Circuit board assembly and electronic device

Abstract

Embodiments of the present application relate to the technical field of circuit board assemblies, and provide a circuit board assembly and an electronic device. The circuit board assembly comprises a circuit board, an electronic component, and a first thermally conductive medium. The electronic component is located on one side of the circuit board and is connected to the circuit board. The first thermally conductive medium comprises a first portion and a second portion. The first portion is located on the side of the electronic component away from the circuit board. The second portion is located on the side of the electronic component away from the circuit board and surrounds the first portion; and / or the second portion and the electronic component are located on the same side of the circuit board, the second portion surrounds the electronic component and the first portion, and the second portion is in contact with the electronic component. The first portion comprises a metal filler-doped thermal interface material, and the second portion comprises an insulating thermal interface material. In this way, the second portion can surround the first portion, serving as a barrier to reduce the risk of the first portion falling onto the circuit board and causing a short circuit on the circuit board.

Description

Circuit board assemblies and electronic devices

[0001] This application claims priority to Chinese patent application filed on November 8, 2024, with application number 202411600201.5 and entitled "Circuit Board Assembly and Electronic Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] Embodiments of this application provide a circuit board assembly and an electronic device, relating to the technical field of circuit board assemblies. Background Technology

[0003] A circuit board assembly typically consists of a circuit board and electronic components, with the electronic components mounted on the circuit board. These electronic components generate a significant amount of heat during operation, thus requiring a heat-conducting medium to quickly transfer the heat to heat dissipation components.

[0004] Thermally conductive media have good electrical conductivity, and when they flow onto a circuit board, they increase the risk of short circuits. Summary of the Invention

[0005] Embodiments of this application provide a circuit board assembly and an electronic device for reducing the risk of circuit board short circuits.

[0006] In one aspect, embodiments of this application provide a circuit board assembly. The circuit board assembly includes a circuit board, electronic components, and a first thermally conductive medium. The electronic components are located on one side of the circuit board and connected to it. The first thermally conductive medium includes a first portion and a second portion. The first portion is located on the side of the electronic components away from the circuit board. The second portion is located on the side of the electronic components away from the circuit board and surrounds the first portion; and / or, the second portion and the electronic components are located on the same side of the circuit board, surrounding the electronic components and the first portion, and the second portion is in contact with the electronic components. The first portion comprises a thermal interface material doped with metal filler, and the second portion comprises an insulating thermal interface material.

[0007] In the embodiments of this application, the first part is provided with a thermal interface material doped with metal filler, which can reduce the thermal resistance of the first part, improve the thermal conductivity of the first part, and facilitate the heat dissipation of electronic devices.

[0008] The second part can be set on the side of the electronic device away from the circuit board, or it can be set on the side of the circuit board closer to the electronic device. Alternatively, part of the second part can be set on the side of the electronic device away from the circuit board, and the other part can be set on the side of the circuit board closer to the electronic device, which improves the flexibility of the second part's setting.

[0009] Furthermore, the second part can enclose the first part and act as a barrier to the first part, that is, it can provide protective constraints to the first part, forming a complete protective ring, realizing physical isolation between the first part and the circuit board, reducing the risk of the first part overflowing or leaking from the surface of the electronic device and falling onto the circuit board, thereby causing a short circuit on the circuit board.

[0010] The second part includes an insulating thermal interface material, giving it good thermal conductivity and facilitating heat dissipation for electronic devices. Furthermore, both the first and second parts can contact the electronic devices, reducing the thermal resistance between the first thermal medium and the devices. In addition, the second part has good insulation properties, preventing short circuits even when mounted on the circuit board, thus improving the reliability of the circuit board assembly.

[0011] In other words, the first thermally conductive medium provided in the embodiments of this application can take into account both insulation and thermal conductivity, thereby reducing the risk of short circuits on the circuit board and ensuring thermal conductivity, which is beneficial for heat dissipation of electronic devices.

[0012] In some possible implementations, the second part includes a thermal interface material doped with a thermally conductive filler. This thermally conductive filler includes at least one selected from zinc oxide, magnesium oxide, aluminum oxide, aluminum nitride, silicon carbide, boron nitride, and diamond. This configuration reduces the thermal resistance of the second part, facilitating heat dissipation for electronic devices. Furthermore, including at least one of zinc oxide, magnesium oxide, aluminum oxide, aluminum nitride, silicon carbide, boron nitride, and diamond in the thermally conductive filler improves the flexibility in material selection. Both the thermally conductive filler and the thermal interface material are insulating materials, enabling the second part to possess excellent insulation properties, reducing the risk of short circuits on the circuit board caused by the first thermally conductive medium, and improving the reliability of the circuit board assembly.

[0013] In some possible implementations, the thermally conductive filler accounts for more than or equal to 50% of the mass in the second part. This setting can improve the thermal conductivity of the second part, reduce its thermal resistance, and facilitate heat dissipation for electronic devices.

[0014] In some possible implementations, the second part has a withstand voltage greater than or equal to 5 volts / 0.3 mm. Understandably, the second part has good insulation properties. Enclosing and blocking the first part with the second part reduces the risk of short circuits on the circuit board, allowing the first thermally conductive medium to maintain both insulation and thermal conductivity, thus improving the reliability of the circuit board assembly.

[0015] In some possible implementations, the thermal conductivity of the second part is greater than or equal to 1 W / m·°C. Understandably, the second part has good thermal conductivity, allowing heat to be rapidly conducted through it, which is beneficial for heat dissipation in electronic devices.

[0016] In some possible implementations, the mass ratio of the metal filler to the mass of the first part is greater than or equal to 80%. This setting allows the first part to have a lower thermal resistance, improves its thermal conductivity, and facilitates heat dissipation for electronic devices.

[0017] In some possible implementations, there are multiple electronic components, including first and second electronic components arranged adjacent to each other. A first portion is located on the side of the first electronic component away from the circuit board. When a second portion surrounds the first electronic component, the second portion is at least located between the first and second electronic components and is in contact with the first electronic component. This arrangement allows the circuit board covered by the second portion to be located in the sensitive area between the first and second electronic components, and the second portion can surround the first portion, i.e., it can provide protective constraint to the first portion, forming a complete protective ring. This achieves physical isolation between the first portion and the circuit board, reducing the risk of the first portion overflowing or leaking from the surface of the first electronic component and falling between the first and second electronic components, thereby causing a short circuit on the circuit board and improving the reliability of the circuit board assembly. Furthermore, the contact between the second portion and the first electronic component reduces the thermal resistance between them, facilitating heat dissipation from the first electronic component.

[0018] In some possible implementations, the second part covers the second electronic device. This arrangement allows heat dissipated from the second electronic device to be conducted outwards through the second part, facilitating heat dissipation. Furthermore, by having the second part cover the second electronic device, compared to placing the second part between the first and second electronic devices, the fabrication process of the second part can be simplified, reducing the cost of the circuit board assembly.

[0019] In some possible implementations, the edge of the first electronic device near the second electronic device is less than 0.1 mm from the edge of the second electronic device near the first electronic device. This arrangement improves the integration of the circuit board assembly. Taking a thermal interface material including a paste-like thermal conductive gel as an example, before curing, the paste-like thermal conductive gel has poor flowability in the height direction of the circuit board but good flowability in the direction parallel to the circuit board surface, exhibiting good gap-filling ability. In this way, the second part can be filled within a gap of less than 0.1 mm according to the arrangement of the electronic devices, allowing for a more compact arrangement of the electronic devices and facilitating their integration. Furthermore, achieving high filling of the gap between the first and second electronic devices reduces the risk of gaps existing between the second part and the circuit board or the first electronic device, which could cause the first part to leak out through the gap, ensuring the blocking effect of the second part on the first part.

[0020] In some possible implementations, the circuit board assembly also includes a shield. The shield covers the electronic components and the first heat-conducting medium. This arrangement can reduce electromagnetic interference between different components on the circuit board and improve the reliability of the circuit board assembly.

