Circuit board assembly, preparation method of circuit board assembly and electronic equipment

Abstract

The embodiment of the invention relates to a circuit board assembly, a preparation method of the circuit board assembly and electronic equipment, belongs to the field of electronic equipment, and is used for solving the problem that the shielding effect of a shielding cover of the circuit board assembly in the related technology is poor. The circuit board assembly comprises a circuit board, an electronic device, a filling material and a shielding cover. And the electronic device is welded and fixed on the circuit board through the salient points. The filling material is located between the electronic device and the circuit board and wraps the salient points. The shielding cover covers the electronic device. The shielding case comprises a cover body and a frame, the frame and the cover body are of an integrally-formed structure, and the frame is located between the cover body and the circuit board and connected with the circuit board. The integrally formed structure can be understood that the cover body and the frame can be manufactured through an integrally formed process. The shielding case is of an integrated structure, so that the sealing performance of the shielding case is improved, and the shielding performance of the shielding case is further improved.

Description

Technical Field

[0001] Embodiments of the present application relate to a circuit board assembly, a preparation method of the circuit board assembly, and an electronic device, belonging to the field of electronic devices. Background Art

[0002] The circuit board assembly may be a printed circuit board assembly (PCBA). The circuit board assembly includes a printed circuit board (PCB) and at least one electronic device electrically connected to the PCB. In order to protect the electronic device from external electromagnetic wave signals, a shielding cover may be disposed outside the electronic device, and the shielding cover may shield external interference signals. However, the shielding effect of the shielding cover in the related art is poor. Summary of the Invention

[0003] Embodiments of the present application provide a circuit board assembly, a preparation method of the circuit board assembly, and an electronic device, which are used to improve the problem that the shielding effect of the shielding cover of the circuit board assembly in the related art is poor.

[0004] To achieve the above object, embodiments of the present application provide the following solutions:

[0005] On the one hand, a circuit board assembly is provided, including: a circuit board, an electronic device, a filling material, and a shielding cover. The electronic device is fixed on the circuit board by bump welding. The filling material is located between the electronic device and the circuit board and wraps the bumps. The shielding cover covers the outside of the electronic device. The shielding cover includes a cover body and a frame, and the frame and the cover body are an integrally formed structure. Herein, the frame is located between the cover body and the circuit board, and the frame is connected to the circuit board. Here, the "integrally formed structure" can be understood as that the cover body and the frame can be made by an integrally formed process, and the integrally formed process may include sintering, casting, injection molding, 3D printing, stamping, etc. By setting the shielding cover as an integral structure, it is beneficial to improve the sealing performance of the shielding cover, and further improve the shielding performance of the shielding cover.

[0006] Further, since the cover body and the frame may be an integrally formed structure, the structural strength of the shielding cover is increased. When the shielding cover is installed on the circuit board, the shielding cover can play a strengthening effect on the circuit board, which is beneficial to improving reliability problems such as wire breakage, board breakage, and solder joint fracture of the circuit board. And, since the cover body and the frame may be an integrally formed structure, in the thickness direction of the circuit board, the size of the shielding cover is reduced, which is beneficial to reducing the occupied space of the circuit board assembly.

[0007] In some implementations, one side of the frame away from the cover body has a first pad, the circuit board has a second pad, and the second pad is located on the side of the circuit board facing the shielding case; the circuit board assembly further includes a connecting portion, and the first pad and the second pad are connected through the connecting portion. Through the above arrangement, the shielding case and the circuit board can be connected together through the connecting portion, which is beneficial to increasing the connection reliability between the shielding case and the circuit board.

[0008] In some implementations, the first pad, the second pad, and the connecting portion together form a welding structure. Through the above arrangement, it is beneficial to increase the connection strength between the shielding case and the circuit board and increase the connection reliability between the shielding case and the circuit board.

[0009] In some implementations, the material of the connecting portion includes a low-temperature solder. Through the above arrangement, it is beneficial to reduce the welding temperature of the first pad, the second pad, and the connecting portion, thereby avoiding the influence of the welding temperature on the filling material and the bumps, being beneficial to improving the aging phenomenon of the physical and chemical properties of the filling material, and also being beneficial to improving failure phenomena such as open circuit or short circuit caused by bump remelting.

[0010] In some implementations, the low-temperature solder includes at least one of a tin-bismuth alloy, a tin-cadmium alloy, or a tin-indium alloy. Through the above arrangement, it is beneficial to further reduce the welding temperature of the first pad, the second pad, and the connecting portion, thereby avoiding the influence of the welding temperature on the filling material and the bumps, being beneficial to improving the aging phenomenon of the physical and chemical properties of the filling material, and further improving failure phenomena such as bump remelting or short circuit.

[0011] In some implementations, the material of the connecting portion includes a high-temperature solder and / or a medium-temperature solder. Through the above arrangement, in an environment with a relatively high temperature, the high-temperature solder and the medium-temperature solder have higher reliability compared to the low-temperature solder, which is beneficial to improving the service life of the circuit board assembly.

[0012] In some implementations, the medium-temperature solder includes at least one of a tin-silver-copper alloy, a tin-lead alloy, a tin-silver-copper-nickel alloy, or a tin-silver alloy. The high-temperature solder includes at least one of a tin-antimony alloy, a lead-tin-silver alloy, a gold-tin alloy, or a gold-cadmium alloy. Through the above arrangement, in an environment with a relatively high temperature, the high-temperature solder and the medium-temperature solder have higher reliability compared to the low-temperature solder, which is beneficial to improving the service life of the circuit board assembly.

[0013] In some implementations, the connecting portion includes a conductive adhesive. By bonding the first pad and the second pad together, it is possible to avoid affecting the filling material and the bumps, which is beneficial to improving failure phenomena such as open circuit or short circuit caused by bump remelting.

[0014] On the other hand, a method for preparing a circuit board assembly is also provided, wherein the circuit board assembly includes a circuit board and an electronic device, and comprises: fixing the electronic device on the circuit board by convex point welding; filling a filling material between the electronic device and the circuit board, and the filling material wraps the convex point; installing a shielding cover on the circuit board, and the shielding cover is arranged outside the electronic device; the shielding cover includes a cover body and a frame, and the frame is arranged around the edge of the cover body, and the frame and the cover body are an integrally formed structure, wherein the frame is located between the cover body and the circuit board, and the frame is connected to the circuit board. By arranging the shielding cover as an integral structure, it is beneficial to improve the sealing of the shielding cover, thereby improving the shielding performance of the shielding cover.

[0015] Furthermore, since the cover and the frame can be an integrally formed structure, the structural strength of the shielding cover is increased, and when the shielding cover is installed on the circuit board, the shielding cover can play a reinforcing effect on the circuit board, which is conducive to improving the reliability problems of the circuit board such as broken wires, broken boards, and broken solder joints. In addition, since the cover and the frame can be an integrally formed structure, the size of the shielding cover is reduced in the thickness direction of the circuit board, which is conducive to reducing the space occupied by the circuit board components.

