WO2023222045A1

WO2023222045A1 - Circuit board assembly and electronic device

Info

Publication number: WO2023222045A1
Application number: PCT/CN2023/094826
Authority: WO
Inventors: 熊振兴; 赵才军; 熊建波; 庄宝山; 赵亚涛
Original assignee: 华为技术有限公司
Priority date: 2022-05-20
Filing date: 2023-05-17
Publication date: 2023-11-23
Also published as: CN218042315U

Abstract

The present application relates to a circuit board assembly and an electronic device. The circuit board assembly comprises a circuit board, an onboard chip, a heat dissipator, a shielding frame and a shielding member. The onboard chip is mounted on a first flat surface of the circuit board; the heat dissipator comprises an attachment surface facing the onboard chip, and a heat conduction layer is provided between the attachment surface and the onboard chip; and the heat dissipator is fixed on the circuit board by means of a fastener, such that the attachment surface is attached to the heat conduction layer. The shielding frame is arranged around the onboard chip, and an annular gap is formed between the shielding frame and the onboard chip. The shielding member is of a hollowed-out structure; the inner edge of the shielding member is fixed onto the onboard chip and the outer edge of the shielding member is in contact with the shielding frame, or the shielding frame is fixed onto the first flat surface, and the outer edge of the shielding member is located on the side of the shielding frame that faces away from the onboard chip, and is spaced apart from the shielding frame; and the shielding member is used for covering the annular gap. The circuit board assembly in the present application has a compact structure and also has a good shielding effect.

Description

Circuit board components and electronic equipment

This application claims priority to the Chinese patent application filed with the China Patent Office on May 20, 2022, with the application number 202221238911.4 and the application name "Circuit Board Components and Electronic Equipment", the entire content of which is incorporated into this application by reference.

Technical field

The present application relates to the field of electronic equipment, and in particular, to a circuit board assembly and an electronic equipment.

Background technique

A circuit board assembly is installed in the electronic device to realize the preset functions of the electronic device. As the functions of electronic equipment expand, the number of chips required to be accommodated in circuit board assemblies also increases accordingly, and the spacing between chips gradually shrinks; at the same time, the transmission rate of the chips themselves also gradually accelerates, which has a negative impact on the electromagnetic field of the chips in circuit board assemblies. Shielding puts forward higher requirements.

Contents of the invention

The purpose of this application is to provide a circuit board assembly with smaller volume and reliable shielding. At the same time, the present application also relates to an electronic device assembled with the circuit board assembly.

In a first aspect, this application relates to a circuit board assembly, including a circuit board, an onboard chip, a heat sink, a shielding frame, and a shield; the onboard chip is mounted on the first plane of the circuit board, and the heat sink includes a heat sink facing the onboard There is a thermal conductive layer between the bonding surface of the chip and the onboard chip; the heat sink is fixed on the circuit board through fasteners so that the bonding surface and the thermal conductive layer are bonded; a shielding frame is set around the onboard chip , an annular gap is formed between the shielding frame and the onboard chip; the shielding element has a hollow structure, the inner edge of the shielding element is fixed on the onboard chip, and the outer edge of the shielding element is in contact with the shielding frame; or the shielding frame is fixed on the third On a plane, the outer edge of the shielding member is located on the side of the shielding frame away from the onboard chip and is spaced apart from the shielding frame; the shielding member is used to cover the annular gap.

The circuit board assembly of this application carries the onboard chip through the circuit board, and then dissipates heat to the onboard chip through the radiator. Between the onboard chip and the heat sink, the circuit board assembly is equipped with a shielding frame and a shielding member structure. The shielding frame surrounds the periphery of the onboard chip and forms an annular gap from the onboard chip. Shields can be used to cover the annular gap. Therefore, in the lateral direction of the onboard chip between the circuit board and the heat sink, the combination of the shielding frame and the shielding member can achieve a shielding effect in this direction, thus preventing the interference between two adjacent onboard chips or between the board and the heat sink. The distance between the carrier chip and other surrounding devices is too close, which may cause electromagnetic interference. The circuit board assembly of the present application has a compact structure and reliable shielding effect, and can realize high-density arrangement design of each device in the circuit board.

In a possible implementation, the onboard chip includes a base substrate, a chip die and a fence. The base substrate is fixed on the first plane, the chip die is fixed on the side of the base substrate away from the first plane, and the fence surrounds It is located on the periphery of the chip die, the thermal conductive layer is provided on the outer surface of the chip die, and the inner edge of the shielding member is fixed on the fence.

In this implementation, the bare chip in the onboard chip is exposed above the fence, and the thermal conductive layer is directly provided on the bare chip. The fitting surface of the radiator can form a better heat dissipation effect on the bare chip.

In a possible implementation, the circuit board assembly further includes a flexible shielding ring. The flexible shielding ring is located around the periphery of the fitting surface and is located between the fence and the radiator. The opposite sides of the flexible shielding ring are respectively connected to the radiator. It resists the fence to form a shielding effect on the bare chip.

In a possible implementation, the fence is made of conductive material.

In this implementation, the flexible shielding ring is held between the radiator and the fence, which can form a shield in the side direction of the bare chip to prevent interference signals from passing through the gap between the fence and the radiator, causing electromagnetic interference. . The flexible shielding ring is made of flexible materials. When it is pressed between the radiator and the fence, it can adapt to the manufacturing tolerance between the radiator and the fence through compression and deformation, ensuring the reliability of the shielding structure.

In a possible implementation, the material of the flexible shielding ring can be conductive foam, conductive sponge, conductive glue, or metal.

In a possible implementation, the inner edge of the shielding member is sandwiched between the flexible shielding ring and the fence.

In this implementation, the inner edge of the shielding member is sandwiched between the flexible shielding ring and the fence to facilitate fixing the shielding member on the flexible shielding ring or the fence, and through the resistance between the flexible shielding ring and the fence, it is ensured that The relative position between the shielding member and the onboard chip is stable, thereby improving the shielding effect of the circuit board assembly of the present application.

In a possible implementation, the onboard chip includes a base substrate, a chip die and a shell. The base substrate is fixed on the first plane, and the shell is fixed on the side of the base substrate away from the first plane. It is surrounded by the base substrate to form a receiving space. The bare chip is received in the receiving space. The inner edge of the shielding member is set on the outer surface of the casing. The casing is also used to form a thermal conductive layer.

