Radio frequency module and electronic device

Abstract

The application discloses a radio frequency module and electronic equipment, and relates to the field of semiconductor packaging. The radio frequency module comprises a first substrate, a power amplifier die arranged on a first surface of the first substrate, and a plurality of matching devices of the power amplifier die arranged on the first surface, wherein the height of the power amplifier die is greater than 0.2 mm; a package arranged on the first surface, wherein the package comprises a second substrate and a plurality of other devices, the plurality of other devices are arranged on two opposite surfaces of the second substrate, and the plurality of other devices are encapsulated to form the package. In this way, the radio frequency module adopts an overall single-side encapsulation and an internal partial double-side encapsulation encapsulation structure, so that the encapsulation size of the radio frequency module is reduced; meanwhile, the heat dissipation capacity of the electronic device is improved without affecting the size of the electronic device in the radio frequency module, so that the performance of the radio frequency module is improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging, and more particularly to a radio frequency module and electronic device. Background Technology

[0002] With the iterative upgrades of electronic devices, users' demands for portability and functionality are increasing. As the functions integrated into electronic devices grow, higher requirements are being placed on the integration level of integrated circuits (ICs) and printed circuit boards (PCBs) to reduce their size and thickness and ensure an ultra-thin and lightweight appearance. Currently, to improve the integration level of electronic devices, their architecture can adopt two-dimensional or even three-dimensional stacked packaging forms, reducing the area required for packaging and thus reducing the size of the packaging structure.

[0003] However, when the above packaging method is applied to electronic devices, the double-sided packaging of electronic components in the packaging structure may increase the height of the packaging structure, limiting the size of electronic components that can be placed in the packaging structure. This becomes a bottleneck for reducing the thickness of electronic devices and may even affect the performance of electronic components in the packaging structure, such as hindering heat dissipation. Utility Model Content

[0004] The embodiments of this application provide a radio frequency module and an electronic device, which adopts an overall single-sided package and an internal partial double-sided package structure, thereby reducing the package size of the radio frequency module; at the same time, without affecting the size of the electronic components in the radio frequency module, the heat dissipation capacity of the electronic components is improved, thereby improving the performance of the radio frequency module.

[0005] In a first aspect, this application provides a radio frequency module, the radio frequency module comprising: a first substrate; a power amplifier die disposed on a first surface of the first substrate, wherein the height of the power amplifier die is greater than 0.2 mm; a plurality of matching devices of the power amplifier die disposed on the first surface; and a package disposed on the first surface, the package comprising a second substrate and a plurality of other devices disposed on two opposite surfaces of the second substrate and packaged to form the package.

[0006] In this embodiment, when multiple other devices are packaged into a package using a double-sided packaging method, the package area of ​​the RF module is reduced. The power amplifier die and its matching devices are arranged together with the package formed by the double-sided packaging on the same surface of the first substrate and packaged as a whole. This allows the RF module to form a package structure with an overall single-sided package and internal partial double-sided packaging. While ensuring a small package area, this also makes the package height of the RF module controllable. Compared to the current overall double-sided packaging structure, the overall single-sided packaging method provided in this application, when the relatively large power amplifier die and its matching devices are packaged on the first substrate, even with additional packages on the first substrate, still results in a package height of the RF module that is close to that of a conventional single-sided packaging structure.

[0007] Since the size and heat generation of a power amplifier die are usually positively correlated with its power, a larger size can be set for a power amplifier die in a single-sided package. By increasing the height of the power amplifier die by more than 0.2mm and setting the power amplifier as a die structure, its heat dissipation capacity can be improved to enhance its performance. Higher power consumption power amplifier dies can be used in RF modules, allowing the power amplifier die to operate in a wider transmit power range. The performance of the RF module is enhanced, thereby meeting the usage requirements of RF modules in electronic devices.

[0008] In some embodiments, the radio frequency module further includes: a molding compound covering the first substrate, the power amplifier die, a plurality of matching devices, and a package; and a metal shielding layer disposed above the molding compound, wherein the side of the power amplifier die away from the first substrate passes through the molding compound and contacts the metal shielding layer.

[0009] In this embodiment, the power amplifier die directly contacts the metal shielding layer. The main upward heat dissipation path is the channel between the power amplifier die and the metal shielding layer, which reduces the path thermal resistance and interface thermal resistance of the power amplifier die. Utilizing the thermal conductivity of the metal shielding layer, the heat generated by the power amplifier die during operation is evenly dissipated throughout the entire metal shielding layer, thereby enhancing the heat dissipation capacity of the power amplifier die. Furthermore, by improving the heat dissipation capacity of the power amplifier die, it can operate in a wider transmit power range, thus improving the performance of the power amplifier die.

[0010] In some embodiments, the molding layer is recessed towards the first substrate to form a recessed portion, and the side of the power amplifier die away from the first substrate contacts the metal shielding layer at the bottom of the recessed portion; the orthographic projection of the recessed portion on the first substrate at least partially overlaps with the orthographic projection of the power amplifier die on the first substrate.

[0011] In this embodiment, when the height of the power amplifier die is insufficient, a molding compound is recessed towards the first substrate to form a recessed portion. The power amplifier die is in direct contact with the metal shielding layer at the bottom of the recessed portion, ensuring that the high-heat-generating power amplifier die can directly contact the metal shielding layer. The heat generated by the power amplifier die during operation is evenly dissipated to the entire metal shielding layer, thereby improving the heat dissipation capacity of the power amplifier die. This allows for the placement of a higher-power power amplifier die in the RF module, enhancing the performance of the RF module.

[0012] In some embodiments, the radio frequency module further includes a first thermal conductive element, one side of which is connected to the side of the power amplifier die away from the first substrate, and the other side of which is in contact with the metal shielding layer.