[0021] In some possible implementations, the shielding includes a cover plate and sidewalls. One edge of the sidewall is connected to the circuit board, and the other edge of the sidewall is connected to the cover plate. The cover plate is located on the side of the electronic device away from the circuit board. A first thermally conductive medium is located between the electronic device and the cover plate, and is in contact with both the electronic device and the cover plate. This arrangement allows heat dissipated by the first electronic device to be conducted to the cover plate via the first thermally conductive medium, and then dissipated to the outside via the cover plate. The fact that the first thermally conductive medium is in contact with both the electronic device and the cover plate reduces the thermal resistance between the first thermally conductive medium and both the electronic device and the cover plate, thus facilitating heat dissipation of the electronic device.

[0022] In some possible implementations, the circuit board assembly further includes a second thermally conductive medium. The second thermally conductive medium includes a third part and a fourth part. The third part is located on the side of the cover plate away from the electronic device. The fourth part is located on the side of the cover plate away from the electronic device and surrounds the third part; and / or, the fourth part and the shield are located on the same side of the circuit board, surrounding the shield and the third part, and the fourth part contacts the sidewall of the shield. The third part comprises a thermal interface material doped with metal filler, and the fourth part comprises an insulating thermal interface material. Using a thermal interface material doped with metal filler in the third part can reduce the thermal resistance of the third part, improve its thermal conductivity, and facilitate heat dissipation for the electronic device. The fourth part can be located on the side of the cover plate away from the electronic device, or it can be located on the side of the circuit board closer to the shield, or a portion of the fourth part can be located on the side of the cover plate away from the electronic device, and another portion can be located on the side of the circuit board closer to the shield, increasing the flexibility of the fourth part's placement. Furthermore, the fourth part can enclose the third part, acting as a barrier and providing protective constraint to the first part, forming a complete protective ring. This achieves physical isolation between the third part and the circuit board, reducing the risk of the third part overflowing or leaking from the shielding surface and falling onto the circuit board, potentially causing a short circuit. The fourth part includes an insulating thermal interface material, giving it good thermal conductivity, which is beneficial for heat dissipation of electronic devices. Both the third and fourth parts can contact the electronic devices, reducing the thermal resistance between the second thermal medium and the shielding. In addition, the fourth part has good insulation properties, so even if it is placed on the circuit board, it will not cause a short circuit, improving the reliability of the circuit board assembly. In other words, the second thermal medium provided in the embodiments of this application can balance insulation and thermal conductivity, reducing the risk of short circuits on the circuit board while ensuring effective heat dissipation for electronic devices.

[0023] In some possible implementations, the circuit board assembly also includes a heat dissipation component. The heat dissipation component is located on the side of the cover plate away from the electronic components. A second thermally conductive medium is located between the heat dissipation component and the cover plate, and contacts both the heat dissipation component and the cover plate. Understandably, heat dissipated by the electronic components can be conducted through the first thermally conductive medium to the shielding cover, then through the shielding cover to the second thermally conductive medium, and then through the second thermally conductive medium to the heat dissipation component, and finally dissipated outwards through the heat dissipation component, reducing the risk of excessive temperature causing the electronic components to malfunction. Positioning the second thermally conductive medium between the heat dissipation component and the cover plate, and making contact with both the heat dissipation component and the cover plate, reduces the thermal resistance between the second thermally conductive medium and the heat dissipation component and the cover plate, thus facilitating heat dissipation for the electronic components.

[0024] In some possible implementations, there are multiple circuit boards stacked on top of each other. The circuit board assembly also includes connectors that connect two stacked circuit boards. Understandably, stacking multiple circuit boards increases the integration of the circuit board assembly. The connectors provide support and connection, allowing electronic devices mounted on different circuit boards to be electrically connected.

[0025] In some possible implementations, there are multiple electronic components located on both sides of a circuit board. The multiple circuit boards include a first circuit board and a second circuit board arranged adjacent to each other. At least one first thermally conductive medium is located between the first and second circuit boards. This arrangement allows the first thermally conductive medium to be suitable for highly integrated circuit board assemblies, meeting various requirements.

[0026] In some possible implementations, the electronic device includes at least one of a system-on-a-chip (SoC), an RF chip, a charging chip, a resistor, and a switching transistor. A first thermally conductive medium is configured to conduct heat dissipated by at least one of the SoC, RF chip, charging chip, resistor, and switching transistor, thereby reducing the risk that at least one of the SoC, RF chip, charging chip, resistor, and switching transistor may malfunction due to excessive temperature.

[0027] In some possible implementations, the thermal interface material includes at least one of thermally conductive gel, thermally conductive grease, and thermally conductive pad. This arrangement increases the flexibility in material selection for the first thermally conductive medium.

[0028] On the other hand, embodiments of this application provide an electronic device. The electronic device includes a housing and a circuit board assembly as described above, the circuit board assembly being located within the housing.

[0029] The electronic device provided in the embodiments of this application includes the circuit board assembly as described above, and therefore has all the aforementioned beneficial effects, which will not be repeated here. Furthermore, by placing the circuit board assembly within a housing, the housing can protect the circuit board assembly and reduce the risk of damage to the circuit board assembly. Attached Figure Description

[0030] Figure 1 is a schematic diagram of the structure of an electronic device provided in some embodiments of this application;

[0031] Figure 2 is a schematic diagram of the circuit board assembly provided in some embodiments of this application;

[0032] Figure 3 is a cross-sectional view of the circuit board assembly in Figure 2 along the A1-A1 direction;

[0033] Figure 4 is a schematic diagram of the circuit board assembly provided in some other embodiments of this application;

[0034] Figure 5 is a cross-sectional view of the circuit board assembly in Figure 4 along the A2-A2 direction;

[0035] Figure 6a is a schematic diagram of the circuit board assembly provided in some embodiments of this application;

[0036] Figure 6b is a schematic diagram of the circuit board assembly provided in some embodiments of this application;

[0037] Figure 7 is a cross-sectional view of the circuit board assembly in Figure 6a along the A3-A3 direction;

[0038] Figure 8 is a schematic diagram of the circuit board assembly provided in some embodiments of this application;

[0039] Figure 9 is a cross-sectional view of the circuit board assembly in Figure 8 along the A4-A4 direction;

[0040] Figure 10 is a schematic diagram of the circuit board assembly provided in some embodiments of this application;

[0041] Figure 11 is a cross-sectional view of the circuit board assembly in Figure 10 along the A5-A5 direction;

[0042] Figure 12 is a cross-sectional structural diagram of a circuit board assembly provided in some embodiments of this application;

[0043] Figure 13 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some other embodiments of this application;

[0044] Figure 14 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some embodiments of this application;

[0045] Figure 15 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some embodiments of this application;

[0046] Figure 16 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some embodiments of this application;

[0047] Figure 17 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some embodiments of this application;

[0048] Figure 18 is a cross-sectional structural diagram of a circuit board assembly provided in some embodiments of this application. Detailed Implementation

[0049] The technical solutions in some embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application are within the protection scope of this application.

[0050] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples.

[0051] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0052] As used herein, “perpendicular” and “parallel” include the described situation and situations that are similar to the described situation, within an acceptable deviation range, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity can be 5%.

[0053] Figure 1 is a schematic diagram of the structure of an electronic device provided in some embodiments of this application. As shown in Figure 1, some embodiments of this application provide an electronic device 200. For example, the electronic device 200 can be a mobile phone, tablet computer, wearable smart device (e.g., smartwatch or smart bracelet), virtual reality (VR) device, augmented reality (AR) device, or other terminal device. The embodiments of this application do not further limit the type of electronic device 200.

[0054] As shown in Figure 1, the electronic device 200 may include a housing 201 and a circuit board assembly 100. The housing 201 can enclose a receiving space, and the circuit board assembly 100 is located inside the housing 201 (within the receiving space enclosed by the housing 201). It can be understood that placing the circuit board assembly 100 inside the housing 201 enables the housing 201 to protect the circuit board assembly 100 and reduce the risk of damage to the circuit board assembly 100.

