An encapsulation structure and a manufacturing method thereof

Abstract

The present application provides a packaging structure and a manufacturing method thereof. The packaging structure includes: a first substrate and a second substrate that are bonded to each other and wrapped in a plastic encapsulation layer; a first device and a first protective cover disposed on a first surface of the first substrate, a first cavity being formed between the first protective cover and the first substrate, and the first device being located in the first cavity; a second device disposed on a first surface of the second substrate; a bonding structure disposed between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface, so that a third cavity is formed between the second surface of the first substrate and the second surface of the second substrate; a third device disposed on the second surface of the first substrate, the third device being located in the third cavity; and a second heat conduction structure disposed on the plastic encapsulation layer.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of semiconductor technology, and in particular, to a packaging structure and a manufacturing method thereof. Background Art

[0002] In recent years, the development trend of device packaging has been comprehensively considered in terms of being thin, light, short, and small, as well as integration. In packaging technology, there is an increasing demand for the flexibility of the usage area and the protection of the package. The development trend of devices is also towards miniaturization. In order to more effectively utilize the space area, this goal is achieved through the improvement and enhancement of the packaging process. Summary of the Invention

[0003] In view of this, embodiments of the present application provide a packaging structure and a manufacturing method thereof to solve at least one technical problem existing in the prior art.

[0004] To achieve the above object, the technical solution of the present application is implemented as follows:

[0005] In a first aspect, an embodiment of the present application provides a packaging structure, which includes:

[0006] A first substrate and a second substrate that are bonded to each other and wrapped in a plastic encapsulation layer;

[0007] A first device and a first protective cover disposed on a first surface of the first substrate, a first cavity is formed between the first protective cover and the first substrate, and the first device is located in the first cavity;

[0008] A second device disposed on a first surface of the second substrate;

[0009] A bonding structure disposed between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface, so that a third cavity is formed between the second surface of the first substrate and the second surface of the second substrate;

[0010] A third device disposed on the second surface of the first substrate, and the third device is located in the third cavity;

[0011] A second heat conduction structure disposed on the plastic encapsulation layer.

[0012] In a second aspect, an embodiment of the present application provides a packaging structure, which includes:

[0013] A first substrate and a second substrate that are bonded to each other and wrapped in a plastic encapsulation layer;

[0014] A first device and a first protective cover disposed on a first surface of the first substrate, a first cavity being formed between the first protective cover and the first substrate, and the first device being located within the first cavity;

[0015] A second device and a second protective cover disposed on a first surface of the second substrate, a second cavity being formed between the second protective cover and the second substrate, and the second device being located within the second cavity;

[0016] A bonding layer disposed between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface;

[0017] A second heat conduction structure disposed on the encapsulation layer.

[0018] In some embodiments, the second heat conduction structure is made of a material with a thermal conductivity greater than that of.

[0019] In some embodiments, the ratio of the thickness of the second heat conduction structure in a direction perpendicular to the first substrate to the thickness of the encapsulation structure in a direction perpendicular to the first substrate ranges from 0.01 to 0.5.

[0020] In some embodiments, the ratio of the area of the positive projection of the second heat conduction structure on the first substrate to the area of the positive projection of the encapsulation structure on the first substrate is greater than or equal to 1 / 3.

[0021] In some embodiments, the second heat conduction structure includes a plurality of heat conduction material layers stacked in a direction perpendicular to the first substrate, and the heat conduction coefficient of the heat conduction material layer closer to the encapsulation layer is greater than or equal to that of the heat conduction material layer farther from the encapsulation layer.

[0022] In some embodiments, the second heat conduction structure includes a plurality of heat conduction material layers stacked in a direction perpendicular to the first substrate, and the thickness of the heat conduction material layer closer to the encapsulation layer in a direction perpendicular to the first substrate is greater than the thickness of the heat conduction material layer farther from the encapsulation layer in a direction perpendicular to the first substrate.

[0023] In some embodiments, the encapsulation structure further includes:

[0024] A printed circuit board PCB electrically connected to the first device, the second device, and the third device, with the first device located between the PCB and the third device.

[0025] In some embodiments, the first device includes at least one of the following: surface acoustic wave filter device, bulk acoustic wave filter device, resistor-inductor-capacitor passive filter device, and integrated passive device filter device;

[0026] The second device includes at least one of the following: power amplifier, low noise amplifier, switch, filter, and passive component;

[0027] The third device includes at least one of the following: surface acoustic wave filter device, bulk acoustic wave filter device, resistor-inductor-capacitor passive filter device, and integrated passive device filter device.

[0028] In a third aspect, an embodiment of the present application provides a manufacturing method for a packaging structure, and the manufacturing method includes:

[0029] Forming a first substrate and a second substrate bonded to each other; wherein, a first device and a first protective cover are disposed on a first surface of the first substrate, a first cavity is formed between the first protective cover and the first substrate, and the first device is located in the first cavity; a second device is disposed on a first surface of the second substrate;

[0030] Providing a printed circuit board (PCB), and disposing the mutually bonded first substrate and second substrate on the PCB;

[0031] Encapsulating the mutually bonded first substrate and second substrate on the PCB to form an encapsulation layer;

[0032] Forming a second heat conduction structure on the encapsulation layer.

[0033] In some embodiments, the forming of the mutually bonded first substrate and second substrate includes:

[0034] Forming a bonding structure between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface, so that a third cavity is formed between the second surface of the first substrate and the second surface of the second substrate.

[0035] In some embodiments, a third device is further disposed on the second surface of the first substrate, and the third device is located in the third cavity.

[0036] In some embodiments, before forming the encapsulation layer, the manufacturing method further includes:

[0037] Forming leads; wherein, the third device is electrically connected to the PCB through the leads.

[0038] In some embodiments, before forming the mutually bonded first substrate and second substrate, the manufacturing method further includes:

[0039] The first device and the first protective cover are formed on a first surface of the first substrate, and a first cavity is formed between the first protective cover and the first substrate so that the first device is located within the first cavity;

[0040] A first redistribution layer is formed on the first protective cover;

[0041] A bump structure is formed on the first redistribution layer; wherein, the first device is electrically connected to the PCB through the bump structure.

[0042] In some embodiments, before forming the first substrate and the second substrate that are bonded to each other, the manufacturing method further includes:

[0043] Forming a conductive via hole penetrating the first substrate; wherein, the conductive via hole is electrically connected to the first redistribution layer.

[0044] In some embodiments, after forming the first substrate and the second substrate that are bonded to each other, the manufacturing method further includes:

[0045] Forming a second redistribution layer on a first surface of the second substrate; wherein, the second device is electrically connected to the PCB through the conductive via hole and the bump structure.

[0046] In some embodiments, after forming the first substrate and the second substrate that are bonded to each other, the manufacturing method further includes:

[0047] Forming a second protective cover on a first surface of the second substrate, and a second cavity is formed between the second protective cover and the second substrate so that the second device is located within the second cavity.

[0048] An embodiment of the present application provides a packaging structure and a manufacturing method thereof. The packaging structure includes: a first substrate and a second substrate bonded to each other and wrapped in a plastic encapsulation layer; a first device and a first protective cover disposed on a first surface of the first substrate, a first cavity being formed between the first protective cover and the first substrate, and the first device being located in the first cavity; a second device disposed on a first surface of the second substrate; a bonding structure disposed between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface, so that a third cavity is formed between the second surface of the first substrate and the second surface of the second substrate; a third device disposed on the second surface of the first substrate, the third device being located in the third cavity; and a second heat conduction structure disposed on the plastic encapsulation layer. In the embodiment of the present application, by providing the second heat conduction structure on the plastic encapsulation layer, the purpose of quickly dissipating the heat generated when the first device and the second device operate to the outside can be achieved while not significantly increasing the size of the packaging structure in the vertical direction. Further, the first substrate and the second substrate are bonded to each other and disposed in the plastic encapsulation layer to form a stacked structure, so as to reduce the area of the packaging structure, which is beneficial to the integration and miniaturization of the packaging structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1A FIG. 1 is a schematic cross-sectional structure diagram I of a packaging structure provided by an embodiment of the present application;

[0050] Figure 1B FIG. 2 is a schematic cross-sectional structure diagram II of a packaging structure provided by an embodiment of the present application;

[0051] Figure 2A FIG. 3 is a schematic cross-sectional structure diagram I of the mutually bonded first substrate and second substrate provided by an embodiment of the present application;

[0052] Figure 2B FIG. 4 is a schematic cross-sectional structure diagram II of the mutually bonded first substrate and second substrate provided by an embodiment of the present application;

[0053] Figure 2C FIG. 5 is a schematic cross-sectional structure diagram III of the mutually bonded first substrate and second substrate provided by an embodiment of the present application;

[0054] Figure 3A FIG. 6 is a schematic cross-sectional structure diagram I of another packaging structure provided by an embodiment of the present application;