[0013] In some embodiments, the first thermally conductive element includes a thermally conductive layer and an adhesive layer; the thermally conductive layer is in contact with the metal shielding layer, and the thermally conductive layer is connected to the side of the power amplifier die away from the first substrate through the adhesive layer.

[0014] In this embodiment, a first heat-conducting component is provided between the power amplifier die and the metal shielding layer to compensate for the insufficient height of the power amplifier die. The high thermal conductivity of the material used in the first heat-conducting component enables the rapid conduction and diffusion of heat generated by the power amplifier die to the metal shielding layer, and the heat is quickly dissipated through the metal shielding layer, thereby improving the heat dissipation capacity of the power amplifier die. This allows for the placement of a higher-power power amplifier die in the RF module, thus enhancing the performance of the RF module.

[0015] In some embodiments, the radio frequency module further includes a second heat-conducting element embedded in the first substrate; the orthographic projection of the power amplifier die on the first substrate at least partially overlaps with the orthographic projection of the second heat-conducting element on the first substrate.

[0016] In this embodiment, a second heat-conducting component is embedded in the first substrate below the power amplifier die. The high thermal conductivity of the material used in the second heat-conducting component enables rapid conduction and diffusion of heat generated by the power amplifier die during operation. Combined with the structure where the other side of the power amplifier die is in contact with the metal shielding layer, the dual heat dissipation path further enhances the heat dissipation capability of the power amplifier die.

[0017] In some embodiments, the first substrate includes signal lines, and the routing area of ​​the signal lines in the first substrate does not overlap with the embedded area of ​​the second heat-conducting element in the first substrate.

[0018] In this embodiment, since the second heat-conducting component is usually made of a metal with high electrical conductivity, if it overlaps with the routing area of ​​the signal line of the power amplifier die, it can easily cause signal interference and loss to the power amplifier die, or even cause a short circuit in the electrical signal transmitted in the signal line. By making the routing avoidance treatment of the embedded area of ​​the second heat-conducting component, the normal operation of the power amplifier die can be guaranteed.

[0019] In some embodiments, no electronic devices are disposed on the second surface of the first substrate, and the second surface is the surface opposite to the first surface.

[0020] In this embodiment, the power amplifier die and its matching devices, along with the package formed by the double-sided packaging, are all arranged on the first surface of the first substrate. No electronic devices are disposed on the second surface of the first substrate. This allows the RF module to form an overall single-sided package with internal partial double-sided packaging. This ensures that the package area of ​​the RF module is small while also making the package height of the RF module controllable.

[0021] In some embodiments, the package is a double-sided exposed die package, a single-sided exposed die package, or a die-free package.

[0022] In this embodiment, when the package height is limited, at least one surface of the double-sided plastic encapsulation structure of the package can be ground and thinned to make the package an exposed die package, thereby forming a double-sided exposed die package or a single-sided exposed die package, so as to reduce the package height of the package and ensure that the package height of the RF module is controllable.

[0023] In some embodiments, the second substrate includes a glass substrate, a ceramic substrate, a metal substrate, or a redistribution layer substrate.

[0024] In some embodiments, the other devices mentioned above include at least one of a power amplifier controller, a switching device, a filter, a filter matching device, and a low-noise amplifier.

[0025] In some embodiments, the power amplifier die, multiple matching devices, and package are flip-chip mounted to the first surface of the first substrate.

[0026] In this embodiment, the flip-chip mounting method eliminates the wire bonding step compared to the conventional mounting method. Since flip-chip mounting does not require reserving space for wire bonding, it not only reduces the package area of ​​the RF module but also reduces the package height of the RF module.

[0027] In some embodiments, the aforementioned additional devices are flip-chip mounted to the second substrate.

[0028] In this embodiment, the flip-chip mounting method eliminates the wire bonding step compared to the conventional mounting method. Since flip-chip mounting does not require reserving space for wire bonding, it not only reduces the package area of ​​the package but also reduces the package height.

[0029] Secondly, this application provides an electronic device, which includes a circuit board and the aforementioned radio frequency module, wherein the radio frequency module is electrically connected to the circuit board.

[0030] In this embodiment, the beneficial effects of the second aspect can also be referred to the description of the first aspect and any of its implementations, which will not be repeated here. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a radio frequency module;

[0032] Figure 2 This is a schematic diagram of another type of radio frequency module;

[0033] Figure 3 This is a schematic diagram of another radio frequency module provided in an embodiment of this application;

[0034] Figure 4 A top view of a radio frequency module provided in an embodiment of this application;

[0035] Figure 5 This is a schematic diagram of the structure of another radio frequency module provided in the embodiments of this application;

[0036] Figure 6 This is a schematic diagram of the structure of another radio frequency module provided in the embodiments of this application;

[0037] Figure 7 This is a schematic diagram of the structure of another radio frequency module provided in the embodiments of this application;

[0038] Figure 8 This is a schematic diagram of the structure of a first heat-conducting element provided in an embodiment of this application;

[0039] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] For ease of understanding, the technical terms used in this application will be explained and described below.

[0042] Passive devices can include resistors, capacitors, inductors, etc. Passive devices are electronic devices that can work without an external power source. Their function depends on their own physical characteristics (such as resistance, capacitance, and inductance) to process electrical signals.

[0043] A die is a chip core unit that has been cut off from a wafer and is not yet packaged. It contains circuit elements such as transistors, capacitors, and resistors, as well as metal wiring layers, and can independently perform specific electrical functions (such as computing and storage).

[0044] Exposed die: A process technology that removes the top covering material (such as molding compound, substrate, etc.) of a chip through mechanical grinding, chemical etching, or laser removal, thereby partially or completely exposing the bare die.

[0045] Quality factor: A parameter that measures the degree of energy loss of energy storage components (inductors, capacitors, resonant circuits, etc.). A higher quality factor means that the energy storage component has lower losses and higher energy storage efficiency.

