Circuit board assemblies, battery protection boards and electronic devices

Abstract

The present application discloses a circuit board assembly, a battery protection board and an electronic device, which relates to the field of electronic technology and can take into account both the heat dissipation performance and miniaturization design of the circuit board assembly. The circuit board assembly includes a substrate, an electronic component and a plastic package, wherein the substrate includes a bearing surface; the electronic component is arranged on the bearing surface of the substrate; the plastic package is encapsulated on the bearing surface of the substrate and wraps the electronic component, and an inwardly concave groove portion is provided on the outer surface of the plastic package, and a first heat dissipation member is provided in the groove portion.

Description

[0001] This application is a divisional application. The application number of the original application is 202211607137.4, and the original application date is December 14, 2022. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of electronic technology, and in particular to a circuit board assembly, a battery protection board and an electronic device. Background Art

[0003] At present, electronic devices such as smart watches, mobile phones, and laptops are becoming one of the necessities of modern people's lives. In order to realize the functions of electronic devices, electronic devices are usually provided with circuit board assemblies. However, the circuit board assemblies in the related art cannot take into account both the heat dissipation performance and miniaturization design of the circuit board assemblies, which limits the development of electronic devices. Summary of the invention

[0004] The embodiments of the present application provide a circuit board assembly, a battery protection board and an electronic device, which can take into account both the heat dissipation performance and the miniaturized design of the circuit board assembly.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a circuit board assembly, which includes a substrate, an electronic component and a plastic package, wherein the substrate includes a bearing surface; the electronic component is arranged on the bearing surface of the substrate; the plastic package is encapsulated on the bearing surface of the substrate and wraps the electronic component, wherein an inwardly concave groove portion is provided on the outer surface of the plastic package, and a first heat sink is provided in the groove portion.

[0007] In this way, by setting a groove portion on the plastic package and setting the first heat sink in the groove portion, the heat generated by the electronic component can be transferred to the plastic package body through the first heat sink to the outside of the plastic package body, so as to achieve heat dissipation of the electronic component, effectively improve the heat dissipation performance of the circuit board assembly, reduce the temperature of the electronic component, improve the reliability of the electronic component, and help increase the layout density of the electronic component in the circuit board assembly and reduce the overall volume of the circuit board assembly. In addition, since the first heat sink is set in the plastic package body, the internal space of the plastic package body can be fully utilized, and the overlapping size of the first heat sink and the plastic package body can be reduced, which is conducive to further reducing the overall volume of the circuit board assembly, so that the miniaturization design of the circuit board assembly can be achieved on the basis of ensuring the heat dissipation performance of the circuit board assembly. Thus, the heat dissipation performance of the battery protection board including the circuit board assembly can be improved, and the high heat dissipation demand and high reliability demand of the battery protection board due to the increase of the fast charging power of the electronic device can be met, which is conducive to increasing the charging wattage of the battery protection board, and is conducive to reducing the overall occupied space of the battery protection board, so as to provide a larger layout space for other components in the electronic device, such as the main board, the battery, etc., which is conducive to expanding the functions of the electronic device and improving the endurance of the electronic device.

[0008] In a possible implementation, the electronic component includes a first electronic component, the first electronic component includes a first top surface, the orientation of the first top surface is the same as the orientation of the bearing surface, the groove portion includes a first groove, and the first groove is located on the side toward which the first top surface is directed; wherein the orthographic projection of the first electronic component on the bearing surface overlaps with the orthographic projection of the first groove on the bearing surface. In this way, it can be ensured that at least part of the first groove is directly opposite to the first electronic component, and the transfer path between the heat generated by the first electronic component and the first heat sink can be shortened, which is conducive to improving the heat conduction efficiency and reducing the heat loss, thereby effectively improving the heat dissipation efficiency of the circuit board assembly.

[0009] In a possible implementation, the first electronic component includes a first top surface, the orientation of the first top surface is the same as the orientation of the bearing surface, the first groove includes a first groove wall surface, the orientation of the first groove wall surface is the same as the orientation of the first top surface, and the first groove wall surface is spaced apart from the first top surface. In this way, by spaced apart from the first top surface and the first groove wall surface, the first heat sink disposed in the first groove can be spaced apart from the first electronic component, which can prevent the force generated by the first heat sink due to the increase in volume and the squeezing of the first groove wall surface directly acting on the first electronic component, which can reduce the stress on the first electronic component and help improve the reliability of the first electronic component. In addition, by spaced apart from the first groove wall surface and the first top surface, a safety distance can be reserved to prevent the first electronic component from being punctured during the process of opening the groove portion, which can effectively protect the first electronic component.

[0010] In a possible implementation, the plastic package includes a first sub-portion, the first sub-portion is located between the first groove and the first electronic component, and the first groove and the first electronic component are separated by the first sub-portion. That is, the first sub-portion is located between the first groove wall and the first top surface.

[0011] In a possible implementation, the distance between the first groove wall and the first top surface is a first distance d1, and the first distance d1 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm. In this way, the heat dissipation performance of the circuit board assembly and the reliability of the first electronic component can be taken into account.

[0012] In a possible implementation, there are multiple first grooves, and at least some of the multiple first grooves are spaced apart; or at least some of the multiple first grooves are intersectingly arranged. In this way, the contact area between the first heat sink and the inner wall surface of the first groove can be increased, thereby improving the heat dissipation performance of the circuit board assembly.

[0013] In a possible implementation, among the plurality of first grooves spaced apart, the spacing d0 between two adjacent first grooves is greater than or equal to 0.1 mm and less than or equal to 0.2 mm. In this way, the number of first grooves can be increased on the basis of ensuring the structural stability of the plastic package, thereby increasing the contact area between the first heat sink and the inner wall surface of the first groove, and improving the heat dissipation performance of the circuit board assembly.

[0014] In a possible implementation, the electronic component includes a first electronic component, and the groove portion includes a second groove, and the second groove is located on the circumferential outside of the first electronic component. In this way, the heat of the first electronic component in the circumferential direction can be absorbed by the first heat sink in the second groove, so that the heat generated by the first electronic component can be transferred to the first heat sink in the second groove through the first peripheral surface of the first electronic component, which can improve the heat conduction efficiency and improve the heat dissipation performance of the circuit board assembly. As a result, in the scheme where the groove portion includes the first groove and the second groove, the heat generated by the first electronic component can not only be transferred to the first heat sink in the first groove through the first top surface, but also can be transferred to the first heat sink in the second groove through the first peripheral surface of the first electronic component, which can improve the heat conduction efficiency and improve the heat dissipation performance of the circuit board assembly.

[0015] In a possible implementation, the second groove is spaced apart from the first outer peripheral surface of the first electronic component. In this way, by spaced apart from the first outer peripheral surface of the first electronic component, the first heat sink disposed in the second groove can be spaced apart from the first electronic component, which can prevent the force generated by the first heat sink due to the increase in volume and the compression of the groove wall of the second groove from directly acting on the first electronic component, which can reduce the stress on the first electronic component and help improve the reliability of the first electronic component. In addition, by spaced apart from the first outer peripheral surface of the first electronic component, a safety distance can be reserved to prevent the first electronic component from being punctured during the process of opening the groove portion, which can effectively protect the first electronic component.

[0016] In a possible implementation, the plastic package body includes a second sub-portion, the second sub-portion is located between the second groove and the outer peripheral surface of the first electronic component, and the second groove and the first electronic component are spaced apart by the second sub-portion.

[0017] In a possible implementation, the second groove is arranged around the first electronic component. In this way, the entire first peripheral surface of the first electronic component can be surrounded by the second groove, so that the heat generated by the first electronic component can be transferred from all directions of the first peripheral surface to the first heat sink in the second groove, which can improve the heat dissipation efficiency and the uniformity of the temperature in the plastic package.

[0018] In a possible implementation manner, the second groove is annular.

[0019] In a possible implementation manner, the second groove includes a plurality of sub-grooves spaced apart in a circumferential direction of the first electronic component.

[0020] In a possible implementation, the first electronic component includes a first top surface, the orientation of the first top surface is the same as the orientation of the bearing surface, the groove portion includes a first groove, the first groove is located on the side toward which the first top surface is directed, and the orthographic projection of the first electronic component on the bearing surface overlaps with the orthographic projection of the first groove on the bearing surface. The first groove is connected to the second groove. In this way, the fluidity of the liquid metal can be improved and the uniformity of the temperature in the plastic package can be ensured.

[0021] In a possible implementation, the second groove includes a second groove wall surface, the second groove wall surface is oriented in the same direction as the bearing surface, and the second groove wall surface is spaced apart from the bearing surface. In this way, the first heat sink can be prevented from directly contacting the substrate. On the one hand, the first heat sink can be prevented from occupying the layout space on the bearing surface, which is conducive to increasing the number of electronic components on the bearing surface. On the other hand, the first heat sink can be prevented from squeezing the substrate when the volume expands, thereby preventing the substrate from cracking and ensuring the reliability of the circuit board assembly.

[0022] In a possible implementation, the spacing between the second groove wall and the bearing surface is the second spacing d2, and the second spacing d2 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm. In this way, on the one hand, the size of the second groove in the Z-axis direction (that is, the thickness direction of the circuit board assembly) can be guaranteed, which is conducive to increasing the contact area between the first heat sink and the inner wall surface of the second groove, and then conducive to increasing the total contact area between the first heat sink and the inner wall surface of the groove portion, which can improve the heat dissipation performance of the circuit board assembly; on the other hand, the spacing between the second groove wall and the substrate can be reduced, which is convenient for the heat absorbed by the first heat sink to be transferred outward through the substrate, thereby further improving the heat dissipation efficiency of the circuit board assembly and ensuring the heat dissipation performance of the circuit board assembly.

[0023] In a possible implementation, the volume of the first heat sink is smaller than the volume of the groove. In this way, the force generated by the first heat sink absorbing heat and expanding in volume to squeeze the inner wall surface of the groove can be reduced, which can effectively avoid cracking of the plastic package and help improve the reliability of the circuit board assembly. In addition, when the first heat sink is liquid metal, it can also prevent the liquid metal from absorbing the heat generated by the electronic component and increasing in volume to overflow from the groove.

[0024] In a possible implementation, the first heat sink includes liquid metal, which is filled in the groove portion; the circuit board assembly also includes a first sealing cover plate, which is sealed and connected to the open end of the groove portion. Liquid metal is a low melting point alloy that is liquid at room temperature. As a thermal interface material, liquid metal has excellent thermal conductivity, stable properties, small expansion coefficient, non-volatile, safe and non-toxic. In addition, since liquid metal has fluidity and strong gap filling ability, when liquid metal is directly filled in the groove portion, the liquid metal can be filled into every corner inside the groove portion, avoiding the occurrence of filling dead corners inside the groove portion, thereby increasing the contact area between the liquid metal and the inner wall surface of the groove portion, improving the heat conduction efficiency between the liquid metal and the plastic package, and thus improving the heat dissipation effect of the circuit board assembly. In addition, during the processing, there is no need to consider the adaptability of the shape of the groove portion and the shape of the first heat sink, and the setting position of the groove portion can be made more flexible, which can reduce the processing difficulty of the groove portion, thereby improving the processing efficiency of the circuit board assembly and reducing the processing cost of the circuit board assembly.

[0025] In a possible implementation, the surface roughness of the inner wall surface of the groove portion is less than or equal to 10 μm. In this way, the liquid metal can flow in the groove portion more easily, thereby improving the heat dissipation efficiency and heat dissipation uniformity.

[0026] In a possible implementation, the thermal conductivity of the liquid metal is greater than or equal to 15 W (mK). In this way, the heat dissipation performance of the first heat sink can be guaranteed, and the heat dissipation effect of the circuit board assembly can be improved.

[0027] In a possible implementation, the ratio of the volume V1 of the liquid metal to the volume V2 of the groove portion is greater than or equal to 0.8 and less than 1. In this way, both the heat dissipation performance and the reliability performance of the circuit board assembly can be taken into account.

[0028] In a possible implementation, the first heat sink includes a tube body and liquid metal, the tube body is disposed in the groove portion, and the liquid metal is filled in the tube body. In this way, during the assembly process, the first heat sink including the tube body and the liquid metal can be directly assembled in the groove portion as a whole, which can reduce the assembly difficulty and improve the assembly efficiency on the one hand, and on the other hand, the first sealing cover plate can be eliminated or the structure of the first sealing cover plate can be simplified, for example, there is no need to set a second anti-corrosion layer on the cover plate body, which is conducive to reducing the cost of the circuit board assembly.

[0029] In a possible implementation, the pipe body includes a pipe body and a first anti-corrosion layer, the pipe body is a metal part; the first anti-corrosion layer covers the inner wall surface of the pipe body. The first anti-corrosion layer can protect the pipe body and prevent the pipe body from being corroded by liquid metal. In this way, the heat dissipation performance and anti-corrosion performance of the pipe body can be guaranteed.

[0030] In a possible implementation, the tube body includes a tube body and a heat-conducting layer, the tube body is a plastic part, and the heat-conducting layer covers the outer wall surface of the tube body. In this way, the heat dissipation performance and anti-corrosion performance of the tube body can also be guaranteed.

[0031] In a possible implementation, the electronic component includes a first electronic component, the first electronic component includes a first top surface, the orientation of the first top surface is the same as the orientation of the bearing surface, the groove portion includes a first groove, and the first groove is located on the side facing the first top surface; the orthographic projection of the first electronic component on the bearing surface overlaps with the orthographic projection of the first groove on the bearing surface; the tube body includes a first tube body, and the first tube body is arranged in the first groove.

[0032] In a possible implementation, the electronic component includes a first electronic component, the groove portion includes a second groove, and the second groove is located at the outer periphery of the first electronic component; the tube body includes a second tube body, and the second tube body is disposed in the second groove.

[0033] In a possible implementation, the circuit board assembly further includes a first sealing cover plate, which is arranged on the open end of the groove portion; a first mounting groove is arranged on the outer surface of the plastic package body, the first mounting groove includes a first groove bottom wall, the first groove bottom wall is opposite to the notch of the first mounting groove, the open end of the groove portion is formed on the first groove bottom wall, and the first sealing cover plate is arranged in the first mounting groove. In this way, the overall volume of the circuit board assembly can be further reduced.

[0034] In a possible implementation, the first sealing cover plate includes a cover plate body and a second anti-corrosion layer, the cover plate body includes a first surface facing the open end, and the second anti-corrosion layer is disposed on at least a portion of the first surface. In this way, the heat dissipation performance and anti-corrosion performance of the first sealing cover plate can be ensured.

[0035] In a possible implementation manner, the first sealing cover plate includes a cover plate body, and the cover plate body is a metal part.

[0036] In a possible implementation, the cover plate body includes an edge portion, the edge portion is located outside the circumference of the second anti-corrosion layer, and the first sealing cover plate is fixedly connected to the bottom wall of the first groove by means of the edge portion. In this way, the first sealing cover plate can be fixedly connected to the plastic sealing body by means of the edge portion of the cover plate body. This helps to reduce the depth of the first installation groove.

