Circuit board assembly, radio frequency module, transceiver and base station

Abstract

The invention provides a circuit board assembly, a radio frequency module, a transceiver and a base station. The circuit board assembly comprises a circuit board, conductive adhesive and an electronic device which are sequentially stacked, the first surface, facing the circuit board, of the electronic device comprises a grounding area, and the projection, on the circuit board, of the conductive adhesive and the projection, on the circuit board, of the grounding area are overlapped. The connection structure between the circuit board and the electronic device can be prevented from cracking, and the electronic device can be prevented from cracking.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and particularly to a circuit board assembly, a radio frequency module, a transceiver, and a base station. Background Art

[0002] In a radio frequency module of a base station, a filter is usually provided and fixed to a circuit board. Moreover, currently, the fixed connection between the filter and the circuit board is mainly achieved by soldering. However, due to a large difference in the coefficient of thermal expansion (CTE) between the filter and the circuit board, during the use of the radio frequency module, the filter and the circuit board generate different amounts of deformation when heated, resulting in cracking of the solder joints between the filter and the circuit board, or cracking of the filter. Summary of the Invention

[0003] To solve the above technical problems, this application provides a circuit board assembly, a radio frequency module, a transceiver, and a base station, which can avoid cracking of the connection structure between the circuit board and the electronic device, and avoid cracking of the electronic device.

[0004] In a first aspect of this application, a circuit board assembly is provided, including a circuit board, a conductive adhesive, and an electronic device stacked in sequence. That is to say, the electronic device is bonded to the circuit board through the conductive adhesive, thereby enabling a reliable connection between the electronic device and the circuit board, and thus avoiding the electronic device falling off the circuit board. Moreover, due to the large flexibility of the conductive adhesive, during the use of the circuit board assembly, both the circuit board and the electronic device are heated and deformed, and the conductive adhesive with large flexibility can absorb the deformation difference between the circuit board and the electronic device, thereby reducing the stress on the electronic device, and further avoiding cracking of the conductive adhesive and cracking of the electronic device. In addition, the cost of the conductive adhesive itself is low, so the cost of the circuit board assembly is low.

[0005] The first surface of the electronic device facing the circuit board includes a grounding area, and the projection of the conductive adhesive on the circuit board overlaps with the projection of the grounding area on the circuit board. In this way, at least part of the conductive adhesive can be in contact with the grounding area, and thus, the grounding area can be electrically connected to the circuit board through the conductive adhesive to achieve grounding of the electronic device, and the grounding performance is stable.

[0006] In some embodiments, the electronic device includes a filter. Thus, the grounding area on the filter can be electrically connected to the circuit board through the conductive adhesive, thereby enabling grounding of the filter.

[0007] The first surface further includes a signal transmission area and an isolation area. The grounding area surrounds the signal transmission area, and the isolation area is located between the signal transmission area and the grounding area.

[0008] Further, in one example, the projection of the conductive adhesive on the circuit board covers the entire projection of the grounding area on the circuit board. Exemplarily, the projection of the conductive adhesive on the circuit board is the same as the projection of the grounding area on the circuit board.

[0009] In another example, the projection of the conductive adhesive on the circuit board covers a partial projection of the grounding area on the circuit board, and there is an air gap between the un-covered part of the grounding area and the circuit board, and there is no physical connection.

[0010] In yet another example, the circuit board assembly further includes a non-conductive adhesive. The projection of the conductive adhesive on the circuit board covers a partial projection of the grounding area on the circuit board, and the projection of the non-conductive adhesive on the circuit board covers the remaining projection of the grounding area on the circuit board. In this way, the electronic device and the circuit board are bonded by the conductive adhesive and the non-conductive adhesive. Thus, not only can reliable bonding between the electronic device and the circuit board be achieved, but also the grounding performance of the filter can be realized. In addition, the cost of the non-conductive adhesive is lower. Therefore, by jointly using the conductive adhesive and the non-conductive adhesive to bond the electronic device and the circuit board, the cost can be further reduced.

[0011] In some embodiments, the circuit board assembly further includes a conductive part connected between the circuit board and the signal transmission area. The conductive part is electrically isolated from the conductive adhesive. In this way, the conductive part can achieve signal transmission between the electronic device and the circuit board.