[0046] Molding: The process of encapsulating chips, electronic devices, or circuit modules into a complete package using thermosetting or thermoplastic plastics through molding, injection, or other processes, to form a molding layer with functions such as mechanical support, electrical isolation, moisture and dirt protection.

[0047] Metal shielding layer: A functional structure that uses the electromagnetic reflection, absorption and conduction properties of metallic materials to block electromagnetic fields, electromagnetic waves or static electricity.

[0048] Redistribution layer (RDL): A method of achieving high-density electrical connections by depositing a metal wiring layer on the surface of a chip or package substrate, which rearranges and extends the pads inside the chip or the pins inside the package. It is used to solve the problem of mismatch between the chip pin pitch and the pin pitch of the external package or substrate, while improving the integration of the package and the signal transmission performance.

[0049] Fan-out packaging: By redistributing the pads inside the chip to a larger area through a redistribution layer, the number of input / output interfaces and integration density of the package can be increased without increasing the chip area.

[0050] To meet diverse user needs, electronic devices integrate numerous modules with varying functions. However, as the functionality of electronic devices becomes increasingly powerful, users' demands for portability are also growing, thus placing higher demands on the integration level of electronic components during packaging. Furthermore, the radio frequency (RF) module, as the core device responsible for signal transmission and reception in electronic devices, faces even stronger and more urgent requirements in this regard. The electronic device can be a mobile phone, tablet computer, laptop computer, smartwatch, or smart wearable device, etc., and is not limited in this embodiment.

[0051] Against this backdrop, the industry has designed packaging forms for electronic devices that have evolved from single-sided packaging to double-sided packaging in two-dimensional space, and even three-dimensional stacking extensions, in response to the above requirements.

[0052] In some implementations, such as Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a radio frequency module 100. The radio frequency module 100 provided in this embodiment is disposed in an electronic device. The radio frequency module 100 includes a substrate 110 and a plurality of electronic devices 120. The plurality of electronic devices 120 adopt a double-layer stacked packaging technology and are disposed on two opposite surfaces of the substrate 110.

[0053] The radio frequency (RF) module 100 includes electronic components 120 that perform RF signal transmission and reception and signal processing, which are divided into active and passive components. The active components include power amplifiers (PAs), power amplifier controllers, filters, switching devices, low-noise amplifiers, etc., with the power amplifier being the main power device in the RF module 100 and being a high-power, high-heat-generating device. The passive components include matching devices for the power amplifiers and matching devices for the filters, where the matching devices can be independent devices or integrated packaged devices.

[0054] In this embodiment, the first surface of the substrate 110 is provided with some of the electronic devices in the plurality of electronic devices 120, such as active devices such as power amplifiers and filters, as well as passive devices. The second surface of the substrate 110, which is opposite to the first surface, is provided with other electronic devices besides some of the electronic devices in the plurality of electronic devices 120.

[0055] During the fabrication of the RF module 100, some electronic components are mounted on the first surface of the substrate 110 using either a flip-chip or upright mounting method. Then, a molding compound is used to encapsulate the substrate 110 and some of the electronic components on the first surface of the substrate 110 to form a first package 130. Furthermore, a heat-dissipating metal layer 131 is provided outside the molding compound to improve the heat dissipation performance of the electronic components 120.

[0056] Furthermore, after the electronic components 120 (excluding some electronic components) are mounted on the second surface of the substrate 110 using a flip-chip or upright mounting method, the substrate 110, the electronic components 120 on the second surface of the substrate 110, and the first package 130 formed by the first molding of the first surface of the substrate 110 are encapsulated using molding compound to form a double-layer stacked radio frequency module 100. Because the electronic components 120 are stacked vertically, the package area of ​​the radio frequency module 100 is significantly reduced, thereby reducing the area occupied by the radio frequency module 100 on the circuit board of the electronic device, increasing the number of package structures that can be integrated into the electronic device, and enabling the electronic device to achieve more functions.

[0057] In one embodiment, a portion of the electronic device 120 on the second surface of the substrate 110 is a bare die. After the substrate 110 is encapsulated, a portion of the encapsulation material on the second surface of the substrate 110 is removed by a grinding process, exposing a portion of the bare die on the second surface of the substrate 110. Additionally, a metal layer is deposited on the surface of the bare die by a sputtering process, allowing the bare die to better contact the external heat dissipation structure, improving the heat dissipation performance of the electronic device 120, thereby enhancing the performance of the electronic device 120. Since the second surface of the substrate 110 also has solder balls distributed for connecting the RF module 100 to external circuits, such as the circuit board of an electronic device, to ensure normal electrical connection between the RF module 100 and the external circuits, a laser encapsulation process is also required to remove the encapsulation material around the solder balls on the second surface of the substrate 110 during the overall encapsulation of the substrate 110 and the electronic devices 120 distributed on both surfaces of the substrate 110. Removing the molding compound exposes the solder balls, allowing for better alignment and soldering of the solder balls with the pads on the circuit board when the RF module 100 is subsequently mounted on the circuit board of an electronic device using surface mount technology (SMT), thus achieving an electrical connection between the RF module 100 and the circuit board.

[0058] In this embodiment, compared to the single-sided packaging of electronic device 120 on substrate 110, the double-sided stacked packaging structure of RF module 100 provided in this embodiment reduces the area required for packaging. Furthermore, compared to package-on-package (POP) structures, which involve stacking two or more packages together, the double-sided stacked packaging shares the substrate 110, reducing the packaging height of RF module 100. However, the packaging height of RF module 100 formed by double-sided stacked packaging is still significantly higher than that of single-sided packaged RF module 100. If there are height restrictions on RF module 100 in electronic devices, it may be difficult to use large-size electronic device 120 within RF module 100, potentially causing the performance of electronic device 120 to fail to meet usage requirements.