[0016] In some implementations, the shielding cover is installed on the circuit board, including: setting a welding portion on the first welding pad or the second welding pad, wherein the side of the frame facing away from the cover body has a first welding pad, and the second welding pad is located on the side of the circuit board facing the shielding cover; welding the circuit board and the shielding cover together, and the first welding pad, the second welding pad and at least part of the welding portion together form a welding structure.

[0017] In some implementations, the welding portion includes solder paste. Through the above configuration, no soldering flux is required during the welding process of the circuit board and the shielding cover, which is conducive to simplifying the welding steps of the circuit board and the shielding cover and improving the preparation efficiency of the circuit board assembly.

[0018] In some implementations, the soldering portion includes at least one of a solder block or a preformed solder sheet. Providing the soldering portion in a block or sheet structure is beneficial for controlling the amount of solder used, thereby facilitating reducing the manufacturing cost of the circuit board assembly.

[0019] In some implementations, solder joints are provided on the first pad or the second pad, including: providing solder joints on the first pad; after providing solder joints on the first pad and before welding the circuit board and the shielding cover together, it further includes: providing a low-temperature soldering flux on the surface of at least one of the solder joints or the second pad; or, providing solder joints on the first pad or the second pad, including: providing solder joints on the second pad; after providing solder joints on the second pad and before welding the circuit board and the shielding cover together, it further includes: providing a low-temperature soldering flux on the surface of at least one of the solder joints or the first pad. Through the above settings, when the circuit board and the shielding cover are welded together, the low-temperature soldering flux can assist and promote the welding process, which is beneficial to improving the preparation efficiency of the circuit board assembly.

[0020] In some implementations, welding the circuit board and the shielding cover together includes: locally heating the first pad, the second pad, and the solder joints to weld the circuit board and the shielding cover together. Locally heating the first pad, the second pad, and the solder joints enables the heating temperature to be concentrated at the first pad, the second pad, and the solder joints, which is beneficial to reaching the melting point temperature and facilitating the welding of the circuit board and the shielding cover together; at the same time, since the first pad, the second pad, and the solder joints are locally heated, it also avoids the heating temperature affecting the filling material and the bumps, which is beneficial to improving failure phenomena such as open circuit or short circuit caused by reflow of the bumps.

[0021] In some implementations, locally heating the first pad, the second pad, and the solder joints includes: using a laser generator or an electromagnetic heater to heat the first pad, the second pad, and the solder joints. The process of locally heating the first pad, the second pad, and the solder joints by a laser generator and welding the circuit board and the shielding cover together can be called laser welding. Laser welding is beneficial to improving the welding quality and increasing the welding speed. The process of locally heating the first pad, the second pad, and the solder joints by an electromagnetic heater and welding the circuit board and the shielding cover together can be called induction high-frequency welding. Induction high-frequency welding is beneficial to increasing the welding speed, has a small heat-affected zone during the welding process, and is not prone to oxidation during the welding process.

[0022] In some implementations, the material of the solder joints includes low-temperature solder, and welding the circuit board and the shielding cover together includes: welding the circuit board and the shielding cover together through a surface mount technology. Through the above settings, welding the circuit board and the shielding cover together is beneficial to increasing the connection reliability between the circuit board and the shielding cover.

[0023] In some implementations, mounting the shielding cover on the circuit board includes: providing a first welding sub-section on the first pad, providing a second welding sub-section on the second pad; welding the circuit board and the shielding cover together, and the first pad, the second pad, at least a portion of the first welding sub-section, and at least a portion of the second welding sub-section together form a welding structure. The above arrangement is conducive to improving the connection strength between the circuit board and the shielding cover, and improving the connection reliability between the circuit board and the shielding cover.

[0024] In some implementations, the shielding cover is mounted on the circuit board, including: setting a conductive glue on the first pad and / or the second pad, wherein the side of the frame facing away from the cover body has a first pad, and the second pad is located on the side of the circuit board facing the shielding cover; applying a preset pressure and a preset temperature to the first pad, the second pad, and the conductive glue to bond the circuit board and the shielding cover together. Through the above arrangement, the circuit board and the shielding cover can be bonded together, and at the same time, since the preset temperature applied to the first pad, the second pad, and the conductive glue is relatively low, the heating temperature is also avoided to affect the filling material and the bump, which is beneficial to improving the aging phenomenon of the physical and chemical properties of the filling material, and is also beneficial to improving the failure phenomenon such as open circuit or short circuit caused by the remelting of the bump.

[0025] On the other hand, an electronic device is also provided, comprising a circuit board assembly and a battery as in any of the above embodiments, wherein the battery supplies power to the electronic components of the circuit board assembly. The electronic device provided in the embodiment of the present application comprises the circuit board assembly as described above, and thus has all the above beneficial effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A structural diagram of an electronic device provided in an embodiment of the present application;

[0027] Figure 2 A structural diagram of a circuit board provided in an embodiment of the present application;

[0028] Figure 3 A structural diagram of a circuit board assembly provided in an embodiment of the present application;

[0029] Figure 4 A flowchart of a method for preparing a circuit board assembly provided in an embodiment of the present application;

[0030] Figure 5 A flowchart of the steps of installing a shielding cover on a circuit board in a method for preparing a circuit board assembly provided in an embodiment of the present application;

[0031] Figure 6 A structural diagram of installing a shielding cover on a circuit board provided in an embodiment of the present application;

[0032] Figure 7Another structural diagram for mounting a shielding cover on a circuit board provided by an embodiment of the present application;

[0033] Figure 8 Another structural diagram for mounting a shielding cover on a circuit board provided by an embodiment of the present application;

[0034] Figure 9 A structural diagram for soldering a first pad, a second pad, and a soldering part together provided by an embodiment of the present application;

[0035] Figure 10 A step flowchart for mounting a shielding cover on a circuit board in another method for preparing a circuit board assembly provided by an embodiment of the present application;

[0036] Figure 11 Another structural diagram for mounting a shielding cover on a circuit board provided by an embodiment of the present application;

[0037] Figure 12 A step flowchart for mounting a shielding cover on a circuit board in another method for preparing a circuit board assembly provided by an embodiment of the present application;

[0038] Figure 13 Another structural diagram for mounting a shielding cover on a circuit board provided by an embodiment of the present application. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0040] Hereinafter, terms such as "first" and "second" are only for convenience of description, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0041] 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 related concepts in a specific manner.

[0042] In the embodiments of the present application, directional indications such as up, down, left, right, front, and back for explaining the structures and movements of different components in the present application are relative. When the components are in the positions shown in the figures, these indications are appropriate. However, if the description of the component positions changes, then these directional indications will also change accordingly.

[0043] When describing some embodiments, the expressions "connected" and its derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or integrated; it can be directly connected or indirectly connected through an intermediate medium. The embodiments disclosed herein are not necessarily limited to the content herein.

[0044] In addition, the use of "based on" implies openness and inclusiveness because a process, step, calculation, or other action "based on" one or more of the stated conditions or values can, in practice, be based on additional conditions or values beyond the stated ones.

[0045] As used herein, "about" or "substantially" includes the stated value and the average value within an acceptable deviation range of the specific value, where the acceptable deviation range is determined by those of ordinary skill in the art considering the measurement being discussed and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system).