[0055] Figure 3B FIG. 7 is a schematic cross-sectional structure diagram II of another packaging structure provided by an embodiment of the present application;

[0056] Figure 4 FIG. 8 is a schematic top view structure diagram of the first heat conduction structure in the packaging structure provided by an embodiment of the present application;

[0057] Figure 5A Schematic diagram I of the cross-sectional structure of the encapsulation structure provided by the embodiment of the present application;

[0058] Figure 5B Schematic diagram II of the cross-sectional structure of the encapsulation structure provided by the embodiment of the present application;

[0059] Figure 5C Schematic diagram III of the cross-sectional structure of the encapsulation structure provided by the embodiment of the present application;

[0060] Figure 5D Schematic diagram of the cross-sectional structure of the encapsulation structure provided by the embodiment of the present application Figure Four ;

[0061] Figure 6A Schematic diagram of the heat conduction principle of the encapsulation structure provided by the embodiment of the present application;

[0062] Figure 6B Schematic diagram of the heat transfer principle of the encapsulation structure provided by the embodiment of the present application;

[0063] Figure 7A Top view structure diagram of another encapsulation structure provided by the embodiment of the present application;

[0064] Figure 7B Is along Figure 7A Cross-sectional structure diagram of BB in;

[0065] Figure 7C Is along Figure 7A Cross-sectional structure diagram of CC in;

[0066] Figure 8 Flowchart of the manufacturing method of the encapsulation structure provided by the embodiment of the present application;

[0067] Figure 9A Schematic diagram I of the cross-sectional structure during the process of manufacturing the encapsulation structure provided by the embodiment of the present application;

[0068] Figure 9B Schematic diagram II of the cross-sectional structure during the process of manufacturing the encapsulation structure provided by the embodiment of the present application;

[0069] Figure 9C Schematic diagram III of the cross-sectional structure during the process of manufacturing the encapsulation structure provided by the embodiment of the present application;

[0070] Figure 9D Schematic diagram of the cross-sectional structure during the process of manufacturing the encapsulation structure provided by the embodiment of the present application Figure Four ;

[0071] Figure 9E Schematic diagram V of the cross-sectional structure during the process of manufacturing the encapsulation structure provided by the embodiment of the present application;

[0072] Figure 9F Schematic cross-sectional structure diagram six of the process for manufacturing the encapsulation structure provided by the embodiment of the present application;

[0073] Figure 9G Schematic cross-sectional structure diagram seven of the process for manufacturing the encapsulation structure provided by the embodiment of the present application;

[0074] Figure 9H Schematic cross-sectional structure of the process for manufacturing the encapsulation structure provided by the embodiment of the present application Figure Eight ;

[0075] Figure 9I Schematic cross-sectional structure diagram nine of the process for manufacturing the encapsulation structure provided by the embodiment of the present application;

[0076] The figure includes: 101, the first substrate; 101a, the first surface of the first substrate; 101b, the second surface of the first substrate; 101-1, the middle area of the first substrate; 101-2, the edge area of the first substrate; 102, the first device; 103, the first protective cover; 104, the first redistribution layer; 105, the bump structure; 106, the third device; 107, the conductive via; 108, the lead; 201, the second substrate; 201a, the first surface of the second substrate; 201b, the second surface of the second substrate; 201-1, 201-3, the middle areas of the second substrate; 201-2, 201-4, the edge areas of the second substrate; 202, the second device; 203, the second protective cover; 204, the second redistribution layer; 300, the plastic encapsulation layer; 400, the bonding layer; 401, 402, 403, the bonding structures; 500, the printed circuit board; 601, the first heat conduction structure; 601a, the first end face; 601b, the second end face; 602, the second heat conduction structure. Detailed implementation manners

[0077] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the embodiments of the present application and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0078] In the following description, a large number of specific details are given to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features known to the public are not described; that is, not all features of the actual embodiments are described here, and the well-known functions and structures are not described in detail.

[0079] In the drawings, for the sake of clarity, the dimensions of layers, regions, elements and their relative dimensions may be exaggerated. Throughout the drawings, like reference numerals indicate like elements.

[0080] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, then no intervening elements or layers are present. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or portions, these elements, components, regions, layers and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or portion from another element, component, region, layer or portion. Thus, without departing from the teachings of the present application, the first element, component, region, layer or portion discussed below may be referred to as the second element, component, region, layer or portion. And when discussing the second element, component, region, layer or portion, it does not imply that a first element, component, region, layer or portion necessarily exists in the present application.

[0081] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. are used herein for convenience in describing the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relationship terms are intended to include different orientations of the device in use and operation. For example, if the device in the figures is flipped, then an element or feature described as "under" or "beneath" or "below" other elements or features will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "below" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0082] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present application. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0083] To thoroughly understand the present application, detailed steps and structures will be presented in the following description to illustrate the technical solutions of the present application. The preferred embodiments of the present application are described in detail below. However, in addition to these detailed descriptions, the present application may have other implementation manners.

[0084] In the embodiments of the present application, the vertical direction refers to the direction perpendicular to the first substrate or the second substrate. In other words, the vertical direction refers to the direction parallel to the thickness direction of the first substrate or the second substrate. In the embodiments of the present application, the horizontal plane refers to the plane parallel to the first substrate or the second substrate, and the vertical direction is perpendicular to the horizontal plane. Here, the vertical direction is defined as the Z direction, and the horizontal plane is defined as the XY plane, and the X direction and the Y direction are perpendicular to each other.

[0085] Reference Figure 1A , Figure 1A is a schematic cross-sectional structure diagram one of a packaging structure provided by an embodiment of the present application. As Figure 1A shown, an embodiment of the present application provides a packaging structure, which includes:

[0086] The first substrate 101 and the second substrate 201 that are bonded to each other and wrapped in the plastic encapsulation layer 300;

[0087] The first device 102 and the first protective cover 103 disposed on the first surface 101a of the first substrate, a first cavity is formed between the first protective cover 103 and the first substrate 101, and the first device 102 is located in the first cavity;

[0088] The second device 202 disposed on the first surface 201a of the second substrate;

[0089] The bonding structure 401 disposed between the second surface 101b of the first substrate and the second surface 201b of the second substrate, so that a third cavity is formed between the second surface 101b of the first substrate and the second surface 201b of the second substrate;

[0090] The third device 106 disposed on the second surface 101b of the first substrate, and the third device 106 is located in the third cavity;

[0091] A plurality of first heat-conducting structures 601 disposed in the plastic encapsulation layer 300, the first heat-conducting structure 601 includes a first end face 601a and a second end face 601b that are oppositely disposed, the first end face 601a is disposed on the first substrate 101 or the second substrate 201, and the second end face 601b is exposed by the plastic encapsulation layer.

[0092] In an embodiment of the present application, a first device is disposed on a first surface of a first substrate. The first device is encapsulated within a first cavity formed between a first protective cover and the first surface of the first substrate. A third device is disposed on a second surface of the first substrate. The third device is encapsulated within a third cavity formed between the second surface of the first substrate and the second surface of a second substrate. A second device is disposed on a first surface of the second substrate. The second device is encapsulated within a second cavity formed between a second protective cover and the first surface of the second substrate. The first device, the third device, and the second device are stacked in the vertical direction, and the first device, the third device, and the second device are respectively encapsulated within the first cavity, the third cavity, and the second cavity. In this way, the arrangement of the devices within the packaging structure is more concentrated, which is conducive to the integration and miniaturization of the packaging structure.

[0093] However, the design of this packaging structure makes it difficult for the heat generated by the first device, the second device, and the third device during operation to dissipate to the outside, and the overall heat dissipation performance of the packaging structure is poor.

[0094] In an embodiment of the present application, by providing a plurality of first heat conduction structures on the first substrate or the second substrate, the second end surface of the first heat conduction structure is flush with the upper surface of the plastic encapsulation layer. That is to say, in the embodiment of the present application, by providing the first heat conduction structure, while not increasing the size of the packaging structure in the vertical direction, it is also possible to achieve the purpose of quickly dissipating the heat generated by the first device, the third device, and the second device during operation to the outside, thereby improving the heat dissipation performance of the packaging structure.

[0095] Reference Figure 1B , Figure 1B is a second schematic cross-sectional structure diagram of a packaging structure provided by an embodiment of the present application. As Figure 1B shown, an embodiment of the present application provides a packaging structure, which includes:

[0096] A first substrate 101 and a second substrate 201 that are bonded to each other and encapsulated within a plastic encapsulation layer 300;

[0097] A first device 102 and a first protective cover 103 disposed on a first surface 101a of the first substrate. A first cavity is formed between the first protective cover 103 and the first substrate 101, and the first device 102 is located within the first cavity;

[0098] A second device 202 disposed on a first surface 201a of the second substrate;

[0099] A bonding structure 401 disposed between a second surface 101b of the first substrate and a second surface 201b of the second substrate, so as to form a third cavity between the second surface 101b of the first substrate and the second surface 201b of the second substrate;

[0100] The third device 106 is disposed on the second surface 101b of the first substrate, and the third device 106 is located within the third cavity;

[0101] The second heat conduction structure 602 is disposed on the encapsulation layer 300.