[0055] Taking a mobile phone as an example, the housing 201 may include a middle frame and a back cover. The back cover is located on one side of the middle frame along the height direction of the middle frame and is connected to the middle frame. As shown in Figure 1, the electronic device 200 may also include a display screen 202. The display screen 202 is located on the side of the middle frame away from the back cover along the height direction of the middle frame and is connected to the middle frame.

[0056] Display screen 202 is capable of displaying image information. For example, display screen 202 can be a liquid crystal display (LCD), an organic light-emitting diode (OLED) display, an active matrix organic light-emitting diode (AMOLED) display, a flexible light-emitting diode (FLED) display, a sub-millimeter light-emitting diode (Mini LED) display, a micro light-emitting diode (Micro LED) display, a quantum dot light-emitting diode (QLED) display, etc.

[0057] The mid-frame may have multiple receiving compartments, with the openings of the multiple receiving compartments facing at least one of the display screen 202 and the rear housing. When the opening of a receiving compartment faces the rear housing, the rear housing can close the opening of the receiving compartment. When the opening of a receiving compartment faces the display screen 202, the display screen can close the opening of the receiving compartment.

[0058] The circuit board assembly 100 may be located within the receiving space formed by the middle frame and the rear shell, or the circuit board assembly 100 may be located within the receiving space formed by the middle frame and the display screen 202. The embodiments of this application do not further limit the placement of the circuit board assembly 100 within the housing 201.

[0059] Taking an electronic device 200 as a wearable smart device as an example, the electronic device 200 may include a main body and a wristband, with the wristband being fixedly and detachably connected to the main body. The wristband can be wrapped around the wrist, arm, leg, or other part of the body to secure the wearable smart device to the user. The main body, as the central element of the wearable smart device, may include a housing 201 and a screen. The housing 201 may include a bezel and a bezel, with the bezel surrounding the screen and its edge adjacent to and fixed to the bezel. That is, the bezel can surround the screen and the bezel. The screen and the bezel form the surface of the main body. For example, the screen may be an organic light-emitting diode (OLED) display. A receiving space is formed between the bezel and the screen, and the circuit board assembly 100 may be disposed within the receiving space formed by the bezel and the screen.

[0060] Figure 2 is a schematic diagram of the structure of a circuit board assembly provided in some embodiments of this application. Figure 3 is a cross-sectional view of the circuit board assembly in Figure 2 along the A1-A1 direction. The circuit board assembly 100 will be described below by way of example.

[0061] In some examples, as shown in Figures 2 and 3, the circuit board assembly 100 includes a circuit board 101 and an electronic device 102, which is located on one side of the circuit board 101 and connected to the circuit board 101.

[0062] Circuit board 101 can be a printed circuit board (PCB). For example, circuit board 101 can be the motherboard of electronic device 200. Alternatively, circuit board 101 can also be other circuit boards in electronic device 200 besides the motherboard, such as a battery management board. Electronic device 102 is located on one side of circuit board 101 and is electrically connected to circuit board 101. Electronic device 102 can be a processor, or it can be a capacitor, resistor, or switching transistor, etc.

[0063] Electronic device 102 generates a significant amount of heat during operation. Figure 4 is a schematic diagram of the circuit board assembly provided in some other embodiments of this application. Figure 5 is a cross-sectional schematic diagram of the circuit board assembly in Figure 4 along the A2-A2 direction. In some examples, as shown in Figures 4 and 5, the circuit board assembly 100 may further include a first thermally conductive medium 110, which is located on the side of electronic device 102 away from circuit board 101.

[0064] The first heat-conducting medium 110 can quickly conduct the heat emitted by the electronic device 102 to other components (such as heat dissipation components), reducing the risk that the electronic device 102 will not work properly due to excessive temperature.

[0065] For example, the first thermal conductive medium 110 may include a metal-doped thermal interface material (TIM). Metals have good thermal conductivity. By setting a metal-doped thermal interface material to form the first thermal conductive medium 110, the first thermal conductive medium 110 can have low thermal resistance and strong thermal conductivity, which is beneficial for heat dissipation of electronic device 102.

[0066] However, metals have good electrical conductivity. By setting a metal filler to dope the thermal interface material to form the first thermal conductive medium 110, the first thermal conductive medium 110 can have good electrical conductivity. As a result, when the first thermal conductive medium 110 overflows or leaks from the surface of the electronic device 102 and falls onto the surface of the circuit board 101, it may cause the circuit board 101 to short-circuit.

[0067] In related technologies, foam or rubber rings are typically used to surround electronic components 102 to reduce the risk of the first heat-conducting medium 110 falling onto the circuit board 101. However, foam and rubber rings have high thermal resistance, affecting the heat dissipation of electronic components 102. Furthermore, when multiple electronic components 102 are densely arranged, the foam and rubber rings cannot fill the small gaps, resulting in gaps between the foam and rubber rings and the circuit board 101 or electronic components 102. The first heat-conducting medium 110 may overflow or leak through these gaps and fall onto the circuit board 101, leading to poor reliability.

[0068] Based on this, embodiments of this application provide a circuit board assembly. Figure 6a is a structural schematic diagram of a circuit board assembly provided in some embodiments of this application. Figure 6b is a structural schematic diagram of a circuit board assembly provided in some embodiments of this application. Figure 7 is a cross-sectional schematic diagram of the circuit board assembly in Figure 6a along the A3-A3 direction. In some examples, as shown in Figures 6a, 6b and 7, the circuit board assembly 100 includes a circuit board 101, an electronic device 102 and a first heat-conducting medium 110, wherein the electronic device 102 is located on one side of the circuit board 101 and connected to the circuit board 101. It is understood that the circuit board 101 and the electronic device 102 have been illustrated in the above embodiments of this application, and will not be repeated here. The first heat-conducting medium 110 is illustrated below.

[0069] As shown in Figures 6a and 6b, the first thermally conductive medium 110 includes a first portion 111 and a second portion 112. The first portion 111 is located on the side of the electronic device 102 away from the circuit board 101. The first portion 111 includes a thermal interface material doped with metal filler.

[0070] For example, the first portion 111 may also cover a portion of the surface of the electronic device 102 away from the circuit board 101. When the first portion 111 covers a portion of the surface of the electronic device 102 away from the circuit board 101, the first portion 111 may be a regular shape (see FIG. 6a), such as a rectangle or other quadrilateral. Alternatively, the first portion 111 may be a curved strip (see FIG. 6b), or it may be a dotted adhesive. In other examples, the first portion 111 may completely cover the surface of the electronic device 102 away from the circuit board 101. The embodiments of this application do not further limit the shape of the first portion 111 or its placement on the surface of the electronic device 102 away from the circuit board 101.

[0071] The first portion 111 includes a thermal interface material doped with metal filler, which reduces the thermal resistance of the first portion 111, improves its thermal conductivity, and facilitates heat dissipation of the electronic device 102. For example, the first portion 111 can be attached to the surface of the electronic device 102 away from the circuit board 101 to reduce the thermal resistance between the first portion 111 and the electronic device 102, thus facilitating heat dissipation of the electronic device 102. In some examples, the metal filler may include one or more metal powders, such as at least one of copper powder, silver powder, or aluminum powder.

[0072] In some examples, the ratio of the mass of the metal filler to the mass of the first part 111 is greater than or equal to 80%.

[0073] Understandably, the ratio of the mass of the metal packing to the mass of the first portion 111 is less than 100%. For example, the ratio of the mass of the metal packing to the mass of the first portion 111 can be 82%, 85%, or 95%, etc. The embodiments of this application do not further limit the value of the ratio of the mass of the metal packing to the mass of the first portion 111.

[0074] The ratio of the mass of the metal filler to the mass of the first part 111 is set to be greater than or equal to 80%, so that the first part 111 can have a lower thermal resistance, improve the thermal conductivity of the first part 111, and facilitate the heat dissipation of the electronic device 102.

