Circuit board assembly and electronic equipment

Abstract

The embodiment of the utility model provides a circuit board assembly and electronic equipment. The circuit board assembly comprises a circuit board, a first shielding body, a first heating body and a first heat-conducting colloid, the first shielding body comprises a hollow copper column located on one side of the circuit board and a first shielding layer connected with the side, opposite to the circuit board, of the hollow copper column, and a first shielding cavity is defined by the hollow copper column and the first shielding layer; the first heating body is located on one side of the circuit board and located in the first shielding cavity. The first heat-conducting colloid is in heat-conducting contact with the first heating body and the first shielding body. According to the technical scheme of the embodiment of the invention, the electromagnetic compatibility and heat dissipation performance requirements of the circuit board assembly can be considered, so that the working performance of the circuit board assembly and the electronic equipment can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of electronic devices, and in particular to a circuit board assembly and an electronic device. Background Art

[0002] In electronic devices, printed circuit board assembly (PCBA) is a very important component, which usually carries the main functions of the electronic equipment, and its performance is the key to determining the performance of the electronic equipment.

[0003] How to balance the electromagnetic compatibility (EMC) and heat dissipation performance requirements of circuit board components is a major topic of research and development for those skilled in the art. Utility Model Content

[0004] The embodiments of the present application provide a circuit board assembly and an electronic device to take into account both the electromagnetic compatibility and heat dissipation performance requirements of the circuit board assembly.

[0005] According to one aspect of an embodiment of the present application, a circuit board assembly is provided, which includes a circuit board, a first shielding body, a first heating element and a first thermally conductive colloid, wherein: the first shielding body includes a hollow copper column located on one side of the circuit board, and a first shielding layer connected to the side of the hollow copper column facing away from the circuit board, the hollow copper column and the first shielding layer form a first shielding cavity; the first heating element is located on one side of the circuit board and in the first shielding cavity; the first thermally conductive colloid is in thermal contact with the first heating element and the first shielding body, respectively.

[0006] In an embodiment of the present application, the first heating element may include one or more electronic components, which are located in the first shielding cavity, so as to meet the electromagnetic compatibility design requirements. The main material of the hollow copper column is metallic copper, which has a high thermal conductivity. Therefore, heat can be quickly transferred between the circuit board and the first shielding layer, and can be quickly transferred to the external environment. Therefore, compared with the related technology, the heat dissipation performance of the circuit board assembly is improved. Therefore, the design of the circuit board assembly in the embodiment of the present application can take into account the electromagnetic compatibility and heat dissipation performance requirements of the circuit board assembly.

[0007] In some embodiments, the surface of the structure of the hollow copper column has a coating, the magnetic permeability of the coating is not greater than 1.06, and the surface impedance of the coating is not greater than 0.1 ohm. Selecting appropriate coating materials and coating thickness can effectively reduce the surface impedance of the hollow copper column and improve its oxidation resistance, thereby improving the shielding effect of the first shielding body.

[0008] In some embodiments, the coating includes at least one of a tin coating and a nickel coating, wherein the thickness of the tin coating ranges from 2 microns to 8 microns, and the thickness of the nickel coating ranges from 2 microns to 7.6 microns. The tin coating can effectively improve the corrosion resistance, conductivity and solderability of the hollow copper column, and the nickel coating can effectively improve the corrosion resistance, wear resistance, solderability of the hollow copper column, and increase the surface hardness. On the surface of the hollow copper column, the tin coating and the nickel coating can be selectively set or combined, and the thickness of each layer can be designed according to the magnetic permeability and impedance design requirements.

[0009] In some embodiments, the hollow copper column includes a supporting wall portion and a connecting portion, wherein the supporting wall portion is supported between the circuit board and the first shielding layer, and the connecting portion is connected to a side of the first shielding layer facing the circuit board. The connecting portion can increase the bonding area and heat conduction area of ​​the hollow copper column and the first shielding layer, so that the two are more reliably connected together and heat transfer is performed.

[0010] In some embodiments, the thickness of the supporting wall is not greater than 2 mm, so that not only can less area of ​​the circuit board be occupied, the layout of electronic components on the circuit board is less affected, but also the thinner wall thickness is more conducive to heat transfer to the outside.

[0011] In some embodiments, the hollow copper column is a hot-cast hollow copper column. The basic structure of the hollow copper column can be formed by a copper hot casting process. Copper hot casting has the advantages of high molding accuracy, high strength, good surface quality, good corrosion resistance, long life and easy subsequent processing.