In this implementation, the bare chip in the onboard chip is accommodated in the accommodation space formed by the casing and the base substrate. The casing can form a shielding protection for the bare chip, and cooperates with the structure of the shielding frame and the shielding member. Ensure the working reliability of bare chips. The outer surface of the housing close to the bonding surface can be in contact with the heat sink for heat conduction, so that the heat generated by the bare chip can be discharged through the heat sink.

In one possible implementation, a thermally conductive interface material is filled between the bare chip and the housing to improve the heat conduction efficiency from the bare chip to the housing.

In a possible implementation, the shielding frame is fixed on the first plane, the outer edge of the shielding member is in contact with the shielding frame, and the shielding member is made of a flexible material.

In this implementation, the shielding member achieves shielding of the annular gap through direct contact with the onboard chip and the shielding frame respectively. And the shielding member is made of flexible material, which can be used to adapt to the manufacturing tolerance between the onboard chip and the shielding frame.

In a possible implementation manner, the material of the shielding member can be conductive foam, conductive sponge, conductive glue, conductive plastic, conductive film or metal.

In a possible implementation, the shielding part includes a connecting part and a shielding part, the inner edge of the shielding part is located on the connecting part, the outer edge of the shielding part is located on the shielding part, and the extending direction of the shielding part is perpendicular to the first plane.

In this implementation, the shielding member extends out of the shielding frame through the connecting part, and forms a gap fit with the shielding frame through the shielding part extending in a direction perpendicular to the first plane, and by controlling the size of the gap, the onboard chip can be protected Achieve electromagnetic shielding effect.

In a possible implementation, the material of the shielding member can be conductive plastic, conductive film or metal.

In a possible implementation, the projection of the shielding member on the radiator is contained within the outer contour of the radiator.

In a possible implementation, the circuit board includes a transmission line. The transmission line is located on the first plane. One end of the transmission line is fixedly connected to and conductive with the onboard chip, and the other end is located on the side of the shielding frame away from the onboard chip. The shielding frame is provided with a In the hollow area that allows transmission lines to pass through.

In this implementation manner, a transmission line may be provided on the first plane of the circuit board to achieve electrical conduction between the on-board chip and other devices on the circuit board. The hollow area provided on the shielding frame is used for transmission lines to pass through.

In a possible implementation, the shielding frame includes a main body, protrusions and conductive glue. The protrusions are arranged at intervals on the side of the main body close to the first plane and protrude toward the first plane. Two adjacent protrusions A hollow area is formed between the two parts, and the conductive glue is arranged between the raised part and the first plane.

In this implementation, the hollow area can be formed by arranging spaced-apart protrusions on the main body of the shield frame. The conductive glue is used to ensure the conductive connection between each protruding part and the first plane, so as to improve the shielding effect of the protruding part.

In a possible implementation, the shielding frame includes a main body, a welding pad and a conductive glue. The welding pads are arranged at intervals on the first plane. The main body is located on the side of the welding pad away from the first plane. The conductive glue is located between the welding pad and the main body. space, a hollow area is formed between two adjacent pads.

In this implementation manner, by arranging spaced-apart pads on the first plane, the structure of the hollow area can also be formed. The conductive glue is located between the pad and the body, which can ensure the conductive connection between the pad and the body to ensure the shielding effect of the pad position.

In a possible implementation, the shielding frame is also fixed on the circuit board through a connector.

In a possible implementation, on any cross section perpendicular to the first plane, the shielding frame includes a first side close to the first plane, and a second side far away from the first plane, and the wall thickness of the first side is greater than The wall thickness of the second side.

In this implementation mode, the first side wall of the shielding frame is set to be thicker to ensure reliable connection between the shielding frame and the circuit board. The second side wall of the shielding frame is thinner, which facilitates the cooperation between the shielding frame and the shielding member and reduces the overall size of the circuit board assembly of the present application.

In a possible implementation, the wall thickness of the first side is 1 mm, and the wall thickness of the second side is 0.75 mm.

In a possible implementation, the shielding member includes a shielding part, the wall thickness of the shielding part is 0.2 mm, and the gap between the shielding part and the shielding frame is 0.1 mm.

In a possible implementation, the shielding frame is fixed on the outer edge of the shielding member, and there is a gap between the shielding frame and the first plane.

In this implementation, the shielding frame can also be fixed on the outer edge of the shielding member, and the shielding frame and the shielding member work together to achieve a shielding effect on the onboard chip. And the gap left between the shielding frame and the first plane facilitates the arrangement of transmission lines on the first plane.

In a possible implementation, the shielding frame is formed on the surface of the shielding part of the shielding member by spraying, electroplating, or immersion.

In a possible implementation, the shielding frame is an injection molded structural member or a molded structural member.

In one possible implementation, the main material of the shielding frame is plastic, and the shielding frame is doped with absorbing particles and/or conductive particles to form a shielding effect.

In a possible implementation, there are multiple onboard chips in the circuit board assembly, and the multiple onboard chips are arranged at intervals, and a shielding frame and a shielding member are provided around each onboard chip to implement Shielding protection effect on each onboard chip.

In a second aspect, this application provides an electronic device, including a housing and a circuit board assembly provided in the first aspect of this application. The circuit board assembly is installed on the housing and used to implement the functions of the electronic equipment.

It can be understood that in the electronic device provided in the second aspect of the present application, because it is equipped with the circuit board assembly provided in the first aspect of the present application, the electronic device of the present application also has the beneficial effects of smaller size and reliable shielding. .

Description of the drawings

Figure 1 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

Figure 2 is a schematic structural diagram of a circuit board assembly in an electronic device according to an embodiment of the present application;

Figure 3 is an exploded structural diagram of a circuit board assembly in an electronic device provided by an embodiment of the present application;

Figure 4 is a schematic structural diagram of a circuit board assembly in an electronic device provided by another embodiment of the present application;

Figure 5 is an exploded structural diagram of a circuit board assembly in an electronic device provided by another embodiment of the present application;

Figure 6 is a schematic cross-sectional structural diagram of a circuit board assembly in an electronic device according to an embodiment of the present application;

Figure 7 is a schematic cross-sectional structural diagram of a circuit board assembly in an electronic device provided by another embodiment of the present application;

Figure 8 is a schematic diagram illustrating standards for chip speed and electromagnetic shielding in circuit board assemblies in the prior art;

Figure 9 is a schematic structural diagram of the cooperation between the heat sink and the circuit board in the circuit board assembly provided by an embodiment of the present application;

Figure 10 is a schematic cross-sectional structural diagram of an onboard chip in a circuit board assembly provided by an embodiment of the present application;