[0046] In the embodiments of the present application, "parallel" includes the stated situation and situations similar to the stated situation, and the range of the similar situations is within an acceptable deviation range, where the acceptable deviation range is determined by those of ordinary skill in the art considering the measurement being discussed and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range of approximate parallelism can be, for example, within 5% deviation.

[0047] The embodiments of the present application provide an electronic device. Among them, the electronic device 1 can be a terminal product such as a mobile phone, a tablet computer (pad), a television, a smart wearable product (e.g., a smart watch, a smart bracelet), a virtual reality (VR) device, an augmented reality (AR) device, etc.

[0048] Figure 1 is a structural diagram of an electronic device provided by the embodiments of the present application; Figure 2 is a structural diagram of a circuit board provided by the embodiments of the present application. Refer to Figure 1 and Figure 2, the electronic device 1 may include a battery 20 and a circuit board assembly 10. The battery 20 is used to supply power to the circuit board assembly 10, and the power source may be a lithium-ion battery 20 for example. Among them, the circuit board assembly 10 may include a circuit board 100. The circuit board 100 may be a printed circuit board (PCB), a flexible circuit board, an integrated circuit (or called a chip), etc. According to the number of electronic components carried on the circuit board 100, the circuit board may be a single-sided board or a double-sided board. A single-sided board may refer to a circuit board with electronic components carried on one side only. A double-sided board may refer to a circuit board with electronic components carried on both sides. According to the type of electronic components carried on the circuit board 100, the circuit board may be a main board, a module board, a frame board (FB), a radio frequency (RF) board, an application processor (AP) board, etc.

[0049] As Figure 1 shown, the electronic device 1 may include two circuit board assemblies 10. Among them, the circuit board 100 in one circuit board assembly 10 may be the main board, and the main board may be the main circuit board in the electronic device 1. The circuit board 100 in the other circuit board assembly 10 may be an RF board. The RF board may be used to carry radio frequency integrated circuits (RF ICs), radio frequency power amplifiers (RF PAs), wireless fidelity (WIFI) chips, etc.

[0050] In an embodiment where the circuit board 100 in the circuit board assembly 10 is the main board, the circuit board assembly 10 may further include electronic devices 200, and the electronic devices 200 are connected to the circuit board 100. The electronic devices 200 may include integrated circuit devices, such as an application processor (AP), a double data rate (DDR), and a universal flash storage (UFS), etc. In some examples, as Figure 2 shown, multiple circuits adapted to specific functions may be integrated on the circuit board 100, such as a display circuit, an RF circuit, a photographing circuit, a storage circuit, an audio circuit, a sensor circuit, etc.

[0051] Figure 3 This is a structural diagram of a circuit board assembly provided by an embodiment of the present application. In some embodiments, refer to Figure 3, the electronic device 200 can be fixedly welded to the circuit board 100 through the bumps 420. For example, the bumps 420 can be solder balls, that is, the electronic device 200 can be connected to the circuit board 100 through a flip chip - ball grid array (FCBGA). The bumps described in this application can refer to solder materials used for mechanical connection and / or electrical connection between the circuit board and the electronic component. The actual shape of the bumps described in this application is not necessarily spherical, and it can be polyhedral, spherical, ellipsoidal, frustum - shaped, chamfered, etc.

[0052] Continuing to refer to Figure 3 , the circuit board assembly 10 can further include a filling material 410. The filling material 410 can be located between the electronic device 200 and the circuit board 100 and wrap the bumps 420. Among them, the filling material 410 can be an underfill. By setting the filling material 410, it is beneficial to improve the connection reliability between the electronic device 200 and the circuit board 100.

[0053] The electronic device 200 may be interfered by external interference signals and interference signals emitted by adjacent electronic devices. If the interference is too strong, it may affect the normal operation of the electronic device 200, and further may affect the normal operation of the electronic device 200. Therefore, continuing to refer to Figure 3 , the circuit board assembly 10 can further include a shielding cover 300. The shielding cover 300 is connected to the circuit board 100 and covers the outside of the electronic device 200. By setting the shielding cover 300, electromagnetic interference received by the electronic device 200 can be avoided, which is beneficial to improving the performance of the electronic device 200.

[0054] In some embodiments of the related art, the shielding cover 300 can include a shielding frame and a shielding cover. The assembly process of the circuit board assembly 10 can include: when the electronic device 200 is fixedly welded to the circuit board 100 through the bumps 420, the shielding frame is fixedly welded to the circuit board 100. Among them, the shielding frame and the electronic device 200 are on the same side of the circuit board 100. After the electronic device 200 and the shielding frame are fixedly welded to the circuit board 100, the filling material 410 is filled between the circuit board 100 and the electronic device 200, and the filling material 410 wraps the bumps 420. After the filling material 410 is filled between the circuit board 100 and the electronic device 200, the shielding cover is bonded to the shielding frame through a conductive adhesive, and the shielding frame is located between the shielding cover and the circuit board 100, and the electronic device 200 is located in the space jointly enclosed by the shielding cover, the shielding frame and the circuit board 100.

[0055] However, there is a structural gap between the shielding frame and the shielding cover in the related art, resulting in poor sealing performance of the shielding cover 300 formed by the shielding frame and the shielding cover, and further resulting in poor shielding performance of the shielding cover 300. At the same time, since the shielding cover is generally fastened to the shielding frame by hand, there is a large assembly error between the shielding frame and the shielding cover, which further results in poor consistency of the shielding cover 300 formed by the shielding frame and the shielding cover, and further reduces the shielding performance of the shielding cover 300.

[0056] In view of this, with continued reference to Figure 3 In a circuit board assembly 10 provided in an embodiment of the present application, the shielding cover 300 may include a cover body 320 and a frame 310, and the frame 310 is located between the cover body 320 and the circuit board 100, and the frame 310 is connected to the circuit board 100. Exemplarily, the frame 310 may be disposed around the edge of the cover body 320, and the cover body 320 may be generally a rectangular flat plate. Correspondingly, the frame 310 may include four plate bodies connected in sequence at the head and tail. Of course, in some other embodiments, the cover body 320 may also be generally a circular flat plate, and correspondingly, the frame 310 may be generally a hollow cylindrical structure. Of course, the shapes of the frame 310 and the cover body 320 in the embodiments of the present application may also be designed according to actual needs, and the embodiments of the present application do not specifically limit the shapes of the cover body 320 and the frame 310.

[0057] Wherein, the cover body 320 and the frame 310 may be an integrally formed structure. Here, the "integrally formed structure" may be understood as that the cover body 320 and the frame 310 may be made by an integrally formed process, and the integrally formed process may include sintering, casting, injection molding, 3D printing, stamping, etc. In some examples, the material of the shielding cover 300 may include, for example, cupronickel, stainless steel, tinplate, etc., so that the shielding cover 300 has a good shielding effect. For example, the cover body 320 and the frame 310 may be formed by stamping from the same stainless steel plate. By setting the shielding cover 300 as an integral structure, the structural gap between the cover body 320 and the frame 310 is avoided, which is beneficial to improving the sealing performance of the shielding cover 300, and further improving the shielding performance of the shielding cover 300.