[0075] Figure 8 is a structural schematic diagram of a circuit board assembly provided in some embodiments of this application. Figure 9 is a cross-sectional schematic diagram of the circuit board assembly in Figure 8 along the A4-A4 direction. Figure 10 is a structural schematic diagram of a circuit board assembly provided in some embodiments of this application. Figure 11 is a cross-sectional schematic diagram of the circuit board assembly in Figure 10 along the A5-A5 direction.

[0076] In some examples, as shown in Figures 6a, 6b and 7, the second portion 112 is located on the side of the electronic device 102 away from the circuit board 101 and surrounds the first portion 111; and / or, as shown in Figures 8, 9, 10 and 11, the second portion 112 and the electronic device 102 are located on the same side of the circuit board 101, surround the electronic device 102 and the first portion 111, and the second portion 112 is in contact with the electronic device 102.

[0077] That is, as shown in Figures 6a, 6b, and 7, the second part 112 can be located on the side of the electronic device 102 away from the circuit board 101; or, as shown in Figures 8 and 9, the second part 112 can also be located on the side of the circuit board 101 close to the electronic device 102, surrounding the electronic device 102 and the first part 111, and in contact with the electronic device 102; or, as shown in Figures 10 and 11, a portion of the second part 112 can be located on the side of the electronic device 102 away from the circuit board 101, surrounding and contacting the electronic device 102; the other portion can be located on the side of the circuit board 101 close to the electronic device 102, surrounding the first part 111. This increases the flexibility of the placement of the second part 112.

[0078] When the second part 112 is located on the surface of the electronic device 102 away from the circuit board 101, as shown in Figures 6a, 6b and 7, the second part 112 surrounds the first part 111, thereby blocking the first part 111 and reducing the risk of the first part 111 overflowing or leaking from the surface of the electronic device 102 and falling onto the circuit board 101, causing a short circuit in the circuit board 101, thus improving the reliability of the circuit board assembly 100.

[0079] For example, along the direction perpendicular to the circuit board 101, the height of the first part 111 is less than the height of the second part 112, so as to ensure that the second part 112 has a blocking effect on the first part 111, reducing the risk that the first part 111 may overflow or leak from the surface of the electronic device 102 and fall onto the circuit board 101, causing a short circuit in the circuit board 101, and improving the reliability of the circuit board assembly 100.

[0080] For example, the second part 112 and the first part 111 can respectively contact the surface of the electronic device 102 away from the circuit board 101 to reduce the thermal resistance between the first heat-conducting medium 110 and the electronic device 102, thereby facilitating heat dissipation of the electronic device 102.

[0081] Understandably, the second part 112 and the first part 111 can be in direct contact, or the second part 112 and the first part 111 can be set at intervals.

[0082] For example, the second portion 112 and the first portion 111 may completely cover the surface of the electronic device 102 away from the circuit board 101, that is, in the direction parallel to the circuit board 101, the sum of the areas of the first portion 111 and the second portion 112 is equal to the area of ​​the electronic device 102. Alternatively, the surface of the electronic device 102 away from the circuit board 101 may also be exposed to the first portion 111 and the second portion 112, that is, in the direction parallel to the circuit board 101, the sum of the areas of the first portion 111 and the second portion 112 is less than the area of ​​the electronic device 102.

[0083] When the second part 112 and the electronic device 102 are located on the same side of the circuit board 101, as shown in Figures 8 and 9, the second part 112 surrounds the electronic device 102 and the first part 111, and the second part 112 is in contact with the electronic device 102. On the one hand, the second part 112 can cover the sensitive area of ​​the circuit board 101 (the area of ​​the circuit board 101 close to the first part 111), realizing physical isolation between the first part 111 and the circuit board 101. On the other hand, the second part 112 can block the first part 111, reducing the risk of the first part 111 overflowing or leaking from the surface of the electronic device 102 and falling onto the circuit board 101, causing a short circuit in the circuit board 101, and improving the reliability of the circuit board assembly 100.

[0084] On the other hand, the second part 112 is in contact with the electronic device 102, which can reduce the thermal resistance between the second part 112 and the electronic device 102, and facilitate the heat dissipation of the electronic device 102.

[0085] As shown in Figures 10 and 11, the second part 112 includes a first sub-part 112a and a second sub-part 112b, wherein one part of the second part 112 is located on the surface of the electronic device 102 away from the circuit board 101, and the other part is located on the same side of the circuit board 101 as the electronic device 102.

[0086] The first sub-part 112a is located on the side of the electronic device 102 away from the circuit board 101 and surrounds the first part 111. It can block the first part 111, reduce the risk of the first part 111 overflowing or leaking from the surface of the electronic device 102 and falling onto the circuit board 101, causing a short circuit in the circuit board 101, and improve the reliability of the circuit board assembly 100.

[0087] The second sub-part 112b and the electronic device 102 are located on the same side of the circuit board 101, surrounding the electronic device 102 and the first part 111, and in contact with the electronic device 102. Understandably, the second sub-part 112b can cover the sensitive area of ​​the circuit board 101 (the area of ​​the circuit board 101 close to the first part 111), achieving physical isolation between the first part 111 and the circuit board 101. Furthermore, the second sub-part 112b can act as a barrier to the first part 111, reducing the risk of the first part 111 overflowing or leaking from the surface of the electronic device 102 and falling onto the circuit board 101, causing a short circuit in the circuit board 101, and improving the reliability of the circuit board assembly 100.

[0088] On the other hand, the second sub-part 112b is in contact with the electronic device 102, which can reduce the thermal resistance between the second sub-part 112b and the electronic device 102, thus facilitating the heat dissipation of the electronic device 102.

[0089] That is, in the embodiments of this application, the second part 112 can form a protective ring to physically isolate the first part 111 and the circuit board 101, reduce the risk of the first part 111 overflowing or leaking from the surface of the electronic device 102 and falling onto the circuit board 101, causing the circuit board 101 to short circuit, and improve the reliability of the circuit board assembly 100.

[0090] Part 112 includes an insulating thermal interface material.

[0091] Understandably, the second part 112 includes an insulating thermal interface material, enabling it to have good thermal conductivity and facilitating heat dissipation from the electronic device 102. Furthermore, the second part 112 can contact the electronic device 102, reducing the thermal resistance between them and further improving heat dissipation. In addition, the second part 112 has good insulation properties, ensuring that even if it is mounted on the circuit board 101, it will not cause a short circuit, thus improving the reliability of the circuit board assembly 100.

[0092] In other words, the first heat-conducting medium 110 provided in the embodiments of this application can take into account both insulation and thermal conductivity. On the one hand, it reduces the risk of short circuit in the circuit board 101, and on the other hand, it can ensure the heat conduction effect, which is beneficial to the heat dissipation of electronic device 102.

[0093] For example, the thermal interface material can be solid or gel-like, or it can be gel-cured. Understandably, the first part 111 and the second part 112 can be solid or gel-like, or they can be gel-cured. The physical forms of the first part 111 and the second part 112 can be the same or different.

[0094] In some examples, the thermal interface material includes at least one of a thermally conductive gel (e.g., a paste-like thermally conductive gel and a post-curing thermally conductive gel), a thermally conductive grease, and a thermally conductive pad. This arrangement increases the flexibility in material selection for the first thermally conductive medium 110. Understandably, the thermal interface material may also include other thermally conductive materials besides thermally conductive gels, thermally conductive greases, and thermally conductive pads.

[0095] Taking thermal interface materials, including paste-like thermal conductive gel, as an example, before curing, the paste-like thermal conductive gel has poor fluidity in the height direction of the circuit board 101, but good fluidity in the direction parallel to the surface of the circuit board 101, and has good gap filling ability.

[0096] In this way, the second part 112 can be filled into irregular gaps and smaller gaps according to the arrangement of electronic components 102. This allows the second part 112 to be adapted to the irregular arrangement and layout of electronic components 102, enabling the electronic components 102 to be arranged more tightly. This facilitates the integration of electronic components 102 and achieves high filling of gaps between electronic components 102 under different layout configurations. It also reduces the risk of gaps between the second part 112 and the circuit board 101 or electronic components 102, which could cause the first part 111 to leak out from the gaps. This ensures the blocking effect of the second part 112 on the first part 111.