[0059] In other implementations, such as Figure 2 As shown, Figure 2 This is a schematic diagram of another radio frequency module 100. The radio frequency module 200 provided in this embodiment includes a substrate 210 and multiple electronic devices 220. The multiple electronic devices 220 adopt double-sided packaging technology and are disposed on two opposite surfaces of the substrate 210.

[0060] In this embodiment, a portion of the multiple electronic devices 220 are disposed on the first surface of the substrate 210, and other electronic devices 220 are disposed on the second surface of the substrate 210 opposite to the first surface. The multiple electronic devices 220 are disposed on the surface of the substrate 210 using either a flip-chip or a conventional mounting configuration. However, when the electronic devices 220 are disposed on the surface of the substrate 210 using a conventional mounting configuration, a larger area is required for electrical connection between the electronic devices 220 and the substrate 210 via wire bonding (WB), which is detrimental to reducing the package area.

[0061] In addition, with Figure 1 Compared to the dual-layer stacked packaging technology of the provided RF module 100, the double-sided packaging technology used in this embodiment allows for the RF module 200 to be formed by encapsulating the substrate 210 and the electronic devices 220 on its surface with molding compound in a single process after multiple electronic devices 220 are disposed on two opposing surfaces of the substrate 210. This eliminates the need for two separate molding processes, reducing packaging costs and further decreasing the packaging height of the RF module 200. However, the double-sided packaging method used in this embodiment still results in a significantly higher packaging height than single-sided packaging. When the height of the RF module 200 is limited, it becomes difficult to use large-sized electronic devices 220, potentially leading to performance limitations of the electronic devices 220.

[0062] To address the aforementioned issues, this application provides an RF module that employs an overall single-sided package with internal partial double-sided packaging, thereby reducing the package size of the RF module. Simultaneously, without affecting the size of the electronic components within the RF module, it enhances the heat dissipation capacity of the electronic components, thereby improving the performance of the RF module.

[0063] Please see Figure 3 , Figure 3 This is a schematic diagram of another radio frequency module 300 provided in an embodiment of this application. Figure 3As shown, the radio frequency module 300 provided in this application embodiment includes a first substrate 310, a power amplifier die 320, a plurality of matching devices 330 for the power amplifier die 320, and a package 340.

[0064] In this embodiment, the power amplifier die 320 and its multiple matching devices 330 are both disposed on the first surface S1 of the first substrate 310. The matching devices 330 of the power amplifier die 320 are passive devices that match the power amplifier die 320, including resistors, capacitors, inductors, etc., such as high-quality factor inductors. The matching devices 330 are used to optimize the impedance matching of the power amplifier die 320, reduce signal reflection, and improve power transmission efficiency, and are key components for the efficient operation of the power amplifier die 320.

[0065] Furthermore, a package 340, including a second substrate 341 and a plurality of other devices 342, is also disposed on the first surface S1 of the first substrate 310. The plurality of other devices 342 in the package 340 are disposed on two opposite surfaces of the second substrate 341 and encapsulated to form the package 340. That is, the second substrate 341 and the plurality of other devices 342 disposed on the two opposite surfaces of the second substrate 341 are encapsulated using a double-sided encapsulation technique to form the package 340. The other devices 342 include at least one of a power amplifier controller, a switching device, a filter, a filter matching device, and a low-noise amplifier.

[0066] In addition, no electronic devices are disposed on the second surface S2 of the first substrate 310. The second surface S2 is the surface opposite to the first surface S1, that is, the power amplifier die 320, the multiple matching devices 330 of the power amplifier die 320 and the package 340 are disposed on the same surface of the first substrate 310.

[0067] In some implementations, such as Figure 4 As shown, Figure 4 A top view of a radio frequency module 300 provided in this application.

[0068] On the first surface S1 of the first substrate 310, a power amplifier die 320 and multiple matching devices 330 of the power amplifier die 320 are independently disposed on the substrate, with the multiple matching devices 330 of the power amplifier die 320 positioned close to the power amplifier die 320. Since the high-frequency signal output from the power amplifier die 320 generates significant skin effect and dielectric loss in the transmission line, if the matching devices 330 are positioned far from the power amplifier die 320, the excessively long transmission line between the power amplifier die 320 and its matching devices 330 may result in poor impedance matching, and may even introduce additional parasitic inductance and capacitance, compromising the accuracy of the matching network. Therefore, given that the arrangement of the multiple matching devices 330 directly affects the impedance matching accuracy and power efficiency of the power amplifier die 320, the multiple matching devices 330 are preferentially positioned close to the power amplifier die 320, resulting in a shorter high-frequency signal transmission path, suppressing the generation of parasitic parameters, and thus ensuring the performance of the power amplifier die 320.

[0069] Multiple other devices 342 serve as auxiliary functional devices for the power amplifier die 320, used to implement functions such as bias control, path switching, and signal cleanup, without affecting the impedance matching accuracy and power efficiency of the power amplifier die 320. Therefore, the layout of the multiple other devices 342 can be flexibly designed. In this application, the multiple other devices 342 are double-sided packaged to form a package 340, and the package 340 is then disposed on the first surface S1 of the first substrate 310. Moreover, the layout area of ​​the package 340 does not need to occupy the adjacent area of ​​the power amplifier die 320, which ensures the performance of the power amplifier die 320 in the RF module 300 while reducing the package area of ​​the RF module 300.

[0070] Optionally, when multiple other devices 342 are disposed on two opposing surfaces of the second substrate 341, the arrangement of the multiple other devices 342 on the second substrate 341 can be freely combined and arranged. For example, when the free combination and arrangement of the multiple other devices 342 achieves a compact arrangement, the packaging area of ​​the package 340 can be reduced without affecting the performance of the multiple other devices 342. Figure 4 The other devices 342 shown as dashed lines on the middle package 340 are other devices 342 disposed on the surface of the second substrate 341 near the first substrate 310.