[0012] In some embodiments, the circuit board assembly also includes: a second shielding body, including a shielding frame located on the other side of the circuit board, and a second shielding layer connected to the side of the shielding frame facing away from the circuit board, wherein the shielding frame and the second shielding layer form a second shielding cavity; a second heating element located on the other side of the circuit board and within the second shielding cavity; and a second thermally conductive colloid in thermal contact with the second heating element and the second shielding body, respectively.

[0013] In these embodiments, the heat generated by the heating elements on both sides of the circuit board assembly and the heat of the circuit board can be dissipated outward through the first shielding body and the second shielding body. In particular, the design of the hollow copper column helps to accelerate the heat dissipation effect. Therefore, the design of the circuit board assembly can take into account both the electromagnetic compatibility design requirements and the heat dissipation performance requirements.

[0014] In some embodiments, the shielding frame is a copper alloy shielding frame; or, the shielding frame is a copper shielding frame, the structural surface of the copper shielding frame has a coating, the magnetic permeability of the coating is not greater than 1.06, and the surface impedance of the coating is not greater than 0.1 ohms. On the other side of the circuit board, the material of the shielding frame can be flexibly selected according to the layout and heat dissipation requirements of the electronic components. For example, when the second heating element has a higher heat dissipation requirement, the shielding frame can adopt a copper shielding frame, which is mainly made of metallic copper material, and the structural surface is provided with a coating for improving surface impedance and enhancing oxidation resistance; when the layout space of the second heating element is relatively tight, the shielding frame can adopt a nickel silver shielding frame with better machining performance, so as to minimize the wall thickness and reduce the area occupied on the circuit board.

[0015] In some embodiments, the circuit board assembly further includes: a first heat dissipation component in thermal contact with a side of the first shielding layer facing away from the circuit board; and a second heat dissipation component in thermal contact with a side of the second shielding layer facing away from the circuit board. The first heat dissipation component and the second heat dissipation component can accelerate the heat dissipation of the circuit board assembly, thereby further improving the heat dissipation effect of the circuit board assembly.

[0016] In some embodiments, the first heat dissipation component includes at least one of a planar heat pipe and a graphite heat dissipation layer; the second heat dissipation component includes at least one of a planar heat pipe and a graphite heat dissipation layer. The graphite heat dissipation layer has a sheet-like structure, which has a unique grain orientation and can conduct heat evenly in two directions. Moreover, the sheet-like structure can adapt well to the fitting surface, so that the heat of the shielding layer can be more efficiently dissipated to the surrounding environment. Compared with ordinary heat pipes, planar heat pipes can conduct heat in a two-dimensional plane, so the heat dissipation efficiency is higher. In addition, the working state of the planar heat pipe is not affected by gravity, so it can be applied to more application scenarios.

[0017] In some embodiments, the first heating element includes a circuit matching element, and the second heating element includes a processing chip and a memory chip. The processing chip and the memory chip are centrally arranged on one side of the circuit board, and the circuit matching element is centrally arranged on the other side of the circuit board, which is conducive to reducing the overall thickness of the circuit board assembly.

[0018] In some embodiments, the processing chip and the memory chip are sequentially arranged in a direction away from the circuit board and stacked on each other. The processing chip and the memory chip are compactly arranged, which not only occupies less area of ​​the circuit board, but also simplifies the wiring design of the circuit board.

[0019] According to one aspect of the embodiments of the present application, an electronic device is provided, which includes a circuit board assembly according to any of the above embodiments. Since the circuit board assembly can meet the electromagnetic compatibility design requirements and has good heat dissipation performance, the performance of the electronic device is also improved.

[0020] In some embodiments, the electronic device can work in a boost heavy load mode. The electronic device in this embodiment can not only meet the electromagnetic compatibility design requirements, but also has better heat dissipation performance. When it works in the boost heavy load mode, the battery life is longer and the performance is better, thereby providing users with a better use experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a cross-sectional structure of a circuit board assembly according to some embodiments of the present application;

[0022] Figure 2 Schematic diagram to assist understanding of the basic principles of electromagnetic shielding;

[0023] Figure 3 A schematic diagram of a cross-sectional structure of a circuit board assembly according to some embodiments of the present application;

[0024] Figure 4 A schematic diagram of a cross-sectional structure of a circuit board assembly according to some embodiments of the present application;

[0025] Figure 5 Schematic diagram of the cross-sectional structure of an electronic device according to some embodiments of the present application.

[0026] Reference numerals:

[0027] 100-circuit board assembly; 10-circuit board; 20-first shielding body; 21-hollow copper column; 210-supporting wall; 211-connecting part;

[0028] 22-first shielding layer; 212-first shielding cavity; 23-first heating element; 24-first heat-conducting colloid; 25-first heat dissipation component;

[0029] 30 - second shielding body; 31 - shielding frame; 32 - second shielding layer; 312 - second shielding cavity; 33 - second heating element; 34 - second heat-conducting colloid;

[0030] 35-second heat dissipation component; 41-processing chip; 42-storage chip; 80-shielding body; 310-electronic components; 311-circuit matching element;

[0031] 500-electronic equipment; 200-display screen; 300-back cover. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0033] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be limiting of the present application. As used in the specification and appended claims of the present application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context.