[0037] In a possible implementation, a connection area is formed on a surface of the first sealing cover plate facing the groove portion, the first groove bottom wall includes a middle area and an edge area, the edge area is located outside the middle area, the connection area is fixedly connected to the edge area, and the surface roughness of at least one of the connection area and the edge area is greater than or equal to 80 μm. In this way, the connection strength between the connection area of ​​the first sealing cover plate and the edge area of ​​the first groove bottom wall can be improved.

[0038] In one possible implementation, the electronic component includes a first electronic component, the first electronic component includes a first top surface and a first peripheral surface, the orientation of the first top surface is the same as the orientation of the bearing surface, the first peripheral surface surrounds the periphery of the first top surface, the groove portion includes a second groove, the second groove is located on the circumferential outside of the first electronic component, the second groove includes a second groove wall, the orientation of the second groove wall is the same as the orientation of the bearing surface, and the circuit board assembly also includes: a through groove, the through groove includes a first through opening and a second through opening, the first through opening penetrates a side surface of the substrate away from the bearing surface, the second through opening penetrates at least a portion of the second groove wall, and a second heat sink is provided in the through groove.

[0039] In this way, the circuit board assembly can use the through groove to achieve communication between the groove portion and the air outside the plastic package, which facilitates the first heat sink and the second heat sink to achieve thermal conduction connection, so that the heat absorbed by the first heat sink can be dissipated to the outside of the plastic package through the second heat sink in the through groove, and the heat generated by the first electronic component can also be directly transferred to the second heat sink and dissipated to the outside of the plastic package through the second heat sink. In this way, the heat dissipation path of the circuit board assembly can be increased, three-dimensional heat dissipation can be achieved, and the heat dissipation efficiency of the circuit board assembly can be further improved, thereby further improving the heat dissipation performance of the circuit board assembly.

[0040] In a possible implementation, the second heat sink includes liquid metal, which is filled in the through groove; the circuit board assembly also includes a second sealing cover plate, which is sealed and connected to the first through opening of the through groove. In this way, the heat conduction efficiency between the first heat sink and the second heat sink can be improved.

[0041] In a possible implementation, the plastic package body includes a first portion, the first portion is located between the groove portion and the electronic component, and the groove portion and the electronic component are separated by the first portion. Exemplarily, the first portion includes the above-mentioned first sub-portion and second sub-portion. In this way, it is possible to avoid the force generated by the first heat sink due to the increase in volume and the squeezing of the inner wall surface of the groove portion directly acting on the electronic component, which can reduce the stress on the electronic component and help improve the reliability of the electronic component. In addition, a safe distance can be reserved between the groove portion and the electronic component to prevent the electronic component from being broken down during the process of opening the groove portion, which can effectively protect the electronic component.

[0042] In a second aspect, the present application provides a circuit board assembly, which includes: a substrate, a first heat sink, an electronic component and a plastic package, wherein the substrate includes a bearing surface; the electronic component is arranged on the bearing surface; the first heat sink is arranged on the bearing surface, the first heat sink includes a tube body and liquid metal, and the liquid metal is arranged in the tube body; the plastic package is encapsulated on the bearing surface, the plastic package wraps the electronic component, and wraps at least part of the first heat sink.

[0043] In this way, after the heat generated by the electronic component is transferred to the plastic package, it can be transferred to the outside of the plastic package through the first heat sink, which can effectively improve the heat dissipation performance of the circuit board assembly. In addition, since the first heat sink is arranged inside the plastic package, the internal space of the plastic package can be fully utilized, and the overlapping size of the first heat sink and the plastic package can be reduced, which is conducive to reducing the overall volume of the circuit board assembly, so that the miniaturization design of the circuit board assembly can be achieved on the basis of ensuring the heat dissipation performance of the circuit board assembly. In addition, the first heat sink in the present embodiment is fixed on the bearing surface of the substrate, that is, the first heat sink in the present embodiment is fixed on the substrate before the plastic package is formed on the bearing surface. In this way, after the plastic package is formed, the plastic package can be wrapped on at least part of the outer surface of the first heat sink. Therefore, the circuit board assembly in the present embodiment does not need to open a groove portion on the plastic package for accommodating the first heat sink, which can simplify the processing technology of the circuit assembly and reduce costs.

[0044] In a possible implementation, a support seat is provided on the bearing surface, and the first heat sink is supported on the support seat. In this way, the first heat sink and the substrate can be fixed by the support seat, which has a simple structure, convenient assembly and low processing cost.

[0045] In a possible implementation, the electronic component includes a first electronic component, the first electronic component includes a first top surface, the orientation of the first top surface is the same as the orientation of the bearing surface, the tube body includes a first tube body, and the first tube body is located on the side facing the first top surface; the orthographic projection of the first electronic component on the bearing surface overlaps with the orthographic projection of the first tube body on the bearing surface.

[0046] In a possible implementation manner, the first tube body and the first electronic component are spaced apart from each other.

[0047] In a possible implementation, the electronic component includes a first electronic component, the tube body includes a second tube body, and the second tube body is located outside the circumference of the first electronic component.

[0048] In a possible implementation manner, the second tube body is spaced apart from the first electronic component.

[0049] In a possible implementation, the electronic component includes a first electronic component, the first electronic component includes a first top surface, and the orientation of the first top surface is the same as the orientation of the bearing surface; the tube body includes a first tube body and a second tube body, the first tube body is located on the side facing the first top surface, and the orthographic projection of the first electronic component on the bearing surface overlaps with the orthographic projection of the first tube body on the bearing surface; the second tube body is located on the circumferential outside of the first electronic component, and the second tube body is connected to the first tube body.

[0050] In a third aspect, the present application provides a battery protection board, which includes a circuit board assembly and a flexible circuit board. The circuit board assembly is the circuit board assembly in any of the above technical solutions; the flexible circuit board is electrically connected to the substrate.

[0051] In a possible implementation, the first sealing cover plate is exposed outside the flexible circuit board, so that the circuit board assembly can dissipate heat outward through the first sealing cover plate, thereby improving the heat dissipation performance of the battery protection board.

[0052] In a fourth aspect, the present application provides a battery, comprising a battery protection board according to any of the above technical solutions.

[0053] In a fifth aspect, the present application provides an electronic device, which includes: a housing and a battery, wherein the battery is disposed in the housing, and the battery includes a battery protection board in any of the above technical solutions.

[0054] In one possible implementation, the housing includes a back cover, the back cover is located on one side of the battery, and a first interface thermal conductive material is arranged between the battery protection plate and the back cover; and / or the electronic device includes a middle plate, the middle plate is arranged in the housing, the battery is arranged on the middle plate, and a second interface thermal conductive material is arranged between the battery protection plate and the middle plate.

[0055] In a sixth aspect, the present application provides a method for preparing a circuit board assembly, which can be used to prepare the circuit board assembly in the above-mentioned technical solution, and the preparation method includes: providing a substrate, the substrate including a bearing surface; electrically connecting the electronic components to the bearing surface; forming a plastic package on the bearing surface, and making the plastic package wrap the electronic components; forming a groove portion on the plastic package; and disposing a first heat sink in the groove portion.

[0056] In a possible implementation, forming the groove portion on the plastic packaging body includes: opening a first installation groove on the plastic packaging body; and opening the groove portion on a first groove bottom wall of the first installation groove.

[0057] In a seventh aspect, the present application provides a method for preparing a circuit board assembly, the preparation method comprising: providing a substrate, the substrate comprising a bearing surface; electrically connecting an electronic component to the bearing surface; fixing a first heat sink on the bearing surface, the first heat sink comprising a tube body and liquid metal disposed in the tube body; forming a plastic package on the bearing surface, the plastic package wrapping the electronic component and wrapping at least a portion of the first heat sink.

[0058] Among them, the technical effects brought about by any design method in the second to seventh aspects can refer to the technical effects brought about by different design methods in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 A perspective view of an electronic device provided for some embodiments of the present application;

[0060] Figure 2 for Figure 1 an exploded view of the electronic device shown;

[0061] Figure 3 A perspective view of a battery provided for some embodiments of the present application;

[0062] Figure 4 for Figure 3 An exploded schematic diagram of the battery shown;

[0063] Figure 5 for Figure 3 The schematic diagram of the cross-sectional structure of the battery shown is at line A1-A1;

[0064] Figure 6 for Figure 5 A schematic diagram of the structure of a battery protection board in the battery shown;

[0065] Figure 7 Based on Figure 6 Schematic diagram of the substrate and electronic components in the battery protection board shown;

[0066] Figure 8 A schematic diagram of a partial structure of a circuit board assembly provided in some embodiments of the present application;

[0067] Fig. 9 for Figure 8 A partial cross-sectional view of the circuit board assembly at line AA;

[0068] Fig.10 for Fig. 9 A schematic diagram of the structure of the plastic package, electronic components and substrate in the circuit board assembly shown in FIG.

[0069] Fig.11 for Fig. 9 A schematic diagram of an orthographic projection of a first electronic component on a carrying surface and an orthographic projection of a first groove on the carrying surface in the circuit board assembly shown;

[0070] Fig.12 for Figure 8 A cross-sectional view of the circuit board assembly shown at line BB;

[0071] Fig.13 for Figure 8 A cross-sectional view of the circuit board assembly shown at line CC;

[0072] Fig.14a A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0073] Fig.14b A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0074] Fig.14c A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0075] Fig.15 for Figure 8 A top view of the circuit board assembly after the first sealing cover plate is removed;

[0076] Fig.16 for Fig.13 An enlarged view of the area A in the cross-sectional view shown in ;

[0077] Fig.17 for Fig.13 A schematic structural diagram of a first sealing cover plate in the circuit board assembly shown;

[0078] Fig.18 for Fig.17 The bottom view of the first sealing cover plate looking toward the cover plate body from the second anti-corrosion layer is shown;

[0079] Fig.19 For Figure 6 A temperature distribution diagram obtained by performing a heat transfer simulation test on the circuit board assembly in the illustrated embodiment;

[0080] Fig. 20 For Figure 8 A temperature distribution diagram obtained by performing a heat transfer simulation test on the circuit board assembly in the illustrated embodiment;

[0081] Fig.21 for Figure 6 The maximum temperature and the maximum temperature of the temperature distribution diagram of the circuit board assembly in the embodiment shown are Fig.18 A schematic diagram of the comparison of the highest temperature in the temperature distribution diagram of the circuit board assembly in the illustrated embodiment;

[0082] Fig. 22 A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0083] Fig.23 for Fig. 22 Another schematic diagram of the structure of the circuit board assembly shown;

[0084] Fig.24 A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0085] Fig.25 A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0086] Fig.26 A schematic diagram of the structure of a circuit board assembly is provided for some other embodiments of the present application;

[0087] Fig. 27 for Fig.26 A top view of a first heat sink in the circuit board assembly;

[0088] Fig.28 for Fig. 27 A cross-sectional view of the first heat sink at line DD;

[0089] Fig.29 A top view of a first heat dissipation element provided in some other embodiments of the present application;

[0090] Fig.30 for Fig.29 A cross-sectional view of the first heat sink at line EE;

[0091] Fig.31 A top view of a first heat dissipation element provided in some other embodiments of the present application;

[0092] Fig.32 A top view of a first heat dissipation element provided in some other embodiments of the present application;

[0093] Fig.33 A cross-sectional view of a tube body of a first heat sink provided in some embodiments of the present application;

[0094] Fig.34 A cross-sectional view of a tube body of a first heat sink provided in some other embodiments of the present application;

[0095] Fig.35 A cross-sectional view of a tube body of a first heat sink provided in some other embodiments of the present application;

[0096] Fig.36 A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0097] Fig.37 A schematic diagram of the structure of a circuit board assembly provided in some other embodiments of the present application;

[0098] Fig.38 for Fig.37 Another schematic diagram of the structure of the circuit board assembly shown;

[0099] Fig.39 Schematic diagram of assembly of a first heat sink and a support base provided in some other embodiments of the present application;

[0100] Fig.40 A schematic diagram of the structure of a circuit board assembly is provided for other embodiments of the present application;

[0101] Fig.41 A partial schematic diagram of an electronic device provided for some embodiments of the present application;

[0102] Fig.42 for Fig. 22 The schematic diagram of the local structure of the circuit board assembly assembled in the electronic equipment is shown.

[0103] Reference numerals:

[0104] 100. Electronic equipment;

[0105] 10. Shell; 11. Front cover; 12. Frame; 13. Back cover; 14. Middle plate; 20. Functional device; 21. Display screen; 22. Camera module; 30. Main board; 40. Sub-circuit board; 50. Battery; 501. Cell; 5011. Shell; 5012. Bare cell; 5013. Tab; 5013a. Positive tab; 5013b. Negative tab; 502. Battery protection board;

[0106] 51, circuit board assembly; 511, substrate; 511a, connection surface; 511b, bearing surface; 511c, positioning groove; 512, electronic component; 5121, metal oxide semi-field effect transistor; 5122, thermistor; 5123, second control chip; 5124, memory; 512a, first electronic component; 512a1, first top surface; 512a2, first peripheral surface; 513, plastic package; 514, groove portion; 514a, open end; 51 41, first groove; 5141a, first groove wall; 5142, second groove; 5142a, first groove body; 5142b, second groove body; 5142c, third groove body; 5142d, fourth groove body; 5142e, second groove wall; 515, first heat sink; 5151, tube body; 5151a, first tube body; 5151b, second tube body; 5151c, first connecting pipe; 5151d, second connecting pipe; 5151e, tube body; 5151f, first anticorrosion layer; 5151g, heat conducting layer; 5152, liquid metal; 516, first mounting groove; 5161, notch; 5162, first groove bottom wall; 5162a, middle area; 5162b, edge area; 517, first sealing cover plate; 517a, connection area; 5171, cover plate body; 5171a, first surface; 5171b, second surface; 5171c, edge portion; 5172, second anticorrosion layer; 518 , bonding structure; 519, through groove; 519a, first through opening; 519b, second through opening; 520, second heat sink; 521, second sealing cover plate; 522, second mounting groove; 5230, support seat; 5231, bottom plate; 5232, support foot; 5232a, support surface; 52, flexible circuit board; 52a, first connecting section; 52b, second connecting section; 52c, third connecting section; 524, nickel sheet; 503, waterproof insulation wrapping layer;

[0107] 61. First interface thermal conductive material; 62. Second interface thermal conductive material; 63. Third interface thermal conductive material; 64. Fourth interface thermal conductive material; D. Positive terminal; E. Negative terminal; S1. First projection; S2. Second projection. DETAILED DESCRIPTION

[0108] In the embodiments of the present application, the terms "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0109] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0110] In the description of the embodiments of the present application, the term "at least one" refers to one or more, and "multiple" refers to two or more. "At least one of the following" or its similar expression refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can be represented by: a, b, c, ab, ac, bc, or abc, wherein a, b, c can be single or multiple. In the description of the embodiments of the present application, "and / or" is only a kind of association relationship describing the associated objects, indicating that there can be three kinds of relationships, for example, A and / or B can be represented by: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present application generally indicates that the associated objects before and after are a kind of "or" relationship.

[0111] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship remains unchanged after the connection. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after the connection.