[0071] In some embodiments, when the power amplifier die 320, multiple matching devices 330 and package 340 are arranged on the first surface S1 of the first substrate 310, for some of the other devices 342, such as the power amplifier controller and switching devices, if there is spare space on the first surface S1, or if some devices are large in size, have high power or high heat dissipation requirements, these devices can be arranged on the first surface S1 of the first substrate 310 without being packaged into the package 340.

[0072] like Figure 3 as well as Figure 4 As shown in the RF module 300, during the process of packaging and forming the RF module 300, firstly, the power amplifier die 320 and a plurality of matching devices 330 of the power amplifier die 320 are disposed on the first surface S1 of the first substrate 310, and the plurality of matching devices 330 are disposed close to the power amplifier die 320 to ensure the performance of the power amplifier die 320.

[0073] Secondly, for the multiple other devices 342, the multiple other devices 342 are first disposed on two opposite surfaces of the second substrate 341, and the second substrate 341 and the multiple other devices 342 are encapsulated to form a package 340 by double-sided encapsulation technology. Then, the package 340 is disposed on the first surface S1 of the first substrate 310, so as to reduce the area occupied by the multiple other devices 342 through double-sided encapsulation.

[0074] Finally, using a package-in-package (PiP) approach, the power amplifier die 320, multiple matching devices 330, and package 340, all disposed on the same surface of the first substrate 310, are packaged with the first substrate 310 to form an RF module 300. This results in an overall single-sided package and a partially double-sided package structure for the RF module 300, thereby reducing the package size of the RF module 300.

[0075] In this embodiment, the power amplifier disposed on the first substrate 310 is the main power device in the RF module 300, and is a high-power device with high power consumption and concentrated heat generation. By exposing the power amplifier die to form the power amplifier bare die 320, the heat dissipation path of the power amplifier bare die 320 is more direct due to the absence of a package shell, which can improve the heat dissipation efficiency of the power amplifier bare die 320. Since the higher the power of the power amplifier bare die 320, the higher the heat dissipation requirement of the power amplifier bare die 320, the exposing die treatment allows the first substrate 310 to be disposed of with a higher power power amplifier bare die 320, thereby improving the performance of the RF module 300.

[0076] Based on this, when the RF module 300 is installed in an electronic device, this application classifies the electronic components in the RF module 300 according to power consumption and height. The high-power, high-heat-generating power amplifier die 320 and its associated matching devices 330 are then placed on the first surface S1 of the first substrate 310. Other devices 342 are packaged using a double-sided encapsulation method to form a package 340, which is then placed on the first surface S1 of the first substrate 310. Since the RF module 300 in this application has an overall single-sided encapsulation with internal partial double-sided encapsulation, the package area of ​​the RF module 300 is reduced while the package height of the RF module 300 is controllable. Even with the package 340 encapsulated on the first substrate 310, the package height of the RF module 300 still approaches the package height of a conventional single-sided encapsulation structure, thereby reducing the package size of the RF module 300.

[0077] In this design, the power amplifier die 320 typically has a larger size and higher power output; for example, the height of the power amplifier die 320 (excluding the bottom solder balls) is greater than 0.2 mm. Thus, the single-sided package design increases the size of the power amplifier die 320 by increasing its height, allowing the first substrate 310 to accommodate a higher-power power amplifier die 320, thereby improving the performance of the RF module 300. Furthermore, the size of the matching device 330 for the power amplifier die 320 typically increases with a higher quality factor. The single-sided package design of the RF module 300 simultaneously improves the height limitations on the power amplifier die 320 and matching device 330 mounted on the first substrate 310, allowing for both higher-power power amplifier dies 320 and higher-quality matching devices 330, further enhancing the performance of the RF module 300.

[0078] Even with limitations on the package height of the RF module 300, its single-sided package structure allows for controllable height. This ensures that the high-power amplifier die 320, mounted on the first substrate 310, can be larger, as can its matching device 330. This reduces size limitations on the power amplifier die 320 and its matching device 330, enhancing heat dissipation. Furthermore, the power amplifier die 320 can operate over a wider power range, and the introduction of a high-quality matching device 330 improves noise suppression, enhancing signal reception and transmission capabilities in weak signal areas. This results in better performance, meeting the requirements of RF modules in electronic devices. Additionally, the small package size of the RF module 300 ensures that its placement within an electronic device maintains a relatively small size and thickness, minimizing impacts on portability.

[0079] To improve the heat dissipation performance of the power amplifier die 320, please refer to [link / reference needed]. Figure 5 , Figure 5 This is a schematic diagram of the structure of another radio frequency module 300 provided in an embodiment of this application. Figure 5 As shown, the RF module 300 provided in this application embodiment includes a first substrate 310, a power amplifier die 320, multiple matching devices 330 of the power amplifier die 320, and a package 340. The RF module 300 is a package structure with an overall single-sided package and internal partial double-sided packages.

[0080] In this embodiment, the package 340 includes a second substrate 341 and a plurality of other devices 342. The plurality of other devices 342 are disposed on two opposite surfaces of the second substrate 341, and are flip-chip mounted to the second substrate 341 to form a double-sided package 340. Compared with the conventional mounting method, the flip-chip mounting method directly solders the electronic device to the substrate with the front side facing down, forming an electrical connection with the substrate, eliminating the wire bonding process. Since flip-chip mounting does not require reserving space for wire bonding, it not only reduces the package area of ​​the package 340, but also reduces the package height of the package 340.

[0081] Furthermore, the second substrate 341 may include a glass substrate, a ceramic substrate, a metal substrate, or a redistribution layer substrate, and this application does not impose any limitations on it. However, when the packaging height of the package 340 is limited, the second substrate 341 may preferably use a redistribution layer substrate, the thickness of which is much smaller than that of ordinary substrates such as glass substrates, ceramic substrates, and metal substrates, thereby reducing the packaging height of the package 340.