[0034] References to "one embodiment" or "a specific embodiment" in this specification mean that one or more embodiments of the present application include a particular feature, structure or characteristic described in conjunction with the embodiment. The terms "include", "comprises", "has" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0035] In the electronics industry, circuit boards, such as printed circuit boards (PCBs), are mainly used for electrical connections between electronic components. Circuit boards are usually designed with structures such as traces, holes, and pads, which can make the connection between electronic components simple and convenient.

[0036] Printed Circuit Board Assembly (PCBA) generally refers to an assembly product formed by fixing electronic components on a circuit board by welding or plugging. The circuit board assembly usually carries the main functions of the electronic equipment, and its electromagnetic compatibility and heat dissipation performance are the main aspects that affect the working performance of the electronic equipment. Electromagnetic compatibility can be understood as the ability of a device or system to operate in accordance with the requirements in its electromagnetic environment and not to cause intolerable electromagnetic interference to any device in its environment.

[0037] Some electronic devices in the related technology, such as mobile phones or tablets, can work in boost heavy load mode. Boost heavy load mode is a heavy load working mode that can improve the system's operating performance and provide users with a faster and smoother user experience, but it will also increase system power consumption and cause the system temperature to rise. When designing such electronic devices, it is necessary to consider the electromagnetic compatibility and heat dissipation performance of the circuit board components. Among them, heat dissipation performance is the key to affecting the battery life of electronic devices in boost heavy load mode.

[0038] In some related technologies, the circuit board assembly is designed with a shielding frame of nickel silver and a shielding cover of stainless steel, wherein nickel silver, also known as zinc nickel silver, is an alloy composed of copper, nickel, zinc and other elements, and the thermal conductivity of nickel silver is about 120 W / (m·K), and stainless steel is steel with stainless and corrosion-resistant as the main characteristics, and the chromium content is at least 10.5%, and the carbon content is not more than 1.2%. For example, electronic components such as SOC (system on a chip) and DDR (double data rate synchronous dynamic random access memory) are fixed on the circuit board and are located in the shielding cavity surrounded by the above-mentioned shielding frame and shielding cover, so that the circuit board assembly can meet the electromagnetic compatibility design requirements, and the heat generated by SOC and DDR can be conducted outward through the shielding frame and shielding cover.

[0039] However, when SOC and DDR are in a high power consumption and high heat generation state, for example, when the electronic device is working in boost overload mode, the circuit board components of the above-mentioned related technologies cannot dissipate the heat in time, which not only restricts the battery life and working performance of the electronic device, but also affects the service life of the circuit board components.

[0040] In view of this, the embodiment of the present application provides a circuit board assembly and an electronic device to take into account the electromagnetic compatibility and heat dissipation performance requirements of the circuit board assembly. The embodiment of the present application will be described in detail below in conjunction with the accompanying drawings.

[0041] The circuit board assembly of the embodiment of the present application can be applied to electronic devices in various fields such as electrical, electronic, and communication. The specific product type of the electronic device is not limited, for example, it can be various electronic products that contain circuit board assemblies, such as mobile phones, tablet computers, laptops, smart wearable devices, car computers, medical electronic equipment, servers, routers, switches, etc.

[0042] According to some embodiments of the present application, a circuit board assembly is provided.

[0043] like Figure 1As shown, it is a schematic diagram of the cross-sectional structure of a circuit board assembly 100 of some embodiments of the present application. The circuit board assembly 100 includes a circuit board 10, a first shielding body 20, a first heating element 23 and a first thermally conductive colloid 24. The first shielding body 20 includes a hollow copper column 21 located on one side of the circuit board 10 (side A as shown in the figure), and a first shielding layer 22 connected to the side of the hollow copper column 21 facing away from the circuit board 10, wherein the hollow copper column 21 and the first shielding layer 22 enclose a first shielding cavity 212. The first heating element 23 is located on one side of the circuit board 10 (side A as shown in the figure) and is located in the first shielding cavity 212. The first thermally conductive colloid 24 is in thermal contact with the first heating element 23 and the first shielding body 20, respectively.

[0044] In the embodiment of the present application, the circuit board 10 may be a printed circuit board (PCB) or a flexible printed circuit board (FPC), which is not specifically limited in the embodiment of the present application. The first heating element 23 is disposed on one side of the circuit board 10 and may include one or more electronic components 310. The specific type of the electronic component 310 is not limited, for example, it may be a processing chip 41, a storage chip 42, or a circuit matching element (in Figure 1 Not shown in the figure) etc.