[0097] Understandably, the thermal interface material of Part 111 and Part 112 may be the same or different.

[0098] In some examples, the second part 112 can be formed first, followed by the first part 111, to reduce the risk that the first part 111 will fall onto the circuit board 101 before the second part 112 is formed.

[0099] In some examples, the second part 112 includes a thermal interface material doped with a thermally conductive filler. The thermally conductive filler includes at least one of zinc oxide, magnesium oxide, aluminum oxide, aluminum nitride, silicon carbide, boron nitride, and diamond.

[0100] Understandably, doping the thermal interface material with the thermally conductive filler to form the second portion 112 reduces the thermal resistance of the second portion 112, facilitating heat dissipation of the electronic device 102. Furthermore, the thermally conductive filler includes at least one of zinc oxide, magnesium oxide, aluminum oxide, aluminum nitride, silicon carbide, boron nitride, and diamond, increasing the flexibility in material selection. Both the thermally conductive filler and the thermal interface material are insulating materials, enabling the second portion 112 to possess good insulation properties, reducing the risk of short circuits in the circuit board 101 caused by the first thermally conductive medium 110, and improving the reliability of the circuit board assembly 100. For example, the thermally conductive filler may also include other insulating and thermally conductive materials; the embodiments of this application do not further limit the material of the thermally conductive filler.

[0101] In some examples, the ratio of the mass of the thermally conductive filler to the mass of the second part 112 is greater than or equal to 50%.

[0102] Understandably, the ratio of the mass of the thermally conductive filler to the mass of the second part 112 is less than 100%. For example, the ratio of the mass of the thermally conductive filler to the mass of the second part 112 can range from 50% to 95%, 60% to 85%, or 65% to 75%, etc. For instance, the ratio of the mass of the thermally conductive filler to the mass of the second part 112 can be 55%, 67%, 78%, 89%, or 98%, etc. The embodiments of this application do not further limit the value of the ratio of the mass of the thermally conductive filler to the mass of the second part.

[0103] Setting the mass ratio of the thermally conductive filler to that of the second part 112 to be greater than or equal to 50% can improve the thermal conductivity of the second part 112, reduce the thermal resistance of the second part 112, and facilitate the heat dissipation of the electronic device 102.

[0104] In some examples, the withstand voltage of Part 112 is greater than or equal to 5 volts / 0.3 mm (V / mm).

[0105] Understandably, withstand voltage performance refers to the highest voltage value that a material or device can withstand under specific conditions. The second part 112, with a thickness of approximately 0.3 mm, can withstand a maximum AC voltage greater than or equal to 5V, for example, 5.5V, 6V, or 7V, for 60 seconds to withstand breakdown. Therefore, the second part 112 has good insulation properties. By setting the second part 112 to enclose and block the first part 111, the risk of short circuits in the circuit board 101 can be reduced, allowing the first thermally conductive medium 110 to balance insulation and thermal conductivity, thereby improving the reliability of the circuit board assembly 100.

[0106] In some examples, the thermal conductivity of the second part 112 is greater than or equal to 1 W / m Kelvin (w / m*k).

[0107] For example, the thermal conductivity of the second part 112 is greater than or equal to 1 watt / meter Kelvin in both the direction parallel to the surface of the circuit board 101 and the direction perpendicular to the surface of the circuit board 101. For example, the thermal conductivity of the second part 112 can be 2 watts / meter Kelvin or 3 watts / meter Kelvin, etc.

[0108] It can be seen that the second part 112 has good thermal conductivity, and heat can be quickly conducted through the second part 112, which is beneficial to the heat dissipation of electronic device 102.

[0109] Figure 12 is a cross-sectional structural diagram of a circuit board assembly provided in some embodiments of this application. In some examples, as shown in Figure 12, the number of electronic devices 102 is multiple.

[0110] In some examples, electronic device 102 includes at least one of a system on chip (SOC), a radio frequency (RF) chip, a charge integrated circuit (charge IC), a resistor, and a switching transistor. For example, the switching transistor may be a metal-oxide-semiconductor field-effect transistor (MOS).

[0111] It is understood that electronic device 102 may also be other devices besides those described above, and the embodiments of this application do not further limit the specific form of electronic device 102. Multiple electronic devices 102 may be of the same type or different types.

[0112] The electronic device 102 is configured to include at least one of a system on chip (SOC), a radio frequency (RF) chip, a charge integrated circuit (charge IC), a resistor, and a switching transistor, such that the first thermally conductive medium 110 can conduct heat dissipated by at least one of the SOC, RF chip, charge IC, resistor, and switching transistor, thereby reducing the risk that at least one of the SOC, RF chip, charge IC, resistor, and switching transistor may malfunction due to excessive temperature.

[0113] As shown in Figure 12, the plurality of electronic devices 102 include first electronic devices 1021 and second electronic devices 1022 arranged adjacent to each other. For example, the first electronic devices 1021 and second electronic devices 1022 may be arranged at intervals on the same side of the circuit board 101. It is understood that the number of first electronic devices 1021 can be one or more, and the number of second electronic devices 1022 can also be one or more. The number of first electronic devices 1021 and the number of second electronic devices 1022 may be equal or unequal.

[0114] When there are multiple second electronic devices 1022, as shown in Figure 12, multiple second electronic devices 1022 can be arranged adjacent to the same first electronic device 1021.

[0115] As shown in Figure 12, the first part 111 is located on the side of the first electronic device 1021 away from the circuit board 101. When the second part 112 surrounds the first electronic device 1021, the second part 112 is located at least between the first electronic device 1021 and the second electronic device 1022, and is in contact with the first electronic device 1021.

[0116] The second part 112 is located at least between the first electronic device 1021 and the second electronic device 1022, such that the circuit board 101 covered by the second part 112 is located in the sensitive area between the first electronic device 1021 and the second electronic device 1022, and the second part 112 can surround the first part 111, realizing physical isolation between the first part 111 and the circuit board 101, reducing the risk of the first part 111 overflowing or leaking from the surface of the first electronic device 1021 and falling between the first electronic device 1021 and the second electronic device 1022, thereby causing a short circuit in the circuit board 101, and improving the reliability of the circuit board assembly 100.

[0117] Furthermore, the second part 112 is in contact with the first electronic device 1021, which can reduce the thermal resistance between the second part 112 and the first electronic device 1021, thus facilitating the heat dissipation of the first electronic device 1021.

[0118] In some examples, as shown in Figure 12, the second part 112 is located between the first electronic device 1021 and the second electronic device 1022, and is in contact with the first electronic device 1021 and the second electronic device 1022, so that the heat dissipated by the second electronic device 1022 can also be conducted outward through the second part 112, which is beneficial to the heat dissipation of the second electronic device 1022.

[0119] In some examples, as shown in Figure 12, the second part 112 covers the second electronic device 1022.

[0120] When there are multiple second electronic devices 1022, the second part 112 may cover multiple second electronic devices 1022, or the second part 112 may include a portion of the multiple second electronic devices 1022 (e.g., one, two or more) of the second electronic devices 1022.

[0121] The second part 112 is provided to cover the second electronic device 1022, so that the heat emitted by the second electronic device 1022 can be conducted outward through the second part 112, which is beneficial to the heat dissipation of the second electronic device 1022.

[0122] Furthermore, by providing the second part 112 to cover the second electronic device 1022, compared to placing the second part 112 between the first electronic device 1021 and the second electronic device 1022, the manufacturing process of the second part 112 can be simplified and the cost of the circuit board assembly 100 can be reduced.

[0123] In some examples, as shown in Figure 12, the edge of the first electronic device 1021 near the second electronic device 1022 is less than 0.1 mm from the edge of the second electronic device 1022 near the first electronic device 1021.

[0124] For example, the distance between the edge of the first electronic device 1021 near the second electronic device 1022 and the edge of the second electronic device 1022 near the first electronic device 1021 can be a first distance L1. When there are multiple second electronic devices 1022, the first distance L1 between different second electronic devices 1022 and the first electronic device 1021 can be the same or different.