[0112] The directional terms mentioned in the embodiments of the present application, such as "inside", "outside", "upper", "lower", etc., are only references to the directions of the drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0113] In the description of the embodiments of the present application, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0114] An embodiment of the present application provides an electronic device, which includes a circuit board assembly. In order to take into account both the heat dissipation performance and the miniaturized design of the circuit board assembly, the present application improves the circuit board assembly based on the following two ideas. Idea 1: A groove portion is provided on the plastic package of the circuit board assembly, and a first heat sink is disposed in the groove portion. Idea 2: Before forming the plastic package on the substrate, a first heat sink including a tube body and liquid metal 5152 filled in the tube body is fixed on the substrate.

[0115] In this way, after the heat generated by the electronic component is transferred to the plastic package, it can be transferred to the outside of the plastic package through the first heat sink, which can effectively improve the heat dissipation performance of the circuit board assembly. In addition, since the first heat sink is arranged inside the plastic package, the internal space of the plastic package can be fully utilized, and the overlapping size of the first heat sink and the plastic package can be reduced, which is conducive to reducing the overall volume of the circuit board assembly, thereby realizing the miniaturization design of the circuit board assembly on the basis of ensuring the heat dissipation performance of the circuit board assembly.

[0116] The electronic device provided in the present application may be a portable electronic device or other suitable electronic device. For example, the electronic device may be a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a camera, a personal computer, a notebook computer, a vehicle-mounted device, and a wearable device (such as a watch or glasses). Among them, the wearable device includes but is not limited to headphones, smart bracelets, smart watches, smart head-mounted displays, smart glasses, etc.

[0117] See also Figure 1and Figure 2 , Figure 1 A perspective view of an electronic device 100 provided in some embodiments of the present application, Figure 2 for Figure 1 The electronic device 100 is an exploded view of the electronic device 100. In this embodiment, the electronic device 100 is a mobile phone. The electronic device 100 includes a housing 10, a functional device 20, a circuit board assembly ( Figure 1 and Figure 2 not shown) and a battery 50.

[0118] Understandably, Figure 1 and Figure 2 The following figures and the related drawings only schematically illustrate some components of the electronic device 100, and the actual shapes, sizes, positions and structures of these components are not subject to the present invention. Figure 1 and Figure 2 As well as the following figures. In addition, in order to facilitate the description of the following embodiments, an XYZ coordinate system is established. Specifically, the width direction of the electronic device 100 is defined as the X-axis direction, the length direction of the electronic device 100 is defined as the Y-axis direction, and the thickness direction of the electronic device 100 is defined as the Z-axis direction. It is understood that the coordinate system setting of the electronic device 100 can be flexibly set according to actual needs and is not specifically limited here.

[0119] See also Figure 2 The housing 10 includes a front cover 11, a frame 12 and a back cover 13. The material of the front cover 11 includes, but is not limited to, glass, plastic and ceramic. The front cover 11 and the back cover 13 are stacked and spaced apart. The material of the frame 12 and the back cover 13 includes, but is not limited to, metal and plastic. The frame 12 is located between the front cover 11 and the back cover 13, and is arranged around the edges of the front cover 11 and the back cover 13. Exemplarily, the frame 12 can be fixedly connected to the back cover 13 by adhesive. The frame 12 can also be an integrally formed structure with the back cover 13, that is, the frame 12 and the back cover 13 are an integral structure. The front cover 11 is fixed to the frame 12. In some embodiments, the front cover 11 can be fixed to the frame 12 by adhesive. The front cover 11, the back cover 13 and the frame 12 enclose an internal accommodation space of the electronic device 100. The internal accommodation space accommodates the functional device 20, the circuit board assembly and the battery 50.

[0120] The functional device 20 is disposed in the housing 10. The functional device 20 is used to implement one or more functions of the electronic device 100. The functional device 20 includes but is not limited to at least one of a display screen 21, a camera module 22, a speaker, a receiver, an antenna, a microphone, a universal serial bus (USB) interface, a subscriber identification module (SIM) card interface, and a button.

[0121] In some embodiments, see Figure 2 The functional device 20 includes a display screen 21 and a camera module 22. The display screen 21 is stacked and fixedly connected to the front cover plate 11. The display screen 21 is used to display images, videos, etc. Exemplarily, the display screen 21 is connected to the front cover plate 11 by gluing. The display screen 21 can be a flexible display screen 21 or a rigid display screen 21. The camera module 22 is used to take photos / videos. The camera module 22 is fixed in the housing 10. The camera module 22 can be used as a rear camera module or a front camera module.

[0122] The circuit board assembly is disposed in the housing 10, and the circuit board assembly is electrically connected to the functional device 20. In some embodiments, the circuit board assembly can be applied to the battery protection board in the battery 50. That is, the battery protection board 502 includes the circuit board assembly. Of course, it can be understood that in other embodiments, the circuit board assembly can also be applied to the main board, auxiliary circuit board, etc. of the electronic device 100. In this way, the circuit board assembly 51 can be used to perform operations such as signal control, data signal processing, and data signal storage on the functional device 20.

[0123] For the sake of convenience, the following takes the application of the circuit board assembly 51 to the battery protection board as an example to explain the specific structure of the circuit board assembly 51, but this cannot be considered as a special limitation of the present application. After reading the present application, those skilled in the art can apply the specific structure of the circuit board assembly 51 described below to a main board, a sub-circuit board or any other circuit board structure, which falls within the protection scope of the present application.

[0124] On this basis, please continue to refer to Figure 2, the electronic device 100 also includes a mainboard 30 and a sub-circuit board 40. The mainboard 30 and the sub-circuit board 40 are both fixed in the housing 10 and spaced apart in the Y-axis direction. The camera module 22 mentioned above is fixed on the mainboard 30. The mainboard 30 is used to integrate a first control chip. The first control chip can be, for example, an application processor (application processor, AP), a double data rate synchronous dynamic random access memory (double data rate, DDR), a universal flash storage (universal flash storage, UFS), an antenna module, a Bluetooth module, a WiFi module, a GPS module, a screen display and operation module, etc. The screen display and operation module on the mainboard 30 is electrically connected to the display screen 21, and is used to control the display screen 21 to display images or videos. The mainboard 30 is also used to be electrically connected to the camera module 22, so as to control the camera module 22 to collect images, etc. The sub-circuit board 40 is used to carry a speaker (speaker) and a USB interface, etc. Of course, it can be understood that in other embodiments, the mainboard 30 and the sub-circuit board 40 can also be integrated into one.

[0125] For some examples, see Figure 2 The electronic device 100 further includes a middle plate 14, which is located in the internal accommodation space of the electronic device 100 and is fixed to the inner surface of the frame 12. The middle plate 14 is used as a supporting "skeleton" in the electronic device 100, and is used to support the functional device 20, etc. The main board 30 and the auxiliary circuit board 40 can be fixedly connected to the middle plate 14. It can be understood that when the electronic device 100 does not include the middle plate 14, the main board 30 and the auxiliary circuit board 40 can also be fixedly connected to the surface of the display screen 21 facing the back cover 13.

[0126] The battery 50 is used to provide power to the functional device 20, the main board 30 and the auxiliary circuit board 40 in the electronic device 100. Figure 2 , the battery 50 is located between the main board 30 and the auxiliary circuit board 40.

[0127] See also Figure 3 , Figure 3 A three-dimensional diagram of a battery 50 provided in some embodiments of the present application. In this embodiment, the battery 50 is a lithium-ion battery 50. The battery 50 includes a battery cell 501 and a battery protection board 502.

[0128] See also Figure 4 , Figure 4 for Figure 3The exploded schematic diagram of the battery 50 shown. The battery cell 501 includes a shell 5011 and a bare battery cell 5012. The shell 5011 is used to encapsulate and protect the bare battery cell 5012. The shell 5011 includes but is not limited to a steel shell and an aluminum-plastic film. Among them, the aluminum-plastic film is also called an aluminum-plastic packaging film, which at least includes three layers of materials: an intermediate layer, an outer layer and an inner layer. The intermediate layer is located between the outer layer and the inner layer. Specifically, the intermediate layer can be an aluminum layer, which serves to isolate moisture. The outer layer can be a nylon adhesive layer, which serves to prevent the penetration of air, especially oxygen. The inner layer is a polypropylene (PP) layer, which serves to seal and prevent the electrolyte from corroding the aluminum layer. The inner layer of the aluminum-plastic film is in contact with the electrolyte.

[0129] The shell 5011 contains an electrolyte. The bare cell 5012 is located in the shell 5011 and is immersed in the electrolyte. The electrolyte exists in the gaps of the bare cell 5012 inside the shell 5011 and is used as a carrier for transmitting lithium ions in the battery 50. The electrolyte is generally prepared from raw materials such as high-purity organic solvents, electrolyte lithium salts, and necessary additives under certain conditions and in a certain proportion.

[0130] The bare cell 5012 generally includes a positive electrode sheet, a negative electrode sheet and a separator. Both the positive electrode sheet and the negative electrode sheet include a current collector and an electrode material coated on the current collector. The current collector of the positive electrode sheet is generally an aluminum foil. The current collector of the negative electrode sheet is generally a copper foil. The separator is also called an isolation membrane, which is arranged between the positive electrode sheet and the negative electrode sheet to separate the positive electrode sheet and the negative electrode sheet of the bare cell 5012 to prevent the two electrodes from directly contacting and causing a short circuit. The material of the separator is generally a polyolefin porous film.

[0131] In order to facilitate the connection of the battery cell 501 to the circuit, a pole ear 5013 is provided on the bare battery cell 5012. The pole ear 5013 is a metal conductor used to lead the electrode of the bare battery cell 5012 to the outside of the shell 5011. Specifically, there are two pole ears 5013, one of the two pole ears 5013 is a positive pole ear 5013a, and the other is a negative pole ear 5013b. Among them, the pole ear 5013 used to lead out the positive electrode of the bare battery cell 5012 is the positive pole ear 5013a, and the pole ear 5013 used to lead out the negative electrode of the bare battery cell 5012 is the negative pole ear 5013b. The positive pole ear 5013a can be connected to the current collector of the positive electrode sheet in the bare battery cell 5012 by welding, and can also be formed by directly extending the current collector of the positive electrode sheet. Similarly, the negative electrode tab 5013b can be connected to the current collector of the negative electrode sheet in the bare battery cell 5012 by welding, or it can be formed by directly extending from the current collector of the negative electrode sheet.

[0132] The positive pole tab 5013a is usually made of aluminum. The negative pole tab 5013b is usually made of nickel or nickel-plated copper (Ni-Cu). In order to prevent the tab 5013 from short-circuiting with the metal layer in the housing 5011 (such as the aluminum layer in the aluminum-plastic film), the positive pole tab 5013a and the negative pole tab 5013b are usually coated with tab glue (also called film) at the part of the housing 5011 to play an insulating and isolating role. That is, the positive pole tab 5013a and the negative pole tab 5013b are both composed of a tab glue and a metal.

[0133] The battery protection board 502 is disposed on the outer side of the housing 5011 and is electrically connected to the tab 5013. Figure 4 The battery protection board 502 has a positive terminal D and a negative terminal E. The positive terminal D and the negative terminal E are electrically connected to the main board 30, respectively. The battery protection board 502 can be used to provide overcharge protection and short circuit protection. When the current and voltage in the battery cell 501 are too high or too low, the battery protection board 502 can be electrically disconnected from the main board 30. Therefore, by connecting the main board 30 and the battery cell 501 through the battery protection board 502, it is possible to prevent the battery 50 from having problems such as overvoltage, overcharge, overcurrent, and overdischarge.

[0134] In some examples, the thickness direction of the battery protection plate 502 and the thickness direction of the battery 50 are consistent with the thickness direction of the electronic device 100 (ie, the Z-axis direction). Figure 2 In the Y-axis direction, the battery protection board 502 is located between the battery cell 501 and the main board 30 to facilitate electrical connection between the main board 30 and the battery cell 501 .

[0135] See also Figure 5 and Figure 6 , Figure 5 for Figure 3 The schematic diagram of the cross-sectional structure of the battery 50 shown is taken along the A1-A1 line. Figure 6 for Figure 5 The battery protection board 502 in the battery 50 is shown in the structure diagram. The battery protection board 502 includes a circuit board assembly 51 and a flexible printed circuit (FPC) 52. The circuit board assembly 51 includes a substrate 511, an electronic component 512 and a plastic package 513.

[0136] See also Figure 6 The substrate 511 includes a connecting surface 511a and a bearing surface 511b which are arranged opposite to each other in the thickness direction (i.e., the Z-axis direction) of the substrate 511. Exemplarily, the substrate 511 is a printed circuit board (PCB). The shape of the substrate 511 includes, but is not limited to, a rectangle, a circle, an ellipse, or a special shape.

[0137] The substrate 511 is electrically connected to the flexible circuit board 52 via the connection surface 511a. Figure 6 The flexible circuit board 52 includes a first connecting section 52a, a second connecting section 52b and a third connecting section 52c. The first connecting section 52a is stacked on the side of the circuit board facing the connecting surface 511a and is fixed to the connecting surface 511a. For example, the first connecting section 52a can be welded to the connecting surface 511a. The flexible circuit board 52 is fixed to the tab 5013 of the battery cell 501 by means of the first connecting section 52a and is electrically connected to the tab 5013. For example, please continue to refer to Figure 5 A nickel sheet 524 is provided on the side of the first connecting section 52a away from the substrate 511, and the flexible circuit board 52 is electrically connected to the tab 5013 by means of the nickel sheet 524. Specifically, there are two nickel sheets 524, namely a positive nickel sheet and a negative nickel sheet. The positive nickel sheet is welded to the positive tab 5013a of the battery cell 501. The negative nickel sheet is welded to the negative tab 5013b of the battery cell 501.

[0138] The second connecting section 52b and the third connecting section 52c are respectively connected to the two ends of the length direction (i.e., the X-axis direction) of the first connecting section 52a. The second connecting section 52b and the third connecting section 52c are bent around the substrate 511 to the side facing the bearing surface 511b. The second connecting section 52b is provided with the above-mentioned positive terminal D, and the third connecting section 52c is provided with the above-mentioned negative terminal E. Of course, it can be understood that in other examples, the third connecting section 52c may not be provided. Instead, both the positive terminal D and the negative terminal E are provided on the second connecting section 52b. Alternatively, in other examples, the flexible circuit board 52 may not be provided, but both the positive terminal D and the negative terminal E are provided on the substrate 511.

[0139] In order to improve the reliability of the circuit board assembly 51 and prevent dust and moisture from affecting its operation, in some embodiments, please continue to refer to Figure 5 The battery 50 further includes a waterproof insulation wrapping layer 503. The waterproof insulation wrapping layer 503 wraps the tab 5013, the substrate 511, the first connecting segment 52a, the nickel sheet 524, etc., and only allows the second connecting segment 52b and the third connecting segment 52c to be exposed. Exemplarily, the waterproof insulation wrapping layer 503 is made of plastic or silicone, for example, the waterproof insulation wrapping layer 503 can be a Mylar sheet.

[0140] See also Figure 7 , Figure 7 Based on Figure 6Schematic diagram of the substrate 511 and the electronic component 512 in the battery protection board 502 shown. The electronic component 512 is electrically connected to the bearing surface 511b. There can be multiple electronic components 512. The multiple electronic components 512 include any one or more of a metal-oxide semiconductor field effect transistor (also known as a metal-oxide-semiconductor field effect transistor 5121, a MOS tube or a MOS switch), a thermistor 5122 (also known as a precision resistor), a second control chip 5123 and a memory 5124.