[0045] The specific type of the processing chip 41 is not limited, and may be, for example, a SOC, a CPU (central processing unit), or a GPU (graphics processing unit).

[0046] The specific type of the above-mentioned storage chip 42 is not limited, for example, it can be DDR, RAM (random access memory), SRAM (static random access memory), or DRAM (dynamic random access memory).

[0047] The specific type of the circuit matching element is not limited, for example, it can be a capacitor, a resistor, or an inductor, etc. The circuit matching element is usually used to achieve circuit matching and improve the performance and reliability of the circuit.

[0048] like Figure 1 As shown, the first heating element 23 including the electronic components 310 is located in the first shielding cavity 212, so that the electromagnetic compatibility design requirements can be met during operation.

[0049] refer to Figure 2As shown, the essence of shielding is to constrain the current to the inner and outer surfaces of the shielding body 80 by the skin effect, thereby isolating the interference source and the sensitive source. The shielding effectiveness is mainly determined by the ratio of the thickness of the shielding body 80 to the skin depth, where the skin depth can be expressed as:

[0050]

[0051] Among them, δ is the skin depth, the unit is, for example, meter; ρ is the resistivity, the unit is, for example, ohm·meter; ω is the angular frequency, the unit is, for example, radian / second; μ is the magnetic permeability, the unit is, for example, Henry / meter.

[0052] Under the premise that the thickness of the shielding body 80 is constant, the smaller the skin depth δ is, the higher the shielding effectiveness is. Therefore, the skin depth δ can be reduced by increasing the magnetic permeability μ of the shielding body 80 and / or reducing the resistivity ρ of the shielding body 80 .

[0053] In some embodiments of the present application, the main material of the hollow copper column 21 is metallic copper, and the copper content is generally 99.5-99.95%. According to the electromagnetic compatibility design requirements of the circuit board assembly 100, the structural surface of the hollow copper column 21 can also be provided with a coating or not provided with a coating. The thermal conductivity of metallic copper is 386.4 watts / (meter·K), which is higher than the thermal conductivity of nickel silver alloy material 120 watts / (meter·K). Therefore, the hollow copper column 21 using metallic copper has better thermal conductivity than using nickel silver. The main difference between metals and alloys is that metals are single-substance raw materials with higher purity, while alloys are mixed with two or more metal elements and other non-metallic elements.

[0054] In some embodiments of the present application, the first shielding layer 22 can be a copper shielding layer (the main material is metallic copper), an aluminum shielding layer (the main material is metallic aluminum) or a stainless steel shielding layer (the main material is stainless steel). The material and thickness of the first shielding layer 22 can be selected and designed according to the electromagnetic compatibility design requirements and heat dissipation requirements of the circuit board assembly 100.

[0055] Return to reference Figure 1 As shown, since the first heating element 23 generates heat when working, it is necessary to conduct the heat away in time through the heat dissipation structure. The first heat-conducting colloid 24 and the first shielding body 20 can serve as at least a part of the heat dissipation structure of the circuit board assembly 100. As shown in the direction of the dotted arrow in the figure, the heat generated by the first heating element 23 can be transferred to the first shielding body 20 through the first heat-conducting colloid 24, and then transferred to the external environment or the external heat dissipation structure by the first shielding body 20. In addition, the heat of the circuit board 10 can also be directly or indirectly transferred to the first shielding body 20, and then transferred to the external environment or the external heat dissipation structure through the first shielding body 20.

[0056] The main material of the hollow copper column 21 is metallic copper, which has a high thermal conductivity. It can quickly transfer heat between the circuit board 10 and the first shielding layer 22, and can quickly transfer heat to the external environment. Therefore, the first shielding body 20 has better thermal conductivity as a whole than the related technology, and thus the heat dissipation performance of the circuit board assembly 100 is also better.

[0057] In some embodiments of the present application, the structural surface of the hollow copper column 21 has a coating (not shown in the figure), wherein the magnetic permeability of the coating is not greater than 1.06, and the surface impedance of the coating is not greater than 0.1 ohms. The structural surface of the hollow copper column 21 can be understood as the surface of the hollow copper column 21 as a part, which is exposed to the air. The magnetic permeability of the coating is mainly related to the coating material, thickness and density. Generally, the higher the magnetic permeability, the lower the impedance and the better the shielding effect. Impedance generally refers to the resistance of a device or circuit to an alternating current of a given frequency flowing through it. Selecting appropriate coating materials and coating thickness can effectively reduce the surface impedance of the hollow copper column 21 and improve its oxidation resistance, thereby improving the shielding effect of the first shielding body 20.