[0058] Furthermore, since the cover body 320 and the frame 310 may be an integrally formed structure, the structural strength of the shielding cover 300 is increased. When the shielding cover 300 is installed on the circuit board 100, the shielding cover 300 can play a strengthening effect on the circuit board 100, which is beneficial to improving the reliability problems such as wire breakage, board breakage, and solder joint fracture of the circuit board 100.

[0059] Moreover, when the cover body 320 and the frame 310 are two independent structures, in order to connect the cover body 320 and the frame 310 together, the cover body 320 needs to be disposed on the side of the frame 310 away from the circuit board 100, that is, the cover body 320 and the frame 310 at least partially overlap in the thickness direction of the circuit board 100, which in turn results in a relatively large size of the shielding case 300 in the thickness direction of the circuit board 100. In the embodiments of the present application, since the cover body 320 and the frame 310 can be an integrally formed structure, in the thickness direction of the circuit board 100, the size of the shielding case 300 is reduced, which is beneficial to reducing the occupied space of the circuit board assembly 10.

[0060] In some embodiments, with continued reference to Figure 3 , a first pad 301 may be provided on the side of the frame 310 away from the cover body 320. Correspondingly, the circuit board 100 may have a second pad 101, and the second pad 101 is located on the side of the circuit board 100 facing the shielding case 300. Exemplarily, in the thickness direction of the circuit board 100, the first pad 301 may at least partially overlap with the second pad 101 so as to realize the connection between the first pad 301 and the second pad 101.

[0061] Based on the above structure, one end of the frame 310 away from the cover body 320 may include an extension portion 312. Exemplarily, one end of the frame 310 away from the cover body 320 may extend in a direction parallel to the circuit board 100 to form the extension portion 312, or one end of the frame 310 away from the cover body 320 may be folded in a direction parallel to the circuit board 100 to form the extension portion 312. The first pad 301 may be provided on the side of the extension portion 312 facing the circuit board 100. By providing the first pad 301 on the extension portion 312, it is beneficial to increase the area of the first pad 301 and facilitate the alignment of the first pad 301 and the second pad 101.

[0062] With continued reference to Figure 3 , the circuit board assembly 10 may further include a connecting portion 500, and the first pad 301 and the second pad 101 may be connected through the connecting portion 500. In some embodiments, the material of the connecting portion 500 may include an adhesive so that the first pad 301 and the second pad 101 can be bonded together through the connecting portion 500. Or, in some embodiments, the material of the connecting portion 500 may include solder so that the first pad 301 and the second pad 101 can be soldered together through the connecting portion 500. The embodiments of the present application do not specifically limit the material of the connecting portion 500. Through the above arrangement, the shielding case 300 and the circuit board 100 can be connected together through the connecting portion 500, which is beneficial to increasing the connection reliability between the shielding case 300 and the circuit board 100.

[0063] In some embodiments, the first pad 301, the second pad 101, and the connecting portion 500 together form a welding structure 600. Exemplarily, the material of the connecting portion 500 may include solder. After the connecting portion 500 is disposed on the first pad 301 and the second pad 101, the first pad 301, the second pad 101, and the connecting portion 500 can be welded so that the first pad 301, the second pad 101, and the connecting portion 500 can together form the welding structure 600. Through the above arrangement, it is beneficial to increase the connection strength between the shielding cover 300 and the circuit board 100 and increase the connection reliability between the shielding cover 300 and the circuit board 100.

[0064] Due to the proportional differences among the three structures of the first pad 301, the second pad 101, and the connecting portion 500 and the process factors of welding, the shapes of the welding interface between the first pad 301 and the connecting portion 500 and the welding interface between the second pad 101 and the connecting portion 500 will have various forms. Therefore, in the embodiments of the present application, the cross-sectional shape of the welding structure 600 and the shape of the welding interface are not limited.

[0065] In the embodiments of the present application, when the first pad 301, the second pad 101, and the connecting portion 500 together form the welding structure 600, the material of the connecting portion 500 may include low-temperature solder.

[0066] During the assembly process of the circuit board assembly 10 in the embodiments of the present application, the electronic device 200 can be welded and fixed on the circuit board 100 through the bumps 420, and then the filling material 410 is filled between the electronic device 200 and the circuit board 100. After filling the filling material 410, the first pad 301 of the shielding cover 300 and the second pad 101 of the circuit board 100 can be welded together through the connecting portion 500. Through the above arrangement, the material of the connecting portion 500 may include low-temperature solder, which is beneficial to reducing the welding temperature of the first pad 301, the second pad 101, and the connecting portion 500. The welding temperature of the low-temperature solder is lower than the melting point of the bumps 420, thereby avoiding the influence of the welding temperature on the filling material 410 and the bumps 420, which is beneficial to improving the aging phenomenon of the physical and chemical properties of the filling material 410 and is also beneficial to improving the failure phenomena such as open circuit or short circuit caused by the re-melting of the bumps 420.

[0067] The embodiments of the present application do not specifically limit the melting point range of the low-temperature solder. When selecting the material of the low-temperature solder, it is only necessary to make the melting point of the low-temperature solder as low as possible under the condition that the welding reliability meets the requirements. In some embodiments, "low-temperature solder" can be understood as solder with a melting point lower than or equal to 180 °C, such as 180 °C, 170 °C, or 160 °C.

[0068] In some examples, the low-temperature solder may include at least one of a tin-bismuth alloy, a tin-cadmium alloy, or a tin-indium alloy. In the embodiments of the present application, the proportion of alloy elements in the tin-bismuth alloy, the tin-cadmium alloy, or the tin-indium alloy is not specifically limited, and it is only necessary to make the melting point of the low-temperature solder as low as possible while ensuring that the welding reliability meets the requirements. For example, at room temperature, the melting point of the tin-bismuth alloy can be 139 °C, and the welding peak temperature of the tin-bismuth alloy can be 185 °C. Through the above settings, it is beneficial to further reduce the welding temperature of the first pad 301, the second pad 101, and the connecting portion 500, thereby avoiding the influence of the welding temperature on the filling material 410 and the bumps 420, which is beneficial to improving the aging phenomenon of the physical and chemical properties of the filling material 410, and further improving the failure phenomena such as open circuit or short circuit caused by the remelting of the bumps 420.

[0069] Of course, the materials of the above low-temperature solder are only exemplary, and the low-temperature solder may also include other tin alloys or other alloy materials. In the embodiments of the present application, the materials of the low-temperature solder are not specifically limited.

[0070] In the embodiments of the present application, the material of the connecting portion 500 may also include a high-temperature solder and / or a medium-temperature solder. Here, "and / or" can be inclusive, which can be understood as only a high-temperature solder, or only a medium-temperature solder, or both a high-temperature solder and a medium-temperature solder at the same time.