[0141] Thermistors 5122 can be divided into positive temperature coefficient thermistors (positive temperature coefficient, PTC) and negative temperature coefficient thermistors (negative temperature coefficient, NTC) according to their temperature coefficients. The characteristics of thermistors are that they are sensitive to temperature and can show different resistance values ​​at different temperatures. Among them, the higher the temperature, the greater the resistance value of the positive temperature coefficient thermistor, and the higher the temperature, the lower the resistance value of the negative temperature coefficient thermistor (NTC). The temperature change coefficient of the negative temperature coefficient thermistor (NTC) is generally expressed in ppm / ℃, that is, a temperature change of 1 degree corresponds to a resistance change of a few parts per million. 100ppm / ℃ is 0.01% / ℃.

[0142] Metal oxide semiconductor field effect transistor (MOSFET), hereinafter referred to as "MOSFET 5121", is a field effect transistor that can be widely used in analog circuits and digital circuits. When a sufficiently large potential difference is applied between the gate and source of MOSFET 5121, the electric field will form an induced charge on the semiconductor surface below the oxide layer, and an "inversion channel" will be formed at this time. The polarity of the inversion channel is the same as its drain and source. Assuming that the drain and source are n-type, the channel will also be n-type. After the channel is formed, MOSFET 5121 can allow current to pass through, and depending on the voltage value applied to the gate, the amount of current that can flow through the channel of MOSFET 5121 will also be controlled and changed.

[0143] The second control chip 5123 is electrically connected to the MOSFET 5121, thermistor 5122, memory 5124, etc. The second control chip 5123 can be used to control the MOSFET 5121 to keep the battery cell 501 electrically connected to the mainboard 30 or disconnect it. When the voltage or loop current of the battery cell 501 does not exceed the specified value stored in the memory 5124, the second control chip 5123 controls the MOSFET 5121 to turn on, so that the battery cell 501 is electrically connected to the mainboard 30. When the voltage or loop current of the battery cell 501 exceeds the specified value, the second control chip 5123 controls the MOSFET 5121 to turn off, so that the battery cell 501 is electrically disconnected from the mainboard 30, thereby protecting the safety of the battery cell 501.

[0144] As the number of functions that the electronic device 100 needs to implement increases, the number of electronic devices arranged on the main board 30 inside the electronic device 100 increases. Accordingly, the space occupied by the main board 30 inside the electronic device 100 increases, which is contrary to the trend of miniaturization of the electronic device 100. In order to resolve the contradiction between the increasing space occupied by the main board 30 inside the electronic device 100 and the miniaturization of the electronic device 100, in some design ideas, the structure of the main board 30 can be optimized to reduce the space occupied by the main board 30 by increasing the arrangement density of the electronic devices on the main board 30.

[0145] However, since there are many electronic devices integrated on the mainboard 30, increasing the arrangement density of the electronic devices on the mainboard 30 results in a smaller distance between two adjacent electronic devices, which affects the signals between the electronic devices. It is difficult to optimize the structure of the mainboard 30 to reduce the occupied space of the mainboard 30 by increasing the arrangement density of the electronic devices on the mainboard 30. On this basis, the spatial layout inside the electronic device 100 can be optimized by optimizing other structures inside the electronic device 100, such as the battery 50, so as to solve the contradiction between the increasing occupied space of the mainboard 30 in the electronic device 100 and the miniaturization of the electronic device 100.

[0146] Specifically, in the battery 50, in order to prevent the electronic component 512 on the substrate 511 from colliding with other structures and causing damage to the electronic component 512, a certain safety distance needs to be reserved between the electronic component 512 and the edge of the substrate 511, so that the distance between the orthographic projection of the electronic component 512 on the bearing surface 511b and the edge of the substrate 511 is generally large, which makes the overall circumferential size of the circuit board assembly 51 relatively large.

[0147] To resolve this technical issue, please continue to Figure 5 and Figure 6, the circuit board assembly 51 also includes a plastic package 513. The plastic package 513 is packaged on the bearing surface 511b of the substrate 511 and wraps the electronic component 512. In some embodiments, the plastic package 513 can be injection molded on the bearing surface 511b of the substrate 511 using a system in a package (SIP) process to package the substrate 511 and the electronic component 512 on the substrate 511 together to form a system-level packaging structure. The material of the plastic package 513 can be epoxy molding compound (EMC). Of course, the material of the plastic package 513 can also be other types of materials, such as ceramic or glass, etc., and the embodiments of the present application are not particularly limited.

[0148] In this way, the plastic package 513 can be used to protect the electronic components 512 on the substrate 511, so there is no need to reserve too much safety distance between the electronic components 512 and the edge of the substrate 511, which can help reduce the distance between the orthographic projection of the electronic components 512 on the bearing surface 511b and the edge of the substrate 511, and then help reduce the circumferential size of the circuit board assembly 51, thereby optimizing the structural layout inside the electronic device 100, and helping to achieve the miniaturization design of the electronic device 100. In addition, compared with the circuit board assembly 51 made of a soft-hard combination board in the related art, the cost is greatly saved. However, in this embodiment, since the electronic components 512 are wrapped by the plastic package 513, the heat generated by the electronic components 512 needs to be dissipated outward through the plastic package 513, and in order to meet the shielding and reliability process requirements of the plastic package 513, the thermal conductivity of the plastic package 513 is low, usually less than 1W (mK), resulting in the heat inside the plastic package 513 cannot be dissipated in time, restricting the charging power and charging efficiency of the electronic device 100.

[0149] In order to take into account both the heat dissipation performance and the miniaturized design of the circuit board assembly 51, please refer to Figure 8-Figure 9 , Figure 8 A schematic diagram of a partial structure of a circuit board assembly 51 provided in some embodiments of the present application, Fig. 9 for Figure 8 The circuit board assembly 51 is a partial cross-sectional view taken along line AA. Figure 8 and Fig. 9 Only some components of the circuit board assembly 51 are schematically shown, and the actual shapes, sizes, positions and configurations of these components are not affected by the present invention. Figure 8 and Fig. 9 In addition, Figure 8 The coordinate system in Figure 6 The coordinate system in is expressed as the same coordinate system. That is, Figure 8 The various components of the circuit board assembly 51 are Figure 8 The orientation relationship in the coordinate system shown is the same as when the circuit board assembly 51 is applied to Figure 6 When the battery protection board 502 is shown, its various components are Figure 6 The orientation relationships in the coordinate systems shown are the same.

[0150] See also Fig. 9 In addition to the substrate 511 , the electronic component 512 and the plastic package 513 , the circuit board assembly 51 in this embodiment further includes a groove portion 514 disposed on the plastic package 513 , and a first heat sink 515 is disposed in the groove portion 514 .

[0151] For details, please refer to Fig.10 , Fig.10 for Fig. 9 Schematic diagram of the structure of the plastic package 513, the electronic component 512 and the substrate 511 in the circuit board assembly 51 shown in . The groove portion 514 is recessed inward from the outer surface of the plastic package 513. During the processing, the plastic package 513 can be formed on the bearing surface 511b of the substrate 511 first, and then the groove portion 514 can be opened on the plastic package 513. Exemplarily, the groove portion 514 can be formed on the plastic package 513 by laser drilling or other processing methods. The groove portion 514 includes an open end 514a, which passes through the outer surface of the plastic package 513, and the first heat sink 515 can be installed in the groove portion 514 through the open end 514a.

[0152] In this way, by setting a groove portion 514 on the plastic package body 513 and setting the first heat sink 515 in the groove portion 514, the heat generated by the electronic component 512 can be transferred to the outside of the plastic package body 513 through the first heat sink 515, thereby realizing the heat dissipation of the electronic component 512, which can effectively improve the heat dissipation performance of the circuit board assembly 51, reduce the temperature of the electronic component 512, and improve the reliability of the electronic component 512. Therefore, under the premise of ensuring the heat dissipation performance of the electronic component 512, the distance between different electronic components 512 can be reduced, which is beneficial to increase the arrangement density of the electronic components 512 in the circuit board assembly 51 and reduce the overall volume of the circuit board assembly 51.

[0153] Furthermore, since the first heat sink 515 is disposed in the plastic package 513, the internal space of the plastic package 513 can be fully utilized to reduce the overlapping dimensions of the first heat sink 515 and the plastic package 513 (for example, the overlapping dimensions of the first heat sink 515 and the plastic package 513 in the thickness direction of the circuit board assembly 51 can be reduced), which is beneficial to further reduce the overall volume of the circuit board assembly 51, thereby enabling the miniaturization design of the circuit board assembly 51 to be achieved while ensuring the heat dissipation performance of the circuit board assembly 51, thereby further facilitating reducing the thickness of the battery protection board 502. Thus, the heat dissipation performance of the battery protection board 502 including the circuit board assembly 51 can be improved, and the high heat dissipation demand and high reliability demand of the electronic device 100 for the battery protection board 502 due to the increase in fast charging power can be met, which is beneficial to increase the charging wattage and current capacity of the battery protection board 502, and is beneficial to reduce the overall occupied space of the battery protection board 502, thereby providing a larger layout space for other components in the electronic device 100, such as the main board 30, the battery 50, etc., which is beneficial to expand the function of the electronic device 100, improve the endurance of the electronic device 100, and facilitate the realization of a lightweight design of the electronic device 100.

[0154] Specifically, in some embodiments, the first heat sink 515 includes liquid metal 5152. Liquid metal 5152 is a low melting point alloy that is liquid at room temperature. Liquid metal 5152 as a thermal interface material has excellent thermal conductivity, stable properties, small expansion coefficient, non-volatile, safe and non-toxic. The "normal temperature" described in the present application may be 15°C to 30°C. It is understandable that when the circuit board assembly 51 is working, the temperature of the circuit board assembly 51 is usually higher than the normal temperature. Therefore, when the circuit board assembly 51 is in working state, the liquid metal 5152 is also in liquid state.

[0155] After the groove 514 is formed on the plastic package 513, the liquid metal 5152 can be poured into the groove 514 through the open end 514a of the groove 514. On this basis, in order to prevent the liquid metal 5152 from flowing out of the groove 514, please refer to Fig. 9 The circuit board assembly 51 further includes a first sealing cover plate 517 , which is used to seal the open end 514 a of the groove portion 514 .

[0156] Of course, the present application is not limited thereto, and it is understood that in other embodiments, the first heat sink 515 may also include thermally conductive gel, solid metal (such as copper, aluminum alloy, magnesium alloy, titanium alloy, stainless steel, etc.). When the first heat sink 515 is solid metal, the open end 514a of the groove portion 514 may not be provided with the above-mentioned first sealing cover plate 517.

[0157] In order to ensure the heat dissipation performance of the circuit board assembly 51, the thermal conductivity of the liquid metal 5152 is greater than or equal to 15W (mK). Further, the thermal conductivity of the liquid metal 5152 is greater than or equal to 20W / (mK). Exemplarily, the thermal conductivity of the liquid metal 5152 can be 15W (mK), 18W (mK), 20W·(mK), 25W·(mK), 30W (mK), 35W (mK), 40W (mK), 50W (mK), 60W (mK), 70W (mK), 80W (mK), 100W (mK), 120W (mK), 150W (mK), 200W (mK), etc.

[0158] In some embodiments, the liquid metal 5152 may include at least one of a gallium alloy and an indium alloy. For example, the liquid metal 5152 may be 75Ga25In. The melting point of 75Ga25In is about 16°C, it is liquid at room temperature, and its thermal conductivity is 26.1W / (mK). The thermal conductivity of 75Ga25In is 164 times that of silicone oil, which can greatly improve the heat dissipation capacity of the circuit board assembly 51.

[0159] Since the liquid metal 5152 is fluid and has strong gap-filling ability, when the liquid metal 5152 is directly filled into the groove 514, the liquid metal 5152 can be filled into every corner inside the groove 514, avoiding the filling dead corner inside the groove 514, thereby increasing the contact area between the liquid metal 5152 and the inner wall surface of the groove 514, improving the heat conduction efficiency between the liquid metal 5152 and the plastic package 513, and further improving the heat dissipation effect of the circuit board assembly 51. In addition, during the processing, there is no need to consider the adaptability of the shape of the groove 514 and the shape of the first heat sink 515, and the setting position of the groove 514 can be made more flexible, which can reduce the processing difficulty of the groove 514, thereby improving the processing efficiency of the circuit board assembly 51 and reducing the processing cost of the circuit board assembly 51.

[0160] In some embodiments, in order to facilitate the flow of liquid metal 5152 in the groove portion 514, the surface roughness of the inner wall surface of the groove portion 514 is less than or equal to 10 μm. Exemplarily, the surface roughness of the inner wall surface of the groove portion 514 can be 10 μm, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, 0 μm, etc. Among them, surface roughness refers to the unevenness of the small spacing and tiny peaks and valleys on the surface. The distance (wave distance) between its two peaks or two valleys is very small (usually less than 1 mm), which belongs to the microscopic geometric shape error. The smaller the surface roughness, the smoother the surface.

[0161] In order to reduce the surface roughness of the inner wall surface of the groove portion 514 and improve the smoothness of the inner wall surface of the groove portion 514, in some embodiments, a smooth layer is formed on the inner wall surface of the groove portion 514. The smooth layer can be formed on the inner wall surface of the groove portion 514 by sputtering, sandblasting, abrasive jet processing, liquid jet processing, fluid dynamic grinding, chemical polishing, etc. The process is simple and the processing is convenient.

[0162] The volume of the first heat sink 515 is smaller than the volume of the groove 514. In this way, the force generated by the first heat sink 515 squeezing the inner wall of the groove 514 after absorbing heat and expanding in volume can be reduced, which can effectively prevent the plastic package 513 from cracking, and is conducive to improving the reliability of the circuit board assembly 51. In addition, when the first heat sink 515 is liquid metal 5152, it can also prevent the liquid metal 5152 from absorbing the heat generated by the electronic component 512 and increasing in volume and overflowing from the groove 514.

[0163] It can be understood that the volume of the first heat sink 515 described in the present application may include at least one of the volume of the first heat sink 515 at room temperature and the volume of the first heat sink 515 after expansion due to absorbing heat.

[0164] On this basis, in order to take into account both the heat dissipation performance and the reliability performance of the circuit board assembly 51, the ratio of the volume V1 of the liquid metal 5152 to the volume V2 of the groove portion 514 is greater than or equal to 0.8 and less than 1. Exemplarily, the ratio of the volume V1 of the liquid metal 5152 at room temperature to the volume V2 of the groove portion 514 is 0.8, 0.85, 0.88, 0.9, 0.95, 0.98, 0.99, etc.

[0165] In order to further improve the heat dissipation efficiency of the circuit board assembly 51 and the reliability of the electronic component 512, the groove portion 514 can be arranged near the first electronic component 512a which has a higher heat generation and / or a higher temperature change requirement in the electronic component 512. Exemplarily, the first electronic component 512a can include at least one of the metal oxide semiconductor field effect transistor 5121 (also known as a MOS tube) and thermistor 5122 (also known as a precision resistor) mentioned above.