[0058] In some embodiments of the present application, the coating may include at least one of a tin coating and a nickel coating, wherein the thickness of the tin coating ranges from 2 microns to 8 microns, and the thickness of the nickel coating ranges from 2 microns to 7.6 microns. The tin coating can effectively improve the corrosion resistance, conductivity and solderability of the hollow copper column 21, and the nickel coating can effectively improve the corrosion resistance, wear resistance, solderability of the hollow copper column 21, and increase the surface hardness. On the surface of the hollow copper column 21, the tin coating and the nickel coating can be selectively set or combined, and the thickness of each layer can be designed according to the magnetic permeability and impedance design requirements. For example, in some embodiments, a tin coating can be first formed on the surface of the hollow copper column 21, and then a nickel coating can be formed.

[0059] In the embodiment of the present application, the material type of the first thermally conductive colloid 24 is not limited, for example, organic silicone thermally conductive glue, epoxy resin AB glue, polyurethane glue, or thermally conductive silicone grease can be selected. Thermally conductive glue is a special adhesive material that can well fill the gap between two objects and improve the heat transfer between the two objects. In some embodiments, the first thermally conductive colloid 24 may include an organic polymer matrix (such as acrylate, polyurethane, etc.) and a thermally conductive filler (such as aluminum oxide, silicon oxide, silicon boron nitride, etc.), and has better thermal conductivity and insulation properties.

[0060] The first heat-conducting colloid 24 can be formed on the surface of the circuit board 10 and the first heating element 23 by coating or dispensing, and can cover the first heating element 23 and fill the first shielding cavity 212 (such as Figure 1In some other embodiments of the present application, the first heat-conducting colloid 24 may not fill the first shielding cavity 212, as long as it can fully contact the first heating element 23 and the first shielding element 20, and reliably transfer heat between the two.

[0061] In the embodiment of the present application, the specific structural form of the hollow copper column 21 is not limited. For example, the hollow copper column 21 can be in a square frame shape, a round frame shape, or a special-shaped polygonal frame shape, such as a convex frame shape or a concave frame shape.

[0062] like Figure 1 As shown, in some embodiments, the hollow copper column 21 may include a supporting wall portion 210 and a connecting portion 211, wherein the supporting wall portion 210 is supported between the circuit board 10 and the first shielding layer 22, that is, extends along the thickness direction of the circuit board 10, and the connecting portion 211 is connected to the side of the first shielding layer 22 facing the circuit board 10. The provision of the connecting portion 211 can increase the bonding area and heat conduction area of ​​the hollow copper column 21 and the first shielding layer 22, so that the two can be more reliably connected together and heat can be transferred. The supporting wall portion 210 and the circuit board 10 can be welded, plugged or bonded by thermal conductive adhesive, and the embodiment of the present application does not limit the specific method for achieving the connection between the two. The connection method of the connecting portion 211 and the first shielding layer 22 may include welding, fixed connection by fasteners, or bonding by thermal conductive adhesive, etc., and the embodiment of the present application does not specifically limit this.

[0063] like Figure 1 As shown, in some embodiments of the present application, the wall thickness c of the support wall portion 210 is not greater than 2 mm, which not only occupies less area of ​​the circuit board 10, but also has less impact on the layout of the electronic components 310 on the circuit board 10, and its thinner wall thickness is more conducive to heat transfer to the outside. In some embodiments, under the premise of meeting the structural strength and electromagnetic compatibility design requirements, the wall thickness c of the support wall portion 210 can be designed to be, for example, 1 mm, 1.5 mm or 2 mm, etc.

[0064] In some implementations of the present application, the hollow copper column 21 is a hot-cast hollow copper column, and its basic structure is formed by a copper hot casting process. Copper hot casting is a molding process method in which the copper material is melted and poured into a mold, and then cooled and solidified in the mold into a desired shape. It has the advantages of high molding accuracy, high strength, good surface quality, good corrosion resistance, long life and easy subsequent processing. The supporting wall portion 210 and the connecting portion 211 of the hollow copper column 21 can be integrally manufactured and molded in a copper hot casting process. In some embodiments, when the hollow copper column 21 is manufactured, its basic structure can be first formed by a copper hot casting process, and then a coating is formed on the surface of its structure, and finally a hollow copper column 21 with a coating is formed.

[0065] like Figure 3As shown, it is a schematic diagram of the cross-sectional structure of a circuit board assembly 100 of some other embodiments of the present application, and the circuit board assembly 100 includes: a first heating element 23, a first shielding body 20 and a first thermally conductive colloid 24 arranged on one side of the circuit board 10 (as shown in the figure, side A), and a second heating element 33, a second shielding body 30 and a second thermally conductive colloid 34 arranged on the other side of the circuit board 10 (as shown in the figure, side B).