[0012] The grounding area surrounds the signal transmission area and has a spacing from the signal transmission area; the conductive adhesive surrounds the conductive part and has a gap from the conductive part. Thus, electrical isolation between the conductive part and the conductive adhesive is achieved.

[0013] In one example, the conductive part can be a conductive adhesive. In this way, the conductive part has greater flexibility. During the use of the circuit board assembly, both the circuit board and the electronic device are heated and deformed, and the conductive part with greater flexibility can absorb the deformation difference between the circuit board and the electronic device, thereby reducing the stress on the electronic device, and further avoiding cracking of the conductive part and cracking of the electronic device. In another example, the conductive part can be a PIN pin.

[0014] In some embodiments, the first surface further includes a non-functional area on the side of the grounding area away from the signal transmission area. The non-functional area can be the area on the first surface other than the signal transmission area, the isolation area, and the grounding area.

[0015] In a possible embodiment, the projection of the conductive adhesive on the circuit board also overlaps with the non-functional area. Thus, the bonding area between the electronic device and the circuit board can be increased, thereby improving the bonding reliability between the electronic device and the circuit board.

[0016] Based on this, in one example, the projection of the conductive adhesive on the circuit board covers not only the entire projection of the grounding area on the circuit board, but also the entire projection of the non-functional area on the circuit board. Exemplarily, the conductive adhesive covers not only the entire area of the grounding area, but also the entire area of the non-functional area, thereby increasing the bonding area between the circuit board and the electronic device, and further improving the bonding effect. In another example, the projection of the conductive adhesive on the circuit board covers not only the entire projection of the grounding area on the circuit board, but also a partial projection of the non-functional area on the circuit board. Exemplarily, the conductive adhesive covers not only the entire area of the grounding area, but also a partial area of the non-functional area. There is an air gap between the area on the non-functional area that is not covered by the conductive adhesive and the non-conductive adhesive and the circuit board.

[0017] In another possible implementation manner, the circuit board assembly further includes a non-conductive adhesive. The projection of the conductive adhesive on the circuit board covers the projection of the grounding area on the circuit board, and the projection of the non-conductive adhesive on the circuit board overlaps with the projection of the non-functional area on the circuit board. That is to say, the electronic device and the circuit board are bonded by the conductive adhesive and the non-conductive adhesive. Thus, reliable bonding between the electrical component and the circuit board can be achieved, and the grounding performance of the filter can also be achieved. In addition, the cost of the non-conductive adhesive is lower. Therefore, by using the conductive adhesive and the non-conductive adhesive together to bond the electronic device and the circuit board, the cost can be further reduced.

[0018] Based on this, in one example, the projection of the non-conductive adhesive on the circuit board covers the entire projection of the non-functional area on the circuit board. Exemplarily, the projection of the non-conductive adhesive on the circuit board is the same as the projection of the non-functional area on the circuit board. In another example, the non-conductive adhesive covers a partial area of the non-functional area. Thus, the bonding area between the electronic device and the circuit board can be increased, thereby improving the bonding reliability between the electronic device and the circuit board.

[0019] In some implementation manners, the conductive adhesive includes a first adhesive layer, a conductive cloth, and a second adhesive layer that are stacked in sequence. Among them, both the first adhesive layer and the second adhesive layer have conductivity. And the first adhesive layer is located between the conductive cloth and the circuit board, and the second adhesive layer is located between the conductive cloth and the electronic device. The structure of this kind of conductive adhesive is simple and the materials are convenient to obtain.

[0020] Furthermore, the material of the first adhesive layer may include epoxy resin, acrylic adhesive, or silicone rubber, and the material of the second adhesive layer may include epoxy resin, acrylic adhesive, or silicone rubber. When the materials of both the first adhesive layer and the second adhesive layer include epoxy resin, since epoxy resin itself is not conductive, conductive media such as mica and carbon black can be added to the epoxy resin, thereby realizing the conductivity of the first adhesive layer and the second adhesive layer.

[0021] In a second aspect of the present application, there is also provided a radio frequency module, including a heat sink and the circuit board assembly of any of the above embodiments, and the heat sink is fixed on the circuit board assembly. The radio frequency module can achieve all the effects of the circuit board assembly.