[0071] In the embodiments of the present application, the melting point ranges of the medium-temperature solder and the high-temperature solder are not specifically limited. In some embodiments, the "medium-temperature solder" can be understood as a solder with a melting point higher than that of the low-temperature solder and lower than that of the high-temperature solder. For example, the melting point of the medium-temperature solder can be higher than 180 °C and lower than or equal to 230 °C, such as 220 °C, 210 °C, or 190 °C. In some embodiments, the "high-temperature solder" can be understood as a solder with a melting point higher than that of the medium-temperature solder. For example, the melting point of the high-temperature solder can be higher than 230 °C, such as 230 °C, 240 °C, or 250 °C. Through the above settings, in an environment with a higher temperature, the high-temperature solder and the medium-temperature solder have higher reliability than the low-temperature solder, which is beneficial to improving the service life of the circuit board assembly 10.

[0072] As described in the above embodiments, after filling the filling material 410, when the material of the connecting portion 500 includes a high-temperature solder and / or a medium-temperature solder, the first pad 301, the second pad 101, and the connecting portion 500 can be locally heated to weld the first pad 301 of the shielding cover 300 and the second pad 101 of the circuit board 100 together through the connecting portion 500. By means of local heating, it is possible to avoid the conduction of the heating temperature to the electronic device 200, thereby avoiding the influence on the filling material 410 and the bumps 420, which is beneficial to improving the failure phenomena such as open circuit or short circuit caused by the remelting of the bumps 420.

[0073] In some examples, the medium-temperature solder includes at least one of tin-silver-copper alloy, tin-lead alloy, tin-silver alloy, or tin-silver-copper-nickel alloy. The high-temperature solder includes at least one of tin-antimony alloy, lead-tin-silver alloy, gold-tin alloy, or gold-cadmium alloy. In the embodiments of the present application, the proportions of the alloying elements in the tin-silver-copper alloy, tin-antimony alloy, tin-lead alloy, tin-silver alloy, tin-silver-copper-nickel alloy, lead-tin-silver alloy, gold-tin alloy, or gold-cadmium alloy are not specifically limited. It is only necessary to ensure that the melting point of the solder is higher than that of the low-temperature solder while meeting the requirements for welding reliability. For example, the tin-silver-copper alloy can be SAC305 (SAC305 is a lead-free alloy containing 96.5% tin, 3% silver, and 0.5% copper). At room temperature, the melting point of SAC305 can be 217°C, and the welding peak temperature of the tin-bismuth alloy can be 245°C. Through the above settings, in a relatively high-temperature environment, the high-temperature solder and the medium-temperature solder have higher reliability compared to the low-temperature solder, which is beneficial to improving the service life of the printed circuit board assembly 10.

[0074] Of course, the materials of the above high-temperature solder and medium-temperature solder are only exemplary. The high-temperature solder and the medium-temperature solder can also include other tin alloys or other alloy materials. The embodiments of the present application do not specifically limit the materials of the low-temperature solder.

[0075] In some embodiments, the connecting portion 500 may further include conductive adhesive.

[0076] As described in the above embodiments, after filling the filling material 410, the first pad 301 of the shielding cover 300 and the second pad 101 of the printed circuit board 100 can be bonded together through the connecting portion 500. When the connecting portion 500 includes conductive adhesive, a preset temperature and a preset pressure can be applied to the first pad 301, the second pad 101, and the connecting portion 500, so that the first pad 301 of the shielding cover 300 and the second pad 101 of the printed circuit board 100 are bonded together through the connecting portion 500. Since the preset temperature can be lower than the melting point of the bumps 420 (for example, the preset temperature can be 150°C), by bonding the first pad 301 and the second pad 101 together, it is possible to avoid affecting the filling material 410 and the bumps 420, which is beneficial to improving failure phenomena such as open circuit or short circuit caused by re-melting of the bumps 420.

[0077] The embodiments of the present application further provide a method for manufacturing a printed circuit board assembly 10, which is used to manufacture the printed circuit board assembly 10 in any of the above embodiments. Among them, the printed circuit board assembly may include a printed circuit board and electronic devices. Figure 4 This is a flowchart of the steps of a method for manufacturing a printed circuit board assembly provided by the embodiments of the present application. Referring below Figure 4 and in conjunction with Figure 3 , the method for manufacturing the printed circuit board assembly 10 may include steps S101 - S103.

[0078] S101, fixing the electronic device on the circuit board by bump welding.

[0079] As described in the above embodiment, the bumps 420 may be solder balls, that is, the electronic device 200 may be connected to the circuit board 100 via a ball grid array.

[0080] In the embodiment of the present application, the method for preparing the circuit board assembly 10 further includes step S102.

[0081] S102, filling a filling material between the electronic device and the circuit board, wherein the filling material wraps the bumps.

[0082] As described in the above embodiment, the filling material 410 may be bottom filling glue, and the filling process between the electronic device 200 and the circuit board 100 may be called a glue dispensing process.

[0083] In the embodiment of the present application, the method for preparing the circuit board assembly 10 further includes step S103.

[0084] S103, installing a shielding cover on the circuit board, wherein the shielding cover is arranged outside the electronic device; the shielding cover comprises a cover body and a frame, wherein the frame and the cover body are an integrally formed structure, wherein the frame is located between the cover body and the circuit board, and the frame is connected to the circuit board.

[0085] Figure 5 A flowchart of the steps of installing a shielding cover on a circuit board in a method for preparing a circuit board assembly provided in an embodiment of the present application. Figure 6 A structural diagram of installing a shielding cover on a circuit board provided in an embodiment of the present application. Figure 6 Figure (a) is a structural diagram of setting solder paste 501 on the second pad 101. Figure 6 Figure (b) is a structural diagram of welding the first pad 301, the second pad 101 and the solder paste 501 together.

[0086] In some embodiments, reference Figure 5 and Figure 6 The step of installing the shielding cover 300 on the circuit board 100 may include steps S201 and S202.

[0087] S201, setting a welding portion on a first pad or a second pad, wherein a first pad is provided on a side of the frame facing away from the cover body, and a second pad is provided on a side of the circuit board facing the shielding cover.

[0088] The structures of the first pad 301 and the second pad 101 may be as described in the above embodiments, which will not be described in detail herein.

[0089] After the welding part 500a is arranged on the first pad 301 or the second pad 101, the step of installing the shielding cover 300 on the circuit board 100 may further include step S202.

[0090] S202. Weld the circuit board and the shielding cover together, and the first pad, the second pad, and at least part of the welding part jointly form a welding structure.

[0091] Exemplarily, the material of the welding part 500a may include solder, so that the circuit board 100 and the shielding cover 300 can be welded together through the welding part 500a. Through the above arrangement, it is beneficial to increase the connection strength between the shielding cover 300 and the circuit board 100 and improve the connection reliability between the shielding cover 300 and the circuit board 100.

[0092] In some embodiments, referring to Figure 6 , the welding part 500a may include solder paste 501. Arranging the welding part 500a on the first pad 301 or the second pad 101 may include: arranging the solder paste 501 on the first pad 301, or arranging the solder paste 501 on the second pad 101.

[0093] It can be understood that since the solder paste 501 is a mixture for bonding metal components together. For example, the alloy component in the solder paste 501 may include a tin-bismuth alloy, and the melting point of the solder paste 501 may be 138 °C. Among them, the solder paste 501 may include solder (such as one of low-temperature solder, high-temperature solder, or medium-temperature solder, where the materials of the low-temperature solder, high-temperature solder, or medium-temperature solder may be as described in the above embodiments and will not be elaborated here), flux, and other additives.