[0125] Setting the edge of the first electronic device 1021 near the second electronic device 1022 and the edge of the second electronic device 1022 near the first electronic device 1021 to be less than 0.1 mm can improve the integration of the circuit board assembly 100.

[0126] Understandably, the thermal interface material has good flowability before curing, allowing the second part 112 to have a non-fixed shape during curing. For example, the thermal interface material can be in a gel state or gel-cured. Taking a paste-like thermally conductive gel as an example, before curing, the paste-like thermally conductive gel has poor flowability in the height direction of the circuit board 101, but good flowability in the direction parallel to the surface of the circuit board 101, thus exhibiting good gap-filling ability.

[0127] In this way, the second part 112 can be filled into a gap of less than 0.1 mm according to the arrangement of the electronic components 102, so that the electronic components 102 can be arranged more tightly, which is conducive to the integration of the electronic components 102. This achieves high filling of the gap between the first electronic component 1021 and the second electronic component 1022, reduces the risk that there may be gaps between the second part 112 and the circuit board 101 or the first electronic component 1021, which could cause the first part 111 to leak out from the gaps, and ensures the blocking effect of the second part 112 on the first part 111.

[0128] Figure 13 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some other embodiments of this application. In some examples, as shown in Figure 13, the circuit board assembly 100 further includes a shield 103. The shield 103 covers the electronic device 102 and the first heat-conducting medium 110.

[0129] For example, the material of the shield 103 can be metal to provide electromagnetic shielding. For instance, the material of the shield 103 may include at least one of nickel silver and stainless steel. Understandably, the shield 103 and the electronic device 102 are located on the same side of the circuit board 101, so that the shield 103 can cover the electronic device 102 and the first heat-conducting medium 110.

[0130] The shield 103 can block the electromagnetic field generated by the electronic device 102 from propagating outside the shield 103, and the shield 103 can also block the electromagnetic field of other devices on the circuit board 101 from entering the shield 103 and interfering with the electronic device 102. When there are multiple electronic devices 102, the shield 103 can cover one electronic device 102, or the shield 103 can cover at least two electronic devices 102.

[0131] The circuit board assembly 100 also includes a shield 103, which can reduce electromagnetic interference between different devices on the circuit board 101 and improve the reliability of the circuit board assembly 100.

[0132] In some examples, as shown in Figure 13, the shield 103 includes a cover plate 1031 and a sidewall 1032. One edge of the sidewall 1032 is connected to the circuit board 101, and the other edge of the sidewall 1032 is connected to the cover plate 1031. For example, the sidewall 1032 and the cover plate 1031 can be a single-piece structure to improve the reliability of their connection. The cover plate 1031 is located on the side of the electronics 102 away from the circuit board 101.

[0133] The first heat-conducting medium 110 is located between the electronic device 102 and the cover plate 1031, and is in contact with the electronic device 102 and the cover plate 1031 respectively.

[0134] In this way, the heat dissipated by the first electronic device 1021 can be conducted to the cover plate 1031 through the first thermally conductive medium 110, and then dissipated to the outside through the cover plate 1031. The first thermally conductive medium 110 is in contact with the electronic device 102 and the cover plate 1031 respectively, which can reduce the thermal resistance between the first thermally conductive medium 110 and the electronic device 102 and the cover plate 1031, thus facilitating the heat dissipation of the electronic device 102.

[0135] Figure 14 is a cross-sectional view of a circuit board assembly provided in some embodiments of this application. Figure 15 is a cross-sectional view of a circuit board assembly provided in some embodiments of this application. Figure 16 is a cross-sectional view of a circuit board assembly provided in some embodiments of this application.

[0136] In some examples, as shown in Figures 14, 15, and 16, the circuit board assembly 100 further includes a second thermally conductive medium 120. The second thermally conductive medium 120 includes a third portion 121 and a fourth portion 122. The third portion 121 is located on the side of the cover plate 1031 away from the electronic device 102. The third portion 121 includes a thermal interface material doped with metal filler.

[0137] The third part 121 is provided with a thermal interface material doped with metal filler, which can reduce the thermal resistance of the third part 121, improve the thermal conductivity of the third part 121, and facilitate the heat dissipation of the electronic device 102. For example, the third part 121 can be attached to the surface of the cover plate 1031 away from the electronic device 102 to improve the thermal conductivity of the third part 121.

[0138] In some examples, the ratio of the mass of the metal filler to the mass of the third part 121 is greater than or equal to 80%.

[0139] Understandably, the ratio of the mass of the metal packing to the mass of the third part 121 is less than 100%. For example, the ratio of the mass of the metal packing to the mass of the third part 121 can be 82%, 85%, or 95%, etc. The embodiments of this application do not further limit the value of the ratio of the mass of the metal packing to the mass of the third part 121.

[0140] The ratio of the mass of the metal filler to the mass of the third part 121 is set to be greater than or equal to 80%, so that the third part 121 can have a lower thermal resistance, improve the thermal conductivity of the third part 121, and facilitate heat dissipation of the electronic device 102. For example, the metal filler and thermal interface material of the third part 121 can be the same as or different from the metal filler and thermal interface material of the first part 111.

[0141] As shown in Figure 14, the fourth part 122 is located on the side of the cover plate 1031 away from the electronic device 102 and surrounds the third part 121; and / or, as shown in Figures 15 and 16, the fourth part 122 and the shield 103 are located on the same side of the circuit board 101, surround the shield 103 and the third part 121, and the fourth part 122 is in contact with the side wall 1032 of the shield 103.

[0142] That is, as shown in Figure 14, the fourth part 122 can be located on the side of the cover plate 1031 away from the electronic device 102; or, as shown in Figure 15, the fourth part 122 can be located on the side of the circuit board 101 near the shielding cover 103; or, as shown in Figure 16, one part of the fourth part 122 can be located on the side of the cover plate 1031 away from the electronic device 102, and the other part can be located on the side of the circuit board 101 near the shielding cover 103. This increases the flexibility of the fourth part 122's placement.

[0143] When the fourth part 122 is located on the surface of the cover plate 1031 away from the electronic device 102, as shown in FIG14, the fourth part 122 surrounds the third part 121, thereby blocking the third part 121, reducing the risk of the third part 121 overflowing or leaking from the surface of the electronic device 102 and falling onto the circuit board 101, causing a short circuit in the circuit board 101, and improving the reliability of the circuit board assembly 100.

[0144] For example, the fourth part 122 and the third part 121 can respectively contact the surface of the cover plate 1031 away from the electronic device 102 to reduce the thermal resistance between the second heat-conducting medium 120 and the shield 103, which is beneficial to the heat dissipation of the electronic device 102.

[0145] Understandably, the fourth part 122 and the third part 121 can be in contact, or the fourth part 122 and the third part 121 can be spaced apart. The fourth part 122 and the third part 121 can cover the surface of the cover plate 1031 away from the electronic device 102, or the surface of the cover plate 1031 away from the electronic device 102 can be exposed to the third part 121 and the fourth part 122.

[0146] When the fourth part 122 and the shield 103 are located on the same side of the circuit board 101, as shown in FIG15, the fourth part 122 surrounds the shield 103 and the third part 121, and the fourth part 122 contacts the side wall 1032 of the shield 103. On the one hand, the fourth part 122 can cover the sensitive area of ​​the circuit board 101 (the area of ​​the circuit board 101 close to the third part 121), realizing physical isolation between the third part 121 and the circuit board 101. On the other hand, the fourth part 122 can block the third part 121, reducing the risk of the third part 121 overflowing or leaking from the surface of the shield 103 and falling onto the circuit board 101, causing a short circuit in the circuit board 101, and improving the reliability of the circuit board assembly 100.

[0147] On the other hand, the fourth part 122 is in contact with the side wall 1032, which can reduce the thermal resistance between the fourth part 122 and the side wall 1032, and facilitate the heat dissipation of the electronic device 102.