[0022] In a third aspect of the present application, there is also provided a transceiver, including an antenna module and the above radio frequency module, and the antenna module is electrically connected to the radio frequency module. The transceiver can achieve all the effects of the radio frequency module.

[0023] In a fourth aspect of the present application, there is also provided a base station, including a processor and the above transceiver, and the processor is electrically connected to the transceiver. The base station can achieve all the effects of the transceiver. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of a radio frequency module in a first related art;

[0026] Figure 2 It is a schematic structural diagram of a radio frequency module in a second related art;

[0027] Figure 3 It is a schematic structural diagram of a bracket in a third related art;

[0028] Figure 4 It is a schematic structural diagram of a radio frequency module in a first embodiment of the present application;

[0029] Figure 5 For Figure 4 a more specific schematic structural diagram of the circuit board assembly shown;

[0030] Figure 6 It is a schematic structural diagram of a circuit board assembly in a second embodiment of the present application;

[0031] Figure 7 For Figure 4 a schematic structural diagram of the conductive adhesive in the circuit board assembly shown;

[0032] Figure 8 It is a schematic structural diagram of a circuit board assembly in a third embodiment of the present application;

[0033] Figure 9 It is a schematic structural diagram of a circuit board assembly in a fourth embodiment of the present application;

[0034] Figure 10 This is a schematic structural diagram of a circuit board assembly in the fifth embodiment of the present application.

[0035] Icons: 100 - Circuit board assembly; 200 - Heat sink; 300 - Screw; 10 - Circuit board; 20 - Electronic device; 21 - Filter; 22 - First surface; 221 - Ground area; 222 - Non-functional area; 223 - Signal transmission area; 224 - Isolation area; 30 - Conductive adhesive; 31 - First adhesive layer; 32 - Conductive cloth; 33 - Second adhesive layer; 34 - Gap; 40 - Non-conductive adhesive; 50 - Conductive part; 51 - Adapter board; 52 - Solder layer; 53 - Bracket; 531 - Body; 532 - Leg. Specific embodiments

[0036] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all 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.

[0037] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Among them, A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" means one or more, and "multiple" means two or more. "At least one (piece) of the following" or its similar expression refers to any combination of these items, including any combination of single item (piece) or plural items (pieces). For example, at least one (piece) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0038] The terms "first" and "second" in the description and claims of the embodiments of the present application are used to distinguish different objects, rather than to describe a specific order of the objects. For example, the first target object and the second target object are used to distinguish different target objects, rather than to describe a specific order of the target objects.

[0039] Terms such as "connected" and "linked" are used to express the interconnection or interaction between different components, which may include direct connection or indirect connection through other components. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a method, system, product, or device that comprises a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices. Terms such as "upper", "lower", "left", and "right" are only used with respect to the orientation of components in the drawings. These directional terms are relative concepts used for description and clarification relative to, and they can change accordingly with the change in the orientation of the components placed in the drawings.

[0040] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0041] In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality of" refers to two or more. For example, a plurality of processing units refers to two or more processing units; a plurality of systems refers to two or more systems.

[0042] A base station generally includes a transceiver and a processor, and the transceiver is electrically connected to the processor. The transceiver may include a radio frequency module and an antenna module, and the radio frequency module is electrically connected to the antenna module. The antenna module can receive signals and send the signals to the radio frequency module, and the radio frequency module processes the signals; the radio frequency module can also send the processed signals to the antenna module, and the antenna module radiates them out.

[0043] As Figure 1 shown, the radio frequency module may include a circuit board assembly 100 and a radiator 200. The circuit board assembly 100 may include a circuit board 10 and a filter 21, and the filter 21 is fixed on the circuit board 10. The circuit board 10 may be a printed circuit board (PCB). The filter 21 may be a ceramic filter, and the ceramic filter has characteristics such as smaller volume, less transmission loss, frequency stability, and small temperature coefficient.

[0044] Currently, the fixed connection between the filter 21 and the circuit board 10 is mainly achieved through the welding direction. However, due to the large difference in CTE between the filter 21 and the circuit board 10, different deformation amounts are generated due to heat during use, resulting in the solder joints between the filter 21 and the circuit board 10 cracking, or the filter 21 cracking.