[0102] In the embodiment of the present application, the first substrate and the second substrate are bonded to each other and disposed within the encapsulation layer to form a stacked structure, so as to reduce the area of the encapsulation structure, which is beneficial to the integration and miniaturization of the encapsulation structure.

[0103] However, such a design of the encapsulation structure makes it difficult for the heat generated by the first device, the second device, and the third device during operation to dissipate to the outside, and the overall heat dissipation performance of the encapsulation structure is poor.

[0104] In the embodiment of the present application, by disposing the second heat conduction structure on the encapsulation layer, while not significantly increasing the size of the encapsulation structure in the vertical direction, it is also possible to achieve the purpose of quickly dissipating the heat generated by the first device, the third device, and the second device during operation to the outside, thereby improving the heat dissipation performance of the encapsulation structure.

[0105] Here, the first surface and the second surface of the first substrate are the opposite surfaces in the first substrate, and the first surface and the second surface of the second substrate are the opposite surfaces in the second substrate. The first surface of the first substrate can be regarded as the front surface of the first substrate, and the second surface of the first substrate can be regarded as the back surface of the first substrate; the first surface of the second substrate can be regarded as the front surface of the second substrate, and the second surface of the second substrate can be regarded as the back surface of the second substrate; then in the encapsulation structure provided by the embodiment of the present application, the back surfaces of the first substrate and the second substrate are bonded to each other.

[0106] Here, a first device is disposed on the front surface of the first substrate, and a third device is disposed on the back surface of the first substrate. The first device and the third device share the first substrate.

[0107] In the embodiment of the present application, the materials of the first substrate and the second substrate can be the same or different.

[0108] In some embodiments, the materials of the first substrate and the second substrate may include materials with piezoelectric properties, such as lithium niobate (LiNbO3), aluminum nitride (AlN), aluminum scandium nitride (AlScN), lead zirconate titanate (PZT), zinc oxide (ZnO), or lithium tantalate (LiTaO3, LT), etc. In other embodiments, the materials of the first substrate and the second substrate may include materials without piezoelectric properties, such as silicon (Si), germanium (Ge), silicon on insulator (SOI), indium gallium phosphide (InGaP), or gallium arsenide (GaAs), etc.

[0109] Figure 1A and Figure 1BIt shows that two first devices are provided on the front side of the first substrate, one third device is provided on the back side of the first substrate, and one second device is provided on the second substrate. In fact, the number of the first devices and the third devices provided on the first substrate is not limited to this, and the number of the second devices provided on the second substrate is not limited to this either. It should be noted that multiple first devices can be arranged side by side on the front side of the first substrate, multiple third devices can be arranged side by side on the back side of the first substrate, and multiple second devices can be arranged side by side on the front side of the second substrate.

[0110] In the embodiment of the present application, a first protection cap is formed on the first substrate. The first protection cap covers the first device and there is a gap between the first protection cap and the first device. In other words, the first protection cap does not contact the first device. The edge region of the first protection cap contacts the first substrate so that a first cavity is formed between the first protection cap and the first substrate, and the first device is located in the first cavity. Here, the first protection cap is located above the first device and the first protection cap completely covers the first device to form a Wafer Level Packaging (WLP).

[0111] In some embodiments, the material of the first protection cap can be selected from at least one of dry film, photoresist (PR) film, photosensitive polymer, SU8 film, resin, silicon substrate, germanium substrate, quartz substrate, glass substrate, silicon on glass (SOG) substrate, lithium tantalate (LiTaO3, LT) substrate, sapphire substrate, gallium arsenide (GaAs) substrate, and silicon carbide (SiC) substrate.

[0112] In the embodiment of the present application, by forming the first protection cap on the first substrate to form the first cavity, the purpose of protecting the first device is achieved. Further, when the first device is a filtering device, the first protection cap can reflect the acoustic wave signal of the first device, thereby reducing the energy loss of the acoustic wave signal of the first device, and finally achieving the purpose of protecting the first device.

[0113] In an embodiment of the present application, the first device includes at least one of the following: a surface acoustic wave (SAW) filter device, a bulk acoustic wave (BAW) filter device, a resistance-inductance-capacitance (RLC) passive filter device, and an integrated passive device (IPD) filter device; the second device includes at least one of the following: a power amplifier (PA), a low noise amplifier (LNA), a switch, a filter, and a passive component; the third device includes at least one of the following: a surface acoustic wave filter device, a bulk acoustic wave filter device, a resistance-inductance-capacitance passive filter device, and an integrated passive device filter device. Among them, the bulk acoustic wave filter device may include: a solidly mounted resonator (SMR) filter device and a film bulk acoustic resonator (FBAR) filter device.

[0114] In an embodiment of the present application, the first substrate may have a dual-sided process for a duplexer, and the first device disposed on the front surface of the first substrate and the third device disposed on the back surface of the first substrate may form a duplexer.

[0115] It should be noted that the first device is disposed on the first surface of the first substrate, and the third device is disposed on the second surface of the first substrate. The types of the first device and the third device may be the same. For example, both the first device and the third device may be solidly mounted resonator filter devices. Another example is that both the first device and the third device may be film bulk acoustic resonator filter devices. It can be understood that when the types of the first device and the third device are the same, the operating frequency bands of the first device and the third device may be different. For example, when both the first device and the third device are film bulk acoustic resonator filter devices, the thickness of the piezoelectric layer of the first device and the thickness of the piezoelectric layer of the third device may be different so that the operating frequency bands of the first device and the third device are different.

[0116] It should be noted that the first device is disposed on the first surface of the first substrate, and the third device is disposed on the second surface of the first substrate. The first device and the third device share the first substrate. Therefore, those skilled in the art need to consider the types of the first device and the third device and whether the first device and the third device can share the same substrate when selecting the types of the first device and the third device.

[0117] In some embodiments, the first device is a transmit filter (TX filter), and the third device is a receive filter (RX filter). Here, the first device is provided as a transmit filter on the first surface of the first substrate; the third device is provided as a receive filter on the second surface of the first substrate.

[0118] In some embodiments, the bonding structure can be formed by oxide fusion bonding, metal-metal bonding, or polymer adhesive bonding.

[0119] In the embodiments of the present application, the encapsulation layer completely wraps the relatively bonded first substrate and second substrate, that is, the encapsulation layer covers the mutually bonded first substrate and second substrate. In some embodiments, the material of the encapsulation layer may include, but is not limited to, one or more of epoxy resin, curing glue, polyimide, and silica gel.

[0120] The bonding structure between the first substrate and the second substrate will be described in detail below in conjunction with Figures 2A to 2C . For ease of description, Figures 2A to 2C only shows the first substrate, the second substrate, and the bonding structure.

[0121] Referring to Figure 2A , the second substrate 201 includes an intermediate region 201-1 of the second substrate and an edge region 201-2 of the second substrate surrounding the intermediate region. The thickness h1 of the intermediate region 201-1 of the second substrate is less than the thickness h2 of the edge region 201-2 of the second substrate; the encapsulation structure includes a bonding structure 401 disposed between the first substrate 101 and the second substrate 201, and a third cavity is formed between the intermediate region of the second substrate and the first substrate. Here, the thickness of the bonding structure 401 is small and can be ignored.

[0122] In the embodiments of the present application, a third cavity for wrapping the third device is formed between the intermediate region of the second substrate and the second surface of the first substrate, and the difference between the thickness of the edge region and the thickness of the intermediate region of the second substrate is greater than the thickness of the third device.

[0123] Here, the first surface of the second substrate includes the first surface of the intermediate region and the first surface of the edge region, and the second surface of the second substrate includes the second surface of the intermediate region and the second surface of the edge region. The heights of the first surface of the intermediate region and the first surface of the edge region in the vertical direction are the same, that is, the first surface of the second substrate formed by the first surface of the intermediate region and the first surface of the edge region is flat. The heights of the second surface of the intermediate region and the second surface of the edge region in the vertical direction are different, that is, the second surface of the second substrate formed by the second surface of the intermediate region and the second surface of the edge region is uneven. Thus, after bonding between the edge region of the second substrate and the second surface of the first substrate, a third cavity is formed between the intermediate region of the second substrate and the second surface of the first substrate. In other words, the front surface of the second substrate is flat, and the back surface of the second substrate is uneven.