Figure 11 is a schematic diagram of the cooperation structure between the onboard chip and the shielding frame in the circuit board assembly provided by an embodiment of the present application;

Figure 12 is a schematic structural diagram of the cooperation between the onboard chip, the shielding frame, and the shielding member in the circuit board assembly provided by an embodiment of the present application;

Figure 13 is a schematic structural diagram of the cooperation between the onboard chip, the shielding frame, and the shielding member in the circuit board assembly provided by another embodiment of the present application;

Figure 14 is a schematic cross-sectional structural diagram of an onboard chip in a circuit board assembly provided by another embodiment of the present application;

Figure 15 is a schematic structural diagram of a shield in a circuit board assembly provided by another embodiment of the present application;

Figure 16 is a schematic cross-sectional structural diagram of a circuit board assembly in the prior art;

Figure 17 is a schematic cross-sectional structural diagram of another circuit board assembly in the prior art;

Figure 18 is a schematic diagram comparing the shielding performance of the absorbing material and its own width of a circuit board assembly in the prior art;

Figure 19 is a schematic diagram of the coplanarity statistical results of the sawtooth structure of the shielding cover of another circuit board assembly in the prior art;

Figure 20 is a schematic plan view of the circuit board, on-board chip and shielding frame in the circuit board assembly provided by an embodiment of the present application;

Figure 21 is a schematic side structural view of a shielding frame in a circuit board assembly provided by an embodiment of the present application;

Figure 22 is a schematic side structural view of a shielding frame in a circuit board assembly provided by another embodiment of the present application;

Figure 23 is a schematic cross-sectional structural diagram of a circuit board assembly of the present application;

Figure 24 is a schematic plan view of the onboard chip in a circuit board assembly of the present application;

FIG. 25 is a schematic cross-sectional structural diagram of a circuit board assembly in an electronic device according to another embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

The serial numbers assigned to components in this article, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The "connection" mentioned in this application includes direct and indirect connections unless otherwise specified. In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "top", "bottom", "inner", "outer", etc. indicate an orientation or position. The relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore It should not be construed as a limitation on this application.

In this application, unless otherwise expressly stated and limited, a first feature being "on" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. touch. Moreover, the terms "above" and "above" the first feature is "above" the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. “Below” and “below” the first feature is the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature has a smaller horizontal height than the second feature.

Please refer to the electronic device 200 provided by the present application as shown in Figure 1 . In the diagram of FIG. 1 , the electronic device 200 is a mobile phone. The electronic device 200 includes a housing 210 and the circuit board assembly 100 provided by the present application. The circuit board assembly 100 is disposed on the housing 210 and is used to implement preset functions of the electronic device 200 . Among them, the preset functions of the electronic device 200 may include functions such as data processing, data storage, signal transceiver, data collection, data output, and implementation of specific mechanism actions.

Correspondingly, the circuit board assembly 100 is equipped with chips and other electronic devices. The circuit board assembly 100 can realize the preset functions of the above-mentioned electronic device 200 through the interaction between the chips and the electronic devices. At this time, the chips in the circuit board assembly 100 of the present application can be a central processing chip, a memory chip, a network chip, a baseband chip, an image processing chip, a display chip, an audio processing chip, etc. Furthermore, the chip in the circuit board assembly 100 can also be an integrated chip of at least two of the above-mentioned chips, or the circuit board assembly 100 can be equipped with multiple chips at the same time to cooperate to realize one or more of the above-mentioned functions.

In the illustration of Figure 1 , the electronic device 200 is a mobile phone. In other embodiments, the electronic device 200 can also be a client terminal device such as a tablet, computer, smart home appliance, vehicle, etc., or it can also be a customer front-end device such as a router or base station. (Customer Premise Equipment, CPE), or any other electronic device 200. This application does not specifically limit the type of electronic device 200 here.

For ease of description, in subsequent embodiments of the present application, the electronic device 200 is a mobile phone and the chip in the circuit board assembly 100 includes a network chip as an example to introduce the solution of the present application.

Please refer to FIG. 2 for a schematic structural diagram of a circuit board assembly 100 provided by this application, and for an exploded structural diagram of the circuit board assembly 100 shown in FIG. 3 .

The circuit board assembly 100 of the present application shown in FIGS. 2 and 3 includes a circuit board 10 , an onboard chip 20 , a heat sink 30 , a shield frame 40 , and a shield 50 . In the circuit board assembly 100 provided in Figure 2, the circuit board 10 has a first plane 11, and an onboard chip 20 is mounted on the first plane 11. The heat sink 30, the shielding frame 40 and the shielding member 50 all correspond to the onboard chip 20. The chip 20 is configured to realize the heat dissipation and electromagnetic shielding protection functions of the onboard chip 20 . The circuit board assembly 100 is also provided with other devices 110 . The other devices 110 are also mounted on the first plane 11 and are arranged adjacent to the onboard chip 20 . Other devices 110 may be capacitors, inductors, resistors, and other devices. The onboard chip 20 is electrically connected to other devices 110 through the circuit board 10 to cooperate in realizing the preset functions of the circuit board assembly 100 in the electronic device 200 .

Please refer to FIG. 4 for a schematic structural diagram of another circuit board assembly 100 provided by the present application, and for an exploded structural diagram of the circuit board assembly 100 shown in FIG. 5 .

In the structure of another circuit board assembly 100 shown in FIG. 4 , a plurality of onboard chips 20 are mounted on the first plane 11 of the circuit board 10 , and each onboard chip 20 is provided with a heat sink to assist in heat dissipation. The radiator 30, as well as the shielding frame 40 and the shielding member 50 used to realize its electromagnetic shielding protection. A plurality of onboard chips 20 are arranged at intervals on the first plane 11. In the diagram of FIG. 4, the number of onboard chips 20 is 8, and the 8 onboard chips are arranged in a matrix in a "2×4" manner. On the first plane 11, the corresponding heat sink 30 is also fixed relative to the circuit board 10 in this arrangement.

It can be understood that in other embodiments, the number of onboard chips 20 in the circuit board assembly 100 can also be other values, and the arrangement of the onboard chips 20 can also be linear arrangement, matrix arrangement, or other arbitrary arrangements. Way. The multiple onboard chips 20 can each realize the preset functions of the circuit board assembly 100 in the electronic device 200; the multiple onboard chips 20 can also be electrically connected to each other and cooperate with each other to realize the preset functions of the circuit board assembly 100 in the electronic device. 200 preset functions. In some embodiments, the circuit board assembly 100 can be equipped with multiple onboard chips 20 and other devices 110 at the same time, and the multiple onboard chips 20 and other devices 110 are arranged side by side and work separately or together to realize the circuit board. The preset function of the component 100 in the electronic device 200.