[0066] The first shielding body 20 includes a hollow copper column 21 and a first shielding layer 22. The hollow copper column 21 and the first shielding layer 22 form a first shielding cavity 212. The first heating element 23 is located in the first shielding cavity 212. The first heat-conducting colloid 24 is in heat-conducting contact with the first heating element 23 and the first shielding body 20. Figure 3 In the illustrated embodiment, the first heating element 23 includes a plurality of circuit matching elements 311. In other embodiments of the present application, the first heating element 23 may also include other electronic components such as chips. The design of the first shielding body 20 may refer to the aforementioned embodiment, and will not be repeated here.

[0067] The second shielding body 30 includes a shielding frame 31 and a second shielding layer 32 connected to the side of the shielding frame 31 facing away from the circuit board 10. The shielding frame 31 and the second shielding layer 32 form a second shielding cavity 312. The second heating element 33 is located in the second shielding cavity 312. The second heat-conducting colloid 34 is in heat-conducting contact with the second heating element 33 and the second shielding body 30. Figure 3 In the illustrated embodiment, the second heating element 33 includes a processing chip 41 and a storage chip 42, and the second heating element 33 is located in the second shielding cavity 312, so that the electromagnetic compatibility design requirements can be met during operation. In other embodiments of the present application, the second heating element 33 may also include other electronic components such as capacitors, resistors, or inductors, which are not specifically limited in the embodiments of the present application.

[0068] The first heating element 23 is disposed on one side of the circuit board 10 (side A as shown in the figure), and the second heating element 33 is disposed on the other side of the circuit board 10 (side B as shown in the figure). The first heating element 23 and the second heating element 33 may each include one or more electronic components 310. As shown in the direction of the dotted arrows in the figure, the heat generated by the first heating element 23 may be transferred to the outside of the first shielding body 20 through the first thermally conductive colloid 24 and the first shielding body 20 in sequence, and the heat generated by the second heating element 33 may be transferred to the outside of the second shielding body 30 through the second thermally conductive colloid 34 and the second shielding body 30 in sequence. In addition, the circuit board 10 may also dissipate heat through the first shielding body 20 and the second shielding body 30.

[0069] By adopting the above-mentioned design scheme, the heat generated by the heating elements on both sides of the circuit board assembly 100 and the heat of the circuit board 10 can be dissipated outward through the first shielding body 20 and the second shielding body 30. In particular, the design of the hollow copper column 21 helps to accelerate the heat dissipation effect. Therefore, the design of the circuit board assembly 100 can take into account both the electromagnetic compatibility design requirements and the heat dissipation performance requirements.

[0070] In some embodiments of the present application, the shielding frame 31 may be a copper alloy shielding frame, such as a nickel silver shielding frame. The second shielding layer 32 may be a copper shielding layer, an aluminum shielding layer, or a stainless steel shielding layer.

[0071] In other embodiments of the present application, the shielding frame 31 may also be a copper shielding frame, and the structural surface of the copper shielding frame may be provided with a coating or not. In some embodiments, a coating is provided on the structural surface of the copper shielding frame, wherein the magnetic permeability of the coating is not greater than 1.06, and the surface impedance of the coating is not greater than 0.1 ohms. Selecting appropriate coating materials and coating thicknesses can effectively reduce the surface impedance of the copper shielding frame, improve its oxidation resistance, and thus improve the shielding effect of the second shielding body 30. For example, in some embodiments, the structural surface of the copper shielding frame is provided with a tin coating and a nickel coating.

[0072] In these embodiments, on one side of the circuit board 10 (side A as shown in the figure), the first shielding body 20 has better thermal conductivity and can quickly transfer heat to the external environment or external heat dissipation structure. On the other side of the circuit board 10 (side B as shown in the figure), the material of the shielding frame 31 can be flexibly selected according to the layout and heat dissipation requirements of the electronic components 310. For example, when the second heating element 33 has a higher heat dissipation requirement, the shielding frame 31 can adopt a copper shielding frame, the main material of which is metallic copper, and the surface of the structure can be further provided with a coating for improving the surface impedance and enhancing the oxidation resistance. The shielding frame 31 can have a structural form similar to the above-mentioned hollow copper column 21; when the layout space of the second heating element 33 is relatively tight, the shielding frame 31 can adopt a nickel silver shielding frame with better machining performance, so as to minimize the wall thickness and reduce the area occupied on the circuit board 10.