[0124] As Figure 2B shown, the second substrate 201 includes the intermediate region 201-3 of the second substrate and the edge region 201-4 of the second substrate surrounding the intermediate region. The thickness of the intermediate region 201-3 of the second substrate is the same as the thickness of the edge region 201-4 of the second substrate, that is, both the front surface and the back surface of the second substrate are flat; the packaging structure includes a bonding structure 402 disposed between the first substrate 101 and the second substrate 201, and a third cavity is formed between the intermediate region of the second substrate and the first substrate.

[0125] Here, after thinning the back surface of the second substrate, the back surface of the first substrate and the back surface of the second substrate are bonded through the bonding structure to form a third cavity.

[0126] In the embodiment of the present application, a third cavity encapsulating the third device is formed between the intermediate region of the second substrate and the second surface of the first substrate, and the thickness of the bonding structure is greater than the thickness of the third device.

[0127] As Figure 2C shown, the first substrate 101 includes the intermediate region 101-1 of the first substrate and the edge region 101-2 of the first substrate surrounding the intermediate region. The thickness h3 of the intermediate region 101-1 of the first substrate is less than the thickness h4 of the edge region 101-2 of the first substrate; the packaging structure includes a bonding structure 403 disposed between the first substrate 101 and the second substrate 201, and a third cavity is formed between the intermediate region of the first substrate and the second substrate. Here, the thickness of the bonding structure 403 is small and can be ignored.

[0128] In the embodiment of the present application, a third cavity encapsulating the third device is formed between the intermediate region of the first substrate and the second surface of the second substrate, and the difference between the thickness of the edge region of the first substrate and the thickness of the intermediate region is greater than the thickness of the third device.

[0129] Here, the first surface of the first substrate includes the first surface of the middle region and the first surface of the edge region, and the second surface of the first substrate includes the second surface of the middle region and the second surface of the edge region. The heights of the first surface of the middle region and the first surface of the edge region in the vertical direction are the same, that is, the first surface of the first substrate formed by the first surface of the middle region and the first surface of the edge region is flat. The heights of the second surface of the middle region and the second surface of the edge region in the vertical direction are different, that is, the second surface of the second substrate formed by the second surface of the middle region and the second surface of the edge region is uneven. In other words, the front surface of the first substrate is flat, and the back surface of the first substrate is uneven.

[0130] Reference Figure 3A , Figure 3A FIG. 1 is a schematic cross-sectional structure diagram of another packaging structure provided by an embodiment of the present application. As Figure 3A shown, an embodiment of the present application provides a packaging structure, which includes:

[0131] A first substrate 101 and a second substrate 201 that are bonded to each other and wrapped in a plastic encapsulation layer 300;

[0132] A first device 102 and a first protective cover 103 disposed on the first surface 101a of the first substrate, a first cavity is formed between the first protective cover 103 and the first substrate 101, and the first device 102 is located in the first cavity;

[0133] A second device 202 and a second protective cover 203 disposed on the first surface 201a of the second substrate, a second cavity is formed between the second protective cover 203 and the second substrate 201, and the second device 202 is located in the second cavity;

[0134] A bonding layer 400 disposed between the second surface 101b of the first substrate and the second surface 201b of the second substrate;

[0135] A plurality of first heat conduction structures 601 disposed in the plastic encapsulation layer 300, the first heat conduction structure 601 includes a first end face 601a and a second end face 601b disposed opposite to each other, the first end face 601a is disposed on the first substrate 101 or the second substrate 201, and the second end face 601b is exposed by the plastic encapsulation layer 300.

[0136] In the embodiments of the present application, the first substrate and the second substrate are bonded to each other and disposed within the encapsulation layer to form a stacked structure, so as to reduce the area of the encapsulation structure, which is beneficial to the integration and miniaturization of the encapsulation structure. However, due to the fact that the first devices disposed on the first substrate and the second devices disposed on the second substrate are relatively concentrated in structure, the overall heat dissipation performance of the encapsulation structure is poor. Therefore, by disposing a plurality of first heat conduction structures on the first substrate or the second substrate, the purpose of quickly dissipating the heat generated during the operation of the first devices and the second devices to the outside can be achieved while not increasing the size of the encapsulation structure in the vertical direction.

[0137] Reference Figure 3B , Figure 3B FIG. 2 is a second schematic cross-sectional structure diagram of another encapsulation structure provided by the embodiments of the present application. As Figure 3B shown, the embodiments of the present application provide an encapsulation structure, which includes:

[0138] The first substrate 101 and the second substrate 201 that are bonded to each other and wrapped within the encapsulation layer 300;

[0139] The first device 102 and the first protective cover 103 disposed on the first surface 101a of the first substrate, a first cavity is formed between the first protective cover 103 and the first substrate 101, and the first device 102 is located within the first cavity;

[0140] The second device 202 and the second protective cover 203 disposed on the first surface 201a of the second substrate, a second cavity is formed between the second protective cover 203 and the second substrate 201, and the second device 202 is located within the second cavity;

[0141] The bonding layer 400 disposed between the second surface 101b of the first substrate and the second surface 201b of the second substrate;

[0142] The second heat conduction structure 602 disposed on the encapsulation layer 300.

[0143] In the embodiments of the present application, by disposing the second heat conduction structure on the encapsulation layer, the purpose of quickly dissipating the heat generated during the operation of the first devices and the second devices to the outside can be achieved while not significantly increasing the size of the encapsulation structure in the vertical direction, thereby improving the heat dissipation performance of the encapsulation structure.

[0144] In some embodiments, the bonding layer can be formed by an oxide fusion bonding method, a metal-metal bonding method, or a polymer adhesive bonding method.

[0145] In some embodiments, an oxide fusion bonding method can be used to form a bonding layer between the second surface of the first substrate and the second surface of the second substrate to achieve mutual bonding of the first substrate and the second substrate. For example, a dielectric layer and pads located within the dielectric layer can be formed on the second surface of the first substrate and the second surface of the second substrate, where the surface of the dielectric layer and the surface of the pads are flush; finally, an oxide fusion bonding process and an annealing process are performed, and the dielectric layer on the second surface of the first substrate and the dielectric layer on the second surface of the second substrate are bonded to form a bonding layer, and the annealing process improves the bonding quality between the dielectric layers and between the pads. In a specific embodiment of the present application, the material of the dielectric layer can be silicon dioxide, and the dielectric layer on the second surface of the first substrate and the dielectric layer on the second surface of the second substrate are bonded through silicon-oxygen bonds; the material of the pads can be copper, and the oxide fusion bonding process is used to achieve bonding between the two substrates, and the bonding process has a low temperature, a small pressure, and a short process time.

[0146] In other embodiments, a metal-metal bonding method can be used to form a bonding layer between the second surface of the first substrate and the second surface of the second substrate to achieve mutual bonding of the first substrate and the second substrate. For example, a first metal layer can be formed on the second surface of the first substrate, and a second metal layer can be formed on the second surface of the second substrate; finally, a metal-metal bonding process is performed, and the first metal layer and the second metal layer are bonded to form a bonding layer. In some embodiments, the first metal layer and the second metal layer are made of materials that can mutually perform metal bonding, for example, gold and gold, aluminum and copper, copper and copper, gold and silver, and so on.

[0147] In other embodiments, a polymer adhesion bonding method can also be used to form a bonding layer between the second surface of the first substrate and the second surface of the second substrate to achieve mutual bonding of the first substrate and the second substrate. For example, an adhesive can be spin-coated on the second surface of the first substrate, and an adhesive can also be spin-coated on the second surface of the second substrate. Here, the thickness of the adhesive must be able to compensate for substrate surface particles and surface topography; then, the polymer is soft-baked or pre-cured so that the second surface of the first substrate and the second surface of the second substrate are in contact, and the polymer adhesive is remelted or cured. In some embodiments, the polymer adhesive can include polymethyl methacrylate or polyimide.

[0148] Of course, an inorganic adhesive can also be used between the first substrate and the second substrate provided in the embodiments of the present application. For example, ceramic materials based on oxides and silicates, and an example is glass powder.

[0149] In the embodiments of the present application, the first device includes at least one of the following: surface acoustic wave filter device, bulk acoustic wave filter device, resistor-inductor-capacitor passive filter device, and integrated passive device filter device; the second device includes at least one of the following: surface acoustic wave filter device, bulk acoustic wave filter device, resistor-inductor-capacitor passive filter device, and integrated passive device filter device. Among them, the bulk acoustic wave filter device may include: a solid-state assembly type filter device and a thin film bulk acoustic wave filter device.

[0150] In some embodiments, the first device is a transmit filter and the second device is a receive filter. Here, the first device is provided on the first substrate as a transmit filter; the second device is provided on the second substrate as a receive filter.

[0151] In the embodiments of the present application, the shape of the orthographic projection of the first heat conducting structure on the first substrate or the second substrate includes at least one of the following: circular, elliptical, polygonal, and a closed figure formed by at least two straight lines and an arc.