[0045] To solve the problem of solder joint cracking or filter 21 cracking, in a related technology, as Figure 2 shown, the circuit board assembly 100 further includes an adapter board 51 and two solder layers 52. The adapter board 51 is located between the filter 21 and the circuit board 10. One of the solder layers 52 is located between the adapter board 51 and the filter 21, and the other solder layer 52 is located between the adapter board 51 and the circuit board 10. The circuit board 10 is connected to the heat sink 200 by screws 300. In this related technology, by adding the adapter board 51, the stress of the solder layer 52 is relieved, thereby improving the reliability of the solder layer 52.

[0046] However, in this related technology, the adapter board 51 needs to be connected to the circuit board 10 by welding, and the adapter board 51 also needs to be connected to the filter 21 by welding. As the size of the filter 21 gradually increases, the welding reliability may not be satisfied, resulting in a low connection reliability between the filter 21 and the circuit board 10.

[0047] Table 1 Figure 2 Materials and CTE of each component in the RF module shown

[0048] Component Name Material CTE (ppm / C) Filter 21 Ceramics 7-10 Soldering Layer 52 Tin 20 Circuit Board 10 FR-4 14 Heat Sink 200 Aluminum 23 Screw 300 Iron 16

[0049] During the use of the RF module, the heat sink 200, the circuit board 10, the screws 300, the solder layer 52, and the filter 21 will all deform due to heat. It can be seen from Table 1 that the CTE of the filter 21 is the smallest, and the deformation amount generated during heating is the smallest. In this way, the heat sink 200 and the circuit board 10 with larger deformation amounts will generate stress and transmit this stress layer by layer to the filter 21, resulting in damage to the filter 21 or the solder layer 52. Moreover, adding the adapter board 51 will increase the cost of the circuit board assembly 100.

[0050] In another related technology, the circuit board assembly 100 uses a bracket 53 as shown in Figure 3 to replace the adapter board 51 shown in Figure 1 The bracket 53 is fixed to Figure 2Between the filter 21 shown and the circuit board 10. The bracket 53 includes a body 531 and a plurality of legs 532. During use, after the circuit board assembly 100 generates temperature changes, the strain caused by the expansion of the circuit board 10 is absorbed by the legs 532, and the legs 532 are deformed, thereby relieving the stress on the filter 21 and preventing the filter 21 from deforming or even cracking.

[0051] However, the bracket 53 needs to be connected to the Figure 2 shown circuit board 10 by welding, and the bracket 53 also needs to be connected to the Figure 2 shown filter 21 by welding. As the size of the filter 21 gradually increases, the welding reliability may not be satisfied. Moreover, the structure of the bracket 53 is complex, the processing is complex, and the cost is high, resulting in a high cost of the circuit board assembly 100.

[0052] Based on this, as Figure 4 shown, the present embodiment provides a circuit board assembly 100, including a circuit board 10, a conductive adhesive 30, and an electronic device 20 stacked in sequence. That is to say, the electronic device 20 is bonded to the circuit board 10 through the conductive adhesive 30, thereby enabling a reliable connection between the electronic device 20 and the circuit board 10, and thus avoiding the electronic device 20 falling off the circuit board 10. That is to say, it is possible to reduce the situation where the welding reliability cannot be satisfied due to the oversize of the circuit board assembly 100 and further affect the connection reliability. Moreover, since the conductive adhesive 30 has a large flexibility, during the use of the circuit board assembly 100, both the circuit board 10 and the electronic device 20 are heated and deformed, and the conductive adhesive 30 with large flexibility can absorb the deformation difference between the circuit board 10 and the electronic device 20, thereby reducing the stress on the electronic device 20, and further avoiding cracking of the conductive adhesive 30 and cracking of the electronic device 20. In addition, the cost of the conductive adhesive 30 itself is low, so the cost of the circuit board assembly 100 is low.

[0053] In the present embodiment, the electronic device 20 may include a filter. Thus, the grounding area 221 on the filter can be electrically connected to the grounding area of the circuit board 10 through the conductive adhesive 30, so that the grounding of the filter 21 can be achieved. The signal transmission area 223 on the filter can be electrically connected to the signal transceiver port of the circuit board 10 through the conductive part 50. In other embodiments, the electronic device 20 may also include other devices, such as an amplifier, etc.