[0082] For example, when the second substrate 341 is a redistribution layer substrate, the redistribution layer process is combined with a fan-out packaging method. First, the redistribution layer substrate extends wiring on both opposite surfaces of the package 340, and the pins of other devices 342 are rearranged in a fan-out manner. Then, the package 340 is double-sided encapsulated to protect the internal circuitry and enhance the mechanical stability of the package 340, ultimately forming an integrated double-sided package 340. Simultaneously, at least one of copper pillars (such as high-copper pillars) and solder balls is used as a connector on the back side of the redistribution layer substrate to achieve electrical connection between the package 340 and the first substrate 310.

[0083] Furthermore, the package 340 can be a double-sided exposed die package, a single-sided exposed die package, or a non-exposed die package, and this application does not impose any restrictions. However, when the package height of the package 340 is limited, after double-sided molding of the second substrate 341 and multiple other devices 342 disposed on two opposing surfaces of the second substrate 341, at least one surface of the double-sided molding structure can be ground and thinned to make the package 340 an exposed die package, thereby forming a double-sided exposed die package or a single-sided exposed die package to reduce the package height of the package 340.

[0084] In this embodiment, the power amplifier die 320, multiple matching devices 330, and the package 340 formed by double-sided encapsulation are disposed on the first surface S1 of the first substrate 310, and the entire assembly is single-sided packaged to form the RF module 300. The power amplifier die 320, multiple matching devices 330, and package 340 are flip-chip mounted to the first surface S1 of the first substrate 310, forming an electrical connection with the first substrate 310. Compared to the conventional mounting method, the flip-chip mounting method not only reduces the package area of ​​the RF module 300 but also reduces the package height, which is beneficial for the miniaturization of the RF module 300 package.

[0085] In some embodiments, the radio frequency module 300 further includes a molding layer 350 and a metal shielding layer 360.

[0086] Optionally, the molding compound 350 covers the first substrate 310, the power amplifier die 320, multiple matching devices 330, and the package 340. That is, after multiple other devices 342 are disposed on two opposite surfaces of the second substrate 341 and encapsulated to form a double-sided package 340, the first substrate 310, the power amplifier die 320, the multiple matching devices 330, and the package 340 are molded together using molding compound to form the molding compound 350.

[0087] In this embodiment, the metal shielding layer 360 is disposed above the molding compound layer 350. The side of the power amplifier die 320 away from the first substrate 310 passes through the molding compound layer 350 and contacts the metal shielding layer 360. Specifically, the top of the power amplifier die 320 is exposed after grinding the molding compound layer 350, and the metal shielding layer 360 is formed above the molding compound layer 350 using a sputtering process. Since the thermal conductivity of the metal material used in the metal shielding layer 360 is much greater than that of the molding compound used in the molding compound layer 350, ... Figure 5 As shown, the power amplifier die 320 directly contacts the metal shielding layer 360. The main upward heat dissipation path of the power amplifier die 320 is the channel between the power amplifier die and the metal shielding layer, which reduces the path thermal resistance and interface thermal resistance of the power amplifier die 320. Utilizing the thermal conductivity of the metal shielding layer 360, the heat generated by the power amplifier die 320 during operation is evenly dissipated to the entire metal shielding layer 360, which can enhance the heat dissipation capacity of the power amplifier die 320 and thus improve the performance of the power amplifier die 320.

[0088] In some embodiments, the RF module 300 further includes a second heat-conducting element 370, which is embedded in the first substrate 310. The orthographic projection of the power amplifier die 320 on the first substrate 310 at least partially overlaps with the orthographic projection of the second heat-conducting element 370 on the first substrate 310. That is, the second heat-conducting element 370 embedded in the first substrate 310 is disposed below the power amplifier die 320. The high thermal conductivity of the material used in the second heat-conducting element 370 enables rapid conduction and diffusion of heat generated by the power amplifier die 320 during operation, thereby further enhancing the heat dissipation capability of the power amplifier die 320. The second heat-conducting element 370 can be a copper block, a copper structure formed by stacking layers of electroplated copper, or a combination of both, i.e., it includes both copper blocks and stacked copper structures. There is no limitation here. The heat dissipation capability of the power amplifier die 320 is improved by embedding copper on the first substrate 310.

[0089] In some embodiments, the area of ​​the power amplifier die 320 projected onto the first substrate 310 is smaller than the area of ​​the second heat conductor 370 projected onto the first substrate 310, and the heat dissipation performance of the second heat conductor 370 increases with the increase of the area of ​​the second heat conductor 370.

[0090] In this embodiment, the first substrate 310 also includes a signal line 311. The routing area of ​​the signal line 311 in the first substrate 310 does not overlap with the embedded area of ​​the second heat-conducting component 370 in the first substrate 310. Since the second heat-conducting component 370 typically uses a metal with high electrical conductivity, if it overlaps with the routing area of ​​the signal line 311 of the power amplifier die 320, it can easily cause signal interference and loss to the power amplifier die 320, and may even cause a short circuit in the electrical signal transmitted in the signal line 311. By routing the signal line 311 to avoid the embedded area of ​​the second heat-conducting component 370, the normal operation of the power amplifier die 320 can be guaranteed.

[0091] In this embodiment, after the power amplifier is exposed to form a bare die 320, the side of the bare die 320 away from the first substrate 310 is positioned to penetrate the molding compound 350 and contact the metal shielding layer 360. Specifically, the top of the bare die 320 contacts the metal shielding layer 360. A second heat-conducting element 370 is embedded within the first substrate 310 at the bottom of the bare die 320. All these measures improve the heat dissipation performance of the bare die 320. Thus, with the RF module 300 forming an overall single-sided package and internally partially double-sided packaged structure, allowing the first substrate 310 to accommodate a larger power amplifier die 320, the aforementioned improvement in heat dissipation performance ensures that the larger, higher-power, and higher-heat-generating power amplifier die 320 can operate normally, thereby improving its performance to meet the usage requirements of the RF module 300 in electronic devices.