[0152] Reference Figure 4 , Figure 4 is a top view structural schematic diagram of the first heat conducting structure in the packaging structure provided by the embodiments of the present application. As Figure 4 (a) shows, the shape presented by the first heat conducting structure in the top view is circular, then the first heat conducting structure is cylindrical; as Figure 4 (b) shows, the shape presented by the first heat conducting structure in the top view is elliptical, then the first heat conducting structure is an elliptical cylinder; as Figure 4 (c) shows, the shape presented by the first heat conducting structure in the top view is a sector; as Figure 4 (d) shows, the shape presented by the first heat conducting structure in the top view is a triangle; as Figure 4 (e) shows, the shape presented by the first heat conducting structure in the top view is a square; as Figure 4 (f) shows, the shape presented by the first heat conducting structure in the top view is a rectangle; as Figure 4 (g) shows, the shape presented by the first heat conducting structure in the top view is a regular hexagon; as Figure 4 (h) shows, the shape presented by the first heat conducting structure in the top view is a hexagon.

[0153] In the embodiments of the present application, the first heat conducting structure may present various shapes in the top view, and there is no special limitation on the shape presented by the first heat conducting structure in the top view, as long as the setting position of the first heat conducting structure can avoid the leads. In other words, in order to avoid the leads, the shape presented by the first heat conducting structure in the top view can be an irregular shape.

[0154] Next, the different cross-sectional structure schematic diagrams of the packaging structure provided by the embodiments of the present application will be described in detail. As Figures 5A to 5D shown,Figure 5A As shown, the encapsulation structure further includes: a second protective cover 203 disposed on the first surface 201a of the second substrate. A second cavity is formed between the second protective cover 203 and the second substrate 201, and the second device 202 is located in the second cavity.

[0155] It should be noted that whether to provide a second protective cover on the first surface of the second substrate can be selected according to the type of the second device. For example, when the second device is a filter, a second protective cover needs to be provided on the first surface of the second substrate. The second protective cover can reflect the acoustic wave signal of the second device, thereby reducing the energy loss of the acoustic wave signal of the second device, and ultimately achieving the purpose of protecting the second device. When the second device is a passive device such as a capacitor or an inductor, the second protective cover may not be provided.

[0156] In the embodiment of the present application, the second protective cover can be formed on the second substrate. The second protective cover covers the second device and there is a gap between the second protective cover and the second device. In other words, the second protective cover does not contact the second device. The edge region of the second protective cover contacts the second substrate so that a second cavity is formed between the second protective cover and the second substrate, and the second device is located in the second cavity. Here, the second protective cover is located above the second device and the second protective cover completely covers the second device to form a wafer-level package.

[0157] In some embodiments, the material of the second protective cover can be selected from at least one of dry film, photoresist film, photosensitive polymer, SU8 film, resin, silicon substrate, germanium substrate, quartz substrate, glass substrate, silicon-on-glass substrate, lithium tantalate substrate, sapphire substrate, gallium arsenide substrate, and silicon carbide substrate.

[0158] As Figure 5A and Figure 5C shown, the first end face of the first heat conduction structure 601 is disposed on the first substrate. At this time, the thickness of the first heat conduction structure 601 is L2. As Figure 5B and Figure 5D shown, the first end face of the first heat conduction structure 601 is disposed on the second substrate. At this time, the thickness of the first heat conduction structure 601 is L1.

[0159] According to the heat conduction formula shown in Equation 1, within the same time, the smaller the thickness of the first heat conduction structure, the more heat dissipates from the encapsulation structure to the outside through the first heat conduction structure, and the higher the heat conduction efficiency of the first heat conduction structure. Within the same time, the larger the contact area of the first heat conduction structure, the more heat dissipates from the encapsulation structure to the outside through the first heat conduction structure, and the higher the heat conduction efficiency of the first heat conduction structure.

[0160] (Equation 1)

[0161] Where Q represents heat, and the unit is W; represents temperature difference, the unit is K; R represents thermal resistance, the unit is ; L represents thickness, unit is m; λ represents thermal conductivity, unit is ; S represents the contact area, unit is m 2 .

[0162] In the embodiment of the present application, the thickness of the first heat-conducting structure disposed on the second substrate is less than the thickness of the first heat-conducting structure disposed on the first substrate. In other words, the smaller the thickness of the first heat-conducting structure, the higher the efficiency of dissipating the heat generated by the devices in the package structure during operation to the outside through the first heat-conducting structure.

[0163] In the embodiment of the present application, when the first end surface of the first heat-conducting structure is disposed on the first substrate, the ratio between the sum of the areas of the orthographic projections of the plurality of first heat-conducting structures on the first substrate and the area of the first substrate is greater than or equal to 0.0014 and less than 1;

[0164] When the first end surface of the first heat conducting structure is disposed on the second substrate, a ratio between the sum of the areas of the orthographic projections of the plurality of first heat conducting structures on the second substrate and the area of the second substrate is greater than or equal to 0.0014 and less than 1.

[0165] Here, the larger the sum of the areas of the orthographic projections of the first heat-conducting structure on the first substrate or the second substrate, the larger the contact area between the first heat-conducting structure and the first substrate or the second substrate, the more heat dissipated from the packaging structure to the outside through the first heat-conducting structure, and the higher the heat conduction efficiency of the first heat-conducting structure. Of course, only one first heat-conducting structure can be set here, and the larger the area of the orthographic projection of the heat-conducting structure on the first substrate or the second substrate, the more heat dissipated from the packaging structure to the outside through the first heat-conducting structure; multiple first heat-conducting structures can also be set here, and the larger the sum of the areas of the orthographic projections of the multiple first heat-conducting structures on the first substrate or the second substrate, the more heat dissipated to the outside through these first heat-conducting structures.

[0166] It should be noted that other structures are also arranged on the first substrate and the second substrate in the packaging structure, such as leads for leading out electrical signals. Therefore, when the first heat-conducting structure is arranged on the first substrate or the second substrate, the leads need to be properly avoided.

[0167] In the embodiment of the present application, there is no special restriction on the number of the first heat-conducting structures. For example, the number of the first heat-conducting structures can be 2, 3 or even more. Here, the more the number of the first heat-conducting structures is, the more heat is dissipated from the packaging structure to the outside through the first heat-conducting structures. In the embodiment of the present application, the number of the first heat-conducting structures can be increased without affecting the overall size of the packaging structure to improve the heat dissipation performance of the packaging structure.

[0168] In a preferred embodiment of the present application, the first heat-conducting structure disposed on the first substrate or the second substrate is symmetrically distributed. Here, the symmetric distribution of the first heat-conducting structure disposed on the first substrate or the second substrate makes the force on the first substrate or the second substrate uniform, effectively avoiding warping and deformation of the first substrate or the second substrate due to uneven force.

[0169] In an embodiment of the present application, the first heat-conducting structure is made of a material with a thermal conductivity greater than 0.05 .

[0170] Here, the ratio range between the thermal conductivity of the material making up the first heat-conducting structure and the thermal conductivity of the heat-insulating material is from 1 to 10,000. In other words, the thermal conductivity of the material making up the first heat-conducting structure is greater than 0.05 and less than 500 .

[0171] In an embodiment of the present application, the first heat-conducting structure is made of a material with a high thermal conductivity. Here, the material with a high thermal conductivity can be a metal material, for example, copper (Cu), tin (Sn), gold (Au), nickel (Ni), or aluminum (Al). Alternatively, the material with a high thermal conductivity can also be a ceramic material, and the ceramic material can include oxides, nitrides, carbides, and borides. For example, aluminum nitride (AlN), silicon nitride (Si3N4), or silicon carbide (SiC).

[0172] In an embodiment of the present application, the number, material, thickness, and the area of the orthographic projection of the first heat-conducting structure on the first substrate or the second substrate can also be selected according to the heat generated during the operation of the first device, the third device, and the second device, so as to realize the regulation of the heat dissipation performance of the packaging structure.

[0173] As Figure 5C and Figure 5D shown, the packaging structure further includes: a second heat-conducting structure 602, and the second heat-conducting structure 602 is located on the plastic encapsulation layer 300 and contacts the second end surface of the first heat-conducting structure 601. Here, the second heat-conducting structure is disposed on the plastic encapsulation layer, and the thickness of the second heat-conducting structure is L3.

[0174] According to the heat conduction formula shown in Equation 1, in the same time, the smaller the thickness of the second heat-conducting structure, the more heat dissipates from the packaging structure to the outside through the second heat-conducting structure, and the higher the heat conduction efficiency of the second heat-conducting structure. In the same time, the larger the area of the second heat-conducting structure, the larger the contact area between the second heat-conducting structure and the first heat-conducting structure, the more heat dissipates from the packaging structure to the outside through the second heat-conducting structure, and the higher the heat conduction efficiency of the second heat-conducting structure.