As the preset functions of the electronic device 200 are stacked, the number of onboard chips 20 and/or other devices 110 that may be mounted on the circuit board 10 also increases accordingly, and the size of the onboard chips 20 also increases accordingly (existing boards The overall size of the chip carrier 20 can reach 50-110mm). The circuit board 10 has formed a design requirement for high-density arrangement. The on-board chip 20 and other adjacent devices 110 Or the spacing between the onboard chips 20 is gradually reduced. As shown in the cross-sectional view of the circuit board assembly 100 shown in FIG. 6 , on the first plane 11 of the circuit board 10 , the distance between the onboard chip 20 and other adjacent devices 110 may be less than 4 mm; while as shown in FIG. 7 In the schematic cross-sectional view of the circuit board assembly 100, the distance between the heat sinks 30 of two adjacent onboard chips 20 may also be less than 4 mm.

On the other hand, the increase in chip speed will also cause greater electromagnetic shielding interference. As shown in Figure 8, when the chip rate is increased from 10Gb/s to 56Gb/s, based on the limit value required by the Federal Communications Commission (FCC), the electromagnetic interference of the 56Gb/s high-speed chip will exceed the standard. About 5dB. The above phenomena all put forward higher requirements on the electromagnetic shielding performance of the on-board chip 20 in the circuit board assembly 100 .

In the cross-sectional diagrams of the circuit board assembly 100 of the present application shown in FIGS. 6 and 7 , the onboard chip 20 is fixed on the first plane 11 of the circuit board 10 , and the heat sink 30 is located on the side of the onboard chip 20 away from the first plane 11 . Referring to FIG. 9 for details, the heat sink 30 includes an opposing fitting surface 31 and a heat dissipation surface 32 , and a fixing hole 33 penetrating between the fitting surface 31 and the heat dissipation surface 32 . The circuit board assembly 100 is provided with fasteners 120 that pass through the fixing holes 33 to fix the heat sink 30 on the outside of the first plane 11 of the circuit board 10, and the fitting surface 31 of the heat sink 30 faces the onboard chip. 20. The heat dissipation surface 32 faces away from the first plane 11. The heat dissipation surface 32 is provided with heat dissipation teeth 321 for increasing the heat dissipation area of the heat dissipation surface 32 . The bonding surface 31 is thermally connected to the onboard chip 20 through the thermal conductive layer 130 to conduct the heat of the onboard chip 20 to the heat dissipation surface 32 to achieve the heat dissipation effect of the onboard chip 20 .

In order to facilitate clear description, in the diagram of FIG. 9 , structures such as the shielding frame 40 and the shielding member 50 as well as the onboard chip 20 are omitted. In the remaining drawings of the embodiment of this application, the fixing holes 33 of the heat sink 30 and the structure of the fasteners 120 in the circuit board assembly 100 are also omitted.

Please refer to the structural diagram of the onboard chip 20 shown in FIG. 10 . In one embodiment of the circuit board assembly 100 of the present application, the onboard chip 20 includes a base substrate 21 , a chip die 22 , and a housing 23 . The base substrate 21 includes an opposite first side 211 and a second side 212, where the first side 211 is attached and fixed on the first plane 11 of the circuit board 10, and the chip die 22 and the housing 23 are located on the base substrate. On the second side 212 of 21. The housing 23 covers the second surface 212 and surrounds the second surface 212 to form a receiving space. The chip die 22 is located in the receiving space and attached to the second surface 212 . The material of the housing 23 can be a conductive material, and by covering the periphery of the bare chip 22, it forms a shielding protection for the bare chip 22.

The chip die 22 is the main heat source of the onboard chip 20. The housing 23 is spaced apart from the chip die 22, and a thermal interface material (Thermal Interface Material, TIM) can also be filled between the chip die 22 and the housing 23. , such as thermal grease, thermal glue or graphite sheets, etc., the thermally conductive cross-section material is used to conduct the heat generated during the operation of the chip die 22 to the casing 23 . The fitting surface 31 of the heat sink 30 is fitted on the housing 23 . At this time, in the diagram of FIG. 6 , the structure of part of the housing 23 located between the chip die 22 and the bonding surface 31 is also used to form the thermal conductive layer 130 . Or it can be described as, the thermal conductive interface material filled between the chip die 22 and the housing 23 and the partial structure of the housing 23 are jointly used to form the thermal conductive layer 130 in this embodiment. One side of the thermal conductive layer 130 is directly attached to the chip die 22, and the other side is attached to the attachment surface 31 of the heat sink 30. The heat generated by the chip die 22 during operation can be transferred to the heat sink through the thermal conductive layer 130. 30 at the heat dissipation surface 32, and heat dissipation is achieved through the heat dissipation teeth 321.

The shielding frame 40 and the shielding member 50 are both located between the circuit board 10 and the heat sink 30 . Please refer to the schematic diagram of the matching structure of the onboard chip 20 and the shielding frame 40 shown in FIG. 11 . In this embodiment, the planar projection of the onboard chip 20 is a rectangle as shown in FIG. 11 , and the shielding frame 40 is also configured as a rectangular frame. The shielding frame 40 is also fixed on the circuit board 10 . The shielding frame 40 is arranged around the periphery of the onboard chip 20 and is spaced apart from the onboard chip 20 . That is, the shielding frame 40 is arranged around the onboard chip 20 . An annular gap 140 is formed between the shielding frame 40 and the onboard chip 20 , and the shielding member 50 is used to shield the annular gap 140 (as shown in FIG. 12 ).

Specifically, in the circuit board assembly 100 of the present application, the shielding member 50 has a hollow structure. The shield 50 includes an inner edge 51 and an outer edge 52, and both the inner edge 51 and the outer edge 52 are rectangular in shape to respectively match the shape structures of the onboard chip 20 and the shielding frame 40. The inner edge 51 of the shield 50 is fixed on the onboard chip 20 , specifically fixed on the housing 23 in this embodiment. The outer edge 52 of the shielding member 50 is in contact with the shielding frame 40 , thereby achieving the shielding effect of the shielding member 50 on the annular gap 140 .