[0092] In some implementations, such as Figure 5 As shown, the height of the power amplifier die 320 is greater than 0.2 mm, and the height of the power amplifier die 320 is higher than the height of the matching device 330 and the package 340 disposed on the first substrate 310. The side of the power amplifier die 320 away from the first substrate 310 can directly contact the metal shielding layer 360 to achieve heat dissipation, thereby improving the heat dissipation capability of the power amplifier die 320.

[0093] In other implementations, such as Figures 6 to 7 As shown, the height of the power amplifier die 320 may be lower than the height of the matching device 330 or package 340 disposed on the first substrate 310. That is, the power amplifier die 320 is no longer the tallest electronic device on the first substrate 310. When the power amplifier die 320 is disposed on the first substrate 310, it may not be able to achieve the effect of direct contact with the metal shielding layer 360.

[0094] As one implementation method, such as Figure 6 As shown, Figure 6This is a schematic diagram of the structure of another radio frequency module 300 provided in the embodiments of this application.

[0095] In this embodiment, the molding compound 350 is recessed towards the first substrate 310 to form a recess 361. After a metal shielding layer 360 is formed above the molding compound 350 by a sputtering process, the side of the power amplifier die 320 away from the first substrate 310 contacts the metal shielding layer 360 at the bottom of the recess 361. Furthermore, the orthographic projection of the recess 361 on the first substrate 310 at least partially overlaps with the orthographic projection of the power amplifier die 320 on the first substrate 310, that is, the recess 361 formed by the molding compound 350 in the direction of the first substrate 310 is located above the power amplifier die 320.

[0096] Thus, even when the height of the power amplifier die 320 is insufficient, the side of the power amplifier die 320 away from the first substrate 310 can still directly contact the metal shielding layer 360, and the heat generated by the power amplifier die 320 during operation is evenly dissipated to the entire metal shielding layer 360, thereby improving the heat dissipation capacity of the power amplifier die 320.

[0097] As another implementation method, such as Figure 7 As shown, Figure 7 This is a schematic diagram of the structure of another radio frequency module 300 provided in the embodiments of this application.

[0098] In this embodiment, the radio frequency module 300 further includes a first heat-conducting element 380. One side of the first heat-conducting element 380 is connected to the side of the power amplifier die 320 away from the first substrate 310, and the other side of the first heat-conducting element 380 is in contact with the metal shielding layer 360. The first heat-conducting element 380 disposed between the power amplifier die 320 and the metal shielding layer 360 is used to compensate for the height difference between the power amplifier die 320 and the metal shielding layer 360.

[0099] In some implementations, such as Figure 7 As shown, the first heat-conducting element 380 can be a single, integral component. The first heat-conducting element 380 is made of a material with high thermal conductivity. One side of the first heat-conducting element 380 is connected to the side of the power amplifier die 320 away from the first substrate 310, such as by bonding, thus fixing the first heat-conducting element 380 to the side of the power amplifier die 320 away from the first substrate 310. The other side of the first heat-conducting element 380 is in contact with the metal shielding layer 360. The thermal conductivity of the material used to fabricate the first heat-conducting element 380 is 20% higher than the thermal conductivity of the substrate material (such as silicon, gallium arsenide, etc.) of the power amplifier die 320.

[0100] For example, when the first heat-conducting element 380 is fabricated using sintered silver technology, the molding compound 350 on the top region of the power amplifier die 320 is first ground or etched to expose the die. Silver nanoparticles or micron-sized silver powder are then coated onto the top of the power amplifier die 320 and cured and sintered to form the first heat-conducting element 380. Finally, a metal shielding layer 360 is formed above the molding compound 350 and the first heat-conducting element 380 using a sputtering process. Because sintered silver has a high thermal conductivity and high hardness and modulus after curing and sintering, it can be used to bond the power amplifier die 320 and conduct electricity from the power amplifier die 320 to the metal shielding layer 360.

[0101] In other embodiments, the first heat-conducting element 380 may be formed by stacking multiple components. For example, as Figure 8 As shown, Figure 8 This is a schematic diagram of the structure of a first heat-conducting element 380 provided in an embodiment of this application.

[0102] The first thermally conductive component 380 provided in this embodiment includes a thermally conductive layer 381 and an adhesive layer 382. The thermally conductive layer 381 is in contact with the metal shielding layer 360, and the thermally conductive layer 381 is connected to the side of the power amplifier die 320 away from the first substrate 310 through the adhesive layer 382. The thermally conductive layer 381 can be made of a material with a high thermal conductivity, such as copper, silver, aluminum, stainless steel, silicon wafers, or their alloys, and is not limited thereto. The adhesive layer 382 can be made of adhesive, silver paste, copper paste, etc., and is mainly used for thermal conduction and bonding of the thermally conductive layer 381 to the power amplifier die 320. The thermal conductivity of the material used in the adhesive layer 382 is also 20% higher than the thermal conductivity of the substrate material of the power amplifier die 320.

[0103] In addition, the interfaces between the power amplifier die 320 and the adhesive layer 382, ​​and between the thermal conductive layer 381 and the adhesive layer 382, ​​can be metallized to ensure the bonding strength of the adhesive layer 382 to the power amplifier die 320 and the thermal conductive layer 381, so that the thermal conductive layer 381, the adhesive layer 382, ​​and the power amplifier die 320 can form a structure with mechanical stability.

[0104] Based on this, the first heat-conducting element 380 disposed between the power amplifier die 320 and the metal shielding layer 360 can compensate for the problem of insufficient height of the power amplifier die 320. The high thermal conductivity of the material used in the first heat-conducting element 380 can enable the rapid conduction and diffusion of the heat generated by the power amplifier die 320 to the metal shielding layer 360, thereby achieving rapid heat dissipation through the metal shielding layer 360.