[0054] As Figure 4As shown, the first surface 22 may include a grounding region 221, a signal transmission region 223, and an isolation region 224. Among them, the signal transmission region 223 may refer to the region on the electronic device 20 that needs to be electrically connected to the circuit board 10 and is used for transmitting signals. The number of signal transmission regions 223 may be multiple, and there is a spacing between the multiple signal transmission regions 223. The number of signal transmission regions 223 is the same as the number of ports of the electronic device 20.

[0055] As Figure 4 shown, the grounding region 221 may refer to the region on the electronic device 20 that needs to be grounded. The grounding region 221 surrounds the outer periphery of the signal transmission region 223, and the isolation region 224 is located between the grounding region 221 and the signal transmission region 223.

[0056] As Figure 4 shown, the circuit board assembly 100 further includes a conductive part 50, and the conductive part 50 is connected between the circuit board 10 and the signal transmission region 223. Since the number of signal transmission regions 223 is multiple, the number of conductive parts 50 is the same as the number of signal transmission regions 223, which is also multiple. And the multiple conductive parts 50 are electrically isolated from each other. One end of the conductive part 50 can be in contact with the signal transmission region 223, and the other end can be in contact with the circuit board 10. Thus, the signal transmission region 223 can be electrically connected to the circuit board 10 through the conductive part 50, thereby realizing signal transmission with the circuit board 10.

[0057] As Figure 4 shown, the conductive adhesive 30 is connected between the grounding region 221 and the circuit board 10. Therefore, the conductive adhesive 30 surrounds the conductive part 50 and has a gap 34 from the conductive part 50. Thus, electrical isolation between the conductive part 50 and the conductive adhesive 30 is achieved.

[0058] As Figure 4 shown, the projection of the conductive part 50 on the circuit board 10 covers the projection of the signal transmission region 223 on the circuit board 10. For example, the projection of the conductive part 50 on the circuit board 10 is the same as the projection of the signal transmission region 223 on the circuit board 10, that is to say, the conductive part 50 covers the entire area of the signal transmission region 223. In this way, the connection area between the conductive part 50 and the signal transmission region 223 is larger, and better signal transmission performance of the electronic device 20 can be achieved.

[0059] In one example, the conductive portion 50 may be conductive adhesive. In this way, due to the relatively large flexibility of the conductive portion 50, during the use of the circuit board assembly 100, both the circuit board 10 and the electronic device 20 will be heated and deformed, and the conductive portion 50 with relatively large flexibility can absorb the deformation difference between the circuit board 10 and the electronic device 20, thereby reducing the stress on the electronic device 20, and further avoiding cracking of the conductive portion 50 and cracking of the electronic device 20. In another example, the conductive portion 50 may be a PIN pin. In other examples, the conductive portion 50 may also be other structures capable of realizing signal transmission.

[0060] As Figure 4 shown, the projection of the conductive adhesive 30 on the circuit board 10 overlaps with the projection of the grounding area 221 on the circuit board 10. Exemplarily, the projection of the conductive adhesive 30 on the circuit board 10 covers the entire projection of the grounding area 221 on the circuit board 10. Exemplarily, the projection of the conductive adhesive 30 on the circuit board 10 is the same as the projection of the grounding area 221 on the circuit board 10. Thereby, the bonding area between the electronic device 20 and the circuit board 10 can be increased, thus improving the bonding reliability.

[0061] In the present embodiment, as Figure 7 shown, the conductive adhesive 30 includes a first bonding adhesive layer 31, a conductive cloth 32, and a second bonding adhesive layer 33 that are stacked in sequence. Among them, both the first bonding adhesive layer 31 and the second bonding adhesive layer 33 have conductivity. As Figure 5 shown, the first bonding adhesive layer 31 bonds the conductive cloth 32 to the circuit board 10, and the second bonding adhesive layer 33 bonds the conductive cloth 32 to the electronic device 20. This kind of conductive adhesive 30 has a simple structure and convenient material selection. It can be understood that when the structure of the conductive portion 50 is also conductive adhesive, the conductive portion 50 can also adopt the structure as Figure 7 shown.