The main body material of the shielding frame 40 may be a conductive material, such as metal. It is fixed on the circuit board 10 and forms a rigid shielding structure on the side of the onboard chip 20 . The electromagnetic signal generated during the operation of the bare chip 22 is shielded by the housing 23 and the shielding frame 40 , so that it will not cause electromagnetic interference to other adjacent devices 110 and/or the onboard chip 20 . The electromagnetic signals of other external devices 110 and/or the onboard chip 20 can also be shielded by the shielding frame 40 and the casing 23, and cannot enter the accommodation space formed by the casing 23 and the substrate 21, ensuring that Reliable operation of chip die 22.

The electromagnetic signal may also propagate through the annular gap 140. At this time, the shielding member 50 in the circuit board assembly 100 of the present application can also form a shielding effect on the annular gap 140 to prevent the bare chip 22 from transmitting or receiving external signals. Electromagnetic interference signal. In some embodiments, the material of the shielding member 50 can be conductive foam, conductive sponge, conductive glue, conductive plastic, conductive film or metal. When the material of the shielding member 50 is conductive foam, conductive sponge, conductive glue, conductive plastic or conductive film, the shielding member 50 behaves as a non-Newtonian body, and the shielding member 50 can deform itself to accommodate the onboard chip 20 and the shielding frame 40 The matching size tolerances between them ensure reliable contact between the inner edge 51 and the housing 23 and reliable contact between the outer edge 52 and the shielding frame 40 .

In the diagram of FIG. 6 , the shielding member 50 is made of conductive film. The inner edge 51 of the shielding member 50 is fixed on the top surface of the housing 23 , and the outer edge 52 is fixed on the top surface of the shielding frame 40 . In the embodiment shown in FIG. 13 , the shielding member 50 can be made of conductive foam, conductive sponge, conductive glue or conductive plastic. The shielding member 50 is entirely embedded in the annular gap 140 , and its inner edge 51 is in contact with the shell. The outer surface of the shield frame 23 is in contact with each other, and the outer edge 52 is in contact with the inner surface of the shielding frame 40 . The above structures can ensure the shielding effect formed by the shielding frame 40 and the shielding member 50 together.

FIG. 14 illustrates the structure of another onboard chip 20 in the circuit board assembly 100 of the present application. In this embodiment, the onboard chip 20 includes a base substrate 21 , a chip die 22 , and a fence 24 . The first surface 211 of the base substrate 21 is used to be attached and fixed to the first plane 11 of the circuit board 10 , and the chip die 22 and the fence 24 are located on the second side 212 of the base substrate 21 . The chip die 22 is located in the central area of the second surface 212 , and the fence 24 is surrounding the periphery of the chip die 22 and is spaced apart from the chip die 22 . The material of the fence 24 can be a conductive material, and the fence 24 can be used to improve the structural stability of the substrate substrate 21 .

In the embodiment of the present application, the chip die 22 is exposed on the side of the onboard chip 20 away from the first plane 11 , that is, the chip die 22 is exposed toward the heat sink 30 . At this time, the thermal conductive layer 130 provided between the chip die 22 and the bonding surface 31 may include a thermal conductive interface material. One side of the thermally conductive interface material is attached to the chip die 22 , and the other side is directly attached to the attachment surface 31 of the heat sink 30 . Therefore, the heat generated by the chip die 22 during operation can be directly transferred to the heat sink 30 through the thermally conductive interface material, and the heat can be dissipated through the heat dissipation teeth 321 located on the heat dissipation surface 32 .

The shielding frame 40 and the shielding member 50 are both located between the circuit board 10 and the heat sink 30 . The shielding frame 40 is fixed on the circuit board 10 . The shielding frame 40 is arranged around the periphery of the onboard chip 20 and is spaced apart from the onboard chip 20 . An annular gap 140 is formed between the shield frame 40 and the onboard chip 20 , and the shielding member 50 is used to shield the annular gap 140 .

In the circuit board assembly 100 of this embodiment, the shielding member 50 also has a hollow structure. Specifically referring to FIG. 15 , the shielding member 50 includes a connecting part 53 and a shielding part 54 . The inner edge 51 of the shielding part 50 is located at the connecting part 53 and the outer edge 52 is located at the shielding part 54 . Therefore, the connecting part 53 is used to be fixedly connected to the fence 24, and the shielding part 54 is used to cooperate with the shielding frame 40 to achieve the electromagnetic shielding effect.

Specifically, in this embodiment, the connecting portion 53 can extend in a direction parallel to the first plane 11 , cross the top of the shielding frame 40 , and extend to the side of the shielding frame 40 away from the onboard chip 20 to achieve the annular gap 140 of covering. At the same time, the shielding portion 54 can be located on a side of the shielding frame 40 away from the onboard chip 20 and is spaced apart from the shielding frame 40 . The shielding portion 54 extends from the top of the shielding frame 40 toward the first plane 11 of the circuit board 10 . In a direction perpendicular to the first plane 11 , the shielding portion 54 at least partially overlaps the shielding frame 40 , that is, the projection of the outer edge 52 of the shielding member 50 on the shielding frame 40 is located at the outer side wall of the shielding frame 40 . The gap between the shielding part 54 and the shielding frame 40 is small, and is used to realize the electromagnetic shielding function of the shielding member 50 on the side of the shielding frame 40 .

It is defined that the electromagnetic wave generated by the onboard chip 20 in this embodiment has a wavelength λ, and the shielding part 54 and the screen can be controlled. If the gap between the shielding frames 40 is less than or equal to 1/4λ, the electromagnetic shielding function of the shielding member 50 on one side of the shielding frame 40 can be achieved. In this embodiment, the shielding member 50 can be made of conductive plastic, conductive film or metal material to ensure the structural stability of the shielding member 50 and to ensure the size spacing of the shielding member 50 relative to the shielding frame 40 and to ensure that the shielding member 50 is in contact with the shielding frame 40 . The shielding frame 40 jointly forms a shielding effect.

It can be understood that the structure of the shield 50 of the present application is also applicable to the embodiment of the circuit board assembly 100 shown in FIG. 6 . At this time, the connecting portion 53 of the shielding member 50 can be fixed on the top surface of the housing 23 , and the shielding portion 54 is used to cooperate with the shielding frame 40 . The structure of the shield 50 shown in FIG. 6 using conductive foam, conductive sponge, conductive glue, conductive plastic, and conductive film can also be applied to the embodiment of the circuit board assembly 100 shown in FIG. 7 . At this time, the inner edge 51 of the shielding member 50 is fixedly connected to the fence 24, and the outer edge 52 is fixedly connected to the shielding frame 40, which can also achieve a better shielding effect.