[0073] like Figure 3 As shown, in some embodiments, relatively large electronic components 310 such as processing chips 41 and storage chips 42 can be concentrated on one side of the circuit board 10 (side B as shown in the figure), and relatively small electronic components 310 such as circuit matching elements 311 can be arranged on the other side of the circuit board 10 (side A as shown in the figure), which is conducive to reducing the overall thickness of the circuit board assembly 100. It can be understood that Figure 3The side A and side B shown in the figure are relative. In other embodiments of the present application, relatively large electronic components 310 such as processing chips 41 and storage chips 42 can be concentrated on the side A shown in the figure, and relatively small electronic components 310 such as circuit matching elements 311 can be arranged on the side B shown in the figure.

[0074] like Figure 3 As shown, in some embodiments, the processing chip 41 and the memory chip 42 can be sequentially arranged in a direction away from the circuit board 10 and stacked on each other. The processing chip 41 and the circuit board 10, and the memory chip 42 and the processing chip 41 can be electrically connected by welding or plugging. In these embodiments, the processing chip 41 and the memory chip 42 are compactly arranged, which not only occupies less area of ​​the circuit board 10, but also simplifies the routing design of the circuit board 10.

[0075] In some embodiments of the present application, Figure 3 Based on the structural design of the circuit board assembly 100 shown in the figure, further heat dissipation optimization design can be performed. Figure 4 As shown, it is a schematic diagram of the cross-sectional structure of a circuit board assembly 100 of some other embodiments of the present application. Figure 3 Based on the structural design of the circuit board assembly 100 shown, it can also include a first heat dissipation component 25 and a second heat dissipation component 35, wherein the first heat dissipation component 25 is in thermal contact with the side of the first shielding layer 22 facing away from the circuit board 10, and the second heat dissipation component 35 is in thermal contact with the side of the second shielding layer 32 facing away from the circuit board 10.

[0076] The first heat dissipation component 25 and the second heat dissipation component 35 can accelerate the heat dissipation of the circuit board assembly 100, thereby further improving the heat dissipation effect of the circuit board assembly 100. The first heat dissipation component 25 and the second heat dissipation component 35 have no limitation on the structural form, and the two can adopt the same or different designs.

[0077] In some embodiments, the first heat dissipation component 25 may include at least one of a planar heat pipe (vapor chambers, VC) and a graphite heat dissipation layer, and the second heat dissipation component 35 may include at least one of a planar heat pipe and a graphite heat dissipation layer.

[0078] The graphite heat dissipation layer has a sheet-like structure with a unique grain orientation, which can conduct heat evenly in two directions. Moreover, the sheet-like structure can adapt well to the bonding surface, thereby dissipating the heat of the shielding layer to the surrounding environment more efficiently.

[0079] A planar heat pipe is a vacuum cavity with a capillary structure on the inner wall, which includes an evaporation zone and a condensation zone. In the evaporation zone, the liquid working medium vaporizes and absorbs the heat conducted by the heat source; in the condensation zone, the vaporized working medium condenses into liquid and flows back to the evaporation zone through the capillary phenomenon of the capillary structure. Compared with ordinary heat pipes, planar heat pipes can conduct heat in a two-dimensional plane, so the heat dissipation efficiency is higher. In addition, the working state of planar heat pipes is not affected by gravity, so they can be applied to more application scenarios.

[0080] In some other embodiments of the present application, the first heat dissipation component 25 and / or the second heat dissipation component 35 may also adopt other heat dissipation structures such as heat dissipation fins or liquid cooling plates.

[0081] like Figure 5 As shown, according to some embodiments of the present application, an electronic device 500 is provided, and the electronic device 500 includes the circuit board assembly 100 of any of the above embodiments. The specific product type of the electronic device 500 is not limited, for example, it can be a mobile phone, a tablet computer, a laptop computer, a smart wearable device, a car computer, a medical electronic device, a server, a router, a switch, and other electronic products containing circuit board assemblies.

[0082] Since the circuit board assembly 100 can meet the electromagnetic compatibility design requirements and has better heat dissipation performance, the performance of the electronic device 500 is also improved.

[0083] In some embodiments, the working mode of the electronic device 500 includes a boost overload mode. The boost overload mode can improve the operating performance of the processing chip and provide users with a faster and smoother user experience. The boost overload mode of the electronic device 500 can be turned on according to user settings or automatically turned on when an application is enabled. For example, in some embodiments, the electronic device 500 is a mobile phone or a tablet computer, and the boost overload mode can be automatically turned on when the user starts a game or watches a video resource.