[0105] In this embodiment, after the power amplifier is exposed to form a bare die 320, the side of the bare die 320 away from the first substrate 310 is arranged to pass through the molding layer 350 and contact the metal shielding layer 360. That is, the top of the bare die 320 contacts the metal shielding layer 360. A second heat-conducting component 370 is embedded in the first substrate 310 at the bottom of the bare die 320. With the addition of dual heat dissipation paths, the heat dissipation performance of the bare die 320 is greatly improved, such as helping to dissipate an additional 20% of the heat generated by the bare die 320. Thus, with the RF module 300 forming an overall single-sided package and an internal partial double-sided package, allowing the first substrate 310 to house a power amplifier die 320 with a larger size, the aforementioned improvement in the heat dissipation performance of the power amplifier die 320 can increase the power rise space of the power amplifier die 320, enabling the larger size, higher power, and higher heat generation power amplifier die 320 to operate normally. This allows the RF module 300 to operate in a weak signal region, increasing the transmission power of the RF module 300 and thereby improving the output signal strength of the electronic device.

[0106] In some implementations, such as Figure 9 As shown, Figure 9 This is a schematic diagram of the structure of an electronic device 400 provided in an embodiment of this application. The electronic device 400 provided in this embodiment may include a circuit board 410 and a radio frequency module 300 provided in the above embodiment, and the radio frequency module 300 is electrically connected to the circuit board 410.

[0107] In this embodiment, the radio frequency module 300 is the core device responsible for signal transmission and reception in the electronic device 400. The radio frequency module 300 provided in this application adopts an overall single-sided package and an internal partial double-sided package structure. Since the package size of the radio frequency module 300 is small, when the radio frequency module 300 is placed in the electronic device 400, the size and thickness of the electronic device 400 can still be kept small, so as to avoid affecting the portability of the electronic device 400.

[0108] Furthermore, the overall single-sided packaging design reduces the size limitations of the power amplifier die 320 and its matching device 330. The RF module 300 achieves this by having the top of the power amplifier die 320 contact the metal shielding layer 360, and a second heat-conducting component 370 is embedded in the first substrate 310 at the bottom of the power amplifier die 320. This dual heat dissipation path enhances the heat dissipation performance of the power amplifier die 320. As a result, the power amplifier die 320 can operate over a wider transmission power range, enhancing its performance and thus improving the signal reception and transmission capabilities of the RF module 300 in weak signal regions, thereby meeting the usage requirements of the RF module 300 in the electronic device 400.

[0109] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A radio frequency module, characterized in that, The radio frequency module includes: First substrate; A power amplifier die is disposed on the first surface of the first substrate, and the height of the power amplifier die is greater than 0.2 mm; Multiple matching devices of the power amplifier die are disposed on the first surface; A package is disposed on the first surface. The package includes a second substrate and a plurality of other devices disposed on two opposite surfaces of the second substrate and encapsulated to form the package.

2. The radio frequency module according to claim 1, characterized in that, The radio frequency module also includes: A molding layer covers the first substrate, the power amplifier die, the plurality of matching devices, and the package. A metal shielding layer is disposed above the molding layer, and the side of the power amplifier die away from the first substrate passes through the molding layer and contacts the metal shielding layer.

3. The radio frequency module according to claim 2, characterized in that, The molding layer is recessed towards the first substrate to form a recessed portion, and the side of the power amplifier die away from the first substrate contacts the metal shielding layer at the bottom of the recessed portion; The orthographic projection of the recessed portion on the first substrate at least partially overlaps with the orthographic projection of the power amplifier die on the first substrate.

4. The radio frequency module according to claim 2, characterized in that, The radio frequency module further includes a first heat-conducting component, one side of which is connected to the side of the power amplifier die away from the first substrate, and the other side of which is in contact with the metal shielding layer.

5. The radio frequency module according to claim 4, characterized in that, The first thermally conductive component includes a thermally conductive layer and an adhesive layer; The thermally conductive layer is in contact with the metal shielding layer, and the thermally conductive layer is connected to the side of the power amplifier die away from the first substrate through the adhesive layer.

6. The radio frequency module according to claim 1, characterized in that, The radio frequency module further includes a second thermal conductive element, which is embedded in the first substrate; The orthographic projection of the power amplifier die onto the first substrate at least partially overlaps with the orthographic projection of the second heat-conducting component onto the first substrate.

7. The radio frequency module according to claim 6, characterized in that, The first substrate includes signal lines, and the routing area of ​​the signal lines in the first substrate does not overlap with the embedded area of ​​the second heat-conducting component in the first substrate.

8. The radio frequency module according to any one of claims 1 to 7, characterized in that, No electronic devices are disposed on the second surface of the first substrate, and the second surface is the surface opposite to the first surface.

9. The radio frequency module according to any one of claims 1 to 7, characterized in that, The package can be a double-sided exposed die package, a single-sided exposed die package, or a non-exposed die package.

10. The radio frequency module according to any one of claims 1 to 7, characterized in that, The second substrate includes a glass substrate, a ceramic substrate, a metal substrate, or a redistribution layer substrate.

11. The radio frequency module according to any one of claims 1 to 7, characterized in that, The other devices include at least one of a power amplifier controller, a switching device, a filter, a matching device for the filter, and a low-noise amplifier.

12. The radio frequency module according to any one of claims 1 to 7, characterized in that, The power amplifier die, the plurality of matching devices, and the package are flip-chip mounted to the first surface of the first substrate.

13. The radio frequency module according to any one of claims 1 to 7, characterized in that, The other devices are flip-chip mounted onto the second substrate.

14. An electronic device, characterized in that, The electronic device includes a circuit board and a radio frequency module as described in any one of claims 1 to 13, wherein the radio frequency module is electrically connected to the circuit board.

Images