[0166] See also Fig. 9 and Fig.10 The first electronic component 512a is electrically connected to the bearing surface 511b of the substrate 511, and the first electronic component 512a includes a first top surface 512a1 and a first peripheral surface 512a2. The first top surface 512a1 is a surface of the first electronic component 512a that is away from the substrate 511, and the orientation of the first top surface 512a1 is the same as that of the bearing surface 511b. The first peripheral surface 512a2 is arranged around the outer edge of the first top surface 512a1.

[0167] Please continue reading Fig. 9 and Fig.10 The groove portion 514 includes a first groove 5141, and the first groove 5141 is located on the side toward which the first top surface 512a1 faces. That is, the first groove 5141 is located on the side of the first electronic component 512a that is away from the substrate 511.

[0168] See also Fig.11 , Fig.11 for Fig. 9 The schematic diagram of the orthographic projection of the first electronic component 512a on the bearing surface 511b and the orthographic projection of the first groove 5141 on the bearing surface 511b in the circuit board assembly 51 is shown. Specifically, the orthographic projection of the first electronic component 512a on the bearing surface 511b overlaps with the orthographic projection of the first groove 5141 on the bearing surface 511b. Fig.11 , the orthographic projection of the first electronic component 512a on the bearing surface 511b is the first projection S1, and the orthographic projection of the first groove 5141 on the bearing surface 511b is the second projection S2, and the first projection S1 overlaps with the second projection S2. In this way, it can be ensured that at least a portion of the first groove 5141 is directly opposite to the first electronic component 512a. For example, it can be ensured that at least a portion of the first groove 5141 is located directly above the first electronic component 512a, which can shorten the transfer path between the heat generated by the first electronic component 512a and the first heat sink 515, which is conducive to improving the heat conduction efficiency and reducing the heat loss, thereby effectively improving the heat dissipation efficiency of the circuit board assembly 51.

[0169] It should be noted that, in the embodiment of the present application, “the first projection S1 overlaps with the second projection S2” means that at least a portion of the first projection S1 and the second projection S2 overlap. Fig.11 In the embodiment shown, the first projection S1 intersects with the second projection S2, that is, a portion of the first projection S1 overlaps with a portion of the second projection S2 (eg, Fig.11 ), and another part of the first projection S1 does not overlap with another part of the second projection S2. It is understandable that, in other embodiments, the first projection S1 and the second projection S2 may completely overlap, or the first projection S1 is included in the second projection S2, or the second projection S2 is included in the first projection S1. As long as the first projection S1 and the second projection S2 can overlap, it is acceptable.

[0170] As the first heat sink 515 expands and increases in volume after absorbing heat, the force between the first heat sink 515 and the inner wall surface of the groove 514 increases accordingly. In order to reduce the influence of the force on the first electronic component 512a, please refer to Fig. 9 and Fig.10The plastic package body 513 includes a first portion 5131, and the first portion 5131 is located between the groove portion 514 and the first electronic component 512a (that is, the electronic component 512). The groove portion 514 and the first electronic component 512a are separated by the first portion 5131. In this way, the force generated by the first heat sink 515 due to the increase in volume and the squeezing of the inner wall surface of the groove portion 514 can be avoided from directly acting on the first electronic component 512a, which can reduce the stress on the first electronic component 512a and help improve the reliability of the first electronic component 512a. In addition, a safe distance can be reserved between the groove portion 514 and the first electronic component 512a to prevent the first electronic component 512a from being broken down during the process of opening the groove portion 514, which can effectively protect the first electronic component 512a.

[0171] The first groove 5141 includes a first groove wall surface 5141a, the first groove wall surface 5141a is oriented in the same direction as the first top surface 512a1, and the first groove wall surface 5141a is spaced apart from the first top surface 512a1. That is, there is a gap between the first groove wall surface 5141a and the first top surface 512a1. For example, please refer to Fig. 9 and Fig.10 The first part 5131 of the plastic package body 513 includes a first sub-part 5131a, which is located between the first groove 5141 and the first electronic component 512a, and the first groove 5141 and the first electronic component 512a are separated by the first sub-part 513a. That is, the first groove wall surface 5141a and the first top surface are separated by the first sub-part 513a.

[0172] In this way, by setting the first top surface 512a1 and the first groove wall surface 5141a apart, the first heat sink 515 disposed in the first groove 5141 can be set apart from the first electronic component 512a, which can prevent the first heat sink 515 from directly acting on the first electronic component 512a due to the increase in volume and the force generated by squeezing the first groove wall surface 5141a, thereby reducing the stress on the first electronic component 512a, which is conducive to improving the reliability of the first electronic component 512a. In addition, by setting the first groove wall surface 5141a and the first top surface 512a1 apart, a safety distance can be reserved to prevent the first electronic component 512a from being broken through during the process of opening the groove portion 514, thereby effectively protecting the first electronic component 512a.

[0173] In some embodiments, please refer to Fig. 9 and Fig.10, the spacing between the first groove wall 5141a and the first top surface 512a1 is the first spacing d1, and the first spacing d1 is greater than or equal to 0.1mm and less than or equal to 0.2mm. Exemplarily, the first spacing d1 can be 0.1mm, 0.12mm, 0.13mm, 0.15mm, 0.16mm, 0.18mm, 0.19mm, 0.2mm, etc. In this way, on the one hand, when the first heat sink 515 absorbs heat and expands, the force generated by the first heat sink 515 squeezing the first groove wall 5141a can be prevented from directly acting on the first electronic component 512a, which can reduce the stress on the first electronic component 512a and help improve the reliability of the first electronic component 512a; on the other hand, the transfer path between the first heat sink 515 and the first top surface 512a1 can be shortened, which facilitates the transfer of heat generated by the first electronic component 512a to the first heat sink 515, which is conducive to improving the heat conduction efficiency and reducing heat loss. Therefore, by setting the distance between the first groove wall surface 5141a and the first top surface 512a1 to 0.1 mm to 0.2 mm, the heat dissipation performance of the circuit board assembly 51 and the reliability of the first electronic component 512a can be taken into consideration.

[0174] Please continue reading Fig. 9 and Fig.10 , the dimension of the first groove 5141 in the first direction is a first dimension h1, the first dimension h1 is greater than or equal to 0.2 mm and less than or equal to 0.5 mm, and the first direction is perpendicular to the bearing surface 511b. In this embodiment, the first direction is the thickness direction of the circuit board assembly 51, that is, Fig. 9 The first dimension h1 can be understood as the depth dimension of the first groove 5141. Exemplarily, the first dimension h1 can be 0.2mm, 0.22mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc. In this way, by setting the first dimension h1 to 0.2mm to 0.5mm, it is beneficial to increase the contact area between the first heat sink 515 and the inner wall surface of the first groove 5141, thereby improving the heat dissipation effect.

[0175] On the basis of any of the above embodiments, in order to further increase the contact area between the first heat sink 515 and the inner wall surface of the first groove 5141, refer to Fig.12 , Fig.12 for Figure 8 The circuit board assembly 51 is shown in a cross-sectional view at line BB. Fig.12 The first electronic component 512a in the embodiment is covered by the plastic package 513, so Fig.12The first electronic component 512a is shown by a dotted line. There are multiple first grooves 5141. The "multiple" mentioned in this application refers to two or more. For example, there can be two, three, four, five, etc. first grooves 5141.

[0176] In some embodiments, a plurality of first grooves 5141 are arranged at intervals. The first groove 5141 may be in the shape of an elongated strip, and the first groove 5141 is arranged across the side of the first electronic component 512a away from the substrate 511. Each first groove 5141 may extend along at least one extension path of a straight line, a curve, or a fold line. The extension paths of different first grooves 5141 may be the same or different. The cross-sectional shape of each first groove 5141 may include at least one of a square, a rectangle, a trapezoid, a circle, an ellipse, and an irregular figure. The cross-sectional shapes of different first grooves 5141 may be the same or different. Among them, the cross-sectional shape of the first groove 5141 refers to the plane obtained by cutting the first groove 5141 with a plane perpendicular to the central axis of the first groove 5141.

[0177] It should be noted that in this embodiment, the first groove 5141 is only provided across the side of one first electronic component 512a away from the substrate 511. It is understandable that in other embodiments, the first groove may also be provided across the side of multiple first electronic components 512a away from the substrate 511 at the same time.

[0178] For example, see Fig.12 , the plurality of first grooves 5141 are spaced apart in the second direction, and the second direction is parallel to the bearing surface 511b. In this embodiment, the second direction is the length direction of the circuit board assembly 51, that is, Fig.12 It is understood that in other embodiments, the second direction may also be the width direction of the circuit board assembly 51, that is, Fig.10 The X-axis direction shown in , or the second direction can also be any direction that is not parallel to the X-axis direction or the Y-axis direction, as long as the second direction is parallel to the carrying surface 511b.

[0179] See also Fig.12, among the plurality of first grooves 5141 spaced apart from each other, the spacing d0 between two adjacent first grooves 5141 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm. Exemplarily, the spacing d0 between two adjacent first grooves 5141 may be 0.1 mm, 0.12 mm, 0.13 mm, 0.15 mm, 0.16 mm, 0.18 mm, 0.19 mm, 0.2 mm, etc. In this way, the number of first grooves 5141 can be increased on the basis of ensuring the structural stability of the plastic package 513, thereby increasing the contact area between the first heat sink 515 and the inner wall surface of the first groove 5141, and improving the heat dissipation performance of the circuit board assembly 51.

[0180] In this embodiment, the plurality of first grooves 5141 are spaced apart from each other. It is understood that in other embodiments, the plurality of first grooves 5141 may also be arranged to intersect with each other. In this case, the plurality of first grooves 5141 intersect at the same intersection. Alternatively, in other embodiments, a portion of the plurality of first grooves 5141 are spaced apart from each other, and another portion of the plurality of first grooves 5141 are arranged to intersect with each other. Alternatively, in other embodiments, a portion of the plurality of first grooves 5141 are spaced apart from each other, and other first grooves 5141 in the plurality of first grooves 5141 are arranged to intersect with at least a portion of the first grooves 5141 spaced apart from each other.

[0181] Please continue reading Fig.12 , the dimension of the first groove 5141 in the third direction is the second dimension w1, and the second dimension w1 is greater than or equal to 0.2 mm and less than or equal to 3 mm. The third direction is parallel to the bearing surface 511b, and the third direction is perpendicular to the central axis of the first groove 5141. In this embodiment, the third direction is the width direction of the circuit board assembly 51, that is, Fig.10 The second dimension w1 can be understood as the width dimension of the first groove 5141. Exemplarily, the second dimension w1 can be 0.2mm, 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.5mm, 3mm, etc. In this way, the number of first grooves 5141 can be increased on the basis of ensuring the structural stability of the plastic package 513, so as to increase the contact area between the first heat sink 515 and the inner wall surface of the first groove 5141, thereby improving the heat dissipation performance of the circuit board assembly 51.

[0182] Furthermore, the second dimension w1 is greater than or equal to 0.2 mm and less than or equal to 1 mm. In this way, the number of the first grooves 5141 can be further increased to ensure that the first heat sink 515 has a larger contact area with the inner wall surface of the first groove 5141, thereby ensuring that the circuit board assembly 51 has excellent heat dissipation performance.

[0183] In some embodiments, in order to further improve the heat dissipation performance of the circuit board assembly 51, please continue to refer to Fig. 9 and Fig.10 The groove portion 514 further includes a second groove 5142, and the second groove 5142 is located outside the circumferential direction of the first electronic component 512a. In this way, the first heat sink 515 in the second groove 5142 can absorb the circumferential heat of the first electronic component 512a, so that the heat generated by the first electronic component 512a can be transferred not only to the first heat sink 515 in the first groove 5141 through the first top surface 512a1, but also to the first heat sink 515 in the second groove 5142 through the first outer peripheral surface 512a2 of the first electronic component 512a, which can improve the heat conduction efficiency and the heat dissipation performance of the circuit board assembly 51.

[0184] In some embodiments, the second groove 5142 is spaced apart from the first outer peripheral surface 512a2 of the first electronic component 512a. Fig. 9 and Fig.10 The first part 5131 of the plastic package body 513 includes a second sub-part 5131b, and the second sub-part 5131b is located between the second groove 5142 and the first electronic component 512a, and the second groove 5142 and the first electronic component 512a are separated by the second sub-part 5131b. In this way, by setting the second groove 5142 and the first outer peripheral surface 512a2 of the first electronic component 512a apart, the first heat sink 515 disposed in the second groove 5142 can be set apart from the first electronic component 512a, which can prevent the first heat sink 515 from directly acting on the first electronic component 512a due to the increase in volume and the force generated by squeezing the groove wall of the second groove 5142, thereby reducing the stress on the first electronic component 512a, which is conducive to improving the reliability of the first electronic component 512a. In addition, a safety distance can be reserved between the second groove 5142 and the first electronic component 512a to prevent the first electronic component 512a from being broken down during the process of forming the groove portion 514, thereby effectively protecting the first electronic component 512a.

[0185] In some embodiments, see Fig.12The second groove 5142 is arranged around the first electronic component 512a. In this way, the entire first peripheral surface 512a2 of the first electronic component 512a can be surrounded by the second groove 5142, so that the heat generated by the first electronic component 512a can be transferred from all directions of the first peripheral surface 512a2 to the first heat sink 515 (that is, the liquid metal 5152) in the second groove 5142, which can improve the heat dissipation efficiency and the uniformity of the temperature in the plastic package 513.

[0186] Specifically, the second groove 5142 may be annular. For example, the second groove 5142 is a rectangular ring. For details, please refer to Fig.12 , the second groove 5142 includes a first groove body 5142a and a second groove body 5142b that are relatively arranged in the X-axis direction, and a third groove body 5142c and a fourth groove body 5142d that are relatively arranged in the Y-axis direction. The first groove body 5142a, the third groove body 5142c, the second groove body 5142b and the fourth groove body 5142d are connected in sequence to form the second groove 5142. It can be understood that in other embodiments, the second groove 5142 can also be in a circular ring shape, an elliptical ring shape, a racetrack shape, etc., as long as the second groove 5142 is annular. In this way, the liquid metal 5152 in the second groove 5142 can flow in the entire circumferential direction of the first electronic component 512a, and the flow path of the liquid metal 5152 is longer, which can further improve the heat dissipation efficiency of the circuit board assembly 51 and the uniformity of the temperature in the plastic package 513.

[0187] It is understood that, in other embodiments, the first groove body 5142a, the third groove body 5142c, the second groove body 5142b and the fourth groove body 5142d may be spaced apart in the circumferential direction of the first electronic component 512a. That is, the second groove 5142 may include a plurality of sub-grooves spaced apart in the circumferential direction of the first electronic component 512a. Alternatively, in other embodiments, the second groove 5142 may also include only one, two or three of the first groove body 5142a, the third groove body 5142c, the second groove body 5142b and the fourth groove body 5142d.

[0188] On the basis of any of the above embodiments, in order to further improve the fluidity of the liquid metal 5152 and further improve the heat dissipation performance of the circuit board assembly 51, please refer to Fig.12 , the first groove 5141 is connected to the second groove 5142.