[0148] As shown in FIG16, when a portion of the fourth part 122 is located on the surface of the cover plate 1031 away from the electronic device 102, and the other portion and the shield 103 are located on the same side of the circuit board 101, the fourth part 122 includes a third sub-part 122a and a fourth sub-part 122b.

[0149] The third sub-part 122a is located on the side of the cover plate 1031 away from the electronic device 102 and surrounds the third part 121. It can block the third part 121, reduce the risk of the third part 121 overflowing or leaking from the surface of the shield 103 and falling onto the circuit board 101, causing a short circuit in the circuit board 101, and improve the reliability of the circuit board assembly 100.

[0150] The fourth sub-part 122b and the shield 103 are located on the same side of the circuit board 101, surrounding the shield 103 and the third part 121, and contacting the sidewall 1032 of the shield 103. Understandably, the fourth sub-part 122b can cover the sensitive area of ​​the circuit board 101 (the area of ​​the circuit board 101 near the third part 121), achieving physical isolation between the third part 121 and the circuit board 101. Furthermore, the fourth sub-part 122b can act as a barrier to the third part 121, reducing the risk of the third part 121 overflowing or leaking from the surface of the shield 103 and falling onto the circuit board 101, causing a short circuit and improving the reliability of the circuit board assembly 100.

[0151] On the other hand, the fourth sub-part 122b contacts the side wall 1032 of the shield 103, which can reduce the thermal resistance between the fourth sub-part 122b and the side wall 1032, thus facilitating heat dissipation of the electronic device 102.

[0152] That is, in the embodiments of this application, the fourth part 122 can form a protective ring to physically isolate the third part 121 and the circuit board 101, reduce the risk of the third part 121 overflowing or leaking from the surface of the shield 103 and falling onto the circuit board 101, causing the circuit board 101 to short circuit, and improve the reliability of the circuit board assembly 100.

[0153] Part 4, section 122, includes insulating thermal interface materials.

[0154] Understandably, the fourth part 122 includes an insulating thermal interface material, enabling it to have good thermal conductivity and facilitating heat dissipation for the electronic device 102. Furthermore, both the third part 121 and the fourth part 122 can contact the shielding cover 103, reducing the thermal resistance between them and further improving heat dissipation for the electronic device 102. In addition, the fourth part 122 has good insulation properties, ensuring that even if it is mounted on the circuit board 101, it will not cause a short circuit, thus improving the reliability of the circuit board assembly 100.

[0155] In other words, the second heat-conducting medium 120 provided in the embodiments of this application can take into account both insulation and thermal conductivity. On the one hand, it reduces the risk of short circuit in the circuit board 101, and on the other hand, it can ensure the heat conduction effect, which is beneficial to the heat dissipation of electronic device 102.

[0156] In some examples, the fourth part 122 can be formed first, followed by the third part 121, to reduce the risk of the third part 121 falling onto the circuit board 101 before the fourth part 122 is formed.

[0157] In some examples, part 422 includes a thermal interface material doped with a thermally conductive filler. The thermally conductive filler includes at least one of alumina, silicon carbide, boron nitride, and diamond.

[0158] Understandably, the thermally conductive filler is doped with a thermal interface material to form the fourth part 122, which can reduce the thermal resistance of the fourth part 122 and facilitate heat dissipation of the electronic device 102. Furthermore, both the thermally conductive filler and the thermal interface material are insulating materials, which enables the fourth part 122 to have good insulation performance, reducing the risk of short circuit of the circuit board 101 caused by the second thermally conductive medium 120 and improving the reliability of the circuit board assembly 100.

[0159] In some examples, the ratio of the mass of the thermally conductive filler to the mass of section 122 is greater than or equal to 50%.

[0160] Understandably, the ratio of the mass of the thermally conductive filler to the mass of the fourth part 122 is less than 100%. For example, the ratio of the mass of the thermally conductive filler to the mass of the fourth part 122 can range from 50% to 95%, 60% to 85%, or 65% to 75%, etc. For instance, the ratio of the mass of the thermally conductive filler to the mass of the fourth part 122 can be 55%, 67%, 78%, 89%, or 98%, etc. The embodiments of this application do not further limit the value of the ratio of the mass of the thermally conductive filler to the mass of the second part.

[0161] Setting the mass ratio of the thermally conductive filler to the mass of the fourth part 122 to be greater than or equal to 50% can improve the thermal conductivity of the fourth part 122, reduce its thermal resistance, and facilitate heat dissipation for the electronic device 102. Understandably, the thermally conductive filler and thermal interface material of the fourth part 122 can be the same as or different from those of the second part 112.

[0162] In some examples, the withstand voltage of Part 4 122 is greater than or equal to 5 volts / 0.3 mm (V / mm).

[0163] Understandably, withstand voltage performance refers to the highest voltage value that a material or device can withstand under specific conditions. Part 4 122, with a thickness of 0.3 mm, can withstand a maximum AC voltage greater than or equal to 5V, for example, 5.5V, 6V, or 7V, for 60 seconds to withstand breakdown. Therefore, Part 4 122 has good insulation properties. By setting Part 4 122 to enclose and block Part 3 121, the risk of short circuit in circuit board 101 can be reduced, improving the reliability of circuit board assembly 100.

[0164] In some examples, the thermal conductivity of Part 4 122 is greater than or equal to 1 W / m Kelvin (w / m*k).

[0165] For example, the thermal conductivity of the fourth part 122 is greater than or equal to 1 watt / meter Kelvin in both the direction parallel to the surface of the circuit board 101 and the direction perpendicular to the surface of the circuit board 101. For example, the thermal conductivity of the fourth part 122 may be 2 watts / meter Kelvin or 3 watts / meter Kelvin.

[0166] It can be seen that the fourth part 122 has good thermal conductivity, and heat can be quickly conducted through the fourth part 122, which is beneficial to the heat dissipation of electronic device 102.

[0167] Figure 17 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some embodiments of this application. In some examples, as shown in Figure 17, the circuit board assembly 100 may further include a heat dissipation component 105. For example, the heat dissipation component 105 may be a vacuum chamber (VC). The heat dissipation component 105 is located on the side of the cover plate 1031 away from the electronic device 102. A second heat-conducting medium 120 is located between the heat dissipation component 105 and the cover plate 1031, and is in contact with both the heat dissipation component 105 and the cover plate 1031.

[0168] Understandably, the heat emitted by the electronic device 102 can be conducted to the shield 103 via the first heat-conducting medium 110, and then to the second heat-conducting medium 120 via the shield 103, and then to the heat dissipation component 105 via the second heat-conducting medium 120, and then dissipated to the outside via the heat dissipation component 105, thereby reducing the risk that the electronic device 102 will not work properly due to excessive temperature.

[0169] The second heat-conducting medium 120 is located between the heat dissipation component 105 and the cover plate 1031, and is in contact with the heat dissipation component 105 and the cover plate 1031 respectively. This can reduce the thermal resistance between the second heat-conducting medium 120 and the heat dissipation component 105 and the cover plate 1031, which is beneficial to the heat dissipation of the electronic device 102.

[0170] Figure 18 is a cross-sectional structural schematic diagram of a circuit board assembly provided in some embodiments of this application. In some examples, as shown in Figure 18, there are multiple circuit boards 101, which are stacked. The circuit board assembly 100 also includes a connecting portion 104, which connects two stacked circuit boards 101.

[0171] Multiple circuit boards 101 are stacked, which can improve the integration of the circuit board assembly 100. Understandably, the connecting portion 104 provides support and connection, allowing electronic devices 102 mounted on different circuit boards 101 to be electrically connected. For example, the material of the connecting portion 104 may include metal.

[0172] In some examples, as shown in FIG18, multiple electronic devices 102 are located on both sides of a circuit board 101. The multiple circuit boards 101 include a first circuit board 1011 and a second circuit board 1012 arranged adjacent to each other. At least one first thermally conductive medium 110 is located between the first circuit board 1011 and the second circuit board 1012.