[0175] In the embodiments of the present application, the second heat-conducting structure is at least in contact with the second end face of the first heat-conducting structure, so as to dissipate the heat conducted out from the encapsulation structure by the first heat-conducting structure to the outside. In some embodiments of the present application, the second heat-conducting structure may even completely cover the plastic encapsulation layer. At this time, the area of the second heat-conducting structure reaches the maximum value, as Figure 5C shown. In some other embodiments of the present application, the second heat-conducting structure may also only cover a part of the plastic encapsulation layer, as Figure 5D shown.

[0176] In the embodiments of the present application, the second heat-conducting structure is made of a material with a thermal conductivity greater than 0.05 .

[0177] Here, the ratio range between the thermal conductivity of the material making up the second heat-conducting structure and the thermal conductivity of the heat-insulating material is from 1 to 10,000. In other words, the thermal conductivity of the material making up the second heat-conducting structure is greater than 0.05 and less than 500 .

[0178] In the embodiments of the present application, the second heat-conducting structure is made of a material with a high thermal conductivity. Here, the material with a high thermal conductivity can be a metal material, or the material with a high thermal conductivity can also be a compound, such as a ceramic material, including oxides, nitrides, carbides, and borides.

[0179] In the embodiments of the present application, the ratio range between the thickness of the second heat-conducting structure in the direction perpendicular to the first substrate and the thickness of the encapsulation structure in the direction perpendicular to the first substrate is from 0.01 to 0.5. In other words, the ratio range between the thickness of the second heat-conducting structure in the vertical direction and the thickness of the encapsulation structure in the vertical direction is from 0.01 to 0.5. More specifically, the ratio range between the thickness of the second heat-conducting structure in the Z direction and the thickness of the encapsulation structure in the Z direction is from 0.01 to 0.5.

[0180] In a specific embodiment, the thickness of the second heat-conducting structure in the direction perpendicular to the first substrate is less than 0.2 mm, and the thickness of the encapsulation structure in the vertical direction is 0.6 mm.

[0181] In the embodiments of the present application, the ratio between the area of the orthographic projection of the second heat-conducting structure on the first substrate and the area of the orthographic projection of the encapsulation structure on the first substrate is greater than or equal to 1 / 3. In other words, the ratio between the area of the orthographic projection of the second heat-conducting structure on the plane where the first substrate is located and the area of the orthographic projection of the encapsulation structure on the plane where the first substrate is located is greater than or equal to 1 / 3. More specifically, the ratio between the area of the orthographic projection of the second heat-conducting structure in the XY plane and the area of the orthographic projection of the encapsulation structure in the XY plane is greater than or equal to 1.

[0182] In an embodiment of the present application, the second heat-conducting structure includes a plurality of heat-conducting material layers stacked in a direction perpendicular to the first substrate, and the heat-conducting coefficient of the heat-conducting material layer closer to the plastic encapsulation layer is greater than or equal to that of the heat-conducting material layer farther from the plastic encapsulation layer. In other words, the heat-conducting coefficient of the second heat-conducting structure decreases in the direction away from the plastic encapsulation layer.

[0183] Here, a plurality of heat-conducting material layers can be provided on the plastic encapsulation layer as the second heat-conducting structure, and the heat-conducting coefficient of the heat-conducting material layer closer to the plastic encapsulation layer is greater than or equal to that of the heat-conducting material layer farther from the plastic encapsulation layer. The inventors of the present application considered that the higher the heat-conducting coefficient of the material, the more expensive the price. Therefore, setting the heat-conducting material layer made of a material with a larger heat-conducting coefficient at a position in direct contact with the first heat-conducting structure is beneficial to heat dissipation and can also save costs.

[0184] In a preferred embodiment of the present application, 2 to 3 heat-conducting material layers are provided on the plastic encapsulation layer. Figure 5C and Figure 5D Only one heat-conducting material layer is schematically shown on the plastic encapsulation layer as the second heat-conducting structure, which does not limit the protection scope of the present application.

[0185] In a preferred embodiment of the present application, the ratio range of the heat-conducting coefficients of any two adjacent heat-conducting material layers is 0.01 to 1.

[0186] Here, when the ratio of the heat-conducting coefficients of two adjacent heat-conducting material layers is 0.01, the heat-conducting coefficient of the heat-conducting material layer closer to the plastic encapsulation layer is 100 times that of the heat-conducting material layer farther from the plastic encapsulation layer; when the ratio of the heat-conducting coefficients of two adjacent heat-conducting material layers is 1, the heat-conducting coefficients of the heat-conducting material layer closer to the plastic encapsulation layer and the heat-conducting material layer farther from the plastic encapsulation layer are the same.

[0187] In an embodiment of the present application, the second heat-conducting structure includes a plurality of heat-conducting material layers stacked in a direction perpendicular to the first substrate, and the thickness of the heat-conducting material layer closer to the plastic encapsulation layer is greater than that of the heat-conducting material layer farther from the plastic encapsulation layer. In other words, the thickness of the heat-conducting material layer decreases in the direction away from the plastic encapsulation layer.

[0188] In an embodiment of the present application, the second heat-conducting structure includes a plurality of heat-conducting material layers stacked in a direction perpendicular to the first substrate, and the area of the orthographic projection of the heat-conducting material layer closer to the plastic encapsulation layer on the first substrate is greater than or equal to the area of the orthographic projection of the heat-conducting material layer farther from the plastic encapsulation layer on the first substrate. In other words, the area of the orthographic projection of the heat-conducting material layer on the plane where the first substrate is located remains unchanged or decreases in the direction away from the plastic encapsulation layer.

[0189] In the embodiments of the present application, on the basis of setting the first heat-conducting structure, a second heat-conducting structure is further set on the encapsulation layer, which can successively dissipate the heat generated during the operation of the first device, the third device, and the second device to the outside through the first heat-conducting structure and the second heat-conducting structure, thereby improving the heat dissipation performance of the encapsulation structure. In addition, in the embodiments of the present application, the material, thickness, and area of the second heat-conducting structure can also be selected according to the heat generated during the operation of the first device, the third device, and the second device, so as to realize the regulation of the heat dissipation performance of the encapsulation structure.

[0190] Still referring to Figures 5A to 5D , the encapsulation structure further includes: a printed circuit board 500 electrically connected to the first device 102, the second device 202, and the third device 106, and the first device 102 is located between the printed circuit board 500 and the third device 106.

[0191] In the embodiments of the present application, a printed circuit board (PCB) is composed of an insulating base plate, connecting wires, and pads for assembling and soldering electronic components, and has the dual functions of a conductive circuit and an insulating base plate. The printed circuit board can replace complex wiring to achieve electrical connection between various components in the circuit. Among them, the material of the insulating base plate can include, but is not limited to, insulating materials such as silicon, glass, silicon oxide, ceramic, and polymer, etc.; the connecting wires can be metal materials such as copper. In the embodiments of the present application, the shape of the PCB can be circular, square, or any other required shape, and the surface area of the PCB is based on its ability to carry subsequent structures. Here, in order to form the encapsulation structure, the surface area of the PCB is larger than the area of the first substrate, and the surface area of the PCB is larger than the area of the second substrate.

[0192] It should be noted that the first device, the third device, and the second device in the encapsulation structure are stacked in sequence in the vertical direction, and the first device, the third device, and the second device are all electrically connected to the PCB, and it is difficult to provide a grounding area on the PCB. If the second heat-conducting structure is made of a metal material, then the second heat-conducting structure can provide a grounding area for the encapsulation structure while conducting heat out, thereby reducing the signal loss of each device in the encapsulation structure.

[0193] In a specific embodiment of the present application, the thickness of the second heat-conducting structure in the vertical direction is less than 0.2 mm, and the thickness of the PCB in the vertical direction is less than 0.3 mm. At this time, the overall size of the encapsulation structure in the vertical direction is less than 0.6 mm.

[0194] Next, the process of dissipating the heat generated during the operation of each device in the encapsulation structure to the outside by using the first heat-conducting structure and the second heat-conducting structure will be described in detail with reference to Figure 6A and Figure 6B Still referring toFigure 6A and Figure 6B , Figure 6A is a schematic diagram of the heat conduction principle of the packaging structure provided by the embodiment of the present application, Figure 6B is a schematic diagram of the heat transfer principle of the packaging structure provided by the embodiment of the present application.

[0195] Figure 6B shows all the thermal resistances in the process from heat generation to dissipation to the outside in the packaging structure. Re represents the thermal resistance of the device; Rp represents the thermal resistance of the pad for leading out the electrical signal of the device; Rd represents the thermal resistance of each redistribution layer in the packaging structure; R1 represents the thermal resistance of the first heat conduction structure; R2 represents the thermal resistance of the second heat conduction structure; R3 represents the thermal resistance of free convection; R4 represents the thermal resistance of thermal radiation.