[0189] In some embodiments, see Fig.13 , Fig.13 for Figure 8The cross-sectional view of the circuit board assembly 51 at the CC line is shown. The second groove 5142 includes a second groove wall 5142e, and the direction of the second groove wall 5142e is the same as that of the bearing surface 511b, and the second groove wall 5142e is spaced apart from the bearing surface 511b. In this way, the first heat sink can be prevented from directly contacting the substrate. On the one hand, it can prevent the first heat sink from occupying the layout space on the bearing surface, which is conducive to increasing the number of electronic components on the bearing surface. On the other hand, it can reduce the squeezing of the substrate when the volume of the first heat sink expands, thereby preventing the substrate from cracking and ensuring the reliability of the circuit board assembly.

[0190] See also Fig.13 The distance between the second groove wall 5142e and the bearing surface 511b is a second distance d2, and the second distance d2 is greater than or equal to 0.1mm and less than or equal to 0.2mm. For example, the second distance d2 can be 0.1mm, 0.12mm, 0.13mm, 0.15mm, 0.16mm, 0.18mm, 0.19mm, 0.2mm, etc. In this way, by setting the second spacing d2 to be greater than or equal to 0.1 mm and less than or equal to 0.2 mm, on the one hand, the size of the second groove 5142 in the Z-axis direction (that is, the thickness direction of the circuit board assembly 51) can be guaranteed, which is beneficial to increase the contact area between the first heat sink 515 and the inner wall surface of the second groove 5142, and then help to increase the total contact area between the first heat sink 515 and the inner wall surface of the groove portion 514, which can improve the heat dissipation performance of the circuit board assembly 51; on the other hand, the distance between the second groove wall 5142e and the substrate 511 can be reduced, which facilitates the heat absorbed by the first heat sink 515 to be transferred outward through the substrate 511, thereby further improving the heat dissipation efficiency of the circuit board assembly 51 and ensuring the heat dissipation performance of the circuit board assembly 51.

[0191] It is understood that in other embodiments, please refer to Figure 14a-Figure 14c , Fig.14a A schematic diagram of the structure of a circuit board assembly 51 provided in some other embodiments of the present application, Fig.14b This is a schematic diagram of the structure of a circuit board assembly 51 provided in some other embodiments of the present application. Fig.14c Schematic diagram of the structure of the circuit board assembly 51 provided in some embodiments of the present application. Fig.14a As shown, the groove portion 514 may also include only the first groove 5141, but not the second groove 5142. Alternatively, as shown in FIG. Fig.14b As shown, the groove portion 514 may also include only the second groove 5142 without including the first groove 5141. Alternatively, as shown in FIG. Fig.14c As shown, the second groove 5142 may not be connected to the first groove 5141. In this way, the heat dissipation performance of the circuit board assembly 51 can also be improved.

[0192] On the basis of any of the above embodiments, in order to further reduce the overall volume of the circuit board assembly 51, please refer to Fig.10 , a first mounting groove 516 which is inwardly recessed is provided on the outer surface of the plastic sealing body 513. The first mounting groove 516 is used to accommodate the first sealing cover plate 517. The first mounting groove 516 includes a first groove bottom wall 5162, which is opposite to the notch 5161 of the first mounting groove 516, and the open end 514a of the groove portion 514 is formed on the first groove bottom wall 5162. In this embodiment, the first groove bottom wall 5162 constitutes part of the outer surface of the plastic sealing body 513. The open end 514a of the groove portion 514 is formed by a part of the first groove bottom wall 5162 which is recessed inwardly.

[0193] Please continue reading Fig.13 The first sealing cover plate 517 is fixed in the first mounting groove 516 and blocks the open end 514a of the groove portion 514. In this way, the overlapping dimension between the first sealing cover plate 517 and the plastic package body 513 can be reduced, which is beneficial to reducing the overall volume of the circuit board assembly 51 and realizing the miniaturized design of the circuit board assembly 51.

[0194] In some embodiments, see Fig.13 , the side surface of the first sealing cover plate 517 away from the groove portion 514 can be flush with the notch 5161 of the first mounting groove 516. In this way, the first sealing cover plate 517 can be prevented from protruding from the notch 5161 of the first mounting groove 516, which can further reduce the overall volume of the circuit board assembly 51 and improve the overall appearance of the circuit board assembly 51.

[0195] It is understandable that, in other embodiments, the surface of the first sealing cover plate 517 on one side facing away from the groove portion 514 may also be located on the side of the notch 5161 of the first installation groove 516 close to the groove portion 514. In this way, the first sealing cover plate 517 can also be prevented from protruding from the notch 5161 of the first installation groove 516, as long as the first sealing cover plate 517 is located in the first installation groove 516 as a whole.

[0196] For details, please refer to Fig.15 , Fig.15 for Figure 8The circuit board assembly 51 is shown in a top view after the first sealing cover plate 517 is removed. The first groove bottom wall 5162 includes a middle area 5162a and an edge area 5162b, and the edge area 5162b is located outside the middle area 5162a. Exemplarily, the edge area 5162b is arranged around the middle area 5162a, and the edge area 5162b is annular. The open end 514a of the groove portion 514 (including the open end of the first groove 5141 and the open end of the second groove 5142) is located in the middle area 5162a, and the first sealing cover plate 517 is fixedly connected to the edge area 5162b of the first groove bottom wall 5162.

[0197] See also Fig.16 , Fig.16 for Fig.13 The enlarged view of the section A in the cross-sectional view is shown in FIG. A connection area 517a is formed on the surface of the first sealing cover plate 517 facing the groove portion 514, and the first sealing cover plate 517 is fixedly connected to the edge area 5162b of the first groove bottom wall 5162 by means of the connection area 517a.

[0198] In some embodiments, please refer to Fig.16 , the connection area 517a can be fixedly connected to the edge area 5162b of the first groove bottom wall 5162 through the adhesive structure 518. The adhesive structure 518 can be an adhesive, a hot pressing adhesive, etc. On this basis, in order to improve the connection strength between the connection area 517a of the first sealing cover plate 517 and the edge area 5162b of the first groove bottom wall 5162, the surface roughness of the edge area 5162b is greater than or equal to 80μm. Exemplarily, the surface roughness of the edge area 5162b can be 80μm, 95μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, etc.

[0199] It is understandable that in other embodiments, the surface roughness of the connection area 517a may be set to be greater than or equal to 80 μm, or the surface roughness of the edge area 5162b and the surface roughness of the connection area 517a may be set to be greater than or equal to 80 μm. It is sufficient as long as the surface roughness of at least one of the edge area 5162b and the connection area 517a is greater than or equal to 80 μm.

[0200] Specifically, the edge area 5162b and / or the connection area 517a can be roughened (mechanical wear or chemical corrosion) by mechanical or chemical methods, thereby obtaining a microscopic rough structure on the edge area 5162b and / or the connection area 517a to increase the surface roughness of the edge area 5162b and / or the connection area 517a.

[0201] In this embodiment, after the heat generated by the first electronic component 512a is transferred to the first heat sink 515, at least a portion of the heat needs to be transferred to the outside of the plastic package 513 through the first sealing cover plate 517. In some embodiments, in order to ensure the heat dissipation performance of the circuit board assembly 51, the first sealing cover plate 517 can be made of a material with a high thermal conductivity. On this basis, in order to prevent the first sealing cover plate 517 from being corroded by the liquid metal 5152, the first sealing cover plate 517 can include a second anti-corrosion layer 5172, or the first sealing cover plate 517 can be made of a material with good anti-corrosion performance as a whole.

[0202] In some embodiments, see Fig.17 , Fig.17 for Fig.13 The schematic diagram of the structure of the first sealing cover plate 517 in the circuit board assembly 51 is shown. The first sealing cover plate 517 includes a cover plate body 5171 and a second anti-corrosion layer 5172. The cover plate body 5171 includes a first surface 5171a and a second surface 5171b opposite to each other. The first surface 5171a faces the open end 514a of the groove portion 514. The second anti-corrosion layer 5172 is disposed on at least a portion of the first surface 5171a.

[0203] In some embodiments, the cover body 5171 is a metal piece. For example, the cover body 5171 can be a copper plate, a stainless steel plate, a magnesium alloy plate, an aluminum alloy plate, etc. In this way, the first sealing cover plate 517 can have good thermal conductivity, and the heat absorbed by the first heat sink 515 can be quickly and efficiently transferred to the outside of the plastic package 513 through the first sealing cover plate 517.

[0204] In order to take into account the structural strength and space occupied by the cover body 5171, please refer to Fig.17 The thickness t11 of the cover body 5171 may be greater than or equal to 20 μm and less than or equal to 25 μm. For example, the thickness t11 of the cover body 5171 may be 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, etc.

[0205] The second anti-corrosion layer 5172 can protect the cover body 5171 and prevent the cover body 5171 from being corroded by the liquid metal 5152. The second anti-corrosion layer 5172 may include but is not limited to a graphene layer, a polymer material layer, etc. Among them, the graphene has a stable structure and a high thermal conductivity, which can ensure the anti-corrosion effect and thermal conductivity of the second anti-corrosion layer 5172. The second anti-corrosion layer 5172 can be formed on the cover body 5171 by chemical vapor deposition (CVD). Chemical vapor deposition is a process in which a gaseous or vaporous substance reacts in a gas phase or at a gas-solid interface to generate a solid deposit. The second anti-corrosion layer 5172 is formed on the surface of the cover body 5171 by chemical vapor deposition, and the connecting medium used to connect the cover body 5171 and the second anti-corrosion layer 5172 can be omitted. On the one hand, the second anti-corrosion layer 5172 can be in direct contact with the cover body 5171, which can improve the thermal conductivity between the second anti-corrosion layer 5172 and the cover body 5171; on the other hand, it is beneficial to reduce the overall thickness of the first sealing cover 517, thereby helping to reduce the overall volume of the circuit board assembly 51 and reducing the depth of the first mounting groove 516; on still another hand, it can improve the bonding strength between the second anti-corrosion layer 5172 and the cover body 5171 to prevent the second anti-corrosion layer 5172 from falling off the cover body 5171.

[0206] The “depth of the first installation groove 516 ” mentioned in the present application refers to the distance between the groove opening 5161 of the first installation groove 516 and the first groove bottom wall 5162 .

[0207] See also Fig.17 , the thickness t12 of the second anticorrosion layer 5172 can be greater than or equal to 20μm and less than or equal to 25μm. Exemplarily, the thickness t12 of the second anticorrosion layer 5172 can be 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, etc. In this way, the overall thickness of the first sealing cover plate 517 can be 40μm to 50μm. In this way, while ensuring the overall structural strength of the first sealing cover plate 517, the occupied space of the first sealing cover plate 517 can be reduced, which is conducive to reducing the overall volume of the circuit board assembly 51, and on the basis of avoiding the first sealing cover plate 517 protruding from the first mounting groove 516, the depth of the first mounting groove 516 can be reduced, which is conducive to reducing the processing difficulty of the circuit board assembly 51.

[0208] It is understood that in other embodiments, the first sealing cover plate 517 may not include the second anti-corrosion layer 5172, but only include the cover plate body 5171. In this case, the cover plate body 5171 may also be a metal part, or the cover plate body 5171 may be made of an anti-corrosion material. For example, the cover plate body 5171 is a graphene part. Fig.17 Combined with Fig.18 , Fig.18 for Fig.17 The first sealing cover plate 517 is shown as a bottom view from the second anti-corrosion layer 5172 to the cover plate body 5171. The cover plate body 5171 includes an edge portion 5171c (such as Fig.17 The edge portion 5171c is located outside the circumference of the second anti-corrosion layer 5172. Fig.18 , the orthographic projection of the second anti-corrosion layer 5172 on the plane where the cover body 5171 is located is located inside the edge portion 5171c of the cover body 5171. That is, the area of ​​the second anti-corrosion layer 5172 is smaller than the area of ​​the cover body 5171.

[0209] So, see Fig.16 The first sealing cover plate 517 can be fixedly connected to the outer surface of the plastic package body 513 by means of the edge portion 5171c of the cover plate body 5171, that is, the connection area 517a is formed on the side surface of the edge portion 5171c facing the groove portion 514. As a result, the first sealing cover plate 517 and the adhesive structure 518 are connected in the depth direction of the first installation groove 516 (for example, Fig.16 The overlapping dimension in the Z-axis direction) is equal to the sum of the thickness of the cover body 5171 and the thickness of the bonding structure 518, and there is no need to consider the thickness of the second anti-corrosion layer 5172, which is beneficial to reducing the depth of the first mounting groove 516.

[0210] The thickness of the cover body 5171 refers to the dimension of the cover body 5171 in the depth direction of the first mounting groove 516. Similarly, the thickness of the adhesive structure 518 refers to the dimension of the adhesive structure 518 in the depth direction of the first mounting groove 516, and the thickness of the second anti-corrosion layer 5172 refers to the dimension of the second anti-corrosion layer 5172 in the depth direction of the first mounting groove 516.

[0211] See also Figure 19-21 , Fig.19 For Figure 6 The circuit board assembly 51 in the illustrated embodiment is subjected to a heat transfer simulation test to obtain a temperature distribution diagram; Fig. 20 For Figure 8 The circuit board assembly 51 in the illustrated embodiment is subjected to a heat transfer simulation test to obtain a temperature distribution diagram;

[0212] Fig.21 for Figure 6 The maximum temperature in the temperature distribution diagram of the circuit board assembly 51 in the embodiment shown is Fig.18A schematic diagram showing the comparison of the highest temperature in the temperature distribution diagram of the circuit board assembly 51 in the illustrated embodiment. The dimensions of the circuit board assembly 51 for the heat transfer simulation test are: length 8.1 cm, width 3.4 cm, thickness 0.15 cm, and when the heat transfer simulation test is performed on the circuit board assembly 51 in different embodiments, the same heating coefficient is used.

[0213] Combination Fig.19 and Fig.21 It can be seen that Figure 6 The maximum temperature of the circuit board assembly 51 in the embodiment shown is 67.02°C. Fig. 20 and Fig.21 It can be seen that Figure 6 The maximum temperature of the circuit board assembly 51 in the embodiment shown is 64.53°C. Figure 6 The circuit board assembly 51 in the illustrated embodiment, Figure 8 The maximum temperature of the circuit board assembly 51 in the illustrated embodiment was reduced by 2.49°C. Figure 8 The heat dissipation performance of the circuit board assembly 51 in the illustrated embodiment is relatively Figure 6 The circuit board assembly 51 in the illustrated embodiment is improved by 3.71%.

[0214] In other embodiments, see Fig. 22 , Fig. 22 Schematic diagram of the structure of the circuit board assembly 51 provided in some other embodiments of the present application. Fig. 9 The difference between the circuit board assembly 51 in the illustrated embodiment is that the circuit board assembly 51 in the embodiment of the present application includes, in addition to the substrate 511, the plastic package 513, the groove portion 514, and the first heat sink 515, a through groove 519 and a second heat sink 520 disposed in the through groove 519. It should be noted that the through groove 519 and the second heat sink 520 in the present embodiment can be combined with the circuit board assembly 51 in any embodiment of the present application.