In the diagram of FIG. 7 , the circuit board assembly 100 of the present application can also be provided with a structure of a flexible shielding ring 60 . The flexible shielding ring 60 is arranged around the periphery of the fitting surface 31 , and the flexible shielding ring 60 is also located between the fence 24 and the radiator 30 . The opposite sides of the flexible shielding ring 60 resist the heat sink 30 and the fence 24 respectively to form a shielding effect on the chip die 22 .

Specifically, the heat sink 30 is also provided with a step surface 34 on the side close to the fitting surface 31 . The step surface 34 surrounds the periphery of the bonding surface 31 and is away from the first plane 11 of the circuit board 10 relative to the bonding surface 31 . Because the bare chip 22 is exposed toward the heat sink 30, an electromagnetic signal transmission channel is also formed between the fence 24 and the step surface 34, which may cause the electromagnetic signal formed by the bare chip 22 to be transmitted outward, causing electromagnetic interference; or causing external The electromagnetic interference signal enters the bare chip 22 and affects the normal operation of the bare chip 22 .

The flexible shielding ring 60 is arranged so that its opposite sides resist the radiator 30 and the fence 24 respectively, which can cut off the transmission channel of the electromagnetic signal and further enhance the shielding effect between the bare chip 22 and the outside world. The flexible shielding ring 60 can be made of conductive foam, conductive sponge, conductive glue, or metal (such as reeds, etc.). Its two opposite sides are respectively engaged with the step surface 34 of the radiator 30 and the top surface of the fence 24 to ensure the sealing effect of the bare chip 22 . At the same time, the material of the flexible shielding ring 60 is elastic and can deform itself to accommodate the matching size tolerance between the radiator 30 and the fence 24 and ensure reliable contact during the resistance process on both sides.

In the embodiment shown in FIG. 7 , on the side where the flexible shielding ring 60 cooperates with the fence 24 , the inner edge 51 of the shielding member 50 is also sandwiched between the flexible shielding ring 60 and the fence 24 . The flexible shielding ring 60 passes through the The shielding member 50 is resisted to directly resist the fence 24 . Such an arrangement can directly fix the flexible shielding ring 60 on the step surface 34 and fix the shielding member 50 on the side of the flexible shielding ring 60 away from the heat sink 30 .

During the process of assembling the circuit board assembly 100 of the present application, the onboard chip 20 and the shielding frame 40 can be fixed on the circuit board 10 first, and then the heat sink 30 can be fixed through the fasteners 120 . Because the flexible shielding ring 60 and the shielding member 50 have been fixed relative to the heat sink 30, the process of assembling the heat sink 30 at this time completes the installation operation of the flexible shielding ring 60 and the shielding member 50 simultaneously, simplifying the assembly of the circuit board assembly 100. The process also ensures the position accuracy of the flexible shielding ring 60 and the shielding member 50 relative to the heat sink 30 .

In the embodiment illustrated in FIGS. 6 and 7 , the overall overall dimensions and width of the shielding member 50 and the shielding frame 40 are smaller than the overall dimensions and width of the heat sink 30 . That is, the projections of the shielding member 50 and the shielding frame 40 on the heat sink 30 are contained within the outer contour of the heat sink 30 . Because the heat sink 30 needs to achieve a preset heat dissipation effect, the area of its heat dissipation surface 32 is usually larger than the area of the fitting surface 31 . The widths of the shielding frame 40 and the shielding member 50 are both accommodated within the outer contour of the radiator 30, so that neither the shielding frame 40 nor the shielding member 50 exceeds the outer contour size of the radiator 30, ensuring that the circuit board assembly 100 of the present application The overall area is smaller, which is conducive to realizing a high-density arrangement design of the circuit board assembly 100 .

16 and 17 respectively illustrate the structures of the circuit board assembly 100a and the circuit board assembly 100b in the prior art. In the diagram of FIG. 16 , the prior art circuit board 100a also includes a circuit board 10a, an on-board chip 20a and a heat sink 30a. Furthermore, the prior art circuit board assembly 100a is also provided with a shielding ring 60a outside the onboard chip 20a. The shielding ring 60a is fixed to the heat sink 30a on the board and surrounding the onboard chip 20a. The material of the shielding ring 60a can be a wave-absorbing material to absorb electromagnetic signals to form a shielding effect; or the shielding ring 60a can be constructed as a frequency selective surface (FSS) to form the onboard chip 20 based on the slot waveguide theory. Electromagnetic shielding protection effect.

However, the shielding performance of the absorbing material is proportional to its own width (as shown in Figure 18). This leads to the fact that in order to achieve the preset shielding effect in the prior art circuit board assembly 100a, its cross-sectional width needs to be at least more than 10 mm, which greatly increases The overall area of the circuit board assembly 100a of the prior art is reduced; the shielding performance of the frequency selective surface is related to the wavelength λ of the electromagnetic wave, which also limits the miniaturization of the overall area of the circuit board assembly 100a.

In the prior art circuit board assembly 100b shown in FIG. 17, a circuit board 10b, an on-board chip 20b and a heat sink 30b are also included. Furthermore, the prior art circuit board assembly 100b is also provided with a shielding cover 40b outside the onboard chip 20b. The shielding case 40b is fixed on the circuit board 10b and surrounds the periphery of the onboard chip 20b. The structure of the shielding cover 40b needs to partially extend between the heat sink 30b and the onboard chip 20b, and form a gap fit with the heat sink 30b and the onboard chip 20b respectively. The height of the gap is not less than 0.5 mm. At this time, the gap between the heat sink 30b and the onboard chip 20b needs to be at least greater than 1 mm, which increases the height of the prior art circuit component 100b and is not conducive to its miniaturization design.

At the same time, the shielding case 40b is fixed on the circuit board 10b, and a transmission line passing through the shielding case 40b may be provided on the surface of the circuit board 10b. The position where the shielding cover 40b is combined with the circuit board 10b needs to be set in a zigzag structure at intervals to avoid the transmission line structure. The fitting accuracy between the spaced sawtooth structure and the circuit board 10b cannot be guaranteed due to process limitations. As shown in Figure 19, when the outer dimensions of the shielding cover 40b reaches 98×89mm, the coplanarity of the sawtooth structures in the six samples reaches 0.12-0.23mm respectively, exceeding the requirement for coplanarity of 0.1mm. Unable to achieve better shielding effect.