[0196] Combined with Figure 6A shown, in the packaging structure provided by the embodiment of the present application, the first device 102, the second device 202, and the third device 106 may all generate heat during operation. The thermal resistance of the device includes the thermal resistances of the first device 102, the second device 202, and the third device 106; the thermal resistance of the redistribution layer includes the first redistribution layer and the second redistribution layer. The first redistribution layer 104 is provided on the first protective cover, and the second redistribution layer 204 is provided on the first surface of the second substrate and the second surface of the first substrate. Figure 6A The pads for leading out the electrical signals of the first device, the second device, and the third device are not shown.

[0197] In the embodiment of the present application, the heat generated by each device during operation is exported sequentially through the first heat conduction structure and the second heat conduction structure, and finally the heat is dissipated to the outside (for example, in the air) through heat convection and heat radiation.

[0198] Next, the packaging structure provided by the embodiment of the present application will be described in detail in combination with Figures 7A to 7C . Referring to Figures 7A to 4 C, Figure 7A is a top view structure schematic diagram of another packaging structure provided by the embodiment of the present application, Figure 7B is a cross-sectional structure schematic diagram along Figure 7A BB in Figure 7C is a cross-sectional structure schematic diagram along Figure 7A CC in Figure 7A . It should be noted that, in order to more clearly show the internal settings of the packaging structure,

[0199] As Figure 7AAs shown, a first heat-conducting structure is disposed on a first substrate, and the distance S between the orthographic projection of the first heat-conducting structure on the first substrate and the orthographic projection of the second substrate on the first substrate is greater than or equal to 10 μm. Here, 10 μm is the process limit for disposing the second heat-conducting structure on the first substrate. If the distance between the orthographic projection of the first heat-conducting structure on the first substrate and the orthographic projection of the second substrate on the first substrate is less than 10 μm, then the process of forming the first heat-conducting structure may damage the second substrate or the second device disposed on the second substrate.

[0200] As Figure 7B shown, the packaging structure further includes: a first redistribution layer 104 disposed on the first protective cover 103; and a bump structure 105 disposed on the first redistribution layer 104; wherein, the first device 102 is electrically connected to the printed circuit board 500 through the bump structure 105.

[0201] In an embodiment of the present application, a first redistribution layer (Redistribution Layer, RDL) is formed on the first protective cover, and a bump structure is formed on the first redistribution layer. Here, the electrical signals of the first device are led out through the first redistribution layer and the bump structure in sequence.

[0202] In an embodiment of the present application, the bump structure may be, for example, a solder ball (bump), a solder block, or a combination thereof. The shape of the bump structure includes but is not limited to Figure 7B the spherical shape shown in. In some embodiments, the material of the bump structure may include but is not limited to conductive materials, for example, one or more of copper, zinc, nickel, lead, gold, and silver.

[0203] Still as Figure 7B shown, the packaging structure further includes: a second redistribution layer 204 disposed on the first surface of the second substrate and the second surface of the first substrate; and a conductive through-hole 107 penetrating the first substrate 101; wherein, the second device 202 is electrically connected to the printed circuit board 500 through the conductive through-hole 107 and the bump structure 105.

[0204] In an embodiment of the present application, the electrical signals of the second device are led out through the second redistribution layer, the conductive through-hole, the first redistribution layer, and the bump structure in sequence.

[0205] In a specific embodiment of the present application, the first substrate may be, for example, a silicon substrate, and the conductive through-hole may be, for example, a Through Silicon Via (TSV).

[0206] In addition, when the second heat-conducting structure is made of a metal material, if the second heat-conducting structure covers the entire encapsulation layer, there may be a parasitic capacitance between the second heat-conducting structure and the second redistribution layer. Therefore, in a preferred embodiment of the present application, when the second heat-conducting structure is made of a metal material, the orthographic projection of the second heat-conducting structure on the first substrate or the second substrate overlaps at least partially with the orthographic projection of the first heat-conducting structure on the first substrate or the second substrate, and the overlapping area between the orthographic projection of the second heat-conducting structure on the first substrate or the second substrate and the orthographic projection of the second redistribution layer on the first substrate or the second substrate is minimized as much as possible. In this way, the parasitic capacitance between the second heat-conducting structure and the second redistribution layer can be minimized as much as possible.

[0207] As Figure 7C shown, the packaging structure further includes: a lead 108; wherein, the third device 106 is electrically connected to the printed circuit board 500 through the lead 108.

[0208] In an embodiment of the present application, wire bonding can be used to form the lead and lead out the electrical signals of the third device.

[0209] In an embodiment of the present application, the electrical connection between the first device and the PCB is achieved through a bump structure, the electrical connection between the second device and the PCB is achieved through a through-silicon via and a bump structure, and the electrical connection between the third device and the PCB is achieved through a lead. When the first device is a transmit filter and the third device is a receive filter, the transmit filter has higher requirements in terms of power tolerance and heat dissipation, and the flip-chip connection method between the first device and the PCB achieved through the bump structure can better meet this requirement.

[0210] Next, the process of forming the packaging structure will be described in detail in conjunction with Figure 8 , Figures 9A to 9I . Referring to Figure 8 , Figure 8 is a flowchart of a manufacturing method of a packaging structure according to an embodiment of the present application.

[0211] As Figure 8 shown, an embodiment of the present application further provides a manufacturing method of a packaging structure, and the manufacturing method includes:

[0212] Step S801, form a first substrate and a second substrate bonded to each other; wherein, a first device and a first protective cover are disposed on a first surface of the first substrate, a first cavity is formed between the first protective cover and the first substrate, and the first device is located in the first cavity; a second device is disposed on a first surface of the second substrate.

[0213] As Figure 9AAs shown, the first device 102 can be formed on the first surface of the first substrate 101. The first surface of the first substrate shown here faces downward, that is, the front side of the first substrate faces downward. In the packaging structure provided by the embodiments of the present application, the number of the first devices is not limited to Figure 9A the two shown in

[0214] Still referring to Figure 9A As shown, the third device 106 can be formed on the second surface of the first substrate. Here, the first device is disposed on the first surface of the first substrate, and the third device is disposed on the second surface of the first substrate, that is, the first device is disposed on the front side of the first substrate, and the third device is disposed on the back side of the first substrate. The first device and the third device share the first substrate. In the packaging structure provided by the embodiments of the present application, the number of the third devices is not limited to Figure 9A the one shown in

[0215] As Figure 9B shown, the first protective cover 103 can be formed on the first surface of the first substrate 101. A first cavity is formed between the first protective cover 103 and the first substrate 101, and the first device 102 is located in the first cavity. There is a gap between the middle region of the first protective cover shown here and the first device, that is, the first protective cover does not contact the first device, and the edge region of the first protective cover contacts the first substrate.

[0216] As Figure 9C shown, the first redistribution layer 104 can also be formed on the first protective cover 103; the bump structure 105 is formed on the first redistribution layer 104. The bump structure shown here is used to lead out the electrical signals of the first device.

[0217] Still as Figure 9C shown, the conductive through hole 107 penetrating the first substrate 101 can also be formed along the thickness direction of the first substrate 101, wherein the conductive through hole 107 is electrically connected to the first redistribution layer 104. In a specific embodiment of the present application, the first substrate can be a silicon substrate, and the conductive through hole can be a through-silicon via.

[0218] As Figure 9D shown, the second device 202 can be formed on the first surface of the second substrate 201. The first surface of the second substrate shown here faces upward, that is, the front side of the second substrate faces upward. In the packaging structure provided by the embodiments of the present application, the number of the second devices is not limited to Figure 9DAs shown in [the figure], for example, the number of the second devices may be one, two, three or even more. Those skilled in the art can select and set the number of the second devices according to actual requirements.

[0219] As Figure 9E shown, the second surface of the second substrate 201 can be etched so that the second substrate includes an intermediate region and an edge region surrounding the intermediate region, and the thickness of the intermediate region is less than that of the edge region.

[0220] In the embodiments of the present application, Figures 9A to 9C as shown, forming the second device on the second surface of the first substrate, forming the first device and the first protective cover on the first surface of the first substrate, forming the first redistribution layer on the first protective cover, forming the bump structure on the first redistribution layer, and forming the conductive through hole penetrating the first substrate, these process steps can be Figures 9D to 9E executed in parallel with the process steps of forming the second device on the first surface of the second substrate and processing the second substrate to form the intermediate region and the edge region as shown. That is to say, the processing of the first substrate can be executed simultaneously with the processing of the second substrate to save manufacturing time.

[0221] As Figure 9F shown, a bonding structure 401 is formed between the edge region and the second surface of the first substrate 101, and a third cavity is formed between the intermediate region and the second surface of the first substrate 101; wherein, the third cavity completely wraps the third device 106 located on the second surface of the first substrate 101.

[0222] Still as Figure 9F shown, after forming the mutually bonded first substrate and second substrate, the manufacturing method further includes: forming a second redistribution layer 204 on the first surface of the second substrate 201 and the second surface of the first substrate 101; here, the electrical signals of the second device 202 are led out through the second redistribution layer 204, the conductive through hole 107, the first redistribution layer 104, and the bump structure 105 in sequence.