[0215] For details, please refer to Fig. 22The through slot 519 includes a first through hole 519a and a second through hole 519b. The first through hole 519a penetrates the connection surface 511a of the substrate 511 (that is, the side surface of the substrate 511 that is away from the bearing surface 511b), and the second through hole 519b penetrates the second slot wall surface 5142e. In this way, the circuit board assembly 51 can realize the communication between the groove portion 514 and the air outside the plastic package 513 by means of the through slot 519, so as to facilitate the thermal conduction connection between the first heat sink 515 and the second heat sink 520, so that the heat absorbed by the first heat sink 515 can be dissipated to the outside of the plastic package 513 through the second heat sink 520 in the through slot 519, and the heat generated by the first electronic component 512a can also be directly transferred to the second heat sink 520, and dissipated to the outside of the plastic package 513 through the second heat sink 520. In this way, the heat dissipation path of the circuit board assembly 51 can be increased, three-dimensional heat dissipation can be realized, and the heat dissipation efficiency of the circuit board assembly 51 can be further improved, thereby further improving the heat dissipation performance of the circuit board assembly 51.

[0216] See also Fig. 22 Combined with Fig.23 , Fig.23 for Fig. 22 Another structural schematic diagram of the circuit board assembly 51 is shown. In this embodiment, the second through hole 519b penetrates part of the second groove wall 5142e. On this basis, the through groove 519 is one or multiple spaced apart. In this way, the layout space occupied by the through groove 519 on the substrate 511 can be reduced while improving the heat dissipation performance of the circuit board assembly 51. Of course, it can be understood that in other embodiments, the second through hole 519b can also penetrate the entire second groove wall 5142e.

[0217] For further information, see Fig. 22 and Fig.23 , the through groove 519 is a cylindrical groove. The inner diameter D of the through groove 519 is greater than or equal to 0.5 mm and less than or equal to 1 mm. Exemplarily, the inner diameter of the through groove 519 is 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc. Of course, in other embodiments, the through groove 519 can also be formed in other shapes. For example, the through groove 519 can be rectangular, conical, etc. In this case, the size of the through groove 519 in the X-axis direction and / or the Y-axis direction can be 0.5 mm to 1 mm.

[0218] In some embodiments, the second heat sink 520 has the same shape and structure as the first heat sink 515. For example, in this embodiment, the second heat sink 520 and the first heat sink 515 are both liquid metal 5152. On this basis, in order to avoid leakage of the liquid metal 5152, please continue to refer to Fig. 22 and Fig.23The circuit board assembly 51 further includes a second sealing cover plate 521. The second sealing cover plate 521 is sealed and connected to the first through opening 519a of the through groove 519. Specifically, the second sealing cover plate 521 can be fixedly connected to the connecting surface 511a of the substrate 511. The structure of the second sealing cover plate 521 can be designed with reference to the structure of the first sealing cover plate 517, which will not be described in detail here.

[0219] On this basis, in order to reduce the space occupied by the second sealing cover plate 521, please refer to Fig.24 , Fig.24 Schematic diagram of the structure of the circuit board assembly 51 provided in some other embodiments of the present application. Fig. 22 The difference of the circuit board assembly 51 in the illustrated embodiment is that, in this embodiment, a second mounting groove 522 for accommodating the second sealing cover plate 521 is provided on the connecting surface 511 a of the substrate 511 .

[0220] It is understandable that in other embodiments, the shape and structure of the second heat sink 520 may also be different from that of the first heat sink 515. For details, please refer to Fig.25 , Fig.25 FIG. 5 is a schematic diagram of the structure of a circuit board assembly 51 provided in some embodiments of the present application. Fig. 22 The circuit board assembly 51 in the illustrated embodiment is different in that the second heat sink 520 in this embodiment is solid.

[0221] Exemplarily, the first heat sink 515 may be liquid metal 5152, and the second heat sink 520 may be solid. Specifically, the second heat sink 520 may be a solid metal part, a graphene part, etc. In this way, the heat dissipation path of the circuit board assembly 51 can be increased, and the heat dissipation efficiency of the circuit board assembly 51 can be further improved, thereby further improving the heat dissipation performance of the circuit board assembly 51.

[0222] On this basis, the second heat sink 520 can be sealed and connected to the second through hole 519b. In this way, the second through hole 519b can be sealed by the second heat sink 520 to prevent the liquid metal 5152 from leaking outward through the second through hole 519b, thereby eliminating the need to set the second sealing cover plate 521, and simplifying the structure of the circuit board assembly 51.

[0223] In some other embodiments, see Fig.26 , Fig.26A schematic diagram of the structure of a circuit board assembly 51 is provided for some other embodiments of the present application. The circuit board assembly 51 in this embodiment is different from the circuit board assembly 51 in any of the above embodiments in that the first heat sink 515 in this embodiment includes a tube body 5151 in addition to liquid heat-conducting materials such as liquid metal 5152. A sealed space for accommodating the liquid metal 5152 is defined in the tube body 5151, and the liquid metal 5152 is accommodated in the sealed space. In this way, during the assembly process, the first heat sink 515 including the tube body 5151 and the liquid metal 5152 can be directly assembled as a whole in the groove portion 514, which can reduce the difficulty of assembly and improve the assembly efficiency on the one hand, and can eliminate the first sealing cover plate 517 or simplify the structure of the first sealing cover plate 517 on the other hand, for example, there is no need to set the second anti-corrosion layer 5172 on the cover plate body 5171, which is conducive to reducing the cost of the circuit board assembly 51.

[0224] In some embodiments, in order to facilitate the flow of liquid metal 5152 in the tube body 5151, the surface roughness of the inner wall of the tube body 5151 is less than or equal to 10 μm. Exemplarily, the surface roughness of the inner wall of the tube body 5151 can be 10 μm, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, 0 μm, etc.

[0225] In order to reduce the surface roughness of the inner wall surface of the tube body 5151 and improve the smoothness of the inner wall surface of the tube body 5151, in some embodiments, a smooth layer is formed on the inner wall surface of the tube body 5151. The smooth layer can be formed on the inner wall surface of the tube body 5151 by processes such as sputtering, sandblasting, abrasive jet processing, liquid jet processing, fluid dynamic grinding, and chemical polishing. The process is simple and the processing is convenient.

[0226] In some embodiments, the volume V1 of the liquid metal 5152 at room temperature is smaller than the volume V3 of the tube 5151. In this way, the liquid metal 5152 can avoid increasing in volume and extruding the tube 5151 after absorbing heat, and can effectively avoid cracking of the tube 5151, which is conducive to improving the reliability of the first heat sink 515.

[0227] On this basis, in order to take into account both the heat dissipation performance and the reliability performance of the circuit board assembly 51, the ratio of the volume V1 of the liquid metal 5152 at room temperature to the volume V3 of the tube body 5151 is greater than or equal to 0.5 and less than 1. Exemplarily, the ratio of the volume V1 of the liquid metal 5152 at room temperature to the volume V3 of the tube body 5151 is 0.5, 0.55, 0.6, 065, 0.7, 0.8, 0.85, 0.88, 0.9, 0.95, 0.98, 0.99, etc.

[0228] For details, please refer to Fig.26 Combined with Figure 27-Figure 28 , Fig. 27 for Fig.26 The top view of the first heat sink 515 in the circuit board assembly 51 is shown. Fig.28 for Fig. 27 The cross-sectional view of the first heat sink 515 at the DD line is shown. In this embodiment, the first heat sink 515 includes a first tube body 5151a and a second tube body 5151b. Liquid heat-conducting materials such as liquid metal 5152 are provided in the first tube body 5151a and the second tube body 5151b. The first tube body 5151a is arranged in the first groove 5141, and the second tube body 5151b is arranged in the second groove 5142. The first tube body 5151a can be one or more. Among them, the shape of the first tube body 5151a can be adapted to the first groove 5141. The shape of the second tube body 5151b can be adapted to the second groove 5142.

[0229] Specifically, the first tube body 5151a is located at the side to which the first top surface 512a1 of the first electronic component 512a faces, and the second tube body 5151b is located outside the circumferential direction of the first electronic component 512a.

[0230] The orthographic projection of the first tube body 5151a on the bearing surface 511b overlaps with the orthographic projection of the first electronic component 512a on the bearing surface 511b. Specifically, the orthographic projection of the first tube body 5151a on the bearing surface 511b is a third projection, and the third projection overlaps with the first projection S1. In this way, at least a portion of the first tube body 5151a can be located directly above the first electronic component 512a, which can shorten the transfer path between the first electronic component 512a and the first tube body 5151a, which is beneficial to improving the heat conduction efficiency and reducing the heat loss, thereby effectively improving the heat dissipation efficiency of the circuit board assembly 51.

[0231] On this basis, in order to improve the heat conduction efficiency between the tube body 5151 and the inner wall surface of the groove portion 514, an interface thermal conductive material (not shown) is provided between the outer wall surface of the tube body 5151 and the inner wall surface of the groove portion 514. Among them, the interface thermal conductive material (thermal interface materials, TIM) is a material commonly used in IC packaging and electronic heat dissipation, mainly used to fill the micro gaps and uneven holes generated when two materials are joined or contacted, reduce heat transfer thermal resistance, and improve heat dissipation performance. The interface thermal conductive material can be a thermal conductive gel, a thermal conductive gasket, a thermal conductive film, etc. Exemplarily, the interface thermal conductive material can be an indium-based alloy thermal conductive gasket, a graphene thermal conductive film / gasket, a carbon fiber thermal conductive gasket, etc.

[0232] It is understandable that in other embodiments, the first heat dissipation element 515 may not include the first tube body 5151a or the second tube body 5151b.

[0233] Please continue reading Fig. 27 and Fig.28 In this embodiment, the second tube body 5151b is annular, and the first tube body 5151a is connected to the second tube body 5151b. In this way, the fluidity of the first heat sink 515 in the tube body 5151 can be improved, which is beneficial to improving the overall heat dissipation performance of the circuit board assembly 51.

[0234] In some embodiments, the first tube body 5151a is connected to the second tube body 5151b. Exemplarily, the first tube body 5151a and the second tube body 5151b are an integrated structure. In this way, the first heat sink 515 can be formed into an integral structure. During assembly, the first heat sink 515 is assembled in the groove portion 514 as an integral structural member, which can further reduce the assembly difficulty and improve the assembly efficiency.

[0235] In other embodiments, see Figure 29-Figure 30 , Fig.29 A top view of a first heat sink 515 provided in some other embodiments of the present application, Fig.30 for Fig.29 The cross-sectional view of the first heat sink 515 at line EE is shown. In addition to the first tube body 5151a and the second tube body 5151b, the first heat sink 515 in this embodiment also includes a first connecting tube 5151c and a second connecting tube 5151d. In some embodiments, the first tube body 5151a and the second tube body 5151b are both in the shape of long strips. The first connecting tube 5151c is used to connect two different first tube bodies 5151a, and the second connecting tube 5151d is used to connect the first tube body 5151a and the second tube body 5151b.

[0236] On this basis, a first connecting groove for accommodating the first connecting tube 5151c and a second connecting groove for accommodating the second connecting tube 5151d can be provided on the plastic package body 513. In this way, the fluidity of the liquid metal 5152 in the first tube body 5151a and the second tube body 5151b can also be improved, and the processing difficulty of the first tube body 5151a and the second tube body 5151b can be reduced.

[0237] Specifically, one or more first connecting tubes 5151c may be provided between two different first tube bodies 5151a. The two different first tube bodies 5151a and the first connecting tube 5151c connected between the two first tube bodies 5151a may be configured as an annular tube, an H-shaped tube, a U-shaped tube, etc. The two different first tube bodies 5151a and the first connecting tube 5151c connected between the two first tube bodies 5151a may be integrally formed, or the first tube body 5151a and the first connecting tube 5151c may be connected as one by bonding, welding, etc.

[0238] Similarly, the first tube body 5151a, the second tube body 5151b, and the second connecting tube 5151d connected between the first tube body 5151a and the second tube body 5151b can be configured as an annular tube, an H-shaped tube, a U-shaped tube, etc. The first tube body 5151a, the second tube body 5151b, and the second connecting tube 5151d connected between the first tube body 5151a and the second tube body 5151b can be integrally formed, or the first tube body 5151a, the second tube body 5151b, and the second connecting tube 5151d can be connected as a whole by bonding, welding, etc.

[0239] It is understandable that in other embodiments, the first heat sink 515 may not include the first connecting pipe 5151c or the second connecting pipe 5151d. Fig.31 , Fig.31 A top view of a first heat dissipation member 515 is provided for some other embodiments of the present application. In this embodiment, the first heat dissipation member 515 includes a first tube body 5151a and a first connecting tube 5151c for connecting two different first tube bodies 5151a. In this case, the first heat dissipation member 515 may include a second tube body 5151b, or may not include the second tube body 5151b.

[0240] For example, see Fig.32 , Fig.32 The top view of the first heat dissipation member 515 provided in some other embodiments of the present application. In this embodiment, the first heat dissipation member 515 includes a first tube body 5151a, a second tube body 5151b and a second connecting tube 5151d for connecting the first tube body 5151a and the second tube body 5151b.

[0241] On the basis of any of the above embodiments, in order to improve the overall heat dissipation performance of the first heat dissipation member 515 and at the same time improve the reliability of the tube body 5151, please refer to Fig.33 , Fig.33 The cross-sectional view of the tube body 5151 of the first heat sink 515 provided in some embodiments of the present application. It should be noted that the tube body 5151 in this embodiment can be used for the first heat sink 515 in any embodiment of the present application. The tube body 5151 can be the first tube body 5151a or the second tube body 5151b.

[0242] Specifically, the tube body 5151 includes a tube body 5151e and a first anti-corrosion layer 5151f. The tube body 5151e is a metal part. Exemplarily, the tube body 5151e can be a copper tube, a stainless steel tube, a magnesium alloy tube, an aluminum alloy tube, etc. In this way, the tube body 5151 can have good thermal conductivity.

[0243] See also Fig.33, the first anti-corrosion layer 5151f is disposed on the inner wall surface of the tube body 5151e. The first anti-corrosion layer 5151f can protect the tube body 5151e and prevent the tube body 5151e from being corroded by the liquid metal 5152. The first anti-corrosion layer 5151f can include but is not limited to a graphene coating, a polymer coating, etc. The first anti-corrosion layer 5151f can be formed on the inner wall surface of the tube body 5151e by chemical vapor deposition, or the first anti-corrosion layer 5151f can also be disposed on the inner wall surface of the tube body 5151e by coating, bonding, etc.

[0244] Please continue reading Fig.33 , the wall thickness of the tube body 5151 is t2. In some embodiments, the wall thickness t2 of the tube body 5151 is greater than or equal to 0.03 mm and less than or equal to 3 mm. Further, the wall thickness t2 of the tube body 5151 may be greater than or equal to 0.03 mm and less than or equal to 0.05 mm. Exemplarily, the wall thickness t2 of the tube body 5151 may be 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm. 1.8 mm, 2 mm, 2.5 mm, 3 mm, etc. In this way, the tube body 5151 can have a certain flexibility while ensuring the heat dissipation performance and structural strength of the tube body 5151. When the first heat dissipating member 515 is assembled into the groove portion 514, the tube body 5151 can be deformed to adapt to the shape of the inner wall surface of the groove portion 514. Therefore, on the one hand, the difficulty of assembling the first heat dissipating member 515 can be reduced, and on the other hand, the degree of fit between the outer wall surface of the tube body 5151 and the inner wall surface of the groove portion 514 can be improved, thereby increasing the contact area between the outer wall surface of the tube body 5151 and the inner wall surface of the groove portion 514, and further improving the heat dissipation performance of the circuit board assembly 51.