The circuit board assembly 100 of the present application, by arranging the structure of the shielding frame 40 and cooperating with the shielding member 50 and the onboard chip 20 to be in direct contact and the shielding member 50 and the shielding frame 40 to be in direct contact or with a small gap, can ensure On the basis of the shielding effect of the onboard chip 20, reducing the overall size of the shielding structure is beneficial to the miniaturization and high-density arrangement design of the circuit board assembly 100, and further reduces the overall volume of the electronic device 200 of the present application.

The circuit board assembly 100 of the present application can be applied to scenarios where the size of the onboard chip 20 is relatively large (such as 50-110 mm). By using the solution of the circuit board assembly 100 of the present application, the high-density arrangement design of the circuit board assembly 100 in this scenario can be realized. .

Refer to FIG. 20 for an embodiment. On the first plane 11 of the circuit board 10, a transmission line 12 is also provided. One end of the transmission line 12 is connected to and conducted with the onboard chip 20 , and the other end is connected to and conducted with other devices 110 to realize the data transmission function of the onboard chip 20 . In one embodiment, the transmission line 12 may be a power line, which is used to provide the on-board chip 20 with the power required for operation. Other devices 110 are located outside the shielding frame 40 , that is, the end of the transmission line 12 away from the onboard chip 20 is located on the side of the shielding frame 40 away from the onboard chip 20 . The number of transmission lines 12 may be multiple, and the multiple transmission lines 12 may pass through one side of the shielding frame 40 to achieve connection and conduction with external devices. In the diagram of FIG. 20 , the multi-channel transmission lines 12 pass through the opposite sides of the shielding frame 40 respectively. It can be understood that in other embodiments, the transmission line 12 can also pass through more sides of the shielding frame 40, which is not specifically limited in this application.

The shielding frame 40 can also be fixed on the circuit board 10 through the connector 150 . To facilitate clear description, the structure of the connector 150 at the shielding frame 40 is omitted in the remaining drawings of the embodiment of the present application.

Please refer to the structural diagram of the shielding frame 40 from one side as shown in FIG. 21 . In this embodiment, the shielding frame 40 includes a main body 41 , a protruding portion 42 and conductive glue 43 . The main body 41 includes a first side 411 and a second side 412 . The first side 411 is located close to the circuit board 10 , and the second side 412 is located away from the circuit board 10 . The protrusions 42 are spacedly arranged on the first side 411 of the main body 41 and protrude toward the first plane 11 of the circuit board 10 . A hollow area 44 is formed between two adjacent protrusions 42 , and the hollow area 44 is used to allow the transmission line 12 to pass through.

It can be understood that each hollow area 44 can be used to allow one transmission line 12 to pass through. In some embodiments, the hollow area 44 may also allow multiple transmission lines 12 to pass through simultaneously. The structure of the shield frame 40 may be based on the number, width, and bit length of the transmission lines 12 The number, spacing distance and position of the protrusions 42 should be set accordingly to ensure that the transmission line 12 can pass through and achieve a better shielding and protection effect.

The conductive glue 43 is at least disposed between the protruding portion 42 and the first flat surface 11 , that is, the conductive glue 43 can be used to fill the gap between the protruding portion 42 and the first flat surface 11 . As mentioned above, in the prior art circuit board 100b shown in FIG. 17, it is difficult to ensure the coplanarity of the sawtooth structure, resulting in the inability to reliably fit between individual sawtooth structures and the circuit board 10b, affecting the shielding effect. In the embodiment of the present application, conductive glue 43 is used to fill the gap between the protruding portion 42 and the first plane 11 , thereby eliminating possible shielding defects caused by the gap. Furthermore, the conductive adhesive 43 can also be coated on the side walls of the protruding portion 42 to increase the contact area between the conductive adhesive 43 and the protruding portion 42 and improve the structural stability of the conductive adhesive 43 .

In the structural diagram of the shielding frame 40 from one side as shown in FIG. 22 , the shielding frame 40 includes a main body 41 , a bonding pad 45 and a conductive adhesive 43 . The soldering pads 45 are arranged at intervals on the first plane 11 of the circuit board 10 , the main body 41 is located on the side of the soldering pads 45 away from the first plane 11 , and the conductive adhesive 43 is located between the soldering pads 45 and the main body 41 . The conductive glue 43 is used to realize electrical connection between the soldering pad 45 and the main body 41 to ensure the shielding effect of the position of the soldering pad 45, and is used to form a hollow area 44 between two adjacent soldering pads 45.

In this embodiment, the structure of the pad 45 is similar to the raised portion 42 in FIG. 21 , and is used to form a hollow area 44 on the first plane 11 of the circuit board 10 to allow the transmission line 12 to pass through. The soldering pads 45 can also be produced simultaneously with the circuit board 10 , thereby improving the positional accuracy of the soldering pads 45 and ensuring the overall shielding effect of the shielding frame 40 .

FIG. 23 illustrates the cross-sectional structure of the circuit board assembly 100 of the present application in an embodiment. The direction of the cross section is perpendicular to the first plane 11 . FIG. 24 illustrates the planar structure of the onboard chip 20 in this embodiment.

In the process of designing the circuit board assembly 100 of the present application, it is first necessary to determine the frequency band in which the onboard chip 20 may generate electromagnetic signals based on the operating characteristics of the onboard chip 20 . In the diagram of FIG. 23 , the lower limit of the transmission rate of the onboard chip 20 is 20.625Gb/s, and the upper limit of the transmission rate is 28Gb/s. From this, it is determined that the suppression frequency band range of the shielding structure is between 20-30GHz.

Then, the overall dimensions of the onboard chip 20 are determined to be 61×61 mm, and the onboard chip 20 adopts the structure of the fence 24 . The outer contour of the fence 24 is substantially aligned with the outer contour of the substrate 21 . The fence 24 has a width of about 6 mm and a thickness of about 2 mm. The peak power consumption of chip die 22 is about 393W.

Further, the gap between the radiator 30 and the fence 24 is 1.2 mm, and the thickness of the connecting portion 53 of the shield 50 is about 0.2 mm. At this time, the installation height of the flexible shielding ring 60 is about 1 mm. The flexible shielding ring 60 can be made in the form of conductive glue. The tolerance zone of the conductive glue is about 0.316mm, and its resilience range is between 5% and 32%. The height of the flexible shielding ring 60 is set to 1.1mm, the width is about 1mm, and the flexibility The shielding ring 60 is compressed after assembly, and its compression elastic force can ensure reliable resistance against the fence 24 and the radiator 30 .