[0094] Exemplarily, when the first pad 301, the second pad 101, and the solder paste 501 are welded together, the solder in the solder paste 501, the first pad 301, and the second pad 101 jointly form a welding structure 600, and the flux in the solder paste 501 can help and promote the welding process during the welding process. Here, "the first pad 301, the second pad 101, and at least part of the welding part 500a jointly form a welding structure 600" can be understood as that when the welding part 500a includes the solder paste 501, the solder in the solder paste 501, the first pad 301, and the second pad 101 jointly form a welding structure 600, and the flux in the solder paste 501 does not form a welding structure.

[0095] Through the above arrangement, there is no need to set flux during the welding process of the circuit board 100 and the shielding cover 300, which is beneficial to simplifying the welding steps of the circuit board 100 and the shielding cover 300 and improving the preparation efficiency of the circuit board assembly 10.

[0096] Figure 7The figure is a structural diagram for mounting a shielding case on a circuit board provided by an embodiment of the present application. Among them, Figure 7 Figure (a) in Figure 7 is a structural diagram of arranging a solder block 502 (or a preformed solder sheet 503) on the first pad 301,

[0097] In some embodiments, referring to Figure 7 , the welding part 500a may include at least one of a solder block 502 or a preformed solder sheet 503. Among them, the solder block 502 may be a block structure made of solder. The preformed solder sheet 503 may be a solder thin sheet with a flat surface. The preformed solder sheet is solder that has been made into a precision shape and is suitable for mass manufacturing processes with small tolerances. The materials of the solder block 502 and the preformed solder sheet 503 may include one of the above-mentioned low-temperature solder, high-temperature solder, or medium-temperature solder. Among them, the materials of the low-temperature solder, high-temperature solder, or medium-temperature solder may be as described in the above embodiments and will not be elaborated here. Setting the welding part 500a into a block or sheet structure is beneficial to controlling the solder usage amount, and thus beneficial to reducing the manufacturing cost of the circuit board assembly 10.

[0098] In addition, in the embodiments of the present application, the specific shapes of the solder block 502 and the preformed solder sheet 503 are not limited. The shape of the orthographic projection of the solder block 502 or the preformed solder sheet 503 on the circuit board 100 may be, for example, circular, oval, rectangular, etc.

[0099] It can be understood that neither the solder block 502 nor the preformed solder sheet 503 contains a soldering flux. To assist and promote the soldering process, it is necessary to set the soldering flux after setting the solder block 502 or the preformed solder sheet 503.

[0100] In some examples, referring to Figure 7 Figure (a) in Figure 7 , the step of arranging the welding part 500a on the first pad 301 or the second pad 101 may include: arranging the welding part 500a on the first pad 301. Correspondingly, referring to

[0101] Exemplarily, the step of disposing the welding portion 500a on the first pad 301 may include welding the welding portion 500a on the first pad 301. After disposing the welding portion 500a on the first pad 301, a soldering flux 700 may be disposed on the surface of the welding portion 500a facing the second pad 101. Alternatively, after disposing the welding portion 500a on the first pad 301, a soldering flux 700 may be disposed on the surface of the second pad 101 facing the welding portion 500a. Of course, in some embodiments, the soldering flux 700 may also be disposed on both the surface of the welding portion 500a facing the second pad 101 and the surface of the second pad 101 facing the welding portion 500a.

[0102] Figure 8 FIG. is a structural diagram of mounting a shielding cover on a circuit board provided by an embodiment of the present application. Among them, Figure 8 FIG. (a) therein is a structural diagram of disposing a solder block 502 (or a preformed solder sheet 503) on the second pad 101, Figure 8 FIG. (b) therein is a structural diagram of welding the first pad 301, the second pad 101, and the solder block 502 (or the preformed solder sheet 503) together.

[0103] In some examples, referring to Figure 8 FIG. (a) therein, the step of disposing the welding portion 500a on the first pad 301 or the second pad 101 may include: disposing the welding portion 500a on the second pad 101. Referring to Figure 8 FIG. (b) therein, after disposing the welding portion 500a on the second pad 101 and before welding the circuit board 100 and the shielding cover 300 together, the step may further include: disposing the soldering flux 700 on at least one surface of the welding portion 500a or the first pad 301.

[0104] Exemplarily, the step of disposing the welding portion 500a on the second pad 101 may include welding the welding portion 500a on the second pad 101. After disposing the welding portion 500a on the second pad 101, a soldering flux 700 may be disposed on the surface of the welding portion 500a facing the first pad 301. Alternatively, after disposing the welding portion 500a on the second pad 101, a soldering flux 700 may be disposed on the surface of the first pad 301 facing the welding portion 500a. Of course, in some embodiments, the soldering flux 700 may also be disposed on both the surface of the welding portion 500a facing the first pad 301 and the surface of the first pad 301 facing the welding portion 500a.

[0105] Through the above settings, when the circuit board 100 and the shielding cover 300 are welded together, the soldering flux 700 can assist and facilitate the soldering process, which is beneficial to improving the preparation efficiency of the circuit board assembly 10. For example, the soldering flux 700 can remove oxides during the soldering process and reduce the surface tension of the materials to be soldered.

[0106] The embodiment of the present application does not limit the structural form of the soldering flux 700. For example, the soldering flux 700 can be a solid soldering flux, a liquid soldering flux or a gas soldering flux. Correspondingly, the embodiment of the present application does not specifically limit the specific steps of setting the soldering flux 700 on the welding part 500a or the pad. For example, the soldering flux 700 can be sprayed, printed or placed on the welding part 500a or the pad.

[0107] Or, when the welding part 500a includes at least one of the solder block 502 or the preformed solder sheet 503, after setting the welding part 500a on the first pad 301 or the second pad 101, the step of setting the soldering flux 700 can be omitted, and the embodiment of the present application does not limit this.

[0108] Of course, in some embodiments, the welding part 500a can include at least one of the solder paste 501, the solder block 502 or the preformed solder sheet 503. Among them, after setting the welding part 500a on the first pad 301 or the second pad 101, the soldering flux 700 can be set to assist and facilitate the soldering process. Or, after setting the welding part 500a on the first pad 301 or the second pad 101, the step of setting the soldering flux 700 can also be omitted to simplify the soldering steps.

[0109] Figure 9 This is a structural diagram provided by the embodiment of the present application for welding the first pad 301, the second pad 101 and the welding part 500a together.

[0110] Refer to Figure 9 , when the welding part 500a includes at least one of the solder paste 501, the solder block 502 or the preformed solder sheet 503, the steps of welding the circuit board 100 and the shielding cover 300 together can include: locally heating the first pad 301, the second pad 101 and the welding part 500a to weld the circuit board 100 and the shielding cover 300 together. Among them, the material of the welding part 500a can include at least one of the low-temperature solder, high-temperature solder or medium-temperature solder in the above embodiments.