[0173] Understandably, the number of electronic devices 102 disposed on the first circuit board 1011 and the number of electronic devices 102 disposed on the second circuit board 1012 may be the same or different. At least one electronic device 102 is located between the first circuit board 1011 and the second circuit board 1012, such that at least one first heat-conducting medium 110 can be located between the first circuit board 1011 and the second circuit board 1012 to improve the integration of the circuit board assembly 100. For example, at least one second heat-conducting medium 120 may also be located between the first circuit board 1011 and the second circuit board 1012.

[0174] At least one first heat-conducting medium 110 is provided between the first circuit board 1011 and the second circuit board 1012, so that the first heat-conducting medium 110 can be applied to the circuit board assembly 100 with a high degree of integration to meet different needs.

[0175] In summary, the embodiments of this application have at least the following beneficial effects:

[0176] In the embodiments of this application, the first part 111 is provided with a thermal interface material doped with metal filler, which can reduce the thermal resistance of the first part 111, improve the thermal conductivity of the first part 111, and facilitate the heat dissipation of the electronic device 102.

[0177] The second part 112 can be located on the side of the electronic device 102 away from the circuit board 101, or the second part 112 can also be located on the side of the circuit board 101 close to the electronic device 102, or a part of the second part 112 can be located on the side of the electronic device 102 away from the circuit board 101, and the other part can be located on the side of the circuit board 101 close to the electronic device 102, which improves the flexibility of the second part 112.

[0178] Furthermore, the second part 112 can surround the first part 111 and act as a barrier to the first part 111, that is, it can provide protective constraints to the first part, forming a complete protective ring, realizing physical isolation between the first part 111 and the circuit board 101, reducing the risk of the first part 111 overflowing or leaking from the surface of the electronic device 102 and falling onto the circuit board 101, thereby causing a short circuit in the circuit board 101.

[0179] The second part 112 includes an insulating thermal interface material, giving it good thermal conductivity and facilitating heat dissipation from the electronic device 102. Furthermore, both the second part 112 and the first part 111 can contact the electronic device 102, reducing the thermal resistance between the first thermal medium 110 and the electronic device 102. In addition, the second part 112 has good insulation properties, preventing short circuits even when it is mounted on the circuit board 101, thus improving the reliability of the circuit board assembly 100.

[0180] In other words, the first heat-conducting medium 110 provided in the embodiments of this application can take into account both insulation and thermal conductivity. On the one hand, it reduces the risk of short circuit in the circuit board 101, and on the other hand, it can ensure the heat conduction effect, which is beneficial to the heat dissipation of electronic device 102.

Claims

1. A circuit board assembly (100), characterized in that, include: Circuit board (101); An electronic device (102) is located on one side of the circuit board (101) and connected to the circuit board (101); and, A first thermally conductive medium (110) includes a first portion (111) and a second portion (112); the first portion (111) is located on the side of the electronic device (102) away from the circuit board (101); the second portion (112) is located on the side of the electronic device (102) away from the circuit board (101) and surrounds the first portion (111); and / or, the second portion (112) and the electronic device (102) are located on the same side of the circuit board (101), surrounding the electronic device (102) and the first portion (111), and the second portion (112) is in contact with the electronic device (102); The first part (111) includes a thermal interface material doped with metal filler, and the second part (112) includes an insulating thermal interface material.

2. The circuit board assembly (100) according to claim 1, characterized in that, The second part (112) includes a thermal interface material doped with a thermally conductive filler; wherein the thermally conductive filler includes at least one of zinc oxide, magnesium oxide, aluminum oxide, aluminum nitride, silicon carbide, boron nitride, and diamond.

3. The circuit board assembly (100) according to claim 2, characterized in that, The ratio of the mass of the thermally conductive filler to the mass of the second part (112) is greater than or equal to 50%.

4. The circuit board assembly (100) according to any one of claims 1 to 3, characterized in that, The second part (112) has a voltage resistance greater than or equal to 5 volts / 0.3 mm.

5. The circuit board assembly (100) according to any one of claims 1 to 4, characterized in that, The thermal conductivity of the second part (112) is greater than or equal to 1 W / m·Kelvin.

6. The circuit board assembly (100) according to any one of claims 1 to 5, characterized in that, The ratio of the mass of the metal filler to the mass of the first part (111) is greater than or equal to 80%.

7. The circuit board assembly (100) according to any one of claims 1 to 6, characterized in that, The number of electronic devices (102) is multiple, and the multiple electronic devices (102) include a first electronic device (1021) and a second electronic device (1022) arranged adjacent to each other; The first portion (111) is located on the side of the first electronic device (1021) away from the circuit board (101); when the second portion (112) surrounds the first electronic device (1021), the second portion (112) is located at least between the first electronic device (1021) and the second electronic device (1022), and is in contact with the first electronic device (1021).

8. The circuit board assembly (100) according to claim 7, characterized in that, The second part (112) covers the second electronic device (1022).

9. The circuit board assembly (100) according to claim 7 or 8, characterized in that, The edge of the first electronic device (1021) near the second electronic device (1022) and the edge of the second electronic device (1022) near the first electronic device (1021) are less than 0.1 mm apart.

10. The circuit board assembly (100) according to any one of claims 1 to 9, characterized in that, It also includes a shield (103); the shield (103) covers the electronic device (102) and the first heat-conducting medium (110).

11. The circuit board assembly (100) according to claim 10, characterized in that, The shielding cover (103) includes a cover plate (1031) and a side wall (1032); one side edge of the side wall (1032) is connected to the circuit board (101), and the other side edge of the side wall (1032) is connected to the cover plate (1031); the cover plate (1031) is located on the side of the electronic device (102) away from the circuit board (101); The first heat-conducting medium (110) is located between the electronic device (102) and the cover plate (1031), and is in contact with the electronic device (102) and the cover plate (1031) respectively.

12. The circuit board assembly (100) according to claim 11, characterized in that, It also includes a second thermally conductive medium (120); the second thermally conductive medium (120) includes a third part (121) and a fourth part (122); the third part (121) is located on the side of the cover plate (1031) away from the electronic device (102); The fourth part (122) is located on the side of the cover plate (1031) away from the electronic device (102) and surrounds the third part (122); and / or, the fourth part (122) and the shield (103) are located on the same side of the circuit board (101), surround the shield (103) and the third part (121), and the fourth part (122) contacts the sidewall (1032) of the shield (103); The third part (121) includes a thermal interface material doped with metal filler, and the fourth part (122) includes an insulating thermal interface material.

13. The circuit board assembly (100) according to claim 12, characterized in that, It also includes a heat dissipation component (105); the heat dissipation component (105) is located on the side of the cover plate (1031) away from the electronic device (102); the second heat-conducting medium (120) is located between the heat dissipation component (105) and the cover plate (1031), and is in contact with the heat dissipation component (105) and the cover plate (1031) respectively.

14. The circuit board assembly (100) according to any one of claims 1 to 13, characterized in that, The number of circuit boards (101) is multiple, and the multiple circuit boards (101) are stacked; the circuit board assembly (100) also includes a connecting part (104), which connects two of the stacked circuit boards (101).

15. The circuit board assembly (100) according to claim 14, characterized in that, The number of electronic devices (102) is multiple, and the multiple electronic devices (102) are located on both sides of the circuit board (101); The plurality of said circuit boards (101) include a first circuit board (1011) and a second circuit board (1012) arranged adjacent to each other; at least one of the first heat-conducting medium (110) is located between the first circuit board (1011) and the second circuit board (1012).

16. The circuit board assembly (100) according to any one of claims 1 to 15, characterized in that, The electronic device (102) includes at least one of a system-on-a-chip, a radio frequency chip, a charging chip, a resistor, and a switching transistor.

17. The circuit board assembly (100) according to any one of claims 1 to 16, characterized in that, The thermal interface material includes at least one of thermally conductive gel, thermally conductive grease, and thermally conductive pad.

18. An electronic device (200), characterized in that, include: Shell (201); The circuit board assembly (100) as claimed in any one of claims 1 to 17, wherein the circuit board assembly (100) is located within the housing (201).

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