[0223] As Figure 9G shown, a second protective cover 203 can be formed on the first surface of the second substrate 201, a second cavity is formed between the second protective cover 203 and the second substrate 201, and the second device 202 is located in the second cavity. There is a gap between the intermediate region of the second protective cover shown here and the second device, that is, the second protective cover does not contact the second device, and the edge region of the second protective cover contacts the second substrate.

[0224] Still referring to Figure 8 shown, the manufacturing method includes:

[0225] Step S802: Provide a printed circuit board (PCB), and dispose the mutually bonded first substrate and second substrate on the PCB.

[0226] As Figure 9H shown, provide a printed circuit board 500, and dispose the mutually bonded first substrate 101 and second substrate 201 on the printed circuit board 500. Here, the second surfaces of the first substrate and the second substrate are mutually bonded and disposed on the PCB. The first device disposed on the first surface of the first substrate, the third device disposed on the second surface of the first substrate, and the second device disposed on the first surface of the second substrate are respectively electrically connected to the PCB. Among them, the front side of the first substrate faces the PCB, the first substrate is integrated on the PCB in a flip-chip form, and the first device is electrically connected to the PCB through the bump structure provided thereon; the back side of the second substrate faces the PCB.

[0227] Still as Figure 9H shown, form a plurality of first heat-conducting structures 601 on the surface of the first substrate 101 away from the printed circuit board 500 or on the surface of the second substrate 201 away from the printed circuit board 500. Here, the end face where the first heat-conducting structure is disposed on the first substrate or the second substrate is defined as the first end face. Figure 9H It shows that the first heat-conducting structure is formed on the surface of the first substrate away from the PCB.

[0228] Still as Figure 9H shown, form leads. Among them, the third device 106 is electrically connected to the printed circuit board 500 through the leads. Here Figure 9H It shows a schematic cross-sectional structure diagram of the first heat-conducting structure in the package structure. Therefore, Figure 9H the schematic cross-sectional structure diagram of the leads in the package structure is not shown. It should be noted that both the first heat-conducting structure and the leads in the package structure can be disposed on the second surface of the first substrate. Therefore, the plurality of first heat-conducting structures can be spaced apart from each other through the leads.

[0229] Still referring to Figure 8 shown, the manufacturing method includes:

[0230] Step S803: Encapsulate the mutually bonded first substrate and second substrate on the PCB to form an encapsulation layer.

[0231] As Figure 9I shown, encapsulate the mutually bonded first substrate 101 and second substrate 201 on the printed circuit board 500 to form an encapsulation layer 300. Here, the upper surface of the encapsulation layer is flush with the second end face of the first heat-conducting structure, that is, the encapsulation layer exposes the second end face of the first heat-conducting structure.

[0232] Still referring to Figure 8As shown, the manufacturing method includes:

[0233] Step S804: Form a second heat conduction structure on the encapsulation layer.

[0234] Still as Figure 9I As shown, a second heat conduction structure 602 that contacts the second end surface of the first heat conduction structure 601 is formed on the encapsulation layer 300.

[0235] An embodiment of the present application provides a packaging structure and a manufacturing method thereof. The packaging structure includes: a first substrate and a second substrate that are bonded to each other and wrapped in an encapsulation layer; a first device and a first protective cover disposed on a first surface of the first substrate, a first cavity is formed between the first protective cover and the first substrate, and the first device is located in the first cavity; a second device disposed on a first surface of the second substrate; a bonding structure disposed between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface, so that a third cavity is formed between the second surface of the first substrate and the second surface of the second substrate; a third device disposed on the second surface of the first substrate, and the third device is located in the third cavity; a second heat conduction structure disposed on the encapsulation layer. In the embodiment of the present application, by providing a second heat conduction structure on the encapsulation layer, the purpose of quickly dissipating the heat generated when the first device and the second device operate to the outside can be achieved while not significantly increasing the size of the packaging structure in the vertical direction. Further, the first substrate and the second substrate are bonded to each other and disposed in the encapsulation layer to form a stacked structure, so as to reduce the area of the packaging structure, which is beneficial to the integration and miniaturization of the packaging structure.

[0236] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the "in one embodiment" or "in an embodiment" that appears throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the magnitude of the serial numbers of the above processes does not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The serial numbers of the embodiments of the present application above are only for description and do not represent the advantages and disadvantages of the embodiments.

[0237] The above are only the preferred embodiments of the present application, which do not limit the patent scope of the present application. Any equivalent structural transformation made under the inventive concept of the present application by using the content of the specification and drawings of the present application, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A packaging structure, characterized in that, The encapsulation structure includes: A first substrate and a second substrate bonded to each other and encapsulated in a plastic package layer; A first device and a first protective cover disposed on a first surface of the first substrate, a first cavity being formed between the first protective cover and the first substrate, and the first device being located in the first cavity; A second device disposed on a first surface of the second substrate; A bonding structure disposed between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface, so that a third cavity is formed between the second surface of the first substrate and the second surface of the second substrate; A third device disposed on the second surface of the first substrate, the third device being located in the third cavity; A second heat conduction structure disposed on the plastic package layer, the ratio of the thickness of the second heat conduction structure in a direction perpendicular to the first substrate to the thickness of the encapsulation structure in a direction perpendicular to the first substrate being in a range of 0.01 to 0.

5.

2. An encapsulation structure, characterized in that, The encapsulation structure includes: A first substrate and a second substrate bonded to each other and encapsulated in a plastic package layer; A first device and a first protective cover disposed on a first surface of the first substrate, a first cavity being formed between the first protective cover and the first substrate, and the first device being located in the first cavity; A second device and a second protective cover disposed on a first surface of the second substrate, a second cavity being formed between the second protective cover and the second substrate, and the second device being located in the second cavity; A bonding layer disposed between a second surface of the first substrate opposite to the first surface and a second surface of the second substrate opposite to the first surface; A second heat conduction structure disposed on the plastic package layer, the ratio of the thickness of the second heat conduction structure in a direction perpendicular to the first substrate to the thickness of the encapsulation structure in a direction perpendicular to the first substrate being in a range of 0.01 to 0.

5.

3. The encapsulation structure according to claim 1 or 2, characterized in that, The second heat-conducting structure has a thermal conductivity greater than 0.05 W·m -1 ·K -1 Made of material.

4. The encapsulation structure according to claim 1 or 2, wherein The ratio of the area of the positive projection of the second heat conduction structure on the first substrate to the area of the positive projection of the encapsulation structure on the first substrate is greater than or equal to 1 / 3.

5. The encapsulation structure according to claim 1 or 2, characterized in that, The second heat conduction structure includes a plurality of heat conduction material layers stacked in a direction perpendicular to the first substrate, and the heat conduction coefficient of the heat conduction material layer closer to the plastic package layer is greater than or equal to the heat conduction coefficient of the heat conduction material layer farther from the plastic package layer.

6. The encapsulation structure according to claim 1 or 2, characterized in that The second heat conduction structure includes a plurality of heat conduction material layers stacked in a direction perpendicular to the first substrate, and the thickness of the heat conduction material layer closer to the plastic package layer in a direction perpendicular to the first substrate is greater than the thickness of the heat conduction material layer farther from the plastic package layer in a direction perpendicular to the first substrate.

7. The encapsulation structure according to claim 1, wherein The encapsulation structure further includes: A printed circuit board PCB electrically connected to the first device, the second device, and the third device, and the first device being located between the PCB and the third device.

8. The encapsulation structure according to claim 1, wherein The first device includes at least one of the following: surface acoustic wave filter device, bulk acoustic wave filter device, resistor-inductor-capacitor passive filter device, and integrated passive device filter device; The second device includes at least one of the following: power amplifier, low noise amplifier, switch, filter, and passive component; The third device includes at least one of the following: surface acoustic wave filter device, bulk acoustic wave filter device, resistor-inductor-capacitor passive filter device, and integrated passive device filter device.

9. A manufacturing method of a packaging structure, characterized in that, The manufacturing method includes: Forming a first substrate and a second substrate bonded to each other; wherein, a first device and a first protective cover are disposed on a first surface of the first substrate, a first cavity is formed between the first protective cover and the first substrate, and the first device is located in the first cavity; a second device is disposed on a first surface of the second substrate; Providing a printed circuit board (PCB), and disposing the mutually bonded first substrate and second substrate on the PCB; Encapsulating the mutually bonded first substrate and second substrate on the PCB to form an encapsulation layer; Forming a second heat conducting structure on the encapsulation layer, and the ratio range of the thickness of the second heat conducting structure in a direction perpendicular to the first substrate to the thickness of the encapsulation structure in a direction perpendicular to the first substrate is 0.01 to 0.5.

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