pad structure are located on a side of the substrate facing the carrier substrate; the pad structure is in contact with the substrate and the carrier substrate respectively in the first direction, and there is a gap between the interdigitated electrodes and the carrier substrate in the first direction; A plastic packaging layer is formed for packaging the surface acoustic wave filter, and the plastic packaging layer is in contact with the outer side wall of the Nth surrounding wall structure.

9. The method for preparing a surface acoustic wave filter packaging structure according to claim 8, wherein: The wall structure and the pad main body structure are formed in the same process, and the wall structure and the pad main body structure are an integrally formed structure.

10. The method for preparing a surface acoustic wave filter packaging structure according to claim 8, wherein: Before fixing the surface acoustic wave filter on the carrier substrate, the method for preparing the surface acoustic wave filter packaging structure further includes: A bonding layer is formed on one side surface of the carrier substrate; after the surface acoustic wave filter is fixed on the carrier substrate, the pad structure contacts the carrier substrate through a groove penetrating the bonding layer.

11. The method for preparing a surface acoustic wave filter packaging structure according to any one of claims 8 to 10, characterized in that: The method for preparing the surface acoustic wave filter packaging structure further comprises: Processing the carrier substrate to form a through hole penetrating the carrier substrate; An external lead structure is formed; the external lead structure is electrically connected to the pad main body structure through the through hole.

12. The method for preparing a surface acoustic wave filter packaging structure according to claim 11, wherein: The method for preparing the surface acoustic wave filter packaging structure further comprises: A protective layer is formed on a side of the carrier substrate away from the surface acoustic wave filter; the protective layer exposes a portion of the surface of the external lead structure.

13. A radio frequency device, characterized in that: The radio frequency device includes the surface acoustic wave filter packaging structure according to any one of claims 1 to 7.

14. A vehicle-mounted device, characterized in that: The vehicle-mounted equipment includes the surface acoustic wave filter packaging structure according to any one of claims 1 to 7.

15. A vehicle-mounted device, characterized in that: The vehicle-mounted device includes the radio frequency device according to claim 13.

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