On the side of the shielding part 54 of the shielding member 50 , the gap between the shielding part 54 and the shielding frame 40 is set to 0.1 mm. In order to ensure that both the shielding member 50 and the shielding frame 40 are accommodated within the outer contour of the heat sink 30 , the width of the first side 411 of the shielding frame 40 is also set to be wider than the width of the second side 412 , that is, the entire shielding frame 40 It is set into a stepped shape as shown in Figure 23. The width of the first side 411 can be set to 1mm to ensure a reliable connection between the shielding frame 40 and the circuit board 10; the width of the second side 412 can be set to 0.75mm so that the shielding portion 54 of the shielding member 50 faces the board. The direction of the chip carrier 20 is shrunk to prevent the shielding portion 54 from extending beyond the outer contour of the heat sink 30 and causing interference with adjacent devices.

In one embodiment, the shielding frame 40 can also be fixed on the outer edge 52 of the shielding member 50 . Referring to FIG. 25 specifically, the shielding frame 40 is fixed to the side of the shielding portion 54 of the shielding member 50 close to the onboard chip 20 . When the shielding frame 40 is fixed on the outer edge 52 of the shielding member 50 , there is a gap between the shielding frame 40 and the first plane 11 . It can be understood that the shielding frame 40 can cooperate with the shielding member 50 to achieve a shielding effect on the onboard chip 20 . Moreover, the gap left between the shielding frame 40 and the first plane 11 also facilitates the arrangement of the transmission lines 12 on the first plane 11 .

In the illustration of FIG. 25 , the shielding frame 40 may be an injection molded structural component or a molded structural component. The main material of the shielding frame 40 is plastic, and the main material of the shielding frame 40 is doped with absorbing particles and/or conductive particles to form a shielding effect of the shielding frame 40 on the onboard chip 20 . In other embodiments, the shielding frame 40 can also be formed by spraying, electroplating, or immersion. on the surface of the shielding portion 54 of the shielding member 50 . Such a structure further reduces the thickness of the shielding frame 40 so that the shielding portion 54 of the shielding member 50 shrinks toward the onboard chip 20 to prevent the shielding portion 54 from extending beyond the outer contour of the heat sink 30 and causing interference with adjacent components. Interference phenomenon between devices.

The above descriptions are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, such as reducing Or adding structural components, changing the shape of structural components, etc., should all be covered by the protection scope of this application; in the case of no conflict, the embodiments of this application and the features in the embodiments can be combined with each other. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A circuit board assembly, characterized in that it includes a circuit board, an onboard chip, a heat sink, a shielding frame, and a shielding member;

The onboard chip is mounted on the first plane of the circuit board, the heat sink includes a fitting surface facing the onboard chip, and a thermal conductive layer is provided between the fitting surface and the onboard chip. ; The heat sink is fixed on the circuit board through fasteners, so that the fitting surface and the thermal conductive layer fit together;

The shielding frame is arranged around the onboard chip, and an annular gap is formed between the shielding frame and the onboard chip;

The shielding member has a hollow structure, the inner edge of the shielding member is fixed on the onboard chip, and the outer edge of the shielding member is in contact with the shielding frame; or the shielding frame is fixed on the third On a plane, the outer edge of the shielding member is located on the side of the shielding frame away from the onboard chip and is spaced apart from the shielding frame; the shielding member is used to cover the annular gap.
The circuit board assembly according to claim 1, wherein the onboard chip includes a base substrate, a chip die and a fence, the base substrate is fixed on the first plane, the chip die Fixed to the side of the base substrate away from the first plane, the fence is set around the periphery of the chip die, the thermal conductive layer is provided on the outer surface of the chip die, and the The inner edge of the shield is fixed to the fence.
The circuit board assembly according to claim 2, characterized in that the circuit board assembly further includes a flexible shielding ring, the flexible shielding ring is arranged around the periphery of the fitting surface and is located between the fence and the Between the heat sinks, opposite sides of the flexible shielding ring resist the heat sink and the fence respectively to form a shielding effect on the bare chip.
The circuit board assembly according to claim 3, wherein an inner edge of the shielding member is sandwiched between the flexible shielding ring and the fence.
The circuit board assembly according to claim 1, wherein the onboard chip includes a base substrate, a chip die and a shell, the base substrate is fixed on the first plane, and the shell Fixed on the side of the base substrate away from the first plane, the housing and the base substrate form a receiving space, the bare chip is received in the receiving space, and the inner part of the shielding member The edge is provided on the outer surface of the housing, and the housing is also used to form the thermally conductive layer.
The circuit board assembly according to any one of claims 1 to 5, characterized in that the shielding frame is fixed on the first plane, the outer edge of the shielding member is in contact with the shielding frame, and the The shielding member is made of flexible material.
The circuit board assembly according to any one of claims 1 to 5, wherein the shielding member includes a connecting portion and a shielding portion, the inner edge of the shielding member is located on the connecting portion, and the shielding member The outer edge is located on the shielding part, and the extending direction of the shielding part is perpendicular to the first plane.
The circuit board assembly according to any one of claims 1 to 7, wherein the circuit board includes a transmission line, the transmission line is located on the first plane, and one end of the transmission line is fixed to the onboard chip. Connect and conduct, and the other end is located on the side of the shielding frame away from the onboard chip. The shielding frame is provided with a hollow area for allowing the transmission line to pass through.
The circuit board assembly according to claim 8, wherein the shielding frame includes a main body, a protruding portion and a conductive Glue, the protrusions are arranged at intervals on the side of the main body close to the first plane and protrude toward the first plane, and a hollow area is formed between two adjacent protrusions. , the conductive glue is provided between the protruding part and the first plane.
The circuit board assembly according to claim 8, wherein the shielding frame includes a main body, soldering pads and conductive glue, the soldering pads are spacedly arranged on the first plane, and the main body is located on the soldering pads. The side of the pad facing away from the first plane, the conductive glue is located between the pad and the main body, and a hollow area is formed between two adjacent pads.
The circuit board assembly according to any one of claims 1 to 10, wherein in any cross section perpendicular to the first plane, the shielding frame includes a first side close to the first plane, and a second side away from the first plane, the wall thickness of the first side being greater than the wall thickness of the second side.
The circuit board assembly according to any one of claims 1 to 5, characterized in that the shielding frame is fixed on the outer edge of the shielding member, and there is a gap between the shielding frame and the first plane.
An electronic device, characterized in that it includes a shell and a circuit board assembly according to any one of claims 1 to 12, the circuit board assembly is installed on the shell and is used to realize the operation of the electronic device. Function.