[0084] like Figure 5 As shown, according to some embodiments of the present application, the electronic device 500 includes a display screen 200 and a back shell 300, and the circuit board assembly 100 is located between the display screen 200 and the back shell 300, wherein the circuit board assembly 100 can be Figure 4 The structural design shown. Figure 4As shown, in the structure of the circuit board assembly 100, the processing chip 41 (such as SOC) and the storage chip 42 (such as DDR) are stacked on the side of the circuit board 10 facing the display screen 200, and the related circuit matching element 311 is arranged on the side of the circuit board 10 facing away from the display screen 200. The first shielding body 20 includes a hollow copper column 21 and a first shielding layer 22, and the second shielding body 30 includes a shielding frame 31 and a second shielding layer 32. The hollow copper column 21 is mainly made of metal copper, and its surface has a tin plating layer and a nickel plating layer to improve the surface impedance of the hollow copper column 21 and improve the surface corrosion resistance. The shielding frame 31 is mainly made of nickel silver. The first shielding layer 22 and the second shielding layer 32 are copper shielding layers, respectively, and copper foil can be used. In addition, a first heat dissipation component 25 (such as a planar heat pipe) is arranged on the side of the first shielding layer 22 facing away from the circuit board 10, and a second heat dissipation component 35 (such as a graphite heat dissipation layer) is arranged on the side of the second shielding layer 32 facing away from the circuit board 10, so as to further improve the heat dissipation effect of the circuit board assembly 100. The electronic device 500 of this embodiment can meet the electromagnetic compatibility design requirements and has better heat dissipation performance. It can work in the boost heavy load mode, and the battery life in this working mode is longer and the performance is better.

[0085] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A circuit board assembly, characterized in that: include: Circuit boards; A first shielding body, comprising a hollow copper column located on one side of the circuit board, and a first shielding layer connected to a side of the hollow copper column facing away from the circuit board, wherein the hollow copper column and the first shielding layer enclose a first shielding cavity; a first heating element, located at one side of the circuit board and in the first shielding cavity; and The first heat-conducting colloid is in heat-conducting contact with the first heating element and the first shielding element respectively.

2. The circuit board assembly according to claim 1, characterized in that: The structural surface of the hollow copper column has a coating, the magnetic permeability of the coating is not greater than 1.06, and the surface impedance of the coating is not greater than 0.1 ohm.

3. The circuit board assembly according to claim 2, characterized in that: The plating layer includes at least one of a tin plating layer and a nickel plating layer, wherein the thickness of the tin plating layer ranges from 2 micrometers to 8 micrometers, and the thickness of the nickel plating layer ranges from 2 micrometers to 7.6 micrometers.

4. The circuit board assembly according to claim 1, characterized in that: The hollow copper column includes a supporting wall portion and a connecting portion, wherein the supporting wall portion is supported between the circuit board and the first shielding layer, and the connecting portion is connected to a surface of the first shielding layer facing the circuit board.

5. The circuit board assembly according to claim 4, characterized in that: The wall thickness of the supporting wall portion is no more than 2 mm.

6. The circuit board assembly according to claim 1, characterized in that: The hollow copper column is a hot-cast hollow copper column.

7. The circuit board assembly according to any one of claims 1 to 6, characterized in that: Also includes: A second shielding body, comprising a shielding frame located on the other side of the circuit board, and a second shielding layer connected to a side of the shielding frame facing away from the circuit board, wherein the shielding frame and the second shielding layer enclose a second shielding cavity; A second heating element is located at the other side of the circuit board and in the second shielding cavity; and The second heat-conductive colloid is in heat-conductive contact with the second heating element and the second shielding element respectively.

8. The circuit board assembly according to claim 7, characterized in that: The shielding frame is a copper alloy shielding frame; or The shielding frame is a copper shielding frame, and a structural surface of the copper shielding frame has a coating, the magnetic permeability of the coating is not greater than 1.06, and the surface impedance of the coating is not greater than 0.1 ohm.

9. The circuit board assembly according to claim 7, characterized in that: Also includes: a first heat dissipation component in thermal contact with a side of the first shielding layer facing away from the circuit board; as well as The second heat dissipation component is in thermal contact with a side of the second shielding layer facing away from the circuit board.

10. The circuit board assembly according to claim 9, characterized in that: The first heat dissipation component includes at least one of a planar heat pipe and a graphite heat dissipation layer; The second heat dissipation component includes at least one of a planar heat pipe and a graphite heat dissipation layer.

11. The circuit board assembly according to claim 7, characterized in that: The first heating element includes a circuit matching element, and the second heating element includes a processing chip and a storage chip.

12. The circuit board assembly according to claim 11, characterized in that: The processing chip and the memory chip are sequentially arranged in a direction away from the circuit board and are stacked on each other.

13. An electronic device, characterized in that: Comprising a circuit board assembly according to any one of claims 1 to 12.

14. The electronic device according to claim 13, characterized in that: The electronic device can operate in a boost heavy load mode.

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