[0245] In some other embodiments, see Fig.34 , Fig.34 The cross-sectional view of the tube body 5151 of the first heat sink 515 provided in some other embodiments of the present application. Fig.33 The difference of the first heat sink 515 shown is that, in this embodiment, the tube body 5151 of the first heat sink 515 includes a tube body 5151e, and the tube body 5151e is a plastic part. On this basis, in order to ensure the heat dissipation performance of the first heat sink 515, a heat conductive layer 5151g is provided on the outer wall surface of the tube body 5151e. The heat conductive layer 5151g includes but is not limited to an electroplated metal layer. It can be understood that the tube body 5151 in this embodiment can also be used for the first heat sink 515 in any embodiment of the present application.

[0246] exist Fig.33 and Fig.34 In the illustrated embodiment, the cross-sectional shape of the tube body 5151 is a rectangle. It is understood that in other embodiments, the cross-sectional shape of the tube body 5151 can also be other shapes. For example, see Fig.35 , Fig.35 1 is a cross-sectional view of a tube body 5151 of a first heat sink 515 provided in some other embodiments of the present application. Fig.35 As shown in (a) of FIG. 5 , the cross-sectional shape of the tube body 5151 may also be circular. Fig.35 As shown in (b) of FIG. 5 , the cross-sectional shape of the tube body 5151 may also be an ellipse. Fig.35 As shown in (c) in FIG. 5 , the cross-sectional shape of the tube body 5151 can also be a racetrack shape. The cross-sectional shape of the tube body 5151 refers to the cross-sectional shape obtained by cutting the tube body 5151 with a plane perpendicular to the central axis of the tube body 5151 .

[0247] Please continue reading Fig.35 In (a) and (b), the tube body 5151 can be formed into a structure with uniform wall thickness, that is, the wall thickness of the tube body 5151 is the same everywhere. Fig.35 In (c), the tube body 5151 may also be formed into a structure with unequal wall thicknesses, that is, the wall thicknesses at different positions of the tube body 5151 may be unequal.

[0248] In any of the above-mentioned embodiments in which the first heat sink 515 includes a tube body 5151 and liquid metal 5152 filled in the tube body 5151 , the first heat sink 515 can also be fixed on the substrate 511 before the plastic package 513 is formed on the supporting surface 511 b of the substrate 511 .

[0249] See also Fig.36 , Fig.36 Schematic diagram of the structure of the circuit board assembly 51 provided in some embodiments of the present application. The circuit board assembly 51 in the embodiment of the present application and Fig.26 The embodiment shown differs in that Fig.26 The first heat sink 515 in the illustrated embodiment is assembled in the groove 514 on the plastic package 513. That is, Fig.26 The first heat sink 515 in the illustrated embodiment is formed after the plastic package 513 is formed on the bearing surface 511b, a groove portion 514 is opened on the plastic package 513, and the first heat sink 515 is assembled in the groove portion 514. The first heat sink 515 in this embodiment is fixed on the bearing surface 511b of the substrate 511. That is, the first heat sink 515 in this embodiment is fixed on the substrate 511 before the plastic package 513 is formed on the bearing surface 511b.

[0250] In this way, after the plastic package 513 is formed, the plastic package 513 can be wrapped around at least a portion of the outer surface of the first heat sink 515. Therefore, the circuit board assembly 51 in this embodiment does not need to have a groove 514 for accommodating the first heat sink 515 on the plastic package 513, which can simplify the processing technology of the circuit assembly and reduce costs.

[0251] See also Fig.36 The first heat sink 515 is directly fixedly connected to the support surface 5232a by means of the tube 5151. In some embodiments, the tube 5151 of the first heat sink 515 can be connected to the bearing surface 511b by bonding, welding, clamping, etc.

[0252] On this basis, in order to reduce the difficulty of connecting the tube body 5151 of the first heat dissipation member 515 with the support surface 5232a, please continue to refer to Fig.36 , a positioning groove 511c is provided on the bearing surface 511b, and at least a portion of the tube body 5151 is accommodated in the positioning groove 511c. The positioning groove 511c can be formed by the bearing surface 511b being recessed in a direction away from the electronic component 512. Alternatively, in other embodiments, the positioning groove 511c can also be defined by a positioning structure protruding from the bearing surface 511b. Of course, in other embodiments, the above-mentioned positioning groove 511c may not be provided.

[0253] Specifically, in this embodiment, the first heat sink 515 can be fixed on the substrate 511 by means of the second tube 5151b. Since the first tube 5151a and the second tube 5151b are connected in this embodiment, the first heat sink 515 can be fixed as a whole by means of the second tube 5151b, and the heat dissipation performance of the circuit board assembly 51 can be ensured while ensuring the difficulty of assembling the first heat sink 515 and the substrate 511.

[0254] It can be understood that in other embodiments, when the first tube body 5151a and the second tube body 5151b are split structures, that is, when the second tube body 5151b is not connected to the first tube body 5151a, the first tube body 5151a can be fixed on the substrate 511 with the aid of other fixing structures (such as the support seat 5230 mentioned below, etc.), or the first tube body 5151a can also be fixed in the groove portion 514 mentioned above.

[0255] In some embodiments, in order to facilitate the heat absorbed by the first heat sink 515 to be dissipated outward, the plastic package 513 wraps a portion of the surface of the first heat sink 515. In this case, a portion of the surface of the first heat sink 515 can be exposed outside the plastic package 513. In this way, the heat dissipation efficiency of the circuit board assembly 51 can be improved, and the heat dissipation performance of the circuit board assembly 51 can be improved.

[0256] It can be understood that the manner in which the first heat sink 515 is connected to the substrate 511 in this embodiment can be combined with the circuit board assembly 51 in any embodiment of the present application.

[0257] In some other embodiments, see Figure 37-Figure 38 , Fig.37 This is a schematic diagram of the structure of a circuit board assembly 51 provided in some other embodiments of the present application. Fig.38 for Fig.37 Another schematic diagram of the structure of the circuit board assembly 51 is shown. The circuit board assembly 51 in this embodiment is Fig.36 The difference of the circuit board assembly 51 in the illustrated embodiment is that the circuit board assembly 51 in this embodiment includes a support seat 5230 in addition to the substrate 511, the electronic component 512, the plastic package 513, and the first heat sink 515. The support seat 5230 is fixedly connected to the bearing surface 511b, and the first heat sink 515 is arranged on the support seat 5230. In this way, the first heat sink 515 can be fixed to the substrate 511 through the support seat 5230, which has a simple structure, convenient assembly and low processing cost.

[0258] In some embodiments, the support base 5230 can be connected to the bearing surface 511b by bonding, welding, clamping, etc. The first heat sink 515 and the support base 5230 can be connected by bonding, welding, clamping, etc.

[0259] See also Figure 37-Figure 38 The support seat 5230 includes a bottom plate 5231 and support legs 5232. The bottom plate 5231 is fixedly connected to the bearing surface 511b, and the support legs 5232 are fixedly connected to the bottom plate 5231. There may be one or more support legs 5232. For example, the support seat 5230 may be U-shaped.

[0260] In some embodiments, the support base 5230 is an integrally formed part, that is, the bottom plate 5231 and the support legs 5232 are an integral structure, so that the processing technology of the support base 5230 can be simplified and the cost can be reduced.

[0261] Of course, in other embodiments, the support base 5230 may not include the bottom plate 5231 . In this case, the support legs 5232 may be directly fixed on the supporting surface 511 b of the base plate 511 .

[0262] The first heat sink 515 is supported on the support legs 5232. Specifically, the support base 5230 can be used to support at least one of the first tube body 5151a and the second tube body 5151b. The support base 5230 used to support the first tube body 5151a and the support base 5230 used to support the second tube body 5151b can be the same support base 5230 or different support bases 5230.

[0263] See also Fig.37 and Fig.38 The end surface of the support foot 5232 facing away from the substrate 511 is formed as a support surface 5232a, and the shape of the support surface 5232a is adapted to the shape of the outer wall surface of the tube body 5151. In this way, the support surface 5232a can be fitted with the outer wall surface of the tube body 5151, which can improve the connection reliability between the first heat sink 515 and the support seat 5230. Fig.35 In the example shown, the support surface 5232a and the outer wall surface of the tube body 5151 are both formed as planes.

[0264] In other embodiments, see Fig.39 , Fig.39 Schematic diagram of assembly of the first heat sink 515 and the support seat 5230 provided in some other embodiments of the present application. In this embodiment, the support surface 5232a and the outer wall surface of the tube body 5151 are both formed as arc surfaces.

[0265] Based on any of the above embodiments, please refer to Fig.40 , Fig.40 A schematic diagram of the structure of a circuit board assembly 51 is provided for other embodiments of the present application. In addition to a substrate 511, an electronic component 512, a plastic package 513, and a first heat sink 515, the circuit board assembly 51 in this embodiment also includes a first sealing cover plate 517 in any of the above embodiments, and the first sealing cover plate 517 is connected to the tube body 5151 of the first heat sink 515.

[0266] When the circuit board assembly 51 including the above circuit board assembly 51 is applied to the electronic device 100, in order to improve the overall heat dissipation performance of the electronic device 100, please refer to Fig.41 , Fig.41 A partial schematic diagram of an electronic device 100 provided in some embodiments of the present application. The electronic device 100 also includes a first interface thermal conductive material 61 and a second interface thermal conductive material 62. The first interface thermal conductive material 61 is disposed between the battery protection plate 502 and the back cover 13, and the second interface thermal conductive material 62 is disposed between the battery protection plate 502 and the middle plate 14. For details, please refer to Fig.41 The second interface thermal conductive material 62 can be disposed between the waterproof insulating wrapping layer 503 of the battery protection plate 502 and the middle plate 14, and the first interface thermal conductive material 61 can be disposed between the flexible circuit board 52 and the back cover 13. The first interface thermal conductive material 61 and the second interface thermal conductive material 62 can be indium-based alloy thermal conductive pads, graphene thermal conductive films / pads, carbon fiber thermal conductive pads, etc.

[0267] Therefore, the heat generated by the electronic component 512 can be transferred outward through different heat dissipation paths, which can achieve three-dimensional heat dissipation, and is beneficial to improving the heat dissipation performance of the circuit board assembly 51, the battery protection board 502, and the electronic device 100.

[0268] See also Fig.42 , Fig.42 for Fig. 22 The circuit board assembly 51 is shown as a schematic diagram of a partial structure of an electronic device 100. The heat generated by the electronic component 512 can be transferred outward through the following heat dissipation path 1 and heat dissipation path 2: Heat dissipation path 1: heat generated by the electronic component 512 → plastic package 513 → first heat sink 515 → first sealing cover plate 517 → second interface thermal conductive material 62 → middle plate 14 → air; Heat dissipation path 2: heat generated by the electronic component 512 → substrate 511 → second sealing cover plate 521 → flexible circuit board 52 → first interface thermal conductive material 61 → back cover 13 → air. In this way, three-dimensional heat dissipation can be achieved, which is beneficial to improving the heat dissipation performance of the circuit board assembly 51, the battery protection board 502, and the electronic device 100.

[0269] It can be understood that, in other embodiments, the electronic device 100 may also include only one of the first interface thermal conductive material 61 and the second interface thermal conductive material 62 .

[0270] On the basis of any of the above embodiments, in order to further improve the heat dissipation performance of the electronic device 100, please continue to refer to Fig.41 The inner gap of the space enclosed by the waterproof insulating wrapping layer 503 is filled with the third interface thermal conductive material 63 .

[0271] In some embodiments, see Fig.42 A fourth interface thermal conductive material 64 may be disposed between the flexible circuit board 52 and the substrate 511. Thus, the heat dissipation performance of the electronic device 100 may be further improved.

[0272] The electronic device 100 in the embodiment of the present application can fully utilize the internal space of the plastic package 513 by disposing the first heat sink 515 in the plastic package 513, reduce the overlapping size of the first heat sink 515 and the plastic package 513, and help reduce the overall volume of the circuit board assembly 51, thereby achieving a miniaturized design of the circuit board assembly 51 while ensuring the heat dissipation performance of the circuit board assembly 51.

[0273] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0274] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A circuit board assembly, characterized in that: include: A substrate, the substrate comprising a bearing surface; A first electronic component, the first electronic component is disposed on the carrying surface; A first heat sink, the first heat sink is disposed on the bearing surface, the first heat sink comprises a tube body and liquid metal, and the liquid metal is disposed in the tube body; A plastic package body is packaged on the bearing surface, and the plastic package body wraps the first electronic component and at least a portion of the first heat sink.

2. The circuit board assembly according to claim 1, characterized in that: A support seat is provided on the bearing surface, and the first heat sink is supported on the support seat.

3. The circuit board assembly according to claim 1 or 2, characterized in that: The first electronic component includes a first top surface, the orientation of the first top surface is the same as the orientation of the bearing surface, the tube body includes a first tube body, and the first tube body is located on the side facing the first top surface; the orthographic projection of the first electronic component on the bearing surface overlaps with the orthographic projection of the first tube body on the bearing surface.

4. The circuit board assembly according to any one of claims 1 to 3, characterized in that: The tube body includes a second tube body, and the second tube body is located outside the circumference of the first electronic component.

5. The circuit board assembly according to any one of claims 1 to 4, characterized in that: The first electronic component comprises a first top surface, and the orientation of the first top surface is the same as the orientation of the bearing surface; The tube body comprises a first tube body and a second tube body, the first tube body is located on the side to which the first top surface faces, and the orthographic projection of the first electronic component on the carrying surface is that the first projection overlaps with the orthographic projection of the first tube body on the carrying surface; The second tube body is located outside the circumference of the first electronic component, and the second tube body is connected to the first tube body.

6. The circuit board assembly according to any one of claims 1 to 5, characterized in that: The tube body comprises: A tube body, wherein the tube body is a metal part; A first anti-corrosion layer is covered on the inner wall surface of the pipe body.

7. The circuit board assembly according to any one of claims 1 to 5, characterized in that: The tube body comprises: A tube body, wherein the tube body is a plastic part; A heat-conducting layer is covered on the outer wall surface of the tube body.

8. A battery protection board, characterized in that: include: A circuit board assembly, wherein the circuit board assembly is the circuit board assembly according to any one of claims 1 to 7; A flexible circuit board is electrically connected to the substrate.

9. An electronic device, characterized in that: include: shell; A battery, wherein the battery is arranged in the housing, and the battery comprises the battery protection plate as claimed in claim 8.

10. The electronic device according to claim 9, characterized in that: The housing comprises a back cover, the back cover is located on one side of the battery, and a first interface thermal conductive material is arranged between the battery protection plate and the back cover; and / or The electronic device comprises a middle plate, the middle plate is arranged in the housing, the battery is arranged on the middle plate, and a second interface heat conductive material is arranged between the battery protection plate and the middle plate.

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