[0062] Furthermore, the material of the first bonding adhesive layer 31 may include epoxy resin, acrylic adhesive, or silicone rubber, and the material of the second bonding adhesive layer 33 may also include epoxy resin, acrylic adhesive, or silicone rubber. When the materials of both the first bonding adhesive layer 31 and the second bonding adhesive layer 33 include epoxy resin, since epoxy resin itself is not conductive, conductive media such as mica and carbon black can be added to the epoxy resin, thereby realizing the conductivity of the first bonding adhesive layer 31 and the second bonding adhesive layer 33. Similarly, conductive media can also be added to acrylic adhesive or silicone rubber to achieve conductivity.

[0063] In other embodiments of the present application, as Figure 6 shown, the difference from the embodiment as Figure 4 shown lies in the size of the projection of the conductive adhesive 30 on the circuit board 10. Exemplarily, as Figure 6As shown, the projection of the conductive adhesive 30 on the circuit board 10 covers a partial projection of the grounding area 221 on the circuit board 10. There is an air gap between the partial area not covered by the conductive adhesive 30 and the circuit board 10, and there is no physical connection.

[0064] In other embodiments of the present application, as Figure 8 shown, the difference from the embodiment Figure 6 shown is that in this embodiment, a non-conductive adhesive 40 is added on the basis of the embodiment Figure 6 shown. The non-conductive adhesive 40 is located between the electronic device 20 and the circuit board 10.

[0065] As Figure 8 shown, the projection of the conductive adhesive 30 on the circuit board 10 covers a partial projection of the grounding area 221 on the circuit board 10, and the projection of the non-conductive adhesive 40 on the circuit board 10 covers the remaining projection of the grounding area 221 on the circuit board 10. That is to say, in this embodiment, the electronic device 20 and the circuit board 10 are bonded through the conductive adhesive 30 and the non-conductive adhesive 40, and the projections of the conductive adhesive 30 and the non-conductive adhesive 40 on the circuit board 10 cover the entire area of the grounding area 221.

[0066] It can be understood that in other embodiments, the projections of the conductive adhesive 30 and the non-conductive adhesive 40 on the circuit board 10 may also cover a partial area of the grounding area 221, and there is an air gap between the non-covered area and the circuit board 10.

[0067] In other embodiments of the present application, the difference from the embodiment Figure 4 shown lies in the structure of the first surface 22. As Figure 9 shown, the first surface 22 further includes a non-functional area 222, and the non-functional area 222 is located on the side of the grounding area 221 away from the signal transmission area 223.

[0068] In this embodiment, as Figure 9 shown, the projection of the conductive adhesive 30 on the circuit board 10 covers the entire projection of the grounding area 221 on the circuit board 10, and also covers the entire projection of the non-functional area 222 on the circuit board 10. Exemplarily, the conductive adhesive 30 covers the grounding area 221 and the non-functional area 222. In this way, a part of the conductive adhesive 30 can be in contact with the grounding area 221. Thus, the grounding area 221 can be electrically connected to the circuit board 10 through the conductive adhesive 30 to realize the grounding of the electronic device 20, and the grounding performance is stable.

[0069] In other embodiments, the projection of the conductive adhesive 30 on the circuit board 10 only covers the entire projection of the grounding area 221 on the circuit board 10. There is an air gap between the non-functional area 222 and the circuit board 10 and there is no physical connection.

[0070] In other embodiments, the projection of the conductive adhesive 30 on the circuit board 10 covers the entire projection of the grounding area 221 on the circuit board 10 and covers a partial projection of the non-functional area 222 on the circuit board 10. There is an air gap and no physical connection between the area of the non-functional area 222 that is not covered by the conductive adhesive 30 and the circuit board 10.

[0071] In other embodiments of the present application, as Figure 10 shown, the first surface 22 further includes a non-functional area 222, and the non-functional area 222 is located on the side of the grounding area 221 away from the signal transmission area 223.

[0072] In this embodiment, as Figure 10 shown, the projection of the conductive adhesive 30 on the circuit board 10 covers the entire projection of the grounding area 221 on the circuit board 10. The projection of the non-conductive adhesive 40 on the circuit board 10 covers the entire projection of the non-functional area 222 on the circuit board 10. For example, the projection of the non-conductive adhesive 40 on the circuit board 10 is the same as the projection of the non-functional area 222 on the circuit board 10, that is to say, the non-conductive adhesive 40 covers the entire area of the non-functional area 222. Thereby, the bonding area between the electronic device 20 and the circuit board 10 can be increased, thus improving the bonding reliability between the electronic device 20 and the circuit board 10. It can be understood that in other embodiments, the projection of the non-conductive adhesive 40 on the circuit board 10 may also cover a partial projection of the non-functional area 222 on the circuit board 10.