[0111] Perform local heating on the first pad 301, the second pad 101, and the welding portion 500a, so that the heating temperature is concentrated at the first pad 301, the second pad 101, and the welding portion 500a, which is conducive to reaching the melting point temperature and facilitating the welding of the circuit board 100 and the shielding cover 300 together. At the same time, since local heating is performed on the first pad 301, the second pad 101, and the welding portion 500a, it also avoids the heating temperature from affecting the filling material 410 and the bumps 420, which is conducive to improving failure phenomena such as open circuit or short circuit caused by the remelting of the bumps 420.

[0112] Among them, the step of performing local heating on the first pad 301, the second pad 101, and the welding portion 500a may include: using a laser generator 710 or an electromagnetic heater 720 to heat the first pad 301, the second pad 101, and the welding portion 500a.

[0113] Exemplarily, the welding process using the laser generator 710 may include: emitting a laser beam through the laser generator 710, and focusing the laser beam on the first pad 301, the second pad 101, and the welding portion 500a, so that the first pad 301, the second pad 101, and the welding portion 500a are melted, and the circuit board 100 and the shielding cover 300 are welded together. The process of locally heating the first pad 301, the second pad 101, and the welding portion 500a through the laser generator 710 and welding the circuit board 100 and the shielding cover 300 together can be called laser welding. Laser welding is conducive to improving the welding quality and increasing the welding speed.

[0114] Exemplarily, the welding process using the electromagnetic heater 720 may include: generating a magnetic field current through the high-frequency oscillation frequency of the electromagnetic heater 720, and using the magnetic field turbulence generated by the high-frequency current in the welding area to cause the welding area to generate heat by itself within the induction coil until the welding portion 500a is melted or in a near-plastic state, so that the circuit board 100 and the shielding cover 300 are welded together. The process of locally heating the first pad 301, the second pad 101, and the welding portion 500a through the electromagnetic heater 720 and welding the circuit board 100 and the shielding cover 300 together can be called induction high-frequency welding. Induction high-frequency welding is conducive to increasing the welding speed, has a small heat-affected area during the welding process, and is not prone to oxidation during the welding process.

[0115] Of course, the above two local heating processes are only exemplary, and other local heating methods may also be adopted in the embodiments of the present application, and the embodiments of the present application do not limit this.

[0116] In some embodiments, the material of the welding part 500a may include low-temperature solder. Among them, the material of the low-temperature solder may be as described in the above embodiments, which will not be elaborated here. It can be understood that since the melting point of the low-temperature solder is lower than that of the high-temperature solder and the medium-temperature solder, the welding temperature when using the low-temperature solder for welding is lower than the welding temperature when using the high-temperature solder and the medium-temperature solder.

[0117] Based on the above structure, the step of welding the circuit board 100 and the shielding cover 300 together may include: welding the circuit board 100 and the shielding cover 300 together through the surface mount technology. Among them, the surface mount technology (SMT) is a circuit assembly technology that mounts pinless or short-lead surface-mounted components on the surface of the circuit board 100 or other substrates and is welded and assembled by methods such as reflow soldering or dip soldering. Through the above settings, the circuit board 100 and the shielding cover 300 are welded together, while ensuring the connection reliability between the circuit board 100 and the shielding cover 300, it is also beneficial to reduce the welding temperature, avoid the welding temperature affecting the filling material 410 and the bumps 420, is beneficial to improving the aging phenomenon of the physical and chemical properties of the filling material 410, and is also beneficial to improving failure phenomena such as open circuit or short circuit caused by the remelting of the bumps 420.

[0118] Figure 10 It is a flow chart of the step of mounting the shielding cover on the circuit board in another method for preparing a circuit board assembly provided by an embodiment of the present application. Figure 11 It is a structural diagram of another method for mounting the shielding cover on the circuit board provided by an embodiment of the present application. Among them, Figure 11 Figure (a) in it is a structural diagram of arranging the first welding sub-part 510 on the first pad 301 and arranging the second welding sub-part 520 on the second pad 101, Figure 11 Figure (b) in it is a structural diagram of welding the first pad 301, the second pad 101, the first welding sub-part 510 and the second welding sub-part 520 together.

[0119] In some embodiments, referring to Figure 10 and Figure 11 , the step of mounting the shielding cover 300 on the circuit board 100 may include steps S301 and S302.

[0120] S301. Arrange the first welding sub-part on the first pad and arrange the second welding sub-part on the second pad.

[0121] Exemplarily, the first welding sub - part 510 may include at least one of the solder paste 501, solder block 502, or pre - formed solder sheet 503 in the above - mentioned embodiments. Similarly, the second welding sub - part 520 may include at least one of the solder paste 501, solder block 502, or pre - formed solder sheet 503 in the above - mentioned embodiments.

[0122] After the first welding sub - part 510 is disposed on the first pad 301 and the second welding sub - part 520 is disposed on the second pad 101, in some examples, a soldering flux 700 may be disposed on at least one of the surface of the first welding sub - part 510 or the surface of the second welding sub - part 520. Alternatively, in some examples, the step of disposing the soldering flux 700 may also be omitted.

[0123] The step of mounting the shielding cover 300 on the circuit board 100 may further include S302.

[0124] S302. Weld the circuit board and the shielding cover together. The first pad, the second pad, at least part of the first welding sub - part, and at least part of the second welding sub - part jointly form a welding structure.

[0125] Here, "at least part" can be understood as follows: when the first welding sub - part 510 may include the solder paste 501 in the above - mentioned embodiments, the solder in the solder paste 501 is used to form part of the welding structure, and the flux in the solder paste 501 does not form part of the welding structure; when the second welding sub - part 520 may include the solder paste 501 in the above - mentioned embodiments, the solder in the solder paste 501 is used to form part of the welding structure, and the flux in the solder paste 501 does not form part of the welding structure. Through the above - mentioned arrangement, it is beneficial to improve the connection strength between the circuit board 100 and the shielding cover 300 and improve the connection reliability between the circuit board 100 and the shielding cover 300.

[0126] Among them, when the material of the first welding sub - part 510 includes the low - temperature solder in the above - mentioned embodiments and the material of the second welding sub - part 520 includes the low - temperature solder in the above - mentioned embodiments, the circuit board 100 and the shielding cover 300 can be welded together by a surface - mount technology.

[0127] Or, when the material of the first welding sub - part 510 may include at least one of the low - temperature solder, high - temperature solder, or medium - temperature solder in the above - mentioned embodiments, and the material of the second welding sub - part 520 may include at least one of the low - temperature solder, high - temperature solder, or medium - temperature solder in the above - mentioned embodiments, local heating can be performed on the first pad 301, the second pad 101, the first welding sub - part 510, and the second welding sub - part 520, so as to weld the circuit board 100 and the shielding cover 300 together.

[0128] Figure 12A flow chart of the steps of installing a shielding cover on a circuit board in another method for preparing a circuit board assembly provided in an embodiment of the present application. Figure 13 Another structural diagram of installing a shielding cover on a circuit board provided in an embodiment of the present application. Figure 13 FIG. (a) is a structural diagram of providing a conductive adhesive 500b on the first pad 301 and / or the second pad 101. Figure 13 Figure (b) is a structural diagram of bonding the circuit board 100 and the shielding cover 300 together.

[0129] In some embodiments, reference Figure 12 and Figure 13 The step of installing the shielding cover 300 on the circuit board 100 may include steps S401 and S402.