[0073] In other embodiments, the projection of the conductive adhesive 30 on the circuit board 10 covers the projection of the grounding area 221 on the circuit board 10. The projection of the non-conductive adhesive 40 on the circuit board 10 covers a partial projection of the non-functional area 222 on the circuit board 10.

[0074] In other embodiments, the projection of the conductive adhesive 30 on the circuit board 10 covers the projection of the grounding area 221 on the circuit board 10 and covers a partial projection of the non-functional area 222 on the circuit board 10. The projection of the non-conductive adhesive 40 on the circuit board 10 covers the remaining partial projection of the non-functional area 222 on the circuit board 10.

[0075] In addition, the cost of the non-conductive adhesive 40 is lower. Therefore, by jointly using the conductive adhesive 30 and the non-conductive adhesive 40 to achieve the bonding between the electronic device 20 and the circuit board 10, the cost can be further reduced.

[0076] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection scope of the present application.

Claims

1. A circuit board assembly, characterized in that, comprising: a circuit board, a conductive adhesive, and an electronic device stacked in sequence. A first surface of the electronic device facing the circuit board includes a grounding area, and a projection of the conductive adhesive on the circuit board overlaps with a projection of the grounding area on the circuit board.

2. The circuit board assembly according to claim 1, characterized in that, the electronic device includes a filter.

3. The circuit board assembly according to claim 1 or 2, characterized in that, a projection of the conductive adhesive on the circuit board covers the entire projection of the grounding area on the circuit board.

4. The circuit board assembly according to claim 1 or 2, characterized in that, a projection of the conductive adhesive on the circuit board covers a part of the projection of the grounding area on the circuit board.

5. The circuit board assembly according to claim 4, characterized in that, the circuit board assembly further includes a non-conductive adhesive, and the non-conductive adhesive is located between the electronic device and the circuit board.

6. The circuit board assembly according to claim 5, characterized in that, a projection of the non-conductive adhesive on the circuit board covers the remaining part of the projection of the grounding area on the circuit board.

7. The circuit board assembly according to any one of claims 1-6, characterized in that, the first surface further includes a signal transmission area; the circuit board assembly further includes a conductive part connected between the circuit board and the signal transmission area, and the conductive part is electrically isolated from the conductive adhesive.

8. The circuit board assembly according to claim 7, characterized in that, the grounding area surrounds the signal transmission area and has a spacing from the signal transmission area; the conductive adhesive surrounds the conductive part and has a gap from the conductive part.

9. The circuit board assembly according to claim 7 or 8, characterized in that, the first surface further includes a non-functional area located on a side of the grounding area away from the signal transmission area, and a projection of the conductive adhesive on the circuit board also overlaps with the non-functional area.

10. The circuit board assembly according to claim 9, characterized in that, a projection of the conductive adhesive on the circuit board covers the entire projection of the non-functional area on the circuit board.

11. The circuit board assembly according to claim 7 or 8, characterized in that, the first surface further includes a non-functional area located on a side of the grounding area away from the signal transmission area, and the circuit board assembly further includes a non-conductive adhesive, and a projection of the non-conductive adhesive on the circuit board overlaps with a projection of the non-functional area on the circuit board.

12. The circuit board assembly according to claim 11, characterized in that, a projection of the non-conductive adhesive on the circuit board covers the entire projection of the non-functional area on the circuit board.

13. The circuit board assembly according to any one of claims 1-12, characterized in that, the conductive adhesive includes a first adhesive layer, a conductive cloth, and a second adhesive layer stacked in sequence.

14. A radio frequency module, characterized in that, comprising a heat sink and the circuit board assembly according to any one of claims 1-13, and the heat sink is fixed on the circuit board assembly.

15. A transceiver, characterized in that, it includes an antenna module and the radio frequency module described in claim 14, and the antenna module is electrically connected to the radio frequency module.

16. A base station, characterized in that, it includes a processor and the transceiver described in claim 15, and the processor is electrically connected to the transceiver.

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