[0130] S401, disposing conductive glue on the first pad and / or the second pad, wherein the first pad is provided on the side of the frame facing away from the cover body, and the second pad is located on the side of the circuit board facing the shielding cover.

[0131] Here, “and / or” may be inclusive, and may be understood as providing the conductive adhesive 500b only on the first pad 301 , or providing the conductive adhesive 500b only on the second pad 101 , or providing the conductive adhesive 500b on both the first pad 301 and the second pad 101 .

[0132] After the conductive adhesive 500 b is disposed on the first pad 301 and / or the second pad 101 , the step of installing the shielding cover 300 on the circuit board 100 may include S402 .

[0133] S402, applying a preset pressure and a preset temperature to the first soldering pad, the second soldering pad and the conductive adhesive to bond the circuit board and the shielding cover together.

[0134] Among them, the conductive glue 500b is an adhesive with a certain conductivity after curing or drying. When the first pad 301 and the second pad 101 are bonded together by the conductive glue 500b, a conductive path can be formed between the first pad 301 and the second pad 101. It can be understood that for different conductive glues 500b, the preset pressure and preset temperature applied are also different. In the embodiment of the present application, the material of the conductive glue 500b is not specifically limited.

[0135] Through the above arrangement, the circuit board 100 and the shielding cover 300 can be bonded together. At the same time, since the preset temperature applied to the first solder pad 301, the second solder pad 101 and the conductive adhesive 500b is relatively low, the heating temperature is prevented from affecting the filling material 410 and the bump 420, which is beneficial to improving the aging phenomenon of the physical and chemical properties of the filling material 410, and is also beneficial to improving the failure phenomenon such as open circuit or short circuit caused by the remelting of the bump 420.

[0136] As described above, it is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application, who thinks of changes or substitutions, should be covered within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claimed rights.

Claims

1. A circuit board assembly, characterized in that, The circuit board assembly includes: A circuit board; An electronic device, which is fixed on the circuit board by bump welding; A filling material, which is located between the electronic device and the circuit board and wraps the bumps; A shielding cover, which covers the outside of the electronic device; The shielding cover includes a cover body and a frame, and the frame and the cover body are an integrally formed structure. Wherein, the frame is located between the cover body and the circuit board, and the frame is connected to the circuit board.

2. The circuit board assembly according to claim 1, wherein One side of the frame away from the cover body has a first pad, and the circuit board has a second pad, and the second pad is located on the side of the circuit board facing the shielding cover; The circuit board assembly further includes a connecting part, and the first pad and the second pad are connected through the connecting part.

3. The circuit board assembly according to claim 2, wherein, The first pad, the second pad and the connecting part together form a welding structure.

4. The circuit board assembly according to claim 3, wherein, The material of the connecting part includes a low-temperature solder.

5. The circuit board assembly according to claim 4, wherein, The low-temperature solder includes at least one of a tin-bismuth alloy, a tin-cadmium alloy or a tin-indium alloy.

6. The circuit board assembly according to claim 3, wherein, The material of the connecting part includes a high-temperature solder and / or a medium-temperature solder.

7. The circuit board assembly according to claim 6, characterized in that, The medium-temperature solder includes at least one of a tin-silver-copper alloy, a tin-lead alloy, a tin-silver alloy or a tin-silver-copper-nickel alloy, and the high-temperature solder includes at least one of a tin-antimony alloy, a lead-tin-silver alloy, a gold-tin alloy or a gold-cadmium alloy.

8. The circuit board assembly according to claim 2, wherein The connecting part includes a conductive adhesive.

9. A method for preparing a circuit board assembly, the circuit board assembly comprising a circuit board and an electronic device, characterized in that, Including: Fixing an electronic device on a circuit board by bump welding; Filling a filling material between the electronic device and the circuit board, and the filling material wraps the bumps; Installing a shielding cover on the circuit board, and the shielding cover covers the outside of the electronic device; The shielding cover includes a cover body and a frame, the frame is arranged around the edge of the cover body, and the frame and the cover body are an integrally formed structure. Wherein, the frame is located between the cover body and the circuit board, and the frame is connected to the circuit board.

10. The manufacturing method of the circuit board assembly according to claim 9, characterized in that, The step of installing the shielding cover on the circuit board includes: Providing a welding part on the first pad or the second pad. Wherein, one side of the frame away from the cover body has the first pad, and the second pad is located on the side of the circuit board facing the shielding cover; Welding the circuit board and the shielding cover together, and the first pad, the second pad and at least part of the welding part together form a welding structure.

11. The preparation method of the circuit board assembly according to claim 10, characterized in that, The welding part includes solder paste.

12. The manufacturing method of the circuit board assembly according to claim 10, characterized in that, The welding part includes one of a solder block or a preformed solder sheet.

13. The preparation method of the circuit board assembly according to claim 12, characterized in that The step of providing a welding part on the first pad or the second pad includes: providing the welding part on the first pad; After providing the welding part on the first pad and before welding the circuit board and the shielding cover together, it further includes: providing a soldering aid on the surface of at least one of the welding part or the second pad; or The step of providing a welding part on the first pad or the second pad includes: providing the welding part on the second pad; After the soldering portion is provided on the second soldering pad and before the circuit board and the shielding cover are soldered together, the method further includes: providing soldering flux on a surface of at least one of the soldering portion or the first soldering pad.

14. The manufacturing method of the circuit board assembly according to any one of claims 10-13, characterized in that, The step of welding the circuit board and the shielding cover together comprises: The first soldering pad, the second soldering pad and the soldering portion are locally heated so that the circuit board and the shielding cover are soldered together.

15. The manufacturing method of the circuit board assembly according to claim 14, characterized in that, The step of heating the first pad, the second pad and the welding portion comprises: The first pad, the second pad, and the welding portion are heated using a laser generator or an electromagnetic heater.

16. The preparation method of the circuit board assembly according to any one of claims 10-13, characterized in that, The material of the welding part includes low-temperature solder, and welding the circuit board and the shielding cover together includes: welding the circuit board and the shielding cover together by a surface mounting process.

17. The method for preparing a circuit board assembly according to claim 9, characterized in that: The step of installing the shielding cover on the circuit board comprises: Disposing a first welding sub-portion on the first welding pad, and disposing a second welding sub-portion on the second welding pad; The circuit board and the shielding cover are welded together, and the first welding pad, the second welding pad, at least a part of the first welding sub-portion, and at least a part of the second welding sub-portion together form a welding structure.

18. The preparation method of the circuit board assembly according to claim 9, wherein, The step of installing the shielding cover on the circuit board comprises: Conductive glue is provided on the first pad and / or the second pad, wherein the first pad is provided on the side of the frame away from the cover body, and the second pad is provided on the side of the circuit board facing the shielding cover; A preset pressure and a preset temperature are applied to the first soldering pad, the second soldering pad and the conductive adhesive to bond the circuit board and the shielding cover together.

19. An electronic device, characterized in that, The invention comprises a circuit board assembly as claimed in any one of claims 1 to 8 and a battery, wherein the battery is used to supply power to electronic devices of the circuit board assembly.

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